Graph of changes in coolant temperatures examples. Temperature graph of the heating system: getting acquainted with the operating mode of the central heating system

home

Internet

Build for closed system heat supply schedule for central quality regulation of heat supply based on the combined load of heating and hot water supply (increased or adjusted temperature schedule).

Accept the calculated temperature of the network water in the supply line t 1 = 130 0 C in the return line t 2 = 70 0 C, after the elevator t 3 = 95 0 C. Design outside air temperature for heating design tnro = -31 0 C. Design air temperature indoors tв= 18 0 С. The calculated heat flows are the same. Temperature hot water in hot water supply systems tgv = 60 0 C, temperature cold water t c = 5 0 C. Balance coefficient for hot water supply load a b = 1.2. The connection diagram for water heaters of hot water supply systems is two-stage sequential.

Solution. Let us first carry out the calculation and construction of a heating and domestic temperature graph with the temperature of the network water in the supply pipeline for the break point = 70 0 C. Values of network water temperatures for heating systems t 01 ; t 02 ; t 03 will be determined using calculated dependencies (13), (14), (15) for outside air temperatures t n = +8; 0; -10; -23; -31 0 C

Let us determine, using formulas (16), (17), (18), the values of quantities

For t n = +8 0С values t 01, t 02 ,t 03 will accordingly be:

Calculations of network water temperatures are carried out similarly for other values. t n. Using the calculated data and accepting minimum temperature network water in the supply pipeline = 70 0 C, let's build a heating and household temperature graph (see Fig. 4). Breaking point temperature chart will correspond to the network water temperatures = 70 0 C, = 44.9 0 C, = 55.3 0 C, outside air temperature = -2.5 0 C. We summarize the obtained values of the network water temperatures for the heating and household schedule in Table 4. Next, we proceed to calculate the elevated temperature schedule. Having specified the value of underheating D t n = 7 0 C we determine the temperature of the heated tap water after the first stage water heater

Let us determine the balance load of hot water supply using formula (19)

Using formula (20), we determine the total temperature difference of the network water d in both stages of water heaters

Using formula (21), we determine the temperature difference of the network water in the first stage water heater for the range of outdoor air temperatures from t n = +8 0 C to t" n = -2.5 0 C

For the specified range of outdoor air temperatures, we determine the temperature difference of the network water in the second stage of the water heater

Let us determine using formulas (22) and (25) the values of quantities d 2 and d 1 for outdoor temperature range t n from t" n = -2.5 0 C before t 0 = -31 0 C. So, for t n = -10 0 C these values will be:

Let us similarly perform calculations of the quantities d 2 and d 1 for values t n = -23 0 C and t n = –31 0 C. The temperatures of the network water in both the supply and return pipelines for an increased temperature curve will be determined using formulas (24) and (26).

Yes, for t n = +8 0 C and t n = -2.5 0 C these values will be

For t n = -10 0 C

Let us similarly perform calculations for the values t n = -23 0 C and -31 0 C. Obtained values d 2, d 1, , we summarize in table 4.

To plot the temperature of the network water in the return pipeline after the air heaters of ventilation systems in the range of outside air temperatures t n = +8 ¸ -2.5 0 C we use formula (32)

Let's determine the value t 2v for t n = +8 0 C. Let us first set the value 0 C. Let us determine the temperature pressure in the heater and, accordingly, for t n = +8 0 C and t n = -2.5 0 C

Let's calculate the left and right sides of the equation

Left side

Right part

Since the numerical values of the right and left sides of the equation are close in value (within 3%), we will accept the value as final.

For ventilation systems with air recirculation, we determine, using formula (34), the temperature of the network water after the air heaters t 2v for t n = t nro = -31 0 C.

Here the values of D t ; t ; t correspond t n = t v = -23 0 C. Since this expression is solved by the selection method, we first set the value t 2v = 51 0 C. Determine the values of D t k and D t

Since the left side of the expression is close in value to the right (0.99"1), the previously accepted value t 2v = 51 0 C will be considered final. Using the data in Table 4, we will construct heating-domestic and elevated temperature control schedules (see Fig. 4).

Table 4 - Calculation of temperature control schedules for a closed heat supply system.

t N	t 10	t 20	t 30	d 1	d 2	t 1P	t 2P	t 2V
+8	70	44,9	55,3	5,9	8,5	75,9	36,4	17
-2,5	70	44,9	55,3	5,9	8,5	75,9	36,4	44,9
-10	90,2	5205	64,3	4,2	10,2	94,4	42,3	52,5
-23	113,7	63,5	84,4	1,8	12,5	115,6	51	63,5
-31	130	70	95	0,4	14	130,4	56	51

Fig.4. Temperature control charts for a closed heating system (¾ heating and domestic; --- increased)

Build for open system heat supply adjusted (increased) schedule of central quality regulation. Accept the balance coefficient a b = 1.1. Accept the minimum temperature of the network water in the supply pipeline for the break point of the temperature graph of 0 C. Take the remaining initial data from the previous part.

Solution. First, we construct temperature graphs , , , using calculations using formulas (13); (14); (15). Next, we will construct a heating and household graph, the break point of which corresponds to the temperature values of the network water 0 C; 0 C; 0 C, and the outside air temperature is 0 C. Next, we proceed to calculate the adjusted schedule. Let's determine the balance load of hot water supply

Let us determine the ratio of the balance load for hot water supply to the design load for heating

For a range of outdoor temperatures t n = +8 0 C; -10 0 C; -25 0 C; -31 0 C, we determine the relative heat consumption for heating using formula (29)`; For example for t n = -10 will be:

Then, taking the values known from the previous part t c ; t h ; q; Dt we determine using formula (30) for each value t n relative costs of network water for heating.

For example, for t n = -10 0 C will be:

Let us perform calculations similarly for other values. t n.

Supply water temperature t 1p and reverse t 2p pipelines for the adjusted schedule will be determined using formulas (27) and (28).

Yes, for t n = -10 0 C we get

Let's do the calculations t 1p and t 2p and for other values t n. Let us determine using the calculated dependencies (32) and (34) the temperature of the network water t 2v after heaters of ventilation systems for t n = +8 0 C and t n = -31 0 C (in the presence of recirculation). At value t n = +8 0 C let’s first set the value t 2v = 23 0 C.

Let's define the values Dt to and Dt To

;

Since the numerical values of the left and right sides of the equation are close, the previously accepted value t 2v = 23 0 C, we will consider it final. Let us also define the values t 2v at t n = t 0 = -31 0 C. Let us first set the value t 2v = 47 0 C

Let's calculate the values of D t to and

We summarize the obtained values of the calculated values in Table 3.5

Table 5 - Calculation of the increased (adjusted) schedule for an open heat supply system.

t n	t 10	t 20	t 30	`Q 0	`G 0	t 1p	t 2p	t 2v
+8	60	40,4	48,6	0,2	0,65	64	39,3	23
1,9	60	40,4	48,6	0,33	0,8	64	39,3	40,4
-10	90.2	52.5	64.3	0,59	0,95	87.8	51.8	52.5
-23	113.7	63.5	84.4	0,84	1,02	113	63,6	63.5
-31	130	70	95	1	1,04	130	70	51

Using the data from Table 5, we will construct heating and domestic, as well as increased temperature schedules for network water.

Fig.5 Heating - household ( ) and increased (----) schedules of network water temperatures for an open heating system

Hydraulic calculation of main heat pipelines of a two-pipe water heating network of a closed heat supply system.

The design diagram of the heating network from the heat source (IT) to the city blocks (CB) is shown in Fig. 6. To compensate for temperature deformations, provide gland compensators. Take the specific pressure loss along the main line in the amount of 30-80 Pa/m.

Fig.6. Design diagram of the main heating network.

Solution. The calculation will be performed for the supply pipeline. Let us take the longest and busiest branch of the heating network from IT to KV 4 (sections 1,2,3) as the main line and proceed to its calculation. According to tables hydraulic calculation given in the literature, as well as in Appendix No. 12 of the textbook, based on known coolant flow rates, focusing on specific pressure losses R in the range from 30 to 80 Pa/m, we will determine the pipeline diameters for sections 1, 2, 3 d n xS, mm, actual specific pressure loss R, Pa/m, water speed V, m/s.

Based on the known diameters in sections of the main highway, we determine the sum of the local resistance coefficients S x and their equivalent lengths L e. Thus, in section 1 there is a head valve ( x= 0.5), tee for passage when dividing the flow ( x= 1.0), Number of stuffing box compensators ( x= 0.3) on a section will be determined depending on the length of the section L and the maximum permissible distance between fixed supports l. According to Appendix No. 17 of the training manual for D y = 600 mm this distance is 160 meters. Therefore, in section 1 with a length of 400 m, three stuffing box expansion joints should be provided. Sum of local resistance coefficients S x in this area will be

S x= 0.5+1.0 + 3 × 0.3 = 2.4

According to Appendix No. 14 of the textbook (if TO e = 0.0005m) equivalent length l uh for x= 1.0 equals 32.9 m. Equivalent section length L uh will be

L e = l e × S x= 32.9 ×2.4 = 79 m

L n = L+ L e = 400 + 79 = 479 m

Then we determine the pressure loss DP in section 1

D P= R×L n = 42 × 479 = 20118 Pa

Similarly, we will perform a hydraulic calculation of sections 2 and 3 of the main highway (see Table 6 and Table 7).

Next, we proceed to the calculation of branches. Based on the principle of linking pressure loss D P from the flow division point to the end points (EP) for different branches of the system must be equal to each other. Therefore, when hydraulically calculating branches, it is necessary to strive to fulfill the following conditions:

D P 4+5 = D P 2+3 ; D P 6 = D P 5 ; D P 7 = D P 3

Based on these conditions, we will find the approximate specific pressure losses for the branches. So, for a branch with sections 4 and 5 we get

Coefficient a, taking into account the share of pressure losses due to local resistance, will be determined by the formula

Then Pa/m

Focusing on R= 69 Pa/m we will determine pipeline diameters and specific pressure losses using hydraulic calculation tables R, speed V, pressure loss D R in sections 4 and 5. We will similarly perform the calculation of branches 6 and 7, having previously determined the approximate values for them R.

Pa/m

Table 6 - Calculation of equivalent lengths of local resistances

Plot number	dн x S, mm	L, m	Type of local resistance	x	Qty	åx	l e, m	Lе,m
1	630x10	400	1. valve 2. stuffing box compensator	0.5 0.3 1.0	1 3 1	2,4	32,9	79
2	480x10	750	1. sudden contraction 2. stuffing box compensator 3. tee for passage when dividing the flow	0.5 0.3 1.0	1 6 1	3,3	23,4	77
3	426x10	600	1. sudden contraction 2. stuffing box compensator 3. valve	0.5 0.3 0.5	1 4 1	2,2	20,2	44,4
4	426x10	500	1. branch tee 2. valve 3. stuffing box compensator 4. tee for passage	1.5 0.5 0.3 1.0	1 1 4 1	4.2	20.2	85
5	325x8	400	1. stuffing box compensator 2. valve	0.3 0.5	4 1	1.7	14	24
6	325x8	300	1. branch tee 2. stuffing box compensator 3. valve	1.5 0.5 0.5	1 2 2	3.5	14	49
7	325x8	200	1. branch tee when dividing the flow 2.valve 3. stuffing box compensator	1.5 0.5 0.3	1 2 2	3.1	14	44

Table 7 - Hydraulic calculation main pipelines

Plot number	G, t/h	Length, m	dнхs, mm	V, m/s	R, Pa/m	DP, Pa	åDP, Pa
L	Le	Lп
1 2 3	1700 950 500	400 750 600	79 77 44	479 827 644	630x10 480x10 426x10	1.65 1.6 1.35	42 55 45	20118 45485 28980	94583 74465 28980
4 5	750 350	500 400	85 24	585 424	426x10 325x8	1.68 1.35	70 64	40950 27136	68086 27136
6	400	300	49	349	325x8	1.55	83	28967	28967
7	450	200	44	244	325x8	1.75	105	25620	25620

Let us determine the discrepancy of pressure losses on the branches. The discrepancy on the branch with sections 4 and 5 will be:

The discrepancy on branch 6 will be:

The discrepancy on branch 7 will be.

When autumn confidently strides across the country, snow is flying above the Arctic Circle, and in the Urals night temperatures stay below 8 degrees, then the word form “heating season” sounds appropriate. People remember past winters and try to understand the normal temperature of the coolant in the heating system.

Prudent owners of individual buildings carefully inspect the valves and nozzles of boilers. By October 1, residents of an apartment building are waiting like Santa Claus for a plumber from the management company. The Lord of valves and valves brings warmth, and with it joy, fun and confidence in the future.

The Gigacalorie Path

Megacities sparkle high-rise buildings. A cloud of renovation hangs over the capital. The outback prays to five-story buildings. Until demolished, the house operates a calorie supply system.

Heating of an economy class apartment building is carried out through a centralized heat supply system. Pipes are included in basement buildings. The supply of coolant is regulated by inlet valves, after which the water enters the mud traps, and from there it is distributed through the risers, and from them it is supplied to the radiators and radiators that heat the home.

The number of valves correlates with the number of risers. When performing repair work in a single apartment, it is possible to turn off one vertical line, rather than the entire house.

The waste liquid is partially discharged through the return pipe, and partially supplied to the hot water supply network.

Degrees here and there

Water for the heating configuration is prepared at a thermal power plant or in a boiler room. The norms for water temperature in the heating system are specified in building regulations Oh: the component must be heated to 130-150 °C.

The supply is calculated taking into account the parameters of the outside air. Yes, for the region Southern Urals minus 32 degrees is taken into account.

To prevent the liquid from boiling, it must be supplied to the network under a pressure of 6-10 kgf. But this is a theory. In fact, most networks operate at 95-110 °C, since the network pipes of most settlements are worn out and high pressure will tear them apart like a hot water bottle.

An elastic concept is a norm. The temperature in the apartment is never equal to the primary indicator of the coolant. Here, the elevator unit - a jumper between the forward and return pipes - performs an energy-saving function. The temperature standards for the coolant in the return heating system in winter allow heat to be maintained at a level of 60 °C.

Liquid from a straight pipe enters the elevator nozzle and is mixed with return water and again goes into the house network for heating. The temperature of the carrier is reduced by mixing the return fluid. What affects the calculation of the amount of heat consumed by residential and utility rooms.

The hot one went

Hot water temperature sanitary rules at analysis points should be in the range of 60-75 °C.

In the network, the coolant is supplied from the pipe:

in winter - with reverse, so as not to scald users with boiling water;
in summer - from a straight line, since in summer time The carrier is heated no higher than 75 °C.

A temperature chart is drawn up. The average daily return water temperature should not exceed the schedule by more than 5% at night and 3% during the day.

Parameters of distributing elements

One of the details of warming a home is the riser through which the coolant enters the battery or radiator from the Coolant temperature standards in the heating system require heating in the riser in winter in the range of 70-90 °C. In fact, the degrees depend on the output parameters of the thermal power plant or boiler house. In the summer, when hot water is needed only for washing and showering, the range moves to 40-60 °C.

Observant people may notice that the heating elements in the neighboring apartment are hotter or colder than in his own.

The reason for the temperature difference in the heating riser lies in the method of hot water distribution.

In a single-pipe design, the coolant can be distributed:

above; then the temperature on the upper floors is higher than on the lower ones;
from below, then the picture changes to the opposite - it is hotter from below.

In a two-pipe system, the degree is the same throughout, theoretically 90 °C in the forward direction and 70 °C in the reverse direction.

Warm like a battery

Let’s assume that the central network structures are reliably insulated along the entire route, the wind does not blow through attics, staircases and basements, and conscientious owners have insulated the doors and windows in the apartments.

Let's assume that the coolant in the riser complies with building code standards. It remains to find out what the normal temperature of the heating radiators in the apartment is. The indicator takes into account:

outdoor air parameters and time of day;
location of the apartment in the house plan;
residential or utility room in the apartment.

Therefore, attention: it is important not what the temperature of the heater is, but what the temperature of the air in the room is.

During the day in corner rooms the thermometer must show at least 20 °C, and in centrally located rooms 18 °C is allowed.

At night, air in the home is allowed to be 17 °C and 15 °C, respectively.

Theory of linguistics

The name “battery” is a common one, meaning a number of identical objects. In relation to home heating, this is a series of heating sections.

Temperature standards for heating radiators allow heating no higher than 90 °C. According to the rules, parts heated above 75 °C are protected. This does not mean that they need to be covered with plywood or bricked. Usually a lattice fence is installed that does not impede air circulation.

Cast iron, aluminum and bimetallic devices are common.

Consumer choice: cast iron or aluminum

The aesthetics of cast iron radiators is the talk of the town. They require periodic painting, since the rules require that the working surface have a smooth surface and allow dust and dirt to be easily removed.

A dirty coating forms on the rough inner surface of the sections, which reduces the heat transfer of the device. But technical specifications cast iron products at height:

are slightly susceptible to water corrosion and can be used for more than 45 years;
have high thermal power per section, therefore they are compact;
are inert in heat transfer, so they smooth out temperature changes in the room well.

Another type of radiator is made of aluminum. Lightweight, factory-painted design, does not require painting, and is easy to maintain.

But there is a drawback that overshadows the advantages - corrosion in an aquatic environment. Of course, the inner surface of the heater is insulated with plastic to avoid contact of aluminum with water. But the film may be damaged, then a chemical reaction will begin with the release of hydrogen, when creating overpressure gas, the aluminum device may burst.

Temperature standards for heating radiators are subject to the same rules as batteries: it’s not so much the heating that’s important metal object how much air is heated in the room.

In order for the air to warm up well, there must be sufficient heat removal from the working surface of the heating structure. Therefore, it is strictly not recommended to increase the aesthetics of the room with shields in front of the heating device.

Staircase heating

Since we are talking about an apartment building, we should mention the staircases. The coolant temperature standards in the heating system state: the degree measure at the sites should not fall below 12 °C.

Of course, the discipline of residents requires closing the entrance doors tightly, not leaving the transoms of the staircase windows open, keeping the glass intact and promptly reporting any problems to the management company. If the management company does not take timely measures to insulate points of probable heat loss and comply with temperature regime in the house, an application for recalculation of the cost of services will help.

Changes in heating design

Replacement of existing heating devices in an apartment is carried out with the obligatory approval of management company. Unauthorized changes in the elements of warming radiation can disrupt the thermal and hydraulic balance of the structure.

When the heating season begins, changes in temperature conditions in other apartments and areas will be recorded. A technical inspection of the premises will reveal unauthorized changes in the types of heating devices, their quantity and size. The chain is inevitable: conflict - court - fine.

Therefore, the situation is resolved like this:

if non-old ones are replaced with new radiators of the same size, then this is done without additional approvals; the only thing you need to contact the management company for is to turn off the riser during repairs;
if new products differ significantly from those installed during construction, then it is useful to interact with the management company.

Heat meters

Let us remember once again that the heat supply network of an apartment building is equipped with thermal energy metering units, which record both the gigacalories consumed and the cubic capacity of water passed through the intra-house line.

In order not to be surprised by bills containing unrealistic amounts for heat when the degrees in the apartment are below normal, before heating season Check with the management company whether the metering device is in working condition and whether the verification schedule has been violated.

Computers have been working successfully for a long time not only on the desks of office workers, but also in production and technological process control systems. Automation successfully controls the parameters of heating systems of buildings, providing...

The specified required air temperature (sometimes changing throughout the day to save money).

But the automation needs to be properly configured, given the initial data and algorithms to work! This article discusses the optimal heating temperature schedule - the dependence of the coolant temperature of a water heating system at different outside temperatures.

This topic has already been discussed in the article about. Here we will not calculate the heat loss of an object, but will consider a situation where these heat losses are known from previous calculations or from data from the actual operation of an existing facility. If the facility is operational, then it is better to take the value of heat loss at the design temperature of the outside air from the statistical actual data of previous years of operation.

In the article mentioned above, to construct the dependences of the coolant temperature on the outside air temperature, a system of nonlinear equations is solved numerically. This article will present “direct” formulas for calculating the “supply” and “return” water temperatures, which represent an analytical solution to the problem.

You can read about the colors of Excel sheet cells that are used for formatting in articles on the page « ».

Calculation of heating temperature graph in Excel.

So, when setting up the operation of the boiler and/or heating unit based on the outside air temperature, the automation system needs to set a temperature schedule.

Maybe, more correct sensor place the air temperature inside the building and configure the operation of the coolant temperature control system based on the internal air temperature. But it is often difficult to choose a location for installing the sensor inside due to different temperatures in different rooms of the facility or due to the significant distance of this place from the thermal unit.

Let's look at an example. Let's say we have an object - a building or a group of buildings that receive thermal energy from one common closed heat supply source - a boiler room and/or a heating unit. A closed source is a source from which the extraction of hot water for water supply is prohibited. In our example, we will assume that in addition to the direct selection of hot water, there is no selection of heat for heating water for hot water supply.

To compare and check the correctness of the calculations, let’s take the initial data from the above-mentioned article “Calculation of water heating in 5 minutes!” and create a small program in Excel to calculate the heating temperature schedule.

Initial data:

1. Estimated (or actual) heat loss of an object (building) Q p in Gcal/hour at the design outdoor temperature t nr write down

to cell D3: 0,004790

2. Estimated air temperature inside the object (building) t vr in °C enter

to cell D4: 20

3. Estimated outside air temperature t nr in °C we enter

to cell D5: -37

4. Estimated water temperature at the “supply” t pr enter in °C

to cell D6: 90

5. Estimated return water temperature t op in °C enter

to cell D7: 70

6. Indicator of nonlinearity of heat transfer of used heating devices n write down

to cell D8: 0,30

7. Current (we are interested in) outside air temperature t n in °C we enter

to cell D9: -10

Cell valuesD3 – D8 for a specific object are written once and are not changed further. Cell valueD8 can (and should) be changed by determining coolant parameters for different weather conditions.

Calculation results:

8. Estimated water flow in the system GR in t/hour we calculate

in cell D11: =D3*1000/(D6-D7) =0,239

GR = QR *1000/(tetc — top )

9. Relative heat flux q define

in cell D12: =(D4-D9)/(D4-D5) =0,53

q =(tvr — tn )/(tvr — tnr )

10. Supply water temperature tP in °C we calculate

in cell D13: =D4+0.5*(D6-D7)*D12+0.5*(D6+D7-2*D4)*D12^(1/(1+D8)) =61,9

tP = tvr +0,5*(tetc – top )* q +0,5*(tetc + top -2* tvr )* q (1/(1+ n ))

11. Return water temperature tO in °C we calculate

in cell D14: =D4-0.5*(D6-D7)*D12+0.5*(D6+D7-2*D4)*D12^(1/(1+D8)) =51,4

tO = tvr -0,5*(tetc – top )* q +0,5*(tetc + top -2* tvr )* q (1/(1+ n ))

Calculation of supply water temperature in Excel tP and on the return line tO for selected outside temperature tn completed.

Let's make a similar calculation for several different outside temperatures and build a heating temperature graph. (You can read about how to build graphs in Excel.)

Let's compare the obtained values of the heating temperature graph with the results obtained in the article “Calculation of water heating in 5 minutes!” - the values are the same!

Results.

The practical value of the presented calculation of the heating temperature schedule is that it takes into account the type of installed devices and the direction of movement of the coolant in these devices. Heat transfer nonlinearity coefficient n, which has a noticeable effect on the heating temperature curve, varies from device to device.

Temperature graph of coolant supply to the heating system

Each management company strives to achieve economical costs for heating an apartment building. In addition, residents of private houses are trying to come.

This can be achieved by drawing up a temperature graph that reflects the dependence of the heat produced by the carriers on the weather conditions outside.

Correct use of this data allows optimal distribution of hot water and heating to consumers.

What is a temperature graph

The coolant should not maintain the same operating mode, because outside the apartment the temperature changes. This is what you need to be guided by and, depending on it, change the temperature of the water in heating objects. Dependence of coolant temperature on outside temperature air is compiled by specialist technologists.

To compile it, the values available for the coolant and the outside air temperature are taken into account.

During the design of any building, the size of the heat-providing equipment installed in it, the dimensions of the building itself and the cross-sections available in the pipes must be taken into account.

In a high-rise building, residents cannot independently increase or decrease the temperature, since it is supplied from the boiler room. Adjustment of the operating mode is always carried out taking into account the temperature curve of the coolant.

note

The temperature scheme itself is also taken into account - if the return pipe supplies water with a temperature above 70°C, then the coolant flow will be excessive, but if it is significantly lower, there will be a deficiency.

But the level of heating maintained indoors depends not only on the coolant:

Outside temperature;
The presence and strength of wind - its strong gusts significantly affect heat loss;
Thermal insulation - high-quality structural parts of the building help to retain heat in the building. This is done not only during the construction of the house, but also separately at the request of the owners.

The heat supply temperature schedule refers to the schedules of heating-carrying pipelines, which are regulated by a centralized system and share the heating load. The system can be either closed or open.

In the case when the system is closed, it goes only to heating objects connected to the heating network. When the system is open, it is also used to supply hot water to consumers.

If an open system is used, adjustments must be made due to constant heat consumption.

How to make a temperature chart

In accordance with SNIP, indoor heating should be maintained at a level of 18 to 25 °C.

SNIP for preschool and school educational institutions usually tougher, since the temperature must be constant and not drop below 22°C.

IN educational institutions strictly monitor the implementation sanitary standards- pipes cannot be covered with mold. To calculate a temperature graph, you need to know the values of several indicators:

Outside air temperature;
In living rooms;
In the supply part of the pipeline;
In the back part of the pipeline;
In the pipeline at the exit from the building.

In addition to this data, you need to know what the nominal heat load is. For residential buildings a similar heating schedule is 105/70 and 95/70. The first indicator reflects the temperature that should be at the water supply in heating system, the second - at the exit from it or the return pipe.

The results obtained from the measurements must be entered into the table. The main indicator for compiling the table is the outside temperature. It must be compiled in such a way that the maximum data of heating devices - 95/70 - ensures heating of the premises.

The temperature regime that must be maintained in apartments is enshrined in the article of the Housing Code of the Russian Federation and the Resolution of the State Standard.

A similar calculation of temperatures maintained in a residential area is made by the management company for each high-rise or two-story building separately. All indicators, thermal insulation of external heating parts and other significant points are taken into account.

A heating schedule built according to all the rules will help not only determine the operating parameters of the system at each moment in time, but also evaluate the efficiency of the coolant.

The construction of such a graph also allows you to determine the amount of load on the heating system.

Table of coolant temperature versus outside air temperature

It is important to take into account their surface power and the drag coefficient available window openings and external walls.

After all the values are taken into account, you need to calculate the difference between the temperature in two pipes - at the entrance to the house and at the exit from it. The higher the value in the input pipe, the higher the value in the return pipe. Accordingly, indoor heating will increase under these values.

Weather outside, C
at the entrance to the building, C
Return pipe, C

10
30
25

5
44
37

5
70
54

10
83
62

15
95
70

Proper use of coolant involves attempts by house residents to reduce the temperature difference between the inlet and outlet pipes. It could be construction work for insulating a wall from the outside or thermal insulation of external heat supply pipes, insulating floors above a cold garage or basement, insulating the inside of a house, or several works performed simultaneously.

Heating in the radiator must also comply with the standards. In central heating systems it usually varies from 70 C to 90 C depending on the outside air temperature. It is important to consider that in corner rooms the temperature cannot be less than 20 C, although in other rooms of the apartment a decrease to 18 C is allowed.

If the temperature outside drops to -30 C, then the heating in the rooms should rise by 2 C. The temperature in the remaining rooms should also rise, provided that in the rooms for various purposes it may be different. If there is a child in the room, then it can fluctuate from 18 C to 23 C.

In storerooms and corridors, heating can vary from 12 C to 18 C.

Schedule for hot water supply to the apartment

In order to deliver optimal hot water to the consumer, CHP plants must send it as hot as possible.

Heating lines are always so long that their length can be measured in kilometers, and the length of apartments is measured in thousands. square meters. Whatever the insulation of the pipes, heat is lost on the way to the user.

Therefore, it is necessary to heat the water as much as possible.

However, water cannot be heated above its boiling point. Therefore, a solution was found - to increase the pressure.

It looks like this:

Boiling temperature
Pressure

The supply of hot water in the winter season must be continuous. Exceptions to this rule include heat supply accidents. Hot water supply can be turned off only in summer for preventative work. Such work is carried out both in closed-type and open-type heat supply systems.

Heating schedule for qualitative regulation of heat supply based on average daily outside air temperature

Looking through the statistics of visits to our blog, I noticed that search phrases such as, for example, “what should be the coolant temperature at minus 5 outside?” appear very often.

I decided to post the old one schedule for qualitative regulation of heat supply based on average daily outside air temperature.

I would like to warn those who, based on these figures, will try to figure out the relationship with housing departments or heating networks: heating schedules for each individual settlement are different (I wrote about this in the article regulating the temperature of the coolant). Heating networks in Ufa (Bashkiria) operate according to this schedule.

I also want to draw attention to the fact that regulation occurs according to average daily outside air temperature, so if, for example, outside at night minus 15 degrees, and during the day minus 5, then the coolant temperature will be maintained in accordance with the schedule at minus 10 оС.

Typically, the following temperature charts are used: 150/70 , 130/70 , 115/70 , 105/70 , 95/70 . The schedule is selected depending on specific local conditions. House heating systems operate according to schedules 105/70 and 95/70. Main heating networks operate according to schedules 150, 130 and 115/70.

Let's look at an example of how to use a chart. Let's say the temperature outside is minus 10 degrees.

Heating networks operate according to a temperature schedule 130/70 , which means when -10 °C temperature of the coolant in the supply pipeline of the heating network should be 85,6 degrees, in the supply pipe of the heating system - 70.8 oC with a schedule of 105/70 or 65.3 oC with a 95/70 schedule. The water temperature after the heating system should be 51,7 oS.

As a rule, the temperature values in the supply pipeline of heating networks are rounded when assigned to a heat source. For example, according to the schedule it should be 85.6 °C, but at a thermal power plant or boiler house it is set to 87 degrees.

Outdoor air temperature Тнв, оС Temperature of network water in the supply pipeline Т1, оС Temperature of water in the supply pipeline of the heating system Т3, оС Temperature of water after the heating system Т2, оС
15013011510595
8

53,2
50,2
46,4
43,4
41,2
35,8

55,7
52,3
48,2
45,0
42,7
36,8

58,1
54,4
50,0
46,6
44,1
37,7

60,5
56,5
51,8
48,2
45,5
38,7

62,9
58,5
53,5
49,8
46,9
39,6

65,3
60,5
55,3
51,4
48,3
40,6

67,7
62,6
57,0
52,9
49,7
41,5

70,0
64,5
58,8
54,5
51,0
42,4

72,4
66,5
60,5
56,0
52,4
43,3

74,7
68,5
62,2
57,5
53,7
44,2

77,0
70,4
63,8
59,0
55,0
45,0

79,3
72,4
65,5
60,5
56,3
45,9

81,6
74,3
67,2
62,0
57,6
46,7

83,9
76,2
68,8
63,5
58,9
47,6

86,2
78,1
70,4
65,0
60,2
48,4

88,5
80,0
72,1
66,4
61,5
49,2

90,8
81,9
73,7
67,9
62,8
50,1

93,0
83,8
75,3
69,3
64,0
50,9

95,3
85,6
76,9
70,8
65,3
51,7

97,6
87,5
78,5
72,2
66,6
52,5

99,8
89,3
80,1
73,6
67,8
53,3

102,0
91,2
81,7
75,0
69,0
54,0

104,3
93,0
83,3
76,4
70,3
54,8

106,5
94,8
84,8
77,9
71,5
55,6

108,7
96,6
86,4
79,3
72,7
56,3

110,9
98,4
87,9
80,7
73,9
57,1

113,1
100,2
89,5
82,0
75,1
57,9

115,3
102,0
91,0
83,4
76,3
58,6

117,5
103,8
92,6
84,8
77,5
59,4

119,7
105,6
94,1
86,2
78,7
60,1

121,9
107,4
95,6
87,6
79,9
60,8

124,1
109,2
97,1
88,9
81,1
61,6

126,3
110,9
98,6
90,3
82,3
62,3

128,5
112,7
100,2
91,6
83,5
63,0

130,6
114,4
101,7
93,0
84,6
63,7

132,8
116,2
103,2
94,3
85,8
64,4

135,0
117,9
104,7
95,7
87,0
65,1

137,1
119,7
106,1
97,0
88,1
65,8

139,3
121,4
107,6
98,4
89,3
66,5

141,4
123,1
109,1
99,7
90,4
67,2

143,6
124,9
110,6
101,0
94,6
67,9

145,7
126,6
112,1
102,4
92,7
68,6

147,9
128,3
113,5
103,7
93,9
69,3

150,0
130,0
115,0
105,0
95,0
70,0

Temperature graph calculation

The method for calculating the temperature graph is described in the reference book “Adjustment and operation of water heating networks” (Chapter 4, paragraph 4.4, p. 153).

This is a rather labor-intensive and time-consuming process, since for each outdoor temperature several values need to be counted: T1, T3, T2, etc.

To our joy, we have a computer and a spreadsheet processor MS Excel. A work colleague shared with me a ready-made table for calculating the temperature graph. It was made at one time by his wife, who worked as an engineer for a group of modes in thermal networks.

Temperature chart calculation table in MS Excel

In order for Excel to calculate and build a graph, you just need to enter a few initial values:

design temperature in the supply pipeline of the heating network T1
design temperature in the return pipeline of the heating network T2
design temperature in the heating system supply pipe T3
Outdoor temperature Tn.v.
Indoor temperature Tv.p.
coefficient " n"(it is, as a rule, unchanged and equal to 0.25)
Minimum and maximum cut of the temperature graph Slice min, Slice max.

Entering initial data into the temperature chart calculation table

All. nothing more is required from you. The calculation results will be in the first table of the sheet. It is highlighted with a bold frame.

The charts will also adjust to the new values.

Graphic representation of the temperature graph

The table also calculates the temperature of direct network water taking into account wind speed.

Download temperature chart calculation

Coolant temperature depending on outside temperature

5/5 (3)

The coolant temperature directly depends on the outside temperature. You should pay attention to this fact. Weather conditions are directly taken into account when determining the required heating parameters.

In Russia, heating systems that operate on a water basis are most often used. However, the temperature of the water that flows through the batteries directly depends on weather conditions. Therefore, when it is cold outside, heat supply companies are obliged to increase the temperature regime, and when it is warm, on the contrary, to reduce it.

The schedule according to which the temperature of water supplied to the house is calculated is approved at the legislative level. It directly reflects the indicators at which the resource should be heated more intensely or weakly.

The schedule was developed based on approved standards for normal room temperature. Therefore, if it’s cold at home and the radiators don’t heat up, it’s the service provider’s fault. You can safely measure heat and draw up a report.

Thermal power plants do not calculate anything on their own. They do not have the right to assert their own norms. All indicators were approved by the Government of the Russian Federation in agreement with SanPiN. The basis is statistical data for the past ten years. When drawing up the graph, the highest and lowest thermometer marks for this period were taken into account.

However, such rules allow heat supply companies to save money on heating, since the highest temperature readings do not occur so often.

ATTENTION! Look at the completed sample application to the Criminal Code for measuring the temperature in the apartment:

The thermal level of water supplied for space heating must be at the level approved by the government. To calculate indicators, you do not need to resort to technical services. At the legislative level, everything has been calculated for a long time.

All that remains is to maintain the required temperature conditions at the inlet, outlet and in the heating system itself. However, to maintain balance, you need to have special knowledge that will help determine the intensity of water heating to increase or decrease its temperature.

Please note! In each region, heat supply companies are required to independently configure the equipment so that it produces water at the required temperature. This is due to the unique climatic conditions in different settlements.

For example, in the south of the country, external indicators never exceed -30 C, so they do not need to introduce increased operation of equipment.

In accordance with the approved rules, the temperature in the room should not be lower than +20C ... +22C. Such standards are considered optimal for living and spending time in an apartment.

The approved schedule contains information about the permitted water temperature:

when leaving the heat supply station (boiler room);
when in the heating system;
when leaving the heating system, for example, when drawing from a tap directly into a heated apartment.

Each heat supply station must be equipped by special means, which help maintain maximum and minimum performance.

However, depending on the installation volume:

large thermal power plants are required to equip the station with devices that produce water with a maximum temperature of 105°C to 130°C. The minimum indicator is at 70°C;
small stations and boiler houses are equipped with devices that produce water with a maximum temperature of 95°C to 105°C. The minimum indicator remains unchanged.

However, in some regions, maximum values are increasing due to a decrease in the average daily air temperature outside.

Previously, until 1991, the responsibility for drawing up the schedule rested with the local administration. Every year in the autumn-winter period they were engaged in calculations. Based on them, heating companies supplied heat to the house.

It cannot be said that such a method helped to find the optimal result. Some houses were cold in winter. However, this made it possible to optimize the temperature regime in many rooms. The majority of the population received the maximum comfortable conditions residence.

note

Unfortunately, such calculation methods have been abolished. The rules have been introduced to simplify the payment system. However, this has resulted in poor service delivery. It seems that the heating company is not violating the law, but the house is still cold all winter.

The introduction of new rules led to a reduction in the costs of thermal power plants, rather than providing the population with sufficient heat.

Numerous complaints about public utilities from ordinary people did not go unnoticed. In 2010, the schedule of thermal indicators was again introduced. It is regulated by Federal Law No. 190 of July 27, 2010 “On Heat Supply”. Now the heat in the house has been restored again.

The new graph is based on average temperatures over the past ten years. The following are taken into account: the highest and lowest temperature of the thermometer in winter.

Attention!Our qualified lawyers will assist you free of charge and around the clock on any issues.Find out more here.

Outdoor temperature, °C
Water temperature at the heating system inlet, °C
Water temperature in the heating system, °C
Water temperature at the outlet of the heating system, in °C

8
+51…+52
+42…+45
+34…+40

7
+51…+55
+44…+47
+35…+41

6
+53…+57
+45…+49
+36…+46

5
+55…+59
+47…+50
+37…+44

4
+57…+61
+48…+52
+38…+45

3
+59…+64
+50…+54
+39…+47

2
+61…+66
+51…+56
+40…+48

1
+63…+69
+53…+57
+41…+50

65…+71
+55…+59
+42…+51

1
+67…+73
+56…+61
+43…+52

2
+69…+76
+58…+62
+44…+54

3
+71…+78
+59-…+64
+45…+55

4
+73…+80
+61…+66
+46…+57

5
+75…+82
+62…+67
+47…+59

6
+77-…+85
+64…+-69
+48…+62

7
+79…+87
+65…+71
+49…+61

8
+80…+89
+66…+72
+49…+63

9
+82…+92
+69…+-75
+50…+64

10
+86…+94
+71…+77
+51…+65

11
+86…+96
+72…+79
+52…+66

12
+88…+98
+74…+-80
+53…+68

13
+90…+101
+75…+82
+54…+69

14
+92…+103
+76…+83
+54…+70

15
+93…+105
+79…+86
+56…+72

16
+95…+107
+79…+86
+56…+72

17
+97…+109
+81…+88
+56…+74

18
+99…+112
+82…+90
+57…+75

19
+101…+114
+83…+91
+58…+76

20
+102-…+116
+85…+-93
+59…+77

21
+104…+118
+88…+94
+59…+78

22
+106…+120
+87…+96
+60…+80

23
+108…+123
+89…+97
+61…+81

24
+109…+125
+90…+98
+62…+82

25
+112…+128
+91…+99
+62…+83

26
+114…+130
+92…+101
+63…+84

27
+116…+134
+94…+103
+64…+86

28
+118…+136
+96…+105
+64…+87

29
+120…+138
+97…+106
+67…+88

30
+122…+140
+98…+108
+66…+89

31
+123…+142
+100…+109
+66…+90

32
+125…+144
+101…+111
+67…+91

33
+127…+146
+102…+112
+68…+92

34
+129…+149
+104…+114
+69…+94

A special schedule is developed for the boiler room of a thermal power plant, on the basis of which it operates. They serve residential apartment buildings, cottages, apartments, administrative buildings, municipalities and other premises.

The schedule makes it possible for thermal stations to prepare for the heating season. With it, the decrease in temperature is not dangerous for the population. In addition, it allows you to save thermal energy when you can heat the room in a reduced mode.

Heating temperature chart

The supply of heat to a room is associated with a simple temperature schedule. The temperature values of the water supplied from the boiler room do not change in the room. They have standard values and range from +70ºС to +95ºС. This temperature schedule for the heating system is the most popular.

Adjusting the air temperature in the house

Not everywhere in the country there is central heating, so many residents install independent systems. Their temperature graph differs from the first option. In this case, temperature indicators are significantly reduced. They depend on the efficiency of modern heating boilers.

If the temperature reaches +35ºС, the boiler will operate at maximum power. It depends on the heating element, Where thermal energy can be picked up by exhaust gases. If the temperature values are greater than + 70 ºС, then the boiler performance drops. In that case, in his technical specifications efficiency is indicated at 100%.

Temperature schedule and its calculation

What the graph will look like depends on the outside temperature. The more negative the outside temperature, the greater the heat loss. Many people do not know where to get this indicator. This temperature is prescribed in regulatory documents. The temperature of the coldest five-day period is taken as the calculated value, and the lowest value over the last 50 years is taken.

Graph of the dependence of external and internal temperatures

The graph shows the relationship between external and internal temperatures. Let's say the outside temperature is -17ºС. Drawing a line upward until it intersects with t2, we obtain a point characterizing the temperature of the water in the heating system.

Thanks to the temperature schedule, you can prepare the heating system even for the most severe conditions. It also reduces material costs for installing a heating system. If we consider this factor from the point of view of mass construction, the savings are significant.

Temperature inside premises depends from temperature coolant, A Also others factors:

Outside air temperature. The smaller it is, the more negatively it affects heating;
Wind. When strong wind occurs, heat loss increases;
The temperature inside the room depends on the thermal insulation of the structural elements of the building.

Over the past 5 years, construction principles have changed. Builders increase the value of a home by insulating elements. As a rule, this applies to basements, roofs, and foundations. These expensive measures subsequently allow residents to save on the heating system.

Heating temperature chart

The graph shows the dependence of the temperature of external and internal air. The lower the outside air temperature, the higher the coolant temperature in the system will be.

A temperature schedule is developed for each city during the heating season. In small settlements, a boiler room temperature schedule is drawn up, which provides the required amount of coolant to the consumer.

Change temperature schedule Can several ways:

quantitative - characterized by a change in the flow rate of coolant supplied to the heating system;
qualitative - consists of regulating the temperature of the coolant before supplying it to the premises;
temporary - a discrete method of supplying water to the system.

The temperature schedule is a schedule of heating pipes that distributes the heating load and is regulated using centralized systems.

There is also an increased schedule; it is created for a closed heating system, that is, to ensure the supply of hot coolant to connected objects.

When using an open system, it is necessary to adjust the temperature schedule, since the coolant is consumed not only for heating, but also for domestic water consumption.

The temperature graph is calculated using a simple method. Hto build it, necessary initial temperature air data:

external;
in room;
in the supply and return pipelines;
at the exit of the building.

In addition, you should know the rated thermal load. All other coefficients are standardized by reference documentation. The system is calculated for any temperature schedule, depending on the purpose of the room.

For example, for large industrial and civilian objects a schedule of 150/70, 130/70, 115/70 is drawn up. For residential buildings this figure is 105/70 and 95/70. The first indicator shows the supply temperature, and the second - the return temperature.

The calculation results are entered into a special table, which shows the temperature at certain points of the heating system, depending on the outside air temperature.

The main factor in calculating the temperature schedule is the outside air temperature. The calculation table must be drawn up so that the maximum values of the coolant temperature in the heating system (graph 95/70) ensure heating of the room. Room temperatures are provided regulatory documents.

Temperature heating devices

Heating device temperature

The main indicator is the temperature of heating devices. The ideal temperature schedule for heating is 90/70ºС. It is impossible to achieve such an indicator, since the temperature inside the room should not be the same. It is determined depending on the purpose of the room.

In accordance with the standards, the temperature in the corner living room is +20ºС, in the rest – +18ºС; in the bathroom – +25ºС. If the outside air temperature is -30ºС, then the indicators increase by 2ºС.

Except Togo, exists norms For others types premises:

in rooms where children are located – +18ºС to +23ºС;
children's educational institutions – +21ºС;
in cultural institutions with mass attendance – +16ºС to +21ºС.

This range of temperature values is compiled for all types of premises. It depends on the movements performed inside the room: the more movements there are, the lower the air temperature. For example, in sports facilities people move a lot, so the temperature is only +18ºС.

Room temperature

Exist certain factors, from which depends temperature heating devices:

Outside air temperature;
Type of heating system and temperature difference: for a single-pipe system – +105ºС, and for a single-pipe system – +95ºС. Accordingly, the differences in for the first region are 105/70ºС, and for the second – 95/70ºС;
Direction of coolant supply to heating devices. With the top feed, the difference should be 2 ºС, with the bottom – 3 ºС;
Type of heating devices: heat transfer is different, so the temperature curve will be different.

First of all, the coolant temperature depends on the outside air. For example, the temperature outside is 0ºC. In this case, the temperature regime in the radiators should be 40-45ºC at the supply, and 38ºC at the return.

When the air temperature is below zero, for example -20ºС, these indicators change. IN in this case the supply temperature becomes 77/55ºС.

If the temperature reaches -40ºС, then the indicators become standard, that is, +95/105ºС at the supply, and +70ºС at the return.

Additional options

In order for a certain temperature of the coolant to reach the consumer, it is necessary to monitor the condition of the outside air. For example, if it is -40ºС, the boiler room should supply hot water with an indicator of +130ºС.

Along the way, the coolant loses heat, but the temperature still remains high when it enters the apartments. The optimal value is +95ºС.

To do this, an elevator unit is installed in the basements, which serves to mix hot water from the boiler room and coolant from the return pipeline.

Several institutions are responsible for the heating main. The boiler room monitors the supply of hot coolant to the heating system, and the condition of the pipelines is monitored by city heating networks. The housing office is responsible for the elevator element. Therefore, in order to solve the problem of coolant supply to new house, you need to contact different offices.

Installation of heating devices is carried out in accordance with regulatory documents. If the owner himself replaces the battery, then he is responsible for the operation of the heating system and changes in temperature conditions.

Adjustment methods

Dismantling the elevator unit

If the boiler room is responsible for the parameters of the coolant leaving the warm point, then the housing office workers must be responsible for the temperature inside the room. Many residents complain about the cold in their apartments. This occurs due to a deviation in the temperature graph. In rare cases, it happens that the temperature rises by a certain value.

Heating parameters can be adjusted in three ways:

If the supply and return coolant temperatures are significantly underestimated, then it is necessary to increase the diameter of the elevator nozzle. This way, more liquid will pass through it.

How to do this? To begin with, shut-off valves are closed (house valves and taps at the elevator unit). Next, the elevator and nozzle are removed. Then it is drilled out by 0.5-2 mm, depending on how much it is necessary to increase the temperature of the coolant. After these procedures, the elevator is mounted on old place and goes into operation.

To ensure sufficient tightness flange connection, it is necessary to replace the paronite gaskets with rubber ones.

In severe cold weather, when the problem of freezing of the heating system in the apartment arises, the nozzle can be completely removed. In this case, the suction may become a jumper. To do this, you need to plug it with a steel pancake 1 mm thick. This process is carried out only in critical situations, since the temperature in pipelines and heating devices will reach 130ºC.

In the middle of the heating season, a significant increase in temperature may occur. Therefore, it is necessary to regulate it using a special valve on the elevator. To do this, the supply of hot coolant is switched to the supply pipeline. A pressure gauge is mounted on the return line. Adjustment occurs by closing the valve on the supply pipeline.

Next, the valve opens slightly, and the pressure should be monitored using a pressure gauge. If you simply open it, the cheeks will sag. That is, an increase in pressure drop occurs in the return pipeline. Every day the indicator increases by 0.2 atmospheres, and the temperature in the heating system must be constantly monitored.

Heat supply. Video

How is the heat supply of private and apartment buildings, you can find out from the video below.

When drawing up a heating temperature schedule, various factors must be taken into account. This list includes not only structural elements building, but the outside temperature, as well as the type of heating system.

Calculation of the temperature schedule for the supply of coolant to the heating system of residential buildings

The coolant is a special type of liquid or gaseous substance, and is used for the purpose of transferring thermal energy.

As a rule, water is used as a coolant.

The dependence of the temperature of the coolant in the heating system on the temperature indicators of the outside air is called a temperature graph.

The temperature of the coolant at the entrance to the heating system, under conditions of high-quality regulation of heat supply, is directly dependent on the atmospheric conditions outside the house.

The lower the values, the greater the temperature output must have a heating system coolant.

Temperature graph parameters are selected during the heating system design process and influence the choice of:

heating appliance sizes;
total coolant flow in the heating system;
cross-section of the distribution pipeline(about compensators for polypropylene pipes heating is written here).

The temperature graph is indicated by two numbers that show the degree of heating of the coolant at the inlet and outlet.

Provided that this is enough to create an optimal, comfortable indoor microclimate.

The use of a graph is necessary in the process of setting up and analyzing the operating mode of heating systems.

Carrying out research allows us to determine the degree of heat consumption or, conversely, heat deficiency.

Main settings

The most significant parameter is the coolant temperature in the heating system, which determines the efficiency of heating the room.

It is also necessary to take into account the level of viscosity, volume thermal expansion and the optimal coolant speed, the minimum values of which are 0.2 m/s.

When choosing a coolant, you need to pay attention for the following characteristics:

the speed of the coolant in the heating system (indicated here) and the transfer of the maximum volume of heat during the minimum time period and with low losses along the entire perimeter of the heating system;
the liquid must not cause corrosive changes in the pipeline;
viscosity indicators that affect the coolant speed and efficiency should be insignificant;
the composition must not contain toxic or harmful substances;
lack of flammability at too high temperatures.

The coolant should be affordable, and purchasing it for refills should not be difficult.

Expensive coolants, as a rule, are operated more long time, and without replacement.

It should be noted that the temperature inside the room largely depends on the outside temperature and wind loads, as well as the degree of insulation and the sealing performance of the joints of the room.

Technical characteristics of radiators

In different rooms according to their purpose, the air temperature should be different.

Therefore, when determining the temperature schedule, it is necessary to focus on the following indicators:

corner living space– 20оС;
not a corner living space– 18oC;
shower or bathroom– 25оС.

When the street temperature is minus 30°C and below, the indicators in the residential premises listed above should, accordingly, be increased to 22°C and 20°C.

In the following premises with large numbers of people, it is necessary to ensure:

children's rooms– 18-23оС;
children's pools– 30oC;
walking verandas– 12оС;
school premises– 21оС;
bedrooms in a children's boarding school– 16oC;
cultural institutions– 16-21оС;
libraries– 18oC.

Temperature standards directly depend on the intensity of human movement indoors.

Therefore in sports complexes the indicator should not exceed 18°C.

Outdoor temperature readings
The lower the street temperature, the greater the load the heating system in the room experiences. At zero street temperature, it is necessary to adhere to 40-45 ° C for supply and 35-40 ° C for outlet on radiator equipment. When using convectors, 41-49 ° C is supplied and 36-40 ° C is discharged

Timing of heating system
In single-pipe systems, the norm of temperature indicators is 105 ° C, and in the presence of a two-pipe system, the indicators are reduced to a level of 95 ° C. The difference in temperature indicators at the supply and outlet should be 105-70 ° C / 95-70 ° C

Supply of coolant to heating equipment
When using top wiring on heating radiators the difference should not exceed 2°C, and the presence of lower wiring requires a difference of 3°C

Type of heating device
Radiator equipment, compared to convectors, is different increased level heat transfer

It is necessary to regulate the supply and removal of coolant in the heating system of residential, utility and other types of premises, depending on the street temperature.

Outdoor temperature indicators
Supply coolant temperature
Return coolant temperature

Zero temperature
40–45оС radiator41–49оС convector
35–38°C radiator 36–40°C convector

Minus 20oC
67–77оС radiator68–79оС convector
53–55оС radiator 55–57оС convector

Minus 40oC
95–105°C radiator and convector
79°C radiator and convector

Dependence on the type of operating fluids

Most often, water is used as a coolant (how a solenoid valve works is written here) or antifreeze for heating.

Running water contains a significant amount of foreign impurities that negatively affect the performance and service life of the heating system.

Therefore, it is advisable to use completely purified water or distillate:

mass density indicators 1000 kg per cubic meter at a temperature of 4°C, with a decrease in specific density during heating;
heat capacity level is 4.2 kJ/kg*C;
boiling point 100oC with an increase under the influence of increased pressure.

Water is non-toxic and harmless, does not change properties when overheated, is affordable, is not limited by service life and can be combined with a pipeline made of any material.

Antifreeze is characterized low temperatures freezing and contains ethylene glycol or propylene glycol.

Main advantage, compared to water, is represented by frost resistance:

most species are characterized by toxicity;
when overheated, foaming and the release of sediment are observed, settling on the walls of the heating equipment;
high price, compared to water, and the impossibility of use in some types of pipelines;
limited service life not exceeding five years under standard conditions of use.

To achieve maximum efficient heating premises and obtain a long-lasting heating system, you need to correctly calculate the coolant (a table of the volume of water in a steel pipe is published here).

Heating pipe section
Coolant volume in ml.

40 mm
1257

50 mm
2467

65 mm
3318

80 mm
5026

100 mm
7854

Standards for individual heating

In apartments equipped with autonomous heat supply, heating standards are represented by the heat transfer of heating devices to the area of the room where this device is installed, and are determined by the formula:

P = S x H x 41,
S– area of the room in square meters;
N– height of the room in meters;
41 – coefficient of minimum thermal power.

The resulting value must be correlated with the indicators of the actual heat transfer of heating devices:

cast iron radiator– 90-160 W;
steel radiator– 60-170 W;
aluminum and bimetallic radiator– 160-200 W.

Under conditions of lower connection, the standard thermal power of the radiator is reduced by 10%.

To connect a one-pipe system, Typically, such indicators decrease by 25-30%.

Underfloor heating system does not require heating the coolant to too high temperatures.

Therefore, return coolant can be used (approximate price for check valve for water).

Under standard conditions, the heating standards of an autonomous system are calculated taking into account the type of heating devices and the actual level of coolant pressure inside the system.

We invite you to watch a video dedicated to creating the simplest automation for adjusting the degree of heating of the coolant in the “Warm Floor” system.

Temperature graph of heating networks for heating houses

In cities, almost everything residential buildings connected to the central heating system. To ensure comfortable living conditions in winter, it is necessary to control the temperature of the coolant supplied by thermal power plants and boiler houses. For this purpose, heating network employees develop a temperature schedule depending on climatic conditions region and outside air temperature.

To make the premises comfortable, you need to develop a temperature schedule

Purpose and scope

The temperature graph of the heating network displays the required temperature of the coolant in accordance with the same indicator of the outside air. He used in central systems heat supply, allowing you to maintain the required temperature in the premises and save energy resources.

You can also use the graph in autonomous systems heating.

With its help, not only is it created desired temperature indoors, but also provided safe operation heating system.

It should be noted that the choice of all parameters of the equipment used to heat an apartment depends not only on the climatic characteristics of the region, but also on the temperature schedule.

Thus, it shows what the coolant temperature should be depending on the outside temperature.

Main types

There are several types of temperature graphs, each of which affects the standard temperature of heating radiators. The choice of a specific type depends on several factors. The most important among them are:

Climatic features of the region.

Equipment of a thermal power plant or boiler house.

Technical and economic indicators of the heating system.

It is customary to distinguish graphs for two- and one-pipe heating systems, consisting of two numbers. For example, a temperature graph of 150-70 means that in order to maintain comfortable conditions in the apartment, the temperature of the coolant entering the system should be 150 degrees, and the return temperature should be 70 degrees.

Features of compilation

When developing schedule indicators, it is necessary to focus on the capabilities of the heating system, the characteristics of the heat generator, as well as temperature fluctuations outside. If there are sharp changes in temperature in the region, then it is necessary to select the correct pipe material and fuel.

When choosing optimal temperature Most often, several factors are taken into account:

Possibility of ensuring efficient coolant supply.

Achievements of stable and economical operation heating systems.

Providing comfortable living conditions.

Each room has its own level of comfortable temperature

Depending on the type of heated room, the standards provide for different temperature parameters. If for the housing stock this figure is 18 degrees, then for hospitals and children's institutions it is 3 degrees higher.

For rational use of fuel, this difference should be minimal. To solve the problem, you need to carry out additional work for insulation of not only heating mains, but also buildings. Any building radiates environment warm. This factor must be taken into account when designing heating systems.

Temperature regulation

Employees of heating networks and thermal power plants are responsible for the parameters of the heating main, and temperature indicators inside buildings are in the department of the housing office. To regulate the room temperature in heating season two methods can be used.

The first is called quantitative and involves a change in water flow at constant temperatures. If a qualitative method is used, then the volume of coolant consumed remains constant, but its thermal parameter changes.

It is the second option that is used most often, as it is the most economical. A high-quality method of heat regulation allows you to provide comfortable living conditions even with sudden changes in temperature outside.

For a heat energy consumer, knowledge of coolant supply standards can be useful.

note

This is due to the fact that if the schedule parameters are not met, recalculation may be required. public utilities. To measure the thermal index of the coolant, it is not necessary to install complex heat metering devices in the apartment.

It is enough to drain a small amount of water from the radiator into a container and then take a measurement.

What laws govern changes in coolant temperature in systems? central heating? What is it - the temperature graph of the heating system is 95-70? How to bring heating parameters into line with the schedule? Let's try to answer these questions.

What it is

Let's start with a couple of abstract theses.

As weather conditions change, the heat loss of any building changes along with them. In frosty weather, in order to maintain a constant temperature in the apartment, much more thermal energy is required than in warm weather.

Let us clarify: heat costs are determined not by the absolute value of the air temperature outside, but by the delta between the street and the interior.
So, at +25C in the apartment and -20 in the yard, heat costs will be exactly the same as at +18 and -27, respectively.

The heat flow from the heating device at a constant coolant temperature will also be constant.
A drop in temperature in the room will increase it slightly (again due to an increase in the delta between the coolant and the air in the room); however, this increase will be absolutely insufficient to compensate for the increased heat losses through the building envelope. Just because lower threshold temperature in the apartment current SNiP limited to 18-22 degrees.

An obvious solution to the problem of increasing losses is to increase the temperature of the coolant.

Obviously, its increase should be proportional to the decrease in street temperature: the colder it is outside, the greater the heat loss will have to be compensated. Which, in fact, brings us to the idea of creating a specific table for reconciling both values.

So, the schedule temperature system heating is a description of the dependence of the temperatures of the supply and return pipelines on the current weather outside.

How everything works

There are two different types of charts:

For heating networks.
For indoor heating system.

To explain the difference between these concepts, it is probably worth starting with a brief excursion into how central heating works.

CHP - heating networks

The function of this bundle is to heat the coolant and deliver it to the end user. The length of heating mains is usually measured in kilometers, the total surface area is measured in thousands and thousands of square meters. Despite measures to insulate pipes, heat loss is inevitable: having passed the path from the thermal power plant or boiler room to the border of the house, process water will have time to partially cool down.

Hence the conclusion: in order for it to reach the consumer while maintaining an acceptable temperature, the supply of the heating main at the exit from the thermal power plant must be as hot as possible. The limiting factor is the boiling point; however, as the pressure increases, it shifts towards increasing temperature:

Pressure, atmosphere	Boiling point, degrees Celsius
1	100
1,5	110
2	119
2,5	127
3	132
4	142
5	151
6	158
7	164
8	169

Typical pressure in the supply pipeline of a heating main is 7-8 atmospheres. This value, even taking into account pressure losses during transportation, allows you to start a heating system in buildings up to 16 floors high without additional pumps. At the same time, it is safe for routes, risers and connections, mixer hoses and other elements of heating and hot water systems.

With some margin, the upper limit of the supply temperature is taken to be 150 degrees. The most typical heating temperature curves for heating mains are in the range of 150/70 – 105/70 (supply and return temperatures).

House

There are a number of additional limiting factors in a home heating system.

The maximum temperature of the coolant in it cannot exceed 95 C for a two-pipe and 105 C for.

By the way: in preschool educational institutions the limit is much more stringent - 37 C.
The price of lowering the supply temperature is an increase in the number of radiator sections: in the northern regions of the country, group rooms in kindergartens are literally surrounded by them.

For obvious reasons, the temperature delta between the supply and return pipelines should be as small as possible - otherwise the temperature of the batteries in the building will vary greatly. This implies rapid circulation of the coolant.
However, too rapid circulation through the home heating system will result in return water returning to the route at an exorbitant rate. high temperature, which is unacceptable due to a number of technical limitations in the operation of thermal power plants.

The problem is solved by installing one or more elevator units in each house, in which return water is mixed with the flow of water from the supply pipeline. The resulting mixture, in fact, ensures rapid circulation of a large volume of coolant without overheating the return pipeline of the route.

For intra-house networks, a separate temperature schedule is set taking into account the elevator operation scheme. For two-pipe circuits, the typical heating temperature curve is 95-70, for single-pipe circuits (which, however, is rare in apartment buildings) – 105-70.

Climate zones

The main factor determining the scheduling algorithm is the estimated winter temperature. The coolant temperature table must be drawn up in such a way that the maximum values (95/70 and 105/70) at the peak of frost provide the temperature in residential premises corresponding to SNiP.

Let's give an example of an intra-house graph for the following conditions:

Heating devices - radiators with coolant supply from bottom to top.
Heating is two-pipe, with .

The estimated outside air temperature is -15 C.

Outside air temperature, C	Feed, C	Return, C
+10	30	25
+5	44	37
0	57	46
-5	70	54
-10	83	62
-15	95	70

A nuance: when determining the parameters of the route and the intra-house heating system, the average daily temperature is taken.
If it is -15 at night and -5 during the day, the outside temperature is -10C.

And here are some values of calculated winter temperatures for Russian cities.

City	Design temperature, C
Arkhangelsk	-18
Belgorod	-13
Volgograd	-17
Verkhoyansk	-53
Irkutsk	-26
Krasnodar	-7
Moscow	-15
Novosibirsk	-24
Rostov-on-Don	-11
Sochi	+1
Tyumen	-22
Khabarovsk	-27
Yakutsk	-48

The photo shows winter in Verkhoyansk.

Adjustment

If the management of the thermal power plant and heating networks is responsible for the parameters of the route, then responsibility for the parameters of the intra-house network rests with the housing residents. A very typical situation is when, when residents complain about the cold in their apartments, measurements show deviations from the schedule downward. It happens a little less often that measurements in thermal wells show an elevated return temperature from the house.

How to bring the heating parameters into line with the schedule with your own hands?

Reaming the nozzle

When the temperature of the mixture and return is low, the obvious solution is to increase the diameter of the elevator nozzle. How it's done?

Instructions are at the reader's disposal.

All valves or valves in the elevator unit (input, house and hot water supply) are closed.
The elevator is being dismantled.
The nozzle is removed and drilled 0.5-1 mm.
The elevator is assembled and started with air bleeding in the reverse order.

Advice: instead of paronite gaskets, you can put rubber gaskets on the flanges, cut to the size of the flange from a car inner tube.

An alternative is to install an elevator with an adjustable nozzle.

Choke suppression

IN critical situation(extreme cold and freezing apartments) the nozzle can be completely removed. To prevent the suction from becoming a jumper, it is suppressed with a pancake made of a steel sheet at least a millimeter thick.

Attention: this is an emergency measure used in extreme cases, since in this case the temperature of the radiators in the house can reach 120-130 degrees.

Differential adjustment

At elevated temperatures, as a temporary measure until the end of the heating season, it is practiced to adjust the differential on the elevator using a valve.

The DHW switches to the supply pipe.
A pressure gauge is installed on the return line.
The inlet valve on the return pipeline is completely closed and then gradually opens with pressure controlled by a pressure gauge. If you simply close the valve, the subsidence of the cheeks on the rod can stop and defrost the circuit. The difference is reduced by increasing the return pressure by 0.2 atmospheres per day with daily temperature control.

Conclusion

Sections