Each heating system has certain characteristics. These include power, heat transfer and operating temperature. They determine the efficiency of work, directly affecting the comfort of living in the house. How to choose the right temperature schedule and heating mode, and its calculation?

Drawing up a temperature chart

Temperature chart The operation of the heating system is calculated using several parameters. Not only the degree of heating of the premises, but also the coolant consumption depends on the selected mode. This also affects the current costs of heating maintenance.

Compiled schedule temperature regime heating depends on several parameters. The main one is the level of water heating in the mains. It, in turn, consists of the following characteristics:

• Temperature in the supply and return pipes. Measurements are taken in the corresponding boiler nozzles;
• Characteristics of the degree of air heating indoors and outdoors.

Correct calculation of the heating temperature schedule begins with calculating the difference between the temperature of hot water in the direct and supply pipes. This value has the following designation:

∆T=Tin-Tob

Where Tin– water temperature in the supply line, Tob– degree of water heating in the return pipe.

To increase the heat transfer of the heating system, it is necessary to increase the first value. To reduce coolant flow, ∆t should be minimal. This is precisely the main difficulty, since the temperature schedule of the heating boiler directly depends on external factors– heat losses in the building, air outside.

To optimize heating power, it is necessary to insulate the external walls of the house. This will reduce heat losses and energy consumption.

Temperature calculation

To determine the optimal temperature regime, it is necessary to take into account the characteristics of heating components - radiators and batteries. In particular - power density(W/cm²). This will directly affect the thermal transfer of heated water to the air in the room.

It is also necessary to make a number of preliminary calculations. This takes into account the characteristics of the house and heating devices:

• Heat transfer resistance coefficient of external walls and window designs. It must be at least 3.35 m²*C/W. Depends on climatic features region;
• Surface power of radiators.

The temperature graph of the heating system is directly dependent on these parameters. To calculate the heat loss of a house, you need to know the thickness of the external walls and the material of the building. The surface power of batteries is calculated using the following formula:

Ore=P/Fact

Where R – maximum power, W, fact– radiator area, cm².

According to the data obtained, a temperature regime for heating and a heat transfer graph are drawn up depending on the outside temperature.

To change heating parameters in a timely manner, install a heating temperature regulator. This device connects to outdoor and indoor thermometers. Depending on the current indicators, the operation of the boiler or the volume of coolant flow into the radiators is adjusted.

The weekly programmer is the optimal heating temperature regulator. With its help, you can automate the operation of the entire system as much as possible.

Central heating

For district heating The temperature regime of the heating system depends on the characteristics of the system. Currently, there are several types of coolant parameters supplied to consumers:

• 150°C/70°C. To normalize the water temperature, the elevator unit mixes it with the cooled flow. IN in this case you can create an individual temperature schedule for a heating boiler room for a specific home;
• 90°С/70°С. Typical for small private heating systems designed to supply heat to several apartment buildings. In this case, you do not need to install the mixing unit.

In duty utilities includes temperature calculation heating schedule and control of its parameters. In this case, the degree of air heating in residential premises should be at +22°C. For non-residential residents this figure is slightly lower – +16°C.

For a centralized system, drawing up a correct temperature schedule for the heating boiler room is required to ensure optimal comfortable temperature in apartments. The main problem is the lack feedback– it is impossible to regulate the coolant parameters depending on the degree of air heating in each apartment. That is why a temperature graph of the heating system is drawn up.

A copy of the heating schedule can be requested from the Management Company. With its help you can control the quality of the services provided.

Heating system

Do similar calculations for autonomous systems Heating a private home is often not necessary. If the circuit includes indoor and outdoor temperature sensors, information about them will be sent to the boiler control unit.

Therefore, to reduce energy consumption, low-temperature heating modes are most often chosen. It is characterized by relatively low heating of water (up to +70°C) and a high degree of circulation. This is necessary for uniform heat distribution across all heating devices.

To implement such a temperature regime for the heating system, the following conditions will need to be met:

• Minimum heat losses in the house. However, one should not forget about normal air exchange - ventilation is mandatory;
• High thermal output of radiators;
• Installation automatic regulators heating temperatures.

If there is a need to perform a correct calculation of the system’s operation, it is recommended to use special software systems. There are too many factors to take into account to calculate on your own. But with their help you can create approximate temperature graphs of heating modes.

However, it should be borne in mind that an accurate calculation of the heat supply temperature schedule is done for each system individually. The tables show the recommended values ​​for the degree of heating of the coolant in the supply and return pipes depending on the outside temperature. When performing calculations, the characteristics of the building and the climatic features of the region were not taken into account. But even despite this, they can be used as a basis for creating a temperature chart for the heating system.

The maximum load of the system should not affect the quality of boiler operation. Therefore, it is recommended to purchase it with a power reserve of 15-20%.

Even the most accurate temperature schedule of a heating boiler room will exhibit deviations in calculated and actual data during operation. This is due to the operating features of the system. What factors can influence the current temperature regime of heat supply?

• Contamination of pipelines and radiators. To avoid this, the heating system should be cleaned periodically;
• Incorrect operation of the regulating and shut-off valves. The functionality of all components must be checked;
• Violation of the boiler's operating mode - sudden changes in temperature and, as a consequence, pressure.

Maintaining the optimal temperature regime of the system is only possible with making the right choice its components. To do this, their operational and technical properties should be taken into account.

The battery heating can be adjusted using a thermostat, the operating principle of which can be found in the video:

Economical energy consumption in heating system, can be achieved if certain requirements are met. One option is to have a temperature diagram, which reflects the ratio of the temperature emanating from the heating source to the external environment. The values ​​of the values ​​make it possible to optimally distribute heat and hot water to the consumer.

High-rise buildings are mainly connected to central heating. Sources that convey thermal energy, are boiler houses or thermal power plants. Water is used as a coolant. It is heated to a given temperature.

Having gone through a full cycle through the system, the coolant, already cooled, returns to the source and reheats. Sources are connected to consumers by heating networks. Since the environment changes temperature, thermal energy should be adjusted so that the consumer receives the required volume.

Heat regulation from central system can be done in two ways:

1. Quantitative. In this form, the water flow changes, but its temperature remains constant.
2. Qualitative. The temperature of the liquid changes, but its flow does not change.

In our systems, the second regulation option is used, that is, qualitative. Z Here there is a direct relationship between two temperatures: coolant and environment. And the calculation is carried out in such a way as to ensure the heat in the room is 18 degrees and above.

Hence, we can say that the temperature graph of the source is a broken curve. The change in its directions depends on temperature differences (coolant and outside air).

The dependency schedule may vary.

A specific diagram has a dependency on:

1. Technical and economic indicators.
2. CHP or boiler room equipment.
3. Climate.

High coolant values ​​provide the consumer with great thermal energy.

Below is an example of a diagram, where T1 is the coolant temperature, Tnv is the outside air:

A diagram of the returned coolant is also used. A boiler house or thermal power plant can estimate the efficiency of the source using this scheme. It is considered high when the returned liquid arrives chilled.

The stability of the scheme depends on the design values ​​of fluid flow of high-rise buildings. If the flow through the heating circuit increases, the water will return uncooled, as the flow rate will increase. Conversely, with minimal flow, the return water will be sufficiently cooled.

The supplier's interest, of course, is in the supply of return water in a cooled state. But there are certain limits for reducing consumption, since a decrease leads to loss of heat. The consumer’s internal temperature in the apartment will begin to drop, which will lead to violation of building codes and discomfort for ordinary people.

What does it depend on?

The temperature curve depends on two quantities: outside air and coolant. Frosty weather leads to an increase in coolant temperature. When designing a central source, the size of the equipment, building and pipe cross-section are taken into account.

The temperature leaving the boiler room is 90 degrees, so that at minus 23°C, the apartments are warm and have a value of 22°C. Then the return water returns to 70 degrees. Such standards correspond to normal and comfortable living in the house.

Analysis and adjustment of operating modes is carried out using a temperature diagram. For example, the return of liquid with an elevated temperature will indicate high coolant costs. Underestimated data will be considered a consumption deficit.

Previously, for 10-story buildings, a scheme with calculated data of 95-70°C was introduced. The buildings above had their own chart of 105-70°C. Modern new buildings may have a different layout, at the discretion of the designer. More often, there are diagrams of 90-70°C, and maybe 80-60°C.

Temperature chart 95-70:

Temperature chart 95-70

How is it calculated?

A control method is selected, then a calculation is made. The design winter and reverse order water inflows, the amount of outside air, the order at the break point of the diagram. There are two diagrams: one of them considers only heating, the second considers heating with hot water consumption.

For an example of calculation, we will use methodological development"Roskommunenergo".

The input data for the heat generating station will be:

1. Tnv– the amount of outside air.
2. TVN- indoor air.
3. T1– coolant from the source.
4. T2– reverse flow of water.
5. T3- entrance to the building.

We will look at several heat supply options with values ​​of 150, 130 and 115 degrees.

At the same time, at the exit they will have 70°C.

The results obtained are compiled into a single table for subsequent construction of the curve:

So we got three various schemes, which can be taken as a basis. It would be more correct to calculate the diagram individually for each system. Here we examined the recommended values, without taking into account the climatic features of the region and the characteristics of the building.

To reduce energy consumption, just select a low temperature setting of 70 degrees and uniform heat distribution throughout the heating circuit will be ensured. The boiler should be taken with a power reserve so that the system load does not affect the quality operation of the unit.

Adjustment

Heating regulator

Automatic control is provided by the heating regulator.

It includes the following parts:

1. Computing and matching panel.
2. Actuator along the water supply section.
3. Actuator, which performs the function of mixing liquid from the returned liquid (return).
4. Boost pump and a sensor on the water supply line.
5. Three sensors (on the return line, on the street, inside the building). There may be several of them in the room.

The regulator closes the liquid supply, thereby increasing the value between return and supply to the value specified by the sensors.

To increase the flow, there is a boost pump and a corresponding command from the regulator. The incoming flow is controlled by a "cold bypass". That is, the temperature decreases. Some of the liquid that has circulated along the circuit is sent to the supply.

Sensors collect information and transmit it to control units, resulting in a redistribution of flows that provide a rigid temperature scheme for the heating system.

Sometimes, a computing device is used that combines hot water and heating regulators.

The hot water regulator has more simple diagram management. The hot water sensor regulates the flow of water with a stable value of 50°C.

Advantages of the regulator:

1. The temperature scheme is strictly maintained.
2. Elimination of overheating of the liquid.
3. Fuel efficiency and energy.
4. The consumer, regardless of the distance, receives heat equally.

Table with temperature graph

The operating mode of boilers depends on the environmental weather.

If we take various objects, for example, a factory premises, multi-storey and a private house, all will have an individual thermal diagram.

In the table we show the temperature diagram of the dependence of residential buildings on outside air:

Outdoor temperature	Temperature network water in the supply line	Return water temperature
+10	70	55
+9	70	54
+8	70	53
+7	70	52
+6	70	51
+5	70	50
+4	70	49
+3	70	48
+2	70	47
+1	70	46
0	70	45
-1	72	46
-2	74	47
-3	76	48
-4	79	49
-5	81	50
-6	84	51
-7	86	52
-8	89	53
-9	91	54
-10	93	55
-11	96	56
-12	98	57
-13	100	58
-14	103	59
-15	105	60
-16	107	61
-17	110	62
-18	112	63
-19	114	64
-20	116	65
-21	119	66
-22	121	66
-23	123	67
-24	126	68
-25	128	69
-26	130	70

SNiP

There are certain standards that must be observed in the creation of projects for heating networks and the transportation of hot water to the consumer, where the supply of water steam must be carried out at 400°C, at a pressure of 6.3 Bar. It is recommended that the heat supply from the source be released to the consumer with values ​​of 90/70 °C or 115/70 °C.

Regulatory requirements must be met in compliance with the approved documentation with mandatory approval from the Ministry of Construction of the country.

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. Residents apartment building by October 1, they are waiting like Santa Claus, a plumber from 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 with 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 centralized system heat supply. 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. By doing repair work in a separate apartment, it is possible to turn off one vertical, and not 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: the component must be heated to 130-150 °C.

The supply is calculated taking into account the parameters of the outside air. Thus, for the Southern Urals region, 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 it performs an energy-saving function elevator unit- a jumper between the forward and return pipes. The temperature standards for the coolant in the return heating system in winter allow heat to be maintained at a level of 60 °C.

The liquid from the direct pipe enters the elevator nozzle, mixes 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

According to sanitary rules, the temperature of hot water at the points of analysis 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 at winter time 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 needed only for washing and showering, the range moves to the range 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 regulations. 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 should 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, and when excess gas pressure is created, the aluminum device may burst.

The temperature standards for heating radiators are subject to the same rules as batteries: it is not so much the heating of a metal object that is important, but the heating of the air in the room.

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

Stairwell heating

Since we're talking about apartment building, then the staircases should be mentioned. 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 maintain temperature conditions 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 the 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 the start of the heating season, check with the management company whether the meter is in working condition and whether the verification schedule has been violated.

From a series of articles “What to do if it’s cold in the apartment”

What is a temperature graph?

The water temperature in the heating system must be maintained depending on the actual outside air temperature according to a temperature schedule, which is developed by heating engineers of design and energy supply organizations using a special methodology for each heat supply source, taking into account specific local conditions. These schedules should be developed based on the requirement that during the cold period of the year, living rooms are maintained optimal temperature*, equal to 20 – 22 °C.

When calculating the schedule, heat losses (water temperature) in the area from the heat supply source to residential buildings are taken into account.

Temperature graphs must be drawn up both for the heating network at the outlet of the heat supply source (boiler house, thermal power plant), and for pipelines after the heating points of residential buildings (groups of houses), i.e. directly at the entrance to the heating system of the house.

Hot water is supplied from heat supply sources to heating networks according to the following temperature schedules:*

• from large thermal power plants: 150/70°C, 130/70°C or 105/70°C;
• from boiler houses and small thermal power plants: 105/70°C or 95/70°C.

*first digit – Maximum temperature direct network water, the second digit is its minimum temperature.

Depending on specific local conditions, other temperature schedules may apply.

Thus, in Moscow, at the outlet of the main heat supply sources, schedules of 150/70°C, 130/70°C and 105/70°C (maximum/minimum water temperature in the heating system) are used.

Until 1991, such temperature graphs were annually before the autumn-winter season. heating season approved by the administrations of cities and other settlements, which was regulated by the relevant regulatory and technical documents (NTD).

Subsequently, unfortunately, this norm disappeared from the NTD; everything was handed over to those “who care for the people”, but at the same time, who did not want to miss out on profits to the owners of boiler houses, thermal power plants, and other factories - steamships.

However regulatory requirement the mandatory compilation of heating temperature schedules was restored by Federal Law No. 190-FZ of July 27, 2010 “On Heat Supply”. This is what Federal Law 190 regulates temperature chart(the articles of the Law are arranged by the author in their logical sequence):

“...Article 23. Organization of the development of heat supply systems for settlements and urban districts
…3. Authorized... bodies [see. Art. 5 and 6 FZ-190] must carry out development, statement and annual updating* * heat supply schemes, which must contain:
…7) Optimal temperature schedule…
Article 20. Checking readiness for heating season
…5. Checking readiness for heating. period of heat supply organizations... is carried out in order to...readiness of these organizations to fulfill the heat load schedule, maintaining the temperature schedule approved by the heat supply scheme…
Article 6. Powers of local self-government bodies of settlements and urban districts in the field of heat supply
1. The powers of local self-government bodies of settlements and urban districts to organize heat supply in the relevant territories include:
…4) fulfillment of the requirements established by the rules for assessing the readiness of settlements and urban districts for the heating season, and readiness control heat supply organizations, heating network organizations, certain categories of consumers to the heating season;
…6) approval of heat supply schemes settlements, urban districts with a population of less than five hundred thousand people...;
Article 4, paragraph 2. To the powers of the fed. Spanish organ authorities authorized to implement state heat supply policies include:
11) approval of heat supply schemes for settlements, mountains. counties with a population of five hundred thousand people or more...
Article 29. Final provisions
…3. Approval of heat supply schemes for settlements ... must be carried out before December 31, 2011.”

And here is what is said about heating temperature schedules in the “Rules and Standards for the Technical Operation of Housing Stock” (approved by the Post of the State Construction Committee of the Russian Federation dated September 27, 2003 No. 170):

“...5.2. Central heating
5.2.1. System Operation central heating residential buildings must provide:
- maintaining optimal (not lower than permissible) air temperature in heated rooms;
- maintaining the temperature of water entering and returning from the heating system in accordance with the schedule for quality control of water temperature in the heating system (Appendix No. 11);
- uniform heating of all heating devices;
5.2.6. The operating personnel premises must have:
...e) a graph of the temperature of the supply and return water in the heating network and in the heating system depending on the outside air temperature, indicating the operating pressure of the water at the inlet, the static and the highest permissible pressure in the system;..."

Due to the fact that home heating systems can be supplied with coolant with a temperature no higher than: for two-pipe systems - 95 ° C; for single-pipe - 105 ° C, at heating points (individual house or group for several houses) before supplying water to houses, hydraulic elevator units are installed, in which direct network water having high temperature, is mixed with the cooled return water returning from the home's heating system. After mixing in the hydraulic elevator, the water enters the house system at a temperature according to the “house” temperature schedule of 95/70 or 105/70°C.

Below, as an example, is the temperature graph of the heating system after heating point residential building for radiators according to the top-down and bottom-up scheme (with outside temperature intervals of 2 ° C), for a city with an estimated outside air temperature of 15 ° C (Moscow, Voronezh, Orel):

WATER TEMPERATURE IN DISTRIBUTION PIPELINES, degrees. C

AT DESIGNED OUTSIDE AIR TEMPERATURE

current outside temperature,	diagram of water supply to radiators
"down up"	"top down"
server	back	server	back

Explanations:
1. In gr. 2 and 4 show the water temperature in the supply pipe of the heating system:
in the numerator - with an estimated water temperature difference of 95 - 70 °C;
in the denominator - with a calculated difference of 105 - 70 °C.
In gr. 3 and 5 show the water temperatures in the return pipeline, which are identical in their values ​​at calculated differences of 95 - 70 and 105 - 70 °C.

Temperature graph of the heating system of a residential building after a heating point

Source: Rules and regulations technical operation housing stock, adj. 20
(approved by order of the State Construction Committee of the Russian Federation dated December 26, 1997 No. 17-139).

Operating since 2003 “Rules and standards for technical operation of housing stock”(approved by the Post of the State Construction Committee of the Russian Federation dated September 27, 2003 No. 170), appendix. eleven.

Current temperature outdoor tour	Heating device design
radiators	convectors
water supply diagram to the device	convector type
		"top down"
water temperature in distribution pipelines, degrees. C
	back	server	back	server	back	server	back	server	back
DESIGN OUTDOOR AIR TEMPERATURE

Water is heated in network heaters, selected steam, in peak water boilers, after which the network water enters the supply line, and then to the subscriber heating, ventilation and hot water supply installations.

Heating and ventilation heat loads clearly depend on the outside air temperature tn.v. Therefore, it is necessary to regulate the heat supply in accordance with load changes. You mainly use central regulation, carried out at thermal power plants, supplemented by local automatic regulators.

With central regulation, it is possible to use either quantitative regulation, which boils down to changing the flow of network water in the supply line at a constant temperature, or qualitative regulation, in which the water flow remains constant, but its temperature changes.

A serious drawback of quantitative regulation is the vertical misadjustment of heating systems, which means unequal redistribution of network water across floors. Therefore it is usually used quality regulation, for which temperature graphs of the heating network must be calculated for the heating load depending on the outside temperature.

The temperature graph for the supply and return lines is characterized by the values ​​of the calculated temperatures in the supply and return lines τ1 and τ2 and the calculated outside temperature tn.o. Thus, a graph of 150-70°C means that at the calculated outside temperature tn.o. the maximum (calculated) temperature in the supply line is τ1 = 150 and in the return line τ2 - 70°C. Accordingly, the calculated temperature difference is 150-70 = 80°C. Lower calculated temperature of the temperature chart 70 °C determined by the need to heat tap water for hot water supply needs to tg. = 60°C, which is dictated by sanitary standards.

The upper design temperature determines the minimum permissible pressure water in the supply lines, eliminating the boiling of water, and therefore the requirements for strength, and can vary in a certain range: 130, 150, 180, 200 °C. An increased temperature schedule (180, 200 °C) may be required when connecting subscribers via independent scheme, which will allow the second circuit to maintain the usual schedule of 150-70 °C. Promotion design temperature network water in the supply line leads to a reduction in the consumption of network water, which reduces costs heating network, but also reduces electricity generation from thermal consumption. The choice of temperature schedule for the heat supply system must be confirmed by a technical and economic calculation based on the minimum reduced costs for the CHP plant and the heating network.

Heat supply to the industrial site of CHPP-2 is carried out according to a temperature schedule of 150/70 °C with a cut-off at 115/70 °C, and therefore the temperature of the network water is automatically controlled only up to the outside air temperature of “-20 °C”. The consumption of network water is too high. Exceeding the actual consumption of network water over the calculated one leads to excessive consumption of electrical energy for pumping coolant. The temperature and pressure in the return pipe do not correspond to the temperature curve.

The level of heat loads of consumers currently connected to the CHP plant is significantly lower than what was envisaged by the project. As a result, CHPP-2 has a thermal power reserve exceeding 40% of the installed thermal capacity.

Due to damage to distribution networks belonging to TMUP TTS, drainage from heat supply systems due to the lack of the required pressure drop among consumers and leaks in the heating surfaces of hot water heaters, there is an increased flow of make-up water at the thermal power plant, exceeding the calculated value of 2.2 - 4, 1 time. The pressure in the return heating main also exceeds the calculated value by 1.18-1.34 times.

The above indicates that the heat supply system to external consumers is not adjusted and requires adjustment and adjustment.

Dependence of network water temperatures on outside air temperature

Table 6.1.

Temperature values

Temperature values

Outside air

submitting master's degree

After the elevator

reverse master's degree

Outside air

applying master's degree

After the elevator

To the back th master Ali