Economical consumption of energy resources in the heating system can be achieved if certain requirements are met. One of the options is the presence of a temperature diagram, which reflects the ratio of the temperature emanating from the heating source to external environment... The value of the values makes it possible to optimally distribute heat and hot water to the consumer.
High-rise buildings are mainly connected to central heating. Sources that transmit thermal energy, are boiler houses or CHP. Water is used as a heat carrier. It is heated to a predetermined temperature.
After passing full cycle through the system, the coolant, already cooled, returns to the source and reheating occurs. Sources are connected to the consumer by heating networks. Since the environment changes the temperature regime, it is necessary to regulate the heat energy so that the consumer receives the required volume.
Heat regulation from central system can be produced in two ways:
- Quantitative. In this form, the flow rate of water changes, but it has a constant temperature.
- Quality. The temperature of the liquid changes, but its consumption does not change.
In our systems, the second control option is used, that is, a quality one. 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 provide heat in the room of 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 the temperature difference (coolant and outside air).
The dependency graph may be different.
A specific diagram depends on:
- Technical and economic indicators.
- CHP or boiler room equipment.
- Climate.
High rates of the heat carrier provide the consumer with large thermal energy.
An example of a circuit is shown below, where T1 is the temperature of the coolant, Tnv is the outside air:
The diagram of the returned heating medium also applies. A boiler house or a CHP plant, according to this scheme, can assess the efficiency of the source. It is considered high when the returned liquid is supplied cooled.
The stability of the scheme depends on the design values of the liquid consumption of high-rise buildings. If the flow through the heating circuit increases, the water will return uncooled, since the flow rate will increase. Conversely, for minimum consumption, the return water will be sufficiently cooled.
The supplier's interest is, of course, in the chilled return water supply. But there are certain limits for reducing the flow rate, since a decrease leads to a loss in the amount 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 the inhabitants.
What does it depend on?
The temperature curve depends on two quantities: outside air and heat carrier. Frosty weather leads to an increase in the degree of the coolant. The design of the central source takes into account the size of the equipment, the building and the cross-section of the pipes.
The value of the temperature leaving the boiler room is 90 degrees, so that at minus 23 ° C, it would be warm in the apartments and had a value of 22 ° C. Then the return water returns to 70 degrees. Such norms correspond to normal and comfortable living in the house.
Analysis and adjustment of operating modes is carried out using a temperature circuit. For example, the return of a liquid with a high temperature will indicate high flow rates of the coolant. Underestimated data will be considered as a deficit of consumption.
Previously, for 10-storey buildings, a scheme was introduced with design data of 95-70 ° C. The buildings above had their own diagram of 105-70 ° C. Modern new buildings may have a different scheme, at the discretion of the designer. More often, there are diagrams of 90-70 ° C, and maybe 80-60 ° C.
Temperature graph 95-70:
Temperature graph 95-70 How is it calculated?
The control method is selected, then the calculation is done. The calculation-winter and reverse order of water intake, the amount of outside air, the order at the break point of the diagram are taken into account. There are two diagrams, when in one of them only heating is considered, in the second heating with consumption hot water.
For an example calculation, we will use methodological development Roskommunenergo.
The initial data for the heat generating station will be:
- TNV- the amount of outside air.
- Tvn- indoor air.
- T1- coolant from the source.
- T2- return flow of water.
- T3- entrance to the building.
We will consider several options for supplying heat with a value of 150, 130 and 115 degrees.
At the same time, at the exit they will have 70 ° C.
The results obtained are brought down into a single table for the subsequent construction of the curve:
So we got three various schemes, which can be taken as a basis. It will be more correct to calculate the diagram individually for each system. Here we reviewed the recommended values, without taking into account the climatic characteristics of the region and the characteristics of the building.
To reduce energy consumption, it is enough to choose a low-temperature order of 70 degrees and an even distribution of heat along the heating circuit will be ensured. The boiler should be taken with a power reserve so that the system load does not affect quality work unit.
Adjustment
Heating regulator Automatic control is provided by the heating controller.
It includes the following details:
- Computing and matching panel.
- Executive device on the water supply section.
- Executive device, performing the function of mixing liquid from the returned liquid (return).
- Boost pump and a sensor on the water supply line.
- Three sensors (on the return line, on the street, inside the building). There may be several of them in the room.
The regulator covers the liquid supply, thereby increasing the value between the return and supply to the value provided by the sensors.
To increase the flow, there is a step-up pump, and a corresponding command from the regulator. The inlet flow is controlled by a "cold bypass". That is, the temperature drops. Some part of the liquid, circulated along the circuit, is sent to the supply.
The sensors remove information and transmit it to the control units, as a result of which there is a redistribution of flows that provide a rigid temperature scheme for the heating system.
Sometimes, a computing device is used, where DHW and heating regulators are combined.
The hot water regulator has more simple scheme management. The hot water sensor regulates the water flow to a stable value of 50 ° C.
Regulator advantages:
- The temperature scheme is strictly adhered to.
- Elimination of liquid overheating.
- Fuel economy and energy.
- The consumer, regardless of distance, receives heat equally.
Temperature chart table
The operating mode of the boilers depends on the ambient weather.
If we take various objects, for example, a factory building, a multi-storey and private house, everyone will have an individual heat chart.
In the table, we show the temperature diagram of the dependence of residential buildings on the outside air:
| Outdoor temperature | Supply water temperature in the supply pipeline | 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 norms 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 steam must be carried out at 400 ° C, at a pressure of 6.3 bar. It is recommended to release heat supply from the source to the consumer with values of 90/70 ° C or 115/70 ° C.
Regulatory requirements should be fulfilled for compliance with the approved documentation with the obligatory agreement with the Ministry of Construction of the country.
There are a number of regularities on the basis of which the temperature of the coolant changes in central heating... To track fluctuations, there are special graphs called temperature. What they are and what they are for, you need to understand in more detail.
What is a temperature graph and its purpose
The temperature graph of the heating system is the dependence of the temperature of the coolant, which is water, on the temperature indicator of the outside air.
The main indicators of the graph under consideration are two values:
- The temperature of the coolant, that is, the heated water that is supplied to the heating system to heat living quarters.
- Temperature readings of the outside air.
The lower the ambient temperature, the more it is required to heat the heat carrier, which is supplied to the heating system. The considered schedule is built when designing heating systems for buildings. Indicators such as size depend on it heating devices, the flow rate of the coolant in the system, as well as the diameter of the pipelines through which the coolant is transferred.
The designation of the temperature graph is carried out using two numbers, which are 90-70 degrees. What does this mean? These figures characterize the temperature of the coolant that must be supplied to the consumer and returned back. To create comfortable conditions indoors in winter period at an outside air temperature of -20 degrees, you need to supply a coolant to the system with a value of 90 degrees Celsius, and return with a value of 70 degrees.
The temperature graph allows you to determine the overestimated or underestimated flow rate of the coolant. If the value of the temperature of the returned coolant is too high, then this will indicate high flow... If the value is underestimated, then this indicates a deficit in consumption.
The 95-70 degree schedule for the heating system was adopted in the last century for buildings up to 10 floors. If the number of storeys of the building exceeds 10 floors, then the values were taken to be 105-70 degrees. Modern standards for heat supply for each new building are different, and are often adopted at the discretion of the designer. Modern norms for insulated houses it is 80-60 degrees, and for buildings without insulation 90-70.
Why do temperature fluctuations occur?
The reasons for temperature changes are due to the following factors:
- When the weather conditions change, the heat loss automatically changes. When cold weather sets in, it is necessary to spend more thermal energy in order to ensure an optimal microclimate in apartment buildings than during warming. The level of consumed heat loss is calculated by the "delta" value, which is the difference between outdoor and indoor.
- The constancy of the heat flux from the batteries is ensured by the stable value of the coolant temperature. As soon as the temperature drops, the apartment radiators will get warmer. This phenomenon is facilitated by an increase in the "delta" between the coolant and the air in the room.
An increase in coolant losses must be carried out in parallel with a decrease in the air temperature outside the window. The colder it is outside the window, the higher the temperature of the water in the heating pipes should be. To facilitate the calculation processes, a corresponding table was adopted.
What is a temperature graph
The temperature graph of the supply of coolant to the heating system is a table that lists the values of the coolant temperature depending on the outdoor temperature.
The generalized graph of the water temperature in the heating system is as follows:
The formula for calculating the temperature graph is as follows:
- To determine the temperature of the heating agent supply: Т1 = tвн + ∆хQ (0.8) + (β-0.5хUP) хQ.
- To determine the return flow temperature, the following formula is used: T2 = tvn + ∆хQ (0.8) -0.5хUPхQ.
In the presented formulas:
Q is the relative heating load.
∆ is the temperature head of the coolant supply.
β is the temperature difference in the forward and reverse flow.
UP is the temperature difference between the inlet and outlet water of the heater.
There are two types of charts:
- For heating networks.
- For apartment buildings.
To understand the details, consider the features of the functioning of centralized heating.
CHP and heating networks: what is the relationship
The purpose of CHP and heating networks is to heat the coolant to a certain value, and then transport it to the place of consumption. In this case, it is important to take into account the losses for the heating main, the length of which is usually 10 kilometers. Despite the fact that all water supply pipes are insulated, it is almost impossible to do without heat losses.
When the coolant moves from the CHP or simply the boiler house to the consumer (apartment building), then a certain percentage of water cooling is observed. To ensure the supply of the coolant to the consumer in the required standardized value, it is required to supply it from the boiler room in the most heated state. However, it is impossible to increase the temperature above 100 degrees, since it is limited by the boiling point. However, it can be shifted towards a higher temperature value by increasing the pressure in the heating system.
The pressure in the pipes according to the standard is 7-8 atmospheres, however, when the coolant is supplied, a pressure loss also occurs. However, despite the pressure loss, a value of 7-8 atmospheres allows you to provide effective work heating systems even in 16-storey buildings.
It is interesting! The pressure in the heating system of 7-8 atmospheres is not dangerous for the network itself. All structural elements remain operational in normal mode.
Taking into account the margin of the upper temperature threshold, its value is 150 degrees. Minimum temperature feed at minus values outside the window is not lower than 9 degrees. The return temperature is usually 70 degrees.
How is the coolant supplied to the heating system
The following restrictions are characteristic of a home heating system:
- The maximum heating indicator is due to a limited value of +95 degrees for a two-pipe system, as well as 105 degrees for a one-pipe network. In preschool educational institutions, stricter restrictions apply. The water temperature in the battery should not rise above 37 degrees. To compensate for the lowered temperature value, additional radiator sections are built up. Kindergartens located directly in regions with harsh climatic zones equipped with big amount radiators with a large number of sections.
- The best option is to achieve minimum value"Delta", which represents the difference between the supply and return temperature of the heating medium. If this value is not achieved, then the degree of heating of the radiators will have a large difference. To reduce the difference, it is necessary to increase the speed of movement of the coolant. However, even with an increase in the speed of movement of the coolant, a significant drawback arises, which is due to the fact that water will return back to the CHP plant with unnecessary high temperature... Such a phenomenon can lead to the fact that there will be disruptions to the functioning of the CHP.
To get rid of such a problem, you should install elevator modules in each apartment building. Through such devices, a portion of the supply water is diluted with a return flow. This mixture will allow to obtain accelerated circulation, thereby eliminating the possibility of excessive overheating of the return pipeline.
If an elevator is installed in a private house, then the heating system is set using an individual temperature schedule. For two-pipe systems heating a private house is characterized by modes 95-70, and for one-pipe - 105-70 degrees.
How climatic zones affect air temperature
The main factor that is taken into account when calculating the temperature graph is presented in the form of the calculated temperature in the winter. When calculating heating, the outside temperature is taken from a special table for climatic zones.
Table temperature coolant should be made so that its maximum value satisfies the SNiP temperature in living quarters. For example, we use the following data:
- As heating devices, radiators are used, which provide the supply of the coolant from the bottom up.
- Heating type of apartments is two-pipe, equipped with a parking pipe distribution.
- The calculated values of the outside air temperature are -15 degrees.
In this case, we get the following information:
- Heating will be started when the average daily temperature does not exceed +10 degrees for 3-5 days. The coolant will be supplied with a value of 30 degrees, and the return flow will be 25 degrees.
- When the temperature drops to 0 degrees, the value of the coolant rises to 57 degrees, and the return flow will be 46 degrees.
- At -15, water will be supplied with a temperature of 95 degrees, and the return flow will be 70 degrees.
It is interesting! In determining average daily temperature information is taken from both daytime thermometer readings and nighttime measurements.
How to regulate the temperature
Employees of the CHP are responsible for the parameters of the value of heating mains, but the control of networks inside residential buildings is carried out by employees of the housing office or management companies. Often, the housing office receives complaints from tenants that the apartments are cold. To normalize the parameters of the system, you will need to take the following measures:
- Increasing the nozzle diameter or installing an elevator with an adjustable nozzle. If there is an underestimated value of the liquid temperature in the return flow, then this problem can be solved by increasing the diameter of the elevator nozzle. To do this, you need to close the latches and valves, and then remove the module. The nozzle is enlarged by drilling it 0.5-1 mm. After completing the procedure, the device returns to its place, after which the procedure for bleeding air from the system is mandatory.
- Silence the suction. To avoid the emergence of a threat of the suction to perform the function of the jumper, it is muffled. To perform this procedure, a steel pancake is used, the thickness of which should be about 1 mm. This method of temperature control belongs to the category of emergency options, since when it is carried out, a temperature jump of up to +130 degrees is not excluded.
- Regulation of drops. The problem can be solved by correcting the differences with the elevator valve. The essence this method correction consists in redirecting DHW to the supply pipe. A pressure gauge is screwed into the return pipe, after which the return pipe valve is closed. Opening the valve, you need to check with the readings of the pressure gauge.
If you install a conventional valve, it will stop and freeze the system. To reduce the difference, it is necessary to increase the pressure in the return line to a value of 0.2 atm / day. What temperature should be in the batteries, you can find out based on the temperature graph. Knowing its value, you can check to make sure it matches the temperature regime.
In conclusion, it should be noted that options for choking suction and regulation of drops are used exclusively in the development of critical situations. Knowing such a minimum of information, you can contact the ZhEK or CHP with complaints and wishes about inappropriate coolant standards in the system.
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, its calculation?
Drawing up a temperature schedule
The temperature schedule of the heating system is calculated according to several parameters. Not only the degree of heating of the premises depends on the selected mode, but also the flow rate of the coolant. This also affects the running 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:
- Supply and return temperature. Measurements are carried out in the corresponding boiler nozzles;
- Characteristics of the degree of heating of air 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 inlet nozzles. This value has the following designation:
∆T = Tin-Tob
Where Tin- the temperature of the water in the supply line, Tob- the 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 the flow rate of the heating medium, ∆t must be minimal. This is precisely the main difficulty, since the temperature schedule of the boiler-house heating directly depends on external factors - heat losses in the building, air outside.
To optimize the heating power, it is necessary to insulate the outer walls of the house. This will reduce heat losses and energy consumption.
Calculation of temperature conditions
To determine the optimal temperature regime, it is necessary to take into account the characteristics of heating components - radiators and batteries. In particular, the specific power (W / cm²). This will directly affect the heat transfer of heated water to the air in the room.
It is also necessary to make a series preliminary calculations... This takes into account the characteristics of the house and heating devices:
- The heat transfer resistance coefficient of the outer walls and window structures... It should be at least 3.35 m² * C / W. Depends on the climatic characteristics of the 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 outer walls and the material of the building. The calculation of the surface power of the batteries is carried out according to 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 schedule are compiled depending on the temperature outside.
To change the heating parameters in a timely manner, a heating temperature controller is installed. This device connects to outdoor and indoor thermometers. Depending on the current indicators, the operation of the boiler or the volume of the coolant inflow into the radiators is adjusted.
The weekly programmer is the optimal temperature controller for heating. With its help, you can automate the work of the entire system as much as possible.
District heating
For district heating the temperature regime of the heating system depends on the characteristics of the system. Currently, there are several types of parameters of the coolant supplied to consumers:
- 150 ° C / 70 ° C... To normalize the water temperature using elevator unit it is mixed with the cooled stream. In this case, you can draw up an individual temperature schedule for a heating boiler room for a specific house;
- 90 ° C / 70 ° C... Typical for small private heating systems designed for heating several apartment buildings. In this case, it is possible not to install the mixing unit.
It is the responsibility of the utilities to calculate the temperature heating schedule and control of its parameters. At the same time, the degree of air heating in residential premises should be at the level of + 22 ° С. For non-residential, this figure is slightly lower - + 16 ° С.
For a centralized system, drawing up the correct temperature schedule for boiler heating is required to ensure the optimal comfortable temperature in the apartments. The main problem is the lack of feedback - it is impossible to adjust the parameters of the coolant depending on the degree of heating of the air in each apartment. That is why the temperature schedule is drawn up. heating system.
A copy of the heating schedule can be requested from Management Company... With its help, you can control the quality of the services provided.
Heating system
Make similar calculations for autonomous systems heat supply of a private house is often not needed. If the circuit provides room and outdoor temperature sensors, information about them will be sent to the boiler control unit.
Therefore, in order to reduce the consumption of energy carriers, the low-temperature mode of heating is most often chosen. It is characterized by a relatively low heating of water (up to + 70 ° C) and a high degree of its circulation. This is necessary to evenly distribute heat across all heating devices.
To implement such a temperature regime of the heating system, the following conditions must be met:
- Minimal heat loss in the house. However, at the same time, one should not forget about the normal air exchange - the arrangement of ventilation is mandatory;
- High thermal efficiency of radiators;
- Installation of automatic temperature controllers in heating.
If there is a need to perform a correct calculation of the system's operation, it is recommended to use special software systems. For self-calculation, there are too many factors to consider. But with their help, you can draw up approximate temperature graphs of heating modes.
However, it should be borne in mind that the exact calculation of the temperature schedule for heat supply 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. The calculations did not take into account the characteristics of the building, the climatic features of the region. Even so, they can be used as a basis for creating a heating system temperature schedule.
The maximum system load should not affect the quality of the boiler. Therefore, it is recommended to purchase it with a power reserve of 15-20%.
Even the most accurate temperature schedule of boiler heating will have deviations in the calculated and actual data during operation. This is due to the peculiarities of the system operation. What factors can affect the current temperature regime of heat supply?
- Contamination of pipelines and radiators. To avoid this, periodic cleaning of the heating system should be carried out;
- Incorrect operation of control and shut-off valves. It is imperative to check the performance of all components;
- Violation of the boiler operation mode - sharp temperature jumps as a result - pressure.
Maintaining the optimal temperature regime of the system is possible only when the right choice its components. For this, their operational and technical properties should be taken into account.
The battery heating can be adjusted using a thermostat, the principle of which can be found in the video:
To maintain a comfortable temperature in the house during the heating season, it is necessary to control the temperature of the coolant in the pipes of heating networks. The workers of the central heating system of residential premises are developing special temperature schedule, which depends on weather indicators, climatic characteristics of the region. The temperature graph may differ in different settlements, it can also change when modernizing heating networks.
A schedule is drawn up in the heating network for simple principle- the lower the temperature outside, the higher it should be for the coolant.
This ratio is important reason for work enterprises that provide the city with heat.
For the calculation, an indicator was applied, which is based on average daily temperature the coldest five days of the year.
ATTENTION! Compliance with the temperature regime is important not only for maintaining heat in an apartment building. It also makes it possible to make the consumption of energy resources in the heating system economical and rational.
The graph, which indicates the temperature of the coolant depending on the outside temperature, allows the most optimal distribution between consumers apartment building not only warm, but also hot water.
How the heat in the heating system is regulated
Heat regulation in an apartment building during the heating season can be carried out in two ways:
- By changing the water flow at a certain constant temperature. This is a quantitative method.
- By changing the temperature of the coolant at a constant flow rate. This is a qualitative method.
Economical and practical is second option, in which the room temperature regime is observed regardless of the weather. Sufficient heat supply to apartment house will be stable even if it is noted sharp drop temperatures outside.
ATTENTION!... The norm is considered to be a temperature of 20-22 degrees in an apartment. If the temperature schedules are respected, such a rate is maintained for the entire heating period, regardless of weather conditions, wind direction.
When the temperature indicator on the street decreases, data is transmitted to the boiler room and the degree of the coolant automatically increases.
The specific table of the ratio of outdoor temperature indicators and the coolant depends on factors such as climate, boiler equipment, technical and economic indicators.
Reasons for using a temperature chart
The basis for the operation of each boiler house serving residential, administrative and other buildings during the heating period is the temperature schedule, which indicates the standards for the indicators of the coolant, depending on what the actual outside temperature is.
- Scheduling makes it possible to prepare heating for a drop in outdoor temperatures.
- It is also energy saving.
ATTENTION! In order to control the temperature of the coolant and have the right to recalculate due to non-compliance thermal conditions, the heat sensor must be installed in the district heating system. Metering devices must be checked annually.
Modern construction companies can increase the cost of housing through the use of expensive energy-saving technologies in the construction of multi-apartment buildings.
Despite the change building technologies, the use of new materials for the insulation of walls and other surfaces of the building, compliance with the temperature of the coolant in the heating system - optimal way maintain comfortable living conditions.
Features of calculating the internal temperature in different rooms
The rules provide for maintaining the temperature for the living space at the level of 18˚С, but there are some nuances in this matter.
- For angular rooms of a residential building coolant must provide a temperature of 20˚С.
- Optimal temperature indicator for a bathroom - 25˚С.
- It is important to know how many degrees should be according to the standards in rooms intended for children. Indicator set from 18˚С to 23˚С. If it is a children's pool, the temperature should be kept at 30 ° C.
- Minimum temperature allowed in schools - 21˚C.
- In institutions where cultural events are held according to the standards, Maximum temperature 21˚C, but the indicator should not fall below 16˚С.
To increase the temperature in the premises during sudden cold snaps or strong northerly winds, boiler house workers increase the degree of energy supply for heating networks.
The heat transfer of batteries is influenced by the outside temperature, the type of heating system, the direction of the flow of the coolant, the state of utilities, the type of heating device, the role of which can be played by both a radiator and a convector.
ATTENTION! The delta of temperatures between the supply to the radiator and the return should not be significant. Otherwise, there will be a big difference in the coolant in different rooms and even apartments in a multi-storey building.
The main factor, however, is the weather. This is why measuring the outside air to maintain the temperature schedule is a top priority.
If it is freezing outside up to 20˚С, the coolant in the radiator should have an indicator of 67-77˚С, while the norm for the return flow is 70˚С.
If the outside temperature is zero, the norm for the coolant is 40-45˚С, and for the return flow - 35-38˚С. It should be noted that the temperature difference between supply and return is not large.
Why does the consumer need to know the norms for the supply of the coolant?
Payment utilities in the column, heating should depend on the temperature in the apartment provided by the supplier.
Table of the temperature schedule, according to which it should be carried out optimal performance boiler, shows at what temperature of the surrounding world and by how much the boiler room should increase the degree of energy for heat sources in the house.
IMPORTANT! If the parameters of the temperature schedule are not met, the consumer may require recalculation for utilities.
To measure the indicator of the coolant, it is necessary to drain a little water from the radiator and check its degree of heat. Also used successfully heat sensors, heat metering devices that can be installed at home.
The sensor is a mandatory equipment for both city boiler houses and ITP (individual heating points).
Without such devices, it is impossible to make the operation of the heating system economical and productive. The measurement of the coolant is also carried out in hot water systems.
Useful video
Water is heated in network heaters, selected steam, in peak hot water boilers, after which the network water enters the supply line, and then to subscriber heating, ventilation and hot water supply units.
Heating and ventilation heat loads unambiguously depend on the outside air temperature tн.в. Therefore, it is necessary to regulate the heat release in accordance with changes in the load. You use mainly central regulation carried out at CHP plants, supplemented by local automatic regulators.
With central regulation, it is possible to apply either quantitative regulation, which reduces to a change in the flow of heating water in the supply line at a constant temperature, or qualitative, in which the flow of water remains constant, but its temperature changes.
A serious disadvantage of quantitative regulation is the vertical misalignment of heating systems, which means an unequal redistribution of heating systems across floors. Therefore, quality control is usually used, for which the temperature graphs of the heating network for the heating load must be calculated depending on the outside temperature.
The temperature schedule 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 tн.o. So, a graph of 150-70 ° C means that at a calculated outside temperature tн.o. the maximum (calculated) temperature in the supply line is τ1 = 150 and in the return line τ2 - 70 ° С. Accordingly, the calculated temperature difference is 150-70 = 80 ° C. Lower design temperature of the temperature curve 70 ° C is determined by the need for heating tap water for hot water supply up to tg. = 60 ° C, which is dictated by sanitary standards.
The upper design temperature determines the minimum allowable water pressure in the supply lines, which excludes water boiling, and, consequently, the strength requirements, and can vary in a certain range: 130, 150, 180, 200 ° C. An increased temperature schedule (180, 200 ° С) may be required when connecting subscribers according to an independent scheme, which will allow maintaining the usual schedule in the second circuit 150-70 ° C. An increase in the design temperature of the supply water in the supply line leads to a decrease in the consumption of the supply water, which reduces the cost of heating network, but also reduces thermal power generation. The choice of the temperature schedule for the heat supply system must be confirmed by a technical and economic calculation at a minimum of the reduced costs for the CHP and the heating network.
Heat supply to the CHPP-2 industrial site is carried out according to a temperature schedule of 150/70 ° C with a cutoff of 115/70 ° C, in connection with which the temperature of the network water is automatically controlled only up to the outside air temperature "- 20 ° C". Supply water consumption is too high. An excess of the actual flow rate of the heating system over the calculated one leads to an excessive consumption of electrical energy for pumping the coolant. The temperature and pressure in the return pipe does not correspond to the temperature schedule.
The level of heat loads of consumers currently connected to the CHPP is significantly lower than it was envisaged by the project. As a result, CHPP-2 has a thermal capacity reserve exceeding 40% of the installed thermal capacity.
Due to damage to the distribution networks belonging to the TMUP TTS, the discharge 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 consumption of make-up water at the CHP, exceeding the calculated value by 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 for external consumers is not regulated and requires adjustment and adjustment.
Dependence of heating water temperatures on the outside air temperature
Table 6.1.
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Temperature value |
Temperature value |
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Outside air |
filing master ali |
After the elevator |
reverse master |
Outside air |
filing master |
After the elevator |
In back th master ali |
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