Economical energy consumption in the heating system can be achieved if certain requirements are met. One of the options is the presence of a temperature chart, 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 connected mainly to central heating. Sources that convey thermal energy, are boiler houses or CHP. Water is used as a heat carrier. It is heated to a predetermined temperature.
Having passed full cycle through the system, the coolant, already cooled, returns to the source and reheating occurs. Sources are connected to the consumer by thermal networks. Since the environment changes the temperature regime, thermal energy should be regulated 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 the temperature is constant.
- Qualitative. The temperature of the liquid changes, but its flow rate does not change.
In our systems, the second variant of regulation is used, that is, qualitative. W 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 curve of the source is a broken curve. The change in its directions depends on the temperature difference (coolant and outside air).
Dependency graph may vary.
A particular chart has a dependency on:
- Technical and economic indicators.
- Equipment for a CHP or boiler room.
- climate.
High performance of the coolant provides the consumer with a large thermal energy.
An example of a circuit is shown below, where T1 is the temperature of the coolant, Tnv is the outdoor air:
It is also used, the diagram of the returned coolant. A boiler house or CHP according to such a scheme can evaluate the efficiency of the source. It is considered high when the returned liquid arrives cooled.
The stability of the scheme depends on the design values of the liquid flow of high-rise buildings. If the flow rate through the heating circuit increases, the water will return uncooled, as the flow rate will increase. And vice versa, when minimum flow, the return water will be sufficiently cooled.
The supplier's interest is, of course, in the flow of return water in a chilled state. But there are certain limits to reduce the flow, since a decrease leads to losses in the amount of heat. The consumer will begin to lower the internal degree in the apartment, which will lead to a violation of building codes and discomfort to the inhabitants.
What does it depend on?
The temperature curve depends on two quantities: outside air and coolant. Frosty weather leads to an increase in the degree of coolant. When designing a central source, the size of the equipment, the building and the section of pipes are taken into account.
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 have 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 scheme. For example, the return of a liquid with an elevated temperature will indicate high coolant costs. Underestimated data will be considered as a consumption deficit.
Previously, for 10-storey buildings, a scheme with calculated data of 95-70°C was introduced. The buildings above had their chart 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 chart 95-70:
Temperature chart 95-70 How is it calculated?
The control method is selected, then the calculation is made. The calculation-winter and reverse order of water inflow, the amount of outside air, the order at the break point of the diagram are taken into account. There are two diagrams, when one of them considers only heating, the second one considers 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- the 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 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 would be more correct to calculate the diagram individually for each system. Here we considered the recommended values, without taking into account the climatic features of the region and the characteristics of the building.
To reduce power consumption, it is enough to choose a low-temperature order of 70 degrees and uniform distribution of heat throughout the heating circuit will be ensured. The boiler should be taken with a power reserve so that the load of the system 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 at the water supply line.
- Executive device, which performs 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 in a 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 booster pump, and the corresponding command from the regulator. The incoming flow is regulated by a "cold bypass". That is, the temperature drops. Some of the liquid that circulates along the circuit is sent to the supply.
Information is taken by sensors and transmitted to control units, as a result of which flows are redistributed, which provide a rigid temperature scheme for the heating system.
Sometimes, a computing device is used, where the DHW and heating regulators are combined.
The hot water regulator has more a simple circuit management. The hot water sensor regulates the flow of water with a stable value of 50°C.
Regulator benefits:
- The temperature regime is strictly maintained.
- Exclusion of liquid overheating.
- Fuel Economy and energy.
- The consumer, regardless of distance, receives heat equally.
Table with temperature chart
The operating mode of the boilers depends on the weather of the environment.
If we take various objects, for example, a factory building, a multi-storey building and private house, all will have an individual heat chart.
In the table, we show the temperature diagram of the dependence of residential buildings on the outside air:
| Outside temperature | Temperature of network water in the supply pipeline | Temperature of network water in the return pipeline |
| +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 water vapor must be carried out at 400 ° C, at a pressure of 6.3 bar. The supply of heat from the source is recommended to be released to the consumer with values of 90/70 °C or 115/70 °C.
Regulatory requirements should be followed for compliance with the approved documentation with the obligatory coordination with the Ministry of Construction of the country.
There are a number of regularities on the basis of which the change in the temperature of the coolant in central heating. To track fluctuations, there are special graphs called temperature graphs. What they are and what they are for, you need to understand in more detail.
What is a temperature chart and its purpose
The temperature curve 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 considered graph are two values:
- The temperature of the heat carrier, that is, the heated water that is supplied to the heating system for heating residential premises.
- Temperature readings of outdoor air.
The lower the ambient temperature, the more it is required to heat the coolant that is supplied to the heating system. The considered schedule is built when designing heating systems for buildings. It depends on factors such as size. heating devices, 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, which must be supplied to the consumer and returned back. To create comfortable conditions indoors in winter period at an outdoor temperature of -20 degrees, you need to supply a coolant with a value of 90 degrees Celsius to the system, and return with a value of 70 degrees.
The temperature graph allows you to determine the overestimated or underestimated flow of the coolant. If the value of the return coolant temperature is too high, this will indicate high flow. If the value is underestimated, then this indicates a deficit in consumption.
The schedule of 95-70 degrees 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 of 105-70 degrees were taken. 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 are 80-60 degrees, and for buildings without insulation 90-70.
Why temperature fluctuations occur
The causes of temperature changes are determined by the following factors:
- When weather conditions change, the heat loss automatically changes. When cold weather sets in, to ensure an optimal microclimate in apartment buildings, it is necessary to spend more heat energy than with warming. The level of consumed heat loss is calculated by the value of "delta", which is the difference between the street and indoors.
- The constancy of the heat flux from the batteries is ensured by a 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 heat carrier 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 chart
The temperature graph for the supply of coolant to heating systems is a table that lists the values of the coolant temperature depending on the outside temperature.
The generalized graph of water temperature in the heating system is as follows:
The formula for calculating the temperature graph is as follows:
- To determine the coolant supply temperature: Т1=tin+∆хQ(0.8)+(β-0.5хUP)хQ.
- To determine the return flow temperature, the following formula is used: T2=tin+∆xQ(0.8)-0.5xUPxQ.
In the presented formulas:
Q is the relative heating load.
∆ is the temperature difference of the coolant supply.
β is the temperature difference in the forward and reverse supply.
UP is the difference between the water temperature at the inlet and outlet of the heater.
Graphs are of two types:
- For heating networks.
- For apartment buildings.
To understand the details, consider the features of the functioning of central heating.
CHP and heat networks: what is the relationship
The purpose of thermal power plants and heating networks is to heat the coolant to a certain value, and then transport it to the place of consumption. At the same time, it is important to take into account the losses on the heating main, the length of which is usually 10 kilometers. Despite the fact that all water supply pipes are thermally insulated, it is almost impossible to do without heat loss.
When the coolant moves from a thermal power plant or simply a boiler house to a consumer (an apartment building), then a certain percentage of water cooling is observed. To ensure the supply of coolant to the consumer in the required normalized value, it is required to supply it from the boiler house 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 in the direction of increasing the 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 efficient 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 reserve 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 limitations are characteristic of the house heating system:
- The maximum heating indicator is determined by the limited value of +95 degrees for a two-pipe system, as well as 105 degrees for a one-pipe network. Stricter restrictions apply in preschools. The value of the water temperature in the battery should not rise above 37 degrees. To compensate for the low temperature value, additional sections of radiators are built up. Kindergartens, which are located directly in regions with severe climatic zones, equipped large quantity radiators with multiple sections.
- The best option is to achieve minimum value"delta", which represents the difference between the supply and output temperature of the coolant. If this value is not achieved, then the degree of heating of the radiators will have a high difference. To reduce the difference, it is necessary to increase the speed 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 CHPP with excessive high temperature. This phenomenon can lead to the fact that there will be violations of the CHP.
To get rid of such a problem, elevator modules should be installed in each apartment building. By means of such devices, a portion of the supply water with the return is diluted. This mixture will allow you to get accelerated circulation, thereby eliminating the possibility of excessive overheating of the return pipeline.
If an elevator is installed in a private house, then the accounting for the heating system is set using an individual temperature graph. For two-pipe systems heating of a private house is characterized by modes of 95-70, and for single-pipe - 105-70 degrees.
How climate zones affect air temperature
The main factor that is taken into account when calculating the temperature graph is presented in the form of an estimated temperature in winter. When calculating the heating, the outdoor temperature is taken from a special table for climatic zones.
table temperature coolant should be drawn up so that its maximum value satisfies the SNiP temperature in residential premises. For example, we use the following data:
- As heating devices, radiators are used, which provide the supply of coolant from the bottom up.
- The type of heating of apartments is two-pipe, equipped with a parking piping.
- The calculated values of the outdoor temperature are -15 degrees.
This gives us 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 will be equal to 25 degrees.
- When the temperature drops to 0 degrees, the coolant value rises to 57 degrees, and the return flow will be 46 degrees.
- At -15, water will be supplied at a temperature of 95 degrees, and the return is 70 degrees.
It is interesting! When determining average daily temperature information is taken both from daytime thermometer readings and from nighttime measurements.
How to regulate the temperature
CHP employees are responsible for the parameters of the 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 residents that it is cold in the apartments. To normalize the system parameters, you will need to carry out the following activities:
- Increasing the diameter of the nozzle or installing an elevator with an adjustable nozzle. If there is an underestimated value of the liquid temperature in the return, then this problem can be solved by increasing the diameter of the elevator nozzle. To do this, close the valves and valves, and then remove the module. The nozzle is enlarged by drilling it by 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 necessarily carried out.
- Shut off the suction. To avoid the threat of the jumper performing the suction function, it is muted. 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 during its implementation the occurrence of a temperature jump of up to +130 degrees is not excluded.
- Variation regulation. You can solve the problem by adjusting the drops with an elevator valve. essence this method correction consists in redirecting the DHW to the supply pipe. A pressure gauge is screwed into the return pipe, after which the valve of the return pipeline is closed. When opening the valve, it is necessary to carry out a reconciliation with the readings of the manometer.
If you install a conventional valve, it will stop and freeze the system. To reduce the difference, you need to increase the return pressure to a value of 0.2 atm / day. What temperature should be in the batteries can be found on the basis of the temperature graph. Knowing its value, you can check to make sure it matches the temperature regime.
In conclusion, it should be noted that the options for damping the suction and regulating the drops are used exclusively in the development of critical situations. Knowing such a minimum of information, you can contact the housing office or thermal power plant with complaints and wishes about inappropriate coolant standards in the system.
Each heating system has certain characteristics. These include power, heat transfer and temperature operation. They determine the efficiency of work, directly affecting the comfort of living in the house. How to choose the right temperature graph and heating mode, its calculation?
Drawing up a temperature chart
The temperature schedule of the heating system is calculated according to several parameters. Not only the degree of heating of the premises, but also the flow rate of the coolant depends on the selected mode. This also affects the ongoing 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 pipelines. Measurements are made in the corresponding boiler nozzles;
- Characteristics of the degree of heating of air indoors and outdoors.
The correct calculation of the heating temperature graph begins with the calculation of the difference between the temperature of the hot water in the direct and supply pipes. This value has the following notation:
∆T=Tin-Tob
Where Tin- water temperature in the supply line, Tob- the degree of heating of water in the return pipe.
To increase the heat transfer of the heating system, it is necessary to increase the first value. To reduce the coolant flow rate, ∆t must be kept to a minimum. This is precisely the main difficulty, since the temperature schedule of the heating boiler directly depends on external factors - heat losses in the building, outdoor air.
To optimize the heating power, it is necessary to make thermal insulation of the outer 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 the heating components - radiators and batteries. In particular, specific power (W / cm²). This will directly affect the heat transfer of heated water to air into the room.
It is also necessary to make a series preliminary calculations. This takes into account the characteristics of the house and heating devices:
- Heat transfer resistance coefficient of external walls and window structures. It must be at least 3.35 m² * C / W. Depends on the climatic features of the region;
- Surface power of radiators.
The temperature curve of the heating system is directly dependent on these parameters. To calculate the heat loss of a house, it is necessary to know the thickness of the outer walls and the building material. The calculation of the surface power of batteries is carried out according to the following formula:
Rud=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 timely change the heating parameters, a temperature heating 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 coolant inflow to the radiators is adjusted.
The weekly programmer is the optimal temperature controller for heating. 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 parameters of the coolant supplied to consumers:
- 150°C/70°C. To normalize the water temperature with elevator node it is mixed with the cooled stream. In this case, it is possible to draw up an individual temperature schedule for a heating boiler house for a particular house;
- 90°C/70°C. It is typical for small private heating systems designed to supply heat to several apartment buildings. In this case, you can not install the mixing unit.
It is the responsibility of 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 a correct temperature schedule for a heating boiler room is required to ensure an 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 air heating in each apartment. That is why the temperature chart is drawn up heating system.
A copy of the heating schedule can be requested from Management Company. With it, you can control the quality of the services provided.
Heating system
Do the same calculations for autonomous systems heating of a private house is often not necessary. If the scheme provides for indoor and outdoor temperature sensors, information about them will be sent to the boiler control unit.
Therefore, in order to reduce energy consumption, a low-temperature heating mode is most often chosen. It is characterized by relatively low water heating (up to +70°C) and a high degree of water circulation. This is necessary to evenly distribute heat to all heaters.
To implement such a temperature regime of the heating system, the following conditions must be met:
- Minimum heat loss in the house. However, one should not forget about normal air exchange - ventilation is a must;
- High heat output of radiators;
- Installation of automatic temperature controllers in heating.
If there is a need to perform a correct calculation of the system, it is recommended to use special software systems. There are too many factors to consider for self-calculation. But with their help, you can draw up approximate temperature graphs for 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 temperature outside. When performing calculations, the characteristics of the building, the climatic features of the region were not taken into account. But even so, they can be used as a basis for creating a temperature graph for a heating system.
The maximum load of the system 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 chart of the heating boiler room will experience deviations in the calculated and actual data during operation. This is due to the peculiarities of the operation of the system. What factors can influence the current temperature regime of heat supply?
- Pollution of pipelines and radiators. To avoid this, periodic cleaning of the heating system should be carried out;
- Incorrect operation of control and shutoff valves. Be sure to check the performance of all components;
- Violation of the boiler operation mode - sudden temperature jumps as a result - pressure.
Maintaining the optimal temperature regime of the system is possible only when right choice its components. For this, their operational and technical properties should be taken into account.
Battery heating can be adjusted using a thermostat, the principle of operation of which can be found in the video:
To maintain a comfortable temperature in the house during the heating period, it is necessary to control the temperature of the coolant in the pipes of heating networks. Employees of the central heating system of residential premises are developing special temperature chart, which depends on weather indicators, climatic features of the region. The temperature graph may differ in different settlements, it can also change during the modernization of heating networks.
A schedule is drawn up in the heating network for simple principle- the lower the temperature outside, the higher it should be at the coolant.
This ratio is important basis for work enterprises that provide the city with heat.
For the calculation, an indicator was used, which is based on average daily temperature the five coldest days of the year.
ATTENTION! Compliance with the temperature regime is important not only for maintaining heat in an apartment building. It also allows you to make the consumption of energy resources in the heating system economical, rational.
The graph, which indicates the temperature of the coolant depending on the outside temperature, allows the most optimal way to distribute between consumers apartment building not only heat, but also hot water.
How is heat regulated in the heating system
Heat regulation in an apartment building during the heating period can be carried out in two ways:
- By changing the flow rate of water at a certain constant temperature. This is a quantitative method.
- The change in the temperature of the coolant at a constant flow rate. This is a quality method.
Economical and practical is second option, at which the temperature regime in the room is observed regardless of the weather. Sufficient heat supply to apartment house will be stable even if noted sharp drop outside temperatures.
ATTENTION!. The norm is the temperature of 20-22 degrees in the apartment. If the temperature schedules are observed, this norm is maintained throughout the 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.
A specific table of the ratio of outdoor temperature and coolant depends on factors such as climate, boiler room 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 chart, which indicates the standards for the coolant indicators, depending on what the actual outside temperature is.
- Drawing up a schedule makes it possible to prepare the heating for a decrease in the temperature outside.
- It is also energy saving.
ATTENTION! In order to control the temperature of the heating medium and be entitled to recalculation due to non-compliance thermal regime, the heat sensor must be installed in the central heating system. Meters 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 construction technologies, the use of new materials for the insulation of walls and other surfaces of the building, compliance with the norms of the temperature of the coolant in the heating system - best way maintain comfortable living conditions.
Features of calculating the internal temperature in different rooms
The rules provide for maintaining the temperature for living quarters at 18˚С, but there are some nuances in this matter.
- For angular rooms of a residential building coolant must provide a temperature of 20 ° C.
- Optimum temperature indicator for the 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 this is a children's pool, you need to maintain the temperature at 30 ° C.
- Minimum temperature allowed in schools - 21˚C.
- In institutions where mass cultural events are held according to the standards, Maximum temperature 21˚C, but the indicator should not fall below the figure 16˚С.
To increase the temperature in the premises during a sharp cold snap or a strong north wind, the boiler house workers increase the degree of energy supply for heating networks.
The heat transfer of the batteries is affected by the outside temperature, the type of heating system, the direction of the flow of the coolant, the state of the utility networks, the type of heater, the role of which can be played by both a radiator and a convector.
ATTENTION! The temperature delta between the supply to the radiator and the return should not be significant. Otherwise, a large difference in the coolant in different rooms and even apartment buildings.
The main factor, however, is the weather., which is why measuring outdoor air to maintain a temperature graph is a top priority.
If it is cold outside up to 20˚С, the coolant in the radiator should have an indicator of 67-77˚С, while the norm for the return is 70˚С.
If the street temperature is zero, the norm for the coolant is 40-45˚С, and for the return - 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 coolant?
Payment utilities in the heating column should depend on what temperature the supplier provides in the apartment.
Table of the temperature graph, according to which optimal performance boiler, shows at what temperature of the environment 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 observed, the consumer may demand a recalculation for utilities.
To measure the coolant indicator, it is necessary to drain some water from the radiator and check its degree of heat. Also successfully used thermal sensors, heat meters that can be installed at home.
The sensor is a mandatory equipment for both city boiler houses and ITPs (individual heating points).
Without such devices, it is impossible to make the operation of the heating system economical and productive. Coolant measurement is also carried out in hot water systems.
Useful video
Water is heated in network heaters, with selective steam, in peak hot water boilers, after which network water enters the supply line, and then to subscriber heating, ventilation and hot water supply installations.
Heating and ventilation heat loads are uniquely dependent on the outdoor temperature tn.a. Therefore, it is necessary to adjust the heat output in accordance with load changes. You use predominantly central regulation carried out at the CHP, 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 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 misalignment of heating systems, which means an unequal redistribution of network water across floors. Therefore, quality control is usually used, for which the temperature curves of the heating network for the heating load must be calculated depending on the outside temperature.
The temperature chart 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 outdoor temperature tn.o. So, the schedule 150-70°C means that at the calculated outdoor 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 design temperature of the temperature curve 70 °C is determined by the need to heat tap water for the needs of 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, excluding water boiling, and therefore 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 heating water in the supply line leads to a reduction in the consumption of heating water, which reduces the cost of heating network, but also reduces the generation of electricity from heat consumption. The choice of the temperature schedule for the heat supply system must be confirmed by a feasibility study based on the minimum reduced costs for the CHP and the heat network.
The heat supply of the industrial site of CHPP-2 is carried out according to the temperature schedule of 150/70 °C with a cutoff of 115/70 °C, in connection with which the regulation of the temperature of the network water is automatically carried out only up to the outdoor temperature of “-20 °C”. The consumption of network water is too high. The excess of the actual consumption of network water over the calculated one leads to an overexpenditure of electrical energy for pumping the coolant. The temperature and pressure in the return pipe does not match the temperature chart.
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 TMUP TTS, the discharge from the heat supply systems due to the lack of the necessary pressure drop for consumers and the leakage of the heating surfaces of the DHW water heaters, there is an increased consumption of make-up water at the CHP, 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 for external consumers is not regulated and requires adjustment and adjustment.
Dependence of network water temperatures on outdoor air temperature
Table 6.1.
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Temperature value |
Temperature value |
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Outside air |
feed line |
After the elevator |
reverse master |
Outside air |
submitting master |
After the elevator |
In back th mainline ali |
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