The task of organizations serving houses and buildings is to maintain standard temperature. The heating temperature schedule directly depends on the outside temperature.
There are three heat supply systems
- Centralized heat supply of a large boiler house (CHP) located at a considerable distance from the city. In this case, heat supply organization, considering heat losses in networks, selects a system with a temperature schedule: 150/70, 130/70 or 105/70. The first number is the temperature of the water in the supply pipe, the second number is the temperature of the water in the return heat pipe.
- Small boiler houses located near residential buildings. In this case, select temperature graph 105/70, 95/70.
- Individual boiler, installed on a private house. The most acceptable schedule is 95/70. Although it is possible to reduce the supply temperature even further, since there will be practically no heat loss. Modern boilers operate automatically and maintain a constant temperature in the heating supply pipe. The temperature chart of 95/70 speaks for itself. The temperature at the entrance to the house should be 95 °C, and at the exit - 70 °C.
IN Soviet times, when everything was state-owned, all parameters of temperature schedules were maintained. If according to the schedule the supply temperature should be 100 degrees, then that’s what it will be. This temperature cannot be supplied to residents, which is why elevator units were designed. Water from the return pipeline, cooled, was mixed into the supply system, thereby lowering the supply temperature to the standard one. In our times of general economy, the need for elevator units disappears. All heat supply organizations have switched to a 95/70 heating system temperature schedule. According to this graph, the coolant temperature will be 95 °C when the outside temperature is -35 °C. As a rule, the temperature at the entrance to the house no longer requires dilution. Therefore, all elevator units must be eliminated or reconstructed. Instead of conical sections, which reduce both the speed and volume of flow, install straight pipes. Plug the supply pipe from the return pipeline with a steel plug. This is one of the heat saving measures. It is also necessary to insulate the facades of houses and windows. Replace old pipes and batteries with new, modern ones. These measures will increase the air temperature in homes, which means you can save on heating temperatures. A drop in outside temperature is immediately reflected in residents' receipts.
Majority Soviet cities built with an “open” heat supply system. This is when water from the boiler room reaches consumers in their homes and is used for personal needs and heating. When reconstructing systems and constructing new heat supply systems, a “closed” system is used. Water from the boiler room reaches the heating point in the microdistrict, where it heats the water to 95 °C, which goes to the houses. This results in two closed rings. This system allows heat supply organizations to significantly save resources for heating water. After all, the volume of heated water leaving the boiler room will be almost the same at the entrance to the boiler room. There is no need to add cold water to the system.
Exist guidelines construction of heating temperature schedules, approved by the Government of the Russian Federation. The essence of the methods comes down to: how much cubic meters need to be heated and how many people should use the hot water.
Temperature charts are:
- optimal . The heat resource of the boiler room is used exclusively for heating houses. Temperature regulation occurs in the boiler room. Supply temperature – 95 °C.
- elevated . The heat resource of the boiler room is used for heating houses and hot water supply. A two-pipe system enters the house. One pipe is heating, the other pipe is hot water supply. Supply temperature 80 – 95 °C.
- adjusted . The heat resource of the boiler room is used for heating houses and hot water supply. Single pipe system approaches the house. The heat resource for heating and hot water for residents is taken from one pipe in the house. Supply temperature – 95 – 105 °C.
How to perform a heating temperature schedule. There are three ways:
- high-quality (coolant temperature regulation).
- quantitative (regulating the volume of coolant by turning on additional pumps on the return pipeline, or installing elevators and washers).
- qualitative and quantitative (to regulate both the temperature and volume of the coolant).
The quantitative method predominates, which is not always able to withstand the heating temperature schedule.
Fight against heat supply organizations. This fight is being waged by management companies. According to the law, the management company is obliged to enter into an agreement with the heat supply organization. Whether it will be a contract for the supply of heat resources or simply an agreement on interaction is decided by the management company. An appendix to this agreement will be a heating temperature schedule. The heat supply organization is required to approve temperature schemes with the city administration. The heat supply organization supplies the heat resource to the wall of the house, that is, to the metering units. By the way, the law establishes that heat engineers are required to install metering units in houses at their own expense with installment payments for residents. So, having metering devices at the entrance and exit of the house, you can control the heating temperature daily. Let's take temperature table, look at the air temperature on the weather website and find in the table the indicators that should be there. If there are deviations you need to complain. Even if deviations in big side, residents will pay more. At the same time, the windows will be opened and the rooms will be ventilated. You should complain about insufficient temperature to the heat supply organization. If there is no response, we write to the city administration and Rospotrebnadzor.
Until recently, there was an increasing coefficient on the cost of heat for residents of houses that were not equipped with communal metering meters. Due to the sluggishness of management organizations and heating workers, ordinary residents suffered.
An important indicator in the heating temperature chart is the temperature indicator of the return pipeline of the network. In all graphs this is 70 °C. At severe frosts When heat loss increases, heat supply organizations are forced to turn on additional pumps on the return pipeline. This measure increases the speed of water movement through the pipes, and, therefore, heat transfer increases and the temperature in the network is maintained.
Again, in a period of general savings, it is very problematic to force heat generators to turn on additional pumps, which means increasing energy costs.
The heating temperature schedule is calculated based on the following indicators:
- ambient temperature;
- supply pipeline temperature;
- return temperature;
- the amount of thermal energy consumed at home;
- required amount of thermal energy.
For different rooms The temperature schedule is different. For children's institutions (schools, kindergartens, art palaces, hospitals), the room temperature should be between +18 and +23 degrees according to sanitary and epidemiological standards.
- For sports premises – 18 °C.
- For residential premises - in apartments not lower than +18 °C, in corner rooms+ 20 °C.
- For non-residential premises– 16-18 °C. Based on these parameters, heating schedules are constructed.
It is easier to calculate the temperature schedule for a private home, since the equipment is installed directly in the house. Thrifty owner will provide heating to the garage, bathhouse, outbuildings. The load on the boiler will increase. Let's count thermal load depending on the maximum low temperatures air of past periods. We select equipment by power in kW. The most cost-effective and environmentally friendly boiler is natural gas. If you have gas turned on, half the job is already done. You can also use gas in cylinders. At home, you don’t have to adhere to the standard temperature schedules of 105/70 or 95/70, and it doesn’t matter if the temperature in the return pipe is not 70 °C. Adjust the network temperature to your liking.
By the way, many city residents would like to put individual meters for heat and control the temperature schedule yourself. Contact heat supply organizations. And there they hear such answers. Most houses in the country are built according to vertical system heat supply. Water is supplied from below - up, less often: from top to bottom. With such a system, the installation of heat meters is prohibited by law. Even if a specialized organization installs these meters for you, the heat supply organization simply will not accept these meters for operation. That is, there will be no savings. Installation of meters is possible only with horizontal heating distribution.
In other words, when the heating pipe comes into your home not from above, not from below, but from the entrance corridor - horizontally. Individual heat meters can be installed at the entry and exit points of heating pipes. The installation of such meters pays for itself in two years. All houses are now built with just such a wiring system. Heating devices are equipped with control knobs (taps). If you think the temperature in the apartment is high, you can save money and reduce the heating supply.
Only we can save ourselves from freezing.
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, for a plumber from the management company. The Lord of valves and valves brings warmth, and with it joy, fun and confidence in the future.
The Gigacalorie Path
Megacities sparkle high-rise buildings. A cloud of renovation hangs over the capital. The outback prays to five-story buildings. Until demolished, the house operates a calorie supply system.
Heating of an economy class apartment building is carried out through a centralized heat supply system. Pipes are included in basement buildings. The supply of coolant is regulated by inlet valves, after which the water enters the mud traps, and from there it is distributed through the risers, and from them it is supplied to the radiators and radiators that heat the home.
The number of valves correlates with the number of risers. By doing repair work in a separate apartment, it is possible to turn off one vertical, and not the entire house.
The spent liquid is partially discharged through 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 ah: 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 most network pipes settlements worn out and high pressure will tear them apart like a hot water bottle.
An elastic concept is a norm. The temperature in the apartment is never equal to the primary indicator of the coolant. Here, the elevator unit - a jumper between the forward and return pipes - performs an energy-saving function. The temperature standards for the coolant in the return heating system in winter allow heat to be maintained at a level of 60 °C.
Liquid from a straight pipe enters the elevator nozzle and is mixed with return water and again goes into the house network for heating. The temperature of the carrier is reduced by mixing the return fluid. What affects the calculation of the amount of heat consumed by residential and utility rooms.
The hot one went
Temperature hot water By sanitary rules at analysis points should be in the range of 60-75 °C.
In the network, the coolant is supplied from the pipe:
- in winter - with reverse, so as not to scald users with boiling water;
- in summer - from a straight line, since in summer time The carrier is heated no higher than 75 °C.
A temperature chart is drawn up. The average daily return water temperature should not exceed the schedule by more than 5% at night and 3% during the day.
Parameters of distributing elements
One of the details of warming a home is the riser through which the coolant enters the battery or radiator from the Coolant temperature standards in the heating system require heating in the riser 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 is needed only for washing and showering, the range moves to 40-60 °C.
Observant people may notice that the heating elements in the neighboring apartment are hotter or colder than in his own.
The reason for the temperature difference in the heating riser lies in the method of hot water distribution.
In a single-pipe design, the coolant can be distributed:
- above; then the temperature on the upper floors is higher than on the lower ones;
- from below, then the picture changes to the opposite - it is hotter from below.
IN two-pipe system the degree is the same throughout, theoretically 90 °C in the forward direction and 70 °C in the reverse direction.
Warm like a battery
Let’s assume that the central network structures are reliably insulated along the entire route, the wind does not blow through attics, staircases and basements, and conscientious owners have insulated the doors and windows in the apartments.
Let's assume that the coolant in the riser complies with building code standards. It remains to find out what the normal temperature of the heating radiators in the apartment is. The indicator takes into account:
- outdoor air parameters and time of day;
- location of the apartment in the house plan;
- residential or utility room in the apartment.
Therefore, attention: it is important not what the temperature of the heater is, but what the temperature of the air in the room is.
During the day, in corner rooms the thermometer 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
Aesthetics cast iron radiators- the talk of the town. They require periodic painting, since the rules stipulate that the working surface must have smooth surface and made it easy to remove dust and dirt.
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 on high:
- 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, therefore they smooth out well temperature changes in the room.
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. Certainly, inner surface The heater is insulated with plastic to avoid contact of aluminum with water. But the film may be damaged, then it will start chemical reaction with the release of hydrogen during creation overpressure gas 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.
Staircase heating
Since we are talking about an apartment building, we should mention staircases. The coolant temperature standards in the heating system state: the degree measure at the sites should not fall below 12 °C.
Of course, the discipline of residents requires closing the entrance doors tightly, not leaving the transoms of the staircase windows open, keeping the glass intact and promptly reporting any problems to the management company. If the management company does not take timely measures to insulate points of probable heat loss and comply with temperature regime in the house, an application for recalculation of the cost of services will help.
Changes in heating design
Replacement of existing heating devices in an apartment is carried out with the obligatory approval of 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 heating season Check with the management company whether the metering device is in working condition and whether the verification schedule has been violated.
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
The temperature schedule 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.
The compiled heating temperature schedule 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 series 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.
The responsibility of utility services is to calculate the temperature heating schedule and control 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 centralized system drawing up the 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 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 scheme 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 high degree its 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 system load 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 the 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 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 passed full cycle According to the system, the coolant, already cooled, returns to the source and reheating occurs. 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:
- Quantitative. In this form, the water flow changes, but its temperature remains constant.
- 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:
- Technical and economic indicators.
- CHP or boiler room equipment.
- 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. And vice versa, at minimum flow, 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 norms 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.
Earlier, at 10 tee storey 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:
- Tnv– the amount of outside air.
- TVN- indoor air.
- T1– coolant from the source.
- T2– reverse flow of water.
- 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 will ensure uniform heat distribution throughout heating circuit. 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 regulator.
It includes the following parts:
- Computing and matching panel.
- Actuator along the water supply section.
- Actuator, 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 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 ensure strict temperature diagram heating systems.
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:
- The temperature scheme is strictly maintained.
- Avoiding overheating of the liquid.
- Fuel efficiency and energy.
- 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 building, a multi-storey building and a private house, they will all 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 of network water 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 standards that must be observed in creating projects on heating network and 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.
What laws govern changes in coolant temperature in systems? central heating? What is it - the temperature graph of the heating system is 95-70? How to bring heating parameters into line with the schedule? Let's try to answer these questions.
What it is
Let's start with a couple of abstract points.
- With change weather conditions heat losses of any building change after them. In frosty weather, in order to maintain a constant temperature in the apartment, much more thermal energy is required than in warm weather.
Let us clarify: heat costs are determined not by the absolute value of the air temperature outside, but by the delta between the street and the interior.
So, at +25C in the apartment and -20 in the yard, heat costs will be exactly the same as at +18 and -27, respectively.
- Heat flow from heating device at a constant coolant temperature it will also be constant.
A drop in temperature in the room will increase it slightly (again due to an increase in the delta between the coolant and the air in the room); however, this increase will be absolutely insufficient to compensate for the increased heat losses through the building envelope. Simply because the current SNiP limits the lower temperature threshold in an apartment to 18-22 degrees.
An obvious solution to the problem of increasing losses is to increase the temperature of the coolant.
Obviously, its increase should be proportional to the decrease in street temperature: the colder it is outside, the greater the heat loss will have to be compensated. Which, in fact, brings us to the idea of creating a specific table for reconciling both values.
So, the schedule temperature system heating is a description of the dependence of the temperatures of the supply and return pipelines on the current weather outside.
How everything works
There are two different types graphs:
- For heating networks.
- For indoor heating system.
To explain the difference between these concepts, it is probably worth starting with a brief excursion into how central heating works.
CHP - heating networks
The function of this bundle is to heat the coolant and deliver it to the end user. The length of heating mains is usually measured in kilometers, the total surface area - in thousands and thousands square meters. Despite measures to insulate pipes, heat loss is inevitable: having passed the path from the thermal power plant or boiler room to the border of the house, process water will have time to partially cool down.
Hence the conclusion: in order for it to reach the consumer while maintaining an acceptable temperature, the supply of the heating main at the exit from the thermal power plant must be as hot as possible. The limiting factor is the boiling point; however, as the pressure increases, it shifts towards increasing temperature:
| Pressure, atmosphere | Boiling point, degrees Celsius |
| 1 | 100 |
| 1,5 | 110 |
| 2 | 119 |
| 2,5 | 127 |
| 3 | 132 |
| 4 | 142 |
| 5 | 151 |
| 6 | 158 |
| 7 | 164 |
| 8 | 169 |
Typical pressure in the supply pipeline of a heating main is 7-8 atmospheres. This value, even taking into account pressure losses during transportation, allows you to start heating system in buildings up to 16 floors high without additional pumps. At the same time, it is safe for routes, risers and connections, mixer hoses and other elements of heating and hot water systems.
With some margin, the upper limit of the supply temperature is taken to be 150 degrees. The most typical heating temperature curves for heating mains are in the range 150/70 - 105/70 (supply and return temperatures).
House
There are a number of additional limiting factors in a home heating system.
- The maximum temperature of the coolant in it cannot exceed 95 C for a two-pipe and 105 C for.
By the way: in preschool educational institutions the restriction is much more stringent - 37 C.
The cost of reducing the supply temperature is to increase the number of radiator sections: in northern regions countries where groups in kindergartens are literally surrounded by them.
- For obvious reasons, the temperature delta between the supply and return pipelines should be as small as possible - otherwise the temperature of the batteries in the building will vary greatly. This implies rapid circulation of the coolant.
However, too rapid circulation through house system heating will lead to the fact that the return water will return to the route with an exorbitant high temperature, which is unacceptable due to a number of technical limitations in the operation of thermal power plants.
The problem is solved by installing one or more elevator units in each house, in which return water is mixed with the flow of water from the supply pipeline. The resulting mixture, in fact, ensures rapid circulation of a large volume of coolant without overheating the return pipeline of the route.
For intra-house networks, a separate temperature schedule is set taking into account the elevator operation scheme. For two-pipe circuits, the typical heating temperature curve is 95-70, for single-pipe circuits (which, however, is rare in apartment buildings) — 105-70.
Climate zones
The main factor determining the scheduling algorithm is the estimated winter temperature. The coolant temperature table must be drawn up in such a way that the maximum values (95/70 and 105/70) at the peak of frost provide the temperature in residential premises corresponding to SNiP.
Let's give an example of an intra-house graph for the following conditions:
- Heating devices - radiators with coolant supply from bottom to top.
- Heating is two-pipe, with .
- Design temperature street air— -15 C.
| Outside air temperature, C | Feed, C | Return, C |
| +10 | 30 | 25 |
| +5 | 44 | 37 |
| 0 | 57 | 46 |
| -5 | 70 | 54 |
| -10 | 83 | 62 |
| -15 | 95 | 70 |
A nuance: when determining the parameters of the route and the intra-house heating system, the average daily temperature is taken.
If it is -15 at night and -5 during the day, the outside temperature is -10C.
And here are some calculated values winter temperatures for Russian cities.
| City | Design temperature, C |
| Arkhangelsk | -18 |
| Belgorod | -13 |
| Volgograd | -17 |
| Verkhoyansk | -53 |
| Irkutsk | -26 |
| Krasnodar | -7 |
| Moscow | -15 |
| Novosibirsk | -24 |
| Rostov-on-Don | -11 |
| Sochi | +1 |
| Tyumen | -22 |
| Khabarovsk | -27 |
| Yakutsk | -48 |
The photo shows winter in Verkhoyansk.
Adjustment
If the management of the thermal power plant and heating networks is responsible for the parameters of the route, then responsibility for the parameters of the intra-house network rests with the housing residents. A very typical situation is when, when residents complain about the cold in their apartments, measurements show deviations from the schedule downward. It happens a little less often that measurements in thermal wells show an elevated return temperature from the house.
How to bring the heating parameters into line with the schedule with your own hands?
Reaming the nozzle
When the temperature of the mixture and return is low, the obvious solution is to increase the diameter of the elevator nozzle. How it's done?
The instructions are at the reader's disposal.
- All valves or valves are closed elevator unit(entrance, house and hot water supply).
- The elevator is being dismantled.
- The nozzle is removed and drilled 0.5-1 mm.
- The elevator is assembled and started with air bleeding in the reverse order.
Advice: instead of paronite gaskets, you can put rubber gaskets on the flanges, cut to the size of the flange from a car inner tube.
An alternative is to install an elevator with an adjustable nozzle.
Choke suppression
In a critical situation ( extreme cold and freezing flats) the nozzle can be completely removed. To prevent the suction from becoming a jumper, it is suppressed with a pancake made of steel sheet at least a millimeter thick.
Please note: this is an emergency measure used in extreme cases, since in this case the temperature of the radiators in the house can reach 120-130 degrees.
Differential adjustment
At elevated temperatures, as a temporary measure until the end of the heating season, it is practiced to adjust the differential on the elevator using a valve.
- The DHW switches to the supply pipe.
- A pressure gauge is installed on the return line.
- The inlet valve on the return pipeline is completely closed and then gradually opens with pressure controlled by a pressure gauge. If you simply close the valve, the subsidence of the cheeks on the rod can stop and defrost the circuit. The difference is reduced by increasing the return pressure by 0.2 atmospheres per day with daily temperature control.
