How to calculate the temperature chart of the boiler room. Choosing a temperature regime for heating: a description of the main parameters and calculation examples

The basis of an economical approach to energy consumption in a heating system of any type is the temperature graph. Its parameters indicate optimal value heating water, thereby optimizing costs. In order to apply these data in practice, it is necessary to learn more about the principles of its construction.

Terminology

Temperature graph - the optimal value of heating the coolant to create comfortable temperature in room. It consists of several parameters, each of which directly affects the quality of the entire heating system.

The temperature in the inlet and outlet pipes of the heating boiler.
The difference between these indicators of heating the coolant.
Temperature indoors and outdoors.

The latter characteristics are decisive for the regulation of the first two. Theoretically, the need to increase the heating of water in the pipes comes with a decrease in the temperature outside. But how much should be increased so that the heating of the air in the room is optimal? To do this, draw up a graph of the dependence of the parameters of the heating system.

When calculating it, the parameters of the heating system are taken into account and residential building. For district heating, the following temperature parameters systems:

150°C/70°C. Before reaching the users, the coolant is diluted with water from the return pipe to normalize the incoming temperature.
90°C/70°C. In this case, there is no need to install equipment for mixing streams.

According to the current parameters of the system, utilities must monitor compliance with the heating value of the coolant in the return pipe. If this parameter is less than normal, it means that the room is not warming up properly. The excess indicates the opposite - the temperature in the apartments is too high.

Temperature chart for a private house

The practice of drawing up such a schedule for autonomous heating not very developed. This is due to its fundamental difference from the centralized one. It is possible to control the water temperature in the pipes in manual and automatic mode. If during design and practical implementation If the installation of sensors for automatic control of the operation of the boiler and thermostats in each room was taken into account, then there will be no urgent need to calculate the temperature schedule.

But to calculate future expenses depending on weather conditions he will be irreplaceable. In order to make it according to the current rules, the following conditions must be taken into account:

Only after these conditions are met, you can proceed to the calculation part. At this stage, difficulties may arise. The correct calculation of an individual temperature graph is a complex mathematical scheme that takes into account all possible indicators.

However, to facilitate the task, there are ready-made tables with indicators. Below are examples of the most common modes of operation of heating equipment. The following input data were taken as initial conditions:

Minimum temperature outdoor air - 30°C
The optimum room temperature is +22°C.

Based on these data, schedules were drawn up for the following types of heating systems.

It is worth remembering that these data do not take into account the design features of the heating system. They only show the recommended values of temperature and power of heating equipment, depending on weather conditions.

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 determines such indicators as the size of the 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, 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.
permanence heat flow from batteries is provided with 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.

Generalized graph of water temperature in heating system is of the following form:

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 CHP and heating networks is to heat the coolant to 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. The minimum supply temperature 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 the minimum value of "delta", which represents the difference between the supply and output temperatures 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 CHP with an excessively high temperature. This phenomenon can lead to the fact that there will be violations of the CHP.

To get rid of such a problem, one should apartment building install elevator modules. 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 heating systems of a private house, modes of 95-70 are typical, and for single-pipe systems - 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 workers are responsible for the parameters of the value of heating mains, but the control of networks inside residential buildings are 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 mandatory.

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. The essence of this correction method is to redirect 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.

When autumn confidently walks across the country, snow flies beyond the Arctic Circle, and in the Urals night temperatures stay below 8 degrees, then the word form “heating season” sounds appropriate. People recall past winters and try to figure out the normal temperature of the coolant in the heating system.

Prudent owners of individual buildings carefully revise the valves and nozzles of the boilers. Residents apartment building by October 1 they are waiting like Santa Claus, a plumber from management company. The ruler of valves and valves brings warmth, and with it - joy, fun and confidence in the future.

The Gigacalorie Path

Megacities sparkle with high-rise buildings. A cloud of renovation hangs over the capital. Outback prays on five-story buildings. Until demolished, the house has a calorie supply system.

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

The number of gate valves correlates with the number of risers. While doing repair work in a single apartment, it is possible to turn off one vertical, and not the whole house.

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

degrees here and there

Water for the heating configuration is prepared at a CHP plant or in a boiler house. The norms of water temperature in the heating system are prescribed in the building rules: the component must be heated to 130-150 ° C.

The supply is calculated taking into account the parameters of the outside air. So, for the South Ural 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 tear them up like a heating pad.

An extensible concept is the norm. The temperature in the apartment is never equal to the primary indicator of the heat carrier. Here it performs an energy-saving function elevator unit- jumper between the direct and return pipe. The norms for the temperature of the coolant in the heating system on the return in winter allow the preservation of heat at a level of 60 ° C.

The liquid from the straight pipe enters the elevator nozzle, mixes with return water and again goes into the house network for heating. The carrier temperature is lowered by mixing the return flow. What affects the calculation of the amount of heat consumed by residential and utility rooms.

Hot gone

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

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

in winter - from the reverse, so as not to scald users with boiling water;
in summer - with a straight line, since in summer 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 a riser through which the coolant enters the battery or radiator from the temperature norms of the coolant in the heating system require heating in the riser in winter time in the range of 70-90 °C. In fact, the degrees depend on the output parameters of the CHP or boiler house. In the summer when hot water needed only for washing and showering, the range moves to the range of 40-60 ° C.

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

The reason for the temperature difference in the heating riser is the way the hot water is distributed.

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

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

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

Warm like a battery

Suppose that the structures of the central network are reliably insulated along the entire route, the wind does not walk through the attics, stairwells and basements, the doors and windows in the apartments are insulated by conscientious owners.

We assume that the coolant in the riser complies with the building regulations. It remains to find out what is the norm for the temperature of the heating batteries in the apartment. The indicator takes into account:

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

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

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

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

Theory of linguistics

The name "battery" is household, denoting a number of identical items. In relation to the heating of housing, this is a series of heating sections.

The temperature standards of heating batteries 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 sheathed with plywood or bricked. Usually they put a lattice fence that does not interfere with air circulation.

Cast iron, aluminum and bimetallic devices are common.

Consumer choice: cast iron or aluminum

Aesthetics cast iron radiators- a parable in the language. They require periodic painting, as the regulations require that the work surface should have a smooth surface and allow dust and dirt to be easily removed.

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

little susceptible to water corrosion, can be used for more than 45 years;
they have a high thermal power per 1 section, therefore they are compact;
they are inert in heat transfer, therefore they smooth out temperature fluctuations in the room well.

Another type of radiators is made of aluminum. Lightweight construction, painted in the factory, does not require painting, easy to clean.

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

The temperature standards of 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 the working surface of the heating structure. Therefore, it is strongly not recommended to increase the aesthetics of the room with shields in front of the heating device.

Stairwell heating

Since we are talking about an apartment building, we should mention the stairwells. The norms for the temperature of the coolant in the heating system state: the degree measure on the sites should not fall below 12 ° C.

Of course, the discipline of the residents requires that the doors of the entrance group be closed tightly, that the transoms of the stair windows not be left open, that the glass be kept intact and that any problems be promptly reported 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 the recalculation of the cost of services will help.

Changes in heating design

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

The heating season will begin, a change in the temperature regime in other apartments and sites will be recorded. A technical inspection of the premises will reveal unauthorized changes in the types of heating devices, their number and size. The chain is inevitable: conflict - trial - fine.

So the situation is resolved like this:

if not old ones are replaced with new radiators of the same size, then this is done without additional approvals; the only thing to apply to the Criminal Code is to turn off the riser for the duration of the repair;
if new products differ significantly from those installed during construction, then it is useful to interact with the management company.

Heat meters

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

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