Individual heating point, etc. Thermal points: device, work, scheme, equipment

The heat point is called a structure that serves to connect local heat consumption systems to heat networks. Heat points are divided into central (CTP) and individual (ITP). Central heating stations are used to supply heat to two or more buildings, ITPs are used to supply heat to one building. If there is a CHP in each individual building, an ITP is required, which performs only those functions that are not provided for in the CHP and are necessary for the heat consumption system of this building. In the presence of its own source of heat (boiler room), the heating point is usually located in the boiler room.

Thermal points house equipment, pipelines, fittings, control, management and automation devices, through which the following are carried out:

Conversion of coolant parameters, for example, to reduce the temperature of network water in the design mode from 150 to 95 0 С;

Control of coolant parameters (temperature and pressure);

Regulation of coolant flow and its distribution among heat consumption systems;

Shutdown of heat consumption systems;

Protection of local systems from an emergency increase in coolant parameters (pressure and temperature);

Filling and make-up of heat consumption systems;

Accounting for heat flows and coolant flow rates, etc.

On fig. 8 is given one of the possible schematic diagrams of an individual heating point with an elevator for heating a building. The heating system is connected through the elevator if it is necessary to reduce the water temperature for the heating system, for example, from 150 to 95 0 С (in the design mode). At the same time, the available pressure in front of the elevator, sufficient for its operation, must be at least 12-20 m of water. Art., and the pressure loss does not exceed 1.5 m of water. Art. As a rule, one system or several small systems with similar hydraulic characteristics and with a total load of no more than 0.3 Gcal/h are connected to one elevator. At large necessary pressure and heat consumption, mixing pumps are used, which are also used for automatic control of the heat consumption system.

ITP connection to the heating network is made by a valve 1. Water is purified from suspended particles in the sump 2 and enters the elevator. From the elevator, water with a design temperature of 95 0 С is sent to the heating system 5. The water cooled in the heating devices is returned to the ITP with a design temperature of 70 0 С. Part return water is used in the elevator, and the rest of the water is cleaned in the sump 2 and enters the return pipeline of the heating system.

Constant flow hot network water is provided by an automatic flow regulator RR. The PP regulator receives an impulse for regulation from pressure sensors installed on the supply and return pipelines of the ITP, i.e. it reacts to the pressure difference (pressure) of water in the specified pipelines. The water pressure can change due to an increase or decrease in water pressure in the heating network, which is usually associated in open networks with a change in water consumption for the needs of hot water supply.

for example If the water pressure increases, then the water flow in the system increases. In order to avoid overheating of the air in the premises, the regulator will reduce its flow area, thereby restoring the previous water flow.

The constancy of water pressure in the return pipeline of the heating system is automatically provided by the pressure regulator RD. A drop in pressure may be due to water leaks in the system. In this case, the regulator will reduce the flow area, the water flow will decrease by the amount of leakage and the pressure will be restored.

Water (heat) consumption is measured by a water meter (heat meter) 7. Water pressure and temperature are controlled, respectively, by manometers and thermometers. Gate valves 1, 4, 6 and 8 are used to turn on or off the substation and the heating system.

Depending on the hydraulic features of the heating network and the local heating system, the following can also be installed at the heating point:

A booster pump on the return pipeline of the ITP, if the available pressure in the heating network is insufficient to overcome the hydraulic resistance of the pipelines, ITP equipment and heating systems. If the pressure in the return line is lower than static pressure in these systems, the booster pump is installed on the ITP supply pipeline;

A booster pump on the ITP supply pipeline, if the network water pressure is not enough to prevent water from boiling at the top points of heat consumption systems;

Shut-off valve on the supply line at the inlet and booster pump with safety valve on the return pipeline at the outlet, if the pressure in the IHS return pipeline may exceed the allowable pressure for the heat consumption system;

A shut-off valve on the supply pipeline at the inlet to the IHS, as well as safety and check valves on the return pipeline at the outlet of the IHS, if the static pressure in the heating network exceeds the allowable pressure for the heat consumption system, etc.

Fig 8. Scheme of an individual heating point with an elevator for heating a building:

1, 4, 6, 8 - valves; T - thermometers; M - pressure gauges; 2 - sump; 3 - elevator; 5 - radiators of the heating system; 7 - water meter (heat meter); RR - flow regulator; RD - pressure regulator

As shown in fig. 5 and 6 DHW systems are connected in ITP to the supply and return pipelines through water heaters or directly, through a mixing temperature controller of the TRZH type.

With direct water withdrawal, water is supplied to the TRZH from the supply or from the return or from both pipelines together, depending on the temperature of the return water (Fig. 9). for example, in summer, when the network water is 70 0 С, and the heating is turned off, only water from the supply pipeline enters the DHW system. The non-return valve is used to prevent the flow of water from the supply pipeline to the return pipeline in the absence of water intake.

Rice. nine. Scheme of the connection point of the DHW system with direct water intake:

1, 2, 3, 4, 5, 6 - valves; 7 - check valve; 8 - mixing temperature controller; 9 - water mixture temperature sensor; 15 - water taps; 18 - mud collector; 19 - water meter; 20 - air vent; Sh - fitting; T - thermometer; RD - pressure regulator (pressure)

Rice. ten. Two-stage scheme serial connection of DHW water heaters:

1,2, 3, 5, 7, 9, 10, 11, 12, 13, 14 - valves; 8 - check valve; 16 - circulation pump; 17 - device for selecting a pressure pulse; 18 - mud collector; 19 - water meter; 20 - air vent; T - thermometer; M - pressure gauge; RT - temperature controller with sensor

For residential and public buildings the scheme of two-stage serial connection of DHW water heaters is also widely used (Fig. 10). In this scheme, tap water is first heated in the 1st stage heater, and then in the 2nd stage heater. In this case, tap water passes through the tubes of the heaters. In the heater of the 1st stage, tap water is heated by return network water, which, after cooling, goes to the return pipeline. In the second stage heater, tap water is heated by hot network water from the supply pipeline. The cooled network water enters the heating system. AT summer period this water is supplied to the return pipeline through a jumper (to the bypass of the heating system).

The flow rate of hot network water to the 2nd stage heater is regulated by the temperature controller (thermal relay valve) depending on the temperature of the water downstream of the 2nd stage heater.

Central heating point (subsequently TsTP) is one of the elements of the heating network located in urban-type settlements. It acts as a connecting link between the main network and distribution heating networks that go directly to consumers of thermal energy (in residential buildings, kindergartens, hospitals, etc.).

Typically, central heating points are located in separate buildings and serve several consumers. These are the so-called quarterly TsTPs. But sometimes such points are located in the technical (attic) or basement buildings and are intended to serve only this building. Such heat points are called individual (ITP).

The main tasks of heat points are the distribution of the heat carrier and the protection of heat networks from hydraulic shocks and leaks. The temperature and pressure of the coolant are also controlled and regulated in the TP. The temperature of the water entering the heating devices is subject to adjustment relative to the outside air temperature. That is, the colder it is outside, the higher the temperature supplied to the distribution heating networks.

Features of the operation of the central heating station installation of heating points

Central heating points can work according to dependent schema when the coolant from the main network goes directly to consumers. In this case, the central heating station acts as a distribution unit - the coolant is divided for the hot water supply system (DHW) and the heating system. That's just the quality hot water, pouring from our taps with a dependent connection scheme, often causes complaints from consumers.

In independent mode of operation, the building The central heating station is being equipped special heaters - boilers. In this case, superheated water (with main pipeline) heats the water passing through the second circuit, which subsequently goes to consumers.

Dependent scheme is economically beneficial for CHP. It does not require the permanent presence of personnel in the central heating building. With this scheme, mounted automatic systems, which allow you to remotely control the equipment of central heating points and adjust the main parameters of the coolant (temperature, pressure).

TsTP are equipped with various devices and units. Shut-off and control valves, DHW pumps and heating pumps, control and automation devices (temperature regulators, pressure regulators), water-water heaters and other devices are installed in the buildings of heating points.

In addition to the working pumps for heating and hot water, backup pumps must be present. The scheme of operation of all equipment in the central heating center is thought out in such a way that work does not stop even in emergency situations. In the event of a prolonged power outage or in the event of an emergency, residents will not be left without hot water and heating for a long time. In this case, emergency coolant supply lines will be activated.

Only qualified personnel are allowed to service equipment directly connected to heating networks.

The block-type central heating point will have reliable equipment. The reason and differences from the notorious TsTP? Thermal points of a western manufacturer almost do not have any spare elements. As a rule, such heat points are equipped with brazed heat exchangers, which is at least one and a half, or even two times cheaper than collapsible ones. But it is important to say that thermal central points of this type will have a relatively small mass and dimensions. ITP elements are cleaned chemically - in fact, this main reason, through which such heat exchangers can last for about a decade.

The main stages of designing the CHP

An integral part capital construction or reconstruction of the central heating point is its design. It refers to complex step-by-step actions, aimed at calculating and creating an accurate scheme of a heating point, obtaining the necessary approvals from the supply organization. Also, the design of the CHP includes consideration of all issues directly related to the configuration, operation and maintenance of equipment for the heating point.

On the initial stage During the design of the central heating station, the necessary information is collected, which is subsequently necessary for calculating the parameters of the equipment. To do this, the total length of pipeline communications is first established. This information is of particular value to the designer. In addition, the collection of information includes information about temperature regime building. This information is then needed for correct setting equipment.

When designing the CHP, it is necessary to indicate the safety measures for the operation of the equipment. This requires information about the structure of the entire building - the location of the premises, their area and other necessary information.

Coordination with the relevant authorities.

All documents that include the design of the CHP must be agreed with the municipal operating authorities. To quickly obtain a positive result, it is important to correctly draw up all project documentation. Since the implementation of the project and the construction of the central heating point is carried out only after the approval procedure is completed. Otherwise, a revision of the project is required.

The documentation for the design of the CHP, in addition to the project itself, should contain an explanatory note. It contains the necessary information and valuable instructions for the installers who will install the central heating unit. The explanatory note indicates the order of work, their sequence and the necessary tools for installation.

Drawing up an explanatory note is the final stage. This document completes the design of the CHP. Installers in their work must follow the instructions set out in the explanatory note.

With a careful approach to the development of the central heating project and the correct calculation of the necessary parameters and modes of operation, it is possible to achieve safe work equipment and its continuous flawless operation. Therefore, it is important to take into account not only the nominal values, but also the power reserve.

This is an extremely important aspect, since it is the power reserve that will keep the heat supply point in working order after an accident or a sudden overload. The normal functioning of the heat point directly depends on correctly drawn up documents.

Installation manual for central heating substation

Except himself drafting a central heating unit in project documentation must be located and explanatory note, which contains instructions for installers on how to use various technologies during the installation of a heating point, the sequence of work, type of tools, etc. is indicated in this document.

An explanatory note is a document that completes the design of the central heating substation, and which must be followed by installers during installation work. Strict adherence to the recommendations recorded in this important document will guarantee the normal functioning of the central heating equipment in accordance with the provided design characteristics.

The design of the CHP also provides for the development of instructions for the current and service maintenance of the CHP equipment. Careful development of this part of the project documentation allows you to extend the life of the equipment, as well as increase the safety of its use.

Central heating point - installation

During the installation of the central heating station, invariable certain stages of the work performed are carried out. The first step is to create a project. It takes into account the main features of the functioning of the CHP, such as the amount of serviced area, the distance for laying pipes, respectively, the minimum capacity of the future boiler house. After that, an in-depth analysis of the project and the supplied with it technical documentation to exclude all possible errors and inaccuracies to ensure the normal functionality of the mounted central heating stations long time. An estimate is drawn up, then everything is purchased necessary equipment. The next step is the installation of the heating main. It contains directly the laying of the pipeline and the installation of equipment.

What is a heat point?

Thermal point- this is a special room where a complex of technical devices is located, which are elements of thermal power plants. Thanks to these elements, it is ensured that power plants are connected to the heating network, workability, the ability to control different modes of heat consumption, regulation, transformation of the parameters of the heat carrier, as well as the distribution of the heat carrier according to the types of consumption.

Individual - only a heating point, unlike the central one, can also be mounted in a cottage. Please note that such heat points do not require the constant presence of service personnel. Again favorably differing from the central thermal point. And in general - ITP maintenance, in fact, consists only in checking for leaks. The heat exchanger of the heat point is able to independently clean itself from the scale that appears here - this is the merit of the lightning-fast temperature difference during the analysis of hot water.

S. Deineko

An individual heating point is the most important component of the heat supply systems of buildings. The regulation of heating and hot water systems, as well as the efficiency of using thermal energy, largely depends on its characteristics. Therefore, heat points are given great attention in the course of thermal modernization of buildings, large-scale projects of which are planned to be implemented in the near future in different regions Ukraine

Individual heating point (ITP) - a set of devices located in a separate room (usually in the basement), consisting of elements that ensure the connection of the heating system and hot water supply to the centralized heating network. The supply pipeline supplies the heat carrier to the building. With the help of the second return pipeline, the already cooled coolant from the system enters the boiler room.

The temperature schedule for the operation of the heating network determines the mode in which the heating point will operate in the future and what equipment must be installed in it. There are several temperature schedules for the operation of a heating network:

• 150/70°C;
• 130/70°C;
• 110/70°C;
• 95 (90)/70°C.

If the temperature of the coolant does not exceed 95 ° C, then it remains only to distribute it over the entire heating system. In this case, it is possible to use only a manifold with balancing valves for hydraulic balancing of circulation rings. If the temperature of the coolant exceeds 95 ° C, then such a coolant cannot be directly used in the heating system without its temperature regulation. This is precisely the important function of the heat point. At the same time, it is necessary that the temperature of the coolant in the heating system varies depending on the change in the outside air temperature.

In the heat points of the old sample (Fig. 1, 2), an elevator unit was used as a control device. This made it possible to significantly reduce the cost of the equipment, however, with the help of such a thermal converter, it was impossible to accurately control the temperature of the coolant, especially during transient operating modes of the system. The elevator unit provided only "high-quality" adjustment of the coolant, when the temperature in the heating system changes depending on the temperature of the coolant coming from the centralized heating network. This led to the fact that the “adjustment” of the air temperature in the premises was carried out by consumers using open window and with huge heat costs going nowhere.

Rice. one.
1 - supply pipeline; 2 - return pipeline; 3 - valves; 4 - water meter; 5 - mud collectors; 6 - manometers; 7 - thermometers; 8 - elevator; 9 - heaters of the heating system

Therefore, the minimum initial investment resulted in financial losses in the long run. Particularly low efficiency of the elevator units manifested itself with an increase in prices for thermal energy, as well as the impossibility of the centralized heating network to work according to the temperature or hydraulic schedule, for which the previously installed elevator units were designed.

Rice. 2. Elevator node of the "Soviet" era

The principle of operation of the elevator is to mix the heat carrier from the centralized heating network and water from the return pipeline of the heating system to a temperature corresponding to the standard for this system. This happens due to the principle of ejection when a nozzle of a certain diameter is used in the design of the elevator (Fig. 3). After the elevator unit, the mixed heat carrier is fed into the heating system of the building. The elevator simultaneously combines two devices: a circulation pump and a mixing device. The efficiency of mixing and circulation in the heating system is not affected by fluctuations thermal regime in thermal networks. All adjustments are correct selection nozzle diameter and ensure required coefficient mixing (normative coefficient 2.2). For the operation of the elevator unit, there is no need to supply electric current.

Rice. 3. circuit diagram elevator assembly designs

However, there are numerous shortcomings that negate all the simplicity and unpretentiousness of maintenance. this device. Fluctuations in the hydraulic regime in heating networks directly affect the efficiency of work. So, for normal mixing, the pressure drop in the supply and return pipelines must be maintained within 0.8 - 2 bar; the temperature at the outlet of the elevator cannot be adjusted and directly depends only on the change in the temperature of the heating network. In this case, if the temperature of the heat carrier coming from the boiler room does not correspond to the temperature schedule, then the temperature at the outlet of the elevator will be lower than necessary, which will directly affect the internal air temperature in the building.

Such devices are widely used in many types of buildings connected to a centralized heating network. However, at present they do not meet the requirements for energy saving, and therefore they must be replaced with modern individual heat points. Their cost is much higher and power supply is required for operation. But, at the same time, these devices are more economical - they can reduce energy consumption by 30 - 50%, which, taking into account the increase in prices for the coolant, will reduce the payback period to 5 - 7 years, and the service life of the ITP directly depends on the quality of the control elements used, materials and the level of training of technical personnel during its maintenance.

Modern ITP

Energy saving is achieved, in particular, by controlling the temperature of the heat carrier, taking into account the correction for changes in the outside air temperature. For these purposes, each heating point uses a set of equipment (Fig. 4) to ensure the necessary circulation in the heating system (circulation pumps) and control the temperature of the coolant (control valves with electric drives, controllers with temperature sensors).

Rice. 4. Schematic diagram of an individual heating point and the use of a controller, a control valve and a circulation pump

Most heating points also include a heat exchanger for connection to internal system hot water supply (DHW) with a circulation pump. The set of equipment depends on specific tasks and initial data. That is why, because of the different options design, as well as their compactness and portability, modern ITPs are called modular (Fig. 5).

Rice. 5. Modern modular individual heating point assembly

Consider the use of ITP in dependent and independent schemes for connecting a heating system to a centralized heating network.

In ITP with dependent accession heating systems to external heating networks, the circulation of the coolant in the heating circuit is supported by a circulation pump. The pump is controlled automatically from the controller or from the corresponding control unit. Automatic maintenance of the required temperature graph in the heating circuit is also carried out by an electronic controller. The controller acts on the control valve located on the supply pipeline on the side of the external heating network ("hot water"). A mixing jumper with a check valve is installed between the supply and return pipelines, due to which the mixture is mixed into the supply pipeline from the return line of the coolant, with lower temperature parameters(Fig. 6).

Rice. 6. Schematic diagram of a modular heating unit connected according to a dependent scheme:
1 - controller; 2 - two-way control valve with electric drive; 3 - coolant temperature sensors; 4 - outdoor air temperature sensor; 5 - pressure switch to protect pumps from dry running; 6 - filters; 7 - valves; 8 - thermometers; 9 - manometers; ten - circulation pumps heating systems; 11 - check valve; 12 - control unit for circulation pumps

In this scheme, the operation of the heating system depends on the pressures in the central heating network. Therefore, in many cases, it will be necessary to install differential pressure regulators, and, if necessary, pressure regulators “downstream” or “downstream” on the supply or return pipelines.

In an independent system to join external source heat exchanger is used (Fig. 7). The circulation of the coolant in the heating system is carried out by a circulation pump. The pump is controlled automatically by the controller or the appropriate control unit. Automatic maintenance of the required temperature graph in the heated circuit is also carried out by an electronic controller. The controller acts on an adjustable valve located on the supply pipeline on the side of the external heating network ("hot water").

Rice. 7. Schematic diagram of a modular heating unit connected according to an independent scheme:
1 - controller; 2 - two-way control valve with electric drive; 3 - coolant temperature sensors; 4 - outdoor air temperature sensor; 5 - pressure switch to protect pumps from dry running; 6 - filters; 7 - valves; 8 - thermometers; 9 - manometers; 10 - circulation pumps of the heating system; 11 - check valve; 12 - control unit for circulation pumps; 13 - heating system heat exchanger

The advantage of this scheme is that the heating circuit is independent of the hydraulic modes of the centralized heating network. Also, the heating system does not suffer from a mismatch in the quality of the incoming coolant coming from the central heating network (the presence of corrosion products, dirt, sand, etc.), as well as pressure drops in it. At the same time, the cost of capital investments when using an independent scheme is higher - due to the need for installation and subsequent maintenance of the heat exchanger.

As a rule, in modern systems collapsible plate heat exchangers are used (Fig. 8), which are quite easy to maintain and maintain: in case of loss of tightness or failure of one section, the heat exchanger can be disassembled and the section replaced. Also, if necessary, you can increase the power by increasing the number of heat exchanger plates. In addition, in independent systems, brazed non-separable heat exchangers are used.

Rice. 8. Heat exchangers for independent ITP connection systems

According to DBN V.2.5-39:2008 “Engineering equipment of buildings and structures. External networks and facilities. Heating network”, in general, it is prescribed to connect heating systems according to a dependent scheme. An independent scheme is prescribed for residential buildings with 12 or more floors and other consumers, if this is due to the hydraulic mode of the system or the customer's specification.

DHW from a heating point

The simplest and most common is the scheme with a single-stage parallel connection of hot water heaters (Fig. 9). They are connected to the same heating network as the building heating systems. Water, from outside water supply network supplied to the DHW heater. In it, it is heated by network water coming from the supply pipeline of the heating network.

Rice. 9. Scheme with dependent connection of the heating system to the heating network and one-stage parallel connection of the DHW heat exchanger

Cooled network water is supplied to the return pipeline of the heating network. After the hot water heater, the heated tap water is supplied to the DHW system. If the devices in this system are closed (for example, at night), then hot water is again supplied through the circulation pipe to the DHW heater.

This scheme with one-stage parallel connection of hot water heaters is recommended if the ratio maximum flow heat consumption for hot water supply of buildings to the maximum heat consumption for heating buildings less than 0.2 or more than 1.0. The circuit is used under normal temperature chart network water in thermal networks.

In addition, a two-stage water heating system is used in DHW system. In her in winter period cold tap water is first heated in the first stage heat exchanger (from 5 to 30 ˚С) with a heat carrier from the return pipeline of the heating system, and then, for the final heating of the water to the required temperature (60 ˚С), network water from the supply pipeline of the heating network is used (Fig. 10 ). The idea is to use waste heat energy from the return line from the heating system for heating. At the same time, the consumption of network water for heating water in the DHW system is reduced. During the summer period, heating occurs according to a single-stage scheme.

Rice. 10. Scheme of a heat point with dependent connection of the heating system to the heat network and two-stage water heating

equipment requirements

The most important characteristic of a modern heat point is the presence of heat energy metering devices, which is mandatory provided for by DBN V.2.5-39:2008 “Engineering equipment of buildings and structures. External networks and facilities. Heating network".

According to section 16 of these standards, equipment, fittings, control, management and automation devices should be placed in the heating point, with the help of which they carry out:

• temperature control of the coolant according to weather conditions;
• change and control of coolant parameters;
• accounting for thermal loads, coolant and condensate costs;
• regulation of coolant costs;
• protection local system from an emergency increase in the parameters of the coolant;
• post-treatment of the coolant;
• filling and replenishing heating systems;
• combined heat supply using thermal energy from alternative sources.

Connecting consumers to the heating network should be carried out according to schemes with minimal water consumption, as well as saving thermal energy through the installation of automatic regulators heat flow and limiting network water costs. It is not allowed to connect the heating system to the heating network through the elevator together with automatic regulator heat flow.

It is prescribed to use highly efficient heat exchangers with high thermal and technical operational characteristics and small dimensions. At the highest points of pipelines of heating points, air vents should be installed, and it is recommended to use automatic devices with check valves. At lower points, fittings with stopcocks for draining water and condensate.

At the input to the heating point on the supply pipeline, a sump should be installed, and strainers should be installed in front of pumps, heat exchangers, control valves and water meters. In addition, the mud filter must be installed on the return line in front of control devices and metering devices. Manometers should be provided on both sides of the filters.

To protect the DHW channels from scale, it is prescribed by the standards to use magnetic and ultrasonic water treatment devices. Forced ventilation, which needs to be equipped with an ITP, is calculated for a short-term effect and should provide a 10-fold exchange with an unorganized influx of fresh air through the entrance doors.

In order to avoid exceeding the noise level, the IHS is not allowed to be located next to, under or above the premises residential apartments, bedrooms and playrooms of kindergartens, etc. In addition, it is regulated that installed pumps must be with an acceptable low noise level.

The heating point should be equipped with automation equipment, heat engineering control, accounting and regulation devices, which are installed on site or at the control panel.

ITP automation should provide:

• regulation of the cost of thermal energy in the heating system and limiting the maximum consumption of network water at the consumer;
• the set temperature in the DHW system;
• maintaining static pressure in the systems of heat consumers with their independent connection;
• the specified pressure in the return pipeline or the required water pressure drop in the supply and return pipelines of heating networks;
• protection of heat consumption systems from high pressure and temperature;
• switching on the backup pump when the main working one is turned off, etc.

In addition, modern projects provide for the arrangement of remote access to the management of heating points. This allows you to organize centralized system dispatching and control the operation of heating and hot water systems. Suppliers of equipment for ITP are leading manufacturers of the corresponding heating equipment, for example: automation systems - Honeywell (USA), Siemens (Germany), Danfoss (Denmark); pumps - Grundfos (Denmark), Wilo (Germany); heat exchangers - Alfa Laval (Sweden), Gea (Germany), etc.

It should also be noted that modern ITPs include rather complex equipment that requires periodic maintenance and after-sales service, which consists, for example, in washing the mesh filters (at least 4 times a year), cleaning the heat exchangers (at least 1 time in 5 years), etc. In the absence of proper Maintenance the equipment of the heating point may become unusable or fail. Unfortunately, there are already examples of this in Ukraine.

At the same time, there are pitfalls in the design of everything ITP equipment. The fact is that under domestic conditions, the temperature in the supply pipeline centralized network often does not correspond to the standard, which indicates heat supply organization in specifications issued for design.

At the same time, the difference in official and real data can be quite significant (for example, in reality, a coolant is supplied with a temperature of no more than 100˚С instead of the indicated 150˚С, or there is an uneven temperature of the coolant from the side of the central heating by time of day), which, accordingly, affects on the choice of equipment, its subsequent performance and, as a result, on its cost. For this reason, it is recommended during the reconstruction of the IHS at the design stage to measure the actual parameters of heat supply at the facility and take them into account in the future when calculating and choosing equipment. At the same time, due to a possible discrepancy between the parameters, the equipment should be designed with a margin of 5-20%.

Implementation in practice

The first modern energy-efficient modular ITPs in Ukraine were installed in Kyiv in 2001-2005. within the framework of the implementation of the World Bank project "Energy saving in administrative and public buildings". A total of 1173 ITPs were installed. To date, due to previously unresolved issues of periodic qualified maintenance, about 200 of them have become unusable or require repair.

Video. Implemented project using an individual heat point in an apartment building, saving up to 30% of heat energy

Modernization of previously installed heat points with the organization of remote access to them is one of the points of the program "Thermosanation in budgetary institutions of Kyiv" with the involvement of loans from the Northern Environmental Finance Corporation (NEFCO) and grants from the Eastern Partnership Fund for Energy Efficiency and Environment (E5P ).

In addition, last year the World Bank announced the launch of a large-scale six-year project aimed at improving the energy efficiency of heat supply in 10 cities of Ukraine. The project budget is 382 million US dollars. They will be directed, in particular, to the installation of modular ITP. It is also planned to repair boiler houses, replace pipelines and install heat meters. It is planned that the project will help to reduce costs, improve the reliability of service and improve the overall quality of heat supplied to more than 3 million Ukrainians.

Modernization of the heating point is one of the conditions for improving the energy efficiency of the building as a whole. Currently, a number of Ukrainian banks are engaged in lending for the implementation of these projects, including within the framework of government programs. You can read more about this in the previous issue of our magazine in the article "Thermomodernization: what exactly and for what means".

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At district heating heating point may be local - individual(ITP) for heat-consuming systems of a specific building and group - central(CTP) for systems of a group of buildings. ITP is located in a special room of the building, the central heating station is most often a separate one-story building. The design of heat points is carried out in accordance with regulatory rules.
The role of a heat generator with an independent scheme for connecting heat-consuming systems to an external heating network is performed by a water heat exchanger.
Currently, so-called high-speed heat exchangers of various types are used. The shell-and-tube water heat exchanger consists of standard sections up to 4 m long. Each section is a steel pipe with a diameter of up to 300 mm, inside of which several brass tubes are placed. In an independent scheme of a heating or ventilation system, heating water from an external heat pipeline is passed through brass tubes, heated water is counterflowed in the annular space, in a hot water supply system, heated tap water is passed through the tubes, and heating water from the heating network is passed through the annulus. A more advanced and significantly more compact plate heat exchanger, assembled from a certain amount profiled steel plates. The heating and heated water flows between the plates countercurrently or crosswise. The length and number of sections of a shell-and-tube heat exchanger or the dimensions and number of plates in a plate heat exchanger is determined by a special thermal calculation.
For heating water in hot water supply systems, especially in an individual residential building, not a high-speed, but a capacitive water heater is more suitable. Its volume is determined based on the estimated number of simultaneously operating draw-off points and the estimated individual features water consumption in the house.
Common to all schemes is the use of a pump to artificially stimulate the movement of water in heat-consuming systems. In dependent circuits, the pump is placed at a thermal station, and it creates the pressure necessary for water circulation, both in external heat pipelines and in local heat-consuming systems.
A pump operating in closed rings of systems filled with water does not lift, but only moves water, creating a circulation, and therefore is called a circulation pump. Unlike a circulation pump, a pump in a water supply system moves water, raising it to the points of analysis. When used in this way, the pump is called a booster pump.
The circulation pump does not participate in the processes of filling and compensating for the loss (leakage) of water in the heating system. Filling occurs under the influence of pressure in the external heat pipes, in the water supply system or, if this pressure is not enough, using a special make-up pump.
Until recently, the circulation pump was included, as a rule, in the return line of the heating system to increase the service life of parts interacting with hot water. In general, to create water circulation in closed rings, the location of the circulation pump is indifferent. If it is necessary to slightly reduce the hydraulic pressure in the heat exchanger or boiler, the pump can also be included in the supply line of the heating system, if its design is designed to move hotter water. All modern pumps have this property and are most often installed after the heat generator (heat exchanger). The electrical power of the circulation pump is determined by the amount of water being moved and the pressure developed at the same time.
In engineering systems, as a rule, special non-foundation circulation pumps are used, which move a significant amount of water and develop a relatively small pressure. These are silent pumps connected in a single unit with electric motors and fixed directly on the pipes. The system includes two identical pumps operating alternately: when one of them is operating, the second is in reserve. Shut-off valves (valves or taps) before and after both pumps (active and inactive) are constantly open, especially if their automatic switching is provided. A check valve in the circuit prevents water from circulating through an idle pump. Easily installed foundationless pumps are sometimes installed one at a time in systems. At the same time, the reserve pump is stored in a warehouse.
The decrease in water temperature in the dependent circuit with mixing to the permissible level occurs when high-temperature water is mixed with return (cooled to a predetermined temperature) water of the local system. The coolant temperature is lowered by mixing return water from engineering systems using a mixing apparatus - a pump or a water jet elevator. pump house mixing plant has an advantage over the elevator. Its efficiency is higher; in case of emergency damage to external heat pipelines, it is possible, as with an independent connection scheme, to maintain water circulation in the systems. The mixing pump can be used in systems with significant hydraulic resistance, while when using an elevator, pressure losses in the heat-consuming system should be relatively small. Water jet elevators are widely used due to their trouble-free and silent operation.
Inner space all elements of heat-consuming systems (pipes, heating appliances, fittings, equipment, etc.) is filled with water. The volume of water during the operation of the systems undergoes changes: when the water temperature rises, it increases, and when the temperature drops, it decreases. Accordingly, the internal hydrostatic pressure. These changes should not affect the performance of the systems and, above all, should not lead to exceeding the ultimate strength of any of their elements. Therefore, the system is introduced additional element- expansion tank.
The expansion tank can be open, vented to the atmosphere, and closed, under variable, but strictly limited overpressure. The main purpose of the expansion tank is to receive the increase in the volume of water in the system, which is formed when it is heated. At the same time, a certain hydraulic pressure is maintained in the system. In addition, the tank is designed to replenish the loss of water in the system with a small leak and when its temperature drops, to signal the water level in the system and control the operation of make-up devices. Through an open tank, water is removed into the drain when the system overflows. In some cases, an open tank can serve as an air vent from the system.
An open expansion tank is placed above top point systems (at a distance of at least 1 m) in the attic or in the stairwell and covered with thermal insulation. Sometimes (for example, in the absence of an attic), an uninsulated tank is installed in a special insulated box (booth) on the roof of the building.
Modern design closed expansion tank is a steel cylindrical vessel, divided into two parts by a rubber membrane. One part is designed for system water, the second is factory filled with an inert gas (usually nitrogen) under pressure. The tank can be installed directly on the floor of a boiler room or heating point, as well as fixed on the wall (for example, in cramped conditions in the room).
In large heat-consuming systems of a group of buildings expansion tanks are not installed, and the hydraulic pressure is regulated by permanently operating booster pumps. These pumps also compensate for water losses that normally occur through leaky pipe connections, fittings, appliances, and other system locations.
In addition to the equipment discussed above, devices are placed in the boiler room or heating point. automatic regulation, shut-off and control valves and instrumentation, with the help of which the current operation of the heat supply system is ensured. The fittings used in this case, as well as the material and methods for laying heat pipes, are discussed in the "Heating of buildings" section.

Heatpoints are called automated complexes, transferring thermal energy between external and internal networks. They consist of thermal equipment, as well as measuring and controlling devices.

Heat points perform the following functions:

1. Distribute thermal energy among consumption sources;

2. Adjust the parameters of the thermal carrier;

3. Control and interrupt heat supply processes;

4. Change the types of thermal media;

5. Protect systems after increasing the allowable volumes of parameters;

6. Record the costs of heat carriers.

Types of heat points

Heat points are central and individual. In the individual, abbreviated: ITP includes technical devices, intended for connection of systems of heating, hot water supply, ventilation in buildings.

Purpose of heat points

The purpose of the CHP, that is, the central heating point, is to connect, transfer and distribute heat energy to several buildings. For built-in and other premises located in the same building, for example, shops, offices, parking lots, cafes, it is required to establish their own individual heat point.

What are heat points made of?

Old-style ITPs have elevator units where the water supply is mixed with heat consumption. In them the consumed thermal energy is not regulated and not economically spent.

Modern automated individual heating points have a jumper between the supply and return pipelines. Such equipment has a more reliable design due to the double pump installed to the jumper. A control valve, an electric drive and a controller, which is called a weather regulator, are mounted to the supply pipeline. Also, the coolant of the updated automatic ITP is equipped with temperature sensors and outside air.

Why are heat points needed?

The automated system controls the temperature in the coolant for supply to the room. It also performs the function of regulating temperature indicators that correspond to the schedule and relative to the outside air. This makes it possible to exclude overexpenditure of heat energy that heats the building, which is important for the autumn-spring period.

The automatic regulation of all modern ITPs meets the high requirements related to reliability and energy savings, as well as their reliable ball valve. shut-off valves and twin pumps.

Thus, in an automated individual heat point in buildings and premises, heat energy is saved up to thirty-five percent. This equipment is a complex technical complex that requires competent design, installation, adjustment and maintenance, which only professional experienced specialists can do.