To meet the heating needs of residents of high-rise buildings, centralized heating systems are well suited. District heating involves the transfer of heated coolant from the boiler room through a network connected to a multi-story building insulated pipes. Centralized boiler houses have sufficient efficiency and make it possible to combine low operating costs and acceptable heat supply efficiency indicators multi-storey buildings.

But in order for the efficiency of the central heating supply to be at the proper level, the heating circuit in apartment building compiled by professionals in their field - heating engineers. The fundamental principles by which a home heating scheme is designed are to achieve maximum efficiency heating with minimal resource consumption.

Contractors and builders are interested in providing apartment owners with a reliable and efficient heating system, so the heating scheme multi-storey building is developed taking into account the current cost of heat resources, the thermal output of heating devices, their energy efficiency and the optimal sequence of connection to the circuit.

Any heating scheme apartment building is radically different from the method and sequence of connecting heating appliances in private homes. It has a more complex structure and guarantees that even in severe frosts, residents of apartments on all floors will be provided with heat and will not encounter such troubles as airy radiators, cold spots, leaks, water hammer and frozen walls.

A well-designed heating system for an apartment building, the scheme for which is developed individually, guarantees that optimal conditions will be maintained inside the apartments.

In particular, the temperature in winter will be at 20-22 degrees, and the relative humidity will be about 40%. To achieve such indicators, it is important not only the basic heating scheme, but also high-quality insulation of apartments, which prevents heat from escaping into the street through cracks in the walls, roof and window openings.

Scheme development

On initial stage Heating engineers work on the development of a heating scheme, carry out a series of calculations and achieve the same efficiency indicators of the heating system on all floors of the building. They draw up an axonometric diagram of the heating system, which is subsequently used by installers. Calculations carried out correctly by specialists guarantee that the designed heating system will be characterized by optimal pressure coolant that will not lead to water hammer and operational interruptions.

Inclusion of an elevator unit in the heating scheme

The central heating scheme for an apartment building, prepared by heating engineers, assumes that the radiators located in the apartment will receive coolant at an acceptable temperature. However, at the exit from the boiler room, the water temperature can exceed 100 degrees. To achieve coolant cooling by mixing cold water, the return and supply lines are connected by an elevator unit.

A reasonable heating elevator design allows the unit to perform a number of functions. The main function of the unit is direct participation in the heat exchange process, since hot coolant, entering it, is dosed and mixed with the injected coolant from the return. As a result, the unit allows you to achieve optimal results in matters of mixing hot coolant from the boiler room and cooled water from the return. After this, the prepared coolant optimal temperature delivered to apartments.

Design features of the circuit

An effective heating system in an apartment building, the design of which requires competent calculations, also implies the use of many other structural elements. Right after elevator unit Special valves are integrated into the heating system to regulate the flow of coolant. They help control the heating process of the entire house and individual entrances, but only employees of service utility companies have access to these devices.

In the heating circuit, in addition to thermal valves, more sensitive devices are used to regulate and adjust the heating.

We are talking about devices that increase the performance of the heating system and allow for maximum automation of the home heating process. These are devices such as collectors, thermostats, automation, heat meters, etc.

Pipeline layout

While heating engineers are discussing optimal scheme heating a house with central heating, the issue of proper piping in the house is raised. In modern multi-storey buildings The heating wiring diagram can be implemented according to one of two possible patterns.

Single pipe connection

The first template provides for a single-pipe connection with upper or lower wiring and is the most used option when equipping heating appliances in multi-storey buildings. At the same time, the location of the return and supply is not strictly regulated and may vary depending on external conditions– the region in which the house was built, its layout, number of floors and design. The direct direction of movement of the coolant along the risers can also change. There is an option for the heated water to move in the direction from bottom to top or from top to bottom.

It is distinguished by simple installation, affordable cost, reliability and long service life, but it also has a number of shortcomings. Among them are the loss of coolant temperature while moving along the circuit and low efficiency indicators.

In practice, various devices can be used to compensate for the disadvantages that characterize a single-pipe heating scheme beam system it may become effective solution Problems. It is designed to use a collector that helps regulate temperature conditions.

Two-pipe connection

A two-pipe connection is the second version of the template. A two-pipe heating scheme for a five-story building (as an example) is devoid of the disadvantages described above and has a completely different design than a single-pipe one. When implementing this scheme, the heated water from the radiator does not move to the next heating device in the circuit, but immediately enters the check valve and is sent to the boiler room for heating. Thus, it is possible to avoid loss of temperature of the coolant circulating along the contour of a multi-story building.

The complexity of the connection, which heating radiators in an apartment require, makes the implementation of this type of heating a long and labor-intensive process, requiring large material and physical costs. Maintenance of the system is also not cheap, but the high cost is offset by high-quality and uniform heating of the house on all floors.

Among the advantages provided by the two-pipe scheme for connecting heating batteries, it is worth highlighting the possibility of installation on each radiator in the circuit special device– heat meter. It allows you to control the temperature of the coolant in the battery, and by using it in the apartment, the owner will achieve significant results in terms of saving money on utility bills, because he will be able to independently regulate the heating if necessary.

Connecting radiators to the system

After the pipe routing method has been chosen, heating batteries are connected to the circuit; the circuit also regulates the connection order and the type of radiators used. At this stage, the heating scheme for a three-story building will not differ radically from the heating scheme for a high-rise building.

Since the central heating system is characterized by stable operation, versatility and has an acceptable ratio of temperature and pressure of the coolant, the connection diagram for heating radiators in an apartment may involve the use of batteries made of various metals. In multi-storey buildings, cast iron, bimetallic, aluminum and steel can be used, which will complement the central heating system and provide apartment owners with the opportunity to live in comfortable temperature conditions.

The final stage of work

At the last stage, the radiators are connected, and their internal diameter and volume of sections are calculated taking into account the type of supply and cooling rate of the coolant. Because the central heating represents complex system interconnected components, it is quite difficult to replace radiators or repair jumpers in a particular apartment, because dismantling any element can cause interruptions in the heating supply of the entire house.

Therefore, apartment owners who use central heating for heating are not recommended to independently carry out any manipulations with radiators and the piping system, since the slightest intervention can turn into a serious problem.

In general, a well-designed, efficient heating scheme for a residential apartment building allows one to achieve good performance in matters of heat supply and heating.

BTP - Block heating point - 1var. - this is a compact thermomechanical installation of complete factory readiness, located (housed) in a block container, which is an all-metal load-bearing frame with fences made of sandwich panels.

IHP in a block container is used to connect heating, ventilation, hot water supply and technological heat-using installations of an entire building or part of it.

BTP - Block heating point - 2var. It is manufactured in a factory and supplied for installation in the form of ready-made blocks. May consist of one or more blocks. The block equipment is mounted very compactly, usually on one frame. Typically used when it is necessary to save space, in cramped conditions. Based on the nature and number of connected consumers, the BTP can be classified as either an ITP or a central heating substation. Supply ITP equipment according to specification - heat exchangers, pumps, automation, shut-off and control valves, pipelines, etc. - supplied in separate items.

BTP is a fully factory-ready product, which makes it possible to connect reconstructed or newly constructed facilities to heating networks in the shortest possible time. The compactness of the BTP helps to minimize the equipment placement area. Individual approach to the design and installation of block individual heating units allow us to take into account all the client’s wishes and translate them into the finished product. guarantee for the BTP and all equipment from one manufacturer, one service partner for the entire BTP. ease of installation of the BTP at the installation site. Manufacturing and testing of BTP in the factory - quality. It is also worth noting that for mass, block-by-block development or extensive reconstruction of heating points, the use of BTP is preferable compared to ITP. Since in this case it is necessary to install a significant number of heating points in a short period of time. Such large-scale projects can be implemented in the shortest possible time using only standard factory-ready BTP.

ITP (assembly) - installation possibility heating point in cramped conditions, there is no need to transport the assembled heating unit. Transport of individual components only. The delivery time of equipment is significantly shorter than that of BTP. The cost is lower. - BTP - the need to transport the BTP to the installation site (transportation costs), the dimensions of the openings for carrying the BTP impose restrictions on the overall dimensions of the BTP. Delivery time from 4 weeks. Price.

ITP - guarantee for various components of a heating point from different manufacturers; several different service partners for various equipment included in the heating unit; higher cost installation work, timing installation work, T. e. when installing ITPs, they are taken into account individual characteristics specific premises and “creative” solutions of a specific performer of work, which, on the one hand, simplifies the organization of the process, and on the other, can reduce the quality. After all weld, bending a pipeline, etc. in a “location” is much more difficult to perform efficiently than in a factory environment.

Multi-storey buildings, high-rise buildings, administrative buildings and many different consumers provide heat from combined heat and power plants or powerful boiler houses. Even relatively simple autonomous system a private house is sometimes difficult to adjust, especially if errors were made during design or installation. But the heating system of a large boiler house or thermal power plant is incomparably more complex. There are many branches leaving the main pipe, and each consumer has different pressure in the heating pipes and the amount of heat consumed.

Pipe lengths vary and the system must be designed so that the furthest consumer receives sufficient heat. It becomes clear why there is coolant pressure in the heating system. Pressure moves water along the heating circuit, i.e. created by the central heating line, it plays the role of a circulation pump. The heating system must not allow imbalance when the heat consumption of any consumer changes.

In addition, the efficiency of heat supply should not be affected by the branching of the system. In order for a complex centralized heating system to operate stably, it is necessary to install either an elevator unit or automated unit control the heating system to eliminate mutual influence between them.

Heating engineers recommend using one of three temperature conditions boiler room work. These modes were initially calculated theoretically and underwent many years of testing. practical use. They ensure heat transfer with minimal losses over long distances with maximum efficiency.

Thermal conditions of a boiler room can be defined as the ratio of the supply temperature to the return temperature:

In real conditions, the mode is selected for each specific region based on the winter air temperature. It should be noted that to use for space heating high temperatures, especially 150 and 130 degrees are not allowed to avoid burns and serious consequences in case of depressurization.

The water temperature exceeds the boiling point and it does not boil in the pipelines thanks to high blood pressure. This means that it is necessary to reduce the temperature and pressure and ensure the necessary heat extraction for a particular building. This task is assigned to the elevator unit of the heating system - special heating equipment located in the heat distribution point.

Design and principle of operation of a heating elevator

At the entry point of the heating network pipeline, usually in the basement, a node that connects the supply and return pipes catches your eye. This is an elevator - a mixing unit for heating a house. The elevator is manufactured in the form of cast iron or steel structure equipped with three flanges. This is an ordinary heating elevator; its operating principle is based on the laws of physics. Inside the elevator there is a nozzle, a receiving chamber, a mixing neck and a diffuser. The receiving chamber is connected to the “return” using a flange.

Superheated water enters the elevator inlet and passes into the nozzle. Due to the narrowing of the nozzle, the flow speed increases and the pressure decreases (Bernoulli's law). Water from the return line is sucked into the area of ​​low pressure and mixed in the mixing chamber of the elevator. The water reduces the temperature to the desired level and at the same time the pressure decreases. The elevator works simultaneously as a mixer. This is briefly the principle of operation of an elevator in the heating system of a building or structure.

Thermal unit diagram

Adjustment of the coolant supply is carried out by the elevator heating units of the house. Elevator – the main element thermal unit, needs strapping. The control equipment is sensitive to contamination, so the piping includes dirt filters that are connected to the “supply” and “return”.

The elevator harness includes:

• mud filters;
• pressure gauges (inlet and outlet);
• temperature sensors (thermometers at the elevator inlet, outlet and return);
• valves (for preventive or emergency work).

This is the simplest circuit option for adjusting the temperature of the coolant, but it is often used as the basic device of a thermal unit. Base node elevator heating any buildings and structures, provides regulation of the temperature and pressure of the coolant in the circuit.

The advantages of using it for heating large objects, houses and high-rise buildings:

But while there are undeniable advantages of using an elevator for heating systems, the disadvantages of using this device should also be noted:

Elevator with automatic adjustment

Currently, elevator designs have been created in which the nozzle cross-section can be changed using electronic adjustment. This elevator has a mechanism that moves the throttle needle. It changes the lumen of the nozzle and as a result the coolant flow changes. Changing the lumen changes the speed of water movement. As a result, the mixing ratio of hot water and water from the “return” changes, thereby achieving a change in the temperature of the coolant in the “supply”. Now it’s clear why water pressure is needed in a heating system.

The elevator regulates the flow and pressure of the coolant, and its pressure drives the flow in the heating circuit.

Main malfunctions of the elevator unit

Even such a simple device as an elevator unit may not work correctly. Malfunctions can be determined by analyzing pressure gauge readings at control points of the elevator unit:

Switchgears

The elevator unit with all its piping can be thought of as a pressure circulation pump, which supplies coolant to the heating system under a certain pressure.

If the facility has several floors and consumers, then the most correct solution is to distribute the total coolant flow to each consumer.

To solve such problems, a comb is designed for the heating system, which has another name - a collector. This device can be represented as a container. The coolant flows into the container from the elevator outlet, which then flows out through several outlets, with the same pressure.

Therefore, the comb distribution system heating allows switching off, adjusting, and repairing individual consumers of the facility without stopping the operation of the heating circuit. The presence of a collector eliminates the mutual influence of the heating system branches. In this case, the pressure in corresponds to the pressure at the elevator outlet.

Three way valve

If it is necessary to divide the coolant flow between two consumers, a three-way heating valve is used, which can operate in two modes:

A three-way valve is installed in those places in the heating circuit where it may be necessary to divide or completely shut off the flow of water. The tap material is steel, cast iron or brass. Inside the faucet there is a shut-off device, which can be ball, cylindrical or conical. The tap resembles a tee and, depending on the connection to the heating system, can work as a mixer. Mixing proportions can be varied within wide limits.

The ball valve is mainly used for:

1. adjusting the temperature of heated floors;
2. adjusting battery temperature;
3. distribution of coolant in two directions.

There are two types of three-way valves - shut-off and control valves. In principle, they are almost equivalent, but with three-way shut-off valves it is more difficult to regulate the temperature smoothly.

Residents of city apartments are usually not interested in how the heating works in their home. The need for such knowledge may arise when the owners want to increase the comfort in the house or improve the aesthetic appearance of engineering equipment. For those who are planning to start a renovation, we will briefly tell you about the heating systems of an apartment building.

Types of heating systems for apartment buildings

Depending on the structure, characteristics of the coolant and piping layouts, heating of an apartment building is divided into the following types:

By location of the heat source

• Apartment system heating, in which a gas boiler is installed in the kitchen or separate room. Some inconveniences and investments in equipment are more than compensated by the ability to turn on and regulate heating at your discretion, as well as low operating costs due to the absence of losses in heating mains. If you have your own boiler, there are practically no restrictions on system reconstruction. If, for example, the owners wish to replace the batteries with warm water floors, there are no technical obstacles to this.
• Individual heating, in which one house or residential complex has its own boiler room. Such solutions are found both in the old housing stock (stokers) and in new luxury housing, where the community of residents decides for itself when to start heating season.
• Central heating in an apartment building it is most common in standard housing.

The installation of central heating in an apartment building, heat transfer from the thermal power plant is carried out through a local heating point.

According to coolant characteristics

• Water heating, water is used as a coolant. In modern housing with apartment or individual heating There are economical low-temperature (low-potential) systems where the coolant temperature does not exceed 65 ºС. But in most cases and in all typical houses, the coolant has design temperature within 85-105 ºС.
• Steam heating apartments in an apartment building (water vapor circulates in the system) has a number significant shortcomings, has not been used in new houses for a long time; old housing stock is being transferred to water systems everywhere.

According to the wiring diagram

Basic heating schemes in apartment buildings:

• Single-pipe - both the supply and return of coolant to the heating devices are carried out through one line. Such a system is found in “Stalin” and “Khrushchev” buildings. It has a serious drawback: the radiators are located in series and, due to the cooling of the coolant in them, the heating temperature of the batteries drops as they move away from the heating station. In order to maintain heat transfer, the number of sections increases as the coolant moves. In a pure one-pipe circuit, it is impossible to install control devices. It is not recommended to change the configuration of the pipes or install radiators of a different type and size, otherwise the operation of the system may be seriously disrupted.
• “Leningradka” is an improved version of the single-pipe system, which, thanks to the connection of heating devices via a bypass, reduces their mutual influence. You can install regulating (not automatic) devices on radiators, or replace the radiator with a different type, but of similar capacity and power.

• The two-pipe heating scheme for an apartment building became widely used in Brezhnevkas and is still popular to this day. The supply and return lines are separated, so the coolant at the entrances to all apartments and radiators has almost the same temperature; replacing radiators with a different type and even volume does not have a significant effect on the operation of other devices. Control devices, including automatic ones, can be installed on batteries.

On the left is an improved version of the single-pipe circuit (analogous to the Leningrad circuit), on the right is the two-pipe version. The latter provides more comfortable conditions, precise regulation and provides greater opportunities for replacing the radiator

• The beam scheme is used in modern atypical housing. The devices are connected in parallel, their mutual influence is minimal. The wiring is usually done in the floor, which allows you to free the walls from pipes. When installing control devices, including automatic ones, accurate dosing of the amount of heat throughout the rooms is ensured. It is technically possible to have both partial and complete replacement heating systems in an apartment building with a radial circuit within the apartment with a significant change in its configuration.

With a radial scheme, the supply and return lines enter the apartment, and the wiring is carried out in parallel with separate circuits through the collector. Pipes are usually placed in the floor, radiators are neatly and discreetly connected from below

Replacement, relocation and selection of radiators in an apartment building

Let's make a reservation that any changes in apartment heating in an apartment building must be agreed upon with executive bodies and operating organizations.

We have already mentioned that the fundamental possibility of replacing and moving radiators is determined by the circuit. How to choose the right radiator for an apartment building? Please note the following:

• First of all, the radiator must withstand pressure, which is higher in an apartment building than in a private one. The greater the number of floors, the higher the test pressure can be, it can reach 10 atm, and in high-rise buildings even 15 atm. The exact value can be obtained from your local operating service. Not all radiators sold on the market have the appropriate characteristics. A significant part of aluminum and many steel radiators are not suitable for an apartment building.
• Is it possible and how much to change? thermal power radiator, depends on the circuit used. But in any case, the heat transfer of the device must be calculated. One typical section of a cast iron battery has a heat transfer of 0.16 kW at a coolant temperature of 85 ºС. Multiplying the number of sections by this value, we obtain the thermal power of the existing battery. Characteristics of the new heating device can be found in its technical data sheet. Panel radiators are not assembled from sections and have fixed dimensions and power.

Averaged heat transfer data various types radiators may vary depending on the specific model

• The material also matters. Central heating in an apartment building is often characterized by low quality coolant. Traditional ones are the least sensitive to contamination. cast iron batteries, aluminum react the worst to aggressive environments. Bimetallic radiators performed well.

Installation of a heat meter

A heat meter can be installed without problems using a radial wiring diagram in an apartment. As a rule, modern houses already have metering devices. As for the existing housing stock with standard systems heating, this possibility is not always available. This depends on the specific piping layout and configuration; advice can be obtained from your local operating organization.

An apartment heat meter can be installed with a radial and two-pipe wiring diagram, if there is a separate branch to the apartment

If it is not possible to install a meter throughout the entire apartment, you can place compact heat meters on each of the radiators.

An alternative to an apartment meter is heat metering devices placed directly on each radiator

Please note that the installation of metering devices, replacement of radiators, and other changes to the heating system in an apartment building require prior approval and must be carried out by specialists representing an organization licensed to carry out the relevant work.

Video: how to supply heating in an apartment building

S. Deineko

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

An individual heating point (IHP) is a set of devices located in a separate room (usually in basement), consisting of elements that ensure the connection of the heating and hot water supply system to the centralized heating network. The supply pipeline supplies coolant to the building. Using the second return pipeline, the already cooled coolant from the system enters the boiler room.

The temperature schedule of the heating network operation determines the mode in which the heating point will operate in the future and what equipment needs to be installed in it. There are several temperature graphs of the heating network:

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

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

In old-style heating points (Fig. 1, 2), an elevator unit was used as a regulating device. This made it possible to significantly reduce the cost of equipment, but with the help of such a TP it was impossible to accurately regulate the temperature of the coolant, especially during transient operating conditions of the system. The elevator unit provided only “qualitative” regulation 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 an open window and with huge heat costs that went to nowhere.

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

Therefore, the minimal initial investment resulted in financial losses in the long term. Particularly low efficiency of elevator units manifested itself with rising prices for thermal energy, as well as the impossibility of operating a centralized heating network based on temperature or hydraulic chart, for which the previously installed elevator units were designed.

Rice. 2. Elevator unit of the “Soviet” era

The principle of operation of the elevator is to mix the coolant 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 occurs due to the ejection principle when using a nozzle of a certain diameter in the elevator design (Fig. 3). After the elevator unit, the mixed coolant is supplied to the building’s heating system. The elevator combines two devices at the same time: 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 heating networks. All adjustment is correct selection nozzle diameter and ensuring the required mixing coefficient (standard coefficient 2.2). There is no need to supply electric current to operate the elevator unit.

Rice. 3. Schematic diagram elevator unit designs

However, there are numerous disadvantages that negate the simplicity and unpretentiousness of servicing this device. Operating efficiency is directly affected by fluctuations in the hydraulic regime in heating networks. Thus, for normal mixing, the pressure difference in the supply and return pipelines must be maintained within 0.8 - 2 bar; the temperature at the elevator exit cannot be adjusted and directly depends only on changes in the temperature of the heating network. In this case, if the temperature of the coolant coming from the boiler room does not correspond to the temperature schedule, then the temperature at the exit from 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 energy saving requirements, and therefore must be replaced with modern individual heating units. Their cost is much higher and they require power supply to operate. But, at the same time, these devices are more economical - they can reduce energy consumption by 30 - 50%, which, taking into account rising prices for coolant, will reduce the payback period to 5 - 7 years, and the service life of the ITP directly depends on the quality of the controls used, materials and level of training of technical personnel when servicing it.

Modern ITP

Energy saving is achieved, in particular, by regulating the temperature of the coolant, taking into account corrections for changes in outside air temperature. For these purposes, a set of equipment is used at each heating point (Fig. 4) to ensure the necessary circulation in the heating system (circulation pumps) and regulate 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, control valve and 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 the specific tasks and initial data. That is why, due to various possible options design, as well as their compactness and transportability, modern ITPs are called modular (Fig. 5).

Rice. 5. Modern modular individual heating unit assembled

Let's consider the use of IHP in dependent and independent schemes for connecting a heating system to a centralized heating network.

In ITP with dependent connection heating systems to external heating networks, the circulation of the coolant in the heating circuit is maintained by a circulation pump. The pump is controlled automatically from the controller or from the corresponding control unit. Automatic maintenance of the required temperature schedule in the heating circuit is also carried out by an electronic regulator. 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 coolant with lower temperature parameters is mixed into the supply pipeline from the return line (Fig. 6).

Rice. 6. Schematic diagram of a modular heating point connected according to a dependent circuit:
1 - controller; 2 - two-way control valve with electric drive; 3 - coolant temperature sensors; 4 - outside air temperature sensor; 5 - pressure switch to protect pumps from dry running; 6 - filters; 7 - valves; 8 - thermometers; 9 - pressure gauges; 10 - circulation pumps of the heating system; 11 - check valve; 12 - control unit 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 “after” or “before” on the supply or return pipelines.

In an independent system, a heat exchanger is used to connect to an external heat source (Fig. 7). The circulation of the coolant in the heating system is carried out by a circulation pump. The pump is controlled automatically by a controller or a corresponding control unit. Automatic maintenance of the required temperature schedule in the heated circuit is also carried out by an electronic regulator. The controller influences 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 circuit:
1 - controller; 2 - two-way control valve with electric drive; 3 - coolant temperature sensors; 4 - outside air temperature sensor; 5 - pressure switch to protect pumps from dry running; 6 - filters; 7 - valves; 8 - thermometers; 9 - pressure gauges; 10 - circulation pumps of the heating system; 11 - check valve; 12 - circulation pump control unit; 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 inconsistencies in the quality of the incoming coolant coming from the central heating network (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 ones are used plate heat exchangers(Fig. 8), which are quite easy to maintain and repairable: if there is a 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. Besides, in independent systems They use brazed non-separable heat exchangers.

Rice. 8. Heat exchangers for independent IHP connection systems

According to DBN V.2.5-39:2008 “Engineering equipment of buildings and structures. External networks and structures. Heating network", in general, it is prescribed to connect heating systems according to a dependent circuit. Independent circuit prescribed for residential buildings with 12 or more floors and other consumers, if this is due to the hydraulic operating mode of the system or the technical specifications of the customer.

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 heating systems of buildings. Water from the external water supply network is supplied to the DHW heater. It heats up in it 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 single-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 is heated tap water supplied to the DHW system. If the devices in this system are closed (for example, at night), then hot water through the circulation pipeline it is again supplied to the DHW heater.

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

In addition, a two-stage water heating system is used in DHW system. In it in winter period cold tap water is first heated in the first stage heat exchanger (from 5 to 30 ˚C) with coolant from the return pipeline of the heating system, and then for final heating of the water to the required temperature (60 ˚C) network water is used from the supply pipeline of the heating network (Fig. 10 ). The idea is to use waste heat 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. IN summer period heating occurs according to a single-stage scheme.

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

equipment requirements

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

According to section 16 of these standards, equipment, fittings, monitoring, control and automation devices must be placed at the heating point, with the help of which the following is carried out:

• regulation of coolant temperature according to weather conditions;
• changing and monitoring coolant parameters;
• accounting for heat loads, coolant and condensate costs;
• regulation of coolant costs;
• protection local system from an emergency increase in coolant parameters;
• coolant tertiary purification;
• filling and recharging 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 an elevator together with automatic regulator heat flow.

It is prescribed to use highly efficient heat exchangers with high thermal and performance characteristics and small dimensions. Air vents should be installed at the highest points of pipelines of heating points, and it is recommended to use automatic devices With check valves. At the lowest points, fittings with shut-off valves should be installed to drain water and condensate.

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

To protect hot water channels from scale, regulations require the use of magnetic and ultrasonic water treatment devices. Forced ventilation, which needs to be installed in the ITP, is designed for short-term action and should provide a 10-fold exchange with an unorganized influx of fresh air through the entrance doors.

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

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

Automation of ITP should provide:

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

Besides, modern projects provide for the arrangement of remote access to the management of heating points. This allows you to organize centralized system dispatch and monitor the operation of heating and hot water systems. Suppliers of equipment for ITP are leading manufacturing companies 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 is also worth noting that modern ITP include quite complex equipment that requires periodic technical and service, which consists, for example, in washing the strainers (at least 4 times a year), cleaning the heat exchangers (at least once every 5 years), etc. In the absence of proper Maintenance The heating point equipment may become unusable or fail. Unfortunately, there are already examples of this in Ukraine.

At the same time, there are pitfalls when designing all ITP equipment. The fact is that in domestic conditions, the temperature in the supply pipeline of a centralized network often does not correspond to the standardized one, which is indicated by the heat supply organization in technical conditions issued for design.

At the same time, the difference in official and real data can be quite significant (for example, in reality, coolant is supplied with a temperature of no more than 100˚C instead of the indicated 150˚C, or there is unevenness in the temperature of the coolant from the central heating system depending on the time of day), which, accordingly, affects on the choice of equipment, its subsequent operational efficiency and, ultimately, its cost. For this reason, it is recommended that when reconstructing IHP at the design stage, measure the actual heat supply parameters at the site and take them into account in the future when making calculations and selecting 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 ITP in Ukraine were installed in Kyiv in the period 2001 - 2005. within the framework 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 heating point in an apartment building, saving up to 30% of heat energy

Modernization of previously installed heating points with the organization of remote access to them is one of the points of the “Thermal Sanitation in Budgetary Institutions in Kiev” program with the attraction of loan funds 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 aimed, in particular, at the installation of modular ITP. It is also planned to repair boiler houses, replace pipelines and install heat energy meters. The project is expected to help reduce costs, increase service reliability and improve the overall quality of heat supplied to over 3 million Ukrainians.

Modernization of a heating unit is one of the conditions for increasing the energy efficiency of the building as a whole. Currently, a number of Ukrainian banks are involved 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 “Thermal modernization: what exactly and for what means”.

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