Types of heating elevators

Oddly enough, not even all plumbers servicing heating elevators know about heating elevators. multi-story houses. IN best case scenario, they have an idea that this device is installed in the system. But how it works and what function it performs is not known to everyone, not to mention ordinary people.

Therefore, let's eliminate this gap in knowledge about heating systems and examine this device in more detail.

What is an elevator?

In simple terms, an elevator is a special device related to heating equipment and performing the function of an injection or water-jet pump. No more, no less.

Its main task is to increase the pressure inside the heating system. That is, increase the pumping of coolant through the network, which will lead to an increase in its volume. To make it clearer, let's give a simple example. 5-6 cubic meters of water are taken from the supply water supply as a coolant, and 12-13 cubic meters enter the system where the apartments of the house are located.

How is this possible? And what causes the increase in coolant volume? This phenomenon is based on certain laws of physics. Let's start with the fact that if an elevator is installed in the heating system, it means that this system is connected to central heating networks, through which hot water moves under pressure from a large boiler house or thermal power plant.

So the temperature of the water inside the pipeline, especially in extreme cold, reaches +150 C. But how can this be? After all, the boiling point of water is +100 C. This is where one of the laws of physics comes into force. At this temperature, water boils if it is in an open container where there is no pressure. But in the pipeline, water moves under pressure, which is created by the operation of the supply pumps. That's why it doesn't boil.

  • Firstly, cast iron does not like large temperature changes. And if cast iron radiators are installed in apartments, they may fail. It's good if they just leak. But they can be torn apart, because under the influence high temperatures cast iron becomes as brittle as glass.
  • Secondly, at this temperature of metal heating elements it will not be difficult to get burned.
  • Thirdly, for piping heating devices they are now often used plastic pipes. And the maximum that they can withstand is a temperature of +90 C (besides, with such figures, manufacturers guarantee 1 year of operation). This means they will simply melt.

Therefore, the coolant must be cooled. This is where an elevator is needed.

What is the elevator unit used for?

Elevator unit connection diagram

So we come to the question of why elevators are needed in the heating system?

These devices are designed to lower the temperature of the supplied water to the required temperature. And already cooled, it is supplied to the apartment heating system. That is, the coolant is cooled in the elevator. How?

Everything is quite simple. This device consists of a chamber where hot superheated water and water coming from the return circuit of the heating system are mixed. That is, the coolant from the boiler room is mixed with the coolant from the return line of the same house. This way, without taking a lot of hot water, you can obtain the required volume of coolant at the required temperature.

Are we losing temperature? Yes, we are losing, and the obvious cannot be denied here. But the coolant is supplied through a nozzle, which is much smaller than the diameter of the pipe supplying hot water to the house. The speed in this nozzle is so high due to the pressure inside the pipeline that the coolant is very quickly distributed throughout all risers. Therefore, no matter where the apartment is located, close or far from the distribution center, the temperature in the heating devices will be the same. Uniform distribution is thus ensured 100%.

Do you know what know-it-all plumbers sometimes do? They remove the nozzle and install metal dampers, thereby trying to manually regulate the flow rate of the coolant. It's good if they install it. And in some houses there are no dampers at all, and then the problems begin.

Apartments located closer to the elevator hub will have an African climate. Here, even in the most severe frosts, the windows are always open. And in distant apartments, especially corner ones, people wear felt boots and turn on electric heating appliances or a gas stove. They criticize everything under the sun, not suspecting that the companies servicing their home are to blame. Here is the result of ignorance and simple incompetence.

How does an elevator work?

The principle of operation of the elevator

The principle of operation of the elevator

The elevator unit is a fairly large container, somewhat similar to a pot. But this is not the elevator itself, although it is called that. This is a whole unit, which also includes:

  • Dirt traps - after all, the water coming from the pipe is not entirely clean.
  • Magnetic mesh filters - the unit must ensure a certain purity of the coolant so that batteries and pipes do not become clogged.

Having been purified, the hot water flows through the nozzle into the mixing chamber. Here it moves at high speed, as a result of which water is sucked in from the return circuit, which is connected to the mixing chamber on the side. The process of suction, or injection, occurs spontaneously. It is now clear that by changing the diameter of the nozzle, you can regulate both the volume of coolant supplied and its temperature at the exit from the elevator.

As you understand, for a heating system, an elevator is a pump and a mixer at the same time. And what is important - no electricity.

There is one more point that experts pay attention to - this is the ratio of the pressure inside the supply pipeline and the resistance of the elevator. This ratio should be 7:1. Only this ratio ensures the efficiency of the entire system.

But that's not all there is to efficiency. Pay attention to the fact that the pressure inside the system - and this is the supply and return circuits - must be the same. It is acceptable if it is a little less in the return. But if the difference is significant, for example, in the supply pipeline it is 5.0 kgf/cm2, and in the return pipeline it is below 4.3 kgf/cm2, this means that the pipeline system and heating devices are clogged with dirt.

Connection diagram for an adjustable water-jet elevator

Another reason is possible - when carrying out overhaul The pipe diameters were changed downwards. That is, the contractor saved money in this way.

Is it possible to regulate the temperature of the coolant? It is possible, and for this it is better to use an adjustable water-jet type elevator.

The design of such a device includes a nozzle, the diameter of which can be changed. Sometimes the adjustment range, and this applies more to foreign analogues, is quite large, which is not so necessary. Domestic elevators have a smaller range shift, but, as practice has shown, this is enough for all occasions.

True, adjustable elevators are rarely installed in residential buildings. Their installation in public or industrial premises is much more effective. With their help, you can save up to 25% on heating costs just because they allow you to reduce the temperature at night, as well as on weekends and holidays.

A heating elevator is a jet pump used in heating systems. apartment buildings with centralized heat supply.

The use of a heating elevator allows you to solve several problems simultaneously:

  • optimize the process of consuming thermal energy coming from the boiler house
  • ensure safe operation of the heating system by reducing the temperature of the coolant in the supply pipeline to a safe level (95C and below)
  • distribute heat evenly throughout the apartment building

The solution to the listed problems is required only in cases of centralized heat supply to residential buildings and buildings. In private homes and small heating systems, in which the water heating temperature allows the coolant to be supplied directly to the radiators, jet pumps are not used.

Main features of central heating systems

Heat from the boiler room is transferred to consumers using a heated coolant moving through a pipeline from boilers to heating points residential buildings. As a rule, there are many houses, but there is only one boiler room, and in most cases, it is located at a distance of several kilometers or hundreds of meters from the consumer.

With the same volume of coolant, the amount of heat entering the house is directly proportional to its heating temperature: the higher it is, the more heat is transferred to consumers. At sub-zero air temperatures, the coolant can be heated to 130-150 degrees Celsius.

To prevent the process of steam formation, the coolant in the heating system is under pressure.

The greater the number of consumers, the greater the volume of coolant that needs to be heated and pumped. At the same time, power engineers must not only supply heat to homes, but also ensure its safe consumption, which is only possible when the water temperature in the radiators is 60-70C. If heating devices become hotter, contact with their surface may cause burns.

A situation arises in which from the side of the boiler room into the house under high pressure coolant is supplied at a temperature of 130-150 C, and water is supplied to apartments at a temperature not higher than the maximum permissible value (for residential buildings 70-80 C, for children's institutions and hospitals no higher than 55-60 C). It is to solve this problem that in the vast majority of cases in our country a heating elevator (also known as a jet pump) is used.

How does a heating elevator work?

The heating elevator consists of a nozzle body, a nozzle and a mixing tee. The operating principle of a heating elevator is extremely simple: the coolant moving from the boiler room under high pressure is supplied to a nozzle whose outlet diameter is smaller than the inlet diameter of the pipe. A narrowing of the diameter leads to an increase in the speed of fluid movement and an increase in its kinetic energy.

The liquid then flows at high speed into a mixing chamber much larger than the nozzle exit diameter, causing the pressure to drop sharply to below atmospheric pressure. A vacuum is created, due to which liquid is sucked from the return pipeline connected to the mixing chamber.

As a result, the heated coolant “captures” part of the return water moving to the boiler and carries it into the next chamber, where both liquids mix, exchanging energy, and then enter the supply pipeline of the heating system of the house, continuing its movement to the heating devices.

By mixing cold return water and hot coolant from the supply pipeline, it is possible to obtain the desired temperature of the coolant and ensure its circulation without the use of additional circulation pumps.

At the same time, all the coolant from the boiler room and part of the return water, which has already cooled down, enters the heating system of the house, and the remaining part of it, not “captured” by the elevator, continues to move along the return pipeline and moves to the boiler room, from where, after heating, it again repeats the movement to the consumer.

As a result, it is possible to reduce the amount of circulating water in the heating main between the boiler room and consumers, which makes it possible to increase the efficiency of the entire heating system as a whole.

Advantages and disadvantages of a heating elevator

The design of the heating elevator is simple and its cost is low. For its operation, you do not need a connection to the electrical network - the heating elevator is a non-volatile device. The efficiency of the elevator is assessed by the suction coefficient or dimensionless flow rate of the medium. Usually, Elevator efficiency is low and averages 30%, but despite this it is premature to abandon their use.

The disadvantage of a jet pump in a heating system is the lack of ability to control the temperature of the coolant, but to solve this problem you can use elevators with an adjustable nozzle diameter, which allows you to control the flow speed, change the vacuum level in the mixing chamber and, therefore, control the water temperature.

To change the nozzle diameter, the elevator design includes an electric drive, as well as a temperature sensor and an automatic control device.

Elevator unit

Heating elevators are installed as part of an elevator unit, which includes additional equipment:

  • shut-off valves
  • pressure gauges
  • thermometers
  • filters (dirt traps)

Elevator piping schemes are part of the heating system design and are carried out in accordance with it. No independent actions by outsiders are allowed in this case.

Unfortunately, appearance elevator, which is a narrowing of the pipeline, often causes bewilderment not only among random citizens, but also among illiterate housing department employees.

There are often cases of attempts to “fix everything” and dismantle the elevator or change its design (for example, by drilling out the nozzle).

The result of such actions is a malfunction of the heating system, in which the heating devices located at the beginning of the system are overheated, and the last radiators are barely warm.

1 – , 2 – valve, 3 – plug valve, 4, 12 – dirt traps, 5 – check valve, 6 – throttle washer, 7 – fitting, 8 – thermometer, 9 – pressure gauge, 10 – elevator, 11 – heat meter, 13 – water meter, 14 – water flow regulator, 15 – sub-steam regulator, 16 – valves, 17 – piping.

This scheme works in manual mode. The elevator design includes a control valve that reduces (increases) the flow of hot water.

The advantages of this system are:

  1. Its operation is possible without connecting to the power supply.
  2. Low cost of design and installation.
  3. Reliability.

Flaws:

  1. There is no automatic operating mode.
  2. Low efficiency, since the temperature of the coolant at the inlet can change at any time, which will immediately affect the heating of residential premises.

But nowadays there are automatic systems that allow you to maintain the desired temperature regime without human intervention.

For this purpose, control valves with an electric drive and a circular pump are used. The electric actuator is connected to a temperature sensor and, when it changes, moves the valve valve. A pump is necessary to ensure circulation of coolant in the system.

S. Deineko

An individual heating point (IHP) is the most important component of heat supply systems for buildings. The regulation of heating and hot water systems, as well as the efficiency of thermal energy use, largely depends on its characteristics. Therefore, ITP is given great attention 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 the 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 individual heating point will operate in the future and what equipment needs to be installed in it. There are several temperature graphs of network operation:

  • 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 the entire 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 exceeds 95°C, it cannot be directly used 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 “quality” regulation, 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 “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 energy prices, as well as with the inability of the centralized heating network to operate according to the temperature or hydraulic schedule for which 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 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 heating system of the building. The elevator combines two devices simultaneously: a circulation pump and a mixing device. The efficiency of mixing and circulation in the heating system is not affected by fluctuations in thermal conditions in heating networks. All adjustment consists of correctly selecting the 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 external 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 energy prices, 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, each ITP uses a set of equipment (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 individual 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 ITP in dependent and independent schemes for connecting a heating system to a centralized heating network.

In IHP with dependent connection of the heating system to external 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 The required temperature schedule 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 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 - circulation pump control unit

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 network. Also, the heating system does not suffer from inconsistencies in the quality of the incoming coolant coming from the external 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, modern systems use collapsible plate heat exchangers (Fig. 8), which are quite easy to maintain and repairable: if one section loses its tightness or fails, 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, soldered non-separable heat exchangers are used.

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. Heat networks”, in general, it is prescribed to connect heating systems according to a dependent circuit. 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 operation of the system or terms of reference customer.

DHW from an individual 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. In it, it is heated by network water coming from the supply pipeline of the external network.

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

Cooled network water is supplied to the return pipeline of the external 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 is again supplied through the circulation pipeline 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 external networks.

In addition, a two-stage water heating system is used in the DHW system. In it, during the 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 from the external supply pipeline is used networks (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, heating occurs according to a single-stage scheme.

Rice. 10. Scheme of an individual 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 individual heating point is the presence of heat energy metering devices, which mandatory provided 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 in the ITP, with the help of which they carry 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 of the local system from emergency increases in coolant parameters;
  • coolant tertiary purification;
  • filling and recharging heating systems;
  • combined heat supply using thermal energy from alternative sources.

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

It is prescribed to use highly efficient heat exchangers with high thermal and operational characteristics and small dimensions. Air vents should be installed at the highest points of TP pipelines, 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 an individual heating point, a mud filter should be installed on the supply pipeline, and strainers should be installed in front of 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 equipped with an ITP, is designed for short-term action and must 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 have an acceptable low noise level.

An individual 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 heat consumer systems when they are connected independently;
  • 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 remote access to the management of individual heating points. This allows you to organize a centralized dispatch system and monitor the operation of heating and hot water systems. Suppliers of equipment for ITP are leading companies producing relevant 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 coolant temperature from external networks 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 of an individual heating point 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% on heating

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”.

More important articles and news in the Telegram channel AW-Therm. Subscribe!

Views: 194,914

The warmth in the house is integral part comfortable conditions residence. A person can no longer imagine his life without this, having long forgotten about previously existing ways to heat his home. A variety of heating systems, which are fully automated, relieve their owners of unnecessary worries. As a result, a person can enjoy the warmth without expending energy.

Not so long ago, the main way to heat a house was. Some people still use a similar method today, but it has long lost its popularity. A huge disadvantage of heating with a stove was the cold floor. According to the laws of physics warm air rose upward, heating the air in the apartment, but remained cold. Consequently, the efficiency of this type of heating decreased.

But progress has affected all industries, improving people's living conditions. Therefore, there was a gradual transition from stove heating to the water one. It has become much more efficient and profitable. The system remains leading in our time, not losing its popularity and firmly occupied positions to new ones alternative ways home heating.

Warmth is equally highly valued regardless of the type of home. Both in an apartment and in one’s own home (cottage or dacha), a person wants to feel comfortable, and warmth is an important component of it. But in order to choose the optimal type of heating, you should take into account the type and category of housing. These parameters are directly related to each other, and the effectiveness of the work done will depend on their compatibility.

For this reason, in their own homes they use individual heating that meets the required parameters. Residents of city apartments are also switching to individual heating. But for now the central one prevails.

This system also requires careful care and special attention in order to work efficiently and without interruption. Key element it is the elevator heating unit. But few people know what it is and what its main functions are.

You can see with your own eyes what an elevator unit is by visiting the basement in any multi-storey building, where it is located. It will be easy to find among all the heating system devices.

But to understand the purpose of the unit, you should remember the way heat enters the apartments. Each building is equipped with two pipelines. One at a time, heat enters the room (supply), the second removes cold water (return). The heated water is supplied to the room through the supply. The reverse returns the water that has given off heat back to the boiler room, where it will heat up again and carry heat into the house.

Heated water does not immediately enter each of the apartments; first it is supplied to the basement. It is important that a special shut-off valves. In some cases, a valve will be sufficient; in others, use Ball Valves(made of steel). , which will be water in the indicated system, has a different temperature. It is this that determines the further operation of the entire system. Accordingly, there are several different heat levels:

  • 90 at 70°С (less often 95 at 70°С)
  • 130 at 70°С
  • 150 to 70°C

In cases where the temperature of the incoming water does not rise above 95°C, then the main task of the system is to distribute the resulting heat throughout the house. To do this, you will need a manifold equipped with balancing valves.

But often the coolant has a temperature that significantly exceeds the mentioned norm. Such hot water should not be allowed to enter the heating system of the building. You should first reduce the heat. The elevator unit in the heating system is responsible for this process.

How does the node work?

The elevator is responsible for cooling the water and bringing the temperature back to normal. After going through the cooling process in the unit, the water enters the heating structure of the house. The cooling process itself occurs on the basis of mixing heated water from the supply and cold water from the return pipelines. Both water flows meet in the elevator, here they are mixed, hot water cools down and can be supplied to the system.

The functional features of the elevator are also indicated by the layout of its placement in the heating system. It follows from this that the efficiency of the entire system depends on the node. At its core, the elevator unit is a multifunctional device, performing the following work:

  • mixer

The efficiency of the unit is ensured by its simple design. This also affects the moderate cost of the equipment. It is important that the unit does not require electric current to operate. But still, in addition to the obvious advantages, the design also has several negative sides.

Among the most serious shortcomings are:

  • The need to keep the pressure inside the pipeline within strict limits (0.8 - 2 Bar). This applies to both the supply and return systems.
  • Inability to regulate output temperature.
  • Accuracy in the calculations of each component node separately.

But, nevertheless, such devices have become very popular and are often used in heating buildings that are part of public utilities.

In heating networks, fluctuations in the main modes (thermal and hydraulic) often occur, but they do not in any way affect the quality of operation of the unit. This explains their frequent use in heat supply systems, despite the obvious disadvantages.

Systems with nodes work much simpler, because elevators do not require constant monitoring. All adjustments to their operation are carried out in advance: before installation, it is necessary to accurately calculate the diameter of the nozzle. This is the essence of adjusting the operation of the unit.

Basic elements of the unit design

The unit is equipped with three main components:

  • Jet elevator
  • nozzle
  • chamber where vacuum occurs.

Additional devices in the elevator are:

  • shut-off valves
  • tonometers
  • pressure gauges

They are used to monitor ongoing processes inside the node and the parameters of the equipment itself. The mentioned devices are sometimes also called “elevator piping”.

At its core, an elevator is a mixing device. Water enters it through a series of filters. They are located immediately after the inlet valve and purify the water from dirt. Therefore, they are simply called mud filters, but in fact they are magnetic mesh filters.

The outer shell of the elevator is made of a steel body, and inside there is a mixing chamber. There is also a constriction device (nozzle).

Hot water that needs to be cooled enters the chamber through a nozzle. The water speed is always very high. Thus, a vacuum occurs in the chamber. This allows water to be drawn in from the return line. That is, the injection process occurs. Insignificantly, but it is still possible to regulate the amount of water that is consumed. This is achieved by changing the size of the nozzle (increasing or decreasing the diameter). In this way, the temperature of the leaving water from the elevator can also be controlled within acceptable limits.

Performing the functions of both a mixer and a circulation pump, the elevator does not require electricity. To operate, it consumes pressure differences. The pressure changes in front of the node, which technicians call the available pressure within the system. It is due to this pressure that the elevator operates.

Secrets of saving heat

Now it has become known that using an elevator can save heat. To do this, it is necessary to reduce the temperature in the apartment at night, or during the day, when most of the residents are absent. The disadvantage of such savings is the need to subsequently increase heat consumption to heat an already cooled room. But you sleep much better in a cool room, scientists say.

To make savings effective, they began to develop an elevator with an adjustable nozzle. It is also water-jet like its predecessor. It differs not so much in design changes as in the depth of possible adjustment, without losing the high quality of its work.

Using water jet elevators with an adjustable nozzle allows you to reduce the heating temperature at night, during weekends, or when the air temperature increases.

But technology continues to develop and soon analogues of conventional elevator units will appear, which can be produced fully automatically.