Elevator unit of the home heating system: purpose and scope. Elevator node of the heating system - principle of operation Elevator heating principle of operation

22.08.202327.05.2017

It is possible to ensure the optimum temperature in the apartments of multi-storey buildings in winter only by supplying hot coolant to the radiators. Water is heated to operating performance using a special thermal unit - an elevator installed in the basement of the house or in the boiler room. We will talk about what this device is and how it works later in the article.

How the elevator assembly works

Before dealing with the device of the elevator unit, we note that this mechanism is designed to connect the end consumers of heat with heating networks. By design, the thermal elevator unit is a kind of pump that is included in the heating system along with shut-off elements and pressure meters.

The elevator heating unit performs several functions. First of all, it redistributes the pressure inside the heating system so that water is supplied to the end consumers in the radiators at a given temperature. When passing through pipelines from the boiler room to apartments, the amount of coolant in the circuit almost doubles. This is only possible if there is a supply of water in a separate sealed vessel.

As a rule, a heat carrier is supplied from the boiler room, the temperature of which reaches 105-150 ℃. Such high rates are unacceptable for domestic purposes from a safety point of view. The maximum temperature of the water in the circuit according to the normative documents cannot exceed 95 ℃.

It is noteworthy that SanPin currently has a coolant temperature standard within 60 ℃. However, in order to save resources, they are actively discussing the proposal to reduce this standard to 50 ℃. According to the expert opinion, the difference will not be noticeable for the consumer, and in order to disinfect the coolant, it will need to be heated up to 70 ℃ every day. However, these changes in SanPin have not yet been adopted, since there is no unequivocal opinion about the rationality and effectiveness of such a decision.

The scheme of the elevator heating unit allows you to bring the temperature of the coolant in the system to the standard values.

This node avoids the following consequences:

Batteries that are too hot can cause skin burns if handled carelessly;
not all heating pipes are designed for long-term exposure to high temperatures under pressure - such extreme conditions can lead to premature failure;
if the wiring is made of metal-plastic or polypropylene pipes, it is not designed for the circulation of hot coolant.

Elevator Advantages

Some users argue that the elevator scheme is irrational, and it would be much easier to supply consumers with a lower temperature coolant. In reality, this approach involves increasing the diameter of the main pipelines to supply colder water, which leads to additional costs.

It turns out that the qualitative scheme of the thermal heating unit makes it possible to mix with the supply volume of water the proportion of water from the return that has already cooled down. Despite the fact that some sources of elevator units of heating systems are old hydraulic units, in fact they are efficient in operation. There are also newer units that have come to replace the schemes of the elevator assembly. Such a heat supply scheme for an apartment building is more efficient and economical.

These include the following types of equipment:

plate type heat exchanger;
mixer equipped with a three-way valve.

How does an elevator work

Studying the scheme of the elevator unit of the heating system, namely what it is and how it functions, one cannot fail to note the similarity of the finished design with water pumps. At the same time, it does not require energy from other systems to operate, and reliability can be observed in specific situations.

The main part of the device from the outside looks like a hydraulic tee installed on the return. Through a simple tee, the coolant would calmly get into the return line, bypassing the radiators. Such a scheme of a heating unit would be impractical.

In the usual scheme of the elevator assembly of the heating system, there are such details:

Pre-chamber and supply pipe with a nozzle of a certain section installed at the end. A coolant is supplied through it from the return branch.
There is a built-in diffuser at the outlet. It is designed to transfer water to consumers.

At the moment, you can find nodes where the nozzle cross section is adjusted by an electric drive. Thanks to this, it is possible to automatically adjust the acceptable temperature of the coolant.

The selection of the scheme of the heating unit with an electric drive is done on the basis of the fact that it is possible to change the mixing ratio of the coolant within 2-5 units. This cannot be achieved in elevators in which the nozzle cross section cannot be changed. It turns out that systems with an adjustable nozzle make it possible to significantly reduce heating costs, which is very important in houses with central meters.

The principle of operation of the thermal unit circuit

Consider the schematic diagram of the elevator unit - that is, the scheme of its operation:

hot coolant is supplied from the boiler room through the main pipeline to the nozzle inlet;
moving through pipes of small cross section, the water gradually picks up speed;
in this case, a somewhat rarefied region is formed;
the resulting vacuum begins to suck water from the return;
homogeneous turbulent flows through the diffuser enter the outlet.

If a heating system of an apartment building is used in the heating system, then its efficient operation can be ensured only if the operating pressure between the supply and return flows is greater than the calculated hydraulic resistance.

A few shortcomings

Despite the fact that the thermal unit has many advantages, it also has one significant drawback. The fact is that it is impossible to regulate the temperature of the outgoing coolant with the elevator. If the measurement of the return water temperature shows that it is too hot, it will need to be lowered. Such a task can be carried out only by reducing the diameter of the nozzle, however, this is not always possible due to the design features.

Sometimes the thermal unit is equipped with an electric drive, with the help of which it is possible to correct the diameter of the nozzle. It sets in motion the main part of the structure - a throttle needle in the form of a cone. This needle moves a predetermined distance into the hole along the inner section of the nozzle. The depth of movement allows you to change the diameter of the nozzle and thereby control the temperature of the coolant.

On the shaft can be installed as a manual type drive in the form of a handle, and an electric remote-controlled motor.

It is worth noting that the installation of such a kind of temperature controller allows you to upgrade the overall heating system with a thermal unit without significant financial investments.

Possible problems

As a rule, most problems in the elevator assembly occur for the following reasons:

the formation of blockage in the equipment;
changes in the diameter of the nozzle as a result of the operation of the equipment - an increase in the cross section complicates the temperature control;
blockages in the mud pits;
failure of shutoff valves;
regulator failure.

In most cases, finding out the cause of the problems is quite simple, since they immediately affect the temperature of the water in the circuit. If the temperature drops and deviations from the standards are insignificant, then there is probably a gap or the nozzle cross section has increased slightly.

A temperature difference of more than 5 ℃ indicates the presence of a problem that only specialists can solve after diagnosing.

If, as a result of oxidation from constant contact with water or involuntary drilling, the nozzle cross-section increases, the balance of the entire system is disturbed. This defect needs to be corrected as soon as possible.

It is worth noting that in order to save finances and use heating more efficiently, electricity meters can be installed at thermal units. And metering hot water and heat make it possible to further reduce the cost of utility bills.

The coolant in district heating systems passes through the heating point before getting directly into the radiator sections of each apartment and individual room. In such a node, the water is brought to the design temperature, and the balance is ensured due to the fact that the circuit of the elevator heating unit is working correctly. In the basement of any multi-storey building heated along the central highway, you can find such an elevator.

The principle of operation of the node

Understanding what an elevator is, it is worth noting the need for this complex to connect heating networks and private consumers with it. A thermal unit is a module that performs the functions of pumping equipment. To see what an elevator is in a heating system, you need to go down to the basement of almost any apartment building. There, among the shut-off valves and pressure meters, it will be possible to find the desired element of the heating system (the diagram is shown in the figure below).

Finding out what an elevator is, it is worth determining its functionality according to the tasks performed. These include the redistribution of pressure from inside the heating system, while a coolant with an acceptable temperature is issued. In fact, the volume of water doubles, moving along the highways from the boiler room. This effect is achieved in the presence of water in a separate sealed vessel.

The temperature of the coolant coming from the boiler room is usually in the range of 105-150 0 C. It is not possible to use it with this parameter in domestic conditions for safety reasons.

Regulatory documents regulate the boundary temperature value for the coolant, which should be no more than 95 0 С.

For reference. Currently, the issue of reducing the temperature of hot water from 60 0 C, provided for by SanPin, to 50 0 C, is being actively discussed, citing the need to save on resources. According to experts, the consumer will not notice such a minimal difference, and in order for proper disinfection of water in pipes to be carried out daily, it is recommended to increase it to 70 0 С. It is too early to judge how rational and thoughtful this initiative is. Changes to SanPin have not yet been made.

Returning to the topic of the heating system elevator, we note that it is he who provides the temperature in the system. These steps help reduce the risk of:

with excessively overheated batteries, it is easy to get burned;
heating radiators are not always able to withstand a long time exposure to elevated coolant temperature under pressure;
wiring from polymer or metal-plastic pipes does not provide for their use with such hot coolants.

How convenient is this node

You can hear the opinion that it would be more convenient not to use a heating elevator with this principle of operation, but to directly supply water at a lower temperature. However, this opinion is erroneous, because it will be necessary to significantly increase the diameters of the lines to transfer a colder coolant.

VIDEO: Elevator node of the central heating main

In fact, a competent scheme of a thermal heating unit allows you to mix part of the volume from the return, which has already cooled down, into the supply volume of water. Although in some sources the elevator assembly of the heating system is classified as outdated hydraulic equipment, it has proven its effectiveness in operation. More modern devices used instead of the elevator assembly scheme are the following types:

plate heat exchanger;
mixer with three-way valve.

Operation of the elevator

Considering the elevator unit of the heating system, what it is and how it works, it is worth noting that the working structure has similarities with water pumps. However, operation does not require the transfer of energy from other systems. It shows its reliability under certain conditions.

From the outside, the base part of the device looks similar to a hydraulic tee mounted on the return branch. However, through a standard tee, the coolant would painlessly penetrate into the return line without passing through the radiators. Such behavior would be meaningless.

Standard elevator layout

In the classical scheme of the elevator unit of the heating system, the following components are present:

A prechamber, a supply pipe, at the end of which there is a nozzle of a certain diameter. It receives the coolant from the return.
A diffuser is installed in the outlet part. It delivers water to consumers.

Today there are nodes where the diameter of the nozzle is controlled by an electric drive. This makes it possible to optimize the temperature of the coolant in automatic mode.

The choice of a unit with an electric drive is based on the fact that it is possible to change the mixing ratio of the coolant within 2-5, which is impossible in elevators where the nozzle diameter is not adjustable. Thus, a system with an adjustable nozzle allows significant savings on heating, which is possible in houses where central meters are installed.

Structure

How does the thermal node scheme work?

In general, the principle of operation can be described as follows:

water moves along the line from the boiler room to the entrance to the nozzle;
during the passage along a small diameter, the speed of the working coolant increases significantly;
an area with a small discharge is formed;
due to the resulting vacuum, water is sucked from the return;
turbulent flows in a homogeneous mass are sent to the outlet through the diffuser.

In more detail, you can see everything on the working diagram.

For the efficient operation of the system, in which the elevator unit circuit of the heating system is involved, it is necessary to ensure that the value of the pressure between the supply and return is greater than the value of the calculated hydraulic resistance.

System Disadvantages

In addition to positive qualities, a thermal node or a thermal node circuit has a certain disadvantage. It consists of the following. The elevator of the heating system does not have the ability to adjust the output temperature mixture. In such a situation, it will be necessary to measure the heated coolant from the main or from the return pipeline. It will be possible to lower the temperature only by changing the dimensions of the nozzle, which cannot be done structurally.

In some cases, elevators with an electric drive are saved. Their design includes a mechanical drive. This unit is powered by an electric drive. In this way, it is possible to vary the diameter of the nozzle. The basic element of this design is a throttle needle, which has a conical shape. It enters the hole along the inner diameter of the structure. Moving a certain distance, it manages to correct the temperature of the mixture precisely by changing the diameter of the nozzle.

Both a manual drive in the form of a handle and a remotely started electric drive engine can be mounted on the shaft.

Due to such modernized solutions, the boiler room in the basement does not undergo significant costly refurbishments. It is enough to mount the regulator to get a modern heating unit.

Faults

In most cases, breakdowns are caused by the following factors:

equipment clogging;
a gradual increase in the diameter of the nozzle during operation, as a result of which the temperature of the coolant is more difficult to control;
clogged mud tanks;
breakage of fittings;
failure of regulators, etc.

It is not difficult to determine the breakdown of this device, it immediately affects the temperature of the coolant and its sharp drop. With minor deviations from the norm, most likely we are talking about clogging or a slight increase in the diameter of the nozzle. If the difference is very significant (more than 5 degrees), then it is already necessary to carry out diagnostics and call a specialist for repair.

The diameter of the nozzle increases either in the process of corrosion in contact with water, or as a result of involuntary drilling. Both ultimately lead to an imbalance in the system and must be eliminated immediately.

You need to know that modern modernized systems can be operated with electricity consumption metering units. In the absence of this device in the heating circuit, it is difficult to achieve an economical effect. Installing heat and hot water meters can significantly reduce utility bills.

VIDEO: The principle of operation of the node

Of course, heating is an important life support system in any home. It can be found in any buildings that are connected to central or autonomous heating. An important mechanism in such a system is the elevator heating unit.

What is an elevator assembly?

Elevator node. Click on the photo to enlarge.

The easiest way to find out what an elevator node is is to go down to the basement of any multi-storey building. Among the various parts of the heating system, you can also see the elevator of the system.

There are 2 pipelines through which heat is supplied to the house - supply and return. The first pipeline supplies hot water to the house. And with the help of the second pipeline, cold water from the system enters the boiler room. The thermal chamber supplies hot water to the basement of the building. Shut-off valves must be installed at the inlet (it can be either a simple valve or steel ball valves).

The scheme of the elevator unit (or the scheme of the thermal unit) is very simple: a supply heat pipe, a return heat pipe, valves, a water meter, mud collectors, thermometers and pressure gauges, the elevator itself and heating devices.

The temperature of the coolant determines its further operation. There are 3 main heat levels:

150/70оС;
130/70оС;
95/70°C (or 90/70°C).

The choice of heat level depends on where you live. For example, for Moscow it will be enough to set the feed to 130 degrees, and the return feed to 70 degrees. And for Irkutsk, a schedule of 150 / 70 ° C will already be needed. The number of maximum pipeline loads depends on the set mode. But depending on the air temperature outside, the boiler room can operate at temperatures of 70/54oC. This is done so that the rooms do not overheat, and it is comfortable to be in them. Heating networks and boiler rooms in this case will work to the maximum. It should be noted that the highest performance of boiler units is obtained precisely at maximum load.

If the temperature of the coolant is 95 or 90 degrees, then you only need to distribute heat throughout the heating system. For example, you can use a manifold with balancing valves.

If the temperature goes beyond 95 degrees, then the heating should be made smaller, since such water cannot be run into the heating system. This is precisely the main function of the elevator assembly.

The principle of operation of the heating elevator

The elevator is necessary in order to cool the hot water that comes from the boiler room to the desired temperature, and then supply it to the heating systems of residential buildings. Cooling in this device occurs by mixing hot water from the supply heat pipe and cold water from the return heat pipe. Then the cooled water passes through the valves and sumps and enters the elevator, inside which there is a constriction mechanism (nozzle).

Scheme of the elevator node. Click on the photo to enlarge.

After that, the water exits the nozzle at high speed and reduced pressure. The amount of incoming and return water is regulated in such a way as to bring the temperature of the water leaving the heating system to the desired value.

In this way, the efficiency of the building's thermal system is increased. The elevator works both as a circulation pump and as a mixer. If the thermal power plant does not set the required parameters of the coolant, then the elevator, having received not very hot water, mixes it with cooled water from the return pipeline, and as a result, the batteries in the apartments will be slightly warm.

Advantages

Among the advantages of the elevator heating system are:

simplicity of design;
high efficiency;
no need to connect to electricity.

As for the disadvantages of elevator heating, the following can be distinguished here:

you need a high-quality selection and accurate calculation of the elevator;
there is no possibility to adjust the outlet temperature;
it is necessary to observe the pressure difference between supply and return supply (the norm is 0.8-2 bar).

Elevator design

This device consists of elements such as a jet elevator, a rarefaction chamber and a nozzle. There is also such a thing as "binding the elevator assembly." It consists in the installation of valves, pressure gauges and thermometers.

Elevator diagram and display of the principle of operation. Click on the photo to enlarge.

Today, elevators are considered popular, which can adjust the nozzle thanks to an electric drive. In addition, it is possible to regulate the flow of the coolant in automatic mode.

Since this equipment has undeniable advantages, there are no prerequisites that utility companies may soon abandon them. Of course, there is an alternative, but other equipment is very expensive, less reliable and requires electricity to operate.

What it is - the elevator unit of the heating system, is not clearly understood by every consumer. In domestic climatic conditions, it is difficult to imagine a home without a source of heating. The system under consideration makes it possible to optimize heating, unlike the stove analogue, which could not heat the floor, due to the significant upward movement of warm air. Let's try to understand the intricacies of elevator equipment and its advantages.

General information

Since technical development does not stand still, the specialists designed a water heating system. Here it is appropriate to ask the question: "What is the elevator unit of the heating system?". It is a design that allows you to heat the air in the room, regardless of the height of the ceilings and the total area of the rooms.

In a private house, owners most often use the type of individual heating. In apartments, as a rule, a central system is operated. Next, we will consider what an elevator block is, what functions it performs.

heating unit?

The unit in question is a device included in the heating unit, which performs the options of a jet or injection pump. The main task of such a modification is to increase the pressure inside the operating heating structure. Simply put, the elevator system pumps the coolant through the system, while simultaneously increasing its volume.

The following example will help to understand what this elevator unit of the heating system is:

When supplied from the main water supply, about 5 cubic meters of fluid for the coolant are supplied.
The production system is already receiving twice as much material.
Increasing feed and volume are predominantly related to ordinary physical laws.
First of all, keep in mind that the elevator in the thermal system is a connection to the central ones where the main thermal power plant is operated under pressure or in the boiler room.

Principle of operation

The operation of the elevator unit of the heating system is to supply water that moves through the pipeline. In winter, the temperature of the liquid can reach 150 degrees Celsius. Despite the fact that the degree of boiling is 100 degrees, one of the laws of physics plays an additional role in the operation of the system. At the considered temperature, water begins to boil only if it is in an open tank without applying additional pressure. Since there is an additional load in the pipeline, the liquid circulates more actively with the help of pumping equipment. In this regard, boiling does not occur even when critical values \u200b\u200bare exceeded.

Peculiarities

The elevator assembly of the heating system, the photo of which is presented below, cannot work efficiently at a temperature of 150 degrees. There are a number of prerequisites for this:

Cast iron does not like thermal extremes. If the apartment uses radiators made of such material, in this case it is subject to deformation and failure. Failure can reach the point of complete destruction of the battery.
Excessive temperatures also actively heat metal radiators, which can result in burns.
Modern binding of fixtures is made of plastic, which can withstand a maximum of 90 degrees. At 150 degrees - it will just start to melt.
To cool the main hearth, just the elevator is used.

purpose

The purpose of the elevator assembly in the heating system is to lower the temperature of the fluid used in the structure. After passing through this node, a coolant of normal temperature enters the dwelling. As it turned out, elevators are necessary in order to lower the water temperature for heating systems.

The process itself is quite simple. The device includes a working chamber where hot water and liquid coming from the return circuit are mixed. This solution makes it possible to obtain a sufficient amount of coolant without excessive water consumption.

Service

Next, consider the features of maintenance of the elevator unit of the heating system. What is it, discussed above. During the operation of the system, certain losses in liquid temperatures occur. At the same time, it should be taken into account that the water supply is carried out through a nozzle with a reduced diameter, in contrast to the dimensions of the hot water pipeline. The increase in the speed of fluid movement is provided by pressure, which makes it possible to provide all risers with coolant. This design guarantees uniform heating of rooms, regardless of the presence or absence of a distribution block.

The numbers of elevator units of the heating system require proper maintenance. Some workers simply remove the nozzle and install metal shutters that are responsible for manually adjusting the rate of water flow. This is not the worst option, it is much more problematic to operate the system without them.

In such a situation, dwellings in the immediate vicinity of the system will receive an excessive amount of heat, even in the most severe frost, residents will have to ventilate the apartment. And in rooms located far from the interchange, on the contrary, it will be cold. People will have to use additional sources of heating. In fact, the culprit is improper maintenance of the system.

Exploitation

The principle of operation of the elevator unit of the heating system is more understandable when studying the diagram. It makes it possible to understand that the design performs the option of two devices at once: a circulation pump and a mixer.

The device configuration is as simple as possible, but quite effective. The system has an affordable price, does not require connection For efficient operation, certain rules must be observed, namely:

In terms of forward and reverse circulation, a pressure of about 0.9-2.0 bar should be maintained.
The temperature regime of the output liquid cannot be adjusted.
All parts of the fixture must fit exactly, which requires appropriate calculations.

Despite some operational difficulties, the elevator assembly of the heating system, the dimensions of which require proper adjustment, is quite popular in the utility industry and has a high efficiency rate. The final results of the construction work are absolutely not affected by differences in thermal and hydraulic parameters. The block does not need constant supervision, and its adjustment is carried out by the correct selection of the nozzle size.

Main malfunctions

Most often, in the node under consideration, breakdowns occur due to the failure of the device itself. This may be due to a change in nozzle diameter or clogging. In addition, fittings, mud collectors may be deformed, or the settings of the regulatory elements may be lost.

It's easy to spot the error. The main sign of a breakdown is the presence of temperature differences before and after connecting to the system. In the case of a significant difference in indicators, we can safely talk about violations in the operation of the unit. If the difference in parameters is not very significant, the problem is most likely a clogged nozzle. For repairs, it is better to use the services of specialists, since self-intervention can lead to a worsening of the situation.

In conclusion

A home heating system with a simple elevator system is not the most perfect design. Such an assembly is difficult to adjust, often requiring disassembly and replacement of an injection type nozzle. The best option is considered to be an installation with the possibility of automatic adjustment of elements that make it possible to mix the coolant in a specific range.

For a heating system in residential premises, there is a norm for the temperature of the coolant. In accordance with the established norm, the temperature of the water that enters the radiators should not exceed +95 degrees. But along the mains of heating networks, a coolant can be supplied, the temperature of which exceeds this indicator and is in the range from 130 to 150 degrees. Therefore, it is necessary to lower the water temperature to the desired value. The solution of this problem is entrusted to the elevator heating unit.

it looks like an elevator for a heating system

The elevator works in this way: the coolant from the main is fed into a removable cone nozzle, in which the speed of water movement increases and as a result, the water jet from the nozzle enters the mixing chamber, where it mixes with chilled water that enters there through a jumper from the return pipeline.

After mixing the superheated main water and chilled water, the coolant of the required temperature enters the heating system and heating devices. And in order to prevent large particles from entering the elevator, a sump is installed in front of the device.

Elevators have become widespread due to their stable operation aimed at changing the thermal and hydraulic regimes in heating networks.

Elevator heating units do not need constant monitoring. Their performance is regulated by the correct choice of nozzle diameter. To select the dimensions, the diameter of the pipes of the elevator assembly and the diameter of the nozzle, you must contact the design office of the relevant competence.

Now let's take a closer look at how the elevator works in the heating system and whether it is possible to do without this device.

Scheme of the elevator heating unit

The scheme of the elevator unit for the heating system looks like this.

Here we see that this scheme includes a supply heat pipe (No. 1), as well as a return heat pipe (No. 2), other components of the elevator assembly are valves (No. 3), a water meter (No. 4), mud collectors (No. 5), pressure gauges and thermometers numbered 6 and 7, and, of course, the elevator itself (8) and heating devices (9).

Scheme of the elevator node

The diagram below shows the simplest basic configuration of an elevator assembly. But if necessary, the elevator unit can be supplemented with other elements: regulators, branches of primary and secondary coolants, filters, metering devices, etc.

The principle of operation of the elevator unit in the heating system

The operation of the elevator unit consists of several stages:

Water from the main network enters the nozzle, narrowed at the outlet, and is accelerated due to the pressure drop.
Superheated water exits the nozzle at low pressure and at high speed. As a result, a vacuum is created and water is sucked into the elevator from the return pipeline.
The amount of both superheated and return chilled water is regulated so that the temperature of the water that leaves the elevator unit corresponds to the design value.

We figured out that the elevator unit, located at the inlet to the local heating system, reduces the temperature of the coolant that is supplied from the central main network to the local heating system, this happens by mixing return water.

Now let's consider what consequences the local sewerage can expect if the elevator node is not installed.

Do I need an elevator in the heating system?

The elevator is a water-jet pump, which, due to the pressure drop, increases the pumping of the coolant in the internal heating system. That is, it takes a certain amount of water from the main network, dilutes it with reverse cooled water from the local heating system and sends it back to heating radiators to heat apartments.

Now let's see what can happen to our heating without this necessary device. If water is supplied to the heating system above 130 degrees, then it will be very hot in the apartments that are located at the beginning of the heating system, and a stable low temperature will be established in the apartments that are located a little further.

It is impossible to supply water with a high temperature (over 130 degrees) to cast-iron batteries, which can burst with a sharp temperature drop. For polypropylene pipes, which are now widely installed in heating systems, the operating water temperature above 95 degrees is unacceptable. For a short time, polypropylene can withstand temperatures of 100 degrees.

From all this we can conclude that the elevator unit for our heating system is vital.