Elevator heating unit - what is it? Scheme and principle of operation. Elevator unit of the home heating system: purpose and scope

Today it is impossible to imagine your life without heating. Even in the last century, the most popular was the oven.

Not many people use it these days. The most. All the air rises and thus the floor is not heated.

Technological progress has come a long way. And now the most profitable and popular is the water heating system. Of course, to ensure comfort in the house, heat is of great importance.

Regardless of whether it is an apartment, or a private house. However, it must be remembered that the type of heating depends on the type and category of housing. In private houses, individual heating is installed.

But most apartment dwellers still use centralized heating system which requires no less attention.

Elevator node is one of the main components of the system. However, not many people know what functions it performs. Let's look at its functional purpose.

What is it and what is it used for

Working device in the basement

The easiest way to find out what an elevator node is is to visit the basement of an ordinary multi-storey building.

Among the many details of the heating system, it will not be difficult to find this important component.

Consider a simple circuit. How does heat enter the house? There are two pipelines: supply and return. The first is the supply of hot water to the house. With the help of the second, already cold water from the system enters the boiler room.

The thermal chamber supplies hot water to the basement of the house. Please note that a shut-off valve must be installed at the entrance.

It can be a simple gate valve, or steel ball valves. The temperature of the coolant determines how it will work further. There are three main levels of heat:

150/70°C
130/70°C
95 (90)/70°С

If the temperature of the heat carrier is not higher than 95 ° C, then it remains only to distribute the heat throughout the heating system. This is where a manifold with balancing valves comes in handy.

However, everything becomes not so simple if the temperature of the coolant goes beyond the norm of 95 ° C. Such water cannot be run into the heating structure, so the heating must be reduced. This is precisely what important function elevator node.

Principle and scheme of work

Scheme and principle of operation

The elevator contributes to the cooling of superheated water to a temperature corresponding to the norm.

Then the coolant supplies it to the heating system of residential premises. At the moment when hot water in the elevator from the supply heat pipeline is mixed with the cooled from the return pipeline, and cooling occurs.

The layout of the elevator allows you to get acquainted with it in more detail. functionality. It is not difficult to understand that it is this part of the heating system that ensures the efficiency of its operation.

It works simultaneously as 2 devices:

Circulation pump
Mixer

The design of the elevator is quite simple, but effective. Differs in an acceptable price. It does not need to be connected to work. electricity. However, there are some disadvantages that you need to pay attention to:

The pressure in the forward and reverse transmission pipelines must be maintained within 0.8-2 bar;
Outlet temperature cannot be adjusted;
Each element of the elevator must be accurately calculated.

It is safe to say that the devices received wide application in the public heating system.

The efficiency of their work is not affected by fluctuations in the thermal and hydraulic regime in heating networks. In addition, the devices do not require constant supervision. By choosing correct diameter nozzles, all adjustments are made.

The main elements of the elevator

The main elements of the node

The main components of the device are:

jet elevator
Nozzle
Vacuum chamber

The elevator heating unit consists of stop valves, control thermometers, manometers. It is also called "elevator piping".

New technical ideas and inventions are rapidly introduced into our lives. Heating is no exception.

The usual elevator units are being replaced by devices that regulate the coolant in automatic mode.

Their cost is much higher, but at the same time, these devices are more economical and energy efficient. In addition, they require a power supply to operate. Sometimes you need it big power. Reliability on the one hand and technological progress on the other.

What will be more important in the end, we will find out over time.

Hello! Internal heating systems mean a group of devices that carry out work on the supply of heat. They include equipment: radiators, control devices, metering and control devices, shut-off and control valves, filters, etc.

These systems are divided into:

- by type of coolant (air, water or steam);

- by the method of wiring (upper or lower);

- according to the method of connection heating appliances(one-pipe or two-pipe system).

With the upper wiring, the coolant is supplied from the network from top to bottom. When, on the contrary, from the bottom up, then this is the bottom wiring.

Ways to connect heating devices

Now the most common are water single-pipe systems, with a lower vertical wiring. In this case, the connection of the radiator is carried out with the help of connections, because they are easy to install and well guarantee uniform heating. Such a heating system requires accurate calculations of the number of sections of the radiators, taking into account the level of cooling of the water and, in addition, carefully adjusted heating devices, since the water in single pipe systems goes through them all in sequence.

The most successful heating concept, in my opinion, is the two-pipe heating system. The principle of its operation provides for the synchronous supply of hot and draining already cold water through different pipes. Besides, this concept, facilitates the calculation of individual consumption.

The elevator circuit of the internal heating system was widespread at one time in apartment buildings due to its ability to maintain stability even under pressure and temperature changes. The elevator does not need constant supervision as the pressure control follows the selected nozzle diameter. Modern residents of MKD have inherited the elevator scheme from Soviet times.

The norm for in-house heating is a water temperature of 95 degrees, but water at a temperature of 130 to 150 degrees Celsius is supplied through the main pipelines of the heating network. Such a difference is justified by the existing temperature curves for the release of the coolant from the heat source, but is not suitable for entering the internal pipeline.

The mechanical elevator in such a scheme is designed to normalize the temperature and pressure of water before it enters the internal heating system. But besides the undoubted advantages, the mechanical heating elevator has a number of significant disadvantages. And I wrote about this in .

Types of heating elevators

They have a whole range of types, each is selected based on the proper implementation of a certain load. These devices differ in their type range by size steps and throttle nozzles, which are calculated and adjusted for each specific option. I wrote about this in .

Heating system device

The thermal unit is a way of connecting the house heating system to the main networks. In the structure of a thermal unit in a typical apartment building built Soviet years includes: sump, shutoff valves, control devices, the elevator itself, etc.

The elevator unit is placed in a separate ITP room (individual heating point). By all means, there must be the presence of shut-off valves in order, if necessary, to disconnect the intra-house system from the main heat supply.
In order to avoid blockages and blockages in the system itself and in the devices of the internal house pipeline, it is necessary to isolate the dirt coming along with hot water from the main heating system, for this a sump is installed. The diameter of the sump is usually from 159 to 200 millimeters; all incoming dirt (solid particles, scale) collects and settles in it. The mud tank, in turn, needs timely and regular cleaning.

Control devices are thermometers and pressure gauges that measure temperature and pressure in the elevator assembly.

The principle of operation of the elevator unit

The mixing elevator serves as a device for cooling superheated water obtained from the heating network to a standard temperature before it is fed into the house heating system. The principle of its lowering is to mix water at an elevated temperature from the supply pipeline and cooled down from the return pipeline.

The elevator consists of several main parts. These are a suction manifold (inlet from the supply), a nozzle (throttle), a mixing chamber (the middle part of the elevator, where two flows are mixed and pressure is equalized), a receiving chamber (admixture from the return), and a diffuser (exit from the elevator directly to the network with a steady pressure ).

The nozzle is a narrowing device located in a steel case elevator device. From it, hot water at high speed and with reduced pressure enters the mixing chamber, where water is mixed from the heating network and the return pipeline by suction. In other words, hot water from the main heating network enters the elevator, in which it passes through a narrowing nozzle at high speed and already reduced pressure, mixes with water from the return pipeline, and then, with an already reduced temperature, moves into the house pipeline. How the mechanical elevator nozzle directly looks can be seen in the photo below.

In modern modifications of the elevator, the technology for controlling the change in the nozzle section occurs automatically using electronics. In such a system, the mixing ratio of hot and chilled water varies, which reduces the cost of the heating system. These are the so-called weather-dependent or adjustable elevators, and I wrote about this in.

This structure of the elevator has an actuator to ensure its stable performance, consisting of a guiding device and a throttle needle, which is driven by a toothed roller. The action of the throttle needle regulates the coolant flow.

Malfunctions of elevator units of the heating system

Malfunctions may occur due to different reasons. This may be a breakdown of the valve, or a failure of the control valve settings. If the nozzle is directly clogged, it must be removed and cleaned. If a blockage occurs in the sump, even before the elevator, then the removal occurs by dumping the accumulated dirt using a relief valve (discharge valve) located in its lower part. In the event that, with this method of cleaning, the clogging cannot be removed, then the sump must be disassembled and a detailed cleaning should be carried out.

When directly changing the diameter of the nozzle in the mechanical elevator as a result of deformation, the internal heating system is unbalanced. A similar problem requires the immediate replacement of the nozzle itself with a new one.

Checking the condition of the elevator unit of the heating system

Such an examination has a clear sequence:

- checking the integrity of pipes;

- reconciliation of readings on control devices (pressure gauges and thermometers);

— check of pressure losses (internal resistance of the heating system);

— calculation of the mixing ratio.

After the examination is completed, the equipment is sealed with fixed settings to avoid unauthorized interventions.

The undeniable advantage of the elevator system is its ease of operation. Since it does not need round-the-clock monitoring, it is quite enough to carry out scheduled inspections. Although, I would like to add that I myself am not a supporter of the elevator scheme of the heating system, and especially the scheme with a mechanical elevator. It is not modern, and got "in the load" from past times. Then, about 30 - 50 years ago, the installation of such heating schemes was fully justified and justified. But much water has flowed under the bridge since then.

Installation of the elevator unit of the heating system

The place for its installation, in order to avoid problems, must comply with certain parameters. A full-fledged room is needed, in which there will be a positive temperature, in elevator units with an automatic (weather-dependent) system, in order to avoid power outages, it is better to provide an autonomous power supply.

Not so long ago I wrote and published a book"The device of ITP (heat points) of buildings". In it on concrete examples I considered various schemes ITP, namely the scheme of the ITP without an elevator, the scheme of a heating point with an elevator, and finally, the scheme of a heating unit with circulation pump and adjustable valve. The book is based on my practical experience I tried to write it as clear and accessible as possible.

Here is the content of the book:

1. Introduction

2. ITP device, scheme without elevator

3. ITP device, elevator scheme

4. ITP device, circuit with a circulation pump and an adjustable valve.

5. Conclusion

The device of ITP (heat points) of buildings.

In this article, we have to find out what an elevator is in a heating system and how it works. In addition to functions, we will study the operating modes of the elevator assembly and how to adjust it. So, let's go.

What it is

Functions

talking in simple words, elevator heating units are a kind of buffer between the heating main and house engineering systems.

They combine several functions:

The pressure drop between the lines of the route (3-4 atmospheres) is converted into 0.2 necessary for the operation of the heating circuit.
Used to start or stop heating and hot water systems.
Allows you to switch between different regimes operation of the DHW system.

To clarify: the temperature of the water in the taps should not exceed 90-95 degrees.
In summer, when the water temperature in the supply line does not exceed 50-55 C, the DHW is supplied from this particular line.
At the peak of cold weather, hot water supply has to be switched to the return pipeline.

Elements

The simplest scheme of the elevator heating unit includes:

A pair of inlet valves on the supply and return threads. The supply is always higher than the return.
A couple of house valves that cut off the elevator unit from the heating system.
Gryazeviki on the supply and, less often, on the return.

In the photo - a mud trap that prevents sand and scale from entering the heating circuit.

Vents in the heating circuit, allowing to completely drain it or bypass the system for discharge, expelling a significant part of the air from it at startup. Dumps are considered good tone discharge into the sewer.
Control valves to measure the temperature and pressure of the supply, return and mixture.
Finally, the actual water jet elevator - equipped with a nozzle inside.

How does it work elevator system heating? The principle of its operation is based on Bernoulli's law, which states that the static pressure in the flow is inversely proportional to its speed.

More hot and under more high pressure water from the supply pipeline is injected through the nozzle into the elevator socket and creates there, paradoxically as it sounds, a rarefaction zone that draws part of the water from the return pipeline into the repeated circulation cycle through suction.

This ensures:

High coolant flow through the circuit with a minimum flow from the route.
Equalization of temperatures close to the elevator and heaters far from it.

How are the pressures measured during heating season? Here are some typical settings.

The temperatures in the route and after the elevator are subject to the so-called temperature graph, the determining factor in which is the street temperature. The maximum value for the supply line of the route is 150 degrees: with further heating, the water will boil, despite overpressure. Maximum temperature mixtures - 95 C for two-pipe and 105 for single-pipe systems.

In addition to the listed elements, the heating system elevator may include hot water tie-ins.

Two basic configurations are possible.

In houses built before the end of the 70s, the hot water supply is fed through one tie-in to the supply and one to the return.
In newer houses, there are two tie-ins on each thread. A retaining washer with a diameter of 1-2 mm larger than the diameter of the nozzle is placed between the tie-ins. It provides a drop sufficient to ensure that when the hot water supply is turned on according to the “from supply to supply” and “from return to return” schemes, water continuously circulates through the twin risers and heated towel rails.

Areas of responsibility

What is an elevator heating unit - we sort of figured it out.

And who is responsible for it?

The section of the route inside the house to the flanges of the inlet valves is the area of responsibility of the organization transporting heat (heat networks).
Everything after the inlet valves, and the valves themselves, is the area of responsibility of the housing organization.

However: the selection of the heating elevator by number (size), the calculation of the diameter of the nozzle and retaining washers are carried out by heating networks.
Residents only provide installation and dismantling.

Control

The controlling organization is again heating networks.

What exactly do they control?

Several times during the winter, control measurements of the temperatures and pressures of the supply, return and mixture are carried out.. In case of deviations from the temperature graph, the calculation of the heating elevator is carried out again with a bore or a decrease in the diameter of the nozzle. Of course, this should not be done at the peak of cold weather: at -40 on the street, driveway heating can catch ice within an hour after the circulation stops.
In preparation for the heating season, the condition of the valves is checked. The check is extremely simple: all valves in the assembly are closed, after which any control valve is opened. If water comes from it, you need to look for a malfunction; in addition, in any position of the valves, they should not have leaks through the stuffing boxes.
Finally, at the end of the heating season, the elevators in the heating system, along with the system itself, are temperature tested. When the DHW supply is turned off, the coolant heats up to maximum values.

Control

Here is the procedure for performing some operations related to the operation of the elevator.

Heating start

If the system is full, you just need to open the house valves - and the circulation will begin.

Several harder instruction to start the reset system.

The return vent opens and the supply vent closes.
Slowly (to avoid water hammer) the upper house valve opens.
After clean, air-free water flows into the discharge, it closes, after which the lower house valve opens.

Useful: if there are modern ball valves on the risers, the direction of the circuit to discharge does not matter.
But for screw fast countercurrent, the valves can be torn off, after which the locksmith will have a long and painful search for the reasons for stopping the circulation in the risers.

Work without a nozzle

At a catastrophically low return temperature at the peak of cold weather, the operation of the elevator without a nozzle is practiced. The coolant enters the system from the route, and not the mixture. The suction is suppressed with a steel pancake.

Differential adjustment

With an overestimated return flow and the impossibility of prompt replacement of the nozzle, adjustment of the differential with a valve is practiced.

How to do it yourself?

The supply pressure is measured, after which the pressure gauge is placed on the return line.
The inlet valve on the return line is completely closed and gradually opens with pressure control on the pressure gauge. If you just close the valve, its cheeks may not completely fall down the stem and slide down later. The price of the wrong course of action is guaranteed defrosted driveway heating.

At a time, no more than 0.2 atmospheres of the difference should be removed. Re-measurement of the return temperature is carried out in a day, when all values are stabilized.

Conclusion

We hope that our material will help the reader understand the scheme of work and the procedure for adjusting the elevator assembly. As usual, the attached video will offer additional information to his attention. Good luck!

The heat supply systems currently used consist of main pipelines and heat points, through which heat is distributed to consumers. Any apartment house equipped with a special thermal unit, which regulates the pressure and temperature of the water. Special devices called elevator nodes are designed to cope with this task.

The elevator unit is a module with the help of which any apartment building is connected to a common heating network. The coolant often has a temperature that exceeds the allowable limits. Strongly heated water should not flow into apartment radiators. Elevator nodes are used to cool water in the heating systems of houses.

These modules lower the temperature of the coolant entering the basements of the houses from the external heating network by adding water from the return pipe to it. Elevators are the most simple options cooling of heat carriers in residential buildings.

The device and principle of operation of the heating elevator

The elevator of the heating system consists of three main elements:

mixing chamber;
nozzle;
jet elevator.

Additionally, the design of the device provides for various thermometers with pressure gauges. Elevators are also equipped with shut-off valves.

The elevator is a device made of cast iron or steel. The device is equipped with three flanges. The principle of its work is as follows:

water heated to high temperatures moves to the elevator and enters its nozzle;
there is an increase in the flow rate of the coolant with a narrowing nozzle and a decrease in pressure;
in the place where low pressure has arisen, cold water flows from the return pipeline;
both liquids (cold and hot) are mixed in the mixing unit of the elevator.

Due to the cold water coming from the return pipe, the heating system is reduced total pressure. The temperature of the coolant drops to the desired value, after which it is distributed among the apartments of a residential building.

By its structure, the elevator unit is a device that simultaneously performs the functions of both a mixer and a circulation pump.

The main advantages of the design are:

low cost of installation in apartment buildings;
simplicity of the installation itself;
savings in the used coolant, reaching 30%;
energy independence of this equipment.

Any elevator assembly requires strapping. Heated water moves along the main through the supply pipeline. Her return occurs through the return pipeline. From main pipes internal system at home can be turned off thanks to the valves. The elements of the thermal unit are attached to each other with a flange connection.

Scheme of the elevator of the heating system

At the entrance to the system, as well as at its exit, special mud collectors are fixed. Their function is to collect solid particles that enter the coolant. Thanks to the mud collectors, particles do not penetrate further into the heating system, settling in them. Direct and oblique types of mud collectors are used. These elements need to be cleaned from the accumulated sediments in them.

Manometers are a must. Data control devices perform the function of regulating the pressure indicators of the coolant inside the pipes.

When it enters the heating system control unit, the coolant can have a pressure of up to 12 atmospheres. At the outlet of the elevator, the pressure is significantly reduced. Its indicator depends on the number of floors in an apartment building.

The system includes thermometers that regulate the temperature of the inline fluid.

The installation of the elevator itself provides for special installation rules:

the presence in the system of a free straight section 25 cm long;
using the inlet pipe, the device is connected to the supply pipe from the central (connection occurs through a flange);
with a branch pipe on the opposite side, the elevator is connected to a pipe, which is part of the house wiring;
the elevator assembly together with the flange is connected to the return pipe using a jumper.

Any intra-house heating structure implies the presence of valves and drainage elements. Gate valves allow you to disconnect the elevator from the internal heating network, and draining elements drain the coolant from the system. This usually happens as part of planned preventive measures or in case of accidents on heating networks.

Elevator with automatic adjustment

Two main types of elevator nodes are used:

without adjustment;
devices with automatic control.

The second type of devices has its own characteristics of operation. Their design allows electronic control methods to change the nozzle cross section. Inside such an element there is a special mechanism by which the throttle needle moves.

The throttle needle affects the nozzle and changes its clearance. As a result of changing the lumen of the nozzle, the indicators of coolant consumption change significantly.

Changing the lumen not only affects the fluid flow inside heating pipes, but also on the speed of its movement. All this is the result of a change in the coefficient at which the cold water from the return pipeline mixes with the hot water flowing through the external main pipe. This is how the temperature of the coolant changes.

By means of the elevator, not only the supply of fluid is regulated, but also its pressure. The pressure of the device itself directs the flow of coolant in the heating circuit.

Since the elevator is partly a circulation pump, switchgears successfully fit into its design. This is necessary in high-rise buildings, where several consumers live at once.

The main switchgear is a collector or comb. The coolant leaving the elevator assembly enters this container. The liquid leaves the comb through many exits, being distributed among the apartments of the house. In this case, the pressure in the system remains unchanged.

It is possible to repair individual consumers without having to stop the entire heating circuit.

Using a three-way valve

As switchgear a three-way valve is used. The mechanism is capable of operating in several modes:

permanent;
variable.

Valves are cast iron, brass, steel. Inside it there is a locking device of a cylindrical, ball or cone type. In its shape, the valve resembles a tee. Working in the heating system, it performs the functions of a mixer.

Ball type valves are more commonly used. Their purpose is to:

temperature control of radiators;
temperature control inside underfloor heating;
the direction of the coolant in two directions.

Three-way valves included in the elevator assembly are divided into two types - control, shut-off. Both types are largely similar in functionality, but the second type is more difficult to cope with the task of smoothly adjusting the temperature regime.

The main malfunctions of elevators

Among the advantages of the device, there are several of its disadvantages, including:

a strong pressure drop is not allowed, which occurs in two pipes (supply and return);
the allowable rate of pressure drop is 2 bar;
the device does not allow to regulate the temperature of the coolant at the outlet of the system;
each element of the elevator assembly needs to make calculations, without which the accuracy of their work is impossible.

Among the frequent cases of malfunctions occurring with these devices are:

clogging of mud tanks;
blockage of all equipment;
valve failure;
an increase in the diameter of the nozzle, which occurs over time and makes it difficult to adjust the water temperature in the heating pipes;
regulator failure.

One example of a clogged sump

Common causes of malfunctions are various blockages equipment and a nozzle increasing in diameter. Any malfunction quickly makes itself felt by a failure in the operation of the node. There is a sharp temperature drop in the coolant in the system. A serious difference is a change in temperature by 5 0 C. In such cases, diagnostics of the structure and its repair are required.

The nozzle increases in diameter for two main reasons:

due to involuntary drilling;
due to corrosion constant contact with water.

The problem leads to an imbalance in the system and temperature regulation in it. Repair work and should be carried out as soon as possible.

At district heating hot water before getting into the radiators apartment buildings, passes through the heat point. There it is brought to the required temperature using special equipment. For this purpose, in the vast majority of house heating points built during the Soviet era, such an element as a heating elevator was installed. This article is intended to tell what it is and what tasks it performs.

The purpose of the elevator in the heating system

The coolant leaving the boiler house or CHP has a high temperature - from 105 to 150 ° C. Naturally, it is unacceptable to supply water with such a temperature to the heating system.

Regulatory documents limit this temperature to 95 ° C and here's why:

for safety reasons: you can get burns from touching the batteries;
not all radiators can operate at high temperature conditions, not to mention polymer pipes.

To reduce the temperature of the network water to a normalized level allows the operation of the heating elevator. You ask - why can't you immediately send water with the required parameters to the houses? The answer lies in the plane of economic feasibility, the supply of a superheated coolant allows you to transfer a much larger amount of heat with the same volume of water. If the temperature is lowered, then the flow rate of the coolant will have to be increased, and then the diameters of the heating network pipelines will increase significantly.

So, the operation of the elevator assembly installed in heating point, consists in lowering the water temperature by mixing the cooled coolant from the return into the supply pipeline. It should be noted that given element considered obsolete, although it is still widely used today. Now, when constructing heat points, mixing units with three-way valves or plate heat exchangers.

How does an elevator work?

In simple words, the elevator in the heating system is a water pump that does not require external energy supply. Thanks to this, and even a simple design and low cost, the element found its place in almost all heating points that were built in the Soviet era. But for its reliable operation it is necessary certain conditions, which will be discussed below.

To understand the device of the heating system elevator, you should study the diagram shown above in the figure. The unit is somewhat reminiscent of a conventional tee and is installed on the supply pipeline, with its side outlet it joins the return line. Only through a simple tee would water from the network pass immediately to the return pipeline and directly to the heating system without lowering the temperature, which is unacceptable.

A standard elevator consists of a supply pipe (pre-chamber) with a built-in nozzle of the calculated diameter and a mixing chamber, where the cooled coolant is supplied from the return. At the outlet of the node, the branch pipe expands, forming a diffuser. The unit operates as follows:

coolant from the network with high temperature is sent to the nozzle;
when passing through a hole of small diameter, the flow velocity increases, due to which a rarefaction zone appears behind the nozzle;
rarefaction causes suction of water from the return pipeline;
the flows are mixed in the chamber and exit the heating system through a diffuser.

How the described process takes place is clearly shown by the diagram of the elevator node, where all flows are indicated in different colors:

An indispensable condition for the stable operation of the unit is that the pressure drop between the supply and return lines of the heat supply network is greater than the hydraulic resistance of the heating system.

Along with the obvious advantages, this mixing unit has one significant drawback. The fact is that the principle of operation of the heating elevator does not allow you to control the temperature of the mixture at the outlet. After all, what is needed for this? If necessary, change the amount of superheated coolant from the network and sucked water from the return. For example, in order to lower the temperature, it is necessary to reduce the flow rate at the supply and increase the flow of coolant through the jumper. This can only be achieved by reducing the nozzle diameter, which is impossible.

problem quality regulation help to solve electric elevators. In them, by means of a mechanical drive rotated by an electric motor, the diameter of the nozzle increases or decreases. This is realized by means of a cone-shaped throttling needle that enters the nozzle from the inside at a certain distance. Below is a diagram of a heating elevator with the ability to control the temperature of the mixture:

1 - nozzle; 2 - throttle needle; 3 - housing of the actuator with guides; 4 - shaft with gear drive.

Note. The drive shaft can be equipped with both a handle for manual control and an electric motor switched on remotely.

Appeared relatively recently adjustable elevator heating allows the modernization of heating points without a radical replacement of equipment. Considering how many more such nodes operate in the CIS, such units are becoming increasingly important.

Calculation of the heating elevator

It should be noted that the calculation of a water jet pump, which is an elevator, is considered rather cumbersome, we will try to present it in an accessible form. So, for the selection of the unit, two main characteristics of elevators are important to us - inner size mixing chamber and nozzle diameter. The camera size is determined by the formula:

dr is the desired diameter, cm;
Gpr - reduced amount mixed water, t/h

In turn, the reduced consumption is calculated as follows:

In this formula:

τcm is the temperature of the mixture used for heating, °С;
τ20 is the temperature of the cooled coolant in the return, °C;
h2 - resistance of the heating system, m. Art.;
Q is the required heat consumption, kcal/h.

To select the elevator unit of the heating system according to the size of the nozzle, it is necessary to calculate it according to the formula:

dr is the diameter of the mixing chamber, cm;
Gpr is the reduced consumption of mixed water, t/h;
u is the dimensionless injection (mixing) coefficient.

The first 2 parameters are already known, it remains only to find the value of the mixing coefficient:

In this formula:

τ1 is the temperature of the superheated coolant at the elevator inlet;
τcm, τ20 - the same as in the previous formulas.

Note. To calculate the nozzle, it is necessary to take the coefficient u equal to 1.15u’.

Based on the results obtained, the selection of the unit is carried out according to two main characteristics. Standard sizes elevators are numbered from 1 to 7, it is necessary to take the one that is closest to the calculated parameters.

Conclusion

Since the reconstruction of all heating points will not take place soon, the elevators will serve as mixers there for a long time to come. Therefore, knowledge of their structure and principle of operation will be useful to a certain circle of people.