Setting up and adjusting the elevator and the heating system of the building. Description of the device and principle of operation of the elevator heating unit
Providing residential buildings and public buildings with heat is one of the main tasks of public utilities in cities and towns. Modern systems heat supply - this is a complex complex that included heat suppliers (CHP or boiler houses), an extensive network of main pipelines, special distribution heat points, from which there are branches to end consumers.
However, the coolant supplied through the pipes to the buildings does not directly enter the intra-house network and the end points of heat exchange - heating radiators. Each house has its own heating unit, in which the corresponding adjustment of the pressure level and water temperature is made. There are special devices that perform this task. AT recent times Increasingly, modern electronic equipment is being installed, which allows you to automatically control the necessary parameters and make appropriate adjustments. The cost of such complexes is very high, they directly depend on the stability of the power supply, therefore organizations operating the housing stock often prefer the old proven scheme for local control of the temperature of the coolant at the entrance to the house network. And the main element of such a scheme is elevator unit heating systems.
The purpose of this article is to give an idea about the structure and principle of operation of the elevator itself, about its place in the system and the functions it performs. In addition, interested readers will receive a lesson on self-calculation of this node.
General brief information about heat supply systems
In order to correctly understand the importance of the elevator assembly, it is probably necessary to first briefly consider how central systems heat supply.
Thermal power plants or boiler houses are the source of thermal energy, in which the coolant is heated to the desired temperature through the use of one or another type of fuel (coal, oil products, natural gas, etc.) From there, the coolant is pumped through pipes to consumption points.
A thermal power plant or a large boiler house is designed to provide heat to a certain area, sometimes with a very large area. Piping systems are very long and branched. How to minimize heat losses and evenly distribute it among consumers, so that, for example, the buildings most remote from the CHPP do not experience shortages in it? This is achieved by careful thermal insulation of thermal lines and maintaining a certain thermal regime in them.
In practice, several theoretically calculated and practically verified temperature conditions the functioning of boiler houses, which provide both heat transfer over considerable distances without significant losses, and maximum efficiency, and the efficiency of the boiler equipment. So, for example, modes 150/70, 130/70, 95/70 are applied (water temperature in the supply line / temperature in the "return"). The choice of a specific mode depends on the climatic zone of the region and on the specific level of the current winter temperature air.
1 - Boiler or CHP.
2 – Consumers of thermal energy.
3 - Hot coolant supply line.
4 - The return line.
5 and 6 - Branches from highways to buildings - consumers.
7 - in-house heat distribution units.
From the supply and return lines, there are branches to each building connected to this network. But here questions immediately arise.
- Firstly, different objects require different amounts of heat - you can’t compare, for example, a huge residential skyscraper and a small low-rise building.
- Secondly, the temperature of the water in the line does not match acceptable standards for supply directly to heat exchangers. As can be seen from the above regimes, the temperature very often even exceeds the boiling point, and water is maintained in a liquid state of aggregation only due to high pressure and tightness of the system.
The use of such critical temperatures in heated rooms is unacceptable. And the point is not only in the redundancy of the supply of thermal energy - it is extremely dangerous. Any contact with batteries heated to such a level will cause a severe tissue burn, and in the event of even a slight depressurization, the coolant instantly turns into hot steam, which can lead to very serious consequences.
The right choice of heating radiators is extremely important!
Not all radiators are the same. The point is not only and not so much in the material of manufacture and appearance. They may differ significantly in their performance characteristics, adaptation to a particular heating system.
How to properly approach
Thus, at the local heating unit of the house, it is necessary to reduce the temperature and pressure to the calculated operating levels, while ensuring the required heat extraction, sufficient for the heating needs of a particular building. This role is performed by special heating equipment. As already mentioned, these can be modern automated complexes, but very often the proven scheme of the elevator unit is preferred.
If you look at the thermal distribution point of the building (most often they are located in the basement, at the entry point of the main heating networks), you can see a node in which the jumper between the supply and return pipes is clearly visible. It is here that the elevator itself stands, the device and the principle of operation will be described below.
How the heating elevator is arranged and works
Externally, the heating elevator itself is a cast-iron or steel structure, equipped with three flanges for tapping into the system.
Let's look at its structure inside.
Superheated water from the heating main enters the elevator inlet pipe (pos. 1). Moving forward under pressure, it passes through a narrow nozzle (pos. 2). Sharp increase the flow velocity at the nozzle exit leads to the injection effect - a rarefaction zone is created in the receiving chamber (pos. 3). According to the laws of thermodynamics and hydraulics, water is literally "sucked" into this area of \u200b\u200blow pressure from the pipe (pos. 4) connected to the "return" pipe. As a result, hot and cooled flows are mixed in the mixing neck of the elevator (pos. 5), the water receives the temperature necessary for the internal network, the pressure is reduced to a level that is safe for heat exchangers, and then the coolant through the diffuser (pos. 6) enters the internal wiring system .
In addition to lowering the temperature, the injector acts as a kind of pump - it creates t t the required pressure of water, which is necessary to ensure its circulation in the house wiring, with overcoming the hydraulic resistance of the system.
As you can see, the system is extremely simple, but very effective, which determines its widespread use even in competition with modern high-tech equipment.
Of course, the elevator needs a certain strapping. An approximate diagram of the elevator unit is shown in the diagram:
Heated water from the heat main enters through the supply pipe (pos. 1), and returns to it through the return pipe (pos. 2). The intra-house system can be disconnected from the main pipes using valves (pos. 3). The entire assembly of individual parts and devices is carried out using flange connections (pos. 4).
The control equipment is very sensitive to the purity of the coolant, therefore, mud filters (pos. 5), straight or "oblique" type, are mounted at the inlet and outlet of the system. They settle in t solid insoluble inclusions and dirt trapped in the pipe cavity. Mud collectors are periodically cleaned from collected sediments.
Filters - "mud collectors", direct (from below) and "oblique" type
In certain areas of the node, control and measuring devices are installed. These are pressure gauges (pos. 6) that allow you to control the level of fluid pressure in the pipes. If at the inlet the pressure can reach 12 atmospheres, then already at the outlet of the elevator unit it is much lower, and depends on the number of storeys of the building and the number of heat exchange points in it.
There are necessarily temperature sensors - thermometers (pos. 7), which control the temperature level of the coolant: at the inlet of their central - t c, entering the intra-house system - t s, on the "returns" of the system and the control panel - t wasps and t ots.
Next, the elevator itself is installed (pos. 8). The rules for its installation require the obligatory presence of a straight section of the pipeline of at least 250 mm. With one inlet pipe, it is connected through the flange to the supply pipe from the central, the opposite - to the pipe of the house wiring (pos. 11). The lower branch pipe with a flange is connected through a jumper (pos. 9) to the "exhaust" pipe (pos. 12).
For preventive or emergency repair work, valves (pos. 10) are provided that completely disconnect the elevator unit from the house network. Not shown in the diagram, but in practice there are always special elements for drainage - drain water from the domestic system, if necessary.
Of course, the diagram is given in a very simplified form, but it fully reflects the basic structure of the elevator unit. Broad arrows show the directions of coolant flows with different temperature levels.
The indisputable advantages of using an elevator unit to control the temperature and pressure of the coolant are:
- Simplicity of a design at non-failure operation.
- Low cost of components and their installation.
- Complete energy independence of such equipment.
- The use of elevator units and heat metering devices makes it possible to achieve savings in the consumption of the consumed heat carrier up to 30%.
There are, of course, very significant drawbacks:
- Each system requires an individual calculation to select the required elevator.
- The need for a mandatory pressure drop at the inlet and outlet.
- The impossibility of precise smooth adjustments with the current change in the system parameters.
The last drawback is rather arbitrary, since in practice elevators are often used, which provide for the possibility of changing its performance.
To do this, a special needle is installed in the receiving chamber with a nozzle (pos. 1) - a cone-shaped rod (pos. 2), which reduces the cross section of the nozzle. This rod in the kinematics block (pos. 3) through the rack and pinion gear (pos. 4 — 5) connected to the adjusting shaft (pos. 6). The rotation of the shaft causes the cone to move in the nozzle cavity, increasing or decreasing the clearance for the fluid to pass through. Accordingly, the operating parameters of the entire elevator unit also change.
Depending on the level of automation of the system, different types adjustable elevators.
So, the transfer of rotation can be carried out manually - the responsible specialist monitors the readings of instrumentation and makes adjustments to the system, focusing on on the a scale carried near the flywheel (handle).
Another option is when the elevator assembly is tied to an electronic monitoring and control system. Readings are taken automatically, the control unit generates signals to transmit them to the servo drives, through which the rotation is transmitted to the kinematic mechanism of the adjustable elevator.
What you need to know about coolants?
In heating systems, especially in autonomous ones, not only water can be used as a heat carrier.
What qualities should it have, and how to choose it correctly - in a special publication of the portal.
Calculation and selection of the elevator of the heating system
As already mentioned, each building requires a certain amount of thermal energy. This means that a certain calculation of the elevator is required, based on the given operating conditions of the system.
The source data include:
- Temperature values:
- at the inlet of their heating plant;
- in the "return" of the heating plant;
- working value for the in-house heating system;
- in the return pipe of the system.
- The total amount of heat required to heat a particular house.
- Parameters characterizing the features of intra-house heating distribution.
The procedure for calculating the elevator is established by a special document - "The Code of Design Rules for the Design of the Ministry of Construction of the Russian Federation", SP 41-101-95, relating specifically to the design of heat points. Calculation formulas are given in this regulatory guide, but they are quite “heavyweight”, and there is no particular need to present them in the article.
Those readers who are not interested in calculation issues can safely skip this section of the article. And for those who wish to independently calculate the elevator unit, we can recommend spending 10 ÷ 15 minutes of time to create your own calculator based on the SP formulas, which allows you to carry out exact counts literally in seconds.
Creating a Calculator for Calculation
To work, you will need the usual Excel application, which, probably, every user has - it is included in the basic Microsoft Office software package. Compiling a calculator will not be difficult even for those users who have never dealt with elementary programming issues.
Consider step by step:
(if part of the text in the table goes beyond the frame, then there is an “engine” for horizontal scrolling below)
| Illustration | Brief description of the operation to be performed |
|---|---|
 | Open a new file (workbook) in the Microsoft Office Excel application. In a cell A1 type the text "Calculator for calculating the elevator of the heating system." Below in the cell A2 we collect "Initial data". Inscriptions can be "raised" by changing the weight, size or color of the font. |
 | Below there will be rows with cells for entering the initial data, on the basis of which the calculation of the elevator will be carried out. Filling cells with text A3 on A7: A3- "Temperature of the coolant, degrees C:" A4– “in the supply pipe of the heating plant” A5– “in the return line of the heating plant” A6– “necessary for the internal heating system” A7– “in the return line of the heating system” |
 | For clarity, you can skip the line, and below, in the cell A9 enter text " Required amount heat for the heating system, kW" |
 | Skip another line, and into the cell A11 we type in "The coefficient of resistance of the heating system of the house, m". To text from a column BUT not found on column AT, where data will be entered in the future, column BUT can be extended to the required width (shown by the arrow). |
 | Data entry area, from A2-B2 before A11-B11 can be selected and filled with color. So it will be different from another area where the results of calculations will be issued. |
 | Skip another line and enter in the cell A13"Calculation results:" You can highlight text in a different color. |
 | Next, the most important stage begins. In addition to entering text into column cells BUT, into adjacent cells of the column AT formulas are entered in accordance with which calculations will be carried out. Formulas should be transferred exactly as it will be indicated, without any extra spaces. Important: the formula is entered in the Russian keyboard layout, with the exception of cell names - they are entered exclusively in Latin layout. In order not to make a mistake with this, in the examples of formulas, cell names will be highlighted in bold. So in a cell A14 we type the text "Temperature difference of the heating plant, degrees C". into a cell B14 enter the following expression =(B4-B5) It is more convenient to enter and control its correctness in the formula bar (green arrow). Don't be confused by what's in the box B14 some value immediately appeared (in this case, “0”, blue arrow), it’s just that the program immediately processes the formula, relying on empty input cells for the time being. |
 | Fill in the next line. In a cell A15- the text "Temperature difference of the heating system, degrees C", and in the cell B15- formula =(B6-B7) |
 | Next line. In a cell A16- text: "The required performance of the heating system, cubic meters / hour." Cell B16 must contain the following formula: =(3600*B9)/(4,19*970*B14) An error message will appear, “dividing by zero” - do not pay attention, this is simply because the initial data has not been entered. |
 | We go below. In a cell A17– text: “Elevator mixing ratio”. Next to the cell B17- formula: =(B4-B6)/(B6-B7) |
 | Next, cell A18- "Minimum head of the coolant in front of the elevator, m". Formula in a cell B18: =1,4*B11*(DEGREE((1+ B17);2)) Do not go astray with the number of brackets - this is important |
 | Next line. In a cell A19 text: "Elevator throat diameter, mm". Formula in a cell B18 next: \u003d 8.5 * DEGREE ((DEGREE ( B16;2)*POWER(1+ B17;2))/B11;0,25) |
 | And the last line of calculations. In a cell A20 the text “Elevator nozzle diameter, mm” is entered. In a cell IN 20- formula: \u003d 9.6 * DEGREE (DEGREE ( B16;2)/B18;0,25) |
 | In fact, the calculator is ready. You can only modernize it a little so that it is more convenient to use, and there is no risk of accidentally deleting the formula. First, let's select an area from A13-B13 before A20-B20, and fill it with a different color. The fill button is shown with an arrow. |
 | Now select a common area with A2-B2 on A20-B20. Drop down menu "boundaries"(shown by arrow) select item "all borders". Our table gets a slender frame with lines. |
 | Now we need to make it so that the values can be entered manually only in those cells that are intended for this (so as not to erase or accidentally break the formulas). Select a range of cells from AT 4 before AT 11(red arrows). We go to the menu "format"(green arrow) and select the item "cell format"(blue arrow). |
 | In the window that opens, select the last tab - “protection” and uncheck the box in the “protected cell” box. |
 | Now back to the menu "format", and select the item in it "protect sheet". |
 | A small window will appear in which you just need to click the button "OK". We simply ignore the offer to enter a password - in our document, such a degree of protection is not needed. Now you can be sure that there will be no failure - only the cells in the column are open for change AT in the value input area. If you try to enter at least something into any other cells, a window will appear with a warning about the impossibility of such an operation. |
 | The calculator is ready. It remains only to save the file. - and he will always be ready for the calculation. |
It is not difficult to carry out a calculation in the created application. It is enough just to fill in the input area with known values - then the program will calculate everything automatically.
- The temperature of the supply and "return" in the heating plant can be found in the nearest heat point (boiler room) to the house.
- The required temperature of the heat carrier in the intra-house system largely depends on which heat exchangers are installed in the apartments.
- The temperature in the "return" pipe of the system is most often taken equal to that in the central.
- The need for a house in the total influx of thermal energy depends on the number of apartments, heat exchange points (radiators), the characteristics of the building - the degree of its insulation, the volume of the premises, the amount of total heat loss, etc. Usually these data are calculated in advance at the stage of designing a house or during the reconstruction of its heating system.
- The resistance coefficient of the internal heating circuit of the house is calculated using separate formulas, taking into account the characteristics of the system. However, it will not be a big mistake to take the average values shown in the table below:
| Types of apartment buildings | Coefficient value, m |
|---|---|
| apartment buildings old building, with heating circuits made of steel pipes, without temperature and coolant flow controllers on risers and radiators. | 1 |
| Houses put into operation or in which major repairs were carried out in the period up to 2012, with the installation polypropylene pipes for the heating system, without temperature and coolant flow controllers on risers and radiators | 3 ÷ 4 |
| Houses put into operation or after a major overhaul after 2012, with the installation of polypropylene pipes for the heating system, without temperature and coolant flow controllers on risers and radiators. | 2 |
| The same, but with installed temperature and coolant flow control devices on risers and radiators | 4 ÷ 6 |
Calculations and selection of the desired elevator model
Let's try the calculator in action.
Let's assume that the temperature in the supply pipe of the heating plant is 135, and in the return pipe - 70 ° С. It is planned to maintain a temperature of 85 ° in the heating system of the house FROM, at the outlet - 70 ° С. For high-quality heating of all rooms is necessary thermal power at 80 kW. According to the table, it is determined that the drag coefficient is "1".
We substitute these values into the corresponding lines of the calculator, and immediately we get the necessary results:
As a result, we have data for the selection of the desired elevator model and the conditions for its correct operation. Thus, the required system performance was obtained - the amount of coolant pumped per unit time, the minimum head of the water column. And the most basic quantities are the diameters of the elevator nozzle and its neck (mixing chamber).
It is customary to round the nozzle diameter down to hundredths of a millimeter (in this case, 4.4 mm). The minimum diameter value should be 3 mm - otherwise the nozzle will simply clog quickly.
The calculator also allows you to "play" with the values, that is, to see how they will change when the initial parameters change. For example, if the temperature in the heating plant is lowered, say, to 110 degrees, then this will entail other parameters of the node.
As you can see, the diameter of the elevator nozzle is already 7.2 mm.
This makes it possible to choose a device with the most acceptable parameters, with a certain range of adjustments, or a set of replacement nozzles for a specific model.
Having calculated data, it is already possible to refer to the tables of manufacturers of such equipment to select the required version.
Usually in these tables, in addition to the calculated values, other parameters of the product are also given - its dimensions, flange dimensions, weight, etc.
For example, water jet steel elevators of the series 40s10bk:
Flanges: 1 - at the entrance 1— 1 - on the tie-in pipe from the "return", 1— 2 - at the exit.
2 - inlet pipe.
3 - removable nozzle.
4 - reception chamber.
5 – mixing neck.
7 - diffuser.
The main parameters are summarized in the table - for ease of choice:
| Number elevator | Dimensions, mm | Weight, kg | Exemplary water consumption from the network t/h |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| dc | dg | D | D1 | D2 | l | L1 | L | |||
| 1 | 3 | 15 | 110 | 125 | 125 | 90 | 110 | 425 | 9,1 | 0,5-1 |
| 2 | 4 | 20 | 110 | 125 | 125 | 90 | 110 | 425 | 9,5 | 1-2 |
| 3 | 5 | 25 | 125 | 160 | 160 | 135 | 155 | 626 | 16,0 | 1-3 |
| 4 | 5 | 30 | 125 | 160 | 160 | 135 | 155 | 626 | 15,0 | 3-5 |
| 5 | 5 | 35 | 125 | 160 | 160 | 135 | 155 | 626 | 14,5 | 5-10 |
| 6 | 10 | 47 | 160 | 180 | 180 | 180 | 175 | 720 | 25 | 10-15 |
| 7 | 10 | 59 | 160 | 180 | 180 | 180 | 175 | 720 | 34 | 15-25 |
At the same time, the manufacturer allows self-replacement nozzles with the desired diameter in a certain range:
| Elevator model, No. | Possible nozzle change range, Ø mm |
|---|---|
| №1 | min 3 mm, max 6 mm |
| №2 | min 4 mm, max 9 mm |
| №3 | min 6 mm, max 10 mm |
| №4 | min 7 mm, max 12 mm |
| №5 | min 9 mm, max 14 mm |
| №6 | min 10 mm, max 18 mm |
| №7 | min 21 mm, max 25 mm |
It will not be difficult to select the required model, having the results of the calculation in hand.
When installing the elevator or when carrying out maintenance work, it must be taken into account that the efficiency of the unit directly depends on the correct installation and integrity of the parts.
So, the nozzle cone (glass) must be installed strictly coaxially with the mixing chamber (neck). The glass itself must enter the elevator seat freely so that it can be removed for revision or replacement.
When carrying out revisions, special attention should be paid to the condition of the surfaces of the elevator departments. Even the presence of filters does not exclude the abrasive effect of the liquid, plus there is no escape from erosive processes and corrosion. The working cone itself must have a polished inner surface, smooth, unworn edges of the nozzle. If necessary, it is replaced with a new part.
Failure to comply with such requirements entails a decrease in the efficiency of the unit and a drop in pressure required for the circulation of the coolant in the intra-house heating distribution. In addition, the nozzle is worn, dirty or too large diameter(significantly higher than calculated), will lead to the appearance of strong hydraulic noise, which will be transmitted through the heating pipes to the living quarters of the building.
Of course, a home heating system with a simple elevator unit is far from perfect. It is very difficult to adjust, which requires disassembly of the assembly and replacement of the injection nozzle. Therefore, the best option seems to be, nevertheless, modernization with the installation of adjustable elevators, which allow changing the parameters of mixing the coolant in a certain range.
And how to regulate the temperature in the apartment?
The temperature of the coolant in the intra-house network may be excessive for a single apartment, for example, if it uses "warm floors". This means that you will need to install your own equipment, which will help maintain the degree of heating at the right level.
Options, how - in a special article of our portal.
And finally - a video with computer visualization of the device and the principle of operation of the heating elevator:
Video: device and operation of the heating elevator
The warmth in the house is integral part comfortable living conditions. A person can no longer imagine his life without it, having long forgotten about the previously existing ways to heat his home. A variety of heating systems, which are fully automated, save their owners from unnecessary worries. As a result, a person can enjoy the warmth without wasting energy.
Not so long ago, the main way to heat a house was. Some still use a similar method today, but it has long lost its prevalence. A huge disadvantage of heating with a stove was a cold floor. According to the laws of physics warm air rose up, heating the air in the apartment, and remained cold. Consequently, the efficiency of the mentioned type of heating decreased.
But progress has touched all industries, improving the living conditions of people. Therefore, there has been a gradual transition from furnace heating to the water. It has become much more efficient and profitable. The system remains the leading one in our time, not losing its popularity and firmly occupied positions to new alternative ways home heating.
Heat is equally highly valued regardless of the type of dwelling. Both in an apartment and in his own house (cottage or summer cottage), a person wants to feel comfortable, and warmth is an important part 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 the compatibility.
For this reason, in own houses use individual heating that meets the required parameters. To individual heating residents of city apartments also move. But in the meantime, the central one prevails.
This system also requires careful maintenance and special attention to work efficiently and without interruption. Its key element 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 node is by visiting the basement in any multi-storey building, where it is located. It will be easy to find it among all devices of the heating system.
But in order to understand the purpose of the node, one should remember the way heat enters the apartments. Each building is equipped with two pipelines. One by one, heat enters the room (supply), the second removes cold water (return). The heated water is supplied to the room through the feeder. The reverse returns the water that has given off heat back to the boiler room, where it will heat up again and carry heat to 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 stop valves. In some cases, a valve will be enough, in others they use Ball Valves(made from steel). , which in the indicated system will be water, has a different temperature. It is she who determines the further work of the entire system. Accordingly, there are several different levels of heat:
- 90 to 70°C (rarely 95 to 70°C)
- 130 at 70°C
- 150 at 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 received heat throughout the house. This will require a manifold equipped with balancing valves.
But often the coolant has a temperature that significantly exceeds the mentioned norm. Such hot water must not be allowed to enter the heating system of the building. Reduce heat first. The elevator unit in the heating system is responsible for this process.
How does a node work?
The elevator is responsible for cooling the water and bringing the temperature back to normal. Having passed the cooling process in the node, the water enters the heating structure of the house. The cooling process itself takes place on the basis of mixing heated water from the supply and cold water from return pipelines. Both water streams meet in the elevator, here they are mixed, hot water cools down and can be fed into the system.
On the functional features the elevator is also indicated by the scheme of its placement in the heating system. From this follows the conclusion that the efficiency of the entire system depends on the node. At its core, the elevator unit is a multifunctional device, performing the work:
- mixer
The efficiency of the node is ensured by a simple design. This also affects the moderate cost of the equipment. It is important that the node does not require electricity. But still, in addition to the obvious advantages, there are several negative sides to the design.
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.
- Unable to control outlet temperature.
- Accuracy in the calculations of each component node separately.
But, nevertheless, such devices have gained great popularity and are often used in heating buildings that are part of public utilities.
In thermal networks, fluctuations in the main modes (thermal and hydraulic) often occur, but they do not affect the quality of the unit. This explains their frequent use in heat supply systems, despite the obvious disadvantages.
Systems with nodes work much easier, because elevators do not need constant monitoring. All adjustment of their work is 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 node.
The main elements of the node design
The node is equipped with three main components:
- Jet type elevator
- nozzle
- chamber where vacuum occurs.
Additional devices in the elevator are:
- shut-off valves
- tonometers
- pressure gauges
They are used to control the ongoing processes inside the node and the parameters of the equipment itself. These devices are sometimes also called "elevator piping".
At its core, the 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, in a simple way they are called mud collectors, but in fact they are mesh-magnetic filters.
The outer shell of the elevator is represented by a steel case, and inside there is a mixing chamber. There is also a narrowing device (nozzle).
Hot water, which 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 sucked from the return pipeline. That is, the injection process takes place. Slightly, but still it is possible to regulate the amount of water that is consumed. This is achieved by changing the dimensions of the nozzle (increase or decrease in diameter). Thus, the temperature of the leaving water from the elevator can also be controlled within acceptable limits.
Performing the functions of both the mixer and circulation pump the elevator does not require electricity. To work, it consumes pressure drops. In front of the node, the pressure changes, which technicians call the available head within the system. It is due to this pressure that the operation of the elevator is carried out.
Heat Saving Secrets
Now it has become known that with the use of an elevator it is possible to save heat. To do this, it is necessary to lower 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 the heat consumption to heat an already cooled room. But in a cool room, sleep is much better, scientists say.
To make the 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.
The use of variable nozzle water jet elevators makes it possible to lower the heating temperature at night, during weekends, or when the air temperature rises.
But the technology continues to develop and analogues of conventional elevator units will soon appear, which are capable of producing fully automatically.
Centralized heating, despite all its real and imaginary shortcomings, is still the most common way to heat both multi-apartment residential buildings, and public and industrial ones.
The principle of operation of central heating
The general scheme is quite simple: a boiler house or CHP heats water, supplies it to the main heat pipes, and then to heating points - residential buildings, institutions, and so on. When moving through pipes, the water cools somewhat and at the final point its temperature is lower. To compensate for the cooling, the boiler room heats the water to a higher value. The amount of heating depends on the temperature outside and the temperature graph.
- For example, with a schedule of 130/70 at an outdoor temperature of 0 C, the parameter of the water supplied to the main is 76 degrees. And at -22 C - at least 115. The latter is quite within the framework of physical laws, since the pipes are a closed vessel, and the coolant moves under pressure.
It is obvious that such superheated water cannot be supplied to the system, since an overheating effect occurs. At the same time, the materials of pipelines and radiators are greatly worn out, the surface of the batteries overheats up to the risk of burns, and plastic pipes in principle, they are not designed for coolant temperatures above 90 degrees.
For normal heating, several more conditions must be met.
- First, the pressure and speed of water movement. If it is small, then superheated water is supplied to the nearest apartments, and too cold to the distant ones, especially the corner ones, as a result of which the house is heated unevenly.
- Secondly, for proper heating, a certain amount of coolant is required. The thermal unit receives about 5–6 cubic meters from the main, while the system needs 12–13.
It is to solve all of the above issues that the heating elevator is used. The photo shows a sample.
Heating elevator: functions
This device belongs to the category of heating technology and performs several functions.
- Decrease in water temperature - since the supplied liquid is too hot, it must be cooled before serving. In this case, the feed rate should not be lost. The device mixes the supplied coolant with water from the return pipeline, thereby reducing the temperature and not reducing the speed.
- Creating a coolant volume - thanks to the above-described mixing of the supplied water and the liquid from the return, the volume necessary for normal functioning is obtained.
- The function of the circulation pump is the intake of water from the return and the supply of coolant to the apartments is carried out due to the pressure drop in front of the heating elevator. In this case, no electricity is used. The regulation of the temperature of the supplied water and its consumption is carried out by changing the size of the hole in the nozzle.
The principle of operation of the device
The device is a rather large capacity, as it includes a mixing chamber. Dirt traps and mesh magnetic filters are installed in front of the chamber: the quality of tap water in our cities is never high. The photo shows a diagram of the heating elevator.
Purified water enters the mixing chamber at high speed. Due to rarefaction, water from the return is sucked spontaneously and mixed with superheated water. The coolant through the nozzle is fed into the network. It is clear that the size of the hole in the nozzle determines the water temperature and pressure. Devices are available with an adjustable nozzle and a constant, general principle their jobs are the same.
A certain ratio must be observed between the pressure inside the supply pipe and the resistance of the heating elevator: 7 to 1. With other indicators, the operation of the device will be inefficient. The pressure in the supply pipe and the return pipe also matters - it should be almost the same.
Heating elevator with adjustable nozzle
The principle of operation of the device is exactly the same: mixing the coolant and distributing it through the network due to the resulting pressure drop. However, the adjustable nozzle allows you to set different temperatures for certain times of the day, for example, and thus save heat.
- The size of the diameter itself does not change, but an additional mechanism is installed in the adjustable nozzle. Depending on the value indicated on the sensor, the throttle needle moves along the nozzle, reducing or increasing its working section, which will change the size of the hole. The operation of the mechanism requires power supply. In the photo - a heating elevator with an adjustable nozzle.
Public institutions and industrial facilities receive the greatest benefit from the apparatus, since for 
For most of them, space heating at night is not necessary - the support of the minimum mode is quite enough. The ability to set a lower temperature at night significantly reduces heat consumption. Savings can reach 20-25%.
In residential apartment buildings a device with an adjustable nozzle is used much less frequently, and in vain: at night, the temperature is + 17-18 C instead of 22-24 C is more comfortable. Reducing the temperature index also reduces heating costs.
The heat carrier in district heating systems passes through 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 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).
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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 the coolant is issued with allowable temperature. 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 heat carrier coming from the boiler room is usually in the range of 105-150 0 C. Use it with this parameter in living conditions not possible for security reasons.
Regulatory documents the boundary temperature value for the coolant is regulated, 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 actions 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 temperatures under pressure;
- wiring made of polymer or metal-plastic pipes does not provide for their use with such hot heat transfer fluids.
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 unit of the central heating main
Actually, competent scheme The 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 node circuit 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 working structure there are 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.
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Standard elevator layout
AT classical pattern the elevator assembly of the heating system contains the following components:
- 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 effective work system, in which the scheme of the elevator unit of the heating system is involved, it is necessary to ensure that the value of the pressure values 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 is as follows. 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. With absence 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
Types of heating elevators
Oddly enough, not even all plumbers serving multi-story houses. At best, 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 such a gap in knowledge about heating systems and analyze this device in more detail.
What is an elevator?
If to speak plain language, then the 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, to increase the pumping of the coolant through the network, which will lead to an increase in its volume. To make it clearer, let's take a simple example. 5-6 cubic meters of water are taken from the supply water supply as a heat carrier, and 12-13 cubic meters enter the system where the apartments of the house are located.
How is this possible? And due to what is the increase in the volume of the coolant? This phenomenon is based on some laws of physics. Let's start with the fact that if an elevator is installed in the heating system, then this system is connected to central heating networks, through which hot water moves under pressure from a large boiler room or CHP.
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 play. 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. Therefore, she does not boil.
- Firstly, cast iron does not like large temperature changes. And if cast-iron radiators are installed in the apartments, they can fail. Well, if they just let it flow. But they can be torn apart, because under the influence high temperatures cast iron becomes brittle, like glass.
- Second, at this temperature metal elements heating it will not be difficult to get burned.
- Thirdly, plastic pipes are now often used to tie heating devices. And the maximum that they can withstand is a temperature of +90 C (besides, with such figures, manufacturers guarantee 1 year of operation). So they just melt.
Therefore, the coolant must be cooled. This is where the elevator is needed.
What is the elevator unit for?
Scheme of connection of the elevator unit
So we come to the question of why we need elevators in the heating system?
These devices are designed to lower the temperature of the inlet water to the required one. And already cooled, it is fed into the heating system of apartments. That is, the coolant is cooled in the elevator. How?
Everything is quite simple. This device consists of a chamber where hot superheated water is mixed with water coming from the return circuit of the heating system. That is, the coolant from the boiler room is mixed with the coolant from the return of the same house. So you can, without taking a lot of hot water, get the right amount 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 that supplies 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 over all risers. Therefore, regardless of where the apartment is located, close or far from the distribution unit, the temperature in the heaters will be the same. Uniform distribution is thus 100% guaranteed.
Do you know what know-it-all plumbers sometimes do? They remove the nozzle and install metal shutters, thereby trying to manually control the flow rate of the coolant. Well, if installed. And in some houses there are no dampers at all, and then the problems begin.
The 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 gas stove. They scold everything in the world, not suspecting that the companies serving 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 assembly is a fairly voluminous container, somewhat similar to a pot. But this is not the elevator itself, although it is called that. This is a whole node, which also includes:
- Dirt traps - because the water from the pipe comes not quite clean.
- Magnetic mesh filters - the unit must ensure a certain purity of the coolant so that batteries and pipes do not clog.
After cleaning, 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 side of the mixing chamber. The process of suction, or injection, occurs spontaneously. Now it is clear that by changing the diameter of the nozzle, it is possible to control both the volume of the supplied coolant and its temperature at the outlet of 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 pressure inside the supply pipeline and the resistance of the elevator. This ratio should be equal to 7:1. Only such a ratio ensures the efficiency of the entire system.
But it's not all about efficiency. Pay attention to the fact that the pressure inside the system - and this is the supply circuit and the return - must be the same. It is acceptable if it is a little less in the return line. But if the difference is significant, for example, in the supply pipeline 5.0 kgf / cm2, and in the return pipe below 4.3 kgf / cm2, this means that the pipeline system and heating devices are clogged with dirt.
Scheme of switching on an adjustable water jet elevator
Another reason is also possible - during the overhaul, the diameters of the pipes were changed to a smaller side. That is, the contractor thus saved.
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.
In the design of such a device, a nozzle is installed, the diameter of which can be changed. Sometimes the adjustment range, and this applies more to foreign analogues, is large enough, which is not so necessary. Domestic elevators have a smaller range shift, but, as practice has shown, this is enough for all occasions.
Truth, adjustable elevators rarely installed in residential buildings. Much more efficient is their installation in public or industrial premises. With their help, you can save up to 25% on heating costs only due to the fact that they allow you to reduce the temperature at night, as well as on weekends and holidays.
