The device and principle of operation of the elevator heating unit. Why do we need an elevator heating unit: diagrams, principles of operation and installation checks
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As you know, heating is indispensable system for absolutely any living space. However, not all owners know that mechanisms such as elevator units of the heating system are very important components of all heat supply systems. This equipment plays important role in the process of heating the coolant, therefore, it is necessary to consider in more detail what an elevator heating unit is, as well as some of its characteristics and properties.
The principle of the elevator heating unit
The elevator heating unit is a special mechanism that serves to provide all heating system coolant and for its proper distribution throughout the room. The principle of its operation is as follows: to a specific room goes hot water as a source of heating, and at the outlet it comes out already moderately cooled.To equip such a unit, it is necessary, first of all, to have the following elements:
- piping system responsible for supply. In this section, the coolant enters the right room;
- outlet pipes. Here, already chilled water is discharged, which is returned back to the boiler room.
For several houses, it is customary to create special heat chambers in which not only hot water is distributed between buildings, but also special fittings are installed that cut off pipelines. In addition, such chambers are usually equipped with special drainage mechanisms designed to empty pipes, for example, during repair work. All subsequent measures directly depend on what temperature the coolant has (read: "").
In domestic heating systems, there are several main modes in which boiler rooms operate:
- feed with a parameter of 150° and return equal to 70°;
- the same characteristics with indicators of 130° and 70° respectively;
- another option is 95° and 70°.
The mode in which the boiler room operates depends, first of all, on the climatic conditions in a particular region. This means that 130°/70° will be fine for cooler areas, while 150°/70° will be needed for more severe climates.
These modes should be taken into account so that the room does not overheat too much and you can stay in it without experiencing any inconvenience.
It should also be noted that the boiler units are most efficient if they operate at the maximum degree of load. The heat carrier supplied to a particular residential area is subsequently regulated by means of such a mechanism as an elevator heat unit.
This element consists of the following functional parts:
- temperature sensor that displays the parameters of outdoor and indoor air;
- servo;
- actuating system equipped with a valve.
Such devices are usually equipped with special devices, taking into account thermal energy in each specific room. Thanks to this, it becomes possible to save a significant part of the financial resources. Comparing the elevator in the heating system and similar improved mechanisms, it is worth saying that the latter are more reliable and have a longer service life.
In this case, if the temperature of the heat carrier does not exceed the parameter of 95 °, then the main work is the correct distribution of thermal energy throughout the system. Devices serving for these purposes are balancing valves and manifolds.
If the temperature exceeds the above figure, then it should be reduced. It is this function that the heating system elevator performs, which supplies chilled water from the return pipeline to the supply pipeline. It is not at all difficult to adjust such a mechanism, but for this it is very important to perform a competent calculation of the heating elevator.
Functional characteristics of the elevator heating unit
As mentioned above, the scheme of a thermal unit with an elevator provides for the cooling of a hot heat carrier to a predetermined value, after which this water enters heating radiators in residential premises.The two main functions that this mechanism performs in the heating system are as follows:
- mixer function;
- circulation function.
- no problems with installation due to the simplicity of the design;
- high performance efficiency;
- no need to connect to the electrical network.
- the need for high-precision calculation and selection of equipment;
- the inability to control the temperature of the water during its withdrawal;
- in addition, the scheme of the elevator heating unit provides for the need to observe the pressure difference between the return and supply of the heat source (more: "").
Today, such designs are widely used among utility-type networks due to the fact that these devices tolerate any unforeseen changes in temperature and hydraulics well. Moreover, their normal functioning does not require the constant presence of a person.
The heating elevator circuit should not be calculated independently, it would be much more correct to entrust this work to qualified craftsmen, since any error in the calculations or when connecting can cause unpleasant and even dangerous consequences. If you wish, you can study various photo and video materials that describe in detail the entire installation process in order to better navigate the principle of operation of such equipment in the future. See also: "".
Due to the fact that modern technologies are constantly developing, heating systems are constantly equipped with new mechanisms that can improve heating performance. It is worth noting that today there are devices that can provide worthy competition to standard heating units - these are devices equipped with automatic temperature control.
Due to this property, they increase the efficiency of energy consumption, but the cost of such units is still higher. It is worth noting that these devices cannot function without electricity, while at times the power must be very large.
It is not yet possible to say which samples are better, since these mechanisms are innovative and they appeared on the market quite recently, however, it can be said with confidence that they have already tightly entered the modern heat supply system and are increasingly used in residential buildings.
Provide in apartments multi-storey buildings optimal temperature in winter time is possible only by supplying hot coolant to the radiators. Heating of water to operating parameters is carried out using a special thermal unit - an elevator installed in basement at home or in a 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. Maximum temperature water in the circuit according to regulatory 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 designed for long term high temperature under pressure like extreme conditions may 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 fact, this approach involves increasing the diameter main pipelines to submit more cold water which results in 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.
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 but 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.
On the this 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 circuit diagram elevator node - that is, the scheme of its work:
- 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 unit scheme is used in the heating system apartment building, then her efficient work can only be ensured 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 node has many advantages, it also has one significant disadvantage. 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 stop 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.
Provision of residential buildings and public buildings heat is one of the main tasks of municipal services of 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. Recently, modern electronic equipment has been increasingly 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 the elevator unit of the heating system.
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 heat carrier is heated to the desired temperature due to 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 tested temperature regimes for the operation of boiler houses are used, which provide both heat transfer over considerable distances without significant losses, and maximum efficiency and economy of 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 climate zone region and on the specific level of the current winter air temperature.
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. state of aggregation only due to the 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 severe tissue burns, 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 operational characteristics, adaptation to a particular heating system.
How to properly approach
Thus, on the local thermal node at home, it is necessary to reduce the temperature and pressure to the design operating levels, while ensuring the required heat extraction, sufficient for the heating needs of a particular building. This role is played by a special heating equipment. As already mentioned, these may be modern automated complexes, but very often a proven elevator assembly scheme 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 inserting 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). A sharp increase in the flow rate at the outlet of the nozzle leads to an 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 (bottom) 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 a 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 basic device elevator node. Broad arrows show the directions of coolant flows with different levels temperatures.
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 assembly also change.
Depending on the level of automation of the system, Various 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 carried near the flywheel (handle) scale.
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 necessary, 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 assembly, we can recommend spending 10 ÷ 15 minutes of time to create your own calculator based on the SP formulas, which allows you to make accurate calculations in just a matter of 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 encountered 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. Fill 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: " Required performance heating systems, cubic meters per 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 entry 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. Just enough to fill known values input area - 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 a major overhaul was carried out in the period before 2012, with the installation of polypropylene pipes for the heating system, without temperature and coolant flow controllers on risers and radiators | 3 ÷ 4 |
| Houses commissioned or after overhaul in the period 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 With, at the outlet - 70 ° С. For quality heating all premises needed 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). Minimum value the diameter 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 independent replacement of the nozzle 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 conducting audits, you should Special attention on 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 necessary for the circulation of the coolant in the intra-house heating distribution. In addition, wear of the nozzle, its contamination or too large a diameter (significantly higher than the calculated one) 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. So the best option it seems, nevertheless, modernization with the installation of adjustable elevators, allowing you to change 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 computer visualization device and principle of operation of the heating elevator:
Video: device and operation of the heating elevator
The elevator unit of the heating system is used to connect the house to an external heating network (heat supply source), if necessary, to reduce the temperature of the coolant by mixing water from the return pipeline to it.
Functions and characteristics
At correct installation the elevator unit of the heating system performs circulation and mixing functions. This device has the following advantages:
- Lack of connection to the electrical network.
- Efficiency.
- Simplicity of design.
Disadvantages:
- Inability to control the outlet temperature.
- Accurate calculation and selection is required.
- The differential pressure must be observed between the return and supply pipes.
Elevator unit of the heating system: diagram
The design of this device provides for the presence of the following elements:
- Nozzle.
- Discharge chamber.
- Jet elevator.
Additionally, the elevator unit of the heating system is equipped with pressure gauges, thermometers and shut-off valves.
As an alternative this device equipment can be used automatic regulation temperature. It is more economical, more energy-saving, but it costs much more. And most importantly, this equipment is not able to work in the absence of electricity.
For this reason, the installation of an elevator is relevant today. It has a number of undeniable advantages, and it will be used by utilities for a long time to come.
The role of the elevator node
Heating domestic apartment buildings carried out by a centralized heating system. For this purpose, in small and big cities small thermal power plants and boiler houses are being built. Each of these objects generates heat for several houses or neighborhoods. The disadvantage of such a system is a significant loss of heat.
If the path of the coolant is too long, it is impossible to control the temperature of the transported liquid. For this reason, every house must be equipped with an elevator unit. This will solve many problems: it will significantly reduce heat consumption, prevent accidents that may occur as a result of a blackout or equipment failure.
This issue becomes especially relevant in the autumn and spring periods of the year. The heat carrier is heated in accordance with established standards, but its temperature depends on the outside air temperature.
Thus, in the nearest houses, in comparison with those located further away, a hotter coolant enters. It is for this reason that the elevator assembly of the system is so necessary. central heating. It will dilute the superheated coolant cold water and thereby compensates for heat loss.
Operating principle
The elevator unit of the heating system functions as follows:
- From the main network, the coolant is directed to the nozzle narrowed at the outlet, and then, due to the pressure difference, it is accelerated.
- The superheated coolant exits the nozzle at an increased speed and with reduced pressure. This creates a vacuum and suction of liquid into the elevator from the return pipeline.
- The amount of superheated and cooled return heat carrier must be regulated in such a way that the temperature of the liquid leaving the elevator corresponds to the design value.
Elevator unit of the heating system: dimensions
| Number | Coolant consumption | Neck diameter | Weight | Dimensions | |||||
| L | l1 | l2 | h | flange 1 | flange 2 | ||||
| 0 | 0.1-0.4 t/h | 10mm | 6.4kg | 256mm | 85mm | 81mm | 140mm | 25mm | 32mm |
| 1 | 0.5-1 t/h | 15mm | 8.1kg | 425mm | 110mm | 90mm | 110mm | 40mm | 50mm |
| 2 | 1-2 t/hour | 20mm | 8.1kg | 425mm | 100mm | 90mm | 110mm | 40mm | 50mm |
| 3 | 1-3 t/hour | 25mm | 12.5kg | 625mm | 145mm | 135mm | 155mm | 50mm | 80mm |
| 4 | 3-5 t/hour | 30mm | 12.5kg | 625mm | 135mm | 135mm | 155mm | 50mm | 80mm |
| 5 | 5-10 t/h | 35mm | 13kg | 625mm | 125mm | 135mm | 155mm | 50mm | 80mm |
| 6 | 10-15 t/h | 47mm | 18kg | 720mm | 175mm | 180mm | 175mm | 80mm | 100mm |
| 7 | 15-25 t/h | 59mm | 18.5kg | 720mm | 155mm | 180mm | 175mm | 80mm | 100mm |
Kinds
There are two types of these devices:
- Elevators that are not amenable to regulation.
- Elevators, the regulation of which is carried out by means of an electric drive.
In the process of installing any of them, it is very important to maintain tightness. This equipment is installed in a heating system that is already in operation. Therefore, before installation, it is recommended to study the place where the subsequent placement of this equipment is planned. This type it is recommended to entrust the work to specialists who are able to understand the scheme, as well as develop drawings and perform calculations.
Provision of multi-apartment buildings is a complex and demanding process. professional approach. The main problem is the length of heat mains, resulting in large heat loss. The solution to this problem can be implemented in a complex way, namely:
- Pipe insulation and the use of new materials for their manufacture.
- Increasing the temperature of the water leaving the boiler room.
To implement the second method, the principle of increasing water pressure is used, as a result of which the boiling point becomes more than 100 ° C. According to this, there are the following temperature regimes for the operation of boilers:
- 150°C.
- 130°C.
- 95°C.
This is very convenient for transportation, but there is a need to reduce the temperature when distributing the coolant in the house. This is possible due to the use of an elevator thermal unit.
The most obvious solution is to reduce the temperature by mixing the cooled coolant from the return pipe. This task is performed by the elevator temperature unit.
The design consists of 3 nozzles:
- Input. It receives hot water from a common line with an elevated temperature.
- Back. Connected to return line.
- mixing. The coolant is supplied with normal temperature in heating appliances premises.
To ensure autonomous operation, an injector is provided in the design. It is necessary to reduce pressure to normal, but, in addition, it performs a very important function.
Superheated water enters the injector nozzle and enters the mixing zone at high speed. This creates a vacuum (a zone of reduced pressure), which ensures the flow of the cooled coolant from the return pipe.
The resulting pressure in the elevator thermal unit allows you to create a constant flow rate. This to some extent facilitates the work of water pumps and contributes to the creation of the same temperature regime for all consumers, regardless of the order of connection to the heating system.
Ways of regulation
An important parameter in the operation of the elevator unit is the regulation of the supply of superheated coolant. Depending on external factors return water temperature may vary. This is affected by the number of users currently connected, the time of year, and the condition of the building.
To ensure optimal temperature conditions, the elevator assembly in without fail must be equipped with temperature sensors and pressure gauges. Each such set must be installed on all three connecting pipes.
One of the most common options for tying the elevator assembly is shown below.
1 - , 2 - valve, 3 - plug valve, 4, 12 - mud traps, 5 - check valve, 6 - throttle washer, 7 - fitting, 8 - thermometer, 9 - pressure gauge, 10 - elevator, 11 - heat meter, 13 - water meter, 14 - water flow regulator, 15 - steam regulator, 16 - valves, 17 - bypass.
This circuit works in manual mode. The design of the elevator provides a control valve, which reduces (increases) the flow of hot water.
The advantages of this system are:
- Its operation is possible without connecting the power supply.
- Low design and installation cost.
- Reliability.
Disadvantages:
- There is no automatic mode of operation.
- Low efficiency, since the temperature of the coolant at the inlet can change at any time, which will immediately affect the heating of residential premises.
But currently there is automatic systems, allowing you to maintain the desired temperature regime without human intervention.
For this, distribution valves with an electric drive and a circular pump are used. The electric drive is connected to the temperature sensor and when it changes, it shifts the valve gate. The pump is also necessary to ensure the circulation of the coolant in the system.