Elevator heating unit

Ensuring residential houses and public buildings with heat - one of the main tasks of municipal services of cities and towns.Modern heating system - this sophisticated complex, including suppliers of heat (thermal power station or boiler), an extensive network of trunk pipelines , special distribution Heat points , from which branches are to the end consumers.

however, is piped to buildings coolant does not directly enters the in-house network and end point of heat - heating radiators.In every house has its own heating unit, which is made corresponding adjustment of the pressure level and temperature of the water.There are special devices that perform this task.In recent years, increasingly established modern electronic equipment, which allows you to automatically control the parameters and make appropriate adjustments.The cost of such systems - is very high, they are directly dependent on the stability of the power, so often exploiting residential Fund preference is given to the old proven scheme of the local adjustment of coolant inlet temperature in the home network.And a key element of such a scheme is Squirrel heating system assembly.

purpose of this article - to give an idea about the structure and principle of operation of the elevator, its place in the system and the functions performed by them.In addition, interested readers will get a lesson in self- calculation this node.

General System Overview heating

to understand the importance of the elevator assembly mustit is necessary to begin with a brief look at how well run the central heating system.

heat mains source of thermal energy are CHP and boiler, in which the coolant heating to a desired temperature through the use of a particular type of fuel (coal, oil, natural gas, etc .) From there the coolant is pumped through pipes to the consumption points.

CHP or large boiler rasschita on to ensure a certain warmth area, sometimes - with a very considerable territory.piping system gets very extent and branched .How to minimize heat loss and evenly distribute it on for consumers, so that, for example, the most remote from CHP building did not experience failure in it ?This is achieved by careful thermal insulation of heating ducts and maintaining them certain thermal regime.

In practice, a few theoretically calculated and practically tested temperature regimes of boiler operation, which provide heat and transfer to a significant distances without significant losses and maximum efficiency and economical operation of the boiler equipment.Thus, for example, apply modes 150/70, 130/70, 95/70 (water temperature in the line feed / temperature « return pipe »).The choice of a particular mode depends on the climate zone in the region and the particular level of the current winter temperatures.

1 - Boiler or CHP.

2 - thermal energy consumers.

3 - Magistral supply heated coolant.

4 - Magistral « the return ».

5 and 6 - an offshoot of the highways to buildings - consumers.

7 - in-house heat distribution units.

From highways feeding and « the return » are branches in every building, connected to the network.But here the question immediately arises.

• Firstly, different objects different amounts of heat is required - can not be compared, for example, a huge high-rise residential and small low-rise building.
• Secondly, the water temperature in the line does not meet acceptable standards for feeding directly on heat exchange devices.As can be seen from the above mode, the temperature is very often even higher than the boiling point, and water maintained in the liquid state of aggregation only for due to high pressure and tightness of the system.

use as critical temperatures in the heated rooms - unacceptable.And it's not just the redundancy of thermal energy input - it is extremely dangerous.Any touch to warm up to this level of the batteries will cause severe burns tissue, and in the case of even a slight depressurization of the coolant instantly turns into a hot steam that can cause very serious consequences.

correct choice of radiators - very important!

Not all radiators are identical.It is not only and not so much in the manufacture of materials and appearance.They may vary significantly with their performance, adaptation of a heating system.

How to approach choosing radiators - in a special article of our portal.

Thus, local thermal unit home is necessary to lower the temperature and pressure to settlement operational levels, while ensuring that the required selection of heat sufficient for heating a particular building.This role is performed by a special heat equipment.As already mentioned, it can be a modern automated systems, but often preference is given to a proven scheme of elevator assembly.

If you look at the heat distribution poon kt rear anija (often they are located in the basement, in the main heating network entry point), you will see a node in whichclearly visible bridge between the feed pipe and « the return ».It is here and he is an elevator, the device and the principle of operation will be discussed below.

How does the work and the elevator heating

Outwardly he elevator heating is cast iron or steel construction, provided with three flanges for tie-in system.

look at its structure inside.

Hot water from the thermal highway enters the inlet elevator (Pos. 1).Moving forward under pressure , it passes through a narrow nozzle (pos. 2).The sharp increase in the flow velocity at the nozzle exit leads to injection effect - in receiving chamber (. Item 3) created discharge zone.In this area of ​​low pressure under the laws of thermodynamics and hydraulics literally "sucked" out of the water pipe (pos. 4), connected to the pipe « the return".As a result, in the mixing throat elevator (pos. 5) the mixing of hot and cooled streams, the water receives the necessary intranet temperature decreases the pressure to secure for heat exchange level of the instrument, and then the coolant through the diffuser (pos. 6) enters the systeminternal wiring.

addition to lowering the temperature, the injector performs the role of a pump - it creates t t rebuemy water pressure, which is necessary to ensure its circulation in intrahouse wiring, overcoming the resistance of the hydraulic system.

As you can see, the system is extremely simple, but very effective as it causes widely used, even in a competitive environment with a modern high-tech equipment.

course, the elevator needs a certain trim.The approximate scheme of elevator assembly given on to scheme:

warm up the water from the heating main acts through the pipe supply (item 1.), And returns to her through the pipe the return ( pos. 2).From the main pipe-house system can be switched off by a valve (Pos. 3).The entire assembly of individual parts and devices made using the flanges (pos. 4 ).

regulating equipment is very sensitive to the purity of the coolant, so the input and output of the system are mounted sumps filters (pos. 5), direct or "oblique" type.They settled t t Verde insoluble inclusions and dirt that gets into the cavity of the pipe.Periodic cleaning is carried out of mud collected from rainfall.

On certain node stations installed instrumentation.It gauges (pos. 6), to monitor the level of fluid pressure in the pipes.If the inlet pressure up to 12 atmospheres, then at the exit of the elevator assembly is significantly lower and depends on the number of storeys of the building and the amount of heat exchange points it .

sure are temperature sensors - thermometers (item 7.) Controlling the temperature of the coolant level: at the entrance of the control panel - t n , the entrance to the in-house system - t with , to " the return »system and control panel - t wasps and t est .

Next, set himself an elevator (pos. 8).Terms of its installation require the obligatory presence of a straight section of the pipeline is not less than 250 mm.One, it is through the inlet flange connected to the supply pipe of the panel, the opposite - the pipe layout intrahouse (11 pos.).Lower tube with a flange connected via jumper (pos. 9) to the pipe « otbratki » (pos. 12).

for maintenance or emergency repairs are provided valves (pos. 10), is completely disconnected from the node Squirrel intrahouse network.The diagram is not shown, but in practice are always present special elements for drainage - drainage water from intrahouse system should the need arise.

course, the scheme is given in very simplified form, but it fully reflects the basic unit of elevator assembly.The broad arrows show the direction of coolant flow with different levels of temperature.

indisputable advantages of using elevator assembly to adjust the temperature and coolant pressure are:

• Simple design with the reliability of operation.
• Low cost components and their installation.
• Full volatility of such equipment.
• Using the elevator units and metering heat can achieve savings in the consumption consumed coolant up to 30%.

There are, of course, very significant disadvantages:

• each system requires individual calculation for the selection of the desired elevator.
• it is imperative differential pressure upstream and downstream.
• impossible to accurately smooth adjustments in the current change of the system parameters.

Last disadvantage - rather conditional, since in practice often used grain elevators, which provide the ability to change its performance.

For this special needle is in receiving chamber with the nozzle (item 1). - Cone-shaped rod (item 2.), Which reduces the cross-section of the nozzle.This rod kinematic unit ( item 3.) Through the rack and pinions gear transmission ( poses 4 -. 5) associated with the adjusting shaft ( item 6.).Rotation of the shaft causes the conical cavity of the nozzle, increasing or decreasing the clearance for the passage of fluid.Accordingly, the change and the operating parameters of the whole elevator assembly.

Depending on the level of automation of the system, can be used various types of controlled elevators.

Thus, the rotation transmission can be carried out manually - responsible specialist monitors indications of instrumentation and makes adjustments to the operation of the system, focusing on on worn about the flywheel (handle) scale.

Another option - when the Squirrel knot tied to electronic monitoring and control system.Readings are taken in automatic mode, the control unit generate signals to transmit them to the actuators, through which the rotation is transmitted on kinematic mechanism controlled elevator.

What you need to know about coolants?

in the heating system - especially in the autonomous, as a coolant can be used not only water.

What qualities should a coolant for heating , and how to choose it - in a special publication of the portal.

calculation and selection of the elevator system heating

As already mentioned, for each building is required certain amounts of thermal energy.This means that there should be a certain calculation elevator , based specified operating conditions of the system.

the source data include:

1. Temperatures:

- at the entrance of the thermal panel;

- in « return pipe» thermal panel;

- operating value for intrahouse heating system;

- in the return pipe of the system.

1. total amount of heat, and a suit for the heating of a particular home.
2. parameters characterizing features intrahouse heating wiring.

Procedure calculation elevator installed a special document - "Code of Practice for the design of the RF Ministry of Construction," JV 41-101-95 relating to it thermal design points.This regulatory guide provides formulas for calculating , but they are - quite "heavy", and bring them in the article - there is no need.

Those readers who have little interest in questions calculation , can safely skip this section of the article.And for those who wish to self-assess Squirrel node, we can recommend to spend a 10 ÷ 15 minutes of time to create your own calculator, based on the joint venture formulas, allowing to carry out precise calculations just a matter of seconds.

Creating a calculator for calculating

For Excel required regular application, which is probably every user - it is included in the basic package MicrosoftOffice programs.Preparation calculator does not present much difficulty, even for those users who have never experienced the issues of elementary programming.

consider steps:

(if part of the text in the table goes beyond the bottom is the "engine" for horizontal scrolling)

Illustration	Brief description of the operation being performed
	Open a new file (book) in Excel in Microsoft Office.