In boiler houses, centrifugal pumps with an electric drive are mainly used, which, according to their purpose, are divided into feed, make-up, network, raw water and condensate.

The main characteristics of the pumps are:

Supply (volume of water supplied by the pump per unit time) in m 3 / h (l/s);

Pressure (pressure difference after the pump and before it) in m of water column;

The permissible water temperature at the pump inlet, at which the water in the pump does not boil, is 0 C.

In order to increase the reliability of water supply to boiler room devices, at least two parallel-connected pumps with the same characteristics are usually used, of which one pump is working and the second is backup. If the pumps operate simultaneously, then the water pressure behind the pumps remains the same, and the water supply increases and becomes equal to the sum of the supply of each of the pumps (Fig. 66).

The pump supply is regulated by valves installed on the pressure sections of the pipelines, and if there is a bypass line (bypass), by bypassing part of the water from the pressure pipeline into the suction pipeline.

Rice. 66. Pumping unit:

1 - pump; 2 - electric motor; 3 - foundation; 4 - spring shock absorber; 5 - flexible insert; 6 - adapter pipe; 7 - check valve; 8 - valve; 9 - pressure gauge; 10 - bypass pipeline.

From centrifugal pumps in boiler houses, single-stage cantilever pumps of type K (KM), single-stage double-suction pumps of type D. and multi-stage pumps of type TsNSG, as well as multi-stage condensate pumps of type KS are widely used

Cantilever pumps are designed for pumping clean, non-aggressive water with temperatures up to 85 0 C in quantities from 5 to 350 m3. At the same time, the pressure they create is 20 - 80 m of water column.

According to the method of installation and fastening, pumps are divided into two types: K and KM (Fig. 67). Type K pumps have a stand-alone stand that is attached to a support frame. The pump shaft is connected to the electric motor shaft by an elastic coupling.

Rice. 67. Console pumps:

1 - housing cover; 2 - body; 3 - sealing ring; 4 - impeller; 5 - stuffing box; 6 - protective sleeve; 7 - oil seal cover; 8 - shaft; 9 - ball bearing; 10 - electric motor.

For KM type (monoblock) pumps, the impeller is mounted on an extended electric motor shaft, and the pump housing is attached to the electric motor flange. Otherwise, the pumps have the same design. Their pumping parts are unified and have identical technical characteristics.

The volute casing of the K-type pump has a discharge pipe and two support legs cast at the same time. In front of the pump, along its axis, a cover with a suction (inlet) pipe is attached to the body. This allows, if necessary, to remove the cover and remove the impeller without completely disassembling the pump. There is a drain hole at the bottom of the housing, and at the top there is a hole for releasing air when the pump is filled with water. The holes are closed with threaded plugs. The impeller is mounted on the cantilever part of the shaft, which rotates in two ball bearings. Bearings are lubricated by oil located in the bearing housing. The pump is protected from water leaks along the shaft by a stuffing box sealed by the stuffing box cover.

The brand of a cantilever pump is indicated by three numbers, for example, K 50 - 32 - 125. The first number indicates the diameter of the suction pipe in mm, the second number indicates the diameter of the discharge pipe in mm, and the third number indicates the diameter of the impeller, mm

Centrifugal horizontal single-stage double-entry pumps are used as network pumps, since they have the highest flow rate for centrifugal pumps (Fig. 68). Its value ranges from 200 to 800 m/h. The pressure created by the pumps is used to overcome resistance in the boiler room and in heating networks and ranges from 40 to 95 m of water. Art.

1, 3 - steam supply; 2 - waste steam removal; 4 - steam cylinder block; 5 - water drainage to the boiler; 6, 8 - discharge valves; 7 - suction valves; 9 - water supply; 10 - water cylinder block; 11 - spool.

Network circulation pumps for installation in a boiler room or heating have been used for a long time by many owners of private households and summer cottages. Steam piston pumps allow you to provide the room with heat at any time of the year, since they do not depend on utility networks.

In this article we will tell you what the operation of such devices for thermal boilers is, what are the features of use, and how to correctly calculate the pressure power, heat and pipeline resistance when purchasing equipment.

1 How to choose a device?

The feed pump for water circulation and heat boilers is selected based on the following nuances:

• the amount of heat that will be required to heat the building;
• calculation of the thermal insulation value of walls;
• climatic conditions of the region where the consumer lives;
• is there in the building window frames and how many of them there are;
• selection is also carried out taking into account the surface structure of the ceiling and floor.

To correctly calculate the water circulation device, The choice of unit for thermal boilers is carried out with the choice of coolant. The selection of this element includes an analysis of the properties of viscosity, heat transfer, and heat capacity. In order for the operation of thermal boilers to be most efficient and balanced, network pumps are selected taking these parameters into account.

1.1 Features of use

Calculation and selection of a device for water circulation must be carried out taking into account all aspects. For example, if you buy an SE 2500 60 pump, and the power of your system is less, then the circulation unit will consume an order of magnitude more electricity. In addition, the SE 2500 60 pump, when operating in a low-power system, will provoke the appearance of noise in the pipes, and this indicates that feed pump was chosen incorrectly.

However, noise in pipes is not always a consequence of incorrect operation of the water circulation device for the boiler room. Often noise occurs when batteries have built up airlock. The process of removing air pockets is carried out using specialized valves, but this must be done before you start heating the house.

In the case when there is no air in the pipes and the system as a whole is running, the feed pump must run for some time, after which the process of removing the air lock is repeated again. Then the pump SE 800 or another brand should be adjusted again, however, most companies produce circulation devices with the function automatic adjustment. When the air lock is completely removed and the device is adjusted, the boiler room will be ready for full operation.

If your steam circulation pump is unregulated, then The first start of water should be done at the lowest pressure. Adjustable SE pumps for thermal boilers only need to be configured so that the release function is turned on - then the device will independently regulate the pressure. Modern water circulation units are equipped with a metal body and ceramic bearings. Thanks to this, the operation of the unit will be almost silent.

1.2 Power calculation

Calculation and selection of power available to SE pumps is carried out by analyzing the heat needs of a house or room. This indicator is calculated taking into account the coldest temperatures climate zone where the consumer lives.

Below we will tell you how to correctly determine the necessary indicators so that the pressure during operation of the device is most optimal and can warm up the entire house.

1.3 Heat

Heat calculation is the first thing you need to do when you select PE feed pumps. First of all, in order for the operation of thermal boilers to be more efficient, it is necessary to calculate the area of ​​the building that it will heat. In accordance with international standards, the calculation is made as follows:

• For one square meter a house containing two apartments will require a SE 800-100 W energy device or from another manufacturer.
• For multi-storey buildings You can purchase a circulation pump SE 1250 70, a device SE 500 70 or any other circulation pump with a power of 70 W.

If the house was built in violation of standards, then when calculating the power a part of the building with a higher level of heat consumption should be used. If your house or building is equipped with additional thermal insulation, then drives with a consumption of 30 to 50 W/m² can be used for thermal boilers of these systems. In the countries of the post-Soviet space, utility companies carry out calculations according to the following principle:

• Small buildings (1-2 floors) consume about 170 W/m² if the air temperature is 25 degrees below zero. If the temperature drops to -30, then this figure increases to 177 W/m².
• If the building is multi-story, then the heat boiler drives will consume about 97-102 W/m².

Now regarding the choice, you need the performance that the drives should have.

This can be a pump SE 1250 70, a device SE 500 70 or any other, the performance is calculated using the formula G=Q/(1.16xDT), where:

• 16 is an indicator of the specific heat capacity of the liquid.
• DT is the difference temperature conditions in the supply and return pipelines. Typically this figure is about 20 degrees. In low-temperature systems it decreases to 10%, and if the building is equipped with a heated floor system, then only 5 degrees.

2 Pressure calculation

In addition to the above parameter, the SE 1250 140 pump or any other drive must create the required pressure, that is, pressure. The pressure indicator must be such that the liquid can circulate through the system without problems. When designing a new building, it will be difficult to calculate pressure calculations so that the result is accurate. As a rule, all information is indicated in the service book for the SE 500 pump or another brand. How to calculate the pressure using the formula H=(RxL+Z)/p*g:

• R – resistance indicator in a flat pipe;
• L – total length of the pipeline;
• Z – indicator of reinforcement resistance;
• p – density;
• g is the gravitational acceleration indicator.

Please note this formula pressure calculations are only relevant for new heating systems.

2.1 Pipe resistance

If you decide to purchase a pump SE 1250 140 or a device SE 800 100, or from another manufacturer, then you should not forget about the resistance of the pipeline. In practice, experts have found that this indicator varies around 100-150 Pa/m.

Then the pressure that the SE 1250 140 or any other pump should have should be from 0.01 to 0.015 m per meter of pipe.

Experts also claim that when water passes through reinforced areas, about 30% of the total pressure is lost. If the system is additionally equipped with a thermostatic valve, then this figure can be increased by 70%.

When you have calculated all the necessary parameters, you need to decide on your budget and choose a device that matches the obtained characteristics. If there is no such unit, then the characteristics should be at least approximately the same. Remember that the numbers obtained are indicators of the device’s performance at maximum loads.

But since the need to use devices with heavy loads is minimal and can arise only several times a year, then if you need to choose a more powerful or less powerful unit, experts recommend choosing a less powerful one. In practice, this does not affect operation in any way. heating system generally.

2.2 Network pump Etaline - dismantling, installation, fault diagnosis (video)

Pumps- devices for pressure movement of mainly liquids with the imparting of energy to them.

Network pump for heating and ventilation systems. This pump serves to circulate water in the heating network. It is chosen according to consumption network water from the calculation of the thermal diagram. Network pumps are installed on the return line of the heating network, where the temperature of the network water does not exceed 70 °C.

Recirculation (boiler, anti-condensation, anti-condensation) pumps installed in boiler rooms with hot water boilers for partial supply of hot network water to the pipeline supplying water to the hot water boiler.

In accordance with SNiP I-35-76 (clause 9.23), the installation of recirculation pumps is carried out if the manufacturers of hot water boilers require a constant water temperature at the inlet or outlet of the boiler. As a rule, it is necessary to provide general circulation pumps for all hot water boilers. The number of pumps must be at least two. The performance of the recirculation pump is determined from the balance equation of the mixing flows of network water in the return line and hot water at the outlet of the hot water boiler. Regulation of the temperature of the water entering the hot water boiler and the temperature of the water supplied to consumers is carried out as follows. Amount of water supplied recirculation pump, is adjusted so as to obtain the required water temperature at the inlet to the hot water boiler. However, the temperature of the water leaving the boiler may be higher than the temperature required by consumers. To maintain the set temperature of water supplied to consumers, part of the water from the return line is directed through a jumper into the forward line. The amount of water taken from the return line to the forward line is regulated by the network water temperature regulator.

Make-up pump. Designed to replenish water leaks from the heating system, the amount of water required to cover the leaks is determined in the calculation of the thermal circuit. The capacity of the make-up pumps is selected equal to twice the amount of water received to replenish possible emergency make-up.

The required pressure of the make-up pumps is determined by the water pressure in the return line and the resistance of the pipelines and fittings in the make-up line; the number of make-up pumps must be at least 2, one of which is a reserve one.

IN production premises and workshops use industrial pump equipment for boiler rooms. Thanks to its use, it is possible to achieve savings on heating costs by quickly moving the coolant through the pipes. In addition, the pumps make it possible to supply even the most remote buildings from the boiler room. hot water. They create the necessary fluid pressure in the system, thanks to which the coolant moves through the pipeline.

All pumps are energy machines that, in order to move liquid through a pipeline, increase its pressure by static or dynamic action. They are divided into two main groups: dynamic and volumetric. The first group includes devices that move liquid due to hydrodynamic forces. Displacement pumps operate by creating surface pressure by changing the working chamber.

Pumps for boilers and other purposes

The two main groups of pumps include many subtypes. Thus, dynamic models can be: centrifugal and axial, inertial, vortex, worm and disk. Volumetric: rotary and reciprocating action.

To choose the right pumping equipment, you need to know the answers to the following questions:

• what is the fluid flow rate and at what pressure is it planned to pump;
• operating conditions, where and at what temperatures the pump will be used - indoors or outdoors;
• for what purposes the equipment is used. Thus, the characteristics of pumps for boilers differ significantly from the parameters of devices designed for supplying water from wells or pumping out waste fluid;
• information about the liquid used: the presence of solid particles and their fraction size, viscosity, toxicity and other parameters.

In relation to heating and hot water supply systems, the most the best option are circulation pumps. They promote constant circulation of coolant in the heating circuit, thereby increasing heat transfer and operating efficiency of the boiler room. The use of circulation pumps optimizes the thermal regime in industrial premises, thereby reducing energy costs and increasing the service life of heating equipment.

Company TPK "European engineering systems» offers circulation pumps that meet the following requirements: silent operation, reliability, low energy consumption and long service life. All products are manufactured by world leaders in pump manufacturing, which are German and Italian companies.

Basic parameters of pumps

For a more detailed selection of a pump, you need to know which parameters to pay attention to first. For any equipment model, this is the pressure “H” and the flow “Q”. Knowing these two parameters, you can freely select a pump for your planned purposes.

Pressure is the difference in fluid energy at the entrance to the pump and after leaving it, it is calculated in meters of water column. This value is also called outlet water pressure.

Flow is the volume of liquid that the pump transfers per unit of time. The parameter is determined in liters per second or cubic meters per hour.

TPK "European Engineering Systems" supplies industrial pumps with a wide range of basic technical characteristics, which are pressure and flow.

Pumps are machines designed to move liquids and impart energy to them. Feeding, make-up, network, condensate, circulation and other pumps are installed in boiler rooms. They are selected based on performance and pressure. The number of pumps must be at least two, one of which is a reserve one. In boiler houses, vane (centrifugal, vortex, axial) and jet (ejectors, injectors) pumps are used. The drive motor for the pump is electric motors, which are usually connected using a coupling.

1. Feed pumps. In boiler rooms with steam boilers Feed pumps are installed, which can be centrifugal or piston (electric or steam driven). Their number must be at least two with independent drives, and one pump (or more) must be steam driven.

Performance of one electric pump, kg/s

Pressure created by the feed pump, MPa

We select the pump according to the table. 15.3. We choose 2 productive pumps.

The capacity of the feed pump (backup) with a steam drive must be at least 50% of the rated capacity of all boilers

The pressure remains the same = 1.672 MPa.

We select piston steam pumps according to table. 15.7.

2. Network pumps. Designed to create circulation and installed on the return line of heating networks, where the water temperature does not exceed 70 °C. The performance of the network pump is determined by total consumption network water = 16.62 kg/s or 59.8 m 3 / h.

1.1*=59,8*1.1=65,8

The pressure of the network pump is MPa

We select network pumps according to the table. 15.4…15.6.

3. Condensate pumps

Their performance is determined based on the maximum amount of condensate, and the pressure must be sufficient to overcome the resistance of the condensate pipelines, the pressure in the deaerator and the hydrostatic head due to the difference in levels of the installation sites of the pump and deaerator (approximately MPa). We select a condensate pump according to the table. 15.10.

4. Make-up pumps. Serve to replenish water leakage from the heating system. We select the capacity of the make-up pump to be twice as large for the possibility of emergency make-up of the heating network

The required pressure of the make-up pump is determined by the water pressure in the return line of the heating network and the resistance of the pipelines and fittings in the make-up line, approximately

We select the feed pump according to the table. 15.10.

5. Source water pump. Designed to supply water from the boiler house water supply source (reservoir, water supply, well) to the water treatment system (WTS). For raw water pumps we use a K brand pump.

The pump capacity is

Select the required source water pump pressure MPa

We select a network pump according to the table. 15.10.

The results of the selection of all pumps are summarized in a final table.

Table 10. Final table for pump selection

Pump purpose		Performance	Head, N, m		Power,	Speed	Electrical type engine
Feed pump
Spare pump
Network pump
Network pump
Make-up pump
Source water pump
Condensate pump