Design and principle of operation of centrifugal network pumps

After the initial filling of the heating circuit, sooner or later, due to various reasons, the coolant level inevitably decreases. To avoid emergency shutdown of equipment during the cold season, timely replenishment of the heating system is required. Let's look at what this procedure is, what types of heating systems there are and what are the features of the coolant circulation in them, what types of coolant are used and what requirements are imposed on them, what are the main reasons for the decrease in coolant level in the system, what are the features of the make-up procedure for open and closed systems.

Charging diagram for a heating system with natural coolant circulation Source kotle.ru

How to choose a circulation pump for heating

To select equipment taking into account the most suitable parameters, you must use certain formulas

. However, only specialists know which formulas need to be used in each specific case. And if the device is selected by an unknowing person, then you should use the following recommendations:

• Marking of the circulation pump
  . For example, Grundfos UPS 25-50 equipment, where the first two digits indicate the thread diameter of the nuts - 25 millimeters (1 inch), which are supplied with the device. There are also pumps with nut diameters of 32 millimeters (1.25 inches). The second two digits are the maximum height of coolant rise in the heating system - 5 meters, that is, using a circulation pump, an excess pressure of no more than 0.5 atmospheres can be created. There are also pumps in which the lift height is 3, 4, 6 and 8 meters.
• Unit performance
  .
  It is the main parameter that determines the operation of the unit. Represented by the volume of coolant pumped using a pump. The formula used for calculation is: Q=N:(t2-t1),
• where N is the power of the heat source. This could be a boiler or a gas water heater;
• t 1 – shows the temperature of the water in the return pipe. As a rule, it is +65-70 0 C;
• t 2 - shows the temperature of the water that is in the supply pipeline (coming out of the boiler or geyser). Often the boiler maintains +90-95 0 C.
• Calculation of the heating system and its losses is carried out in order to correctly select the design parameters of the unit that is able to cope with the resistance in the heating system.

Mass-produced equipment has average characteristics. Therefore, it is necessary to take into account the individuality of each heating system.

Note! Selecting a suitable pump should take into account the ability of the unit to operate in several modes, and its power should exceed the design power by 5-10 percent

Operating principle of the automatic recharge unit

Once a drop in system pressure is detected, the adjustable pressure sensor is activated and the pump contacts are closed. The coolant is topped up either from the water supply or from a storage tank. After reaching the required coolant pressure in the system, the pump turns off.

Such a device has another undeniable advantage - using a make-up pump you can pump coolant into the system without disassembling the heating system. This may be necessary to repair or replace the coolant.

How to use a boiler room thermal diagram

The thermal circuit helps monitor the condition and operation. Due to flue gases, corrosion of low-temperature or sulfuric acid metal coatings cannot be ruled out. And to prevent it from appearing, the water temperature should be monitored. It is noteworthy that at the entrance to the boiler the optimal temperature will be 60-70 degrees.

And in order to be able to increase the temperature to the required levels, a recirculating pump is installed. Water heating boilers need to be monitored so that their service life is decent; control the consistency of water consumption. Typically, the minimum data for this indicator is set by the manufacturer.

In order for boiler rooms to work well, you need to use vacuum deaerators. Typically, a water jet ejector will create a vacuum, and the released steam will be used for deaeration. But, the main thing that they are afraid of when installing a boiler room is permanent attachment to the place. Modern automation simplifies many processes.

Why do you have to add water to the system?

For the boiler to work correctly, it is necessary to maintain the recommended pressure in the system. Obviously, for this to happen, a constant volume of coolant must circulate in the water heating system. And it can change during operation even in a perfectly designed and assembled structure. Loss of coolant occurs when:

• The air is bleed through the Mayevsky valve located on the radiator. As you know, you have to open the air vent and wait until a trickle of water comes out of it.
• In automatic mode, excess pressure is released through a safety valve due to a change in the operating mode of the system. In this case, the coolant escapes into the atmosphere in a gaseous state.
• The filters are cleaned from mechanical contaminants.
• There are significant or microscopic leaks, for example through dismountable connections.
• In systems with natural circulation, water evaporates through an open expansion tank.

Working principle of safety valve

Features of connecting pumping equipment

If a forced circulation system is used to service the house, then when the electrical power is turned off, the boiler pump must continue to operate, receiving energy from a backup source. In this regard, it is best to equip the heating system with a UPS, which will maintain the operation of the structure for several more hours. External batteries connected to it will help extend the life of the backup source.

When connecting the pump, you must avoid the possibility of condensation and moisture getting into the terminals. If the coolant heats up to more than 90 °C, then a heat-resistant cable is used for connection. You will also need to avoid contact of the pipe walls and power cable with the motor and pump housing. The power cable is connected to the terminal box on the right or left side by changing the location of the plug. In the case of a side-mounted terminal box, the cable must be routed only from the bottom. A prerequisite is that grounding must be connected to the pump.

Mains pumps are often used in boiler rooms. Such products perform the function of pumping hot water in a heating network system. The temperature of the network water, which the installed unit is capable of driving through the pipes, reaches +180 degrees.

At the same time, the device and design of network pumps are relatively simple, and at the same time, the devices show a high level of performance along with reliability.

Forced circulation system elements

Forced circulation is a process that requires the installation of not only a pump, but also other required elements.

These include:

expansion tank to compensate for the volume of coolant when temperature changes; safety group, including pressure gauge, thermometer, safety valve; radiators connected according to one of the wiring diagrams; Mayevsky taps or air separator; check valve; system fill and drain taps; coarse filter.

In addition, when using a solid fuel boiler as a heater. without the automatic fuel loading function, it is recommended to include a heat accumulator in the system - a storage tank of the required volume. This will equalize the temperature of the coolant and avoid its daily fluctuations.

Feed pump for steam boiler device device

Each pump for a heating boiler performs its tasks in a closed-type heating system. The main element of such a pump is the rotor, on which the efficiency of the unit directly depends. When the pump operates, the rotor rotates inside the stator, which is fixedly mounted on a solid base. Some models are equipped with a ceramic stator, which protects the rotor from limestone.

The edges of the rotor are equipped with blades, the rotation of which pushes the coolant further through the pipes. For the most part, boiler pumps are equipped with one rotor, but there are models with several working elements. The rotor is driven by an electric motor. The motors of most pump models are characterized by high power and long service life. All pump elements are housed in a durable aluminum or stainless steel housing.

Rules for installing boiler pumps

Any equipment, be it a unit for a heating system, or a pump for flushing boilers, must be installed strictly in accordance with the manufacturer’s recommendations. One of the most important conditions is to choose the correct location of the device. The pump shaft must be positioned strictly horizontally. Otherwise, air pockets will form inside the system, which will leave the bearings and other elements of the unit without lubrication. The result of this will be rapid wear of the device parts.

Another important condition is the correct choice of location for inserting the pump. The unit must force liquid to move through the pipeline

The standard installation diagram of the device is shown in the image below.

The main elements in the diagram are shown in this order:

• boiler;
• coupling connection;
• valves;
• alarm system;
• pump;
• filter;
• membrane type tank;
• heating radiators;
• liquid feed line;
• Control block;
• temperature sensor;
• emergency sensor;
• grounding

This scheme ensures the most efficient operation of the pump and heating system. At the same time, energy consumption by each individual element of the system is reduced to a minimum.

Video description

Video on how to install the make-up valve:

• If replenishment is carried out through the return, then the boiler must be turned off. Otherwise, cold coolant entering a heated heat exchanger can lead to thermal deformation of the latter. This is especially true for cast iron models.
• Automatic make-up for a floor-standing boiler with a cast-iron heat exchanger is best done through a direct manifold.
• If possible, it is better to make replenishment through a hydraulic arrow so that the cold coolant quickly mixes with the hot one and eliminates thermal shock for the heat exchanger.
• On condensing-type boilers, it is advisable to install the make-up in the return line - to increase the efficiency of the system.
• If there is indirect heating in the boiler system used for hot water supply to the house, it is allowed to supply heated water from it for replenishment through the return line.

Reference! Modern boiler models from official manufacturers are equipped with technical documentation, which includes important technical information. This is, first of all, a diagram of the correct piping indicating the location of the recharge unit.

Classification

All pumps are divided into two types:

Dry rotor pump

The working part of the rotor does not have direct contact with water thanks to the protection of several sealing wheels. These parts are made from carbon agglomerate, high-quality steel or ceramics, aluminum oxide - it all depends on the type of coolant used.

The device is launched by the movement of the rings relative to each other. The surfaces of the parts are perfectly polished, in contact with each other, they create a thin layer of water film. As a result, a sealing connection is created. With the help of springs, the rings are pressed towards each other, due to which, as the parts wear out, they independently adjust to each other.

The service life of the rings is approximately three years, which is much longer than the life of the stuffing box, which requires periodic lubrication and cooling. The efficiency indicator is 80 percent. The main distinguishing feature of the unit is its high noise level, as a result of which a separate room is required for its installation.

Glandless rotor pump

The working part of the rotor - the impeller - is immersed in the coolant, which simultaneously acts as a lubricant and as an engine coolant. Using a sealed stainless steel cup installed between the stator and rotor, the electrical part of the engine is protected from moisture.

As a rule, ceramics are used

, for bearings - graphite or ceramics, for the housing - cast iron, brass or bronze. The main feature of the unit is its low noise level, long period of use without maintenance, easy and simple settings and repairs.

The efficiency indicator is 50 percent. This is explained by the fact that sealing the metal sleeve, which separates the coolant and the stator, is impossible if the rotor diameter is large. However, for domestic needs, where coolant circulation is ensured in short-length pipelines, it is advisable to use such circulation pumps.

Composed of a modular design

modern “wet” type devices include:

• Frame;
• Electric motor with stator;
• Box with terminal blocks;
• Working wheel;
• A cartouche consisting of a shaft with bearings and a rotor.

The modular assembly is convenient because at any time it is possible to replace a failed part of the circulation pump with a new part, and accumulated air can be easily removed from the cartouche.

Grundfos make-up pumps develop quite high pressure

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Commissioning

Pumping technology has evolved quite a lot since its introduction into the national economy. At the moment, such devices are often equipped with all kinds of automation. Starting from protection against dry running, mechanical check valves that prevent reverse flow of the pumped substance, and ending with powerful electronic units that allow you to regulate the rotation speed, changing the frequency of the electric current, and measure various characteristics in real time: temperature, current, flow rate, and the like .

These processes did not pass by Grundfos pumps for recharging the heating system and boiler. These modern devices combine excellent quality with the use of the latest achievements of science and technology. Despite, at first glance, their auxiliary function, these devices are capable of creating quite high pressure, which allows them to be used even during the initial filling of the system, or during a planned replacement of the coolant.

And for a more detailed overview of the range, you can refer to the catalog of Grundfos charging pumps, located on the website of the official representative of the manufacturer in our country.

Installation of a chiller and air conditioning system in a shopping center building on Kashirskoye Shosse in Moscow

Employees of JSC “Unified Service Center” installed a chiller and related equipment in the building of a shopping center on Kashirskoye Shosse.

Where to buy “Grundfos charging pumps”?

Shipment of the product “Grundfos make-up pumps”

– pick up at the address Moscow, 127282, Polyarnaya street, building 31A, building 1. (show map)

In other cities

The cost of delivery to these cities depends on the availability of goods at the local warehouse. You can check current availability by calling our office in your city:

We can offer you the lowest possible price and shortest delivery times compared to competitors in your region.

The role of Grundfos booster pumps in the heating system

For heating systems, the role of pumping technology is especially important. Firstly, many modern systems require forced circulation of coolant in the circuit, and secondly, from time to time the system requires replenishment of the volume of coolant fluid. It is possible to create an absolutely sealed circuit, but this will not be a panacea, because after a certain period of time a partial or complete replacement of the coolant is required, depending on the technical conditions of the heating system. Also, do not forget about scheduled maintenance, which involves flushing the radiators and the circuit as a whole, which implies depressurization of the heating circuit. Therefore, regardless of the geographical location of the owner of the heating system (for example, in Lyubertsy), he will need a Grundfos feed pump.

Why are make-up pumping units needed?

The answer to this question covers many areas of industrial and domestic applications. We are talking about air conditioning, heating, ventilation and other engineering structures. And implementation in various auxiliary and main production processes allows the use of Grundfos booster pumps even for aggressive environments and liquids. This will ensure the non-stop operation of a production line, for example a SIP washing machine, which is a critical element in the food industry.

Various designs of the units allow them to be used under any environmental conditions: in a residential area, in a workshop, in a boiler room, outdoors. After all, the manufacturer has taken care of all possible ways to use this type of equipment. And even a Grundfos street pump has been developed, which is popular in Korolev and Mytishche.

Now you only need to carefully select the model of the required booster pump, based on the technical conditions of your system.

Current advice on configuration and maintenance

Whatever power supply you choose, remember, first of all, it should be safe and easy to use, made of high-quality materials. If the heating system is small, give preference to a device with the simplest possible design. The central support with moving parts and the internal compensation piston must be made of materials with a low adhesion coefficient: the risk of lime formation in the unit must be minimized. It is no secret that they are the main reason for the poor performance of the device.

Please note whether the product has a replaceable cartridge: this will greatly facilitate and speed up the process of inspecting the unit for you. Periodic maintenance of the make-up device will help avoid malfunctions in the entire heating system.

Periodic maintenance of the make-up device will help avoid malfunctions in the entire heating system.

To clean or replace the entire cartridge, proceed as follows:

1. Insulate the installation.
2. Unscrew the control knob located at the bottom.
3. Unscrew the adjustment screw until it stops and remove the cover.
4. Remove the cartridge with pliers.
5. After the necessary manipulations, reassemble the device.

All that remains is to set up the equipment again and continue to enjoy the uninterrupted operation of the heating system in your home!

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Monoblock pump

Previously, pumping units mounted on a foundation or frame, consisting of a pump and a drive, were used as network pumps. Mechanical energy was transmitted from the drive to the pump through a group of drive mechanisms. This was primarily due to the need to use powerful drives.

• The modern range of pumping equipment allows the use of monoblock pumps as network pumps.
• The use of monoblock pumps allows, first of all, to significantly save installation space.
• This is especially true when using monoblock pumps with a vertical shaft.
• The use of modern pumping equipment when modernizing existing boiler houses makes it possible to reduce the required installation area by two or more times.

Buy a network monoblock pump from Interpamps

Interpamps LLC offers reliable pumping equipment of the Etaline and Etaline-R series, with a capacity of up to 2000 cubic meters per hour, and a pressure of up to 100 meters of water column, designed for operating pressure up to 25 bar and temperatures from -30 to +140 degrees Celsius . Due to their design and operating parameters, Etaline pumps can be used as network pumps, both in stationary boiler houses and in block-modular ones. The nozzles located on the same axis in Etaline pumps greatly simplify the piping of the pumps. Allowing, among other things, the installation of Etaline pumps directly into an existing pipeline without changing the latter. The high efficiency and reliable design of the pumps can significantly reduce the cost of subsequent operation.

The central office of Interpamps LLC is located in Moscow, we offer our partners to buy high-quality pumping equipment inexpensively. We select pumping equipment at the request of our partners free of charge and in the shortest possible time.

The circulation pump for a heating system boiler performs a rather important function - it is responsible for the uninterrupted circulation of coolant through pipes and radiators. The efficiency of the heating system and the comfort of living in a private house or apartment largely depend on the choice of unit.

Reasons for reducing coolant volume

A decrease in the level in heating systems of a private house occurs due to the following number of reasons:

• Leak. Often the coolant begins to flow at the joints. It most often appears immediately after the crimping process. Therefore, they can be detected and eliminated immediately. However, there are also hidden, old leaks. It is quite difficult to identify them, due to the fact that they are located in concrete floor or wall screeds. To detect such an accident, it is often necessary to use a thermal imager. The only way to avoid this is to make all joints in an open, serviceable area.
• Exceeding operating parameters of a critical level. For example, if the coolant suddenly overheats, its pressure will increase sharply and exceed the permissible level for the equipment. As a result, the emergency valve will operate, which, in contrast to the replenishment module, will independently begin to eject liquid from the heating system until the internal pressure returns to normal.

Triggering of the emergency valve leads to the release of part of the coolant from the system Source stroy-podskazka.ru

Monoblock pump

Previously, pumping units mounted on a foundation or frame, consisting of a pump and a drive, were used as network pumps. Mechanical energy was transmitted from the drive to the pump through a group of drive mechanisms. This was primarily due to the need to use powerful drives.

• The modern range of pumping equipment allows the use of monoblock pumps as network pumps.
• The use of monoblock pumps allows, first of all, to significantly save installation space.
• This is especially true when using monoblock pumps with a vertical shaft.
• The use of modern pumping equipment when modernizing existing boiler houses makes it possible to reduce the required installation area by two or more times.

Buy a network monoblock pump from Interpamps

Interpamps LLC offers reliable pumping equipment of the Etaline and Etaline-R series, with a capacity of up to 2000 cubic meters per hour, and a pressure of up to 100 meters of water column, designed for operating pressure up to 25 bar and temperatures from -30 to +140 degrees Celsius . Due to their design and operating parameters, Etaline pumps can be used as network pumps, both in stationary boiler houses and in block-modular ones. The nozzles located on the same axis in Etaline pumps greatly simplify the piping of the pumps. Allowing, among other things, the installation of Etaline pumps directly into an existing pipeline without changing the latter. The high efficiency and reliable design of the pumps can significantly reduce the cost of subsequent operation.

The central office of Interpamps LLC is located in Moscow, we offer our partners to buy high-quality pumping equipment inexpensively. We select pumping equipment at the request of our partners free of charge and in the shortest possible time.

If the boiler room is designed correctly, it will serve the heating system, ventilation, and supply of hot and cold water. It can be said that no one designs communications independently. Focus on at least a standard plan. Its choice depends on the type of room for which it is intended.

The graphic drawing must reflect all the mechanisms, apparatus, instruments, as well as the pipes connecting them. Standard boiler room plans include boilers, pumps (circulation, make-up, recirculation, network), and battery and condensation tanks. Also provided are devices for fuel supply and combustion, as well as devices for deaerating water, heat exchangers, the same fans, heat shields, and control panels.

Those heating networks that operate on water are divided into two groups:

• Open (the liquid is taken from local installations);
• Closed (water returns to the boiler, giving off heat).

The most popular example of a schematic diagram is an example of an open-type hot water boiler house. The principle is that a circular pump is installed on the return line; it is responsible for delivering water to the boiler, and then throughout the entire system. The supply and return lines will be connected by two types of jumpers - bypass and recirculation.

The technological diagram can be taken from any reliable sources, but it would be good to discuss it with specialists. He will advise you, tell you whether it is suitable for your situation, and explain the entire system of action

In any case, this is the most important structure for a private home, so maximum attention should be paid

What you need to know about it

First of all, it is advisable to study the design of the heating system and understand the essence of its operation. Let's start with the fact that heating begins with boiler rooms, where some kind of fuel is burned (gas, coal, wood), and then the heat is transferred through pipes using a coolant. There are several types of coolants: air, steam and the most common - water. But water tends to freeze at low temperatures. Therefore, where necessary, antifreeze diluted with water is used in order to reduce the negative destructive effect on the pipeline. A calculation is made to help determine the correct ratio of water and antifreeze. With central heating, the coolant can be directed through a pumping system or through a conventional one.

The conventional, or natural, system is very simple: water heated in the boiler moves through some pipes, warming up the radiators, and then returns through others to heat up again. This simple device also has an expansion tank and air vents. The latter are needed in order to eliminate air bubbles and various gases that may accumulate in the pipes. And excess moisture, which appears when water expands from heating, goes into the expansion tank.

A closed heating system is characterized by a pump. It helps to accelerate the water faster than it moves in a conventional pumpless system. A pump is especially needed if the pipes are too narrow and this prevents the coolant from circulating.

Why is it needed?

The make-up valve is necessary to maintain the minimum pressure of the heating system within the specified parameters by pumping water from the water supply system. Normal pressure for heating is from 1.5 to 3 bar, water supply is from 2.5 to 6 bar. If the pressure drops for any reason, the make-up valve will automatically restore it.

According to standards, the valve is mounted on a pipe where ordinary water circulates. That is, on a pipe that is connected to the water supply system. It is worth remembering this, since purified water is used for the heating system (it leaves less deposits from the inside of pipes and radiators).

At the same time, the usual tap water was not filtered. It would be rational to install a small filter at the inlet and replace it periodically. This way you will protect pipes and joints from the rapid accumulation of deposits.

The make-up valve is installed only in a heating system where the heat carrier is water. If antifreeze is poured in, then not dosed dilution of the antifreeze can cause sediment to form, and this, in turn, will have a bad effect on the entire heating system.

https://youtube.com/watch?v=gKR1XgwF_bQ

What pumps are used for boiler rooms

Network pumps for boiler houses are most often centrifugal, equipped with an electric motor. By type they can be divided into: condensate, network, make-up, intended for raw water. You can also find this type of pump as a nutrient pump.

In water supply boiler systems, it is customary to install several devices at once that have the same characteristics. The pumps are connected in parallel, with one of them being the main one, and the second being a backup and starting as needed when the first one fails. However, it is also possible to operate two devices at once. In this case, the water pressure in the pipes remains the same as when operating one installation, but the water supply increases, the level of which becomes equal to the sum of the supply of each of the devices.

Pumps for boiler rooms can have enormous weight and dimensions

For boiler houses, the best option would be to install a centrifugal 1-stage pump type KM, a 1-stage unit type D with 2-way suction, or a multi-stage product type TsNSG. In addition, many professionals recommend installing condensate type KS units in the boiler room. In this case, the final choice depends on the specific requirements of the buyer, which, as a rule, are determined by the operating conditions of the future equipment.

Selecting a device and calculating the required pressure

Pumps for boiler rooms are selected strictly based on the requirements of the heating system, or more precisely, on the required pressure. To understand what pressure is needed for optimal operation of your system, you can refer to the formula created for this purpose.

The formula at first glance does not look the simplest, but when studying each value, calculating the required pressure is not difficult. The symbols in the formula by which you can calculate the required pressure mean:

Along with the pumps, pressure gauges, taps, and filters are installed

• H – the required pressure value in meters of water column;
• Ltotal is the total length of the circuits, taking into account the return and supply pipes. If you use a heated floor, you need to take into account the length of the pipes laid under the floor in the calculation;
• Rsp is the specific resistance level of the system pipes. Taking into account the reserve, take 150 Pa per 1 linear meter;
• r is the total resistance value of the system pipeline;
• Pt – specific density of the coolant;
• G is a constant that is equal to 9.8 meters per square centimeter, or the unit of acceleration due to gravity.

It is often difficult to calculate the total resistance of system elements. However, in this case, you can simplify the general formula by replacing the coefficient k, which is a correction factor, instead of this sum. Thus, the correction factor of a system in which any thermostats are installed will be equal to 1.7.

For a conventional system with standard fittings and taps that do not have elements for thermostatic regulation, the correction factor is 1.3. A system that has many branches and highly saturated shut-off and control valves has this coefficient at 2.2. The calculation using the final formula, in the case of a correction factor, will have the following form: H=(Lsum*Rud*k)/(Pt*g).

By calculating using this formula, you will be able to understand what parameters and characteristics the pump you need to purchase has. We emphasize that it is recommended to choose a pump for boiler rooms whose power will not exceed that necessary to create the required pressure. If you buy a pump with more power than is needed to provide the desired pressure, you will simply be wasting your money.

Automation and boiler installation diagram

Automation makes it possible to use a set of programs that control heat flows. It also depends on the daily routine and the weather. This is also needed for heating additional rooms: a playroom, a swimming pool.

There are some popular user functions that adapt the operation of the equipment taking into account the lifestyle of the home owners. This is both a conventional hot water supply system and a set of some individual options that are convenient and economical for these particular residents. In the same way, you can develop a boiler room automation scheme by choosing one of the popular modes.