Heating system with forced circulation. Heating circuit

Many, tired of the city bustle, dream of a summer cottage or a cottage. But to be there all year round, it is necessary to install heating at home.

Types of heating system

There are two types of heating systems, which differ in the way of circulation of heat carriers. The principle of a simple system is the spontaneous movement of liquid through a pipeline. In this case, no additional device is required, but the required pipe slope and diameter should be taken into account. Natural circulation occurs when the heat carrier, heated in the boiler, expands, moves under pressure through the heating pipes and gradually cools down in the radiator. Such a system is used in buildings with a small area and for boilers with low power. The efficiency of natural circulation through pipes is very low.

When a forced circulation heating system is used, a pump is used to ensure the flow of coolant in the pipeline, which must be installed in the return pipe. When installing the pump in the return pipe it is protected from contact with the hot coolant, which significantly extends its service life. The pump is better to choose with high power, since the higher the fluid velocity in the system, the higher the room temperature.

The pump requires a constant supply of electricity, but if there is a failure, it does not matter, the device can run from a gasoline generator.

Advantages of the circulation system

- The house heating system is simplified, since there is no need to install an overhead wiring, there is no need to ensure the slope of the pipeline.

- Funds are saved for mounting large diameter risers, as they are not required.

- You can use a system with a collector type of wiring, when it is used, the radiators are evenly heated.

- It is possible to increase the length of the pipes.

- This heating scheme allows you to arrange an additional system of "warm floors".

- The operating mode is adjusted.

- The possibility of connecting metal pipes to the boiler.

disadvantages

Disadvantages of this system, although not significant, but they still are:

- The operation of the pump requires the supply of electric current, which leads to a cost overrun, but if there is no energy, the pump stops working.

- There is a noise during the work, albeit insignificant.

- Requires large material costs for the installation of additional elements and for installation.

The circulation pump is installed on the "return" in front of the boiler. An expansion tank is also installed nearby, which is mandatory in a closed system.

Open and closed heating circuits

As a rule, in open wiring of the heating medium, the heating circuit has an expansion tank, where water evaporates as evaporation evaporates. A system with open wiring requires constant monitoring, as if the water boils, then the entire heating system may fail.

The most common is dual-circuit heating. It is a two-pipe system with forced circulation. To make it work correctly, special equipment is additionally installed.

Pump Selection

For forced circulation heating to function correctly and for a long time, two basic rules must be taken into account when choosing a pump. It must meet the following requirements:

- have energy-saving qualities;

- its use should be simple and reliable.

Which pump is best

The power and head of the device are selected depending on the heated area, but which pump is best used, it is very difficult to say, in this case it is necessary to perform the calculation of heating. Correctly this can be done only by a professional, since it is necessary to provide for certain factors.

When calculating it is necessary to take into account the diameter of the pipes used, the material, the required number of radiators, all the stop valves, the fuel used for heating.

From the above, we can conclude that making the calculation of heating is very difficult.

It also happens that when private heating systems are used, there is no circulation. The reason can serve as air cushions, for the elimination of which a radiator is installed on each radiator to release air. This is the best method to circulate the system. Purchasing cranes Maevskogo, it is important not to forget that the sale of designs with automatic release of air, which allows you not to control its formation.

Membrane Expansion Tank

Unlike open tanks, the closed system does not come into contact with the atmosphere. The increase and decrease of the volume of the liquid is controlled by the membrane located inside the closed tank. It has the form of a hermetically sealed container, which is internally separated by a flexible membrane. The upper half of the tank is filled with air or nitrogen, and the lower one is connected to the heating system. This unit is able to control an unexpected increase or decrease in pressure, saving the system from breakdowns. The capacitance value is chosen taking into account the thermal expansion of the coolant. Approximately 10% of the volume of coolant in the pipeline. But it is important to carry out pressure monitoring, observing the technical requirements for the boiler and the pump.

Before installation, the diaphragm tank is pumped up to the required pressure, established by the norms. In some cases, the tanks come on sale already with pumped capacity. In this regard, they are pre-checked. For domestic systems, the pressure should not exceed 4 bar.

Also, many are wondering about where to install the tank. The heating system with forced circulation provides for the installation of the tank on the "return", to the pump, it is located closer to the boiler. To avoid an accident in the event of an increase in pressure in the pipes, which will be greater than the expansion tank can withstand, a safety valve must be installed .

Automatic air vent

The forced circulation heating system also includes an air vent with an automatic device. It plays an important role in the system and performs the function of air removal and prevents cavitation during pump operation. How is air etched? At the highest point of the system, the coolant can dramatically change the velocity and direction, which leads to the release of bubbles. Here and install a drain.

Its device has the form of a flask with a float, which is necessary for the release of air. When the air accumulates, the float settles and opens the valve. If the pressure rises, the coolant fills the flask, and the raised float locks the valve. The most easy-to-use air vent is with a shut-off valve. It can easily be screwed and unscrewed. If this element fails, a leak occurs, the cause of which can be determined, there are only two of them:

- There was a clogging of the needle with salts, which can be caused by hard water. You can eliminate this breakdown by clearing the needle yourself. The lid is opened for access, and after cleaning it is assembled into place.

- The O-ring under the housing cover has failed. Also, the gasket itself changes, or the thread can be wound with a ribbon.

The forced circulation heating system also provides for air removal in other wiring elements. For convenience, on the radiators recently began to use angled automatic air vent. It is important to take into account when installing this design that the nipple should be pointed upwards, otherwise the float will not perform its functions.

System Adjustment

The house heating system is regulated by several parameters. But before operating it is important to read the instructions for use. It is also necessary to invite a specialist to adjust the start and stop functions.

It should be taken into account that the heating circuit, which has a large number of rotations and knees of heating pipes, does not have a positive effect on the operation of the system. The knees, which have a small angle of rotation, are recommended to be replaced in order to avoid the least hydraulic resistance. To increase heat transfer, pipes that are not located in a residential area are recommended to be insulated.

Some nuances during installation

To heat the house has functioned without problems for a long time, the installation of important units must be approached with all responsibility, since a properly executed work depends on the operability of the entire system.

To increase the efficiency of the circulation pump, it is installed on the return water pipe. This is explained by the fact that the coolant, when it reaches the "return", is already cooling down, as the heat remains in the radiators. The design of the pump includes cuffs and seals, which are made of rubber, and with constant interaction with high temperature it is able to lose its former properties. And in this connection, the cooled water entering the return pipe does not destroy the rubber parts, which contributes to the preservation of the original functions.

Also, the system with forced circulation allows the use of pipes with a minimum diameter, which significantly reduces the cost of material and its installation. Reducing the volume of the coolant filling the pipeline significantly affects the volume of the membrane tank and the capacity of the boiler, which directly leads to cost savings.

At present, all technological and constructive directions are aimed at reducing fuel consumption costs and reducing operating costs.