Principles of operation of the heat pump

What is a heat pump

heat pump is a steam compression unit that transfers heat from cold, low potential heat sources to hot, high-potential. Heat is transferred through condensation and evaporation of the refrigerant, as which a freon circulating in a closed loop is most commonly used. The electricity from which the heat pump runs is only spent on this forced circulation.

The principle of operation of the heat pump is based on the so-called Carnot cycle, which is perfectly familiar to you on the work of refrigeration units. In fact, the household fridge standing in your kitchen is also a heat pump. When you put in it products, even though cold, but the temperature of which is still higher than the temperature in the refrigerator, according to the law of conservation of energy the heat emitted by them is not going anywhere. Since the temperature inside should not rise, heat is excreted outward through the radiator grille, heating the air in the kitchen. The more products you put at the same time in the fridge, the more heat transfer will be.

The simplest option for a heat pump will be an open refrigerator placed on the street, the radiator of which is in the room. But let the refrigerator perform its direct duties, because there are already special devices – heat pumps that have efficiency much higher. The principle of their action is quite simple.

How the heat pump works

Any heat pump consists of a vaporizer, a capacitor, a pressure-lowering extender, and a compressor that raises the pressure. All of these devices are connected into a single closed loop by piping. A refrigerant, an inert gas with a very low boiling point circulates through the pipes, so in one part of the circuit, cold, it is a liquid, and in the second, warm, it goes to gaseous state. The boiling point, as it is known from physics, can vary depending on the pressure, that’s why an extender and compressor are needed in this system.

Suppose that outside the heat carrier circulates through pipes laid in the ground, because it has a low temperature, then passing through them, it heats even when the external temperature is only about 4-5os. By entering the evaporator, which serves as a heat exchanger, the heat transfer conveys the resulting heat to the internal circuit of the system, which is filled with refrigerant. Even that heat is enough for the refrigerant to go from liquid to gaseous state.

Moving on, the gas moves to the compressor, where under the influence of high pressure is compressed, and its temperature increases. By becoming hot, the gas enters the capacitor, which is also a heat exchanger. It takes place heat transfer from the hot gas to the heat carrier of the reverse pipeline entering the heating system of the house. After giving away heat, the gas cools and goes into a liquid state again, while the heated heat carrier enters the hot water supply and heating system. Passing through the dilator reduction valve, the liquefied gas enters the evaporator again — the cycle closes.

During the cold season, heat pumps work to heat the house, and in heat – to cool it. In this case, the principle of operation is the same, only in summer the heat transfer comes from the interior, not outside.

Design features of heat pumps

At present, heat pumps with different designs are used. So, an open cycle pump is used when the house is located next to the body of water. In this case, the heat carrier, the water, enters the open circuit, passes the entire cycle and, cooled, re-drains into the body of water.

Closed geothermal pumps pump a heat carrier — air or water — through pipes laid deep into the ground and laid on the bottom of the body of water. A closed cycle is considered safer in environmental terms. The closed type includes vertical and horizontal heat exchanger pumps, which are used when there are no water bodies nearby. Vertical heat pumps are applied when the land area on which the house is located is small. Sometimes vertical pumps are installed in wells drilled nearby.

The complex of works on installation of the heat pump includes internal electrical works, laying of external piping and internal ducts.

Advantages of using heat pumps

The economic benefit of using heat pumps is obvious — their operation is reasonably cheap is cost because electricity is spent slightly more than when the refrigerator works. The price of equipment is also low, as is the cost of installation and installation. Use of heat pump, allows you to get rid of the worries about purchase and storage of fuel resources, installation and operation of heating equipment, at your house are exempt additional premises in which the boiler room used to be located.

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