How does the cooling, heating, and dehumidification mode switch freely

How does the cooling, heating, and dehumidification mode switch freely

Nowadays, almost every home has air-conditioning, which is cooled in summer, which brings coolness, heat in winter, provides warmth, dehumidification in the rainy season, and creates a refreshing environment. The air conditioner has greatly improved the comfort of our lives, so how does it achieve the free switching of multiple modes? Let's take Freon refrigerant as an example, and first introduce the four major components of air conditioners: compressor, condenser, evaporator, and throttle.

　　The compressor absorbs the low-temperature and low-pressure gas freon from the evaporator, drives the piston to compress it through the operation of the motor, and discharges the high-temperature and high-pressure gaseous freon to provide power for the refrigeration cycle.

　　The condenser is a heat exchanger, which cools and liquefies the high-temperature and high-pressure gaseous Freon into a normal temperature and high-pressure liquid Freon. A large amount of heat is released during the liquefaction process.

　　 The evaporator is also a heat exchanger. The liquid Freon enters the evaporator through a capillary tube. The space suddenly increases and the pressure decreases. The liquid Freon will vaporize and become a gaseous low-temperature Freon, and the vaporization process needs to absorb a lot of heat. Finally, the gaseous Freon returns to the compressor to continue compression, forming a cycle.

　　 The function of the throttle valve is to throttle the saturated liquid or subcooled liquid under the condensing pressure in the condenser to the evaporating pressure and evaporating temperature, and adjust the flow of refrigerant into the evaporator according to the change of load.

In the cooling mode, the circulation direction of the refrigerant is compressor-outdoor unit-indoor unit-compressor, and the outdoor unit is the condenser, so hot air is blown out; the indoor unit is the evaporator, and the fan removes the indoor hot air from the evaporator It turns into cold wind, so the air conditioner achieves cooling effect.

In heating mode, the air conditioner uses a component called a four-way valve to make the flow direction of Freon in the indoor unit and outdoor unit opposite to that of cooling, that is, the circulation direction of the refrigerant is compressor-indoor unit-outdoor unit-compressor. At this time, the high-temperature and high-pressure steam discharged from the compressor is directly sent to the indoor unit through the four-way valve. The indoor unit acts as a condenser to cool the superheated steam in the cold room and release heat. The cold indoor air is turned into hot air by the fan, so the air conditioner To achieve the heating effect. The outdoor unit functions as an evaporator, so it blows out cold air.

　　 It can be seen that the heating cycle and the refrigeration cycle actually use the principle of heat dissipation (from gas to liquid) in junior high school physics and absorption of heat when vaporizing (from liquid to gas).

In the dehumidification mode, the principle that moisture in the air will be condensed into water when it is cold. When the refrigerant in the air conditioner evaporator evaporates, it absorbs a lot of heat, which reduces the surface temperature of the evaporator. At this time, the water vapor in the indoor air will be liquefied into water when it is cold. The condensed water is discharged outside through the outlet pipe. Part of the moisture is removed in this way, so dehumidification will inevitably be accompanied by the air conditioning and refrigeration process.

It should be noted that in summer, when the temperature is set to 26~27 degrees Celsius, the cooling load can be reduced by more than 8%; in winter, when the temperature is set 2 degrees Celsius lower, it can also save 10% of electricity; when a person sleeps, the metabolism Reduce by 30%~50%, set the air conditioner in sleep mode, set the temperature to 2 degrees Celsius higher, and save 20% of electricity.

　　Practice has proved that for people who sit quietly or work lightly, if the room temperature is maintained at 28~29 degrees Celsius and the relative humidity is maintained at 50%~60%, people will not feel stuffy and sweat, which belongs to the comfortable range.