Air-cooled cooling and heating units are widely used in many fields. I will explain its working principle from the aspects of its structure, cooling and heating process, so that you can have a comprehensive and clear understanding of it.

Working principle of air-cooled cooling and heating units

As a common air conditioning equipment, air-cooled cooling and heating units are widely used in industrial production, commercial places and civil buildings. Their efficient and stable working performance creates a comfortable ambient temperature for people. To have a deep understanding of air-cooled cooling and heating units, we need to start with their basic structure and working principle.

Air-cooled cooling and heating units are mainly composed of four core components: compressor, condenser, throttling device and evaporator. Each component works together to achieve heat transfer and temperature regulation.

The compressor is the "heart" of the entire system and plays a vital role. Its main function is to increase the pressure and temperature of the refrigerant and promote the circulation of the refrigerant in the system. In air-cooled chillers and heaters, commonly used compressor types include screw compressors and scroll compressors. When the unit is started, the compressor starts to operate and sucks in the low-temperature and low-pressure gaseous refrigerant in the evaporator. Through the mechanical structure inside the compressor, the refrigerant is compressed, causing its pressure and temperature to rise sharply, turning into a high-temperature and high-pressure gaseous refrigerant. This process is like the heart pumping blood, providing power for the entire circulatory system, ensuring that the refrigerant can continue to circulate in the system and achieve heat transfer.

After leaving the compressor, the high-temperature and high-pressure gaseous refrigerant enters the condenser. The condenser is a key component for achieving heat dissipation. The air-cooled condenser uses air as the cooling medium and uses a fan to force the outdoor air to blow through the cooling fins of the condenser to take away the heat of the refrigerant. In the condenser, the high-temperature and high-pressure gaseous refrigerant exchanges heat with the low-temperature air. After the refrigerant releases heat, it gradually cools and condenses into a liquid. This process is similar to the phenomenon in nature where water vapor turns into water droplets when it is cooled, except that here the heat exchange process is accelerated by the artificially designed condenser structure and air flow. After the condenser, the heat of the refrigerant is transferred to the outdoor air, thereby achieving heat dissipation. This is an important link in the refrigeration cycle where heat is transferred from indoors to outdoors.

The high-pressure liquid refrigerant coming out of the condenser then enters the throttling device. The function of the throttling device is to reduce the pressure and throttle the refrigerant. Common throttling devices include capillary tubes, thermal expansion valves, etc. When the high-pressure liquid refrigerant passes through the throttling device, the pressure of the refrigerant drops rapidly due to the sudden narrowing of the channel, and the temperature also drops accordingly, turning into a low-temperature and low-pressure liquid refrigerant. This process is similar to suddenly reducing the diameter of a water pipe, which speeds up the water flow and reduces the pressure. The reduced-pressure refrigerant is ready for the subsequent evaporation and heat absorption in the evaporator.

After the low-temperature and low-pressure liquid refrigerant enters the evaporator, it begins to play its core role in refrigeration. The evaporator is also a heat exchange component, but here it absorbs heat. The hot air in the room is forced to blow over the surface of the evaporator by the fan, and the hot air exchanges heat with the low-temperature and low-pressure liquid refrigerant in the evaporator. After the refrigerant absorbs the heat from the hot air, it quickly evaporates and vaporizes into a gaseous state. This process is the opposite of the condensation process in the condenser and is a process of absorbing heat. As the refrigerant continues to evaporate, the heat of the indoor air is continuously taken away, thereby achieving the cooling of the indoor air. The refrigerant that has become a gas is sucked into the compressor again, starting a new cycle.

In heating mode, the air-cooled chiller changes the flow direction of the refrigerant through a four-way reversing valve. The component that originally served as a condenser during cooling becomes an evaporator during heating, and the original evaporator becomes a condenser. At this time, the high-temperature and high-pressure gaseous refrigerant discharged by the compressor first enters the indoor evaporator (condenser at this time), releases heat to the indoor air, warms up the indoor air, and achieves a heating effect. The outdoor condenser (evaporator at this time) absorbs heat from the outdoor air. Although the outdoor air temperature is low, the refrigerant can still absorb a certain amount of heat from the air through evaporation at low temperatures. The refrigerant that absorbs heat in the evaporator is then compressed by the compressor and continues to circulate. Through this ingenious reversing design, the air-cooled chiller realizes two different functions of cooling and heating, meeting the temperature regulation needs in different seasons and environments.

Air-cooled cooling and heating units achieve cooling and heating functions through the coordinated work of components such as compressors, condensers, throttling devices and evaporators, and utilize the physical changes of refrigerants and the principle of heat transfer to provide people with a comfortable indoor ambient temperature. Whether it is the cooling demand in the hot summer or the heating demand in the cold winter, air-cooled cooling and heating units can play an important role with their efficient and stable working performance. With the continuous advancement of science and technology, the performance and efficiency of air-cooled cooling and heating units are also constantly improving. In the future, they will be more widely used in more fields, bringing more convenience to people's lives and production.