The structure of an air conditioner generally consists of the following four parts.
Refrigeration system: This is the cooling and temperature reduction component of the air conditioner, consisting of a sealed refrigeration cycle formed by the refrigeration compressor, condenser, capillary tube, evaporator, electromagnetic reversing valve, filter, and refrigerant.
Airflow system: This is the component within the air conditioner that accelerates heat exchange of room air, consisting of equipment such as centrifugal fans and axial fans.
Electrical System: This component within the air conditioner ensures the safe operation of the compressor and fan, as well as temperature control. It consists of a motor, thermostat, relay, capacitor, and heater.
Box and panel: It is the frame of the air conditioner, the supporting seat of each component, and the guiding part of the airflow, consisting of the box, panel, and louver grille.
The main components and working principles of a refrigeration system
The refrigeration system is a complete sealed cycle system, consisting of the main components of a compressor, condenser, throttling device (expansion valve or capillary tube), and evaporator. The various components are connected by pipes to form a closed cycle system, and a certain amount of Freon refrigerant is added to the system to achieve cooling.
Air conditioner cooling is achieved by installing a complete refrigeration system in the air conditioner, followed by a fan and some controllers. The basic principle of refrigeration is achieved through four processes based on the components and functions of the refrigeration cycle system.
Compression process: Starting from the compressor, the refrigerant gas enters the compressor in a low-temperature and low-pressure state, is compressed in the compressor, increases the pressure and temperature of the gas, and is discharged into the condenser.
Condensation process: The high-temperature and high-pressure gas discharged from the compressor enters the condenser, transfers heat to the outside air or cooling water, condenses into liquid refrigerant, and flows towards the throttling device.
Throttling process: also known as expansion process, the refrigerant liquid flowing out of the condenser flows under high pressure to the throttling device for throttling and pressure reduction.
Evaporation process: The low-pressure refrigerant liquid flowing out of the throttling device flows into the evaporator, absorbs heat from the outside (air or water) and evaporates into gas, thereby reducing the temperature of the outside (air or water). The low-temperature low-pressure gas evaporated is then sucked back by the compressor for further compression, condensation, throttling, evaporation, and continuously circulates and cools. The structure of a single cooling air conditioner is simple, mainly composed of a compressor, condenser, drying filter, capillary tube, and evaporator. The applicable range of ambient temperature for single cooling air conditioners is 18 ℃ to 43 ℃.
Dual use air conditioners can be divided into three types: electric heating type, heat pump type, and heat pump assisted electric heating type.
(1) Electric heating air conditioner
An electric heater is installed between the indoor evaporator and the centrifugal fan in the electric heating air conditioner. During summer use, the cold and hot switch can be turned to the cold air position, and its working state is the same as that of a single cooling air conditioner. When used in winter, the cold hot switch can be placed in the hot air position. At this time, only the electric fan and heater work, and the compressor does not work.
(2) Heat pump air conditioner
The indoor cooling or heating of a heat pump air conditioner is achieved by changing the direction of refrigerant flow through an electromagnetic four-way reversing valve, as shown in Figure 1. An electromagnetic four-way reversing valve is installed between the compressor suction and exhaust pipes and the condenser and evaporator. In summer, when cold air is provided, the indoor heat exchanger serves as the evaporator and the outdoor heat exchanger serves as the condenser. During winter heating, the direction is changed through an electromagnetic four-way reversing valve, and the indoor heat exchanger is converted into a condenser while the outdoor heat exchanger is converted into an evaporator, allowing hot air to be obtained indoors. The drawback of heat pump air conditioners is that they cannot be used when the ambient temperature is below 5 ℃.
(3) Heat pump assisted electric heating air conditioner
The heat pump assisted electric heating air conditioner is a product that adds an electric heater on the basis of the heat pump air conditioner, thereby expanding the working environment temperature of the air conditioner. It is a combination of electric heating and heat pump types, and the applicable range of environment temperature is -5 ℃ to 43 ℃.
Introduction to the principle of central air conditioning
The principle of central air conditioning includes:
1、 The refrigeration principle of central air conditioning: there are compression type, absorption type, etc., which will not be described in detail here;
2、 The principle of central air conditioning system includes the working principle of air system, water system, coil system, etc. The working principle is similar to that of household air conditioning. Household air conditioning directly connects the evaporator to the room through copper pipes and achieves cooling through fan coil units. And central air conditioning uses water as a refrigerant to circulate. First, water is used to absorb the energy generated by the central air conditioning unit, causing the temperature of the water to rise or fall. Then, the water is pumped into the fan coil unit inside the house to achieve cooling or heating! Household air conditioners generally use refrigerant circulation, and central air conditioning uses the cold and heat generated by the refrigerant to regulate the temperature of the circulating water to achieve cooling and heating. Because most central air conditioners use groundwater, which is a constant temperature, it is lower than room temperature in summer and higher than room temperature in winter. Therefore, we use the temperature difference between water and air to achieve energy conservation. Secondly, we adjust the temperature of each room through a central control system. When the temperature of a certain room reaches the set temperature, it will transmit a signal to the control system, which will then transmit a signal to the compressor. The compressor’s speed will decrease, and the power will decrease to achieve energy saving
Central air conditioning fresh air system operation:
The fresh outdoor air is attracted by the air handling unit and enters the air cabinet. After filtering, cooling, and dehumidification, it is sent into each room through the air duct. At this time, the fresh air cannot meet the indoor heat and humidity load, only the required amount of fresh air indoors. As the indoor fan coil unit processes the indoor air heat and humidity load, the excess air is partially discharged outside through the return fan according to the opening ratio of the valve, and partially returned to the inlet for reuse
Post time: Jan-26-2026