To understand air source heat pumps, you first need to understand its four core components, namely: compressor, throttle valve, evaporator, and condenser. Air source heat pumps drive compressors and motors to work through the input of electrical energy, allowing the evaporator to absorb heat and the condenser to release heat. The heating effect is as high as 400%, and it is one of the green products that the HVAC industry focuses on developing under the dual carbon policy.
1. Heart component-compressor
The compressor is a driven fluid mechanical device that lifts low-pressure gas to high-pressure gas. It is the heart of the air source heat pump. The compressor inhales low-temperature and low-pressure refrigerant gas from the suction pipe, compresses it through the operation of the motor to drive the piston, and discharges high-temperature and high-pressure refrigerant gas to the exhaust pipe, providing power for the refrigeration cycle, thereby realizing the refrigeration cycle of compression → condensation → expansion → evaporation (heat absorption).
Common types of compressors include rotary, scroll, and screw. The performance of the compressor determines the lower limit of the air source heat pump. The better the quality of the compressor, the higher its heating efficiency. Household heat pumps generally use rotary type, while commercial heat pumps have higher requirements and generally use vortex type and screw type.
2. Throttling component - expansion valve (throttle valve)
The expansion valve (throttle valve) is a device that controls the refrigerant flow rate by changing the throttling section or throttling length in the air source heat pump system. It is generally installed between the evaporator and the liquid storage cylinder. The expansion valve (throttle valve) allows the medium-temperature and high-pressure liquid refrigerant to become low-temperature and low-pressure wet steam through its throttling, and then the refrigerant absorbs heat in the evaporator to achieve the cooling effect. The expansion valve (throttle valve) controls the valve flow rate through the change of superheat at the end of the evaporator to prevent the evaporator area from being underutilized and the occurrence of knocking cylinders.
Throttling components can be divided into three categories: capillary throttling, thermal expansion valve throttling and electronic expansion valve throttling. The role they play in air source heat pumps is similar to that of capillaries in the human body. The capillary structure is simple and cannot be adjusted. It is only suitable for small refrigeration systems. The expansion valve structure is relatively complex and adjustable. In addition to controlling the evaporator, the adjustment of the refrigerant flow can also be used to adjust the condenser. The electronic expansion valve can work normally above -70℃, but the thermal expansion valve can only reach -60℃ at the lowest.
3. Heat-absorbing component-evaporator
The evaporator is a kind of heat exchanger. It is a very important component among the four major components and the most critical component for the air source heat pump to absorb heat energy from the air. The refrigerant passes through the throttling and pressure reduction of the expansion valve, and the temperature after spraying is very low. When passing through the evaporator, the refrigerant absorbs heat from the air through the copper tube and fins. With the absorbed heat, the refrigerant enters the compressor for the next cycle.
In the air source heat pump, the evaporator is mainly fin-type, which belongs to the dry evaporator. The fins used in the evaporator are flat, corrugated, shutters and bridges. The heat exchange capacity of different forms is also different. The stronger the heat exchange capacity, the greater the wind resistance.
4. Heat release component - condenser
The condenser is also a kind of heat exchanger, and its function is just opposite to that of the evaporator. During the operation of the air source heat pump, the high-pressure and high-temperature refrigerant steam formed by the evaporator and compressor will release heat in the condenser and be absorbed by water, realizing the heat exchange between steam and water. After the water absorbs heat, the temperature rises, and the refrigerant in the condenser changes from high-temperature and high-pressure gas to high-pressure liquid. This is actually the reason why the air source heat pump produces hot water.
The quality of the condenser directly affects the heat exchange efficiency of the air source heat pump. There are about four types of condensers currently used in the market, including coil type, plate type, sleeve type and shell and tube type. In household air source heat pumps, the main type used is the coil type, which is placed in water for heat transfer, and also relies on the inner tank to transfer heat outside the water tank.
To understand air source heat pumps, you first need to understand its four core components, namely: compressor, throttle valve, evaporator, and condenser. Air source heat pumps drive compressors and motors to work through the input of electrical energy, allowing the evaporator to absorb heat and the condenser to release heat. The heating effect is as high as 400%, and it is one of the green products that the HVAC industry focuses on developing under the dual carbon policy.
1. Heart component-compressor
The compressor is a driven fluid mechanical device that lifts low-pressure gas to high-pressure gas. It is the heart of the air source heat pump. The compressor inhales low-temperature and low-pressure refrigerant gas from the suction pipe, compresses it through the operation of the motor to drive the piston, and discharges high-temperature and high-pressure refrigerant gas to the exhaust pipe, providing power for the refrigeration cycle, thereby realizing the refrigeration cycle of compression → condensation → expansion → evaporation (heat absorption).
Common types of compressors include rotary, scroll, and screw. The performance of the compressor determines the lower limit of the air source heat pump. The better the quality of the compressor, the higher its heating efficiency. Household heat pumps generally use rotary type, while commercial heat pumps have higher requirements and generally use vortex type and screw type.
2. Throttling component - expansion valve (throttle valve)
The expansion valve (throttle valve) is a device that controls the refrigerant flow rate by changing the throttling section or throttling length in the air source heat pump system. It is generally installed between the evaporator and the liquid storage cylinder. The expansion valve (throttle valve) allows the medium-temperature and high-pressure liquid refrigerant to become low-temperature and low-pressure wet steam through its throttling, and then the refrigerant absorbs heat in the evaporator to achieve the cooling effect. The expansion valve (throttle valve) controls the valve flow rate through the change of superheat at the end of the evaporator to prevent the evaporator area from being underutilized and the occurrence of knocking cylinders.
Throttling components can be divided into three categories: capillary throttling, thermal expansion valve throttling and electronic expansion valve throttling. The role they play in air source heat pumps is similar to that of capillaries in the human body. The capillary structure is simple and cannot be adjusted. It is only suitable for small refrigeration systems. The expansion valve structure is relatively complex and adjustable. In addition to controlling the evaporator, the adjustment of the refrigerant flow can also be used to adjust the condenser. The electronic expansion valve can work normally above -70℃, but the thermal expansion valve can only reach -60℃ at the lowest.
3. Heat-absorbing component-evaporator
The evaporator is a kind of heat exchanger. It is a very important component among the four major components and the most critical component for the air source heat pump to absorb heat energy from the air. The refrigerant passes through the throttling and pressure reduction of the expansion valve, and the temperature after spraying is very low. When passing through the evaporator, the refrigerant absorbs heat from the air through the copper tube and fins. With the absorbed heat, the refrigerant enters the compressor for the next cycle.
In the air source heat pump, the evaporator is mainly fin-type, which belongs to the dry evaporator. The fins used in the evaporator are flat, corrugated, shutters and bridges. The heat exchange capacity of different forms is also different. The stronger the heat exchange capacity, the greater the wind resistance.
4. Heat release component - condenser
The condenser is also a kind of heat exchanger, and its function is just opposite to that of the evaporator. During the operation of the air source heat pump, the high-pressure and high-temperature refrigerant steam formed by the evaporator and compressor will release heat in the condenser and be absorbed by water, realizing the heat exchange between steam and water. After the water absorbs heat, the temperature rises, and the refrigerant in the condenser changes from high-temperature and high-pressure gas to high-pressure liquid. This is actually the reason why the air source heat pump produces hot water.
The quality of the condenser directly affects the heat exchange efficiency of the air source heat pump. There are about four types of condensers currently used in the market, including coil type, plate type, sleeve type and shell and tube type. In household air source heat pumps, the main type used is the coil type, which is placed in water for heat transfer, and also relies on the inner tank to transfer heat outside the water tank.
