Generally speaking, expansion valves are used in refrigeration systems. So can refrigeration be performed without an expansion valve? The answer is that it is possible, but it is not the best choice.
First, let us understand the role of the expansion valve in the refrigeration system. The expansion valve is a flow regulating device that compresses the high-pressure, high-temperature refrigerant and relaxes it at the expansion valve, thereby reducing the temperature and pressure. In this way, the refrigerant can enter the evaporator, absorb heat from the air and form steam to complete the refrigeration process.
If there is no expansion valve, other components in the refrigeration system need to replace the function of the expansion valve. For example, components such as capillaries and throttle valves can be used to control the flow and temperature of the refrigerant. These alternative components can ensure the normal operation of the refrigeration system, but will affect the refrigeration effect and the energy consumption of the system.
The refrigeration system using capillaries needs to introduce the refrigerant from the high-pressure area to the low-pressure area to form a condensation and evaporation process. Due to the extremely thin diameter of the capillary tube, its resistance will cause the flow rate of the refrigerant to slow down, resulting in a decrease in the efficiency of condensation and evaporation. At the same time, the capillary tube cannot adapt well to the load changes in the refrigeration system, which can easily lead to system instability.
The throttle valve can adjust the flow and pressure of the refrigerant to achieve the effect of the control system. However, the disadvantage of the throttle valve is that a large amount of pressure loss will be generated in the high-pressure area, which will reduce the efficiency of the refrigeration system. Moreover, the throttle valve cannot adapt well to the load changes in the refrigeration system.
Therefore, although there is no expansion valve for refrigeration, it is recommended to use an expansion valve in the refrigeration system as much as possible, because it can ensure the efficiency and stability of the refrigeration system.
