The built-in protection function of the heat pump unit
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- publisher
- Howard
- Issue Time
- Oct 24,2024
Summary
In order to ensure the normal operation of the heat pump and to promptly alarm or automatically shut down the system in case of abnormal operating parameters or operating conditions, and to protect the safety of the system, heat pump manufacturers generally embed many protection functions in the control system.
Water flow protection
Heat pump exchanges heat with refrigerant through the flow of water in the heat exchanger, thereby achieving the effect of raising or lowering water temperature. If the water system is blocked or the water pump fails, causing the interruption of water flow, the heat exchanger will not be able to complete the heat exchange in the system, which may cause abnormal high pressure in the system. During cooling or defrosting, water flow failure may even cause the water inside the heat exchanger to freeze and damage the heat exchanger, resulting in the scrapping of the entire system. Therefore, water flow protection is set in the heat pump to actively stop the operation of the system when the water flow is low or interrupted, which can effectively protect the system and prevent system damage.
Pressure protection
Heat pumps transport and exchange heat through the phase change of refrigerant in the system, which is manifested as changes in pressure and temperature. Therefore, during normal operation of the heat pump, the system will be divided into a high pressure section and a low pressure section, both of which have limited values. When the pressure exceeds the limit, it may cause damage to the system pipeline due to high pressure, or insufficient heat exchange capacity and pipeline frosting due to low pressure. Therefore, in order to ensure the stable and effective operation of the heat pump unit, the system is equipped with high and low pressure switches for pressure control. When the pressure exceeds the limit abnormally, the system will be shut down for protection to avoid damage to the system.
Temperature protection
When the heat pump is working normally, the refrigerant undergoes a transition from gas to liquid and then to gas. During this process, the temperature performance of the refrigerant at different positions in the system will also vary. The heat pump control system will set temperature sensors at various key nodes to detect the temperature values at relevant positions during the operation of the heat pump. When the temperature performance is abnormal, the heat pump will also adopt an automatic shutdown method to protect the system from damage due to abnormal operation.