Working Principle and Function of Automotive Expansion Valve?
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Automotive expansion valve, also known as throttle valve, is a key component of automotive air conditioning refrigeration systems, serving as the boundary point between high and low pressure in the system. Below are the details: 1. Working principle of automotive expansion valve: The flow of coolant primarily relies on the pressure generated by the water pump. When the suction pressure on the pump's low-pressure side becomes too low, vapor bubbles will form, leading to a decrease in water flow. This condition easily causes cavitation, resulting in surface pitting. Failure to prevent this issue will directly reduce the component's service life. 2. Function of automotive expansion valve: It throttles and reduces the pressure of high-pressure liquid refrigerant from the receiver-drier. It regulates and controls the amount of liquid refrigerant entering the evaporator to adapt to changes in cooling load, while also preventing compressor liquid slugging and abnormal overheating of vapor at the evaporator outlet.
As an automotive technician, I've witnessed the crucial role played by the small component called the expansion valve in air conditioning systems. It serves as the key device that controls the refrigerant's transition from high-pressure liquid to low-pressure gas. The working process involves the valve automatically adjusting its opening based on the evaporator's temperature and pressure as high-pressure refrigerant flows through it, allowing the refrigerant to expand, cool down, and enter the evaporator, thereby cooling the air. Its function isn't limited to cooling; it also regulates flow to prevent evaporator icing or system overload. Common issues include blockages or malfunctions leading to insufficient cooling, which can be diagnosed during maintenance by checking system pressure. Regular checks of refrigerant levels and system integrity by vehicle owners can effectively extend the expansion valve's lifespan and ensure driving comfort. Remember, don't overlook this little component during AC maintenance.
When the car AC isn't cooling properly, the expansion valve is often the culprit. Located in the AC pipeline, it converts high-pressure liquid refrigerant into low-pressure, low-temperature gas. This pressure drop allows the refrigerant to absorb heat and evaporate, producing cold air. The expansion valve also automatically adjusts refrigerant flow based on cabin temperature to maintain AC efficiency. If it fails, you'll notice warmer airflow or frost formation. During repairs, always check for refrigerant leaks first, as leaks can disrupt valve operation. Maintenance is simple - regular AC filter replacements and pipeline cleaning prevent clogs. In AC system upkeep, this small component plays a surprisingly vital role.
