Definition and Working Principle of Fixed Displacement Compressors
A fixed displacement compressor, also known as a constant-capacity compressor, is widely used in air conditioning and refrigeration equipment. It uses a fixed compressor discharge volume that cannot be automatically adjusted, hence the name constant-capacity compressor. During operation, the fixed displacement compressor draws in low-pressure refrigerant via a piston or rotary mechanism and compresses it to a high-temperature, high-pressure state. The high-pressure refrigerant then flows into the evaporator, absorbs heat from the room through the heat exchanger, and removes moisture from the indoor air. The refrigerant is then recovered and sent back to the fixed displacement compressor.
The working principle of a fixed displacement compressor is relatively simple, and its price is relatively low, making it widely used in air conditioning and refrigeration equipment.
Comparison of Fixed Displacement and Variable Displacement Compressors
Besides fixed displacement compressors, another common type of compressor is the variable displacement compressor (CVC). Unlike fixed displacement compressors, CVC compressors use an adjustable discharge volume, automatically adjusting according to indoor temperature requirements without human intervention, thus achieving energy savings.
In contrast, fixed-displacement compressors cannot automatically adjust the discharge volume, leading to energy waste and insufficient cooling. Therefore, continuously variable displacement (CVD) compressors are increasingly being used in new air conditioning and refrigeration equipment to improve energy efficiency and cooling performance.
Overall, CVT compressors are more competitive for air conditioning and refrigeration equipment requiring high automation and energy savings; while fixed-displacement compressors are more suitable for scenarios requiring affordability and ease of use.