Piston refrigeration compressor

　　The piston refrigeration compressor is a device that relies on the reciprocating motion of the piston to compress gas, and is mainly used in refrigeration systems. Its working principle and structural characteristics are as follows:

　　Working principle

　　The working process of the piston refrigeration compressor includes three main steps: suction, compression and exhaust:

　　The suction process: When the piston is at the lowest position, the cylinder is filled with low-pressure refrigerant vapor sucked from the evaporator, and the suction process ends.

　　Compression process: The piston begins to move upward driven by the crankshaft-connecting rod mechanism. At this time, the suction valve is closed, the cylinder working volume gradually decreases, the gas is compressed, and the temperature and pressure gradually increase. When the pressure of the gas in the cylinder rises to slightly higher than the pressure of the gas in the exhaust chamber, the exhaust valve opens and exhaust begins.

　　Exhaust process: The piston continues to move upward, and the high-temperature and high-pressure refrigerant vapor in the cylinder continuously flows out through the exhaust pipe until the exhaust process ends when the piston moves to the highest position.

　　Structural features

　　The piston refrigeration compressor is mainly composed of the following parts:

　　The body: including the cylinder block and crankcase, usually cast as a whole with high-strength gray cast iron, used to support the cylinder liner, crankshaft connecting rod mechanism and other parts.

　　Cylinder block: The cylinder liner is installed in the cylinder liner seat hole on the cylinder block for easy maintenance or replacement.

　　Piston group: including piston, piston pin and piston ring, which reciprocates in the cylinder driven by the connecting rod.

　　Connecting rod assembly: converts the reciprocating motion of the piston into the rotational motion of the crankshaft.

　　Valve: including intake valve and exhaust valve to control the in and out of gas.

　　Cooling system: used to cool the internal components of the compressor to prevent overheating.

　　Types and application scenarios

　　Piston refrigeration compressors can be classified according to different standards:

　　According to the refrigerant used: such as ammonia compressor and Freon compressor.

　　According to the number of compression stages: single-stage compression and two-stage compression.

　　‌According to the position of the cylinder centerline‌: upright, V-type, W-type and S-type.

　　‌According to the overall structure‌: open, semi-enclosed and fully enclosed.

　　Piston refrigeration compressors are widely used in various refrigeration equipment, such as cold storage. They have a simple structure and are easy to maintain.