What is a piston cold storage refrigeration compressor?

Update:09 Dec 2021
Summary:

The piston-type cold storage compressor is the heart of […]

The piston-type cold storage compressor is the heart of the refrigeration system. It sucks in low-temperature and low-pressure refrigerant gas from the suction port, drives the piston to compress it through the operation of the motor, and discharges the high-temperature and high-pressure refrigerant gas to the exhaust port, which is a refrigeration cycle Provide power to realize the refrigeration cycle of compression→condensation→expansion→evaporation (heat absorption).

  The cold storage compressor is generally composed of a shell, a motor, a cylinder, a piston, control equipment (starter and thermal protector) and a cooling system.

When the piston is at the lowest position (called inner dead center or bottom dead center), the cylinder is filled with low-pressure refrigerant vapor sucked in from the evaporator, and the suction process ends; the piston starts to move upward under the drive of the crankshaft-connecting rod mechanism Move, the suction valve is closed at this time, the working volume of the cylinder gradually decreases, the gas in the cylinder 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 When the exhaust valve opens, the exhaust starts. The process in which the gas in the cylinder rises from the low pressure during intake to the exhaust pressure is called the compression process.

   Cold storage compressor exhaust process

   The piston continues to move upwards, and the high-temperature and high-pressure refrigerant vapor in the cylinder continuously flows out through the exhaust pipe until the piston moves to the highest position (called outer dead center or top dead center) when the exhaust process ends. The process of gas output from the cylinder to the exhaust pipe is called the exhaust process.

   Cold storage compressor expansion process

   When the piston moves to the top dead center, due to the structure and manufacturing process of the cold storage compressor, there is still some space in the cylinder. The volume of this space is called the clearance volume. At the end of the exhaust process, the gas in the clearance volume is high-pressure gas. When the piston starts to move downwards, the exhaust valve is closed, and the low-pressure gas in the suction chamber cannot immediately enter the cylinder. At this time, the high-pressure gas in the clearance volume decreases due to the increase in volume, until the pressure of the gas in the cylinder drops to a little lower When the pressure of the gas in the suction chamber starts, the process is called the expansion process.

   At the end of the expansion process of the suction process, the suction valve opens, and low-pressure gas is sucked into the cylinder until the piston reaches the bottom dead center position. It is the inhalation process.