How much do you know about piston compressors

How much do you know about piston compressors

The piston compressor is driven by a motor. The motor drives the crankshaft to make a circular motion through a coupling or gear and belt. The crankshaft drives the connecting rod (changes the direction of the force) for reciprocating swing motion, and the connecting rod pushes the crosshead to make a reciprocating linear motion (completed The change in the direction of the force), the crosshead drives the piston through the piston rod to reciprocate work in the cylinder.

The main components of compressed gas are composed of cylinder, piston and valve. The piston reciprocates in the cylinder, causing the expansion and contraction of the working chamber volume. When the volume expands, the pressure in the cylinder decreases, and the inlet pipe gas enters the cylinder. When the expansion reaches the maximum, the end point is reached and the inhalation is completed; when the piston returns, the volume decreases and the pressure in the cylinder rises. Once the compression reaches the outlet pressure and can overcome the resistance of the spring, the compression process is completed; when the pressure in the cylinder is slightly higher than the outlet pressure, The outlet valve opens to start the exhaust process, until the piston runs to the end to complete a cycle. Immediately after the next cycle of compression again and again.

　　 One, the working principle of piston compressor

　　 When the crankshaft of the piston compressor rotates, the piston reciprocates through the transmission of the connecting rod, and the working volume formed by the inner wall of the cylinder, the cylinder head and the top surface of the piston changes periodically. When the piston of a piston compressor starts to move from the cylinder head, the working volume in the cylinder gradually increases. At this time, the gas follows the intake pipe and pushes the intake valve to enter the cylinder until the working volume reaches the maximum. , The intake valve is closed; when the piston of the piston compressor moves in the reverse direction, the working volume in the cylinder is reduced and the gas pressure increases. When the pressure in the cylinder reaches and is slightly higher than the exhaust pressure, the exhaust valve opens and the gas is discharged from the cylinder , Until the piston moves to the limit position, the exhaust valve is closed. When the piston of the piston compressor moves in the reverse direction again, the above process repeats. In a word, the crankshaft of the piston compressor rotates once, the piston reciprocates once, and the process of air intake, compression, and exhaust is realized in the cylinder, which completes a working cycle.

　　 2. Advantages of piston compressor

　　1. The applicable pressure range of piston compressor is wide, and the required pressure can be reached regardless of the flow rate;

　　2, the thermal efficiency of the piston compressor is high, and the unit power consumption is low;

　　3. Strong adaptability, that is, a wide exhaust range, and is not affected by the pressure level, and can adapt to a wider pressure range and cooling capacity requirements;

　　4. The maintainability of the piston compressor is strong;

　　5. Piston compressors have low requirements for materials, and use ordinary steel materials, which are easier to process and cheaper to manufacture;

　　6. ​​Piston compressors are relatively mature in technology and have accumulated rich experience in production and use;

　　7. The device system of the piston compressor is relatively simple.

　　 Three, the disadvantages of piston compressor

　　 1. The speed is not high, the machine is big and heavy;

　　2. Complex structure, many wearing parts and large maintenance;

　　3. The exhaust is discontinuous, causing airflow pulsation;

　　 4. There is a big vibration during operation.

　　 Piston compressor has become the most widely used model with the largest production batch in various occasions, especially in the small and medium refrigeration range.