The basics, principles, and classification of ac compressor installation in Waitara
The AC compressor is installed on the right side of the outdoor unit and fixed on the base of the outdoor unit; the AC compressor terminal is connected to the electric control system, and the suction pipe and the exhaust pipe are connected to the refrigeration system.
Rotary AC compressor is equipped with suction pipe, exhaust pipe, wiring terminal, gas-liquid separator and other interfaces. The compressor consists of a motor part and a compression part. The main function is to compress low-temperature and low-pressure gas into high-temperature and high-pressure gas.
Types of AC Compressors
There are three common types of AC compressors: piston type, rotary type, scroll type:
Piston compressor: The reciprocating piston compressor is mainly composed of a cylinder, a piston, a crankshaft and a connecting rod mechanism. The crankshaft is driven by the motor to rotate, and the piston reciprocates up and down in the cylinder through the connecting rod. Each time the compressor completes a cycle, the crankshaft rotates one circle, in turn carry out a process of suction, compression, exhaust and expansion. The compressor runs continuously under the drive of the electric motor, and the piston reciprocates continuously in the cylinder to realize the refrigeration cycle. HVAC South Club
The advantages are high operational reliability and low vibration; the disadvantages are complex structure, many moving parts, large mechanical losses, and large volume. Its coefficient of performance is lower than that of rotary compressors and scroll compressors.
Rotary Compressors: Rotary compressors are generally used in household air-conditioning compressors. Rotary compressors are classified according to the number of cylinders. Rotary compressors can be divided into single-rotor and double-rotor compressors according to the number of cylinders.
The single-rotor compressor has only 1 cylinder; The dual-rotor compressor is equipped with two cylinders and is mostly used in current high-end or high-power air conditioners.
Classified by power supply voltage
According to the different power supply, the compressor can be divided into AC power supply and DC power supply, and AC power supply is divided into AC 220V and AC 380V.
- AC 220V power supply compressors are common in 1～3P fixed frequency air conditioners;
- AC 380V-powered compressors are commonly found in 3～5P fixed-frequency air conditioners. DC-powered compressors are usually found in DC or full-DC inverter air conditioners. Early inverter air conditioners used AC-powered compressors.
Classification by motor speed
The AC compressor can be divided into two types: fixed frequency and variable frequency according to the motor speed.
- Internal structure: The AC compressor is composed of a liquid storage bottle, an upper cover, a stator, a rotor, and a lower cover.
- Overload protector: The built-in overload protector is installed near the terminal;
- When overheating: the bimetallic sheet is bent and deformed after being heated to control the opening and closing of the protector.
- Over current: The heating wire inside the protector increases heat, which causes the temperature inside the protector to rise, and finally achieves the purpose of protection through temperature changes.
- Motor: The motor part includes a stator and a rotor.The compressor coil is embedded in the stator slot. The outer ring is the running winding and the inner ring is the starting winding. It uses a 2-pole motor with a speed of about 2900r/min. The rotor and the compression component are installed together. The rotor is located on the upper side and is in phase with the motor stator during installation. correspond.
The working principle of the compression part of the rotary compressor is shown in the figure, according to the process of forming a high pressure cavity and a low pressure cavity in the cylinder when the rolling piston is in different positions.
1) The low-pressure chamber has the largest volume, and the suction port sucks refrigerant gas.
2) The rolling piston begins to compress the refrigerant gas in the cylinder, while the suction port continues to suck in.
3) The volume of the low-pressure chamber and the high-pressure chamber are equal, while the low-pressure chamber continues to inhale, and the high-pressure chamber is further compressed to increase the pressure of the gas until the exhaust valve opens, and the high-pressure gas is discharged through the exhaust port.
4). The low-pressure chamber continues to inhale, and the high-pressure chamber is exhausted.
Under high load conditions and the high and low pressure or voltage exceeds the AC compressor application range, it may cause the compressor to reverse rotation. Because the increase in torque will cause the speed to drop, reaching zero at the limit, at this time the high-pressure gas recoil causes reverse rotation. In the application range, even high load will not reverse.