What is the principle of compressor? When the compressor is working, the low-temperature and low-pressure refrigerant gas is sucked from the suction pipe, and after the piston is driven by the motor to compress it, the high-temperature and high-pressure refrigerant gas is discharged to the exhaust pipe to provide power for the refrigeration cycle. In this special topic of Encyclopedia, I will introduce compressors from many aspects, such as compressor principle, compressor maintenance, and solutions for refrigerator compressors not starting.
1 Compressor principle
The compressor is a driven fluid machine that lifts low-pressure gas into high-pressure gas, and is the heart of the refrigeration system. It inhales low-temperature and low-pressure refrigerant gas from the suction pipe, 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 pipe to provide power for the refrigeration cycle. So as to realize the refrigeration cycle of compression→condensation (exothermic)→expansion→evaporation (endothermic).
2 Compressor Parts Cylinder | Cylinder Head Cross Head Cooler Gas Cutting | Cutting Piece Crankshaft Connecting Rod Small End Tile | Large End Tile Piston Rod Seal Ring Oil Scraper 3 Advantages of screw air compressors
High performance and high efficiency
Air compressor equipment-screw air compressors High-capacity compression components are used, with low rotor outer speed and optimal oil injection, achieving high efficiency and high reliability. As of 2012, manufacturers have designed designs to ensure extremely low system and compressed air temperatures. Guarantees optimum cooling and maximum service life for all components.
Drive Concept: Air Compressor Equipment – Screw air compressors drive the compression components at the optimum speed for the application through an efficient drive system. Completely maintenance-free during normal operation. It has the advantages of maintenance-free, high reliability and high efficiency.
Low Maintenance Costs
Air Compressor Equipment – Screw Air Compressors The original compressor design saves unnecessary maintenance costs. All components are designed for long life, and the large size inlet filter, oil filter and fine separator ensure optimum compressed air quality. All oil filters and separator components up to 22kW (30hp) are centrifugally opened and closed, further reducing maintenance time. “Speed up to repair point” enables repair work to be completed within minutes, greatly reducing downtime and repair costs.
Intelligent built-in controls
To reduce operating costs, sophisticated operational controls are essential. All screw compressors are equipped with an intelligent control system with an easy-to-use control menu.
4 Silent Air Compressor Buying Guide
1. Discharge pressure
Compression The higher the exhaust pressure of the machine, the more energy is consumed. The sum of the operating pressure, pipeline resistance loss and the pressure drop of the supporting equipment is set as the lower limit of the rated exhaust pressure of the screw air compressor. In general, the diameter of the gas pipeline should be larger. In order to reduce the resistance loss and achieve the purpose of reducing energy consumption in long-term operation. The higher the discharge pressure of the compressor, the more energy is consumed. So don’t choose a compressor with too high discharge pressure
2. Discharge volume
Calculate the actual total gas consumption ╳1.1-1.2 coefficient, As the model with the selected displacement, if the selection is too low, it will not reach the specified value of the gas-using equipment, and if the selection is too large, it will cause large energy consumption for load reduction and uneconomical operation of load reduction. At the same time, the purchase cost of purchasing a large-displacement screw air compressor is relatively high.
Three. Compressed air quality
According to the requirements of industrial gas equipment for compressor gas, screw air compressors and supporting equipment should be appropriately purchased . The following points need to be considered:
1) To reduce the oil content in the compressed gas, a degreasing purifier can be used. If the treatment index is high, a multi-stage treatment can be used.
2) To reduce the water content in the compressed gas, water removal equipment can be used.
5 Refrigerator compressor failure maintenance
The failure of the motor compressor can be divided into motor failure and mechanical failure (including crankshaft, connecting rod, piston, valve plate, cylinder head gasket, etc.).
Mechanical failure often makes the motor overload or even stall, which is one of the main reasons for motor damage.
The damage of the motor is mainly manifested in the destruction of the insulation layer of the stator winding (short circuit) and open circuit. After the stator winding is damaged, it is difficult to detect it in time, which may eventually lead to the burning of the winding. After the winding is burned, some phenomena or direct causes that lead to the burning are covered up, making post-event analysis and cause investigation more difficult. However, the operation of the motor is inseparable from the normal power input, reasonable motor load, good heat dissipation and the protection of the winding enameled wire insulation.
Starting from these aspects, it is not difficult to find that the reasons for the burning of windings are as follows:
(1) Abnormal load and stall;
(2) Winding short circuit caused by metal chips;
(3) Contactor problem;
(4) Power supply phase loss and abnormal voltage;
(5 ) Insufficient cooling;
(6) Use a compressor to evacuate.
6 The refrigerator compressor does not start
1. The refrigerator temperature is set too high, and the internal temperature has reached the set temperature, so it does not start.
2. Check the external power supply and compressor input voltage. Check whether the power supply and compressor input voltage meet the standard requirements (187V ~ 242V), and use a multimeter to connect the external power supply and compressor input voltage. .
3. The ambient temperature is too low
a. When the ambient temperature is too low (1～10℃), if the refrigerator is in manual compensation mode, the compensation switch needs to be turned on at this time. If the temperature compensation switch is used, it is necessary to check whether the magnetic switch is normal: because the ambient temperature is too low, especially for the refrigerator with dual temperature and single control refrigerator, as long as the compressor works for a short time, the refrigerator will reach the predetermined temperature (1 ~ 10 ℃) , At the same time, due to the low ambient temperature, the temperature of the refrigerating room is very slow or does not rise, the compressor does not work for a long time, and the shutdown time is too long, which causes the temperature of the freezing room to be too high, which cannot reach below -18 ℃.
b. When the ambient temperature is lower than 0°C, the refrigerator should be stopped: because when the ambient temperature is lower than 0°C, the compressor oil will thicken and the lubricating performance will be worse; The refrigerant will not flow into the evaporator, and if you continue to use the refrigerator at this time, it will not work properly and may cause damage to the compressor.
4. PTC starter failure
Use a multimeter to measure whether the resistance between the PTC starter running jack and the start jack is normal (normal resistance is 16 ~50 ohms), such as infinity or 0, the PTC starter is damaged and should be replaced.
5. The overload protector is faulty
Use an ammeter to measure whether the compressor starts and runs normally (the starting current is generally about 5 to 8 times the running current), if the current is normally overloaded If the protector acts, the overload protector fails and should be replaced. Otherwise, the compressor is faulty.
