The important role of air conditioning compressors

1. Overview of Air Conditioner Compressors

The air conditioner compressor is the heart of the refrigeration system. It draws in low-temperature, low-pressure refrigerant gas from the suction pipe, compresses it using a motor-driven piston, and discharges high-temperature, high-pressure refrigerant gas into the discharge pipe. This provides the power for the refrigeration cycle, achieving the refrigeration cycle of compression → condensation → expansion → evaporation (heat absorption). Air conditioner compressors generally consist of a housing, electric motor, cylinder, piston, control devices (starter and thermal protector), and cooling system. There are basically two types of starters: hammer type and PTC type, with the latter being more advanced. Cooling methods include oil cooling and natural cooling. Generally, household air conditioner compressors use single-phase AC power, and their structural principles are basically the same. Air conditioner compressors have relatively low power, usually under 250W. However, air conditioners themselves typically have compressor power ranging from 230-900W. The refrigerants used are different.

2. Production Methods of Air Conditioner Compressors

Air conditioner compressors are produced using an assembly line. In the machining workshop (including casting), parts such as the cylinder, piston (spindle), valve plate, connecting rod, crankshaft, and end cover are manufactured; the rotor and stator are assembled in the motor workshop; and the housing is manufactured in the stamping workshop. Then, in the final assembly workshop, assembly, welding, cleaning, and drying are performed, after which the finished product is inspected, packaged, and shipped. Most air conditioner compressor manufacturers do not produce starters and thermal protectors, but purchase them from the air conditioning market as needed.

3. Types of Air Conditioner Compressors

Currently, household air conditioner compressors are all positive displacement compressors, which can be further divided into reciprocating and rotary types. Reciprocating air conditioner compressors use a piston, crank, and connecting rod mechanism or a piston, crank, and slide mechanism; rotary types use a rotary crankshaft mechanism. By application range, they can be divided into low-back pressure, medium-back pressure, and high-back pressure types. Low-back pressure type (evaporation temperature -35～-15℃), medium-back pressure type (evaporation temperature -20～0℃), generally used in beverage coolers, milk refrigerators, etc. High-back pressure type (evaporation temperature -5～15℃), generally used in room air conditioners, dehumidifiers, heat pumps, etc.

4. Specifications and Quality of Air Conditioner Compressors

The specifications of air conditioner compressors are classified according to input power. Generally, each specification differs by about 50W. In addition, there is also classification by cylinder volume. The main performance indicators of air conditioner compressors include: input/output power, performance coefficient, cooling capacity, starting current, operating current, rated voltage, frequency, cylinder volume, noise, etc. To measure the performance of an air conditioner compressor, comparison is mainly made in terms of weight, efficiency, and noise. According to Chinese standards, the performance testing of air conditioner compressors is carried out according to the items specified in GB9098-96. The main items are cooling capacity, input power, operating current, starting performance, residual water content and impurity content of the whole machine, and life test. The safety performance test is carried out according to the items specified in GB4706.17-96. The main items include dielectric strength, insulation resistance, leakage current, running test under stall conditions, as well as motor winding temperature rise, housing temperature, and on-off test. For performance testing of air conditioner compressors for air conditioners, the provisions of GB10870～10876-89 are followed. Safety standards refer to those of air conditioner compressors. In addition, type testing must be conducted when major changes that may affect product performance occur during product development and production, when production is resumed after a full year or more than a year, and when there is a significant difference between factory inspection results and type testing results.

5. Packaging and Transportation of Air Conditioner Compressors

The packaging and transportation of air conditioner compressors can be handled according to the contract. Large quantities of imported air conditioner compressors are generally packed in cartons and then shipped in containers. Air conditioner compressors should be firmly secured within the packaging box, with moisture-proof and shock-proof measures. They must not be inverted during storage and transportation, and should be stored in well-ventilated warehouses with a relative humidity not exceeding 80% and no corrosive gases present.

6. Main Importing Countries of Air Conditioner Compressors

Due to insufficient domestic supply of air conditioner compressors, China still needs to import a certain amount each year. The main trading partners are the United States, Italy, Denmark, Brazil, South Korea, etc. In recent years, domestic air conditioner compressor manufacturers have significantly improved the quality and output of domestic air conditioner compressors through technological introduction and equipment upgrades.

7. Precautions for Air Conditioner Compressors

The sealed rubber plug of an air conditioner compressor may only be removed during use. If the plug is found to be loose or detached during storage and transportation, it should be promptly checked and handled before storage. Air conditioner compressors are subject to import safety and quality licensing. Foreign manufacturing or business enterprises must obtain import quality licenses issued by the National Entry-Exit Inspection and Quarantine Bureau and affix the corresponding marks on the products in order to import them.