Compressor Working Principle
Compressor, is a passive fluid machine that lifts low-pressure gas into high-pressure gas, is the heart of the refrigeration system. It sucks the low temperature and low pressure refrigerant gas from the suction pipe, drives the piston through the motor to compress it, discharges the high temperature and high pressure refrigerant gas to the exhaust pipe, and provides the power for the refrigeration cycle.
So as to achieve compression → condensation (exothermic) → expansion → evaporation (heat absorption) of the refrigeration cycle. Compressor is divided into piston compressors, screw compressors, centrifugal compressors, linear compressors and so on. The working principle, classification, accessories, specifications, operation requirements, compressor production, common faults and environmental requirements, selection principle, installation conditions and development trend of the compressor are introduced.
Compressor according to its principle can be divided into volume type compressor and speed type compressor. Volume type is divided into: reciprocating compressors, rotary compressors; speed compressors are divided into: axial compressor, centrifugal compressor and mixed-flow compressor.
Today, home refrigerators and air conditioners are volumetric coupons, which can be divided into reciprocating and rotary. Reciprocating compressors use pistons, cranks, connecting rods or pistons, cranks, pipe mechanisms, rotary use mostly rolling rotor compressors. In commercial air conditioning, the other is centrifugal, scroll, screw type.
According to the scope of application can be divided into low back pressure, in the back pressure, high back pressure type. Low back pressure (evaporation temperature -35 ~ -15 ℃), generally used for household refrigerators, food freezers and so on. In the back pressure (evaporation temperature -20 ~ 0 ℃), generally used for cold drinks counters, milk and other refrigerated containers. High back pressure (evaporation temperature -5 ~ 15 ℃), generally used for room air conditioners, dehumidifiers, heat pumps and so on.
Used in the air compressor is mainly to adjust the air compressor start and stop the state, by adjusting the pressure inside the tank to allow air compressor downtime, the maintenance of the machine in the air compressor factory commissioning, according to The customer needs to adjust to the specified pressure, and then set a pressure difference.For example, the compressor starts to start, to the tank to cheer, to the pressure of 10kg, the air compressor shutdown or unloading, when the pressure to 7kg when the air compressor Start to start, there is a pressure difference here, this process can let the compressor take a break, to protect the role of air compressor.
Driven by the motor directly to the compressor, the crankshaft to produce a rotary motion, driven connecting rod to reciprocate the piston, causing the cylinder volume changes. Due to changes in the cylinder pressure, through the intake valve to air through the air filter (muffler) into the cylinder, in the compression process, due to the cylinder volume reduction, compressed air through the exhaust valve, the exhaust pipe, To the valve (check valve) into the gas tank, when the exhaust pressure reaches the rated pressure of 0.7MPa by the pressure switch control and automatically shut down. When the tank pressure drops to 0.5 - 0.6MPa when the pressure switch automatically connected to start.
Compressors are produced in a pipelined manner. In the machining workshop (including casting) to create a cylinder, piston (shaft), valve, connecting rod, crankshaft, end caps and other parts; in the motor plant assembly of the rotor, stator; in the stamping workshop to create a shell. And then in the assembly shop for assembly, welding, cleaning and drying, and finally tested by qualified packaging factory.
Most compressor manufacturers do not produce starters and thermal protectors, but are purchased from the market as needed. Compressors on behalf of enterprises: Meizhi, Mitsubishi, Embraco and so on.