Compressor Ask For
Compressors, a moving fluid machine that elevating low pressure gas to high pressure gas, is the heart of the refrigeration system. It from the suction suction low temperature low pressure refrigerant gas, through the motor run a piston to compress, the exhaust pipes of high temperature and high pressure refrigerant gas, provide power for refrigeration cycle.
Thus, the refrigeration cycle of compression, condensation (exothermic), expansion, evaporation (heat absorption) is achieved. Compressor is divided into piston compressor, screw compressor, centrifugal compressor, linear compressor etc. Entry of compressor are introduced working principle, classification, accessories, specifications, and operating requirements, the compressor production, common faults, and environmental protection requirements, the selection principle, installation conditions and development trends.
The compressor is divided into the volumetric compressor and the speed type compressor according to its principle. The volume type is divided into: reciprocating compressor, rotary compressor; The speed type compressor is divided into: axial flow compressor, centrifugal compressor and mixed flow compressor.
Nowadays household refrigerator and air conditioner compressor are volume type, which can be divided into reciprocating and rotary type. Reciprocating compressor USES piston, crank, connecting rod mechanism or piston, crank, slide tube mechanism, and the rotary rotor compressor is used. On commercial air conditioning, more is centrifugal type, vortex type, screw type.
According to the application range can be divided into low back pressure type, mid-back pressure type, high back pressure type. Low back pressure type (evaporation temperature - 35 ~ 15 ℃), commonly used in domestic refrigerators, food cooler, etc. In the back pressure type (evaporation temperature - 20 ~ 0 ℃), commonly used in soda fountain, milk cooler, etc. High back pressure type (evaporation temperature - 5 ~ 15 ℃), is generally used in room air conditioner and dehumidifier, heat pump, etc.
Used on air compressor is mainly to adjust air compressor start-stop state, by adjusting the pressure inside the storage tanks to stop to rest, let the air compressor maintenance for machine. At the time of air compressor plant commissioning, according to the customer need to adjust to the specified pressure, and then set a pressure difference. For example, the compressor to start, to storage tanks, pressure to 10 kg, stop or uninstall air compressor, when the pressure to 7 kg air compressor to start again, it's a pressure difference, this process can make the compressor have a rest, to protect the role of air compressor.
The motor drives the compressor directly, causes the crankshaft to rotate and drives the connecting rod to cause the piston to reciprocate, causing the cylinder volume to change. Due to the change of pressure in the cylinder, through the inlet valve Make the air through the air filter (silencer) into the cylinder, in the compression stroke, due to the cylinder volume reduction, the role of compressed air through the exhaust valve, the exhaust pipe, one-way valve (check valve) to storage tanks, when the exhaust pressure to achieve the rated pressure of 0.7 MPa is controlled by a pressure switch and automatic stop. When the pressure of the storage tank is reduced to 0.5-- 0.6mpa, the pressure switch automatically joins up.
The first load operation of the compressor is carried out after the operation of the empty car and the blow-cleaning. The compressor shall carry out load operation according to the following requirements :
1. Gradually close the release valve or oil-water blowoff valve after driving, and operate for 1 hour under the pressure of 1/4 of the compressor; Operate 4-8 hours under pressure of 1/2 rated pressure.
2. The compressor runs under the minimum pressure, and the pressure will gradually increase after no abnormal phenomenon.
3. For large high-pressure compressors, the operating time under the nominal pressure shall not be less than 24 hours;
4. During operation, check the following items:
1. Lubricating oil pressure, temperature and oil supply conditions. The oil pressure shall not be less than 1kg/cm before the pipe is sent to the distribution piping. Crankcase or lubricating oil inside the fuselage wet should be: have a crosshead compressor shall not exceed 60 ℃. The crosshead must not exceed 70 ℃.
2. The compressor runs smoothly and the sound of the moving parts should be normal.
3. The water temperature and the supply of cooling water are measured and the cooling water is not allowed to flow and bubble and clog. Cooling water drainage temperature shall not exceed 40 ℃.
4. Connecting flange part, shaft seal, inlet, exhaust valve, cylinder cover and water jacket, must not leak gas, oil leakage, leakage.
5. The work of inlet and exhaust valve should be normal and safe.
6. No loose phenomena shall be found in the connection parts.
7. Measurement of exhaust temperature and pressure values at all levels should meet the requirements of technical conditions.
8. The heating conditions of the motor and the current value shall be in accordance with the regulations.
5. After operation, the following items are removed:
1. Remove the air valve at all levels and the front cover of the cylinder, check the surface friction of the cylinder, and find out the reason when there are friction marks.
2. Check the surface friction of piston rod, it should not be worn and pulled.
3. Remove the air valve at all levels, check the fitting of the valve disc and valve body, and replace the cut with spare parts if there is a crack.
4. Check the friction surface of the cross slide and the friction surface of the guide rail.
5. Remove the rod - head tile, crosshead pin and check the friction surface.
6. Replace the body oil. After the first operation of the compressor; Because of the part everywhere to get up to speed, and lubricating oil cleaning effect, a large number of tiny metal powder into the lubricating oil, therefore, the machine after 24 hours of work after all the lubricating oil should be changed. After 200 hours of operation, change the oil once again. After two replacement, change oil according to regular maintenance.
In order to achieve uniformity, the first operation must make full oil everywhere.