Detailed description of the structural characteristics of the compression part in the ammonia refrigeration system

The ammonia refrigeration system should include a refrigerant circulation system, a lubricating oil circulation system, a cooling water circulation system, and a refrigerant circulation system.
 
The advantages of ammonia as a refrigerant are: easy to obtain, low in price, moderate in pressure, large in unit cooling capacity, high in heat release coefficient, almost insoluble in oil, low in flow resistance, and easy to find when leaking. The disadvantages are: irritating odor, toxic, combustible and explosive, corrosive to copper and copper alloys.
 
The compression section in the ammonia refrigeration system consists of a compressor, an exhaust pipe, an intercooler of a two-stage system, and the like.
 
1. Single-stage compression: When the refrigeration system has two or more evaporation circuits, the machines of the respective circuits must first satisfy the temperature reduction of the respective systems. On this basis, it should be considered that other evaporation circuits can also be undertaken under special circumstances. Cooling task. That is to say, under the premise of not using equipment, the system can be flexibly connected by adding a small number of pipes and valves. In this way, the reliability of the refrigeration unit is improved, and the flexibility of machine scheduling is also increased. However, it should be noted that the bridge valve and the connecting pipe should not be added too much, so as to avoid complicating the system, waste material and increase the resistance, and the actual use value is not large.
 
2. Two-stage compression:
 
As mentioned above, the two-stage compression is to operate two or more compressors in series, and then set an intercooler to reduce the temperature of the suction gas of the high-pressure compressor, thereby reducing the exhaust temperature of the high-pressure compressor and improving the operation. situation. Some intercoolers also serve to separate oil and supercool the high pressure liquid refrigerant. Two-stage compression has two types: two-stage and two-stage.
 
Single-stage two-stage compression is a compressor that integrates high-pressure cylinders and low-pressure cylinders, and is called a single-stage two-stage compressor. Two-stage compression can be achieved with a single two-stage machine. The low-pressure cylinder is pressurized with low-pressure gas and pressurized to the intermediate pressure and discharged into the intercooler, and then sucked and compressed by the high-pressure cylinder to discharge the condensing pressure to the exhaust pipe.
 
3. Integrated system in ammonia refrigeration system: The refrigeration system with single-stage compression and double-stage compression is very common in the actual refrigeration equipment. The machine and pipeline configuration schemes must meet the needs of the respective circuits. It can be considered that it can switch between different evaporation circuits and be flexible.
 
The setting of the reverse running device: the reverse running is to exchange the refrigerant gas of the high pressure system into the low pressure system through the exchange of the suction and exhaust pipes of the compressor, and the high pressure system is vacuumed for use in maintenance and the like. Due to the infrequent use of the device, the entire refrigeration system can be set up, and the Zui is well set on the single-stage machine.