氨压缩机（Ammonia compressor）.docVIP

氨压缩机（Ammonia compressor） The role of 10.2.1 intercooler In multistage compression, the cooling of refrigerant gas between the high and low pressure stages is called intermediate cooling. A complete inter cooling and incomplete cooling, the low pressure exhaust cooling to the intermediate pressure under dry saturated vapor state, two-stage compression ammonia often uses this method; the latter for the vapor mixture evaporation of low pressure exhaust and intercooler, reduce the temperature, but did not reach the middle pressure saturated dry the vapor state, commonly used in the R12 and R22 double stage compression. The ratio of absolute pressure to absolute pressure before compression is called compression ratio. Pressure ratio. In a refrigerator, the ratio of condensing pressure (absolute pressure) to evaporation pressure (absolute pressure) is often used instead. The compression ratio of single-stage refrigeration compressor (usually ammonia compressor) is not more than 8, R12 and R22 are not more than 10. Otherwise, the compressor gas flow will be reduced, the exhaust temperature will rise, and the refrigerant throttling loss will increase, which will be detrimental to the reliability and economy of the refrigerator. Under normal circumstances, the condensing pressure of the refrigerator usually changes little. The main reason for the increase of compression ratio is that the evaporation temperature is low and the evaporation pressure decreases. When the compression ratio exceeds the above limit, double stage compression shall be adopted. When the exhaust temperature of the compressor increases, the cylinder wall temperature rise, on the one hand, the steam inhalation of the temperature rise, the increase in the volume fraction, the inspiratory volume decreased; on the other hand, the lubrication condition worsened, the operation of the compressor is difficult. For example, when the condensing temperature is 40 DEG C and the evaporating temperature is 30 DEG C, t