Investigation of energy consumption reduction in multistage compression process and its solutions

During hot seasons the inlet temperature of Nitrogen increases, as a result compressor consumes more power for compressing a specific mass ratio of fluid and consequently total energy consumption of the compressor increases as well. In this research, a three stage centrifugal compressor with intercooler was modeled thermodynamically in order to decreases the energy consumption of the compressor. In each compressor, isentropic efficiency, outlet temperature of the Nitrogen gas and power compression was investigated. The effect of inlet Nitrogen temperature and cooling water temperature on intercoolers’ efficiency were investigated. In this study, Nitrogen gas is considered as an ideal gas. It is found that, in each compressor any growth in inlet temperature of the Nitrogen gas will result in linear increase in the outlet temperature of the Nitrogen gas and power compression furthermore, it is observed that increasing the temperature of Nitrogen gas has the most negative effect on efficiency and power compression of the first compressor in comparison to the second and the third compressor consequently, it will result in a 10 percent decrease in special power compression specially during summer time. According to the results, it is figured out that any growth in inlet Nitrogen temperature causes a smooth decline in isentropic and Power Compression of the first, second and third compressors besides increasing the temperature of the Nitrogen gas increases the isentropic efficiency up to 3 Percent and increasing the cooling water temperature decreases the intercooler efficiency up to 7 Percent.

Keywords:

Three Stage Centrifugal Compressor , Shell and tube heat exchanger , Isentropic Efficiency , Compression Power