Multi-stage variable speed turbo compressor for enhancing seasonal energy efficiency ratio of air conditioners using R718 as refrigerant.

Author(s) : AMIBE D. A., LI Q., MÜLLER N.

Summary

An air-conditioning system using water as refrigerant (R718) that compresses water vapour with multistage stage variable speed axial compressor with intercooling between stages by water injection is considered. Four stage compression with flash intercooling resulted in 50% improvement of COP at full load compared to conventional refrigerants like R134a. The energy-efficiency of an air-conditioning unit is specified by seasonal energy efficiency ratio (SEER). SEER is defined as the ratio of cooling output of an air conditioner measured and electrical energy consumption as per AHRI 210/240 during cooling season. The SEER is computed after determining the evaporator cooling capacity and the electrical energy demand of the compressor at each bin temperature using assumed compressor isentropic efficiency, mechanical efficiency and electrical efficiency and multiplying by the weight of each bin temperature to determine the total for the cooling season. As a result of multistage compression, best part load performance of water as a refrigerant and operation of compressor near design point at part load due to variable speed drive, 50-60% improvement in SEER is obtained compared to the best available in the market using conventional refrigerants such as R134a with single stage compression.

Details

  • Original title: Multi-stage variable speed turbo compressor for enhancing seasonal energy efficiency ratio of air conditioners using R718 as refrigerant.
  • Record ID : 2011-0282
  • Languages: English
  • Publication date: 2010/06/14
  • Source: Source: ASME Conf. Proc., Glasgow
    vol. 5; pap. n. GT2010-22502; pp. 349-355; fig.
  • DOI: http://dx.doi.org/10.1115/GT2010-22502