Analysis of energy consumption and energy conservation of multi-effect condensed refrigeration unit in small cold storage

Liu Xiaohui 1,Lu Mosen 2※,Wang Shuzhen 2,Xin Li 2,Zhang Qian 2,Lu Rong 3(1.School of Agriculture and Food Engineering,Shandong University of Technology,Zibo 255049,China;2.Shandong Institute of Pomology,Tai'an 271000,China;3.Yi Xin Preservation Equipment Factory,Tai'an 271000,China)

refrigerating machinery,cold storage,energy efficiency,exhaust pressure of compressor,temperature field,copper-constantan thermocouples

Air-cooled unit is mainly used in small and medium-sized refrigeration storage currently,which still has many problems with higher consumption of energy,inefficiency,longer starting time and failure shutdown due to high compressor exhaust pressure.Multi-effect condensed refrigeration unit combining air-cooled,water-cooled and transpiration-cooled in one was designed.A ten-ton fresh-preserved storehouse whose temperature range was 0-3℃was used as experimental subject.Energy eficiency experiments,safety and efficiency experimental researches were conducted with multi-effect condensed refrigeration unit by using thermocouples,data acquisition system,three-phase electricity parameters monitor,computer processing system etc,which the ambient temperature was kept at 36℃or so.The experimental results showed that per cooling time of multi-effect condensed refrigeration unit was only 0.38 h.Electricity consumption saving of the multi-effect condensed refrigeration unit reached over 46%,28.79℃compressor discharge temperature dropped,and 0.9 MPa exhaust pressure of compressor reduced than air-cooled unit.It had lower condensing temperature and uniform temperature field for fins-and-tubes heat exchanger of multi-effect condensed refrigeration unit.Therefore,multi-effect condensed refrigeration unit has remarkable energy efficiency effect in small cold storage and belongs to energy efficiency,high efficiency and safety refrigerating machine set.