Abstract:
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.