Test facility for a multiejector R744 refrigeration system

A test facility for experimental investigation of a new multiejector R744 refrigeration system was designed and manufactured. An expansion/pre-compression block consisting of multiple ejectors was introduced into the parallel compression system, partially substituting for a classic high pressure valve. The ejectors, operated for both vapor and liquid pre-compression, in parallel or individually, entrain refrigerant from the suction accumulator at low pressure (28 bar - 32 bar) and transport it to the liquid receiver at the intermediate pressure (34 bar - 38 bar). The preliminary experimental results reported individual ejector efficiencies up to 30%, dependent on operational conditions (discharge pressure and temperature, pressure lift, evaporation pressure).