An experimental investigation of steam ejectors for applications in jet-pump refrigerators powered by low-grade heat

The jet-pump refrigerator cycle offers a low-capital-cost solution for util izing low-grade waste heat in the production of cooling for buildings and p rocess refrigeration. The heart of the jet-pump refrigerator is an ejector, the performance of which strongly determines the thermal efficiency of the cycle. This paper describes and evaluates the results of an experimental i nvestigation into the operation of ejectors primarily for use in jet-pump r efrigerators. The construction of a steam-steam ejector test facility and e xperimental method are described. Experimental results are provided concern ing the effects of primacy nozzle exit position within the mixing-entrainme nt section, primary nozzle exit and diffuser throat areas. The causes and e ffects of flow instability under conditions of high secondary pressure rati o are also discussed and methods of increasing the critical condenser press ure are identified and rated in order of effect.