Fig. 5a shows a schematic diagram of a jet refrigeration cycle. A boiler, an ejector, and a pump are used to replace the mechanical compressor of a conventional vapour compression refrigeration system. As heat is added to the boiler, the high pressure and temperature refrigerant vapour is evolved and used as the primary fluid for the ejector. The ejector draws low pressure refrigerant from the evaporator as its secondary fluid. This causes the refrigerant to evaporate at low pressure and produce the useful refrigeration. The ejector discharges its exhaust to the condenser where it is liquefied at the ambient temperature. Part of the liquid refrigerant is pumped back to the boiler whilst the remainder is returned to the evaporator via a throttling device. Often, the operating condition of boiler, evaporator and condenser of a jet refrigeration cycle are defined by heat source, refrigerated purpose and local climate respectively. The input required for the pump is typically less than 1% of the heat supplied to the boiler, thus, the actual COP