Steam jet ejector cooling powered by waste or solar heat

A small scale steam jet ejector experimental setup was designed and manufactured. This ejector setup consists of an open loop configuration and the boiler operate in the temperature range of T-b=85-140 degrees C. The typical evaporator liquid temperatures range from T-e=5 degrees C to 10 degrees C while the typical water-cooled condenser pressure ranges from P-c=1.70 kPa to 5.63 kPa (T-c=15-35 degrees C). The boiler is powered by two 4 kW electric elements while a 3 kW electric element simulates the cooling load in the evaporator. The electric elements are controlled by means of variacs. Primary nozzles with throat diameters of 2.5 mm, 3.0 mm and 3.5 mm are tested while the secondary ejector throat diameter remains unchanged at 18 mm. These primary nozzles allow the boiler to operate in the temperature range of T-b=85-110 degrees C. When the nozzle throat diameter is increased, the minimum boiler temperature decreases. A primary nozzle with a 3.5 mm throat diameter was tested at a boiler temperature of T-b=95 degrees C, an evaporator temperature of T-e=10 degrees C and a critical condenser pressure of P-crit=2.67 kPa (22.6 degrees C). The system's COP is 0.253. In a case study the experimental data of a solar powered steam jet ejector air conditioner is investigated. Solar powered steam ejector air conditioning systems are technical and economical viable when compared to conventional vapour compression air conditioners. Such a system can either utilise flat plate or evacuated tube solar thermal collectors depending on the type of solar energy available. (C) 2008 Elsevier Ltd. All rights reserved.