A Simulation Study to Evaluate the Vapor Jet Refrigeration Cycle Driven by Solar Thermal Energy for Air Conditioning Application at Two Different Areas in Palestine

Abstract

The need for air conditioning in rural areas in which there is no source of traditional electrical power leads to look for an alternative solutions. Usually the population of these areas use typical movable houses (TMH’s) as residence. Solar thermal system drive vapor jet refrigeration cycle (VJRC) is a valid solution for this kind of situation, which replaces the traditional vapor compression refrigeration cycle that used the electricity. Mathematical model was carried out for (VJRC) using Engineering equation solver (EES) software at various design conditions (generator, evaporator and condenser temperature), characteristic curves and tables for the (VJRC) were found at 10°C evaporator temperature. Hourly simulation of cooling load demand for specific construction TMH was calculated using TRNBuild subsystem in TRNSYS software with the standard design conditions in Hebron and Jericho cities. Furthermore hourly simulation of the overall solar thermal cooling system was carried out over the study period (May-September), while considering climatic data for the two cities using TRANSYS software compiled with Excel software which contained the characteristic tables of the VJRC that obtained from the EES. The instantaneous performance of the system, Cooling load demand and evaporator cooling load available were calculated. Effect of climate according to the location, solar collector area, storage tank volume were studied to produce the maximum suitable evaporator cooling load to meet the requirement of the human comfort. EES Mathematical model for the VJRC demonstrated that the performance of the cycle is increased with increasing the generator and evaporator temperature, but decreases with increasing condensing temperatures. Cooling load simulation for Hebron and Jericho TMH demonstrated that the maximum cooling load demand during the study period were: 5.35 kW and 7.02 kW respectively; and the seasonal cooling energy demands were: 5749 kWh/year and 14864 kWh/year respectively according to the climate conditions. Simulation for the overall system demonstrated that the proposed system was efficient for Hebron city in contrast to Jericho city where the proposed system showed lake of cooling energy produced. Also the optimal sizes and options of the overall system were determined for Hebron city. An economical study was done on the proposed system where the results demonstrated that the proposed system in Hebron city is more economically than Jericho where the simple payback period of Hebron city reached to12.9 year while in Jericho city is 15 year at the same system size