Efficient Solar Driven Air Conditioning System for Hot Climates: Case Study of Doha

Abstract

An advanced thermal solar driven air conditioning system for hot climate is described and a steady state thermodynamic model is used to predict its performance by using weather data for Doha (Qatar). The proposed system combined both Organic Rankine Cycle (ORC) and conventional mechanical Vapour Compression Cycle (VCC) whereby the expender (Turbine) is coupled to the compressor. Both cycles operate with ammonia refrigerant. For the same collector surface area (20 m2), the corresponding average daily cooling production is high with Evacuated Tube Solar Collector (ETSC) compared to Flat Plate Solar Collector (FPSC): ranging from 3.4 kW (in July) to around 7.6 kW (in April) for FPSC and from 4.5 kW (July) to around 10.2 kW (in April) for ETSC. The maximum values of COPs obtained (0.50 to 1.60 with an optimum driving temperature of about 118oC) are overall above those of standard heat driven systems such as absorption or adsorption refrigeration systems (typical maximum values range: 0.4 to 0.8).