SOLAR-DRIVEN DOUBLE - STAGE STEAM EJECTOR REFRIGERATION SYSTEM
ANAN PONGTORNKULPANICH *
Division of Chemical Engineering, Faculty of Engineering and Architecture, Rajamangala University of Technology Tawan-Ok, Uthenthawai Campus, Bangkok, 10330, Thailand
PAKASIT HONGTHONG
Division of Civil Engineering, Faculty of Engineering and Architecture, Rajamangala University of Technology Tawan-Ok, Uthenthawai Campus, Bangkok, 10330, Thailand
*Author to whom correspondence should be addressed.
Abstract
In order to encourage ejector refrigeration system to be another choice in cooling market, improvement of system performance, which is defined as coefficient of performance, COP, and developing from single stage ejector refrigeration, basic ejector unit, to be double stage ejector refrigeration is performed. The double stage ejector refrigeration system with solar assisted, in this research, is designed and fabricated to be experimentally tested. The computer simulation program of double-stage ejector refrigeration system has been developed to simulate various parameters such as optimum mass flow rate of entrained fluid, load at condenser, boiler, evaporator, ejector performance, COP and dimension of ejector to be used to design system. Double-stage ejector system, which differs from one ejector for single stage, uses two identical ejectors which are placed to be parallel in the system. Saturation boiling steam at 110°C is used to be primary vapor to drive ejectors and evaporator condition uses at temperature of 10°C. Overall system performance is defined as solar fraction, SF. The experimental testing results show that average monthly SF of double stage system is 0.59. Effect of condenser pressure and temperature on ejector performance and COP is investigated. The lowest chilled water temperature is obtained at 18.5°C.
Keywords: Double-stage ejector, refrigeration system, solar energy, system performance