DESIGN AND PERFORMANCE OF FUNCTION PROVING AUTOMOBILE METAL HYDRIDE REFRIGERATION/AIR CONDITIONING SYSTEMS DRIVEN BY EXHAUST GAS

QIN Feng  CHEN Jiangping  NI Jiujian  CHEN Zhijiu

(Institute of Refrigeration and Cryogenics Engineering, Shanghai Jiaotong University, Shanghai 200030)

Abstract: A function proving automobile metal hydride(MH) refrigeration/air conditioning system is designed. The MH working pair LaNi4.61Mn0.26Al0.13/La0.6Y0.4Ni4.8Mn0.2 with working temperature 150 ºC/20~50 ºC/0 ºC is researched, their Van’t-Hoff diagram is drawn and reaction enthalpy, entropy, theoretical cycling coefficient of performance (ε0) as well as minimum refrigeration temperature (θm) are deduced. Based on this working pair, reaction beds are designed, a function proving MH intermittent refrigeration water cooling system driven by heat conducting oil is constructed. The regulations of cycling performance and θm are determined by altering the average temperature of high temperature reaction beds. The test results show that the MH working pair has satisfied reaction dynamics and small hysteresis; The low temperature MH reaction enthalpy reaches −27.1 kJ/mol H2. The reaction beds have perfect mass transfer ability, while their heat conduction coefficients are merely 1.5 W/(m·K) which results in long cycle period and low cooling power per MH. Intermittent refrigeration cycle is achieved, 238 W cooling power is obtained at 150 ºC/30 ºC/0ºC with ε0 being 0.26. In the test range, with the growth of average temperature of the high temperature reaction beds, cooling power and system ε0 increase while θm decreases, which agrees well with MH refrigeration theories.

Key words: Metal hydride  Air conditioner  Exhaust gas  Reaction bed  Automobile

CLC No: TB6  TK91

国家自然科学基金资助项目(50276063). Received 20050418, received in revised form 20051219