Performance analysis of a novel expansion valve and control valves designed for a waste heat-driven two-adsorber bed adsorption cooling system

摘要

Two new ideas for the expansion valve and control valves of an adsorption cooling system (ACS) for vehicle air conditioning applications are suggested to reduce its weight and parasitic power consumption, and simplify its control system. A check valve with cracking pressure of 3.5-7 kPa is proposed for the expansion valve and a combination of low cracking pressure check valves and solenoid valves with an innovative arrangement is proposed for the control valves. These new designs are installed on a two-adsorber bed silica gel/CaCl2-water ACS and tested under different operating conditions. These designs result in reducing the total mass of the ACS up to 10.5 kg and the parasitic power consumption of the control valves by 50%. The results show that the expansion valve and control valves operate effectively under the heating and cooling fluid inlet temperatures to the adsorber beds of 70-100 degrees C and 30-40 degrees C, respectively, the coolant water inlet temperature to the condenser of 30-40 degrees C, and the chilled water inlet temperature to the evaporator of 15-20 degrees C. Also, an ACS thermodynamic cycle model is developed and compared against the experimental data for prediction and further improvement of the ACS performance. The results of the numerical modeling show that by increasing the adsorber bed heat transfer coefficient and surface area, the specific cooling power of the system increases up to 6 times. (C) 2016 Elsevier Ltd. All rights reserved.