Wednesday August 28, 2019 from 13:30 to 15:10
Improving performance of a rechargeable personal cooling system with low GWP refrigerants
Rohit DHUMANE1, Yiyuan QIAO1, Jiazhen LING1, Vikrant AUTE1, Yunho HWANG1, Reinhard RADERMACHER1.
1Center for Environmental Energy Engineering, University of Maryland, College Park, United States
Personal cooling systems (PCS) enable 10-30% saving in building energy consumption, which takes up 41% of US primary energy. An innovative PCS called Roving Comforter (RoCo) uses R134a based vapor compression cycle (VCC) to provide cooling. To reduce environmental impact, it is necessary to evaluate RoCo performance with low GWP refrigerants.
The condenser heat of VCC is stored in a phase change material (PCM) storage, which limits the cooling operation duration. A recharge operation is conducted after the cooling operation.
A validated dynamic model (using Modelica) of VCC integrated with PCM is used to simulate the cooling operation with R32, R1234yf, R1234ze(E) and R290. The system performance is then evaluated with a smaller compressor to obtain reduced evaporator capacity (75 W to 150 W) and up to 50% longer operation.
The change in COP is -30%, -16% and -8% and -20% with R32, R1234yf, R1234ze (E) and R290 respectively. Dynamic pressure, mass flow rates, temperature and power are presented.