Dongxi Liu is a postgraduate studying at the Key Laboratory of Efficient Utilization of Low & Medium Grade Energy and Geothermal Research & Training Center, Tianjin University, China.. The main research directions are the optimal design of geothermal energy heating system and hot dry rock power generation system. And He is currently designing and developing a geothermal heating and energy storage device. And He is currently designing and developing a geothermal heating and energy storage device. At present, one EI paper and several international conference papers have been published. Besides, he has applied for 5 national invention patents and 4 utility model patents.