The heat exchanger is very important to the major loop of the reflooding test.It can cool the fluid in the loop,so that the fluid temperature can agree with the requirements of the major pump and the preheater.Herein,an evaporative exchanger with U-shape tubes is adopted.The heat transfer calculation The heat exchanger is very important to the major loop of the reflooding test. It can cool the fluid in the loop, so that the fluid temperature can agree with the requirements of the major pump and the preheater. Herein, an evaporative exchanger with U- shape tubes is adopted. heat transfer calculation