An experimental setup was established based on a closed loop plate pulsating heat pipe with parallel channels and a series of experiments were conducted to study its operational performance with acetone and ethanol. Heating copper block and cold water bath were adopted as thermal conditions in the experiments. The characteristics were investigated for different inclinations (90°

75°

and 60°) and cooling conditions (4.5 and 9.0 g·s-1). The heat-transfer performance of the pulsating heat pipe was mainly evaluated by thermal resistance and wall temperature. The results show that gravity has great influence on the heat transfer. At smaller inclination

thermal resistance is larger and heat transfer limit is lower. Heating power and cooling capacity need to be matched each other

and heat transfer limit will be higher with higher matching degree

especially with inclination. There is a best mass flow rate during the operation

and the thermal resistance is the lowest under the best cooling condition.