The present project involves the design and construction of a new type of heat pipe in which the vapor and the condensate circulates in the same direction. The objective is to reduce the entrainment and burn-out effect which may occur in the conventional heat pipe at high heat flux. The test results show that at low heat flux the constructed closed loop heat pipe can transfer heat from the evaporator section to the condenser section approximately 100% better than the conventional heat pipe of the same material. In particular, the copper closed loop heat pipe at high heat flux test shows that it can transport axial heat at a rate above 464 watts, which in terms of equivalent thermal conductivity is 157 times better than that of copper. In additions, the effects of such variables as the volume of working fluid, the angle of inclination and the flow rate of cooling water on the performance of the constructed heat pipes have also been investingated both in terms of the response time and the steady-state heat transfer rate.
