Abstract
In this paper, the results of the performance tests of the air to air heat exchanger and the heat pipe used in the unit are presented. The heat exchanger is consisted of 28water-copper grooved type heat pipes with 9.74mm diameter. The number of rows of heat pipes is 8 rows with plate Al fins. Face area is 0.01852m2.
As the results of the tests, it can be concluded that
(1) the experimental values of the over-all heat transfer coefficients are nearly equal to the values calculated by equation being based on over-all thermal resistance of the heat pipe.
(2) the experimental values of outside heat transfer film coefficient including fin effi-ciency and contact resistance between fin and heat pipe are lower than the values obtained by using Vampola's equation by 10 percent.
(3) the heat transfer rate of the heat pipe exchanger can be obtained diagrammatical on the curve of the evaporator zone surface temperature vs condenser zone surface temperature under a constant heat input.
(4) the pressure drop across a heat pipe bunk is higher than the calculated values, but there is not a big difference between the experimental values and the calculated values.
