การศึกษาประสิทธิผลของเครื่องอุ่นอากาศแบบท่อความร้อนหน้าตัดแบนชนิดสั่นวงรอบ

Abstract

This experimental research has been carried out to investigate the effectiveness of air pre-heater with closed loop oscillating flat heat pipe (CLOFHP). The lengths of both the evaporator and condenser sections of the air pre-heater were 0.30 m, and adiabatic section had a length of 0.10 m. The CLOFHP made from a copper tube with a circular cross section, which bent and pressed for a flat thickness of 2 mm. Distilled water was used as the working fluid with a fill ratio of 50% of the total internal volume. A test rig was constructed for a test of the effectiveness of an air pre-heater. The temperature of fresh-air inlet the condenser section was approximately 30^oC while the hot-air temperature flow into the evaporator section was varied in the range of 90–150^oC. Both of the hot and fresh air velocities across the air pre-heater were varied in the range of 0.5-2.0 m/s. The results found that, when the hot-air inlet-temperature increased with a lower velocity, the effectiveness of the air pre-heater also increased.  Moreover, the minimum effectiveness occurs at the hot and fresh air velocity was equal.