The flat plate solar water heater, using the closed-loop oscillating heat
pipes (CLOHP), was constructed and investigated. The flat plate collector
consisted of 10 pipes of CLOHP and the collector area was 1.5?1 m2. Each
CLOHP was made of a copper capillary tube with a 1.5 mm inner diameter, a
2.8 mm outer diameter and had 20 turns. The distilled water was used as the
working fluid with a filling ratio of 50% the tube?s total internal volume.
The evaporator section of the CLOHP was placed on the absorber plate of the
collector, and its condenser section was wrapped around the copper tube, in
which hot water flowed through. The solar water heater was tested under the
solar simulator with halogen lamps generating the uniform artificial solar
energy. The irradiation intensity and the water flow rate of the solar water
heater were adjusted. It was found that the thermal performance of the solar
water heater clearly improved with an increase in the irradiation intensity
from 480 to 1086 W/m2. However, the water flow rate in the range of 1.5-3.0
L/min, had a thermal performance that was slightly different. The thermal
efficiency of 0.67 was archived at the high irradiation intensity of
947-1086 W/m2. Moreover, the mathematical model to predict the thermal
efficiency of the flat plate solar water heater with the CLOHPs was
obtained.
Experimental Study of the Thermal Performance for the Novel Flat Plate Solar Water Heater with Micro Heat Pipe Array Absorber
