Experimental Investigation on the Plate Heat Pipe Heat Exchanger for Heat Recovery Characteristic in Room Ventilation

A plate HPHE (heat pipe heat exchanger) has been designed and constructed for heat recovery in this paper. The plate HPHE is constituted by plate heat pipes with microchannels. Many parameters affect the performance of the HPHE. In this paper, the effect of three parameters: inlet air temperature (27–40°C), working fluid (methanol, acetone, R113, R141b), and heat exchange area (single layer, double layer) were investigated experimentally. The overall experiments were carried out under the simulated summer condition, the vacuum of the HPHE was set at 1×10⁻³Pa, and the filling ratio was 1/3. The air volume rates were changed from 60, 90, 120 and 150 m³/h. The fresh air temperature varied from 27 to 40°C, whereas the return air temperature was kept at about 24°C. The results show that, at the same air volume, the effectiveness increases with increase of the inlet temperature of fresh air. The effectiveness of HPHE_d with R141b as working fluid is superior to R113, acetone and methanol, and the maximum effectiveness reaches to 58%. The effectiveness of the HPHE of single layer is lower than that of double layer by about 6%–18% at the temperature from 29 to 40°C.