Experimental and theoretical analysis of a heat pipe heat exchanger operating with a low global warming potential refrigerant

In the present paper the experimental and theoretical analysis of a Heat Pipe Heat Exchanger (HPEH) is reported. The HPHE consists of 54 horizontal 12.7 mm micro-fin copper tubes 700 mm in length and aluminium continuous fins 0.115 mm in thickness with 3 mm of fin spacing. The HPHE presents an evaporator section of 270 mm, a condenser section of 270 mm and adiabatic section of 160 mm. The performance of the heat exchanger operating with the well-known hydrofluorocarbon refrigerant HFC134a is compared with the results obtained using the new low global warming potential hydrofluoro-olefin HFO1234ze(E). Tests were run in a double wind channel with air operating conditions typical for air-conditioning in European countries for both summer and winter seasons. The consistency of the experimental results is proved by the comparison with a semi-empirical model of the heat exchanger based on heat transfer correlations available in literature.