年間 4 号発行
ISSN 印刷: 2151-7975
ISSN オンライン: 2151-7991
EVAPORATOR USING HEAT PIPE HEAT EXCHANGER FOR A HEAT RECOVERY SYSTEM
要約
The recovery system consists in a heat pipes based heat exchanger that allows the efficient transfer of the waste energy to a heat pump refrigerant which the heat is transferred. The experimental work involved the characterization of the previously built heat pipes by measuring the thermal resistance under different operating conditions, such as the pipe's horizontal inclination, thermal bath temperature and supplied power. It was found that the average thermal resistance of the heat pipes is 0.02[K/W] for the 50-300 W power range. With these data, the heat recovery system (a bench of tubes) was designed, formed by 90 tubes with 2.54cm diameter and 500cm length. A CFD program based on Comsol 4.2a was developed for simulating the energy transfer between the humidified air and the heat pipes. It was used for sizing the heat pipes exchanger, predicting the humidified air condensation and evaluating the pressure drop through the tubes array. Finally falling film evaporation was simulated with Comsol 4.2a to quantify the refrigerant evaporation rate; also the heat transferred from the heat pipes to refrigerant was calculated with empirical correlations of several authors.