Energy saving into an absorption heat transformer by using heat pipes between evaporator and condenser

• Published in: Applied thermal engineering Vol. 128; pp. 737 - 746
• Main Authors: Heredia, M.I., Siqueiros, J., Hernández, J.A., Juárez-Romero, D., Huicochea, A., González-Rodríguez, J.G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05.01.2018; Elsevier BV
• Subjects: Absorption; Absorption heat transformer; Coefficient of performance; Energy conservation; Energy saving; Enthalpy; Evaporation; Feasibility studies; Heat; Heat exchanger; Heat exchangers; Heat pipe; Heat pipes; Heat pump; Heat transfer; Heat transformers; Thermal resistance; Absorption heat transformer; Heat pump; Energy saving; Heat pipe; Coefficient of performance; Heat exchanger
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2017.09.017

•The usage of heat pipes into an absorption heat transformer is analyzed for energy saving.•The initial heat for a conventional AHT is reduced almost 25% by using heat pipes.•The COP enhances up to 20%, if the all condenser heat is recovered by the evaporator inside an AHT.•The local heat transfer coefficients for the evaporator and condenser were of 720W/m2°C and 250W/m2°C respectively. This study explores the feasibility of using heat pipes as heat exchangers inside an absorption heat pump type II (Absorption Heat Transformer) of a thermal capacity of 0.7kW. The heat pipe is a passive device to transfer heat because of low thermal resistance. A heat exchanger with heat pipes can be integrated between the condensation and evaporation processes of an Absorption Heat Transformer. This study has demonstrated that seven commercial heat pipes are required to condense 0.714kW and to reuse 0.177kW at 60°C in the evaporator, representing almost a third part of total heat supplied without heat pipes, provided that the generator temperature is over 55°C. Therefore, the efficiency of the Absorption Heat Transformer can be improved based on the concept of the Coefficient of Performance up to 20%.