Thermal performance of a heating system working with a PCM plate heat exchanger and comparison with a water tank

• Numerical study of a heating micro-CHP system with different Thermal Energy Storages.
• Analysis of coverage peaks in the most demanding week at an office in northern Spain.
• The overall thermal load demand is better met by the Palmitic Acid PCM-HE.
• Palmitic Acid provides greater heat transfer rates and accumulates more energy.
• Using Palmitic Acid means fewer Thermal Energy Storage units are required.

Heat storage equipment plays a very important role in micro-cogeneration plants as unconsumed heat can be released when needed. PCM heat exchangers are an alternative to commonly used storage tanks. Moreover, PCM heat exchangers occupy less space for the same amount of stored energy. This paper examines the energy performance of a heating-power micro-cogeneration system applied to a 450 m2 office space. A hot water thermal energy storage system and two latent heat thermal energy storage systems based on PCM plate heat exchangers are compared and their performances are analyzed under dynamic conditions.Operating strategies for the PCM heat exchanger and water tank are discussed in terms of the heat demand and power supplied by the internal combustion engine of a micro-CHP system. The thermal performance of two possible PCMs: RT60 paraffin and Palmitic Acid, in the form of plates inside the heat exchanger, are analyzed under processes of charging (PCM melting) and discharging (PCM solidification). Charge and discharge duration as well as the capability to deliver the appropriate heat transfer rate are compared. Palmitic Acid provides better results, with higher heat transfer rates, more accumulated energy and less storage units needed to meet the heating demand.

Figure optionsDownload as PowerPoint slide