Experimental investigation on the heat transfer enhancement in a novel latent heat thermal storage equipment. (September 2018)

• Record Type: Journal Article
• Authors: Liu, Yang; Duan, Jianguo; He, Xiufen; Wang, Yaxiong
• Is Part Of: Applied thermal engineering. Volume 142(2018)
• Page Start: 361
• Page End: 370
• Publication Date: 2018-09
• Subjects: PCM -- Copper foam -- Heat storage capacity -- Dissipation rate -- Latent heat thermal energy storage; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2018.07.009
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: A novel latent heat thermal storage equipment is designed and built. The U-tube in rectangular latent storage unit under different operation conditions is studied. The thermal performance of units filled with paraffin and paraffin/copper foam have been compared and discussed. The optimum operating conditions are investigated when the copper foam is embeded in paraffin. Abstract: Latent heat thermal energy storage (LHTES) is a potential and promising technology for efficient utilization of renewable energy. In order to achieve efficient heat storage and release capacity, a novel and compact LHTES equipment which is integrated with several parallel U-tube rectangular heat storage units (HSUs) has been developed and investigated experimentally. The thermal storage equipment developed here can be applied in many areas such as low-temperature waste heat recovery, solar heat utilization, agricultural green house heating, etc. Filled with modified paraffin enhanced by large porosity copper foam in the HSUs in the LHTES equipment, the maximum heat storage capacity and rate reached 1.907 MJ and 198.7 W respectively when the inlet temperature of heat transfer fluid (HTF) was set to be 85 °C. In addition, the dissipation rate was 13.3 W in the condition of 100% opening ratio of air convective channel and the ambient temperature of 23 °C. This outstanding thermal performance of the developed equipment was the combinative contribution of copper foam and U-tube structure in the rectangular thermal storage units due to the thermal conductivity improvement of the modified PCM and extension of the heat transfer area of the heating tube. Furthermore, the thermal storage equipment has advantages of good integrity, compactness and flexibility to meet the requirement of large-scale thermal energy storage and controllable heat dissipation by assembling the number of the heat storage units in the equipment.