Thermal performance investigation of large-scale latent heat storage for heat supply

Abstract

This work conducts a thermal performance investigation on an industrial-scale low-temperature latent heat storage unit based on thermal behavior identification and parametric analysis of the storage unit. The thermal performance of thermal power-driven and heat transfer fluid temperature-driven charges and discharges are investigated. Two groups of parametric analyses are conducted to reveal the effects of different operating conditions and heat transfer structures on the power rate and thermal efficiency of the storage unit. Two practical application scenarios including a space heating system and a domestic hot water supply system using the storage unit are designed and simulated. The results show that the charging/discharging thermal power and charging/discharging efficiency are always inversely correlated. Using densified fin structures can effectively improve the charging rate and discharging efficiency of the storage unit at specific operating conditions. In addition, a single storage unit with a storage capacity around 100 kWh can meet a 16-h heating demand of space heating with a base heating load of 30 W m−2 and a minimum heating temperature of 40 °C for an area of 195.7 m2,and can provide 2500 L of domestic hot water above 45 °C for the daily use of 25 residents within 6 h.