Study on thermal performance of casing‐type mine heat recovery device with phase change materials filling in annular space

Abstract

The underground mine contains abundant geothermal energy resources. The casing-type mine heat recovery device with encapsulated phase change material (PCM) embedded in the backfill body is efficient technology for extraction of geothermal energy in mines. A heat transfer model of a casing-type mine heat recovery unit was established to study the influence of PCMs thermophysical property and phase transition process on the thermal performance of backfill body. The effects of phase transition temperature, thermal conductivity, specific heat capacity and phase transition latent heat of PCMs on the temperature variation in backfill body and the thermal performance of casing-type mine heat recovery device were studied in the heat storage/release mode. The result indicates that the phase transition temperature is expected to be lower in heat storage mode and higher in heat release mode, respectively. The heat transfer rate

Standardised methods for the determination of key performance indicators for thermal energy storage heat exchangers

“…The mass flow rate, in-, and outlet temperature of the HTF are some of the most accessible measurements for LTES heat exchangers and are therefore often reported in experimental studies (e.g., [62, 63, 65, 66, 89, 91, 92, 95-97, 106, 123, 124, 141, 152]). Most authors calculate the efflux of energy (e.g., [62,72,76,77,83,90,92,96,97,106,108,110,117,118,124,126,152]), and some the integrated efflux of energy (e.g., [83,87,92,95,97,100,101,103,117,126,152]).…”