Experimental Investigation of Process Concepts for PCM Thermal Energy Storage

Description

Thermal energy storage tanks operating with phase change materials (PCMs) are described in the literature as special process concepts for low-temperature thermal energy storage. In conventional latent heat storage tanks, heat transfer is limited by the heat conductivity of the PCM. A well investigated concept to avoid this limitation is using a packed bed storage tank. The present study compares operation parameters of a shell-and-tube storage tank and a packed bed storage tank to those of an experimental tank with forced PCM convection. Performance characteristics of laboratory-scale storage tank models as heat transfer rates and charging and discharging time are compared. Three different laboratory-scale PCM storage tanks are available for experimental investigation: • 1 shell-and-tube storage tank model with PCM in the annular gap • 1 packed bed storage tank model with macro-encapsulated PCM • 1 storage tank model with agitated-phase forced PCM convection The objective of this work is to add experimental investigations on a forced-convection storage tank concept to the existing examinations [1, 2] on shell-and-tube heat storage tanks and on packed bed storage tanks [3, 4]. The present laboratory plants were built for measurement series that deliver data for heat exchange as well as for melting and solidification of PCM. Based on those data, advantages and disadvantages of storage tanks with continuous phase of PCM, tanks with packed PCM bed and tanks with agitated phase of PCM are shown. Storage capacity, heat storage efficiency and charging and discharging time were considered in this work. Both the relation between thermal output and total amount of PCM and the relation between thermal output and total system volume are discussed. The advantages and disadvantages of the present PCM storage concepts compared to a water heat storage tank are regarded.

Period	17 Jun 2015
Event title	ACHEMA 2015
Event type	Conference
Location	GermanyShow on map