EXPERIMENTAL INVESTIGATION OF POSSIBLE USE OF HDPE AS THERMAL STORAGE MATERIAL IN THERMAL STORAGE TYPE SOLAR COOKERS

Abstract

Many Phase Change Materials (PCMs) have been investigated by researchers. They reported limitations of PCMs for use in the thermal storage systems, some of them are: high volumetric change in the PCM while undergoing phase change and low thermal conductivity of the PCMs. Literature survey shows that High Density Polyethylene (HDPE) has relevant thermal properties and can be used as PCM. To investigate the possible use of HDPE in the thermal storage type solar cookers. The simple thermal storage device cum cooking device was designed with two stainless steel utensils easily available in the market. Use of HDPE as the PCM in the thermal storage will eliminate the problem of volumetric change as it has low volume change property during phase transition. To eliminate problem of low thermal conductivity rectangular brass fins were used in the design. Bottom of smaller stainless steel vessel (cooking cavity) was brazed with rectangular brass fins in radial manner with roughly equal angular spacing. HDPE was filled in the void space between cooking cavity with fins and outer stainless steel vessel. The device was then tested for heating, cooling and cooking. The results obtained and conclusions drawn from the experimentation are enlisted in this paper.