Experimental study of density effect and natural convection in a latent heat storage unit with paraffin wax and air

Abstract

Experimental analysis is carried out on tube in tube type heat exchanger. The phase change material (PCM) is melted under the influence of hightemperature air as HTF. PCM density effect is presented with the temperature change in axial and radial positions. During charging, the lower elevation temperature curve's intersection with the higher elevation's temperature curves is identified. The earliest intersection is found at 20 minutes with 51 C. The late intersection is found at 62 minutes and 75 C. Natural convection jump phenomenon is also spotted. Each temperature curve in middle and outer radial positions is classified into three categories (before the jump, during the jump, and after the jump). Natural convection jumps are found in the range of 2.667 to 8.5 C/minute. The density effect and natural convection jump are found to be insignificant during discharging.