Impact of phase change material on the amount of emission in the double-glazed window frame for different window angles

Abstract

The conduction, convection, and radiation heat transfer in a double-glazed window (DGW) containing air are simulated in this paper. Phase change material (PCM) is used in the window frame (WF) to control the temperature. By changing the window angle from 0 (vertical position) to 60°, the melting time of PCM and the amount of heat loss from the window are analyzed. Also, the amount of heat loss is investigated by changing the distance between the glasses. The governing equations are solved by considering the cold air outside and the warm air inside and assuming the air as a gray body. Two-dimensional simulations are performed using the CVM (Control Volume Methods). PCM n−eicosane is used in the WF. The results show that an increment in the window angle reduces the free convection heat transfer (FCHT) in the cavity and the heat transfer rate. The highest heat loss occurs for the vertical window, and the minimum one takes place for the 60° window. An increment in the window angle by 60° reduces the heat transfer rate from the window by 10%. An enhancement in the air gap reduces the amount of heat transfer in the window. The lowest PCM melting time occurs when the window angle is 0°, and the maximum one occurs for a window angle of 60° The window angle is favorable in terms of heat transfer from the glass and is unfavorable in terms of energy storage in the PCM in the frame. An enhancement in the air gap between the two glasses by 40 mm reduces the amount of heat transfer by 44%.