The Visualization of Evaporation in Plate Heat Exchanger for Low-grade Thermal Energy Conversion

Abstract

The plate type heat exchanger (PHE) is higher performance and compacter than the tube type and has been used in LTEC (Low-grade Thermal Energy Conversion). The flow with phase change is a complex, internal flow pattern of PHE has a great influence on PHE performance. Therefore, it is important to know the internal flow pattern for the development of a new heat transfer surface shape to enhance the performance. Visualization of the internal PHE is an effective method to reveal the two phase flow pattern. Therefore, in this research, the effect of the inlet quality and the mass flux on the heat transfer performance of the PHE transparent was examined on the by a direct the visualization. The experiments were conducted by means of PHE of the herringbone type (The chevron angle is 130, 90 and 60) with the working fluid of HFE7000. As a result, when the larger chevron angle, higher heat transfer performance.