Experimental Study On Thermal Performanee Of Phase Cbange Trombe Wall System Enhanced By Longitudinal Vortex Generattors

This paper studies thermal performance of phase change trombe wall (abbreviated as phase change wall) system enhanced by longitudinal vortex generators. Trombe wall in the experiments is made up by setting up shape-stabilized phase change material on the ordinary wall. Decorating longitudinal vortex generators on the surface of phase change wall strengthens heat transfer. The paper mainly focuses on the effect of different height, different arrangement of plane triangle winglet vortex generator (ZSLVG) on enhancing the system heat transfer with different types and having or not punching holes in the center of vortex generators that are arranged on the surface of phase change wall,Through single value change of vortex generator height, arrangement, the paper carried on the optimization of vortex generator and comparative experiments. The experimental results show that the heat transfer coefficient of phase change wall with ZSLVG is higher than that without ZSLVG in the liquid-solid phase change process, and ZSLVG that is3cm height has the highest average heat transfer coefficient. Also, the optimal value of the front distance is0.2cm, and the best column spacing is15cm. The convective heat transfer coefficient with ZSLVG is9.0W/(m2-K), and increases by43.77%comparing with the case without ZSLVG. There are the highest value of heat transfer coefficient that the phase change wall laying out a row and three pairs ZSLVG.In the comparison experiment of different type vortex generators, the paper applied the best arrangement of ZSLVG. And the experiments study on heat transfer effect of six different types vortex generators that respectively is plane triangle vortex generator, plane trapezoid vortex generator, plane rectangle vortex generator, half elliptical triangle vortex generator, half elliptical trapezoid vortex generator, half elliptical rectangle vortex generator. The experiments show plane trapezoid winglet vortex generators have the highest average heat transfer coefficient that is10.04W/(m2. K). The heat transfer difference of half elliptical vortex generators is small.In order to improve the heat transfer performance of the vortex generators and reduce the resistance of gas flow, this article modifies the plane and half elliptical vortex generators that have large frontal area, and sets up0.8cm holes in the center of the vortex generators. The experiments show that the punching holes can reinforce the heat transfer effect of the rectangular vortex generators, reduce the trapezoid ones, and maintain the half elliptical rectangular and trapezoidal ones. The paper also process the experiments that change the center hole’s size of right-angled trapezoid, and the hole’s size have0.5cm,0.8cm,1.2cm. And the experimental data show that the heat exchange effect is better when the diameter is0.8cm under the experimental condition.