Experimental and numerical study of closed loop solar chimney assisted with PCM and CFM as thermal energy storage collector

Abstract EN

In this work, a test room was built in Baghdad city, with selective dimensions, while the solar chimneys (SC) where designed with aspect ratio (ar) bigger than 12 and setup to the oriented wall to the south.

Collector of SC consist of paraffin wax as a phase change material (PCM) and supported by copper foam matrix (CFM), to enhance the combined of thermal energy storage material box (TESMB).

Double transparent acrylic sheets covered the collector from outside.

TESB supported by array of evacuated tubular collector with thermosyphon to sincere heat storage in the TESB.

Results of experimental work that achieved in 25 January and 26 February refer to effectiveness using TESM in closed loop SC in day time and its effect cover the night time also.

The heating system of test room is arrived to the biggest room temperature after sun set, at that moment the difference between indoor and outdoor approximately 15oC, and room temperature value still bigger after five hours from sun- set with a different in temperature by approximately 8 oC.

Numerical solution done by employing CFD with solution the PDE’s that present continuity, momentum, energy equations, by using the FVM with algebraic forms of turbulent viscosity and diffusion coefficient and employing turbulent standard model.

The comparison between numerical and experimental results indicated that the heat transfer inside test room is dominate by condition, also results shows acceptable convergence in velocity and temperature profile, while the experimental results for air flow inside SC gap appears the turbulent behavior in most duration time.