Heating performance of a solar chimney combined PCM: A numerical case study

• The heating performance of the proposed system was numerically studied.
• Seven design and operating parameters of the proposed system were investigated.
• The first five parameters need to be carefully selected to maximize the performance.
• Thermal conductivity of absorber has less impact on the performance of the system.
• Inlet air temperature is also an important factor in this study.

An experimentally validated numerical model is developed to study the effects of seven design and operational parameters on the heating performance of a solar chimney incorporated with phase change material (PCM) in this paper. It is found that when the latent heat increases from 70 to 170 kJ/kg, the melting time is increased by 103% and freezing time is prolonged by 60%. If heat flux is increased by 33%, the melting time is reduced by 36.4%. Increasing thermal conductivity of the insulation material from 0.02 to 0.06 W/m K, the melting time is prolonged by 47.2%. When absorptivity of the absorber is increased from 0.8 to 1.0, the melting time is decreased by 26.3%. When transmissivity of the glass cover is increased by 25%, the melting time is reduced by 26.7%. For the inlet air temperature, when it decreases from 25 to 15 °C, the freezing time is shortened by 39%. The melting time is only reduced by 8% when thermal conductivity of the absorber is increased by 25 times. Therefore, it can be concluded that the first six parameters have more impact on the system's performance while the thermal conductivity of absorber slightly impacts it.