Chimney Effect of Solar Hybrid-double Wall with Different Thickness PCM of Na2CO3•10H2O

The experiment of the chimney effect of the solar hybrid-double wall with various thicknesses Na2CO3
• 10H2O was carried out by the simulated solar energy resulted from the adaptable voltage heater. The effect of the various thicknesses on the temperature distribution of the both sides of PCM, the air gap and on the velocity distribution of the air gap were discussed and analyzed. The nature ventilation air volume induced by the chimney effect and the heat gained by the air were also discussed. The results show that the temperature of PCM initially began to rise gradually from ambient temperature, after having absorbed radiation. When the heat storage materials melt completely, the temperature continues to rise until the maximum value at about 10 hour's point. The thicker the PCM, the higher the peak temperature is. At the beginning of heating, the values of average air velocity, air mass flow and the heat gained by the air in the gap increase rapidly to a certain value, and then tends to be stable, which reach a maximum peak at the PCM thickness of 20 mm.