Comparative study on dynamic heat transfer characteristics of CaCl2 center dot 6H(2)O and Na2SO4 center dot 10H(2)O used in PCM-filled glass window

摘要

Physical and mathematical models of a hollow glass window (W-air) and two phase change windows(W-Na and W-Ca)are established. The W-Na and W-Ca utilize Na2SO4 center dot 10H(2)O and CaCl2 center dot 6H(2)O as phase-change materials (PCMs), respectively. The accuracy of the model was validated by comparing the simulation results with previous experimental results. The dynamic heat transfer characteristics of the three windows were calculated under four typical weather conditions in Changsha. The difference in energy savings between these two PCMs are compared comprehensively. Results showed that W-Na and W-Ca have energy-saving advantages over W-air on summer sunny days. The peak temperature on the interior surface of W-Na is lower than that of W-Ca by 3.57 degrees C, the temperature time lag of W-Na is longer than that of W-Ca by 1h, and the energy-saving rate of W-Ca is higher than that of W-Na by 13.8%. On summer rainy days, the energy saving rate of W-Ca is higher than that of W-Na by 16.2%. However, neither of them has any energy saving advantage over W-air on summer rainy days, winter sunny days, and rainy days for their insufficient or even not melting.