Study on Wheat Straw/ Sodium Sulfate /Water Glass Shaped Phase Change Plate for Walling Material

Abstract:

Novel shaped phase change plate was made of wheat straw impregnated with Na₂SO₄ solution and water glass as cementing agent. The plate was subsequently inserted into the concrete bricks with rectangular holes, assembled as phase change bricks. The latent heat of phase change of the plate was measured by DSC, the microstructure of the plate was observed by SEM, and the performance of the plate was also measured. In addition, the heat insulating property of the brick was investigated. The results are as follows. The wheat straws can encapsulate 1.86 times Na₂SO₄•10H₂O in mass,and the phase change heat of the plate is 113 J/g. The microstructure shows that the straws and hardened water glass play an encapsulating action for Na₂SO₄•10H₂O. The weight loss of the plate was 1.8% after 30 times of phase change cycles. For the concrete bricks (size: 240×240×115 mm) inserted with phase change plates, when the heated surface temperature was 80 oC for 5 h or 8 h , the cold surface temperature increased by only 1.8 oC and 4.4 oC respetively ,that is, the temperature difference between the cold with hot surface was 63.7 oC and 61.1 oC. This study reflects that if the brick is used as walling material, interior temperature does not fluctuate, even in extreme heat summer. It has dramatically saving energy and the effect of improving inhabited environment.

• Periodical: Advanced Materials Research (Volumes 168-170)
• Pages: 1111-1116
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.168-170.1111
• Online since: December 2010
• Authors: Gui Hua Hou, Xiang Zhu, Yui Chi Cui
• Keywords: Heat Insulation Material, Na₂SO₄•10H₂O, Phase Change Materials (PCM), Wheat Straw

References

[1] Tsinghua university energy saving building research centre: China yearly progress report of energy saving building(China construction industry publication, Beijing 2008), In Chinese.

[2] A. C. Evers , M. A. Medina , F. Yuan: Building and Environment Vol. 45 (2010), p.1762.

[3] Z. Tang, A. Liu, Z. Chen: . Energy Conversion and Management Vol. 51 (2010) 1459.

[4] L. Baye, L. Ventol., R. Cordobilla: Solar Energy Materials & Solar Cells 94 (2010) 1235.

[5] J. Li, P. Xue, G. Sun: Solar Energy Materials & Solar Cells 93 (2009) 1761.

[6] T. Nomura, N. Okinaka, T. Akiyama: Materials Chemistry and Physics 115 (2009) 846.

[7] B. M. Diaconu, A. C. Oliveira: Applied Energy 87 (2010) 620.

[8] G.H. Hou,X. Zhu, submitted to ICAMMP(2010).