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Thermal Model for Building External Wall under Low Atmospheric Pressure and High Solar Radiation Conditions in Plateau Area

  • Yin ZhangEmail author
  • Enshen Long
  • Jin Li
  • Fei Gao
Conference paper
  • 241 Downloads
Part of the Environmental Science and Engineering book series (ESE)

Abstract

Conventional building heat transfer modelling approach is mainly for low-altitude places, which neglect the unique climatic features in plateau areas. The improved building thermal model of external wall in plateau area is established, with the consideration of low atmospheric pressure and high solar and long-wave radiations. The impact of low air density on heat convection coefficient is analysed. Hence, the correction factor is proposed to assess the radiation influence on building external walls. According to the theoretical modelling and analysis, the coefficients of convection drop by 25% and 33% for inside and outside wall surfaces, respectively, when the altitude rises from 0 m to 4500 m. Moreover, the equivalent temperature has close relationship with the wall-facing direction, as well as the absorption ratio of solar radiation. Heat transfer correction factor always declines with growing solar heat gains. The present study can provide guidance and reference for the design optimisation of plateau buildings.

Keywords

Solar Building Envelope Heat convection High altitude 

Nomenclature

a

Heat diffusion rate (m2/s)

A

Area (m2)

cp

Specific heat ((J/(kg °C))

Gr

Grashof number

h

Convection coefficient (W/(m2 K))

H

Elevation (m)

k

Thermal conductivity (W/(m K))

L

Length/thickness (m)

Nu

Nusselt number

p

Atmospheric pressure (Pa)

Pr

Prandtl number

q

Heat flow density (W/m2)

Q

Heat gain (W)

r

Solar absorption ratio (%)

R

Thermal resistance (m2 K/W)

T

Temperature (K/°C)

U

Heat transfer coefficient (W/(m2 K))

v

Motive viscosity (m2/s)

V

Velocity (m2/s)

τ

Time (s)

ε

Heat transfer correction factor

ρ

Density (kg/m3)

φ

View factor

Notes

Acknowledgement

The study is financed by National Natural Science Foundation of China (51376098) and Sichuan Science and Technology Research Program (2017JY0333).

References

  1. 1.
    Si, P.F., Feng, Y., Lv, Y.X., et al.: An optimization method applied to active solar energy systems for buildings in cold plateau areas—the case of Lhasa. Appl. Energy 194(5), 487–498 (2017)CrossRefGoogle Scholar
  2. 2.
    Serrano, A., Borreguero, A.M., Garrido, I., et al.: Reducing heat loss through the building envelope by using polyurethane foams containing thermos-regulating microcapsules. Appl. Therm. Eng. 103(6), 226–232 (2016)CrossRefGoogle Scholar
  3. 3.
    Li, Y.R., Long, E.S., Jin, Z.H., et al.: Heat storage and release characteristics of composite phase change wall under different intermittent heating conditions. Sci. Technol. Built Environ. 25(3), 336–345 (2019)CrossRefGoogle Scholar
  4. 4.
    Mirsadeghi, M., Costola, D., Blocken, B., et al.: Review of external convective heat transfer coefficient models in building energy simulation programs: implementation and uncertainty. Appl. Therm. Eng. 56(1–2), 134–151 (2013)CrossRefGoogle Scholar
  5. 5.
    Laaouatni, A., Martaj, N., Bennacer, R., et al.: Thermal building control using active ventilated block integrating phase change material. Energy Build. 187(3), 50–63 (2019)CrossRefGoogle Scholar
  6. 6.
    Ricciu, R., Ragnedda, F., Galatioto, A., et al.: Thermal properties of building walls: Indirect estimation using the inverse method with a harmonic approach. Energy Build. 187(3), 257–268 (2019)CrossRefGoogle Scholar
  7. 7.
    Talyor, R.A., Miner, M.: A metric for characterizing the effectiveness of thermal mass in building materials. Appl. Energy 128(5), 156–163 (2014)CrossRefGoogle Scholar
  8. 8.
    Ozel, M.: Effect of wall orientation on the optimum insulation thickness by using a dynamic method. Appl. Energy 88(7), 2429–2435 (2011)CrossRefGoogle Scholar
  9. 9.
    Xiao, W., Wang, X., Zhang, Y.P.: Thermal analysis of a retrofitted direct-gain solar house without auxiliary heat source in southwest Tibet. Int. J. Low-Carbon Technol. 10(1), 1–7 (2010)Google Scholar
  10. 10.
    Fu, B.H., Shi, P.L., Guo, H.D., et al.: Surface deformation related to the 2008 Wenchuan earthquake, and mountain building of the Longmen Shan, eastern Tibetan Plateau. J. Asian Earth Sci. 40(4), 805–824 (2011)CrossRefGoogle Scholar
  11. 11.
    Hagishima, A., Tanimoto, J.: Field measurements for estimating the convective heat transfer coefficient at building surfaces. Build. Environ. 38(7), 873–881 (2003)CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.School of Architecture and EnvironmentSichuan UniversityChengduChina
  2. 2.Key Laboratory of Deep Earth Science and EngineeringSichuan University, Ministry of EducationChengduChina
  3. 3.Institute for Disaster Management and Reconstruction, Sichuan UniversityChengduChina

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