Abstract
In large-space building, the distribution of vertical temperature has obvious difference. According to this feature, the energy consumption in air-conditioning would be greatly reduced if the designs of airflow are preferable in these buildings. The low sidewall air supply system is widely installed in the large-space buildings since it can directly sent the handled air to the personnel activity area, thereby has lower energy consumption than other systems. In this paper, a Gebhart-Block synchronous solving model is built to solve the vertical temperature distribution of an actual large-space building with low sidewall air supply system. The simulative physical model is divided into eight blocks in the vertical direction. According to the mechanism of heat transfer, unsteady-state heat balance equation is established for indoor air and wall in each block. The unsteady and synchronous solving model is established with integrating these balance equations. Furthermore, to predict the temperature distribution of indoor air and inner wall surface, the theoretical values of this model are calculated with programming by Visual Basic.
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Abbreviations
- \( q^{p}_{d,w,I} \) :
-
Convection transfer heat from outdoor air to outside wall per area at time p, W/m 2
- \( q^{p}_{r,I} \) :
-
Radiation heat transfer from inside wall surface to other internal surface per area at time p, W/m 2
- \( q^{p}_{d,n,I} \) :
-
Convection transfer heat from the indoor air to the wall internal surface per area at time p, W/m 2
- \( V_{w,I} \) :
-
Wall volume of the I layer, m³
- \( (\rho C)_{W} \) :
-
Unit heat capacity of the wall, \( kJ/(m^{3} \cdot K) \)
- \( \theta^{p}_{{w,pj,{\rm{ }}I}} \) :
-
Average temperature of the I layer at time p, K
- \( A_{w,I} \) :
-
Internal surface area of the I layer, m 2
- \( \alpha_{h,w,I} \) :
-
Coefficient of convection heat transfer from outdoor air to the outside surface of I layer wall, \( W/(m^{2} \cdot K) \)
- \( T^{p}_{m} \) :
-
Area-weighted average temperature of all the inner wall temperature at time p, K
- \( t^{p}_{zw} \) :
-
Comprehensive temperature of the outdoor air at time p, K
- \( \theta^{p}_{{w,w,{\rm{ }}I}} \) :
-
Temperature of the I layer outside wall at time p, K
- \( \varepsilon_{I} \) :
-
Surface radiation rate of Wall I
- \( \sigma \) :
-
Stefan–Boltzmann constant, \( {\rm{5}}.{\rm{67}}\, \times \,{\rm{1}}0^{{ - {\rm{8}}}} W/(m^{2} \cdot K^{4} ) \)
- \( F_{Ij} \) :
-
Radiation angle coefficient of Wall I to wall j
- \( F_{Ic} \) :
-
Radiation angle coefficient of wall I to the roof
- \( F_{If} \) :
-
Radiation angle coefficient of wall I to the floor
- \( \theta^{p}_{{w,n,{\rm{ }}I}} \) :
-
Temperature of internal face of the wall in the I layer at time p, K
- \( \theta^{p}_{w,n,j} \) :
-
Temperature of the j layer internal face of the wall at time p, K
- \( \alpha^{p}_{h,n,I} \) :
-
Coefficient of convection heat transfer of indoor air and the inner surface of I layer wall at time p, \( W/(m^{2} \cdot K) \)
- \( T^{p} \left( I \right) \) :
-
Air temperature of Block(I) at time p, K
- \( m^{p}_{{{\rm{in}}}} \left( {I,K} \right) \) :
-
Air mass flow from interior wall surface K into Block(I) at time p, kg/s
- \( m^{p}_{{{\rm{out}}}} \left( {I,K} \right) \) :
-
Air mass flow from Block(I) into interior wall surface at time p, kg/s
- \( m^{p}_{c} \left( {I + 1} \right) \) :
-
Air mass flow from Block(IÂ +Â 1) into Block(I) at time p, kg/s
- \( m^{p}_{c} \left( I \right) \) :
-
Air mass flow from Block(I) at time p, kg/s
- \( m_{s} \) :
-
Air supply of Block(I), kg/s
- \( m_{h} \) :
-
The amount of return air of Block(I), kg/s
- \( T_{m}^{p} \left( {I,K} \right) \) :
-
Mean temperature of inner wall surface at time p, K
- \( \alpha_{h\left( I \right)} \) :
-
Coefficient of inner wall surface heat transfer, W/(m 2 ·K)
- \( \theta^{p}_{wI} \) :
-
Over temperature of wall surface, K
- \( \alpha_{w} \left( I \right) \) :
-
Heat transfer coefficient from the side of the outdoor to the inner wall surface, W/(m 2 ·K)
- \( t_{z} \left( \tau \right) \) :
-
Wave function of the outdoor temperature.
References
Togari S, Arai Y, Miura K (1993) A simplified model for predicting vertical temperature distribution in a large space. ASHRAE Trans 99(1):84–90
Huang C, Li ML (1999) Study of vertical temperature distribution in a large space building. Doctoral thesis. University of Shanghai for Science and Technology, Shanghai
Li YG, Sandberg M, Fuchs L (1992) Vertical temperature profiles in rooms ventilated by displacement: full-scall measurement and nodal modelling. Indoor Air 2:225–243
Wang X (2008) Study of motion mechanism and theoretical models of complex ventilation in large space building. Doctoral thesis, University of Shanghai for Science and Technology, Shanghai
Song Y, Huang C, Wang X (2008) Application of the Gebhart-Block model for predicting vertical temperature distribution in a large space building with natural ventilation. HV&AC 38(12):22–25
Cai N, Huang C, Cao WV (2001) Study on a synchronous solving model for stratified air conditioning under low sidewall air supply system in a large space building. J Refrig 32(3):42–47
Acknowledgments
This work is financially supported by the Leading Academic Discipline Project of Shanghai Municipal Education Commission (J50502) and the National Natural Science Foundation of China (51108263; 51278302).
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Rong, W., Huang, C., Zhang, X. (2014). Study on an Unsteady and Synchronous Solving Model for Low Sidewall Air Supply System in the Large-Space Building. In: Li, A., Zhu, Y., Li, Y. (eds) Proceedings of the 8th International Symposium on Heating, Ventilation and Air Conditioning. Lecture Notes in Electrical Engineering, vol 261. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-39584-0_29
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DOI: https://doi.org/10.1007/978-3-642-39584-0_29
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