Abstract:The free-running temperature is a essential indicator to evaluate the thermal performance of a passive solar house in early design. However a easy-fast, accurate, and dynamic prediction method is lacking for decision-making in early design. Exited accurate and elaborate methods need detailed building information and simulation tools, which are complex and time-comsuming. Besides, exited simpilied methods are still complex for architects or have large hourly error. This paper introduced the virtual sphere method to calculate the dynamic thermal storage of the room, and proposed a new quasi-steady method to predict free-running temperatur. The study on thermal storage performance of a wall indicated only a indoor-side thin effective thermal capacitance layer has dominated effect on thermostability of the indoor space, and the depth of thin layer can be determined by thermal penetration depth formula. In addition, the room effetive thermal capacitance can be equivalent to a virtual sphere, and the dynamic thermal storage can be fast calculated by fitted formula of the classic unsteady heat transfer of a sphere. Then the hourly room free-running temperature can be fast predicted. The empirical validion of a light-weight and a heavy weight passive solar house demonstrated the hourly prediction can be all within the deviation range of ± 3.0 C

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	1. A new virtual sphere method to predict free-running temperature
	Li Xiang,Chen Bin,Fan Xinying
	Civil and Architectural Engineering 08 March 2017
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	Abstract:The free-running temperature is a essential indicator to evaluate the thermal performance of a passive solar house in early design. However a easy-fast, accurate, and dynamic prediction method is lacking for decision-making in early design. Exited accurate and elaborate methods need detailed building information and simulation tools, which are complex and time-comsuming. Besides, exited simpilied methods are still complex for architects or have large hourly error. This paper introduced the virtual sphere method to calculate the dynamic thermal storage of the room, and proposed a new quasi-steady method to predict free-running temperatur. The study on thermal storage performance of a wall indicated only a indoor-side thin effective thermal capacitance layer has dominated effect on thermostability of the indoor space, and the depth of thin layer can be determined by thermal penetration depth formula. In addition, the room effetive thermal capacitance can be equivalent to a virtual sphere, and the dynamic thermal storage can be fast calculated by fitted formula of the classic unsteady heat transfer of a sphere. Then the hourly room free-running temperature can be fast predicted. The empirical validion of a light-weight and a heavy weight passive solar house demonstrated the hourly prediction can be all within the deviation range of ± 3.0 C
	TO cite this article:Li Xiang,Chen Bin,Fan Xinying. A new virtual sphere method to predict free-running temperature[OL].[ 8 March 2017] http://en.paper.edu.cn/en_releasepaper/content/4721233


	2. Hydrodynamic model for a hypolimnetic aerator
	SUN Xin,DUAN Feifei,LIU Wei,HUANG Tinglin,ZHANG Wushou,CONG Haibing
	Civil and Architectural Engineering 31 December 2013
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	Abstract:The water velocity in the aeration chamber of a hypolimnetic aerator directly influences the efficiency of mixing and oxygenation in the hypolimnion, and consequently the effect of water quality improvement. Based on the energy balance between the energy input and the energy loss for the gas-liquid two-phase flow in the aeration chamber, a one-dimensional hydrodynamic model for the aeration chamber was developed. Various types of energy loss were analyzed, an equation for the energy loss due to the wakes was particularly proposed. The average gas holdup and water velocity in the riser of the aeration chamber were predicted by solving the developed model with the reeal-domain method of MATLAB. Sensitivity analysis of the model parameters showed that the prediction results were greatly dependant on the flow resistance coefficient at the top and the coefficient due to local disturbances at the entrance and exit. Using optimized parameters, both gas holdup and water velocity were well predicted within ±7% and ±15% of the measured ones respectively. Developed hydrodynamic model for the aeration chamber can be used to accurately predict the average water velocities under different air flowrates in the aeration chamber, and can be used to design and optimize the hypolimnetic aerator.
	TO cite this article:SUN Xin,DUAN Feifei,LIU Wei, et al. Hydrodynamic model for a hypolimnetic aerator[OL].[31 December 2013] http://en.paper.edu.cn/en_releasepaper/content/4579050

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	3. Energy Input of destratification for a stratified source reservoir: a case study of Jinpen Reservoir
	SUN Xin,YE Lili,LIU Wei,HUANG Tinglin
	Civil and Architectural Engineering 30 December 2013
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	Abstract:The theoretical energy required for destratification of a source water reservoir is important to determine the energy input of a mixing system and to estimate the energy efficiency of the system. A theoretical method of determining the energy input required for destratification of stratified source reservoirs. Taking Jinpen Reservoir in Xi'an as a study case, the water volumes under different water levels of the reservoir were numerically calculated using the geometry data obtained with a RTK system. The total potential energy (PE) was determined by integrating the PE in each thin sub-layer over the water depth with density dependent on the water temperature. The average water temperature after complete mixing was calculated based on the heat exchange theory. The difference of total potential energy before and after mixing was calculated for each month with the data of water temperature, water density and water volume. The minimum energy required for destratification increasing with the temperature gradient, was relatively high during the period from June to October, and reached a peak of 2432.08 kW?h in July. The actual energy input of a mixing system depends on the theoretical energy for destratification and the energy efficiency of the system. The calculation results implicated the best time of running a destratification system was the beginning of stratification when the energy required for destratification is low.
	TO cite this article:SUN Xin,YE Lili,LIU Wei, et al. Energy Input of destratification for a stratified source reservoir: a case study of Jinpen Reservoir[OL].[30 December 2013] http://en.paper.edu.cn/en_releasepaper/content/4578833


	4. Engineering application analysis on ground-coupled heat pump system in hot summer and cold winter region
	CHEN Jinhua,XIA Lei
	Civil and Architectural Engineering 23 December 2013
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	Abstract:The performance and energy efficiency of seven ground-coupled heat pump (GCHP) systems in hot summer and cold winter region are analyzed on the basis of summer and winter testing data and compared with that of air source heat pump system as well as screw water chiller with boiler system. The results demonstrate that: the cooling energy efficiency ratio reaches 3.5~4.2 for units and 2.8~3.3 for systems, the heating energy efficiency reaches 3.2~4.0 for units and 2.2~3.3 for systems. Rates of improvement in energy efficiency of GCHP system are 8.2%~28.8% for cooling and 5.0%~40.4% for heating compared with air source heat pump system. The cooling energy efficiency ratio of GCHPs is a little bit higher than that of water chiller, whereas the heating energy efficiency ratio is 5.8%~47.5% higher than that of boiler. The energy saving rate is obvious.
	TO cite this article:CHEN Jinhua,XIA Lei. Engineering application analysis on ground-coupled heat pump system in hot summer and cold winter region[OL].[23 December 2013] http://en.paper.edu.cn/en_releasepaper/content/4577793


	5. The impact of using light-weight external thermal insulation materials on building surrounding thermal environment in summer
	LUO Guozhi,LI Nan,LI Baizhan
	Civil and Architectural Engineering 18 August 2011
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	Abstract:Introduce a method for calculating surface heat storage coefficient of wall, and make a calculation on outside surface heat storage coefficient of several common walls with light-weight external thermal insulation materials and the traditional solid clay brick wall. In order to study the impact of using light-weight external thermal insulation materials on the surface temperature of external wall, carry out a contrasting experiment between an external insulation room and an uninsulated room in August, 2010, in Chongqing, China. Calculated result shows that outside surface heat storage coefficient of the insulated wall is much less than that of the traditional wall, the outside surface heat storage capability of the insulated walls is poor, and the surface temperature has great fluctuation. Experimental result shows that, during sunny time, surface temperature of external walls of the insulated room is obviously higher than that of the uninsulated one. In different orientations, due to different amount of solar radiation and being irradiated in different time, the contrasting temperature difference (CTD) appears different varied regularity. In a word, using light-weight external thermal insulation materials is bad for building surrounding thermal environment and has a negative impact on people's health. Finally, some suggestions on how to eliminate the impact, such as improving the surface condition of the building envelop, plating vertical greening etc, are put forward.
	TO cite this article:LUO Guozhi,LI Nan,LI Baizhan. The impact of using light-weight external thermal insulation materials on building surrounding thermal environment in summer[OL].[18 August 2011] http://en.paper.edu.cn/en_releasepaper/content/4439020


	6. Optimization of the architectural design for natural ventilation in residences using CFD
	Jin Ming ,Li Baizhan
	Civil and Architectural Engineering 24 June 2010
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	Abstract:In order to achieve more efficient natural ventilation and better indoor environment in residences, this paper utilizes numerical simulation to explore the optimization of residential architecture design. In case study, the natural ventilation efficiency of a residence in Chongqing is evaluated by quantitatively analyzing the fields of air velocity and PMV from CFD simulations results, which are validated by field measurements. The analysis shows that the natural ventilation is efficient in the living room, but inefficient in some other rooms. In view of this, some feasible alternative configurations without major changes in the building structures have been studied, including different styles of windows and door positions. It is found that the optimized design could improve the indoor environment by reducing the dead zone and increasing thermal comfort zone. Finally, some architectural design suggestions on the doors and windows in natural ventilated residences are put forward.
	TO cite this article:Jin Ming ,Li Baizhan . Optimization of the architectural design for natural ventilation in residences using CFD[OL].[24 June 2010] http://en.paper.edu.cn/en_releasepaper/content/4377002


	7. Adsorption of Nickel on Chinese Loess in Aqueous Solution
	WANG Yan,TANG Xiaowu,HE Xi
	Civil and Architectural Engineering 13 May 2010
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	Abstract:Nickel is a trace element that has severe toxic effect to living organisms. The loess soil from Chinese Loess Plateau was investigated to remove Ni(II) from aqueous solution. Batch tests were carried out and the appropriate loess dosage was determined to be 10 g L-1. The Freundlich model was found better to describe Ni(II) adsorption on loess soil than the Langmuir model. The adsorption capacity of loess soil towards Ni(II) was 16.71 mg g-1, and loess is a potential appealing adsorbent for removing heavy metals. Clay minerals and organic matter both play important roles in removing Ni(II) from aqueous solution.
	TO cite this article:WANG Yan,TANG Xiaowu,HE Xi. Adsorption of Nickel on Chinese Loess in Aqueous Solution[OL].[13 May 2010] http://en.paper.edu.cn/en_releasepaper/content/4372234


	8. Harmony Search Optimization for Design of Water Distribution Systems
	Yu Lian,Xin Kunlun
	Civil and Architectural Engineering 11 May 2007
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	Abstract:This paper describes a new meta-heuristic algorithm, called the harmony search (HS), which was conceptualized using the musical process of searching for a perfect state of harmony. The HS algorithm does not require initial values and uses a random search instead of a gradient search, so derivative information is unnecessary. This study focused on pipe diameter optimization while minimizing design cost, then compared the results of HS with genetic algorithm.The results are very promising and demonstrate the usefulness of harmony search algorithms in solving this kind of optimization problem.
	TO cite this article:Yu Lian,Xin Kunlun. Harmony Search Optimization for Design of Water Distribution Systems[OL].[11 May 2007] http://en.paper.edu.cn/en_releasepaper/content/12769

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