Browsing by Author "Li, G."

Now showing 1 - 11 of 11
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    Application of Phase Change Wallboard to an Energy-Conservation Building in the Cold Area in North China
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Feng, G.; Deng, D.; Li, G.
    The application of phase change energy storage has become an academic focus in building energy conservation. This paper considers day and night climate conditions and the governmental regulation of price of electricity in testing and analyzing the characteristics of phase change energy storage material with DSC. We selected two kinds of fatty acid as phase change material to make a phase change wallboard, and then carried out a thermal functional analysis of performance of the wallboard. The results indicate that the application of phase change wallboard in the cold northern region, where there are abundant natural resources, combined with the national policy of reducing the cost of electricity and shifting portions of the load from periods of maximum demand, can reduce costs and HVAC energy consumption, and is an effective way of reducing building energy consumption and improving the environment.
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    Application Prospect Analysis of the Surface Water Source Heat-Pump in China
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Zhang, C.; Zhuang, Z.; Huang, L.; Li, X.; Li, G.; Sun, D.
    Surface water resources in China are rather abundant and it can be use as the heat or cool source for heat pump. The winter surface water temperatures of 17 typical cities are investigated in December, and they are all distributed in the interval of 2~5?. The critical technical issue in the surface water heat pump is how to extract the freezing latent heat. The urban surface water supplying areas of 102 large or median cities in China are measured and counted. The supply area ratio, and mean heating or cooling need index are calculated separately and the 102 cities are classified by the three parameters. The data indicate that surface water can supply heat and cool source for 42.1% of the urban waterside buildings in China.
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    Application Study on Combined Ventilation System of Improving IAQ
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Hu, S.; Li, G.; Zhang, C.; Ye, B.
    A type of combined ventilating system is put forward in this paper. Through CFD simulation and testing of contaminant concentrations in a prototype residential room, the results demonstrate that the new ventilating system is advantageous for improving IAQ and ensuring thermal comfort of indoor environments.
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    Discussions on Disposal Forms of Auxiliary Heat Source in Surface Water Heat Pump System
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Qian, J.; Sun, D.; Li, X.; Li, G.
    This paper presents two common forms of auxiliary heat source in surface water heat pump system and puts forward the idea that the disposal forms affect operation cost. It deduces operation cost per hour of the two forms. With a project calculation, it illuminates that the post-located auxiliary heat source cheaper and superior to the fore-located one.
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    Improvement of the Performance for an Absorption Refrigeration System with Lithium bromide-water as Refrigerant by Increasing Absorption Pressure
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Xie, G.; Sheng, G.; Li, G.; Pan, S.
    Because the absorption refrigeration system uses the Lithium bromide- water solution as refrigerant, it is profitable for the environment that human beings are living since the values of ODP and GWP of the refrigerant almost are zero. However, the low COP of the absorption machine was limited seriously to compete with the refrigeration machine that is drove by electricity. Therefore, most researchers focus their attention on the improvement of performance of the absorption system through many approaches. In this paper, an improved cycle was adopted to raise the pressure inside the absorber of the machine in order to intensify the absorption effect of thick Lithium bromide solution and enhance the COP of the absorption refrigeration system. A mathematical model that is used for predicting the performance of the system will be established, and the influence of pressure change on the overall performance of the machine will be discussed in the paper.
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    Optimization of the Fin Heat Pipe for Ventilating and Air Conditioning with a Genetic Algorithm
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Qian, J.; Sun, D.; Li, G.
    This paper illustrates that use of a heat pipe as a heat-reclaiming device can significantly influence the air-conditioning system. It analyzes the heat transfer model of the uniform annular fin heat pipe under the condition of air conditioning. It establishes functions of the fin structure parameters such as height,spacing and thickness of the fin when the volume of fin is the smallest under unit temperature difference and unit quantity of heat. It uses a genetic algorithm to optimize the model of the uniform annular fin heat pipe. The calculation result shows that the method of genetic algorithm is effective.
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    Research on Cool Storage Time of a Phase Change Wallboard Room in the Summer
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Feng, G.; Liang, R.; Li, G.
    Through testing and analysis of the parameters of the indoor thermal property in a phase change wallboard room and an ordinary room, the effects of using phase change wallboards on indoor temperature in summer and with air conditioning are analyzed. The combination of construct enclosure and phase change materials can stabilize indoor temperature, improve indoor thermal comfort, reduce the frequency of the operation of air conditioning facility, cut the initial investment and operation expense, and meanwhile play an practical role in “the power balancing between the peak period and the valley period” policy.
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    State-of-the-Art and Outlook: Thermal Properties of Phase Change Wallboard Rooms
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Feng, G.; Liang, R.; Li, G.
    Phase change energy storage (PCES) has become more and more important in air conditioning and construction energy conservation, and has also become the focus of international research. This paper analyzes the domestic and foreign development of PCES technology and the thermal characteristic- analyzing method commonly applied in building envelopes, proposes future research methods for phase change material wall rooms, and lays a solid foundation for the research of the heat transfer mechanism and thermal characteristics.
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    Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.
    The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Given the schematic diagram of TDHT system, introducing the definition of equivalent fouling roughness height, and using the Niklaus semi-rational resistance coefficient formula in rough region, the calculation methods of the sewage flow resistance are explained. Through the resistance contrastive analysis of sewage and pure mediate water, the results indicate that the mediate water sub-system is the primary design point of the TDHT system. The economical ratio of flux and velocity is determined by optimization analysis of investment and operating cost in the technical feasible range. The paper will provide reference for pipe design and pump selection of urban sewage cool or heat source applied delivery heat transfer methods.
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    Urban Sewage Delivery Heat Transfer System (2): Heat Transfer
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.
    The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Using the efficiency-number of transfer units method ( ), the heat-transfer efficiencies of the parallel-flow and reverse-flow TDTH forms are analyzed and the calculation formulas and characteristic are also given. The results indicate that the efficiency of the parallel-flow form is greater than that of the reverse-flow, so the TDTH system must choose the parallel-flow form. The distance-load ratio (DLR) is defined and the minimum DLR is obtained by the technical and economic feasibility analysis. The paper will provide references for heat-transfer calculation and schematic determination of urban sewage cool or heat source applied delivery heat transfer methods.
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    VFD Technology's Energy Conservation Application at Metro Ventilation Air-conditioning System
    (Energy Systems Laboratory (http://esl.tamu.edu), 2006) Li, G.
    Shenzhen metro has been applied the VFD control technique and close loop negative control logic to adjust and control the temperature and humidity of public area and conserve the energy on HVAC system of children palace station and Fumin station of NO.4 line of the first phase project of the metro, which can save over 70% electrical energy than before. And the equipment operated very well in more than one year, and the environment quality is very stable, has achieved obvious efficient.