Advanced Materials Research Vols. 374-377

Abstract: Solar light-vent pipe system, which is a new kind of green, ecological, energy-saving construction equipment, combining natural ventilation with solar light pipe, can not only improve the architecture luminous environment, but also optimize indoor air quality. This study introduces solar light-vent pipe systems theories and the related technical key point to combine natural ventilation with solar light pipes, gives an overview of the research and development of solar light-vent pipe systems and discusses the current situation and future prospects.

Abstract: This paper is concerned with a mathematical model for numerical simulation of 2D flow accompanied with a hydraulic jump. The governing water equations are solved by the MacCormack’s predictor-corrector technique. The mathematical model is used to numerically predict 2D hydraulic jump in a rectangular open channel. The comparison and the analysis show that the proposed method is accurate, reliable and effective in simulation of hydraulic jump flows.

Abstract: For the air conditioning system of a modern building, the paper proposes a design method of composite cold and heat sources system based on the ground source heat pump. The author describes the design principle of this system, the design of ground heat exchanger system and the control of soil heat pump system etc. Through the actual measurement, this design greatly reduces power consumption and can be used as references for future applications.

Abstract: Proposed a two-stage compression refrigeration heat pump cycle, it can realize the control of refrigeration and heating capacity simultaneously and independently. Through actual cases, the performance of the new cycle with different refrigerant flow ratio, the ambient temperature, the hot water temperature, the degree of superheat and the degree of subcooling was theoretically analyzed. The influencing factor of the characteristic temperature is also studied.

Abstract: This paper, by means of the accelerated test under acidic environment, studies the physical chemistry and mechanical properties of the mortar materials in the different periods, analyzes the change regularity of hydrogen and calcium ions concentrations in acid solution in different periods and the mechanism of mortar subjected to hydrochloric acid corrosion, reveals the phased characteristic in corrosion process, puts forward the generalized model of the change of sample porosity considered corrosion process, and deduces the formula of flexural strength changed with time, preliminarily verifies the good consistency between calculation and experimental results.

Abstract: This paper aims to solve the current energy problems. After careful analysis of the building energy consumption, energy saving measures and ways were concluded in the matter of building design, application of green energy and building greening. The result of the study shows that actually integrated application of energy-saving measures will realize energy-saving purposes.

Abstract: How to reduce the energy consumption of the central air-conditioning is important for the building energy efficiency. The energy efficiency reconstruction of the central air-conditioning system on one library in Guangzhou is completed with the network control system self-developed. The operational control and operational management is integrated in the network control system. The energy consumption before and after reconstruction about the air-conditioning system of the library is detected and analyzed in the paper. The result shows the mode that operational control and operational management integrated has better energy efficiency.

Abstract: A numerical study of the flow over a two-dimensional car model in proximity to the ground is presented. The numerical method is based on a pressure-correction algorithm of the SIMPLE-type．A multigrid technique based on the full approximation storage (FAS) scheme is employed to accelerate the numerical convergence, while as a turbulence model the standard κ-ε model with wall functions is used. The numerical results for the u and v velocity ,as well as for the pressure distribution over the car surface are obtained．

Abstract: The second phase of Weihai Baidu City project plans to become a three-star certificated program which is labled by China’s enviromental building evaluation. Heating and ventilated air conditioning program is one of the most important aspects in evaluation of energy saving. Feasibility study on GSHP, GWHP, air-source heat pump, seawater source heat pump were carried out, it’s confirmed that the most energy-saving and reliable way is that using municipal pipe networks for heating in winter and using split air conditioning or multi-connected air-conditioning system in summer. Summer air-conditioning adopts the new idea “part of time, part of space", representative the latest concept of energy efficiency in buildings in China.

Abstract: Assessing the energy saving of natural ventilation is difficult, especially for large scale naturally ventilated buildings, due to the lack of deterministic data and method. This paper presents a method, integrating simulation by both software of DeST-h and computational fluid dynamics (CFD) in typical meteorological year (TMY) in Guangzhou, to evaluate quantitatively the natural ventilation cooling effect. The results showed that the cooling effect of natural ventilation was influenced by the windows and doors switching. Air conditioning operating hours reduction in the living room can reach 509h by natural ventilation during the occupied time with the windows and doors opened, which can reach 325h with the windows opened and doors closed. The cooling effect of natural ventilation was more significant in windows and doors opened case than that in windows opened and doors closed case. Annual rate of cooling loads reduction in rooms and building were 0.34~10.50% and 6.14% respectively. It is necessary to organize and design building opening to maximize the natural ventilation using.