Advanced Materials Research Vols. 374-377

Abstract: The variable air volume (VAV) air-conditioning system with its superior energy saving effect has been applied in many developed countries, also drawn more and more attention in China. Due to the characteristics of VAV air-conditioning system are nonlinear, large time lag, strong coupling, multi-variable and multi-disturbance, the control complexity of the VAV system increase greatly. The energy conservation and comfort of the VAV air-conditioning system can not fully been embodied in application. The research on the VAV system has become the hot spot in the science and technology workers, many new methods and strategies have emerged. From the three aspects: the air system, the water system and the large scale system, the paper describes the control strategies, the control methods and the research progress about the VAV air-conditioning system.

Abstract: By means of experiment, the author analyzed the operation performance of the capillary radiant air-conditioning terminal integrated with DC variable speed new air unit. The results show that the operation mode that the capillary radiant air-conditioning terminal running combined with DC variable speed new air unit not only avoid the disadvantages of the capillary radiant air-conditioning such as temperature dropping slowly, condensation of moisture under hot and humid conditions during the cooling season, but also effectively overcome the problem that the cooling ability of the radiation surface is low caused by avoiding condensation, and the system can also take the moisture load indoor away as well as achieve the purpose of dehumidification. Besides, using the heat storage capacity of the capillary radiant air-conditioning terminal, controlling water- system of capillary radiant air-conditioning terminal to open and close appropriately can achieve the goal of energy saving.

Abstract: The GPS-X was used to simulate the denitrifying phosphorus removal in the A²/O.The improvement actions were obtained due to the simulation result.Moreover, the effect of denitrifying phosphorus removal was forecasted after the application of optimization and improvement. The prediction shows that: by adjusting the operating parameters such as SRT was adjusted to 15ds, the internal reflux ratio was adjusted to 300% and the external reflux ratio was adjusted to 100%,the denitrifying phosphorus removal in the A²/O was obviously increased. Therefore, the employment of GPS-X software in simulation and optimization can provide guidance for the operation and control in wastewater treatment plants.

Abstract: Making exhaust hood model in laboratory according to exhaust hood in commercial kitchen, steam instead of fume, and characteristics of flow field are studied in kitchen exhaust hood. The distribution of velocity and temperature at typical planes was measured at valve opening of 45 degrees when water boiling. Results show that in a certain range, air velocity of exhaust hood decreases when air from the exhaust opening distance increases, velocity reduces with x and y increasing, steam velocity reaches maximum value close to exhaust outlet of fan.

Abstract: This paper studies the variable load ratio characteristics by experimental methods for the multi-spilt air-conditioning system K-1, which is installed in school of Environmental and Municipal Engineering of Xi’an University of Architecture and Technology. The temperature changes along with the refrigerant liquid pipe were tested under different partial load ratio conditions in summer. Experimental results demonstrate that the liquid refrigerant temperature for outdoor unit at outlet increased with the increment of the load ratio. On different load ratio conditions, the liquid refrigerant temperature decreased rapidly along refrigerant vertical pipe and turned to change slowly along horizontal pipe. When load rate is between 50% and 80%, energy efficiency ratio (EER) value is relatively high, about 2.63~2.84. EER value reaches a maximum of 2.84 with 65% load ratio.

Abstract: As complement to air conditioners, ventilation systems are playing important roles in keeping human health as well as saving energy. They improved indoor air quality by replacing inside polluted air with outside fresh air. To reduce the energy needed to condition the induced fresh air, heat exchanging processes are designed to reduce the temperature differences between this fresh air and the indoor air. Heat exchanging processes using total heat exchange membranes (THEM) allowed not only the exchange of heat but also humidity, generally providing better energy saving and air quality improvement results. Recently, we have studied a novel class of THEM made from a casting process using inorganic and organic functional materials. Their structure and properties characterized with Scanning Electron Microscopy (SEM), BET Adsorption test, Water-vapor Permeability Analysis, CO2 Permeation Test, and Heat Exchange Efficiency Test are discussed here.

Abstract: From the view of impedance, this article calculates the exhaust air volume of the smoke exhaust ventilator of the kitchen on each floor when opens individually comprehensively using CFD-FLUENT numerical simulation, origin data fitting and fluid mechanics theory calculation method, which chooses some 50-square meter rooms in a 20-floor building in Shenyang as the research object. This article then certifies the influence of thermocompression on the exhaust air volume of the kitchen on each floor of high-rise apartment building and summarizes the changing regularity of the exhaust air volume. Finally, the author draws a reasonable analysis method which could be used for calculating exhaust air volume of the kitchen on each floor under the condition of high operating rate.

Abstract: Sewage discharged form urban dwelling community is warm in winter and cool in summer, which is a sustainable resource and has not utilized fully. Sewage-source heat pump (SSHP) system has advantage of energy efficient, economic, environment friendly and broad foreground, which has significance for the development of building energy efficiency (BEE). The past research of SSHP usually set the heat source and heat sink in sewage farm or main-pipe of urban sewage system, and few take the cesspool of dwelling community as heat source and heat sink directly. The author wanted to develop SSHP system by using sewage on the spot of cesspool in urban dwelling community. He chose a representative urban dwelling community from Chongqing and has tested the temperature and flow volume of sewage for more than one year. Based on testing data, the paper developed SSHP applying schemes for air-conditioning, heating and hot-water supplying, which can be handy-applied in the urban dwelling community. The research of this paper aims to broaden the use of SSHP and promote the development of BEE technology.

Abstract: A experimentally study has been carried out to predict airflow rate, temperature field and velocity field for different chimney gap and heat flux. Results showed that, for veritical solar chimney,there is an optimum ratio of chimney width-to height to achieve a maximum airflow rate. The optimum ratio is about 1：2. Meanwhile,temperature and velocity field of solar chimney channel were analyzed. The air temperature and the velocity approaching to the surface of the heated wall are higher than that away from the surface of the heated wall.

Abstract: Abstract: The wastewater from the production of polytetrahydrofuran (PolyTHF) was treated with union between of the extraction method and adsorption method. The results showed that using chloroform as extraction agent, CODCr removal rate could reach as high as 75%, then the treatment of wastewater was treated by adsorption method, which meet the national level of discharging standard, CODCr removal could reach at 100mg/L.