Advanced Materials Research Vols. 516-517

Abstract: The paper analyses whether load index includes fresh air cooling load when calculating cooling load, air wet-bulb temperature and outdoor air enthalpy are hourly, how to determine fresh air volume and angle scale line in the system.

Abstract: Comparing the calculated results based on different AUST, point out some problems in current design process, the calculation shows that the increase of AUST leads to greater initial cost. To avoid this error, summarize the relationship of radiant cooling ability between surface temperatures of radiant floor, indoor temperature, pipe space and average temperature of water, find out the performance parameters of radiant plate. Then expounds a specific design steps, provide reference for engineering designing.

Abstract: Chinese territory is vast, on one hand, the underground engineering distributes extensively, the weather condition is quite different from different regions; on the other hand, the various factors impacting the thermal parameters are different from surface engineering. The way of traditional design temperature was very limited, it was very necessity to explored the rational thermal comfort model. The theory related to thermal comfort was studied, especially focusing on adaptive thermal comfort model. Based on the analysis of factors influencing thermal comfort and research of some engineering, the thermal comfort model for the protective engineering was proposed and its rationality and energy saving effect were explored.

Abstract: Use of vortex tube as an expansion device in transcritical CO₂ cycle could reduce the throttle loss and improve the coefficient of performance. In this paper, a vortex tube expansion two-stage transcritical CO₂ refrigeration cycle(VTTC) is established and compared to that of the two-stage transcritical CO₂ refrigeration cycle with throttle valve(TVTC). Thermodynamic analysis results indicate that there is also an optimum heat rejection pressure for the vortex tube cycle, and the COP improvement is 2.4%~16.3% at given conditions. Decrease in evaporation temperature or increase in gas-cooler outlet temperature decrease the COP, but the COP improvement will increase. The effect of cold mass fraction on the COP is negligible, but the COP improvement will increase fast with the increase of cold mass fraction.

Abstract: Due to energy reserves reduces gradually and uneven distribution, all countries pay more and more attention to energy saving and improve the effective utilization of energy, China also attaches great important to this. Energy saving of buildings is a necessary development trend. Air conditioning system as a large important part of building energy consumption has a huge energy-saving potential. This article mainly introduced the related strategies of energy saving in central air conditioning water system from the following three points of view: the water treatment, the cooling tower, and the variable frequency pump.

Abstract: Since indoor particles accumulate on the floors easily, there is a high possibility of allergic reactions in child whose breathing zone is near the floor surface. Ventilation is one of the best ways to remove indoor particles. The aim of this study is to clarify the diffusion characteristics of indoor particles in different ventilation strategies room by experiments and CFD. Comparison of the number of particle in experimental monitoring point shows that the number of particle in the ceiling exhaust was a little higher than the slit exhaust ventilation strategy. CFD simulations concerning diffusion fields completed. From the data we can conclude that slit exhaust ventilation strategy will produce less indoor particles in the room to compare ceiling exhaust ventilation strategy.

Abstract: The application of frequency conversion technique in secondary pump and variable flow system is expounded in this essay. In the view of energy conservation, the secondary frequency conversion pump in variable flow system is in favor of energy conservation due to its variability on power according to the end load change, the principle of frequency conversion pump is also analysed. Combined with actual project case, he energy saving potential of secondary pump and variable flow system is discussed.

Abstract: Air purifier was used more and more widely, its placement and characteristics of indoor air have a significant impact on the efficiency of air purifiers. Based on CFD software, the effect of five different ways of the placement were analyzed; according to experimental station, the effect of three cases were detected, which verified the correctness of the simulation. The results show that: the placement of the air purifier should be placed by considering the impact of air distribution, purifiers should be put in near the outlet, and far away from the return air, supply air could expand the work area of air purifier to achieve better effect It provide some basis for optimizing the use of air purifier and improving. indoor air quality.

Abstract: According to the characteristics of high expansion foam，In view of large underground garage fire characteristic, On the use of high expansion foam fire ventilation feasibility of underground garage, And emphatically discusses the high expansion foam fire extinguishing system in the underground garage fire ventilation application.

Abstract: This article presents a new hybrid evaporative cooling air-conditioning refrigeration system using two-stage liquid desiccant, and carries off the theoretical study on it. Compared with the conventional liquid desiccant air-conditioning refrigeration system, the new system adopts direct mixing heat transfer technology and evaporative cooling technology instead of water-cooled or air-cooled technology. Thus the cooling water usage is reduced. Using the two-stage adiabatic absorber and using refrigerant rather than water as the cooling medium of desiccant solution, the pressure difference of mass transfer is increased. Compared with the conventional system, the heat of regenerating solution is decreased because the mass ratio of air to desiccant solution is increased which gives rise to the decline of solution's mass rate. The results of theoretical calculation show that the new system has the better performance in power consumption, usage of water and equivalent coefficient of performance than the conventional system.