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Zhou G.-W.,Nanjing Southeast University | Zhou G.-W.,Guangzhou Design Institute | Zhang Z.-Q.,Nanjing Southeast University | Li A.-Q.,Nanjing Southeast University | Xu J.-J.,Internal Trade Engineering Design and Research Institute
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2012

There are two main problems in the study of damping effect of composite structures: the first is how to calculate the damping ratio of the whole structure when adopting different materials; the second is how to modify the low damping material after obtaining the integral damping ratio of the whole structure. Taking the high-rise building with steel tower on top as an example, a construction method of non-classical damping matrix was proposed. The result shows the damping ratio based on this matrix can reflect the energy dissipation of 4 orders of modes which play the most important influence on the main structure and the steel tower on top. By the response spectrum method, the inaccuracy of the steel tower's result due to using the calculated integral damping ratio was deduced and a modification equation was provided. The comparison with the accurate result shows the modification factor obtained by the equation has certain reference value to the earthquick response calculation.

Jin W.,Tianjin University of Commerce | Jin W.,Internal Trade Engineering Design and Research Institute | Jia L.,Tianjin University of Commerce | Wang Q.,Tianjin University of Commerce | Yu Z.,Internal Trade Engineering Design and Research Institute
Procedia Engineering | Year: 2015

This paper studies the condensation features of radiant panel by means of experiment and simulation. The temperature of radiant panels and relative humidity of the attached layer are tested and their effect on condensation time are analysed, in the start-up stage. In stable stage, the impact of wet source features on the condensation time are analysed using numerical calculation method. The results show that, in the start-up stage, the condensation occurs 6 min after the starting. In the start-up stage the surface temperature of radiant decrease quickly. With the increasing of radiant temperature decrease rate, the condensations occur on the panel in advanced. So special attention should be paid on the surface temperature and effective measures should be taken to prevent condensation. In the stable stage, with the increasing of moisture diffusion rate the condensation occurs in advance but the advanced rate of time decreases accordingly. The panel which is above the wet source was the first to occur dews. Condensation time is proportional to the distance between radiant panel and wet source. And the proportion decreases with the moisture diffusion rate increasing. Therefore, in order to prevent condensation in the stable stage, the temperature of the panel which is above the wet source must be tested and controlled. © 2015 The Authors. Published by Elsevier Ltd.

Wang Y.,Harbin University of Commerce | Liang L.,Harbin University of Commerce | Sun Y.,Harbin University of Commerce | Wu B.-X.,Internal Trade Engineering Design and Research Institute
6th Asian Conference on Refrigeration and Air Conditioning, ACRA 2012 | Year: 2012

The auto-cascade refrigeration cycle is a new type refrigeration cycle on the basis of traditional cascade refrigeration theory. This system not only has features of simple structure, low cost, small vibration, reliable running and single stage compression, and can reach to -40 single stage cycle, but also can decrease irreversible lose caused by heat transfer temperature difference and enhance the COP of system. During the auto-cascade refrigeration cycle in operation, the regulating station of system always has problems of no enough liquid supplying and liquid supplying interruption. This article makes an experiment improvement of the auto-cascade refrigeration system. Using the siphon-type liquid level control device in the auto-cascade refrigeration system can adjust liquid level of condensation evaporator. The experiment result demonstrates that, the new auto-cascade refrigeration system with siphon-type liquid level control device can avoid the above questions, and can ensure the temperature of refrigerator at -62 °C.

Wang Y.,Harbin University of Commerce | Zhang J.,Harbin University of Commerce | Sun Y.,Harbin University of Commerce | Wu B.,Internal Trade Engineering Design and Research Institute
6th Asian Conference on Refrigeration and Air Conditioning, ACRA 2012 | Year: 2012

The structure of automatic cascade refrigeration system is simple, and the operation is reliable. Using only a single stage compression can achieve to -40°C or even uses the non-azeotropic mixed refrigerants, whether the condensing separation is complete or not directly affects the cooling efficiency. And the actual engineering often uses multilevel condensing filtration separation device to separate mixed refrigerant, which improves the separation efficiency, so that the cooling efficiency and the stability of the system is improved. But the traditional separation devices are universally poor separation effect, low operation efficiency or complicated structure, high cost, which makes it hard to get high efficient separation of the mixed refrigerant in actual application. Because of this problem, we propose a new type of multistage condensing filtration disengaging gear and adopt automatic cascade refrigeration system equipping with the device to set up a text-bed for actual application research. The results show that the device can separate high and low boiling point group efficiently, and the separation efficiency is as high as 98% and because of its simple structure, low cost, practical production are made easily. At present, this technology has been granted the national patent.

Lin X.-Q.,North China Electrical Power University | Ren J.-W.,North China Electrical Power University | Zhang B.-H.,Internal Trade Engineering Design and Research Institute | Zhou X.-H.,Beijing Join Bright Digital Power Technology Co. | Zhou Q.-J.,Beijing Join Bright Digital Power Technology Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

Network reconfiguration is a best solution for power supply, which generally aims to balance load and enhance power supply reliability and stability or to realize both of them. At present, the designing of the intelligent dispatching operation-tickets system in electric power system based on network reconfiguration has not been researched. With the constant expansion of power network, the structure of the network is becoming more and more complex. In view of the characteristics of modern power interconnection, network reconfiguration thought is applied to the reasoning of the dispatching operation-tickets system. When a route needs repair or malfunctions, the system first uses depth-search method/backtracking method to search all the paths of power supply, then finds out the best switch operation plan based on the network reconfiguration thought and the power flow static safety analysis. It can make the dispatching operation-tickets system more intelligent and practical.

Zhang Y.,Beijing University of Technology | Yan S.-Y.,Beijing University of Technology | Yan S.-Y.,Internal Trade Engineering Design and Research Institute | Zhang Y.-Q.,Beijing University of Technology | And 3 more authors.
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology | Year: 2013

The succession of the microbial community in the biofilm was studied in three-stage catching bed reactor system using PCR-DGGE and cloning technology. The homology of the microbial community in the biofilm was analyzed and the phylogenetic trees were constructed. Meanwhile, the contributions of microbial community in the biofilm on removal rates of COD and total nitrogen in the simultaneous nitrification denitrification (SND) system were discussed. The results showed that the microbial community in the biofilm appeared to have great evolution and high diversity during running. Furthermore, according to denaturing gradient gel electrophoresis (DGGE) analysis, the dominant bacterial community in the reactor could be mainly consisted of 5 groups: β-proteobacteria, γ-proteobacteria, unclassified bacteria, α-proteobacteria and Actinobacteria. In addition, β-proteobacteria had an advantage in numbers, which played an important role in the degradation of COD removal. Nitrosomonas sp. and uncultured Nitrospirae bacterium which could oxidize ammonia and nitrite in the system were also found, Pseudomonas. stutzeri which was recognized as aerobic denitrifying bacteria was detected in the reactor.

Zhou X.-Y.,Tongji University | Liu C.-Q.,Tongji University | Liu C.-Q.,Internal Trade Engineering Design and Research Institute | Gu M.,Tongji University | Tan M.-H.,Tongji University
Gongcheng Lixue/Engineering Mechanics | Year: 2015

Based on the Lagrangian method, the development process of snowdrift in an open field is modelled. The characteristics of snow particles are analyzed, and the motion of each snow particle is tracked, in which a splash function is adopted. At the same time, the influence of snow particles on a wind field is taken into account. The variation of the number of saltation particles, the mass transport rate, the friction velocity and snow mass flux distribution along the height at a steady state are studied. The computational results in this paper agree well with the field measurement results in other literatures. ©, 2015, Tsinghua University. All right reserved.

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