Wang Y.,Nanjing Southeast University |
Cai L.,Nanjing Southeast University |
Shao X.,Emerson Electric |
Jin G.,Han Jia Design Group Co. |
Zhang X.,Nanjing Southeast University
International Journal of Refrigeration | Year: 2013
Taking a novel hybrid-power gas engine heat pump as an example, fuel-consumed rate, fuel-consumed flow, fuel conversion efficiency and life cycle assessment were used to analyze energy-saving effect and natural gas environmental benefits on human health, ecosystem quality and resource consumption through contrast with electric power consumption model. The test results show that the fuel conversion efficiency under different operating conditions of HPGHP is higher than conventional GHP under the same load. Besides, from the total indicator, scores on resource consumption is the highest. Gaseous product is mainly CO2 and other carbon or sulfur oxide gases are discharged in form of negative or water body, which means the use of natural gas effectively control the pollution gas emissions. At last, concept of environmental benefit time was established; the result shows that HPGHP can embody better environmental benefits than gas heat pump when running more than 1778 h. © 2012 Elsevier Ltd and IIR. All rights reserved.
Yan G.,Xi'an Jiaotong University |
Feng Y.,Hanjia Design Group Co. |
Peng L.,Xi'an Jiaotong University
International Journal of Refrigeration | Year: 2014
This study introduced a novel energy saving cooling system, i.e. a combined cycle coupled with a traditional vapor compression cycle with a pumped liquid two-phase cooling cycle. The system has two operation modes, i.e. the compression cycle mode driven by compressor and the pump cycle mode driven by refrigerant pump. A multi-purpose test bench was constructed to experimentally evaluate the performance of the integrated cycle system under various operation conditions. The effects of cycle working condition and the shift temperature between the two operation modes on the overall cycle performance were investigated in detail. It is found that the novel cycle system has a higher EER compared to the traditional compressor system when the ambient temperature is relatively low. The further experimental results and comparative annual energy saving analysis also indicated that the proper shift temperature is about -5 °C from the system EER and cooling capacity point of view. © 2014 Elsevier Ltd and IIR.
Jiang B.,Hanjia Design Group Co. |
Lou D.-H.,Hanjia Design Group Co. |
Guo Y.,Hanjia Design Group Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2012
Based on the theoretical analysis, a method to optimize the design of circular strut system in deep excavations is proposed. A FEM program based on the model is developed. By comparing the calculate results, some optimized design parameters are obtained. The proposed method is used to analyze a deep excavation in Shaoxing. The analytical results are compared with the measured data. It is indicated that the suggested method can be used to simulate the excavation process of similar excavations. The circular strut system is an effective way in some deep excavations with special space.
Wang X.-Z.,Zhejiang University |
Wang X.-Z.,Hanjia Design Group Co. |
Jin W.-L.,Zhejiang University |
Yan Y.-D.,Zhejiang University
Zhejiang Daxue Xuebao (Gongxue Ban)/Journal of Zhejiang University (Engineering Science) | Year: 2010
For the status that corrosion of reinforcement, indetectable corrosion degree and corrosion-induced crack of existing concrete structures in chloride-laden environment, a path probability model (PPM) to predict the stochastic corrosion-crack development of reinforced concrete (RC) structures with time was proposed. The time-dependent probability distribution of steel corrosion ratio, crack width of concrete due to corrosion and percentage of corroded steel samples of elements were estimated effectively on a series of random paths of corrosion-crack process simulated by computer programme. The substructure of an RC bridge in chloride-laden environment was illustrated to verify the precise and effectiveness of the present model by the assessment result of field inspection data. The model can effectively predict the durability behavior of existing concrete structures and the predicted result is a reasonable proof for optimal strategies of maintenance and repair.
Zhao C.,Beijing Jiaotong University |
Zhang W.,Beijing City University |
Gao Z.,Hanjia Design Group Co.
Beijing Jiaotong Daxue Xuebao/Journal of Beijing Jiaotong University | Year: 2014
In this paper, an existing bounding-surface is modified and a state parameter based on phase transformation state is introduced. The deformation tendency of a sand at any time or any conditions can be judged correctly by state parameter. As a result, the dilatancy depends on the state in a way that yields a zero value at phase transformation state. This dependence allows a realistic modelling of the response of a sand in either loose or dense state, or in the transition from one state to another state. A comparison between model simulations and a sequence of experimental results for drained, monotonic loading conditions shows that the simulation results are consistent with the test results, which can better reflect the mechanics characteristics of sandy soil.
Fang H.,Hanjia Design Group Company Ltd |
Zhou C.,Hanjia Design Group Company Ltd |
Yang F.,Hanjia Design Group Company Ltd
Advanced Materials Research | Year: 2011
Sunflower-patterned cable dome which gets stiffness by prestress tensioning and force self-balance is a kind of cable-strut spatial tensile structure. If distribution of prestress in each layer of the structure is appropriate in construction, its deformation under vertical loads will be uniform. In finite element analysis software ANSYS, principle and method of selecting the optimal prestress distribution of sunflower-patterned cable dome were obtained through applying several different kinds of prestress on each layer of loop cable in calculation model and analyzing its deformation uniformity under full-span load respectively. © (2011) Trans Tech Publications.
Zhan T.L.T.,Zhejiang University |
Xu X.B.,Zhejiang University |
Chen Y.M.,Zhejiang University |
Ma X.F.,Hanjia Design Group Co. |
Lan J.W.,Zhejiang University
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2015
Landfill gas (LFG) collection efficiency is low at many municipal solid waste (MSW) landfills in China. The relevant mechanism and potential solution for this problem are studied through laboratory gas permeability tests on MSW, field LFG extraction tests at a landfill subjected to leachate drawdown, numerical assessment of the LFG collection efficiency at the landfill with different leachate levels, and engineering application of the measures to improve LFG collection. The research work outcomes are as follows: High water content in the food-rich MSW is one of the major reasons causing the high leachate level at many Chinese landfills. High leachate mounds tend to result in a high degree of saturation in waste, and hence a low gas permeability of the waste. Therefore, the LFG collection efficiency at Chinese landfills with high leachate level is lower than expected. A drawdown of leachate level at a Chinese landfill by pumping resulted in a significant increase in the LFG collection rate and the influence radius of LFG extraction wells. The dependence of LFG collection efficiency on the leachate level relative to the total waste thickness was verified and quantified. The leachate level is suggested to be controlled to less than 30% of the total waste thickness to achieve a high LFG collection efficiency. Engineering application at a Chinese landfill indicated that the retrofitted facilities, including deep vertical wells and horizontal drainage trenches, were effective in lowering high leachate level. The drawdown of leachate level resulted in an increase of LFG collection efficiency from 10-20 to 60-90%. © 2015 American Society of Civil Engineers.
Ye J.,Hanjia Design Group Co. |
Fang H.,Hanjia Design Group Co.
Applied Mechanics and Materials | Year: 2011
Base on renewal transformation practice of urban buildings, firstly new green reconstruction ideas are put forward aiming at improving and enhancing work performance and safety performance of urban buildings, enhancing ability resist earthquake, typhoon, etc, guaranteeing the safety of people's lives and property, improving the efficiency of resource utilization, energy-saving, land-saving, water-saving, material-saving, protecting and improving the environment, prolonging service life of existing buildings. Secondly, system of technical standards for renewal and reconstruction of urban buildings is established, which includes aspects of exploration, inspection, identification, evaluation, design, construction, project acceptance, and operation management. Finally, a new green reconstruction mode of existing buildings is presented. It has been proved the effectiveness through applications and practices for many years. © (2011) Trans Tech Publications, Switzerland.
Zhao C.L.,Beijing Jiaotong University |
Zhang W.H.,Beijing City University |
Gao Z.H.,Hanjia Design group Co.
Applied Mechanics and Materials | Year: 2013
A bounding-surface model is modified and introduced a state parameter γ based on phase transformation state, e.g., when subjected to shear, sand will contract until phase transformation is reached, while γ=1, then dilatant until the ultimate where γ =constants simultaneously. With state parameter the deformation tendency of a sand at any time or any conditions can be judged correctly. As a result the dilatancy depends on the state in a way that yields a zero value at phase transformation state. This dependence allows a realistic modelling of the response of a sand in either loose or dense state, or in the transition from one state to another state. A comparison between model simulations and a sequence of experimental results for drained, monotonic loading conditions shows that the proposed concept and modelling technique work effectively using a unique set of parameters (or parameter dependence) for a given sand. © (2013) Trans Tech Publications, Switzerland.
Zhang H.,Hanjia Design Group Co. |
Fang H.,Hanjia Design Group Co.
Proceedings of the 12th International Symposium on Structural Engineering, ISSE 2012 | Year: 2012
This paper considers the effects of annual temperature changes on the response of a over-long high-rise building in Hangzhou, east of China. Several scenarios with varying assumptions of construction sequence, temperature conditions and material properties are considered. The thermally induced forces and deformations in structural members are computed using finite element analysis (ETABS). Various references were used to compute the demands on structural elements considering thermal loads, and shrinkage and creep, and to estimate the implications of those forces on the structure including prediction of frequency and size of cracking that may be expected and localized strengthening of certain areas in order to control cracking and/or improve strength resistance. Recommendations from those references were evaluated in conjunction with results from the structural analysis of the building.