Applied Mechanics and Materials Vols. 580-583

Abstract: With the promotion of building energy conservation, many residential areas are closely link with energy saving in design phase, and natural ventilation becomes the key to reduce building energy consumption. Thus, house design and building distribution of residential district is particularly important. Computational fluid dynamics (CFD) get rapid development in recent 20 years, especially in architectural design. This text established a model of part of a residential district in Zhuzhou based upon ANSYS FLUENT CFD software, and used numerical simulation method to simulate the condition of indoor natural ventilation under typical summer climate when the doors and windows of buildings were opened. The distribution regularities of indoor velocity field and pressure field and etc have been gotten. These data provide a theoretical basis to evaluate the building distribution of residential area.

Abstract: The numerical simulation is widely used in study of the ice storage system. The model about melting is established and solved by using enthalpy method. Natural convection of the melted water in the course of melting is studied. Effects on the performance of heat-exchange, caused by variation of velocity of the refrigerant, inner diameter of the tube, initial temperature of the external water and inlet temperature of the refrigerant, are simulated and analyzed. 1. As the increase of cryogen inlet temperature, the influence of natural convention is more and more in the process of melting heat transfer. 2. Under the conditions of the different cryogen velocity, the different diameter of tube and the different initial temperature of ice layer, the effect of natural convention also is different in the process of melting heat transfer.

Abstract: The heat pump system by using earth energy is increasing very rapidly. In this paper, by studying the underground heat exchanger heat transfer mode, the computing platform for ground source heat pump system was established. Through a engineering case, the influence character of the circulation flow velocity in ground heat exchangers on the fluid temperature, the heat pump power consumption, and the length of system were analyzed, which provide an approach for system engineering design and operation prediction, and for the thermodynamic analysis of performance of system year by year and prospective study to guide the engineering practice.

Abstract: A training center design as an example, the impact of building energy-saving design on building energy consumption are showed. Energy-saving design options of air conditioning system and refrigerator are given. Lighting power density of the lighting system energy-saving design and the project of energy-saving design are provided.

Abstract: Formula of the maximum length of direct burial cooling pipes used in the district cooling system (DCS) was derived, by means of establishing the mathematical relationship between the maximum temperature rise of the pipe, under which the energy efficiency of the refrigeration unit would not decrease, and the thermal equilibrium of the pipe. And an engineering application with DCS in Zhuzhou was analyzed. The results showed that the insulation measures should be applied to the directly buried cooling pipes in engineering applications, appropriately with a thermal insulation layer of 0.04m.

Abstract: Based on the calculation method and the analysis method of the ventilation requirement, the paper discussed the necessary ventilation referring to the standard of the allowed indoor CO₂ concentration, the necessary ventilation with oxygen as the standard and the calculation method and correction method of the full amount of required ventilation to remove the waste heat or wet. According to the pros and cons of the methods described above, the paper proposed the corresponding countermeasures to meet the indoor air quality and the fresh air needed by indoor personnel.

Abstract: In view of high discharge temperature of compressor, the heating performance attenuated seriously, even unable to work properly and other issues of normal heat pump air conditioning system for electric vehicles under low temperature conditions, a gas-mixing heat pump air conditioning system for pure electric vehicles is designed. Based on the first law of thermodynamics and coupling properties among all components, the mathematical model of this system is established. The analog computation of main performance parameters of this system is carried out by this model, having a better match in comparison with experimental results. By simulation, the results show that the system can effectively solve the problems of high exhaust temperature from compressor and heating performance attenuation seriously of non-gas-mixing heat pump air conditioning system for pure electric vehicles under low temperature condition.

Abstract: One of the most important topic of 21th century is energy savings, and many countries create enterprises which develop standards and codes for construction, repairs and building renovations, including a realistic, cost-effective recommendation aimed at making city buildings become cleaner and more energy efficient. For example, one of these enterprises is C 40 Cities Climate Leadership Group.

Abstract: As the continual improvement of human living standards, healthy housing became a hot topic and was attached more and more emphasis whatever from the profession or the public. Professionally, better ventilation is one of the most important facets of the healthy housing. Compared with the traditional ventilation system, this paper illustrates the new air system that makes a full use of natural resources, directly and simply changes the normal traditional housing to the healthy housing, through the concept, philosophy, typology and property of the new air system. Additionally, it takes the "Dong Ya Shi Ji Cheng" in Batou as typical example of healthy housing, in order to demonstrates the advantages of the new air system more clearly.

Abstract: 5 radial heat exchange wells were designed, and the different angle drilling, drilling pipe, and grouting backfill construction technology was studied. In addition, the heat transfer performance of the buried radial heat exchange wells was tested. The results show that, design of pipe equipment is feasible, construction is convenient, and the ratio of backfill material is reasonable; the heat transfer performance of 90 °buried tube is the best. The smaller the angle with the ground heat exchanger, the greater the heat exchange performance is affected by the surface temperature.