Applied Mechanics and Materials Vols. 170-173

Abstract: Energy-conservation and environmental protection are keys to sustainable development of domestic economy. The solar-assisted cascade refrigeration cycle system is developed. The system consists of electricity-driven vapor compression refrigeration system and solar-driven vapor absorption refrigeration system. The vapor compression refrigeration system is connected in series with vapor absorption refrigeration system. Refrigerant and solution reservoirs are designed to store potential to keep the system operating continuously without sunlight. The results indicate that the system obtains pretty higher COP as compared with the conventional vapor compression refrigeration system. COP of the new-type vapor compression refrigeration system increases as sunlight becomes intense.

Abstract: This paper chooses 7 kinds of fabrics and made stretch tight pants on the subjective comfort experiment. Gotten the sports time 0, 15, 30 minutes, 30 minutes of subjective feeling, the results showed that at the static, the feeling of stretch tight pants is mainly static comprehensive intimacy and touch feeling in the sensory threshold region. At Sports time to 15 minutes, subjective feeling of stretch tight pants is mainly weight feeling and sticky feeling in the sensory threshold region. At Sports time to 30 minutes, subjective feeling of stretch tight pants is mainly burns feeling, weight feeling and sticky feeling in the sensory threshold region.

Abstract: Three types of bell mouth with the inward bell mouths whose exit diameter are larger than the impeller inner diameter of multi-blade centrifugal fan used in floor standing air-conditioner are investigated by using the numerical simulation method. Three bell mouths are as follows: The first type of bell mouth is the inward inlet used in the original air-conditioner. The second type is the inward inlet whose axial height is larger than the first type. The third type is the new mold line inward inlet with smaller slope angle than the first type. Calculation results show that the later two type bell mouths can help to improve air volume flow ratio, reduce the vortex in the back of volute exit and increase the air volume flow rate of 6.8 % and 4.2% respectively. The experimental verification was conducted for the simulation results and the experimental results shows that the air volume rates increase 4.7 % and 3% respectively, the level of noise is constant. The entire performances of the two types are both improved.

Abstract: The mixed absorption refrigeration cycle which was suitable for the solar air-conditioning was presented. On the base of characters of working process, the models of each component were established in the paper. The universal module of thermo-physical properties of LiBr solution and water was written, control flow graph of program was given and simulation program of the mixed absorption refrigeration system was developed. The simulation results showed that the relations between LiBr solution concentrations and performance of mixed absorption system. The simulation program provided theoretical rules of optimization designs for commercial solar absorption air-conditioning.

Abstract: The model of solution heat exchangers of mixed absorption refrigeration cycle was developed. The effects of strong solution temperature difference between inlet and outlet of solution heat exchanger on the coefficient of performance (COP) and cooling water flow rate of mixed absorption refrigeration cycle were analyzed, at the same time, the effects of temperature difference on the unit heat exchange area of counter-flow and cross-flow solution heat exchangers were analyzed. The theoretical analysis results showed that there was an optimal value for the strong solution temperature difference, for the mixed absorption system, the optimal temperature difference was about 12°C, the corresponding COP was 11.2% higher and the cooling water flow rate was 7.8% less than that of system without heat exchanger.

Abstract: The main objective of this work is to introduces the finite difference method based on calculation ground-coupled heat pump implanted tube temperature distribution in the soil around the calculation method of the buried depth, and calculated the 1-m, different quality bury pipe flow around the change rule of soil temperature. The calculation results show that: buried tube weeks with the temperature distribution in soil of fluid flow pipe changes, the change rule is, the greater the fluid quality. Discharge inside around burying tube soil temperature is lower.

Abstract: On account of regional energy structure optimization, scheme of hot water heating source is deeply studied. A comprehensive evaluation index system of heating source is established in terms of economic, energy efficiency, environmental protection, technology and policy. Combining the fuzzy comprehensive evaluation and AHP, the optimal scheme is determined. The air-source water heater is the relatively satisfactory scheme. The research will have an important effect on a wide range of residential buildings in china, which is also in favor of optimizing regional energy supply structure. The conclusion will push related industry to be energy-saving, secure and sustainable, provide important theoretical basis for energy planning on decision-making of city development, and provides an important reference for engineering design.

Abstract: With the rapid development of the highway industry, the steel structure as the main Long Span Bridge build more and more, the highways are carrying more and more traffic than before and vehicle fires are becoming more frequent. This paper, (which is based on previous literature on the behavior of fire, and the main research method of fire heat release-rate) proposes a mathematical model for the heat release-rate of highway fires. Using the fire numerical simulation software FDS to do an analysis of the temperature field of an open space formed by a 300 mw heat release-rate reveals that the maximum temperature decrease is non-linear when the height increase.

Abstract: This paper developed the air-conditioning system with supplying hot water. The system can work in three modes: only refrigeration, only supplying hot water and refrigeration with supplying hot water. The experimental results showed that the system is more effective than traditional systems, the maximum coefficient of performance (COP) is about 5.34 at refrigeration mode, the COP is 5.78 at static heating mode of heating, and the COP is 4.5 at refrigeration and water heater mode.

Abstract: An experimental test has been conducted to determine the effect of heat pipe heat exchangers for pre-cooling and re-heating performance of central air-conditioning systems in Hung Hom Sport Centre. The objectives of this research project are to investigate the energy recovery efficiency from using the heat pipe heat exchangers in air conditioning system. The annual energy saving by using the heat pipe heat exchangers. The effect of energy recovery efficiency is significant.