Advanced Materials Research Vols. 805-806

Abstract: In order to solve problems of high energy consumption and poor indoor thermal comfort in existing rural residential buildings, Tianjin city developed Tianjin energy efficiency standard for rural residential buildings, the building envelope insulation technique in the standard-including determination of heat transfer coefficient, principle of choosing insulation materials for building envelope, energy efficiency standards of walls, windows, and roofs are unscrambled particularly in this paper. It is suggested that natural materials and appropriate techniques are used to achieve the energy-saving goal for rural residential buildings with minimum energy consumption.

Abstract: In order to provide the reference and basis to construction scheme and post-construction settlement prediction, this article based on a dynamic compacted red soil foundation of large-scale oil tank first-stage project of Guangxi, took settlement and conical surface deformation observation and used consolidation degree logarithm method to predict the final settlement of red soil foundation. According to the research, the effect of dynamic compaction was promising, and this method provided a reference to settlement prediction of red soil foundation.

Abstract: Passive housing is a combination of technological products which base on building energy saving concept, and it makes full use of solar energy, geothermal energy and other renewable energy to reduce the consumption of primary energy used in heating to 15 kw/h·m²·y, however, the energy consumption in low-energy house, which has equipped with various kinds of energy saving technologies, is about 30-75 kw/h·m²·y, thus, passive house has a better performance in energy saving than low-energy house. Energy saving technologies suitable for passive house and low-energy house in hot summer and cold winter area are proposed in this paper through introducing the contribution Germany has made and development of technology in passive housing, using its advanced technologies and practical experience ins passive house as reference and taking Chinese unique climate condition, building types and residents living habits into account.

Abstract: Select a tunnel in Nanjing as a modeling object and simulate the smoke control capability of the air curtain when nozzle spacing changes.By analysis, the dynamics characteristic with the wider spacing parameters of air curtain nozzle is superior to the narrower one under the same condition.The top of the spacing of the air curtain nozzle is recommended to be 2 to 3 times the width of a single nozzle.

Abstract: Waterborne polyurethane (PU) coatings are diluted with water as the medium, without volatile organic solvents and harmful to human body and environment. Adding insulation materials in building individually is a waste of resource. We found a kind of waterborne PU phase change energy storage material easily dissolved and formed film after solvent evaporating having the potential of coating. In this article, we synthesized a new kind of waterborne PU phase change energy storage coating additive via two-step synthesis method, of which a new type of aromatic tetrahydroxycompound (ATTC) is used as branch unit, 4, 4'-diphenylmethanediisocyanate (MDI) and polyethylene glycol (PEG) respectively as hard and soft segments. POM photographs show that the sphaerocrystals of this new coating additive can reach 200-500μm. The crystal structure is characterized by XRD, and the phase change unit is PEG. DSC tests show that the phase change enthalpy value of this coating additive is very high reached more than 90 J/g. The preservation of this water-soluble PU coating is relatively simple, using water as solvent, which can be easy to dissolve in water and form film after water evaporated.

Abstract: For provide outstanding thermal insulation capacity for the refuge chambers, this paper firstly put forward a 5 layer heat insulation structure for refuge chambers. Mineral wool and acrogel were used as the heat insulation materials because of their excellent heat insulation and fire resistance capability. Then the paper determined the thickness of each layer by theoretic analyze using heat transfer theory, and found two 10 mm layers of acrogel and a 62mm layer mineral wool were ideal thickness. Then the paper designed the cooling system, according the heat analysis. And found the ice cake was best fit for refuge chambers, but it must equip with air flue to keep the enclosed air flowing. At last, 8 people were employed in the closed chamber for 106 hours, and raised outside temperature to 55°C for 5 hours. The chambers inside temperature was most controlled under 35°C. Then the paper increased the thickness of acrogel layer according to the experiment results at last. Theory analysis and experiment show that the designed heat insulation structure and cooling system had an excellent thermal protection capability.

Abstract: Induced ventilation system with the advantages of simple system and convenient installation has been widely used in China's underground garage ventilation design and showed an increasing trend. In this paper, the numerical simulation is done to the different air exhaust way of induction ventilation system of an underground garage. The two air exhaust ways are upper exhaust and upper 1/3 and lower 2/3. By analyzing airflow organization and pollutant concentration of the two exhaust ways, we can derive that upper 1/3 and lower 2/3 air exhaust way is conducive to the discharge of pollutants.

Abstract: TEWI (total equivalent warming impact) index, a comparatively scientific method to evaluate the environmental impact of air-conditioning cold and heat source, is introduced. Taking some engineering in Hunan Province for example, the TEWI analysis was performed on the environmental impact assessment of four air-conditioning cold and heat source plans. Also the first investment and energy consumption were analyzed. The results indicate that: water loop heat pump unit, due to investment recovery period with only 2.9 years and carbon emission reduction up to 22.68%, has significant economy and environmental protection, which is followed by water source heat pump; the screw chilled water units plus gas boiler is poor. Gas direct-fired machine has certain economic advantage, but its environmental performance is general. Among four schemes, the proportion of indirect effects of CO₂ emissions from fossil fuels used to generate energy to operate the equipment throughout its lifetime are all larger, respectively is 95.1%, 95.2%, 100% and 89.9%. It fully showed the importance of developing clean and renewable energy, reducing energy consumption and increasing performance coefficient of refrigeration and air conditioning device.

Abstract: Reducing the amount of outdoor air entering a space has distinct advantages for ventilation system. However, it often brings the consequence of depressing indoor air quality (IAQ). For laboratories, on average, the laboratory IAQ conditions of low TVOCs and low particulates permitted the substantial reduction of minimum air change rates. With many modern laboratories operating with fewer fume hoods and more energy-efficient equipment and lighting, the labs minimum air exchange rate requirement is often the dominant energy use driver. Current codes or specifications for laboratories ventilation system are the most straight forward approaches. They do not optimize a laboratory's ventilation rate, or verify whether the intended levels of safety and comfort have been achieved by the labs design. Demand controlled ventilation (DCV) can also avoid over-ventilation by providing outdoor air rates based on actual occupancy rather than on design occupancy or full occupancy.

Abstract: The dynamic modeling and simulation based on components for parallel type and series type absorption refrigeration using novel working pairs [mmim]DMP/CH₃OH were conducted. The modified UNIFAC model and Wilson model were used to describe the vapor liquid equilibrium and excess enthalpy of the [mmim]DMP/CH₃OH solution, respectively. Under certain assumptions, the dynamic model was developed including the HPG (high pressure generator) model, the LPG (low pressure generator)-condenser model, the absorber-evaporator model and the SHX (solution heat exchanger) model. The effect of exhaust gas inlet temperature and chilled water inlet temperature on the thermodynamic performances were presented and discussed. The best COP of 1.27 and 1.17 for parallel type and series type system, respectively, were observed. The transient responses at step changes of two variables and on experimental conditions were carried out and analyzed, and the latter had been compared with the experimental data in literature. It is indicated that the model well describes the stable and transient characteristics of the double effect absorption refrigeration using [mmim]DMP/CH₃OH, and can be employed to enable the further parameter optimization and control design.