Advanced Materials Research Vols. 594-597

Abstract: The building air permeability plays a major role in both building energy performance and indoor air quality. The performance of structural tightness is set as an evaluation index of building air permeability, which is employed to analyze the relationship among building air permeability, building construction and window/door air permeability. Based on some assumptions, the coefficient of building structural tightness is established to summarize the influential factors on building air permeability, and the theory method is provided to improve the building air permeability. A model of air permeability for a small room is taken as an example. The results indicate that the building structural tightness coefficient is available to analyze the building air permeability.

Abstract: How to reduce the energy consumption of air conditioning, to use new energy such as solar appropriately, and to achieve energy savings, are the problems must be treated in HVAC industry. Because of the high energy consumption of traditional air-conditioning and the need for reduction of emission, an air conditioning system (utilizing solar dehumidifying applied to heating/cooling radiant floor) is designed and installed in this paper. At the same time, as an example, the energy saving potential of system is analyzed. This type of heating/cooling radiant floor system is worth promoted if solve the dehumidification properly. By separating to deal with heat and moisture can reduce the energy-cost of traditional air-conditioning, and to achieve purposes of primary energy saving.

Abstract: This study intends to investigate indoor air quality of kitchen such as velocity, temperature, humidity and air contaminant (carbon monoxide and carbon dioxide). Test results show that workspace local temperature is up to 49.6°C at 12:50 due to the workload increased at the diner peak and the largest CO and CO₂ concentration were 14.8 ppm and 2145 ppm respectively after 2 hours cooking, which are above the acceptance criteria (CO<10ppm and CO2<1000ppm), and it gives serious impact on the staff's physical health. It is necessary to improve indoor air quality through kitchen ventilation.

Abstract: In this paper, the thermal stress characteristics of polystyrene plate - thin plaster wall are present. A three-dimensional element is selected to mesh the wall model, which can simulate the coupling effects of thermal stress and structural stress field. Thermal stress and deformation distribution are proposed after comparing and analyzing the two simulation results. Numerical simulation results indicate that: (1) Polystyrene plates thin plaster wall insulation system has very good thermal insulation properties；(2) Different stress fields concentrate significantly around windows and in the middle of wall especially around the windows. (3) The deformation of the polystyrene plate - thin plaster wall insulation system reach the maximum at the edge of the wall while the minimum in central.

Abstract: If the dust laden gas is cleaned by a dust separator, the rest particles become very small. Then, the fine particulate behavior looks like fluid. Therefore, particle concentration becomes one of the most important affecting factors on the impeller abrasion. It is more reasonable to simulate gas-solid two-phase flow field in the impeller of a centrifugal fan by Reynolds Stress Model and Tabakoff - Grant Erosion Model. The erosion location and rate of working surfaces of blades with different particle diameters and inlet concentration have been predicted. These results show that the erosion location has relationship with different particle diameters, and effect of particles number concentration is more important than particles mass concentration on erosion rates.

Abstract: In order to reduce the concentration of explosive gas, experimental research was carried out on the high pressure secondary rotating water jet ventilation characteristic, and the principle of high pressure secondary rotating water jet ventilation was analyzed. Experiments of the relationship between pressure and the suction air flow characteristics were carried out with different structure of jet pipe, different structure of nozzles, different throat in high pressure single rotating water jet ventilation, and the secondary rotating ventilation characteristic were tested with different guide vane angle. The results show that the air-sucking quantity approximatively increased with water pressure in accordance with parabola in the high press secondary rotating water jet ventilator, the air-sucking quantity of different structure of jet pipe was not same, the air-sucking quantity was significantly greater than that of swirl nozzle, the secondary rotary ventilation acts on the larger range.

Abstract: The V-shaped solar flat-plate air collector was put forward according to the existing problems of solar flat-plate air collector. V-shaped grid plate is used in the solar flat-plate air collector which can improve the efficiency of a flat-plate solar air collector via increase of solar energy absorption efficiency and heat transfer area. Energy balance model of the V-shaped solar flat-plate air collector is established according to the characteristics of internal structure and air flow way, and vent opening position is optimized using the CFD, the results showed that the temperature distribution is uniform when air inlet locates in the central axis of collector, it will provide a theoretical basis for the design of the V-shaped solar flat-plate collector.

Abstract: The V-shaped solar flat-plate air collector was design in order to improve the efficiency of solar flat-plate air collector, and the heat transfer model was established on the base of solar collector working principle. Internal temperature distribution of collector and temperature change rule under different sunshine condition is simulated and the relation of collector height, solar radiation intensity and collector efficiency is analyzed. The result showed that internal air temperature of collector increases with collector height increase and gradually achieves a stable value. It will provide a theoretical basis for collector layout of solar house.

Abstract: The previous research on temperature prediction presented different approaches which are physical-rule based adaptive neuro-fuzzy inferential sensor (ANFIS) model and GA-BP (genetic algorithm back propagation) based model to estimate the average indoor temperature in the building environment. Their good prediction performances improved energy efficiency of district heating system and indoor comfort ratio. However, either of these two models has its drawback in a certain condition. In this paper, the two prediction models are reviewed and evaluated by three performance measures (RMSE, RMS, and R2). Their limitations are discussed and potential solution is proposed.

Abstract: To solve the problem of enhancing the heat transfer capability of antifreeze mixture in a ground source heat pump system, the existing proximal support vector machines [1] was updated into a weighted Proximal Support Vector Machine (PSVM) model. Also, a new classification method of mixed antifreeze heat transfer capability was given in the paper by analyzing antifreeze [2] heat transfer capability of the ground source heat pump system and applying the weighted PSVM mode.