Numerical analysis of Natural Ventilation in Built-in Photovoltaic-Trombe Wall

The natural ventilation in a novel built-in photovoltaic-Trombe wall (BiPV-TW) was numerically simulated by CFD method. The effect of solar radiation, channel width and height on the air flow pattern and ventilation rate was analyzed. Results show that the solar radiation, channel width and height influenced the ventilation rate remarkably. As the solar radiation and BiPV-TW height increased,the ventilation rate increased. As the channel width increasing from 0.1 m to 0.4 m, the ventilation rate monotonously increased. However, when the channel width exceeded 0.5 m, the reverse flow was formed in the top zone and the ventilation rate decreased. A maximum air volume flow rate was achieved when the channel width was approximately equal to 0.4 m in a 3 m height model. The channel width was the dominant factor that influenced the flow pattern in the channel. When the channel width was smaller than 0.4 m, the airflow was thermally stratified laminar flow. When the channel width exceeded 0.5 m, thermally stratified flow disappeared due to the reverse flow formed in the top zone and the laminar flow became turbulent.     

One Dimensional Steady Model for Natural Ventilation of Solar Chimney

Solar chimney is effective to enhance the natural ventilation by heating the air with solar radiation. Based on the research by other authors, a revised mathematical model is proposed. One dimensional heat conduction model is proposed when the thermal resistance of both the glass cover and heat absorbing wall are taken into account. The mean temperatures of the air and heat absorbing wall, the air mass rate and heat collection efficiency in the solar chimney are calculated with the present model. The results of the present model are compared with the related experimental data and reasonable agreement is validated. It is shown that the present revised model is able to predict the temperatures of the air and wall, the air mass rate and heat collection efficiency more preciously than the original model.     

Experimental Analysis of Solar Energy Combined with Phase change Energy Storage Ventilation System

Solar Ventilation System is unstable and uncontrollable, so a new technology is proposed to get a system that takes solar energy as heat source and applies phase change material in daytime to store energy which is used to keep ventilation in nighttime by thermal pressure. This new system is helpful to get the ideal ventilation effect for buildings. Through the experiments on ventilation with PCM of 63℃ and 44℃, ventilation rate change curve is obtained to analyse ventilation system efficiency. The results indicate that using the PCM of 63℃ and 44℃, the total ventilation of the solar ventilation system in 10 hours are respectively 8066 m3 and 6154 m3 at night, and the average ventilation per hour and area are 538 m3/h and 41 m3/h. Based on the experiment, when PCM is palmitic acid, the ventilation effect is superior than that of lauric acid. To sum up, the system of conventional solar rooftop ventilation system combined with phase change materials can intensify the nature ventilation effectively in nighttime for buildings, improve indoor thermal environment and reduce the energy consumption in air conditioning building.     

Simulation for the Effect of Building Plan andOrientation on Natural Ventilation

Indoor thermal comfort can be significantly improved by natural ventilation with reasonable architectural design. In order to compare natural ventilation effect, the distribution of velocity field, temperature field and the PMV in different architecture layout and orientation design were analyzed with house types in Best House Type Competition. It was found that indoor natural ventilation effect was obviously improved by means of altering the layout and orientation, where the maximum velocity varied from 0.24m/s to 0.82m/s. And the temperature decreased 0.9℃ and the value of PMV was more approximate to comfort.     

Application of Indoor Natural Ventilation Simulation in Residential Space Layout

Tatural ventilation of indoor air flow and thermal comfort space plays an important role, especial y in the interior design of passive cooling factors, indoor space layout, and the location of doors, windows and other factors on the indoor natural ventilation effect has great influence. Using the method of fluid mechanics, and Airpak3.0 software, indoor natural ventilation for residential buildings was simulated, and the thermal comfort of indoor natural ventilation in a residential building in Xuzhou City was analyzed to explore the effect of indoor spatial layout, location of doors, window opening types on indoor natural ventilation. The results showed that indoor spatial layout played an essential role in indoor natural ventilation, application of numerical simulation for the simulation of the indoor natural ventilation and assessment of indoor natural ventilation effect was a scientific instruction for the indoor spatial design.     

Optimizing Design of Displacement Ventilation in Cinema

In order to research the displacement air conditioning in cinem conditioning system with wall diffuser in cinema with the CFD. According a, the writer simulates the displacement air to the result of the computing, we can find that if we adjust the position of the openings and parameter of air-inlet in reason. It is useful to make good use of displacement air conditioning system with wall diffuser and extend the saving energy methods by using the CFD technology in designing the air condition system in cinema.     

A Mathematical Model of Solar Energy Storage Ventilation System

A mathematical model of solar energy storage ventilation system was built in order to calculate the heat storage during daytime and the ventilation rate during nighttime. Based on meteorological parameters of Kunming in China, phase change materials(PCM) were used at the temperature of 38 ℃, 44 ℃, 50 ℃ and 63 ℃ respectively to search the relationship between ventilation volume and the angle of chimney. The modeling calculation results show that for different phase change materials, and in any angle, the trend of heat accumulation is consistent, namely heat accumulation is smaller with a higher phase change temperature. Considering both the average hourly ventilation volume and the duration, the best angle of this system should be 45°, and the best phase change material should be 38 ℃ myristoyl.     

Research of the Ignition Timing System for Compressed Natural Gas Vehicle

Compared to bi-fuel engine,it uses completely CNG(Compressed nature gas) to replace diesel which can save more oil fuel than bi-fuel engine that reffited diesel engine into CNG engine. A 4102 diesel engine is refitted into CNG engine and a mechanical ignition timing system is designed by the method of gear and belt. The principles and the construction of the system is introduced and the characteristics of the design is analyzed. The system performed well and had good liability when run in a platform. Compared with the previous one, it kept higher dynamic character and emitted lower. It is a cheap one and can be use to reform the diesel engines.     

The Curtain Wall Technology in Green Building

Based on the conception of green building, this paper discusses the effect of curtain wall in adjusting the interior environment quality, reducing building energy consumption, and emphasizes the curtain wall technology in natural lighting, natural ventilation, as well as building energy efficiency.     

Effect of Natural Resource on Improving Indoor Thermal Environment in Chongqing

Analyzes the potentials of natural resource to improve the indoor thermal environment in Chongqing through the statistical analysis of natural resource including solar energy, wind, water and earth etc. The building forms, systems and principle of usage of natural resources are briefly analyzed through the building site-decision, building form design and computer simulation which will be the real reference for the design of building energy efficiency.     

Analysis and Calculation of Ventilation System of Xuefengshan Highway Tunnel

Some problems about ventilation in extra long highway tunnels have been discussed in this paper. The ventilation modes and geometry parameters of longitudinal blow-suction ventilation of Xuefengshan Tunnel in Hunan Province (7 000 m) have been studied and calculated. Based on this, the general design, principle design, technical design and relative structural design of ventilation for the tunnel have been successfully done.     

Analyses of Annual Running Conditions for Ventilation System in Residences in Hot Summer and Cold Winter Regions

Based on the definitions of air conditioning period, dehumidifying period and heating period, this paper puts forward the exchanging conditions and psychrometric process of ventilation system in residences. Because of the remarkable humid climate in hot summer and cold winter regions, the ventilation dehumidification becomes a more important part of the air treatment system. In order to improve the indoor thermal environment quality, new strategies must be founded to control both temperature and humidity of ventilation system.     

西南典型喀斯特洼地风景园林规划设计探析

基于风景园林多学科交叉的性质,以毕节撒拉溪示范区风景园林规划为例,探讨喀斯特洼地景观规划设计与水土保持措施。通过文献法、实地调查法、多学科综合研究法,分析喀斯特洼地在空间、视觉、文化等方面的特征,从自然条件、环境容量与规模预测、区位交通、资源分析、使用人群以及SWOT分析等方面,对喀斯特洼地进行功能分区、景观空间布局、道路布局、植物配植以及园林建筑营造研究,将景观营造与石漠化治理相结合,探索一种适宜喀斯特洼地的风景园林规划设计方法。     

Approach to Design Strategies of an Ecological Sustainable Residential Area in Beibei,Chongqing

The residential area studied in this paper is situated on the special borderland between Beibei town and Jinyun Mountain,which is a national beauty spot and natural conservation region.In order to conserve the ecological environment of JinYun Mountain,prevent the excessive development,and promote sustainable progress of the residential area,it is suggested in this article that an ecological sustainable residential area should be designed for this area. Then this paper puts emphasis on the design strategies in following three parts:(i) protecting ecological environment,(ii) providing healthy building environment,and(iii) enhancing building energy efficiency.     

Model of Critical Velocity for Fire Ventilation in Horizontal Tunnels

1/20 scale model test and full scale field test were carried out to study the critical velocity for fire ventilation in horizontal tunnels. Combined with the test results, small scale test results by Jae and full scale test and simulation by Hu, a semi empirical model was developed to predict the longitudinal critical velocity for tunnel fire ventilation. Compared with the predictions of the proposed model and other models using air as fire source, it was found that the predictions by Wu and Barker was underestimates.     

Effects of Radon Exhalation by Ventilation Styles in the Over-broken Granite Tunnel

The regularity of radon exhalation is affected by the weather and the ventilation in the over-broken granite tunnel. Based on the calculation model of radon exhalation in tunnel, some experiments have been carried out to analyze the variation of the radon exhalation in natural ventilation, blowing and exhaust conditions separately. The result showed that there is a linear relation between the radon exhalation and the natural ventilation, the temperature outside the tunnel also works as the same. It also shows that in the same condition of the tunnel's air flux and the outside temperature,the radon exhalation in exhaust case is 63% higher than the blowing case. When the temperature outside is high works in tunnel should avoid, and the blowing ventilation could be an effective way for reduction of radon concentration.     

Experimental Study of the Cup-Flame Gas-Burning Installation of Swirl Flow

The cup-flame burning installation with swirl-flow of natural gas is a new type device with high performance. It possesses the characteristics of fast speed heating up, homogeneous heating, fuel conservation and novel structure. It can be widely used for forging furnaces, heat treatment hardening furnaces, low fusing point melting furnaces and some other kinds of kilns. This installation is one with promising prospect.     

Natural Outcrossing in Rice Bean

Natural outcrossing in rice bean (Vigna umbellata [Thumb.] Ohwi and Ohashi) was studied in the progenies of recessive plants in F generation of six crosses involving three loci — Ti (seed coat base colour), (seed coat mosaic) and Rr (seedling colour), The estimate of outcrossing (α) varied from 0.27 10 0.81 and the percentage of line showing outcrossing varied from 86.S to 100 and the outcrossing was non random.     

寒冷地区冬季自然通风时段选择优化分析

为获得最优的冬季自然通风时段,以兰州地区某地板供暖民用住宅为研究对象,考虑围护结构对室外温度波的衰减和延迟效应,得到建筑围护结构的等热流边界条件。在此基础上,采用FLUENT软件对不同通风时段的室内污染物浓度场进行了数值分析,结果表明：同一开窗方式时,不同时段的通风时长不同,不同进风温度对室内污染物的时空分布及迁移特性影响显著,综合考虑污染物排除效果及舒适性,发现 17:00时开始通风为最优通风时段。     

The Influence of Air Inlet on Ventilation Effect in Indoor SubstationTransformer Rooms

Ventilation design is the difficulty of transformer room design. Temperature field and velocity field in a transformer room was simulated by CFD method . By comparing simulation value with the experimental value in related document , the effectiveness of the mathematical model was verified. Based on it, an indoor substation transformer built was taken as the simulation object, then designed and simulated six kinds of ventilation condition by changing the location and area of air inlet, focused on the influence of air inlet on the ventilation effect by comparing the temperature field ,velocity field and temperature characteristic value in different condition. The simulation results show that when air inlet area is fixed, the air inlet should be arranged in the radiator side and its center height should be controlled in the radiator center height or slightly offset position, it should not be higher than the radiator. When the air inlet location is fixed, air inlet area should be increased along the high direction to improve ventilation effect. The conclusions can provide technical support for the ventilation design of transformer room.