Coupled simulation of BES-CFD and performance assessment of energy recovery ventilation system for office model

Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recovery ventilator and to investigate the effect of the air supply arrangement. Three types of mixing ventilation are chosen for the analysis of coupling ANSYS/FLUENT (a computational fluid dynamics (CFD) program) with TRNSYS (a building energy simulation (BES) software). The adoption of mutual complementary boundary conditions for CFD and BES provides more accurate and complete information of indoor air distribution and thermal performance in buildings. A typical office-space situated in a middle storey is chosen for the analysis. The office-space is equipped with air-conditioners on the ceiling. A heat recovery ventilation system directly supplies fresh air to the office space. Its thermal performance and indoor air distribution predicted by the coupled method are compared under three types of ventilation system. When the supply and return openings for ventilation are arranged on the ceiling, there is no critical difference between the predictions of the coupled method and BES on the energy consumption of HVAC because PID control is adopted for the supply air temperature of the occupied zone. On the other hand, approximately 21% discrepancy for the heat recovery estimation in the maximum between the simulated results of coupled method and BES-only can be obviously found in the floor air supply ventilation case. The discrepancy emphasizes the necessity of coupling CFD with BES when vertical air temperature gradient exists. Our future target is to estimate the optimum design of heat recovery ventilation system to control CO₂ concentration by adjusting flow rate of fresh air.     

江苏银环精密钢管股份有限公司

苏银环精密钢管股份有限公司是由银环控股集团和中国广东核电集团公司以股份制合作方式成立的国家重点高新技术企业,现有四个全资工厂、一个合资工厂和一个国家级工程技术中心。公司创建于1992年,通过走自主创新之路,研究开发高性能管材,提高了企业核心竞争能力。近年来公司引进中国广东核电集团、宝钢集团、中国核工业集团、国家核电技术公司、东方电气集团等大型央企,通过合资合作结成战略联盟,打破国际垄断,为国家节约了150多亿元的建设成本,产品不仅填补了多项国内空白替代进口实现国产化,还出口到日本、德国、美国等发达国家,实现了企业的跨越式发展。     

纯电动轿车制动能量回收节能潜力仿真分析

从整车能量消耗入手,分析纯电动轿车能量流机理,建立整车耗电量与工况、整车参数、部件效率以及制动能量回收比例之间的函数关系,通过求解基于工况的特征权值,研究不同车型在各工况中的节能潜力,为纯电动轿车整车参数匹配提供理论依据。通过分析制动力分配策略,量化制动能量回收比例,进一步计算整车节能度,研究制动能量回收效果。通过在Matlab/Simulink中构建仿真模型,完成整车节能度的计算,并与AVL/Cruise仿真结果进行对比分析,结果表明本文方法能够很好地反映整车节能效果,完全满足整车节能潜力分析的要求。     

载银纤维的抗耐药菌性能研究

通过对含有耐氨苄青霉素质粒的转化制备得到了耐药菌,并通过定性和定量试验,介绍了载银纤维的抗菌性能,并结合SEM结果分析了载银纤维的抗菌机理。结果表明该载银纤维对含有耐氨苄青霉素质粒的耐药菌有很好的抑制作用,甚至导致了细菌的膨胀破裂。     

电厂锅炉高温炉渣余热回收利用技术

电厂锅炉高温炉渣通常利用循环水进行冷却,循环水将炉渣余热代入冷却塔并排入大气,这不仅使炉渣的热量不能得到充分利用,影响锅炉的热效率,而且循环水的蒸发也造成水资源在一定程度上的浪费,同时对环境也造成热污染。锅炉高温炉渣余热的回收对节能减排、提高锅炉整体热效率十分重要。设计3种利用余热加热锅炉给水方案,并对技术方案的节能减排效果及经济效益进行了优化计算。计算结果表明,将出自冷渣机的热水引入7#及8#低温加热器之间,对减少汽轮机抽汽量、降低汽轮机的发电热耗率、提高整个发电厂发电效率有十分明显的效果。此结论可推广到其他电厂锅炉以及低温余热的回收利用。     

离子印迹磁性硅胶固相萃取-火焰原子吸收光谱法测定抗菌食品包装材料银溶出量

制备了离子印迹磁性硅胶(Ion Imprinting Magnetic Silica,IIMS),并以其为磁性固相萃取剂,建立了磁性固相萃取(Magnetic Solid Phase Extraction,MSPE)-火焰原子吸收光谱测定抗菌食品包装材料银溶出量的新方法.考察了样品pH值、洗脱剂类型和体积、超声萃取和洗脱时间等参数的影响,评价了IIMS的选择性.结果表明,Ag+在pH 4.0条件下可以实现完全萃取,2.0 mL硫脲(2%,M/V)-HNO3(0.2 mol/L)可实现Ag+的定量洗脱.在优化的试验条件下,IIMS的吸附容量为91.4 mg/g(Ag+);该法的检出限(3σ)为0.26 ng/mL(Ag+),富集倍数为91.8.该法成功应用于抗菌水杯、抗菌饭盒和食品抗菌保鲜膜银溶出量的测定,加标回收率在96.4%~101.0%之间.     

金融危机环境下的电费回收应对策略

电费回收工作是供电企业经营效益的重要体现,虽然供电企业作为基础行业承担着很多社会责任,在为经济发展提供有效动力的同时,也应通过对不同用户的分析和评价,采取有效的催费措施,杜绝一些不良用户的恶意欠费,提高企业的经营效益,促进企业良性发展,更好的为社会发展提供优质服务。     

THE NATURAL CONVECTION OF AQUIFERS WITH CONSTANT HEAT SOURCES AND ITS INFLUENCE ON TEMPERATURE FIELDS

By combining sand tank tests with numerical simulations, this paper studies the temperature fields around constant heat sources to reveal the mechanism of the natural convection and its influence on the temperature fields in the process of energy storage. Using the "24-channel temperature auto acquisition system" developed by our research group in the tests, the temperatures are recorded at measuring points within the research area in the tests, the revised Brinkman equation and a transfer-convection balance model are used for solving the aquifer water-thermal coupling problems, and through comparison of the test results with the calcula- tion results, it is discovered that the influence ranges and the variations of the two temperature fields are consistent, which validates the mathematical model. On the basis of this, we also study the influences of the heat source positions and the boundary conditions on the temperature fields, and the results show that, under the natural convection, the heat source positions may influence the distri- bution of the temperature fields, thus affect the energy storage. For the same energy storage layer, the temperature field for the top energy storage is characterized by a smaller heat influence range and a relatively concentrated temperature distribution. However, when the heat source is at the bottom, the range of a temperature field, and the temperature is relatively dispersed, which is not favorable to heat recycle, with the same heat source position, the boundary conditions determine the size of the critical Rayleigh number, and thus have an influence on the occurrence and the strength of the natural convection, and accordingly, on the temperature fields.     

广州太古汇商业中心给排水设计

广州太古汇商业中心建筑总高度为211.95m,总建筑面积457 584m2。介绍了项目室内外给排水设计,包括给水系统、热水系统、中水系统、生活排水系统、雨水排水系统、游泳池系统等,最后统计了各系统的管材选用及消声与隔振措施。     

钢结构建筑是建筑产业转型的方向

正钢结构住宅是钢结构建筑的一种形式,在我国早有实例。从1994年在上海北蔡建起的第一栋8层钢结构住宅算起,已有18年的时间了。18年来,我国的钢结构企业在钢结构住宅方面积累了一定的经验,从建筑技术、结构体系、建筑产品配套到设计、施工、维护等方面已经拥有了一些比较成功的经验和工程范例,譬如青岛的华阳慧谷住宅小区、上海奉贤的32万平方米住宅、沈阳铁西区7.2万平方米的工人村、武汉的黄金口岸等。