变频器在恒温水暖系统中的应用

本系统采用PLC控制,运行稳定性好,维修成本低,保证了使用的连续性。通过进出口温度传感器实现双系统用变频器自动调速控制,保证了共暖,达到了燃煤最优化,确保锅炉内水温为65℃左右,减少了锅炉的结垢现象,相对增强了热传导,提高了热效率,也延长了锅炉的使用寿命,真正做到节约能源的目的。     

10.1寸液晶屏幕总成散热模拟分析及优化设计

LED在液晶显示器使用中的发热问题,是影响其发光效率和画面质量的关键技术难题之一。为此利用Solidworks Simulation软件对某公司10.1寸手持平板电脑产品的液晶屏幕总成进行了散热效果模拟。综合主要发热源LED和驱动IC的发热分析结果,表明在金属背板和绝缘胶带的长宽尺寸均已固定的情况下,需通过调整金属背板和绝缘胶带的材质与厚度优化屏幕总成的散热性能。结合产品实际,改用热导率更高的铝合金AL5052背板和石墨片绝缘胶带,同时增加金属背板和绝缘胶带的厚度,可使稳态工况下最高温度从优化前的49.8℃下降到36.1℃,有效提升了液晶屏幕总成的散热效果。样品实物温升和机械强度测试均证明了研究的准确性,可满足实际生产组装的需要。     

微小尺度孔径受限冲击射流的强化换热实验研究

为研究微小孔径气体受限冲击射流的换热特性,采用电阻丝加热方形酚醛树脂薄板作为模拟发热芯片的换热表面,沿对角线均匀布置热电偶以采集表面温度分布。以3mm孔径的圆形单孔及1mm孔径两种不同排列的圆形多孔喷射板对发热面进行中低Re数的射流冲击换热实验．通过改变风数及高度孔径比等参数得到了批数的径向分布及驻点区的换热特性,为射流冲击换热在封装芯片冷却上的应用提供了实验基础。     

HLA在个体发育中的作用分析

HLA（人体白细胞抗原）首先发现于白细胞表面,是人类主要组织相容性抗原。后来研究发现,与这种抗原相关的HLA基因群是迄今已知的人体最复杂的基因系统,具有高度多态性。从受精卵的着床发育到个体的成熟,在整个人体发育的历程中,人类组织相容性抗原每时每刻都发挥着重要的作用。本文在说明HLA基因结构的基础上,从母胎耐受、胚胎及个体发育等方面阐述了HLA的功能。     

某工程大体积混凝土施工温度测试与分析

根据某工程地下室大体积混凝土施工过程中水化热的现场测试结果,通过理论计算并结合现场环境分析了各温度测试点随时间和沿厚度方向的变化情况.分析结果表明,地下室板底的温度由于受周边淤泥土的包裹,温度消散速度较慢,板底温度接近板中心区温度,比板面混凝土的温度高出较多.实测结果,板顶与板底的温差已超过25 ℃,因此当底板下地基土的散热效果较差时,对板厚较大的地下室板底实施降温,同时对底板面混凝土采取保温措施,对减少混凝土内部的温差,防止混凝土裂缝的出现非常重要.     

Water and heat transport in hilly red soil of southern China： I. Experiment and analysis

INTRODUCTION Located in subtropical monsoon area, the redsoil region in western Zhejiang, China, is one of themain cash crop production bases of this province. Dueto the climate, the temporal and spatial distribution ofrainfall varies greatly in this region. Only 15 percentof rainfall occurs in summer (July, August and Sep-tember), while about 60 percent of rainfall occurs inspring (from March to June). The region suffersdrought in summer and waterlogging in spring. Theparent ma…     

供热中分户计量收费问题探讨

本文讨论了供热地区分户计量热价收费问题,结合我国具体情况,分析了分户计量中用热收费计量方法和系统形式,针对供热收费需注意的问题,提出了自己的一些见解。     

Study on performance of a packed bed latent heat thermal energy storage unit integrated with solar water heating system

INTRODUCTION Efforts of rational and effective energy man-agement, as well as environmental considerations, increase the interest in using renewable energy sources, especially solar energy. Because of discrep-ancy between the energy supply and demand in solar heating applications, a thermal energy storage (TES) device has to be used for the most effective utilization of the energy source. Energy storage combined with solar collectors and photovoltaic systems have been developed over the…     

Numerical prediction of temperature distribution in thermoset composites during laser curing process

The temperature distribution in the advanced thermoset composite during the laser curing process was predicted with the use of the two-dimensional thermo-chemical model presented in this paper which also gives the governing equations based on the thermal history of the curing process. The finite-difference method was used to get the temperature distribution. This paper also deals with the effect of some factors (such as the winding velocity, the tape thickness and the laser heat source) on the temperature distribution.     

一体化智能热量表的开发和设计

针对当前国内与市场经济体制极其不符的供暖包费制的供暖体制现状和国外热量表的昂贵价格，自行开发设计了一款低功耗、高抗干扰性、高保密性和高精度的一体化智能化控制系统，实现暖气的计量和预付费智能控制。