共查询到20条相似文献，搜索用时 31 毫秒
1.
In this paper ,the innovational research is based on widely absorbing patents and applied technique at home and abroad and pointing out the disadvantage and ameliorative method of heat/low meter. According to the principle of therrnopile, and the three - dimensional loop wire laying is substituted by new - style plane wire laying. The construction and manufacture of new - style heat flow meter is declared. The new method will facilitate the manufacture and reduce the cost and the high precision feeler is assured by consistent line length, capacitance, resistance and inductance and the cost of determination in present demarcation will be cheaper than traditional feeler of heat flow meter. The high precision energy saving detection instrument is provided for the field of heat energy. 相似文献
2.
Using Designer's Simulation Toolkit DeST h developed by Tsinghua University, research was carried out on the energy consumption of a typical residential building in Ningbo, P. R. China, with a focus on the heat transfer coefficient of external windows facing every direction. Results show that variation of the heat transfer coefficient of external windows in all directions has a substantial effect on energy consumption for heating but little effect on energy consumption for cooling. It is difficult to decrease cooling energy consumption by decreasing the heat transfer coefficient of external windows in summer. The heat transfer coefficient of external windows facing south has a significant effect on building energy consumption, but the windows facing north have less effect, and those facing east and west have the least impact. Decreasing the heat transfer coefficient of external windows facing north and south from 4.7 to 3.2 produces the most favorable performance cost ratio for energy saving investments. Reasons for the decrease in the heat transfer coefficient of external windows leading to increased air conditioning energy consumption were discussed. The conclusions are useful for guiding energy efficient building design in other subtropical cities. 相似文献
3.
4.
熏蒸气体浓度检测仪的研制及其在检疫中的应用 总被引：4，自引：0，他引：4
经过比较分析，热导气体检测仪被认为是最有应用前途的现场熏蒸剂气体浓度检测仪。为此，在实验室采用了一个四丝直通型热导池和分流稳流装置，研制出了一台结构紧凑的试验用熏蒸气体浓度检测仪。该仪器拥有必需的电子线路、内部可充电直流电源、电动采样泵、流量控制和液晶显示器。室内实验和熏蒸现场大量使用的结果表明，该议器易于操作，其检测灵敏度达到0．1mg/L，在0－100mg/L的线性范围内，其检测精度达到满量程的2％（在20－60mg/L的检测范围内，其精度为0．2mg/L）。同时进行了一系列规范的熏蒸试验，并定时测定了熏蒸空间内各点的熏蒸剂气体浓度，然后经过CT值计算，确定了熏蒸期间定时检测时的最低浓度读数值。 相似文献
5.
Wang Tiesun Yang Yang 《保鲜与加工》1988,(2)
This paper introduces the comprehensive hydraulic testing set for many kinds of hydraulic elements with hydraulic drive, hydraulic regulation and hydraulic loading. It has rational structure compact arrangement, reliable characteristics and advanced technique. In order to reduce the energy loss in the hydraulic system of the testing set, 1 ad sensing control is used. The static and dynamic characteristics of the load sensing system are analysed with the method of numeral simulation on computer. the testing witk load sensing control results show energy may be saved obviously and the heat load in hydraulic system may be reduced effectively, then testing quality is improved and the volume cf oil case is lessened. The lead sensing valve design is satisfied with simplifying structure so that it may be used reliably for the fixed flow hydraulic system of the testing set or other machines. 相似文献
6.
The forms of water transportation, arrangement and operation of pumps contribute to the water transportation energy consumption, which influences the energy-saving effect of surface water source heat pump. The relation between the pumping height and energy consumption of pumps is found by analyzing the model of pump energy consumption. The concept and calculation of critical pumping height is presented considering the limited rate of system energy efficiency. Based on the principle that the pump power changes with water flow rate, the determination of pumps arrangement of one or two stage pumps is described with a concrete example. The influence of water flow rate on heat pumps and water pumps is analyzed, and the energy efficiency of constant and variable water volume are compared. The operation way of this example is concluded for the optimal system energy efficiency. It is found that there is a critical pumping height for the energy-saving effect of surface water source heat pump compared with the traditional system. Moreover, the operation strategies should be determined by the system optimal model since the energy consumptions proportions of heat pumps and water pumps are variable. 相似文献
7.
Due to the bad heat dissipation of the existing heat dissipation structure of DC-DC and IPU for hybrid electric vehicle(HEV), the temperature of DC-DC and IPU will rise during the running process, which in turn decreases the stability and reliability of the hybrid electric system. Aiming at this problem, a three-dimensional, transient heat dissipation model is built for DC-DC and IPU heat dissipation structure based on the mass, momentum and energy conservation equations. By using computational fluid dynamics (CFD) software, flow field and temperature field of DC-DC and IPU heat dissipation structure are numerically simulated. Based on the simulation, and combined with heat transfer theory, an improvement scheme of heat dissipation structure is proposed. The simulation results and experiment results of thermal performance and temperature rise show that the improvement scheme can improve the thermal performance, and decrease the temperature rise of DC-DC and IPU effectively, thus satisfy the application requirements in HEV. 相似文献
8.
北方粳稻品种类群划分及亲缘关系的RAPD分析 总被引：1，自引：0，他引：1
鉴于国内粳稻的类群划分及亲缘关系还鲜有RAPD分析的相关研究报道,本研究利用RAPD分子标记技术对18个北方粳稻品种进行了分类和亲缘关系研究,从80个随机引物中筛选出了21个引物用于PCR反应,共在146个位点上扩增出条带,平均每个引物扩增的位点数为6.95个,多态性位点104个,多态性比率为71.23%,显示了较高的多态性。其中,有15个引物具有单一标记条带或特异缺失条带,共可鉴别10个品种。应用SPSS11.5分析软件对18种供试材料进行了聚类分析,实验结果显示：18种粳稻品种可明显分为3类,第Ⅰ类的10个粳稻品种有8个品种与系谱分析结果相符,第Ⅱ类和第Ⅲ类中的粳稻品种都分别具有血缘关系,与系谱分析结果基本吻合。综上所述,RAPD技术在北方粳稻品种类群划分及亲缘关系研究中的应用是可行的。但两者的分析结果也存在一定的差异,我们建议在实际工作中应将分子标记法和系谱法有机结合、相互印证,减少亲本选择的盲目性,提高育种工作的可预见性。 相似文献
9.
Li Yourong Jin Mingcong Tang Jingwen 《保鲜与加工》1993,(6):46-50
The concept of loss rate of available energy was introduced for evaluating heat exchanger performance. At the same time, the general expression of loss rate of available energy was obtained for heat exchangers of several typical. And NL criteria was recommended for evaluation of the loss rate of available energy of heat exchanger. Then. the influences of inlet temperatures ratio, heat capacity ratio of fluids, the number of heat transfer units and flow patterns of heat exchanger on ,VL criteria were also discussed. 相似文献
10.
Air stream of hot mines is taken as research object, and energy balance equation is established. Cooling load expressions under five different conditions are derived through strict theoretical derivation, i.e. unsteady multi-stream, steady flow, steady flow ignoring kinetic energy change, steady flow ignoring potential energy change and steady flow ignoring fan power change. Then the enthalpy variable expression of the subsurface moist air and heat calculating process of surrounding rock are deduced. Finally, Yong Chuan coal mine illustrates and summarizes the process of calculation cooling load quantitatively. It is conducive to scientificly manage hot mine and design mine ventilation. 相似文献
11.
A sving energy system can get natural ventilation in the storied healthy build-ings with air condition or heating. The principal component of this system is an efficient heat ex-changer made of a set of heat pipes. This system can be operated between two sides of one floor slabto change the energy carried both by the hot air flow and the cold air flow, This svstem can make aspossibly keeping indoor air fresh with a little energy air loss only. It is possible for using this systemto cure a sick building into a healthy building. This system can be put dperation between both thepipes of waste air flow and fresh air flow for an integrated air conditional svstem with fresh air. 相似文献
12.
CHEN Hai-hui 《保鲜与加工》2005,(1):37-40
The energy consumption and sight pollution of glazing curtain wall are two problems to be urgently managed. Intelligent curtain wall is a new type one of energy conservation and environment protection, in which the thermal channel to save building energy consumption and automatic sunshade to adjust sunlight are adopted. Four engineering examples of oversea intelligent curtain wall are briefed. The construction and energy saving principle of ventilative curtain wall as the core technique of intelligent curtain wall are presented. The earliest ventilative curtain wall in China Mainland, and its test results of heat preservation in winter are stressed. The design experience of how to choose three key parameters: the width of thermal channel, the layout of inlet and outlet and the type of glass is discussed. 相似文献
13.
关于系统耦合理论的探讨 总被引：8，自引：0，他引：8
系统耦合理论是近年来研究的热点问题。以农牧交错带为例,针对在生态经济系统目前该理论的定量化方面研究不足的事实,提出用能值方法考虑农牧交错带系统耦合的机制,并指出农牧交错带系统耦合机制应建立在土地利用方式、子系统间能值转化过程和生态系统的能值储备上;同时影响系统耦合机制的主要因素有初级生产力的大小、畜牧业的内部结构和畜牧业的发展规模以及生态系统服务价值的大小。还探讨性地提出系统耦合度的概念化公式,期望能更好地应用并发展这一理论。 相似文献
14.
芒和荻作为草本能源植物的潜力分析 总被引：6，自引：0，他引：6
利用多年生草本植物发展生物质能源产业是可再生能源发展的一个新方向。研究发现,芒和荻是我国本土多年生高大C4草本植物,具有作为能源植物的开发潜力,在欧洲已被广泛应用,在我国仅仅用于水土保持、造纸、饲料等。该文综述了芒和荻的生物学特征、生物质品质特性、生态效益、国内外利用现状,认为该类植物具有生态类型多、野生资源丰富、适应性广,抗逆性强,产量高,净能产出高,生物质品质好,转化利用途径广,生态价值好等特点,是优良的草本能源植物,适合在我国边际土地上种植利用,目前的研究重点应集中于种质资源的搜集、评价和新品种选育及适用于边际土地的栽培管理技术。 相似文献
15.
Annual Energy Consumption and Feasibility Assessment of Ground -Source Heat Pump in Residential Building in Fuzhou City 
下载免费PDF全文
下载免费PDF全文 This paper describes the annual energy consumption and economic assessment of air-source heat pump(ASHP) and ground-source heat pump(GSHP),based on hourly building load of typical house in Fuzhou.Analysis results show that the energy consumption of GSHP is 15% less than that of ASHP through all year,where there is 13% less in summer and 20% less in winter.Although the seasonal energy efficiency ratio of GSHP in Fuzhou is higher than that of ASHP,it has no obvious effect on the energy efficiency as it is in the hot summer and cold winter zone.In comparison with ASHP,the GSHP is not cost-effective. 相似文献
16.
中国叶子花属植物种质资源及其繁殖技术研究 总被引：8，自引：0，他引：8
为了为叶子花属植物的综合开发及应用提供参考依据,文章论述了叶子花属植物的生物学和生态学特性,综述了我国叶子花属植物资源的分类、分布、收集保存、引种栽培及繁育情况,总结了叶子花扦插育苗、高压、嫁接和和组织培养育苗的研究现状,指出了叶子花属植物种质资源研究方面存在的问题．提出了叶子花属植物种质资源创新研究和开发利用的建议。 相似文献
17.
18.
针对不同的粮库内部太阳能制冷机组空调分布形式,利用CFD计算软件,采用标准k-e模型对粮库内部的大空间气流组织的非稳定特性进行三维数值模拟,分别比较了集中辐射式分布和沿四壁周向式分布两种形式的粮食表面附近的截平面的速度和温度分布,模拟结果显示:采用集中辐射式分布的模型流场扰动范围大,换热效果好,温度场分布均匀,整体降温效果好.由此可以看出流体计算技术在研究空调换热空间速度场和温度场分布的巨大作用,为空调的设计运行参数提供了重要依据,从而可以选用换热效果更好的空调分布形式. 相似文献
19.
智慧节能工业园区（SEEIP）的核心企业能源配置对产业集群的循环经济节能降耗具有重要作用。针对SEEIP建设与既有工业园区核心企业能源系统的智慧化改造,提出一种基于信息和通信技术（ICT）的局域智慧能源网络框架,并给出了能源生产模块、能源转换模块与能源蓄存模块中各种能源介质及品位的能量计算数学模型。以经济成本与环境影响为目标的函数,给出了SEEIP企业能源网络系统配置的优化模型,并采用改进的差异演化算法（DE）结合数据库查询技术求解该混合整数非线性规划（MINLP）优化问题,给出企业能源系统最佳配置方案,以满足用户冷、热、电需求。 相似文献
20.
With the development of circulating fluidized bed boiler(CFB),the study field of external heat exchanger(EHE) is greater in extent and degree.In order to research the working process of EHE,the model which deals with flow and heat transfer of EHE for 300MW CFB of Dong Fang Boiler Grou PCo.Ltd.is presented.Based on the cell modeling theory,the EHE is divided into several chamber by heating surfaces.The mass and energy conservation equations of each cell have been developed according to some reasonable assumption.The complete mathematical model has been compiled by Fortran and solved by classical Algorithm of Runge-Kutta.The static test and perturbation experiment of simulating model has been performed.The simulation results show that the model has been reached the steady state rapidly,the dynamic responses are reasonable and the modeling presented in the paper is reliable and appropriate. 相似文献