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基于MC9S08DZ60单片机、K型热电偶和MAX31855冷端补偿热电偶至数字输出转换器设计分布式热电偶温度采集系统,实现多路热电偶温度的数据采集及处理。采集系统的分辨率为0.5℃,可进行热电偶的开路及短接等故障检测,具有较高的检测速度和精度。测试试验结果表明,设计的热电偶温度采集系统能够实现温度的实时检测,具有良好的稳定性,可满足实际应用的要求。 相似文献
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近几年来,热电偶的类型急聚增多,为了避免混乱,合理地进行使用,必须了解它的类型及其使用特性、测量范围等。热电偶通常按术语分为贵金属热电偶、廉金属热电偶、高温或难熔金属热电偶,对于它的使用特性和测量范围等都要根据实际需要测量的温度而定。一般地,测量0~1000℃内的温度,使用中温热电偶,测量1000℃以上的,使用高温热电偶。然而,在电池负极生产中所用电炉(一般为沟槽式感应立式电炉)的使用温度是400~500℃。 相似文献
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微热电偶的制作及测试误差分析 总被引:1,自引:0,他引:1
本文介绍了铜一康铜微热电偶(Φ0.2mm)的制作过程及其标定方法,采用最小二乘法对每个热电偶的标定曲线逐一进行了拟合,找出实际热电偶热电效应特征与通用分度表之间的差别。证明热电偶质量是可靠的。最后,结合实用情况,分析了应用这种热电偶进行温度场测试时,可能引起的误差大小。 相似文献
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为研究不同工况砾砂回填条件下土壤源热泵地理管换热器周围温度场的变化规律,通过自主设计的可模拟地下水渗流的砂箱试验台,以砾砂为回填材料,测试了多种工况下地埋管换热器周围的温度场,并利用Surfer软件绘制等温线。结果表明,饱和无渗流条件下,温度场呈圆形对称分布,随着热负荷的增加,温度场达到稳定的时间延长;稳定后的温度变化量增加;温度变化明显区域的范围增大。饱和有渗流条件下,温度场沿渗流方向向下偏移,随着渗流速度的增加,温度场达到稳定的时间缩短;上游各点达到稳定后的温度变化量减小,温度变化明显区域的范围缩小;下游各点达到稳定后的温度变化量先增大后减小,温度变化明显区域的范围扩大。研究成果提供了一种温度场测试的新方法。 相似文献
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通过历年我国钢铁企业、宝钢和首钢风温变化,反映了我国近年的风温现状和技术进步,特别指出了首钢风温的巨大进步。从热风炉高风温、热风管道输送高风温和高炉接受高风温三方面介绍了高风温技术研究进展。通过高风温技术在迁钢2号高炉的应用,首钢在2008年高风温试验基础上,2009年取得重大突破,实现日均风温最高1283℃,连续4月月均1270℃以上风温,年均风温为1258.7℃。通过分析2008和2009试验风温均匀性,表明风温均匀指数有所提高。并分析了热风炉炉顶温度、混风、空煤气预热温度、操作制度等风温影响因素,从高炉原燃料、技术指标和操作方面,阐述了高风温在高炉使用情况,反映了高风温受热风炉系统、热风管道和高炉等因素制约。提出了本次高风温试验存在的风温潜力、高风温节能作用和风温稳定性等问题,为进一步高风温研究提供指导。 相似文献
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Wei-Mon Yan Xiao-Dong Wang Sen-Sin Mei Xiao-Feng Peng Yi-Fan Guo Ay Su 《Journal of power sources》2008
Cell performance and pressure drop were experimentally investigated for two commercial size 16 cm × 16 cm serpentine flow field proton exchange membrane fuel cells with Core 5621 and Core 57 membrane electrode assemblies at various cell temperatures and humidification temperatures. At cell temperature lower than the humidification temperature, the cell performance improved as the cell temperature increased, while reversely at cell temperature higher than the humidification temperature. At a specified cell temperature, increasing the cathode and/or anode humidification temperature improved the cell performance, and their effects weakened as cell temperature decreased. The effects of the cell and the humidification temperature on the pressure drops were closely related to the reactant feed mode. For the constant stoichiometric flow rate mode, both cathode and anode pressure drops increased as humidification temperature and average current density increased. For the constant mass flow rate mode, both cathode and anode pressure drops increased as humidification temperature increased, while anode pressure drops decreased and cathode pressure drops increased as average current density increased. The optimal cell performance occurred at cell temperature of 65 °C and humidification temperature of 70 °C. The effects of these operating parameters on the cell performance and pressure drop were analyzed based on the catalytic activity, membrane hydration, and cathode flooding. 相似文献
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为研究混凝土在不同初始温湿度条件下内部温湿度的演化规律,通过预埋温湿度传感器和预处理产生不同温湿度分组试件及绝热、绝湿边界,同时结合加热板和恒温恒湿箱,使试件内部温度沿单一方向传导,从而监测混凝土内部等湿热传导过程中的温湿度演化规律。试验表明,混凝土内部湿度越大,温度响应速率越快,但湿度对最终稳定时试件内部的温度几乎无影响;混凝土内部湿度相同时,试件两侧温差越大,湿度响应速率越快,且变幅越大;此外,混凝土内部湿度迁移与温度传导存在耦合作用,湿度在温度驱动力和浓度梯度下发生迁移,同时湿迁移过程带走热能,能进一步促进温度传导。 相似文献
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Deterioration in heat transfer of endothermal hydrocarbon fuel 总被引:5,自引:0,他引:5
Numerical studies under supercritical pressure are carried out to study the heat transfer characteristics in a single-root coolant channel of the active regenerative cooling system of the scramjet engine, using actual physical properties of pentane. The relationships between wall temperature and inlet temperature, mass flow rate, wall heat flux, inlet pressure, as well as center stream temperature are obtained. The results suggest that the heat transfer deterioration occurs when the fuel temperature approaches the pseudo-critical temperature, and the wall temperature increases rapidly and heat transfer coefficient decreases sharply. The decrease of wall heat flux, as well as the increase of mass flow rate and inlet pressure makes the starting point of the heat transfer deterioration and the peak point of the wall temperature move backward. The wall temperature increment induced by heat transfer deterioration decreases, which could reduce the severity of the heat transfer deterioration. The relational expression of the heat transfer deterioration critical heat flux derives from the relationship of the mass flow rate and the inlet pressure. 相似文献
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应用模糊控制技术,将土壤源热泵的两个水系统看成一个整体,以房间设定温度与实际温度的误差、冷却水侧供回水温差与设定温差的误差为输入参数,直接控制循环水泵的输入电流功率,进而控制水泵转速。避免了阀门开度变化引起的管网系统特性变化,最大程度地节省系统运行能耗。 相似文献
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为探究常温注水井对水源热泵热贯通现象的影响,利用FlowHeat1.0软件模拟了3组情景下含水层渗流场、温度场时空分布特征,并分析了常温注水井对含水层热贯通的影响机理和抽水井水温变化规律。结果表明,常温注水井通过减小回灌井、常温注水井之间的水力坡度和延长地下水渗透途径的方式达到缓解热贯通的效果;回灌井、常温注水井流量比相同时,常温注水井在抽灌井连线的位置对含水层热贯通的影响小;抽灌量不变时,常温注水井与回灌井的流量比越大,常温注水井缓解热贯通的效果越明显;在有利地下水回灌的水源热泵系统中,布设常温注水井能有效地降低含水层热贯通程度。 相似文献
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Juan-Luis Domenech-Garret 《Solar Energy》2011,85(2):256-264
The aim of this work is to show the effects in a PV cell of the combined profiles of non-uniform temperature and radiation. Particular attention is paid to the modelling of cell operation at open circuit voltage with those profiles, as long as they serve as a general model in different circumstances: combined direct Gaussian temperature and radiation profiles, with several temperature amplitudes and movement of these profiles across the cell; analysis under Gaussian concentrated illumination and inverse Gaussian temperature profile simulating a general cell cooling device. In addition, we will study the cell behaviour under truncated radiation and temperature profiles. Irregular radiation and temperature distributions will also be studied. 相似文献