共查询到18条相似文献,搜索用时 156 毫秒
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分析了在高温蒸汽环境的条件下,通过红外辐射方式对转子表面温度进行测量的可行性及影响测量精度的各种因素。同时通过试验方式研究了高温蒸汽及石英视窗玻璃对单色、双色及宽波段红外测温精度的影响。研究表明,以红外辐射方式对高温蒸汽环境中的物体(转子)进行表面红外测温是基本可行的,其响应速度能满足热应力分析的需求;单/双波段测温方式各有其优缺点;红外石英视窗玻璃对红外能量透射的干扰可控制在能接受范围内。上述结论为利用红外测温技术对汽轮机转子表面进行直接温度测量奠定基础。 相似文献
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水雾遮蔽表面辐射测温问题的实验研究 总被引:1,自引:0,他引:1
在工业生产条件下,高温表面辐射测温方法的准确性常常受到参与性介质的影响.以连铸二冷区铸坯表面测温问题为背景,建立了一套水雾遮蔽表面辐射测温系统,进行了水雾对Raytek MRIS-B 单色/双色红外辐射测温仪测温影响的研究.不同温度水平下的测温实验表明,由于水雾介质的衰减作用,单色辐射测温仪的测量值比被测表面真实温度偏低,出现了负偏差,比色辐射测温仪的测量值比被测表面的真实值偏高,出现了正偏差;随着被测表面温度的升高,水雾对两种辐射测温仪的影响增大,测温仪的测量偏差增大;当被测表面温度一定时,水雾粒子数密度增大,由水雾引起的测量偏差增大.研究结果可为开发工业生产条件下在线辐射测温技术奠定基础,也可为工业生产过程中测温仪的选取提供理论依据. 相似文献
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汕头发电厂一台柴油发电机组的排气测温系统出现较大的误差,通过对 测温系统热量损失的计算与分析,找出了引起热电偶测温误差的主要原因,并用 红外辐射测温仪对热电偶测温误差进行了检验。在此基础上提出了修正方法。 相似文献
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热电偶测温和红外测温的比较研究 总被引:1,自引:0,他引:1
对两种常用的测温方式——热电偶测温和红外测温进行了比较研究,分别从测温原理、误差来源、校准方法等几方面来讨论,分析了各自的优、缺点及改进方向。 相似文献
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红外热像仪的最大测温误差分析 总被引:5,自引:0,他引:5
根据红外辐射理论和红外热像仪的测温原理,考虑环境,大气,太阳等多方面影响,得出最大测温误差的计算公式,通过分析各种因素对热像仪测温误差的影响程度,讨论了减小误差的对策。 相似文献
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提出了一种由光纤光谱仪与黑白CCD相机构成的新型实时在线高温温度场测量系统.该系统用光纤光谱仪和黑白CCD相机同时测得高温辐射源的真实发射率和光强场,然后根据发射率和光强场计算得到高温辐射源的温度场.利用该系统对高温发光物体——卤素灯灯丝的温度场进行测量,得到了不同电压值下卤素灯灯丝的温度场分布图,并将所得温度场的最高温度与相应工况下发射光谱法测量得到的最高温度进行比较.结果表明:两者相对偏差在5%以内;所提出的测量方法既弥补了发射光谱法不能获得场分布的缺陷,又避免了比色法测温中单色波长带宽和发射率瞬时变化带来的误差,是一种有效的温度场测量方法. 相似文献
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Y.H ZhouY.J Shen Z.M Zhang B.K TsaiD.P DeWitt 《International Journal of Heat and Mass Transfer》2002,45(9):1945-1949
Advances in microelectronics led to the development of rapid thermal processing (RTP). Accurate in situ temperature measurement and control are crucial for RTP furnaces to be largely accepted in the fabrication of semiconductor chips. This paper describes an effective emissivity model based on the Monte Carlo method to facilitate radiometric temperature measurements. The results showed that for non-diffuse wafers the “true” effective emissivity (defined in this paper) should be used, instead of the hemispherical effective emissivity, to correct thermometer readings. The geometric parameters and surface radiative properties can significantly influence the effective emissivity. The numerical aperture of the lightpipe radiation thermometer and the wafer-to-shield distance may be optimized to improve the measurement accuracy. 相似文献
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This paper presents preliminary measurements of a 2-stage axial turbine with shrouded rotor cavities. The research facility and measurement techniques are reported. The flow field at both inlet and outlet was measured using 5-hole probes as well as temperature probes. The measurement results indicate that the inlet flow field is periodical in the tangential direction due to the influence of the first-stator leading-edge. The horse-shoe vortexes cause substantial flow blockage and turbulence near the endwall. Unsteady measurements of the rotor radial tip clearance show that one of the second-rotor blades has a little bigger clearance than the others. 相似文献
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Measuring transient temperature of the medium in power engineering machines and installations 总被引:1,自引:0,他引:1
Under steady-state conditions when fluid temperature is constant, there is no damping and time lag and temperature measurement can be made with high accuracy. But when fluid temperature is varying rapidly as during start-up, quite appreciable differences occur between the true temperature and the measured temperature because of the time required for the transfer of heat to the thermocouple placed inside a heavy thermometer pocket. In this paper, two different techniques for determining transient fluid temperature based on the first and second order thermometer model are presented. The fluid temperature was determined using measured thermometer temperature, which is suddenly immersed into boiling water. To demonstrate the applicability of the presented method to actual data, the air temperature which changes in time, was calculated based on the temperature readings from the sheathed thermocouple. 相似文献
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600MW汽轮机转子冷态启动热应力计算与分析 总被引:8,自引:2,他引:6
利用差分法计算亚临界600MW汽轮机转子冷态启动过程中温度场和热应力场。通过对计算结果分析,提出了对运行的建议。文中公式可直接用在汽轮机转子热应力在线监控上,与有限元法比较,数据处理快,能满足快速控制的要求。 相似文献