Improving the Quality of Thermocouple Wire Made of Platinum-rhodium Alloys

For the manufacture of S-type thermocouple the so-called thermocouple wire of platinum and platinum-rhodium alloy is used.One of the main technical requirements for the quality of the wire,according to State Standard of Russia(GOST 10821),is the uniformity of its largest thermoelectric force(Thermo-emf) in the length different sections.It was found that a determining impact on the uniformity of the wire thermo-emf is the distribution of rhodium along the length of the wire.The impact of platinum-rhodium melt crystallization conditions on the inhomogeneity of wire manufactured from it.It was suggested that the chemical inhomogeneity of the wire is related to the liquation phase of platinum-rhodium alloy.     

WC-Co涂层磨削过程中的温度与相变

针对WC-Co涂层在磨削中磨削温度会引起相变,进而导致磨削缺陷的问题,以DMU70V数控铣床为平台进行WC-Co涂层磨削实验,利用K型热电偶和DGF40N光纤式红外测温仪测量磨削温度,借助x-射线衍射仪分析磨削前后WC-Co涂层物相组成.实验结果表明,利用热电偶测得的磨削温度与根据磨削过程中WC-Co涂层物质相变推测得到的磨削温度相差较大,利用WC-Co涂层物质相变推测的磨削最高温度与DGF40N光纤式红外测温仪测得的磨削最高温度一致,说明可以利用WC-Co涂层物质相变来推测磨削最高温度,为一些不能直接测量磨削温度的场合提供了新方法.WC晶粒在WC-Co涂层干磨削时大多异质生核,磨削后产生的WC晶粒粒度大,从而导致WC-Co涂层的强度下降,WC-Co涂层不宜干磨削.     

基于USB-4716的工业热电偶自动检定系统设计

针对工业中常用的温度采集、处理系统的分析,利用USB-4716数据采集模块对热电偶检定过程中加热炉温度进行采集和处理,通过对热电偶锌、铜和铝3个检定点热电动势的采集和误差分析,判定被检热电偶是否合格,进而给出检定报表。整个过程结合计算机控制技术,实现了热电偶自动检定、数据存储、报表打印以及历史记录查询等功能。     

节能技术在精馏系统中的应用

能源问题始终困扰着石化行业,因此节能还是主要旋律。精馏依然是物系分离的耗能大户,改进精馏设备和精馏流程还是重中之重。文章主要介绍几种新型的精馏流程,并简要描述它们在一些体系中的应用。     

The Researches on Performance and Technology of Strengthened Pure Platinum Wire

This paper discusses about the purity of strengthened pure platinum wire and the development method of platinum micro wire, in order to solve the difficulties of low tensile strength, easy to break, and low rate of micro wire. And it contrasts some performance of strengthened pure platinum wire and sponge Pt wire. The researches draw a conclusion that the thermoelectric properties of strengthened pure platinum micro wire was in accordance with national standards and satisfied users’ requirements.     

THERMOCOUPLE USED FOR TEMPERATURE MEASUREMENT OF ALUMINIUM CELLS BY DYNAMIC METHOD

ＴＨＥＲＭＯＣＯＵＰＬＥＵＳＥＤＦＯＲＴＥＭＰＥＲＡＴＵＲＥＭＥＡＳＵＲＥＭＥＮＴＯＦＡＬＵＭＩＮＩＵＭＣＥＬＬＳＢＹＤＹＮＡＭＩＣＭＥＴＨＯＤ￥Ｙｕ，Ｘｕｅｂｉｎ（ＩｎｓｔｉｔｕｔｅｏｆＣｏｍｐｏｓｉｔｅＭａｔｅｒｉａｌ，ＪｉａｏＴｏｎｇＵｎｉｖｅ...     

浅谈铂铑热电偶测温准确性的影响因素

贵金属热电偶具有优良的测温性能。综述了热电偶的制作和使用过程中影响测温准确性的主要因素。在生产过程中要保证原料的纯度,避免杂质污染,控制热电偶不均与热电势;熔炼过程中,合理的浇铸温度、设备和工艺条件能降低热电势的不均匀性。热电偶使用前应充分退火,消除其加工应力产生的晶格畸变;良好的使用环境和必要的避潮保存条件能延长热电偶使用寿命。     

Correct shielding gas selection in dual wire GMAW

K-type thermocouples are fabricated using a chromel wire and an alumel wire of 50 m by the non-contact discharge welding method. The welding is carried out at six different butt angles. The size of the hot junction tends to decrease with an increase in butt angle, when the butt angle is larger than 1.4 rad. The response rate is measured and it is almost proportional to the reciprocal of the size of the hot junction. It is shown that the size of the hot junction is an important factor for the response rate. Wire diameter is another important factor for temperature measurement of small objects. When temperature is measured at the same point by a thermocouple under the conditions that only the hot junction and its vicinity are heated, the output of electromotive force, i.e. indicated temperature, will depend on the wire diameter. As the metal wire is a good thermal conductor and the rate of heat transport is proportional to the area of the wire cross section, deviation from the true value increases with an increase in wire diameter. Our experiments showed that the indicated temperature decreased linearly with the wire diameter. Furthermore, we measured the discharge voltage and current at various setting currents and discharge gaps.     

大力神130型焦炉煤气燃气轮机T5热电偶故障原因分析

大力神130型焦炉煤气燃气轮机点火升速期间出现AL_T5_TC_Fail（T5热电偶故障）报警、CL_5_TC_Fail（多个E热电偶故障）并且导致停机。对各个相关系统进行检查分析,提出解决办法。最终发现该故障原因为部分喷嘴堵塞,故障检查可为同类机组提供参考。     

热电偶在天然气净化厂中的应用问题及处理技巧

主要论述了热电偶在忠县天然气净化厂应用过程中出现的主要问题,通过分析问题产生的原因,提出了相应的解决措施,以提高热电偶测温的可靠性、稳定性,从而确保天然气净化装置的平稳运行。