分布式光纤测温技术及其在稠油开采中的应用

分布式光纤测温技术利用光纤后向喇曼散射光谱的温度效应和光时域反射技术实现温度测量,它是一种利用既是传输介质,又是传感介质的光纤进行实时测量空间温度场分布的传感系统。文章介绍了分布式光纤测温系统进行井温测量的工作原理、系统构成及在稠油注蒸汽井中进行测量的测试工艺和现场应用。该系统具有良好的测量精度和分辨率,可以在不影响温度场原始分布的情况下实现实时快速的测量。     

锦45块Ⅱ类稠油蒸汽驱先导试验区光纤测温技术的应用

分布式光纤测温技术利用光纤后向喇曼散射光谱的温度效应和光时域反射技术实现温度测量,它是一种利用既是传输介质,又是传感介质的光纤进行实时测量空间温度场分布的传感系统.文章介绍了分布式光纤测温系统进行井温测量的工作原理、系统构成及在稠油热采井中进行测量的测试工艺和现场应用.该系统具有良好的测量精度和分辫率,可以在不影响温度场原始分布的情况下实现实时快速的测量.     

分布式感温光纤测温原理及其在油罐上的应用

油库罐区储备量越来越大,导致罐区火灾事故频发,基于此提出了分布式感温光纤火灾报警系统在罐区的应用,介绍感温光纤测温原理,以实际工程项目为例,表明分布式感温光纤火灾报警系统在油罐上应用的可行性和有效性。     

分布式光纤测温系统在管道泄漏检测中的应用

管道运输是我国能源存储领域的一种重要方式,采用有效方式进行管道泄漏检测是保障管道安全运行的重要保障。文中阐述了分布式光纤测温系统监测管道泄漏的工作原理:光的散射和光时域反射定位;分析了不同功能运输管道光纤的安装工艺方式:缠绕、双层布置、内置和外置等;列举了光纤测温系统在管道测漏实际工程中的应用案例。分析认为,分布式光纤测温系统具有检测距离长、成本低、操作简单和实时监测等特点,在管道运输泄漏检测的实际工程应用中具有技术可行性。     

分布式光纤传感技术在集油系统工程中的应用

本文就分布式光纤传感技术在塔里木油田分公司某集油系统工程中的应用基础上,分析了油气工程中的周界防范和集油管道全天候实时安全监测的需求,分析分布式光纤系统结构原理和应用,将应用效果与传统技术对比,验证了分布式光纤传感系统在油气工程周界防范与管线测温方面的优势。结论认为,分布式光纤传感系统运行稳定,可靠性高,能有效对油气工程周界情况,集油管道工况进行实时监控,降低了运行过程中的安全及环保风险。     

基于分布式光纤温度传感技术的油气储罐火灾监测系统的应用实践

本文介绍了分布式光纤温度传感开发意义和工作原理,不仅对油罐安全生产提供了技术保障、提升了数字化水平,同时技术本身采取无电测量,防电磁感应、抗干扰能力强,在实际生产应用体现出极大的技术和安全优势。     

浅谈分布式光纤感温线预警系统新技术在变电站中的应用

分布式光纤温度传感系统是一种利用激光在光纤中传输时产生的背向喇曼散射信号和光时域反射原理来获取空间温度分布信息的监控系统,其核心技术采用了先进的激光、电子技术、高速DSP数据处理技术和先进的WDM光学波分技术及卫星拍照数字处理等技术。本文结合目前日益发展的电力系统建设以及对其越来越高的技术、信息方面的要求,浅述一下分布式光纤感温在线预警系统在变电站中的应用。     

分布式光纤压裂监测技术应用及效果分析

分布式光纤测量技术近年来逐步应用到油田开发中，通过全井筒的实时连续状态监测，实现研判产层压裂监测效果、产液量及流体性质，准确分析井筒生产状况，成为评价生产井生产动态的新方法新技术。分布式光纤利用下入井筒的光纤，以实时、全井段、长时间监测的方式，测量整个井筒温度场变化来监测井筒的动态生产状况，其实时监测的优势，远优于常规测井方式。在此介绍了分布式光纤测温原理和解释原理，研究了生产井的测温测量方法及解释流程。基于压力和温度数据，采用解释模型对压裂监测实测光纤数据进行处理评价，以及与油藏地质情况进行对比分析，试验结果验证了分布式光纤在产液剖面压裂监测方面的适用性和技术优势，试验中形成的苏里格地区一套分布式光纤测温解释流程和方案，助力油田公司实时优化调整开发方案，实现增产上产。     

用于承压构件的在线光纤监测技术研究

分析了分布式光纤检测系统和光纤光栅检测系统在实验室材料疲劳试验中的应用。基于光纤在线监测的试验研究,分析了该方法的优缺点,提出了应用于在役压力容器和工业管道系统的光纤监测实施方法。     

油井产液分布式光纤声波传感监测的应用与研究进展

掌握井下产液状况是实施精准生产调控的关键,分布式光纤声波传感技术是一种实时、高效的产液监测新技术。本文从分布式光纤声波传感技术工作原理出发,介绍并讨论了基于分布式光纤声波传感数据的油井产液分析和机器学习的最新进展,同时指出了各种方法的局限性和研究的热点问题,为分布式光纤声波传感技术在我国油井产液监测中的应用提供技术参考。     

Preparation,luminescence properties,and application of temperature sensing and anti-counterfeiting of La2MgTiO6:Yb3+/Ln3+/Mn4+

The doping of transition metal ions in the up-conversion (UC) luminescent material doped with Yb³⁺/Ln³⁺ is a facile way to increase their UC luminescence intensities and alter their colors. In this study, La₂MgTiO₆:Yb³⁺/Mn⁴⁺/Ln³⁺ (Ln³⁺ = Er³⁺, Ho³⁺, and Tm³⁺) phosphors showing excellent luminescence properties were prepared by a solid-state method. The sensitivity of the La₂MgTiO₆:Yb³⁺/Ln³⁺/Mn⁴⁺ phosphor was double that without Mn⁴⁺, because Mn⁴⁺ affects the UC emissions of Ln³⁺ via energy transfer between these ions. Moreover, Mn⁴⁺ also acts as a down-conversion activator, which can combine with UC ions to achieve multi-mode luminescence at different wavelengths. Under 980 nm excitation, these samples emit green light (from Er³⁺ and Ho³⁺) and blue light (from Tm³⁺). In contrast, under 365 nm excitation, they emit red light (from Mn⁴⁺). Further testing revealed that the La₂MgTiO₆:Yb³⁺/Mn⁴⁺/Ln³⁺ phosphors have potential applications in temperature sensing and anti-counterfeiting.     

用于发光温度传感的金属有机框架材料

金属有机框架(Metal organic frameworks,MOFs)由于其显著的结构多样性和可调的发光性能,为制备不同种类的发光传感器提供了良好契机。近年来,利用发光MOFs探测温度传感技术受到了人们的广泛关注。结合对发光测温的描述后,总结了发光型MOF温度计的最新研究进展,重点介绍了双发射型MOF在温度传感领域中的广泛应用。     

High-temperature persistent luminescence and visual dual-emitting optical temperature sensing in self-activated CaNb2O6: Tb3+ phosphor

The long persistent luminescence (PersL) and color adjustable properties in high-temperature environment are of great significance for luminescent materials in the fields of multiple anti-counterfeiting, biological imaging, and optical temperature sensing (OTS). In this work, a series of self-activated CaNb₂O₆ (CNO): Tb³⁺ phosphors have been successfully synthesized by solid-state reaction route, the OTS, and temperature-dependent PersL of these phosphors is carried out and investigated in detail. Relying on the energy transfer from host to the activator Tb³⁺ ion, the visual color-tunable emissions from blue to green were detected with the increase of temperature and the maximum absolute and relative sensitivities reach 0.955% K^-1 and 1.243% K^-1. Moreover, the temperature-dependent PersL characteristics were investigated systematically, and the initial brightness and the lasting time all reach a maximum value at 323 K in the representative CNO: 1%Tb³⁺ sample. All the results show that the high-temperature persistent phosphor has potential applications in OTS and anti-counterfeiting field.     

Multicolor upconversion emission and highly optical temperature sensing based on lanthanide-doped double perovskite Sr2LaNbO6 phosphors

Here we adopt trivalent lanthanide (Ln³⁺ = Er³⁺, Er³⁺/Ho³⁺, and Yb³⁺/Tm³⁺) doped Sr₂LaNbO₆ (SLNO) as novel upconversion luminescence (UCL) materials for achieving UCL and optical temperature sensing under 980 nm excitation. Specifically, Er³⁺ single doped Sr₂LaNbO₆ phosphors present bright high-purity green emission under the 980 nm excitation. While co-doping with the Ho³⁺ ions, the component of red emission from Er³⁺ ions increases significantly and sample show a remarkable enhancement of luminescent intensity relative to SLNO:Er³⁺ sample. The above-mentioned phosphors and Yb³⁺/Tm³⁺ co-doped phosphor (blue emission) successfully achieve high-purity trichromatic UCL and mixed white light output in the same host. Furthermore, the temperature sensing performance of the SLNO:Er³⁺/Ho³⁺ phosphor based on the fluorescence intensity ratio (FIR) is systematically studied for the first time. The temperature sensing based on the non-thermal coupling levels (NTCLs) exhibit higher sensitivity than that based on the thermal coupling levels (TCLs). The maximum absolute and relative sensitivity for ⁴F_9/2/⁴I_9/2 NTCLs reach 0.16803 K^?1 at 427 K and 0.01591 K^?1 at 641 K, respectively. Interestingly, NIR emission of ⁴I_9/2 → ⁴I_15/2 transition presents a thermal enhancement, while visible emissions show thermal quenching. These results indicate that the Ln³⁺ doped Sr₂LaNbO₆ UCL phosphors have potential applications in the fields of non-contact temperature sensors, full-color displays, and anti-counterfeiting.     

Adverse effect of substrate surface impurities on O2 sensing properties of TiO2 gas sensor operating at high temperature

It is well known that surface state of substrates greatly influences the sensing characteristics of gas sensors. In this work, alumina (Al₂O₃) substrates with different distribution of surface impurity concentrations were utilized to prepare TiO₂ based lambda sensors. Several methods, including XPS, XRD and SEM were employed to exam the substrate surface impurity contents, as well as the structure of the sensing films and the interface morphology between the substrates and sensing films. The results indicated that the gas sensors prepared on alumina substrates containing higher Ca impurities displayed lower oxygen sensitivities and longer response times at high operating temperatures above 600 °C. Therefore, it was concluded that Ca impurities on alumina substrates had to be limited to lower possible levels when fabricating TiO₂ lambda sensors.     

Photoluminescence and optical temperature sensing in Sm3+-doped Ba0.85Ca0.15Ti0.90Zr0.10O3 lead-free ceramics

A series of orange-red emitting Sm³⁺ activated Ba_0.85Ca_0.15Ti_0.90Zr_0.10O₃ (BCZT: xSm³⁺, x?=?0.001–0.007) are synthesized by a conventional solid-state reaction method. The Sm³⁺ ions composition dependent photoluminescence properties are systematically investigated. Under the excitation of a 407?nm near-ultraviolet light, the ceramics exhibit strong characteristic emission of Sm³⁺ ions with dominant orange-red emission peak at around 595?nm, which is ascribed to the transition of ⁴G_5/2 → ⁶H_7/2. The BCZT: 0.004Sm³⁺ ceramic displays the optimal emission among these Sm³⁺-doped BCZT solid solutions. Moreover, the photoluminescence intensity exhibits extremely sensitive to temperature, suggesting that BCZT: 0.004Sm³⁺ could be applicable for temperature sensing. A maximum relative sensitivity of 1.89%?K^?1 at 453?K is obtained. Furthermore, the existence of ferroelectricity in the BCZT host combined with Sm³⁺ activated photoluminescence properties could be useful for developing optical-electro multifunctional materials and devices.     

Polyacrylonitrile‐carbon Nanotube‐polyacrylonitrile: A Versatile Robust Platform for Flexible Multifunctional Electronic Devices in Medical Applications

Flexible multifunctional electronic devices are of high interest for a wide range of applications including thermal therapy and respiratory devices in medical treatment, safety equipment, and structural health monitoring systems. This paper reports a scalable and efficient strategy of manufacturing a polyacrylonitrile‐carbon nanotube‐polyacrylonitrile (PAN‐CNT‐PAN) robust flexible platform for multifunctional electronic devices including flexible heaters, temperature sensors, and flexible thermal flow sensors. The key advantages of this platform include low cost, porosity, mechanical robustness, and electrical stability under mechanical bending, enabling the development of fast‐response flexible heaters with a response time of ≈1.5 s and relaxation time of ≈1.7 s. The temperature‐sensing functionality is also investigated with a range of temperature coefficient of resistances from ?650 to ?900 ppm K^?1. A flexible hot‐film sensing concept is successfully demonstrated using PAN‐CNT‐PAN with a high sensitivity of 340 mV (m s^?1)^?1. The sensitivity enhancement of 50% W^?1 is also observed with increasing supply power. The low cost, porosity, versatile, and robust properties of the proposed platform will enable the development of multifunctional electronic devices for numerous applications such as flexible thermal management, temperature stabilization in industrial processing, temperature sensing, and flexible/wearable devices for human healthcare applications.     

Y4.67Si3O13-based phosphors: Structure,morphology and upconversion luminescence for optical thermometry

How to improve the sensitivity of the temperature-sensing luminescent materials is one of the most important objects currently. In this work, to obtain high sensitivity and learn the corresponding mechanism, the rare earth (RE) ions doped Y_4.67Si₃O₁₃ (YS) phosphors were developed by solid-state reaction. The phase purity, structure, morphology and luminescence characteristics were evaluated by XRD, TEM, emission spectra, etc. The change of the optical bandgaps between the host and RE-doped phosphors was found, agreeing with the calculation results based on density-functional theory. The temperature-dependence of the upconversion (UC) luminescence revealed that a linear relationship exists between the fluorescence intensity ratio of Ho³⁺ and temperature. The theoretical resolution was evaluated. High absolute (0.083 K⁻¹) and relative (3.53% K⁻¹ at 293 K) sensitivities have been gained in the YS:1%Ho³⁺, 10%Yb³⁺. The effect of the Yb³⁺ doping concentration and pump power on the sensitivities was discussed. The pump-power–dependence of the UC luminescence indicated the main mechanism for high sensitivities in the YS:1%Ho³⁺, 10%Yb³⁺. Moreover, the decay-lifetime based temperature sensing was also evaluated. The above results imply that the present phosphors could be promising candidates for temperature sensors, and the proposed strategies are instructive in exploring other new temperature sensing luminescent materials.     

Bi-material strip based temperature sensor design and optimization through thermo-mechanical multi-physics modeling

ABSTRACT

With the capability of additive manufacturing, complex structures are easily fabricated to achieve various design purposes. In this work, a bi-material strip temperature sensor with complex periodic pattern design is purposed and investigated through both the analytical modeling and multi-physics finite element analysis. Three design patterns are considered: standard, E-shape and S-shape. In the standard solid strip design, the curvature of the bi-material strip under temperature variation is in a linear relationship with the coefficient of thermal expansion (CTE) difference, but in a reciprocal relationship with the strip thickness. The curvature of the bi-material strip depends on the Young’s modulus ratio and layer thickness ratio of the two materials, but is independent of the magnitude of the materials’ Young’s modulus. Based on analytical derivation and numerical validation, the optimized design parameters can be provided. Compared to S-shape pattern design, E-shape pattern design can significantly increase the temperature sensitivity of the bi-material strip. An analytical prediction of the E-shape pattern’s temperature sensitivity is introduced and discussed. This work proves the concept that new design space becomes available with the capability of additive manufacturing, and provides the general design guideline for a bi-material strip based temperature sensor with possible design patterns.     

Ho3+-doped (K,Na)NbO3-based multifunctional transparent ceramics with superior optical temperature sensing performance

Ho³⁺-doped (K_0.5Na_0.5)NbO₃-based transparent ceramics have been prepared via pressureless solid-state method. The ceramics possess moderate optical transparency with the energy band gap of ~2.9 eV and submicron-sized grains (<500 nm). The temperature-dependent dielectric properties and ferroelectric polarization-electric field hysteresis loops demonstrate that the ceramics own relaxor-like characteristics. The up-conversion photoluminescence and optical temperature sensing properties of the ceramics have been investigated. The temperature dependence of photoluminescence provides a fluorescent method to detect phase transitions, which can be expanded to other ferroelectric systems. The outstanding optical temperature sensitivity (~0.0075/K at 430 K) of the ceramic is higher than many other rare-earth-doped ceramics or glasses. These results suggest that the Ho³⁺-doped (K_0.5Na_0.5)NbO₃-based transparent ceramics are promising lead-free transparent materials for multifunctional applications, especially in temperature sensing devices.