Graduate Program in Electrical Engineering, Federal University of Espirito Santo (UFES),Vitória 29075-910, Brazil.
Physics Department & I3N, University of Aveiro, 3810-193 Aveiro, Portugal.
Sensors (Basel). 2021 Oct 19;21(20):6922. doi: 10.3390/s21206922.
The assessment of heat transfer is a complex task, especially for operations in the oil and gas industry, due to the harsh and flammable workspace. In light of the limitations of conventional sensors in harsh environments, this paper presents a fiber Bragg grating (FBG)-based sensor for the assessment of the heat transfer rate (HTR) in different liquids. To better understand the phenomenon of heat distribution, a preliminary analysis is performed by constructing two similar scenarios: those with and without the thermal insulation of a styrofoam box. The results indicate the need for a minimum of thermal power to balance the generated heat with the thermal losses of the setup. In this minimum heat, the behavior of the thermal distribution changes from quadratic to linear. To assess such features, the estimation of the specific heat capacity and the thermal conductivity of water are performed from 3 W to 12 W, in 3 W steps, resulting in a specific heat of 1.144 cal/g °C and thermal conductivity of 0.5682 W/m °C. The calibration and validation of the HTR sensor is performed in a thermostatic bath. The method, based on the temperature slope relative to the time curve, allowed for the measurement of HTR in water and Kryo 51 oil, for different heat insertion configurations. For water, the HTR estimation was 308.782 W, which means an uncertainty of 2.8% with the reference value of the cooling power (300 W). In Kryo 51 oil, the estimated heat absorbed by the oil was 4.38 kW in heating and 718.14 kW in cooling.
传热评估是一项复杂的任务，特别是在石油和天然气行业的操作中，由于工作环境恶劣且易燃。鉴于传统传感器在恶劣环境中的局限性，本文提出了一种基于光纤布拉格光栅（FBG）的传感器，用于评估不同液体中的传热速率（HTR）。为了更好地理解热分布现象，通过构建两个类似的场景：有和没有泡沫盒隔热的场景，进行了初步分析。结果表明，需要最小的热功率来平衡产生的热量和装置的热损失。在这个最小热功率下，热分布的行为从二次变为线性。为了评估这些特征，从 3 W 到 12 W，以 3 W 的步长，对水的比热容和热导率进行了估计，结果为水的比热容为 1.144 cal/g °C，热导率为 0.5682 W/m °C。在恒温浴中对 HTR 传感器进行了校准和验证。该方法基于温度相对于时间曲线的斜率，可以测量水和 Kryo 51 油在不同的热插入配置下的 HTR。对于水，HTR 的估计值为 308.782 W，这意味着与冷却功率（300 W）的参考值相比，不确定度为 2.8%。在 Kryo 51 油中，油吸收的热量在加热时估计为 4.38 kW，在冷却时估计为 718.14 kW。
