Characterization of Particle and Heat Losses From Falling Particle Receivers
Characterization of Particle and Heat Losses From Falling Particle Receivers
复制标题
下落颗粒接收器的颗粒和热损失的表征
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Vanderlei Martins
中科院分区：
文献类型：
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作者：
C. Ho;Sean M. Kinahan;Jesus D. Ortega;P. Vorobieff;A. Mammoli;Vanderlei Martins
评估了基于相机的成像方法，以量化高温颗粒接收器孔径的颗粒和对流热损失。建立了现场测试的太阳粒子接收器的实验模型，并使用该模型记录了粒子的速度和温度。在熔炉中加热到700°C以上的颗粒从槽孔中释放出来，并允许它们穿过相机拍摄的区域。比较了粒子图像、粒子跟踪和图像相关测速方法，确定了获得粒子速度的最佳方法。利用高速红外摄像机测量颗粒温度，建立了颗粒和对流热损失模型。此外，在日光下对颗粒接收器进行现场测试时，部署了颗粒取样仪器，以确定是否正在产生可能造成吸入危险的小颗粒。结果表明，虽然在测试期间有一些可记录的排放，但测量到的颗粒浓度远低于可接受的15毫克/立方米的健康标准。还进行了额外的实验，以量化颗粒在连续震动和下落过程中形成的颗粒。在两个尺寸范围（< ~ 1微米和~ 8-10微米）的小颗粒的连续形成被观察到，分别是由于颗粒碰撞过程中的去团聚和机械破裂。
Camera-based imaging methods were evaluated to quantify both particle and convective heat losses from the aperture of a high-temperature particle receiver. A bench-scale model of a field-tested on-sun particle receiver was built, and particle velocities and temperatures were recorded using the small-scale model. Particles heated to over 700 °C in a furnace were released from a slot aperture and allowed to fall through a region that was imaged by the cameras. Particle-image, particle-tracking, and image-correlation velocimetry methods were compared against one another to determine the best method to obtain particle velocities. A high-speed infrared camera was used to evaluate particle temperatures, and a model was developed to determine particle and convective heat losses. In addition, particle sampling instruments were deployed during on-sun field tests of the particle receiver to determine if small particles were being generated that can pose an inhalation hazard. Results showed that while there were some recordable emissions during the tests, the measured particle concentrations were much lower than the acceptable health standard of 15 mg/m3. Additional bench-scale tests were performed to quantify the formation of particles during continuous shaking and dropping of the particles. Continuous formation of small particles in two size ranges (< ∼1 microns and between ∼8–10 microns) were observed due to de-agglomeration and mechanical fracturing, respectively, during particle collisions.