Collaborative Research: Development of Diagnostic Tools for High Temperature Fluidized Beds

本研究涉及高温流化床诊断工具的设计、开发和校准。一种耐磨热流密度传感器将用于测量高温流化床与浸入表面之间的局部热流密度。将开发一种光学探针来探测高温床中局部气泡的存在。光学探针将用于测量气泡大小分布、气泡上升速度和体积气泡分数。该装置研制完成后，将用于了解高温流化床在各种工况下的传热情况。高硫煤和其他固体燃料的流化床燃烧技术的发展受到了广泛的关注，因为该技术的硫排放很容易达到空气质量标准。流化床燃烧器在燃料类型方面也具有灵活性的优点，因为它们可以设计成燃烧几种不同类型的燃料。大多数以前的研究的瞬时局部床到表面的传热测量仅限于近室温条件下。提高我们对流化床的认识需要对高温现象进行实验表征。本项目将提供实验设备和数据，以满足这一总体目标。

This research addresses the design, development and calibration of diagnostic tools for high temperature fluidized beds. An abrasion- resistant heat flux transducer will be used to measure the local heat flux between a high temperature fluidized bed and an immersed surface. An optical probe will be developed to detect the local presence of bubbles in high temperature beds. The optical probe will be used to measure the bubble size distribution, bubble rise speed, and volumetric bubble fraction. After the devices have been developed and calibrated, they will be used to understand the heat transfer in high temperature fluidized beds under a variety of operating conditions. Considerable attention has been devoted to the development of fluidized bed combustion processes for high sulfur coal and other solid fuels since the sulfur emissions from this technology can easily meet the air quality standards. Fluidized bed combustors also have the advantage of flexibility in regard to fuel type because they can be designed to burn several different types of fuels. Most of the previous studies of instantaneous local bed-to-surface heat transfer measurements are restricted to near room temperature conditions. The advancement of our understanding of fluidized beds requires the experimental characterization of the high temperature phenomena. This project will provide the experimental devices and data to meet this overall objective.