Non-Intrusive Furnace Exhaust Gas Temperature Monitor

非侵入式熔炉废气温度监测仪

• 批准号: 9022383
• 负责人: Michael Frish
• 金额: $ 22.16万
• 依托单位: Physical Sciences Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-15 至 1994-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9022383&HistoricalAwards=false
• 关键词: Non; Intrusive; Furnace; Exhaust; Gas

Heat recovery in utility boilers is maximized when a particular temperature distribution within the furnace and its downstream heat recovery apparatus is maintained. This design temperature distribution provides the optimum balance between steam production by radiant heat transfer in the furnace section and steam reheating or superheating in the convective heat transfer section. When the temperature distribution deviates from its design condition, turbine efficiency declines either because: a) the steam production is too low due to insufficient heat absorption in the furnace; or, b) not enough sensible heat remains in the exhaust to superheat the steam (since too much heat is absorbed in the furnace). Off- design operation can also lead to tube overheating failures, ash deposition, and cold-end corrosion. This SBIR project continues the development and testing of a non-intrusive rapid-response instrument able to monitor ash particle temperatures in furnace exhaust gases. Because the particles are thermally equilibrated with the gas, the measurement is, in fact, an accurate representation of the local gas temperature. The instrument employs an innovative variation of two-color pyrometry to eliminate errors, associated with radiation from the primary combustion zone and boiler walls, which have confounded previous attempts to accurately measure exhaust gas temperatures. The prototype instrument will be coupled to a furnace control system and, after verification of proper operation, used to control and optimize one aspect of the combustion process. This will lead to increased plant efficiency. The instrument can also be used to control incinerator furnace temperatures, specifically to maintain them above 1700oF in order to minimize emission of toxic organics such as aromatic hydrocarbon or chlorinated dioxin/furans. Indirect benefits of the device include increased plant longevity, reduced pollutant emissions, and the extended lifetime of our finite fossil fuel resources. As part of this program, an instrument for calibrating furnace exhaust gas spectral signatures is also being built. This instrument will be useful for acquiring data needed to commercialize the temperature monitor.

当在炉膛及其下游热回收装置内保持特定的温度分布时，电站锅炉的热回收是最大的。这种设计温度分布提供了炉段辐射换热产生蒸汽和对流换热段蒸汽再加热或过热之间的最佳平衡。当温度分布偏离其设计条件时，汽轮机效率下降，原因是：a)由于炉膛内的热吸收不足，蒸汽产量太低；或b)排气中没有足够的显热余热来过热蒸汽(因为炉膛吸收了太多的热量)。非设计操作还可能导致管道过热故障、积灰和冷端腐蚀。该SBIR项目继续开发和测试一种非侵入性快速反应仪器，能够监测炉膛废气中的灰粒温度。由于颗粒与气体处于热平衡状态，测量结果实际上是局部气体温度的准确表示。该仪器采用了一种创新的双色测温方法，以消除与主燃区和锅炉壁上的辐射相关的误差，这些误差扰乱了以前准确测量废气温度的尝试。样机仪表将连接到炉膛控制系统，并在验证正确操作后，用于控制和优化燃烧过程的一个方面。这将导致工厂效率的提高。该仪器还可用于控制焚烧炉炉膛温度，特别是将其保持在1700oF以上，以便将芳香烃或氯化二恶英/呋喃等有毒有机物的排放降至最低。该装置的间接好处包括延长工厂寿命、减少污染物排放以及延长我们有限的化石燃料资源的寿命。作为这一计划的一部分，还在建造一台校准炉膛废气光谱特征的仪器。该仪器将有助于获取将温度监测器商业化所需的数据。