油气比对燃气分析法燃烧效率、气态污染物测试精度的影响

Influence of air-fuel ratio on accuracy of combustion efficiency and exhaust emission under gas analysis method

在燃气分析单点测试偏差的基础上,针对燃气轮机、主燃烧室及加力燃烧室目前采用的取样方式的现状,建立了燃气分析法和流量法的油气比偏差对燃烧效率和气态污染物测试精度的影响规律。结果表明:对于采用移位机构进行测量的主燃烧室,流量法和燃气分析法油气比相差在5.1%以内时,说明有足够的测点密度,数据有效,此时的燃烧效率精度优于0.5%;对于加力燃烧室和整机测试,由于取样点不足,油气比偏差较大,燃烧效率的精度还取决于油气比和CO的体积分数。保证足够的取样点密度是燃气分析测试结果具有较高精度的前提。

Based on the gas analysis error of a single position,the influence law of the fuel-air ratio error between gas analysis and flow measurement on the testing precision of combustion efficiency and exhaust emission was founded for the current sampling mode of primary combustor,afterburner and gas turbine engine.The data were valid for primary combustor test by swing mode when fuel-air ratio error was less than 5.1% between flow measurement and gas analysis;meanwhile,the error of combustion efficiency was less than0.5% and sampling density was considered enough.The error of fuel-air ratio of flow measurement to gas analysis was large due to less sampling density in afterburner and gas turbine engine,the precision of combustion efficiency was also affected by fuel-air ratio and the volume fraction of CO.It indicates that enough sampling density for gas analysis is necessary for high test precision.