New experimental results for lean flammability limits (LFLs) of syngas/air (H₂/CO/air) mixtures have been obtained at temperatures up to 200 °C and pressures up to 9 bar. ASTM Standard E918 (1983) provided the framework for tests at these elevated conditions, using a 1-L pressure-rated test cylinder in which the fuel–air mixtures were prepared and then ignited. The purpose for characterizing the flammability limits for these gaseous mixtures is to facilitate development of appropriate procedures for the safe industrial use of syngas, which contains large quantities of hydrogen and carbon monoxide gas. The LFLs for each gas mixture are found to decrease linearly with increasing temperature at all test pressures. The LFL results at atmospheric pressure are consistent with previous flammability studies, while those at elevated pressures represent new flammability data. An increase in the initial test pressure results in an increase of the LFLs for each test mixture, which also serves to address the lack of syngas/air flammability data at elevated pressures. An empirical formula is derived that allows for the calculation of the LFLs of all syngas/air test mixtures in the temperature and pressure range of the current study in an effort to promote the ease of use in practical applications. Predicted LFL values obtained using Le Chatelier’s mixing rule and an appropriate choice for the lower flammability limit of pure carbon monoxide are consistent with the experimentally determined values near ambient conditions of temperature and pressure.

中文翻译：

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在升高的温度和压力下合成气/空气混合物的贫燃极限

合成气/空气（H ₂）的稀薄燃烧极限（LFL）的新实验结果/ CO /空气）混合物已在最高200°C的温度和最高9 bar的压力下获得。ASTM E918标准（1983）提供了在这些升高的条件下进行测试的框架，使用的是1升耐压试验气缸，在其中准备了燃料-空气混合物，然后将其点燃。表征这些气态混合物的可燃性极限的目的是促进开发适用于安全工业使用合成气的程序，该合成气包含大量的氢气和一氧化碳气体。在每种测试压力下，发现每种气体混合物的LFL随着温度的升高呈线性下降。在大气压下的LFL结果与以前的可燃性研究一致，而在高压下的LFL结果代表了新的可燃性数据。初始测试压力的增加导致每种测试混合物的LFL升高，这还可以解决在高压下合成气/空气可燃性数据不足的问题。得出了一个经验公式，该公式可以计算当前研究的温度和压力范围内所有合成气/空气测试混合物的LFL，以努力促进在实际应用中的易用性。使用勒夏特列混合规则和用于纯一氧化碳的可燃下限的适当选择而获得的预测LFL值与邻近的温度和压力的环境条件下的实验确定的值一致。得出了一个经验公式，该公式可以计算当前研究的温度和压力范围内所有合成气/空气测试混合物的LFL，以努力促进在实际应用中的易用性。使用勒夏特列混合规则和用于纯一氧化碳的可燃下限的适当选择而获得的预测LFL值与邻近的温度和压力的环境条件下的实验确定的值一致。得出了一个经验公式，该公式可以计算当前研究的温度和压力范围内所有合成气/空气测试混合物的LFL，以努力促进在实际应用中的易用性。使用勒夏特列混合规则和用于纯一氧化碳的可燃下限的适当选择而获得的预测LFL值与邻近的温度和压力的环境条件下的实验确定的值一致。