초록 ▼

The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from flow ratios and power levels determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air,

The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from flow ratios and power levels determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air, and flowed to a body of material (26, 52) which is heated to a temperature sufficient for oxidation of the gas mixture. The size of spaces in a first embodiment of a heater device (9, 11, 25, 26) and in a second embodiment of a heater device (50) are limited to prevent formation of an open flame. In a preferred "lean mixture" embodiment, the gas-air mixture of the reference gas, and the gas-air mixture of the sample gas, respectively, are each adjusted until a selected power level of combustion at a temperature lower than the point of stoichiometric combustion is reached. In a second, "rich mixture" embodiment, the gas-air mixture of the reference gas, and the gas-air mixture of the sample gas, respectively, are each adjusted from a "rich mixture" to reach a point of stoichiometric combustion. Based on flow rates and the selected power ratio, the heating value of the sample gas is calculated by the microcontroller (12) and output to a visual display or other output device.

대표청구항 ▼

[ We claim:] [1.] A method of measuring heating value of a combustible gas, the method comprising:heating a body of material to a temperature sufficient for combustion of the combustible gas and quenching any flame resulting from said combustion;flowing a first mixture of a reference gas having a kn

[ We claim:] [1.] A method of measuring heating value of a combustible gas, the method comprising:heating a body of material to a temperature sufficient for combustion of the combustible gas and quenching any flame resulting from said combustion;flowing a first mixture of a reference gas having a known heating value and a combustion supporting gas into contact with the heated body of material to cause combustion of the reference gas;varying the first mixture of the reference gas and the combustion supporting gas to obtain a changing combustion power;detecting at least one molar flow rate of the reference gas supplied to the first mixture and corresponding to a first occurrence of at least one selected combustion power level of the changing combustion power;flowing a second mixture of a sample gas and the combustion supporting gas into contact with the heated body of material to cause combustion of the sample gas;varying the second mixture of the sample gas and the combustion supporting gas to obtain a second occurrence of the changing combustion power;detecting at least one molar flow rate of the sample gas supplied to the second mixture and corresponding to a second occurrence of the selected combustion power level for said second occurrence of the changing combustion power; andcalculating the heating value of the sample gas in response to a ratio of the reference gas molar flow rate and the sample gas molar flow rate for the reference gas and the sample gas, respectively, and in response to the known heating value of the reference gas. [25.] An apparatus for determining the heating value of a sample combustible gas, the apparatus comprising:a heated body of material for combusting gas-air mixtures while quenching any flame;first flow means for varying the flow of a combustible gas, while flowing said combustible gas into contact with said heated body of material in a presence of a combustion supporting gas to cause oxidation of said combustible gas;second flow means for selectively flowing the combustible gas to said first flow means, said combustible gas including, at a first time, a reference combustible gas, and at a second time, a sample combustible gas;first sensing means for sensing combustion power levels for a changing combustion power of said combustible gas when said combustible gas is variably flowed into contact with said body of material;second sensing means for sensing at least one molar flow rate corresponding to at least one selected combustion power level first, for the reference combustible gas, and second, for the sample combustible gas; andmeans responsive to said first sensing means and to one molar flow rate sensed by said second sensing means for said reference combustible gas and said sample combustible gas, respectively, and to the known heating value of the reference combustible gas, for calculating the heating value of said sample combustible gas.