Direct sampling of engine emissions for instantaneous analysis
First Claim
1. A method of on-line gas analysis of a multicomponent gas emission flow comprising gas species, comprising:
- (a) continuously withdrawing a first sample flow from said gas emission flow and regulating the first sample flow pressure;
(b) continuously withdrawing a second sample flow from said first sample flow, said second sample flow being diluted with mass controlled amounts of diluent to lower the dew point of the second sample flow to below room temperature;
(c) controlling the absolute pressure of said diluted second sample to the range of 920-950 mbar;
(d) frequently periodically analyzing the diluted second sample flow, controlled as to pressure, by fourier-transform infrared spectrometric techniques to render a concentration measure for one or more of said gas species and carbon in such species; and
(e) correcting said one or more concentration measures for dilution to derive an undiluted concentration measure, said correction being accomplished by measuring the actual air/fuel ratio used to provide the gas emission flow, such actual A/F measurement being used to provide a theoretical carbon concentration for each said undiluted concentration measure and thereafter ratioing said theoretical carbon concentration to said carbon concentration measure for said ne or more gas species to provide a correction factor.
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Accused Products
Abstract
A method and associated apparatus for on-line gas analysis of a multicomponent gas emission flow, comprising: continuously withdrawing and regulating the pressure of a first sample flow from the emission flow, continuously withdrawing a second sample flow from the first sample flow, the second flow sample being diluted with mass controlled amounts of diluent (N2 or air) to lower the dew point of the gas sample to below room temperature; controlling the absolute pressure of the diluted sample to the range of 920-950 mbar; frequently periodically analyzing the diluted sample flow, controlled as to pressure, by fourier-transform infrared spectrometric techniques to render a concentration measurement for each desired gas species; and correcting each concentration measurement for dilution to derive an undiluted concentration measurement representative of the actual exhaust gas, said correction being accomplished by measuring the actual air/fuel ratio of the gas emission flow to provide a theoretical carbon concentration in the undiluted exhaust gas and thereafter ratioing the theoretical total carbon concentration to the measured carbon concentration in the sample to provide the needed correction factor.
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Citations
17 Claims
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1. A method of on-line gas analysis of a multicomponent gas emission flow comprising gas species, comprising:
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(a) continuously withdrawing a first sample flow from said gas emission flow and regulating the first sample flow pressure; (b) continuously withdrawing a second sample flow from said first sample flow, said second sample flow being diluted with mass controlled amounts of diluent to lower the dew point of the second sample flow to below room temperature; (c) controlling the absolute pressure of said diluted second sample to the range of 920-950 mbar; (d) frequently periodically analyzing the diluted second sample flow, controlled as to pressure, by fourier-transform infrared spectrometric techniques to render a concentration measure for one or more of said gas species and carbon in such species; and (e) correcting said one or more concentration measures for dilution to derive an undiluted concentration measure, said correction being accomplished by measuring the actual air/fuel ratio used to provide the gas emission flow, such actual A/F measurement being used to provide a theoretical carbon concentration for each said undiluted concentration measure and thereafter ratioing said theoretical carbon concentration to said carbon concentration measure for said ne or more gas species to provide a correction factor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An improved method for on-line gas analysis of a multicomponent gas emission flow, comprising:
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(a) means for withdrawing by suction a sample flow from the emission flow emitted by an internal combustion engine, the sample flow being diluted with a mass controlled diluent to lower the dew point of the gas sample to below room temperature; (b) means for controlling the pressure of the diluted sample flow to a level of about 933 mbar; (c) FTIR spectrometric device for measuring the concentration for each desired gas species within said diluted sample flow; and means for correcting the concentration measure to derive an undiluted concentration measure, such correction being accomplished by measuring the actual air/fuel ratio used to provide the gas emission flow, such actual A/F ratio being used to provide a theoretical carbon concentration for each undiluted concentration measure and thereafter ratioing said theoretical total carbon concentration to said carbon concentration measure for each gas species to provide a correction factor for such each gas species. - View Dependent Claims (14, 15, 16, 17)
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Specification