Exhaust gas analysis device, exhaust gas analysis method, and program storage medium for exhaust gas analysis device

Patent metadata

Field	Value
Publication number	US-12480882-B2
Application number	US-202118029911-A
Country	US
Kind code	B2
Filing date	Sep 22, 2021
Priority date	Oct 2, 2020
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

An exhaust gas analysis device analyzes exhaust gas generated when fuel is combusted. This exhaust gas analysis device includes a first analyzer that measures a concentration of a component to be measured in the exhaust gas, a second analyzer that measures a concentration of CO 2 in the exhaust gas, a storage portion that stores a hydrogen/carbon ratio, which is a ratio between hydrogen and carbon composing the fuel, or an input receiving portion that receives an input of the hydrogen/carbon ratio, a moisture concentration estimating portion that, based on the measured CO 2 concentration and on the hydrogen/carbon ratio of the fuel, estimates a concentration of moisture in the exhaust gas, and a correcting portion that, based on the estimated moisture concentration, corrects the measured concentration of the component to be measured.

First claim

What is claimed is:

1 . An exhaust gas analysis device that analyzes exhaust gas generated as a result of fuel being combusted comprising:
a first analyzer that measures a concentration of a component to be measured in the exhaust gas; a second analyzer that measures a concentration of CO 2 in the exhaust gas; a storage portion that stores a hydrogen/carbon ratio, which is a ratio between hydrogen and carbon composing the fuel, or an input receiving portion that receives an input of the hydrogen/carbon ratio; a moisture concentration estimating portion that, based on the concentration of CO 2 and on the hydrogen/carbon ratio of the fuel, estimates a concentration of moisture in the exhaust gas; and a correcting portion that, based on the concentration of moisture and a sensitivity coefficient that shows a relationship between the concentration of moisture and a sensitivity of the first analyzer, corrects effects of moisture on the concentration of the component to be measured.

2 . The exhaust gas analysis device according to claim 1 , wherein the first analyzer measures the concentration of the component to be measured by performing wet measurement, and the second analyzer measures the concentration of CO 2 by performing dry measurement.

3 . The exhaust gas analysis device according to claim 2 wherein the moisture concentration estimating portion estimates the concentration of moisture in the exhaust gas by multiplying the hydrogen/carbon ratio by a wet CO 2 concentration that is obtained by converting the concentration of CO 2 acquired by performing a dry measurement into a wet measurement value.

4 . The exhaust gas analysis device according to claim 2 , wherein the exhaust gas analysis device further comprises a CO 2 concentration converting portion that converts the concentration of CO 2 acquired by the second analyzer by means of a dry measurement into a wet measurement value based on the hydrogen/carbon ratio, and
the correcting portion corrects the concentration of the component to be measured using the concentration of moisture estimated by the moisture concentration estimating portion, and the concentration of CO 2 obtained after the conversion performed by the CO 2 concentration converting portion.

5 . The exhaust gas analysis device according to claim 4 , wherein the CO 2 concentration converting portion converts the concentration of CO 2 acquired by the second analyzer by means of a dry measurement into a wet measurement value based on the hydrogen/carbon ratio of the fuel, and on a partial pressure of a CO 2 component in the exhaust gas.

6 . The exhaust gas analysis device according to claim 4 , wherein the moisture concentration estimating portion estimates the moisture concentration in the exhaust gas based on the concentration of CO 2 , the hydrogen/carbon ratio of the fuel, a concentration of moisture in atmosphere, a partial pressure of a CO 2 component in the exhaust gas, and a partial pressure of an H 2 O component in the exhaust gas.

7 . The exhaust gas analysis device according to claim 1 ,
wherein the moisture concentration estimating portion estimates the moisture concentration in the exhaust gas based on the concentration of CO 2 , the hydrogen/carbon ratio of the fuel, a concentration of moisture in atmosphere, a partial pressure of a CO 2 component in the exhaust gas, and a partial pressure of an H 2 O component in the exhaust gas.

8 . The exhaust gas analysis device according to claim 7 , wherein the exhaust gas analysis device further comprises a calculating portion that, based at least on composition of the fuel and on a complete combustion mode of the fuel, calculates the respective partial pressures of the CO 2 component and the H 2 O component in the exhaust gas.

9 . The exhaust gas analysis device according to claim 1 , wherein the component to be measured is NO x .

10 . The exhaust gas analysis device according to claim 9 , wherein the first analyzer is a chemiluminescence detector.

11 . An exhaust gas analysis method that is employed to analyze exhaust gas generated as a result of fuel being combusted in which:
a concentration of a component to be measured in the exhaust gas is measured by a first analyzer; a concentration of CO 2 in the exhaust gas is measured; a concentration of moisture in the exhaust gas is estimated based on the concentration of CO 2 and on a ratio between hydrogen and carbon composing the fuel; and effects of moisture on the concentration of the component to be measured are corrected based on the concentration of moisture and a sensitivity coefficient that shows a relationship between the concentration of moisture and a sensitivity of the first analyzer.

12 . A non-transitory computer-readable storage medium containing instructions for a program for an exhaust gas analysis device that analyzes exhaust gas generated as a result of fuel being combusted and comprises a first analyzer that measures a concentration of a component to be measured in the exhaust gas, and a second analyzer that measures a concentration of CO 2 in the exhaust gas, wherein the instructions when executed by a computer cause the computer to perform functions of:
a storage portion that stores a hydrogen/carbon ratio, which is a ratio between hydrogen and carbon composing the fuel; a moisture concentration estimating portion that, based on the concentration of CO 2 and on the hydrogen/carbon ratio of the fuel, estimates a concentration of moisture in the exhaust gas; and a correcting portion that, based on the concentration of moisture and a sensitivity coefficient that shows a relationship between the moisture concentration and a sensitivity of the first analyzer, corrects effects of moisture on the concentration of the component to be measured.

Assignees

• Horiba Ltd

Inventors

• Ishizaki Tomohiko
• Yoshimura Tomoshi

Classifications

• G01N2001/386

  Other diluting or mixing processes · CPC title

• G01N33/004

  CO or CO2 · CPC title

• G01N1/38

  Diluting, dispersing or mixing samples · CPC title

• G01N1/2252

  in a vehicle exhaust · CPC title

• G01N33/006

  Avoiding interference of water vapour with the gas to be measured · CPC title