Exhaust gas analyzer

• US 20090039284A1
• Filed: 04/28/2006
• Published: 02/12/2009
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd., Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Mitsubishi Heavy Industries, Ltd., Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Deguchi, Yoshihiro, Yamakage, Masahiro, Goto, Katsutoshi, Yamaura, Taketoshi
• Granted Patent: US 8,208,143 B2
• Time in Patent Office: Days
• US Class Current: 250/432.R
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2560/02 the means being an exhaust gas sensor
• CPC Class Codes: F01N 2560/14 having more than one sensor of one kind
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/021 using plane or convex mirrors, parallel phase plates, or particular reflectors
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01M 15/108 using optical methods
• CPC Class Codes: G01N 21/031 Multipass arrangements
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis

Abstract

An exhaust gas analyzer capable of real-time analysis of the concentration, temperature, and the like of an exhaust gas component in a cross-section of an exhaust path in a spot-wise manner reduces analysis cost. An exhaust gas analyzer (10) comprises sensor units (11) to (14) disposed along the exhaust path, which comprises an exhaust manifold (3) for the engine (2) discharging exhaust gas, an exhaust tube (4), a first catalyst device (5), a second catalyst device (6), a muffler (7), and an exhaust pipe (8). Each sensor unit includes an optical fiber (25) for irradiating the exhaust gas with laser light, and a detector (26) for receiving the laser light emitted by the optical fiber that has been transmitted through the exhaust gas. Based on the laser light received by the detector, the condition of an exhaust gas component, such as its concentration, temperature, and the like, is measured for the analysis of the exhaust gas. The sensor unit has a through-hole (21) allowing the passage of exhaust gas that is formed in a shape matched with a cross-sectional shape of the exhaust path. The infrared laser light R is emitted via the optical fiber (25) into the through-hole (21), travels across the exhaust path, and is then received by the detector (26).

Claims

1. An exhaust gas analyzer comprising a sensor unit disposed in an exhaust path via which exhaust gas is discharged from an internal combustion engine, the sensor unit comprising an irradiation unit for irradiating the exhaust gas with laser light, and a photoreceiving unit for receiving the laser light emitted by the irradiation unit that has been transmitted through the exhaust gas, wherein the concentration, temperature, and the like of an exhaust gas component is measured on the basis of the laser light received by the photoreceiving unit for analyzing the exhaust gas,

wherein the sensor unit includes a through-hole allowing the passage of the exhaust gas that is formed in a shape matched with a cross-sectional shape of the exhaust path, wherein the laser light is shone by the irradiation unit into the through-hole and is received by the photoreceiving unit across the exhaust path.

2. The exhaust gas analyzer according to claim 1, wherein the exhaust path has a circular cross-sectional shape, and wherein the sensor main body has a through-hole formed therein which has a circular basic shape with the same diameter as the circular cross-section of the exhaust path.

3. The exhaust gas analyzer according to claim 1 or 2, wherein the through-hole has a reflecting portion formed on the internal circumferential surface thereof, wherein the laser light emitted by the irradiation unit is reflected by the reflecting portion and then received by the photoreceiving unit.

4. The exhaust gas analyzer according to claim 3, wherein the reflecting portion comprises two reflecting plates disposed in parallel and opposite each other such that they face the inside of the through-hole, wherein the laser light is reflected in a direction perpendicular to the exhaust path.

5. The exhaust gas analyzer according to any one of claims 1 to 4, wherein the laser light comprises a multiplexing of laser light having absorption wavelengths matched with a plurality of components of the exhaust gas.

6. The exhaust gas analyzer according to any one of claims 1 to 5, wherein the sensor unit is disposed at a plurality of locations along the exhaust path.