Emission sampling apparatus and method

• US 20030136177A1
• Filed: 11/19/2002
• Published: 07/24/2003
• Est. Priority Date: 05/25/2000
• Status: Active Grant

• Current Assignee: Her Majesty The Queen In Right of Canada As Represented By The Minister of National Defence
• Original Assignee: Her Majesty The Queen In Right of Canada As Represented By The Minister of National Defence
• Inventors: Ainslie, Bruce, Hendren, Fredrick
• Granted Patent: US 6,959,590 B2
• Time in Patent Office: Days
• US Class Current: 73/23.31
• CPC Class Codes: G01N 1/2252 in a vehicle exhaust
• CPC Class Codes: G01N 2001/2264 with dilution
• CPC Class Codes: G01N 33/0011 Sample conditioning preparing specimens for investigation G01N1/28
• CPC Class Codes: G01N 33/0018 by diluting a gas

Abstract

A self contained field sampling system for measuring engine exhaust emissions includes a mini-dilution tunnel adapted for the collection of proportional samples of emissions to be analyzed, an engine air intake flow measurement instrument, a system controller and data acquisition system, and an optionally portable generator to provide electrical power. Several probes withdraw dilute and undiluted exhaust for emission analysis. Various engine emissions may be isolated. As well, engine emissions mass rate may be calculated by reference to engine RPM, inlet flow rate, exhaust temperature and emissions output rate.

Claims

1. In a portable self-contained system for sampling and analysing engine exhaust emissions of a mobile or stationary emission source in which the system has an inlet pipe (16) for receiving an emission sample, a dilution tunnel (20) having a plurality of sampling probes (70, 72, 74) within said dilution tunnel (20) for withdrawing controlled volumes of diluted engine exhaust upstream from said dilution tunnel (20), emissions analysing means (80, 82, 84) downstream of said tunnel, control means (28, 29) for introducing dilution air into said tunnel, an air inlet measuring means (15), in operative association with said control means, characterized by:

air inlet measuring means (40) measuring air inlet flow rate into an engine (12), a plurality of pump means (91, 93, 95) with which to draw a sample of said diluted engine exhaust through said probe means (70, 72, 74), and control means (28, 29) comprising a variable controller for controlling the volume of dilution air of said exhaust in inverse proportion to the ratio of engine air inlet flow rate and the engine inlet air flow rate at engine idle.

2. A system as defined in claim 1, wherein said engine air inlet measuring means comprises laminar flow elements (40).

3. A system as defined in claim 1, comprising means for collecting and concentrating a plurality of emission samples for measuring specific emissions selected from one or more of:

THC;

CO;

NO_x;

CO₂;

aldehydes;

ketones;

semi-volatile organic compounds;

volatile organic compounds;

PAH;

n-PAH; and

,

particulates.

4. The system as defined in claim 1, said control means further comprising means for integrating data over an engine cycle of an engine ranging from idle to full engine load, said date comprising emissions mass number or average emissions mass rate, engine air inlet flow rate, exhaust temperature, and engine RPM.

5. The system as defined in any one of claims 1 to 4, further comprising means for collecting and concentrating emission samples with sampling media selected from one or more of:

Tedlar™

bag;

2, 4-DNPH prepared cartridge;

Tenax cartridge; and

,

polyurethane foam.

6. The system as defined in claim 1, wherein the volume of exhaust drawn from the emission source is varied, said volume being varied by a mass air flow rate controller at the exit of said tunnel.

7. In a method for analysing and measuring engine exhaust emissions from a stationary or mobile emission source in a portable self-contained system having a volume of exhaust drawn from said emission source, said volume is varied by a mass air flow controller at the exit of said tunnel including the steps of:

connecting said portable self-contained system to said mobile or stationary emission source;

drawing a portion of engine exhaust emissions into a dilution tunnel (20) upstream from said dilution tunnel during operation of said emission source;

characterized by;

measuring the air intake flow rate from an engine during operation;

diluting said engine exhaust emissions in inverse proportion to the ratio of engine air inlet flow rate of said engine during an analysing event and engine air inlet flow rate of said engine during idle;

collecting samples of said diluted exhaust emission with a plurality of sampling probes; and

,

analysing emission mass rates for one or more emission component being measured.

8. A method as defined in claim 7, further comprising measuring and recording parameters selected from one or more of:

engine inlet mass air flow rate, engine exhaust temperature, engine RPM, engine torque, and speed.

9. A method as defined in claim 7 and claim 8, further comprising analysing one or more of:

mass number, average emissions mess rate, engine air inlet flow rate, exhaust temperature, and engine RPM during operation of said emission source.

10. A method as defined in any one of claims 7 to 9, further comprising sampling diluted exhaust with a plurality of probes each having an inlet within said dilution tunnel and delivering diluted exhaust samples to a plurality of collection media for concentrating selected emission components.

11. A method as defined in any one of claims 7 to 10, further comprising measuring emission components selected from one or more of:

THC;

CO;

NO_x;

CO₂;

aldehydes;

ketones;

semi-Volatile organic compounds;

volatile organic compounds;

PAH;

n-PAH; and

,

particulates.