Exhaust volume measurement device
First Claim
1. A vehicle exhaust measurement system comprising:
- a conduit defined by an outer wall and having an conduit inlet and a conduit outlet;
an make-up air tube connected to and in fluid communication with said conduit inlet, said make-up air tube providing make-up air for mixing with an exhaust gas;
a mixed gas tube connected to and in fluid communication with said conduit outlet, said mixed gas tube conveying a mixture of the make-up air and the exhaust gas to analysis equipment; and
an exhaust gas tube extending through said outer wall of said conduit, and a mixing plate disposed in at least one of said conduit and said mixed gas tube with said exhaust gas tube extending to a position adjacent to said mixing plate, said exhaust gas tube conveying the exhaust gas to said mixing plate to mix the exhaust gas and the make-up air at said mixing plate.
5 Assignments
0 Petitions
Accused Products
Abstract
A vehicle exhaust measurement system is provided includes that a conduit having a conduit inlet and a conduit outlet. A make-up air tube is connected to and is in fluid communication with the conduit inlet. The make-up air tube provides make-up air for mixing an exhaust gas. A mixed gas tube is connected to and is in fluid communication with the conduit outlet. The mixed gas tube conveys a mixture of make-up air and exhaust gas to analysis equipment. In the preferred embodiment, the exhaust gas tube extends through an outer wall of the conduit. A mixing plate is arranged in either the conduit or the mixed gas tube with the exhaust gas tube extending to a position adjacent to the mixing plate. The exhaust gas tube conveys the exhaust gas to the mixing plate to mix the exhaust gas and the make-up air at the mixing plate. A correction factor may be applied to the measurements taken by a differential pressure based fluid flow measurement device such as a smooth approach orifice (SAO) to provide an adjusted flow of measurement at the flow measurement device to correct for the pressure pulsations. The correction factor is calculated based upon the intensity of the pulsations of the differential pressure signal, which indicates the flow through the SAO.
-
Citations
29 Claims
-
1. A vehicle exhaust measurement system comprising:
-
a conduit defined by an outer wall and having an conduit inlet and a conduit outlet;
an make-up air tube connected to and in fluid communication with said conduit inlet, said make-up air tube providing make-up air for mixing with an exhaust gas;
a mixed gas tube connected to and in fluid communication with said conduit outlet, said mixed gas tube conveying a mixture of the make-up air and the exhaust gas to analysis equipment; and
an exhaust gas tube extending through said outer wall of said conduit, and a mixing plate disposed in at least one of said conduit and said mixed gas tube with said exhaust gas tube extending to a position adjacent to said mixing plate, said exhaust gas tube conveying the exhaust gas to said mixing plate to mix the exhaust gas and the make-up air at said mixing plate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method of correcting an exhaust flow measurement in a vehicle exhaust measurement system comprising the steps of:
-
a) measuring a pressure differential across a head type flow meter indicative of exhaust gas flow and pressure pulsation magnitude;
b) determining the frequency of the exhaust gas pulsations;
c) calculating an correction factor based upon the magnitude and frequency of the exhaust gas pulsations; and
d) applying the correction factor to the measurements taken by a head type flow measurement device in the system to provide an adjusted flow measurement at the flow measurement device. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. A vehicle exhaust measurement system comprising:
-
an exhaust gas tube for receiving an exhaust gas from an exhaust gas source, an make-up air tube connected to and in fluid communication with said exhaust gas tube for providing make-up air to mix with the exhaust gas;
a first flow measurement device arranged in said make-up air tube for measuring the make-up air flowing there through;
a differential pressure sensor arranged in fluid communication with said make-up air tube by first and second conduits of substantially equal length spaced from one another and proximate to said first flow measurement device;
a mixed gas tube in fluid communication with said exhaust gas and make-up air tubes, said mixed gas tube downstream from said exhaust gas and make-up air tubes for mixing the make-up air and exhaust gas and producing a generally homogeneous mixture of the make-up air and exhaust gas;
a conduit connected to and in fluid communication with said mixed gas tube receiving the mixture; and
a second flow measurement device arranged in said conduit regulating flow of the mixture through said conduit. - View Dependent Claims (17, 18)
-
-
19. A method of acoustically balancing a differential pressure sensor for a flow measurement device, comprising the steps of:
-
a) connecting opposing lengths of conduit fluidly connected to a differential pressure sensor to a tee;
b) connecting the tee proximate to a flow measurement device to a source of pressure pulsations;
c) detecting a pressure differential with the sensor;
d) adjusting the lengths of the conduit to achieve a net zero pressure differential;
e) removing the tee and the conduits from the tee; and
f) individually connecting the conduits proximate to the flow measurement device.
-
-
20. A vehicle exhaust measurement system comprising:
-
an exhaust gas tube for receiving exhaust gas from an exhaust gas source, a make-up air tube connected to and in fluid communication with said exhaust gas tube for providing make-up air to mix with the exhaust gas;
a smooth approach orifice arranged in said make-up air tube for measuring the make-up air flowing there through;
a differential pressure sensor arranged in fluid communication with said make-up air tube by first and second conduits spaced from one another and proximate to said smooth approach orifice, and first and second valves respectively arranged in said first and second conduits between said differential pressure sensor and said make-up air tube;
a third valve arranged in said exhaust gas tube;
a mixed gas tube in fluid communication with said exhaust gas and make-up air tubes, said mixed gas tube downstream from said exhaust gas and make-up air tubes for mixing the make-up air and exhaust gas and producing a generally homogeneous mixture of the make-up air and exhaust gas;
a critical flow venturi in fluid communication with said mixed gas tube regulating flow of the mixture through said critical flow venturi at a known flow rate; and
a controller connected to said differential pressure sensor, said valves, and said sensors, wherein said controller defines a calibration procedure including moving said valves between open and closed positions, drawing make-up air through said smooth approach orifice and said critical flow venturi, calculating a difference in flow rates though said smooth approach orifice and said critical flow venturi, and applying a correction factor to said differential pressure sensor. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27)
-
-
28. A method of correcting an exhaust flow measurement in a vehicle exhaust measurement system comprising the steps of:
-
a) closing an exhaust tube valve;
b) measuring the flow of make-up air through a smooth approach orifice and the flow of the make-up air through the critical flow venturi;
c) comparing the flow of make-up air through the smooth approach orifice with the flow of make-up air through the critical flow venturi;
d) calculating an correction factor based upon the comparison; and
e) applying the correction factor to a differential pressure sensor at the smooth approach orifice. - View Dependent Claims (29)
-
Specification