Method for controlling dilution air
AssigneeCaterpillar Inc.
InventorsRichard R. Dickson, Russell R. Graze, Jr.
Life of this patent
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Abstract
A method for controlling the dilution air supply to a partial flow dilution tunnel in a gas sampling system is provided. The gas sampling system is capable of testing and certifying internal combustion engines under transient conditions and includes a partial flow dilution tunnel, master and slave mass flow controllers and a transient dilution air flow controlling arrangement. The transient dilution air flow controlling arrangement measures the transient changes in intake air and varies the flow of diluent air to the partial flow dilution tunnel. By controlling the diluent air in this manner ensures that a particle sample can be taken at any time that is at a constant proportion to the exhaust flow rate.
Claims14
A method for controlling dilution air supply to a partial flow dilution tunnel of a gas sampling system, comprising:
- monitoring an excursion of intake air to an internal combustion engine during transient conditions;
- and
- varying the dilution air supply in response to the excursion of intake air.
A method for sampling exhaust particles in an exhaust stream from an internal combustion engine comprising:
- connecting a partial flow dilution tunnel to the exhaust stream of the internal combustion engine;
- providing a filtered and scrubbed supply of dilution air to the partial flow dilution tunnel;
- varying the supply of dilution air in response to excursions of an amount of intake air supplied to the internal combustion engine;
- drawing the exhaust sample and the dilution air from the partial flow dilution tunnel;
- and
- filtering the exhaust sample and the dilution air to trap the exhaust particles at an outlet end of the partial flow dilution tunnel.
Dependencies are inferred from the claim text.