Apparatus and method for a gas quantity setting system
AssigneeSiemens Aktiengesellschaft
InventorsHans-Josef Decker, Klaus-Peter Schwarz
Life of this patent
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Abstract
A gas quantity setting system, such as for the testing and/or certification of "low emission vehicles", provides a dilution air/exhaust gas mixture for investigation and has a continuously cross-sectionally variable, venturi nozzle and an axially adjustable conical, nozzle needle. The nozzle needle of the venturi nozzle is adjustable by a computing device, taking into consideration a temperature, a pressure and measured values of a mass rate of flow meter, in such a way that a dilution ratio (dilution factor) of the exhaust gas has a predetermined, preferably constant, value in spite of fluctuations in the feeding of quantities of exhaust gas.
Claims18
An apparatus for a gas quantity setting system in which a mixture of dilution air and exhaust gas is sampled for analysis, the apparatus comprising:
- a cross-sectionally variable, venturi nozzle, the venturi nozzle defining an axis;
- and
- an axially adjustable, conical, nozzle needle,
- wherein a position of the nozzle needle in the venturi nozzle is adjusted based on a temperature, a pressure and measured values of a mass rate of flow meter, such that a dilution ratio of the exhaust gas has a predetermined constant value despite fluctuations in quantities of exhaust gas fed to the apparatus.
A process for controlling a gas quantity setting system comprising the steps of:
- drawing a dilution gas into a tubular flow element;
- receiving an exhaust gas in said tubular flow element;
- mixing said dilution gas and said exhaust gas thereby forming a mixture;
- sensing a pressure and a temperature of the mixture;
- sampling the mixture;
- drawing the mixture toward a cross-sectionally variable venturi nozzle having an axially adjustable conical, nozzle needle;
- and
- adjusting a position of said conical nozzle needle with respect to said venturi nozzle taking into account the sensed pressure and temperature wherein a dilution ratio of the exhaust gas has a constant value despite fluctuations in a feeding quantity of the exhaust gas.
Dependencies are inferred from the claim text.