Method of and apparatus for monitoring operation of a catalytic converter
AssigneeLucas Industries public limited company
InventorsBenjamin J. Bradshaw, Russell W. Jones, David Williams
Life of this patent
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Abstract
Sensors measure the temperatures of exhaust gas upstream and downstream of a catalytic converter for internal combustion engine exhaust gas. The difference between the temperatures is multiplied by the rate of mass flow of exhaust gas and the result is integrated or low pass filtered to provide a measure of converter operation. Alternatively, the multiplication is omitted and the difference between the temperatures is integrated or filtered. Thus, the performance of the catalytic converter is monitored by evaulating the difference in the heat supplied to the catalytic converter and the heat removed from the catalytic converter by the exhaust gas.
Claims14
An apparatus for monitoring operation of a catalytic converter for exhaust gas of an internal combustion engine, said apparatus comprising a first temperature sensor for measuring entry temperature of the exhaust gas entering the converter, a second temperature sensor for measuring exit temperature of the exhaust gas leaving the converter, differencing means responsive to said first and second temperature sensors for forming a difference between the exit temperature and the entry temperature, determining means for determining a rate of mass flow of the exhaust gas, a multiplier responsive to said differencing means and said determining means for forming a product of the difference and the rate of mass flow of the exhaust gas, and processing means responsive to said multiplier for processing the product to provide a measure of operation of the converter, said processing means having a transfer function including an integral term.
A method for monitoring operation of a catalytic converter for exhaust gas of an internal combustion engine, said method comprising the steps of:
- measuring an entry temperature of the exhaust gas entering the converter;
- measuring an exit temperature of the exhaust gas leaving the converter;
- forming a difference between the exit temperature and the entry temperature;
- multiplying the difference by a rate of mass flow of the exhaust gas to form a product;
- and
- subjecting the product to processing by a transfer function having an integral term to provide a measure of converter operation.
Dependencies are inferred from the claim text.