Method for estimating water content, and estimation device
AssigneeDenso Wave Incorporated
InventorYotaro Murakami
Life of this patent
Estimating the term…
Abstract
In a method for estimating water content of exhaust gas, a first gas concentration at a first position in an exhaust passage, a second gas concentration at a second position downstream of the first position, and a gas temperature at the second position are obtained. A saturated water vapor at the gas temperature is calculated as a water content at the second position. By using the water content at the second position and the second gas concentration, an excess air amount of a fuel-air mixture supplied to a combustion apparatus is calculated based on a chemical reaction formula of combustion of the mixture. By using the excess air amount and the first gas concentration, a water content at the first position is estimated.
Claims8
A method for estimating water content of exhaust gas, the estimation method comprising:
- obtaining a first gas concentration that is a concentration of the exhaust gas detected at a first position in an exhaust passage through which the exhaust gas of a combustion apparatus flows, a second gas concentration that is a concentration of the exhaust gas detected at a second position which is downstream of the first position in the exhaust passage and where a temperature of the exhaust gas is lower than 100° C., and a gas temperature that is the temperature of the exhaust gas detected at the second position;
- calculating a saturated water vapor amount at the gas temperature as a water content at the second position;
- calculating an excess air amount of a fuel-air mixture supplied to the combustion apparatus by using the water content at the second position and the second gas concentration based on a chemical reaction formula of combustion of the mixture;
- estimating a water content at the first position by using the excess air amount and the first gas concentration based on the chemical reaction formula;
- and
- performing a combustion control of the combustion apparatus based on the water content at the first position.
An estimation device for estimating water content of exhaust gas, the estimation device comprising:
- a detection sensor provided at a first position in an exhaust passage through which exhaust gas of a combustion apparatus flows, and configured to detect a first gas concentration which is a concentration of the exhaust gas at the first position;
- a determination sensor provided at a second position which is downstream of the first position in the exhaust passage and where a temperature of the exhaust gas is lower than 100° C., and configured to detect a second gas concentration which is a concentration of the exhaust gas at the second position;
- a temperature sensor provided at the second position and configured to detect a gas temperature which is the temperature of the exhaust gas at the second position;
- and
- a controller programmed to:
- calculate a saturated water vapor amount at the gas temperature as a water content at the second position;
- calculate an excess air amount of a fuel-air mixture supplied to the combustion apparatus by using the water content at the second position and the second gas concentration based on a chemical reaction formula of combustion of the mixture;
- estimate a water content at the first position by using the excess air amount and the first gas concentration based on the chemical reaction formula;
- and
- perform a combustion control of the control apparatus based on the water content at the first position.
Dependencies are inferred from the claim text.