A driver circuit drives a heater associated with a sensor in an exhaust system of a vehicle at a duty cycle. A feedback circuit generates a feedback signal indicating a temperature of the sensor. A ramp circuit outputs a first ramping set point indicating a first rate at which the temperature of the sensor is to be changed over a first time period after an engine of the vehicle is turned on, and a second ramping set point indicating a second rate at which the temperature of the sensor is to be changed after the first time period until the temperature of the sensor reaches a predetermined temperature. An error circuit generates first and second error signals based on the feedback signal and the first and second ramping set points. A controller controls the duty cycle of the driver circuit to drive the heater based on one or more gains.

An inline reductant filter assembly includes a filter housing, a filter media, and one or more valves. The filter housing is fluidly coupled to an upstream portion of a reductant line and a downstream portion of the reductant line. The filter media is positioned in the filter housing. The one or more valves are selectively movable from a first position to a second position. In the first position, the one or more valves permit fluid to flow along a first fluid flow path from the upstream portion of the reductant line, through the filter media, to the downstream portion of the reductant line. In the second position, the one or more valves prevent fluid from flowing along the first fluid flow path through the filter media.

A plant according to an embodiment includes a gas turbine; a heat recovery unit that includes a primary heat recovery steam generator in which a primary heat exchanging unit generates primary steam by exchanging heat that is the thermal energy of the flue gas from the gas turbine, and a secondary heat recovery steam generator that is installed independently from the primary heat exchanging unit, and in which a secondary heat exchanging unit generates secondary steam by exchanging heat that is the thermal energy of the flue gas partly having exchanged heat in the primary heat exchanging unit included in the primary heat recovery steam generator; a primary steam turbine; a CO.sub.2 recovery unit; and a first reboiler heat supply line.

A plant according to an embodiment includes a gas turbine; a heat recovery unit that includes a primary heat recovery steam generator in which a primary heat exchanging unit generates primary steam by exchanging heat that is the thermal energy of the flue gas from the gas turbine, and a secondary heat recovery steam generator that is installed independently from the primary heat exchanging unit, and in which a secondary heat exchanging unit generates secondary steam by exchanging heat that is the thermal energy of the flue gas partly having exchanged heat in the primary heat exchanging unit included in the primary heat recovery steam generator; a primary steam turbine; a CO.sub.2 recovery unit; and a first reboiler heat supply line.

A catalyst temperature estimation device that estimates a temperature of a catalyst provided in an exhaust passage of an internal combustion engine includes a storage device and processing circuitry. The storage device stores mapping data that specifies a mapping that uses multiple input variables to output an estimation value of the temperature of the catalyst. The multiple input variables include at least one variable of an ambient temperature variable or an excess amount variable. The multiple input variables further include a fluid energy variable, which is a state variable related to energy of fluid flowing into the catalyst, and a previous cycle value of the estimation value of the temperature of the catalyst. The processing circuitry is configured to execute an acquisition process, a temperature calculation process, and an operation process. The mapping data includes data that is learned through machine learning.

A catalyst temperature estimation device that estimates a temperature of a catalyst provided in an exhaust passage of an internal combustion engine includes a storage device and processing circuitry. The storage device stores mapping data that specifies a mapping that uses multiple input variables to output an estimation value of the temperature of the catalyst. The multiple input variables include at least one variable of an ambient temperature variable or an excess amount variable. The multiple input variables further include a fluid energy variable, which is a state variable related to energy of fluid flowing into the catalyst, and a previous cycle value of the estimation value of the temperature of the catalyst. The processing circuitry is configured to execute an acquisition process, a temperature calculation process, and an operation process. The mapping data includes data that is learned through machine learning.

A determination method is for an exhaust gas treatment device mounted in a work machine and having at least one of a diesel oxidation catalyst and a catalyzed soot filter. The determination method includes acquiring heat damage information, acquiring cumulative heat damage information, and determining a usability of the exhaust gas treatment device based on the cumulative heat damage information. The heat damage information indicates an extent of heat damage of the exhaust gas treatment device based on a unique identification symbol of the exhaust gas treatment device. The cumulative heat damage information is acquired by accumulating the heat damage information.

A controller is configured to control a vehicle that includes an internal combustion engine and an automatic transmission. The controller is configured to execute a shifting process that switches a gear ratio of the automatic transmission and a lean operation process that operates the internal combustion engine with an air-fuel ratio of the air-fuel mixture in a cylinder leaner than a stoichiometric air-fuel ratio. The controller is further configured to, when executing the shifting process during execution of the lean operation process, set an air-fuel ratio in a case in which the shifting process is being executed to a value closer to the stoichiometric air-fuel ratio than an air-fuel ratio in a case in which the shifting process is not being executed.

A method for controlling an internal combustion engine system including a catalyst includes receiving a desired output for an internal combustion engine, and receiving sensor information including information indicative of a temperature of the catalyst. The method includes calculating a plurality of sets of engine performance values based on respective sets of candidate control points, the engine performance values including a temperature change rate at which the temperature of the catalyst changes over time, and determining whether the temperature change rate satisfies a minimum warmup rate for the catalyst. The method also includes controlling the internal combustion engine based on a selected set of candidate control points and the minimum warmup rate.

A method for controlling an internal combustion engine system including a catalyst includes receiving a desired output for an internal combustion engine, and receiving sensor information including information indicative of a temperature of the catalyst. The method includes calculating a plurality of sets of engine performance values based on respective sets of candidate control points, the engine performance values including a temperature change rate at which the temperature of the catalyst changes over time, and determining whether the temperature change rate satisfies a minimum warmup rate for the catalyst. The method also includes controlling the internal combustion engine based on a selected set of candidate control points and the minimum warmup rate.