Control strategy for heated fluid lines
AssigneeCaterpillar Inc.
InventorsDarin McCoy, Edward King, Steve Funke
Life of this patent
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Abstract
A control strategy selectively controls the heating of fluid lines equipped with line heaters that may be utilized with a selective catalytic reduction system. The control strategy measures a tank temperature representative of reductant agent in a storage tank and a representative ambient temperature representative of an ambient temperature proximate the fluid line. The control strategy determines a lowest possible reductant agent temperature (“LPRAT”) based on the measured tank temperature and representative ambient temperature. The LPRAT is compared with a desired reductant agent temperature and, in response to the comparison, the control strategy may activate the line heater.
Claims20
A method of controlling a line heater proximate a fluid line for communicating a reductant agent in a selective catalytic reduction system, the method comprising:
- measuring a tank temperature representative of the reductant agent accommodated in a storage tank;
- measuring a representative ambient temperature representative of an ambient temperature proximate the selective catalytic reduction system;
- determining a lowest possible reductant agent temperature from the tank temperature and the representative ambient temperature;
- comparing the lowest possible reductant agent temperature with a predetermined desired reductant agent temperature;
- and
- activating the line heater in response to comparing the lowest possible reductant agent temperature with a predetermined desired reductant agent temperature.
A selective catalytic reduction system for use with an internal combustion engine, the selective catalytic reduction system comprising:
- a storage tank for accommodating a reductant agent, the storage tank including a tank temperature sensor for measuring a tank temperature representative of the reductant agent in the storage tank;
- an ambient temperature sensor for measuring a representative ambient temperature;
- a fluid line communicating the reductant agent from the storage tank to an introduction point in an exhaust system associated with the internal combustion engine, the fluid line including a line heater;
- and
- a controller communicating with the tank temperature sensor, the ambient temperature sensor, and the line heater, the controller including logic for determining a lowest possible reductant agent temperature based in part on information from the tank temperature sensor and the ambient temperature sensor;
- wherein the controller activates or deactivates the line heater upon determining the lowest possible reductant agent temperature.
A method of reducing nitrous oxides in exhaust from an internal combustion engine, the method comprising:
- providing a catalyst in an exhaust system associated with the internal combustion engine;
- providing a storage tank for accommodating a reductant agent, the storage tank in fluid communication with the exhaust system via a fluid line;
- measuring a tank temperature representative of the reductant agent in the storage tank;
- measuring a representative ambient temperature representative of an ambient temperature proximate the internal combustion engine;
- determining a lowest possible reductant agent temperature based in part on the tank temperature and the representative ambient temperature;
- and
- activating a line heater proximate the fluid line in response to determining the lowest possible reductant agent temperature.
Dependencies are inferred from the claim text.