Fluid delivery system with line pressure control valve
View Patent ↗An exhaust treatment fluid delivery system ( 16, 22, 116 ) may include a supply passageway ( 46, 146 ), a supply manifold ( 38, 138 ), injectors ( 42, 142 ), a bypass passageway ( 50, 150 ) and first and second pressure sensors ( 34, 134, 40, 140 ). The supply passageway ( 46, 146 ) receives the exhaust treatment fluid from a tank ( 26, 126 ) and provides the exhaust treatment fluid to the supply manifold ( 38, 138 ). The bypass passageway ( 50, 150 ) connects the supply passageway ( 46, 146 ) with the return passageway ( 48, 148 ) and includes a bypass valve ( 36, 136 ) controlling fluid flow therebetween. The first pressure sensor ( 34, 134 ) measures a first pressure of exhaust treatment fluid in the supply passageway ( 46, 146 ) based upon which the bypass valve ( 36, 136 ) is controlled. The second pressure sensor ( 40, 140 ) measures a second pressure of exhaust treatment fluid in the supply manifold ( 38, 138 ) based upon which the injectors ( 42, 142 ) are controlled.
1. An exhaust aftertreatment system for treating exhaust gas discharged from a combustion engine, the exhaust aftertreatment system comprising:
a catalyst component; and
an exhaust treatment fluid delivery system for injecting an exhaust treatment fluid into an exhaust stream at a location upstream of the catalyst component, the exhaust treatment fluid delivery system including:
a tank for holding the exhaust treatment fluid;
a supply passageway receiving the exhaust treatment fluid from the tank and providing the exhaust treatment fluid to a supply manifold;
a plurality of injectors that receive the exhaust treatment fluid from the supply manifold and dose the exhaust treatment fluid into the exhaust stream;
a return passageway through which exhaust treatment fluid from the injectors is returned to the tank;
a bypass passageway connecting the supply passageway with the return passageway and including a bypass valve controlling fluid flow therebetween, the bypass valve selectively allowing a portion of the exhaust treatment fluid in the supply passageway to return to the tank via the bypass passageway without flowing through the injectors; and
a control module controlling the bypass valve and the injectors based on a first fluid pressure in the supply passageway and a second fluid pressure between the supply manifold and the injectors.
2. The exhaust aftertreatment system of claim 1 , wherein the control module controls the bypass valve to achieve a predetermined fluid pressure in the supply passageway that is higher than a target fluid pressure at the injectors.
3. The exhaust aftertreatment system of claim 1 , wherein the exhaust treatment fluid is a hydrocarbon exhaust treatment fluid, the hydrocarbon exhaust treatment fluid being dispersed at a location adjacent the catalyst component.
4. The exhaust aftertreatment system of claim 1 , wherein the exhaust treatment fluid is a urea exhaust treatment fluid, the urea exhaust treatment fluid being dispersed at a location adjacent the catalyst component.
5. The exhaust aftertreatment system of claim 4 , wherein the catalyst component is a selective-catalytic-reduction catalyst.
6. The exhaust aftertreatment system of claim 4 , further comprising a urea quality sensor disposed upstream of at least one of the injectors.
7. The exhaust aftertreatment system of claim 1 , wherein the plurality of injectors inject the exhaust treatment fluid into a common exhaust stream.
8. An exhaust aftertreatment system for treating exhaust gas discharged from a combustion engine, the exhaust aftertreatment system comprising:
a catalyst component; and
an exhaust treatment fluid delivery system for injecting an exhaust treatment fluid into an exhaust stream at a location upstream of the catalyst component, the exhaust treatment fluid delivery system including:
a tank for holding the exhaust treatment fluid;
a supply passageway receiving the exhaust treatment fluid from the tank and providing the exhaust treatment fluid to a supply manifold;
a plurality of injectors that receive the exhaust treatment fluid from the supply manifold and dose the exhaust treatment fluid into the exhaust stream;
a bypass valve selectively allowing a portion of the exhaust treatment fluid in the supply passageway to return to the tank via a bypass passageway without flowing through the injectors; and
a control module controlling the bypass valve and the injectors based on a first fluid pressure in the supply passageway and a second fluid pressure between the supply manifold and the injectors, wherein the plurality of injectors inject the exhaust treatment fluid into separate exhaust streams corresponding to multiple combustion engines.
9. A fluid delivery system for injecting exhaust treatment fluid into a stream of exhaust gas discharged by a combustion engine, the fluid delivery system comprising:
a tank for containing the exhaust treatment fluid;
a supply passageway receiving the exhaust treatment fluid from the tank;
a supply manifold receiving the exhaust treatment fluid from the supply passageway;
a plurality of injectors receiving the exhaust treatment fluid from the supply manifold;
a return passageway through which exhaust treatment fluid from the injectors is returned to the tank;
a bypass passageway connecting the supply passageway with the return passageway and including a bypass valve controlling fluid flow therebetween;
a first pressure sensor measuring a first pressure of exhaust treatment fluid in the supply passageway based upon which the bypass valve is controlled; and
a second pressure sensor measuring a second pressure of exhaust treatment fluid downstream of the supply passageway based upon which the injectors are controlled.
10. The fluid delivery system of claim 9 , wherein the bypass passageway includes a check valve that allows fluid flow through the bypass passageway in a first direction from a first location between a return valve and the tank and a second location between the return valve and a return manifold and prevents fluid flow through the valve-bypass line in a second direction opposite the first direction.
11. The fluid delivery system of claim 9 , wherein the plurality of injectors inject the exhaust treatment fluid into a common exhaust stream.
12. The fluid delivery system of claim 9 , wherein the plurality of injectors inject the exhaust treatment fluid into separate exhaust streams corresponding to multiple combustion engines.
13. A method comprising:
supplying exhaust treatment fluid from a tank to a supply manifold;
controlling an injector that receives the exhaust treatment fluid from the supply manifold based on a first fluid pressure in the supply manifold;
providing a return passageway through which exhaust treatment fluid from the injector is returned to the tank;
providing a bypass passageway connecting the supply manifold with the return passageway and including a bypass valve controlling fluid flow therebetween;
selectively allowing a portion of the exhaust treatment fluid to bypass the injector; and
controlling an amount of the exhaust treatment fluid that is allowed to bypass the injector based on a second fluid pressure upstream of the supply manifold.
14. The method of claim 13 , wherein controlling the injector includes adjusting a pulse-width-modulation duty cycle of the injector.
15. The method of claim 13 , wherein controlling the amount of the exhaust treatment fluid that is allowed to bypass the injector includes adjusting a pulse-width-modulation duty cycle of a bypass valve.
16. The method of claim 13 , further comprising controlling a backpressure of fluid at the injector with a return valve disposed in the return passageway through which exhaust treatment fluid is returned from the injector to the tank.
17. The method of claim 16 , wherein controlling the backpressure of fluid at the injector with the return valve includes controlling the return valve based on a third fluid pressure in the return passageway, wherein controlling the return valve includes adjusting a pulse-width-modulation duty cycle of the return valve.
18. The method of claim 17 , further comprising selectively allowing exhaust treatment fluid to bypass the return valve.
19. A method comprising:
supplying exhaust treatment fluid from a tank to a supply manifold;
controlling an injector that receives the exhaust treatment fluid from the supply manifold based on a first fluid pressure in the supply manifold;
selectively allowing a portion of the exhaust treatment fluid to bypass the injector;
controlling an amount of the exhaust treatment fluid that is allowed to bypass the injector based on a second fluid pressure upstream of the supply manifold,
controlling a backpressure of fluid at the injector with a return valve disposed in a return passageway through which exhaust treatment fluid is returned from the injector to the tank; and
detecting fluid leaks by pumping fluid through the return passageway toward a return manifold.
20. The method of claim 13 , further comprising controlling a plurality of injectors that receive the exhaust treatment fluid from the supply manifold based on the first fluid pressure in the supply manifold.