초록 ▼

The present disclosure is directed to a system for reducing the cold start time for a vehicle with a twin fuel engine. The system has an exhaust system, from which exhaust is discharged and collected on an exhaust manifold. A heat exchanger is positioned within the exhaust system, with coolant flow

The present disclosure is directed to a system for reducing the cold start time for a vehicle with a twin fuel engine. The system has an exhaust system, from which exhaust is discharged and collected on an exhaust manifold. A heat exchanger is positioned within the exhaust system, with coolant flow passages in thermal communication with the engine, and the heat exchanger. A control valve is coupled to a first flow path operable to direct the exhaust through the heat exchanger across the first flow path and a second flow path in selective amounts.

대표청구항 ▼

1. A method for vaporizing cryogenic liquid natural gas (LNG) for use in an engine, the engine including an exhaust manifold, the method comprising: directing a portion of exhaust through a first heat exchanger;directing a circulating liquid through the first heat exchanger;heating the circulating l

1. A method for vaporizing cryogenic liquid natural gas (LNG) for use in an engine, the engine including an exhaust manifold, the method comprising: directing a portion of exhaust through a first heat exchanger;directing a circulating liquid through the first heat exchanger;heating the circulating liquid within the first heat exchanger to at least a first predetermined temperature;directing the circulating liquid from the first heat exchanger through a second heat exchanger; andvaporizing the cryogenic LNG within the second heat exchanger using heat from the circulating liquid. 2. The method of claim 1, wherein the circulating liquid is engine coolant. 3. The method of claim 1, wherein vaporizing the cryogenic LNG includes pumping the cryogenic LNG from a pressurized LNG tank into the second heat exchanger. 4. The method of claim 1, further comprising: measuring the temperature of the circulating liquid within the first heat exchanger with an electronic thermostat; andtransmitting a temperature signal of the circulating liquid to a controller, the controller operable to modulate a control valve controlling the flow of exhaust. 5. The method of claim 1, further comprising: measuring the temperature of the circulating liquid when exiting the first heat exchanger with an electronic thermostat; andtransmitting a temperature signal of the circulating liquid to a controller operable to modulate a control valve controlling the flow of exhaust. 6. The method of claim 1, wherein the engine is configured to run on either a first type of fuel or a second type of fuel, wherein the first fuel is different from the second fuel and one of the first fuel and the second fuel is natural gas. 7. The method of claim 1, wherein the first predetermined temperature is a temperature at which the circulating liquid is able to vaporize the cryogenic LNG without the circulating liquid freezing. 8. The method of claim 1, wherein the circulating liquid vaporizes the cryogenic LNG within a predetermined time from initializing the engine, where the predetermined time is a shorter period time than a time period to vaporization of the cryogenic LNG in the absence of a heat exchange relationship between a portion of the exhaust and the circulating liquid. 9. The method of claim 1, further comprising limiting the flow of exhaust when the circulating liquid reaches a second predetermined temperature within the first heat exchanger. 10. The method of claim 9, wherein the second predetermined temperature is a temperature at which the circulating liquid vaporizes the cryogenic LNG without the circulating liquid freezing. 11. The method of claim 1, further comprising stopping the flow of exhaust to the first heat exchanger when the circulating liquid reaches a third predetermined temperature within the first heat exchanger. 12. The method of claim 11, wherein the third predetermined temperature is a temperature at which the circulating liquid is below its boiling point. 13. A system for reducing a cold-start time in a vehicle with an engine, comprising: an exhaust manifold that is configured to receive and collect discharged exhaust gas from the engine;a first heat exchanger connected to the exhaust manifold;a second heat exchanger connected to the first heat exchanger;coolant flow passages in thermal communication with the first heat exchanger and the second heat exchanger, the coolant flow passages configured to receive a coolant;a control valve, coupled to a first flow path, operable to direct the exhaust through the first heat exchanger across the first flow path and a second flow path in selective amounts;wherein the first heat exchanger is configured to heat the coolant using heat from the exhaust gas and the second heat exchanger is configured to vaporize cryogenic LNG using heat from the coolant. 14. The system of claim 13, further comprising liquid natural gas flow passages in thermal communication with the second heat exchanger. 15. The system of claim 13, wherein the control valve is a turbocharger waste gate control valve. 16. The system of claim 13, further comprising: a thermostat operable to sense the temperature of the coolant in, or exiting, the heat exchanger; anda controller operable to receive a thermostat signal and send a signal to modulate the control valve to a first, a second, and a third position based on the thermostat signal. 17. The system of claim 16, wherein: the first position is a fully open position of the control valve where the exhaust flows through the first flow path and the second flow path,the second position is a partially closed position of the control valve where the exhaust flows through the first flow path and the second flow path, the amount of exhaust flowing through the first flow path being less than the amount flowing through the first flow path in the first position, andthe third position is a fully closed position of the control valve, where the exhaust flows through only the second flow path. 18. A cold-start reduction system for a twin-fuel engine comprising: an engine configured to run on either a first fuel or a second fuel, wherein the first fuel is different from the second fuel and one of the first fuel and the second fuel is liquid natural gas (LNG);an exhaust manifold in fluid communication with the engine, the exhaust manifold configured to receive exhaust gas from the engine;a coolant reservoir configured to receive a coolant;a first heat exchanger coupled to the exhaust manifold by a first conduit, the first heat exchanger further coupled to the coolant reservoir by a second conduit, the first heat exchanger configured to transfer heat from the exhaust gas to the coolant;a storage tank that is configured to receive cryogenic LNG; anda second heat exchanger coupled to the first heat exchanger by a third conduit, the second heat exchanger further coupled to the storage tank by a fourth conduit, the second heat exchanger configured to transfer heat from the coolant heated by the first heat exchanger to the cryogenic LNG so as to vaporize the LNG. 19. The system of claim 18, further comprising: a thermostat operable to sense a temperature of the coolant after the coolant is heated by the exhaust gas; anda controller operable to receive a thermostat signal and send a signal to modulate the control valve based on the thermostat signal. 20. The system of claim 19, wherein the controller modulates the control valve to: a fully open position in which the exhaust gas flows from the exhaust manifold to the first heat exchanger at a first rate,a partially closed position in which the exhaust gas flows from the exhaust manifold to the first heat exchanger at a second rate, wherein the first rate is greater than the second rate, anda fully closed position in which exhaust gas does not flow to the heat exchanger.