초록 ▼

A fuel reforming system has a reformer (4) for reforming a fuel to produce a reformate gas; a shift converter (5) for reacting carbon monoxide (CO) contained in a reformate gas with water to produce hydrogen (H2); a CO oxidizer (6) which removes CO discharged from the shift converter; and a startup

A fuel reforming system has a reformer (4) for reforming a fuel to produce a reformate gas; a shift converter (5) for reacting carbon monoxide (CO) contained in a reformate gas with water to produce hydrogen (H2); a CO oxidizer (6) which removes CO discharged from the shift converter; and a startup combustor (11 ) for supplying combustion gas to the reformer (4), a shift converter (5) and CO oxidizer (6) to warm up them. An NOx trap (16) is disposed downstream of the startup combustor so as to adsorb nitrogen oxides (NOx) in combustion gas. A fuel reforming system further has a controller for controlling warm-up operations. When the warm-up operation for the reformer, the shift converter and the CO oxidizer is completed, the reformate reactions are commenced in the reformer (4). The NOx trapped by the NOx trap is decomposed by the reformate gas which contains CO gas and H2 gas.

대표청구항 ▼

The invention claimed is: 1. A fuel reforming system having a reformer for reforming fuel to produce a reformate gas containing hydrogen (H2) gas and carbon monoxide (CO) gas; a shift converter for reacting carbon monoxide contained in the reformate gas with water (H2O) to produce hydrogen; a CO ox

The invention claimed is: 1. A fuel reforming system having a reformer for reforming fuel to produce a reformate gas containing hydrogen (H2) gas and carbon monoxide (CO) gas; a shift converter for reacting carbon monoxide contained in the reformate gas with water (H2O) to produce hydrogen; a CO oxidizer which removes CO gas from the reformate gas discharged from the shift converter and supplies the reformate gas to equipment using hydrogen gas; a startup combustor for supplying combustion gas to the reformer, the shift converter and the CO oxidizer so as to warm-up the fuel reforming system; and a gas passage allowing flow of combustion gas/reformate gas, the gas passage extending to the equipment using hydrogen gas from the startup combustor through the reformer, the shift converter and the CO oxidizer; the fuel reforming system comprising: a first fuel supply device for supplying fuel to the startup combustor; a second fuel supply device for supplying fuel to the reformer; an air supply device for supplying air to the startup combustor; a spark plug for igniting fuel supplied to the startup combustor; an NOx trap disposed between the startup combustor and the equipment using hydrogen gas, the NOx trap adsorbing nitrogen oxides in the combustion gas; and a controller for controlling a warm-up operation of the fuel reforming system, the controller having functions of: commanding the air supply device to supply air to the startup combustor; commanding the first fuel supply device to supply fuel to the startup combustor; commanding the spark plug to ignite fuel in the startup combustor so as to initiate combustion in the startup combustor; controlling a flow amount of air supplied to the startup combustor from the air supply device and a flow amount of fuel supplied to the startup combustor from the first fuel supply device, in response to a temperature of the NOx trap; and commanding the first fuel supply device to stop supplying fuel to the startup combustor after a first predetermined time has elapsed after initiating combustion, and then commanding the second fuel supply device to supply fuel to the reformer. 2. The fuel reforming system as defined in claim 1, wherein at least one member selected from the group consisting of the reformer, the shift converter and the CO oxidizer comprises the NOx trap. 3. The fuel reforming system as defined in claim 1, wherein the controller has the function of controlling the flow amount of air supplied to the startup combustor from the air supply device and the flow amount of fuel supplied to the startup combustor from the first fuel supply device at a first lean air fuel ratio (C1) until the NOx trap reaches a predetermined temperature, and at a second lean air fuel ratio (A1) after the NOx trap reaches the predetermined temperature, wherein the first air fuel ratio (C1) is leaner than the second air fuel ratio (A1). 4. The fuel reforming system as defined in claim 3, wherein the predetermined temperature is substantially equal to 100째 C. 5. The fuel reforming system as defined in claim 1, wherein the NOx trap is disposed in the gas passage between the reformer and the shift converter. 6. The fuel reforming system as defined in claim 5, wherein another NOx trap is disposed in the gas passage between the reformer and the startup combustor. 7. The fuel reforming system as defined in claim 1, wherein the first predetermined time is the time required for warming up the shift converter, the reformer and the CO oxidizer. 8. The fuel reforming system as defined in claim 1, wherein nitrogen oxides adsorbed by the NOx trap are reduced by hydrogen (H 2) gas and carbon monoxide (CO) gas contained in the reformate gas. 9. The fuel reforming system as defined in claim 1, wherein the NOx trap is provided with an NOx trap material which comprises at least one member selected from the group consisting of a precious metal and a transition metal and which further comprises at least one member selected from the group consisting of an alkali metal and an alkali-earth metal. 10. A fuel reforming system having a reformer for reforming fuel to produce a reformate gas containing hydrogen (H2) gas and carbon monoxide (CO) gas; a shift converter for reacting carbon monoxide contained in the reformate gas with water (H2O) to produce hydrogen; a CO oxidizer which removes CO gas from the reformate gas discharged from the shift converter and supplies the reformate gas to equipment using hydrogen gas; a startup combustor for supplying combustion gas to the reformer, the shift converter and the CO oxidizer so as to warm-up the fuel reforming system; and a gas passage allowing flow of combustion gas/reformate gas, the gas passage extending to the equipment using hydrogen gas from the startup combustor through the reformer, the shift converter and the CO oxidizer; the fuel reforming system comprising: a first fuel supply device for supplying fuel to the startup combustor; a second fuel supply device for supplying fuel to the reformer; an air supply device for supplying air to the startup combustor; a spark plug for igniting fuel supplied to the startup combustor; an NOx trap disposed between the startup combustor and the equipment using hydrogen gas, the NOx trap adsorbing nitrogen oxides in the combustion gas; and a controller for controlling a warm-up operation of the fuel reforming system, the controller having functions of: commanding the air supply device to supply air to the startup combustor; commanding the first fuel supply device to supply fuel to the startup combustor; commanding the spark plug to ignite fuel in the startup combustor so as to initiate combustion in the startup combustor; controlling a flow amount of air supplied to the startup combustor from the air supply device and a flow amount of fuel supplied to the startup combustor from the first fuel supply device, in response to the elapsed time after initiation of combustion in the startup combustor; and commanding the first fuel supply device to stop supplying fuel to the startup combustor after a first predetermined time has elapsed after initiating combustion, and then commanding the second fuel supply device to supply fuel to the reformer. 11. The fuel reforming system as defined in claim 10, wherein the controller has the function of controlling the flow amount of air supplied to the startup combustor from the air supply device and the flow amount of fuel supplied to the startup combustor from the first fuel supply device so that a lean air fuel ratio is produced until a second predetermined time elapses after the initiation of combustion by the startup combustor, and so that a rich air fuel ratio is produced after the second predetermined time elapses after the initiation of combustion by the startup combustor, the second predetermined time is shorter than the first predetermined time. 12. The fuel reforming system as defined in claim 11, wherein the second predetermined time is the elapsed time after the initiation of combustion by the startup combustor until a temperature of the NOx trap is reached to a temperature at which nitrogen oxides adsorbed by the NOx trap can oxidize hydrogen (H2) gas and carbon monoxide (CO) gas. 13. The fuel reforming system as defined in claim 10, wherein the NOx trap is disposed in the gas passage between the reformer and the shift converter. 14. The fuel reforming system as defined in claim 13, wherein another NOx trap is disposed in the gas passage between the reformer and the startup combustor. 15. The fuel reforming system as defined in claim 10, wherein the first predetermined time is the time required for warming up the shift converter, the reformer and the CO oxidizer. 16. The fuel reforming system as defined in claim 10, wherein nitrogen oxides adsorbed by the NOx trap are reduced by hydrogen (H 2) gas and carbon monoxide (CO) gas contained in the reformate gas. 17. The fuel reforming system as defined in claim 10, wherein the NOx trap is provided with an NOx trap material which comprises at least one member selected from the group consisting of a precious metal and a transition metal and which further comprises at least one member selected from the group consisting of an alkali metal and an alkali-earth metal. 18. A control method for controlling a fuel reforming system, the fuel reforming system having a reformer for reforming fuel to produce a reformate gas containing hydrogen (H2) gas and carbon monoxide (CO) gas; a shift converter for reacting carbon monoxide contained in the reformate gas with water (H2O) to produce hydrogen; a CO oxidizer which removes CO gas from the reformate gas discharged from the shift converter and supplies the reformate gas to equipment using hydrogen gas; a startup combustor for supplying combustion gas to the reformer, the shift converter and the CO oxidizer so as to warm-up the fuel reforming system; an NOx trap disposed between the startup combustor and the equipment using hydrogen gas; and a gas passage allowing flow of combustion gas/reformate gas; the NOx trap adsorbing nitrogen oxides in the combustion gas, the gas passage extending to the equipment using hydrogen gas from the startup combustor through the reformer, the shift converter and the CO oxidizer; the control method comprising: supplying fuel to the startup combustor; supplying air to the startup combustor; igniting fuel supplied to the startup combustor; controlling a flow amount of air supplied to the startup combustor from the air supply device and a flow amount of fuel supplied to the startup combustor from the first fuel supply device, in response to a temperature of the NOx trap; stopping supplying fuel to the startup combustor after a first predetermined time has elapsed after initiating combustion; and supplying fuel to the reformer. 19. A fuel reforming system having a reformer for reforming fuel to produce a reformate gas containing hydrogen (H2) gas and carbon monoxide (CO) gas; a shift converter for reacting carbon monoxide contained in the reformate gas with water (H2O) to produce hydrogen; a CO oxidizer which removes CO gas from the reformate gas discharged from the shift converter and supplies the reformate gas to equipment using hydrogen gas; a startup combustor for supplying combustion gas to the reformer, the shift converter and the CO oxidizer so as to warm-up the fuel reforming system; and a gas passage allowing flow of combustion gas/reformate gas, the gas passage extending to the equipment using hydrogen gas from the startup combustor through the reformer, the shift converter and the CO oxidizer; the fuel reforming system comprising: an NOx trap disposed between the startup combustor and the equipment using hydrogen gas, the NOx trap adsorbing nitrogen oxides in the combustion gas; first means for supplying fuel to the startup combustor; second means for supplying fuel to the reformer; third means for supplying air to the startup combustor; fourth means for igniting fuel supplied to the startup combustor; and fifth means for commanding the third means to supply air to the startup combustor; sixth means for commanding the first means to supply fuel to the startup combustor; seventh means for commanding the fourth means to ignite fuel in the startup combustor so as to initiate combustion in the startup combustor; eighth means for controlling a flow amount of air supplied to the startup combustor from the air supply device and a flow amount of fuel supplied to the startup combustor from the first fuel supply device, in response to a temperature of the NOx trap; ninth means for commanding the first means to stop supplying fuel to the startup combustor after a first predetermined time has elapsed after initiating combustion, and tenth means for commanding the second means to supply fuel to the reformer. 20. A control method for controlling a fuel reforming system, the fuel reforming system having a reformer for reforming fuel to produce a reformate gas containing hydrogen (H2) gas and carbon monoxide (CO) gas; a shift converter for reacting carbon monoxide contained in the reformate gas with water (H2O) to produce hydrogen; a CO oxidizer which removes CO gas from the reformate gas discharged from the shift converter and supplies the reformate gas to equipment using hydrogen gas; a startup combustor for supplying combustion gas to the reformer, the shift converter and the CO oxidizer so as to warm-up the fuel reforming system; an NOx trap disposed between the startup combustor and the equipment using hydrogen gas; and a gas passage allowing flow of combustion gas/reformate gas; the NOx trap adsorbing nitrogen oxides in the combustion gas, the gas passage extending to the equipment using hydrogen gas from the startup combustor through the reformer, the shift converter and the CO oxidizer; the control method comprising: supplying fuel to the startup combustor; supplying air to the startup combustor; igniting fuel supplied to the startup combustor; controlling a flow amount of air supplied to the startup combustor from the air supply device and a flow amount of fuel supplied to the startup combustor from the first fuel supply device, in response to the elapsed time after initiation of combustion in the startup combustor; stopping supplying fuel to the startup combustor after a first predetermined time has elapsed after initiating combustion; and supplying fuel to the reformer. 21. A fuel reforming system having a reformer for reforming fuel to produce a reformate gas containing hydrogen (H2) gas and carbon monoxide (CO) gas; a shift converter for reacting carbon monoxide contained in the reformate gas with water (H2O) to produce hydrogen; a CO oxidizer which removes CO gas from the reformate gas discharged from the shift converter and supplies the reformate gas to equipment using hydrogen gas; a startup combustor for supplying combustion gas to the reformer, the shift converter and the CO oxidizer so as to warm-up the fuel reforming system; and a gas passage allowing flow of combustion gas/reformate gas, the gas passage extending to the equipment using hydrogen gas from the startup combustor through the reformer, the shift converter and the CO oxidizer; the fuel reforming system comprising: an NOx trap disposed between the startup combustor and the equipment using hydrogen gas, the NOx trap adsorbing nitrogen oxides in the combustion gas; first means for supplying fuel to the startup combustor; second means for supplying fuel to the reformer; third means for supplying air to the startup combustor; fourth means for igniting fuel supplied to the startup combustor; and fifth means for commanding the third means to supply air to the startup combustor; sixth means for commanding the first means to supply fuel to the startup combustor; seventh means for commanding the fourth means to ignite fuel in the startup combustor so as to initiate combustion in the startup combustor; eighth means for controlling a flow amount of air supplied to the startup combustor from the air supply device and a flow amount of fuel supplied to the startup combustor from the first fuel supply device, in response to the elapsed time after initiation of combustion in the startup combustor; ninth means for commanding the first means to stop supplying fuel to the startup combustor after a first predetermined time has elapsed after initiating combustion, and tenth means for commanding the second means to supply fuel to the reformer.