초록 ▼

The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a pre

The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that is to be regenerated (e.g., 20% through the leg to be regenerated, 80% of the flow to the other leg). A quantity of hydrocarbon is injected into the reduced-flow leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst. Once the leg has been regenerated, the flow distribution between the parallel legs is reversed, and the other catalyst leg is regenerated while the other side (which is now clean) receives the majority of the exhaust flow. Another advantage of the present invention is that since NOx is being stored in one leg while the other leg is being regenerated, the regeneration operation can be performed for a longer period of time, resulting in greater regeneration efficiency. Once both catalyst legs have been regenerated, the exhaust flow is adjusted back to normal (e.g. 50-50) until the catalysts are again ready for regeneration and reduction.

대표청구항 ▼

The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a pre

The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that is to be regenerated (e.g., 20% through the leg to be regenerated, 80% of the flow to the other leg). A quantity of hydrocarbon is injected into the reduced-flow leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst. Once the leg has been regenerated, the flow distribution between the parallel legs is reversed, and the other catalyst leg is regenerated while the other side (which is now clean) receives the majority of the exhaust flow. Another advantage of the present invention is that since NOx is being stored in one leg while the other leg is being regenerated, the regeneration operation can be performed for a longer period of time, resulting in greater regeneration efficiency. Once both catalyst legs have been regenerated, the exhaust flow is adjusted back to normal (e.g. 50-50) until the catalysts are again ready for regeneration and reduction. in the additional connections and the existing connections are within a common network. 7. The system of claim 6 wherein the one or more additional connections are opened between the content source and the proxy server disposed between the content source and the content consumer.8. The system of claim 7 wherein the proxy server seams together data streams received from the content source across the additional connections before passing a resultant seamed stream to a subsequent content consumer.9. The system of claim 8 wherein the proxy server constructs the seamed stream by filling in information gaps in any of the data streams received from the content source with content derived from others of the data streams received from the content source.10. The system of claim 9 wherein the content is derived from others of the data streams on the basis of contents of packets from each of the data streams received from the content source.11. A proxy server, comprising: a processor; memory coupled to the processor; a network interface that connects to a content source and a content consumer; and one or more instructions stored in the memory, that when executed by the processor open one or more additional connections between the content consumer and the content source in response to an indication that data loss has occurred over one or more existing connections between the content source and the proxy server, while continuing use of the one or more existing connections, wherein the content source is a Web server, and wherein the additional connections and the existing connections are within a common network. 12. The proxy server of claim 11, wherein the one or more additional connections are opened between the content source and the proxy server disposed between the content source and the content consumer.13. The system of claim 12, wherein the proxy server seams together data streams received from the content source across the additional connections before passing a resultant seamed stream to a subsequent content consumer.14. The system of claim 13, wherein the proxy server constructs the seamed stream by filling in information gaps in any of the data streams received from the content source with content derived from others of the data streams received from the content source.15. The system of claim 14, wherein the content is derived from others of the data streams on the basis of contents of packets from each of the data streams received from the content source.16. A computer readable medium, having stored thereon computer-readable instructions, which when executed in a computer system, cause the computer system to perform opening one or more additional connections between a content consumer and a content source in response to an indication that data loss has occurred over one or more existing connections between the content source and a proxy server, while continuing use of the one or more existing connections, wherein the content source is a Web server, and wherein the additional connections and the existing connections are within a common network. 17. The computer-readable medium of claim 16, wherein the one or more additional connections are opened between the content source and the proxy server disposed between the content source and the content consumer.18. The computer-readable medium of claim 17, wherein the proxy server seams together data streams received from the content source across the additional connections before passing a resultant seamed stream to a subsequent content consumer.19. The computer-readable medium of claim 18, wherein the proxy server constructs the seamed stream by filling in information gaps in any of the data streams received from the content source with content derived from others of the data streams received from the content source.20. The computer-readable medium of claim 19, wherein the content is derived from others of the data streams on the basis of contents of packets from each of th