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US 11,802,687 B2Granted
Method of efficiency enhancement of fired heaters without air preheat systems
AssigneeUop LLC
InventorsNitin P. Chitgopekar, William Yanez, Ka L. Lok
Life of this patent
Estimating the term…
Abstract
A method for improving the efficiency of a fired heater without an air preheat system is described. The method involves the use of an additional outboard convection section which is separate from the regular convection section of the fired heater. The outboard convection section uses the boiler feed water or an alternate cold sink to reduce the temperature of the flue gas, thereby improving the efficiency.
Claims20
A method for improving the efficiency of a fired heater comprising:
- providing the fired heater comprising a radiant section and a fired heater convection section mounted on the radiant section, the radiant section comprising at least one burner;
- combusting fuel gas and an oxygen-containing gas in the at least one burner of the radiant section forming flue gas, the flue gas flowing from the radiant section to the fired heater convection section;
- passing a boiler feed water stream through the fired heater convection section to increase a temperature of the boiler feed water stream and form a heated boiler feed water stream, wherein optionally a portion of the heated boiler feed water stream comprises steam;
- passing a circulating water stream from a steam drum through the fired heater convection section to add heat to the circulating water stream and form a mixture of water and steam;
- combining the heated boiler feed water stream and the heated circulating water stream into a combined stream;
- separating the combined stream in the steam drum into a steam stream and the circulating water stream;
- passing at least a portion of the flue gas from the fired heater convection section to an outboard convection section spaced apart from the fired heater convection section, or optionally bypassing the step of passing the at least the portion of the flue gas from the fired heater convection section to the outboard convection section;
- and
- releasing the flue gas to atmosphere.
6 more elements
A method for improving the efficiency of a fired heater comprising:
- providing the fired heater comprising a radiant section and a fired heater convection section mounted on the radiant section, the radiant section comprising at least one burner;
- combusting fuel gas and an oxygen-containing gas in the at least one burner of the radiant section forming flue gas, the flue gas flowing from the radiant section to the fired heater convection section;
- passing a boiler feed water stream through the fired heater convection section to increase a temperature of the boiler feed water stream and form a heated boiler feed water stream, wherein optionally a portion of the heated boiler feed water stream comprises steam;
- passing a circulating water stream from a steam drum through the fired heater convection section to add heat to the circulating water stream and form a mixture of water and steam;
- combining the heated boiler feed water stream and the heated circulating water stream into a combined stream;
- separating the combined stream in the steam drum into a steam stream and the circulating water stream;
- passing at least a portion of the flue gas from the fired heater convection section vertically downward through an outboard convection section spaced apart from the fired heater convection section, or optionally bypassing the step of passing the at least the portion of the flue gas from the fired heater convection section to the outboard convection section;
- passing the boiler feed water stream through the outboard convection section before passing the boiler feed water stream through the fired heater convection section to cool the flue gas and increase a temperature of the boiler feed water stream, or optionally bypassing the step of passing the boiler feed water stream through the outboard convection section;
- and
- releasing the cooled flue gas to atmosphere.
7 more elements
Dependencies are inferred from the claim text.