Patent ID: 10808923

Abstract:
A high efficiency multi-stage duct fired heat recovery steam generator (HRSG) is provided to generate steam for use in thermal enhanced oil recovery (EOR) applications. The HRSG is equipped with a plurality of duct burners in series and a plurality of evaporators for transferring heat from the duct burners to the water to generate steam, with at least one evaporator corresponding to each of the duct burners. Each evaporator is arranged downstream from the corresponding duct burner. At least one perforated plate is configured to disperse and distribute available oxygen within a subsequent duct burner. Hot exhaust gas from a gas turbine (over 1000° F.) is directed to the duct burners in series, allowing further combustion and maximizing thermal efficiency for the HRSG to have a thermal efficiency of at least 92%, and for the exhaust gas exiting the HRSG to contain oxygen in a range of 2% to 8%.