Abstract: A small supercritical once-through steam generator (OTSG) includes a radiant section with a furnace coil, and a convection section downstream of the radiant section that includes a superheater which is fluidically connected to the furnace coil. Optionally, the OTSG is devoid of a steam separator. An economizer can also be included downstream of the superheater. Supercritical steam can be generated using the OTSG, for use, among other things, in enhanced oil recovery applications.

Abstract: A small supercritical once-through steam generator (OTSG) includes a radiant section with a furnace coil, and a convection section downstream of the radiant section that includes a superheater which is fluidically connected to the furnace coil. Optionally, the OTSG is devoid of a steam separator. An economizer can also be included downstream of the superheater. Supercritical steam can be generated using the OTSG, for use, among other things, in enhanced oil recovery applications.

Abstract: A control system for maintaining a desired heat exchanger outlet flue gas temperature across a range of boiler loads. The heat exchanger includes a plurality of tubular configurations in heat exchange contact with the flue gas with each tubular configuration having a separate feedwater inlet. Flue gas temperature control is achieved by modulating the feedwater flow rates through the tubular configurations. In a system having two tubular configurations, the overall heat transfer capacity of the heat exchanger may be reduced to maintain the desired heat exchanger outlet flue gas temperature by reducing feedwater flow through one tubular configuration and overflowing the other, while maintaining the total flow of feedwater through the heat exchanger substantially constant.

Abstract: A gas temperature control system for maintaining a desired economizer outlet gas temperature across a range of boiler loads comprises a plurality of tubular configurations having surfaces that are in contact with the flue gas. Each tubular configuration, preferably, comprises a plurality of serpentine or stringer tubes arranged horizontally or vertically back and forth within the economizer, and each tubular configuration having a separate feedwater inlet. Heat transfer from the flue gas is accomplished by controlling the feedwater flow rates through the tubular configurations. In a temperature control system having two tubular configurations, the overall heat transfer capacity of the economizer may be reduced to maintain the desired economizer outlet gas temperature during low boiler loads by reducing feedwater flow through one tubular configuration and by overflowing the other tubular configuration, such that total flow of feedwater through the economizer is maintained substantially constant.