An axial flow baffle for a shell and tube heat exchanger includes a substantially planar body configured for transverse arrangement in a longitudinally elongated shell of the shell and tube heat exchanger, a plurality of axial flow tube apertures each comprising a central tube hole configured to receive a tube of the heat exchanger, and an array of peripheral primary flow holes circumferentially spaced apart around the tube hole. The primary flow holes each interrupt the central tube hole and formed a radially inward projecting tube support protrusions between the primary flow holes which engage a single tube. Each primary flow hole has a non-polygonal configuration, which may be semicircular in some embodiments. The primary flow holes create axial flow around the periphery of the tubes through the baffles. In another aspect, a hybrid cross-flow baffle includes a combination of axial flow tube apertures and circular tube support holes.

An axial flow baffle for a shell and tube heat exchanger includes a substantially planar body configured for transverse arrangement in a longitudinally elongated shell of the shell and tube heat exchanger, a plurality of axial flow tube apertures each comprising a central tube hole configured to receive a tube of the heat exchanger, and an array of peripheral primary flow holes circumferentially spaced apart around the tube hole. The primary flow holes each interrupt the central tube hole and formed a radially inward projecting tube support protrusions between the primary flow holes which engage a single tube. Each primary flow hole has a non-polygonal configuration, which may be semicircular in some embodiments. The primary flow holes create axial flow around the periphery of the tubes through the baffles. In another aspect, a hybrid cross-flow baffle includes a combination of axial flow tube apertures and circular tube support holes.

Disclosed is a Once-Through Steam Generator (OTSG) coil (52) and method, comprising a plurality of vertically arranged serpentine conduits (90) in a horizontal heat recovery steam generator (HRSG) that replaces a traditional natural circulation HP evaporator for producing super-critical steam. The OTSG comprises a lower equalization header system (130) that promotes system stability in multiple operating conditions. The equalization header allows a partial flow of fluid from the lower serpentine curved flow path (120) through an equalization conduit (125) into the equalization header (130) Disclosed also are: a flow restriction device in serpentine conduits; drainage structure from serpentine conduits through the equalization header, a drainage expansion section to accommodate stresses, and drainage bypass connections; and flow through serpentine conduits in upstream and downstream directions, mixed flow directions and longitudinally staggered directions.

Disclosed is a Once-Through Steam Generator (OTSG) coil (52) and method, comprising a plurality of vertically arranged serpentine conduits (90) in a horizontal heat recovery steam generator (HRSG) that replaces a traditional natural circulation HP evaporator for producing super-critical steam. The OTSG comprises a lower equalization header system (130) that promotes system stability in multiple operating conditions. The equalization header allows a partial flow of fluid from the lower serpentine curved flow path (120) through an equalization conduit (125) into the equalization header (130) Disclosed also are: a flow restriction device in serpentine conduits; drainage structure from serpentine conduits through the equalization header, a drainage expansion section to accommodate stresses, and drainage bypass connections; and flow through serpentine conduits in upstream and downstream directions, mixed flow directions and longitudinally staggered directions.

Systems and methods axe disclosed herein that generally involve a double pinch criterion for optimization of regenerative Rankine cycles. In some embodiments, operating variables such as bleed extraction pressure and bleed flow rate are selected such that a double pinch is obtained in a feedwater heater, thereby improving the efficiency of the Rankine cycle. In particular, a first pinch point is obtained at the onset of condensation of the bleed and a second pinch point is obtained at the exit of the bleed from the feedwater heater. The minimal approach temperature at the first pinch point can be approximately equal to the minimal approach temperature at the second pinch point. Systems that employ regenerative Rankine cycles, methods of operating such systems, and methods of optimizing the operation of such systems are disclosed herein in connection with the double pinch criterion.

Systems and methods axe disclosed herein that generally involve a double pinch criterion for optimization of regenerative Rankine cycles. In some embodiments, operating variables such as bleed extraction pressure and bleed flow rate are selected such that a double pinch is obtained in a feedwater heater, thereby improving the efficiency of the Rankine cycle. In particular, a first pinch point is obtained at the onset of condensation of the bleed and a second pinch point is obtained at the exit of the bleed from the feedwater heater. The minimal approach temperature at the first pinch point can be approximately equal to the minimal approach temperature at the second pinch point. Systems that employ regenerative Rankine cycles, methods of operating such systems, and methods of optimizing the operation of such systems are disclosed herein in connection with the double pinch criterion.

A system for warming a power generation system including a boiler and a mixer fluidly coupled to the boiler, a turbine first section operable to receive steam from the boiler at a first temperature. The turbine supplies steam at a second temperature to a first heat exchanger operably connected to receive the heated steam at the second temperature from the output of at least the first section of the turbine and transfer heat to at least one of water and steam in the boiler or the mixer, feedwater for the boiler, and a thermal energy storage system. The system further includes a control unit configured to receive the monitored operating characteristic and control the amount of steam directed through the turbine.

The invention relates generally to methods and apparatus for start-up and control of liquid salt energy storage combined cycle systems.

An apparatus and method for recovery of waste heat in a boiler system, wherein heat from the low pressure steam in the feed water tank, which otherwise would be lost through dissipation, is used for other applications. Particularly, the waste heat energy recovered in the form of low pressure steam can be used to heat make-up water for the boiler system.

An apparatus and method for recovery of waste heat in a boiler system, wherein heat from the low pressure steam in the feed water tank, which otherwise would be lost through dissipation, is used for other applications. Particularly, the waste heat energy recovered in the form of low pressure steam can be used to heat make-up water for the boiler system.