The present disclosure relates to a boiler water supply preheater system which preheats water (boiler water supply) supplied to a boiler by a predetermined preheating means, wherein the preheating means is a Rankine cycle (thermal cycle) which moves heat of a waste heat source in the boiler to the boiler water supply to perform preheating and drives a generator to generate electric power using a heat medium.

The present disclosure relates to a boiler water supply preheater system which preheats water (boiler water supply) supplied to a boiler by a predetermined preheating means, wherein the preheating means is a Rankine cycle (thermal cycle) which moves heat of a waste heat source in the boiler to the boiler water supply to perform preheating and drives a generator to generate electric power using a heat medium.

A condensing heat recovery steam generator (cHRSG) includes a main stack for an exhaust hot gas main flow, a bypass stack for allowing a fraction of exhaust hot gas to bypass the exhaust hot gas main flow, and a heat pump. The cHRSG includes a primary water circuit, a secondary water circuit, and a tertiary water circuit. The cHRSG additionally includes a feedwater line, a first heat exchanger for providing heat exchange between the feedwater line and the secondary water circuit, and a second heat exchanger for providing heat exchange between the primary water circuit and the tertiary water circuit. In the cHRSG, latent heat is partially recovered from said exhaust hot gas circulating in the bypass stack through the second heat exchanger and additional heat is extracted in the tertiary water circuit by said heat pump, contributing to a preheating performed in a preheater of the primary water circuit.

A condensing heat recovery steam generator (cHRSG) includes a main stack for an exhaust hot gas main flow, a bypass stack for allowing a fraction of exhaust hot gas to bypass the exhaust hot gas main flow, and a heat pump. The cHRSG includes a primary water circuit, a secondary water circuit, and a tertiary water circuit. The cHRSG additionally includes a feedwater line, a first heat exchanger for providing heat exchange between the feedwater line and the secondary water circuit, and a second heat exchanger for providing heat exchange between the primary water circuit and the tertiary water circuit. In the cHRSG, latent heat is partially recovered from said exhaust hot gas circulating in the bypass stack through the second heat exchanger and additional heat is extracted in the tertiary water circuit by said heat pump, contributing to a preheating performed in a preheater of the primary water circuit.

A device with a heat exchanger with a feed pipe for a medium leading from a medium inlet to the heat exchanger entrance and with a discharge pipe leading away from the heat exchanger exit is characterized in that it has a first bypass from the medium inlet to the discharge pipe and a second bypass from the feed pipe to the medium outlet and valves, so that the medium can also flow from the heat exchanger exit to the heat exchanger entrance.

A device with a heat exchanger with a feed pipe for a medium leading from a medium inlet to the heat exchanger entrance and with a discharge pipe leading away from the heat exchanger exit is characterized in that it has a first bypass from the medium inlet to the discharge pipe and a second bypass from the feed pipe to the medium outlet and valves, so that the medium can also flow from the heat exchanger exit to the heat exchanger entrance.

In a power generation facility (10) wherein a fluidized bed combustion unit (12) produces steam to power a steam turbine generator (32), a heat recovery steam generator (20) produces steam for the steam turbine generator. Electrical power from the steam turbine generator is conducted to a motor (40) that drives and air compressor (36). The air compressor provides pressurized air back to the fluidized bed combustion unit (12) to promote fuel combustion. Flue gas from the heat recovery steam generator is selectively conducted to a CO2 capture unit (18) and then to a gas expander (42) that assists the motor in driving the air compressor (36). A heat exchanger (46) that is upstream of the CO2 Capture Unit and a heat exchanger (56) that is downstream of the CO2 Capture Unit and upstream of the air expander have thermal fluid sides that are connected in a closed circuit. The heat exchangers (46 and 56) convey heat away from the CO2 Capture Unit and provide heat to flue gas flowing to the gas expander to avoid icing conditions in the gas expander and acid condensation in the air emission stack.

In a power generation facility (10) wherein a fluidized bed combustion unit (12) produces steam to power a steam turbine generator (32), a heat recovery steam generator (20) produces steam for the steam turbine generator. Electrical power from the steam turbine generator is conducted to a motor (40) that drives and air compressor (36). The air compressor provides pressurized air back to the fluidized bed combustion unit (12) to promote fuel combustion. Flue gas from the heat recovery steam generator is selectively conducted to a CO2 capture unit (18) and then to a gas expander (42) that assists the motor in driving the air compressor (36). A heat exchanger (46) that is upstream of the CO2 Capture Unit and a heat exchanger (56) that is downstream of the CO2 Capture Unit and upstream of the air expander have thermal fluid sides that are connected in a closed circuit. The heat exchangers (46 and 56) convey heat away from the CO2 Capture Unit and provide heat to flue gas flowing to the gas expander to avoid icing conditions in the gas expander and acid condensation in the air emission stack.

A steam generator apparatus for generating steam from a feedwater inlet stream including impurities is disclosed. The apparatus includes a tubing circuit in communication with an inlet for receiving the feedwater stream, the tubing circuit having a substantially unrifled bore defined by a metal wall, and a heat source operable to deliver a heat flux to the feedwater stream through the metal wall of the tubing circuit, the heat flux being operable to cause evaporation of feedwater within the tubing circuit and to produce an outlet stream at an outlet of the tubing circuit, the outlet stream includes a steam portion and liquid phase portion, the steam portion being greater than about 80% of the outlet stream by mass, the steam portion providing sufficient cooling of the metal wall to maintain a wall temperature at less than a threshold temperature associated with safe operation of the steam generator apparatus.

A steam generator apparatus for generating steam from a feedwater inlet stream including impurities is disclosed. The apparatus includes a tubing circuit in communication with an inlet for receiving the feedwater stream, the tubing circuit having a substantially unrifled bore defined by a metal wall, and a heat source operable to deliver a heat flux to the feedwater stream through the metal wall of the tubing circuit, the heat flux being operable to cause evaporation of feedwater within the tubing circuit and to produce an outlet stream at an outlet of the tubing circuit, the outlet stream includes a steam portion and liquid phase portion, the steam portion being greater than about 80% of the outlet stream by mass, the steam portion providing sufficient cooling of the metal wall to maintain a wall temperature at less than a threshold temperature associated with safe operation of the steam generator apparatus.