A preheating system for preheating fluid medium to be fed into the HRSG is disclosed. The system includes a feed line and a recirculation line. The feed line is adapted to feed the fluid medium to a Low Pressure Economizer (LPE) of the HRSG. The feed line is adapted to be adjoined to an inlet of the LPE, and an outlet of the LPE enables therefrom the flow of the fluid medium in further portion of the HRSG. The recirculation line is adapted to be connected between the outlet and the inlet of the LPE, in parallel to LPE to recirculate the fluid medium to the LPE. A particular method of preheating using such a system is equally disclosed.

A method of steam cracking includes using a steam cracking arrangement that has a fired cracking furnace, a quench cooling train, and rotating equipment at least partly driven by electric energy. A process gas stream is passed through the furnace and the cooling train. A steam generation arrangement, operated in thermal association with the cracking arrangement, results in superheated high pressure steam at a first pressure level of 30 and 175 bar absolute pressure and at a first temperature level. No steam at a higher temperature level than the first is generated. The superheated high pressure steam is partially adiabatically and isenthalpically expanded to a second lower pressure level. The first temperature level is selected such that each intermediate temperature level reached at intermediate pressure levels of more than 20 bar during the adiabatic and isenthalpic expansion process is between 5 and 120 K above the dew point of steam.

A power generation system includes a power generation plant portion including a feedwater heating system configured to channel a feedwater stream and a carbon dioxide capture portion coupled in flow communication with the power generation plant portion. The carbon dioxide capture portion includes a solvent circuit configured to channel a solvent stream through at least a portion of the carbon dioxide capture portion. The carbon dioxide capture portion also includes a heat recovery system coupled in flow communication with the solvent circuit and the feedwater heating system. The heat recovery system is configured to transfer heat energy from the solvent stream to the feedwater stream and to channel the heated feedwater from the heat recovery system to the feedwater heating system.

A vertical heat recovery steam generator, the low-pressure stages of which are designed as a once-through system, having a condensate preheater with at least one condensate preheater heating surface, through which a flow medium flows and which is disposed in a hot gas channel through which hot gas flows, a low-pressure preheater with at least one low-pressure preheater heating surface through which the flow medium flows and which is disposed in the hot gas channel, and a low-pressure evaporator with at least one low-pressure evaporator heating surface through which the flow medium flows and which is disposed in the hot gas channel. The flow medium flows successively through the at least one low-pressure preheater heating surface and the at least one low-pressure evaporator heating surface in one pass and without additional pressure compensation.

A device and method for generating electrical energy from hydrogen and oxygen, includes a combustion engine, a heat recovery steam generator connected into the exhaust gas duct of the combustion engine, wherein the heat recovery steam generator has only one pressure stage. An H.sub.2O.sub.2 reactor is provided to which steam from the heat recovery steam generator, water, oxygen and hydrogen are fed, such that, in the H.sub.2O.sub.2 reactor, a reaction of oxygen and hydrogen forms steam, the water that is introduced is evaporated, additional steam is generated, the resultant superheated steam is fed to a steam turbine, and a generator connected to the steam turbine provides an electric power. High-pressure feed water is injected from the heat recovery steam generator into the H.sub.2O.sub.2 reactor via a line to control the reaction in the H.sub.2O.sub.2 reactor in a targeted manner and set the steam exit temperature from the H.sub.2O.sub.2 reactor.

A power plant with a fossil fuel fired boiler, an air feed system, flue gas system and condensate system. A unitary flue gas heat exchanger spans a bypass line in the flue gas system and the condensate system so as to improve the thermal efficiency of the power plant while minimising complexity.

Methods and systems generate steam for injection in a well to facilitate oil recovery. Water is preheated at a central processing facility, transported to a well pad by hot water lines, and converted to steam by a steam generator at the well pad.

A low-carbon energy utilization system for steam and power cogeneration of oil field is provided, which includes a first water pump device, a second water pump device, electric heating devices, a liquid mixer, a fossil-fuel steam injection boiler, a steam mixer, a super-heater, and a new energy generation station. The electric heating devices are connected to the first water pump device. The liquid mixer is connected to the second water pump device and the electric heating devices. The fossil-fuel steam injection boiler is connected to the liquid mixer. The steam mixer is connected to the electric heating devices and the fossil-fuel steam injection boiler. The super-heater is connected to the steam mixer. The new energy generation station is used for supplying power to the electric heating devices.

Apparatus and method to wet start the HRSG and combined cycle in the fastest time with minimum thermal stress. This wet start provides the earliest possible cooling steam during acceleration, reducing stress in the superheater, reheater and steam turbine. The gas turbine is started and loaded to full power in the fastest possible time without holds. A once-through HRSG filled with saturated boilerwater including the superheater generates dry steam during acceleration. Start apparatus positions the dryout zone in each superheater tube, controls surge swell, ensures uniform pressure rise, and controls the steam temperature. The superheater generates temperature controlled steam to cool the tubes while heating headers. Superheater and reheater tubes and headers start at saturation and increase to operating with minimum differential temperatures. The superheater evaporating boilerwater supplies constant low temperature dry steam to start the steam turbine without the use of attemporators.

The steam boiler system comprises a steam boiler comprising a burner and a chimney for exhausting flue gases, a feedwater line for leading feedwater to said steam boiler for producing steam, a steam line leading from said steam boiler to at least one application heat exchanger for feeding steam to said application heat exchanger, said application heat exchanger for heating an application fluid, and a condensate line leading away from said application heat exchanger for recuperating condensate from said application heat exchanger. An economizer heat exchanger is provided in said chimney, wherein at least one of said condensate return line and said feedwater line circulates through said economizer heat exchanger for allowing at least one of said condensate and said feedwater to be in heat exchange relationship with the flue gases for simultaneously cooling the flue gases while heating at least one of the condensate and the feedwater.