Abstract: Solar/Rankine steam cycle hybrid concentrating solar power (CSP) systems and methods for designing or retrofitting existent natural circulation boilers using saturated or superheated steam produced by direct steam generation (DSG) or Heat Transfer Fluid (HTF) steam generators and CSP solar field technology systems are described. Additionally, methods and processes of retrofitting the existent Heat Recovery Steam Generators (HRSG) or biomass, gas, oil or coal fired boilers to operate integrated to a molten salt/water-steam heat exchangers are disclosed. The hybrid CSP systems are highly efficient due to the increase of steam generated by a heating section comprising either the DSG receiver or the molten salt-water-steam sequential heat exchangers, heaters, boiler/saturated steam generators, super-heaters and re-heaters.

Abstract: The present application relates to a heat recovery apparatus and a method thereof, according to the heat recovery apparatus and a method thereof according to an embodiment of the present application, steam of 120° C. or more may be generated using only one heat exchanger using waste heat of a low-grade heat source in the state of a sensible heat of 70° C. or more discharged in industrial sites or various chemical processes, for example, such as a manufacturing process of petrochemicals, and the generated steam may also be used in various processes, and thus the use of high temperature steam which is an external heat source to be used in a reactor or a distillation column may be decreased, thereby maximizing energy saving efficiency.

Abstract: In a gasification apparatus, a gasification furnace (101) having an octagonal hollow cross-sectional shape, a heat exchanger (102) having a quadrangular hollow cross-sectional shape, and a connection portion (103) which connects an upper portion of the gasification furnace (101) to a lower portion of the heat exchanger (102) are provided, thereby simplifying structures and enhancing efficiencies can be achieved.

Abstract: A once-through steam generator comprises a duct having an inlet end in communication with a source of a hot gas; and a tube bundle installed in the duct and comprising multiple heat transfer tubes. The tube bundle has an economizer section, an evaporator section, and a superheater section. A steam separating device may be positioned between the evaporator section and the superheater section, wherein, as part of a wet start-up, hot water collected by the steam separating device is delivered from the steam separating device to mix with cold feedwater before it is introduced into the economizer section. A start-up module may be positioned in the duct near the inlet end, wherein, as part of a dry start-up, cold feedwater is delivered into the start-up module to generate hot water that is then mixed into the feedwater stream before it is introduced into the economizer section.

Abstract: A power plant is suggested with an additional heat transfer between the flue gas that flows through a flue gas line (5) and the feed-water in a feed-water line (19). The claimed arrangement of the first heat exchanger (13) upstream and adjacent to a precipitator (7) leads to a reduced space demand and optimises dust precipitation as well as the pressure drop of the flue gas.

Abstract: A device for recovering residual heat from exhaust gas includes: a dry economizer which heats to-be-heated water by utilizing sensible heat of the exhaust gas, the dry economizer being provided in a duct extending to a funnel through which the exhaust gas is emitted to atmosphere; and a condensation economizer which heats to-be-heated water by utilizing latent heat of condensation of the exhaust gas, the condensation economizer being provided on a downstream side of the dry economizer. The duct includes an upstream duct in which the dry economizer is provided and a downstream duct connected to the upstream duct and directing the exhaust gas to flow upwardly. The condensation economizer is arranged in the downstream duct so that temperature of the exhaust gas amounts to condensation temperature at a vicinity of an upper part of the condensation economizer.

Abstract: A module for heat recovery from exhausted flue gas in a steam generator is described comprising a flue gas outlet conduit defining a flow path for flue gas from a flue gas outlet of a steam generator to a flue gas conduit junction; a first flue gas conduit defining a flow path for flue gas from the junction to a first air heater; a second flue gas conduit defining a flow path for flue gas from the junction to at least one high pressure and at least one low pressure process liquid economiser. A steam generator using the module, a method implementing the flow principles embodied in such a module, and a method of incorporation of such a module into a steam generator, especially by retrofit, are also described.

Abstract: A heat recovery boiler has a casing, a superheater having a heat transfer pipe, an evaporator provided with a steam drum, and an economizer. The superheater, evaporator and economizer arranged in the casing along a flow of an exhaust gas from the combustion system. A lead pipe connects an inlet of the pipe line to the steam drum while a superheated steam pipe line connects an outlet of the pipe line to the steam drum of the evaporator. A drain pipe is connected to the pipe line while a superheater bypass pipe having a superheater bypass valve has a first end operatively connected to the steam drum and a second end connected to the superheated steam pipe. With this arrangement, the superheater bypass valve incorporated into the superheater bypass pipe and a drain valve in the drain pipe are opened. Force is applied to water collected in the bottom of the superheater by passing saturated steam generated from the steam drum through the lead pipe and the superheater bypass pipe.

Abstract: A flue gas desulfurizer having an absorption tower for bringing untreated flue gas into gas-liquid contact with an absorbent slurry, wherein there is provided heat recovery means for recovering heat from the flue gas passing through the flue gas inlet section of the absorption tower prior to gas-liquid contact, and to boiler equipment including heat release means for releasing the recovered heat to heat utilization equipment. This invention also relates to thermal electric power generation equipment including extraction feedwater heaters for heating boiler feedwater with steam from steam turbines, a flue gas desulfurizer using an absorbent slurry, and means for recovering heat from the flue gas passing through the flue gas desulfurizer and/or the absorbent slurry within the flue gas desulfurizer, whereby boiler feedwater is preheated by the recovered heat and then introduced into the extraction feedwater heaters.

Abstract: A mixed-pressure waste-heat boiler (7) has a forced-flow steam generator, essentially composed of a low-pressure economizer (15), of a low-pressure drum (17) and of a low-pressure evaporator (16), and a once-through forced-flow steam generator, essentially composed of a high-pressure economizer (21), of a high-pressure evaporator (22) and of a high-pressure superheater (23). The high-pressure economizer (21) is fed from the steam drum (17) of the forced-circulation steam generator via a high-pressure feed pump (20). Arranged between the high-pressure evaporator (22) and high-pressure superheater (23) is a separation bottle (25) which is connected to the steam drum (17) via a recirculation line (26). During startup, until superheated conditions are reached at the outlet of the high-pressure evaporator (22), high-pressure saturated water is recirculated into the drum (17) of the forced-circulation steam generator via the separation bottle (25).

Abstract: A steam power plant for generating electric power has a fossil-fuelled boiler, a water-steam cycle for generating high-tension, superheated steam for a steam turbine, an economizer to transmit heat from flue gas to the feed-water, an air preheater to transmit flue gas heat to fresh air and devices for removing dust, sulphur and possibly nitrogen from the flue gases. In order to optimize heat exchange in the air preheater during operation and reduce the heat loses during start-up of the steam power plant, a heat exchanger system is provided with sections through which recirculated air and a heat vehicle medium flow, in which the section carrying the air is connected on the intake side to the fresh-air outlet of the air preheater and on the outlet side to the fresh-air intake of the air preheater.

Abstract: An arrangement for utilizing the heat contained in the exhaust gas from a coal-fired boiler for preheating feed water for the boiler and for preheating primary air. The arrangement includes a rotating heat transfer unit and lines for conducting exhaust gas and preheated combustion air to the heat transfer unit. A heat shifting unit is connected in parallel to the heat transfer unit. A line conducts primary air to the heat shifting unit and another line conducts cooled exhaust gas from the heat transfer unit to the heat shifting unit. The exhaust gas line and the cooled exhaust gas line connecting the heat transfer unit and the heat shifting unit are connected through a bypass which bridges the heat transfer unit. The bypass includes a heat exchanger and/or steam generator, wherein the boiler feed water flows through the heat exchanger and/or steam generator.

Abstract: A once-through steam generator comprises an economizer, an evaporator and a superheater connected in series one below the other in a boiler pass, and are acted upon by a hot gas mass flow flowing in the opposite direction. In order to prevent thermal shock during the introduction of cold feed water when starting the steam generator from a hot state, i.e., with an economizer, evaporator and superheater which are empty and heated to the exhaust gas temperature, a high-temperature starter is connected upstream of the economizer and is arranged above the latter in the boiler pass. The starter acts as a heat buffer so that the economizer, evaporator and superheater are first acted upon by superheated steam and are continuously cooled to their normal operating temperature. The starter is constructed in such a way that its portion which first comes into contact with the cold feed water does not support the steam pressure so that it need only absorb thermal stresses.

Abstract: A waste heat recovery boiler comprising heat exchange rate switching means for controlling the rate of heat exchange between an exhaust gas and feedwater in a heat exchanger by changing the state of the feedwater in accordance with the concentration of sulfur oxides in the exhaust gas, thereby maintaining the temperature at which low temperature corrosion due to the exhaust gas is prevented in a downstream portion of the heat exchanger in the direction in which the exhaust gas flows. Accordingly, it is possible to achieve the maximum efficiency of heat recovery since the phenomenon of steaming in the heat exchanger is eliminated irrespective of whether the kind of exhaust gas is a dirty gas or a clean gas.

Abstract: A method and apparatus for recovery of heat from the flue gas of the combustion furnace of a steam boiler or power generation plant uses a heat pump heat extracted from a lower temperature point in the system to a higher temperature point in the system. The flue gas is passed through an economizer to preheat the boiler feed water. The flue gas then passes to a direct contact gas cooler where a second stream of cooling water extracts heat from the flue gas. The second stream of cooling water is passed through the evaporator of the heat pump to heat a refrigerant. The refrigerant is compressed and then condensed in thermal contact with the boiler feed water to heat it before it enters the economizer. In a second embodiment a power generation plant has a steam turbine and an auxiliary vapor turbine. The flue gas is passed through a gas cooler and gives up heat to a stream of cooling water.

Abstract: A cartridge boiler designed for use in multiples in a furnace, each cartridge boiler having a vertically oriented cylindrical drum top and bottom with hemispherical end caps, with a plurality of free-expansion boiler tubes having internal feed water supply tubes depending in a cluster through the bottom end cap. The supply tubes are gravity fed by an open feed water pan within the drum, the feed water supply being controlled by a boiler level monitoring device. The boilers are used in multiples to generate the steam required, the relative small size of individual cartridge boiler being designed to minimize fabrication costs by minimizing drum diameters, and maximize system performance by allowing select cartridge replacement without system shutdown.

Abstract: In a steam generating system, steam condensate extracted from steam used to reheat boiler water in heaters (H1, . . . , H4) is revaporized in the recuperators-vaporizers (RV1, . . . , RV3) by heat exchange contact with the flue gas from boiler (B). The steam thus formed is recycled to contribute to the reheating of the water fed to the boiler.

Abstract: The present invention relates to a waste heat boiler construction where the convection chamber (5) of the waste heat boiler is located on essentially lower level than the radiation chamber (2). In order to lower the end of the radiation chamber (2) gradually onto the level of the convection chamber (2), into the radiation chamber are placed walls (1) essentially in transversal direction to the gas flow, which walls at the same time divide the radiation chamber into separate sections. In order to profitably conduct the gas flow in the radiation chamber, the roof of the radiation chamber (2) is provided with panels (3) located in the gas flow direction, so that the gas flows from the previous section are divided roughly into two by means of the panels (3) of the following section.

Abstract: Heat recovery boiler equipment comprising high and low pressure boiler drums and high and low pressure evaporators is disclosed. A recirculation pipeline system is also disclosed in which a control device is provided to control the flow rate of recirculated feed water to maintain a temperature below which cold corrosion occurs. The recirculation of feed water allows for a shorter starting time during restart. Additionally, pressure can be held at a predetermined value to prevent corrosion due to the intrusion of air.

Abstract: Energy and water are recovered from flue gases by cooling them to a temperature sufficiently below the acid dew point temperature by contact with an aqueous stream so as to recover the sensible heat and to reduce the water content of the flue gases by about 50%. The water by which the aqueous stream is enriched is subsequently flashed off to cool the stream back to its original temperature and the water vapor is then compressed to generate a higher temperature vapor stream which is condensed to recover the water and extract heat. The aqueous stream is continuously enriched with material such as calcium carbonate to control the pH sufficiently as to avoid substantial corrosion due to acidic gases removed from the flue gases and the aqueous stream is purged continuously or periodically to remove compounds such as chlorides, calcium sulphates, and fly ash solids picked up from the flue gases.

Abstract: A once-through steam generator has both radiant and convection sections. The flue gases discharged from the convection section are passed through a wet scrubber to remove both sulfur oxides (SO.sub.x) and particulate matter. The feedwater to the convection section has its temperature controlled by the temperature of the flue gases discharged from the convection section, reducing the temperature of the feedwater by the use of a feedwater exchanger, as the convection section progressively fouls due to particulates in the flue gases. An additional heat exchanger upstream of the feedwater exchanger and convection section which scavenges additional heat from the wet scrubber liquids while the temperature of the flue gases into the scrubber are lowered to a temperature equal to or less than the water dew point temperature of the flue gases entering the scrubber.

Abstract: An apparatus and method are disclosed for the recovery of sensible heat from a hot tar-free gas produced in a coal gasification process and in combined-cycle power generation. The recovered heat is utilized to generate a flow of superheated steam which may be used in the gasification plant. The apparatus includes a first boiler and a superheater fabricated from materials susceptible to damage from thermal shock when a flow of the tar-free gas having a temperature in excess of a predetermined safety temperature is introduced to the superheater when it is dry. The first boiler, filled with a flow of saturated water, initially receives the flow of gas. Within the first boiler, the gas indirectly heats the water converting it to a flow of saturated steam and reducing the gas temperature below the safety temperature. The reduced temperature gas is passed to the superheater and the saturated steam is passed to the superheater.

Abstract: Device for preventing flashing to steam in an economizer of a flow-through steam generator wherein the economizer has heating surfaces disposed downstream of an evaporator and superheater surfaces in direction of a flue-gas path, including at least one partition separating the cross section of the flue-gas path in vicinity of the economizer into at least two joint areas separated from one another, the economizer having tubes disposed only in one of the thus formed joint areas, and further including shut-off devices for the flue-gas disposed upstream of the tubes of the economizer as viewed in the direction of the flue-gas path.

Abstract: A boiler economizer includes a first heat exchanger disposed in a boiler flue and a second heat exchanger which is external. Boiler feedwater is delivered in series to the first and second heat exchangers before passage to the boiler. A flow controller directs a first portion of the boiler feedwater directly to the first heat exchanger and a second portion is first delivered through the second heat exchanger where it is passed in a heat exchange relation with the feedwater exiting the first heat exchanger. The flow controller is positioned by a temperature transponder which is responsive to the temperature of the discharge flue gases and the feedwater entering the first heat exchanger.