1526results about "Fluidized bed combustion" patented technology

The invention discloses a coordinated control system (CCS) of a large-size circulating fluidized bed boiler (CFBB) unit, consisting of a computer algorithm realization program and a human-machine interface program (HMI). The computer algorithm realization program mainly processes data and executes corresponding logical operation according to input parameters and outputs a turbine and boiler coordinated control instruction to various closed loop control systems of a dispersion control system (DCS). The HMI provides a human-machine interface which carries out instruction interaction with low-layer control equipment for a running operator and consists of a CCS operation interface and a parameter resetting panel. The system mainly achieves the coordinated control function of the CFBB unit andthe aims of completely and automatically controlling the generation process of the CFBB unit and reducing the labor intensity and economic running of the running operators.

An apparatus for pyrolysis and gasification of organic substances and mixtures thereof is provided with a pyrolysis reactor (1), a fluidized-bed firing (3) for pyrolysis residue, a reaction zone (2) for the pyrolysis gases (13) and circulating fluidized-bed material (35). The pyrolysis reactor (1) has a sluice for introducing application material (10) thereinto. An inlet for the fluidized-bed material (35) is disposed next to the combustion fluidized bed (3). Transport apparatus (14) for mixture of solid pyrolysis residue and circulating fluidized bed material (35) is disposed at or near a bottom of the fluidized bed (3) and lower end of the pyrolysis reactor (1). An overflow is situated at or near the top of the fluidized bed (3) while a heat transfer member is positioned within the reaction zone (2).

A method for controlling combustion of circulation fluidized bed boiler includes using turbine to regulate load and using boiler to regulate pressure as well as using control system to receive load command when machine set is under coordination control system; carrying out uncoupling operation on load, main steam pressure, bed temperature and bed pressure of fluidized bed boiler when turbine load is changed greatly; and controlling carbon residual content in firepot for realizing energy balance control of machine set.

The present invention relates to a gas-steam joint production method and circulating fluidized-bed boiler. It includes the following portions: fluidized-bed combustion chamber, cyclone separator, hot ash distributor, pyrolysis gasification chamber, heat exchanger and differential bed material-retuning device. Said invention also provides its concrete technological process, it can be used as steam boiler, and can implement gas-steam joint production.

The invention relates to horizontal type circulating fluid bed combustion equipment and its circulating combustion method. It belongs to inferior fuel combustion equipment and combustion method. It is made up of main combustion chamber, multistage subsidiary combustion chamber, and gas solid separator. It can change the national single stage vertical type circulating structure of the circulating fluid bed, effectively reduce boiler height, and reduce the cost. In the combustion equipment, the material is formed two stages or more material circulating. So the combustion efficiency is high. The combustion equipment has the all advantages of the circulating fluid bed. And it can use inferior fuel such as inferior coal, solid waste, and so on. So its fuel adaptability is wide. It is the high efficiency combustion equipment with cleaning combustion, compact structure, and long using life.

The invention discloses a combustion process multivariable control method for a CFBB (circulating fluidized bed boiler), which is realized in the following procedures: in each control period, collecting operational parameters of the boiler through data collecting equipment and storing the operational parameters in a data storage module; utilizing the history data in a memorizer to on-line identify the CARIMA model and present P step future moment predominant values such as process output variable main steam pressure, material bed temperature and flue gas oxygen content through a model on-lineparameter identification module of GPC (generalized prediction control); performing error compensation to the process future moment prediction output through an error estimation module of an LSSVM (least square support vector machine); and referring the reference trace obtained by a trace generator, performing rolling optimization in GPC for the process future moment prediction output, and calculating through the optimized algorithm to enable the process actual output to reach the set value. The method provided by the invention solves the time varying problem of the model parameter, and enables the control system to have stronger robustness.

An automatic regulation system for the combustion of circulating fluidized-bed boiler (CFBB) features that it has several regulation loops for the discharged cinder quantity, primary blowing rate, supplied coal quantity, secondary blowing rate and draught air volume, which are based on the coordination between fluidizing, combustion and heat exchange, the expert system, fuzzy control and composite cascaded PI regulation are combined, and the protecting tactics such as override protection, output restriction and lock distribution choosing and tracking are used.

The object of the invention is a combustion method for a solid feed using a chemical loop wherein an oxygen-carrying material circulates, said method comprising at least:

• contacting the solid feed particles in the presence of metallic oxide particles in a first reaction zone (R1) operating in dense fluidized bed mode,
• carrying out combustion of the gaseous effluents from first reaction zone (R1) in the presence of metallic oxide particles in a second reaction zone (R2),
• separating in a separation zone (S3) the unburnt particles and the metallic oxide particles within a mixture coming from second reaction zone (R2),
• re-oxidizing the metallic oxide particles in an oxidation zone (R4) prior to sending them back to first zone (R1).

The invention relates to a horizontal type circulating fluidized bed boiler with a horizontal cyclone separator, belonging to combustion equipment of inferior fuels such as inferior coal, solid waste, sludge or biomass and the like, and the horizontal type circulating fluidized bed boiler is particularly suitable for fluidized combustion of a biomass boiler with less ash content. The horizontal type circulating fluidized bed boiler consists of a main combustion chamber, a secondary combustion chamber, a burnout chamber and a tail gas flue, and a horizontal cyclone separator is arranged in the burnout chamber. The horizontal type circulating fluidized bed boiler in the invention changes a single-stage vertical circulating structure of a vertical circulating fluidized bed, can effectively reduce the height of a boiler and reduce the requirement for building height of a factory, meanwhile, the horizontal cyclone separator is integrated in the burnout chamber, the structure is more compact, thereby being beneficial to miniaturization of a circulating bed boiler and reducing the cost effectively. The horizontal type circulating fluidized bed boiler has all the advantages of a circulating fluidized bed and can combust fuels such as inferior coal, solid waste, municipal and industrial sludge, biomass and the like, has wide fuel adaptability and is high-efficiency combustion equipment with clean combustion, a compact structure and long service life.

A membrane-type water-cooled wall four-flue biomass circulating fluidized bed boiler, including a drum, a furnace, a cyclone separator, a feeder, a second flue, a third flue, a fourth flue, an economizer, and a dust collector Devices, induced draft fans, chimneys. Among them, the furnace, the second flue and the third flue are surrounded by membrane water-cooled walls; Refractory castables are laid around the joints of the ducts; a medium-temperature panel superheater is arranged at the upper end of the second flue, and high-temperature and low-temperature convective superheaters are arranged at intervals in the third flue, and the tundish wall adopts a tapered wall structure; low-temperature convective superheating The first water spray desuperheater and the second water spray desuperheater are respectively arranged between the high temperature convective superheater and the medium temperature panel convective superheater. The invention improves the utilization rate of combustion heat energy of the biomass fluidized bed boiler, reduces the abrasion of the inner wall of the flue and the corrosion of the alkali metal by the high-speed and high-temperature flue gas, and enhances the wear resistance of the wall surface.

The invention relates to a control method of a combustion system of a circulating fluidized bed boiler, which adopts multivariable expert intelligent self-calibration PID control and is provided with an on-line calculation module for the static characteristics of the circulating fluidized bed boiler. The on-line calculation module for the static characteristics of the circulating fluidized bed boiler calculates the coal supply quantity, the limestone quantity and the deslagging quantity for realizing the optimizing combustion of the boiler under different loads, the primary air quantity and the secondary air quantity are optimized and proportioned and are used as load feedforward signals which are applied to a main steam pressure control loop, a limestone quantity control loop, a bed pressure drop control loop, a bed temperature control loop and an oxygen quantity control loop, and each control loop adopts an expert intelligent self-calibration PID controller to form a multivariable combustion control system of a CFB boiler. The invention is provided with the calculation module for the static characteristics of the circulating fluidized bed boiler, which can accurately send out each regulation quantity instruction at real time and realize automatic control; the multivariable expert system is in consideration of the nonlinearity and the strong-coupling property of the combustion system of the boiler and ensures the performance robustness of the control system; and meanwhile, the PID parameters are automatically regulated according to the change of the characteristics of a controlled object, so the automatic combustion control system of the circulating fluidized bed boiler has stable robustness.

The invention relates to a low-ratio biomass circulating fluidized bed boiler and a combustion method thereof, relating to a circulating fluidized bed boiler and a combustion method thereof and solving the problems of difficult feeding, grate slagging, bed material coking, tempering and output reduction, and the like existing in the operation of traditional grate furnaces and circulating fluidized bed boilers. A middle air chamber corresponds to the middle of a dense-phase area at the lower part, lateral grid plates are arranged between a lateral air chamber and the dense-phase area at the lower part, and a medium-temperature steam-cooled cyclone separator is arranged at the joint between a flue shaft at the tail part and a health outlet of a boiler body, respectively communicated with the flue shaft and the health outlet and communicated with the dense-phase area at the lower part through a material returner. The method adopts a negative-pressure feeding manner so that the fluidization air velocity of a high-speed area of the dense-phase area at the lower part is 4-5 m/s, the fluidization air velocity of a low-speed area is 1.5-2.0 m/s, the temperature of the dense-phase area at the lower part is 650-780 DEG C, and the material circulation ratio is below 10. The invention is suitable for the biomass circulating fluidized bed boiler for an electric power plant.

The invention relates to a method and to a plant for producing high-purity oxygen, said method comprising a chemical loop wherein circulates a fluidized bed material having the capacity to release gaseous oxygen through oxygen partial pressure lowering, at a temperature ranging between 400° C. and 700° C. The oxygen thus produced can be used in applications such as oxycombustion methods, production of syngas under pressure or FCC catalyst regeneration.

The invention discloses a fluidized bed boiler control and combustion optimization system. The problem that a fluidized bed boiler system is not easy to control for a long time is solved. According to a method, a control strategy of combining an advanced control algorithm and a conventional control algorithm is adopted, and continuous, economical and stable operating of the boiler system is guaranteed; multivariable model-free adaptive control is adopted, and decoupling control of the fuel quantity and the air supply quantity over the bed temperature under the variable load work condition is achieved; and a nerual network technique is adopted for building a boiler combustion prediction model, online calculation of the boiler efficiency and NOX and SOX emissions is achieved, a multi-objective optimization function is constructed according to the prediction result, a combustion self-optimization algorithm is adopted, the flue gas oxygen content and the bed temperature are optimized constantly so as to adapt to work condition changes, and a fluidized bed boiler can operate in an optimal combustion area.

A recirculation fluidized bed combustion boiler of straw is prepared as setting material feed mouth and residue extraction mouth on firepot, setting cooling device being connected to ignition combustion chamber and refeeder with secondary wind opening at bottom of firepot, using water cooling wall with top and bottom collection boxes as side wall of firepot, connecting outlet of firepot to separation device being connected to refeeder and two stages of thermo reduction devices separately, connecting one stage of thermo reduction device to a overheat unit with economizer and preheater as well as setting steam pocket and water supply pipe at top of firepot.

The invention belongs to the gas-solid fluidized bed reactor field and relates to a dual-distributing plate coal-based serial fluidized bed chemical-chain combustion apparatus suitable for the chemical-chain combustion of burning coal and other solid fuels; the bottom of a bubbling fluidized bed is provided with a gas inlet and a feed port; the inside of the bubbling fluidized bed is divided into three regions by two distributing plates; the bottom of a low gas velocity region and the bottom of a high gas velocity region are respectively provided with a distributing plate; the middle between two regions is provided with a transition region with a reduce section to realize different gas flow velocities in the low gas velocity gasification region and the high gas velocity deoxidization region; the upper part of a bubbling fluidized bed is in tubular communication with the upper part of a cyclone separating device; the top of the cyclone separating device is provided with an exhaust port which is communicated with a gas inlet of the bubbling fluidized bed; the lower part of the cyclone separating device is pumped to the low gas velocity gasification region by a feed leg; the bottom of the high gas velocity deoxidization region is communicated with a circulating fluidized bed by a feed returning device; the bottom of the circulating fluidized bed is provided with an air inlet; the upper part of the circulating fluidized bed is communicated with the cyclone separating device. The dual-distributing plate coal-based serial fluidized bed chemical-chain combustion apparatus has the advantages of low cost, flexible operation, high thermal efficiency, wide application range, etc.

A plant for generating electricity includes a gas turbine, a compressor driven by the gas turbine, a reduction reactor configured to reduce metal oxides, fed with a fuel and having a first circulating fluidized bed, a first cyclone configured to separate the metal oxide solids, and feeding at least a portion of the metal oxide solids to the reduction reactor via a first connecting line, an oxidation reactor configured to oxidize the metal oxides having a second circulating fluidized bed and fed only with pressurized air from the compressor, and a second cyclone configured to separate the metal oxide solids and feeding at least a portion of the metal oxide solids to the oxidation reactor via a second connecting line.

The present invention discloses a compact parallel connection type external fluidized bed heat exchanger, and relates to a fluidized bed heat exchange technology. The compact parallel connection type external fluidized bed heat exchanger comprises a material inlet, a material dispenser, two heat exchange chambers arranged in a parallel connection manner, and a material returning chamber. According to the compact parallel connection type external fluidized bed heat exchanger of the present invention, a pneumatic way is adopted to precisely control the amounts of circulating ash entering the two parallel heat exchange chambers, such that independent adjustments and controls of heat exchange powers of the two heat exchange chambers according to requirements can be achieved; with arrangement of the two heat exchange chambers in the parallel connection manner, heat exchange of the two heat exchange chambers has high heat transfer temperatures and high heat transfer pressures, such that a heat exchange efficiency between high temperature circulating particles and the heat exchange pipe bundles is improved while uniformity of the returned material of the large-size hearth and stability of the bed temperature are improved; and with the compact integration design, structure arrangement and operation adjustment of the large circulating fluidized bed boiler are flexible.

The invention relates to an automatic control method of 300MW grade circulating fluid bed unit, which sets the automatic control methods for the coordination of machine and furnace, the deviation of single bed pressure and double bed pressure, the water level of the deaerator and the condenser, the secondary air quantity/oxygen quantity and the secondary air pressure, the boiler bed temperature, the fuel flow and the limerock feeding during making the first 300 MW circulating fluid bed unit as the localization of manufactures, meanwhile, the 300 MW circulating fluid bed unit has the advantages of stable operation, safety, reliable and remarkable economic operation passing through the coordination and control for the system.

Embodiments of apparatuses and methods for controlling heat for rapid thermal processing of carbonaceous material are provided herein. The apparatus comprises a reactor, a reheater for forming a fluidized bubbling bed comprising an oxygen-containing gas, inorganic heat carrier particles, and char and for burning the char into ash to form heated inorganic particles. An inorganic particle cooler is in fluid communication with the reheater. The inorganic particle cooler comprises a shell portion and a tube portion. The inorganic particle cooler is configured such that the shell portion receives a portion of the heated inorganic particles and the tube portion receives a cooling medium for indirect heat exchange with the portion of the heated inorganic particles to form partially-cooled heated inorganic particles.

The invention has its object to arbitrarily adjust an amount of particles to be circulated without changing a flow rate of a gasification agent to thereby enhance gasification efficiency in a fluidized bed gasification furnace.

The fluidized bed gasification furnace 107 comprises first and second chambers 113 and 114 in communication with each other in a fluidized bed 105. The hot particles 102 separated in the separator 104 and raw material M are introduced into the first chamber 113. The particles 102 introduced from the first chamber 113 through interior in the fluidized bed 105 to the second chamber 114 are supplied in an overflow manner to the fluidized bed combustion furnace 100. A first pressure controller 121 is provided to control the resultant gas induction means 116 such that the pressure in the first chamber 113 is kept to preset pressure 120; and a second pressure controller 124 is provided to control the exhaust gas induction means 118 such that difference between pressure in the first and second chambers 113 and 114 is equal to the preset differential pressure 123, so that the fluidized bed 105 in the first chamber 113 is controlled in height to control an amount of particles 102 to be circulated.

The present invention is directed to a hydrocarbon conversion apparatus. The apparatus comprises the following: a plurality of riser reactors, each of the riser reactors having a first end into which a catalyst can be fed and a second end through which the catalyst can exit the riser reactor; a separation zone provided to separate the catalyst from products of a reaction conducted in the hydrocarbon conversion apparatus; at least one transport conduit having a first end in fluid communication with at least two of the second ends of the riser reactors and a second end extending into the separation zone; and at least one catalyst return in fluid communication with the separation zone and the first ends of the riser reactors, the catalyst return being provided to transfer the catalyst from the separation zone to the first ends of the riser reactors.

An integrated combustion chamber and fluidized bed pyrolysis reactor. In one embodiment, the combustion chamber is cylindrical and the pyrolysis reactor is provided annularly about the combustion chamber with an annular wall that provides a common surface for heat transfer. A lift tube in fluid communication with the pyrolysis reactor is provided within the combustion chamber for circulating biomass and an inert fluidizable media upwardly through the lift tube; this advantageously increases heat transfer and leads to more rapid pyrolysis. The media and biomass exit the lift tube into either a freeboard area of the pyrolysis reactor or into a low density region of the fluidized bed. A condensable gaseous product is produced during pyrolysis that has economic value. The apparatus and process are especially well suited to the pyrolysis of low density agricultural biomass. The apparatus is compact and particularly well suited to mobile operation.

The objective of the present invention is to provide a fluidized bed incinerator which will increase the thermal capacity of the freeboard to respond to fluctuations of the load imposed by waste matter such as sludge or garbage with a high moisture content; which would absorb local and momentary temperature spikes due to load fluctuations or variations in the characteristics of the waste material. This invention comprises the steps of 1) injecting the primary air for fluidizing the fluidizing medium from a bottom of the fluidizing region; 2) injecting the secondary air into the splash region in which the bubbles on the surface of the fluidized sand blast and the particles are propelling upward when the bubbles are burst; 3) entraining and conveying upward the fluidizing medium to out of said incinerator via the freeboard; 3) recirculating the fluidizing medium to the fluidizing region; and 4) controlling the thermal capacity of the freeboard, and the temperature of the fluidizing medium to be constant by controlling the ration of the primary and secondary air.

The invention discloses a monitoring method and an optimal control method for supercritical circulating fluidized bed (CFB) boiler combustion signals. The monitoring method comprises the following steps of: step 1, acquiring and pre-processing field data, and determining an auxiliary variable of an instant combustion carbon quantity model; step 2, building the instant combustion carbon quantity model based on mechanism modeling and data analysis hybrid modeling, and estimating the storage amount of instant combustion carbon in a hearth through a generalized Kalman filter information fusion technology, wherein the instant combustion carbon quantity model is shown in the description; and step 3, building a dynamic heat signal model, a hearth bed temperature signal model and a hearth outlet oxygen signal model through the instant combustion carbon quantity, and predetermining heat, bed temperatures and oxygen. The methods provided by the invention can accurately measure signals of heat, bed temperatures, oxygen and the like of a supercritical CFB boiler in real time, so that the optimal control on supercritical CFB boiler combustion is realized, and the combustion stability of the supercritical CFB boiler is improved.

A combined desulfurizing process for removing the SO2 gas from the flue gas generated by circualting fluidized-bed boiler is characterized by that the raw lime stone reacts with the SO2 in the bed layer of boiler to remove part of SO2 by combustion and the unreacted and escaped calcium oxide further reacts with SO2 in the moistening tower for external removal of SO2. Its advantages are low cost and optimal desulfurizing effect.

The invention provides a fluidized-bed boiler, which comprises a fluidized-bed combustion chamber. The bottom of the fluidized-bed combustion chamber is provided with a wind chamber of a wind distributor, and the fluidized-bed combustion chamber is communicated with a blower; combusted flue gas of the combustion chamber is exhausted from a chimney through an induced draught fan; the outlet of the induced draught fan is connected with a flue gas recirculation tube which is respectively communicated with the fluidized-bed combustion chamber and the wind chamber; an upper layer wind adjusting valve is arranged between the flue gas recirculation tube and the fluidized-bed combustion chamber; an upper layer fan is arranged between the upper layer wind adjusting valve and the combustion chamber; an air draft pipe with an air regulating valve is arranged between the upper layer fan and the upper layer wind adjusting valve; upper layer wind is formed by the air and flue gas; the blower is connected with an air-flue gas mixing chamber; the other end of the mixing chamber is communicated with the flue gas recirculation pipe through a flue gas secondary fan and a flue gas secondary regulating valve; and the upper part of the mixing chamber is communicated with the air chamber to form one-time wind. The fluidized-bed boiler has the advantages of improving the utilization rate of fuel, reducing the emission of pollutants, and having higher desulphurization efficiency and wide application of coal fuel.

A grid construction for a fluidized bed reactor, the reactor including a reaction chamber defined by substantially vertical walls, in which a fluidized bed of solid particles is maintained, and a windbox under the reaction chamber, in a lower portion of the reactor. The grid construction is positioned between the reaction chamber and the windbox and includes (a) multiple continuous nozzle lines for distributing fluidizing gas from the windbox into the reaction chamber, for suspending the fluidized bed in the reaction chamber, and (b) continuous trenches between the nozzle lines. The nozzle lines include multiple gas outlets, having a main gas flow direction, at side faces of said nozzle lines, for directing fluidizing gas jets towards an adjacent trench.

A method for upgrading a boiler is provided. When operating at a first capacity, the boiler is used such that an open space is kept in radiation communication with a firebox. The open space is also kept as empty. A first set of water circulation tubes are connected to the boiler cylinder in connection with the ascending tubes. When the boiler is operated at a second capacity, which is higher than the first capacity, at least one additional part is arranged in the open space to expand the basic super heater arrangement. Additionally, or alternatively at the second capacity, a second set of water circulation tubes may be connected to the boiler cylinder in connection with the ascending tubes. The second set of water circulation tube has a capacity exceeding that of the first set of water circulation tubes.

A method of combusting sulfur-containing fuel in a circulating fluidized bed boiler includes the steps of (a) feeding sulfur-containing fuel into a furnace of the circulating fluidized bed boiler, (b) combusting the fuel with oxidant gas consisting essentially of pure oxygen and circulated exhaust gas, so as to form exhaust gas having carbon dioxide and water as its main components, and (c) feeding calcium carbonate containing material into the furnace so as to capture sulfur dioxide into calcium sulfate in the furnace. The temperature in the furnace is maintained above 870° C.