728results about "Superheating control" patented technology

A pressure sensor measures an organic Rankine cycle (ORC) working fluid pressure in front of a radial inflow turbine, while a temperature sensor measures an ORC working fluid temperature in front of the radial inflow turbine. A controller responsive to algorithmic software determines a superheated temperature of the working fluid in front of the radial inflow turbine based on the measured working fluid pressure and the measured working fluid temperature. The controller then manipulates the speed of a working fluid pump, the pitch of turbine variable inlet guide vanes when present, and combinations thereof, in response to the determined superheated temperature to maintain the superheated temperature of the ORC working fluid in front of the radial inflow turbine close to a predefined set point. The superheated temperature can thus be maintained in the absence of sensors other than pressure and temperature sensors.

Systems and methods for controlling exhaust steam temperatures from a finishing superheater are provided. In certain embodiments, the system includes a controller which includes control logic for predicting an exhaust temperature of steam from the finishing superheater using model-based predictive techniques (e.g., based on empirical data or thermodynamic calculations). Based on the predicted exhaust temperature of steam, the control logic may use feed-forward control techniques to control the operation of an inter-stage attemperation system upstream of the finishing superheater. The control logic may determine if attemperation is required based on whether the predicted exhaust temperature of steam from the finishing superheater exceeds a set point temperature as well as whether the inlet temperature of steam into the finishing superheater drops below a set point temperature of steam. The attemperation system may include a characterizing function to linearize the valve operation controlled by the control logic to inject cooled, high-pressure feedwater into the steam upstream of the finishing superheater, which may, in turn, control the exhaust temperature of steam from the finishing superheater. The disclosed embodiments may also be applied to any systems where an outlet temperature of a fluid from a heat transfer device may be controlled.

A solar concentration plant which uses water/steam as a heat-carrying fluid, in any thermodynamic cycle or system for the exploitation of process heat, which is comprised of an evaporation subsystem, where saturated steam is produced under the conditions of pressure of the system, and a superheater subsystem through which the steam reaches the required conditions of pressure and temperature at the turbine inlet, and in which an attemperation system (10) may be incorporated, these being physically separated and interconnected by means of a drum (5) in which the separation of water and steam takes place, and in which a strategic control of the pointing of the field of heliostats (1) towards either of the subsystems (evaporator or superheater) may be carried out, with individual or group pointing of the heliostats, in such a way that they jointly control both the pressure within the drum (5) and the outlet temperature of the superheated steam (11).

The invention relates to a thermal power generating unit reheated steam temperature controlling method. According to the operating characteristics of the boiler reheater and the theoretic study on a steam-temperature control system, a state feedback control method based on incremental state observer is adopted, and the concept of an algebraically equivalence observer is used to direct the parameter setting of an incremental state observer; in addition, a special control circuit is arranged in the steam-temperature control circuit to resolve the problems that the process of steam-temperature adjustment is relatively long when the reheated steam temperature set value is changed, non-linearity exists during steam-temperature control, the process of steam-temperature variation is very slow, etc., and variation parameter PID regulator is combined to jointly form a comprehensive reheated temperature automatic adjusting system. The invention is capable to ensure reheated steam temperature control to escape spray water upon large-range load variation, and effectively overcomes the disadvantage of the poor effect of the traditional PID regulation on the control of big lagged object; the reheated temperature control effect is improved remarkably; and a sample is provided for controlling the controlled object with big inertia and serious lagging in relation to reheated steam temperature.

The invention relates to a detecting method used to on-line detect the wall temperature and life consumption of the tubes of boiler over-heater and regenerator. Wherein, it inputs the temperature detected at the entrance external gas temperature detecting point and other parameters of boiler into the computer, to real-time calculate out the wall temperature of each section of tube, to judge if there is over heated and calculate out the life consumption and the smoke temperature difference, while the result will be displayed on the detector and recorded in the database.

An improved combustion method and corresponding apparatus is disclosed, where the method includes oxidizing a fuel in a combustion chamber with an oxidizing stream including an air stream and a first recycled flue gas stream and mixing a produced hot flue gas stream with a second recycled flue gas stream to form reduced temperature flue gas stream which can be used directly in a power generator or to heat a reactor. The method and apparatus allow flow rates of the streams to be adjusted so that temperatures in the combustion chamber and in the heat transfer unit or units of the power generator or reactor can be kept below temperature that would thermally damage the combustion chamber, heat transfer unit or units or the reactors.

A system for controlling steam temperature that includes steam circuit including a reheater circuit, at least one reheater dilution region, at least one reheater dilution conduit, and at least one reheater supply region disposed upstream of the at least one reheater dilution region, wherein the at least one reheater supply region and the at least one reheater dilution region are associated via the reheater circuit and the at least one reheater dilution conduit.

The invention discloses a reheated gas temperature optimization control method based on multi-variable predictive control. According to the method, the whole hot steam temperature system is regarded as a two-in one-out multi-variable object, and the flow rate of reheated de-superheating jet water and the opening of a flue gas baffle plate are simultaneously controlled by adopting a multi-variable predictive control method; moreover, optimization of economical efficiency of the system is realized by adding a steady state target value of the opening of a reheated de-superheating jet water adjusting valve into optimization indexes of the conventional predictive control. By adopting the multi-variable predictive control method, coordination of side adjustment of flue gas and side adjustment of steam can be better realized, and the dynamic adjusting quality of the reheated steam temperature is further improved; and meanwhile, by adding the steady state target value of the de-superheating water adjusting valve into the conventional predictive control performance indexes, optimization of the de-superheating water jet quantity is realized, so that the circulating efficiency of a unit can be effectively improved.

The invention discloses a feedforward signal control method in a boiler steam temperature automatic control system, which is used for improving quality of boiler steam temperature control. The technical scheme comprises the following steps of: measuring boiler furnace pressure, boiler steam pocket pressure (or steam-water separator pressure), boiler overheater outlet steam pressure, and boiler reheater outlet steam pressure; and calculating by utilizing the signals to form a combustion disturbing signal, an overheat steam flow disturbing signal, a reheat steam flow disturbing signal, an overheat steam temperature control system feedforward signal and a reheat steam temperature control system feedforward signal in turn. The method can effectively improve the quality of boiler steam temperature control, reduces steam temperature fluctuation caused by combustion disturbance and steam flow disturbance, does not need any additional hardware equipment, only needs increasing a little of software control logic, has low cost and cannot reduce the system reliability.

Disclosed is a nozzle assembly comprising a nozzle housing and a valve element axially slidable therewithin between a closed and an open position. The nozzle housing has a housing inlet and a housing outlet fluidly interconnected by a plurality of housing passages. The valve element has a truncated conical valve body including a conical outer surface and a concave inner surface with a plurality of valve apertures extending through the valve body. The outer surface is sealingly engagable to a valve seat formed in the housing outlet such that the flow of cooling water through the valve apertures is prevented when the valve element is in the closed position. The outer surface and valve seat collectively define an annular gap when the valve element is axially displaced to the open position such that a portion of the cooling water flowing through the annular gap may pass through the valve apertures.

A one piece spray cylinder/nozzle, with integrally machined nozzles, for use on a high pressure and temperature, probe style, variable nozzle, gas and steam coolers. The nozzle holes can be made by deep drilling techniques such as laser, gun drilling and others methods that produce a hole, with a diameter to depth ratio of less than 1:3. No separately machined nozzles are used. On the outlet end of the nozzle (on the outside of the cylinder only), there are surface machining treatments to produce small, controllable liquid droplets that vaporize quickly into the gas or vapor stream. The spray cylinder bore can be coated, lined or hard faced to resist the ware of the piston rings sliding in it without adding stresses to the spray cylinder body at braze and weld joints. The flow and patterns and valve characteristics can be modified.

Modularized, superheated steam generators comprise a steam module (46), a thermocouple module (41), and an electrode module (45) assembled within a containment enclosure (66). The multi-stage steam module (46) comprises a plurality of first stage pressure vessels (77) surrounding and feeding a second stage pressure vessel (78). The steam module (46) is coaxially surrounded by insulation (48) disposed within a cylindrical shroud (72). The electrode module (45) radiantly heats the steam module with resistive heating elements (119). The thermocouple module (41) includes thermocouples monitoring first stage temperatures within and between pressure vessels (77). PLC computer SCADA software (600) operates the generators. Thermocouple data is analyzed to control heater temperatures, the water feeding system (340), and outputted steam temperature. PLC software (600) provides operating logic (602) establishing a start up subroutine (602), a ramp up subroutine (603), a steady state subroutine (605), and a shut down subroutine (606).

Provided is a dynamic compensation method of an attemperation water impact leading steam temperature measuring point in a boiler steam temperature control system. According to the method, an attemperation water impact leading steam temperature measuring point correction factor on-line computation module is arranged in the overheating and reheating steam temperature cascade control system of a power station boiler, the correction factor of the attemperation water impact leading steam temperature measuring point is computed on line through the module, the difference between a steam temperature set value and a controlled steam temperature feedback value is divided by the correction factor to compensate changing of inertia zone object gain, output of an auxiliary adjuster is multiplied by the correction factor to compensate changing of leading zone object gain, and accordingly dynamic compensation of the attemperation water impact leading steam temperature measuring point is achieved. The method achieves dynamic compensation of the attemperation water impact leading steam temperature measuring point in the steam temperature control system and has the advantages of being good in compensation effect, field conduction is convenient, control effect is good, control quality of the overheating and reheating steam temperature cascade control system of the power station boiler can be guaranteed, and safety and economy of operation of the power station boiler are improved.

The invention discloses a tower-type boiler with a primary reheater and a secondary reheater. A superheater of the boiler comprises a low-temperature superheater and a high-temperature superheater; a technological process of a main steam system comprises the following steps that: feeding water enters a front flue coal economizer and a rear flue coal economizer which are arranged in parallel; water from outlets of the coal economizers enters water-cooling walls from the lower part of a hearth; outlets of the water-cooling walls are connected with a separator; and steam of an outlet of the separator enters the low-temperature superheater and the high-temperature superheater sequentially. According to a low-to-high flow direction of temperatures on a steam side, the primary reheater sequentially comprises primary reheating low-temperature reheaters and a primary reheating high-temperature reheater, the secondary reheater sequentially comprises secondary reheating low-temperature reheaters and a secondary reheating high-temperature reheater, and the primary reheater and the secondary reheater are connected with each other in parallel in a perpendicular flue.

The invention discloses a multi-model disturbance estimation predictive-control method for superheated steam temperature of a thermal power generating unit. According to the method, a superheated steam temperature system serves a controlled object, cooling spray water flow serves as system control input, superheated steam temperature serves as system output, a plurality of disturbance models are established to respectively expand the system state on the basis of a controlled object state space model, and a disturbance model set is formed. Sub-models in the disturbance model set are subjected to weighted averaging, thus the influence of immeasurable disturbance upon the system output is fitted. According to the concept of predictive control, optimization solution is performed once for each step so that optimal system controlled input is obtained. Compared with common predictive control algorithms, the method has the advantages that immeasurable disturbance can be inhibited more effectively, and steam temperature is kept around a set value stably; when no immeasurable disturbance occurs, the method is as effective as the common predictive control algorithms, and tracking regulation performance is fine.

An enhanced steam cycle utilizing a dual pressure recovery boiler with reheat allows a large increase in electrical generation with various turbine cycles while overcoming traditional lower furnace material limitations. A dual pressure designed recovery boiler furnace is provided with a lower furnace and an upper furnace. The lower furnace is operated at a lower temperature to prevent or reduce corrosion of the lower furnace wall tubes caused by the reducing environment. The lower furnace can be either a low pressure natural circulation steam generating (drum) system or economizer. Unlike the lower furnace, the upper furnace is not exposed to a reducing environment and is therefore not as susceptible to severe corrosion rates. The upper furnace is operated at higher temperatures and pressures which permit implementation of higher efficiency reheat steam cycles. The upper furnace thus operates as a high pressure natural circulation steam generating (drum) system, or as a once-through supercritical steam generating system. The dual pressure recovery boiler can thus be coupled to a variety of condensing, non-condensing or a combination of condensing and non-condensing turbine cycles to provide a large increase in electrical generation.

The invention provides a method for detecting a hearth radiation energy signal and a method for controlling boiler combustion by using the same, and belongs to the field of combustion monitoring and controlling. The method for detecting the hearth radiation energy signal comprises steps of analog-to-digital conversion, color value extraction and hearth radiation energy signal calculation. In the method for controlling air quantity of hearth combustion, the optimum oxygen quantity calculated by using the hearth radiation energy signal, set oxygen quantity and set offset are added, and the sum is sent to an oxygen quantity regulator to control the air quantity of the hearth combustion. The method for controlling superheater attemperating water comprises the steps of combining the hearth radiation energy signal with a heat signal to form a heat value signal; and introducing the heat value signal to a heat regulator to control the superheater attemperating water. The radiation energy signal detected by the method has the advantages of stability, reliability, capability of accurately reflecting the combustion situation in the hearth space in real time, and strong correlation with unit operation parameters; and when the new heat value signal constructed by the radiation energy signal is introduced to air supply and attemperating water control loops of the unit, the control effect of the unit can be optimized, and the efficiency of the unit can be improved. Therefore, the method for controlling the boiler combustion is suitable for combustion optimization control of a pulverized coal fired boiler of a thermal power generating unit.

Systems and methods for exhaust gas recirculation in which a desired oxygen concentration is maintained for stable combustion at increased recirculation rates. Exhaust gas of an energy generation system is divided and reintroduced at different locations of the system.

The invention relates to an improved method of limitation generalized predictive control for thermal power unit reheat steam temperature. In the invention, an interior model for improving limitation predictive control is obtained through a reheat steam temperature set value step experience; a reheat steam temperature control system records a spray desuperheating valve opening instruction sequence and a reheat steam temperature measured value sequence in real time; and an opening increment instruction of a current spray desuperheating valve is obtained through simple calculation. The control method solves the problems that the traditional limitation generalized predictive control has complicated optimization problem and large calculated amount and the regulation of the reheat steam temperature control system is lagged and has slow response, thereby causing rapid and stable temperature control of a reheater without dynamic deviation.

The invention relates to an outer drying steam triple-effect heat exchange system. A flow divider is arranged in the liquid phase space of a water-bath-type saturated steam generator, and a steam discharge pipeline of the flow dividier is sequentially provided with a steam water separator and a steam drying heat exchanger; overheated steam enters the flow divider through a pressure control valve; wet saturated steam from the saturated steam generator is heated into dry saturated steam by overheated steam; the dry saturated steam enters a main steam heat exchanger and becomes high-temperature condensation water after materials are heated for the third time; flash steam of the high-temperature condensation water heats the materials in the flash steam heat exchanger for the second time; condensed flash steam enters the condensation water heat exchanger; the condensation water in the high-temperature condensation water continuously releases sensible heat to heat the material for the first time; the condensation water after temperature reduction enters a water collecting tank, and is pumped into the saturated steam generator by a water supplying pump; and the aperture of the pressure control valve is regulated by a PLC (programmed logic controller) according to the material outlet temperature. The system achieves cascading utilization of steam heat energy, guarantees that the steam heat energy can be used up, and improves the energy efficiency.

The embodiment of the invention discloses a control method for the steam temperature of a meager coal boiler of a 1045MW ultra supercritical unit. The control method is used for solving the technical problems that because mature ultra supercritical steam temperature control technologies capable of being applied to actual production fields lack currently, heating surface over-temperature pipe explosion is frequently caused by unreasonable steam temperature control of a field ultra supercritical boiler, large potential safety hazards are caused to safe and stable operation of a power plant, and severe economic loss of a large thermal power plant is caused. The control method includes the steps that in the boiler unit starting process, design performance data of the unit are compared, and overall regulation and control are conducted according to the corresponding relation curve of water supply quantity, coal supply quantity and air volume under different loads; when the load of the boiler unit is increased or decreased, the air volume, coal supply quantity and water supply quantity are increased or decreased with the same ratio; when the boiler unit normally operates, the superheat degree of the intermediate point is controlled to regulate the water-fuel ratio to be proper; and water spraying adjustment is carried out, so that deviation in regulation of the water-fuel ratio is eliminated.

A spray nozzle assembly for a steam desuperheating or attemperator device. In one embodiment, the spray nozzle sub-assembly of the spray nozzle assembly comprises a fixed nozzle element which is integrated into a spring-loaded nozzle element, and is specifically adapted to improve water droplet fractionation at higher flow rates while further providing an effectively higher spray area through the formation of two water cones (rather than a single water cone), such water cones being sprayed into a flow of superheated steam in order to reduce the temperature of the steam. In another embodiment, the spray nozzle sub-assembly of the spray nozzle assembly comprises a nested pair of spring-loaded primary and secondary nozzle elements which are also adapted to provide an effectively higher spray area through the formation of two water cones.