Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C6/00—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion
  • F23C6/02—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in parallel arrangement
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C6/00—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion
  • F23C6/04—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection
  • F23C6/045—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with staged combustion in a single enclosure
  • F23C6/047—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with staged combustion in a single enclosure with fuel supply in stages
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D1/00—Burners for combustion of pulverulent fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
  • F23K1/00—Preparation of lump or pulverulent fuel in readiness for delivery to combustion apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
  • F23K3/00—Feeding or distributing of lump or pulverulent fuel to combustion apparatus
  • F23K3/02—Pneumatic feeding arrangements, i.e. by air blast
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N1/00—Regulating fuel supply
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
  • F23K2201/00—Pretreatment of solid fuel
  • F23K2201/10—Pulverizing
  • F23K2201/1006—Mills adapted for use with furnaces
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
  • F23K2203/00—Feeding arrangements
  • F23K2203/10—Supply line fittings
  • F23K2203/103—Storage devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
  • F23K2203/00—Feeding arrangements
  • F23K2203/10—Supply line fittings
  • F23K2203/105—Flow splitting devices to feed a plurality of burners

Definitions

• the invention relates to a method and arrangement for improving the dynamic behavior of a coal-fired power plant at primary and / or secondary requirements of the electricity grid operator to the power delivery to the grid.
• Deviations from the specified mains frequency value occur especially when the power demand on the power plants connected to the electricity grid suddenly changes, for example because a power plant is disconnected from the grid due to an accident or a large consumer is switched on or because the network configuration or network distribution changes.
• the primary control is still supported by the secondary control or secondary control power, which compensates for quasi-stationary deviations of both the frequency and the transfer capacity after the sudden adjustment of the power consumed or generated by the primary control.
• coal-fired power plants are usually formed with coal dust firing in which the coal ground in the coal grinding plant are fed directly via pulverized coal pipes of the combustion chamber of the power plant (so-called "direct” coal dust firing).
• direct coal dust firing The treatment of the fuel is one of the main factors for a good combustion, a good efficiency, low emissions and little unburned in the ash to use this by-product.
• the coal grinding plant or coal mill must be in a stationary heat and mass flow equilibrium, which means that load changes to the pulverized coal firing and thus the power plant itself can be carried out only slowly and thus a delay occurs when made or required load changes ,
• the delay time of the coal mill with changing fuel quantity or -aufgäbe is an integral part of the total system delay time.
• the delay time of the coal mill can be long according to the raw coal preparation process (depending on fineness, moisture, hardness of the raw coal and the mill load) and therefore has an adverse effect on the delay time of the entire system.
• the object of the invention is therefore to provide a method for improving the dynamic behavior of a coal-fired power plant at primary and / or secondary requirements of the electricity network operator to the power delivery to the network, in which the delay time of coal dust firing of the power plant is reduced so that the power plant complies with the specifications or conditions of respective national electricity grid operators. It is a further object of the invention to provide an arrangement for improving the dynamic behavior of a coal-fired power plant at primary and / or secondary requirements of the electricity grid operator to the power delivery to the grid.
• the solution according to the invention provides a method and an arrangement for improving the dynamic behavior of a coal-fired power plant with primary and / or secondary requirements of the electricity grid operator for the supply of electricity to the grid, which has the following advantages:
• An advantageous embodiment of the invention provides that the storage volume V Sp having silo in normal operation of the indirect combustion system volume side in about half filled with coal dust for provision and use in increasing the primary and / or secondary requirements of the electricity network operator to the power delivery to the grid and the remaining storage volume is used to receive and store the excess coal dust produced while reducing the primary and / or secondary requirements of the electricity grid operator to the power delivery to the grid.
• the increase or decrease of indirectly supplied amount of pulverized coal by a controlled increase or decrease in the throughput of the metering organs. This makes it possible to precisely address the needs or the dynamic behavior of the coal-fired power plant.
• An advantageous embodiment provides to increase or reduce the volume flow of the conveying gas blower in a controlled manner in increasing or decreasing the amount of indirectly supplied pulverized coal dust.
• the smooth entry of coal dust is maintained in the combustion chamber.
• the increase or decrease in the throughput of the metering organs and / or the increase or decrease in the volume flow of the delivery gas blower is effected by the affected by the requirements of the electricity grid block power control of the coal-fired power plant.
• the primary requirement or the primary control is triggered by a remote-controlled signal.
• the secondary requirement or the secondary control is also triggered by a remote-controlled signal.
• the secondary requirement or the secondary regulation can also be triggered by written or verbal instruction to the operating personnel of the power plant.
• FIG. 3 schematically shows an arrangement for improving the dynamic behavior of a coal-fired power plant with primary and / or secondary requirements of the electricity grid operator to the power delivery to the grid, the coal grinding plant including pulverized coal pipes of the firing of the power plant is shown,
• Fig. 4 shows schematically the relation of a power increase as a function of time and the firing process.
• the power generated must be constantly in balance with the load power. Changes in the load of the load or faults in power plants affect this balance and cause frequency deviations in the network to which the machines participating in the primary control or the primary demand react.
• the primary control or equivalent primary demand ensures, due to its control behavior, the restoration of the balance between generated and consumed power within a few seconds, keeping the frequency within the permissible limits.
• the electricity grid after regulating a sudden change in the power consumed or generated by the primary control or the primary demand, there are quasi-stationary deviations (with respect to the set values) both the frequency ⁇ f and the transfer power ⁇ Pi between the individual control zones.
• the secondary control or secondary demand comes into operation, the objective of which is to return the frequency to its desired value and the transfer rates to the agreed values and thus to have the entire activated primary control capacity available as a reserve again.
• FIG. 1 shows the interpretation of the primary and secondary control or primary and secondary response values of the British Electricity Grid Regulations (Grid Code UK), which in the case of a frequency deviation (Frequency Change ) of -0.5 Hz from the target frequency of the electricity grid.
• the diagram of FIG. 1 shows that a power plant connected to the electricity grid according to the primary control P within a time period T Sp of 10 seconds to respond with a plant response and while the power plant capacity must be increased. The amount of power increase within this period T Sp depends on the load range with which the power plant is currently operating at the time of the frequency drop.
• the British Electricity Network regulations set at a specified requested Minimum load (minimum generation) of 65% of the rated power RC (Registered Capacity) of the power plant determines that at this part load the power plant output must be increased within 10 seconds by 10% (percentage A P ) of the nominal power or capacity RC of the power plant ( see Figure 2).
• the abscissa shows the load range (in% of the RC) of the power plant
• the ordinate shows the primary and secondary control ranges (in% of the RC)
• the increase is 10% of the nominal capacity RC of the power plant between the partial load range of 65 to 80% of the nominal power plant RC to ensure.
• the power increase decreases linearly from 10% to 0.
• the power plant capacity in the partial load range between 95% and 70% of the rated power of the power plant within 10 seconds by 10% of Lower nominal power RC of the power plant. Between the partial load ranges of 70% to 65% of the power plant rated power RC, the power reduction decreases linearly from 10% to approx. 6.5 and between 100% and the partial load range of 95% the power reduction increases linearly from approx. 5% to 10%.
• Figure 2 further shows the minimum load (minimum generation MG) of the power plant required by the UK electricity grid, which is 65% of the rated power of the power plant.
• FIG. 3 shows by way of example how these requirements, which are based on the British Electricity Network Regulations, can be met.
• the furnace 1 of the power plant according to the invention and not shown, for example, four coal grinding 2.1, 2.2, 2.3, 2.4 formed, all of which directly fire the combustion chamber of the power plant not shown directly (direct firing or direct firing system), wherein at least one of the coal -Mahlanlagen 2.1, 2.2, 2.3, 2.4 is designed such that so that the combustion chamber instead indirectly fired directly (indirect firing or indirect firing system) can be, ie that at least one of the coal grinding 2.1, 2.2, 2.3, 2.4 next to direct firing system is additionally formed with an indirect firing system.
• each coal grinding plant 2.1, 2.2, 2.3, 2.4 each have a burner level are served and emanating from the respective coal grinding plants 2.1, 2.2, 2.3, 2.4 outgoing coal dust pipes 3.1, 3.2, 3.3, 3.4 do not serve each illustrated burner in the respective corners or side walls of the generally rectangular combustion chamber of the coal-fired power plant.
• the feed devices 9.1, 9.2, 9.3, 9.4 downstream of the feeder elements 10 are supplied with a conveying gas, for example air, via a conveying gas line 11 a winningg ⁇ s blower 12 is introduced.
• the feeder 15 may be, for example, an injector, a feed shoe, a dust pump or the like.
• the separated in the separator 4 carrier gas or carrier air is discharged via a carrier gas discharge line 14 and fed to the atmosphere, where it is previously cleaned again in a Staubabscheidesystem.
• the carrier gas may also be introduced into the combustion chamber or into the combustion chamber downstream flue passages of the coal-fired power plant instead of into the atmosphere and freed of dust in the existing dust collection system (e.g., E-filter, baghouse filter or the like) of the power plant.
• each of the storage lines 7.1, 7.2, 7.3, 7.4 each have their own separator 4 and its own downstream silo 5, from which then depart the respective supply lines 9.1, 9.2, 9.3, 9.4.
• the coal grinding plants 2.1, 2.2, 2.3 of the furnace 1 according to FIG. 3 operate such that the pulverized coal pulverized therein is supplied directly to the combustion chamber for combustion via the respective pulverized coal pipes 3.1, 3.2, 3.3, 3.4.
• the coal grinding plant 2.4 which is an example (it may be any other grinding system instead of the grinding plant 2.4) in addition to the direct firing system is additionally formed with an indirect firing system, are in the coal dust lines 3.1, 3.2, 3.3, 3.4 respectively arranged pulverized coal Turnouts 6 and 13 are set such that the pulverized coal pulverized in the coal grinding plant 2.4 is not fed directly to the combustion chamber but via the silo 5 to the combustion chamber.
• the conveying gas line 1 1 arranged in the supply lines 9.1, 9.2, 9.3, 9.4 Zuteilorgane 10 and feeders 15 in operation and delivery gas is provided by the conveying gas line 1 1 and the conveying gas blower 12 the feeders 15.
• the conveying gas takes in the feeders 15 each assigned by the metering organs 10 coal dust and promotes him into the combustion chamber.
• the mode of operation of the grinding plant 2.4 is such that, as a rule, at the beginning of the operation, the grinding capacity of the grinding plant 2.4 compared to the grinding capacity of the grinding plants 2.1, 2.2, 2.3 and 2.3 compared to the current demand of the grinding capacity of the grinding plant 2.4 or compared to the instantaneous actual performance of the grinding plant 2.4 is increased to fill with the oversupply of crushed fuel, the storage volume V Sp having silo 5 volume side about half. After the filling of the silo 5, the grinding capacity of the grinding plant 2.4 is equalized with those of the grinding plant 2.1, 2.2, 2.3 or the current demand of the grinding capacity of the grinding plant 2.4.
• the discharge or delivery rate of the metering elements 10 corresponds to the volume grinding performance of the grinding plant 2.4, ie after the filling process, the amount of pulverized coal from the silo 5 is discharged as produced by the grinding plant 2.4 and entered into the silo 5 , with smallest losses in the separator 4 are taken into account.
• the block power control of the coal-fired power plant influenced, which significantly increases the amount of coal discharged through the metering elements 10 from the silo 5 and the combustion chamber indirectly supplied pulverized coal compared to the instantaneous actual performance or against the by the coal grinding plants 2.1, 2.2, 2.3 respectively supplied coal dust.
• the instantaneous actual power designates the power or the partial load with which the coal-fired power station is currently operated and from which the fuel quantity supplied to the combustion chamber and thus also the respective throughput of the individual coal grinding plants 2.1, 2.2, 2.3, 2.4 are dependent ,
• the coal grinding plant 2.4 downstream silo 5 is designed and formed with a corresponding capacity or storage volume V Sp for the coal dust to be stored.
• V Sp capacity or storage volume
• the storage volume V Sp of the silo 5 is designed such that during normal operation, ie at steady state, the storage volume V Sp of the silo 5 is filled in about half and thereby has stored enough coal dust, in the event of Frequenz ⁇ bf ⁇ lles or a primary and / or secondary requirement of the electricity network operator to the power delivery to the network, ie a transient state, to bring an increased amount of pulverized coal in the combustion chamber to improve the dynamic behavior of the power plant.
• the silo 5 must still have enough storage capacity to bring in the case of frequency exceeding or a primary and / or secondary requirement of the electricity network operator to the power delivery to the network, so again a transient state, a reduced amount of coal dust in the combustion chamber can and absorb the stored during the transient condition of the grinding plant 2.4 excess amount of coal dust in the silo 5 and store it.
• the feeders 15 and the coal dust lines (feed lines 9.1, 9.2, 9.3, 9.4 and coal dust lines 3.1, 3.2, 3.3, 3.4) downstream of the silo or the silo 5 up to the Combustion chamber dimensionally appropriate to be formed in order to pass the required amounts of fuel in the required short time and to be able to supply the combustion chamber.
• the conveying gas or carrying air required for this purpose is brought in regulated manner by the conveying gas line 11 and by means of the conveying gas blower 12.
• FIG. 4 schematically shows the dynamic behavior of a direct and an indirect firing or of a direct and an indirect firing system of a coal-fired power plant. While the increase of the steam generator power from L 0 to L 1 in direct firing from t 0 requires the time t 2 , the increase of the same steam generator power in indirect firing from t 0 requires only the time t, and thus comes with an ideal, jump-shaped Increase within a time t 0 (step response) much closer.
• Increasing the steam generator capacity from L 0 to L 1 represents a percentage A P of the power plant rated power RC, for example an increase of 10% of the power plant rated power RC.
• the coal grinding 2.4 can be operated as a direct firing system by the coal dust switches 6 and 13 converted and the coal dust through the pulverized coal pipes 3.1, 3.2, 3.3, 3.4 is fed directly to the combustion chamber and the silo 5 and the allocating organs 10 and the feeders 15 thus bypassed (bypass).
• additional coal grinding plants 2.1, 2.2, 2.3 are additionally designed with an indirect firing system, then one or more coal grinding plants can be converted to the operation as indirect firing system by conversion of the pulverized coal switches 6 and 13 and thus the indirect firing system in maintenance temporarily replace the coal grinding plant 2.4.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Supply And Distribution Of Alternating Current (AREA)
• Feeding And Controlling Fuel (AREA)
• Breeding Of Plants And Reproduction By Means Of Culturing (AREA)

Priority Applications (5)

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Publications (1)

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Cited By (1)

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Citations (5)

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• 2009
  • 2009-04-03 DE DE102009016191A patent/DE102009016191B4/de not_active Withdrawn - After Issue
• 2010
  • 2010-03-19 CN CN201080016884.XA patent/CN102388267B/zh active Active
  • 2010-03-19 EP EP10718437.6A patent/EP2414731B1/de active Active
  • 2010-03-19 HU HUE10718437A patent/HUE029851T2/en unknown
  • 2010-03-19 PL PL10718437T patent/PL2414731T3/pl unknown
  • 2010-03-19 US US13/262,391 patent/US20120122042A1/en not_active Abandoned
  • 2010-03-19 WO PCT/DE2010/000323 patent/WO2010115396A1/de active Application Filing
  • 2010-03-19 ES ES10718437.6T patent/ES2597961T3/es active Active
• 2016
  • 2016-10-12 HR HRP20161325TT patent/HRP20161325T1/hr unknown

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