JP2010091481A - Method of managing viscosity of slurry supplied to fluidized bed boiler as fuel, and slurry supply device for executing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of managing viscosity of slurry capable of accurately and rapidly adjusting the viscosity of slurry and stably operating a fluidized bed boiler regardless of the component of the slurry supplied to the fluidized bed boiler as a fuel, and to provide a slurry supply device for executing the method. <P>SOLUTION: The slurry supply device 40 for supplying slurry to the fluidized bed boiler 10 includes an ammeter 60 for measuring a consumption current of a kneading machine 54 for kneading slurry 2, a water supply route 44 for supplying water included in the slurry 2 to the kneading machine 54, a flow rate regulating valve 52w for adjusting the flow rate of water supplied to the kneading machine 54 by the water supply route 44, and a viscosity control unit 62 for adjusting the opening of the flow rate regulating valve 52w by the kneading machine 54 according to the consumption current measured by the ammeter 60. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for managing the viscosity of a slurry supplied as fuel to a fluidized bed boiler and a slurry supply apparatus for performing the method, and in particular, regardless of the constituent material of the slurry, the viscosity of the slurry is accurately and quickly adjusted, and the fluidized bed The present invention relates to a technology capable of stably operating a boiler.

As one of the coal-fired power plants, a pressurized fluidized bed combined power generation (PFBC) system in which a steam turbine is driven by steam generated from a fluidized bed boiler and a gas turbine is driven by exhaust gas from a fluidized bed boiler (PFBC). Is adopted.
This power plant supplies slurry (CWP: Coal Water Paste), which is a mixture of coal, limestone, and water as fuel, to the furnace of the fluidized bed boiler while maintaining the inside of the fluidized bed boiler in a pressurized state. The slurry can be burned efficiently.

  In recent years, coal-fired power plants equipped with such fluidized bed boilers have switched between multiple types of coking coal as raw materials for slurry in order to increase energy efficiency and perform stable operations and reduce the environmental burden as much as possible. Or use new fuels such as biomass fuel. At this time, the water content of the slurry, the calorific value, the contained components, etc. differ depending on the coal type of the raw coal and the new fuel.

For this reason, the present applicant has conventionally proposed a technique for appropriately managing the operation of the pressurized fluidized bed boiler according to the coal type of the raw coal supplied to the pressurized fluidized bed boiler. , A viscosity management method for slurry is disclosed in which the viscosity of CWP is determined and the viscosity of CWP is corrected to an appropriate value based on the determination result of the viscosity of CWP.
JP 2008-14505 A

  By the way, Patent Document 1 does not disclose any special measures for means for obtaining information on the viscosity of the slurry, and the measurement of the viscosity of the slurry supplied into the fluidized bed of the fluidized bed boiler can be performed by hand analysis or This is performed by a continuous measurement viscometer installed in a kneader for kneading CWP.

  However, in manual analysis, it takes a certain amount of time to collect a slurry sample from a kneader or the like and obtain a measurement result. In continuous measurement viscometer measurement, it depends on the type of raw coal and the new fuel. In some cases, it is impossible to measure the viscosity, which may affect the stable operation of the fluidized bed boiler.

  The present invention has been made in view of the above points. Regardless of the constituent material of the slurry supplied as fuel to the fluidized bed boiler, the viscosity of the slurry is accurately and quickly adjusted to stabilize the fluidized bed boiler. It is an object of the present invention to provide a slurry viscosity management method that can be operated and a slurry supply apparatus that performs the method.

To achieve the above object, the present invention is a method for managing the viscosity of a slurry supplied as fuel to a fluidized bed boiler,
Measure the current consumption of the kneader kneading the slurry,
The viscosity of the slurry kneaded by the kneader is adjusted according to the current consumption.

The present inventor has found that there is a correlation between the current consumption of the kneader and the viscosity of the slurry kneaded in the kneader. That is, the current consumption of the kneader can be used as an index representing the degree of viscosity of the slurry, and the current consumption of such a kneader can be easily measured by installing an ammeter or the like in the power supply system of the kneader. Can grasp quickly.
Therefore, according to the slurry viscosity management method of the present invention, the viscosity of the slurry can be quickly adjusted by adjusting the viscosity of the slurry kneaded by the kneader according to the current consumption of the kneader thus measured. Thus, the fluidized bed boiler to which the slurry is supplied can be stably operated.

  In the present invention, the constituent material of the slurry introduced into the kneader includes coal, limestone, and water, and the amount of the water introduced into the kneader is adjusted as the viscosity of the slurry. It is good as well. According to this configuration, the viscosity of the slurry can be easily adjusted by adjusting the amount of water used as the constituent material.

  In the present invention, the adjustment of the amount of water is performed by increasing the amount of water introduced into the kneader when the measured current consumption of the kneader exceeds a predetermined range. It is good also as reducing the quantity of the water introduce | transduced into the said kneader when it falls below. According to this configuration, the viscosity of the slurry supplied as fuel to the fluidized bed boiler can be maintained within a predetermined range.

  In this invention, it is good also as using the sludge slurry which processed the sewage sludge produced | generated in the sewage treatment plant etc. into the slurry form as said material.

  The present invention is a slurry supply apparatus for supplying a fluidized bed boiler as fuel, an ammeter for measuring current consumption of a kneader for kneading the slurry, and water for supplying water contained in the slurry to the kneader. A viscosity that adjusts the opening of the water flow control valve according to the water flow control valve that is provided in the supply path and adjusts the flow rate of the water supplied to the kneader and the current consumption measured by the ammeter. And a control device.

  In the present invention, the viscosity control apparatus, when the measured current consumption of the kneading machine exceeds a predetermined range in accordance with the current consumption of the kneading machine measured by the ammeter, The opening degree of the water flow rate adjustment valve may be opened by a predetermined amount, and the opening degree of the water flow rate adjustment valve may be adjusted to be closed by a predetermined amount when it falls below the predetermined range.

  ADVANTAGE OF THE INVENTION According to this invention, irrespective of the constituent material of the slurry supplied as a fuel to a fluidized bed boiler, the viscosity of the slurry can be adjusted accurately and quickly, and the fluidized bed boiler can be operated stably. A method and a slurry supply apparatus for performing the method can be provided.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a power plant 1 using a pressurized fluidized bed boiler 10 according to the present embodiment.

  As shown in FIG. 1, the power plant 1 includes a pressurized fluidized bed boiler 10 that generates steam by burning fuel, a steam turbine generator 70 driven by the steam, and a pressurized fluidized bed boiler 10. And a gas turbine generator 90 that uses exhaust gas generated by the combustion inside.

  The pressurized fluidized bed boiler 10 includes a pressure vessel 20, a furnace main body 30 provided therein, and a slurry supply device 40 that supplies slurry 2 as fuel to the furnace main body 30. A predetermined amount of slurry 2 is accommodated in the furnace body 30. The slurry 2 is fluidized with pressurized air blown from the bottom of the furnace body 30 in the pressure vessel 20 in a pressurized state to form a fluidized bed. And the slurry 2 supplied to the furnace main body 30 from the slurry supply apparatus 40 is burned in a pressurized state.

  A heat transfer tube 72 connected to the steam turbine generator 70 is routed in the furnace main body 30, and the heat generated by burning the slurry 2 in the furnace main body 30 is used in the heat transfer tube 72. Steam is generated, the steam turbine 74 is rotated, and a generator 76 connected coaxially with the steam turbine 74 is operated to generate power. The steam after rotating the steam turbine 74 is condensed by the condenser 80, passes through the exhaust heat recovery boiler 32, and is guided again into the pressurized fluidized bed boiler 10.

  Further, the exhaust gas generated by the combustion in the pressurized fluidized bed boiler 10 is supplied to the gas turbine 92. A generator 94 and a compressor 96 are coaxially connected to the gas turbine 92. When the gas turbine 92 rotates, the generator 94 is driven to generate electric power, and the compressor 96 is driven to generate compressed air. Is fed into the pressure vessel 20 of the pressurized fluidized bed boiler 10. The exhaust gas exits the gas turbine 92, passes through the exhaust heat recovery boiler 32, and is exhausted from the chimney 34.

The slurry supply device 40 manufactures the slurry 2 as fuel and supplies it to the furnace body 30. Here, the slurry 2 refers to a mixture of dehydrated sludge or concentrated sludge in CWP (Coal Water Paste) composed of coal, water, and limestone as main fuels.
FIG. 2 is a schematic configuration diagram of the slurry supply apparatus 40.
As shown in FIG. 2, the slurry supply apparatus 40 is manufactured by a coal supply path 42, a water supply path 44, a limestone supply path 46, a sludge slurry supply path 48, a kneader 54, and a kneader 54. A viscosity controller 62 that adjusts the viscosity of the slurry 2 and a slurry pump 64 that supplies the slurry 2 produced by the kneader 54 to the furnace body 30 are provided.

  The coal supply path 42 is a system that supplies coal to a kneader 54 from a coal bunker or the like that stores coal. For example, a coarse pulverizer and a fine pulverizer that pulverize coal between the coal bunker and the kneader 54. Are arranged (not shown). Coal is crushed by a coarse pulverizer, and crushed by a coarse pulverizer, then sent to a fine pulverizer, further finely pulverized and mixed with water, and mixed with a kneader 54. To be supplied.

  The water supply path 44 is a system that supplies water from the water tank 51 to the kneader 54. The limestone supply path 46 is a system that supplies limestone to the kneader 54 from a limestone bunker or the like that stores limestone. The sludge slurry supply path 48 is a system for supplying sludge slurry to the kneader 54 from a storage facility such as a sludge slurry tank.

  These slurry material supply paths 42 and 46 are provided with conveyors for adjusting the supply amount (not shown). The supply passages 44 and 48 are each provided with a material pressure feed pump 50 and a flow rate adjusting valve 52, and the amount of each material supplied to the kneading machine 54 is adjusted, and these slurry materials are contained in the kneading machine 54. Are mixed.

  The water supply path 44 is provided with a flow rate adjustment valve 52w capable of controlling the flow rate of water flowing inside from the outside. The flow rate adjustment valve 52w is connected to the viscosity control device 62, and the viscosity control device The flow rate of water flowing through the water supply path 44 is adjusted by the control of 62.

The kneading machine 54 is connected to the supply paths 42 to 48 and kneads the supplied slurry material to produce the slurry 2. The kneader 54 includes, for example, a plurality of stirring blades 56 and an electric motor 58 that rotates the stirring blades 56, and the slurry material is kneaded by rotating the stirring blades 56 with the electric motor 58.
The kneader 54 is provided with an ammeter 60 for measuring the consumption current of the electric motor 58, and the ammeter 60 is connected to the viscosity control device 62.

  The viscosity control device 62 includes, for example, a CPU and a storage device such as a ROM, a RAM, and a hard disk, and includes an information processing device including a display unit such as a liquid crystal screen and an input unit such as a keyboard. The viscosity control device 62 controls the opening degree of the flow rate adjusting valve 52w installed in the water supply path 44 according to the consumption current measured by the ammeter 60 installed in the electric motor 58 of the kneading machine 54, and kneading. The flow rate of water supplied to the machine 54 is adjusted so that the viscosity of the slurry 2 produced by the kneader 54 becomes a value within a predetermined range.

FIG. 3 is a scatter diagram showing an actual measurement of the current consumed by the electric motor 58 of the kneader 54 and the viscosity of the slurry 2 collected from the kneader 54 when the current is shown, and its approximation. It is a graph which shows a straight line. The viscosity of the slurry 2 was measured by manual analysis. Further, in order to confirm the reproducibility of the measurement results, the current value and the viscosity of the slurry 2 were measured under different operating conditions of the kneader 54, and a scatter diagram and a graph were compiled for each measurement result.
As shown in FIG. 3, in any kneader 54, the viscosity of the slurry 2 tends to increase as the current of the electric motor 58 of the kneader 54 increases, and the current of the electric motor 58 and the slurry 2 are increased. There is a positive correlation with the viscosity of
This is because the viscosity of the slurry 2 is increased, the resistance acting on the stirring blade 56 for stirring the slurry 2 is increased, and the load applied to the electric motor 58 of the kneader 54 is increased accordingly. This is probably because the current of the motor 58 also increases.
In this embodiment, the current consumption of the kneader 54 is reduced by utilizing the relationship between the current consumption of the electric motor 58 of the kneader 54 and the viscosity of the slurry 2 kneaded in the kneader 54. 2 is used for control for adjusting the viscosity of the slurry 2 by the viscosity controller 62.

FIG. 4 is a flow showing an example of the control of the viscosity control device 62 for supplying an appropriate amount of water into the kneader 54.
As shown in FIG. 4, first, as step S <b> 1, it is determined whether or not the consumption current of the kneader 54 measured by the ammeter 60 is within a predetermined range.
The predetermined range of the consumption current used for the determination here is, for example, the consumption current of the electric motor 58 of the kneader 54 as shown in FIG. 3 and the slurry 2 collected from the kneader 54 when the current is shown. The relationship with the viscosity is determined in advance by an approximate line or the like, and a current consumption range corresponding to the viscosity range of the slurry 2 in which the pressurized fluidized bed boiler 10 can be stably operated is adopted based on the approximate line or the like. .
In step S1, when the current consumption of the kneader 54 is within the predetermined range, the process returns to step S1 again without particularly controlling the flow control valve 52w.
On the other hand, when the consumption current of the kneader 54 is not within the predetermined range, the process proceeds to step S2.

  In step S2, it is determined whether or not the consumption current of the kneader 54 measured by the ammeter 60 exceeds a predetermined range. When the current consumption exceeds the predetermined range, that is, it is determined that the slurry 2 in the kneader 54 is larger than the predetermined range of viscosity, and the viscosity control device 62 opens the opening with respect to the flow control valve 52w. Is increased by a predetermined amount (step S3). As a result, the flow rate of the water supplied into the kneader 54 increases, so that the viscosity of the slurry 2 decreases. After that control, the process returns to step S1 again.

  On the other hand, in step S2, if the current consumption does not exceed the predetermined range, that is, if the current consumption is lower than the predetermined range, it is determined that the slurry 2 in the kneader 54 is smaller than the viscosity in the predetermined range. The viscosity controller 62 controls the flow control valve to reduce its opening by a predetermined amount (step S4). As a result, the flow rate of the water supplied into the kneader 54 is decreased, so that the viscosity of the slurry 2 is increased. After that control, the process returns to step S1 again.

  When the viscosity control device 62 performs such control, the viscosity of the slurry 2 manufactured in the kneader 54 is maintained within a predetermined range.

  Then, the slurry 2 adjusted to have a viscosity within a predetermined range in the kneader 54 is supplied to the furnace body 30 by the slurry pump 64 so that it is burned well in the pressurized fluidized bed boiler 10 and pressurized. The fluidized bed boiler 10 is stably operated.

  As described above, according to the pressurized fluidized bed boiler 10 according to the present embodiment, the ammeter 60 that measures the consumption current of the kneader 54 that kneads the slurry 2 and the water contained in the slurry 2 are mixed with the kneader 54. The water flow rate adjusting valve 52w is provided in the water supply path 44 for supplying water to the kneading machine 54, and the water flow rate adjusting valve 52w And a viscosity control device 62 for adjusting the opening degree. Thereby, the viscosity of the slurry 2 kneaded by the kneader 54 is quickly adjusted according to the measured current consumption of the kneader 54, so that the pressurized fluidized bed boiler 10 to which the slurry 2 is supplied is stabilized. Drive.

  Further, when the viscosity control device 62 adjusts the water and the consumption current of the kneading machine 54 measured by the ammeter 60 exceeds a predetermined range, the flow control valve is opened and introduced into the kneading machine 54. Slurry 2 produced in the kneader 54 by increasing the amount of water and reducing the amount of water introduced into the kneader 54 by decreasing the opening of the flow control valve when the amount falls below a predetermined range. Since the viscosity of is kept within a predetermined range, it can contribute to stable operation of the fluidized bed boiler.

  In the present embodiment, the viscosity control device 62 performs control for adjusting the opening of the water flow rate adjustment valve 52w according to the current consumption measured by the ammeter 60. However, the present invention is not limited to this. May visually adjust the current consumption of the ammeter 60 and manually adjust the opening of the water flow rate adjustment valve 52w according to the current consumption. In this case, the worker can keep the viscosity of the slurry 2 manufactured in the kneader 54 within a predetermined range by performing the same control as the flow described in FIG.

It is a schematic block diagram of the power plant 1 using the pressurized fluidized bed boiler 10 which concerns on this embodiment. 2 is a schematic configuration diagram of a slurry supply device 40. FIG. It is a graph which shows the scatter diagram which showed the consumption current of the electric motor 58 of the kneading machine 54, and the viscosity of the slurry 2 sampled from the kneading machine 54 when the current was shown, and its approximate line. It is a flow which shows an example of control of the viscosity control apparatus 62 for supplying a suitable quantity of water in the kneading machine 54. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power plant 2 Slurry 10 Pressurized fluidized bed boiler 20 Pressure vessel 30 Furnace main body 32 Exhaust heat recovery boiler 34 Chimney 40 Slurry supply device 42 Coal supply path 44 Water supply path 46 Limestone supply path 48 Sludge slurry supply path 50 Pump for material pressure feeding 51 Water Tank 52, 52w Flow Control Valve 54 Kneading Machine 56 Stirring Blade 58 Electric Motor 60 Ammeter 62 Viscosity Controller 64 Slurry Pump 70 Steam Turbine Generator 72 Heat Transfer Tube 74 Steam Turbine 76 Generator 80 Condenser 90 Gas Turbine Power Generation Machine 92 Gas turbine 94 Generator 96 Compressor S1, S2, S3, S4 Step 1

Claims (6)

A method for managing the viscosity of a slurry supplied as fuel to a fluidized bed boiler,
Measure the current consumption of the kneader kneading the slurry,
A method for managing the viscosity of a slurry, wherein the viscosity of the slurry kneaded by the kneader is adjusted according to the current consumption. As a constituent material of the slurry introduced into the kneader, including coal, limestone and water,
The slurry viscosity management method according to claim 1, wherein the amount of the water introduced into the kneader is adjusted as adjustment of the viscosity of the slurry.   The adjustment of the amount of water is performed when the measured current consumption of the kneader exceeds a predetermined range, increases the amount of water introduced into the kneader, and falls below the predetermined range. The method for managing the viscosity of a slurry according to claim 2, wherein the amount of water introduced into the kneader is reduced.   4. The slurry viscosity management method according to claim 2, wherein sludge slurry obtained by processing sewage sludge generated in a sewage treatment plant or the like into a slurry is used as the material. A slurry supply device for supplying a fluidized bed boiler as fuel,
An ammeter for measuring current consumption of a kneader for kneading the slurry;
A water flow rate adjusting valve that is provided in a water supply path for supplying water contained in the slurry to the kneader and adjusts the flow rate of water supplied to the kneader;
A slurry supply device comprising: a viscosity control device that adjusts an opening degree of the water flow rate control valve in accordance with current consumption measured by the ammeter.   The viscosity control device is configured to open the water flow control valve when the measured current consumption of the kneader exceeds a predetermined range in accordance with the current consumption of the kneader measured by the ammeter. The slurry supply apparatus according to claim 5, wherein when a predetermined amount is opened, and the opening of the water flow rate adjustment valve is closed by a predetermined amount when the value falls below the predetermined range, the slurry supply device is adjusted.

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