JP4845712B2 - Pressurized fluidized bed combined power generation system and method for maintaining constant bed height of pressurized fluidized bed boiler - Google Patents

Description

  The present invention relates to a pressurized fluidized bed combined power generation system and a method for maintaining the bed height of a pressurized fluidized bed boiler constant.

  In coal-fired power generation, the combustion method of the boiler that burns the coal is different from the pulverized coal combustion method in which the coal type of fuel is limited, and the normal pressure fluidized bed combustion method in which there is a limit to higher efficiency and higher output. However, it is predicted that the system will be shifted to a pressurized fluidized bed combustion combined power generation system (hereinafter abbreviated as PFBC) with high power generation efficiency.

  The pressurized fluidized bed boiler used for PFBC is accommodated in the pressure vessel. During power generation, the inside of a pressurized fluidized bed boiler (hereinafter sometimes abbreviated as “boiler”) is maintained in a pressurized state by combustion air from a compressor. In this pressurized boiler, when coal particles as fuel, limestone particles flowing as a fluidized medium (BM), and a kneaded material in which water is kneaded are introduced (supplied), the limestone particles and the fluid flow The coal is burned efficiently. In PFBC, it is possible to drive a gas turbine by the combustion gas generated at this time. Conventionally, a so-called single-can single-shaft type combined power generation device including a boiler and a gas turbine has been the mainstream as a device used in the PFBC (hereinafter sometimes abbreviated as a combined power generation device).

  By the way, when installing this pressurized fluidized bed boiler at the installation location, rather than bringing the boiler material into the installation location and making it from scratch, the boiler manufactured by the factory was transported to the installation location and installed. However, it is possible to achieve a significant reduction in local construction.

  However, with an increase in the size of a pressurized fluidized bed boiler, it has become difficult to transport the pressurized fluidized bed boiler to the site, and further, it has become difficult to install the pressurized fluidized bed boiler locally. In view of this, a so-called two-can type combined power generator having two pressurized fluidized bed boilers has been devised, which solves the above problem by dividing the pressurized fluidized bed boiler into two parts (see Patent Document 1).

An example of a two-can type combined power generator is shown in FIG. As shown in FIG. 11, the two-can type combined power generation apparatus 300 includes boilers 312 and 314, and further, as a kneaded material supply facility for supplying a kneaded material to the boiler 312, coal, limestone particles, limestone slurry, and A kneader 322 for kneading water at a predetermined mixing ratio, a storage tank 352 for storing the kneaded product, a conveyor 332 for conveying the kneaded product from the kneader 322 to the storage tank 352, and a kneaded product stored in the storage tank 352 Is provided with a charging pump 372 for charging the boiler 312. The combined power generation apparatus 300 includes a kneader 324, a storage tank 362, a transfer conveyor 334, and a charging pump 374 that are installed corresponding to the boiler 314. That is, the two-can type combined power generation apparatus 300 includes two systems of kneaded material supply equipment for supplying the kneaded material to the boilers 312 and 314, respectively.
Japanese Unexamined Patent Publication No. 1995-145709

  However, when a part of the kneaded product supply facility of one system of the two-can type combined power generation apparatus 300, for example, the kneader 322, the transfer conveyor 332, or the storage tank 352 breaks down, the kneaded product to the boiler 312 Since the supply is stopped, it is necessary to take measures such as lowering the power generation output until the malfunctioning equipment is repaired or stopping the operation of the boiler 312. Therefore, in order to perform stable power generation, a new combined power generation device different from the conventional kneaded material supply facility has been demanded.

  The present invention has been made in view of the above problems, and even when a part of equipment for supplying a kneaded product to a pressurized fluidized bed boiler fails, the power generation output is not lowered, or It is an object of the present invention to provide a pressurized fluidized bed combined power generator capable of performing stable power generation without stopping the pressurized fluidized bed boiler and a method for maintaining a constant bed height of the pressurized fluidized bed boiler. .

  (1) Two pressurized fluidized bed boilers, limestone particles each forming a fluidized bed in the pressurized fluidized bed boiler, coal particles serving as fuel in the pressurized fluidized bed boiler, and water 2 kneaders that knead at a mixing ratio of 2 to obtain a kneaded product, and two tank groups each corresponding to each pressurized fluidized bed boiler, each storing the kneaded product 2 Two tank groups having a base storage tank, four charging devices each provided in each storage tank of each tank group, and two transport devices each installed corresponding to each kneader Each charging device feeds the kneaded material stored in each storage tank of each tank group to each pressurized fluidized bed boiler corresponding to each tank group, and one and the other of the conveying devices are respectively the kneading Each tank from one and the other of the machine PFBC combined power generation device for conveying the kneaded product in the storage tanks of the group.

  The invention of (1) is provided in two pressurized fluidized bed boilers, two kneaders, two transport devices, two tank groups each having two storage tanks, and each storage tank 4 It is a pressurized fluidized bed combined power generation device having two charging devices. Here, for example, even if one of the two kneaders, for example, one of the two kneaders breaks down, the other of the conveying devices can transfer the kneaded material from the other kneader to each storage tank of each tank group. It can be transported.

  In addition, each of the two tank groups according to the present invention is installed corresponding to each pressurized fluidized bed boiler, and since one tank group has two storage tanks, when one of the storage tanks fails However, the kneaded product can be supplied to the pressurized fluidized bed boiler from the other storage tank.

  As described above, according to the present invention, even when a part of the facility for supplying the kneaded product to the pressurized fluidized bed boiler fails, the power generation output is not lowered to operate, or the pressurized fluidized bed boiler is not stopped. In addition, stable power generation can be performed.

  (2) One of the conveying devices includes a first conveyor installed corresponding to one of the kneaders, a second conveyor installed corresponding to one of the tank groups, and the tank group A third conveyor installed corresponding to the other, and the other of the transfer devices corresponds to a fourth conveyor installed corresponding to the other of the kneaders and one of the tank groups And a sixth conveyor installed corresponding to the other of the tank groups, and one and the other of the pressurized fluidized bed boilers have a layer height change characteristic. In the pressurized fluidized bed combined power generation apparatus according to (1), the bed height of the pressurized fluidized bed boiler is maintained constant, and the third conveyor and the fifth conveyor are stopped, The kneaded material kneaded by one of the kneaders is The predetermined mixing ratio of one of the kneaders is determined so that the layer height of one of the pressurized fluidized bed boilers does not change over time when charged into one of the fluidized bed boilers, When the kneaded material kneaded by the other is charged into the other of the pressurized fluidized bed boiler, the predetermined height of the other of the kneader is kept so that the other layer height of the pressurized fluidized bed boiler does not change with time. The kneaded product is transferred from one of the kneaders to the second conveyor by the first conveyor, and the kneaded product is transferred from one of the kneaders to the second conveyor by the fourth conveyor. 6, the kneaded material conveyed by the first conveyor by the second conveyor is conveyed to one of the tank groups, and is conveyed by the fourth conveyor by the sixth conveyor. A method of maintaining a constant bed height of a pressurized fluidized bed boiler that conveys the fed kneaded material to the other tank group.

  “Different layer height change characteristics” can be defined as follows. After charging, two pressurized fluidized bed boilers of the same type were charged with the same mixture of L / C, which is the mass ratio of limestone (L) and coal (C), under the same conditions. The change in bed height of each pressurized fluidized bed boiler may be different. That is, even with two pressurized fluidized bed boilers of the same type, the temporal change in bed height may be different. Thus, in two pressurized fluidized bed boilers of the same type, the difference in change in bed height over time is referred to as “different bed height change characteristics”.

  “Layer height” can be defined as follows. When a pressurized fluidized bed boiler in a pressurized state is charged (supplied) with coal as fuel, limestone particles that flow as a fluidized medium (BM), and water, the bottom of the boiler Coal particles are efficiently burned by the air ejected from the limestone, and the limestone particles float to a certain height and move violently (flow). This fluidized bed is called a fluidized bed, and the height of the fluidized bed (layer) in the vertical direction of the fluidized fluid medium is called the “bed height”.

  In the invention of (1), since the kneaded material kneaded by the two kneaders is mixed in the storage tank, the L / C of the kneaded material charged into each pressurized fluidized bed boiler is the same. Therefore, for example, as in the invention of (2), when the bed height change characteristic is different between one and the other of the pressurized fluidized bed boilers, the one bed height of the pressurized fluidized bed boiler can be maintained constant. However, the other bed height of the pressurized fluidized bed boiler cannot be kept constant. Thus, for example, when the height of the other layer of the pressurized fluidized bed boiler is gradually increased, the fluidity from the other of the pressurized fluidized bed boiler is maintained in order to keep the other layer height of the pressurized fluidized bed boiler constant. Remove the media. On the contrary, when the other layer height of the pressurized fluidized bed boiler is gradually lowered, the fluid medium previously extracted is supplied to the other of the pressurized fluidized bed boiler. However, it is difficult to maintain a constant bed height of the pressurized fluidized bed boiler by extracting or supplying such a fluid medium, and it is not efficient.

  According to the invention of (2), the third conveyor and the fifth conveyor are stopped, and the kneaded material kneaded by one of the kneaders is transferred from one of the kneaders to the first conveyor, the second conveyor, The kneaded material conveyed in the order of one of the tank groups and kneaded by the other of the kneaders is conveyed from the other of the kneaders in the order of the fourth conveyor, the sixth conveyor, and the other of the tank groups. That is, in the present invention, the route for supplying the kneaded material is different between one and the other of the pressurized fluidized bed boilers.

  Therefore, according to the present invention, by setting the predetermined mixing ratio set on one side of the kneading machine and the predetermined mixing ratio set on the other side of the kneading machine to different values, the pressurized fluidized bed boiler It is possible to control the height of one and the other of the layers separately. Furthermore, when the kneaded material kneaded by one of the kneaders is put into one of the pressurized fluidized bed boilers, the predetermined height of one of the kneaders is not changed so that one layer height of the pressurized fluidized bed boiler does not change with time. Kneaded so that the other layer height of the pressurized fluidized bed boiler does not change over time when the kneaded material kneaded by the other of the kneader is charged into the other of the pressurized fluidized bed boiler. Since the other predetermined mixing ratio of the machine is determined, the bed height of both of the pressurized fluidized bed boilers is kept constant without changing over time.

  As described above, according to the present invention, even when the bed height change characteristic is different between one and the other of the pressurized fluidized bed boilers, the bed heights of both of the pressurized fluidized bed boilers change with time. Will be kept constant without.

  According to the present invention, even when a part of the facility for supplying the kneaded material to the pressurized fluidized bed boiler fails, the power generation output is not lowered to operate, or the pressurized fluidized bed boiler is not stopped. Power generation operation can be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an outline of a pressurized fluidized bed combined power generation apparatus in the first embodiment. FIG. 2 is a diagram illustrating the height of the liquid level of each storage tank of the pressurized fluidized bed combined power generation apparatus according to the first embodiment. FIG. 3 is a schematic diagram illustrating a process of transporting the kneaded material to the storage tank in the pressurized fluidized bed combined power generation apparatus according to the first embodiment. FIG. 4 is a schematic diagram illustrating a process of transporting the kneaded material to the storage tank in the pressurized fluidized bed combined power generation apparatus according to the first embodiment. FIG. 5 is a diagram showing a change in the bed height of the pressurized fluidized bed boiler in the pressurized fluidized bed combined power generation apparatus according to the first embodiment. FIG. 6 is a diagram illustrating a change in the bed height of the pressurized fluidized bed boiler in the pressurized fluidized bed combined power generation apparatus according to the first embodiment. FIG. 7 is a diagram illustrating the height of the liquid level of each storage tank of the pressurized fluidized bed combined power generation apparatus according to the second embodiment. FIG. 8 is a schematic diagram illustrating a process of transporting the kneaded material to the storage tank in the pressurized fluidized bed combined power generation apparatus according to the second embodiment. FIG. 9 is a schematic diagram illustrating a process of transporting the kneaded material to the storage tank in the pressurized fluidized bed combined power generation apparatus according to the second embodiment. FIG. 10 is a diagram illustrating a change in the bed height of the pressurized fluidized bed boiler in the pressurized fluidized bed combined power generation apparatus according to the second embodiment.

[First Embodiment]
A first embodiment of the pressurized fluidized bed combined power generation apparatus of the present invention will be described with reference to FIGS.

<Configuration of pressurized fluidized bed combined power generation system>
As shown in FIG. 1, a pressurized fluidized bed combined power generation apparatus 10 according to the present invention includes two cans of pressurized fluidized bed boilers 12 and 14, kneaders 22 and 24, two tank groups 56 and 66, and inputs. Pumps 72, 74, 76, 78, and conveying devices 36, 38 are provided.

  Further, the pressurized fluidized bed combined power generation apparatus 10 may include BM tanks 82, 84, 92, 94, a relay silo 96, and a recycling facility 98.

  The pressurized fluidized bed boilers 12 and 14 are accommodated in a pressure vessel (not shown). During power generation, pressurized fluidized bed boilers 12 and 14 (hereinafter may be abbreviated as boilers 12 and 14) are combustion air from a compressor (not shown) provided in the pressurized fluidized bed combined power generator 10. Is kept under pressure. When boilers 12 and 14 in a pressurized state are charged (supplied) with coal as fuel, limestone particles flowing as a fluidized medium (BM), and water kneaded, the lower part of the boiler Coal particles are efficiently burned by the air from the compressor ejected from the limestone, and the limestone particles float to a certain height and move violently (flow). This fluidized bed is called a fluidized bed, and the height of the fluidized bed (layer) in the vertical direction of the fluidized fluid medium is called the bed height. The pressurized fluidized bed boiler adjusts the mass ratio of limestone (L) and dry coal (C) in the kneaded material charged into the pressurized fluidized bed boiler, in other words, L / C represented by the following formula: By doing so, the bed height of the fluidized bed is controlled.

  That is, the L / C of the kneaded material charged into the pressurized fluidized bed boiler has an appropriate value for maintaining the layer height of each boiler, and when L / C is lower than the appropriate value, the layer height is The layer height gradually decreases, and when L / C is higher than an appropriate value, the layer height gradually increases.

  Further, combustion gas generated by burning coal is sent to a gas turbine via a dust device (not shown) to drive the gas turbine. When the gas turbine is driven, the generator is driven to generate power.

  The pressurized fluidized bed boilers 12 and 14 are provided with an evaporator, a superheater, and a reheater (not shown). The water supplied into the evaporator becomes steam, and this steam is sent to the superheater to become main steam, which is sent to a high-pressure turbine (not shown) to become low-temperature reheat steam. This low temperature reheat steam is sent to a reheater to become high temperature reheat steam, and this high temperature reheat steam is sent to a medium pressure turbine. The generator is driven by driving the high-pressure turbine and the intermediate-pressure turbine with each steam to generate power.

  In the present embodiment, the fluidized bed height changing method is adopted for controlling the pressurized fluidized bed boilers 12 and 14. That is, by comparing the load with the bed height, the bed height is increased to increase the heat transfer area in the layer at high loads, and the bed height is lowered to expose part of the heat transfer area outside the layers at low loads. .

  The kneaders 22 and 24 are devices that knead limestone particles, coal particles, coal slurry, and water at a predetermined mixing ratio to obtain a kneaded product. In the pressurized fluidized bed combined power generation apparatus 10 of the present embodiment, the mixing ratio of limestone particles, coal particles, coal slurry, and water is determined based on the above L / C, and the determined mixing ratio of limestone particles, Coal particles, coal slurry, and water are put into the kneaders 22 and 24 and kneaded.

  Further, each of the kneaders 22 and 24 is one machine, and the amount of the kneaded material exceeds the sum of the maximum kneaded product consumption of the pressurized fluidized bed boiler 12 and the maximum kneaded product consumed of the pressurized fluidized bed boiler 14. Has the ability to knead. That is, even if one of the kneading machines 22 and 24 fails, the other kneading machine conveys an amount of the kneaded material that can normally operate the pressurized fluidized bed boilers 12 and 14. Can be supplied to.

  The tank groups 56 and 66 are installed corresponding to the pressurized fluidized bed boilers 12 and 14, respectively. The tank groups 56 and 66 have storage tanks 52 and 54 and storage tanks 62 and 64 for storing the kneaded material, respectively.

  Moreover, each of the storage tanks 52 and 54 can store the kneaded material in an amount exceeding the maximum kneaded material consumption of the pressurized fluidized bed boiler 12. Similarly, each of the storage tanks 62 and 64 can store a kneaded material in an amount exceeding the maximum kneaded material consumption of the pressurized fluidized bed boiler 14. That is, even if one of the storage tanks 52 and 54 fails, the other storage tank can store an amount of the kneaded material that allows the pressurized fluidized bed boiler 12 to operate normally. it can. Similarly, even if one of the storage tanks 62 and 64 fails, the other storage tank stores an amount of the kneaded material that allows the pressurized fluidized bed boiler 14 to operate normally. Can do.

  The conveying devices 36 and 38 are installed corresponding to the kneaders 22 and 24, respectively. That is, the conveying device 36 is installed in the kneader 22, and the conveying device 38 is installed in the kneader 24.

  The transport device 36 includes a transport conveyor 32 installed corresponding to the kneader 22 and transport conveyors 42 and 46. The conveyors 42 and 46 are installed corresponding to the tank groups 56 and 66, respectively.

  Further, the transport device 38 includes a transport conveyor 34 installed corresponding to the kneader 24 and transport conveyors 44 and 48. The conveyors 44 and 48 are installed corresponding to the tank groups 56 and 66, respectively.

  The conveying devices 36 and 38 convey the kneaded material from the kneaders 22 and 24 to the tank groups 56 and 66, respectively.

  Specifically, the conveyance conveyor 32 is provided in the vicinity of the kneading machine 22 so that the kneaded material can be conveyed from the kneading machine 22 to the conveyance conveyors 42 and 46. The transport conveyor 42 is provided in the vicinity of the transport conveyor 32 so that the kneaded material transported by the transport conveyor 32 can be transported to the tank group 56. The transport conveyor 46 is provided in the vicinity of the transport conveyor 32 so that the kneaded material transported by the transport conveyor 32 can be transported to the tank group 66.

  Further, the transport conveyor 34 is provided in the vicinity of the kneader 24 so that the kneaded material can be transported from the kneader 24 to the transport conveyors 44 and 48. The transport conveyor 44 is provided in the vicinity of the transport conveyor 34 so that the kneaded material transported by the transport conveyor 34 can be transported to the tank group 56. The transport conveyor 48 is provided in the vicinity of the transport conveyor 34 so that the kneaded material transported by the transport conveyor 34 can be transported to the tank group 66.

  Each of the conveying devices 36 and 38 conveys an amount of the kneaded material exceeding the sum of the maximum kneaded material consumption of the pressurized fluidized bed boiler 12 and the maximum kneaded material consumption of the pressurized fluidized bed boiler 14. can do. That is, even if one of the transfer devices 36 and 38 fails, the other transfer device may store an amount of the kneaded material that can normally operate the pressurized fluidized bed boilers 12 and 14 in the storage tank 52, 54, 62, 64.

  The input pumps 72, 74, 76, 78 supply (supply) the kneaded material stored in the storage tanks 52, 54, 62, 64 to the pressurized fluidized bed boilers 12, 14 corresponding to the tank groups 56, 66. The storage tanks 52 and 54 of the tank group 56 and the storage tanks 62 and 64 of the tank group 66 are provided. Accordingly, the charging pump 72 applies the kneaded material stored in the storage tank 52 to the pressurized fluidized bed boiler 12 corresponding to the tank group 56, and the charging pump 74 applies the kneaded material stored in the storage tank 54 to the pressurized fluidized bed boiler. 12, the charging pump 76 applies the kneaded material stored in the storage tank 62 to the pressurized fluidized bed boiler 14 corresponding to the tank group 66, and the charging pump 76 applies the kneaded material stored in the storage tank 64 to the pressurized fluidized bed boiler. 14.

  Each of the input pumps 72 and 74 can supply an amount of the kneaded material exceeding the maximum kneaded material consumption of the pressurized fluidized bed boiler 12 to the pressurized fluidized bed boiler 12. Similarly, each of the input pumps 76 and 78 can supply an amount of kneaded material exceeding the maximum amount of kneaded material consumed by the pressurized fluidized bed boiler 14 to the pressurized fluidized bed boiler 14. That is, even if one of the charging pumps 72 and 74 fails, the other charging pump supplies an amount of kneaded material capable of operating the pressurized fluidized bed boiler 12 normally. The boiler 12 can be charged. Similarly, even if one of the charging pumps 76 and 78 fails, the other charging pump pressurizes and flows the kneaded material in an amount that allows the pressurized fluidized bed boiler 14 to operate normally. It can be put into the floor boiler 14.

  The BM tanks 82 and 84 and the BM tanks 92 and 94 are installed corresponding to the pressurized fluidized bed boilers 12 and 14, respectively. That is, the BM tanks 82 and 84 are installed corresponding to the pressurized fluidized bed boiler 12, and the BM tanks 92 and 94 are installed corresponding to the pressurized fluidized bed boiler 14. The BM tanks 82 and 84 and the BM tanks 92 and 94 are tanks for storing a fluid medium (BM) mainly composed of limestone particles extracted from the pressurized fluidized bed boilers 12 and 14, respectively. Specifically, the BM tanks 82 and 84 extract and store the fluid medium from the pressurized fluidized bed boilers 12 and 14 when the pressurized fluidized bed boilers 12 and 14 are under a low load. Conversely, the BM tanks 82 and 84 and the BM tanks 92 and 94 return the stored fluid medium to the pressurized fluidized bed boilers 12 and 14 when the pressurized fluidized bed boilers 12 and 14 are under high load.

  As will be described later, the BM tanks 82, 84, 92, 94 are tanks for storing a fluid medium extracted from coal ash extracted from the bottoms of the pressurized fluidized bed boilers 12 and 14.

  The relay silo 96 is a silo for temporarily storing the coal ash extracted from the bottoms of the pressurized fluidized bed boilers 12 and 14. The temporarily stored coal ash is sent to the recycling facility 98.

  The recycling facility 98 is a facility that performs a sieving process on the coal ash stored in the relay silo 96 and extracts a fluid medium from the coal ash. The extracted fluid medium is sent to the BM tanks 82, 84, 92, 94.

  In addition, in this embodiment, although the conveyance conveyor was illustrated as an example of the apparatus which conveys kneaded material from a kneader to a storage tank, if it is an apparatus which conveys kneaded material from a kneader to a storage tank, it will not specifically limit.

<Kneaded material conveying method of pressurized fluidized bed combined power generation device>
Next, the kneaded material conveyance method of the pressurized fluidized bed combined power generation apparatus 10 according to this embodiment will be described with reference to FIGS.

  FIG. 2 is a diagram showing the transition of the liquid level of the kneaded product in the storage tanks 52, 54, 62, 64, and shows the remaining amount of the kneaded product in the storage tanks 52, 54, 62, 64. Yes. As shown in FIG. 2, when the liquid level of the kneaded material is lowered to a predetermined height, the kneaded material is conveyed by the conveying device, and the kneaded material is supplied to each storage tank. In other words, the transfer devices 36 and 38 transfer the kneaded material from the kneaders 22 and 24 to the storage tanks 52 and 54 according to the liquid level of the kneaded material in the storage tanks 52, 54, 62 and 64, respectively. , 62, 64.

That is, for example, when the liquid level of the kneaded material in the storage tank 52 is lowered to a predetermined height L1 (time: T ₁ ), the liquid level of the kneaded material in the storage tank 52 is a predetermined height. until the L2 _{(time: T} 2), the kneaded material is transported to a storage tank 52. When the liquid level of the kneaded material in the storage tank 62 is lowered to the predetermined height L1 (time: T ₃ ), the liquid level of the kneaded material in the storage tank 62 is set to the predetermined height L2. Until it becomes (time: T ₄ ), the kneaded material is conveyed to the storage tank 62. Similarly, when the liquid level of the kneaded material in the storage tanks 54 and 64 is lowered to the predetermined height L1, the liquid level of the kneaded material in the storage tank 62 is set to the predetermined height L2. The kneaded material is conveyed to the storage tanks 54 and 64.

  Next, the process which conveys a kneaded material to the storage tanks 52 and 62 is demonstrated as an example using FIGS. For convenience, FIGS. 3 and 4 omit the boilers 12 and 14, the BM tanks 82, 84, 92 and 94, the relay silo 96, and the recycling facility 98. In addition, description and illustration of a control device for performing the following processing are omitted.

As shown in FIGS. 2 and 3, when the liquid level height of the kneaded product in the storage tank 52 is reduced to L1 (time: T ₁ ), the kneaders 22, 24 have limestone particles, coal particles, coal slurry, and Then, water is kneaded at a predetermined mixing ratio to generate a kneaded product, and the generated kneaded product is supplied to the conveyors 32 and 34 (step 1). The conveyors 32 and 34 perform a process of conveying the kneaded materials kneaded by the kneaders 22 and 24 to the conveyors 42 and 44, respectively (step 2). Further, the transport conveyors 42 and 44 perform processing for transporting the kneaded material transported by the transport conveyors 32 and 34 to the storage tank 52, respectively (step 3). When the liquid level of the kneaded material in the storage tank 52 reaches a predetermined height L2 (time: T ₂ ), the processing of step 1 to step 3 is stopped.

Also, as shown in FIGS. 2 and 4, when the liquid level of the kneaded product in the storage tank 62 decreases to L1 (time: T ₃ ), the kneaders 22 and 24 have limestone particles, coal particles, coal slurry. Then, water is kneaded at a predetermined mixing ratio to produce a kneaded product, and the produced kneaded product is supplied to the conveyors 32 and 34 (step 1). The conveyors 32 and 34 perform a process of conveying the kneaded materials kneaded by the kneaders 22 and 24 to the conveyors 46 and 48, respectively (step 2). Further, the transport conveyors 46 and 48 perform a process of transporting the kneaded materials transported by the transport conveyors 32 and 34 to the storage tank 62, respectively (step 3). When the liquid level of the kneaded material in the storage tank 62 reaches a predetermined height L2 (time: T ₄ ), the processing of step 1 to step 3 is stopped.

  In the present embodiment, two pressurized fluidized bed boilers 12 and 14, two kneaders 22 and 24, two transport devices 36 and 38, two tank groups 56 and 66 each having two storage tanks. , And a pressurized fluidized bed combined power generation apparatus 10 including four charging devices provided in each storage tank. Here, for example, even if one of the two kneading machines 22, 24, for example, the kneading machine 22 fails, the conveying device 38 moves from the kneading machine 24 to the storage tanks 52, 54 of the tank group 56, and the tank group 66. The kneaded material can be conveyed to the storage tanks 62 and 64.

  Further, the two tank groups 56 and 66 according to the present embodiment are respectively installed corresponding to the pressurized fluidized bed boilers 12 and 14, and each tank group has two storage tanks. Even when one of the storage tanks fails, the kneaded product can be supplied from the other storage tank to the pressurized fluidized bed boiler.

  As described above, even when a part of the facility for supplying the kneaded material to the pressurized fluidized bed boiler fails, stable power generation can be achieved without lowering the power generation output and without operating the pressurized fluidized bed boiler. Is possible.

  Next, a method for maintaining the bed height of the pressurized fluidized bed boilers 12 and 14 in the pressurized fluidized bed combined power generation apparatus 10 of the present embodiment constant will be described with reference to FIGS. 5 and 6.

  In the pressurized fluidized bed combined power generator 10 of this embodiment, the pressurized fluidized bed boiler 12 and the pressurized fluidized bed boiler 14 may have different bed height change characteristics. Here, "the bed height change characteristic is different between the pressurized fluidized bed boiler 12 and the pressurized fluidized bed boiler 14" can be defined as follows. That is, the change in the bed height of each pressurized fluidized bed boiler after charging was made in each of the two pressurized fluidized bed boilers of the same type, even though the same kneaded material with L / C was charged under the same conditions. May be different. In other words, even two pressurized fluidized bed boilers of the same type may have different bed height changes over time. Thus, in two pressurized fluidized bed boilers of the same type, the difference in change in bed height over time is referred to as “different bed height change characteristics”. The reason why the bed height change characteristics are different between two pressurized fluidized bed boilers of the same type is because, for example, the number of feed pipes in the boiler, the structures of the evaporator, the superheater, and the reheater are different.

As shown in FIG. 6, when the layer height change characteristics are different between the pressurized fluidized bed boiler 12 and the pressurized fluidized bed boiler 14, they are kneaded materials kneaded by the kneaders 22 and 24 and have the same L / C. When the kneaded material set to a value is put into the pressurized fluidized bed boilers 12 and 14 (time: T ₀ ), the bed height of the pressurized fluidized bed boiler 12 becomes constant, but the pressurized fluidized bed boiler 14 The layer height formed is gradually increased. As a countermeasure, the fluid medium is extracted from the pressurized fluidized bed boiler 14 and returned to the BM tanks 92 and 94 (time T ₁ , T ₂ , step A).

Next, the process of extracting coal ash from the bottom of the PFBC boiler 14 (time _T 3 through T _4, Step B). The extracted coal ash is sent to the relay silo 96, further sent to the recycling facility 98, and recycled to the fluid medium. The recycled fluid medium is sent to the BM tanks 82, 84, 92 and 94.

Next, since the tank levels of the BM tanks 82, 84, 92, and 94 are increased, the extraction of the fluid medium from the bottom of the pressurized fluidized bed boiler 14 is stopped, and further, the pressurized fluidized bed boiler 14 is formed. A process of lowering the value of L / C set in the kneaders 22 and 24 is performed so that the layer height is constant (time T ₄ , step C). Therefore, the rise in the bed height formed in the pressurized fluidized bed boiler 14 can be prevented, but the L / C value of the kneaded material set in the kneaders 22 and 24 is lowered, whereby the pressurized fluidized bed boiler. The layer height formed in 12 gradually decreases. Therefore, a process for returning the fluid medium from the BM tanks 82 and 84 to the pressurized fluidized bed boiler 12 is performed (time T ₅ , T ₆ , step D). However, if the L / C set in Step C is maintained, the bed height formed in the pressurized fluidized bed boiler 12 gradually decreases, so the L / C set in the kneaders 22 and 24 is reduced. Is increased to the value of L / C before being changed in step C (time T ₇ , step E). Thereafter, the processes of steps B, C, D, and E are repeated according to the bed height of the pressurized fluidized bed boilers 12 and 14 and the tank level of the BM tanks 82 and 84.

[Second Embodiment]
Next, a second embodiment of the pressurized fluidized bed combined power generation apparatus of the present invention will be described with reference to FIGS. Unlike the first embodiment, the pressurized fluidized bed combined power generator 11 of the present invention can easily maintain the bed height of the pressurized fluidized bed boilers 12 and 14 easily. In the following embodiments, parts that are not particularly described are the same as those in the above-described embodiments, and the same reference numerals are given to the numbers given in the drawings when they are the same as those in the above-described embodiments.

  The pressurized fluidized bed boiler 12 is a pressurized fluidized bed boiler having higher bed height change characteristics than the pressurized fluidized bed boiler 14. And as shown in FIG.8 and FIG.9, the point from which the pressurized fluidized bed combined power generation apparatus 11 which concerns on 2nd Embodiment differs from the pressurized fluidized bed combined power generation apparatus 10 which concerns on 1st Embodiment is the conveyance conveyor 44 and 46 is to stop. Hereinafter, the kneaded material conveyance method of the pressurized fluidized bed combined power generation apparatus 11 in the present embodiment will be described with reference to FIGS. 7 to 9.

  FIG. 7 is a diagram showing the transition of the liquid level of the kneaded material in the storage tanks 52 and 62 and the storage tanks 54 and 64, and the kneading in the storage tanks 52 and 62 and the storage tanks 54 and 64, respectively. Indicates the remaining amount of the object. As shown in FIG. 7, when the liquid level of the kneaded material is lowered to a predetermined height, the kneaded material is conveyed by the conveying device, and the kneaded material is supplied to each storage tank. In other words, the conveying devices 36 and 38 store the kneaded material from the kneaders 22 and 24 in accordance with the level of the kneaded material in the storage tanks 52 and 54 and the storage tanks 62 and 64, respectively. Transport to tanks 52 and 54 and storage tanks 62 and 64.

That is, for example, when the liquid level of the kneaded material in the storage tanks 52 and 62 is lowered to a predetermined height L1 (time: T ₁ ), the liquid level of the kneaded material in the storage tanks 52 and 62 is reduced. The kneaded material is conveyed to the storage tanks 52 and 62 until the predetermined height L2 is reached (time: T ₂ ). Further, when the liquid level of the kneaded material in the storage tanks 54 and 64 is lowered to a predetermined height L1 (time: T ₂ ), the liquid level of the kneaded material in the storage tanks 54 and 64 is predetermined. The kneaded material is conveyed to the storage tanks 54 and 64 until the height L2 is reached (time: T ₃ ).

  Next, as an example, a process in which the kneaded material is conveyed to the storage tanks 52 and 62 and the storage tanks 54 and 64 will be described with reference to FIGS. For convenience, FIGS. 8 and 9 omit the boilers 12 and 14, the BM tanks 82, 84, 92, and 94, the relay silo 96, and the recycling facility 98. In addition, description and illustration of a control device for performing the following processing are omitted.

As shown in FIG. 7 and FIG. 8, when the liquid level height of the kneaded material in the storage tanks 52 and 62 decreases to L1 (time: T ₁ ), the kneaders 22 and 24 have limestone particles, coal particles, coal slurry. Then, water is kneaded at a predetermined mixing ratio to generate a kneaded product, and the generated kneaded product is supplied to the conveyors 32 and 34 (step 1). The conveyors 32 and 34 perform a process of conveying the kneaded materials kneaded by the kneaders 22 and 24 to the conveyors 42 and 48, respectively (step 2). Further, the transport conveyors 42 and 48 perform processing for transporting the kneaded materials transported by the transport conveyors 42 and 48 to the storage tanks 52 and 62, respectively (step 3). When the liquid level of the kneaded material in the storage tanks 52 and 62 reaches a predetermined height L2 (time: T ₂ ), the processing of step 1 to step 3 is stopped.

As shown in FIGS. 7 and 9, when the liquid level of the kneaded product in the storage tanks 54 and 64 decreases to L1 (time: T ₁ ), the kneaders 22 and 24 have limestone particles, coal particles, coal slurry. Then, water is kneaded at a predetermined mixing ratio to generate a kneaded product, and the generated kneaded product is supplied to the conveyors 32 and 34 (step 1). The conveyors 32 and 34 perform a process of conveying the kneaded materials kneaded by the kneaders 22 and 24 to the conveyors 42 and 48, respectively (step 2). Further, the transport conveyors 42 and 48 perform a process of transporting the kneaded materials transported by the transport conveyors 42 and 48 to the storage tanks 54 and 64, respectively (step 3). When the liquid level of the kneaded material in the storage tanks 54 and 64 reaches a predetermined height L2 (time: T ₂ ), the processing of step 1 to step 3 is stopped.

  Next, a method for maintaining the bed height of the pressurized fluidized bed boilers 12 and 14 in the pressurized fluidized bed combined power generator 11 of the present embodiment constant will be described with reference to FIG.

As shown in FIG. 10, when the bed height change characteristics are different between the pressurized fluidized bed boiler 12 and the pressurized fluidized bed boiler 14, the bed height formed in the pressurized fluidized bed boiler 12 is constant even if time passes. In contrast, the bed height formed in the pressurized fluidized bed boiler 14 increases with time. Accordingly, the L / C of the kneaded product put into the pressurized fluidized bed boiler 12, that is, the L / C value set in the kneader 22 is an appropriate value, whereas the pressurized fluidized bed boiler is used. It is considered that the L / C of the kneaded product charged in 14, that is, the L / C value set in the kneader 24 exceeds the appropriate value. Therefore, the value of L / C set in the kneader 24 is lowered (time T ₁ ). As a result, the L / C value of the kneaded product charged in the pressurized fluidized bed boiler 14 also becomes an appropriate value, and the bed height formed in the pressurized fluidized bed boiler 14 is formed in the pressurized fluidized bed boiler 12. As with the layer height, it remains constant over time.

  In the first embodiment, as shown in FIG. 6, various measures have been taken in order to maintain a constant bed height formed in each of the pressurized fluidized bed boilers 12 and 14.

  In this embodiment, by stopping the conveyors 44 and 46, the kneaded material kneaded by the kneader 22 is conveyed from the kneader 22 in the order of the conveyor 32, the conveyor 42, and the tank group 56, and kneaded. The kneaded material kneaded by the machine 24 is conveyed from the kneader 24 in the order of the conveyer 34, the conveyer 48, and the tank group 66. That is, in this embodiment, the route for supplying the kneaded material is different between the pressurized fluidized bed boilers 12 and 14. In other words, by stopping the transfer conveyors 44 and 46, only the kneaded material kneaded by the kneader 22 is transferred to the storage tanks 52 and 54 of the tank group 56, and the storage tanks 62 and 64 of the tank group 66 are transferred. Only the kneaded material kneaded by the kneader 24 is conveyed.

  Therefore, the predetermined mixing ratio set in the kneader 22, that is, the value of L / C, and the predetermined mixing ratio set in the other of the kneader, that is, the value of L / C are set to different values. By doing so, the bed height of the pressurized fluidized bed boilers 12 and 14 can be controlled separately.

  Further, when the kneaded material kneaded by the kneader 22 is put into the pressurized fluidized bed boiler 12, the predetermined mixing ratio of the kneader 22 is set so that the layer height of the pressurized fluidized bed boiler 12 does not change with time. The predetermined mixing ratio of the kneader 24 is determined so that the layer height of the pressurized fluidized bed boiler 14 does not change with time when the kneaded product determined and kneaded by the kneader 24 is charged into the pressurized fluidized bed boiler 14. Therefore, in both the pressurized fluidized bed boilers 12 and 14, the bed height remains constant without changing over time.

  As described above, in the present embodiment, it is easy to maintain a constant bed height of each pressurized fluidized bed boiler.

It is the schematic which shows the outline of the pressurized fluidized bed combined power generator in 1st Embodiment. It is a figure which shows the height of the liquid level of each storage tank of the pressurized fluidized bed combined power generation device in 1st Embodiment. It is the schematic which shows the process which conveys a kneaded material to a storage tank in the pressurized fluidized bed combined power generator in 1st Embodiment. It is the schematic which shows the process which conveys a kneaded material to a storage tank in the pressurized fluidized bed combined power generator in 1st Embodiment. It is a figure which shows the change of the bed height of a pressurization fluidized bed boiler in the pressurization fluidized bed combined power generator in a 1st embodiment. It is a figure which shows the change of the bed height of a pressurization fluidized bed boiler in the pressurization fluidized bed combined power generator in a 1st embodiment. It is a figure which shows the height of the liquid level of each storage tank of the pressurized fluidized bed combined power generation device in 2nd Embodiment. It is the schematic which shows the process which conveys a kneaded material to a storage tank in the pressurized fluidized bed combined power generation device in 2nd Embodiment. It is the schematic which shows the process which conveys a kneaded material to a storage tank in the pressurized fluidized bed combined power generation device in 2nd Embodiment. It is a figure which shows the change of the bed height of a pressurization fluidized bed boiler in the pressurization fluidized bed combined power generator in a 2nd embodiment. It is the schematic which shows the outline of the conventional pressurization fluidized bed combined power generator.

Explanation of symbols

10,11 Pressurized fluidized bed combined power generator 12,14 Pressurized fluidized bed boiler 22,24 Kneader 36,38 Conveyor 32,34,42,44,46,48 Conveyor 52,54,62,64 Storage tank 56, 66 Tank group 72, 74, 76, 78 Input pump

Claims (2)

Two cans of pressurized fluidized bed boilers;
Two machines for obtaining a kneaded product by kneading limestone particles each forming a fluidized bed in the pressurized fluidized bed boiler, coal particles serving as fuel in the pressurized fluidized bed boiler, and water at a predetermined mixing ratio Kneading machine,
Two tank groups each corresponding to each pressurized fluidized bed boiler, each having two storage tanks for storing the kneaded product,
Four dosing devices each provided in each storage tank of each tank group;
Each comprising two conveying devices installed corresponding to each kneader,
Each charging device charges the kneaded material stored in each storage tank of each tank group to each pressurized fluidized bed boiler corresponding to each tank group,
One and the other of the conveying devices are respectively a pressurized fluidized bed combined power generation device that conveys the kneaded material from one and the other of the kneaders to each storage tank of each tank group. One of the conveying devices corresponds to a first conveyor installed corresponding to one of the kneading machines, a second conveyor installed corresponding to one of the tank groups, and the other of the tank groups And a third conveyor installed
The other of the conveying devices corresponds to the fourth conveyor installed corresponding to the other of the kneaders, the fifth conveyor installed corresponding to one of the tank groups, and the other of the tank groups And a sixth conveyor installed
2. The pressurized fluidized bed combined power generator according to claim 1, wherein one of the pressurized fluidized bed boilers and the other of the pressurized fluidized bed boilers have different bed height change characteristics. And
Stop the third conveyor and the fifth conveyor,
The kneader so that the layer height of one of the pressurized fluidized bed boilers does not change over time when the kneaded material kneaded by one of the kneaders is put into one of the pressurized fluidized bed boilers. Determining the predetermined mixing ratio of one of
In order to prevent the other layer height of the pressurized fluidized bed boiler from changing with time when the kneaded material kneaded by the other of the kneader is charged into the other of the pressurized fluidized bed boiler, Determining the other predetermined mixing ratio;
The kneaded product is conveyed from one of the kneaders to the second conveyor by the first conveyor,
The kneaded product is conveyed from one of the kneaders to the sixth conveyor by the fourth conveyor,
The kneaded material conveyed by the first conveyor by the second conveyor is conveyed to one of the tank groups;
A method of maintaining a constant bed height of a pressurized fluidized bed boiler that conveys the kneaded material conveyed by the fourth conveyor to the other of the tank group by the sixth conveyor.

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