JP4712010B2 - Cleaning method of fuel supply nozzle in pipe - Google Patents

Description

The present invention is a pressurized fluidized bed boiler that burns solid fuel in a pressurized fluidized bed, drives a steam turbine with the generated steam, and further drives a gas turbine with high-pressure and high-temperature combustion gas to obtain electric power with high efficiency. It relates to a combined power plant.
The present invention also relates to an in-tube cleaning method for a nozzle that supplies a paste-like fuel composed of a solid fuel and a water mixture supplied to a pressurized fluidized bed combustion furnace to the fluidized bed combustion furnace.

  Fuel is burned in a pressurized fluidized bed furnace, steam is generated in a heat transfer tube installed in the fluidized bed to drive the steam turbine, and the high pressure and high temperature generated in the pressurized fluidized bed boiler are driven. There is known a pressurized fluidized bed boiler combined power plant that can drive a gas turbine with combustion gas and obtain electric power with high efficiency.

  One of the problems of the pressurized fluidized bed boiler is to supply coal particles continuously and stably in a large quantity into a pressurized fluidized bed furnace. As means for solving this problem, for example, in Japanese Patent Laid-Open No. Sho 62-155433, coal and water are mixed to form a paste-like fluid (hereinafter abbreviated as Coal-Water Paste; CWP), and the CWP is pumped. Discloses a wet feeding method in which the pressure is fed and fed from a spray nozzle into a fluidized bed furnace.

  FIG. 20 shows a fuel production / supply system for supplying CWP to a pressurized fluidized bed furnace. Fuel coal is supplied from the raw coal bunker 1 to the coarse pulverizer 3 by the coal feeder 2, and the coarsely pulverized coal is sent to the relay hopper 4. A part of the coarsely pulverized coal is sent to the wet tube mill 5 and pulverized together with water sent from the tube mill water pump 10 to produce a pulverized coal slurry. The produced pulverized coal slurry is temporarily stored in the slurry tank 6. CWP is manufactured by supplying coal from the relay hopper 4, pulverized coal slurry from the slurry tank 6, and water from the water tank 7 to the kneader 13 and kneading. The produced CWP is stored in the CWP tank 14, is pumped to the CWP transport pipe 19 by the piston pump 15, and is supplied to the pressurized fluidized bed (not shown) via the CWP nozzle 21.

  The piston pump 15 for supplying the CWP to the pressurized fluidized bed is driven by the hydraulic pressure of the piston pump hydraulic device 17, and the CWP is sent from the CWP tank 14 through the suction port 16 to the piston pump 15 and sent to the CWP transport pipe 19. The Water can be injected into the suction port 16 of the piston pump 15 by the water injection water pump 12 and the injection pipe 22, and pulverized coal slurry can also be injected from the injection slurry pump 9 and the injection pipe 22. The piston pump hydraulic device 17 includes a hydraulic pressure gauge 18 that detects the hydraulic pressure of the piston pump 15. The CWP transport pipe 19 has a pressure gauge 20 and detects the internal pressure of the CWP transport pipe 19 during CWP pumping.

  The amount of water supplied is set so that the sum of the water content of the raw coal, the water content of the pulverized coal slurry produced by the wet tube mill 5 and the water amount supplied by the water pump 11 for the kneader becomes the water content of the CWP. The water content of CWP produced by the kneading machine 13 is set to a minimum water content necessary for pumping with the piston pump 15.

  In the production of the CWP, it is important to reduce the amount of water added to coal as much as possible in order to maintain the power generation efficiency of the boiler plant at a high level. For this reason, CWP in which the amount of water added to coal is limited has a high viscosity, and since the chemical for dispersing coal particles is not added to reduce the production cost, the fluidity is extremely poor. Furthermore, since CWP coal has a maximum diameter of 6 to 10 mm, an average diameter of 1 to 2 mm, and a coarse particle size, a particle size configuration including an appropriate amount of fine particles is required to obtain CWP having a low moisture content. That is, the coal particles in CWP are characterized by existing in a wide particle size range from fine particles of several tens of microns to coarse particles of about 10 mm at the maximum.

  In order to produce a stable CWP under the above-described constraints, it is desirable to adjust the viscosity of the CWP to a range of 5 to 20 Pa · s. This is because when the viscosity of the CWP is 20 Pa · s or more, the suction port of the piston pump 15 is clogged by CWP, and the pump cannot be transported. The viscosity of CWP is mainly correlated with the coal concentration and particle size composition in CWP.

  That is, when the coal concentration is high, the viscosity of CWP increases. Conversely, when the coal concentration is low, the concentration of CWP decreases. Also, the viscosity increases as the particle size becomes finer. Therefore, in order to supply CWP stably, the method of managing the coal concentration and viscosity in CWP is the most effective. Therefore, the inventors of the present invention invented a device 101 for branching the CWP discharged from the kneader outlet 13 shown in FIG. 20 and measuring the viscosity of the CWP and a control device 102 for adjusting the viscosity of the device (patent application ( JP-A-9-145487).

  The CWP viscosity measuring device 101 is provided on the outlet side surface portion of the kneader 13, detects the CWP viscosity, and supplies the amount of water from the water tank 7 supplied to the kneader 13 by the viscosity control device 102 or pulverized coal slurry from the pulverized coal slurry tank 6. The amount is increased or decreased. FIG. 21 is a structural cross-sectional view of the CWP viscosity measuring device 101 provided on the outlet side surface of the kneader 13 shown in FIG. The CWP viscosity measuring apparatus 101 includes a guide plate 105 for introducing CWP, a viscosity measuring container 106, a pin type rotor 107 for detecting viscosity, and a torque meter 110. In the viscosity measuring container 106, a pin type rotor 107 for measuring the viscosity of CWP is installed at the center. The pin type rotor 107 is connected to the torque meter 110.

  At the bottom of the CWP viscosity measuring vessel 106, a CWP transfer gate valve 111 is provided. The opening / closing operation of the CWP discharge gate valve 111 is controlled by a cylinder 112 (compressed air type or hydraulic type). CWP discharged from the outlet of the kneader 13 is supplied from the guide plate (θ <40 degrees) 105 into the viscosity measuring container 106 and held in the viscosity measuring container 106 for a certain period of time. Thereafter, the gate valve 111 provided at the bottom of the viscosity measurement container 106 is opened to discharge CWP, and the gate valve 111 is closed again to guide the CWP into the viscosity measurement container 106. This is repeated and the viscosity of CWP is continuously measured.

  Further, CWP obtained by the above wet method is pumped to the furnace by the piston pump 15 (see FIG. 20), but it is necessary to reduce the amount of water in the CWP as much as possible in order to maintain the power generation efficiency at a high level. And the chemical | medical agent which disperse | distributes coal particles is not added for CWP manufacturing cost reduction. For this reason, CWP has a high viscosity and extremely poor fluidity compared to high-concentration coal / water slurry developed as an alternative fuel to heavy oil.

  If the water content of CWP is small, CWP is not fluid and cannot be pumped by piston pump 15. For pumping by the pump 15, the particle size distribution of CWP is, for example, that coal having a weight average diameter in the range of 1.0 to 2.0 mm and coal having a weight average diameter in the range of 0.03 to 0.07 mm. A predetermined particle size distribution is a necessary condition, such as mixing 10-40% of the total coal weight with pulverized coal slurry previously mixed with water. However, if the water content is gradually increased, fluidity (viscosity) appears in the CWP, and the pumping by the piston pump 15 becomes possible. Since the fluidity of CWP is caused by the fine powder component of coal and water, the viscosity of CWP increases when the content of water in CWP is reduced by 1/10% in an area where moisture is low. There is.

  Due to the above characteristics of CWP, the minimum necessary for CWP pumping by pump 15 in the production of fuel (CWP) in consideration of variations in moisture content of raw coal and controllability of the supply amount of each CWP component Manufactures CWP that contains several percent more water than moisture.

  Conventionally, as shown in FIG. 20, in the CWP supply method, coal particles having a maximum diameter of about 6 mm, water, and limestone as a furnace desulfurization agent are mixed in a kneader 13 to obtain a CWP having a water content of about 25%. After temporarily storing in the tank 14, the pressure is increased by a plurality of piston pumps 15b and 15c, for example, two piston pumps 15b and 15c in the example of FIG. 22, and the respective CWP transport pipes 19b and 19c and CWP supply nozzles (hereinafter referred to as nozzles or CWP). (It may be called a nozzle) 21b and 21c are fed to a furnace 34 contained in a pressurized vessel 33, sprayed and dispersed in a fluidized bed 35 in the furnace 34, and burned. The heat transfer tube 36 in the furnace 34 is heated to generate steam from the water in the tube.

  When the supply of CWP to the furnace 34 is stopped, the flow path is switched to the conduits 38b and 38c by the switching valves 37b and 37c, and the CWP is returned to the tank 14.

  In FIG. 22, the pressurized container 33, the furnace 34, the heat transfer tube 36, and the CWP supply nozzles 21b and 21c of the fluidized bed boiler are shown in a plan view. FIG. 23 shows an arrangement relationship of the furnace 34, the heat transfer tube 36, and the CWP supply nozzle 21. In FIG. 23, the furnace 34 is filled with a fluidized medium (sometimes referred to as BM), fluidized by combustion air supplied from below the furnace 34 through the air dispersion plate 41, and a fluidized bed 35 is formed. Yes. Heat transfer pipes 36 are arranged in the fluidized bed 35 to generate steam and supply it to a steam turbine (not shown). A dust removing device (not shown) for removing scattered ash is installed at the outlet of the furnace 34, and after dedusting, the combustion gas is supplied to a gas turbine (not shown).

  FIG. 24 shows the appearance of the CWP supply nozzle 21. The nozzle 21 is inserted into an outer cylinder 42 connected to the furnace wall 34 a and the pressure vessel wall 33 a and is fixed by a flange 43. An expansion 44 that absorbs the thermal expansion of the outer cylinder 42 is provided.

  The total length of the CWP supply nozzle 21 is 4.5 to 6 m, and the inner diameter of the CWP supply pipe 46 is about 50 mm, which is long and thin. The outer diameter of the multiple pipe including the passage of the cooling water and the dispersed air is about 220 mm, and since it has a complicated multiple pipe structure as a whole and penetrates the pressure vessel 33 and the furnace 34, the weight is also heavy. There are many joints, and once installed, it cannot be easily removed.

  Here, at the time of emergency stop of the furnace 34, it is required to stop and hold the supply of paste-like CWP in the CWP supply nozzle 21. The reason is as follows. That is, at the time of an emergency stop, the supply air necessary for the flow of CWP is instantaneously shut off, so that the fluidization of the furnace 34 is stopped. In this case, the supply of CWP that has been continued to be supplied from the CWP supply nozzle 21 until then needs to be stopped immediately. This is because when CWP is continuously supplied into the furnace 34 in which the fluidized bed 35 is not fluidized, incomplete combustion occurs in the bed, and a large mass called agglomerate is formed. This is because serious problems such as damage to the heat pipe 36 and a decrease in the flow performance of the fluidized bed 35 may be caused.

  Therefore, if the CWP supply is also stopped at the time of an emergency stop, the fuel stays in the CWP supply nozzle 21. Since this pasty fuel is produced together with water, the higher the temperature is close to the boiling point of water, the more severe the separation of coal and water becomes, and it becomes unstable and easily solidifies. According to experiments, it is said that the temperature at which the pipe can be stably transported is 50 ° C. or less.

  Therefore, even during normal operation, the CWP supply pipe 46 is covered with a cooling water pipe (not shown), and the CWP temperature is maintained below the stable supply temperature by the effect of the cooling water until immediately before being supplied into the furnace fluidized bed. It has become. Here, cooling water is allowed to flow in the cooling water pipe even when the boiler is stopped urgently. However, since CWP is stopped in the CWP supply nozzle 21 unlike the case of normal operation, CWP supply is performed. Radiant heat corresponding to the furnace inner layer temperature (about 800 ° C. to 900 ° C.) flows from the furnace 34 at the tip of the nozzle 21 into the pipe.

For this reason, even if the CWP staying in the CWP supply nozzle 21 as a whole is below a predetermined temperature, the CWP located at the tip of the CWP supply nozzle 21 rises in temperature by receiving the radiant heat of the furnace 34 directly. , Solidify. Even if it is a part of CWP, once it is solidified in the pipe, it becomes difficult to supply CWP to the furnace in the case of restart.
Japanese Patent Laid-Open No. Sho 62-155433 JP-A-9-145487

  Accordingly, an object of the present invention is to provide a cleaning device that, when the fuel is solidified in the CWP supply nozzle, pulverizes the solidified fuel quickly and removes it outside the pipe.

The problems of the present invention are solved by the following configuration.
That is, the dynamic layer furnace flow by the addition of liquid to the solid fuel to obtain a paste fuel (34) Fuel supply nozzle for supplying into (21), the tube of the fuel supply nozzle (21) when packed in the fuel a cleaning apparatus, a cleaning water on the outside of the inner injection tube for injecting the feed water (86) to the solidified fuel portion of the tip portion of the fuel supply nozzle (21) (85) and said inner injection tube (85) It has a double structure with the outer cylinder (87) arranged with a gap for discharging the fuel, and the fuel in the fuel supply nozzle (21) is externally provided between the inner water injection pipe (85) and the outer cylinder (87). A cleaning shaft (80) wound with a spiral fin (134) to be conveyed and a drive device for rotating and driving the outer cylinder (87) to insert and remove the cleaning shaft (80) from the fuel supply nozzle (21). (81) and drive device (81) outside the fluidized bed furnace (34) A pipe cleaning apparatus for a fuel supply nozzle (21), characterized in that a flange mounting support (97) for mounting to the flange portion (99) Luo fuel supply nozzle (21).

The fuel supply nozzle according to claim 1, wherein a drill portion (130) is provided at the tip of the inner water injection pipe (85) that reaches the tip of the fuel supply nozzle (21). (21) In-pipe cleaning apparatus.
According to a third aspect of the present invention, there is provided a fuel supply nozzle in which a fuel supply nozzle (21) for supplying a paste-like fuel by adding a liquid to a solid fuel into a fluidized bed furnace (34) is clogged with the fuel. (21) A method for cleaning the inside of a pipe, which has a double structure in which an inner water injection pipe (85) and an outer cylinder (87) outside thereof are arranged with a clearance for discharging cleaning water and fuel, Using the cleaning shaft (80) in which a spiral fin (134) for conveying the fuel in the fuel supply nozzle (21) to the outside is wound between the water pipe (85) and the outer cylinder (87), the cleaning shaft ( The outer cylinder (87 ) of 80) is rotationally driven by the drive device (81) , the cleaning shaft (80) is inserted into the fuel supply nozzle (21), and the fuel part solidified in the fuel supply nozzle (21) is reached. Delivered from the inside of the tip of the inner water injection pipe (85) of the cleaning shaft (80) Water (86) is injected, and the fuel in the fuel supply nozzle (21) is injected between the inner water injection pipe (85) and the outer cylinder (87) by the helical fin (134) as the cleaning shaft (80) rotates. It is a pipe cleaning method for the fuel supply nozzle (21), which is scraped out together with clean water.

The in-pipe cleaning method using the in-pipe cleaning apparatus of the present invention is performed as follows.
When the fluidized bed furnace is shut down and the furnace (34) and the furnace (34) are housed in the pressure vessel (33), the fuel is supplied when the pressure in the pressure vessel (33) decreases and becomes atmospheric pressure. The flange portion outside the pressure vessel of the nozzle (21) is disassembled so that the inner surface of the tube of the nozzle (21) can be accessed from the outside of the vessel. A nozzle cleaning device is installed at the position of the fuel supply nozzle (21) outside the container (33), and the long shaft (80) is inserted into the nozzle (21) while being rotated.

  At this time, in order to insert the device into the long nozzle (21), it is important to align the center of the device with the nozzle (21). However, in order to install the device on the nozzle flange portion, positioning is easy. A drill portion (130) is provided at the tip of the long shaft (80), and the solidified fuel portion is cut and pulverized by the rotational force of the drill portion (130) with respect to the solidified fuel portion. The pulverized solid fuel is discharged to the outside of the container through a spiral fin (134) provided around the shaft (80).

  Since it is preferable to supply moisture to make the solidified CWP easy to cut and pulverize, the inside of the rotating shaft (80) is supplied in the form of a cavity. After this supply water is supplied to the tip of the drill part (130), it is discharged together with the pulverized solid fuel to the outside of the container (33) through the spiral fin (134) part. Therefore, this supply water also contributes to the smooth discharge of the solidified fuel in the nozzle (21) to the outside.

  When the length of the nozzle (21) is long and the length of the cleaning shaft of the device is insufficient, the shaft length (136) (FIG. 16) of the cleaning device is appropriately connected to increase the shaft length of the device. Since the weight of the shaft (80, 136) is deposited in the nozzle (21) via the fins (134, 139) provided around the shaft (80, 136), even if the shaft length of the device is extended, it is cleaned by bending or the like. There is no problem with the function of the device.

  Even in the situation where the solidified part and the non-solidified part of the fuel in the nozzle (21) are mixed, the rotational torque and feed speed of the drill part (130) at the tip should be set appropriately. Thus, the residual fuel in the nozzle (21) can be removed to clean the inside of the nozzle (21).

  According to the present invention, even when the fuel supply nozzle for supplying CWP to the fluidized bed furnace is long and small in diameter, even when the fuel is solidified in the nozzle, the fuel remaining in the nozzle including the solidified fuel is removed from the system. And the inside of the nozzle can be cleaned quickly and easily. Moreover, since CWP solidified in the furnace fluidized bed can be discharged, the operation of the fluidized bed furnace is not hindered.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system diagram of a cleaning device of a CWP viscosity measuring device and a control device thereof provided in the CWP manufacturing apparatus of the embodiment of the present invention, and FIG. 2 is a flow chart of cleaning of the cleaning device of the CWP viscosity measuring device of FIG. It is a program. FIG. 3 is a system diagram of a CWP production / supply apparatus for supplying CWP to the pressurized fluidized bed according to the embodiment of the present invention.

  A viscometer 101 and its control device 102, a water injection nozzle 51 (51a, 51b), and its control device 53 are provided in the middle portion of the flow path 23 that guides CWP discharged from the kneader 13 shown in FIG. 3 to the CWP tank 14. . The viscometer 101 includes an inclined guide plate 105 for introducing CWP, a viscosity measuring container 106, a pin type rotor 107, a torque meter 110, and a CWP discharge gate valve 111.

  In order to clean the viscometer 101, water injection nozzles 51 a and 51 b are provided on the guide plate 105 and the viscosity measuring container 106. The water injection nozzle 51 a is for cleaning the guide plate 105, and the water injection nozzle 51 b is for cleaning the viscosity measuring container 106 and the shaft of the pin type rotor 107. Although not shown here, it is desirable that the injection holes of the water injection nozzles 51a and 51b have a slit shape and the injection pattern has a fan shape. Washing with water injection is performed by the opening / closing valves 53a, 53b provided in the water supply pipes 52a, 52b to the water injection nozzles 51a, 51b by the output signals of the operation control device 56 of the kneading machine 13 (FIG. 3) and the opening / closing control device 113 of the gate valve 111. Open / close control is used.

  FIG. 2 shows a cleaning program of the viscometer 101, and the guide plate 105 is cleaned when the gate valve 111 is opened after an arbitrary time after the operation of the kneader 13 is stopped. The viscosity measuring container 106 is cleaned when the kneading machine 13 is stopped and when the gate valve 111 is opened at an arbitrary time interval during operation of the kneading machine 13.

  The measurement of the CWP viscosity is performed by branching the CWP discharged from the kneader 13 by the guide plate 105 and guiding it into the viscosity measuring vessel 106, measuring the torque value by the pin type rotor 107, and converting it to the viscosity. When the CWP viscosity measurement is completed, the gate valve 111 at the bottom of the viscosity measurement container 106 is opened to discharge the CWP. This operation is repeated to measure the viscosity of CWP. When the viscosity measurement is performed for a long time, CWP adheres to the guide plate 105 and the inner wall of the viscosity measurement container 106. In particular, the CWP adheres to the surface of the CWP attached to the pin-type rotor 107 and the inner wall of the viscosity measuring vessel 106 when the CWP is discharged from the viscosity measuring vessel 106 when the kneader 13 is stopped or during operation. Is caused by

  In this way, in order to prevent CWP from adhering to the members constituting the viscometer 101 and further drying and solidifying after adhering, the water injection nozzles 51a and 51b are provided on the guide plate 105 and the viscosity measuring container 106. The guide plate 105 is cleaned when the gate valve 111 is open any time after the operation of the kneader 13 is stopped. Cleaning of the viscosity measuring container 106 is performed when the gate valve 111 is opened at any time interval when the kneader 13 is stopped and during operation.

By performing the cleaning operation according to the above procedure, CWP does not adhere to the inner walls of the guide plate 105, the pin-type rotor 107, and the viscosity measuring container 106. The washed water is mixed into the CWP, and the amount of water increases slightly. When the amount of water increases, the properties of CWP may be deteriorated. In order to improve the cleaning effect, increase the injection pressure of the cleaning water (for example, 5 kg / cm ² ), shorten the injection time (for example, 2 seconds), and reduce the amount of water mixed into the CWP as much as possible. Is desirable.

  As described above, in order to accurately measure the CWP viscosity after CWP production online, by installing a cleaning device that removes CWP adhering to the viscosity measuring device 101, stable CWP can be measured over a long period of time. The viscosity adjustment can also be controlled with high accuracy and efficiency.

  FIG. 3 shows a system of a CWP production / supply apparatus for supplying CWP to a pressurized fluidized bed. The same number is attached | subjected to the same apparatus as the structure shown to the system diagram of the CWP manufacturing / supply apparatus of FIG. That is, the raw coal bunker 1, the coal feeder 2, the coarse pulverizer 3, the relay hopper 4, the wet tube mill 5, the slurry tank 6, the water tank 7, the slurry pump 8 for the kneader, the slurry pump 9 for injection, and the water for tube mill Pump 10, kneading machine injection pump 11, injection water pump 12, kneading machine 13, CWP tank 14, piston pump 15, suction port 16, piston pump hydraulic device 17, hydraulic gauge 18, CWP supply nozzle 21, injection pipe 22 Etc.

  In the CWP manufacturing / supplying apparatus having the above-described configuration, coal is supplied from the relay hopper 4, pulverized coal slurry is supplied from the slurry tank 6, and water is supplied from the water tank 7 to the kneader 13. Manufacturing. The produced CWP is temporarily stored in the CWP tank 14, is pumped to the CWP transport pipe 19 by the piston pump 15, and is supplied to the pressurized fluidized bed furnace 34 (see FIG. 4) through the CWP supply nozzle 21.

  The piston pump 15 that supplies CWP to the furnace 34 is driven by the hydraulic pressure of the piston pump hydraulic device 17, and the CWP is sent from the CWP tank 14 through the suction port 16 to the piston pump 15 and is pressure-fed to the CWP transport pipe 19. . Water can be injected into the suction port 16 of the piston pump 15 by the water injection water pump 12 and the injection pipe 22, and pulverized coal slurry can also be injected from the injection slurry pump 9 and the injection pipe 22. The piston pump hydraulic device 17 includes a hydraulic pressure gauge 18 that detects the hydraulic pressure of the piston pump 15. The CWP transport pipe 19 has a pressure gauge 20 and detects the internal pressure of the CWP transport pipe 19 during CWP pumping.

  Here, injection of the slurry pump 9 for injection from the pulverized coal slurry tank 6 and water injection into the water tank 7 according to the degree of pressure due to the blockage of the CWP inside the CWP transport pipe 19 measured by the pressure gauge 20 of the CWP transport pipe 19 A control device 24 is provided for controlling the flow rates of the respective injection pipes 22 and 22 using the water pump 12.

  The amount of water supplied is set so that the sum of the water content of the raw coal, the water content of the pulverized coal slurry produced by the wet tube mill 5 and the water amount supplied by the water pump 11 for the kneader becomes the water content of the CWP. The water content of CWP produced by the kneading machine 13 is set to a minimum water content necessary for pumping with the piston pump 15. When the water content of the CWP does not change, the resistance in the CWP transport pipe 19 is also constant, and the indicated value of the pressure gauge 20 and the indicated value of the hydraulic gauge 18 are also constant.

  When the moisture content of the raw coal decreases or the supply amount to the kneading machine 13 fluctuates and the moisture content of the produced CWP decreases, the fluidity of the slurry that freely moves in the CWP deteriorates. As a result, the piston pump 15 The fluidity of CWP in the CWP transport pipe 19 becomes worse, and the indicated value of the pressure gauge 20 or the hydraulic gauge 18 increases. If the water injection pump 12 is started before the pressure is closed in the pipe 19 or the like, and the water is injected into the suction port 16 of the piston pump 15, the CWP sucked into the piston pump 15 is in the form of a fine slurry. This improves the fluidity of the pipe 19 and reduces the resistance in the pipe 19 and the like.

  As described above, the pressure in the CWP transport pipe 19 is monitored by the pressure gauge 20, and the hydraulic pressure of the piston pump 15 is monitored by the hydraulic gauge 18, thereby monitoring the flow state in the CWP transport pipe 19. 20 or a blockage in the CWP transport pipe 19 due to CWP is detected in advance according to an increase in the indicated value of the hydraulic gauge 18. When it is detected in advance, water is injected from the water tank 7 into the suction port 16 of the piston pump 15 to improve the fluidization of the CWP and avoid clogging. Further, even if pulverized coal slurry in the slurry tank 6 is injected instead of water to be injected into the suction port 16, fluidization of CWP can be improved, and blockage of the pipe 19 and the like can be avoided.

  FIG. 4 is a flow chart when CWP is supplied to the plurality of CWP supply nozzles 21 of the pressurized fluidized bed boiler using the piston pump 15, and the same parts as those shown in FIG. The description of the same flow is omitted.

  As shown in FIG. 4, the CWP stored in the CWP tank 14 is a case where a plurality of, for example, two two-cylinder piston pumps 15b and 15c are provided in FIG. From the two pistons of the pump 15c to the fluidized bed 35 in the furnace 34 through the CWP transport pipes 19c, 19d and the CWP feed nozzles 21c, 21d, respectively. Supplied. Thereby, CWP can be supplied to the four nozzles 21a to 21d by the two pumps 15b and 15c. When stopping the supply of CWP to the fluidized bed 35, the switching valves 37a, 37b, 37c, and 37d are switched to the conduits 38a, 38b, 38c, and 38d, respectively, and returned to the tank 14.

Next, an example of the structure of the CWP supply nozzle 21 of the present embodiment will be described with reference to the drawings.
FIG. 5 shows a CWP supply nozzle 21 configured to inject water into the CWP in the CWP transport pipe 19.
The CWP supply nozzle 21 is composed of concentric tubes in the order of a CWP supply tube 46, a cooling water tube 47 having a reciprocating water channel, and a dispersion air tube 48 from the center. A feature of the nozzle 21 shown in FIG. 5 is that a water injection conduit 55 is provided, and the tip 55 a is provided in the CWP supply pipe 46 through the annular cooling water 47, and the CWP in the CWP supply pipe 46 is provided. Water is poured into the water. The water injection conduit 55 is prevented from being vaporized by passing through the cooling water pipe 47.

  The cooling water pipe 47 flows through the cooling water and keeps the wall temperature of the CWP supply pipe 46 at 60 ° C., preferably 50 ° C. or less, to prevent evaporation of water in the CWP. The dispersion air pipe 48 is a high-pressure jet air conduit for jetting CWP supplied through the CWP supply pipe 46 into the fluidized bed, and jets high-pressure air from the dispersion air jet slit 48a to the CWP supply pipe 46. The CWP is caused to collide with the CWP exiting from the CWP supply pipe 46 and sprayed and supplied to the fluidized bed 35 in the fluidized bed furnace 34.

  In the above structure, the CWP is sent through the CWP supply pipe 46, and the cooling water is sent through the cooling water pipe 47, returned from the tip of the nozzle 21, and discharged. The dispersed air is ejected from the dispersed air ejection slit 48a to the CWP supply pipe 46, and the CWP is ejected and supplied into the fluidized bed 35 by the dispersed air. The injected water is supplied to the CWP supply pipe 46 from the tip 55a through the injected water conduit 55.

  As described above, when CWP is supplied from one piston 15 of the two-cylinder piston pump 15 through one CWP supply pipe 46 and CWP supply nozzle 21, respectively, the CWP is as shown in FIG. It will be supplied intermittently. That is, in the CWP suction process, the CWP temporarily stagnates in the CWP supply pipe 46, and the stagnation of the CWP is evaporated and dried and solidified by heat entering from the fluidized bed 35. However, according to the CWP supply nozzle 21 shown in FIG. 5, the CWP in the CWP supply pipe 46 is poured into the CWP from the water injection conduit 55 so that it does not dry and solidify.

  FIG. 6 shows the relationship between the water injection amount of the water injection type nozzle 21 shown in FIG. 5 used in this embodiment and the pump discharge pressure. In the CWP supply nozzle 21 having a diameter of 27 mm of the CWP supply pipe 46, the temperature of the CWP transport pipe 19 is maintained at 50 ° C., and the combustion of the fluidized bed furnace 34 is performed when water is injected into the CWP at the tip of the nozzle 21. The temperature is 860 ° C., the furnace pressure is 0.9 MPa, and the CWP supply amount is about 600 kg / h (time average value is about 300 kg / h).

  It was confirmed that the pump outlet CWP pressure does not increase when the amount of water injected is 0.10 kg / h or more, that is, the CWP can be discharged and supplied to the furnace without the nozzle tip clogging. Although a slight increase was observed in the CWP pressure at the pump outlet when the amount of injected water was 0.03 kg / h, the CWP discharge and supply to the furnace 34 were not hindered. These are the effects of the CWP temperature rise caused by the radiant heat from the fluid medium in the furnace to the remaining CWP end of the nozzle tip being suppressed by the injected water from the conduit 55 and simultaneously replenishing the evaporated water.

  As described above, the amount of water supplied to the CWP supply nozzle 21 is 0.10 kg / h or more with respect to the time average supply amount of CWP of about 300 kg / h, and a very small amount of 0.03% or more in terms of rate. Yes, the influence on the combustion rate and power generation efficiency in the furnace 34 is negligible.

  On the other hand, although CWP is intermittently supplied to the furnace 34 as fuel, the number of CWP supply nozzles 21 is doubled and the CWP supply stop period by the adjacent CWP supply nozzles 21 does not overlap. By adjusting to, there was no increase in unburned content and no combustion phenomenon on the bed. The interval between the suction and discharge processes by the piston pump 15 was 0.5 to 3 minutes although it was changed depending on the CWP supply load.

  Furthermore, a slurry can be supplied from one pump 15 to two or more slurry supply nozzles by combining the water injection type nozzle 21 and the multi-cylinder piston pump 15 having two or more pistons.

  FIG. 7 shows an example of an apparatus suitable for implementing a nozzle extracting apparatus that can repair a failed nozzle part or replace a new nozzle during operation without stopping the pressurized fluidized bed boiler. The CWP supply nozzle 21 for supplying CWP into the fluidized bed furnace 34 is inserted into the outer cylinder 42 connecting the furnace wall 34a and the pressure vessel wall 33a and set at a predetermined position. The outer cylinder 42 includes an expansion 44, a flow medium backflow prevention plate 60, a gas shutoff valve 61, a purge gas introduction pipe 62, a pressure detection pipe 64, a forward and backward screw 65 of the CWP supply nozzle 21, and a cooling pipe using cooling water. 66.

  The fluid medium backflow prevention plate 60 is installed on the furnace 34 side from the gas shutoff valve 61, and the vertical drive part is a dedicated compressed gas cylinder 67 of the fluid medium backflow prevention plate 60 or the fluid medium backflow as shown in FIG. The prevention plate 60 is fixed to the gas cutoff valve 61 by welding or bolts.

  The gas shut-off valve 61 is a gate type or a ball type, and has a mechanism in which a vertical or rotational drive is performed by a compressed gas type cylinder 69. The purge gas introduction pipe 62 is provided with a plurality of ejection holes 71 below the gas shutoff valve 61 on the furnace 34 side. Since the outer cylinder 42 is installed in an atmosphere of 350 ° C., an expansion 44 is installed in consideration of thermal expansion. The pressure detection conduit 64 is installed outside the gas cutoff valve 61, and the conduit 64 is provided with a pressure detector 72 and a valve 73 outside the pressure vessel wall 33a. The mechanism for advancing and reversing the nozzle 21 has a structure in which a screw 65 is installed inside the outer cylinder 42 and outside the nozzle 21 to rotate and extract the nozzle 21. In addition, a water-cooled tube 66 is installed outside the outer cylinder 42.

When CWP is supplied to the pressurized fluidized bed furnace 34, if the CWP supply nozzle 21 fails, the following operation is performed.
(1) First, the operation of the piston pump 15 is stopped, the valve 74 in front of the CWP supply nozzle 21 is closed, and a part of the piping is removed to extract the nozzle 21 out of the system.
(2) After the purge gas in the vicinity of the gas shutoff valve 61 provided in the outer cylinder 42 is jetted, when the nozzle 21 is rotated and extracted out of the system, the nozzle 21 passes through the fluid medium backflow prevention plate 60. The fluid medium backflow prevention plate 60 is lowered.

(3) Further, when the nozzle 21 is pulled out of the system, the gas cutoff valve 61 is closed when the nozzle 21 passes the gas cutoff valve 61.
(4) In order to check the sealing performance of the gas shutoff valve 61, the valve 73 of the pressure detection conduit 64 in the outer cylinder 42 is opened, the pressure in the outer cylinder 42 is brought to atmospheric pressure, and then the valve 73 is closed to detect the pressure. The pressure is checked with a vessel 72.
(5) A blind flange is attached to the flange 75 of the outer cylinder 42 after the nozzle 21 is completely removed from the system.
(6) The fluid medium that has flowed back to the tip of the outer cylinder 42 by the exhaust gas or nitrogen gas in the purge gas injection hole 71 provided in the vicinity of the gas shutoff valve 61 is returned into the furnace 34.

(7) The repaired nozzle 21 or new nozzle is rotated and inserted into the outer cylinder 42, opened in front of the gas shutoff valve 61, and the fluid medium backflow prevention plate 60 is raised and inserted to a predetermined position. Supply CWP.
(8) Stop the purge gas.

  Other embodiments will be described with reference to FIGS. The example shown in FIG. 8 is a mechanism in which the fluid medium backflow prevention plate 60 is lowered while the gas shutoff valve 61 is closed by fixing the fluid medium backflow prevention plate 60 shown in FIG. It has become.

  FIG. 9 shows a cross-sectional view of the hinged fluid medium backflow prevention plate 76. The hinged fluid medium backflow prevention plate 76 naturally falls when the nozzle 21 is pulled out of the system, and the outer cylinder 42 is removed. Occluded to prevent back flow of the fluid medium. Further, by inserting the nozzle 21 to the fluidized bed furnace 34 side, when the nozzle 21 comes into contact with the fluid medium backflow prevention plate 76, the nozzle 21 is pushed upward. In FIG. 10, the drive unit for moving the nozzle 21 forward and backward is formed by hollowing the cylinder 79 of the compressed gas cylinder 78, and the nozzle 21 is installed in the hollow portion and fixed by a flange 82. The compressed gas is compressed nitrogen or air.

  In this way, the nozzle 21 which has failed during the boiler operation can be extracted without repairing the load reduction and operation of the pressurized fluidized bed boiler, and repair and replacement of new nozzles can be easily performed, and long-term operation can be continued. .

Next, a description will be given of a cleaning device that quickly crushes and removes the solidified fuel when the fuel is solidified in the CWP supply nozzle.
Embodiments of the nozzle cleaning device structure are shown in FIGS. FIG.11 and FIG.12 is the top view and side view of the whole structure of this nozzle cleaning apparatus. A cleaning shaft 80 for cleaning the inside of the CWP nozzle 21 is supported by the inside of the driving device 81 and a shaft support 84. The cleaning shaft 80 has a double pipe structure, and the supply water 86 passes through the inside of the water injection pipe 85 (FIG. 15), and the CWP discharged between the water injection pipe 85 and the outer cylinder 87 (FIG. 15) and Cleaning water passes. The supply water 86 is supplied from a hose 88 and a union joint 89, and the amount of water injected is adjusted by a water supply source valve 90. Further, the supply water 86 is guided to a water injection pipe 85 (FIG. 15) in the cleaning shaft 80 through a swivel joint 92 that prevents the rotation of the shaft 80 from being transmitted to the hose 88 side and a coupler 93.

  Further, the CWP and cleaning water discharged through the water injection pipe 85 and the outer cylinder 87 are collected by the hose 120 from the CWP receiver 94. These components are supported by a support frame 95 attached to the drive device 81, and the drive device 81 is attached to the flange portion 99 (FIG. 17) of the CWP supply nozzle 21 using the flange attachment support 97. Since the flange portion 99 is machined according to the hole shaft core of the CWP nozzle 21, the cleaning device can be easily centered automatically by attaching the drive device 81 to the flange portion 99. become. Since part of the CWP and cleaning water is discharged outside the outer cylinder 87 (FIG. 15) of the cleaning shaft 80, the cleaning water is supplied from the shaft cleaning water inlet 118 of the hose 120, and the outer cylinder 87 is It is cleaned and discharged to the shaft cleaning water outlet 119 so that the inside of the drive device 81 is not contaminated.

  FIG. 13 is a partial detailed view of the driving device 81, and FIG. 14 is a view taken along the line AA in FIG. The rotational force of the gear motor 122 is transmitted from the motor pulley 123 to the cleaning shaft 80 via the drive roller 124. In order to properly transmit the rotational force, a presser roller 125 is installed, and is properly adjusted and attached by a jack nut 127. The outer surface of the outer cylinder 87 of the cleaning shaft 80 has a screw structure, and the cleaning shaft 80 is inserted into the tube of the nozzle 21 in conjunction with the rotation by the shaft feeding device 126 attached to the driving device 81 and is pulled out.

  FIG. 15 is a detailed view of the cleaning shaft 80 of the tip drill part. The water injection hole 132 is provided in the drill portion 130 of the water injection pipe 85, and the supply water 86 is injected from here to facilitate the cleaning of the solidified CWP. A fin 134 is spirally wound and attached between the water injection pipe 85 and the outer cylinder 87, and plays the role of conveying the internal CWP to the outside as the shaft 80 rotates. The outer cylinder 87 is fixed to the water injection pipe 85 with a fixing pin 135.

  FIG. 16 shows a cleaning shaft 136 that is appropriately connected as an extension when the length of the cleaning shaft 80 of FIG. 15 is insufficient, and is composed of a water injection pipe 137 and an outer cylinder 138, with a fin 139 interposed therebetween. Is provided. The cleaning shaft 136 is connected to the cleaning shaft 80 with a set screw 140. The outer cylinder 138 is fixed to the water injection pipe 137 with a fixing pin 141.

  17 to 19 show an outline of a cleaning procedure using the cleaning device. FIG. 17 shows a state in which the cleaning device is set on the CWP nozzle flange 99. The CWP and cleaning water discharged from the CWP nozzle 21 are collected in the CWP cleaning water receiving box 142 or the cleaning water receiving box 143. FIG. 18 is a diagram illustrating a state diagram of the apparatus during cleaning. FIG. 19 is a view showing a state in which the cleaning device is removed and the CWP transport pipe 19 (FIG. 4) is attached and restored after cleaning the CWP nozzle pipe. Since the inside of the pipe is cleaned, the plant can be started up smoothly by supplying CWP.

  Thus, even when the fuel supply nozzle 21 for supplying CWP to the fluidized bed furnace 34 solidifies in the long and small diameter nozzle, the fuel remaining in the nozzle including the solidified fuel is removed out of the system. In addition, the inside of the nozzle can be quickly and easily cleaned. Further, the CWP solidified in the furnace fluidized bed is discharged and does not hinder the operation.

  The present invention is a pressurized fluidized bed boiler that burns solid fuel in a pressurized fluidized bed, drives a steam turbine with the generated steam, and further drives a gas turbine with high-pressure and high-temperature combustion gas to obtain electric power with high efficiency. It can be stably supplied as boiler fuel for combined power plants, and is highly available.

It is a systematic diagram of the cleaning apparatus of the CWP viscosity measuring device provided in the CWP manufacturing apparatus of embodiment of this invention, and its control apparatus. It is a program of the washing | cleaning flow of the washing | cleaning apparatus of the CWP viscosity measuring apparatus of FIG. It is a systematic diagram of the CWP manufacturing and supply apparatus for supplying CWP to the pressurized fluidized bed of the embodiment of the present invention. It is a figure which shows embodiment of the fuel supply system to the pressurized fluidized bed boiler by this invention. It is a figure which shows embodiment of the slurry (CWP) supply nozzle used for the boiler of FIG. It is a figure which shows the relationship between the amount of water injection to CWP used for the boiler of FIG. 4, and a piston pump outlet pressure. It is an extraction structure sectional view of the CWP supply nozzle of the pressurization fluidized bed boiler of an embodiment of the invention. It is a structure sectional view of a fluid medium backflow prevention plate of a pressurization fluidized bed boiler of an embodiment of the invention. It is a structure sectional view of a fluid medium backflow prevention plate of a pressurization fluidized bed boiler of an embodiment of the invention. It is a cylinder structure extraction structure sectional view of the CWP supply nozzle of the pressurization fluidized bed boiler of an embodiment of the invention. It is a whole top view showing a fuel supply nozzle cleaning device of a boiler of an embodiment of the invention. It is a whole front view showing the fuel supply nozzle cleaning device of the boiler of an embodiment of the invention. FIG. 12 is a partial detail view showing details of a drive device of the apparatus of FIG. 11. It is an AA arrow directional view of FIG. FIG. 12 is a partial detail view illustrating details of the nozzle cleaning shaft of FIG. 11. FIG. 12 is a partial detail view illustrating details of the nozzle cleaning shaft of FIG. 11. It is the schematic diagram showing the operation | movement order of the nozzle cleaning apparatus of FIG. It is the schematic diagram showing the operation | movement order of the nozzle cleaning apparatus of FIG. It is the schematic diagram showing the operation | movement order of the nozzle cleaning apparatus of FIG. It is a systematic diagram of the conventional CWP manufacturing apparatus. It is sectional drawing of the online viscosity measuring apparatus shown in FIG. It is a figure which shows the fuel supply system of the conventional pressurized fluidized bed boiler. It is a figure which shows the longitudinal cross-section of a general pressurized fluidized bed boiler. It is a structural diagram of a CWP supply nozzle of a conventional pressurized fluidized bed boiler. Cleaning device for CWP viscosity measuring device provided in conventional CWP manufacturing device It is a figure which shows the general CWP supply amount characteristic of a single cylinder type piston pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coal bunker 2 Coal feeder 3 Coarse grinder 4 Relay hopper 5 Wet tube mill 6 Slurry tank 7 Water tank 8 Slurry pump for kneading machine 9 Slurry pump for injection 10 Water pump for tube mill 11 Water pump for kneading machine 12 Water pump for injection 13 Kneading Machine 14 CWP Tank 15 Piston Pump 16 Suction Port 17 Piston Pump Hydraulic Device 18 Hydraulic Meter 19 CWP Transport Pipe 20 Pressure Gauge 21 CWP Supply Nozzle 22 Injection Pipe 23 CWP Discharge Channel 24 Control Device 33 Pressure Vessel 34 Furnace 35 Fluidized bed 36 Heat transfer pipe 37 Switching valve 38 Conduit 41 Dispersion plate 42 Outer cylinder 43 Flange 44 Expansion 46 CWP supply pipe 47 Cooling water pipe 48 Dispersed air pipe 48a Dispersed air ejection slits 51a, 51b Injecting nozzle 52 Feed water pipe 53 Controller 53a 53b Open / close 55 water injection conduit 56 kneader operation controller
60 Flow medium backflow prevention plate 61 Gas shutoff valve 62 Purge gas introduction pipe 64 Pressure detection conduit 65 Screw 66 Cooling pipe 67 Compressed gas cylinder 69 Compressed gas cylinder 71 Purge gas injection hole 72 Pressure detectors 73 and 74 Valve 75 Flange 76 Flow Medium backflow prevention plate 78 Compressed gas cylinder 79 Cylinder 80 Cleaning shaft 81 Drive device 82 Flange 84 Shaft support 85 Water injection pipe 86 Water supply 87 Outer cylinder 88 Hose 89 Union joint 90 Water injection source valve 92 Swivel joint 93 Coupler 94 CWP receiver 95 Support frame 97 Flange mounting support 99 CWP nozzle flange portion 100 CWP pump 101 Viscometer 102 Viscosity control device 105 Guide plate 106 Viscosity measuring container 107 Pin type rotor 110 Torque meter 111 Gate valve 12 cylinder
113 Open / Close Control Device 118 Shaft Washing Water Inlet 119 Shaft Washing Water Outlet 120 Hose 121 Shaft Washing Water Inlet / Outlet 122 Gear Motor 123 Motor Pulley 124 Drive Roller 125 Roller 126 Shaft Feeder 127 Jack Nut 130 Drill Portion 132 Water Jetting Holes 134, 139 Fin 135 Fixed pin 137 Water injection pipe 138 Outer tube 140 Set screw 141 Fixed pin 142 CWP cleaning water receiving box 143 Washing water receiving box

Claims (3)

A device for cleaning the inside of the pipe of the fuel supply nozzle (21) when the fuel supply nozzle (21) for supplying the liquid fuel to the solid fuel into a fluidized bed furnace (34) is pasted with the fuel. Because
An inner water injection pipe (85) for injecting supply water (86) to the solidified fuel part at the tip of the fuel supply nozzle (21) and a gap for discharging cleaning water and fuel are provided outside the inner water injection pipe (85). A spiral fin that has a double structure with the outer cylinder (87) arranged in a row and conveys the fuel in the fuel supply nozzle (21) between the inner water injection pipe (85) and the outer cylinder (87). A cleaning shaft (80) wound with (134);
A driving device (81) for rotating and driving the outer cylinder (87) to insert and remove the cleaning shaft (80) from the fuel supply nozzle (21);
Flange mounting support (97) for mounting the drive device (81) to the flange portion (99) of the fuel supply nozzle (21) from the outside of the fluidized bed furnace (34)
An in-pipe cleaning device for a fuel supply nozzle (21), wherein:   The in-pipe cleaning device for a fuel supply nozzle (21) according to claim 1, wherein a drill portion (130) is provided at the tip of the inner water injection pipe (85) reaching the tip of the fuel supply nozzle (21). A method for cleaning the inside of the pipe of the fuel supply nozzle (21) when the fuel supply nozzle (21) for supplying the solid fuel with a liquid in a paste form into the fluidized bed furnace (34) is clogged with the fuel Because
The inner water injection pipe (85) and the outer cylinder (87) outside thereof have a double structure arranged with a clearance for discharging cleaning water and fuel between the inner water injection pipe (85) and the outer cylinder (87). A cleaning shaft (80) wound with a spiral fin (134) that conveys the fuel in the fuel supply nozzle (21) to the outside is used to drive the outer cylinder (87) of the cleaning shaft (80 ) to a drive device ( 81) , and the cleaning shaft (80) is inserted into the fuel supply nozzle (21).
Supply water (86) is injected from the inside of the tip of the inner water injection pipe (85) of the cleaning shaft (80) that has reached the solidified fuel part in the fuel supply nozzle (21),
As the cleaning shaft (80) rotates, the fuel in the fuel supply nozzle (21) is scraped out together with clean water between the inner water injection pipe (85) and the outer cylinder (87) by the spiral fin (134). In-pipe cleaning method of fuel supply nozzle (21) characterized by the above-mentioned.

Images