JP2003148707A - Fluidized bed device and electric power generating system with fluidized bed device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the bed height of a bed material at the initial packing of the bed material of the fluidized bed device having a fluidized reactor. SOLUTION: A fluidized bed device comprises a fluidized bed vessel 2 which forms a fluidized bed 1 by fluidizing a particulate bed material using a flow gas, a bed material feeding nozzle 5a which feeds a bed material to the body of the fluidized bed vessel 2, a raw material feeding nozzle 6 which feeds raw materials to the body of the fluidized bed vessel 2, a gas feeding nozzle which feeds a flow gas to the bottom of the fluidized bed vessel 2, a secondary raw material nozzle which feeds secondary raw materials reacting with the raw materials to the body of the fluidized bed vessel 2, an discharging nozzle 7 which discharges a gas produced by a reaction from the top of the fluidized bed vessel 2, a dispersing plate 8 installed at the bottom of the bed of the fluidized bed 1 which evenly disperses the flow gas, wherein a plurality of temperature sensors 9a to 9c are installed which detect a temperature at a position higher by a constant height above the top surface of the dispersing plate 8, and a fluidized bed height detecting means 12 which detects the fluidized bed height of the bed material packed on the dispersing plate 8 from the detecting value of the temperature sensors while the flow gas hiving higher temperature than that of the bed material is blown from the gas feeding nozzle.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fluidized bed apparatus.

[0002]

2. Description of the Related Art Conventionally, a fluidized bed apparatus comprises a fluidized bed reactor for fluidizing a particulate fluidized medium with a fluidizing gas to form a fluidized bed, and a fluidized medium feeder for supplying the fluidized medium to the fluidized bed reactor. , A raw material supplier for supplying raw materials to the fluidized bed reactor, a sub raw material supplier for supplying auxiliary raw materials that react with the supplied raw materials to the fluidized bed reactor, and a gas supply for blowing fluidized gas to the fluidized bed reactor It is known that the machine is provided with a dispersion plate formed at the bottom of the fluidized bed so that the gas blown from the gas supplier is evenly blown into the fluidized reactor.

In the fluidized bed apparatus constructed as described above, the fluidized medium is filled on the dispersion plate to a certain height and fluidized by the gas blown from the bottom of the fluidized bed reactor to form a fluidized bed. The raw material and the auxiliary raw material are supplied to the layer to be reacted.

Such a fluidized bed reactor is used as a reactor for causing a chemical reaction in a fluidized bed or a combustor for burning fuel. Generally, in this fluidized bed reactor, the residence time of fuel and reactants is long, the heat capacity of the fluidized bed is large, and the heat generated can be used efficiently. Therefore, fluidized bed reactors are mainly used in power generation systems, waste treatment plants, chemical plants and the like.

When a fluidized bed apparatus is applied to the power generation system, the output of the power generation system becomes unstable depending on the state of the fluidized medium in the fluidized bed reactor, for example, fluctuations in the bed height and volume. Therefore, the pressures of the lower part and the upper part of the fluidized bed are measured, the bed height of the fluidized bed is measured from the pressure difference, and the supply amount of the fluidized medium is adjusted.

[0006]

By the way, when the raw material is charged at the start of the operation of the fluidized bed, it is necessary to confirm that the upper surface of the dispersion plate is uniformly filled with the fluidized medium with a uniform thickness. This is because, if the fluidized medium does not spread all over the dispersion plate, or if part of the dispersion plate is exposed evenly in a part of the dispersion plate, the exposed raw material is not dispersed in the fluidized bed and is exposed. This is because the device may be dropped on the surface and the device may be damaged by sintering due to reaction heat or high temperature due to local reaction.

However, it is difficult to measure the bed height of the fluidized medium by pressure loss during the initial filling of the fluidized medium before the operation of the fluidized bed apparatus is started. The first reason is that at the time of initial filling, the temperature inside the device is low and the gas flow velocity is slow, so the layer pressure loss characteristics differ during and before operation, and an accurate differential pressure cannot be measured. The second reason is that at the time of initial filling, the fluidized medium is unevenly filled in a part of the dispersion plate, so that it is difficult to determine the bed height by the differential pressure which is the average value of the horizontal plane.

An object of the present invention is to detect the bed height of a fluidized medium at the initial filling of the fluidized medium in a fluidized bed reactor.

[0009]

The above-mentioned object is to provide a fluidized bed container for fluidizing a particulate fluidized medium with a fluidizing gas to form a fluidized bed, and a fluidized bed for supplying the fluidized medium to the body of the fluidized bed container. A medium nozzle, a raw material nozzle that supplies a raw material to the body of the fluidized bed container, a gas nozzle that blows a fluidizing gas to the bottom of the fluidized bed container, and a sub-reactor that reacts with the raw material in the body of the fluidized bed container. An auxiliary material nozzle for supplying a raw material, a discharge nozzle for discharging a reaction gas at the top of the fluidized bed container, and a dispersion plate formed so that the fluidized gas can be uniformly blown into the container at the bottom of the bed of the fluidized bed. In a fluidized bed apparatus provided with a plurality of temperature sensors at a certain height position from the upper surface of the dispersion plate, while detecting the temperature sensor while blowing a fluidized gas having a temperature higher than the temperature of the fluidizing medium from the gas nozzle. By value It can be solved by providing a fluidized bed height detecting means for detecting a bed height of has been fluidized medium filled in the diffusion plate upper surface.

That is, since the temperature of the fluidized medium is lower than that of the fluidized gas, when the fluidized medium reaches the installation position of the temperature sensor, the detection value of the temperature sensor decreases, so that the fluidized bed height can be detected. Therefore, by appropriately disposing multiple temperature sensors, it is possible to confirm that the fluidized medium is evenly filled to a certain height on the dispersion plate before fuel is supplied. You can solve the problem.

Further, it is preferable that the operation permission signal of the fluidized bed apparatus is output based on the output signal of the fluidized bed height detecting means. By doing so, since the operation of the fluidized bed apparatus is permitted after the bed height of the fluidized bed filled on the upper surface of the dispersion plate is detected, the operation can be safely started.

When the present invention is applied to a power generation system,
In a fluidized bed combustion furnace that combusts fuel while forming a fluidized bed with fluidizing and combustion air supplied from an air supplier, a boiler having a heat transfer tube installed in the fluidized bed combustion furnace, and the boiler The steam turbine generator driven by the generated steam, the gas turbine generator driven by the combustion gas discharged from the fluidized bed combustion furnace, and the air installed at the bed bottom of the fluidized bed evenly flow A dispersion plate formed so as to be blown into the layer combustion furnace, a plurality of temperature sensors are provided at a constant height position from the upper surface of the dispersion plate, and the fluid medium filled on the upper surface of the dispersion plate according to the detection value of the temperature sensor. A fluidized bed height detecting means for detecting the bed height may be provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a system diagram of an embodiment of a pressurized fluidized bed combustion apparatus to which the present invention is applied.

As shown in FIG. 1, a pressurized fluidized bed combustor is a fluidized bed which combusts fuel while forming a fluidized bed 1 with air for fluidization and combustion supplied from an air supplier (not shown). Bed combustion furnace 2, pressure vessel 3 that houses fluidized bed combustion furnace 2, fluidized medium nozzle 5a that supplies fluidized medium from fluidized medium container 4 to the body of fluidized bed combustion furnace 2, fluidized bed combustion furnace 2
A fuel nozzle 6 for supplying fuel from a fuel feeder (not shown) to the body of the reactor, an exhaust nozzle 7 for discharging combustion gas to the top of the fluidized bed combustion furnace 2, and air to the bottom of the fluidized bed 1 evenly. And an air dispersion plate 8 formed so as to be blown into the fluidized bed combustion furnace 2. Further, a plurality of temperature sensors 9a to 9 for detecting the temperature at a certain height position from the upper surface of the air dispersion plate 8.
c is provided. These temperature sensors 9a to 9c are provided with temperature detecting ends 10a to 10c, respectively. And
Fluidized bed height detecting means 1 for detecting the bed height of the fluidized medium filled on the upper surface of the air dispersion plate 8 based on the detection value of the temperature sensor.
2 is provided.

FIG. 2 is a schematic diagram showing a horizontal cross section of the fluidized bed combustion furnace 2 shown in FIG. As shown in FIG. 2, the fluidized bed combustion furnace 2 has a rectangular cross section with a rectangular horizontal cross section, and fluid medium nozzles 5a and 5b are provided on one long side of the rectangle. Further, the temperature detection ends 10a to 10c are arranged at equal intervals on the air dispersion plate 8 near the furnace wall having the fluidized medium nozzles 5a and 5b, and the temperature detection is performed on the air dispersion plate 8 near the furnace wall opposite to the temperature detection ends 10a to 10c. The ends 10d to 10f are arranged at equal intervals. Here, the fluidized medium supplied from the fluidized medium nozzles 5a, 5b is, for example, about 100 ° C., and the temperature of the air blown from the air dispersion plate 8 is about 200 ° C.

Next, the operation of the pressurized fluidized bed combustion apparatus configured as described above will be described. At startup, the fluidized medium is supplied from the fluidized medium nozzle 5a to the fluidized bed combustion furnace 2 until the initial bed height a is reached. Further, the fluidized medium is fluidized by the air that is dispersed from the air dispersion plate 8 into the fluidized bed combustion furnace 2 and is supplied to form the fluidized bed 1. After that, the fluidized bed 1 is preheated to a temperature equal to or higher than a specified temperature by a startup burner (not shown), and then pulverized coal which is a fuel is injected into the fluidized bed combustion furnace 2 from the fuel nozzle 6. Then, the pulverized coal is burned while forming the fluidized bed 1 with air, and the generated combustion gas is discharged from the discharge nozzle 7 provided at the top of the fluidized bed combustion furnace 2. The initial bed height a is set to a bed height (for example, about 1000 mm) that can shorten the preheating of the fluidized bed 1 before fuel injection and the temperature rise time after fuel injection.

Further, in order to increase the load of the fluidized bed combustion furnace 2 during the operation of the pressurized fluidized bed combustion apparatus, a fluidized medium, fuel, etc. are additionally supplied to the fluidized bed combustion furnace 2 and the fluidized bed 1 Raise the height of. On the other hand, in order to reduce the load, the fluidized medium is withdrawn from the fluidized bed combustion furnace 2 into the fluidized medium container 4 via the fluidized medium withdrawal pipe 11, and the bed height of the fluidized bed 1 is lowered.

In the pressurized fluidized bed combustion apparatus which operates as described above, it is necessary to detect the height of the fluidized medium layer filled on the upper surface of the air dispersion plate 8 before supplying the fuel. This is because when the fluidized medium does not reach the entire air dispersion plate 8 or when a part of the air dispersion plate 8 is exposed evenly in a part of the air distribution plate 8, the injected fuel is the fluidized bed 1. This is because they fall onto the exposed plate surface without being dispersed, and the device is damaged by the high temperature due to the sintering due to combustion or the local combustion.

Therefore, in this embodiment, focusing on the temperature difference between the temperature of the fluidized air supplied and the temperature of the fluidized medium stored in the fluidized medium container 4, the temperature detection end 10a on the air dispersion plate 3 is considered. By utilizing the temperature change of -10b, the height of the fluidized bed of the fluidized medium at the time of the initial filling of the fluidized medium is detected.

Now, the fluidized bed height detecting means 12 will be described in detail. FIG. 3 shows the filling state of the fluidized medium and the temperature change over time of the fluidized bed combustion furnace shown in FIG. The horizontal axis represents time, and the vertical axis represents the temperature detecting ends 10a-10.
represents the temperature measured at f.

As shown in FIG. 3, when the fluidized medium is started to be supplied from the fluidized medium nozzle 5a to the fluidized bed combustion furnace 2, the temperature at the temperature detecting end 10a is lowered by about 80 ° C. at time T ₁ . From this, at the time T ₁ , the flowing medium changes to the temperature detecting end 1
It can be seen that the measurement position of 0a has been filled. Next, when the fluidized medium is started to be supplied to the fluidized bed combustion furnace 2 from the fluidized medium nozzle 5b, the temperature of the temperature detection end 10c decreases by about 50 ° C. at time T ₂ . This proves the fluidized medium at time T ₂ has been filled to the measurement position of the temperature detection end 10c. At this point, the temperature detecting ends 10b, 10d-1
The fluidized medium does not yet exist at the measurement position of 0f. Then, as a result of continuously supplying the flowing medium from the flowing medium nozzles 5a and 5b at the same time, the temperature of the temperature detecting end 10f and the temperature of the temperature detecting end 10e decrease at time T ₃ , and then the temperature and the temperature of the temperature detecting end 10d. The temperature of the detection end 10b gradually decreased. Therefore, at time _{T 3,} the fluidized medium temperature detecting end 10a, 10c, 10d, are filled to 10f measurement position of the time _{T 4,} the fluidized medium to all the upper surface of the air dispersion plate 8 is filled I understand.

Next, with reference to FIG. 4, an appropriate arrangement position of the temperature detecting end will be described. FIG. 4 shows the arrangement of the temperature sensor of the present invention. As shown in the figure, three fuel nozzles 20a to 20c and 2
Two fluidized medium nozzles 21a and 21b are installed, and three fuel nozzles 20d to 20f are installed on the opposite long sides Y. Further, the temperature detecting end 22 is attached to the air dispersion plate 24.
a to 22o are provided.

In this case, the temperature detecting ends 22a-2
The measurement position of 2o is located at the height from the air dispersion plate 8 to the initial layer height (for example, about 1000 mm). By doing so, the temperature change of the temperature detecting ends 22a to 22o can be detected within the planned initial filling amount range.

Further, the temperature detecting ends 22a to 22e and the temperature detecting ends 22k to 22o are respectively arranged on two plates which are divided by the center line Z on the left and right sides of the air dispersion plate. By arranging in this way, it can be confirmed that the fluidized medium has diffused into each of the regions separated by the center line.

Here, the temperature detecting end 22d is arranged at a position where the distance b from the furnace wall X closest to the fluidized medium nozzle 21b is smaller than the height of the initial fluidized bed. Since the angle of repose of the flowing medium is about 45 degrees at the maximum, it is possible to confirm that the flowing medium is diffused and filled up to the wall X by arranging in this way and detecting the temperature change of the temperature detecting end 22d.

The temperature detecting end 22n is arranged at a position where the distance b from the wall Y farthest from the fluidized medium nozzle 21b is smaller than the height of the initial fluidized bed. Since the angle of repose of the flowing medium is about 45 degrees at the maximum, it is possible to confirm that the flowing medium has diffused and filled up to the wall Y by detecting the temperature change of the temperature detecting end 22n by arranging in this way.

Further, the temperature detecting end 22k is arranged at a position where the distance c from the fuel nozzle 20d is smaller than the height of the initial fluidized bed. In this case as well, the angle of repose of the fluid medium is about 45 degrees at the maximum, so that the fluid medium is filled in the fuel nozzle 20d by detecting the temperature change of the temperature detection end 22k by arranging in this way. I can confirm.

Further, the temperature detecting ends 22f to 22j are arranged with the air dispersion plate 24 on the center line Z. By arranging in this way, the process of diffusing and filling the fluidized medium supplied from the fluidized medium nozzles 21a and 22b can be confirmed in more detail.

Further, the temperature detecting end 22h is arranged at the center point W of the air dispersion plate 24. By arranging in this way, it can be confirmed that the center of the air dispersion plate 24 is filled with the fluid medium.

FIG. 5 shows a system diagram of a combined power generation system to which the present invention is applied. As shown in the figure, the combined cycle power generation system includes a fluidized bed combustion furnace that combusts fuel while forming a fluidized bed 31 with fluidizing and combustion air supplied from an air supplier 30, and a pressure that stores the fluidized bed combustion furnace. A container 38, a boiler 33 having a superheat transfer tube 32 installed in the fluidized bed combustion furnace, a steam turbine generator 34 driven by steam generated in the boiler 33, and a combustion gas discharged from the fluidized bed combustion furnace. The gas turbine generator 35 driven by the above and a dispersion plate 36 formed so as to uniformly blow air into the fluidized bed combustion furnace installed at the bottom of the fluidized bed 31 are provided from the upper surface of the dispersion plate 36. Multiple temperature sensors 3 at the height of
7a and 37b are provided, and a fluidized bed height detecting means 49 for detecting the bed height of the fluidized medium filled on the upper surface of the air dispersion plate 8 based on the detection value of the temperature sensor is provided.

The operation of the combined power generation system having the above structure will be described below. First, at startup, the fluidized medium is supplied from the fluidized medium container 39 to the fluidized bed combustion furnace via the fluidized medium nozzle 40. At this time, the fluidized bed height detection means 49 monitors changes in the detection values of the temperature sensors 37a and 37b to confirm the filling state of the fluidized medium. The temperature sensor 37 indicates that the fluid medium is evenly and evenly filled on the dispersion plate 36.
After confirming with a and 37b, the air supplied from the air supplier 30 is evenly dispersed and blown into the fluidized bed combustion furnace by the dispersion plate 36 to fluidize the fluidized medium to form the fluidized bed 31.
Then, after preheating the fluidized bed 31 to a specified temperature or higher with a start burner (not shown), fuel such as pulverized coal is added to the fuel nozzle 4
1 to the fluidized bed combustion furnace. Pulverized coal burns while forming a fluidized bed to generate combustion gas. The combustion gas passes through an exhaust port 42 installed in the upper part of the boiler 5 to remove dust by a cyclone 43, and then is introduced into a gas turbine 44 to drive a gas turbine generator 35. The combustion gas that has worked in the gas turbine 44 is heat-exchanged with water in the exhaust heat recovery heat exchanger 45, the harmful components are removed by the denitration device 46, and the smoke is discharged from the chimney 47 to the atmosphere. On the other hand, the feed water whose temperature has been raised in the exhaust heat recovery heat exchanger 45 flows through a steam heat transfer tube (not shown). Only the steam in the steam heat transfer tube flows through the superheat heat transfer tube 32, is overheated by the combustion heat of the pulverized coal to become high-temperature superheated steam, and is introduced into the steam turbine 48 to drive the steam turbine generator 34. The steam that has worked in the steam turbine 48 becomes condensate in a condenser (not shown), is supplied to the exhaust heat recovery heat exchanger 45, is preheated by the combustion gas from the gas turbine 44, and returns to the steam heat transfer tube again. Supplied.

By applying the present invention to a power plant that operates in this manner, the dispersion plate 36 is added before the addition of pulverized coal.
Since it can be confirmed that the fluidized medium is filled up to a certain height, the plant operation can be safely started.

Although the present invention has been described based on the embodiment, the present invention is not limited to the pressurized fluidized bed combustion apparatus. For example, a fluidized bed reactor that causes a chemical reaction in a fluidized bed has the same problems as a pressurized fluidized bed combustor. By applying the present invention to the fluidized bed reactor, it is possible to prevent the fluidized medium from being filled. It is possible to solve the problem caused by the generated heat of reaction.

It goes without saying that the pressurized fluidized bed combustion apparatus to which the present invention of FIG. 1 is applied can be used in a waste treatment plant, a chemical plant and the like in addition to the power generation system. Further, the fluidized bed combustion furnace to which the present invention of FIG. 1 is applied has a rectangular tubular shape, but can be applied to a cylindrical fluidized bed combustion furnace. Although the present embodiment shown in FIG. 1 has been described using the pressure type fluidized bed apparatus, the present invention is not limited to this and can be applied to a fluidized bed apparatus. Further, in the present embodiment shown in FIG. 1, the initial bed height of the fluidized bed 1 is, for example, about 1000 m.
However, it is not limited to this as long as the preheating time of the fluidized bed 1 and the temperature rising time after fuel injection are short. Further, although pulverized coal is used as the fuel in the present embodiment shown in FIG. 1, the present invention is not limited to this. In short, any fuel can be used as long as it can burn while forming the fluidized bed 1.

Further, it is preferable that the temperature detecting ends 10a to 10f described in this embodiment are covered with a cap in order to prevent damage. Further, in the embodiment shown in FIG. 4, the arrangement positions of the temperature detection ends 22a to 22o have been described, but the present invention is not limited to this. For example, the arrangement positions of the temperature detecting ends 22a to 22o can be appropriately changed based on the angle of repose of the flowing medium. Further, it is preferable to provide an interlock for outputting the output of the temperature detection end of the present embodiment as an operation permission signal of the fluidized bed combustion device. By doing so, the fuel can be safely charged into the fluidized bed combustion furnace 2.

As described above, according to the embodiment of the present invention, since the fluidized bed height of the fluidized medium can be detected at the time of the initial filling of the fluidized medium in the pressurized fluidized bed combustion apparatus, the fluidized medium height of the fluidized medium can be detected. The problem caused by unfilling can be solved.

[0037]

As described above, according to the present invention, the height of the fluidized bed of the fluidized medium can be detected during the initial filling of the fluidized medium in the fluidized reactor.

[Brief description of drawings]

FIG. 1 shows a system diagram of an embodiment of a pressurized fluidized bed combustion apparatus to which the present invention is applied.

FIG. 2 is a schematic view showing a horizontal cross section of the fluidized bed combustion furnace 2 of FIG.

3 shows changes in the filling state of a fluidized medium and the temperature detected by a temperature sensor over time in the fluidized bed combustion furnace of FIG.

FIG. 4 is a diagram illustrating the arrangement of temperature sensors of the present invention.

FIG. 5 shows a system diagram of a combined power generation system to which the present invention is applied.

[Explanation of symbols]

2 Fluidized bed combustion furnace 8 Air dispersion plate 5a Fluidized medium nozzle 9a Temperature sensor 12 Fluidized bed height detection means

Claims (3)

[Claims] 1. A fluidized bed container for fluidizing a particulate fluidized medium with a fluidizing gas to form a fluidized bed, a fluidized medium nozzle for supplying the fluidized medium to the body of the fluidized bed container, and the fluidized bed container. A raw material nozzle for supplying a raw material to the body of the fluidized bed, a gas nozzle for blowing a fluidizing gas to the bottom of the fluidized bed container, and a sub raw material nozzle for supplying a sub raw material that reacts with the raw material to the body of the fluidized bed container. A fluidized bed apparatus comprising a discharge nozzle for discharging a reaction gas at the top of the fluidized bed container, and a dispersion plate formed so that the fluidized gas is uniformly blown into the container at the bottom of the fluidized bed, Providing a plurality of temperature sensors that detect the temperature at a certain height position from the upper surface of the dispersion plate,
A fluidized bed height detecting means for detecting the bed height of the fluidized medium filled on the upper surface of the dispersion plate by the detection value of the temperature sensor while blowing a fluidized gas having a temperature higher than the temperature of the fluidized medium from the gas nozzle was provided. A fluidized bed apparatus characterized by the above. 2. The fluidized bed apparatus according to claim 1, wherein an operation permission signal of the fluidized bed apparatus is output based on an output signal of the fluidized bed height detecting means. 3. A boiler having a fluidized bed combustion furnace that combusts fuel while forming a fluidized bed with air for fluidization and combustion supplied from an air supply machine, and a heat transfer tube installed in the fluidized bed combustion furnace. A steam turbine generator driven by steam generated in the boiler, a gas turbine generator driven by combustion gas discharged from the fluidized bed combustion furnace, and air installed at the bottom of the fluidized bed And a dispersion plate formed so as to be uniformly blown into the fluidized bed combustion furnace, and a plurality of temperature sensors for detecting the temperature at a constant height position from the upper surface of the dispersion plate are provided, and the temperature sensor detects the temperature. A fluidized bed power generation system comprising fluidized bed height detection means for detecting the bed height of the fluidized medium filled on the upper surface of the dispersion plate.