JPH0756363B2 - Multiple bed fluidized bed boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a plurality of swirl-flow type fluidized-bed boilers, and the heat recovery parts of the respective boilers are independent of each other, and a steam generation part, a steam heating part, and / or Alternatively, the present invention relates to a multi-bed swirling flow type fluidized bed boiler used as a steam reheating section.

[Technical background of the invention]

The present inventors have previously conducted various studies on a method for recovering heat from a fluidized medium in a swirling type fluidized bed incinerator that uses a granular solid having a diameter of about 1 mm as a fluidized medium. Independently of the reflective wall that formed a part of the above, a reflective partition is independently provided in the furnace, and the space between the back surface of the reflective partition and the furnace wall serves as a heat recovery chamber. By forming a moving layer of a heating medium and arranging a heat transfer surface for heating the heat receiving fluid in the heat recovery chamber,
The inventors have found that heat can be efficiently recovered from the fluidized medium without causing wear of the heat transfer surface and the amount of heat recovered can be controlled, and a patent has been filed (Japanese Patent Application No. 62-9057).

In the conventional incinerator, when the amount of combustibles increases, or when the calorific value of the combustibles becomes large, fluidization is prevented in order to prevent problems due to burning or melting of the fluidizing medium due to the temperature rise of the fluidizing medium. Although the fluidized medium was cooled by injecting water into the medium, heat can be efficiently recovered from the fluidized medium by providing the heat recovery chamber in the furnace as described above, that is, the heat is recovered. By doing so, it became possible to cool the fluidized medium, so that it was possible to use it as a combustion part of a coal boiler, for example.

Furthermore, since the heat recovery section is separated from the combustion section, and the combustion section is a swirling fluidized bed, it is possible to perform exclusive combustion of the combustion material containing incombustibles and co-firing with coal or the like. That is, all combustible materials can be used as fuel.

Hereinafter, a swirling type fluidized bed boiler having a heat recovery chamber provided in a furnace will be described with reference to the drawings.

FIG. 5 shows an embodiment of a fluidized bed boiler in which a heat recovery chamber is provided in the furnace, and the heat recovery chamber is provided in the fluidized bed furnace described in JP-A-57-124608. is there.

In FIG. 5, the inner bottom of the furnace 51 is provided with a dispersion plate 52 for the fluidizing gas introduced from the flow gas introduction pipe 53 by the blower 57, and both side edges of the dispersion plate 52 are lower than the central part.
A mountain-shaped cross section (roof) that is almost symmetrical with respect to the center line of 51
Is formed in. The flowing gas sent from the blower 57 is adapted to be jetted upward from the dispersion plate 52 via the air chambers 54, 55, 56, and the air chambers 54 on both side edges,
The mass velocity of the fluidizing gas ejected from 56 is sufficient to form a fluidized bed of the fluidized medium in the furnace 51, but the mass velocity of the fluidizing gas ejected from the air chamber 55 in the central portion is the former. Is chosen smaller than.

At the upper portions of the air chambers 54, 56 on both side edges, as a reflection wall that blocks the upward flow path of the fluidizing gas and reflects and turns the fluidizing gas ejected from the air chambers 54, 56 toward the center of the furnace 51. A plate-shaped reflective partition 58 whose upper part is folded inward is provided, and a swirl flow in the direction indicated by the arrow in the drawing is generated due to the difference in mass velocity between the reflective partition 58 and the fluidized gas jetted. On the other hand, a heat recovery chamber 59 is formed between the rear surface of the reflective partition 58 and the furnace wall, and a part of the fluidized medium is configured to enter the heat recovery chamber 59 over the upper portion of the reflective partition 58 during operation. Due to this tilted reflective partition, the fluidized gas is most severely ejected in the vicinity of the upper end of the reflective partition, so that the fluidized medium blown up from the fluidized bed is easily recovered over the upper end of the reflective partition. Can enter the room side.

In addition, at a level higher than the bottom of the heat recovery chamber 59,
Air diffuser 62 that introduces gas from blower 60 through introduction pipe 61
Is provided, an opening 63 is provided in the vicinity of the heat recovery chamber 59 where the air diffuser 62 is installed, and the fluidized medium that has entered the heat recovery chamber 59 is retained as a fixed bed depending on the operating state, or It sediments continuously or intermittently while forming a moving bed or a weak fluidized bed, slips between the diffusers, and circulates from below to the combustion section.

The amount of sedimentation is controlled to some extent by the amount of diffused air to the heat recovery chamber and the amount of fluidized gas in the combustion section. That is, the amount G ₁ of the fluidized medium entering the heat recovery chamber 59 is determined by the fluidizing gas ejected from the dispersion plate 52 in order to fluidize the combustion section, particularly from the air chambers 54 and 56 at the ends as shown in FIG. It increases when the amount of fluidizing gas ejected is increased. Further, as shown in FIG. 9, when the amount of air blown into the heat recovery chamber is changed within the range of the moving bed of 0 to less than 1 Gmf, the amount of the fluidized medium settling in the heat recovery chamber changes in a substantially proportional manner. It becomes almost constant in the case of a fluidized bed with an air volume of 1 Gmf or more. This constant fluid medium amount is approximately equal to the fluid medium amount G ₁ entering the heat recovery chamber. The amount of the fluidizing medium settled in the heat recovery chamber is the amount according to G ₁ . By adjusting both the air volumes, the sedimentation amount of the fluid medium that sediments in the heat recovery chamber 59 is controlled. In order to secure effective G ₁ for fluid medium overheating suppression and heat recovery without blowing upwards by flow or high-speed flow or jet in the heat recovery chamber, the gas flow ejected from the fluidized bed combustion section is maximized. In the vicinity, it is necessary to put the falling fluidized medium into the heat recovery chamber. For this purpose, the reflective partition protruding toward the combustion section side is the rising gas flow accelerating function of the combustion section and protrudes into the fluidized medium. It has an optimum shape that also has the function of receiving.

As shown in FIG. 6, in the heat recovery chamber 59, a heat transfer pipe 65 through which a heat receiving fluid is passed is arranged inside a pipe 64 which communicates with a waste heat boiler 67. By exchanging the heat, heat is recovered from the fluid medium. The heat transfer coefficient in the heat recovery section changes greatly and gently as shown in FIG. 29, when the diffused air volume of the heat recovery chamber is changed from 0 to 2 Gmf. Note that FIG. 29 shows an air diffuser of the principle shown in FIG. 21, in which the fluid medium has an average particle size of 1.2 mm and a temperature of 8
It is a value around 50 ° C.

In order to control the heat recovery amount, as described above, the fluid medium circulation amount is controlled, and at the same time, the heat transfer coefficient is controlled. In other words, if the amount of fluidized gas in the combustion chamber is constant, increasing the amount of diffused air in the heat recovery chamber increases the circulating amount of the fluidized medium and at the same time increases the heat transfer coefficient, which has a synergistic effect on the heat recovery amount. Increase to. This relationship is shown in FIG. Considering the temperature of the fluidized medium in the fluidized bed, this has an effect of preventing the temperature of the fluidized medium from rising above a predetermined temperature.

Various devices can be considered as a means for introducing gas into the heat recovery chamber 59, but generally, a method of horizontally installing an air diffuser as shown in FIG. 10 is adopted. In FIG. 10, the explanation is simplified, and in order to clearly show the partial fluidization, the circulation of the fluid medium with the combustion section is ignored and the phenomenon of the moving bed is omitted.
In this case, if the openings for introducing gas are provided uniformly over the entire hearth surface, the amount of gas supplied per unit area will be uniform over the entire hearth regardless of the amount of gas supplied to the diffuser. . Then, when the gas supply amount to the air diffuser is gradually increased, the fluidized medium in the heat recovery chamber changes from the fixed bed to the fluidized bed at a certain supply gas amount called the minimum fluidization rate Gmf as a boundary.

Considering the heat transfer amount in the heat recovery chamber in such a case, in the heat recovery chamber according to the present invention, the heat transfer coefficient between the heat transfer surface and the fluidized medium is the fluidized mass velocity of 1 Gmf of the supplied gas. Since it rapidly changes in the vicinity of the fluidized mass velocity, the heat transfer coefficient on the surface in contact with the fluidizing medium changes remarkably at this fluidization mass velocity, and thus the total heat transfer amount in the heat recovery chamber also changes rapidly. It will be.

When the heat transfer amount is controlled by the gas supply amount to the air diffuser under such a situation, the fluidized mass velocity is substantially higher than around 1 Gmf and the heat transfer amount is large. Is less than 1 Gmf and the amount of heat transfer is small, or the state where the amount of heat transfer is extremely small by stopping the gas supply to the air diffuser is selected in a stepwise control.

On the other hand, the air diffuser is installed at an angle as shown in FIG. 17, or the opening diameter of the gas ejection port to the heat recovery chamber 59 of the air diffuser is changed depending on the location, or the opening diameter is Even if the density is the same, if the gas pressure loss is changed by changing its density, not only will the amount of gas introduced into the heat recovery chamber vary depending on the location, but it will also be supplied to the air diffuser. This condition will be promoted depending on the amount of gas that flows. For example, if the amount of gas supplied to the air diffuser is gradually increased, the rate of increase in the amount of gas supplied to the fluidized medium layer from the gas ejection port (opening) with a relatively small gas pressure loss becomes relatively large. Conversely, the rate of increase in the amount of gas supplied to the fluidized medium layer from the gas ejection port (opening) having a relatively large gas pressure loss is relatively small.

For this reason, only the fluidized medium layer above the gas inlet with a relatively small gas flow pressure loss becomes a fluidized bed, and the other parts remain in the fixed bed, or conversely, gas with a relatively large gas flow pressure loss. A state occurs in which only the fluidized medium layer near the mouth is the fixed bed, and the other portions are fluidized beds.

That is, as the amount of gas supplied to the diffuser increases,
The fluidized medium layer in the heat recovery chamber is the fluidized mass velocity of the introduced gas.
From the state of the fixed bed in the case of less than 1 Gmf, part of the fluidized bed is formed at a fluidization mass velocity of 1 Gmf or more, the other is the state of the fixed bed, the ratio of the hearth area occupied by these both gradually becomes the fluidized bed The number of states increases, and finally the entire fluidized medium layer transitions to the fluidized bed state.

As a result, regarding the amount of heat transfer in the heat recovery chamber,
As the amount of gas supplied to the air diffuser increased, the heat transfer amount initially less than the fluidization mass velocity of 1 Gmf blown into the heat recovery chamber was small. In the large state, the others remain in a state where the heat transfer amount less than 1 Gmf is small, the area ratio of the heat transfer surface in both states gradually increases in the part with a large heat transfer amount, and finally the whole fluidized mass velocity of 1 Gmf or more. Transition to a state where the amount of heat transfer is large. Since the total heat transfer amount in the heat recovery chamber is the sum of the heat transfer amounts of these parts, the increase or decrease in the heat transfer amount based on the increase or decrease in the gas supply amount to the air diffuser shows a smooth increase or decrease, and the continuous heat transfer amount. Various controls can be easily performed.

An example of such an air diffuser is shown in FIG. 19, FIG. 20 and FIG.

FIG. 19 shows an example in which a plurality of gas ejection ports having different opening diameters are provided in a horizontally installed air diffusing pipe, and the resistance when the gas passes through the ejection ports is different, so the amount of gas passing through each ejection port is different. different. That is, assuming that the opening diameter of the ejection port is A>B> C as shown in FIG. 19, the gas flow rate is A> B.
> C.

FIG. 20 shows an example in which an air diffuser having jets with the same opening diameter is installed in a tilted manner, and the discharge pressure for blowing out to the fluidized medium layer is proportional to the depth of the fluidized medium layer. The amount of passing gas ejected from the outlet is different. That is, assuming that the jet outlets are A, B, and C in the order of increasing depth of the fluidized medium layer, the gas passing amounts are in the order of A <B <C.

FIG. 21 is an example in which an air diffuser equipped with jets having different opening diameters is installed in a slanted manner, in which the diameter of the fumarole located in the deep portion of the fluidized medium layer is increased and the depth of the fluidized medium layer is increased. The opening diameter of the jet port located in the shallow portion is set to be small, and the difference in the gas pressure loss due to the depth of the fluidized medium layer is corrected by the opening diameter.

That is, by setting the size of the opening diameter to A>B> C, the amount of gas passing through each opening at any design point is A = B = C.
In this case, the gas flow rate is A <B <C below the design point, and the gas flow rate is A>B> C above the design point.
Can be

In the previously proposed invention, the fluidized bed described so far is partitioned by the reflective partition 58 so that the fluidized bed main combustion section (fluid swirling bed section) is formed.
And the heat recovery section (circulation layer section) 59 are provided in the fluidized bed boiler in a fluidized bed boiler in which the heat recovery amount of the circulation layer section (heat recovery section) is steplessly and within a large range in the order of magnitude. Paying attention to the fact that it can be easily adjusted by the blown air volume (aeration amount), steam is passed through the heat transfer tube inserted in the circulation layer section (heat recovery section) to form a steam superheater tube, and the temperature on the outlet side of the steam is adjusted. Detect
The superheated steam temperature obtained by adjusting the opening of the supply air amount adjusting damper to the diffuser pipe of the circulation layer based on the outlet temperature is controlled to be a predetermined temperature.

That is, when the temperature on the outlet side of the steam changes to a lower side than the set value, the damper is opened to increase the amount of diffused gas in the heat recovery chamber of the part where the steam superheater tube is inserted to increase the amount of heat transfer. When the steam outlet temperature is raised and the temperature rises above the set value, the opposite is done. By doing so, the superheated steam temperature easily becomes a temperature near the set temperature.

One example of the amount of gas blown into the fluidized medium layer from each jet when the amount of gas supplied to the diffuser is changed by using these diffusers is shown in FIGS. 22, 23 and 24. Shown in the figure.

FIG. 22 is a diagram when an air diffuser as shown in FIG. 19 is used,
FIG. 23 is a diagram when an air diffuser as shown in FIG. 20 is used,
FIG. 24 is a diagram when the air diffuser as shown in FIG. 21 is used.

In FIG. 22, FIG. 23, and FIG. 24, the jet port B is shown on the horizontal axis.
The mass velocity of the gas blown out from the nozzle is shown, and the vertical axis shows the mass velocity of the gas blown out from each jet.

From these figures, even if the mass velocity of the gas blown from the jet B is less than 1 Gmf, the mass velocity of the gas blown from another jet becomes 1 Gmf or more, or the gas blown from the jet B is Even if the mass velocity is 1 Gmf or more, it is clear that the mass velocity of the gas blown out from another jet may be less than 1 Gmf.

FIGS. 25, 26 and 27 show the mass velocity relationships of the gas blown out from the respective ejection ports shown in FIGS. 22, 23 and 24, respectively, with the horizontal axis representing the ejection ports, The vertical axis shows the mass velocity of the gas blown from each jet.

FIG. 25 is a diagram corresponding to the case where the air diffuser as shown in FIG. 19 is provided, FIG. 26 is a diagram corresponding to the case where the air diffuser as shown in FIG. 20 is provided, and FIG. It is a figure corresponding to the case where the air diffuser as shown in the figure is provided.

In these figures, each plot under the same supply gas amount to the air diffuser is connected by a broken line.

In this way, when the gas mass velocities are different from each other depending on each jet, the total heat transfer amount is the product of the heat transfer area in the region corresponding to each jet and the heat transfer coefficient corresponding to each fluidized mass velocity. Is the sum of For example, in FIGS. 25 to 27, the amount of gas supplied to the air diffuser having a fluidized mass velocity of 1 Gmf differs from each other depending on the jet outlets. It won't happen.

When the amount of gas supplied to the diffuser is increased, the heat transfer surface in the area corresponding to each jet will gradually change to a high amount of heat transfer at a little over 1 Gmf, and when the amount of gas supplied is decreased. The opposite phenomenon occurs. Therefore, Figs. 19 to
When any of the three examples shown in FIG. 21 is used, the characteristic of the increase / decrease in the amount of heat transfer with respect to the increase / decrease in the amount of gas supplied to the diffuser can be made smooth as described above. 21st
In the example shown in the figure, for example, as shown in Fig. 24, the mass velocity
It can be designed so that the amount of gas blown out from each nozzle is uniform at 2 Gmf.

By doing so, as shown in FIG. 4, the region where the mass velocity is 2 Gmf or more, that is, the amount of heat transfer becomes rather negative, and the wear rate of the heat transfer surface rapidly increases in accordance with the mass velocity. It can be designed so that no operating points occur.

That is, if the ejection port B is, for example, 2 Gmf, the ejection port A in FIG. 22 and the ejection port C in FIG. 23 are 2 Gmf or more, but if the ejection port B is 2 Gmf in the example shown in FIG. All nozzles have a uniform gas flow rate of 2 Gmf. That is, the wear rate of all the heat transfer surfaces of the heat recovery chamber is low, and the maximum amount of heat recovery can be obtained.

The coincidence point of the gas flow amount can be easily designed depending on the diameter of the ejection port, the ejection port density, the depth from the surface of the sand in the heat recovery chamber to the nozzle, and the like.

For this reason, it is preferable that the air diffuser is installed obliquely as shown in FIG. 21, and the opening diameter or the outlet density is made larger at the deeper the outlet.

The relationship between the mass velocity of the supplied gas and the amount of heat transfer in the case of using such an air diffuser is compared with the case where the air diffuser is provided horizontally and the openings of the ejection ports are evenly provided. Shown in Figure 28.

In FIG. 28, the curve y shows the case where an air diffuser having a uniform jet is installed horizontally, and the curve x shows the case where the air diffuser as shown in FIG. 21 is provided.

From the curve shown in FIG. 28, the characteristics of the heat transfer amount increase / decrease due to the increase / decrease in the supply gas amount are gradually increased by providing the air diffuser obliquely and increasing the nozzle opening diameter toward the gas introduction part. Therefore, it is clear that the heat transfer amount can be controlled easily and continuously by adjusting the supply gas amount (curve x).

In addition to the effect of making the flow non-uniform, in the case of a moving bed which is slid down due to the action of the fluid medium G ₁ flowing in from the combustion part by blowing gas as in the present invention, the average If the amount of diffused gas is around 1.5 Gmf or less, the effect becomes peculiar to the moving bed.

That is, the heat transfer coefficient below 1 Gmf is several times larger than that of the fixed bed and increases in proportion to the amount of diffused gas.
Even if the amount of diffused gas exceeds the range, it becomes difficult to fluidize due to the effect of movement. As a result of progressive fluidization at 1 to 1.5 Gmf,
As shown in Fig. 29, the relationship between the heat transfer coefficient that gradually increases from 0 to 2 Gmf and the average amount of diffused gas in the heat recovery chamber is obtained.

The control of the amount of heat recovery by the amount of diffused air in the heat recovery chamber can be performed rapidly as described later.

Next, the relationship between the fluidized bed height and the circulating amount of the fluidized medium will be described in more detail.

When the surface of the fluidized bed is lower than the upper end of the reflective partition or at about the same position, the gas flow rising from below along the reflective partition is given a direction by the reflective partition, and along the reflective partition from the fluidized bed. Ejection, and the accompanying flow medium is also given directionality, and mainly ejects from the fluidized bed surface in the vicinity of the reflective partition. Unlike the fluidized bed, the jetted gas flow loses the fluidized medium that was filled in the flow path and the flow path cross-section rapidly expands, causing the jet flow to also scatter and form a gentle flow with a flow velocity of 1 m / sec or less. The fluidized medium exhausted to, and thus entrained in, has a large particle size of about 1 mm to be carried by its flow velocity, and therefore falls without losing kinetic energy due to gravity or friction with exhaust gas. Then, some of the particles will fly over the combustion section due to inertia and will jump into the heat recovery section. However, the flight distance of the fluidized medium ejected from the surface of the fluidized bed is 1 to 2 m or less in relation to the particle size or the specific gravity,
Only when the width of the furnace is 1 to 2 m or less, it is possible to secure the amount of fluid medium required for heat recovery and fluid medium overheating prevention in the heat recovery chamber.

By the way, when the surface of the fluidized bed is above the upper end of the reflective partition, the higher the fluidized bed height, the more the fluidized gas thickened by the partition is blown up almost directly above the upper end of the reflective partition. The direction in which the gas is ejected changes, and the fluidized medium is accompanied by a change in the direction from the fluidized bed surface near the upper end of the reflective partition to the fifth position.
As shown by the arrow a in the figure, it will be blown up and then dropped, and a large amount can easily be inserted into the back surface of the reflective partition, that is, the heat recovery chamber.

That is, as the height of the fluidized bed increases, the directionality of the ejected fluidized medium due to the reflective partition becomes closer to the direct upward direction, and as the height of the fluidized bed increases, more fluidized medium enters the heat recovery chamber. The rate of increase is larger as the distance of the fluidized bed height from the upper end of the reflective partition is smaller.

In FIG. 5, 66 is a combustion material inlet provided in the upper part of the furnace 51, 67 is a steam drum provided near the exhaust gas outlet 68,
A circulation path is formed with the heat transfer tube 65 in the heat recovery chamber 59. Further, 69 is an incombustible discharge port connected to the outside of both side edges of the dispersion plate 52 at the bottom of the furnace 51, and 70 is a screw conveyor having a screw 71 arranged in the reverse screw direction.

Then, the combustion product F charged into the furnace 51 through the combustion product charging port 66 combusts while flowing together with the fluidizing medium that is swirling by the fluidizing gas. At this time, the fluid medium in the vicinity of the upper central portion of the air chamber 55 does not undergo a vigorous up-and-down motion, and forms a descending moving layer in a weakly flowing or moving state. The width of this moving layer is narrow in the upper part, but it is slightly wider in the hem part due to the effect of the inclination of the dispersion plate 52, and part of the hem part is located above the air chambers 54, 56 on both side edges. Since it has reached, it is blown up by the injection of fluidizing gas with a large mass velocity from both air chambers. Then, a part of the fluid medium at the skirt is slowed down, and the layer immediately above the air chamber 55 descends by its own weight.

The fluid medium from the fluidized bed is replenished and accumulated above this layer as described later, and by repeating this, the fluidized medium above the air chamber 55 forms a moving layer that gradually and continuously descends.

The fluidized medium that has moved to the air chambers 54 and 56 is blown upward, but it is reflected and diverted toward the reflective partition 58 and swung toward the center of the furnace 51, and then falls onto the top of the moving layer in the central part. It is circulated again as described above, and at the same time, a part of the fluid medium crosses over the upper portion of the reflective partition 58 and enters the heat recovery chamber 59. Then, when the sedimentation velocity of the fluidized medium accumulated in the heat recovery chamber 59 is low, a repose angle is formed at the upper part of the heat recovery chamber and the surplus fluidized medium falls from the upper part of the reflective partition to the combustion part.

The fluidized medium that has flowed into the heat recovery chamber 59 does not flow due to the gas blown from the air diffuser 62 and moves in a slipping manner, or forms a circulation layer of the fluidized medium that gradually descends while performing a gentle flow. After the heat is exchanged with the heat transfer surface, it is returned to the combustion section through the opening 63 at the lower end of the reflective partition.

The mass velocity of the diffused gas introduced from the diffuser 62 in the heat recovery chamber 59 is selected from a value within the range of 0 to 3 Gmf, preferably 0.5 to 2 Gmf.

The reason is that, as shown in FIG. 4, in the case of 3 Gmf or less, the heat transfer coefficient is large and the wear rate is small.

When the mass velocity of the diffused gas in the heat recovery chamber 59 is changed to 0 to 1 Gmf, the sedimentation velocity of the moving bed in the heat recovery chamber changes substantially linearly as shown in FIG. The amount of high temperature medium can be controlled arbitrarily. However, when heat is recovered from the fluidized medium due to unnecessary use of steam or the calorific value of the combusted material is small and good combustion cannot be achieved, the fluidized gas amount in this part should be set to 0. For example, the operation can be performed without recovering the heat from the fluid medium. Further, the heat recovery section is outside the main combustion area inside the furnace 51,
Since the heat transfer tube 65 is less susceptible to corrosion than the conventional one because it does not have strong corrosiveness such as the atmosphere in which redox is repeated, and as mentioned above, the flow rate is low in this part, the heat transfer tube 65 Wear is extremely low.

Although the mass velocity of the fluidizing gas is 0.5 to 2 Gmf, the gas velocity is 0.1 to 0.4 m / sec (superficial velocity), which is extremely low at the fluid medium temperature of 800 ° C, depending on the particle size of the fluid medium. Is.

When there is an incombustible substance having a diameter larger than that of the fluidized medium in the combusted material, the combustion residue is discharged together with a part of the fluidized medium from the screw conveyor 70 at the bottom.

Further, the heat transfer in the heat recovery chamber 59 includes heat transfer by direct contact between the fluid medium and the heat transfer tube 65, and also by gas that rises while vibrating violently and irregularly due to the flow of the fluid medium. There is. The latter is a stationary medium because there is almost no boundary layer on the surface of the solid which hinders heat transfer, and the fluid mediums are well agitated by the flow, as compared with the normal gas-solid contact state. The heat transfer in the powder different from the above becomes negligible and it shows extremely large heat transfer characteristics.

Therefore, in the heat recovery chamber of the present invention, a heat transfer coefficient close to 10 times can be taken at the maximum when compared with heat recovery from ordinary combustion gas.

As described above, the heat transfer phenomenon between the fluidized medium and the heat transfer surface largely depends on the amount of the blown gas, the circulating amount of the fluidized medium can be adjusted by adjusting the amount of gas introduced from the air diffuser 62, and the moving bed By making the heat recovery chamber 59 independent from the main combustion chamber in the furnace, a fluidized bed heat recovery device that is compact and has a large turndown ratio and is easy to control can be provided.

In a boiler that uses a combustion product with a slow burning rate such as coal or petroleum coke as a fuel, it is often the case that even if it is desired to suddenly change the evaporation rate, it can only change at a rate commensurate with the burning rate. Although the burning rate itself is improved in, it is further inferior because of the heat recovery through the fluidized bed.

However, in the method described with reference to FIG. 5, the heat transfer amount in the heat recovery chamber can be instantly changed to several times to several times by changing the gas diffusion amount. Therefore, a change in the amount of heat input to the fluidized bed due to a change in the amount of the combustion material supplied depends on the combustion speed, and thus a time delay occurs, but the amount of heat recovered from the fluid medium in the heat recovery chamber of the present invention is It can be rapidly changed by the amount of air diffused, and the difference in the response speed between the heat input amount and the heat recovery amount is absorbed by the sensible heat storage capacity of the fluidized medium forming the fluidized bed as a temporary temperature change of the fluidized medium temperature. it can. Therefore, the heat can be used without waste, and the evaporation amount control with high followability, which is not possible with the conventional coal-fired boiler, can be performed.

The position of the incombustibles discharge port 69 is positioned so as to be in contact with the opening 63 at the bottom of the reflective partition 58 of the heat recovery chamber 59 and both side edges of the air dispersion plate in the furnace 51 as shown in the illustrated example. It is preferable, but not limited to this.

It is also preferable to provide a partition 50 in order to prevent discharge of the fluidized medium from the heat recovery chamber 59 to the incombustibles discharge port 69 due to a short circuit, and to effectively return the medium after heat transfer to the fluidized bed which is the combustion chamber. As shown in FIGS. 10 and 11, the partition 50 may be a plate-like member which is attached to a diffuser tube forming a diffuser 62 with a band or the like, or as shown in FIG. It can also be formed by utilizing.

In FIG. 5, the air distribution plate 52 has a mountain shape, the air chambers are three chambers (54, 55, 56), and the mass velocity of the fluidizing gas ejected from the air chambers 54 and 56 is the fluidizing gas ejected from the air chamber 55. I explained the case of making it larger than the mass velocity of gas,
Even if the mass velocity of the air blown from the lower part of the fluidized bed is the same, due to the action of the reflective partition, that is, the air velocity in the part along the reflective partition is higher than that in the central part, and a swirling flow is formed in the fluidized bed. Therefore, the mass velocity of the fluidizing gas ejected from each air chamber may be the same, and for the same reason, as shown in FIG. 7, the air dispersion plate 52 is horizontal and a single air chamber is used. May be 56 '. Further, in this case, the air chamber 56 'may be divided into classrooms instead of being a single chamber. When the air chambers are divided into classrooms, it is natural that the mass velocity of the fluidizing gas may be different for each chamber as described with reference to FIG.

Further, in the case of burning a combustion product such as coal having a low content of non-combustible substances, the non-combustible substance discharge port can be omitted as shown in FIG.

Next, another embodiment is shown in FIG. The swirling fluidized bed heat recovery apparatus shown in FIG. 12 is provided with two swirling fluidized beds shown in FIG. 5 in the same furnace, and accordingly, the heat recovery chamber 59 in the central part is provided with two reflective partitions in the central part. It is exactly the same except that it is provided between the rear surfaces of 58 and the lower partition of the heat recovery chamber 59 in the central part has the structure shown in FIG.

Next, still another embodiment is shown in FIG. 13, FIG. 14, FIG. 15 and FIG.

In these embodiments, mainly the shape of the reflective partition 58 and its mounting method are different from those in the embodiments shown in FIGS. 5, 7 and 12, and FIGS.
The embodiment shown in FIG. 14 is a drawing showing an embodiment in which a heat recovery unit is provided in a furnace having one swirling fluidized bed.

Incidentally, FIG. 14 is a diagram showing an example in which the gas dispersion plate 52 is horizontal, the air chamber 56 ′ is a single chamber and the incombustibles discharge port is omitted in the swirling type fluidized bed furnace shown in FIG. The operation is the same as that described with reference to FIG.
In FIG. 14, reference numeral 69 'denotes a fluidized medium discharge nozzle.

Reference numerals 50 to 71 in FIGS. 13, 14, 15, and 16
Has the same meaning as described in FIG. 5 and FIG. 12, reference numeral 80 is a water pipe, 81 and 82 are pipe heads provided on the outer wall, and 83 and 84.
Indicates a heading provided in the furnace.

In the example shown in FIG. 13, FIG. 14, FIG. 15, FIG. 16, the furnace wall is composed of a membrane outer wall, and the pipe headers 81, 82 provided above and below the membrane outer wall and provided in the furnace The water pipe 80 is branched from the pipe heads 83, 84 (only in the example shown in FIG. 16), and the partition walls of the membrane walls are inclined and provided as reflective partitions 58 in the respective oblique lower portions.

The water pipe group shown in these drawings is bent at one place or two places so as to absorb thermal expansion, and since it is fixed by vertically moving pipes, it can sufficiently withstand the vigorous motion of the fluid medium. Further, since the vertical portion of the water pipe 80 is sufficiently long to penetrate the top of the fluidized medium, incombustibles will not be deposited on the upper inclined portion, and the passage resistance will be small,
In order to prevent clogging due to incombustibles and the like, it is preferable that the vertical portion of the water pipe 80 and the lower opening portion 63 of the heat recovery chamber 59 be staggered in a staggered manner as shown in FIG.

Further, as shown in FIG. 17, it is preferable that the heat transfer tubes 65 are similarly arranged in a staggered manner, and the air diffuser (air diffuser) 62 is
Instead of arranging in the lower part of the heat recovery chamber in parallel with the heat transfer tubes,
As shown in FIG. 13 to FIG. 16, it is preferable that the heat recovery chamber is provided in the lower part along the back surface of the reflective partition 58. By enlarging the gas ejection port near the gas introduction port of the air diffuser and gradually decreasing it toward the tip, it is possible to diffuse air substantially uniformly regardless of the depth of the fluid medium.

The lower end of the reflective partition 58 is preferably positioned at a portion outside the end of the dispersion plate 52 where the fluid medium is not in a violently flowing state. The reason is to prevent the heat recovery chamber from being affected by a violent fluidized bed, and to facilitate control of the sedimentation velocity of the fluidized medium in the heat recovery chamber.

Further, the mass velocity of the fluidizing gas from the lower part of the moving bed in the combustion section is 0.5 to 3 Gmf, preferably 1 to 2.5 Gmf, and 50% or less of the amount blown from the lower part of the fluidized bed is preferable.

Further, as shown in FIG. 13 and FIG.
When the combustion product is directly fed into the downward moving bed by
The supply of pulverized coal to the combustion products is continuous due to the scraping action of the fluidized medium, there is little air leakage from the supply device, the combustion efficiency of pulverized coal, etc. is high, and the flow in the furnace when the operation is stopped The medium does not leak or cut off the air, and the heat inside the furnace does not ignite the combustion products remaining in the supply section, which will burn the supply section. You don't have to close it with.

In addition, combustion products including oversized materials such as municipal waste and garbage are shown in Fig. 5,
As shown in Fig. 7, Fig. 12, Fig. 15 and Fig. 16, it is possible to operate without difficulty by inserting from the inlet provided on the ceiling, but when burning solid fuel such as coal of several tens of millimeters or less It is preferable to use a sprayer such as a type in which springs are blown off by rotating blades from a position higher than the fluidized bed surface on the side wall of the combustion section but lower than the surface of the fluidized bed on the side wall of the combustion section.

Therefore, when it is used as a furnace for burning solid fuel such as coal,
It is possible to use only the above-mentioned spreader without providing the ceiling charging port, and it is also possible to charge the combustion products containing coarse particles from the charging port of the ceiling and to supply the solid fuel from the above-mentioned spreader for co-firing.

In the swirling-flow type fluidized bed boiler having the heat recovery chamber described above, the heat recovery amount can be controlled by controlling the ventilation amount of the air diffuser. As a part of the utilization of the heat recovery chamber, the steam is passed as a heat receiving fluid through at least a part of the heat transfer chambers in a part of the divided heat recovery chamber, and the downstream side of the heat recovery chamber of the steam. The amount of gas supplied to the air diffuser is adjusted according to the temperature, and the amount of gas supplied to other air diffusers is predetermined by adjusting the amount of gas supplied to the air diffuser based on the fluidized bed temperature. We proposed a steam temperature raising device for a fluidized bed boiler that obtains superheated steam at the temperature of 10 ℃ and controls the temperature of the fluidized bed at a constant temperature.
-159707).

That is, this device will be described with reference to FIG.

In FIG. 30, the bottom of the furnace 1 is provided with a dispersion plate 2 for fluidizing gas introduced from a flow gas introduction pipe 3 by a blower 7, and this dispersion plate 2 is shown in FIG. Similarly, it is formed in a roof shape that is substantially symmetrical with respect to the center of the furnace 1. The flowing gas sent from the blower 7 is adapted to be jetted upward from the dispersion plate 2 via the air chambers 4, 5 and 6, and the fluidizing gas of the jetted from the air portions 4 and 6 on both side edges is generated. The mass gas velocity (the mass gas velocity 1 is the minimum amount of air required to fluidize the fluidized medium) is a velocity sufficient to form a fluidized bed of the fluidized medium in the furnace 1, but is ejected from the central portion 5. The mass velocity of the fluidizing gas is chosen smaller than the former.

At the upper portions of the air chambers 4 and 6 on both side edges, the upward passage of the fluidizing gas is blocked, and the fluidizing gas blown out from the air chambers 4 and 6 is reflected and diverted toward the center of the furnace 1. A reflection wall partition 8 is provided, and a swirl flow in the same direction as the direction shown by the arrow in FIG. 5 is generated due to the difference between the reflection wall partition 8 and the mass velocity of the fluidizing gas ejected. On the other hand, a circulating layer portion (heat recovery portion) 9, 9'for the fluidized medium is formed between the reflective partition 8 and the furnace wall, and a part of the fluidized medium exceeds the upper end portion of the reflective partition 8 during operation to circulate the circulating layer portion. Go into 9,9 '. Further, at a level higher than the bottom of the circulating layer section 9, 9 ', the blower 10 introduces the introduction pipes 11, 11'.
Air diffusers 12 and 12 'for introducing gas through the are installed obliquely along the back surface of the reflective partition, and on the introduction pipes 11 and 11' for controlling the amount of diffused air introduced into the diffuser. Flow control dampers 24, 24 'are provided. Further, openings 13 and 13 'are provided in the circulation layer portions 9 and 9'in the vicinity of the air diffusers 12 and 12', so that the fluidized medium that has entered the circulation layer portions 9 and 9'depends on the operating condition. The sediment continuously and intermittently forms a moving bed and circulates through the openings 13 and 13 'to the combustion section.

In addition, the waste heat boiler 17 is connected to the circulation layer parts 9 and 9'through pipes 14 and 20.
Heat transfer tubes 15 and 15 'through which steam and heating boiler water pass are arranged inside the communicating with the above, and by exchanging heat with the flowing medium moving downward in the circulation layer part, superheated steam is obtained from the pipe 14'. The boiler water, which is more heated than the pipe 20 'and contains the generated steam, is circulated to the waste heat boiler 17 to recover heat.

Then, the temperature of the steam extracted from the pipe 14 'is measured by the temperature measuring device 21, and the temperature controller 22 adjusts the opening of the flow rate adjusting damper 24 based on this temperature to adjust the flow rate of the fluidizing gas in the circulation layer. Is adjusted to control the temperature of the superheated steam to a predetermined temperature. That is, when the temperature of the superheated steam is lower than the predetermined temperature, the opening degree of the flow rate adjusting damper 24 is increased, and the amount of diffused air to the circulation layer is usually increased within the range of Gmf 0.5 to 3 to make the fluid medium. The temperature of the superheated steam can be raised to a predetermined temperature by increasing the circulation amount and the heat transfer coefficient to increase the heat recovery amount. When the temperature of the superheated steam is higher than the predetermined temperature, the control is reversed to the above.

On the other hand, the temperature of the main combustion part of the fluidized bed is an optimum temperature of the combustion part, for example, 600 ° C to 800 ° C in the case of municipal waste, 800 ° C to 850 ° C in the case of coal and coke, or a constant temperature within a certain range When the temperature is lower than the range, the temperature controller 26 reduces the opening of the flow rate adjustment damper 27 based on the temperature measured by the temperature measuring device 25 in the main combustion section of the fluidized bed to reduce the amount of air diffused into the circulating layer. As a result, the flow medium circulation amount is reduced and the heat transfer coefficient is reduced, so that the heat recovery amount is reduced and the temperature of the main combustion section of the fluidized bed is controlled to rise. Also, when the temperature of the main part of the fluidized bed rises above a predetermined temperature, it is controlled in the opposite way to avoid troubles such as the temperature of the fluidized medium rises above the prescribed temperature and the fluidized medium is sintered. To do.

[Problems to be solved by the invention]

In the steam temperature raising device shown in Fig. 30, since the steam superheater (or steam reheater) and the evaporator are installed in the same furnace, changes in the recovered heat of the superheater or reheater are evaporated. Since it needs to be absorbed by the evaporator, the load on the evaporator increases, and since the amount of recovered heat is adjusted by the evaporator, only about half of the amount of recovered heat can be used for raising the temperature of steam (overheating or reheating).

There is a limit to the amount of heat recovery in the formation, and if the steam superheat temperature rises or the steam reheat temperature rises, the amount of heat will be insufficient, so unless the gas superheater 18 shown in FIG. 30 is used together. However, the advantage of eliminating this gas type superheater is lost.

The temperature of the heat transfer surface of the steam superheater or reheater is higher than that of the evaporator, and when the steam outlet temperature is high,
Since the heat transfer surface of the superheater or reheater enters the high temperature corrosion area due to Cl, Na, K, SO ₄ groups, etc. (area of about 300 ° C or more in Fig. 3), waste containing these components should be collected. In the case of fuel, it was necessary to use high nickel-corrosion-resistant nickel-chromium alloy as the material of the heat transfer surface.

[Structure of Invention]

The present invention provides a boiler for solving the above problems and a control device for efficiently operating the boiler, wherein: 1. Air for ejecting fluidizing gas upward from the furnace bottom. A gas which is provided with one or more sets of dispersion plates and which blocks the upward passage of the fluidizing gas above the end of the air dispersion plate and which does not block the upward passage of the fluidizing gas. By providing a reflective partition for diverting and reflecting toward the upper part of the jet part, a moving bed in which the fluidized medium settles in a fixed bed or fluidized bed state is formed at the upper part of the jet part where the upward flow path is not blocked, and The fluidized medium is actively fluidized in the upper portion in the vicinity of the jetting portion where the countercurrent flow path is blocked, and the fluidized medium in this portion is swirled toward the upper portion of the moving bed by the action of the reflective partitioning to form a swirl type fluidized bed. Formation In addition, a heat recovery chamber is formed between the reflective partition back and the furnace wall or between the reflective partition back and the reflective partition back, and part of the fluidized medium enters the heat recovery chamber beyond the upper part of the reflective partition during operation. And a ventilation gas diffuser for changing the fluidized medium in the heat recovery chamber in the range from a fixed bed to a weak fluidized bed in the lower part of the heat recovery chamber and on the back side of the reflective partition, Two swirl flow type fluidized bed boilers are provided with an opening communicating with the upper part of the furnace bottom at the bottom of the recovery chamber and a heat recovery chamber having a heat transfer surface for passing a heat receiving fluid inside the heat recovery chamber. The heat recovery part of is a liquid heater for generating steam in the steam drum, and the heat recovery part of the other furnace 1'passes the steam generated in the steam drum or the low temperature steam recovered from the turbine etc. Steam to generate superheated steam Superheater and / or double bed revolving flow-type fluidized-bed boiler and the steam reheater.

2. In the multi-bed swirl flow type fluidized bed boiler according to the above-mentioned item 1, the steam that detects the outlet steam temperature of the steam superheater and / or the steam reheater and outputs a steam temperature signal corresponding to the steam temperature. A temperature detecting means and means for controlling the amount of combustibles supplied to the fluidized bed combustion section of the boiler 1'having the steam superheater and / or the steam reheater in response to the steam temperature signal; Steam pressure detecting means for detecting the steam pressure of the water drum and outputting a steam pressure signal corresponding to the steam pressure, and controlling the amount of combustible material supplied to the fluidized bed combustion section of the boiler 1 in response to the steam pressure signal. And a fluidized bed swirl type fluidized bed boiler.

3. In the multi-bed swirl flow type fluidized bed boiler according to the above-mentioned item 1, the steam that detects the outlet steam temperature of the steam superheater and / or the steam reheater and outputs a steam temperature signal corresponding to the steam temperature. A fluid medium which detects the fluid medium temperature of the fluidized bed combustion section of the boiler 1'having a temperature detecting means and a vapor superheater and / or a vapor reheater, and outputs a fluid medium temperature signal corresponding to the fluid medium temperature. Temperature detecting means, means for controlling the supply amount of combustible material supplied to the boiler 1'based on the steam temperature signal and the set temperature of the fluid medium temperature setting device of the boiler 1 ', and the fluid medium temperature signal based on the means. And a means for controlling the aeration rate of the diffused gas to the heat recovery section of the boiler 1 ', and further, a steam pressure for detecting the steam pressure of the steam drum and outputting a steam pressure signal corresponding to the steam pressure. The detection means and the steam generator And a fluid medium temperature detecting means for detecting a fluid medium temperature of the boiler 1 and outputting a fluid medium temperature signal corresponding to the temperature of the fluid medium, and further, based on the vapor pressure signal, fluid medium temperature setting of the boiler 1 And a means for controlling the amount of combustible material supplied to the boiler 1 based on the steam pressure signal, and a means for controlling the set temperature of the boiler to the heat recovery section of the boiler 1 based on the fluidized bed medium temperature signal. A multi-bed swirl type fluidized bed boiler equipped with a means for controlling the flow rate of the air gas.

4. In the multi-bed swirl flow type fluidized bed boiler according to the first or third aspect, a steam pressure detecting means for detecting the steam pressure of the steam drum and outputting a steam pressure signal corresponding to the steam pressure. In addition, a vaporization amount detection means for detecting the flow rate of the vapor supplied from the steam drum and outputting a signal corresponding to the vapor amount is provided, and the combustible material to the boiler 1 is based on the vapor pressure signal and the vaporization amount signal. A multi-bed swirl type fluidized bed boiler equipped with means for controlling the supply amount.

And 5. In the compound bed swirl flow type fluidized bed boiler according to the above-mentioned item 1, item 2, item 3 or item 4, the amount of combustible material supplied to the boiler 1 and / or 1'is further detected. However, a multi-bed swirl flow type provided with means for controlling the amount of combustion air supplied to the boiler 1 and / or 1'on the basis of the combustible material supply amount signal which outputs a signal corresponding to each supply amount. It is a fluidized bed boiler.

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view showing an embodiment of the present invention, in which swirl flow type fluidized bed boilers 1 and 1'having heat recovery chambers 9 and 9 ', respectively, are provided. The movement of the fluidized bed, the heat recovery chamber, etc. are as described above, but in the present invention, the can water is supplied from the water / water drum 19 through the pipe 20 into the heat transfer pipe 15 of the heat recovery unit 9 of the furnace 1. After being heated and heated, it is circulated to the steam / water drum 19 through the pipe 20 'to generate steam. The heat transfer tube 15
Since the canned water is supplied to the inside as described above, its heat transfer surface is not exposed to high temperatures. Therefore, the fuel supplied to the furnace 1 via the fuel supply device 17 is Cl, Na, K, SO. _It does not matter if you supply municipal waste with high content such as ₄ units. Therefore, the furnace 1 can be used as a refuse-only firing furnace or a mixed firing furnace for refuse and coal.

In addition, part or all of the can water supplied to the heat transfer tube of the heat recovery unit 9 may be replaced with boiler water supply.

Next, the steam generated in the steam / water drum 19 is supplied to the heat transfer pipe 15 'of the heat recovery section 9'of the furnace 1'through the pipe 14, becomes superheated steam, and is drawn out via the pipe 14'. When generating high temperature steam, the heat transfer tube 15 'is exposed to relatively high temperature,
As the fuel supplied from the fuel supply device 17 'to the furnace 1', it is preferable to supply coal or the like having a low content of Cl, Na, K, SO ₄ groups and the like that cause high temperature corrosion. By doing so, it is not necessary to use an expensive alloy containing Ni and Cr as the material of the heat transfer tube 15 '.

Next, a method for controlling the boiler shown in FIG. 1 will be described.

First, regarding the boiler 1, a steam withdrawal pipe of the steam drum 1
The steam pressure detector 23 is provided on 14 and the steam pressure signal from the steam pressure detector is compared with the set value in the pressure controller 31,
The comparison value and the steam flow rate signal from the steam flow rate detector 14a provided on the steam withdrawal pipe 14 are input to the calculator 34, and the calculation is performed when the steam output and the steam flow rate are lower than a predetermined value. Based on the control, the number of revolutions of the motor 16 of the combustion material supply device is increased to increase the fuel supply amount, and when the steam pressure and the steam flow rate are larger than a predetermined value, the fuel supply amount becomes small based on the calculated value. To control. In this case, when the required control accuracy may be low, the control may be performed only by the vapor pressure.

Further, the steam pressure detector 23 may be provided directly on the steam drum 1.

On the other hand, the comparison value of the pressure from the pressure controller 31
Input to 32 and change the setting value of comparator 32. That is, for example, when the pressure detected by the pressure detector 23 is higher than a predetermined value, the set value of the comparator 32 is increased, and the temperature signal is compared with the temperature signal from the temperature detector 25 in the fluidized bed. And the set value are compared with each other, and based on the comparison signal, the diffuser air flow rate controller 33 to the heat recovery unit 9 controls the valve 11a on the diffuser air inlet pipe.
Is controlled so that the amount of diffused air from the diffuser pipe 12 is small and the amount of heat recovered in the heat recovery unit 9 is small. Further, when the pressure detected by the pressure detector 23 is lower than the predetermined value, the control opposite to the above case is performed to control the heat recovery amount in the heat recovery unit 9 to be large, and the evaporation amount of water. Is set to a large value, and the steam pressure drawn from the steam drawing pipe of the steam / water drum 1 is controlled to be large.

Next, the control of the swirling type fluidized bed boiler 1'where the heat recovery unit is a steam heater (or a steam reheater) will be described.

In controlling the boiler, the temperature of the steam temperature detector 21 provided on the extraction pipe 14 'of the steam heated by the heat transfer pipe 15' of the heat recovery unit of the fluidized bed boiler 1'through the steam introduction pipe 14 The signal is compared with a set value in the temperature controller 31 ', and the comparison value and the steam flow rate detector 14a provided on the steam drawing pipe 14 are compared.
The steam flow rate signal is input to the calculator 34 'to perform the calculation, and when the steam temperature and the steam flow rate are lower than a predetermined value, the rotation speed of the motor 16' of the fuel supply device 17 'is controlled based on the calculated value. Then, the supply amount of fuel such as coal is adjusted. That is, when the steam temperature and the steam flow rate are lower than a predetermined value, the rotation speed of the motor 16 'of the fuel supply device 17' is increased to increase the fuel supply amount based on the calculated value. Is higher than a predetermined value, the number of revolutions of the motor 16 'of the fuel supply device 17' is reduced based on the calculated value, and the fuel supply amount is controlled to be small.

In this case, when the required control accuracy may be low, the control may be performed based on only the steam temperature.

On the other hand, the comparison value from the temperature controller 31 'is input to the comparator 32' to change the set value of the comparator 32 '. That is, for example, when the temperature detected by the steam temperature detector 21 is higher than a predetermined value, the comparator 32 'based on the signal from the temperature controller 31'.
Is set to a large value and compared with the temperature signal from the temperature detector 25 'in the fluidized bed of the fluidized bed boiler 1', the temperature signal is compared with the set value, and based on the comparison signal. The diffuser air flow controller 33 'in the heat recovery unit 9'controls the valve 11a' on the diffuser air introduction pipe 11 'in the closing direction to reduce the diffused air flow from the diffuser pipe 12' to reduce the amount of diffused air. Control is performed so that the steam recovery temperature is lowered by reducing the heat recovery amount in ′. Further, when the temperature detected by the steam temperature detector 21 is lower than a predetermined value, the control opposite to the above case is performed to control the heat recovery amount in the heat recovery unit 9'to be large, and the steam temperature Control to be high.

In the present invention, since the fluidized bed boiler 1 is controlled based on the pressure of the steam drawn from the steam / water drum, it is possible to prevent the pressure of the steam / water drum from exceeding a predetermined value, and the fluidized bed boiler 1'is Since control is performed based on the steam temperature,
It is possible to supply steam at the temperature desired by the user.

Next, a means for controlling the combustion air supplied from the lower part of the fluidized bed in accordance with the fuel supply amount in the control mechanism shown in FIG. 1 will be described with reference to FIG.

The means for controlling the combustion air is exactly the same as the means shown in FIG. 1 except that a means for controlling the combustion air is provided. Therefore, only the means for controlling the combustion air will be described.

As described above, the combustion material supply amount of the fluidized bed boiler 1 is controlled based on the calculated value output from the calculator 34,
In the apparatus shown in FIG. 2, the combustion air supply controller 35 controls the valve 37 on the combustion air pipe 3 based on the signal of the operation value from the operation device 35 to control the combustion material supply amount. The control is performed so as to supply a combustible air of a corresponding amount.

That is, when the steam pressure and the steam flow rate are lower than a predetermined value, the rotation speed of the motor 16 of the fuel supply device is increased based on the calculated value output from the calculator 34, and the fuel supply amount is increased. A combustion air amount controller 35 based on the calculated value
Thus, the valve 36 on the combustion air pipe is controlled in the opening direction to supply the combustion air in an amount commensurate with the fuel supply amount. When the steam pressure and the steam flow rate are higher than the predetermined values, the control opposite to the above is naturally performed.

By controlling the combustion air according to the fuel supply amount,
It is possible to operate with a constant air ratio in the fluidized bed, which enables low air operation and high desulfurization / denitration efficiency.

The amount of combustion air supplied to the fluidized bed boiler 1'is also controlled in exactly the same manner as the fluidized bed boiler 1 except that the control is performed based on the temperature signal on the steam extraction tube.

Incidentally, FIG. 5, FIG. 7, FIG. 12, FIG. 13, FIG. 14, and FIG.
The swirling type fluidized bed boiler shown in FIGS.
As described with reference to FIGS. 2 and 2, the same operation can be performed by providing two boilers. In this case, it is advisable to provide one steam recovery drum and one heat recovery device from the combustion gas.

[Brief description of drawings]

FIG. 1 is a schematic view showing a multi-bed swirl flow type fluidized bed boiler of the present invention and a means for controlling a combustion product (fuel) supply amount and diffused air, and FIG. 2 is further shown in the apparatus shown in FIG. A schematic diagram showing a multi-bed type swirling flow type fluidized bed boiler of the present invention in which a combustion air supply amount control means is added according to a combustion product (fuel) supply amount,
Fig. 3 shows the change in corrosion rate of the heat transfer tube in the heat recovery zone of the furnace due to temperature, and Fig. 4 shows the fluidized mass velocity (Gm
f), heat transfer coefficient and wear rate, FIG. 5 and FIG. 7 are swirl flow type fluidized bed heat recovery apparatus and an overall longitudinal sectional view showing one embodiment, and FIG. A-A in the boiler room in the figure
Fig. 8 shows the flow of air in the heat recovery chamber (Gm
Fig. 9 is a diagram showing the relationship between f) and the circulating amount of the fluid medium circulated in the heat recovery chamber, Fig. 9 is a diagram showing the relationship between the diffused gas flow rate (Gmf) in the heat recovery chamber and the descending moving bed sedimentation velocity, The figure is a cross-sectional view for explaining the partition provided in the opening at the bottom of the heat recovery chamber.
FIG. 11 is a view taken along the line DD in FIG. 10, and FIGS.
FIG. 14, FIG. 15, FIG. 15 and FIG. 16 are overall sectional views showing other embodiments of the swirling type fluidized bed heat recovery apparatus, respectively, and FIG. 17 is shown in FIG. 13 to FIG. Drawing for explaining the heat transfer tube and the air diffuser of the heat recovery chamber in the embodiment, FIG. 18 is a drawing for explaining the vertical portion of the water tube, and the arrangement of the openings, FIG. 19, FIG. 20 and FIG. FIG. 21 is a drawing for explaining the installation state of the air diffuser and the state of the opening of the gas jet port provided in the air diffuser, and FIGS. 22, 23 and 24 are respectively 19th and 19th drawings. Gas mass velocity from opening B and opening A when an air diffuser as shown in FIGS. 20, 20 and 21 is provided,
Drawing showing the relationship of gas mass velocity from B and C, Fig. 25,
FIGS. 26 and 27 are drawings showing the correlation of the mass velocity of the gas ejected from each ejection port when the air diffuser as shown in FIG. 19, FIG. 20 and FIG. 21 is provided, respectively. FIG. 28 shows the relationship between the average air diffused gas mass velocity and the average heat transfer amount when the air diffuser is provided horizontally and the jet ports are evenly provided, and when the air diffuser as shown in FIG. 21 is provided. 29 is a drawing showing the relationship between the average diffused gas amount of the heat recovery chamber and the heat transfer coefficient, and FIG. 30 is a drawing for explaining the case where the heat recovery part is divided into two parts for use. Is. 1,51 …… Furnace, 2,52 …… Dispersion plate, 4,5,6,54,55,56,56 ′…
… Air chamber, 8,58 …… Reflection wall partition, 9,59 …… Circulation layer part (heat recovery part), 12,12 ′, 62 …… Aeration device, 13,63 …… Opening part, 15,15 ′, 65 …… Heat transfer tube, 19,67 …… Air-water drum, 23
...... Pressure detector, 21,25,25 '…… Temperature detector, 23 …… Steam pressure detector, 31 …… Pressure controller, 31 ′ …… Temperature controller, 32,32 ′ …… Comparator, 33,33 ′ …… Aeration air flow controller,
34,34 ′ …… Calculator, 35,35 ′ …… Combustion air flow controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Kosugi 11-1 Haneda-Asahicho, Ota-ku, Tokyo Ebara Corporation (72) Inventor Naoki Inumaru 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo (56) References JP-A-53-31001 (JP, A) JP-A-62-196522 (JP, A)

Claims (5)

[Claims] 1. A single or two or more sets of air dispersion plates for ejecting the fluidizing gas upward from the bottom of the furnace are provided, and an upward passage of the fluidizing gas is provided above the end of the air dispersion plate. By blocking the fluidized gas, the upward flow path is directed to the upper part of the gas ejection part where the upward flow path is not obstructed, and a reflective partition is provided to turn the upward flow path to the upper part of the ejection part where the upward flow path is not obstructed. The medium forms a fixed bed or a moving bed that sinks in a fluidized bed state, and the fluidized medium is actively fluidized in the upper part in the vicinity of the jetting part that is blocked by the upward flow path, and due to the action of the reflective partition, A swirl type fluidized bed is formed by swirling a fluidized medium toward the upper part of the moving bed, and a heat recovery chamber is formed between the reflective partition back and the furnace wall or between the reflective partition back and the reflective partition back. Medium fluid medium A part is configured to enter the heat recovery chamber beyond the upper part of the reflective partition, and the fluidized medium in the heat recovery chamber is located in the lower part of the heat recovery chamber and on the rear side of the reflective partition in the range from the fixed bed to the weak fluidized bed state. In addition to providing a gas diffuser for ventilation for changing the temperature, a heat recovery chamber is provided in the lower part of the heat recovery chamber that opens above the furnace bottom, and a heat recovery chamber that has a heat transfer surface through the heat receiving fluid Two swirling flow type fluidized bed boilers are provided, and the heat recovery part of one of the furnaces (1) is a liquid heater for generating steam in a steam / water drum,
A steam superheater and / or a steam reheater for generating superheated steam by passing through the heat recovery section of the other furnace (1 ') through the steam generated in the steam / water drum or the low temperature steam recovered from a turbine or the like. A multi-bed swirl type fluidized bed boiler. 2. A multi-bed swirling fluidized bed boiler according to claim 1, wherein the steam temperature corresponding to the steam temperature is detected by detecting the outlet steam temperature of the steam superheater and / or the steam reheater. A steam temperature detecting means for outputting a temperature signal and a boiler (1 ') equipped with the steam superheater and / or the steam reheater in response to the steam temperature signal are used to control the amount of combustibles supplied to the fluidized bed combustion section. Means for detecting the steam pressure of the steam drum and outputting a steam pressure signal corresponding to the steam pressure, and a fluidized bed of the boiler (1) in response to the steam pressure signal. A multi-bed type swirling flow type fluidized bed boiler provided with means for controlling the amount of combustibles supplied to the combustion section. 3. A multi-bed swirl type fluidized bed boiler according to claim 1, wherein the steam temperature corresponding to the steam temperature is detected by detecting the outlet steam temperature of the steam superheater and / or the steam reheater. A steam temperature detecting means for outputting a temperature signal and a fluid medium temperature of a fluidized bed combustion section of a boiler (1 ′) equipped with a steam superheater and / or a steam reheater are detected to detect a fluid flow corresponding to the fluid medium temperature. A fluid medium temperature detecting means for outputting a medium temperature signal, and based on the vapor temperature signal, a combustible material supply amount to be supplied to the boiler (1 ') and a set temperature of a fluid medium temperature setter of the boiler (1'). And a means for controlling the aeration rate of the gas for diffusion to the heat recovery section of the boiler (1 ′) based on the temperature signal of the fluidized medium, and further detecting the vapor pressure of the water-water drum. Outputs a steam pressure signal corresponding to the steam pressure The steam pressure detecting means and the fluid medium temperature detecting means for detecting the fluid medium temperature of the boiler (1) provided with the steam generator and outputting the fluid medium signal corresponding to the temperature of the fluid medium are further provided, and the vapor pressure is further provided. The fluidized bed is provided with means for controlling the set temperature of the fluid medium temperature setting device of the boiler (1) based on the signal, and means for controlling the supply amount of combustible material to the boiler (1) based on the steam pressure signal. A multi-bed swirl flow type fluidized bed boiler equipped with means for controlling the amount of gas diffused to the heat recovery section of the boiler (1) based on the medium temperature signal. 4. A multi-bed swirl flow type fluidized bed boiler according to claim 2 or 3, wherein the steam pressure of a steam drum is detected and a steam pressure signal corresponding to the steam pressure is output. In addition to the steam pressure detecting means, the evaporation amount detecting means for detecting the flow rate of the steam supplied from the steam drum and outputting a signal according to the steam amount is provided, and based on the steam pressure signal and the steam amount signal. A multi-bed type swirling flow type fluidized bed boiler provided with means for controlling the amount of combustible material supplied to the boiler (1). 5. The multi-bed swirl flow type fluidized bed boiler according to claim 2, 3, or 4, further comprising a combustible material for the boiler (1) and / or (1 '). A means for controlling the amount of combustion air supplied to the boiler (1) and / or (1 ′) based on the combustible material supply amount signal which detects the supply amount and outputs a signal corresponding to each supply amount. Multi-bed swirl type fluidized bed boiler.