JPH11237036A - Slurry supply nozzle and supply method of pressurized fluidized bed boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slurry supply nozzle that can suppress combustion at an upper portion of a layer by relaxing oxygen shortage near the nozzle in a flow layer and can prevent the wear of a nozzle tip part. SOLUTION: A nozzle for supplying CWP with dispersed air is constituted of a slurry conduit 31, a cooling water conduit 33, a cooling water return pipe 35, and an air conduit 37 that are arranged concentrically around it, a pipe edge member 39 in a conical trapezoid shape that is mounted to the tip of the slurry conduit 31 and the cooling water return pipe 35 and has an opening being connected to the inner diameter of slurry conduit 31 that is mounted to the tip of the slurry conduit 31 and the cooling water return pipe 35, and a nozzle tip 40 that is mounted to the tip of the air conduit 37 and has a recess in a conical trapezoid shape at a rear and an emission hole 42 at an axial center part. Also, a slit 41 of an annular section being formed between a nozzle chip 4 and the pipe edge member 39 is connected to an air channel 36, a conical angle is set to 75-105 deg., the convergence point of the slit 41 is located at the front end of or in front of the nozzle tip 40, and the diameter of the emission hole of the nozzle chip 40 is set to the same inner diameter of a slurry conduit exit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to combustion of coal in a pressurized fluidized-bed furnace, driving of a steam turbine by steam generated by a heat exchanger installed in the furnace, and combustion of coal. A coal / water slurry that supplies a mixed slurry of coal and water to the combustion furnace of a fluidized-bed boiler of a pressurized fluidized-bed boiler combined cycle power plant that drives a gas turbine with high-temperature, high-pressure combustion gas to obtain high-efficiency power Hereinafter, it may be simply referred to as a slurry).

[0002]

2. Description of the Related Art A pressurized fluidized-bed boiler can obtain energy from steam and high-pressure combustion gas generated therein, so that high-efficiency power generation is possible. However, it is important to continuously and stably supply solid coal particles into a pressurized fluidized bed furnace in a large amount. As a method of supplying coal to a fluidized bed furnace, there is a wet supply method (for example, JP-A-62-155433). As shown in FIG. 5, the wet feed method uses coal particles 116 having a maximum diameter of about 6 mm, water 114, and limestone 11 as a desulfurizing agent in the furnace.
5 is mixed and kneaded with a stirrer 117 to form a slurry 113 having a water content of about 25%. The slurry 113 is temporarily stored in a tank 121 with a stirrer 122, and then pressurized by a pump 126 to flow through a slurry supply pipe 127. The slurry is supplied from a slurry supply nozzle 110 (hereinafter, may be simply referred to as a nozzle) inserted and installed in the bed furnace 101 to the fluidized bed 109 of the fluidized bed furnace 101 by dispersion air 51 and supplied.
When the supply of the slurry 113 to the fluidized bed furnace 101 is stopped, the switching valve 123 connects the flow path to the conduit 12.
8 and circulates through the tank 121.

In FIG. 5, a fluid medium 1 in a fluidized bed 109 is shown.
Numeral 02 is fluidized by the combustion air 107 uniformly supplied to the cross section by the air distribution plate 112 at the bottom of the furnace, and the heat transfer tube 105 is installed in the fluidized bed 109 so that the steam 1
Generates 11. At the outlet of the furnace 101, a dust removing device 103 for removing ash in the combustion gas is installed, and the removed combustion gas 108 is supplied to a gas turbine (not shown).
Fluidized bed furnace 101 is housed in a pressurized vessel 104 and receives pressurized air 106 from an air compressor driven by a gas turbine.
Is maintained under pressure.

In a pressurized fluidized-bed boiler using the above-mentioned wet feed system, a slurry feed nozzle 110 has been conventionally provided with a slurry flow near a nozzle outlet for the purpose of dispersing the slurry in a fluidized bed with a relatively small amount of dispersed air. A structure in which the cross section of the road is reduced in the direction of the slurry outlet and outlet is used. For example, in Japanese Patent Laid-Open Publication No. Hei 6-510847, a taper that becomes gradually narrower near the nozzle outlet in the vicinity of the nozzle outlet of the slurry supply conduit is provided near the nozzle outlet, and is further directed toward the nozzle outlet. A nozzle having a dispersed air supply jet is disclosed.
In Japanese Patent Application Laid-Open No. 6-317309, the center angle near the nozzle outlet, which gradually narrows toward the nozzle outlet, is set to 3 degrees.
It is shown that the angle is set in the range of 5 ° to 45 °.

On the other hand, the present inventors have found that a structure that does not reduce the cross section of the slurry flow passage is effective in suppressing the wear of the slurry ejection hole near the nozzle outlet. A plurality of dispersing air ejection holes for dispersing a certain structure and a coal slurry fuel (hereinafter abbreviated as CWP) are provided on a circumferential wall of a slurry conduit near a nozzle outlet, and a direction of ejection of the dispersing air from the ejection holes is a slurry. Japanese Patent Application Laid-Open No. 5-18512 discloses a structure in which an angle is set so as to form a swirling flow in a conduit.

[0006]

The coal particles in the slurry supplied into the fluidized bed 109 of the fluidized-bed furnace 101 flow through the bed together with the fluidized medium 102 while the air dispersion plate 1
Although the combustion air is uniformly supplied to the section from the combustion section 12, the combustion air is uniformly supplied to the section, whereas the slurry has a limited number of supply nozzles, and the coal particles flow. Even though combustion is performed while dispersing and flowing in the bed, conventionally, the concentration of coal present in the vicinity of the slurry supply nozzle with respect to the combustion air is high, and oxygen tends to be insufficient. As a result, the pulverized coal or the volatile matter released from the coal, which is easily scattered, flows out to the upper part of the fluidized bed 109 and burns in the upper part of the furnace 101 without burning, and the combustion gas temperature rises above the limit temperature. There was a problem to do.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a slurry supply nozzle which alleviates a shortage of oxygen in the vicinity of a slurry supply nozzle in a fluidized bed, suppresses combustion at an upper portion of the bed, and further prevents wear of a tip for ejecting slurry. Is to provide a structure.

[0008]

Means for Solving the Problems As a result of intensive studies and investigations to solve the above-mentioned problems, it was found that by increasing the amount of dispersed air in a slurry supply nozzle for dispersing slurry in a fluidized bed furnace, It has been found that oxygen deficiency in the vicinity of the slurry supply nozzle is alleviated, and combustion in the upper part of the fluidized bed is suppressed. That is, the above problem can be solved by supplying a dispersing air amount of 0.1 to 0.4 kg / kg, preferably 0.2 to 0.3 kg / kg, relative to the slurry flow rate to be supplied. I found it.

However, experiments have shown that when a slurry is supplied at the above-described supply ratio using a conventional slurry nozzle having a reduced front end flow path cross section, excessive wear occurs at the flow path cross section reduced portion. Also, by the structure of the inventors not reducing the cross section of the slurry flow path,
In the structure in which a plurality of CWP dispersed air ejection holes are provided in the circumferential wall of the slurry conduit in the swirling direction, the air ejection speed becomes excessive and the swirling air flow wears the peripheral wall of the slurry conduit excessively. Was.

The present invention relates to a structure of a slurry supply nozzle which hardly causes abrasion even at the above preferable air ratio of dispersed air, and the first slurry supply nozzle for a pressurized fluidized bed boiler of the present invention (sometimes a slurry supply nozzle). Supply nozzle)
The diameter of the nozzle tip is the same as the diameter of the slurry conduit reaching the tip of the nozzle, and the ejection port of the CWP dispersed air to the slurry conduit is constituted by a slit having an annular cross section formed by the nozzle tip and the pipe end member of the cooling water conduit, The direction in which the dispersed air is ejected from the annular slit is tapered and conical and ranges from 105 degrees to 75 degrees starting from the tip point of the nozzle or its downstream point on the center line of the nozzle. .

A second slurry supply nozzle for a pressurized fluidized bed boiler according to the present invention comprises: a slurry conduit; a cooling water conduit, a cooling water return pipe, and an air conduit which are sequentially and concentrically arranged around the slurry conduit. A frusto-conical tube-end member attached to the tip of the slurry conduit and the cooling water return tube and having an opening at the shaft center and continuing to the inside diameter of the slurry conduit; and a tapered cone of the tube-end member attached to the tip of the air conduit and attached at the rear. A nozzle tip having a depression similar to a trapezoid and having an opening in the axial center portion, and a slit having an annular cross section formed between the nozzle tip and the pipe end member is formed between the cooling water return pipe and the air conduit. The conical angle of the frusto-conical shape is set to 75 to 105 °, and the convergence point of the annular slit is positioned at the tip or front of the nozzle tip. Characterized in that the same as the inner diameter of the conduit outlet.

A third slurry supply nozzle for a pressurized fluidized bed boiler according to the present invention comprises a slurry conduit, an air conduit, a cooling water conduit, and a cooling water return conduit which are sequentially and concentrically arranged around the slurry conduit. A frusto-conical tube end member attached to the tip of the slurry conduit and having an opening at the shaft center following the inner diameter of the slurry conduit, and a tapered frusto-conical tube end member attached to the ends of the air and drain conduits at the rear. And a nozzle tip having an opening similar to that of the nozzle tip and having an opening at the axial center thereof, and a slit having an annular cross section formed between the nozzle tip and the pipe end member. The conical angle of the frustoconical shape is set to 75 ° to 105 °, and the convergence point of the slit having the annular cross section is positioned at the tip or front of the nozzle tip. Opening hole of the axial center is characterized by the same as the inner diameter of the slurry conduit outlet.

[0013] In each of the first to third slurry supply nozzles, the inner diameter of the tip of the slurry conduit may be tapered.

The slurry supply method for a pressurized fluidized-bed boiler according to the present invention employs any one of the slurry supply nozzles described above, and the dispersion air flow rate to the coal slurry fuel flow rate is 0.1 to 0.4 by weight. It is characterized by the following.

Hereinafter, the operation of the slurry supply method and slurry supply nozzle of the present invention will be described. In the slurry supply method, the flow rate of the slurry-dispersed air is increased to increase the supply ratio to the slurry supply flow rate to 0.1 to 0.1 in comparison with the conventional method.
By setting the pressure in the range of 0.4 kg / kg, preferably 0.2 to 0.3 kg / kg, oxygen deficiency around the slurry supply nozzle is reduced, and the coal particles in the fluidized bed and the volatile matter released from the coal are reduced. And the amount of unburned coal or unburned gas scattered on the fluidized bed is reduced. On the other hand, the oxygen concentration distribution on the furnace plane is made more uniform, and the combustion of unburned components on the fluidized bed is suppressed.

However, the dispersion air supply ratio is 0.3 kg /
When the air velocity increases to above kg, the local air velocity near the slurry supply nozzle gradually increases, and the coal particles supplied from the nozzle become more violent in the vertical direction than in the horizontal direction, and conversely flow The amount of unburned coal or unburned gas scattered on the formation increases, and the degree of combustion on the formation increases.
From this viewpoint, the upper limit of the dispersion air supply ratio is 0.4 kg / kg.

In the slurry supply nozzle of the present invention,
By avoiding a structure in which a plurality of dispersed air jet holes of the conventional CWP are provided on the circumferential wall of the slurry conduit in the turning direction, a slit having an annular cross section formed between the nozzle tip and the pipe end member of the cooling water conduit is provided. In addition, since the area for ejecting air is increased, the speed of ejecting the dispersed air from the slit is reduced, and the ejected air for the dispersion is made to converge to the axis of the slurry conduit. There is no contact, and wear is suppressed.

Furthermore, the diameter of the nozzle tip is the same as that of the slurry conduit leading to the nozzle tip without reducing the cross section, and the dispersed air is injected from the annular cross-section slit formed between the nozzle tip and the pipe end member of the cooling water conduit. Since the angle is in the range of 105 to 75 degrees, preferably 90 degrees, starting from the nozzle tip point or the downstream point on the nozzle center line, the dispersed air from the dispersed air slit spreads Is generally said to be the jet divergence angle 1
Even when the angle is 4 degrees (one-sided angle), since the nozzle tip diameter is the same as the diameter of the dispersing air supply slit portion, the dispersing air does not directly contact the inner wall of the slurry conduit and does not cause abrasion. Further, the dispersing air ejection slit angle is set in the range of 105 to 75 degrees, preferably 90 degrees, starting from the nozzle tip point or the downstream point on the center line of the slurry ejection hole of the chip and on the center line of the nozzle chip. The length from the feed slit position to the nozzle tip is at most about the radius of the slurry conduit and short, and the coal particles in the slurry are at a speed that causes abrasion on the slurry conduit wall. Since it is fed into the furnace fluidized bed without being accelerated, it does not cause wear by the coal particles.

The dispersed air jet slit angle of 75 ° at the nozzle tip is about 14 ° (one-sided angle) at which the spread angle of the dispersed air is generally referred to as a jet spread angle, and the dispersed air is spread in the slurry jet hole. This angle does not cause wear on the wall of the slurry ejection hole even if it collides with the coal particles and rebounds. On the other hand, the upper limit of 105 degrees is an angle at which the dispersed air collides with the coal particles in the slurry ejection hole to effectively disintegrate the slurry into coal particles and supply and disperse the slurry into the furnace fluidized bed. When the temperature exceeds 105 degrees, it is effective for dismantling the slurry, but the effect of supplying and dispersing the slurry into the furnace layer is reduced, and the dispersion distance from the nozzle tip to the layer is shortened. From the above, it is necessary to prevent wear on the wall of the slurry discharge port, and to dismantle the slurry effectively and supply it into the furnace fluidized bed and disperse it as far as possible from the nozzle. Is 90 degrees.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a slurry supply nozzle according to the present invention will be described in detail with reference to the drawings. <First Embodiment> FIG. 1 is a configuration diagram of a slurry supply nozzle of a pressurized fluidized-bed boiler according to a first embodiment of the present invention.
The slurry supply nozzle generally includes a slurry conduit 31 that is located at the nozzle axis and conveys slurry, and a cooling water conduit 33 that is sequentially and concentrically disposed around the slurry conduit 31.
Cooling water return pipe 35, air conduit 37, and slurry conduit 3
1 and a frusto-conical frusto-conical tube end member 39 attached to the distal end of the cooling water return tube 35 and having a hole extending in the axial center thereof to the inside diameter of the slurry conduit 31; and an air conduit 37 located in front of the tube end member 39. The nozzle tip 40 has a concave portion similar to the above-mentioned tapered frustoconical shape attached to the front end, and has a slurry ejection hole 42 at an axial center portion.
A cooling water supply passage 32 is provided between the slurry conduit 31 and the cooling water conduit 33, a cooling water return passage 34 is provided between the cooling water conduit 33 and the cooling water return tube 35, and a cooling water return tube 35 and an air conduit 37 are provided. A dispersing air channel 36 is formed between them.

A recess connecting the cooling water supply passage 32 and the cooling water return passage 34 is formed at the rear of the tapered frustoconical tube end member 39. This recess is not necessary if the cooling water supply passage 32 and the cooling water return passage 34 are connected, for example, if the tip of the cooling water conduit 33 is shortened. The nozzle tip 40 and the pipe end member 39 form an annular cross-sectional flow path by a gap between the tapered frustoconical recess formed at the rear of the nozzle tip 40 and the tapered frustoconical tip of the pipe end member 39. , And these are referred to as dispersed air slits 41. The air slit 41 has a frustoconical cone angle of 75 to 10
5 °, and the convergence point of this annular slit is
The nozzle tip 40 is located on the axis of one or in front of the tip of the nozzle tip 40. The inside diameter of the nozzle tip 40 is the same as the inside diameter of the slurry conduit 31, and this hole becomes the slurry ejection hole 42.

The cooling water conduit 33 supplies the cooling water 53 to the supply passage 3
2 and the cooling water return flow path 34, and the tube wall temperature of the slurry conduit 31 is maintained at 60 ° C., preferably 50 ° C. or less, to prevent evaporation of water in the slurry. 54 is a cooling drain. The dispersing air conduit 37 transfers the slurry 113 supplied through the slurry passage 30 to the nozzle tip 4 at the tip thereof.
Dispersed air 5 for dispersion and supply in fluidized bed at 0
The slurry is ejected from the dispersed air ejection slit 41 into the slurry flow channel 30 to collide with the slurry 113 supplied through the flow channel 30, and the slurry is discharged from the slurry ejection hole 42 into the fluidized bed furnace 101. Is dispersed and supplied to the fluidized bed 109. Reference numeral 60 denotes a flange fixed to the dispersion air conduit 37 and for attaching the nozzle 110 to the fluidized-bed furnace 101. Numeral 61 designates the slurry conduit 31 as slurry 113
It is a flange for connecting with the mother pipe of the above.

FIG. 2 is an enlarged view of the tip of the nozzle, which is the main part of the present invention. A feature of the present invention is that the diameter of the slurry ejection hole 42 corresponding to the inner diameter of the tube end member 39 and the nozzle tip 40 is set to the same diameter as the slurry conduit 31. Further, the pipe end member 39 and the nozzle tip 40 form a dispersed air slit 41 that converges forward in the annular cross section, and the dispersed air ejection angle α from the annular slit formed by both ranges from 105 degrees to 75 degrees, Preferably 9
That is, it was set to 0 degrees. Furthermore, the dispersed air ejection angle α
Is provided on the center line 43 of the slurry ejection hole 42 of the nozzle tip 40 so as to be the tip point (P) of the nozzle or a downstream point thereof.

In the above configuration, the wall of the slurry conduit 31 is cooled to 60 ° C., preferably 50 ° C. or lower by the cooling water 53 and supplied. The temperature of the slurry 113 is prevented from rising and solidifying and closing. The dispersion air 51 reaches the dispersion air ejection slit 41 through the dispersion air conduit 36 and is ejected at the dispersion air ejection angle α formed by the pipe end member 39 and the nozzle tip 40, so that the supplied slurry 113 is effected by the dispersion air. At the same time, and simultaneously dispersed and supplied into the fluidized bed from the slurry ejection holes 42. In spite of the fact that the amount of dispersed air has increased compared to the prior art in order to suppress combustion on the fluidized bed, the inner wall of the slurry ejection hole 42 of the nozzle tip 40 does not wear out due to the effect of the present invention. High reliability is maintained at the same time as suppression of combustion.

Second Embodiment FIG. 3 shows a configuration of a slurry supply nozzle according to a second embodiment of the present invention. Here, the same parts as those in FIG. The difference from FIGS. 1 and 2 is that the cross section of the slurry flow channel 30 or the slurry conduit 31 at the center of the nozzle is reduced near the nozzle tip. In this case, too, the same as shown in FIG. In addition, the diameter of the slurry ejection hole 42 of the nozzle tip 40 is set to be the same as the diameter of the slurry conduit 31 after the cross section is reduced. Further, the jet angle α of the dispersed air from the annular slit formed by the pipe end member 39 and the nozzle tip 40 is in the range of 105 ° to 75 °, preferably 90 °, and is used for the jet of the dispersed air ejected in a tapered conical shape. The intersection point on the extension line of the nozzle tip 40 forming the ejection angle α is provided on the center line 43 of the slurry ejection hole 42 so as to be the tip point (P) of the nozzle or the downstream point thereof. According to the present invention, since the pipe diameter can be increased closer to the nozzle tip, the pressure loss generated in the slurry conduit can be reduced, and the slurry can be dispersed and supplied without being restricted by the diameter of the slurry ejection hole 42 to the diameter of the slurry conduit 31. Can be optimized and designed.

Third Embodiment FIG. 4 shows the structure of a slurry supply nozzle according to a third embodiment of the present invention. Here, the same parts as those in FIG. 1 and 2 is different from the slurry supply nozzle shown in FIGS. 1 and 2 in that the dispersion air flow path 36 is provided on the outer peripheral side of the slurry supply nozzle. In the dispersion air passage 36, the slurry conduit 3 at the center of the nozzle 3
1 is provided in the vicinity of the first. That is, from the center of the nozzle, the slurry flow path 30, slurry flow path 31, dispersion air flow path 36, dispersion air flow path 37, cooling water supply flow path 3
2. The cooling water conduit 33, the cooling water return flow path 34, and the cooling water return pipe 35 are constituted by concentric tubes in this order. The end of the cooling water return pipe 35 is closed by the nozzle tip 40.
The dispersion air conduit 37 has an annular dispersion air slit 41 formed at the pipe end by the nozzle tip 40 and the pipe end of the slurry conduit 31. Nozzle tip 4
0 is provided with a slurry outlet 42 having the same diameter as the slurry conduit 31. The jet angle α of the dispersed air ejected in a tapered conical shape formed by the dispersed air slit 41 having an annular cross section is in the range of 105 to 75 degrees, preferably 90 degrees, as in FIG. The ejection angle α is provided such that the tip point (P) of the nozzle or the subsequent flow point becomes the starting point on the center line 43 of the slurry ejection hole 42. According to the present invention, since the nozzle tip 40 and the cooling water conduit 33 can be maintained at a lower temperature by the cooling water, it is possible to provide a slurry supply nozzle that is elongated and has reduced thermal distortion.

[0027]

According to the present invention, oxygen deficiency in the vicinity of the slurry supply nozzle in the fluidized bed can be alleviated, combustion at the upper portion of the fluidized bed can be suppressed, and further, abrasion of the tip of the slurry supply nozzle can be achieved. , A stable and reliable pressurized fluidized bed combustion boiler can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a slurry supply nozzle according to Embodiment 1 of the present invention.

FIG. 2 is an enlarged view of a tip portion of a slurry supply nozzle according to the first embodiment.

FIG. 3 is a configuration diagram of a slurry supply nozzle according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a slurry supply nozzle according to a third embodiment of the present invention.

FIG. 5 is a supply system diagram of a coal / water slurry to a pressurized fluidized bed combustion furnace to which the slurry supply nozzle of the present invention is applied.

[Explanation of symbols]

 REFERENCE SIGNS LIST 30 slurry flow path 31 slurry conduit 32 cooling water supply flow path 33 cooling water conduit 34 cooling water return flow path 35 cooling water return pipe 36 dispersed air flow path 37 dispersed air conduit 39 pipe end member 40 nozzle tip 41 dispersed air slit 42 slurry Spouting hole 51 Dispersed air 101 Fluidized bed furnace 104 Pressurized vessel 109 Fluidized bed 110 Slurry supply nozzle 113 Coal / water slurry 114 Water 116 Coal 121 Slurry tank 126 Slurry pump

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Susumu Yoshioka, No. 3-36, Takara-cho, Kure-shi, Hiroshima Pref. Inside the Kure Research Laboratories, K.K. (72) Inventor Hiroshi Takezaki 3-36 Takara-cho, Kure-shi, Hiroshima Prefecture Babcock Hitachi Co., Ltd. (72) Inventor Yoshinori Otani 3-36 Takara-cho, Kure-shi, Hiroshima Babcock-Hitachi Research Co., Ltd. In-house (72) Inventor Teruhumi Kawasaki 6-9 Takaracho, Kure City, Hiroshima Prefecture Inside the Babcock Hitachi Kure Factory (72) Inventor Kodai 6-9 Takaracho Kure City, Hiroshima Prefecture Inside the Babcock Hitachi Kure Factory

Claims (5)

[Claims] 1. A nozzle tip is disposed at a tip of a slurry pipe whose periphery is water-cooled, and air is jetted from an air flow path formed on an outer peripheral portion of the nozzle tip to disperse coal slurry fuel conveyed through the slurry pipe. In the slurry supply nozzle to be supplied to the pressurized fluidized bed boiler, the nozzle tip forms a slit hole tapering in a circular cross section with a cone angle of 75 to 105 ° as an air flow passage in the outer peripheral portion thereof, A slurry for a pressurized fluidized bed boiler, characterized in that the convergence point of the hole is located at the tip or forward of the nozzle hole of the nozzle tip on the axis of the slurry conduit, and the nozzle hole has the same inner diameter as the outlet of the slurry conduit. Feed nozzle. 2. A nozzle for dispersing coal slurry fuel by dispersing air and supplying it to a pressurized fluidized bed boiler, comprising: a slurry conduit; a cooling water conduit which is sequentially and concentrically arranged around the slurry conduit; A return pipe and an air conduit, a tapered frusto-conical pipe end member attached to the tip of the slurry conduit and the cooling water return pipe and having an opening at an axial center and continuing to the inside diameter of the slurry conduit; and a rear end attached to the tip of the air conduit. A nozzle tip having a recess similar to the tapered frusto-conical shape of the pipe end member and having an opening in the axial center portion, and cooling the slit having an annular cross section formed between the nozzle tip and the pipe end member. It is connected to the air flow path formed between the water return pipe and the air conduit, the frustoconical cone angle is set to 75 to 105 °, and the convergence point of the annular slit is located at the tip or front of the nozzle tip, Pressurized Doso slurry supply nozzle boiler, wherein the opening hole of Ruchippu is to be equal to the inside diameter of the slurry conduit outlet. 3. A nozzle for dispersing coal slurry fuel by dispersing air and supplying it to a pressurized fluidized-bed boiler, comprising: a slurry conduit; an air conduit and a cooling water conduit which are sequentially arranged concentrically around the slurry conduit. A cooling water return pipe, a tapered frustoconical pipe end member attached to the tip of the slurry conduit and having an opening at the shaft center and continuing to the inside diameter of the slurry conduit, and a pipe at the rear attached to the tip of the air conduit and the drainage conduit. A nozzle tip having a recess similar to the tapered frustoconical shape of the end member and having an opening in the axial center portion, and
A slit hole having an annular cross section formed between the nozzle tip and the pipe end member is connected to an air flow path formed between the slurry conduit and the air conduit, and the cone angle of the truncated cone is set to 75-1.
A pressurized fluidized-bed boiler wherein the convergence point of the slit of the annular cross section is set at the tip or forward of the nozzle tip, and the opening at the axis of the nozzle tip is the same as the inner diameter of the outlet of the slurry conduit. Slurry supply nozzle. 4. The slurry supply nozzle for a pressurized fluidized-bed boiler according to claim 1, wherein the inside diameter of the slurry conduit tip is a tapered hole. 5. The dispersion air flow rate to the flow rate of coal slurry fuel is 0.1% by weight using the slurry supply nozzle for a pressurized fluidized bed boiler according to claim 1.
A slurry supply method for a pressurized fluidized-bed boiler, wherein