JPH1182932A - Premix gas feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce premix gas having no unevenness in mixture and feed it to a premix gas combustion part for preventing the generation of a local high temperature part in a combustion area and realizing low p combustion. SOLUTION: Combustion air 92 supplied from a combustion air supply pipe 54a is divided into air 92a to be mixed and non-mixed air 92b by a distributing cylinder 54b. In the distributing cylinder 54b, gaseous fuel 91 is jetted and mixed with the air 92a to be mixed to obtain primary mixed gas 9, and a turning force is applied to the primary mixed gas by a swing vane 55b. The primary mixed gas 9 turning and flowing out of the distributing cylinder 54b is mixed with the non-mixed gas 92b passing outside the distributing cylinder 54b to obtain secondary mixed gas 9. This secondary mixed gas is mixed together while it passes through a meandering secondary mixing passage 56b, the mixture is rectified by a rectifying plate 56c, a turning force is applied to the rectified mixture by a swing vane 57c, and the mixture is further mixed and stirred to obtain premix gas 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a premixed gas which is configured to mix a gaseous fuel and combustion air and to supply the mixed gas as a mixed gas to a predetermined premixed gas combustion section. The present invention relates to a supply device.

[0002]

2. Description of the Related Art As a conventional premixed gas supply apparatus of this type, generally, at a downstream portion of a gas passage connected to a premixed gas combustion section, gaseous fuel is introduced into combustion air flowing through the passage in the air flow direction. There is known a device configured to obtain a premixed gas by ejecting the gas in a direction perpendicular to the direction (hereinafter, referred to as a “conventional device”). That is, by causing gaseous fuel to be ejected in a direction perpendicular to the direction of air flow, a vortex is generated on the downstream side of the ejection portion, and the combustion air and the gaseous fuel are mixed by the stirring action of the vortex.

Meanwhile, natural gas, LP gas, and the like generally used as gaseous fuels have a large specific gravity difference (difference in molecular weight in molar equivalent) with respect to combustion air, that is, a mixed gas of nitrogen and oxygen. Yes, with low diffusivity.

[0004] Therefore, it is difficult for the gaseous fuel and the combustion air to be sufficiently mixed by the stirring action of the vortex, and the premixed gas is supplied to the premixed gas combustion section in a state of uneven mixing. become.

[0005]

However, when a premixed gas having such uneven mixing is supplied to the premixed gas combustion section, the combustion temperature is not stabilized, and a local high temperature section is generated in the combustion region. As a result, NO _x (particularly, thermal NO _x ) cannot be reduced. Such a problem is common to various combustion apparatuses using a premixed gas (such as a cyclone combustion apparatus to be described later), and in fact, there is a strong demand for a solution.

[0006] The present invention has such has been made in view, to prevent the occurrence of local high-temperature portion in the combustion zone to occupy perform low NO _x combustion of homogeneously mixed with uneven mixing It is an object of the present invention to provide a premixed gas supply device capable of generating premixed gas and supplying the same to a premixed gas combustion section.

[0007]

A premixed gas supply device according to the present invention mixes a gaseous fuel and combustion air, and supplies the premixed gas as a mixed gas to a predetermined premixed gas combustion section. In order to achieve the above-mentioned object, in particular, a flow dividing mechanism for dividing a predetermined flow rate of combustion air to form a premixed gas into mixed air and non-mixed air, and a mixed air And a secondary mixing mechanism that mixes the primary mixed gas obtained by the primary mixing mechanism with the unmixed air that has passed through the branching mechanism. And a premixed gas generating mechanism for further mixing and stirring the secondary mixed gas obtained by the secondary mixing mechanism by applying a swirling force thereto, and a premixed gas obtained by the premixed gas generating mechanism. Premix gas supplied to the mixed gas combustion section Those comprising a supply mechanism.

[0008] In this premixed gas supply device, more specifically, the premixed gas supply mechanism is provided with a nozzle for ejecting the premixed gas to the premixed gas combustion section. The premixed gas generation mechanism is provided with a premixed gas generation cylinder having a circular cross section having a nozzle connected to a downstream end thereof and a swirl vane disposed in the premixed gas generation cylinder; and A concentric and meandering secondary mixing passage for causing the secondary mixing mechanism to flow toward the upstream end of the premixed gas generation cylinder while changing the direction of the secondary mixed gas, and the downstream end of the secondary mixing passage for the secondary mixed gas It is preferable to provide a rectifying plate that uniformly flows in the circumferential direction into the upstream end portion of the premixed gas generation cylinder while rectifying the premixed gas. Further, the swirl vane is a plate-like member having an inclination angle of 10 to 20 ° with respect to the axis of the premixed gas generation cylinder, and a premixed gas generation cylinder and a bottomed cylinder arranged concentrically inside thereof. It is preferable to radially attach in the circumferential direction between the opposed peripheral surfaces of the above.

The operation of the premixed gas supply device of the present invention can be maximized by attaching it to a cyclone type combustion device. Such a cyclone-type combustion device is configured such that gaseous fuel and combustion air are mixed in a cylindrical combustion chamber in a tangential direction along the inner peripheral surface from a nozzle port opened on the inner peripheral surface. It is configured to eject a mixed gas,
In particular, a storage area for the medium to be heated surrounding the peripheral wall of the combustion chamber is provided, and the peripheral wall is configured as a heat transfer wall in contact with the medium to be heated, and is formed by the premixed gas ejected from the nozzle port. It is preferable that the flame is cooled and cooled by a medium to be heated. When such a cyclone-type combustion device is used as a hot water boiler, a flue tube type boiler, or the like, the combustion chamber has one end closed and the other end opened as a combustion gas outlet.
It is immersed in the storage area of the medium to be heated in a state where its axis is horizontal. For example, when the heating medium is used as a hot water boiler or the like, the heating medium is used as the heating medium water, and the combustion gas is discharged from the combustion gas outlet to the stack through a heat transfer water pipe group that opens to a storage area of the heating medium water. It is preferable to have such a configuration. Also, when used as a furnace tube smoke tube boiler, etc., the combustion medium is discharged from the combustion gas outlet through a group of smoke pipes immersed in the storage area of the heating medium water and discharged into a flue, using the heating medium as still water. It is preferable to configure so that Further, in such a cyclone type combustion device, a plurality of nozzle ports for ejecting the premixed gas in the tangential direction along the inner peripheral surface of the combustion chamber are opened on the inner peripheral surface of the combustion chamber. In such a case, it is preferable to set the number and arrangement of the nozzle openings as follows. For example, a plurality of nozzle ports are arranged in parallel in the circumferential direction of the combustion chamber without inconsistency in the axial direction of the combustion chamber. In this case, it is preferable that the flame due to the premixed gas ejected from each nozzle port heats the nozzle port adjacent to the nozzle port in the premixed gas ejection direction. It is also possible to arrange a plurality of nozzle ports in parallel in the axial direction of the combustion chamber without inconsistency in the circumferential direction of the combustion chamber. In this case, it is preferable to make the interval between the nozzle ports in the axial direction of the combustion chamber as small as possible so that each nozzle port is heated by the flame from the nozzle port adjacent in the axial direction of the combustion chamber. . Further, the plurality of nozzle ports are divided into a plurality of sets of nozzle ports each including a plurality of nozzle ports arranged in parallel in the axial direction of the combustion chamber without inconsistency in the circumferential direction of the combustion chamber. The nozzle group can be arranged so as to be inconsistent in both the circumferential direction and the axial direction of the combustion chamber.

[0010]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be specifically described based on FIGS. In the following description, front and rear mean left and right in FIGS. 1, 4, 10, 12 and 14.

1 to 8 show a first embodiment, in which a premixed gas supply device 5 according to the present invention is a cyclone type combustion device (hereinafter, referred to as a hot water boiler). are attached as "first combustion device") 1 _1, and supplies ejecting premixed gas 9 is mixed with the combustion air 92 and gaseous fuel 91 at a predetermined ratio in the combustion chamber 3 serving premixed gas combustion unit It is configured as follows.

Namely, the first combustion device 1 _1, as shown in FIGS. 1 to 3, the combustion chamber 3 to the main body casing 2, formed by providing the heat exchanger 4 and the ignitor 6.

The main body case 2 is, as shown in FIGS.
It has a rectangular box-shaped metal plate wall structure, and stores a predetermined amount of heating medium water 71 as a medium to be heated. The space above the storage area of the heat medium water 71 (hereinafter referred to as “heat medium water storage area”) 7 is a reduced pressure area 10 in which the pressure is reduced to a predetermined pressure. In the decompression region 10, a hot water circulation path (not shown) for hot water supply, heating, and the like is arranged as in a normal hot water boiler.

As shown in FIGS. 1 to 3, the combustion chamber 3 has a furnace tube structure having a combustion gas outlet 31 at its rear end, and has a cylindrical peripheral wall 32 and a disk closing its front end. It is made of a metal plate and has an end wall 33 in a shape of a circle. Combustion chamber 3
Is immersed and disposed in the heat medium storage area 7 with its axis lined horizontally and with the end wall 33 separated from the front wall 2a of the main body case 2 by a predetermined amount. That is, the peripheral wall 32
And the end wall 33 has a heating medium 71 serving as a medium to be heated.
The heat transfer wall is configured to be cooled by heat exchange with the heat transfer water 71. Further, on the inner peripheral surface of the front end portion 3a of the combustion chamber 3, that is, the inner surface of the peripheral wall 32,
As will be described later, a plurality of nozzle ports 51 and 52 for ejecting the premixed gas 9 in the tangential direction along the inner peripheral surface of the combustion chamber 3.
Is in the axial direction of the combustion chamber 3 (hereinafter referred to as the “combustion chamber axial direction”) (the position in the combustion chamber axial direction is the same), but in the circumferential direction of the combustion chamber 3 (hereinafter “combustion chamber circumferential direction”). ) In parallel. The end wall 33 is attached to the front wall 2a of the main body case 2 by an appropriate stay (not shown). Further, for safety measures, the end wall 33 is provided with a flame detector 11 for detecting the state of the flame from the nozzle ports 51 and 52 and the state of the flame by the pilot burner 6 described later. This flame detector 11 is attached in a state of being inclined inward and downward of the combustion chamber 3 in order to prevent dew condensation water.

The heat exchanger 4 is, as shown in FIGS.
It is located behind the combustion chamber 3 and immersed in the heat medium storage area 7, and is penetrated and supported by a rectangular cylindrical peripheral wall 41 connected to the combustion gas outlet 31 of the combustion chamber 3 and upper and lower ends thereof. And a heat transfer water pipe group 42. Each water pipe 42 extends in the up-down direction, and has upper and lower ends opened to the storage area 7.
The water pipe groups 42 are arranged in a zigzag pattern as shown in FIG. 2. As is well known, the interval (pitch) between the water pipes is set so as to become smaller from the combustion gas outlet 31 to the rear, and the rear Fins 43... Of an appropriate shape are attached to the outer peripheral surface of the water pipes 42. Heat exchanger 4
A flue 8 composed of a metal cylinder is connected to the rear end of the cylinder. The combustion gas 95 generated in the combustion chamber 3 is discharged from the combustion gas outlet 31 through the water pipe group 42 to the flue 8, and the heat transfer water 71 in each water pipe 42 is exchanged with the combustion gas 95 by heat exchange. Heated and allowed to circulate naturally.

As shown in FIG. 3, the igniter 6 is composed of a pilot burner provided inside an auxiliary nozzle 52a, which will be described later, in the vicinity of the nozzle port 52 thereof. Nozzle port 51,
The premixed gas 9 squirted from 52 is ignited. The pilot burner 6 is stopped after the premixed gas 9 is ignited. Prior to the ignition of the pilot burner 6, the combustion chamber 3 and the heat exchanger 4 are purged by air supply by the premixed gas supply device 5.

The premixed gas supply device 5 is shown in FIGS.
As shown in FIG. 8, a premixed gas 9 obtained by mixing a gaseous fuel 91 such as natural gas and combustion air 92 is supplied to a premixed gas combustion section, that is, the combustion chamber 3.
Of the combustion air 92 having a predetermined flow rate to be mixed
a and a diverting mechanism 54 for diverting the air into the non-mixed air 92b;
A primary mixing mechanism 55 for mixing the air to be mixed 92a and a gaseous fuel 91 having a predetermined flow rate to form the premixed gas 9;
Primary mixing gas 9 was obtained in the primary mixing mechanism 55 ₁ and diverter mechanism 54 and the secondary mixing mechanism 56 for mixing the unmixed air 92b passing through the secondary mixing mechanism two obtained in 56 primary mixing gas 9 ₂ A premixed gas generating mechanism 57 that further mixes and agitates the premixed gas by applying a swirling force thereto, and the premixed gas 9 obtained by the premixed gas generating mechanism 57 is injected and supplied to the combustion chamber 3 serving as a premixed gas combustion unit. Premixed gas supply mechanism 51
a, 52a.

The premixed gas supply mechanism includes nozzle ports 51 and 5
2 comprises a main nozzle 51a and an auxiliary nozzle 52a each having an opening on the inner peripheral surface of the combustion chamber 3. Both nozzles 51a, 52a
As shown in FIGS. 1 to 4, at a position spaced apart from the end wall 33 by a predetermined amount L _{1 and} at a position inconsistent in the circumferential direction of the combustion chamber 3, the premixed gas 9 is discharged from the nozzle ports 51 and 52. It is attached to the peripheral wall 32 of the combustion chamber 3 in such a manner that it can be ejected tangentially to the inner peripheral surface of the combustion chamber 3 and that the ejection direction is the same in the circumferential direction of the combustion chamber 3. Each of the nozzles 51a and 52a is formed of a metal pipe having a cross-sectional shape capable of smoothly flowing the premixed gas 9 without generating a slow portion or a stagnation portion in order to effectively prevent occurrence of flashback. In this example, the section is circular. As will be described later, arc-shaped flames 93 and 94 are formed along the inner peripheral surface of the combustion chamber 3 by the ignition of the premixed gas 9 ejected from the nozzles 51a and 52a.
Inside diameter d ₁ of 1a has been designed for larger than the inner diameter d ₂ of the auxiliary nozzle 52a (d _1> d _2), the flame 93 is due to the gas injected 9 from the auxiliary nozzle hole 52 by the gas injected 9 from the main nozzle outlet 51 It is designed to be longer than the flame 94. In particular, the inner diameter d ₁ of the main nozzle 51a Although it is preferable to set according to the inner diameter D of the combustion chamber 3, where it was confirmed by experiments in order to make effectively perform cyclonic combustion, which will be described later D / It is preferable to set d ₁ > 4.5. Further, theta ₂ (angle relative to the center of the combustion chamber 3) distance between the nozzle openings 51, 52 in the direction of the gas jet from the auxiliary nozzle hole 52 is directly heat the flame 94 is the main nozzle outlet 51 from the auxiliary nozzle hole 52 So that the distance between the two nozzle ports 51 and 52 in the gas ejection direction from the main nozzle port 51 (the angle with respect to the center of the combustion chamber 3)
theta predetermined amount less than ₁ (θ _1> θ ₂₎ are set.
Further, under the condition that the flame 94 directly heats the main nozzle port 51, the ratio of the distances θ ₁ and θ ₂ is substantially equal to the ratio of the length of the flames 93 and 94, and the main nozzle port 51 is heated. It is more preferable that the flame 93 from the part 51 also directly heats the auxiliary nozzle port 52. In addition, the nozzle port 5 in the front-rear direction (the axial direction of the combustion chamber)
The distance L ₁ between the end plates 33, 52 and the end plate 33 is
It is preferable to set in accordance with the nozzle diameter (particularly, the diameter d ₁ of the main nozzle 51a having a large gas ejection amount) so that the combustion gas is recirculated in the region between the end plate 33 and the end plate 33. . According to experiments, L ₁ > d
It is preferable to set so that ₁ (> d ₂ ). The distance L ₂ between the nozzle port 51 and the combustion outlet 31 in the front-rear direction (the combustion chamber axially), as cyclonic combustion, which will be described later is performed, it is set in response to the combustion chamber diameter D preferable. It has been confirmed by experiments that it is preferable to set L ₂ > 1.5D. In addition, it has been confirmed by experiments that the nozzle ports 51 and 5 are required to perform cyclone combustion well.
It is preferable to set the gas ejection speed from Step 2 to 15 m / s or more.

The flow dividing mechanism 54 has a cylindrical flow dividing tube 54b concentrically arranged at the downstream end of a combustion air supply pipe 54a having a circular cross section for supplying a predetermined flow rate of combustion air 92 to constitute the premixed gas 9. Thus, the combustion air 92 reaching the downstream end of the combustion air supply pipe 54a is divided into the mixed air 92a flowing into the inner peripheral area of the flow dividing cylinder 54b and the non-mixed air 92b flowing into the outer peripheral area thereof. Has become. The flow dividing cylinder 54b is fixedly supported on the inner peripheral portion of the fuel air supply pipe 54a via a stay (not shown) that does not hinder the flow of the non-mixed air 92b.

The primary mixing mechanism 55 is provided with a gaseous fuel supply pipe 55a having a circular cross section for supplying a predetermined flow rate of the gaseous fuel 91 to constitute the premixed gas 9, and is provided at a distal end thereof at equal intervals in the circumferential direction. Plural rotating vanes 55 fixed radially
b ... The front end of the gaseous fuel supply pipe 55a is inserted into the flow dividing cylinder 54b through the pipe wall of the combustion air supply pipe 54a,
Are fixedly supported concentrically on the inner peripheral portion of the flow dividing cylinder 54b through the. Front end 55c of gaseous fuel supply pipe 55a
Are closed, and a plurality of ejection holes 55d are formed all around the pipe wall of the gaseous fuel supply pipe 55a at the rear portion of the swirl vanes 55b. 91 is radially ejected toward the inner peripheral portion of the flow dividing cylinder 54b. As shown in FIGS. 6 and 8, the swirl vanes 55b are formed in a trapezoidal plate shape attached at an angle α to the axis of the flow dividing cylinder 54b (or the front end of the gaseous fuel supply pipe 55a). Things. Therefore, according to the primary mixing mechanism 55, the mixed air 92a and the gaseous fuel 91 ejected from the ejection holes 55d of the gaseous fuel supply pipe 55a are mixed in the flow dividing cylinder 55b, and the swirl vanes 55b The turning force is given by ...
Further mixing would be agitated, serving a mixed gas of both 91,92a primary mixing gas 9 ₁ is obtained. This primary mixed gas 9 ₁ flows out from the front end portion of the shunt tube 54b becomes swirling flow.

As shown in FIGS. 4 to 7, the secondary mixing mechanism 56 includes a secondary mixing cylinder 56a having a circular section and connected to the front end of the fuel air supply pipe 55a so as to have the same axis. A secondary mixing passage 56b formed in the secondary mixing passage 56a, and a plurality of rectifying plates 56 provided at a downstream end of the secondary mixing passage 56b.
c ... is provided. The secondary mixing cylinder 56a has a larger diameter than the fuel air supply pipe 55a, and has a frusto-conical rear end narrowing rearward and connected to the front end of the fuel air supply pipe 55a.
The secondary mixing passage 56b includes an inner cylinder 56d having a circular cross section and a rear end portion of a premixed gas generating cylinder 57a having a circular cross section, which will be described later, and a secondary mixing cylinder 56a.
a closing plate 56 for closing the front end of the inner cylinder 56d and the rear end of the inner cylinder 56d.
e, 56f.
The concentric cylindrical passage portions 56 ′ b, 56 ″ b formed between the inner and outer peripheral portions of the a, 56 d, and 57 a communicate in a meandering manner. Thus, in the secondary mixing passage 56b,
By flowing into the separation tube 54b meandering while merging the unmixed air 92b passing through swirling flow and the primary gas mixture 9 ₁ flowing at an outer peripheral region of the flow tube 54b from the front end of, both 9 _1, Secondary mixed gas 9 mixed with 92b
₂ is obtained. That is, a primary mixing gas 9 ₁ The unmixed air 92b, on the first cylindrical passage portion 56'b formed between the secondary mixing tube 56a and the inner cylinder 56d and flow forward, secondary The direction is changed by the collision of the mixing cylinder 56a with the closing plate 56e, and the inner cylinder 56d and the premixed gas generation cylinder 57
a flows backward through the second cylindrical passage portion 56''b formed between the premixed gas generation cylinder 57a and the premixed gas generation cylinder 57a. It will flow into the ends and will mix during this time. The rectifying plates 56c are attached between the inner peripheral portion of the inner cylinder 56d and the outer peripheral portion of the premixed gas generating cylinder 57a in a radial state parallel to the axial direction and at equal intervals in the circumferential direction. the following mixed gas 9 _2, after rectified in while passing through the second cylindrical passage portion 56''B, adapted to uniformly flow from the entire periphery thereof to the upstream end portion of the premixed gas generator tube 57a I have.

As shown in FIGS. 4, 5, and 7, the premixed gas generation mechanism 57 includes a main nozzle 51a and an auxiliary nozzle 52.
a, and a plurality of swirling vanes 57c... disposed in the premixed gas generating cylinder 57a. The rear end portion of the premixed gas generating cylinder 57a penetrates the closing plate 56a of the secondary mixing cylinder 56a and is inserted concentrically into the inner cylinder 56d. In the rear end portion of the premixed gas generation cylinder 57a, a bottomed cylinder 57b whose rear end is closed is concentrically arranged and both cylinders 57a, 57
A plurality of swirling vanes 57c are radially attached at equal intervals in the circumferential direction between the inner and outer peripheral portions of b. The swirl vanes 57c are formed at an appropriate angle β with respect to the axes of the cylinders 57a and 57b.
It is a trapezoidal plate attached in an inclined shape.
The front end portion of the premixed gas generating cylinder 57a is a secondary mixing cylinder 56a.
From the main nozzle 51a.
And the auxiliary nozzle 52a are connected to each other. Note that the front end of the premixed gas generation cylinder 57a is closed. Therefore, according to the premixed gas generation mechanism 57, the current plate 56c
The secondary mixed gas 9 ₂ flowing into the rear end of the premixed gas generation cylinder 57a from the second cylindrical passage portion 56 ″ _{b where}
Are mixed and agitated by the application of the swirling force by the swirling vanes 57 c.
And the combustion air 92 are uniformly mixed to obtain a premixed gas 9. At this time, secondary mixed gas 9 ₂ rectifying plates 56c ...
And flows uniformly into the premixed gas generating cylinder 57a in the circumferential direction, so that the swirl vanes 57c ...
Mixing of the secondary gas mixture 9 ₂ by the swing imparting effect and pivoting by, so that the stirring action is more uniformly and effectively. The premixed gas 9 thus obtained flows forward in a swirling flow from the swirling vanes 57c and is ejected from the nozzles 51a and 52a into the combustion chamber 3. The premixed gas generation cylinder 57a is provided with a pressure detector 13 to determine whether or not an appropriate pressure corresponding to the premixed gas amount necessary to secure a predetermined combustion amount in the combustion chamber 3 is maintained. It is devised that the combustion is stopped for safety when the pressure is reduced from an appropriate pressure.

The degree of the turning force applied by the turning vanes 55b, 57c depends on the turning vanes 55b, 57c.
It is determined by the inclination angles α and β of c, but it has been confirmed by experiments that the specific gravity between the gaseous fuel 91 and the combustion air 92 is greatly different. When the inclination angles α and β exceed 20 °, the agitating action due to the swirling becomes excessive and mixing is not possible. There is a possibility that the gaseous fuel and the air may be separated again. Therefore, the inclination angles α and β of the swirl vanes 55b and 57c are preferably set in the range of 10 ° to 20 °, and in this example, set to 15 °. Although the number of the swirling vanes 55b and 57c also affects the swirling force, it is not preferable to increase the number more than necessary from the viewpoint of pressure loss. In this example, the number is set to eight.

The above first combustion device configured as 1 ₁
According to the so-called cyclone combustion is performed in the combustion chamber 3, it is possible to realize a low-NO _x combustion.

First, after the combustion chamber 3 and the heat exchanger 4 are purged by the premixed gas supply device 5 as described above, the premixed gas 9 is ejected from the nozzle ports 51 and 52. At this time, since the premixed gas supply device 5 is configured as described above, the premixed gas with extremely high mixing accuracy in which the gaseous fuel 91 and the combustion air 92 are uniformly mixed is supplied to each of the nozzles 51a and 52a. 9 will be supplied.

That is, the combustion air 92 supplied from the combustion air supply pipe 54a is mixed air 92a flowing into the flow dividing cylinder 54b and non-mixed air 92 flowing outside the flow dividing cylinder 54b.
b. In the branch cylinder 54b, the gaseous fuel 91 is radially ejected from the ejection holes 55d of the gaseous fuel supply pipe 55a in a direction orthogonal to the inflow direction of the mixed air 92a, and the ejected gas 91 and the mixed air 92a are jetted. Are mixed. Further, the mixture gas 91,92a serving primary mixing gas 9 ₁ shunt tube 5 through the swirl vanes 55b ...
While flowing from the front end of 4b, in the meantime, the inclination angle α as set above the the swirl vanes 55b ..., turning clogging weak enough to its constituent gases 91,92a into the primary mixing gas 9 ₁ does not re-isolated will be turning is applied, thus improving the mixing accuracy of the primary gas mixture 9 _1. Primary mixing gas 9 ₁ flowing out from the front end of the shunt tube 54b flows into the secondary mixing tube 56a with a non-mixed air 92b passing through the outer peripheral portion of the shunt tube 54b, formed in the secondary mixing cylinder 56a meander It flows while changing the direction in the secondary mixing passage 56b. At this time, since the turning force is applied by the turning vanes 55b ... in the primary gas mixture 9 ₁ flowing out of shunt tube 54b, the secondary mixing primary gaseous mixture at beginning of the passage 56b 9 ₁ and unmixed air 92b DOO is a well mixed, desired premixed gas 9 and the secondary gas mixture formed by the same component 9 ₂ is obtained. By the way, since there is a large specific gravity difference between the gaseous fuel 91 and the combustion air 92, the primary gas obtained by mixing the gaseous fuel 91 with a part 92 a of the combustion air 92 to constitute the premixed gas 9 is obtained. mixing accuracy of the mixed gas 9 ₁ was further mixed with the combustion air 92b of the remainder secondary mixed gas 9 ₂ is higher than the those in the combustion air 92 of the total amount obtained by mixing gaseous fuel 91.

Furthermore, secondary mixed gas 9 ₂ is flow while diverting the serpentine secondary mixing passage 56b, it will be uniformly mixed by stirring action by turning. Moreover, although the secondary mixing axial length of the passage 56b (front-rear length) is short, it is of serpentine, flow path of the secondary gas mixture 9 ₂ in the secondary mixing passage 56b is sufficiently since it is longer, mixing accuracy of the secondary gas mixture 9 ₂ during flowing in the secondary mixing passage 56b will be further enhanced. In other words, the secondary mixing passage 56
By forming b in a meandering shape, it is possible to increase the mixing accuracy of the gaseous fuel 91 and the combustion air 92 while miniaturizing the premixed gas supply device 5 as much as possible.

[0028] The secondary mixed gas 9 ₂ flows into the secondary mixing passage 56b to the premixed gas generator tube 57a, the swirl vanes 57c ... it is imparting swirl force, eventually mixed precision stirring action caused by the turning Adjusted premixed gas 9
Is obtained. At this time, secondary mixed gas 9 _2, the downstream end portion of the secondary mixing passage 56b (second cylindrical passage portion 56''
b) provided in b), the turbulence due to the reverse flow in the secondary mixing passage 56b is rectified,
The gas is uniformly flown into the premixed gas generating cylinder 57a from the entire periphery at the rear edge. Therefore, swirl vane 5
7c ... by secondary mixing uneven turning force applied to the gas 9 ₂ does not occur, a uniform pivoting force is to be applied to the secondary mixed gas 9 _2. As a result, the mixing accuracy of the premixed gas 9 flowing out of the swirl vanes 57c becomes extremely high. At this time, since the swirl vanes 57c have the inclination angle β set as described above, the inconvenience of imparting swirl, that is, the gaseous fuel 9 having a specific gravity difference,
The premixed gas 9 with high mixing accuracy can be obtained without inconvenience such as re-separation of 1 and the combustion air 92.

The premixed gas 9 thus obtained is supplied from the premixed gas generating cylinder 57a to each of the nozzles 51a and 52a, and is ejected from the nozzle ports 51 and 52 into the combustion chamber 3.
At this time, since the swirling force is applied to the premixed gas 9 obtained in the premixed gas generating cylinder 57a, the premixed gas 9 is supplied to the nozzles 51a and 52a while maintaining the mixing accuracy. Thus, the premixed gas 9 having extremely high mixing accuracy is ejected from the nozzle ports 51 and 52.

When the premixed gas 9 is supplied to the combustion chamber 3 in this manner, each nozzle port 5 is
The premixed gas 9 ejected from the fuel tanks 1 and 52 is ignited, and cyclone combustion is started. That is, since the premixed gas 9 is ejected in the tangential direction of the inner peripheral surface of the combustion chamber 3, FIG.
As shown in FIG. 5, arc-shaped flames 93 and 94 are formed from the respective nozzle ports 51 and 52 along the inner peripheral surface of the combustion chamber 3, that is, the inner peripheral surface of the peripheral wall 32 so as to lick the inner peripheral surface.

At this time, since the peripheral wall 32 of the combustion chamber 3 is a heat transfer wall in contact with the heat medium water 71, the flames 93 and 94 are cooled by the heat medium water 71.
Such cooling of the flame 93 and 94, the low temperature, so that the generation of thermal NO _x is suppressed.

By the way, when the flames 93 and 94 are cooled,
Although the generation of NO _x can be suppressed, there is a possibility that the flames 93 and 94 become unstable. However, as described above, the flame 94 from the auxiliary nozzle port 52 directly heats the main nozzle port 51 and a part of the flame 93 from the main nozzle port 51 heats the auxiliary nozzle port 52; , since it has to recirculation zone of the combustion gases 95 to the front side of the nozzle openings 51, 52 and as set to said longitudinal distance L ₁ to the end wall 33 is formed from 52, the problem No fire occurs, and the flames 93 and 94 are stabilized. That is, the flames 93 and 9 are heated by the flame of the nozzle ports 51 and 52 and the recirculation of the combustion gas 95.
4 is in a stable state. In addition, as illustrated in FIG.
By arranging them so that they can be sufficiently heated, the flame can be stabilized even in a state where the recirculation of the combustion gas 95 does not occur. As described above, the number and arrangement of the nozzle ports can be arbitrarily set within a range in which good cyclone combustion and stable flame can be ensured.

The peripheral wall 32 extends from each nozzle port 51, 52.
By causing the premixed gas 9 to be ejected at a high speed in the tangential direction of the combustion gas 95, the combustion gas 95 forms a swirling flow along the inner peripheral surface of the combustion chamber 2 and heads toward the combustion gas outlet 31, and a so-called cyclone flame is formed. Thus, a recirculation region by the combustion gas 95 is formed at the center of the combustion chamber 2.
Due to the recirculation effect of the combustion gas 95, NO
The generation of _x will be suppressed. In was confirmed by experiments, varies by the combustion conditions, including the structure of the device 1 _1, the ejection speed of the general, such recirculating act to occupy perform good cyclonic combustion caused sufficiently premixed gas 9 Is preferably set to 15 m / s or more.

Further, since the premixed gas 9 ejected from each of the nozzle ports 51 and 52 has a high mixing accuracy in which the gaseous fuel 91 and the combustion air 92 are uniformly mixed as described above, the combustion chamber 9 3 does not burn evenly and does not produce local hot spots, which also results in NO _x
Is suppressed.

[0035] Thus, in the first combustion device 1 _1, a significant reduction of the NO _x is reduced, a good cyclonic combustion is performed.

[0036] This has been confirmed from the results of experiments performed using the first combustion device 1 _1. In other words, this experiment, gaseous fuel: natural gas 13A, the ejection speed of the premixed gas: 15 m / s, the combustion chamber diameter (D): 600 mm, the combustion chamber length _{(L 1 + L 2):} 1200mm, main nozzle diameter ( d ₁ ): 116 mm, auxiliary nozzle diameter (d ₂ ): 60 m
rated combustion (140 Nm ³ / h) under the condition of
₂ NO _x concentration occurring in the combustion chamber 3 in relation to the concentration (ppm (O ₂ = 0% conversion)) and CO concentration (ppm
(O ₂ = 0% conversion)) was measured. As a result, low power (amount of combustion gas: 32~44Nm ³ / h) and high power: amount of CO generated in any of (amount of combustion gas 123~155Nm ³ / h) is 0 ppm, the generation amount of the NO _x Was also significantly reduced as shown in FIG. In FIG. 9,
The solid line is limited to showing concentration of NO _x in the low output, the chain line shows the concentration of NO _x at the time of high output.

FIGS. 10 to 13 show a second embodiment, in which a premixed gas supply device 50 according to the present invention is a cyclone constructed in a furnace tube type boiler. form a combustion apparatus (hereinafter, "second combustion device" hereinafter) 1 ₂ are attached to, gaseous fuel 91 and combustion air 92 and the premixed gas 9 premixed gas combustion unit serving the combustion chamber is mixed with a predetermined ratio 30.

[0038] That is, the second combustion device 1 _2, 10 to
As shown in FIG. 13, a main body case 20 is provided with a combustion chamber 30, a heat exchanger 40, and an igniter 60.

As shown in FIGS. 10 and 11, the main body case 20 has a cylindrical metal plate wall structure, and has a storage area for canned water 72 as a medium to be heated (hereinafter referred to as a "canned water storage area"). 70) is formed. The upper space of the canned water storage area 70 is the steam generation area 12.

As shown in FIGS. 10 and 11, the combustion chamber 30 has the same structure as that of the combustion chamber 3 and has a cylindrical peripheral wall 32 whose front end is closed and whose rear end is used for combustion. The gas outlet 31 is made of a metal plate. That is, the combustion chamber 30 is immersed in the canned water storage area 70 with its axis being horizontal, and the peripheral wall 32 and the end wall 33 of the combustion chamber 30 serve as heat transfer walls cooled by heat exchange with the canned water 72. It is configured. As will be described later, the premixed gas 9 extends along the inner peripheral surface of the combustion chamber 30 in the tangential direction along the inner peripheral surface of the front end portion 30a of the combustion chamber 30, that is, the inner surface of the peripheral wall 32.
Are opened in parallel with each other in the axial direction of the combustion chamber without inconsistency in the circumferential direction of the combustion chamber.

As shown in FIGS. 10 and 11, the heat exchanger 40 is provided with submerged fire tube groups 44 which are located on the sides of the combustion chamber 30 and extend horizontally in the front-rear direction. The rear end of the stack of pipes 44 is connected to the combustion gas outlet 31 via the communication chamber 45 and the front end of the stack of pipes 44 is connected to the flue 80 so that the combustion gas 95 passes from the combustion gas outlet 31 to the stack of pipes 44. The heat is exchanged with the canned water 72 as the medium to be heated while being discharged to the flue 80 via the stack.

As shown in FIG. 11, the igniter 60 has a pilot burner 62 disposed on an ignition nozzle 61 provided on the peripheral wall 32 of the combustion chamber 30. The ignition nozzle 61 is flush with the inner peripheral surface of the combustion chamber 30 so that combustion air 97 can be ejected toward a nozzle port 53 described later. According to this igniter 60, the combustion air 9
7 is formed while the pilot flame is formed by the bi-rot burner 6, so that the premixed gas 9 ejected from the nozzles 53a is ignited. The supply of the combustion air 97 and the ignition of the pilot burner 62 are stopped after the ignition of the premixed gas 9. Further, the combustion chamber 30 and the heat exchanger 40 are purged by air supply by the premixed gas supply device 50 before the ignition of the pilot burner 62.

Thus, the premixed gas supply device 50 has the configuration shown in FIG.
As shown in FIGS. 0 to 13, a premixed gas 9 obtained by mixing a gaseous fuel 91 such as natural gas and combustion air 92 is supplied to a premixed gas combustion section, that is, a combustion chamber 30. A flow dividing mechanism 54 for dividing a predetermined flow rate of combustion air 92 to be mixed into the mixed air 92a and the non-mixed air 92b; a predetermined flow rate of the gaseous fuel 91 to form the mixed air 92a and the premixed gas 9; And a primary mixed gas 9 ₁ obtained by the primary mixing mechanism 55.
Further mixed by the secondary mixing mechanism 56 for mixing the unmixed air 92b passing through the diverter mechanism 54 to impart a swirling force to secondary mixed gas 9 ₂ obtained in the secondary mixing mechanism 56, A premixed gas generation mechanism 57 for stirring, and a premixed gas supply mechanism 5 for supplying the premixed gas 9 obtained by the premixed gas generation mechanism 57 to the combustion chamber 30 serving as a premixed gas combustion unit.
3a ... are provided.

The premixed gas supply mechanism includes a plurality of nozzles 53 each having an opening on the inner peripheral surface of the combustion chamber 30 (3 in the illustrated example).
) Nozzles 53a. These nozzles 53a ...
Are formed of cylindrical metal pipes having the same cross-sectional shape. As shown in FIGS.
Are arranged in parallel in the axial direction of the combustion chamber without inconsistency in the circumferential direction of the combustion chamber, and the premixed gas 9 can be ejected from the nozzle ports 53 in a tangential direction to the inner peripheral surface of the combustion chamber 30. It is attached to the peripheral wall 32 of the combustion chamber 30 in such a configuration that the ejection direction is the same in the circumferential direction of the combustion chamber 30. By the way, the first combustion device 1
In the _1, the distance L ₁ from end wall 32 to the nozzle opening installation place, by setting the sufficient dimension recirculation zone of forward combustion gas 95 of the nozzle port 51 is formed, the flame While working to stabilize the 93 and 94, in the second combustion device 1 _2, the front-rear direction from the fact that disposed close several nozzle orifices 53 ..., the end wall 33 and the nozzle opening groups 53 ... and It is not necessary to consider the distance as described above. That is,
In the second combustion device 1 _2, heating the nozzle opening 53 to a mutual spacing in the nozzle port 53 ... combustion chamber axially of the flame 96 by the premixed gas 9 ejected from the nozzle opening 53 is adjacent to the nozzle opening 53 As a result, the flame 96 from each nozzle port 53 is stabilized by the heating action of the nozzle port 53 despite the cooling and lowering of the temperature by the can water 72 by the heating action of the nozzle port 53 by the flame 96. It is devised so that it can be done. Note that the distance L ₃ between the nozzle opening 53 of the last position and the combustion gas outlet 31, to occupy satisfactorily perform cyclonic combustion, is set similarly to the corresponding distance L ₂ in the first combustion device 1 _1. In addition, each nozzle 53
a is provided with a flow controller (orifice or the like) 53b to make the amount of premixed gas ejected from the nozzle ports 53 ... uniform. The gas ejection speed from each nozzle opening 53, as in the first combustion device 1 _1, 15 m / s
It is preferable to set the above.

The diverter mechanism 54 is formed in a diverter mechanism identical structure in the first combustion device 1 _1. That is, FIG.
As shown in the figure, a cylindrical flow dividing tube 54b is concentrically arranged in the downstream end of a combustion air supply pipe 54a having a circular cross section for supplying a predetermined flow rate of combustion air 92 to constitute the premixed gas 9, and the combustion air The combustion air 92 reaching the downstream end of the supply pipe 54a is divided into mixed air 92a flowing into the inner peripheral area of the flow dividing cylinder 54b and non-mixed air 92b flowing into the outer peripheral area thereof.

The primary mixing mechanism 55, as shown in FIG.
Except having a baffle plate 55e instead of the swirl vane 55b, it is those which form a primary mixing mechanism similar structure in the first combustion device 1 _1, gaseous fuel at a predetermined flow rate should constitute premixed gas 9 It comprises a gaseous fuel supply pipe 55a having a circular cross section for supplying 91, and a baffle plate 55e disposed in front of and near the flow dividing cylinder 54b. Gaseous fuel supply pipe 55a
Is inserted into the flow dividing cylinder 54b through the pipe wall of the combustion air supply pipe 54a, and the distal end 55c is closed. A plurality of ejection holes 55d are provided on the pipe wall at the tip of the gaseous fuel supply pipe 55a over the entire circumference thereof.
Are formed to radially eject the gaseous fuel 91 toward the inner peripheral portion of the flow dividing cylinder 54b. Therefore, in the branch cylinder 55b, the mixed air 92a
And is mixed with gaseous fuel 91 ejected from the ejection hole 55d of the gaseous fuel supply pipes 55a ..., the mixture serving gas the primary mixing gas 9 ₁ is stirred by collision effects on the baffle plate 55e, shunt tube 55b Is discharged from the annular gap between the baffle plate 55e and the baffle plate 55e. Incidentally, while closing the downstream end of the flow tube 55b, to the blocking portion provided primary mixing gas 9 ₁ of ejection holes, the baffle plate 55e may be keep waste.

The secondary mixing mechanism 56 is shown in FIGS.
As shown, the secondary mixing cylinder 56a is connected to the fuel air supply pipe 55a.
Except that the axis is orthogonally connected to the downstream end, the first
Combustion device 1₁It has the same structure as the secondary mixing mechanism of
Inside the secondary mixing cylinder 56a having a circular cross section.
Meandering secondary mixing passage 56b formed in
Plural straightening plates 56c provided at the downstream end of the path 56b
…. The secondary mixing cylinder 56a is connected to the fuel air supply pipe 5
5a with a diameter larger than that of the combustion chamber 30
In a state where the fuel air supply pipe 55a is
Connected in a cross. The secondary mixing passage 56b is used for secondary mixing.
Cylinder 56a and circular cross-section arranged concentrically inside it
Of the inner cylinder 56d and the premixed gas generation cylinder 57a having a circular cross section
Concentric cylindrical passage portion 56 'formed between inner and outer peripheral portions
b, 56''b are connected in a meandering manner. Thus, two
In the next mixing passage 56b, the front end of the flow dividing cylinder 54b
Primary mixed gas 9 flowing out in a swirling flow from₁And diverter
Merge with the non-mixed air 92b that has passed through the outer peripheral area of the 54b
By flowing them in a meandering manner,₁, 9
Secondary mixed gas 9 mixed with 2b_TwoIs obtained. Sand
And primary mixed gas 9 ₁And the non-mixed air 92b
From the downstream end of the air supply pipe 55a, the secondary mixing cylinder 56a and the inner cylinder
56d formed between the first cylindrical passage portion 56'b and the first cylindrical passage portion 56'b.
Flows forward, and the closing plate 56 of the secondary mixing cylinder 56a
changed direction by collision with e and premixed with inner cylinder 56d
Second cylindrical passage formed between the gas generation cylinder 57a
The minute portion 56''b flows backward, and the inner cylinder 56d is closed.
The direction is changed by the collision with the plate 56f, and the premixed gas
It will flow into the rear end of the forming cylinder 57a.
Will be mixed. The current plates 56c ...
The inner peripheral portion of the cylinder 56d and the outer peripheral portion of the premixed gas generation cylinder 57a
Parallel to the axial direction and equally spaced in the circumferential direction
The secondary mixed gas 9_TwoThe
Rectification while passing through two cylindrical passage portions 56 "b
After that, the premixed gas generation cylinder 57a
So that it flows in evenly from the entire circumference.

The premixed gas generating mechanism 57, as shown in FIG. 12, the premixed gas generator mechanism 5 in the first combustion device 1 ₁
7, and has a circular premixed gas generation cylinder 57a connecting the nozzles 53a, and a plurality of swirling vanes 57c disposed in the premixed gas generation cylinder 57a.
…. The rear end portion of the premixed gas generating cylinder 57a penetrates the closing plate 56a of the secondary mixing cylinder 56a and is inserted concentrically into the inner cylinder 56d. In the rear end portion of the premixed gas generation cylinder 57a, a bottomed cylinder 57 having a closed rear end is provided.
are concentrically arranged, and a plurality of swirling vanes 57c are radially attached at equal intervals in the circumferential direction between the inner and outer peripheral portions of both cylinders 57a and 57b. Turning vane 57c ...
Is tubular 57a, suitable angle relative to the axis of 57b (the it is preferable to set the same manner 10 to 20 ° and the inclination angle β of the first combustion device 1 _1, generally is set at 15 °) It is a trapezoidal plate attached in an inclined shape. The front end of the premixed gas generation cylinder 57a projects forward from the secondary mixing cylinder 56a, and the nozzle 5
Are connected to each other. Note that the front end of the premixed gas generation cylinder 57a is closed. Therefore,
According to the premixed gas generating mechanism 57, the rectifier plate 56c ... secondary mixed gas 9 ₂ which has flown into the rear end of the premixed gas generator tube 57a from the second cylindrical passage portion 56''b placing the can swivel The swirling force is applied by the vanes 57c to mix and agitate, thereby obtaining the premixed gas 9 in which the gaseous fuel 91 and the combustion air 92 are uniformly mixed. At this time, on the secondary mixed gas 9 ₂ is rectified by the rectifier plate 56c ..., two by the fact evenly flows in the circumferential direction in the premixed gas generator tube 57a, swirl applying operation and turning by the turning vanes 57c ... mixing the following mixed gas 9 _2, so that the stirring action is more uniformly and effectively. The premixed gas 9 thus obtained is supplied to the swirl vane 5
7c... And flows forward in a swirling flow.
The fuel is ejected from 3a into the combustion chamber 30.

The second combustion device 1 ₂ configured as described above
According to the same manner as in the first combustion device 1 _1, so-called cyclone combustion is performed in the combustion chamber 30, a low NO _x
Combustion can be realized.

That is, the premixed gas supply device 50 performs the same mixing and stirring operations as in the premixed gas supply device 5, and the gaseous fuel 91 and the combustion air 92 are uniformly mixed. A premix gas 9 with mixing accuracy is generated and supplied to the nozzles 53a. At this time,
The premixed gas 9 obtained in the premixed gas generation cylinder 57a includes:
Since the swirling force to the extent that the component gas does not separate again is applied, the premixed gas 9 is supplied to the nozzles 53a while maintaining the mixing accuracy.
.., A premixed gas 9 with extremely high mixing accuracy is ejected.

When the premixed gas 9 ejected from each nozzle port 53 is ignited by the pilot burner 62, as shown in FIG.
An arc-shaped flame 96 is formed to extend along the inner peripheral surface along the inner peripheral surface. At this time, since the peripheral wall 32 of the combustion chamber 30 is a heat transfer wall in contact with the water 72, each flame 96 is cooled by the water 72. Further, the premixed gas 9 is jetted from each nozzle port 53 in a tangential direction of the peripheral wall 32 at a high speed, so that the combustion gas 9
5 form a swirling flow along the inner peripheral surface of the combustion chamber 2 and head toward the combustion gas outlet 31 to form a so-called cyclone flame.
A recirculation region by the combustion gas 95 is formed at the center of the. Further, since the premixed gas 9 ejected from each nozzle port 53 has a high mixing accuracy in which the gaseous fuel 91 and the combustion air 92 are uniformly mixed as described above, the premixed gas 9 is uniformly mixed in the combustion chamber 30. It does not burn and produce localized hot spots. The uniformity of such flame 96 ... combustion temperature due to premixed gas 9 of the recirculation operation and high mixing accuracy cooling effect and combustion gases 95, similarly to the first combustion device 1 _1, the reduction of CO, of course, NO _{x will} also be significantly reduced. Further, since each nozzle port 53 is heated by the flame 96 from the nozzle port 53 adjacent to and adjacent to the nozzle port 53, the flame 96 is stabilized despite the fact that the flame 96 is cooled and the temperature is lowered. Combustion can take place.

The present invention is not limited to the above-described embodiments, but can be appropriately improved and changed without departing from the basic principle of the present invention.
For example, a combustion apparatus premixed gas supply device 5,50 according to the present invention is applied, the first and second devices 1 _1, 1 ₂
The gaseous fuel 91 and the combustion air 92 are preliminarily mixed,
The present invention can be applied to any type of combustion device (including a surface combustion device) having a premixed gas combustion section for igniting and burning the premixed gas 9. However, there is a great advantage when applied to a cyclone combustion apparatus in which the adverse effects caused by the uneven mixing of the premixed gas 9 are large. Needless to say, the configuration of the cyclone combustion apparatus to which the present invention is applied is arbitrary. For example, even when the present invention is applied to a configuration as illustrated in FIGS. 14 to 18, the first or second apparatus ₁₁ , 1 is used. The same effect as when applied to ₂ can be obtained.

That is, the cyclone type combustion device (hereinafter referred to as “third combustion device”) 1 shown in FIGS.
_3, with the following exceptions are those that are configured similarly structured as the first combustion device 1 _1. That is, in the third combustion device 1 _3, as shown in FIGS. 14 and 15, the front end portion 3a is ejected part of the premixed gas 9 in the combustion chamber 3, forward of the front wall 2a of the body case 2 It is made to protrude and is surrounded by bulging portions 2b and 2c provided on the front wall 2a of the main body case 2. With this configuration, the device can be easily manufactured, and the adverse effects due to thermal stress generated between the main body case 2 and the combustion chamber 3 can be eliminated. The bulging portion has a cylindrical portion 2b surrounding the front end portion of the peripheral wall 32 and a disk portion 2 which closes the front end of the cylindrical portion 2b and directly faces the end wall 33.
c, and the front end portion 3a of the combustion chamber 3 is
2c is cooled by a heating medium 71 filled between the heating medium 2c. The heat transfer water 71 in the bulging portions 2b and 2c is circulated between the swelling portions 2b and 2c. Also,
The inner peripheral surface of the combustion chamber 3, a plurality of nozzles 53a forming the nozzle has the same cross-sectional shape of the second combustion device 1 ₂ in the peripheral wall 32
... by attaching a second combustion device 1 ₂ in definitive Similarly, if the combustion chamber parallel to the adjacent shape in the axial direction comprising a plurality of nozzle orifices 53 ... two sets of nozzle opening group 53 _1, 53
₂ are opened in a state where there is no inconsistency in the axial direction of the combustion chamber, that is, opposed to each other at an interval of 180 ° in the circumferential direction of the combustion chamber. The same amount is ejected in the tangential direction of the inner peripheral surface of No. 3. Each nozzle 53a is provided with a flow controller 53b.
Is connected to the premixed gas supply cylinder 57a of the premixed gas supply device 5 or 50 through the connection. In the third combustion device 1 _3, as in the second combustion device 1 _2,
Nozzle ports 5 whose nozzle ports 53 are adjacent in the axial direction of the combustion chamber
Heated by the flame 96 from the combustion chamber 3 (depending on conditions such as the inner diameter of the combustion chamber 3 and the like, heating may also be performed by the flame 96 from the nozzle port 53 adjacent in the circumferential direction of the combustion chamber).
By, and than each flame 96 can be stabilized, consideration such set aside a predetermined recirculation zone in front of the nozzle opening groups 53 ..., that is such in the first combustion device 1 _1, premixed the distance L ₁ from the gas ejection part to the end wall 33 considerations such is set to the size that can form a recirculation zone for flame stabilization is not particularly required. Of course, the cyclonic combustion action is performed similarly to the first and second combustion device 1 _1, 1 _2.

The cyclone combustion apparatus shown in FIG.
(Hereinafter referred to as “fourth combustion device”) 1 _FourThen, the third combustion equipment
Place 1_ThreeParallel to the combustion chamber axial direction as in
Nozzle group 5 composed of a plurality of nozzle ports 53.
3₁, 53_TwoBut 180 ° apart in the circumferential direction of the combustion chamber
Opened in a state that is inconsistent with the combustion chamber axial direction
I have. Fourth combustion device 1_FourOther than the above points
The combustion operation including the combustion and flame stabilization operations is performed by the third combustion device 1
_ThreeThe same as in.

The cyclone shown in FIG. 17 and FIG.
Combustion device (hereinafter referred to as “fifth combustion device”) 1_FiveThen
An appropriate number of nozzle ports 53 are inconsistent in the axial direction of the combustion chamber.
It is arranged at equal intervals in the circumferential direction of the combustion chamber,
Number of nozzle ports 53 and mutual spacing in the circumferential direction of the combustion chamber
Of the premix gas from the inner diameter of the combustion chamber 3 and each nozzle port 53.
The flame from each nozzle port 53 is
The nozzle port 53 adjacent in the exit direction can be directly heated.
Is set to In the illustrated example, four nozzle ports 53 are provided.
Are arranged at 90 ° intervals in the circumferential direction of the combustion chamber,
From these nozzle ports 53 ... in the same circumferential direction in the combustion chamber
Premixed gas 9 in the tangential direction along the inner peripheral surface of the combustion chamber 3
It is made to squirt. In addition, the swelling of the main body case 2
Around the part (cylindrical part 2b), a circular cross-section head
A nozzle pipe 53c is provided, and the nozzle 5 is attached to the header pipe 53c.
Are connected to each other and the premixed gas supply device 5
Alternatively, fifty premixed gas generation cylinders 57a are connected and connected.
You. Each nozzle 53a has a flow rate of the above-mentioned orifice or the like.
An adjuster (not shown) is provided, and each nozzle port 53 is provided.
Device so that the amount of premixed gas ejected from the
You. Further, the fifth combustion device 1_Five, The body case
2 and through the end wall 33 of the combustion chamber 3.
A circular inspection window 34 through which the inspection window 34 is formed is formed.
It is structured so that it can be removably closed with a lid 35 made of refractory material.
And maintenance and inspection of the combustion chamber 3 can be easily performed.
It is devised so that. Fifth combustion device 1_FiveIn the upper
The configuration and the combustion action other than those described are the same as those of the fourth combustion device 1._FourTo
It is the same as In addition, the present invention can be suitably applied.
The cyclone device includes the hot water boiler 1 described above.₁, 1_Three,
1 _Four, 1_FiveAnd flue tube boiler 1_TwoAnd combustion chamber 3,3
0 is cylindrical, and its peripheral wall 32 is covered with water 71, 72 or the like.
Heat transfer walls that can be cooled by a heating medium
Of any form, provided that
You. In such a cyclone combustion apparatus, the nozzle port 5
The premixed gas ejection conditions such as the number and arrangement of 1, 52 and 53 are also
In addition to the above, according to the combustion conditions such as the inner diameter of the combustion chambers 3, 30
To secure the cyclone combustion and flame stabilization described above.
It can be set arbitrarily within a range. In particular, the Lord
In addition to the nozzle port 51, an auxiliary nozzle functioning as an ignition
First combustion device 1 provided with a slip port 52₁In the ignition
Depending on the means, the auxiliary nozzle port 52 is not provided, and
So that cyclone combustion is performed only by the
It can also be done. In this case, the stabilization of the flame 93
Recirculation action of combustion gas generated in the area near the nozzle port 51
It will be done by. In addition, the ignition means
1st and 2nd combustion device 1₁, 1_TwoThe igniter adopted in
Premixing not limited to 6,60
Any structure that can ignite the gas 9 is optional.
It is.

[0056]

As will be easily understood from the above description, according to the premixed gas supply device of the present invention, the premixed gas in a uniform mixing state without mixing unevenness is supplied to the combustion chamber of the cyclone combustion device. Therefore, the premixed gas can be supplied to the premixed gas combustion section, and good premixed gas combustion can be performed without generating a local high-temperature portion in the combustion region. Therefore, the NO _x generation due to uneven mixing of the premixed gas is effectively prevented, it is possible to realize a low-NO _x combustion.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a premixed gas supply device according to the present invention, and is a longitudinal sectional front view of a first combustion device provided with the premixed gas supply device.

FIG. 2 is a cross-sectional plan view taken along the line II-II of FIG.

FIG. 3 is a vertical sectional side view taken along line III-III of FIG. 1;

FIG. 4 is a longitudinal sectional front view showing a premixed gas supply device attached to a first combustion device.

FIG. 5 is an enlarged detail view showing a main part of FIG. 4;

FIG. 6 is an enlarged detail view showing another main part of FIG. 4;

FIG. 7 is a vertical sectional side view taken along line VII-VII in FIG. 5;

8 is a vertical sectional side view taken along line VIII-VIII in FIG.

FIG. 9 is a graph showing combustion characteristics in the first combustion device.

FIG. 10 shows a second embodiment of the premixed gas supply device according to the present invention, and is a longitudinal sectional front view of a second combustion device provided with a premixed gas.

11 is a cross-sectional side view taken along line X1-X1 in FIG.

FIG. 12 is a longitudinal sectional front view showing a premixed gas supply device attached to a second combustion device.

FIG. 13 is a vertical sectional side view taken along line XIII-XIII in FIG. 12;

FIG. 14 is a vertical sectional front view showing a third combustion device provided with a premixed gas supply device according to the present invention.

FIG. 15 is a longitudinal sectional side view taken along line XV-XV in FIG. 14;

FIG. 16 is a vertical sectional front view showing a fourth combustion device provided with a premixed gas supply device according to the present invention.

FIG. 17 is a vertical sectional front view showing a fifth combustion device provided with a premixed gas supply device according to the present invention.

18 is a longitudinal sectional side view taken along line XVIII-XVIII in FIG.

[Explanation of symbols]

1 ₁ ... 1st combustion device (cyclone type combustion device), 1 ₂ ...
The second combustion device (cyclone combustion apparatus), 1 ₃ ... third combustion apparatus (cyclone combustion apparatus), 1 ₄ ... fourth combustion apparatus (cyclone combustion apparatus), 1 ₅ ... fifth combustion apparatus (cyclone combustion Device), 2,20 ... body case, 3,30
… Combustion chamber, 4,40 heat exchanger, 5,50 premixed gas supply device, 6 igniter (pilot burner), 7,70
.., A storage area for the medium to be heated, 8, 80 flues, 9, premixed gas, 9 _1, primary mixed gas, 9 _2, secondary mixed gas, 42
... heat transfer water pipe, 44 ... smoke pipe, 51, 52, 53 ... nozzle port, 51a, 52a, 53a ... nozzle (premixed gas supply mechanism), 54 ... branching mechanism, 54a ... combustion air supply pipe, 5
4b: split cylinder, 55: primary mixing mechanism, 55a: gaseous fuel supply pipe, 55b: swirl vane, 55d: ejection hole, 56
.. Secondary mixing mechanism, 56a secondary mixing cylinder, 56b secondary mixing passage, 56c rectifying plate, 57 premixed gas generation mechanism
57a: premixed gas generation cylinder, 57b: bottomed cylinder, 57c
... Swirl vane, 60 ... Ignition device, 61 ... Ignition nozzle, 62
... Pilot burner, 71 ... Water medium (medium to be heated), 7
2. Can water (medium to be heated), 91: gaseous fuel, 92: combustion air, 92a: air to be mixed, 92b: non-mixed air.

Claims (2)

[Claims] 1. A premixed gas supply device configured to mix a gaseous fuel and combustion air and to supply a premixed gas as a mixed gas to a predetermined premixed gas combustion section, A flow dividing mechanism for diverting a predetermined flow rate of combustion air to form a premixed gas into air to be mixed and non-mixed air, and a primary flow to mix the air to be mixed and a gaseous fuel at a predetermined flow rate to form a premixed gas A mixing mechanism, a secondary mixing mechanism that mixes the primary mixed gas obtained by the primary mixing mechanism with the non-mixed air that has passed through the branching mechanism, and a swirling force by using the secondary mixed gas obtained by the secondary mixing mechanism. And a premixed gas supply mechanism for supplying the premixed gas obtained by the premixed gas generation mechanism to the premixed gas combustion section. Characteristic premix gas supply equipment . 2. A premixed gas supply mechanism comprising a nozzle for ejecting a premixed gas to a premixed gas combustion section, wherein the premixed gas generation mechanism has a circular cross section having a downstream end connected to the nozzle. And a swirl vane disposed in the premixed gas generating cylinder, wherein the secondary mixing mechanism changes the direction of the secondary mixed gas while maintaining the upstream end of the premixed gas generating cylinder. A concentric and meandering secondary mixing passage that flows in the direction, and the secondary mixed gas flows uniformly in the circumferential direction into the upstream end of the premixed gas generation cylinder while rectifying the secondary mixed gas from the downstream end of the secondary mixing passage. The premixed gas supply device according to claim 1, further comprising a rectifying plate for causing the premixed gas to be supplied.