KR20180132506A - Burner device for submerged combustion vaporizer - Google Patents

Abstract

(Problem) The combustion state is improved by making the flow of air in the burner uniform, thereby suppressing the generation of harmful substances.
A burner apparatus (1) for an underwater combustion type vaporizing apparatus includes an inner cylinder (2) for partitioning an air flow path for combustion, an outer cylinder (3) arranged coaxially to the inner cylinder (2) A top plate 4 provided at an upper end of the outer cylinder 3 and forming a space between the inner cylinder 2 and the upper end of the inner cylinder 2, And the air has an inlet flow passage 5 which pivots in one direction around the central axis of the outer cylinder 3. [

Description

FIELD OF THE INVENTION [0001] The present invention relates to a burner device for an underwater combustion type vaporizer,

The present invention relates to a burner apparatus used in an underwater combustion vaporizer.

In the underwater combustion type LNG vaporizer, the burner has a function of stabilizing the flame with a flame stabilizer in the inner cylinder to burn in the downcomer and to supply the secondary air to the outer circumference of the flame. In the burner, an inner cylinder for partitioning an air passage for combustion is provided, and secondary air is passed through an annular passage between the primary air and the inner passage outer cylinder to the inner cylinder (refer to Patent Document 1 below).

  In such a burner apparatus, the ratio of the primary air and the secondary air is adjusted in accordance with the amount of fuel (load of the burner) supplied to the burner, while maintaining the flow rate of the air supplied from the blower at a predetermined set amount. Specifically, when the supplied fuel amount is small (load is low), the primary air is made small and the secondary air is made large, and when the supplied fuel amount is large (load is high) Less air. By this adjustment, the flow rate of the air supplied from the blower is set to a predetermined amount, and combustion at an optimum air-fuel ratio in the entire combustion range is realized.

Japanese Laid-Open Patent Publication No. 2013-2734

1 (a), the burner J is disposed in the direction perpendicular to the burner axis J0, which is the central axis of the inner cylinder J1 and the outer cylinder J2, And a flow path J3. In the annular passage between the inner passage J3 and the inner passage J1 and the outer cylinder J2, there is provided a partition wall J4 for dividing the flow path up and down. The air flowing in the upper side of the partition wall J4 of the air introduced into the inlet passage J3 is discharged from the space below the top plate J5 of the burner J as the primary air through the fuel gas nozzle J7 And the air flowing below the partition wall J4 flows from the space between the inner cylinder J1 and the outer cylinder J2 into the lower portion of the burner J as the secondary air And is introduced into the downcomer J6 which is connected to the downstream side.

In this conventional burner apparatus, as shown in Fig. 1 (b), the air introduced from the inlet passage J3 is divided into left and right channels in an annular oil passage between the inner cylinder J1 and the outer cylinder J2 And collides at a portion T opposed to the inlet passage J3 to rise from the upper side of the partition wall J4 to become primary air and down from the lower side of the partition wall J4 to become secondary air. Therefore, both the primary air and the secondary air are increased in pressure in the space T between the inner cylinder J1 and the outer cylinder J2 where the air flow collides, (Drift) of the flow distribution occurs.

As described above, when the primary air and the secondary air both have a large amount of flow at the portion T opposed to the inlet passage J3 and a nonuniform air flow distribution that flows less at the inlet passage J3 side, Particularly, in the downcomer on the side of the portion T, the flame is diluted with a large amount of air and is excessively cooled, so that the combustion temperature is lowered and the generation of harmful substances such as carbon monoxide is increased .

  The present invention is directed to coping with such circumstances. That is, it is an object of the present invention to uniformize the flow in the circumferential direction in the burner to uniformize the combustion in the circumferential direction to improve the combustion state, thereby suppressing the generation of harmful substances.

In order to solve these problems, the present invention has the following configuration.

A top plate which is provided at an upper end of the outer cylinder and forms a space between the upper end of the outer cylinder and the upper end of the outer cylinder; Wherein the air flowing between the inner passage and the outer casing is provided with an inlet flow passage pivoting in one direction around the central axis of the outer casing.

According to the present invention having such features, the air flow in the burner can be made uniform by circulating the air injected between the inner and outer tubes of the burner apparatus in one direction around the central axis of the outer tube (or inner tube). Thus, the combustion state of the burner can be improved and the generation of harmful substances can be suppressed.

1 (a) is a longitudinal sectional view along the central axis, and Fig. 1 (b) is a transverse sectional view (X1-X1 sectional view or X2-X2 sectional view) of an inner cylinder and an outer cylinder orthogonal to the central axis .
FIG. 2 is an explanatory diagram of a burner apparatus (an example in which a baffle plate is provided) according to one embodiment of the present invention (FIG. 2 (a) is a longitudinal section along the central axis, And a cross-sectional view (X1-X1 sectional view or X2-X2 sectional view) of the outer cylinder.
3 is an explanatory view showing an example of the structure of the primary air swirler and the secondary air swirler (Fig. 3 (a) is a view showing a structure in which the ratio of the overlapping length L of the adjacent swirler to the blade interval P is larger than 1 (L / P > 1)). For example, FIG. 3 (b) shows that the ratio of the overlapping length L of the adjacent vortices to the blade interval P is less than 1 (L / P <1).
4 is an explanatory view schematically showing the combustion state of the burner apparatus according to the embodiment of the present invention.
FIG. 5 is an explanatory diagram (an example in which the direction in which the inlet flow path is eccentric) according to another embodiment of the present invention (FIG. 5A is a vertical sectional view along the central axis, and FIG. 5B is a cross- (X1-X1 cross-sectional view or X2-X2 cross-sectional view)).
6 is an explanatory view showing a burner apparatus (an example in which a plurality of fuel gas nozzles are formed) according to another embodiment of the present invention.
7 is an explanatory view showing an underwater vaporization apparatus (SMV) provided with a burner apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, like reference numerals in the other drawings denote parts having the same function, and redundant description in each drawing is omitted as appropriate.

2, the burner apparatus 1 is provided with an inner cylinder 2 for defining an air flow path for combustion, an outer cylinder 3 arranged coaxially with the inner cylinder 2, And a top plate (4) for forming a space between the top end of the inner tube (2). A fuel gas nozzle 6 is disposed below the inner cylinder 2. In addition, the outer cylinder 3 is provided with an inlet channel 5 for introducing air from the side of the outer cylinder 3.

In the example shown in the drawing, a partition wall 7 dividing the space into upper and lower spaces is provided between the inlet passage 5 and the inner cylinder 2 and the outer cylinder 3. An upper side of the partition wall 7 The air flowing in the lower side of the partition wall 7 flows into the downcomer 8 which is connected to the lower end of the outer cylinder 3 and the secondary air flows into the downcomer 8, do.

2, a space between the inner cylinder 2 and the outer cylinder 3 is defined on the side of one end of the inlet passage 5 as a center axis (the inner cylinder 2 and the outer cylinder 3) And a baffle plate 10 which is parallel to the center axis O of the baffle plate. 2 (b), the flow of air introduced between the inner cylinder 2 and the outer cylinder 3 in the direction toward the baffle plate 10 is limited, A flow swirling in only one direction around the central axis O is formed in the annular flow path between the inner cylinder 2 and the outer cylinder 3 by the air introduced from the flow path 5. [

According to such a burner apparatus 1, air flowing in a space between the inner cylinder 2 and the outer cylinder 3 is prevented from being divided and collided in different directions to increase the pressure, can do. Such equalization of the air flow rate can be obtained from both the primary air flowing above the division wall 7 and the secondary air flowing below the division wall 7. [

The primary air flowing on the upper side of the partition wall 7 flows into the inner cylinder 2 via the lower space of the top plate 4 and becomes a swirling flow in the inner cylinder 2, 6 into the downcomer 8 (combustion chamber S) through the primary air swirler 11 disposed on the outer periphery of the downcomer 8.

The primary air swirler 11 disposed at the lower portion of the inner cylinder 2 has a plurality of swirling vanes as will be described later and rotates the space between the inner cylinder 2 and the outer cylinder 3 only in one direction And has a function of further strengthening or maintaining the swirling flow of the primary air. As a result, a swirling flow with no flow (uneven flow rate distribution) flows into the downcomer 8, and the fuel gas and the primary air ejected from the jet port 6A of the fuel gas nozzle 6 are uniformly And mixed.

The secondary air flowing below the division wall 7 passes through the annular flow path between the inner cylinder 2 and the outer cylinder 3 while turning in one direction and flows through the annular flow path between the inner cylinder 2 and the outer cylinder 3 And flows into the downcomer 8 through the secondary air swirler 12 to the secondary air outlet of the annular flow path. The secondary air swirler 12 has a plurality of swirling vanes as will be described later, and swirls the secondary air swirling only in one direction between the inner cylinder 2 and the outer cylinder 3 It has the ability to strengthen or maintain. This makes it possible to form a swirling flow of secondary air (without uniform flow distribution) around the flame formed in the downcomer 8 (combustion chamber S) The phenomenon that the formed flame is locally cooled can be suppressed.

Fig. 3 shows a configuration example of the above-described primary air wheel turning machine 11 and secondary air wheel turning machine 12. Fig. The primary air swirler 11 and the secondary air swirler 12 have a plurality of swirlers 20. The swirling vane 20 has an airflow guide surface 20A inclined at a predetermined angle (for example, 45 占 with respect to the central axis O in Fig. 2) Axis symmetry. The dimension and positional relationship between the blade pitch P (number of turns) and the length (the overlap length L of the adjacent vortexes) of the vortex 20 is such that the distance between the inner tube 2 and the outer tube 3 So as to reliably provide turning to the air flowing through the annular flow path.

3A, when the ratio of the overlapping length L of the adjacent vortexes 20 to the vane spacing P is larger than 1, the distance between the airflow guide surfaces 20A of the vane 20 Most of the flow of air passing therethrough is regulated by the inclination angle of the airflow guide surface 20A. Therefore, by properly setting the angle of the vane 20, it is possible to obtain an effect of further strengthening or maintaining the swirling flow of the air flowing through the space between the inner cylinder 2 and the outer cylinder 3.

3 (b), when the ratio of the overlapping length L of the adjacent vortexes 20 to the vane spacing P is smaller than 1, the air flow guide surface 20A of the vane 20, The flow of the air passing between the airflow guide surface 20A and the airflow guide surface 20A is largely unaffected by the inclination angle of the airflow guide surface 20A. Therefore, a flow of air is formed irrespective of the angle of the swirler vane 20, so that it is not possible to add a further swirling force to the swirling flow of air flowing in the space between the inner cylinder 2 and the outer cylinder 3 do.

Fig. 4 schematically shows the combustion state of the burner apparatus 1. As shown in Fig. When the fuel gas is radially ejected from the fuel gas nozzle 6 having a plurality of radial ejection openings 6A, the swirling flow AR1 of the primary air is formed around the circumference, and the fuel gas in the circumferential direction and the primary air Is uniformly axially symmetrical. The flame F in the downcomer 8 is shaped like a bell by the generation of the swirling flow of the mixer (mixing), and the combustion reaction proceeds uniformly in the axisymmetric manner. Therefore, Generation of minute particles is suppressed.

In the case of a burner having a large amount of combustion, as shown in Fig. 6, four to eight fuel gas nozzles 6 having injection ports 6A of a plurality of fuel gas radially are arranged in a ring-like shape. In this case, the primary air swirler 11 is disposed inside a plurality of fuel gas nozzles 6 arranged in a torus shape. When the fuel gas nozzles 6 are made plural, the fuel gas is dispersed and injected in the primary air flow, so that the mixing of the fuel gas and the primary air is promoted.

The swirling flow AR2 of the secondary air is formed in the outer peripheral portion of the downcomer 8 by the secondary air swirling flow that flows out between the inner cylinder 2 and the outer cylinder 3. [ A strong swirling flow is formed in the downcomer 8 by the phase effect of the primary air swirling flow AR1 and the secondary air swirling flow AR2 on the inner side. By the strong turning, a negative pressure region is formed in the vicinity of the upper center in the downcomer 8, and the back flow (recirculation flow) of the combustion exhaust gas G is formed.

The flame spreads in the downcomer 8 due to the strong turning and the tip of the flame F is wound inward by the recirculation flow in the central portion so that the length of the flame F can be shortened. The combustion exhaust gas G which is an inert gas having a small oxygen content is mixed with the flame F on the inner side of the flame F and the oxygen concentration in the flame F is lowered and the flame temperature is lowered , The NOx reduction effect can be expected.

Fig. 5 shows another configuration example of the burner apparatus 1. As shown in Fig. In this example, the inlet direction of the inlet channel 5 of the burner apparatus 1 is disposed toward the tangential direction of the outer peripheral circle of the inner cylinder 2. In this way, the air introduced from the side of the outer cylinder 3 shifts in the space between the inner cylinder 2 and the outer cylinder 3 by shifting the loading direction of the inlet channel 5 laterally from the center line O, The swirling flow turns in one direction around the axis. The swirling flow of the primary air can be sent to the downcomer 8 (combustion chamber S) and the swirling flow of the secondary air can be sent to the downcomer 8 similarly to the above-described example . According to this example as well, a favorable combustion state as shown in Fig. 4 can be obtained.

The burner apparatus 1 described above can be applied to various boilers such as a water pipe boiler and a non-pipe-related boiler, but in this case, the burner apparatus 1 is arranged horizontally. Fig. 7 shows a submerged combustion vaporizer equipped with a burner apparatus 1. As shown in Fig.

The in-water vaporization device 30 of the present embodiment is a vaporizing device for liquefied natural gas (LNG), for example, a plurality of heat transfer pipes 32a which are immersed in a rectangular parallelepiped- And a heat exchanger (32) configured by bending in multiple stages. One end of the heat exchanger 32 communicates with the LNG introduction pipe 32b serving as the inlet of the LNG and the other end communicates with the NG discharge pipe 31c discharging the vaporized natural gas (NG). In Fig. 7, the bundle of heat transfer tubes 32a is illustrated as being simplified, but actually, heat transfer tubes 32a of a plurality of rows are arranged in the passageway of Fig. 7 and are in communication with each other.

The water tank 31 is covered with, for example, a top plate 31a in the form of a rectangular plate. The top plate 31a can be hung by an operator, and a cylindrical downcomer 8 is arranged at a predetermined position so as to be immersed in the water tub 31. [

At the upper end of the downcomer 8, the above-described burner apparatus 1 is disposed. A fuel supply pipe 40 communicating with the above-described fuel gas nozzle 6 is connected to the burner apparatus 1 and a blower 34 communicating with the aforementioned inlet flow path 5 is connected.

A sparge pipe 35 communicating with the downcomer 8 and formed with a plurality of small holes 35a through which the combustion gas of the burner apparatus 1 is formed is disposed at the bottom of the water tank 31. [ This sparge pipe 35 is actually arranged in a plurality of directions in the longitudinal direction of Fig. 7, and the bubble B containing the combustion gas drifts over the entire heat exchanger 32. [

A manifold 37 is interposed between the downcomer 8 and each sparge pipe 35. The base end of the manifold 37 is connected to the lower end of the downcomer 8 and extends in the direction in which the sparge pipe 35 is juxtaposed. Each spark pipe 35 communicates with the manifold 37. The manifold 37 has a function of distributing the combustion gas discharged from the downcomer 8 to each spark pipe 35 I have.

A stack (chimney) 36 for exhausting the combustion exhaust gas is provided on the top plate 31a of the water tank 31, and the upper end thereof communicates with the atmosphere.

Such an underwater combustion vaporizer 30 sprays the combustion gas of the burner apparatus 1 into the water tank 31 through the small holes 35a of the sparge pipe 35 as bubbles B, While stirring the water, the LNG passing through the heat exchanger 32 is heated. Thereby, the LNG is vaporized to NG, and the LNG is sent out from the outlet of the NG discharge pipe 31c. The underwater combustion vaporizer 30 sprays combustion gas into the water tank 31 as a bubble B and stirs the water in the water tank 31 to promote heat transfer from the hot water to the heat exchanger, The heat transfer from the bubbles B to the hot water becomes good and the temperature of the combustion exhaust gas discharged from the water tank to the stack is lowered to almost the hot water temperature. In the course of the heat exchange between the bubbles B and the hot water, the gaseous state moisture (steam) in the combustion gas is almost condensed to become a liquid when the temperature is lowered, and most of the latent heat is given to the hot water. have.

In the case where the above-described burner apparatus 1 is used in such an underwater combustion vaporizer 30, the generation of harmful substances such as carbon monoxide and NOx can be prevented by the improvement of the combustion state, Both of the high load operation and the high load operation can improve the environmental performance. Further, in the case of using the burner apparatus 1 described above, since the secondary air introduced into the downcomer 8 can be effectively turned, it is possible to improve the combustion characteristics of a low load with a large secondary air flow rate have.

Although the embodiment of the present invention has been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and even if the design is changed within the range not deviating from the gist of the present invention, do. Further, each of the above-described embodiments can combine the techniques with each other so long as there are no contradictions or problems particularly with respect to its object and configuration.

1: burner device, 2: inner tube, 3: outer tube, 4: top plate, 5:
6: fuel gas nozzle, 6A: jet port, 7: partition wall, 8: downcomer,
10: baffle plate, 11: primary air swirler, 12: secondary air swirler,
20: turning wing, 20A: air flow guide surface, 30: underwater combustion vaporizer,
S: combustion chamber, O: center axis

Claims (10)

An inner passage for partitioning the air passage for combustion,
An outer cylinder disposed coaxially with the inner cylinder,
A top plate provided at an upper end of the outer cylinder to form a space between the upper end of the inner cylinder and the upper end of the outer cylinder,
Wherein the air flowing from the side of the outer cylinder to the air passing between the inner and outer cylinders has an inlet flow path which swings in one direction around the central axis of the outer cylinder. The method according to claim 1,
Wherein a baffle plate is provided on one side of the inlet passage so as to divide a space between the inner passage and the outer passage along the central axis. The method according to claim 1,
Wherein an inlet direction of the inlet channel is disposed toward a tangential direction of an outer peripheral circle of the inner cylinder. 4. The method according to any one of claims 1 to 3,
A partition wall for dividing a space into upper and lower spaces is provided between the inlet passage and the inner passage and the outer cylinder, and air injected to the upper side of the partition wall becomes primary air flowing into the inner cylinder, Wherein the air introduced into the lower side of the wall is secondary air introduced into a downcomer connected to the outer cylinder. 4. The method according to any one of claims 1 to 3,
In the inner cylinder, a fuel gas nozzle is disposed, a primary air circulator is disposed,
Wherein the primary air swirler includes a plurality of swirling vanes having an airflow guide surface inclined with respect to the central axis, wherein a ratio of the overlapping length of the adjacent swirling vanes to the vane interval is greater than 1, A burner device for a device. 4. The method according to any one of claims 1 to 3,
A secondary air swirler is provided between the inner passage and the outer cylinder,
The secondary air swirler includes:
Wherein a plurality of swirling vanes having an airflow guide surface inclined with respect to the central axis are provided, and the ratio of the overlapping length of the adjacent swirling vanes to the vane interval is larger than 1. A burner apparatus for an underwater combustion vaporizer, comprising: 5. The method of claim 4,
In the inner cylinder, a fuel gas nozzle is disposed, a primary air circulator is disposed,
Wherein the primary air swirler includes a plurality of swirling vanes having an airflow guide surface inclined with respect to the central axis, wherein a ratio of the overlapping length of the adjacent swirling vanes to the vane interval is greater than 1, A burner device for a device. 5. The method of claim 4,
A secondary air swirler is provided between the inner passage and the outer cylinder,
The secondary air swirler includes:
Wherein a plurality of swirling vanes having an airflow guide surface inclined with respect to the central axis are provided, and the ratio of the overlapping length of the adjacent swirling vanes to the vane interval is larger than 1. A burner apparatus for an underwater combustion vaporizer, comprising: 6. The method of claim 5,
A secondary air swirler is provided between the inner passage and the outer cylinder,
The secondary air swirler includes:
Wherein a plurality of swirling vanes having an airflow guide surface inclined with respect to the central axis are provided, and the ratio of the overlapping length of the adjacent swirling vanes to the vane interval is larger than 1. A burner apparatus for an underwater combustion vaporizer, comprising: 8. The method of claim 7,
A secondary air swirler is provided between the inner passage and the outer cylinder,
The secondary air swirler includes:
Wherein a plurality of swirling vanes having an airflow guide surface inclined with respect to the central axis are provided, and the ratio of the overlapping length of the adjacent swirling vanes to the vane interval is larger than 1. A burner apparatus for an underwater combustion vaporizer, comprising:

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