JP2659517B2 - Combustion superheater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

In recent years, in order to make effective use of the heat energy generated in a refuse incinerator, a generator that generates heat by exchanging the heat contained in the exhaust gas generated by the incinerator with a waste heat boiler. Urban garbage incineration facilities equipped with are attracting attention. Such municipal garbage incineration equipment includes a waste heat boiler that recovers waste heat from exhaust gas generated in an incinerator and generates steam,
And a power generator for generating electricity by driving the turbine with the generated steam, and a combustion superheater for heating the steam in the passage in a steam path from the waste heat boiler to the power generator. In such a combustion type superheater, when the amount of steam from the waste heat boiler is less than a predetermined amount of steam that can effectively drive the turbine,
In order to compensate for the shortage of steam, a water spray mechanism is provided. The present invention relates to a combustion type superheater provided with such a water spray mechanism, and more specifically, a combustion chamber provided with a burner for burning fuel gas, and directly connected to the combustion chamber, A heat exchange chamber into which exhaust gas generated in the combustion chamber is introduced, and a water spray mechanism provided at a base end side, and a heat spray chamber is provided at a downstream side of an installation position of the water spray mechanism from one side wall of the heat exchange chamber. A steam path introduced into the exchange chamber, a reciprocating path section reciprocating in the width direction of the heat exchange chamber, which is a direction away from and close to the one side wall, provided in the steam path existing in the heat exchange chamber, an overheat path section And a combustion type superheater configured to superheat steam flowing in the superheat path with the exhaust gas flowing in the longitudinal direction of the heat exchange chamber substantially orthogonal to the width direction of the heat exchange chamber.

[0002]

2. Description of the Related Art A conventional combustion type superheater is provided with a single burner burner at a substantially central portion in the width direction of a combustion chamber, and is disposed in the heat exchange chamber and serves as a steam passage specific portion serving as the superheat passage portion. Has been constituted by a general equal thickness pipe having the same wall thickness in the pipe axis direction. Therefore, in the heat exchange chamber, the central position in the approximate width direction of the superheat path section that traverses the chamber in the width direction is mainly heated with respect to the superheat path section (or the heat exchange chamber is heated substantially uniformly in the width direction of the heat exchange chamber). Yes) configuration was taken.

[0003]

However, as described above, the water spray mechanism is provided outside one side wall of the heat exchange chamber, and the water spray mechanism supplies water to increase the steam amount to a predetermined amount. In the combustion type superheater provided, with the water spray from the water spray mechanism, the temperature of the steam path (superheat path section) on one side wall of the heat exchange chamber located in the vicinity of the mechanism greatly decreases, In extreme cases, drainage will occur. Such a situation is unlikely to occur when water spray is used for controlling the temperature of steam, but poses a practical problem when the purpose is to increase the amount of steam as in the present application. When such a situation occurs, the life of the combustion type superheater is impaired. Further, in the combustion type superheater of this configuration, fuel gas enough to superheat the sprayed water to a predetermined superheated state is additionally supplied to the combustion chamber, and is controlled so as to keep the steam temperature constant. In the pipe, a decrease in steam temperature due to spray water occurs first, and a rise in steam temperature due to combustion overheating is easily delayed, so that it is difficult to avoid fluctuations in steam temperature. Therefore, an object of the present invention is to solve the above-mentioned conventional drawbacks, and even in a case where the amount of steam generated from a waste heat boiler is insufficient and it is necessary to perform water spray to replenish the amount of steam, the heat exchange chamber is provided. An object of the present invention is to provide a combustion type superheater that can stably generate superheated steam at a constant temperature without causing a problem such as drain in a disposed steam path (superheat path section).

[0004]

In order to achieve the above object, a combustion superheater according to the present invention is characterized in that the superheat path is heated by exhaust gas and is located on a side close to one side wall. There is provided a heating amount adjusting mechanism capable of setting the heating amount of the superheated path portion higher than the heating amount of the superheated path portion on the side to be separated. Further, in the characteristic configuration of the first aspect, the width direction of the combustion chamber and the width direction of the heat exchange chamber are configured to be the same, and the combustion chamber is provided with a multi-flame port burner having a large number of flame ports in the width direction. Preferably, the heating amount adjusting mechanism is provided with a combustion amount adjusting mechanism for adjusting and controlling the combustion amount of each of the plurality of flame openings. This configuration is claimed in claim 2
1 is a characteristic configuration of a combustion type superheater according to the present invention relating to the present invention. Furthermore, in the characteristic configuration of the above-mentioned claim 1, the combustion chamber width direction is the same as the heat exchange chamber width direction, and a single flame port burner having a single flame port in the heat exchange chamber width direction as a burner. Is preferably provided in the combustion chamber, and a single flame port burner moving mechanism for moving the position of the single flame port burner in the width direction of the heat exchange chamber is provided to form the heating amount adjusting mechanism. This configuration is claimed in claim 3
1 is a characteristic configuration of a combustion type superheater according to the present invention relating to the present invention. Furthermore, in the above-mentioned configuration of the second or third aspect, the superheat path portion is located at a position close to one side wall in a heat flow relation between steam flowing in the path and exhaust gas in the heat exchange chamber. It is preferable that the heat transmission coefficient of the part is larger in the part. This configuration is a characteristic configuration of the combustion type superheater of the present invention according to claim 4.

[0005]

When the characteristic structure according to claim 1 of the present application is adopted, the portion on the side close to one side wall of the superheated path portion is heated extra by the function of the heating amount adjusting mechanism. The superheated path is a part in which water is sprayed into the pipe by the water spray mechanism to easily cause a temperature drop and a state of steam to be most unstable. However, in the present application, since the degree of heating by the exhaust gas to this portion can be adjusted, it is possible to solve the problem of extremely lowering the steam temperature and instability of the steam state, and realize a stable operation state and a long life. A long combustion superheater can be obtained. In addition, when the decrease in steam temperature due to spray water is compensated for by adding fuel gas, the effect of both on the steam temperature (temperature decrease due to spray water and temperature increase due to additional combustion of fuel gas) occurs simultaneously. It is possible to prevent the temperature from fluctuating apparently.
In the case of adopting the characteristic configuration according to claim 2 of the present application, a multi-flame port burner is provided in the width direction of the combustion chamber (heat exchange chamber), and the combustion amount is adjusted and controlled between the flame ports in this direction. An adjustment mechanism is provided. Therefore, when water spraying is performed, the combustion amount adjusting mechanism increases the amount of combustion at the flame port on one side wall, and the superheated path portion containing water from the water spraying mechanism and flowing into the heat exchange chamber. Can be more strongly heated. Therefore, the operation described in claim 1 can be easily realized. In the case of adopting the characteristic configuration according to claim 3 of the present application, instead of the case of claim 2, a single flame port burner is provided, and a single flame port burner moving mechanism capable of moving the burner in the width direction is provided. Therefore, when water spraying is performed, the flame port is moved to one side wall by this single flame port burner moving mechanism,
It is possible to more strongly heat the one side wall side portion of the superheated path portion that contains water from the water spray mechanism and enters the heat exchange chamber. Therefore, also according to this configuration, the operation described in claim 1 can be easily realized. Claim 4 of the present application
In the case of adopting the characteristic configuration related to the above, instead of the operation of the configuration on the heating side as described above, in the configuration on the heat receiving side (superheating path portion), the amount of heating at the superheating path portion existing on one side wall side is increased. It is intended to realize rapid heating of the steam flowing in this portion. That is, by selecting a high heat transmission coefficient of the superheated path portion of the portion on one side wall side and selecting a low heat transfer rate of the separated side portion, heating on the side close to the water spray mechanism is performed early, and generation of drainage, system Instability can be avoided. As the configuration for changing the heat transmission coefficient in the pipe axis direction referred to here, as described later, the pipe inner diameter is changed in the axial direction with the same pipe outer diameter, or the pipe wall thickness is made the same in the axial direction. In the configuration of the fin provided outside the pipe outer wall, or by changing the size of the fin in the pipe axis direction, the heat transmission coefficient can be changed by changing the pipe inner diameter.
Further, since the above-described superheat amount adjusting mechanism is provided in addition to this configuration, heating control can be easily performed.

[0006]

As a result, even when the amount of steam generated from the waste heat boiler is insufficient and it is necessary to replenish the amount of steam by spraying water, the steam path ( It is possible to provide a combustion type superheater capable of stably generating superheated steam without causing a problem such as drain in the superheat path section).

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A waste power generation system employing a combustion type superheater according to the present invention will be described below. As shown in FIG. 3, the garbage incinerator is a stoker-type incinerator 1 for incinerating municipal garbage.
And an exhaust gas treatment device 2 that purifies exhaust gas generated from the incinerator 1, a power generation device 3 that generates power using heat of the exhaust gas, and the like.

The incinerator 1 includes a hopper 4 for receiving the incinerated material, a pusher Pu for injecting municipal garbage, which is an incinerated material in the hopper 4, from the lower end into the furnace, and an incinerator charged by the pusher Pu. While stirring and transporting the material, a stoker S is sequentially provided for drying, burning, and incineration with the high-temperature primary combustion air supplied from the bottom of the stoker S, and an upper portion of the stoker S is provided to complete the combustion of unburned gas. A secondary combustion space 7 is formed in the space, and a secondary combustion air supply unit 9 for supplying secondary combustion air to the space 7 is provided facing the space 7, and a space downstream of the space 7 is provided. 8 is provided with a waste heat boiler 6 for recovering the thermal energy of the combustion exhaust gas.

The exhaust gas treatment device 2 comprises a bag filter 12, a smoke washing device 13 and the like provided in the middle of a flow path from an exhaust gas passage 10 provided downstream of the space 8 to a chimney 11.

The power generator 3 comprises a steam turbine 14 and a generator 15 connected to its output shaft.
About 70 kgf / cm ² generated from the waste heat boiler 6,
The high-pressure steam of 310 ° C. is led to a combustion type superheater 17 through a steam path 16 which is a main steam path, and is superheated to about 500 ° C. by the combustion type superheater 17 before being supplied to the steam turbine 14. The steam supplied to the steam turbine 14 and used for generating all the energy is cooled by a cooler 18 through an exhaust passage 14 c, collected, and returned to a condensate passage 25 circulated to the waste heat boiler 6. In addition, a part of the steam supplied to the steam turbine 14 is extracted from the extraction passages 14 a and 14 b after a part of the energy is supplied to the power generation, and is guided to the water supply preheater 19 provided in the condensate passage 25.

A branch 20 is provided in the steam path 16, and a pressure reducing mechanism 20 a comprising a pressure reducing valve for reducing a part of the steam generated in the waste heat boiler 6 to 40 kgf / cm ² in the branch 20. An accumulator A for accumulating the reduced-pressure steam is provided, and an air passage 21 for passing the steam from the accumulator A is connected to the extraction passage 14a of the turbine 14.

In the waste heat boiler 6, not only does the steam amount of several percent fluctuate frequently in a cycle of several seconds, but also,
When the incineration condition in the incinerator 1 is good (flammable garbage is stably supplied), the amount of steam generated in the waste heat boiler 6 increases as a whole, and the incineration condition deteriorates (moisture content). (A large amount of unburnable refuse is supplied), the amount of steam generated in the waste heat boiler 6 is reduced as a whole, and the steam amount fluctuates by several tens of percent due to a period of tens of minutes. Therefore, when surplus steam is generated in response to a change in steam amount of several tens percent due to a period of tens of minutes, the flow control valve 22 provided in the steam path 16 is provided.
Is adjusted to accumulate surplus steam in the accumulator A. On the other hand, if the steam generated in the waste heat boiler 6 runs short, the accumulation of steam in the accumulator A is stopped.
The amount of heat supplied to the turbine 14 is effectively used for power generation by squeezing a bleed air amount adjustment valve 23 provided in the bleed air passage 14 a of the turbine 14, and a ventilation amount adjustment valve 24 provided in the air passage 21 is opened. , The accumulator A
(24 kgf / cm ² ) is supplied to the bleed passage 14a.

FIG. 1 is a schematic configuration diagram of a main part of a refuse incineration facility having a combustion type superheater 17 of the present invention in the steam path 16. As shown in FIG. 1, the combustion type superheater 17 is provided with a combustion chamber 17c having a multi-flame port burner 17a for burning fuel gas, and is directly connected to the combustion chamber 17c and is generated in the combustion chamber 17c. A heat exchange chamber 17b into which the exhaust gas is led. Here, the heat exchange chamber 17b
In FIG. 1, it is configured as a rectangular chamber that is long in the longitudinal direction L, which is the left-right direction, and short in the width direction M, which is the up-down direction. I have. The steam path 16 provided inside and outside the heat exchange chamber 17b of the combustion type superheater 17 will be described.
The steam passage 16 includes the water spray mechanism 17d on the base end side, and is located on the lower side (downstream) side of the installation position of the water spray mechanism 17d from one side wall 17e of the heat exchange chamber 17b into the heat exchange chamber 17b. Introduced and configured. Further, the steam path 16 includes a reciprocating path section that reciprocates in the heat exchange chamber width direction M, which is a direction away from and adjacent to the one side wall 17e, and the reciprocating path section is configured as an overheating path section 17f. On the other hand, the exhaust gas generated for heating in the combustion chamber 17c flows in the longitudinal direction L of the heat exchange chamber, which is a direction substantially orthogonal to the width direction M of the heat exchange chamber, and the steam flowing in the superheat path 17f is removed. It is configured to overheat. Here, as shown in the figure, in the embodiment shown in FIG. 1, the combustion chamber 17c and the heat exchange chamber 17b are directly connected directly and have substantially the same cross-sectional shape. M
1 and the width direction M of the heat exchange chamber are the same. Combustion chamber 1
7c, a multi-flame port burner 17a having a large number of flame ports along the combustion chamber width direction M1 is provided, and a combustion amount adjusting mechanism 17g for adjusting and controlling the combustion amount of each of the large number of flame ports is provided. I have. Therefore, it is separated from the one side wall 17e,
The amount of exhaust gas in the approach direction can be changed, and as a result, the amount of heating in this direction in the superheat path 17f is adjusted. For example, when water spray is involved, one side wall 1
The combustion amount of the flame port located on the 7e side is made larger than that on the distant side, and the width direction of the combustion chamber, that is, the heat exchange chamber 17b
In the width direction, the amount of heating increases toward the side wall. here,
In order to heat the superheat path section 17f with the exhaust gas, one side wall 17
A mechanism capable of setting the heating amount of the superheated path portion on the side close to e higher than the heating amount of the superheated path portion on the separated side is referred to as a heating amount adjustment mechanism.

Further, the piping configuration of the superheat path section 17f will be described. The pipe in this section is close to the one side wall 17e in the heat transmission relationship between the steam flowing in the path and the exhaust gas in the heat exchange chamber 17b. The position of the superheat path portion is configured such that the heat transmission coefficient of the portion is larger. That is, the pipe of this part is configured as a pipe having the same outer diameter, and the pipe thickness of the part located on the side close to the one side wall 17e is thin, and the inner diameter is reduced as the distance from the one side wall increases. The heat transmission coefficient is set to be small. This configuration is shown in FIG.
In the figure, the lower side is the one side wall 17e side, and the upper side is the separated side. Further, arrows indicate the flow direction of the steam. As such a configuration for adjusting the heat transmission coefficient, as described above, in addition to the configuration in which the outer diameter is constant and the wall thickness of the tube wall is thinner near the one side wall 17e and thicker as the distance from the side wall 17e, as shown in FIG. As described above, while the wall thickness of the pipe remains the same, it is also possible to make the pipe narrower near the side wall 17e and thicker the pipe closer to the far side.
Further, as shown in FIG. 2C, when a plurality of fins projecting in the radial direction of the pipe in the axial direction are provided on the peripheral part of the pipe having a constant thickness, the fins project closer to the side wall 17e. The fins may be configured such that the fins protrude less in the pipeline as the distance increases. This structure is the most realistic.

Next, another configuration of the combustion type superheater 17 will be described. In the combustion type superheater 17, a part of the exhaust gas discharged from the heat exchange chamber 17b as a cooling gas is supplied to a flow control valve 17h. And a cooling air supply passage 30 for supplying other exhaust gas as secondary combustion air for the incinerator 1 while providing a cooling circulation passage 17i for supplying the combustion chamber 17c to the combustion chamber 17c. Further, the overheating path portion 17f
In the middle of the above, the above-mentioned water spraying mechanism 17d is provided in two stages before and after, and the steam flow meter 17
j is provided. At the outlet of the heat exchange chamber 17b, a temperature detector 17k for detecting the temperature of the exhaust gas is provided, and the flow rate control valve 17h is adjusted so as to keep the temperature detected by the temperature detector 17k constant. I have.

Hereinafter, another embodiment of the present invention will be described.
In the above embodiment, to configure the heating amount adjusting mechanism, a multi-flame port burner, and a combustion amount adjusting mechanism for adjusting the amount of combustion between the respective flame ports, the mechanism was configured, In order to adjust the heating amount in the width direction of the combustion chamber (heat exchange chamber), even in the case where a single flame port burner is provided, this can be realized by adopting the following configuration. That is, as in the case of the above-described embodiment, when the combustion chamber width direction M1 and the heat exchange chamber width direction M are configured in the same manner, a single flame port in the heat exchange chamber width direction M1 is used as a burner. Single burner burner 1 equipped with
70a is provided in the combustion chamber 17c.
If a single-flame-port burner moving mechanism 170b for moving the position a in the width direction M of the heat exchange chamber is provided, the single-flame-port burner 170a is moved closer to the side wall 17e, for example, depending on the position of the burner 170a. Thereby, the above object can be realized. This configuration is shown in FIG.

Further, the above-mentioned heating amount adjusting mechanism can be constituted by the structure of the rectifying section 171 provided between the combustion chamber 17c and the heat exchange chamber 17b. In other words, the plurality of rectifying plates 171a constituting the rectifying portion 171 are arranged in the vertical direction of the combustion chamber 17c (the front and back direction in the example shown in FIG. 5).
Is configured so as to be movable around the axis, and when the water spray mechanism 17d is operated, the flow direction of the exhaust gas from the rectifying unit 171 is directed to the one side surface 17e side. With this configuration, a portion of the overheating path portion 17f on the side close to the one side wall 17e can be heated more, and the same effect as described above can be obtained. This configuration is shown in FIG.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of a refuse incineration system including a combustion type superheater of the present application having a multi-flame outlet burner.

FIG. 2 is a diagram showing a structure of a piping in an overheating path portion and another embodiment thereof.

FIG. 3 is a schematic configuration diagram of a garbage incineration facility.

FIG. 4 is a view showing another embodiment of the combustion type superheater of the present application provided with a single burner burner and a single burner burner moving mechanism.

FIG. 5 is a view showing another embodiment of the combustion type superheater of the present application provided with an exhaust gas flow direction adjusting mechanism.

[Explanation of symbols]

 Reference Signs List 16 steam path 17 combustion type superheater 17a multi-flame port burner 17b heat exchange chamber 17c combustion chamber 17d water spray mechanism 17e one side wall 17f superheat path section 17g combustion amount control mechanism 170a single flame burner 170b single flame burner moving mechanism M heat Exchange chamber width direction M1 Combustion chamber width direction

Claims (4)

(57) [Claims] 1. A combustion chamber (17c) having a burner for burning fuel gas, and a heat exchange chamber directly connected to the combustion chamber (17c) and into which exhaust gas generated in the combustion chamber (17c) is led. (17b), and a water spray mechanism (17d) on the base end side, and one side wall (17e) of the heat exchange chamber (17b) downstream of the installation position of the water spray mechanism (17d). A reciprocating path portion that includes a steam path (16) that is introduced into the heat exchange chamber (17b), and that reciprocates in the width direction (M) of the heat exchange chamber that is separated and approached from the one side wall (17e). A superheat path portion (17f) provided for the steam path (16) existing in the heat exchange chamber (17b), and a longitudinal direction (L) of the heat exchange chamber substantially orthogonal to the width direction (M) of the heat exchange chamber. ) With the exhaust gas flowing into the superheat path section (17).
f) a combustion type superheater for superheating the steam flowing in the superheater section, wherein the amount of heating of the superheater section on the side close to the one side wall (17e) is used to heat the superheater section (17f) with the exhaust gas. The combustion type superheater provided with a heating amount adjusting mechanism for setting the heating amount higher than the heating amount of the superheated path portion on the separated side. 2. The combustion chamber width direction (M1) and the heat exchange chamber width direction (M) are configured to be the same, and the combustion chamber (17
c) includes a multi-flame burner (17a) having a plurality of flames in the width direction thereof, and a combustion amount adjusting mechanism (17g) for adjusting and controlling the combustion amount of each of the plurality of flames. The combustion type superheater according to claim 1, wherein a heating amount adjusting mechanism is configured. 3. The combustion chamber width direction (M1) and the heat exchange chamber width direction (M) are configured to be the same, and a single flame port is provided as the burner in the heat exchange chamber width direction (M). A single flame port burner (170a) provided in the combustion chamber (17c) and a single flame port burner moving mechanism (17) for moving the single flame port burner (170a) in the width direction (M) of the heat exchange chamber.
The combustion type superheater according to claim 1, wherein the heating amount adjusting mechanism is configured to include 0b). 4. The superheat path section (17f) comprises:
In the heat flow relationship between the steam flowing in the passage and the exhaust gas in the heat exchange chamber (17b), the one side wall (1
The combustion type superheater according to claim 2 or 3, wherein the superheat path portion located closer to 7e) has a higher heat transmission coefficient at the portion.