KR20080057886A - Method and device for cooling of bottom ash in circulating fluidized bed combustion boiler - Google Patents

Abstract

An apparatus and a method of cooling ashes on the bottom in a circulating fluidized bed combustion boiler are provided to reduce the load of a cooler and raise boiler efficiency by improving an ash movement structure. An ash outlet pipe(110) is connected to one end of a bottom surface of a boiler(100) so that ashes on the bottom surface are withdrawn by the gravity. A ash removing unit(120) is connected to an external device to supply compressed air and removes minute particles of the aches from the air outlet pipe by injecting compressed air into the ash outlet pipe. An ash amount adjusting unit(130) opens or closes a passage of the ash outlet pipe to adjust an amount of withdrawn ashes. A cooler(140) includes a plurality of nozzles(142) to inject air in order to cool or move the ashes. An heated air inlet pipe(150) connects the cooler with a boiler to supply heated air to the boiler.

Description

Floor and Cooling System for Circulating Fluidized Bed Boiler {Method and Device for Cooling of Bottom Ash in Circulating Fluidized Bed Combustion Boiler}

1 is a sectional front view showing the configuration of a conventional flooring cooling device;

Figure 2 is a plan sectional view showing the configuration of a conventional floor ash cooling device,

Figure 3 is a schematic diagram showing the configuration of the floor ash cooling apparatus of the circulating fluidized bed combustion boiler according to a preferred embodiment of the present invention,

4 is a cross-sectional view showing the configuration of a first on-off valve of the present invention;

5 is a plan sectional view showing an internal structure of a cooler according to the present invention;

6 is a plan sectional view showing another internal structure of the cooler according to the present invention;

7 is a plan sectional view showing another internal structure of the cooler according to the present invention;

8 is a plan view of a nozzle according to the present invention;

<Description of the symbols for the main parts of the drawings>

100: boiler 110: withdrawal tube

(120): flooring separator (130): withdrawal adjustment means

(131): first on-off valve (131a): housing

131b: opening and closing member 131c: opening and closing cylinder

(132): second on-off valve 140: cooler

141: guide wall 142: nozzle

143: flow path 144: protruding wall

(145): circulating pipe (150): heating air input pipe

160: auxiliary injector 161: valve

The present invention relates to a bottom ash cooling device of a circulating fluidized bed combustion boiler, and in particular, to improve the structure of separating fine particles in the bottom ash, and to improve the flow structure of the bottom ash in the cooler to reduce the load of the cooler and improve the efficiency of the boiler. The floor ash cooling apparatus of the circulating fluidized bed combustion boiler that can.

In general, the circulating fluidized bed combustion boiler has a wide range of application for various fuels (coal, sludge, solidified fuel, etc.), and the operating temperature (870 ℃) is relatively lower than that of pulverized coal-fired combustion or general incinerator combustion. It is less, it is possible to desulfurize the furnace by injecting limestone during the combustion process, and has the advantage of easy temperature control in the furnace.

The circulating fluidized bed combustion boiler as described above is to burn the fuel injected into the boiler while fluidizing with the flooring to generate steam for supply to the steam turbine for power generation. As such, the bottom ash used for the combustion of fuel is cooled and discharged through the cooler, and the heated air used for cooling the bottom ash and fine particles separated from the bottom ash are supplied to the boiler to assist the combustion and heat transfer of the fuel to improve the efficiency of the boiler. Will be improved.

An example of a cooler for cooling a flooring as described above is disclosed in US Pat. No. 5,218,932. The published cooler 20 is connected to the bottom side A of the boiler 10 as shown in FIGS. 1 and 2 by means of a duct 11 and installed to receive the flooring A. The guide walls 21 are separated. Here, the front end of the cooler 20 separated by the guide wall 21 is used as a separation chamber 20-1 for separating fine particles and resupplying it to the boiler, and the rear end is a cooling chamber 20-2 for cooling the flooring material. It is used, the guide wall 21 has a sand structure so as to increase the residence time in the cooler of the incoming flooring material to be sufficiently cooled to the required temperature.

In addition, an air injection nozzle 30 is installed at the bottom of the cooler 20, and the separation chamber 20-1 separates particles for injecting heated combustion air or circulating combustion gas, and also combustion air or circulating combustion. The gas is recycled to the inside of the boiler, and in the cooling chamber 20-2, the combustion air at room temperature is injected to cool the flooring material, and the heated air is introduced into the boiler to be used as the combustion air. .

However, the cooler as described above separates the fine particles of the flooring material from the separation chamber 20-1 of the cooler 20, so that the load of the cooler increases, and to the injection air of the nozzle installed in the bottom of the boiler and the duct 11. It is difficult to control the amount of drawing according to the condition of the flooring material as the flooring material is pulled out and stopped by the flooring material.In addition, even when the injection air of the nozzle is stopped, the excess flooring material is supplied to the cooler or the outlet or the nozzle is blocked by the flooring material. There is a problem in that it is impossible to withdraw the flooring to stop the operation of the boiler.

In addition, it is difficult to control the floor ash withdrawal as described above, and continuous operation is impossible, and intermittent operation is inevitable, and if the floor ash is excessively drawn, it may impede the efficient operation of the boiler. As the pressure and combustion state inside the boiler is changed repeatedly, the operating state of the surrounding equipment must also be repeatedly modified, which makes it difficult to operate the boiler stably.

On the other hand, some components are used to separate the fine particles from the cooler's separation chamber by separating them from the cooler's separation chamber, but require periodic maintenance due to deterioration and wear of the separate separation chamber. There was a problem.

The present invention has been made in consideration of the above problems, and an object of the present invention is to easily control the amount of extraction of the flooring material, and circulating fluidized bed combustion in which fine particles are naturally separated during extraction of the flooring material from the boiler to reduce the load of the cooler. To provide a boiler floor cooling device.

Another object of the present invention is to provide a bottom ash cooling apparatus of a circulating fluidized bed combustion boiler capable of uniformly cooling the bottom ash by improving the bottom ash flow structure in the cooler so that the bottom ash flows smoothly without partially stagnation.

The present invention to achieve the object as described above and to perform the problem for eliminating the conventional drawback is connected to the bottom end of the boiler drawer tube to draw the bottom ash in the boiler by gravity;

A flooring separator installed in the outlet pipe and connected to an external device for supplying compressed air to separate the fine particles of the flooring material drawn out through the outlet pipe by spraying compressed air into the outlet pipe;

A pull-out amount adjusting means installed in the draw-out pipe to adjust the opening or withdrawal of the flooring material by controlling the opening and closing of the flow path of the drawing pipe;

Is connected to the other end of the outlet pipe is supplied with a flooring material, the guide wall is provided to form a spiral or similar-shaped flow path therein, a plurality of injecting air for cooling and flow of the floor material on the bottom of the flow path A cooler equipped with nozzles; And

It characterized in that the bottom ash cooling device of the circulating fluidized bed combustion boiler having a; connecting the cooler and the boiler, the heating air inlet pipe for supplying the heated air used to cool the floor ash to the boiler.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Figure 3 shows a schematic diagram showing the configuration of the bottom ash cooling device of the circulating fluidized bed combustion boiler according to a preferred embodiment of the present invention. Referring to FIG. 3, the flooring material cooling apparatus according to the preferred embodiment of the present invention includes a drawing pipe 110, a flooring material separator 120, a drawing amount adjusting means 130, a cooler 140, and heating air input. It consists of a tube 150. Such a floor ash cooling device is configured to draw the floor ash by gravity, and the fine particles are firstly separated by gravity and fluidity when the floor ash is taken out, and the second ash is separated through the bottom ash separator 120, thereby being introduced into the cooler 140. It is configured to reduce the load of the cooler 140 by minimizing fine particles, and the inside of the cooler 140 has a flow path 143 of the spiral or similar shape by the guide wall 141 to see the bottom ash It is configured to effectively cool, and each component is described in detail as follows.

The outlet pipe 110 connects the boiler 100 and the cooler 140 to form a passage through which the bottom ash drawn out from the boiler 100 is supplied to the cooler 140, and one end of the outlet pipe 110 is connected to the bottom surface of the boiler 100. The other end is configured to be connected to the top or side of the cooler 140.

The flooring separator 120 is installed in the outlet pipe 110 to separate fine particles in the floor ash drawn out through the outlet pipe 110 to be re-supplied to the boiler 100, not shown to supply compressed air It is connected to the external device, it is configured to spray the supplied compressed air into the outlet pipe (110). Here, a conventional blower and an air compressor may be used as the external device, and an air distribution pipe and a nozzle may be used as a means for injecting compressed air into the drawing pipe 110.

The drawing amount adjusting means 130 is to block the bottom ash drawn out through the drawing pipe 110 or to adjust the drawing amount of the bottom ash, it is composed of the first opening and closing valve 131 and the second opening and closing valve 132. . In this case, the first opening / closing valve 131 is installed to be positioned higher than the second opening / closing valve 132 to perform the function of opening and closing the drawing pipe 110, and is closed when the drawing stop or the maintenance of the connection facility is installed. 2 opening and closing valve 132 is to control the amount of drawing the flooring material by controlling the area in which the outlet pipe 110 is opened.

4 is a sectional view showing the configuration of the first on-off valve of the present invention. Referring to FIG. 4, the first and second on / off valves 131 and 132 have the same configuration except that the positions and operating functions of the first and second on / off valves 131 and 132 are described. ) Is composed of a housing (131a), the opening and closing member (131b) and the opening and closing cylinder (131c). The housing 131a provides a space in which the opening / closing member 131b is installed, and is installed in the drawing pipe 110 and is configured to form a flow path that is continuous with the flow path of the drawing pipe 110. The opening and closing member 131b is rotatably installed in the housing 131a and configured to open and close the flow path, and is configured to receive a load less by the flooring material with which the upper end is drawn out during rotation. The opening and closing cylinder 131c is connected to the opening and closing member 131b and configured to rotate the opening and closing member 131b by pneumatic pressure.

Among the first and second on-off valves 131 and 132 as described above, the first on-off valve 131 is always open when the boiler 100 is operated, and is closed when the drawing stop or the connection facility is repaired, and the second on-off valve 132 is By controlling the area in which the drawing pipe 110 is opened, the drawing amount of the flooring material is adjusted.

Figure 5 shows a plan sectional view showing the internal structure of the cooler according to the present invention, Figure 6 shows a plan sectional view showing another internal structure of the cooler according to the present invention, Figure 7 is a view of the cooler according to the present invention A cross-sectional view showing another internal structure is shown. 5 to 7, the cooler 140 cools the flooring material to an appropriate temperature, and is provided with a guide wall 141 that forms a flow path 143 having a spiral or similar shape, and the flooring material on the floor. A plurality of nozzles 142 are provided to provide air for cooling and flow of the air. Meanwhile, the helical guide wall 141 may be configured such that the distance between neighboring guide walls 141 is always constant so that the width of the flow path 143 is uniform (see FIG. 5). The distance between the adjacent guide walls 141 may be irregular so that the width is irregular (see FIG. 6). In addition, when the width of the flow path 143 is uniform, a plurality of protruding walls 144 for inducing bottlenecks to increase the residence time in the cooler 140 of the flooring at regular intervals may be formed in the guide wall 141. It may be formed to protrude laterally (see FIG. 7).

On the other hand, when the width of the flow path 143 is uniform as described above, it is possible to cool the flooring as a whole, and the width of the flow path 143 is irregular or protruding wall protruding in the side direction of the guide wall 141. When 144 is provided, a bottleneck occurs in the flow of the flooring material, thereby increasing the residence time in the cooler 140 of the flooring material. Therefore, the width of the flow path 143 is uniformly or irregularly formed in consideration of the capacity of the boiler 100 and the cooler 140.

Referring to FIG. 3 again, at least one of the floor, the wall, and the ceiling constituting the cooler 140 is provided with a circulation pipe 145 through which the boiler feed water is circulated to cool the flooring more effectively and to supply the boiler feed water. It is configured to allow preheating.

8 shows a top view of a nozzle according to the invention. Referring to FIG. 8, each nozzle 142 provided in the cooler 140 to supply air for cooling and flowing the flooring material is provided with at least two air injection holes 142a to have one existing air injection hole. Compared to using a nozzle, a smaller number of nozzles are required, thereby facilitating installation and repair work and improving heat exchange efficiency between flooring and air.

Referring to FIG. 3 again, the heating air inlet pipe 150 is used to cool the flooring material by connecting the cooler 140 and the boiler 100 so that the air in the heated cooler 140 is introduced into the boiler 100. It is configured to be used as combustion air.

Meanwhile, when the outlet pipe 110 is blocked by the flooring material, an auxiliary injector 160 may be further provided to inject the high-pressure compressed air into the outlet pipe 110 to pierce the blocked outlet pipe 110. The auxiliary injector 160 is installed in the flooring separator 120, is connected to an external device for supplying high-pressure compressed air, and is provided with a valve 161 that is opened and closed by an automatic injection by a timer or a manager's operation. When opening 161, the high pressure compressed air is injected into the outlet pipe 110 to pierce a portion blocked by the flooring material.

Referring to the operation of the flooring cooling device configured as described above are as follows.

The flooring material used for the combustion of fuel in the boiler 100 is introduced into the drawing pipe 110 by gravity. At this time, some of the relatively light fine particles are separated from the bottom ash is introduced back into the boiler 100.

On the other hand, the bottom ash introduced into the outlet pipe 110 is further subjected to the process of separating the fine particles by the bottom ash separator 120. That is, the fine particles in the bottom ash introduced into the outlet pipe 110 are floated by the compressed air injected into the outlet pipe 110 by the bottom ash separator 120, and then introduced back into the boiler 100, and only the remaining floor ash is cooled by the cooler ( 140).

Meanwhile, the first opening / closing valve 131 installed on the drawing pipe 110 maintains an open state during the operation of the boiler 100 so as to secure a flow path so that the flooring material passed through the flooring material separator 120 can be continuously drawn out. The second opening / closing valve 132 positioned below the first opening / closing valve 131 controls the opening area of the flow path so that the appropriate amount of flooring material can be supplied to the cooler 140.

The flooring material supplied to the cooler 140 through the outlet pipe 110 is cooled while passing through a spiral or similar-shaped flow path 143 by nozzles 142 provided at the bottom of the cooler 140, wherein the flow While the residence time of the flooring is increased by the furnace structure, it is more effectively cooled by the boiler feed water flowing through the circulation pipe 145 provided on the bottom, wall, or ceiling of the cooler 140, and cooled to a constant temperature. It is discharged to a predetermined place through a discharge pipe provided at the end of the flow path (143).

On the other hand, the air used to cool the flooring material is heated to the boiler 100 through the heating air inlet pipe 150 to be used as the combustion air of the fuel.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

The present invention can reduce the load of the cooler by separating the fine particles before the flooring is supplied to the cooler by using a flooring separator for spraying compressed air to the flooring material is drawn out in the manner that the flooring is drawn out by gravity as described above. . Furthermore, the first and second opening and closing valves facilitate the control and opening and closing of the drawing amount, and the flooring material can be cooled uniformly and effectively as a whole by a cooler having a flow path having a spiral or similar shape structure.

Claims (9)

A drawing pipe 110 having one end connected to a bottom of the boiler 100 so that the flooring material in the boiler 100 is drawn out by gravity; A flooring separator installed at the outlet pipe 110 and connected to an external device for supplying compressed air to separate compressed particles of the flooring material drawn out through the outlet pipe 110 by spraying compressed air to the outlet pipe 110 ( 120); A draw amount adjusting means (130) installed in the draw pipe (110) to control the drawing or drawing amount of the flooring material by opening and closing the flow path of the drawing pipe (110); The guide wall 141 is provided to be connected to the other end of the outlet pipe 110 to receive a flooring material, and form a spiral or similar flow path 143 therein, and a flooring material on the bottom of the flow path 143. A cooler 140 having a plurality of nozzles 142 for spraying air for cooling and flowing the air; And A heating air input pipe 150 for connecting the cooler 140 and the boiler 100 to supply the heated air to the boiler 100 by cooling the flooring material; Flooring cooling device of the circulating fluidized bed combustion boiler comprising: a. The method of claim 1, Guide wall 141 of the cooler 140 is formed so that the distance between the neighboring guide wall 141 is always constant so that the width of the flow path 143 is uniform floor cooling of the circulating fluidized bed combustion boiler Device. The method of claim 2, Cooling the bottom ash of the circulating fluidized bed combustion boiler, characterized in that a plurality of protruding walls 144 formed to protrude in the lateral direction of the guide wall 141 is formed at predetermined distance intervals so that the width of the flow path 143 is partially reduced. Device. The method of claim 1, Guide wall 141 of the cooler 140 is a floor material cooling device of the circulating fluidized bed combustion boiler, characterized in that the distance between the adjacent guide wall 141 is formed irregularly the width of the flow path 143 is irregular. . The method of claim 1, wherein the drawing amount adjusting means 130, The first opening and closing valve 131 is composed of the first and second on-off valves (131, 132) installed to have a height difference between the outlet pipe 110, the upper opening and closing valve 131 controls the opening and closing of the outlet pipe (110) , The second on-off valve 132 located at the bottom controls the area in which the flow path of the outlet pipe 110 is opened so as to adjust the withdrawal amount of the bottom ash, the floor ash cooling apparatus of the circulating fluidized bed combustion boiler. The method of claim 5, wherein the first and second on-off valves (131, 132) have the same configuration, A housing 131a installed in the middle of the outlet pipe 110 to form a flow path continuous with the outlet pipe 110; An opening and closing member (131b) installed inside the housing (131a) and having an upper end portion formed in a hemispherical shape to open and close the flow path; And Opening and closing cylinder (131c) is connected to the opening and closing member (131b) for rotating the opening and closing member (131b); Floor material cooling apparatus of the circulating fluidized bed combustion boiler, characterized in that consisting of. The method of claim 1, At least one or more of the bottom, wall and ceiling of the cooler 140 is provided with a circulation pipe 145 through which the boiler feed water is circulated, and the circulating fluidized bed characterized in that it is configured to preheat the boiler feed water using the heat of the bottom ash. Floor cooler for combustion boilers. The method of claim 1, Each nozzle 142 is at least two or more air injection port (142a) characterized in that the bottom ash cooling device of the circulating fluidized bed combustion boiler. The method of claim 1, Is installed in the outlet pipe 110, is connected to another external device for supplying high-pressure compressed air, is provided with a valve 161 that is opened and closed by the automatic injection by the timer or the operation of the manager, the outlet pipe by the flooring If the flow path is opened by the operation of the valve 161 when the 110 is blocked, the secondary injector 160 for ejecting the high-pressure compressed air to the outlet pipe 110 to pierce the outlet pipe 110 blocked by the flooring material. Flooring cooling device of a circulating fluidized bed combustion boiler comprising a.

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