JP2017101902A - Combustion furnace to be used for power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generating system using a small incinerator and heat exchanger with high thermal efficiency.SOLUTION: The present invention relates to a combustion furnace of a power generating system utilizing a waste combustion device. A primary combustion chamber burns dry distillation gas from a pyrolysis furnace. A secondary combustion chamber is a cavity continuous to the primary combustion chamber, and incinerates unburnt gas in the primary combustion chamber. An exchange chamber is arranged over both sides and an upper part of the secondary combustion chamber, and filled with a heat medium (for example, water). A returning smoke pipe consists of many pipes for returning smoke exhaust from the secondary combustion chamber from an end to a starting end direction of the secondary combustion chamber through both sides in the heat exchanger chamber. A going smoke pipe returns the smoke exhaust from the returning smoke pipe from the starting end to a rear end direction of the secondary combustion chamber through an upper side of the heat exchange chamber. In addition, steam obtained in the heat exchange chamber is supplied to a power generating turbine via an air-water separator and a steam header.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a combustion furnace, and more particularly to a combustion furnace used in a power generation system using a waste combustion apparatus.

  In recent years, power generation using heat generated by incineration of garbage has been widely performed. On the other hand, in developing countries, transmission lines cannot be laid, but there are many areas where there are many fuel resources such as general garbage, plastic garbage, or forests. In this case, the power merit using the fuel resource has a greater cost merit than laying a transmission line.

  When the heat generated by the incinerator is used for power generation, it is of course desirable that the heat efficiency is high. In this case, in order to increase the thermal efficiency as much as possible, a waste combustion apparatus combining a dry distillation gasification furnace that generates waste gas in a steamed state and a combustion furnace that uses the gas generated by the dry distillation gasification furnace as fuel. It is conceivable to use (see, for example, JP-A-2001-342476).

  Furthermore, the applicant of the present application proposes a waste incineration system in Japanese Patent No. 4381613 that collects dry distillation gas from general combustible waste and burns it in a combustion furnace, collects oil from plastic waste, and uses it effectively. doing.

  With this system, it is possible to switch between the combustion of general combustible waste and the combustion of plastic waste to perform incineration, thereby reducing the area of the facility, resulting in high cost performance. It will be possible.

JP 2001-342476 A Japanese Patent No. 4381613

  A combustion furnace applied to a conventional waste combustion apparatus was obtained in a primary combustion chamber for burning fuel, a secondary combustion chamber for burning unburned gas in the primary combustion chamber, and a secondary combustion chamber. Heat treatment is performed through a heat exchanger that obtains water vapor from a hot gas. That is, the site to be combusted and the site to exchange heat have different structures, and the equipment is large and the cost performance is not so good.

  The proposal of the above-mentioned Patent No. 4381613 is effective in that plastic waste and general combustion waste can be processed with one system without emitting dioxins. However, when this device is applied to power generation, which is the purpose of the present application, further steam is generated. It is necessary to add a heat exchange function to obtain. The structure for providing the heat exchange function is different from the primary combustion chamber and the secondary combustion chamber when trying to follow the conventional configuration, and a small system cannot be assembled.

  The present invention has been proposed in view of the above-described conventional circumstances, and an object thereof is to provide a configuration having an efficient heat exchange function in the combustion furnace disclosed in Japanese Patent No. 4381613 with a simple configuration. Is.

  The present invention relates to a combustion furnace of a power generation system that uses a waste combustion apparatus including a carbonization furnace and a combustion furnace that uses carbonization gas from the carbonization furnace as a fuel. The combustion furnace includes a primary combustion chamber, a secondary combustion chamber, a heat exchange chamber, a flue pipe, and a forward smoke pipe.

  The primary combustion chamber burns dry distillation gas from the dry distillation furnace. The secondary combustion chamber is a cavity continuous to the primary combustion chamber, and incinerates unburned gas in the primary combustion chamber. The heat exchange chamber is disposed over both sides and the upper portion of the secondary combustion chamber, and is filled with a heat medium (for example, water). The flue pipe is composed of a number of pipes that return the smoke exhausted from the secondary combustion chamber from the end of the secondary combustion chamber toward the start end through both sides of the heat exchange chamber. The forward smoke pipe returns the flue gas from the exhaust pipe through the upper side of the heat exchange chamber from the start end to the rear end of the secondary combustion chamber.

  The effect of the heat medium filled in the heat exchange chamber can be further improved by using a heat medium preheated on the peripheral wall of the dry distillation furnace. Further, the steam obtained in the heat exchange chamber is supplied to a power generation turbine through a steam separator and a steam header.

  With the above configuration, since the heat exchanger is integrated with the combustion furnace, the entire system can be downsized and the thermal efficiency can be increased, and efficient heat exchange can be achieved even on a small scale. There is an effect that can be activated.

It is a perspective view which shows the external appearance of the combustion furnace of this invention. It is an exploded perspective view of the present invention. It is a schematic diagram which shows the direction of the flow of the flue gas by this invention. 1 shows a power generation system to which the present invention is applied. It is sectional drawing which shows another embodiment of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG.

  FIG. 1 is a perspective view showing the appearance of a combustion furnace of the combustion furnace of the present invention, FIG. 2 is an exploded perspective view, and FIG. 3 is a schematic diagram showing the direction of smoke flow according to the present invention.

  The primary combustion chamber 2X of the combustion furnace 2 is provided with a gas inlet 40 of a branch duct (described later) 4 into which dry distillation gas from a dry distillation gasification furnace (described later) flows. A secondary burner 28 is provided for burning the oil (or separately supplied oil). The dry distillation gas from the gas inlet 40 is initially combusted by the combustion of the secondary burner 28, but the oil from the oil generator is required only when the dry distillation gas is ignited, and the temperature in the furnace As the value rises, the dry distillation gas spontaneously burns even if the secondary burner 28 does not burn. But when the carbonization furnace 2 fails, it functions as an oil cooking boiler using the oil of the said oil refiner or the oil supplied separately.

  As shown in FIG. 2A, a secondary combustion chamber 2Y is provided continuously to the primary combustion chamber 2X, and air is supplied to the secondary combustion chamber 2Y through an air hole 29a by a blower 29. The unburned gas in the primary combustion chamber 2X is completely burned, and the dioxin can be decomposed.

  A heat exchange chamber 90 is provided across both sides and the upper side of the secondary combustion chamber 2Y with a furnace wall therebetween, and each end of the secondary combustion chamber 2Y (exhaust gas) is provided in each heat exchange chamber 90 on both sides. A plurality of flue pipes 91a and 91b are arranged from the smoke direction downstream side to the start end (upstream side in the flue gas direction), and the flue pipes 91a and 91b are folded back at the start end side of the secondary combustion chamber to return the forward smoke pipe 91c. Then, after passing through the upper heat exchange chamber 90, it is opened to the downstream smoke exhaust duct 51 (see FIG. 4).

  Since the secondary combustion chamber is around 800 to 900 ° C., the heat medium filled in the heat exchange chamber 90 becomes steam with the amount of heat given from the smoke pipes 91a, 91b, 91c passing through the heat exchange chamber 90.

  FIG. 3 shows a smoke exhaust path through the above-described smoke pipes 91a, 91b, 91c. First, the flue gas generated in the primary combustion chamber 2X flows from the upstream to the downstream while burning unburned gas in the secondary combustion chamber (flow path a), and then upstream through the flue pipes 91a and 91b. (Flow path b), and further, smoke is discharged to the downstream smoke exhaust duct 51 via the forward smoke pipe 91c (flow path c).

  FIG. 4 is a diagram showing an outline of a power generation system using a waste combustion apparatus to which the present invention is applied.

  This waste combustion apparatus includes a carbonization furnace 1 for carbonizing a treated product, a combustion furnace 2 according to the present invention for combusting a carbonization gas discharged from the carbonization furnace 1, and an oiling process for separating the carbonization gas into an oil component and a gas component. An apparatus 3 and a branch duct 4 that selectively guides the carbonization gas from the carbonization furnace 1 to the combustion furnace 2 and the oil generator 3 are provided.

  The waste combustion apparatus includes a hot water boiler 5 that uses the heat of the flue gas emitted from the combustion furnace 2, a dust collector 7 that removes dust in the flue gas, and a gas fan 8 that causes the flue gas to flow. And a chimney 9 for releasing gas into the atmosphere.

  The waste is general combustible waste, plastic waste, wood, or the like, and is dropped into the dry distillation furnace 1 from the inlet 12 provided at the upper part of the dry distillation furnace 1.

  The inlet 12 is provided with an upper lid 13 that opens and closes the upper end opening of the inlet 12 and a shutter 14 that opens and closes the intermediate height of the inlet 12. For example, the upper lid 13 is closed with the shutter 14 closed. After opening and dropping a predetermined amount of general waste, plastic waste, wood, etc. into the inlet 12, the upper lid 13 is closed and then the shutter 14 is opened to drop the waste into the dry distillation furnace 1.

  The bottom 15 of the dry distillation furnace 1 is made of a refractory material, and the furnace side wall 16 and the ceiling 17 are constituted by a water jacket through which cooling water flows, and these furnace side walls 16, the ceiling 17, the grate 18, and the furnace inner wall that supports the furnace wall. 19 and the shutter 14 are made to circulate a heat medium (cooling water).

  A water jacket is also formed on the peripheral wall of the branch duct 4, communicated with the water jacket 16 of the dry distillation furnace 1 and the water jacket of the ceiling 17, and further, a heat exchange chamber 90 provided around the combustion furnace 2. It is better to have a configuration that communicates with each other. Thus, in the heat exchange chamber 90, water preheated by the furnace side wall 16 and the like is heated, so that more efficient heating can be performed.

  Further, the heat medium (cooling water) is consumed to some extent by the turbine 94, but the consumed amount is replenished from the outside.

  By the way, the waste dropped into the dry distillation furnace 1 from the charging port 12 is received by the grate 18 and is injected into the dry distillation furnace 1 by the primary burner 20 that jets a flame into the dry distillation furnace 1 from below the grate 18. Is heated to dry distillation.

  The primary burner 20 is supplied with oil by a fuel pump 47 from an oil recovery tank 41 (described later), and the inside of the dry distillation furnace 1 is maintained at the following predetermined temperature by the combustion of the oil. Of course, air is required for combustion, and combustion air is supplied from the primary fan 21.

  When the waste is heated to several hundred degrees, for example, 300 to 600 ° C. in the carbonization furnace 1, the carbon combustible waste or plastic waste is carbonized without generating dioxin, and volatilized and volatilized. The carbonaceous matter that has been pyrolyzed to the carbonaceous matter that has not been volatilized falls from between the grate 18 onto the furnace bottom 15. This carbon material (so-called charcoal) can be used as a separate fuel.

  Further, the portion volatilized by the dry distillation is led to the combustion furnace 2 or the oil generator 3 by the branch duct 4 as a dry distillation gas.

  The branch duct 4 is formed of a refractory material, and as shown in FIG. 4, a switching valve 25 driven by a motor M1 (not shown) is provided at the branch point. By operating it, the position of the switching valve 25 is switched, and the destination of the dry distillation gas is switched to the combustion furnace 2 or the oil generator 3.

  That is, when combusting general combustible waste and wood, the dry distillation gas is guided to the combustion furnace 2, and when processing plastic waste, the dry distillation gas is guided to the oil generator 3. Thus, the position of the switching valve 25 is switched.

  The oil generator 3 is provided with a plurality of (in this case, two) condensers 30 connected in series, and the condenser used depending on the concentration of dry distillation gas detected by the gas detector (not shown). 30 stages can be switched.

  Here, the capacitors 30 in each stage are configured in the same manner, and the oil components liquefied in the vertical cylindrical tanks A and B are collected in the oil collecting tank 31 at the lower end.

  The two capacitors 30 are selectively used depending on the concentration of the reflux gas. That is, a gas detector (not shown) detects the concentration of the reflux gas flowing from the branch duct 4 to each capacitor 30 and determines the concentration. When the concentration is high, the dry distillation gas is led from the branch duct 4 side to the first-stage tank A, and flows through the capacitors 30 in the order of the first and second stages. When the concentration is low, the dry distillation gas is allowed to flow only from the branch duct 4 to the second stage tank B. In order to efficiently execute the above operation, it is necessary to provide various opening / closing valves in the branch duct 4, but this point is not the essence of the invention, and thus the description thereof is omitted.

  Further, the OFF gas remaining without being liquefied by the oil refiner 2 is returned to the reflux furnace 1 and burned (FIG. 4, path X).

  In addition, the flue gas from the combustion furnace 2 can be recirculated to the dry distillation furnace 1 via the electric valve MK and the primary fan 21 (FIG. 4, path Y). Then, as shown in FIG. 4, the gas temperature of the combustion furnace 1 is monitored by a temperature sensor TICAR1, and for example, when a high temperature of 800 ° C. or higher continues for 2 seconds or longer, the motor-operated valve MK is opened to perform combustion. A part of the gas in the furnace 2 is returned to the dry distillation furnace 1 so that the gas temperature from the chimney 9 does not exceed a certain value. As a result, the reflux gas to the carbonization furnace 1 serves as a combustion aid for the burner 20, and combustion can be continued at a predetermined temperature or higher without the burner 20.

  When the furnace temperature of the combustion furnace 2 is a low temperature that does not continuously exceed a predetermined temperature for a predetermined time or longer, the motor-operated valve MK is closed, and the entire amount of gas is released from the chimney 9 to the atmosphere.

  As described above, since the furnace temperature of the combustion furnace 2 is controlled to be maintained at 800 ° C. or higher, sufficient heat can be generated by the heat exchanger 90, and the heat here is also sufficient. The temperature is high, and the hot water boiler 5 is supplied via the smoke exhaust duct 51. By using the heat from the combustion furnace 2 (gas emitted from the smoke pipe 91 (c)) as a heat source for the hot water boiler 5, the heat temperature is cooled to 200 ° C. or less, for example.

  Here, the steam of the heat medium obtained from the hot water boiler 5 is also partly supplied to the steam header 93 and contributes to the driving of the turbine 94, and the heat medium returned to the liquid by the turbine 94 is as described above. Thus, it is returned to the heat exchanger 90 and returned to the hot water boiler 5.

  When the gas temperature is a low temperature lower than the heat resistance performance of the dust collector 7, the motor-operated valve MK is closed, and there is no recirculation to the dry distillation furnace 1, and all the gas passes through the dust collector 7 and dust in the gas is discharged. To be removed.

  As described above, the present invention includes a combustion furnace capable of incinerating a dry distillation gas generated when general garbage is carbonized in a dry distillation furnace, and an oiling apparatus capable of liquefying the dry distillation gas generated when a plastic is carbonized. Since the waste combustion apparatus has a configuration in which a heat exchanger is externally mounted on the combustion apparatus, a heat medium gas (water vapor gas) for power generation can be obtained easily and efficiently.

  In addition, by using the carbonization furnace in combination with the carbonization process in the gasification combustion method and the gasification process in the oiling method, the site for installing the carbonization furnace 1 compared to the case of installing two carbonization furnaces dedicated to each method. As a result, the entire apparatus can be made inexpensive.

  5, 6 and 7 show another embodiment of the incinerator of the present invention.

  The outer side of the peripheral wall of the primary combustion chamber 2X and the secondary combustion chamber 2Y is covered with a water jacket 24. A large number of water pipes 25 communicating with the water jacket 24 are arranged along the axial direction of the inner wall of the secondary combustion chamber 2Y to absorb the heat of combustion in the secondary combustion chamber 2Y. Further, a large number of heat absorbing fins 26 are arranged along the axial direction and the circumferential direction along the inner wall of the secondary combustion chamber 2Y, so that the heat absorption efficiency of the heat medium filled in the water jacket 24 is increased. ing.

  A heat exchange chamber 90 is provided downstream of the secondary combustion chamber 2Y in the direction of smoke emission. The heat exchange chamber 90 includes a water tank 95 communicating with the water jacket 24 and a plurality of smoke pipes 96 penetrating the water tank 95 from the upstream (secondary combustion chamber) in the smoke exhaust direction to the downstream. The flue gas heated to 800 to 900 ° C. in the secondary combustion chamber 2Y is discharged to the downstream flue gas duct 51 through the many smoke pipes 96, and the heat medium filled in the water tank 91 in the process is discharged. Will be heated. With this configuration, the heat medium filled in the water jacket 20 is heated more efficiently.

  Since the secondary combustion chamber is around 800 to 900 ° C., the heat medium filled in the heat exchange chamber 90 becomes steam with the amount of heat given from the smoke pipe 92 passing through the heat exchange chamber 90. The gas-liquid separator 92 disposed on the upper side of the water jacket 24 sends only water vapor to the power generation turbine 94 via the steam header 93 (FIG. 4).

  On the other hand, the steam fed into the power generation turbine 94 as described above returns to water in the turbine 94 and returns to the heat exchanger 90 again (see FIG. 4).

  The point that the above-described combustion apparatus is applied to a combustion system including a carbonization furnace and the power generation turbine is driven as described above is as described with reference to FIG.

  As described above, the present invention has a simple system configuration, can downsize the entire furnace, has high thermal efficiency, and can use general waste, plastic garbage, wood, etc. Or, even in developed countries, it can be used with small-scale power generation systems.

DESCRIPTION OF SYMBOLS 1 Carbonization furnace 2 Combustion furnace 3 Oil refiner 2X Primary combustion chamber 4 Branch duct 7 Dust collector 12 Input port 13 Top cover 14 Shutter 15 Furnace bottom 16 Furnace side wall 17 Ceiling 18 Grate 19 Furnace inner wall 20 Primary burner 28 Secondary burner 29 Blower 29a Air hole 40 Gas inlet 41 Conversion recovery tank 47 Fuel pump 90 Heat exchange chamber 51 Smoke duct 91a, 91b, 91c Smoke pipe 93 Steam header 94 Turbine

Claims (6)

In a combustion furnace of a power generation system using a waste combustion apparatus including a carbonization furnace and a combustion furnace that uses carbonization gas from the carbonization furnace as a fuel,
A primary combustion chamber for combusting carbonization gas from the carbonization furnace;
A cavity continuous to the primary combustion chamber, wherein the secondary combustion chamber incinerates unburned gas in the primary combustion chamber;
The heat exchange chamber disposed over both sides and the upper portion of the secondary combustion chamber and filled with a heat medium;
A flue gas pipe made up of a number of pipes, from which the flue gas from the secondary combustion chamber returns from the end of the secondary combustion chamber toward the start end through both sides of the heat exchange chamber;
The forward smoke pipe that opens the exhaust gas from the exhaust pipe through the upper side of the heat exchange chamber from the start end to the rear end direction of the secondary combustion chamber to the exhaust duct;
A combustion furnace characterized by comprising:   The combustion furnace according to claim 1, wherein the water circulating in the combustion furnace is water preheated on a peripheral wall of the dry distillation furnace.   The combustion furnace according to claim 1, wherein steam generated in the heat exchanger is supplied to a turbine through a steam head. In a combustion furnace of a power generation system using a waste combustion apparatus including a carbonization furnace and a combustion furnace that uses carbonization gas from the carbonization furnace as a fuel,
A primary combustion chamber for combusting carbonization gas from the carbonization furnace;
A secondary combustion chamber which is a cavity continuous to the primary combustion chamber and incinerates unburned gas in the primary combustion chamber;
A water jacket covering the furnace wall across the primary combustion chamber and the secondary combustion chamber;
A water pipe communicating with the water jacket disposed along the peripheral wall of the secondary combustion chamber;
Arranged downstream of the secondary combustion chamber in the direction of flue gas, communicating with the water jacket, filled with a heat medium, and disposed with a plurality of smoke pipes penetrating downstream from the secondary combustion chamber. A combustion furnace comprising a heat exchange chamber.   The combustion furnace according to claim 4, wherein the water circulating in the combustion furnace is water preheated on a peripheral wall of the dry distillation furnace.   The combustion furnace according to claim 4, wherein steam generated in the heat exchanger is supplied to a turbine via a steam head.

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