JPH09184609A - Waste heat generating system in incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce NOx and the amount of use of fuel and improve a generating efficiency by providing a waste heat boiler, an independent superheater under the combustion and heating of hydrocarbon fuel in a steam pipeline from the waste heat boiler to a steam turbine and mixing exhaust gas from the independent superheater with the hydrocarbon fuel supplied to a secondary combustion zone. SOLUTION: The exhaust and waste gas of the top part of the combustion chamber of a refuse incinerator 1 is discharged to atmospheric air from a chimney 22 through a waste gas duct 21. A waste heat boiler 23 and a waste gas treating equipment 24 are provided in the waste gas duct 21. The waste heat boiler 23 is so designed as to suppress steam temperature to a temperature not higher than 300 deg.C in order to prevent the generation of the common corrosion with various corrosive materials included in waste gas or dust. In a steam pipeline 25 for steam at a temperature not higher than 300 deg.C, an independent superheater 28 in accordance with a clean natural gas combustion system is provided. Thus, low temperature steam at a temperature not higher than 300 deg.C from the waste heat boiler 23 is superheated to a level of 420 deg.C, enters a steam turbine 26 and a power is generated by a generator 27, so that a generating efficiency is raised by 21 to 24 %.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cogeneration system in an incinerator, more particularly by blowing the hydrocarbon-based fuel such as natural gas while achieving low NO _X reduction in refuse incinerators, the incineration The present invention relates to a waste heat power generation system in an incinerator that performs high-efficiency power generation by the heat energy contained in the high-temperature waste gas of the furnace.

[0002]

2. Description of the Related Art In recent years, the amount of refuse to be treated has been increasing in cities and the like. Some of these wastes are recycled, but most of them are actually incinerated at waste incineration plants. At the time of incineration in the waste incineration plant, nitrogen oxides (NO _X), carbon monoxide (C
Air pollutants such as O) and dioxins are emitted, and these air pollutants have a considerable effect on the urban environment.

Conventionally, in order to suppress the emission of such air pollutants, as disclosed in Japanese Examined Patent Publication No. 7-62524, a method of reburning exhaust gas using natural gas (natural gas Reburning method) has been proposed. The natural gas reburning method, NO _X in the reducing atmosphere of the combustion gases above the secondary combustion zone in the primary combustion zone to the main combustion by the primary combustion air to be combusted was blown natural gas
And the residual hydrocarbons after the reduction of the natural gas and the hydrocarbons and CO generated in the combustion chamber are completely burned by the secondary combustion air. According to this natural gas reburning method, compared with the case where natural gas is not used, N
O _X, 60% emissions CO with maximum respectively, has been demonstrated to be able to suppress in reduction rate of 50%.

Here, the NO _x removal mechanism is as follows. That is, it is considered that the following reactions proceed in the secondary combustion zone of the reducing atmosphere. _{C n H m + O 2 →} C n 'H m' + CO + H 2 O NO + C n 'H m' → C n "H m" + N 2 + CO + H 2
O or NO + C _n 'H _m ' → C _n "H _m " + NH _i + CO + H
₂ O (however, 'represents a radical at the initial stage of chemical reaction, and NH _i represents a nitrogen compound.)

As can be seen from this reaction formula, hydrocarbon radicals (C _n 'H _m ') generated by the reaction between hydrocarbons (C _n H _m ) and oxygen (O ₂ ) in the primary combustion air are converted. Reacting with the nitrogen oxides (NO) results in the reduction of the NO and the resulting removal.

By the way, when the above-mentioned natural gas re-combustion method is used, the amount of natural gas blown into the combustion chamber becomes excessive and deficient when the type of material to be burned changes. In JP 6-307619 A, the concentration of CO generated in the secondary combustion zone and the concentration of NO _X discharged from the secondary combustion zone are detected,
A combustion control device for an incinerator has been proposed in which the supply amounts of natural gas and primary combustion air are controlled so that these concentrations reach predetermined values. According to this combustion control device, it is possible to suppress the emission of air pollutants such as CO and NO _X at a stable reduction rate at all times.

On the other hand, the thermal energy contained in the high temperature waste gas generated by the incineration of the waste by the incinerator as described above is usually taken out as steam by the waste heat boiler provided in the waste gas passage, and the conventional thermal power generation. Like the above, it is used for power generation using a steam turbine.

This conventional typical power generation system will be described with reference to FIG. In this power generation system, incinerator 5
Waste gas from No. 1 is discharged from the chimney 53 through the waste gas duct 52. A waste heat boiler 54 for recovering heat from the high-temperature waste gas is arranged in the waste gas duct 52, and air pollutants such as HCl, SO _x , and dust contained in the waste gas are removed. Waste gas treatment facility (dry gas treatment device 55 and wet gas treatment device 5)
6) and the induction blower 57 are arranged. Further, a denitration device 58 is provided on the downstream side of the wet gas treatment device 56, and a gas reheater 59 for reheating the gas is provided on the upstream side of the denitration device 58. On the other hand, the steam from the waste heat boiler 54 passes through the steam pipe 60 and the steam turbine 6
1, and the generator 6 is rotated by the rotation of the steam turbine 61.
2 is driven. On the other hand, the condensate from the steam turbine 61 is circulated through the condensate pipe 63 through the condenser 64 and the deaerator 65, and is circulated as the feed water for the waste heat boiler 54.

[0009] By the way, in such waste power generation, unlike thermal power generation using fuel, hydrogen chloride (HCl) caused by chlorine components contained in the waste and many metals similar to those contained in the waste. Since various corrosive substances such as ## STR3 ## are contained in the waste gas, eutectic corrosion is caused by them. For this reason, as a measure to prevent this symbiotic corrosion, it is customary to keep the steam temperature within a temperature range where corrosion is unlikely to occur (practically 300 ° C. or less), which results in power generation efficiency. The actual situation is that it is only a dozen percent.

Therefore, in order to improve the power generation efficiency of this waste power generation, an independent steam superheater is provided which superheats the steam from the waste heat boiler by combustion of natural gas which is a clean fuel. A system has been proposed in which it is sent to a steam turbine after being overheated.

[0011]

When [0005] using natural gas re-combustion method as described above in waste incinerators, not only very effective as a NO _X reduction measures, natural gas used as the heat energy, further Has the advantage that it is not lost at all because it is recovered as electrical energy.

However, since the amount of natural gas used in this natural gas re-combustion method is an amount corresponding to about 10% in terms of the calorific value of the input waste, the input is always performed during operation of the refuse incinerator. It is necessary to supply natural gas in an amount equivalent to about 10% in terms of the heat quantity ratio of waste, and when constructing a waste incinerator, it is necessary to supply about 10% compared to a normal waste incinerator.
There is a problem that a thermal energy recovery device which is larger by% is required.

On the other hand, in waste power generation in which high temperature waste gas generated by waste incineration is used for power generation, providing an independent steam superheater is an extremely effective means for improving power generation efficiency. A significant amount of new natural gas is needed.

Thus, the nitrogen oxides (NO
_x ), a natural gas re-combustion system for suppressing air pollutants such as carbon monoxide (CO), and a power generation system using an independent steam heater by natural gas combustion heating, a combination of two natural gas systems This makes it possible to achieve pollution-free and high-efficiency power generation in the refuse incinerator. However, in such a system, there is a problem that a considerable amount of natural gas is required for each of the purpose of pollution-free and high-efficiency power generation.

In order to solve the above problems, the present invention can minimize the amount of hydrocarbon fuel such as natural gas used while maintaining the NO _X reducing effect. An object of the present invention is to provide a waste heat power generation system in an incinerator that can further improve power generation efficiency.

[0016]

In order to achieve the above-mentioned object, the waste heat power generation system in the incinerator according to the present invention is arranged above the primary combustion zone in which the material to be burned is mainly burned by the primary combustion air. Hydrocarbon fuel is supplied to the secondary combustion zone of the above to make the secondary combustion zone a reducing atmosphere, and unburned or incompletely burned matter is completely burned by the secondary combustion air above this secondary combustion zone. A waste heat power generation system for an incinerator, which is provided with a waste heat boiler for recovering waste heat from the combustion furnace, and is independent by combustion heating of hydrocarbon fuel in the steam pipe from the waste heat boiler to the steam turbine. A superheater is provided, and the exhaust gas from this independent superheater is mixed with the hydrocarbon fuel supplied to the secondary combustion zone.

The natural gas used in the natural gas re-combustion method, which is the basic technology of the present invention, is for removing NO _X by using the primary combustion gas of the incinerator as a complete reducing atmosphere. Therefore, the amount of this natural gas depends on the amount of oxidizing substances such as residual oxygen present in the primary combustion gas. That is, in order to minimize the amount of natural gas, the amount of oxidizing substances in the primary combustion gas must be minimized. On the other hand, in the incinerator, it is necessary to completely burn the burnable matter such as refuse, and a large amount of unburned solids or incompletely burned solids remains in the incineration ash discharged from the incinerator. It must not be.

In order to satisfy both of these requirements, in the natural gas re-combustion method, the dry stoker part and the combustion stoker part are usually used in an incinerator comprising a dry stoker part, a combustion stoker part and a post-combustion stoker part. The primary combustion air supplied to the stake is extremely suppressed, and as a result, the primary combustion gas generated from each stoker part contains a large amount of incomplete combustion gas such as carbon monoxide and hydrocarbon gas or unburned gas. It is a gas with a strong reducing atmosphere. Thus, the amount of oxygen remaining in the dry stoker part and the combustion stoker part is small (2% or less). On the other hand, in the post-combustion stoker portion, combustion air is supplied so as to have a larger air-fuel ratio than other portions so that unburned solids or incompletely burned solids do not remain in the incineration ash. . Therefore,
The combustion gas immediately above the post-combustion stoker part is an oxidizing atmosphere gas containing a large amount of oxygen (about 17 to 19%).

By the way, the above-mentioned primary combustion gas having a strong reducing atmosphere generated in the dry stoker portion and the combustion stoker portion and the combustion gas in the oxidizing atmosphere generated in the post-combustion stoker portion are combined to form a whole. Forms a primary combustion zone and still maintains a reducing atmosphere. Natural gas is introduced into the upper part of the primary combustion zone to create a completely reducing atmosphere, and NO _X is removed by the reaction shown in the above chemical reaction formula. In this case, it is necessary to quickly and completely mix the primary combustion gas and the natural gas to create a uniform and complete reducing atmosphere. For this reason, it is common practice to recirculate some of the flue gas downstream of the incinerator and mix it with natural gas, which is then fed into the primary combustion zone in the furnace to provide sufficient gas disturbance. To achieve perfect mixing.

However, this flue gas is an exhaust gas completely burned by secondary combustion, and since this gas contains a large amount (8 to 12%) of oxygen, a new oxygen supply source. As a result, it contributes to increase the consumption of natural gas required to create a completely reducing atmosphere in the combustion chamber.

In the present invention, a hydrocarbon-based fuel such as natural gas is blown into the primary combustion gas and completely mixed to create a uniform and complete reducing atmosphere to remove NO _x and to mix the hydrocarbon-based fuel. Exhaust gas from an independent superheater is used as a medium for use instead of flue gas having a relatively large amount of oxygen. The exhaust gas of this independent superheater has a low oxygen concentration in the gas (about 1 to 2%) as described later, and is effective as a medium for mixing hydrocarbon fuels as well as the recirculation gas from the flue gas. However, it rarely becomes a new oxygen supply source and contributes little to the increase in the consumption of the hydrocarbon-based fuel necessary for fostering a completely reducing atmosphere.

According to the present invention, the NO _x reduction effect by applying the natural gas re-combustion method to the refuse incinerator and the effect of each independent system of ensuring high power generation efficiency by applying the independent steam superheater are achieved. Using these hydrocarbon-based fuels by combining these systems while maintaining the utilization of the exhaust gas from the independent superheater as a mixed medium for injecting hydrocarbon-based fuels such as natural gas into the primary combustion gas It is possible to significantly reduce the amount and improve the utilization rate.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of a waste heat power generation system in an incinerator according to the present invention will be described with reference to the drawings.

A schematic configuration diagram of a refuse incinerator according to an embodiment of the present invention is shown in FIG. Waste incinerator 1 of this embodiment
, A hopper 3 into which the refuse 2 as the object to be burned is charged, a stoker 4 for burning the refuse 2 introduced from the hopper 3, and a combustion defined by the furnace wall 5 provided above the stoker 4 Chamber 6, a primary combustion air supply device 7 for supplying primary combustion air into the combustion chamber 6 through the stoker 4, and an ash outlet 8 for taking out incinerated ash after combustion.
Are provided.

The stoker 4 comprises a dry stoker 4a, a combustion stoker 4b, and a post-combustion stoker 4c, and the air conduits 7a, 7b, 7c of the primary combustion air supply device 7 are associated with the stokers 4a, 4b, 4c. Each is provided. The primary combustion air is supplied to these air conduits 7a, 7b, 7c from a forced air blower 7d. Thus, the refuse 2 introduced from the hopper 3 is supplied to the respective stokers 4a, 4b, 4c via the respective air conduits 7a, 7b, 7c while moving forward in the order of the drying stoker 4a, the combustion stoker 4b, and the post-combustion stoker 4c. Primary combustion by the primary combustion air. At this time, the primary combustion air supplied to the drying stoker 4a and the combustion stoker 4b is suppressed to a small amount in order to minimize the amount of the oxidizing substance in the primary combustion gas.

In the dry stoker 4a, the high temperature combustion gas generated by the combustion in the post-stage combustion stoker 4b and the post-combustion stoker 4c mainly dries the dust, and a partial combustion starts. However, since the primary combustion air supplied from the air conduit 7a is suppressed as described above, the gas discharged from the portion of the drying stoker 4a into the combustion chamber 6 is carbonized by the vaporization of water and carbonization. Examples include hydrogen gas and CO produced by incomplete combustion.

Next, in the combustion stoker 4b, the air conduit 7 is
b. The main combustion is performed by the primary combustion air supplied from the combustion stoker 4b, and the primary combustion air is also suppressed. Is contained in large quantities,
Unreacted oxygen in the gas is suppressed to less than 2%. Thus, although the combustion gas in the primary combustion zone 6a above the dry stoker 4a and the combustion stoker 4b has reached a high temperature of 1000 to 1300 ° C., the reducing atmosphere is strong and the generated NO _X is relatively low. Have been.

The post-combustion stoker 4c is relatively larger than the dry stoker 4a portion and the combustion stoker 4b portion so that a large amount of unburned solid matter or incompletely burned solid matter does not remain in the incinerated ash. Primary combustion air is supplied so as to have an air-fuel ratio. Therefore, the combustion gas in the primary combustion zone 6b above the post-combustion stoker 4c has a temperature around 500 to 600 ° C. and 17 to 19 ° C.
% Of oxygen remains and has an oxidizing atmosphere. However, because this combustion gas is relatively low temperature and the nitrogen component in the garbage is almost gone,
Thereafter, NO _X generated in the portion of the combustion stoker 4c is in a state of being kept low.

In this way, the combustion gases in the primary combustion zones 6a and 6b below the combustion chamber 6 are mixed to maintain a reducing atmosphere. A supply port 5a is provided in the furnace wall 5 above the primary combustion zones 6a, 6b of the reducing atmosphere, and a hydrocarbon fuel (natural gas) is supplied from the supply port 5a into the combustion chamber 6 through a supply pipe 9. It is supposed to be done. As a result, a complete reducing atmosphere is formed in the vicinity of the secondary combustion zone (reburn zone) 6c above the primary combustion zones 6a and 6b, and NO _X generated during the primary combustion is also generated in the secondary combustion zone 6c. Up to 60 after being reduced
It is reduced at a reduction rate of at least%.

By the way, a large amount of oxygen still remains in the combustion gas near the primary combustion zone 6b above the post-combustion stoker 4c. Therefore, the combustion gas in the vicinity of the primary combustion zone 6b is sucked from the exhaust port 5b of the furnace wall 5 by the booster 10 via the supply pipe 11a, and the supply pipe 11
Along with fresh air from another supply pipe 11b connected to a, it is supplied as secondary combustion air to a zone (burnout zone) 6d above the secondary combustion zone 6c via a supply port 5c.

Thus, the hydrocarbon gas, CO gas, surplus hydrocarbon gas and the like produced in the combustion gas by the primary combustion are completely combusted by the secondary combustion air in the burnout zone 6d. In the burnout zone 6d, NO _X has already been reduced by blowing natural gas, and 900 to 100
Since the combustion is performed at a relatively low temperature of 0 ° C, new NO
_X almost no occurrence of, NO _X in the exhaust gas 50PP
It can be kept below M.

As shown in FIG. 2, the refuse incinerator 1
Waste gas discharged from the top of the combustion chamber 6 is discharged from the chimney 22 to the atmosphere by the waste gas duct 21. In the waste gas duct 21, a waste heat boiler 23 for recovering heat from the high temperature waste gas, and an HC contained in the waste gas
1, a series of waste gas treatment equipment 24 for removing air pollutants such as dust and soot. Here, the waste gas treatment facility 24 is characterized in that it does not have a denitration facility or is significantly simplified. In addition, the waste heat boiler 23 does not easily corrode the steam temperature in order to avoid violent synergistic corrosion between HCl contained in the waste gas and various corrosive substances contained in the dust. The temperature is designed to be kept at 300 ° C or lower, preferably 280 ° C. The steam having a temperature of 300 ° C. or lower enters the steam turbine 26 through the steam pipe 25, and the rotation of the steam turbine 26 drives the generator 27 to generate electric power.

From the waste heat boiler 23 to the steam turbine 26
An independent superheater 28 based on a clean natural gas combustion system is provided in the steam pipe 25 up to, and by this independent superheater 28, low temperature steam of 300 ° C. or less from the waste heat boiler 23 is brought to a level of 420 ° C. It is supposed to overheat. By providing such an independent superheater 28, the power generation efficiency can be increased to 21 to 24%.

The typical composition of the exhaust gas produced by combustion of this natural gas is shown in Table 1.

[Table 1]

As is clear from Table 1, HCl or other corrosive substances is not contained in the exhaust gas produced by the combustion of natural gas. Therefore, this independent superheater 2
In Example 8, even if the steam is heated to 420 ° C., the heat transfer surface is not corroded. The exhaust gas from this independent superheater 28 is
Since the steam is still at a high temperature of about 400 ° C. even after superheated, the heat is further recovered by the low-pressure boiler 30 before being discharged to the atmosphere by the chimney 22 via the exhaust pipe 29, and the steam obtained by this is supplied to the steam pipe 31. Is used as a heat source for heating, heating, air conditioning, etc. in the refuse incinerator. On the other hand, the condensate from the steam turbine 26 is circulated by the condensate pipe 32 through the condenser 33 and the deaerator 34 to be used as the feed water for the waste heat boiler 23, and partly as the feed water for the low pressure boiler 30.

In this embodiment, the exhaust gas of natural gas combustion after heat transfer in the independent superheater 28 and the low pressure boiler 30 is introduced into the combustion chamber 6 through the introduction pipe 35 branched from the exhaust pipe 29. Is introduced into the supply pipe 9.
In this way, the natural gas supplied into the primary combustion gas of the combustion chamber 6 is rapidly and completely mixed with the primary combustion gas by using the exhaust gas as a mixing promoting medium. As shown in Table 1, the exhaust gas of this natural gas combustion has an oxygen content of 1.1%, and the exhaust gas from the waste incinerator waste gas used as a mixing promoting medium for natural gas by the normal natural gas recirculation method. Recirculation gas (Fig. 3
The oxygen content (8-12%) of the dashed line is significantly lower than that of oxygen, which is disadvantageous for creating a complete reducing atmosphere in the secondary combustion zone (reburn zone) 6c in the combustion chamber 6. Can be reduced, which can reduce the amount of natural gas used. Here, FIG. 3 shows an example of a system in which both the natural gas reburning method and the independent steam superheater are applied, and a part of the flue gas is mixed with the natural gas and is recirculated to the combustion chamber. Is. In FIG. 3, the same parts as those of the system of FIG. 2 are designated by the same reference numerals. The reference numeral 36 is a feed water heater.

[0037]

EXAMPLES Next, the effect of reducing the amount of natural gas used will be described with reference to specific examples.

The amount of refuse incinerated is 25,000 kg / h (60
For the large continuous waste incinerator (0t / 24h), the four cases shown in Table 2 were compared.

[Table 2]

Case A (Comparative Example 1) In this case, as shown in FIG.
This is a case of a classic refuse incinerator that does not have an independent superheater (independent SH) by itself and does not adopt the natural gas reburning method. In this case, the pressure and temperature of the waste heat boiler 54 are 28 ata and 300 ° C., respectively, and the pressure and temperature of the steam at the inlet of the steam turbine 61 are 27 ata and 3 respectively.
00 ° C. Case B (Comparative Example 2) This case is a case where the waste heat boiler and the independent superheater are provided, but the natural gas re-combustion method is not adopted (not shown). In this case, the pressure and temperature of the waste heat boiler are 65ata and 279 ° C, respectively, and the pressure and temperature of the steam that enters the steam turbine by superheating this steam are 62ata and 420 ° C, respectively. Case A
Since neither case nor case B uses the natural gas re-combustion method, the NO _x value in the combustion chamber of the refuse incinerator is high, and therefore it is necessary to install a denitration device in a series of waste gas treatment facilities. . Case C (Comparative Example 3) In this case, as shown in FIG.
And the independent superheater 28 and the natural gas re-combustion method is adopted. However, the exhaust gas of natural gas combustion after heat transfer in the independent superheater 28 and the low pressure boiler 30 is released from the chimney 22 to the atmosphere. In this case, the pressure and temperature of the waste heat boiler are 65ata and 279 ° C, respectively, and the pressure and temperature of the steam that enters the steam turbine by superheating this steam are 62ata and 420 ° C, respectively. Case D (this embodiment) This case, as shown in FIG.
And an independent superheater 28 are provided, and the natural gas recombustion method is adopted, and a part of the exhaust gas of the natural gas combustion after the heat transfer in the independent superheater 28 and the low-pressure boiler 30 is blown with the natural gas in the natural gas recombustion method. This is the case when it is used as a mixed medium of time. In this case, the pressure and temperature of the waste heat boiler are 65ata and 279 ° C, respectively, and the pressure and temperature of the steam that enters the steam turbine by superheating this steam are 62ata and 420 ° C, respectively.

The results of these four cases A, B, C and D are shown in Table 3.

[Table 3]

As is clear from Table 3, in case A of the classical system, the power generation efficiency remains at 16.2%, while in the case of adding the independent superheater (cases B, C,
In D), it increased to 21.5 to 24.3%, especially when using the independent superheater and the natural gas reburning method together (Case C,
In D), the power generation efficiency is 2.5 to 2.8% compared to Case B.
Got higher. In addition, the input natural gas is Case B,
It was used with high efficiency of 47 to 51% through C and D. In particular, in the case where the exhaust gas from the independent superheater is used as a mixed medium in the natural gas recirculation method as in this example (case D), the case where the recirculation gas of the waste incinerator waste gas is used (case C) is used. In comparison, the amount of natural gas is 720 Nm ³ / h
To 430 Nm ³ / h, the utilization rate of natural gas for power generation was as high as 50.8%. Incidentally, the exhaust gas of natural gas combustion independent superheater outlet is 17,000Nm ³ / h, the amount of mixing medium gases require in natural gas re-combustion method 13,600Nm ³ /
It is not necessary to use the waste incinerator waste gas at all because it can sufficiently cover h.

Although the stoker incinerator has been described in this embodiment, the present invention can be applied to a fluidized bed furnace.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a refuse incinerator according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a waste heat power generation system in an incinerator according to the present embodiment.

FIG. 3 is a configuration diagram of a waste heat power generation system according to a comparative example of the present invention.

FIG. 4 is a configuration diagram of a conventional waste heat power generation system.

[Explanation of symbols]

 1 incinerator 2 refuse (combustibles) 4 stoker 4a dry stoker 4b combustion stoker 4c post-combustion stoker 5 furnace walls 5a, 5c supply port 6 combustion chamber 6a, 6b primary combustion zone 6c secondary combustion zone (reburn zone) 6d Burnout zone 7 Primary combustion air supply device 8 Ash discharge port 9 Supply pipe 21 Waste gas duct 22 Chimney 23 Waste heat boiler 24 Waste gas treatment facility 25 Steam pipe 26 Steam turbine 27 Generator 28 Independent superheater 29 Exhaust pipe 30 Low pressure boiler 31 Steam piping 35 Introduction piping

Claims (1)

[Claims] 1. A hydrocarbon-based fuel is supplied to a secondary combustion zone above a primary combustion zone in which a material to be burned is mainly burned by primary combustion air, and the secondary combustion zone is made into a reducing atmosphere, and this secondary combustion zone. Is a waste heat power generation system in an incinerator that completely burns unburned materials or incompletely burned materials by secondary combustion air above the waste heat boiler for recovering waste heat from the combustion furnace. An independent superheater for combustion heating of hydrocarbon fuel is provided in the steam pipe from the waste heat boiler to the steam turbine, and the exhaust gas from this independent superheater is mixed with the hydrocarbon fuel supplied to the secondary combustion zone. A waste heat power generation system in an incinerator, which is characterized by that.