JP2002022126A - System for waste gasification-melting and its operation- control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively time a completion of temperature rise of a melting furnace with a completion of temperature rise of a gasifier by starting temperature-elevating operation of the gasifier and the melting furnace as an integrated furnace. SOLUTION: The waste gasifier 6 and the melting furnace 9 for burning a combustible gas generated in the gasifier are provided in the waste gasification-melting system. A liquid or gas fuel is burned with an actuation burner 26 for temperature-elevating operation of the gasifier to burn the fuel with an excess air, and the temperature of the gasifier is raised. A combustible gas is generated by the gassifier by combusting the fuel in lean air by using blowing nozzles 36, 37 for the fuel. The combustible gas is burned by a pilot burner 51 for ignition provided in the melting furnace, and the temperature of the melting furnace is raised at least to a melting temperature of ash of the waste. The fuel supply from the blowing nozzles in to the gasifier is reduced from the blowing nozzles into the gasifier is decreased, and the waste is supplied to the gasifier to generate a combustible gas and char containing ash, and the combustible gas and the char are combusted and melted in the melting furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for simplifying equipment of a refuse gasification / melting power generation system, improving operability, improving safety and reliability.

[0002]

2. Description of the Related Art In recent years, a refuse gasification / melting system capable of simultaneously reducing the volume of refuse and detoxifying refuse ash has attracted attention. FIG. 4 shows a system of a fluidized bed waste gasification and melting system according to the prior art. The refuse is put into a dust hopper 1 from a storage pit (not shown), and a predetermined amount of refuse is supplied by a fixed amount feeder 2 through a pipe 3 and a seal mechanism 4.
The gas is supplied to the gasification furnace 6. The refuse supplied to the gasification furnace 6 undergoes a partial oxidation reaction with air supplied to the fluidized bed 8 through the pipe 7 to generate flammable gas such as CO and hydrogen, solid char, and a small amount of tar. The solid char containing unburned matter and ash is pulverized by vigorous mixing and agitation of the fluidized medium (usually sand) in the fluidized bed 8 and sent to the melting furnace 9 through the flue 27 together with the produced gas and tar to form a pipe. The ash in the solid reacts with and reacts with the oxygen in the air supplied through 10 and is melted and discharged as harmless slag through the discharge pipe 11.

[0003] The high-temperature combustion gas from the melting furnace 9 is cooled through a flue 12, through a heat recovery unit 13 and an air heater 14, is converted into clean exhaust gas by a dust collector 15, and is exhausted through an induction blower 16 and a chimney 17.

The pressure inside the gasification furnace 6 is monitored by a pressure detector 24 and automatically controlled by a controller 33 by adjusting the opening degree of a damper 18 at the entrance of the induction blower 16 so that the pressure is always negative.

[0005] This gasification and melting system is composed of two furnaces, a gasification furnace 6 and a melting furnace 9. When the system is started, the temperature of the melting furnace 9 needs to be sufficiently high at the time when the combustible gas containing the char is sent from the refuse gasification furnace 6 through the pipe 27. If the melting furnace 9 has not reached a sufficient temperature, the ash in the char sent from the refuse gasification furnace 6 cannot be melted. In the worst case, the ash sticks and solidifies in the melting furnace 9 and the furnace Blockage and plant shutdown. Therefore, this refuse gasification and melting system is activated in the following procedure.

The refuse gasification furnace 6 can gasify refuse at about 500 ° C., but the melting furnace 9 for melting ash and turning it into slag.
Must be raised to at least 1350 to 1400 ° C. That is, if the temperature is raised at the same rate, the temperature of the melting furnace 9 must be raised to about three times as high as that of the gasification furnace 6, so that the time required for the temperature rise becomes about three times. However, since the refractory material constituting the furnace is vulnerable to thermal shock, the heating rate is regulated to a constant value, and a large-capacity starting burner is installed in the melting furnace 9 so that the temperature cannot be raised rapidly. . In short, the temperature of the gasification furnace 6 can be raised in a short time, but the temperature of the melting furnace 9 needs a long time. Therefore, as shown in FIG. 5, first, the melting furnace 9 is activated first, and the temperature is raised to a temperature at which the ash can be melted.

The temperature of the refuse gasification furnace 6 starts rising later than that of the melting furnace 9, and the timing at which the melting furnace 9 completes the temperature rise coincides with the timing at which the refuse gasification furnace 6 completes the temperature rise. You need to start like that. However, the melting furnace 9,
The gasifier 6 has different furnace sizes, heat capacities, and heat radiation conditions, and the time required from the furnace stop to the next restart, that is, a cold start after a long-term stop, a hot start after a short-term stop, The furnace state (initial temperature) at startup, such as starting from an intermediate state, is not always constant. Therefore, it is very difficult to make the temperature rise completion time of the melting furnace 9 and the waste gasification start time of the gasification furnace 6 coincide with each other with good timing.

For example, even if the temperature of the melting furnace 9 has already been raised to 1400 ° C., if the temperature of the gasification furnace has not been raised, the melting furnace 9 will remain In addition, the consumption of expensive oil fuel for heating must be continued. Conversely, if the heating of the melting furnace 9 is not completed even if the heating of the gasification furnace 6 is completed, the gasification furnace 6 must continue to uselessly heat the fuel for heating during that time. As a result, the start-up time and expensive fuel for heating (heavy oil, light oil, etc.) are wasted.

In addition, apart from the above-described problem, in the cylindrical swirling melting furnace 9, the gas from the gasification furnace 6 is swirled in the furnace to cause the char to collide with the furnace wall by centrifugal force. It is characterized by being expensive. Starting burner 28 of melting furnace 9
Is mounted with its burner axis aligned with the axis of the cylindrical revolving melting furnace 9 because of its complicated structure and large opening. In this case, the air from the start-up burner is prevented from hindering the swirling flow of the gas from the gasification furnace 6 by the swirling vanes, etc. Can not.

Therefore, after completion of the temperature rise of the melting furnace 9, the melting furnace 9
It is desirable to completely stop the burner air and fuel. However, as a practical matter, when the air is completely stopped, the radiant heat in the high-temperature melting furnace 9 causes the metal part of the starting burner of the melting furnace 9 to burn out. Troubles such as being blocked by the For this reason, the burner protection air must be constantly flowed, and this burner protection air hinders the swirling of the gas in the melting furnace 9 and reduces the slag conversion rate.

From this point of view, it is desirable that the starting burner 28 of the melting furnace 9 is also mounted tangentially to the cylindrical swirling melting furnace 9, but it is structurally unreasonable due to the large burner opening.

If the calorific value of the gas generated by the gasification furnace 6 is reduced due to interruption of the waste supply or an extremely low quality of the waste due to a trouble in the waste supply system, the temperature of the melting furnace 9 is lowered and the ash is solidified. Therefore, the starting burner 28 of the melting furnace 9 must be re-ignited. At this time, the combustion air for the start-up burner 28 is blown together with the oil fuel, so that the exhaust gas of the melting furnace 9 rapidly increases. To address this,
As a plant, it is necessary to increase the capacity or spare capacity of the heat recovery, exhaust gas treatment, and induction blower in the subsequent stage. There is such a problem.

[0013]

In the prior art, there are the following problems to be solved.

(1) Since the timing of the completion of the temperature rise of the melting furnace and the timing of the completion of the temperature rise of the gasification furnace cannot be reliably matched, an extra startup time and startup fuel are wasted.

(2) The flow of swirling gas in the melting furnace is obstructed by the protective air for the burner for heating the melting furnace of the melting furnace, and the slag conversion rate is reduced.

(3) It is necessary to provide a temperature raising burner in both the gasification furnace and the melting furnace, which not only increases the equipment cost but also complicates the operation and control.

(4) If the calorific value of the gas generated by the gasification furnace is reduced due to interruption of the waste supply or extreme decrease in the quality of the waste due to a trouble in the waste supply system, the temperature of the melting furnace is reduced and the ash is solidified. Therefore, the starting burner of the melting furnace must be re-ignited. At that time, the combustion air for the start-up burner is blown together with the oil fuel, so that the exhaust gas of the melting furnace rapidly increases as a result, and it is necessary to increase the capacity or spare capacity of the heat recovery, exhaust gas treatment, and the induction blower in the subsequent stage.

(5) It takes a lot of time and fuel to raise the temperature of the melting furnace. However, since the melting furnace requires high-temperature combustion, an expensive fuel such as kerosene or light oil containing almost no N is used. However, there is a disadvantage that a large amount of thermal NOx is generated. Although inexpensive fuels containing N, such as waste oil and heavy oil, also generate fuel NOx in addition to thermal NOx, they could not be used practically as melting furnace fuels.

An object of the present invention is to provide a specific configuration capable of starting up the temperature of a gasification furnace and a melting furnace as an integrated furnace in order to solve the above-mentioned problems.

[0020]

In order to solve the above problems, the present invention mainly employs the following configuration.

In a refuse gasification and melting system comprising a gasification furnace for waste or fossil fuel and a melting furnace for burning combustible gas generated in the gasification furnace, the gasification furnace includes a gasification furnace A fuel injection nozzle for liquid or gaseous fuel is provided outside the starting burner, and a pilot burner for igniting combustible gas generated in the gasifier without installing a starting burner for heating the melting furnace in the melting furnace. Provide a garbage gasification and melting system.

[0022] Further, in an operation control method of a waste gasification and melting system comprising a gasifier for waste or fossil fuel and a melting furnace for burning combustible gas generated in the gasifier,
After starting up the gasification furnace by burning the liquid or gaseous fuel with excess air using a startup burner for heating the gasification furnace,
The liquid or gaseous fuel is burned with a shortage of air using a liquid or gaseous fuel injection nozzle to generate flammable gas in the gasification furnace, and the flammable gas is ignited using an ignition pilot burner provided in the melting furnace. The gas is burned to heat the melting furnace to a temperature equal to or higher than the melting temperature of waste or fossil fuel ash, and then the supply of liquid or gaseous fuel from the blowing nozzle to the gasification furnace is restricted, and the waste or An operation control method for a refuse gasification / melting system in which fossil fuel is supplied to the gasification furnace to generate char containing combustible gas and ash, and the combustible gas and char are burned and melted in the melting furnace.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A gasification melting system and an operation control method according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration diagram of the refuse gasification and melting system of the present embodiment.

In FIG. 1, refuse is put into a dust hopper 1 from a storage pit (not shown), and a predetermined amount of refuse is supplied to a gasification furnace 6 via a pipe 3 and a seal mechanism 4 by a constant-rate feeder 2. Is done. The refuse supplied to the gasification furnace 6 undergoes a partial oxidation reaction with the air supplied through the pipe 7,
Flammable gases such as CO, hydrogen, solid char and small amounts of tar are formed.

The solid char containing unburned matter and ash is pulverized by vigorous mixing and stirring of the fluidized medium (usually sand) in the fluidized bed 8 and sent to the melting furnace 9 through the flue 27 together with the produced gas and tar. The ash is reacted with oxygen in the air supplied through the pipe 10 and burns, and the ash in the solid is melted and discharged as harmless slag through the discharge pipe 11. The high-temperature combustion gas from the melting furnace 9 passes through a flue 12 and passes through a heat recovery unit 1.
3. It is cooled through the air heater 14 and becomes clean exhaust gas by the dust collector 15 and is exhausted through the trigger blower 16 and the chimney 17.

The pressure inside the gasification furnace 6 is automatically controlled by the controller 43 by adjusting the degree of opening of the damper 18 at the entrance of the induction blower 16 so that the pressure is always negative.

Next, the starting of the waste gasification and melting system according to the embodiment of the present invention will be described. First, the induction blower 16 and the blower 19 are started, the starting burner 26 of the gasification furnace 6 is ignited, and the fluidized bed 8 and the empty tower above the fluidized bed 8 are heated and heated. At this time, a combustion gas of about 900 ° C. including the residual O _{2 of} the air sent into the gasification furnace is sent from the gasification furnace 6 to the melting furnace 9 through the flue 27, and the melting furnace is also heated to about 900 ° C. Is heated and heated by the combustion gas.

Since the starting burner 26 of the gasification furnace 6 uses a fuel containing almost no ash, such as a liquid or gaseous fuel, the high-temperature combustion gas from the gasification furnace 6 contains no ash, The trouble that ash sticks in 9 does not occur.

When the temperature of the fluidized bed 8 reaches about 500 ° C. by the starting burner 26 of the gasification furnace 6, the fuel injection nozzle 3
The oil fuel is blown into the fluidized bed and the empty tower of the gasification furnace 6 through the fuel injection nozzle 6 and the fuel injection nozzle 37, and the inside of the gasification furnace 6 is gasified. That is, a large amount of oil fuel is blown at once so that the inside of the gasification furnace 6 becomes a reducing atmosphere. Valve 3 at the same time
At the same time, the air for combustion is fed into the melting furnace 9 by opening 8, and at the same time, the pilot burner 51 (for igniting the gas generated by the gasification furnace) of the melting furnace 9 is ignited.

Normally, air of about 0.05 to 0.4 of the theoretical combustion air amount of the oil blown into the gasification furnace 6 is sent to the gasification furnace 6 and the amount of air blown into the melting furnace 9. Adjusts the opening degree of the valve 38 by the controller 44 so that the residual O ₂ in the combustion gas at the outlet of the melting furnace 9 becomes about 0.5 to several percent. That is, the gasifier 6
Is adjusted to make the oil gasification state due to lack of air, and to make the melting furnace 9 a combustion state with excess air.

By doing so, 500 to 900
A large amount of combustible gas in which oil has been gasified in the gasification furnace 6 is burned in the melting furnace 9 at an air ratio of about 1.1, and a high-temperature combustion gas of about 1700 ° C. is generated. The temperature can be raised above. In short, in FIG. 3 showing the relationship between the air ratio of the fuel and the temperature of the combustion exhaust gas, the gasification furnace 6 is used in the air-deficient combustion (gasification) region, and the melting furnace 9 is used in the air-excessive high-temperature combustion region.
To drive. At this time, since the combustible gas generated from the gasification furnace 6 contains almost no ash, there is no ash sticking trouble in the melting furnace 9 during the temperature rise.

Further, even if inexpensive waste oil or heavy oil containing a large amount of N is used as the oil fuel, the N in the fuel is reduced to stable N ₂ because of the reducing atmosphere at the time of gasification. As a result, the generation of NOx in the melting furnace does not increase. Also,
Since the melting furnace is in a gas combustion state suitable for NOx suppression combustion such as two-stage combustion, low NOx combustion that is higher than that of the related art is possible.

When the temperature of the fluidized bed and the temperature of the superficial portion of the gasification furnace 6 become about 950 ° C. or more, the medium in the fluidized bed and the superficial portion scattered in the superficial portion becomes semi-molten and sticks. Since a trouble such as the clinker adhering to the empty tower furnace wall occurs, the temperature in the empty tower section in the furnace and the temperature in the layer are measured by the thermometers 39 and 40, and the valves 46, 47 and 48 are measured by the controller 41.
Is controlled by the controller 42 to control the valves 49 and 50 so that the fluidized bed temperature of the gasification furnace 6 and the air column temperature do not exceed 950 ° C.
Control oil and air flow. That is, the oil amount is controlled by the valves 46, 47,
The air quantity is controlled by valves 48 and 49. In this case, the control of the oil amount by the blowing nozzles 36 and 37 has a greater influence on the temperature control than the control by the start burner 26.

In this state, the temperature of the melting furnace 9 is 1400 ° C.
At the time when the temperature can be raised as described above, as shown in FIG. 2, the amount of refuse supplied to the gasification furnace 6 is increased, the amount of oil is reduced, and finally the refuse is gasified alone.

As described above, the gasification furnace 6 and the melting furnace 9 can be heated and started as an integrated furnace only by supplying the oil fuel to the gasification furnace 6. Since complicated operations such as synchronizing the temperature rise of the furnace are not required and the temperature rise of both furnaces can be surely matched, unnecessary use of expensive oil fuel is avoided. Furthermore, the start-up burner dedicated to the melting furnace 9 and the accompanying equipment such as oil and air piping required in the prior art can be omitted, and the cost can be reduced. Further, the problem of the adverse effect on the swirling flow in the furnace due to the air for protecting the burner that starts the melting furnace 9 can be solved, and the slag conversion efficiency is also improved. In addition, since the oil fuel is once gasified and used, it is possible to use inexpensive waste oil and heavy oil which has a large N content but is inexpensive.

As described above, the embodiment of the present invention includes the one having the following configuration, function, or operation.

By providing a pilot burner for igniting the gas generated by the gasification furnace 6 in the melting furnace, the combustible gas sent from the gasification furnace to the melting furnace can be ignited and stably burned even if there is no burner for starting the melting furnace. it can. That is, since the melting furnace startup burner that generates an axial flow component that hinders the swirling flow in the melting furnace can be omitted, the swirling flow in the furnace is used,
The ash particles can collide and adhere to the inner wall of the melting furnace with high efficiency to increase the slag conversion rate. Furthermore, the cost of the equipment can be reduced by omitting the burner for starting the melting furnace.

Further, a single or a plurality of fuel injection nozzles are provided in both the fluidized bed of the gasification furnace and the empty tower, and the fuel to the nozzles contains almost no ash, such as liquid or gas. Use fuel. By using this nozzle and fuel, the melting furnace can be heated with the combustion gas of about 950 ° C generated by the gasification furnace while the gasification furnace is being heated with liquid or gaseous fuel. Gasification of liquid fuel in a gasifier can produce high-calorie gas containing almost no ash. The melting furnace can be heated to a temperature at which the ash can be melted by the high-calorie gas fuel containing almost no ash. In this way,
The two furnaces can be heated efficiently without regard to the timing of the completion of the heating of the gasification furnace and the timing of the completion of the heating of the gasification furnace.

The calorie reduction of the gas generated by the gasification furnace caused by the interruption of the waste supply or the extremely low quality of the waste due to the trouble of the waste supply system can be recovered by the simple operation of injecting oil into the gasification furnace. Unlike the prior art, there is no need to inject additional oil fuel or air into the melting furnace, so that a situation in which the exhaust gas amount of the whole plant temporarily increases suddenly can be avoided.

In addition, since the fuel for raising the temperature is not directly injected into the melting furnace, but once the liquid fuel is gasified by the gasification furnace, inexpensive fuel containing a large amount of N such as waste oil and heavy oil is used. Even if used, the N content in the fuel is reduced to stable N ₂ because of the reducing atmosphere in the gasification furnace. for that reason,
Fuel gas N, which is unstable and easily becomes NOx, is no longer contained in the product gas from the gasification furnace. Therefore, the use of waste oil does not lead to an increase in NOx in the melting furnace. Further, since the melting furnace is in a gas combustion state, it becomes easier to adopt a NOx controlled combustion method such as two-stage combustion than liquid fuel (light oil, kerosene) combustion. As a result, generation of NOx can be suppressed as compared with the conventional method.

Further, the amount of fuel blown into the fluidized bed and into the empty tower is controlled so that the temperature of the fluidized bed of the gasifier and the temperature of the empty tower of the gasifier do not exceed a predetermined temperature, for example, 950 ° C. By adopting a control structure, if high calorie fuel such as kerosene or heavy oil is blown into the gasification furnace, the fluidized bed temperature and the air column temperature will be too high, and the furnace walls will be burned. Can be prevented.

It is to be noted that, depending on the gasification temperature, only one of the blowing nozzles in the fluidized bed and the blowing nozzle in the empty tower portion shown in the lower diagram of FIG. 2 may be used.

[0043]

According to the present invention, the following effects can be obtained. That is, since complicated operations such as synchronization of the temperature rise timing of the gasification furnace and the melting furnace are not required, unnecessary use of expensive oil fuel is not required.
Further, even if inexpensive waste oil or heavy oil is used as fuel, NOx from the melting furnace can be kept low.

Further, since the system can be started reliably and in the shortest time, the operation rate of the plant can be increased.
Further, since a burner for starting the extra furnace can be omitted, the system can be simplified and the cost can be reduced.

Further, the calorie reduction of the gas generated by the gasification furnace caused by the interruption of the waste supply or the extremely low quality of the waste due to the trouble of the waste supply system can be performed by a simple operation of injecting oil into the gasification furnace. It can respond and the driving operation is easy. Further, when the calorie of the gas generated by the gasification furnace is reduced, it is not necessary to inject extra fuel and air into the melting furnace, so that the remaining heat recovery, exhaust gas treatment, and induction blower at the subsequent stage can be reduced.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a waste gasification and melting system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing changes with time in starting fuel, furnace temperature, and the like at the time of startup in the gasification furnace and the melting furnace according to the present embodiment.

FIG. 3 is a diagram showing a relationship between a calculated temperature of combustion exhaust gas and an air ratio.

FIG. 4 is a system configuration diagram of a waste gasification / melting system according to the related art.

FIG. 5 is a schematic diagram showing time-dependent changes in startup fuel, furnace temperature, and the like at the time of startup in a gasification furnace and a melting furnace according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dust supply hopper 4 Seal mechanism 5 Supply chute 6 Gasification furnace 8 Fluidized bed 9 Melting furnace 13 Heat recovery unit 14 Air heater 15 Dust collector 16 Induction blower 17 Chimney 19 Blower 20 Medium discharge device 24 Pressure detector 26 Gasification furnace start burner 37 fuel blowing nozzle 39 thermometer 41, 42, 43, 44 controller 45 O ₂ meter 46-50 valves 51 melting furnace pilot burner

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F23G 5/16 ZAB F23G 5/30 ZABF 5/30 ZAB 5/50 ZABJ 5/50 ZAB ZABM F23C 11/02 301 (72) Inventor Kazuki Kobayashi 3-36 Takara-cho, Kure-shi, Hiroshima Prefecture Inside Kure Laboratory, Babcock Hitachi Co., Ltd. Reference) 3K061 AA11 AA23 AB02 AB03 AC01 AC19 BA02 BA03 CA02 CA07 DA18 DA19 DB01 DB18 FA02 FA10 FA21 FA27 3K062 AA11 AA23 AB02 AB03 AC01 AC06 AC19 BA02 CB03 DA01 DB08 DB12 3K064 AA01 AA08 AA11 AA15 BA03 AD12 AD01 AD02 AA02 AA03 BA03 BA21 BA22 BA24 CA02 CA13 CA21 CA24

Claims (4)

[Claims] 1. A refuse gasification / melting system comprising a gasifier for waste or fossil fuel and a melting furnace for burning combustible gas generated in the gasifier, wherein the gasifier includes a gasifier. A fuel injection nozzle of a liquid or gaseous fuel is provided outside the starting burner for warming, and the melting furnace is used for igniting a combustible gas generated in the gasification furnace without installing a starting burner for heating the melting furnace. A waste gasification / melting system characterized by providing a pilot burner. 2. A method for controlling the operation of a refuse gasification and melting system comprising a gasification furnace for waste or fossil fuel and a melting furnace for burning a combustible gas generated in the gasification furnace, comprising: After starting up the gasifier by burning the liquid or gaseous fuel with excess air using a startup burner,
The liquid or gaseous fuel is burned with a shortage of air using a liquid or gaseous fuel injection nozzle to generate flammable gas in the gasifier, and the flammable gas is ignited using an ignition pilot burner provided in the melting furnace. The gas is burned to raise the temperature of the melting furnace to a temperature equal to or higher than the melting temperature of waste or fossil fuel ash, and then the supply of liquid or gaseous fuel from the blowing nozzle to the gasification furnace is reduced, and the waste or An operation control of a refuse gasification and melting system, wherein fossil fuel is supplied to the gasification furnace to generate a char containing combustible gas and ash, and the combustible gas and char are burned and melted in the melting furnace. Method. 3. The refuse gasification and melting system according to claim 1, wherein the fuel injection nozzle is installed in the fluidized bed of the gasification furnace and in an empty column, and the fluidized bed temperature and the empty column temperature are set to predetermined temperatures. A waste gasification / melting system characterized in that the amount of fuel injected from each fuel injection nozzle is controlled so as not to exceed. 4. The method for controlling operation of a refuse gasification and melting system according to claim 2, wherein the temperature of the melting furnace is reduced by reducing the calorie of combustible gas generated in the gasification furnace after supplying waste or fossil fuel. A method for controlling the operation of the refuse gasification and melting system, wherein the fuel is blown from the fuel injection nozzle into the gasification furnace to increase the calories of the combustible gas when the fuel gas is reduced.