JP2016169341A - Biomass gasification system and boiler equipment using the same - Google Patents

Abstract

A biomass gasification system that generates gas fuel that can be efficiently burned while reducing the influence on an oil / gas-fired boiler and a boiler facility that uses the biomass gasification system are provided.
A biomass gasification system 2 that generates gas fuel from biomass, comprising a gasification furnace 4 that generates gas fuel by burning and gasifying the biomass as fuel, gasification after the biomass is dried The biomass supply unit 3 that supplies biomass to the furnace 4, the cooler 5 that cools the gas fuel generated in the gasification furnace 4 to 400 to 500 ° C., and foreign substances contained in the gas fuel that has passed through the cooler 5 A biogas cissis system 2 having a filter device 6 that collects and discharges gas fuel that has collected foreign matters at 400 ° C. or higher, and a control device 7 that controls the operation of each part.
[Selection] Figure 1

Description

  The present invention relates to a gasification furnace that generates carbon monoxide, hydrogen, and the like by burning and gasifying biomass, and generating this as gas fuel, a biomass gasification system that generates gas fuel using biomass, and gas fuel It is related with the boiler equipment which can be burned together with other fuel as a fuel, and can collect | recover the heat | fever generated by this combustion.

  Various gasification furnaces have been proposed in which carbon monoxide, hydrogen, and the like are generated by gasifying biomass as fuel, and this is generated as gas fuel. In addition, various boilers have been proposed in which heat is generated by burning fossil fuels such as coal and oil as fuel, and the generated heat is recovered. And the equipment which supplies the gas fuel produced | generated with the gasification furnace to a boiler, uses this gas fuel and a fossil fuel together as a fuel, burns, and collect | recovers heat is described in the following patent document 1, for example Has been.

US Pat. No. 4,676,177

  In a facility that combines such a gasification furnace and a boiler, gas fuel and air are injected into the boiler body by a combustion burner, and fossil fuel and air are injected by another combustion burner and ignited. And burn. Here, as the boiler, there is a so-called oil / gas-fired boiler that uses liquid or gaseous fossil fuel as fuel. Oil / gas-fired boilers burn fuel with fewer impurities than coal. For this reason, if there are many impurities contained in the gas fuel produced | generated from biomass, it will affect the combustion in a boiler.

  The present invention solves the above-described problems, and a biomass gasification system that generates gas fuel that can be efficiently burned while reducing the influence on an oil / gas-fired boiler and boiler equipment using the same The purpose is to provide.

  The present invention for achieving the above object is a biomass gasification system that generates gas fuel from biomass, and a gasification furnace that generates gas fuel by burning and gasifying biomass as fuel, After drying, a biomass supply unit that supplies biomass to the gasification furnace, a cooler that cools the gas fuel generated in the gasification furnace to 400 ° C. or more and 500 ° C. or less, and gas that has passed through the cooler It has a filter device that collects foreign matters contained in the fuel, and discharges the gas fuel that has collected the foreign matters at 400 ° C. or higher, and a control device that controls the operation of each part.

  A temperature detector for detecting a temperature between the cooler and the filter, and the control device controls cooling of the cooler based on a detection result of the temperature detector. The gas combustion discharged from the cooler is preferably 400 ° C. or more and 500 ° C. or less.

  The cooler is preferably a heat exchanger that cools the gas fuel by exchanging heat between the gas fuel generated in the gasifier and the air supplied to the gasifier. .

  Moreover, it is preferable that the said filter apparatus has a backwashing mechanism which injects inert gas from the direction opposite to the passage direction of the said gas fuel, and removes the collected foreign material.

  Further, the combustion apparatus is disposed in a path through which the gas fuel passes between the gasification furnace and the cooler, and the control device operates the combustion apparatus when the gasification furnace is started, It is preferable to burn the gas fuel and heat the path and the filter device.

  Further, the gasifier has an ash treatment device from which internal ash is discharged, and the ash treatment device supplies a part of the ash to the upstream side of the mechanism for drying the biomass of the biomass supply device. It is preferable.

  The present invention for achieving the above object is a boiler facility, wherein the biomass gasification system according to any one of the above, a gas fuel supplied from the biomass gasification system, a liquid or gas fuel, And a boiler that burns.

  ADVANTAGE OF THE INVENTION According to this invention, it can be made to burn efficiently, reducing the influence which acts on an oil and gas fired boiler.

Drawing 1 is a schematic structure figure showing the boiler equipment of this embodiment. FIG. 2 is a schematic configuration diagram illustrating a boiler of the boiler facility illustrated in FIG. 1. FIG. 3 is a flowchart showing an example of the operation of the biomass gasification system. FIG. 4 is a flowchart showing an example of the operation of the biomass gasification system.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.

  FIG. 1 is a schematic configuration diagram illustrating a boiler facility according to the present embodiment. FIG. 2 is a schematic configuration diagram illustrating a boiler of the boiler facility illustrated in FIG. 1.

  The boiler facility 1 shown in FIG. 1 uses a gas fuel generated using biomass and a liquid or gaseous fossil fuel such as oil or LNG as a fuel for combustion, and recovers heat generated by the combustion. It is a possible boiler facility.

  As shown in FIG. 1, the boiler facility 1 according to the first embodiment includes a biomass gasification system 2 that generates gas fuel by burning and gasifying biomass, and a gas fuel generated by the biomass gasification system 2. And a boiler 30 that mixes and burns gas or liquid fossil fuel.

  The biomass gasification system 2 cools the gas fuel generated in the gasification furnace 4, the biomass supply device 3 that supplies the biomass after drying, the gasification furnace 4 that gasifies the supplied biomass to generate gas fuel, An air preheater 5 that passes through the air preheater 5 and collects gas fuel foreign matter, and a control device 7 that controls the operation of each part.

  Here, biomass is defined as organic resources derived from renewable organisms, excluding fossil resources. For example, thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and pellets such as recycled fuel (pellets and chips) reduced in weight, and are not limited to those presented here. .

  The biomass supply device 3 includes a biomass storage unit (biomass yard) 70, a transporter 72, a receiving unit 74, conveyors 76 and 78, a magnetic separator 80, an iron storage yard 82, a hopper 84, and a drying device. 86, a weighing conveyor 88, a hopper 90, and a supply pipe 92. The biomass storage part (biomass yard) 70 stores biomass before processing. Biomass is conveyed to the biomass storage unit 70 from the outside. The transporter 72 is a hydraulic excavator, a wheel loader, or the like, and transports the biomass stored in the biomass storage unit 70. The receiving unit 74 is loaded with the biomass conveyed by the transporter 72. The transport conveyor 76 transports the biomass input to the receiving unit 74 to the transport conveyor 78. The transport conveyor 78 transports the biomass transported from the transport conveyor 76 to the hopper 84. The magnetic separator 80 adsorbs the metal foreign matter contained in the biomass with an electromagnet or the like and removes it from the biomass. Examples of the foreign material include a nail and a hinge. The magnetic separator 80 discharges the metal foreign matter removed from the biomass to the iron storage yard 82. The hopper 84 is a device capable of storing a predetermined amount of biomass. The hopper 84 stores the biomass supplied from the transport conveyor 78 and supplies the stored biomass to the drying device 86. The drying device 86 removes moisture from the biomass. As the drying device 86, a drying device that supplies hot air to the biomass, or a fluidized bed drying device that fluidizes and moves the biomass while arranging a heating source therein can be used. The weighing conveyor 88 measures the dried biomass discharged from the drying device 86 and then transports it to the hopper 90. The hopper 90 can store a predetermined amount of biomass, and supplies the stored biomass by a predetermined amount with a screw feeder or the like. The supply pipe 92 connects the hopper 90 and the gasification furnace 4, and supplies biomass discharged from the hopper 90 to the gasification furnace 4.

  The biomass supply device 3 is configured as described above, and removes foreign substances from the biomass, and after drying, supplies the biomass to the gasification furnace 4. The structure of the biomass supply apparatus 3 is not limited to this. For example, the biomass supply device 3 may further include a crushing device such as a mill for crushing the biomass.

  The gasification furnace 4 is a circulating fluidized bed type gasification furnace, and includes a gasification furnace main body 11, a cyclone 17, a discharge pipe 18, a circulation pipe 19, a seal pod 20, an air supply pipe 21, and It has an air supply branch pipe 22, an ash discharge pipe 23, a gas fuel line 24, an ash treatment device 27, a fluid material transport device 28, and a starting burner 29. The gasification furnace 4 is a circulating fluidized bed type gasification furnace, but is not limited to a circulating fluidized bed format, and may be a bubble type circulating fluidized bed format.

The gasification furnace main body 11 has a hollow shape and is installed along the vertical direction. The upper and lower walls and the surrounding wall portions are entirely made of a refractory material, and can prevent heat dissipation to the outside. Operation is possible at ~ 1000 ° C. The gasification furnace main body 11 can supply fluidized sand as a fluidized material and biomass as a fuel. The temperature of the fluidized sand is increased by burning and gasifying the biomass inside, and carbon dioxide is mainly used. A combustible gas is generated as a component, and a gasification reaction occurs using this combustible gas as a gasifying agent. Here, as the fluidized sand, for example, silica sand (as a main component, SiO ₂ , Al ₂ O _3, etc.) is used to remove (desulfurize) sulfur from the gas generated in the gasification furnace main body 11. , Calcium carbonate (CaCO ₃ ) may be added.

  Further, the upper portion of the gasification furnace main body 11 is connected to the upper portion of the cyclone 17 via the discharge pipe 18. The cyclone 17 separates combustible gas and fluidized sand. The lower part of the cyclone 17 is connected to the lower side of the gasification furnace main body 11 via a circulation pipe 19, and a seal pod 20 is attached to the circulation pipe 19.

  The air supply pipe 21 and the air supply branch pipe 22 are connected to the gasification furnace main body 11 and supply air for combustion and gasification. An end of the air supply pipe 21 is connected to the lower part of the gasification furnace main body 11. The air supply branch pipe 22 branches from the air supply pipe 21 and is connected to the seal pod 20. The air supply pipe 21 can supply high-temperature air heated to, for example, 200 to 350 ° C. by the air preheater 5 from the lower portion of the gasification furnace main body 11. The air supply branch pipe 22 supplies high-temperature air heated to, for example, 200 to 350 ° C. by the air preheater 5 to the seal pod 20.

  The ash discharge pipe 23 is connected to the lower part of the gasifier main body 11 and discharges accumulated ash. The ash discharge pipe 23 is discharged in a state where ash, fluid material and foreign matter are mixed. The gas fuel line 24 is connected to the upper part of the cyclone 17. The gas fuel line 24 discharges combustible gas that has passed through the cyclone 17, that is, gas fuel. The gas fuel line 24 is connected to the air preheater 5.

  The ash treatment device 27 processes the mixture of ash, fluidized material and foreign matter discharged from the ash discharge pipe 23. The ash treatment device 27 includes a conveyor belt 27a, a separation device 27b, and a fluid material carry-out line 27c. The conveyor belt 27a conveys the mixture of ash, fluidized material, and foreign matter discharged from the ash discharge pipe 23 to the separation device 27b. The separation device 27b separates the mixture of ash, fluid material, and foreign matter, supplies the fluid material to the fluid material carry-out line 27c, and supplies other substances to the ash circulation device 100. Note that the ash treatment device 27 may supply the mixture to the fluidized material carry-out line 27c and the ash circulation device 100 as it is without performing separation by the separation device 27b.

  The fluidized material transport device 28 supplies a substance containing the fluidized material supplied from the fluidized material carry-out line 27 c to the gasifier main body 11 and the circulation pipe 19. The gasification furnace 4 returns the fluidized material to the path circulating through the gasification furnace main body 11 and the circulation pipe 19 in this way. The start burner 29 is a combustion device connected to the gasifier main body 11. The activation burner 29 has a fuel supply device 29a for supplying fuel (for example, LNG, liquefied natural gas) and an air supply device 29b for supplying air. By supplying air from the air supply device 29b while supplying fuel from the fuel supply device 29a, a flame is generated and the gasification furnace main body 11 is heated. The activation burner 29 is used when the gasification furnace main body 11 is heated when the biomass gasification system 2 is activated.

  The air preheater 5 is connected to the gas fuel line 24 and the gas fuel line 118, and after the gas fuel supplied from the gas fuel line 24 is cooled by heat exchange, the air preheater 5 is discharged to the gas fuel line 118. The air preheater 5 is connected to the blower fan 116. The air preheater 5 performs heat exchange between the air supplied from the blower fan 116 and the gas fuel, heats the air to 200 to 300 ° C. to raise the temperature, and brings the gas fuel to 400 ° C. or more and 500 ° C. or less. Reduce the temperature. The air preheater 5 is connected to the air supply pipe 21 and the air supply branch pipe 22, and supplies the heated air to the air supply pipe 21 and the air supply branch pipe 22.

  The filter device 6 is connected to the gas fuel line 118 and the gas fuel line 124, and the gas fuel supplied from the gas fuel line 118 is discharged to the gas fuel line 124 after removing foreign matters. The filter device 6 includes a filter that can be used at a high temperature such as a ceramic filter, specifically, a temperature of 400 ° C. or higher. The filter device 6 only needs to be able to remove foreign substances using a filter while suppressing a temperature drop of the gas fuel, and may be a cyclone structure as a structure through which the gas fuel passes through a fixed filter. The foreign matter discharge device 122 conveys the foreign matter separated from the gas fuel by the filter device 6 to the outside. The gas fuel line 124 supplies the gas fuel supplied from the filter device 6 to the boiler 30.

  The control device 7 controls the operation of each part of the biomass gasification system 2. The operation control by the control device 7 will be described later.

  Further, the biomass gasification system 2 includes an ash circulation device 100, a duct burner 114, and a temperature detector 120. The ash circulation device 100 supplies the mixture containing the ash discharged from the separation device 27 b of the ash treatment device 27 to the receiving unit 74 of the biomass supply device 3. The ash circulation device 100 includes a circulation line 102 and a supply fan 104. The circulation line 102 is a pipe that connects the separation device 27 b and the receiving unit 74. The supply fan 104 forms a flow from the separation device 27 b toward the receiving unit 74 in the circulation line 102 by sending air. The ash circulation device 100 sends the mixture containing the ash supplied from the separation device 27 b to the circulation line 102 to the receiving unit 74 by sending air with the supply fan 104.

  The duct burner 114 is installed in the gas fuel line 24. The duct burner 114 is a combustion device that generates a flame in the gas fuel line 24. The duct burner 114 generates a flame and heats installed piping. Further, the duct burner 114 generates a flame and heats the air flowing through the gas fuel line 24 to heat the downstream equipment. Further, the duct burner 114 combusts combustible components when combustible components such as gas fuel flow through the gas fuel line 24.

  The temperature detector 120 is installed in the gas fuel line 118 and detects the temperature of the gas fuel that has passed through the air preheater 5.

  On the other hand, the boiler 30 is an oil / gas-fired conventional boiler, and has a boiler body 31 capable of burning gas fuel and liquid or gaseous fossil fuel such as oil and LNG. The boiler main body 31 has a hollow shape and is installed in the vertical direction, and a combustion device 32 is provided at the lower part of the boiler main body wall constituting the boiler main body 31. The combustion device 32 includes a plurality of fossil fuel combustion burners 33 mounted on the boiler body wall and a plurality of gas fuel combustion burners 34. In the present embodiment, four combustion burners 33 for fossil fuels are arranged in four stages along the circumferential direction. On the other hand, four combustion burners 34 for gas fuel are disposed below the plurality of combustion burners 33 for fossil fuels, and four are disposed along the circumferential direction in the vertical direction. The arrangement relationship between the combustion burner 33 for fossil fuel and the combustion burner 34 for gas fuel may be upside down. In each combustion burner 33, 34, the number in the circumferential direction is not limited to four, and the number of stages is not limited to four or one stage. Furthermore, you may arrange | position so that each combustion burner 33 and 34 may be opposed.

  The combustion burner 33 for fossil fuel is connected to a pulverized coal supply unit 35 via a supply pipe 36 and to a fuel oil (or fuel gas) supply part 37 via a supply pipe 38. In this case, pulverized coal or fuel oil can be supplied as the fossil fuel. On the other hand, the gas fuel combustion burner 34 is connected to the gas fuel line 24 from the gasification furnace 4. In this case, the gas fuel supplied from the gas fuel line 24 to the combustion burner 34 for gas fuel is preferably maintained at 400 ° C. or higher.

  Further, the combustion device 32 has an air supply pipe 39 capable of supplying combustion air to the combustion burners 33 and 34. The air supply pipe 39 has a blower 40 attached to a base end portion thereof, and a distal end portion. Is connected to a wind box 41 provided on the outer peripheral side of the boiler body 31. Therefore, the air supplied to the wind box 41 can be supplied to the combustion burners 33 and 34.

  The boiler body 31 has a flue 42 connected to the upper portion thereof, and the superheaters 43 and 44, the reheaters 45 and 46, and the nodes for recovering the heat of the exhaust gas as a convection heat transfer section are connected to the flue 42. Charcoal units 47, 48, and 49 are provided, and heat exchange is performed between the exhaust gas generated by the combustion in the boiler body 31 and water.

  The flue 42 is connected to an exhaust gas pipe 50 through which the exhaust gas subjected to heat exchange is discharged downstream. The exhaust gas pipe 50 is provided with an air heater 51 between the air supply pipe 39 and performs heat exchange between the air flowing through the air supply pipe 39 and the exhaust gas flowing through the exhaust gas pipe 50, and It is desirable to raise the temperature of combustion air to be supplied to a range of 200 to 300 ° C. The exhaust gas pipe 50 is located upstream of the air heater 51 and is provided with a selective reduction type catalyst 54, and is located downstream of the air heater 51 and is provided with an electric dust collector 55, an induction fan 56, and a desulfurization device 57. A chimney 58 is provided at the end.

  Accordingly, when the blower 40 is driven in the boiler 30 to suck air, the air is heated by the air heater 51 through the air supply pipe 39 and then supplied to the combustion burners 33 and 34 through the wind box 41. . Further, pulverized coal or fuel oil as fossil fuel is supplied to the combustion burner 33 for fossil fuel through the supply pipes 36 and 38, and gas fuel from the gasifier 4 is supplied to the gas fuel through the gas fuel line 24. The combustion burner 34 is supplied.

  Then, the combustion burner 33 for fossil fuel injects combustion air and fossil fuel into the boiler body 31 and ignites at the same time, and the combustion burner 34 for gas fuel ignites combustion air and gas fuel to the boiler body 31. Ignites simultaneously with injection. In the boiler body 31, combustion air, fossil fuel, and gas fuel are burned to generate a flame. When a flame is generated in the lower part of the boiler body 31, the combustion gas rises in the boiler body 31 and is discharged to the flue 42.

  At this time, water supplied from a water supply pump (not shown) is preheated by the economizers 47, 48, and 49, then supplied to a steam drum (not shown), and supplied to each water pipe (not shown) on the boiler body wall. It is heated to become saturated steam and fed into a steam drum (not shown). Further, saturated steam of a steam drum (not shown) is introduced into the superheaters 43 and 44 and is heated by the combustion gas. The superheated steam generated by the superheaters 43 and 44 is supplied to a power plant (not shown) such as a turbine. Further, the steam taken out in the middle of the expansion process in the turbine is introduced into the reheaters 45 and 46, overheated again, and returned to the turbine. In addition, although the boiler main body 31 was demonstrated as a drum type | mold (steam drum), it is not limited to this structure.

  Thereafter, the exhaust gas that has passed through the economizers 47, 48, and 49 of the flue 42 is removed of harmful substances such as NOx by the selective reduction catalyst 54 in the exhaust gas pipe 50, and the particulate matter is removed by the electric dust collector 55. After the sulfur content is removed by the desulfurization device 57, it is discharged from the chimney 58 to the atmosphere.

Here, operation | movement of the biomass gasification system 2 of this embodiment is demonstrated. The biomass gasification system 2 conveys biomass at each part of the biomass supply device 3, removes metallic foreign matters, and after drying, supplies the biomass to the gasification furnace 4. The gasification furnace 4 generates gas fuel by heating while flowing together with the supplied biomass and fluidizing material. Specifically, the gasification furnace main body 11 is supplied with fluidized sand from the fluidized material conveying device 28 and is supplied with biomass from the biomass supply device 3. Further, the gasification furnace main body 11 is supplied with high-temperature air for gasification from the lower part through the air supply pipe 21. Then, fluidized sand and biomass are fluidly mixed in the gasification furnace main body 11, and the biomass is combusted and gasified to generate combustible gas. The combustible gas generated by the combustion and gasification is discharged to the cyclone 17 through the discharge pipe 18 together with the fluidized sand, and is separated into the combustible gas and the fluidized sand by the cyclone 17. The separated combustible gas is supplied as gas fuel to the air preheater 5 through the gas fuel line 24. The high-temperature fluidized sand separated by the cyclone 17 is returned to the gasification furnace main body 11 by the circulation pipe 19 through the seal pod 20. Further, a part of the mixture discharged from the ash discharge pipe 23 is returned to the gasification furnace main body 11 and the circulation pipe 19 by the fluidized material transport device 28, and a part thereof is supplied to the biomass supply device 3 by the ash circulation device 100. The Here, the temperature inside the gasification furnace 4 is 500 ° C. or higher and 1000 ° C. or lower. The gasification furnace 4 can control the temperature by changing the fire of supplied air. The gas fuel produced in the gasification furnace 4 is composed mainly of carbon monoxide (CO), hydrogen (H ₂ ), carbon dioxide (CO ₂ ), nitrogen (N), etc., and has a viscosity of 300 to 1100 kcal / Nm ^3. It is a low-calorie gas of a degree, and it becomes the range of 650-850 degreeC.

  In the biomass gasification system 2, the gas fuel discharged from the gasification furnace 4 and passing through the gas fuel line 24 is supplied to the air preheater 5. The air preheater 5 changes the temperature of the gas fuel to 400 ° C. or more and 500 ° C. or less by exchanging heat between the supplied gas fuel and air. Moreover, the air preheater 5 heats the air of atmospheric temperature to heating to 200 to 350 ° C., for example.

  The biomass gasification system 2 supplies gas fuel, which is 400 ° C. or more and 500 ° C. or less by the air preheater 5, to the filter device 6 through the gas supply line 118, and removes foreign matters contained in the gas fuel. The bimass gasification system 2 supplies foreign gas to the boiler 30 with the filter device 6 removing foreign substances and maintaining the temperature at 400 ° C. or higher. In addition, the biomass gasification system 2 can make the temperature in each position into the said range by setting an operating condition previously.

  The biomass gasification system 2 sets the gas fuel to 400 ° C. or more and 500 ° C. or less, and then removes foreign matters with the filter device 6, so that the alkali metal component contained in the gas fuel deposited at 500 ° C. or less is removed with the filter device 6. Can be removed. Moreover, precipitation of a tar part can be suppressed by passing the filter apparatus 6 in the state which maintained gas fuel 400 degreeC or more, and supplying to the boiler 30. FIG. Thereby, it can suppress that a tar part adheres and can increase the component which can be combusted with the boiler 30 more. Moreover, gas fuel can be supplied to the boiler 30 in a state with high energy by allowing the filter device 6 to pass through and supplying it to the boiler 30 while maintaining the gas fuel at 400 ° C. or higher. Thereby, the operating efficiency of the boiler equipment 1 can be made high. Moreover, it can suppress that an alkali metal is thrown into the oil-and-gas-fired boiler 30, and the biomass gasified with the oil-and-gas-fired boiler 30 can be combusted suitably.

  Here, it is preferable that the filter device 6 has a backwashing mechanism that injects an inert gas from a direction opposite to the gas fuel passage direction and removes the collected foreign matter. Here, examples of the inert gas include exhaust gas from the boiler 30, carbon dioxide, nitrogen, and the like. By using an inert gas for cleaning the filter device 6, it is possible to suppress the combustion of the gas fuel in the filter device 6 through which the gas fuel passes at a high temperature.

  The biomass gasification system 2 is provided with the ash circulation device 100 and supplies a part of the ash to the biomass supply device 3 so that the ash containing the combustion components can be returned to the biomass transport path again, and the fuel efficiency is improved. Can be used well. In addition, the wet state can be improved by supplying the dried ash to the region where the wet state biomass in the upstream of the drying device 86 of the biomass supply device 3 is conveyed or stored. The handling property can be improved.

  FIG. 3 is a flowchart showing an example of the operation of the biomass gasification system. The operation shown in FIG. 3 can be realized by the control device 7 executing the operation of each unit. The control device 7 detects the temperature with the temperature detector 120 (step S12). When detecting the temperature, the control device 7 determines whether the temperature of the gas fuel flowing through the gas fuel line 118 is 400 ° C. or higher (step S14). When it is determined that the temperature is not 400 ° C. or higher (No in step S14), that is, the temperature is lower than 400 ° C., the control device 7 decreases the amount of air to be supplied (step S16). The control device 7 controls the operation of the blower fan 116 to reduce the amount of air supplied to the air preheater 5. By reducing the amount of air supplied to the air preheater 5, the amount of heat absorbed by the air in the air preheater 5 can be reduced, and the temperature of the gas fuel discharged from the air preheater 5 can be increased. it can.

  When it is determined that the temperature is 400 ° C. or higher (Yes in Step S14), the control device 7 determines whether the temperature of the gas fuel flowing through the gas fuel line 118 is 500 ° C. or lower (Step S18). When it is determined that the temperature is not 500 ° C. or lower (No in step S18), that is, higher than 500 ° C., the control device 7 increases the amount of air to be supplied (step S20). The control device 7 controls the operation of the blower fan 116 and increases the amount of air supplied to the air preheater 5. By increasing the amount of air supplied to the air preheater 5, the heat absorption amount of air with respect to the gas fuel in the air preheater 5 is increased, and the temperature of the gas fuel discharged from the air preheater 5 can be lowered. it can. When it is determined that the temperature is 500 ° C. or lower (Yes in step S18), the control device 7 ends this process.

  The biomass gasification system 2 controls the operation of the blower fan 116 based on the detection result of the temperature detector 120, and controls the heat exchange of the air preheater 5, so that more gas fuel is supplied to the filter device 6. It can surely be 400 ° C. or higher and 500 ° C. or lower. Thereby, an alkali metal can be suitably removed from gas fuel, and generation | occurrence | production of a tar part can be suppressed. In the above control, the lower limit of 400 ° C. and the upper limit of 500 ° C. are used as control criteria. However, it is preferable to use a temperature higher than 400 ° C. and a temperature lower than 500 ° C. Thereby, even if an error occurs in the control, the gas fuel supplied to the filter device 6 can be more reliably set to 400 ° C. or more and 500 ° C. or less.

  Here, the biomass gasification system 2 of the above embodiment efficiently heats the entire system by heating the air while cooling the gas fuel discharged from the gasification furnace 4 by heat exchange by the air preheater 5. Can be used well. The biomass gasification system 2 may be provided with a cooler instead of the air preheater 5. Further, a medium other than air supplied to the gasification furnace 2 and gas fuel may be subjected to heat exchange.

  Moreover, in the said embodiment, although the temperature detector 120 was installed in the gas fuel line 118 and it controlled based on the detection result of the gas fuel line 118, it is not limited to this. For example, a temperature detector may be installed in the gas fuel line 24 and control may be performed based on the result. Moreover, in the said embodiment, although the quantity of the air supplied to the air preheater 5 was controlled, you may perform another control. For example, the duct may be heated by the duct burner 114 to increase the temperature.

  FIG. 4 is a flowchart showing an example of the operation of the biomass gasification system. The operation shown in FIG. 4 can be realized by the control device 7 executing the operation of each unit. The control device 7 determines whether or not the system (biomass gasification system 2) is activated (step S32). If it is determined that the system (biomass gasification system 2) is activated (Yes in step S32), the control device 7 operates the duct burner (step S34). When it is determined that the system (biomass gasification system 2) is not activated (No in step S32), the control device 7 stops the duct burner 114 (step S36).

  In this way, the biomass gasification system 2 activates the duct burner 114 at the time of system activation and heats the gas fuel line 24, thereby increasing the temperature of the entire system and shortening the activation time. . Further, the gas fuel discharged from the gasification furnace 4 at the time of startup can be burned by the duct burner 114. Thereby, low temperature gas fuel can distribute | circulate and it can suppress that a tar part precipitates.

  Further, the duct burner 114 can burn the gas fuel even when the gas fuel cannot be input depending on the state of the boiler 30, and can prevent the gas fuel from flowing into the boiler 30. That is, the duct burner 114 can also be used as a flare stack. Thereby, it is not necessary to use a flare stack in the biomass gasification system 2, and the apparatus configuration can be simplified.

DESCRIPTION OF SYMBOLS 1 Boiler equipment 2 Biomass gasification system 3 Biomass supply apparatus 4 Gasification furnace 5 Air preheater 6 Filter apparatus 7 Control apparatus 11 Gasification furnace main body 17 Cyclone 18 Exhaust piping 19 Circulation piping 20 Seal pod 21 Air supply piping 22 Air supply branch Piping 23 Ash discharge piping 24, 118, 124 Gas fuel line 27 Ash processing device 27a Conveying belt 27b Separating device
27c Fluidized material delivery line 28 Fluidized material conveying device 29 Start-up burner 29a Fuel supply device 29b Air supply device 30 Boiler 31 Boiler body 32 Combustion device 33 Combustion burner for fossil fuel 34 Combustion burner for gas fuel 39 Air supply piping 42 Smoke Road 51 Air heater 70 Biomass storage (biomass yard)
72 Transporter 74 Receiving part
76, 78 Conveyor 80 Magnetic separator 82 Iron storage yard 84, 90 Hopper 86 Drying device 88 Weighing conveyor 92 Supply pipe 100 Ash circulation device 102 Circulation line 104 Supply fan 114 Duct burner 116 Blower fan 120 Temperature detector 122 Foreign matter discharge device

Claims (7)

A biomass gasification system that generates gas fuel from biomass,
A gasification furnace that generates gas fuel by burning and gasifying biomass as fuel;
A biomass supply unit for supplying biomass to the gasifier after drying the biomass;
A cooler that cools the gas fuel generated in the gasification furnace to 400 ° C. or more and 500 ° C. or less;
A filter device that collects foreign matter contained in the gas fuel that has passed through the cooler, and discharges the gaseous fuel that has collected the foreign matter at 400 ° C. or higher;
A biomass gasification system comprising: a control device that controls operation of each unit; A temperature detector for detecting a temperature between the cooler and the filter;
The said control apparatus controls cooling of the said cooler based on the detection result of the said temperature detector, The gas combustion discharged | emitted from the said cooler shall be 400 degreeC or more and 500 degrees C or less. The biomass gasification system according to 1.   The cooler is a heat exchanger that performs heat exchange between the gas fuel generated in the gasification furnace and air supplied to the gasification furnace, and cools the gas fuel. The biomass gasification system according to claim 1 or 2.   The said filter apparatus has a backwashing mechanism which injects inert gas from the direction opposite to the passage direction of the said gas fuel, and removes the collected foreign material. The biomass gasification system described in 1. A combustion apparatus disposed in a path through which the gas fuel passes between the gasifier and the cooler;
The said control apparatus operates the said combustion apparatus at the time of starting of the said gasification furnace, burns the said gas fuel, and heats the said path | route and a filter apparatus, It is any one of Claim 1 to 3 characterized by the above-mentioned. The biomass gasification system described. The gasifier has an ash treatment device from which internal ash is discharged,
The biomass gasification system according to any one of claims 1 to 5, wherein the ash treatment device supplies a part of ash to an upstream side of a mechanism for drying the biomass of the biomass supply device. . A biomass gasification system according to any one of claims 1 to 6;
A boiler facility comprising a boiler that burns a gas fuel supplied from the biomass gasification system and a liquid or gaseous fuel.

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