JP2016169708A - Gas engine system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently combust fuel including gasified biomass while reducing damage to a gas engine.SOLUTION: A gas engine system comprises a biomass gasification system, a gas engine to combust gas fuel supplied from the biomass gasification system and a control device to control performance of respective sections. The biomass gasification system has: a gasification furnace; a biomass supply unit to supply biomass to the gasification furnace after drying the biomass; a first cooler to cool gas fuel produced by the gasification furnace; a filter device to collect foreign substances included in the gas fuel passing through the first cooler and discharge the gas fuel with the foreign substances removed; a second cooler to cool the gas fuel passing through the filter device to a temperature not more than 400°C; a scrubber device to collect a tar component in the gas fuel by bringing medium oil into contact with the gas fuel passing through the second cooler; and a gas fuel line to supply the gas fuel passing through the scrubber device to the gas engine while maintaining the temperature of the gas fuel at not less than 70°C.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas engine system that burns a gas fuel generated by burning and gasifying biomass.

  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. Further, Patent Document 2 describes a mechanism for bringing cleaning oil into contact with and absorbing the tar content in the cleaning oil as a mechanism for removing the tar content from the gas fuel obtained by gasifying biomass.

US Pat. No. 4,676,177 JP 2005-501169 A

  Here, the use of a gas engine as a device for burning gas fuel obtained by gasifying biomass has been studied. When gas fuel is burned with a gas engine, depending on the conditions of the supplied gas fuel, a large amount of nitrogen oxide may be generated, or the amount of deposits on the inside of the gas engine will increase, which will affect the gas engine. There is a case.

  This invention solves the subject mentioned above, and it aims at providing the gas engine system which can burn the fuel containing the gasified biomass efficiently, reducing the influence which it has on a gas engine. To do.

  In order to achieve the above object, the present invention provides a biomass gasification system that generates gas fuel from biomass, a gas engine that burns the gas fuel supplied from the biomass gasification system, and a control that controls the operation of each part. The biomass gasification system includes a gasification furnace that generates gas fuel by burning and gasifying the biomass as fuel, and supplying the biomass to the gasification furnace after drying the biomass. A biomass supply unit, a first cooler that cools the gas fuel generated in the gasification furnace, and a gas fuel that collects foreign matter contained in the gas fuel that has passed through the first cooler and collects the foreign matter. Device that discharges gas, a second cooler that cools gas fuel that has passed through the filter device to 400 ° C. or less, and gas that has passed through the second cooler A scrubber device for bringing the fuel oil into contact with the fuel to collect tar content in the gas fuel; a gas fuel line for maintaining the gas fuel that has passed through the scrubber device at 70 ° C. or higher and supplying the gas fuel to the gas engine; It is characterized by having.

  A temperature detector that detects a temperature between the second cooler and the scrubber device; and the control device is configured to control the second cooler based on a detection result of the temperature detector. It is preferable to control the cooling so that the gas combustion discharged from the cooler is 400 ° C. or less.

  The second cooler is a heat exchanger that cools the gas fuel by exchanging heat between the gas fuel generated in the gasification furnace and the medium oil circulated in the scrubber device. Is preferred.

  In addition, it is preferable that a gas engine fuel supply device that supplies gas engine fuel serving as pilot fuel of the gas engine to the scrubber device is included, and the scrubber device includes the gas engine fuel in the medium oil.

  Moreover, it is preferable to have a gas engine fuel supply line for supplying the medium oil of the scrubber device to the gas engine.

  In addition, it is preferable to have a gas engine fuel supply device that supplies gas engine fuel, which serves as pilot fuel for the gas engine, to the gas engine.

  Further, the heat of the fuel that heats the gas engine fuel by exchanging heat between the gas fuel flowing between the gas furnace and the first cooler and the gas engine fuel supplied by the gas engine fuel supply device. And an exchanger.

  The gas engine fuel supply device preferably supplies a part of the gas engine fuel to a gas fuel line through which the gas fuel flows between the filter device and the scrubber device.

  Further, the gasification furnace has a starter burner, and has a burner fuel supply device that supplies burner fuel that is fuel of the starter burner to the scrubber device, and the scrubber device supplies the burner fuel to the scrubber device. It is preferable to include in medium oil.

  Moreover, it is preferable to have a burner fuel supply line for supplying medium oil of the scrubber device to the activation burner.

  Moreover, it is preferable that the said gasification furnace has a burner for starting, and has a burner fuel supply apparatus which supplies the burner fuel which is the fuel of the said starting burner to the said starting burner.

  And a fuel heat exchanger for exchanging heat between the gas fuel flowing between the gas furnace and the first cooler and the burner fuel supplied by the burner fuel supply device to raise the temperature of the burner fuel. It is preferable to have.

  The burner fuel supply device preferably supplies a part of the burner fuel to a gas fuel line through which the gas fuel flows between the filter device and the scrubber device.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel containing the gasified biomass can be burned efficiently, reducing the influence which acts on a gas engine.

FIG. 1 is a schematic configuration diagram illustrating a gas engine system of the present embodiment. FIG. 2 is a flowchart showing an example of the operation of the gas engine system. FIG. 3 is a schematic configuration diagram illustrating a gas engine system according to another embodiment. FIG. 4 is a schematic configuration diagram illustrating a gas engine system according to another embodiment.

  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 gas engine system according to the present embodiment. FIG. 2 is a schematic configuration diagram showing a gas engine of the gas engine system shown in FIG.

  A gas engine system 1 shown in FIG. 1 is a gas engine system capable of recovering heat generated by combustion by using a gas fuel generated from biomass as fuel as a fuel.

  As shown in FIG. 1, the gas engine system 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 control device 150 that controls the operation of each part.

  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, a filter device 6 that passes through the air preheater 5 and collects foreign substances of gas fuel, a scrubber device 7, and a heat exchanger 8.

  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, removes foreign matter from the gas fuel supplied from the gas fuel line 118, and then discharges it to the gas fuel line 124. 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 scrubber device 7.

  The scrubber device 7 is connected to the gas fuel line 124 and the gas fuel line 126, removes tar from the gas fuel supplied from the gas fuel line 124, and then discharges it to the gas fuel line 126. The scrubber device 7 collects a tar content contained in the gas fuel while bringing the medium oil into contact with the gas fuel, while cooling the gas fuel. The scrubber device 7 includes a scrubber body 130 and a circulation device 132. The scrubber main body 130 has a storage unit for storing the medium oil, a catalyst unit for promoting the reaction, and a spray unit for spraying the medium oil, and sprays the medium oil from the spray unit onto the catalyst unit. The medium oil that has passed through the catalyst part is stored in the storage part. The circulation device 132 supplies the medium oil stored in the storage unit to the spray unit. The scrubber device 7 preferably cools the gas fuel to 80 ° C. or higher and 400 ° C. or lower.

The heat exchanger 8 circulates a refrigerant (heat medium), and performs heat exchange between the medium oil that flows through the circulation device 132 of the scrubber device 7 and the gas fuel that flows through the gas fuel line 124. The heat exchanger 8 performs heat exchange between the medium oil and the refrigerant, increases the temperature of the medium oil, and decreases the temperature of the refrigerant.
The heat exchanger 8 performs heat exchange between the gas fuel and the refrigerant, increases the temperature of the refrigerant, and decreases the temperature of the gas fuel. The heat exchanger 8 cools the gas fuel to 400 ° C. or lower. The gas fuel line 126 supplies the gas fuel supplied from the scrubber device 7 to the gas engine 32. The gas fuel line 126 maintains the temperature of the gas fuel supplied from the scrubber device 7 at 70 ° C. or higher and supplies it to the gas engine 32.

  Further, the biomass gasification system 2 includes a temperature detector 140 and a temperature detector 142. The temperature detector 140 is installed downstream of the heat exchanger 8 in the gas fuel line 124 (on the scrubber device 7 side), and detects the temperature of the gas fuel that has passed through the filter device 6 and the heat exchanger 8. The temperature detector 142 is installed in the gas fuel line 126 and detects the temperature of the gas fuel that has passed through the scrubber device 7.

  On the other hand, the gas engine 32 is an internal combustion engine that burns gas fuel. The gas engine 32 can also burn liquid fuel as pilot fuel. The gas engine 32 converts energy generated by burning gas fuel into rotational energy of the drive shaft. A generator 34 is connected to the drive shaft of the gas engine 32. The generator 34 generates electric power when the rotating part rotates together with the drive shaft of the gas engine 32. The gas engine 32 discharges exhaust gas generated by burning gas fuel from the exhaust gas line 146. A drying device 142 is disposed in the exhaust gas line 146. The drying device 142 includes biomass before drying, for example, raw wood, inside, and dries the biomass with heat contained in the exhaust gas.

  The control device 150 controls the operation of each part of the biomass gasification system 2. The operation control by the control device 150 will be described later.

Next, operation | movement of the gas engine system 1 of this embodiment is demonstrated. The gas engine system 1 generates gas fuel from biomass by the biomass gasification system 2. 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 gas 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 200-350 degreeC, 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 fuel line 118, and removes foreign matters contained in the gas fuel. The by-mass gasification system 2 removes foreign matters with the filter device 6 and supplies the gas fuel maintained at 400 ° C. or higher to the scrubber device 7 through the gas fuel line 124. A heat exchanger 8 is provided in the gas fuel line 124. The heat exchanger 8 performs heat exchange between the gas fuel passing through the gas fuel line 124 and the refrigerant, and brings the gas fuel to 400 ° C. or lower. Moreover, the heat exchanger 8 heats the medium oil while performing heat exchange between the refrigerant and the medium oil and cooling the refrigerant.

  The scrubber device 7 sprays the medium oil in the space where the supplied gas fuel is circulated, brings the gas fuel and the medium oil into contact with each other, and collects the tar content contained in the gas fuel with the medium oil. As a result, the tar content of the gas fuel is removed and reduced. The scrubber device 7 cools the gas fuel by bringing the gas fuel into contact with the medium oil. The scrubber device 7 is set to a temperature at which moisture is not reduced in the pipe, for example, 70 ° C. or higher. The scrubber device 7 supplies the gas fuel from which tar has been removed to the gas engine 32. 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 gas engine 32 burns the supplied gas fuel, rotates the drive shaft, and generates power with the generator 34. The drying device 148 uses the heat of the exhaust gas to dry the object disposed inside.

  The biomass gasification system 2 performs heat exchange with the heat exchanger 8, cools the gas fuel to 400 ° C. or less, and then supplies it to the scrubber device 7, so that tar can be suitably recovered by the scrubber device 7. . That is, the tar can be suitably recovered by the scrubber device 7 by cooling the heat exchanger 8 below the condensation temperature of tar. In addition, after the gas fuel is cooled by the scrubber device 7, the biomass gasification system 2 supplies the gas engine 32 with the gas fuel maintained at 70 ° C. or higher, thereby increasing the nitrogen oxide generated during combustion in the engine. This can be suppressed.

  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 tar can be suppressed by passing the filter device 6 in a state where the gas fuel is maintained at 400 ° C. or higher and supplying it to the gas engine 32. Thereby, it can suppress that a tar part adheres and can increase the component which can be combusted with the gas engine 32 more. Moreover, the gas fuel can be supplied to the gas engine 32 with high energy by passing through the filter device 6 and supplying the gas fuel to the gas engine 32 with the gas fuel maintained at 400 ° C. or higher. Thereby, the operating efficiency of the gas engine system 1 can be increased. Moreover, it can suppress that an alkali metal is injected | thrown-in to the oil / gas-fired gas engine 32, and the biomass gasified with the oil / gas-fired gas engine 32 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 gas engine 32, 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.

  FIG. 2 is a flowchart showing an example of the operation of the gas engine system. The operation illustrated in FIG. 3 can be realized by the control device 150 executing the operation of each unit. The control device 150 detects the temperature with the temperature detector 140 (step S12).

  When detecting the temperature, the control device 150 determines whether the temperature of the gas fuel flowing downstream of the heat exchanger 8 in the gas fuel line 124 is 400 ° C. or less (step S14). When it is determined that the temperature is not 400 ° C. or lower (No in step S14), that is, higher than 400 ° C., control device 150 increases the amount of refrigerant circulating in heat exchanger 8 (step S16). The control device 150 increases the amount of refrigerant that circulates in the heat exchanger 8, thereby increasing the amount of heat absorbed by the refrigerant with respect to the gas fuel and reducing the temperature of the gas fuel supplied to the scrubber device 7. When it is determined that the temperature is 400 ° C. or lower (step S14 Yes), the control device 150 ends this process.

  The biomass gasification system 2 controls the operation of the heat exchanger 8 based on the detection result of the temperature detector 140, and controls the heat exchange between the gas fuel and the refrigerant, and the refrigerant and the medium oil. The gas fuel to be supplied to can be more reliably set to 400 ° C. or lower. Thereby, the tar content can be suitably removed from the gas fuel. In the above control, the upper limit of 400 ° C. is used as the control criterion. However, it is preferable to use a temperature lower than 400 ° C. as the criterion. 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 less. Moreover, in the said control, although the lower limit of temperature is not set, you may set a lower limit. The biomass gasification system 2 reduces the amount of refrigerant to be circulated when the temperature becomes lower than the lower limit value.

  Here, the biomass gasification system 2 of the above embodiment efficiently uses the heat of the entire system by heating the medium oil while cooling the gas fuel discharged from the filter by heat exchange by the heat exchanger 8. be able to. The biomass gasification system 2 may be provided with a cooler instead of the heat exchanger 8. Further, heat exchange may be performed between a medium other than the medium oil and the gas fuel.

  Moreover, the biomass gasification system 2 of the said embodiment heats air, cooling the gaseous fuel discharged | emitted from the gasification furnace 4 by the heat exchange by the air preheater 5, and efficiently heats the whole system. Can be used. 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 140 was installed in the gas fuel line 124 and it controlled based on the detection result of the gas fuel line 124, it is not limited to this. For example, the control may be performed based on the result of the temperature detector 142 installed in the gas fuel line 126. In this case, nitrogen oxides generated in the gas engine 32 can be reduced by controlling the operation of the scrubber device 7 so that the temperature of the gas fuel discharged from the scrubber device 7 is within a set range.

  FIG. 3 is a schematic configuration diagram illustrating a gas engine system according to another embodiment. The gas engine system 1a shown in FIG. 3 has the same configuration as the gas engine system 1 except that it includes a fuel supply unit 160. Hereinafter, the fuel supply unit 160, which is a feature of the gas engine system 1a, will be described. The fuel supply unit 160 supplies pilot fuel to the gas engine 32 and supplies start-up burner fuel to the start-up burner 29. Here, the pilot fuel and the starting burner fuel are oils (liquid fuel) such as kerosene, light oil, and heavy oil. The fuel supply unit 160 includes a gas engine fuel supply device 162, a burner fuel supply device 164, fuel supply lines 166 and 168, and liquid feed pumps 170 and 172.

  The gas engine fuel supply device 162 stores gas engine fuel that is pilot fuel of the gas engine 32 and supplies the stored gas engine fuel to the scrubber device 7. The burner fuel supply device 164 stores the starter burner fuel (burner fuel) of the starter burner 29 and supplies the stored burner fuel to the scrubber device 7. The fuel supply line 166 connects the scrubber device 7 and the gas engine 32. The fuel supply line 168 connects the scrubber device 7 and the fuel supply device 29 a of the activation burner 29. The liquid feed pump 170 is installed in the fuel supply line 166 and forms a flow for supplying the medium oil stored in the scrubber device 7 to the gas engine 32 as gas engine fuel. The liquid feed pump 172 is installed in the fuel supply line 168, and forms a flow for supplying the medium oil stored in the scrubber device 7 to the activation burner 29 as burner fuel. The fuel supply unit 160 of the gas engine system 1a drives the liquid feed pumps 170 and 172 when the gas engine 32 is activated or when the activation burner 29 is used, and sends the medium oil to each part.

  The fuel supply unit 160 of the gas engine system 1 a supplies the gas engine fuel supply device 162 and the fuel stored in the burner fuel supply device 164 to the scrubber device 7, whereby the gas engine fuel and the burner fuel are supplied to the medium of the scrubber device 7. Can be used as oil. Thereby, the oil in gas engine system 1a can be used efficiently, the kind of oil to be used can be decreased, and an apparatus can be simplified.

  Further, the fuel supply unit 160 of the gas engine system 1 a is stored in the scrubber device 7 by supplying the medium oil stored in the scrubber device 7 to the gas engine 32 through the fuel supply line 166 and the liquid feed pump 170. The medium oil that has collected the tar content can be burned by the gas engine 32. The fuel supply unit 160 of the gas engine system 1a is stored in the scrubber device 7 by supplying the medium oil stored in the scrubber device 7 to the activation burner 29 with the fuel supply line 168 and the liquid feed pump 172. The medium oil that has collected the tar content can be burned by the starter burner 29. The gas engine system 1a can supply new medium oil to the scrubber device 7 by using the medium oil collected by the scrubber device 7 as fuel, and remove the tar content of the scrubber device 7. The performance can be maintained. Further, by using the medium oil that has collected the tar content by the scrubber device 7 as the fuel for the gas engine 32 or the start burner 29, the medium oil can be used efficiently and the energy efficiency can be increased.

  In the fuel supply unit 160, the gas engine fuel supply device 162 for supplying gas engine fuel and the burner fuel supply device 164 for supplying burner fuel are separately provided, but they may be supplied from the same supply device. The fuel supply unit 160 may be provided with only one of the fuel supply line 166 for supplying gas engine fuel and the fuel supply line 168 for supplying burner fuel.

  FIG. 4 is a schematic configuration diagram illustrating a gas engine system according to another embodiment. The gas engine system 1b shown in FIG. 4 has the same configuration as the gas engine system 1 except that it includes a fuel supply unit 160a. Hereinafter, the fuel supply unit 160a which is a feature of the gas engine system 1b will be described. The fuel supply unit 160 a supplies pilot fuel to the gas engine 32 and supplies startup burner fuel to the startup burner 29. The fuel supply unit 160a includes a fuel supply device 190, a fuel supply line 192, a fuel heat exchanger 193, fuel supply lines 194, 196, 198, and control valves 195, 197, 199.

  The fuel supply device 190 stores liquid fuel (oil) corresponding to gas engine fuel and burner fuel. The fuel supply line 192 is connected to the fuel supply device 190, and liquid fuel is supplied from the fuel supply device 190. The fuel supply line 192 is connected to the fuel supply lines 194 and 196. The fuel heat exchanger 193 is connected to the fuel supply line 192 and the gas fuel line 124. The fuel heat exchanger 193 performs heat exchange between the liquid fuel flowing through the fuel supply line 192 and the gas fuel flowing through the gas fuel line 124, thereby increasing the temperature of the liquid fuel and decreasing the temperature of the gas fuel.

  The fuel supply line 194 connects the fuel supply line 192 and the gas engine 32. The control valve 195 is installed in the fuel supply line 194 and controls the flow of liquid fuel flowing from the fuel supply line 192 to the gas engine 32. The fuel supply line 196 connects the fuel supply line 192 and the activation burner 29. The control valve 197 is installed in the fuel supply line 196 and controls the flow of the liquid fuel flowing from the fuel supply line 192 to the activation burner 29. The fuel supply unit 160a of the gas engine system 1b opens the control valves 195 and 197 when the gas engine 32 is started up or when the starting burner 29 is used, and sends the liquid fuel to each part.

  The fuel supply line 198 connects the fuel supply device 190 and the gas fuel line 124. The control valve 199 is installed in the fuel supply line 198 and controls the flow of liquid fuel flowing from the fuel supply device 190 to the gas fuel line 124.

  The fuel supply unit 160a may be provided with a fuel heat exchanger 193 to perform heat exchange between the liquid fuel and the gas fuel and to reduce the temperature of the gas fuel, thereby reducing the amount of heat exchange in the air preheater 5. And the load on the air preheater 5 can be reduced. Further, the fuel supply unit 160a is provided with a fuel heat exchanger 193, performs heat exchange between the liquid fuel and the gas fuel, and raises the temperature of the liquid fuel, thereby increasing the fluidity of the liquid fuel, As the liquid fuel, a high-viscosity fuel, for example, a post-viscosity tar recovery medium oil of C heavy oil or higher can be used.

  The fuel supply unit 160a is provided with a fuel supply line 198, and by supplying the liquid fuel to the gas fuel line 124, the gas fuel flowing through the gas fuel line 124 can be cooled with the liquid fuel, and the tar content of the gas fuel can be reduced. It can be absorbed into liquid fuel. Thereby, the tar content can be removed from the gas fuel in the gas fuel line 124 before being supplied to the scrubber device 7, and the temperature of the gas fuel can be reduced. Thus, in the fuel supply unit 160a, the fuel supply device 190 and the fuel supply line 198 that supply liquid fuel to the gas fuel line 124 serve as coolers.

  The fuel supply unit 160a supplies the gas engine fuel and the burner fuel with one fuel supply device, but the gas engine fuel supply device that supplies the gas engine fuel and the burner fuel supply device that supplies the burner fuel are separately provided. It may be provided. The fuel supply unit 160a may include at least one of a fuel supply line 194 for supplying gas engine fuel, a fuel supply line 196 for supplying burner fuel, and a fuel supply line 198 for supplying fuel to the fuel supply line 124. Good.

  Further, the gas engine system may be a combination of the embodiment shown in FIG. 3 and the embodiment shown in FIG. For example, the gas engine system may supply the fuel heat-exchanged by the fuel heat exchanger 193 to the scrubber device 7 and supply the medium oil from the scrubber device 7 to the gas engine 32 and the starting burner 29. Further, the gas engine system may exchange heat between the liquid fuel and the gas fuel supplied from the scrubber device 7 to the gas engine 32 and the activation burner 29 by the fuel heat exchanger 193. In the gas engine system, the fuel supply device 190 and the fuel supply line 198 supply liquid fuel to the gas fuel line 124, supply the liquid fuel from the gas fuel line 124 to the scrubber device 7, and supply the gas engine from the scrubber device 7. 32, medium oil may be supplied to the start burner 29.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Gas engine system 2 Biomass gasification system 3 Biomass supply apparatus 4 Gasification furnace 5 Air preheater 6 Filter apparatus 7 Scrubber apparatus 8 Heat exchanger 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 unloading line 28 Fluidized material conveying device 29 Starter burner 29a Fuel supplying device 29b Air supply device 32 Gas engine 34 Generator 70 Biomass reservoir (biomass yard)
72 Transporter 74 Receiving part
76, 78 Transport conveyor 80 Magnetic separator 82 Iron storage yard 84, 90 Hopper 86 Drying device 88 Weighing conveyor 92 Supply pipe 100 Ash circulation device 116 Blower fan 122 Foreign matter discharge device 124, 126 Gas fuel line 130 Scrubber body 132 Circulation device 140, 142 temperature detector 146 exhaust gas line 148 drying device 160, 160a fuel supply unit 162 gas engine fuel supply device 164 burner fuel supply device 166, 168 fuel supply line 170, 172 liquid feed pump 190 fuel supply device 192 fuel supply line 193 fuel heat Exchanger 194, 196, 198 Fuel supply line 195, 197, 199 Control valve

Claims (13)

A biomass gasification system that generates gas fuel from biomass;
A gas engine for burning the gas fuel supplied from the biomass gasification system;
A control device for controlling the operation of each part;
The biomass gasification system includes:
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 first cooler for cooling the gas fuel generated in the gasifier;
A filter device that collects foreign matter contained in the gas fuel that has passed through the first cooler and discharges the gaseous fuel that has collected the foreign matter;
A second cooler that cools the gas fuel that has passed through the filter device to 400 ° C. or lower;
A scrubber device for bringing a medium oil into contact with the gas fuel that has passed through the second cooler and collecting a tar content in the gas fuel;
A gas fuel line that holds the gas fuel that has passed through the scrubber device at 70 ° C. or higher and supplies the gas fuel to the gas engine. A temperature detector for detecting a temperature between the second cooler and the scrubber device;
The said control apparatus controls cooling of the said 2nd cooler based on the detection result of the said temperature detector, The gas combustion discharged | emitted from the said cooler shall be 400 degrees C or less. The gas engine system as described in.   The second cooler is a heat exchanger that performs heat exchange between the gas fuel generated in the gasification furnace and a medium oil circulated in the scrubber device to cool the gas fuel. The gas engine system according to claim 1 or 2. A gas engine fuel supply device for supplying gas engine fuel, which serves as pilot fuel for the gas engine, to the scrubber device;
The gas engine system according to any one of claims 1 to 3, wherein the scrubber device includes the gas engine fuel in the medium oil.   The gas engine system according to claim 4, further comprising a gas engine fuel supply line that supplies medium oil of the scrubber device to the gas engine.   The gas engine system according to any one of claims 1 to 3, further comprising a gas engine fuel supply device that supplies gas engine fuel, which serves as pilot fuel for the gas engine, to the gas engine.   A fuel heat exchanger for exchanging heat between the gas fuel flowing between the gas furnace and the first cooler and the gas engine fuel supplied by the gas engine fuel supply device to raise the temperature of the gas engine fuel The gas engine system according to any one of claims 4 to 6, characterized by comprising:   8. The gas engine fuel supply device according to claim 4, wherein a part of the gas engine fuel is supplied to a gas fuel line through which the gas fuel flows between the filter device and the scrubber device. The gas engine system according to one item. The gasifier has a start burner,
A burner fuel supply device for supplying burner fuel, which is fuel for the start burner, to the scrubber device;
The gas engine system according to any one of claims 1 to 8, wherein the scrubber device includes the burner fuel in the medium oil.   The gas engine system according to claim 9, further comprising a burner fuel supply line that supplies medium oil of the scrubber device to the starter burner. The gasifier has a start burner,
The gas engine system according to any one of claims 1 to 8, further comprising a burner fuel supply device that supplies burner fuel, which is fuel for the startup burner, to the startup burner.   A fuel heat exchanger for exchanging heat between the gas fuel flowing between the gas furnace and the first cooler and the burner fuel supplied by the burner fuel supply device to raise the temperature of the burner fuel; The gas engine system according to claim 9, wherein the gas engine system is provided.   The burner fuel supply device supplies a part of burner fuel to a gas fuel line through which the gas fuel flows between the filter device and the scrubber device. The gas engine system as described in.

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