JP4297488B2 - Internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel filling device for high-pressure gas such as hydrogen gas and natural gas (CNG), which is being put into practical use as a fuel for automobiles, and a general liquid fuel.
[0002]
[Prior art]
Carbon dioxide CO to prevent global warming ₂ Emission control is a common issue worldwide.
And CO ₂ When it comes to emissions of CO2 in Japan, such as carbon tax and emission rights ₂ There is also a direction that regards the emissions themselves as a business. Under such circumstances, CO ₂ There is a movement to separate and collect the gas from the exhaust gas.
And the collected CO ₂ To make more efficient use of CO2 as fuel (CO ₂ Hydrogen H ₂ And a liquid fuel such as dimethyl ether “DME” is purified).
[0003]
On the other hand, in a combustion engine such as an industrial internal combustion engine such as power generation, in order to use fuel stored in a fuel tank in advance, such as fuel supplied from a fuel supply pipe such as a gas pipe network, oil or light oil, In the event of an emergency when these fuel supplies stop or when the fuel in the tank is exhausted, engine operation has become impossible.
Combustion engines that are difficult to independently start and control independently, such as dual fuel engines that use light oil to promote ignition and premixed compression self-ignition engines that use natural gas with poor self-ignitability as fuel. However, it is necessary to periodically procure fuel for ignition, combustion control, and start-up by a conveying means such as a truck and store it in a fuel tank.
[0004]
Therefore, the carbon dioxide contained in the exhaust of the engine is absorbed by the carbon dioxide adsorbent, and then the carbon dioxide adsorbent is heated to recover the carbon dioxide, and the carbon dioxide and the methane gas that is the main fuel are reacted. A natural gas reforming internal combustion engine using fuel has been proposed (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
JP 2002-13447 A (page 5, FIG. 2)
[0006]
The present inventor confirmed that the above proposal (Japanese Patent Laid-Open No. 2002-13447) recovered CO from exhaust gas. ₂ The heat efficiency of the engine is improved by using a mixed gas of hydrogen H2 and carbon monoxide CO obtained by reacting methane gas as the main fuel with the operating fuel of the engine, but recovered from the exhaust gas CO ₂ And H obtained by reforming the main fuel (for example, city gas “13A”) ₂ Synthesizes liquid fuel such as methanol and dimethyl ether “DME” and stores it in a tank, which can be used as an auxiliary fuel for ignition and combustion control in normal operation, and as a main fuel at engine start We paid attention to the fact that it can be used as the main fuel during emergency operation.
[0007]
[Problems to be solved by the invention]
The present invention provides NO fuel as auxiliary fuel for ignition and combustion control during normal operation, auxiliary fuel during engine start-up, and reserve fuel for emergency operation. _x The purpose of the present invention is to provide an incidental device that allows the engine itself to supply and reserve synthetic fuel with a low emission amount and to control the supply amount.
[0008]
According to the present invention, the hydrogen gas supply means 23 for extracting and supplying hydrogen gas by reforming from the primary fuel, and the carbon dioxide and hydrogen gas supply means recovered and separated by the recovery means 18 for recovering carbon dioxide. Reaction means 22 for reacting with the hydrogen supplied by 23 to generate secondary fuel, and mixing the primary fuel and air in the mixer 12 and flowing into the intake port 15 to store the secondary fuel. In the internal combustion engine supplied from the tank 25 to the fuel injection device 28, the recovery means 18 is provided in the exhaust branch pipe 17 branched from the exhaust pipe 16 to recover carbon dioxide from the exhaust gas. A flow control valve 27 is provided in the fuel supply line 26 leading to the fuel injection device 28, and the carbon dioxide recovery line 21 extending from the recovery means 18 to the reaction means 22 is charged with carbon dioxide. An element concentration sensor SR2 is provided, and a control unit 30 is provided for receiving a signal from the load sensor SR1 of the internal combustion engine and a signal from the carbon dioxide concentration sensor SR2 to control the supply amount of the secondary fuel. The control unit 30 is connected to the load sensor SR1. When the output signal and the opening degree signal of the flow control valve 27 are read, it is determined whether or not the secondary fuel supply amount is appropriate for the load of the internal combustion engine, and the secondary fuel supply amount is excessive. If it is determined, the supply amount or generation amount of the secondary fuel is decreased, and if the secondary fuel is insufficient, it is determined whether or not the generation amount of the secondary fuel is maximum. Has a function of increasing the amount of primary fuel supplied and, if maximum, the amount of primary fuel supplied.
[0009]
According to the internal combustion engine of the present invention having such a configuration, the recovery means for separating and recovering carbon dioxide from the exhaust gas, the hydrogen gas supply means for supplying hydrogen gas, and the recovered carbon dioxide and hydrogen gas supply means Reaction means that reacts with the supplied hydrogen to generate liquid fuel that is auxiliary fuel for ignition and control at the start, and the liquid fuel generated by the reaction means supplies main fuel Separately from the supply system, the internal combustion engine itself is configured to store or supply.
That is, as in the prior art, the internal combustion engine itself can supply the ignition liquid fuel by itself without transporting and supplementing the liquid fuel by a transport means such as a truck each time there is no liquid fuel for ignition.
[0010]
In addition, the liquid fuel to be synthesized contains methanol “CH” as a main component. ₃ OH "and dimethyl ether, so-called DME" (CH ₃ ) ₂ OH "and emits less harmful substances such as NOx than conventional auxiliary fuels such as light oil and gasoline.
[0011]
Furthermore, since hydrogen used for synthesizing liquid fuel is generated using a reformer obtained by reforming main fuel used in normal operation, hydrogen for fuel synthesis is specially used for trucks, etc. There is no need to carry it by means of transport. In other words, according to the present invention, the liquid fuel is transported by a transport means such as a truck every time when there is no liquid fuel used for ignition, combustion control, engine start-up and emergency operation as in the prior art. The internal combustion engine can obtain and store liquid fuel for ignition.
[0013]
Further, according to the present invention, hydrogen gas supply means 23 for extracting and supplying hydrogen gas by reforming from the primary fuel, and carbon dioxide recovered from the exhaust gas and separated and supplied by the hydrogen gas supply means 23 Reaction means 22 for reacting with hydrogen to generate secondary fuel, and mixing the primary fuel and air in the mixer 12 and flowing them into the intake port 15, and fuel injection of the secondary fuel from the storage tank 25 In the internal combustion engine supplied to the apparatus 28, the diversion pipe 17C branched from the exhaust pipe 16 has a heater 34 therein and is filled with an adsorbent 32 via a three-way valve VT and an on-off valve VC1 that open to the atmosphere. 29, and further connected to the reaction means 22 via a suction blower 36 and a carbon dioxide concentration sensor SR2, and reaches the fuel injection device 28 from the storage tank 25. A flow rate control valve 27 is provided in the fuel supply line 26, and a control unit 30 for controlling the supply amount of the secondary fuel in response to signals from the load sensor SR1 and the carbon dioxide concentration sensor SR2 of the internal combustion engine is provided. Is inputted with the octane number of the primary fuel and the octane number of the secondary fuel. When the engine is started with the secondary fuel as the starting fuel, the output or ignition timing is detected by the load sensor SR1, and the The opened on-off valve VC1 is opened, and the on-off valve VC1 is closed when a predetermined time has elapsed. Then, it is determined whether the octane number of the primary fuel is equal to or higher than the octane number of the secondary fuel. If it is above the octane number of the fuel, it is judged whether the ignition timing is late or whether the output is reduced, and if YES, the flow control If NO is opened, the flow control valve 27 is throttled, and if the octane number of the primary fuel is lower than the octane number of the secondary fuel, it is determined whether the ignition timing is late / or the output is lowered. If YES, the flow control valve 27 is throttled. If NO, the flow control valve 27 is opened.
[0014]
By having such a configuration, when the ignition timing is early and / or when the output is excessive, the ratio of the low octane fuel having good ignitability is reduced, and when the ignition timing is late and / or the output is reduced. In this case, it is possible to increase the proportion of the low octane fuel having good ignitability. This stabilizes the ignition timing of the internal combustion engine and / or stabilizes the output of the internal combustion engine.
[0016]
According to such a configuration, only the fuel with good ignitability and low octane number is supplied at the time of starting, so that the starting performance is improved.
[0022]
According to the present invention, the hydrogen gas supply means 23 that extracts and supplies hydrogen gas by reforming from the primary fuel, and the carbon dioxide and hydrogen gas supply means 23 that are recovered and separated from the exhaust gas are supplied. Reaction means 22 for reacting with hydrogen to generate secondary fuel, and mixing the primary fuel and air in the mixer 12 and flowing them into the intake port 15, and fuel injection of the secondary fuel from the storage tank 25 The internal combustion engine supplied to the apparatus 28 includes a carbon dioxide recovery device 40 provided with a separation membrane that allows only carbon dioxide to pass through a blower 46 in an exhaust branch pipe 17D branched from the exhaust pipe 16, and from the storage tank 25 to the A flow control valve 27 is provided in the fuel supply line 26 leading to the fuel injection device 28, and the carbon dioxide recovery line 2 extending from the carbon dioxide recovery device 40 to the reaction means 22. A carbon dioxide concentration sensor SR2 is provided in D, and a control unit 30 is provided for controlling the supply amount of the secondary fuel in response to a signal from the load sensor SR1 of the internal combustion engine and the carbon dioxide concentration sensor SR2. When the octane number of the fuel and the octane number of the secondary fuel are input, the output or ignition timing is detected by the load sensor SR1, and it is determined whether or not the octane number of the primary fuel is equal to or greater than the octane number of the secondary fuel. Is equal to or greater than the octane number of the secondary fuel, it is determined whether ignition is slow or the output is decreasing. If YES, the flow control valve 27 is opened, and if NO, the flow control valve 27 is throttled. If the octane number of the primary fuel is lower than the octane number of the secondary fuel, it is determined whether the ignition timing is late or the output is reduced, Y If S, the flow control valve 27 is throttled. If NO, the flow control valve 27 is opened. After the flow control valve 27 is opened, the number of rotations of the blower 46 is increased, and after the flow control valve 27 is throttled, the blower 46 is opened. Has a function of reducing the number of rotations.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0024]
First, a first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, a gas engine 1 mixes a fuel gas (for example, city gas “13A”) supplied from a fuel gas supply line 10 as a main fuel and supply air from an air supply line 11 by a mixer 12. The mixed gas fuel is made to flow into the intake port 15 through a mixed gas supply line 14 having a throttle 13 interposed therebetween. The fuel gas supply line 10 and the mixed gas supply line 14 are connected by a bypass line 10B that bypasses the mixer 12 via a throttle valve Vb.
[0025]
On the other hand, an exhaust gas distribution pipe 17 for diverting a part of the exhaust gas is branched from the exhaust pipe 16 of the gas engine 1, and a three-way valve VT is interposed in the exhaust gas distribution pipe 17, and the three-way valve VT. The line branched from the exhaust gas distribution pipe 17 is normally closed and communicates with the atmosphere opening side.
[0026]
The exhaust gas diverter 17 is a carbon dioxide CO consisting of two tanks whose bottoms communicate with each other. ₂ The recovery tank 18 communicates with one tank 18a below.
Carbon dioxide CO ₂ The recovery tank 18 has a CO 2 interior such as an amine solution. ₂ The carbon dioxide CO contained in the exhaust gas when the exhaust gas filled with the absorption liquid and flowing down the exhaust gas distribution pipe 17 is submerged in the solution. ₂ Is configured to dissolve in the solution. And carbon dioxide CO ₂ The remaining exhaust gas dissolved in the solution is returned to the exhaust pipe 16 through a reflux pipe 19 that communicates the upper part of one tank 18a with the exhaust pipe 16.
[0027]
Carbon dioxide CO ₂ In the other tank 18b of the recovery tank 18, a part of the cooling water flow line 20 for distributing and circulating the cooling water of the gas engine 1 is disposed, and the cooling water heated from the engine in the tank 18b. (Hot heat held by) and CO2 ₂ Carbon dioxide CO in the recovery tank 18 ₂ Heat exchange is carried out with the solution in which is dissolved.
Carbon dioxide CO in the cooling water flow line 20 ₂ A cooling water flow rate control valve Vw for adjusting the cooling water amount is interposed on the side flowing into the recovery tank 18 (18b).
[0028]
Once carbon dioxide CO ₂ Carbon dioxide CO in the exhaust gas dissolved in the solution in the recovery tank 18 ₂ Is carbon dioxide CO ₂ When the solution in the recovery tank 18 is warmed by the heat stored in the cooling water, the gas (carbon dioxide CO ₂ Gas) to be separated and discharged above the tank 18b.
Above the tank 18b is carbon dioxide CO. ₂ A recovery line 21 communicates with the reactor 22.
[0029]
On the other hand, the fuel gas supply line 10 is connected to a reformer 23 via a branch line 10A, and the reformer 23 is connected to the reactor 22 by a hydrogen gas supply line 24. Then, when the fuel gas flows from the branch line 10A into the reformer 23, the hydrogen gas H is reformed from the fuel gas. ₂ Is extracted and the extracted hydrogen gas H ₂ Flows from the hydrogen gas supply line 24 into the reactor 22.
[0030]
In the reactor 22, the above-mentioned CO that has flowed in. ₂ And hydrogen H ₂ Reacts with methanol “CH ₃ OH "and water" H " ₂ O ”and methanol“ CH ” ₃ OH ”is dimethyl ether, so-called DME“ (CH ₃ ) ₂ OH "and water" H " ₂ O ".
Methanol “CH” which is the liquid fuel obtained in the reactor 22 ₃ OH "and / or" (CH ₃ ) ₂ OH "is stored in one end in the storage tank 25 of the liquid fuel supply line 26 provided with the storage tank 25, and is supplied to the fuel injection device 28 of the gas engine 1 in accordance with a control method described later.
A flow rate control valve 27 is interposed downstream of the storage tank 25, and the flow rate control valve is configured such that the opening degree is controlled by the control unit 30.
[0031]
The control unit 30 includes load sensors SR1 and CO attached to the gas engine 1. ₂ CO interposed near the reactor 22 in the recovery line 21 ₂ Based on the information from the concentration sensor SR2, the opening of the cooling water flow rate control valve Vw, the H of the reformer 23, ₂ It is configured to adjust the rotational mass, the opening degree of the flow control valve 27 interposed in the liquid fuel supply line 26, and the opening and closing of the three-way valve VT interposed in the exhaust branch pipe 17. In addition, H of the reformer 23 ₂ The amount of reforming is the recovered CO ₂ It is designed to be automatically determined by the amount (or the amount of secondary fuel produced).
Here, in the figure, symbol Li indicates an input signal line Lo and output signal line.
[0032]
Next, a combustion control method according to the first embodiment will be described with reference to FIGS.
2 and 3 are flowcharts for conceptually explaining the combustion control method.
First, the octane number of the primary fuel (main fuel) is the secondary fuel (produced fuel: liquid fuel: methanol “CH” ₃ OH ", dimethyl ether DME" (CH ₃ ) ₂ In the case where the octane number is higher than “OH” or the like, control is performed as shown in FIG.
In FIG. 2, first, output or ignition timing is detected by the load sensor SR1 (step S1). Then, the control unit 30 determines whether the ignition timing is late or whether the output is reduced (step S2).
[0033]
If the ignition timing is late or the output is low (YES in step S2), the process proceeds to step S3, where the generated fuel (liquid fuel: methanol “CH”) that has a low octane number and is easy to ignite. ₃ OH ", dimethyl ether DME" (CH ₃ ) ₂ OH ") is increased and the control is terminated.
On the other hand, if the ignition timing is not late or the output has not decreased (NO in step S2), the process proceeds to step S4, where control is performed to reduce the generated fuel (liquid fuel), and the control is terminated. .
[0034]
Next, a case where the octane number of the primary fuel (main fuel) is lower than the octane number of the secondary fuel (generated fuel) will be described with reference to FIG.
In FIG. 3, first, the output or ignition timing is detected by the load sensor SR1 (step S11), and the control unit 30 determines whether the ignition timing is late or whether the output is reduced (step S12). ).
[0035]
If the ignition timing is late or the output is low (YES in step S12), the process proceeds to step S13, and control is performed so as to reduce the generated fuel (liquid fuel) that has a high octane number and is difficult to ignite. finish. On the other hand, if the ignition timing is not late or the output has not decreased (NO in step S12), the process proceeds to step S14, where control is performed to increase the generated fuel (liquid fuel) and the process ends.
[0036]
The combustion control method will be described in more detail with reference to FIG.
First, the octane number of the main fuel and the octane number of the fuel (produced fuel) generated by the reactor are input (step S21), and the output or ignition timing is detected by the load sensor SR1 (step S22).
[0037]
In the next step S23, the control unit 30 determines whether or not the octane number of the main fuel is greater than or equal to the octane number of the refined fuel.
If the octane number of the main fuel is greater than or equal to the octane number of the produced fuel (YES in step S23), the process proceeds to step S24. If the octane number of the main fuel is less than the octane number of the refined fuel (NO in step S23), the process proceeds to step S25.
[0038]
In step S24, the control unit 30 determines whether the ignition timing is late or whether the output is decreasing.
If the ignition timing is late or the output is decreasing (YES in step S24), the process proceeds to step S26, and if the ignition timing is not delayed or the output is not decreasing ( (NO in step S24), the process proceeds to step S28.
[0039]
On the other hand, in step S25, the control unit 30 determines whether the ignition timing is late or whether the output is decreasing, and if the ignition timing is late or the output is decreasing (step) If YES in S25), the process proceeds to step S28, and if the ignition timing is not delayed or the output has not decreased (NO in step S25), the process proceeds to step S26.
[0040]
In step S <b> 26, the control unit 30 transmits a control signal to open the flow control valve 27 interposed in the liquid fuel (generated fuel) supply line 26.
At the same time, a control signal is output to open the cooling water flow rate control valve Vw. Carbon dioxide CO ₂ Increasing the amount of heat of cooling water (stored) in the recovery tank 18 ₂ The temperature of the solution in the recovery tank 18 is increased, and carbon dioxide CO ₂ Carbon dioxide CO in the exhaust gas dissolved in the solution in the recovery tank 18 ₂ This is because the amount of gas separation is increased, thereby increasing the supply amount of generated fuel that has a low octane number and is easy to ignite.
[0041]
On the other hand, in step S <b> 28, the control unit 30 transmits a control signal to throttle the flow control valve 27 interposed in the liquid fuel (generated fuel) supply line 26.
At the same time, a control signal is output so as to throttle the cooling water flow valve Vc. Carbon dioxide CO ₂ Decrease the amount of heat of cooling water (held) put into the recovery tank 18, ₂ The temperature of the solution in the recovery tank 18 is lowered and carbon dioxide CO ₂ Carbon dioxide CO in the exhaust gas dissolved in the solution in the recovery tank 18 ₂ This is because the gas separation amount is reduced, and the supply amount of the generated fuel that has a low octane number and is easy to ignite is reduced.
[0042]
2 to 4 describe the supply fuel amount increase / decrease control during operation of the gas engine 1, while FIG. 5 illustrates the control at the start of the gas engine 1.
In FIG. 5, first, in step S61, it is determined whether or not the gas engine 1 is being started. Here, the determination itself of whether or not it is at the time of starting is conventionally determined by a known method.
[0043]
If it is determined in step S61 that the engine is “starting” (YES in step S61), the octane number of the main fuel is compared with the octane number of the generated fuel (step S62). In other words, it is determined which of the main fuel and the generated fuel is easy to ignite.
This is because fuel that is easy to ignite (fuel having a low octane number) is used at the time of starting.
[0044]
If the generated fuel is more easily ignited, that is, if the octane number of the generated fuel is low (NO in step S62), the main fuel that is difficult to ignite is not supplied to the gas engine 1 but ignited. Only the easily generated fuel is supplied to the gas engine 1 (step S63).
On the other hand, when the main fuel is easier to ignite (when the octane number of the main fuel is lower: YES in step S62), only the main fuel that is easily ignited is supplied to the gas engine 1 (step S64).
That is, at the time of start-up, only the easily ignitable fuel of the generated fuel (step S63) or the main fuel (step S64) is supplied to the gas engine 1. Then, the process returns to step S61.
[0045]
If it is determined in step S61 that it is not “starting” (NO in step S61), the control described above with reference to FIGS. 2 to 4 and / or the control described later with reference to FIG. 6 is executed. (Step S65).
[0046]
Next, with reference to FIG. 6, the aspect which controls the generation amount of produced | generated fuel in 1st Embodiment is demonstrated.
First, the output signal of the load sensor SR1 and the opening signal of the flow control valve 27 are read into the control unit 30 (step S71).
The control unit 30 determines whether or not the supply amount of the generated fuel is appropriate for the load of the gas engine 1 (step S72).
[0047]
When it is determined that the supply amount of the generated fuel is excessive with respect to the load of the gas engine 1 (step S72 is “excess”), control is performed to reduce the supply amount or generation amount of the generated fuel (step S72). S73).
[0048]
As a specific method for reducing the supply amount or generation amount of the generated fuel, the opening degree of the flow control valve 27 that controls the supply flow rate to the gas engine 1 is reduced via the signal transmission line Lo (control valve). 27), the amount of generated fuel supplied to the gas engine 1 is reduced, and the remaining generated fuel is stored in the storage tank 25.
Alternatively, the operation of the reformer 23 is controlled to reduce the amount of generated hydrogen gas. Since the hydrogen gas generated in the reformer 23 is used as a raw material for the generated fuel, if the amount of generated hydrogen gas is reduced, the amount of generated fuel is naturally reduced.
Further, the opening degree of the three-way valve VT communicating with the atmosphere opening side is increased to increase the flow rate of the exhaust gas released into the atmosphere. As a result, the carbon dioxide CO is discharged via the exhaust shunt pipe 17. ₂ The flow rate of the exhaust gas reaching the recovery tank 18 is reduced, and the supply amount of carbon dioxide, which is a raw material of the generated fuel, is reduced, so that the generated fuel generation amount is also reduced.
[0049]
Here, in addition to reducing the generated fuel generation amount in step S <b> 73, the control unit 30 performs necessary control to store the surplus generated fuel in the storage tank 25.
As for the specific contents of the control relating to the stockpile in the tank 25, a conventionally known method in a general liquid storage tank may be applied as it is.
[0050]
If the control for reducing the generated fuel generation amount has been executed (step S73 is completed), the process goes to step S77.
If it is determined that the supply amount of the generated fuel is appropriate for the load of the gas engine 1 (step S72 is “valid”), the process goes to step S77.
[0051]
When it is determined that the supply amount of the generated fuel is insufficient with respect to the load of the gas engine 1 (step S72 is “insufficient”), it is determined whether or not the generated fuel generation amount is the maximum at that time. (Step S74).
If the generated fuel generation amount is not the maximum (NO in step S74), the generated fuel generation amount or supply amount is increased (step S75).
[0052]
As a specific method of increasing the generation amount or supply amount of the generated fuel, the flow control valve 27 is increased in opening degree (the control valve 27 is opened) and stored in the storage tank 25 as necessary. Consume the generated fuel.
Alternatively, operation of the reformer 23 is controlled to increase the amount of generated hydrogen gas, thereby increasing the amount of generated fuel.
Further, the opening degree of the three-way valve VT communicating with the atmosphere opening side is reduced to reduce the flow rate of the exhaust gas released to the atmosphere, and the carbon dioxide CO through the exhaust branch pipe 17 is reduced. ₂ The flow rate of exhaust gas reaching the recovery tank 18 is increased, and the supply amount of carbon dioxide, which is a raw material of the generated fuel, is increased.
[0053]
When the generated fuel generation amount is the maximum in step S74 (YES in step S74), the main fuel supply amount is increased for the amount corresponding to the shortage of the generated fuel (step S76).
This is because the operation is continued without stopping the gas engine 1 even if the output is somewhat reduced.
[0054]
After increasing the generated fuel generation amount (step S75) or increasing the main fuel supply amount (step S76), the process proceeds to step S77.
[0055]
In step S77, it is determined whether or not the control is finished. If the control is not finished (NO in step S77), the process returns to step S71.
[0056]
In the first embodiment having the configuration and the combustion control method as described above, the liquid fuel generated by the reactor 22 is supplied by the internal combustion engine itself separately from the mixed gas supply line (supply system) 14 for supplying the main fuel. It is configured to (self).
That is, the liquid fuel for igniting the internal combustion engine (the octane number of the generated fuel is higher than that of the main fuel) without transporting and supplementing the liquid fuel by a transport means such as a truck each time the liquid fuel for ignition is exhausted as in the prior art. Can be generated in the system.
[0057]
In addition, the main component of the synthesized liquid fuel (produced fuel) is methanol “CH”. ₃ OH "and dimethyl ether, so-called DME" (CH ₃ ) ₂ OH "and emits less harmful substances such as NOx than conventional auxiliary fuels such as light oil and gasoline.
[0058]
Further, since the hydrogen used for synthesizing the liquid fuel is generated using a reformer obtained by reforming the main fuel used in normal operation, for example, city gas “13A”, the fuel synthesis Therefore, it is not necessary to carry hydrogen for transportation by a transport means such as a truck.
[0059]
Next, a second embodiment of the present invention will be described with reference to FIG.
In the first embodiment of FIGS. ₂ CO of collection device 18b ₂ The engine cooling water flow tube 20 is a line for applying heat to the solution. On the other hand, in the second embodiment shown in FIG. 7, the exhaust gas branch pipe 17B provided with the exhaust gas flow control valve Vb is used to ₂ CO of collection device 18B ₂ The exhaust gas after the heat exchange is converted into CO2 ₂ It is configured to be dissolved in the solution of the recovery device 18Bb.
[0060]
In relation thereto, in the control method (see FIG. 4) in the first embodiment, the cooling water flow rate control valve Vw is controlled to open and close, and the CO ₂ CO of collection device 18b ₂ Although the amount of heat input to the solution is controlled, in the second embodiment of FIG. 7, the open / close control of the exhaust gas flow control valve VB configured as a three-way valve controls the CO 2. ₂ CO of recovery unit 18Bb ₂ The amount of heat input to the solution will be controlled.
Regarding other configurations and operational effects, the second embodiment is the same as the first embodiment. In addition, the second embodiment is the same as the first embodiment in terms of control at start-up and control of the amount of generated fuel or the amount of generated fuel.
[0061]
Next, a third embodiment of the present invention will be described with reference to FIGS.
In the embodiment of FIGS. ₂ As a means to extract CO ₂ CO in exhaust gas using recovery tank ₂ Once the CO ₂ Dissolved in the liquid in the recovery tank, CO ₂ CO2 from the exhaust gas by warming the dissolved liquid ₂ Only separated and recovered.
[0062]
On the other hand, the third embodiment of FIGS. ₂ As a means for taking out, an adsorbent such as activated carbon or zeolite is filled inside, and a container equipped with an interior or exterior heater is used. The adsorbent in the container is once filled with CO in the exhaust gas. ₂ Adsorbed and then adsorbed CO ₂ Is taken out or collected.
Where the adsorbed CO ₂ In order to take out or collect the product outside the container, the temperature and pressure in the container may be adjusted.
[0063]
Hereinafter, differences of the third embodiment of FIGS. 8 and 9 from the embodiments of FIGS. 1 to 6 will be mainly described.
In FIG. 8, an exhaust gas branch pipe 17C is branched from the exhaust pipe 16, and a part of the exhaust gas is branched.
A three-way valve VT is interposed in the exhaust gas branch pipe 17C. This three-way valve VT is the same as the three-way valve VT of FIG.
The exhaust gas branch pipe 17C branches at a branch point P into a pair of branch pipes 17Cb and 17Cb, and then joins at a junction G and communicates with the reactor 22.
[0064]
Each branch pipe 17Cb, 17Cb is filled with an on-off valve VC1 and an adsorbent 32 in order from the upstream side, and a CO 34 in which a heater 34 is incorporated. ₂ An adsorption container 29, a suction blower 36, and a three-way valve VC2 are provided.
Although the line (reference symbol B) of the three-way valve that does not face the confluence G is not clearly shown in FIG. 8, both are returned to the exhaust pipe 16.
[0065]
The control unit 30C periodically performs opening / closing control of the opening / closing valve VC1 interposed in the exhaust gas distribution pipe 17Cb. And load sensor SR1 attached to gas engine 1, CO ₂ CO interposed near the reactor 22 in the recovery line 21 ₂ Based on the information from the concentration sensor SR2, adjustment of the negative pressure of the suction blower 36, and CO ₂ It is configured to control ON / OFF of the heater 34 built in the adsorption container.
Further, the control at the time of starting and the control of the generation amount or supply amount of the generated fuel are the same as those described with reference to FIGS.
[0066]
The flow path switching pattern of the three-way valve VC2 is linked to the opening / closing of the on-off valve VC1, and when VC1 is open, the line “I” to the line “B” (the direction returned to the exhaust pipe) When VC1 is closed, it flows from line “I” to line “C” (reactor direction).
About another structure, it is the same as that of embodiment of FIGS.
[0067]
Next, the combustion control of the third embodiment will be described mainly using FIG. 9 and also referring to FIG.
First, the octane number and H of the main fuel ₂ And CO ₂ After inputting the octane number of the produced fuel obtained by the above reaction (step S31), the engine 1 is started (step S32). Here, when the engine 1 is started, the generated fuel stored in the storage tank 25 in advance is used as the starting fuel.
[0068]
Next, an output or ignition timing is detected by the engine load sensor SR1 (step S33). Then, the on-off valve VC1 interposed in the branch pipe 17Cb is opened (step S34).
[0069]
The control unit 30C keeps the on-off valve VC1 open until the required time elapses (step S35), and closes the on-off valve VC1 when the required time elapses (step S36).
[0070]
Next, the control unit 30C determines whether or not the octane number of the main fuel is greater than or equal to the octane number of the produced fuel (step S37). If the octane number of the main fuel is greater than or equal to the octane number of the produced fuel (YES in step S37), step Proceeding to S38, if the octane number of the main fuel is lower than the octane number of the produced fuel (NO in step S37), the process proceeds to step S39.
[0071]
In step S38, the control unit 30C determines whether the ignition timing is late or whether the output is decreasing, and if the ignition timing is late or the output is decreasing (step S38). YES), the process proceeds to step S40. On the other hand, if the ignition timing has not been delayed or the output has not decreased (NO in step S38), the process proceeds to step S42.
[0072]
On the other hand, also in step S39, the control unit 30C determines whether the ignition timing is late or whether the output is decreasing, and if the ignition timing is late or the output is decreasing ( Step S39 YES), the process proceeds to Step S42. If the ignition timing is not delayed or the output has not decreased (NO in step S39), the process proceeds to step S40.
[0073]
In step S40, the control unit 30C transmits a control signal to open the flow control valve 27 interposed in the supply line 26 in order to increase the supply amount of the generated fuel (liquid fuel) that has a low octane number and easily ignites. .
In conjunction with this, a control signal is transmitted so as to increase the negative pressure of the blower 36 (increase the rotational speed of the blower) (step S41). By increasing the negative pressure of the Prowa 36, CO ₂ CO adsorbed in the adsorption container 29 ₂ This is for increasing the amount of recovered (raw material of generated fuel).
Then, the process proceeds to step S44.
[0074]
On the other hand, in step S42, the control unit 30C throttles the flow control valve 27 interposed in the liquid fuel (generated fuel) supply line 26 in order to reduce the supply amount of fuel with good ignitability (fuel with low octane number). A control signal is transmitted as follows.
In conjunction with this, a control signal is transmitted so as to decrease the negative pressure of the blower 36 (decrease the rotational speed of the blower) (step S43), and the process proceeds to step S44.
Decrease the negative pressure of Prowa 36, CO ₂ CO adsorbed in the adsorption container 29 ₂ This is to reduce the amount of recovery.
[0075]
Although not clearly shown in FIG. 9, in step S41 and step S43, on / off control of the heater 34 is performed instead of controlling the negative pressure of the blower or in addition to the negative pressure control of the blower. May be.
That is, in step S41, CO ₂ In order to increase the amount of CO ₂ The temperature in the adsorption container 29 is increased. In step S43, the CO ₂ In order to reduce the amount of recovered CO ₂ The temperature in the adsorption container 29 is maintained at room temperature.
In other words, instead of controlling the negative pressure of the blower or in addition to the negative pressure control of the blower, by performing ON-OFF control of the heater 34, the CO ₂ Control is performed to increase or decrease the recovery amount.
[0076]
In step S44, the control unit 30C determines whether or not to end the operation. If finished (YES in step S44), the control is finished, and if the operation is continued (NO in step S44), the current state is maintained until a predetermined time elapses (step S45). S34 and subsequent steps are repeated.
[0077]
In the third embodiment, the control at the time of starting and the control of the generation amount or supply amount of the generated fuel are the same as those shown in FIGS.
The operational effects of the third embodiment are also the same as those of the embodiment of FIGS.
[0078]
Next, a fourth embodiment will be described with reference to FIGS. 10 and 11.
In the embodiment of FIGS. ₂ As a means to extract CO ₂ CO in exhaust gas using recovery tank ₂ Once the CO ₂ Dissolved in the liquid in the recovery tank, CO ₂ CO2 from the liquid by warming the dissolved liquid ₂ Only separated and recovered.
[0079]
On the other hand, the fourth embodiment of FIGS. ₂ As a means to extract CO ₂ CO that has a separation membrane is used. ₂ CO to be recovered by adjusting the pressure of the exhaust gas flowing into the recovery device ₂ Is controlling the amount.
[0080]
Hereinafter, differences from the embodiment of FIGS. 1 to 6 will be mainly described.
In FIG. 10, in the fourth embodiment, a CO having a double structure of an inner container 42 formed of a separation membrane 42 a and an airtight outer container 44. ₂ A recovery device 40 is used.
[0081]
From the exhaust pipe 16, an exhaust shunt pipe 17D branches, and the CO ₂ The other end of the external container 44 communicates with one end of the recovery device 40, and the other end of the external container 44 is configured to return to the exhaust pipe 16, although not clearly depicted in the drawing.
[0082]
On the other hand, the inner container 42 formed of the separation membrane 42a has a side opposite to the side from which the exhaust gas split flows in, as shown in FIG. ₂ It communicates with the reactor 22 via a recovery line 21D.
[0083]
A pressurizing blower 46 is interposed upstream of the exhaust branch pipe 17D into the outer container 44. The pro 46 is connected to the control unit 30D through the output signal line Lo.
Other devices and configurations are substantially the same as those in the embodiment of FIGS.
[0084]
Next, the combustion control method of the fourth embodiment will be described mainly using FIG. 11 and also referring to FIG.
[0085]
First, the octane number of the main fuel and the octane number of the fuel produced by the reactor are input (step S51), and the output or ignition timing is detected by the load sensor SR1 (step S52).
[0086]
In the next step S53, the control unit 30D determines whether or not the octane number of the main fuel is greater than or equal to the octane number of the refined fuel. If the octane number of the main fuel is greater than or equal to the octane number of the refined fuel (YES in step S53), the control unit 30D If the octane number of the main fuel is less than the octane number of the refined fuel (NO in step S54), the process proceeds to step S55.
[0087]
In step S54, the control unit 30D determines whether the ignition timing is late or whether the output is decreasing, and if the ignition timing is late or the output is decreasing (step S54). If YES, the process proceeds to step S56, and if the ignition timing is not delayed or the output has not decreased (NO in step S54), the process proceeds to step S58.
[0088]
On the other hand, a similar process is performed in step S55. That is, the control unit 30D determines whether the ignition timing is late or whether the output is decreasing, and if the ignition timing is late or the output is decreasing (YES in step S55). The process proceeds to step S58, and if the ignition timing is not delayed or the output has not decreased (NO in step S55), the process proceeds to step S56.
[0089]
In step S56, the control unit 30D issues a control signal to open the flow control valve 27 interposed in the supply line 26 in order to increase the supply amount of the generated fuel (liquid fuel) that has a low octane number and is easy to ignite. To do.
In conjunction with this, a control signal is output so as to increase the rotational speed of the exhaust gas pressurizing blower 46 (step S57).
Increase the rotational speed of the exhaust gas pressurizing blower 46 to ₂ The pressure of the exhaust gas in the space between the outer container 44 and the inner container 42 of the recovery device 40 is increased to permeate the separation membrane 42a and be sent to the reactor 22 ₂ This is to increase the amount.
Then, the process goes to step S60.
[0090]
On the other hand, in step S58, the control unit 30D transmits a control signal so as to throttle the flow control valve 27 interposed in the liquid fuel (generated fuel) supply line 26.
In conjunction with this, a control signal is output so as to reduce the rotational speed of the exhaust gas pressurizing blower 46 (step S59).
Reduce the rotational speed of the exhaust gas pressurizing blower 46 to reduce the CO ₂ The pressure of the exhaust gas in the space between the outer container 44 and the inner container 42 of the recovery device 40 is reduced, and the CO that is permeated through the separation membrane 42a and sent to the reactor 22 ₂ This is to reduce the amount.
Then, the process goes to step S60.
[0091]
In step S60, it is determined whether or not the control is finished. If the control is not finished (step S60 is NO), the process returns to step S52.
[0092]
Also in the fourth embodiment of FIGS. 10 and 11, the control at the time of start-up and the control of the generation amount or supply amount of the generated fuel are the same as those described with reference to FIGS.
Moreover, the effect of 4th Embodiment is the same as that of 1st Embodiment of FIGS.
[0093]
It should be noted that the illustrated embodiment is merely an example, and is not a description of the purpose of limiting the technical scope of the present invention.
For example, in the illustrated example, CO ₂ In the recovery tanks 18 and 18B, CO is discharged from exhaust gas. ₂ The remaining exhaust gas dissolved in the liquid is recirculated to the exhaust pipe 16, but it may be diffused to the atmosphere independently.
Also, CO filled with adsorbent ₂ Although two sets of the adsorption container 29 and the re-extraction blower 36 are used, one set may be used, or three or more sets may be used.
[0094]
Further, in the illustrated embodiment, the hydrogen gas is generated by reforming the city gas. However, other methods may be adopted for supplying the hydrogen gas. For example, it is possible to use hydrogen generated by electrolyzing water using hydrogen gas cylinders or other generating means such as wind power or solar power.
[0095]
【The invention's effect】
The effects of the present invention are listed below.
(1) At the time of start by reacting the recovery means for separating and recovering carbon dioxide from the exhaust gas, the hydrogen gas supply means for supplying hydrogen gas, and the recovered carbon dioxide and hydrogen supplied by the hydrogen gas supply means The liquid fuel generated by the reaction means is supplied by the internal combustion engine itself separately from the supply system for supplying the main fuel. Therefore, as in the prior art, the internal combustion engine is transported without being transported and supplemented by transport means such as a truck each time the liquid fuel used for ignition, combustion control, engine start-up and emergency operation is exhausted. Can self-accumulate and store liquid fuel for ignition.
(2) The main component of the synthesized liquid fuel is methanol “CH ₃ OH "and dimethyl ether, so-called DME" (CH ₃ ) ₂ OH "and emits less harmful substances such as NOx than conventional auxiliary fuels such as light oil and gasoline.
(3) Hydrogen used for synthesizing liquid fuel is generated using a reformer obtained by reforming the main fuel used in normal operation. It is not necessary to carry it in by the carrying means.
(4) Since the fuel with good ignitability is supplied at the start, the startability is improved.
(5) It is possible to cope with the case where the generated fuel is excessive.
(6) Even when the produced fuel is insufficient, it is possible to continue the low output operation without stopping the operation of the internal combustion engine.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a first example of a first embodiment of the present invention.
FIG. 2 is a flowchart showing a schematic combustion control method when the octane number of the main fuel is equal to or higher than the octane number of the produced fuel in the first embodiment.
FIG. 3 is a flowchart showing a schematic combustion control method when the octane number of the main fuel is less than the octane number of the produced fuel in the first embodiment.
FIG. 4 is a flowchart showing a detailed combustion control method according to the first embodiment.
FIG. 5 is a flowchart showing a control method at start-up in the first embodiment.
FIG. 6 is a flowchart showing a method for controlling the generation amount or supply amount of generated fuel in the first embodiment.
FIG. 7 is a block diagram showing a schematic configuration of a second embodiment of the present invention.
FIG. 8 is a block diagram showing a schematic configuration of a third embodiment of the present invention.
FIG. 9 is a flowchart showing a detailed combustion control method according to a third embodiment of the present invention.
FIG. 10 is a block diagram showing a schematic configuration of a fourth embodiment of the present invention.
FIG. 11 is a flowchart showing a detailed combustion control method according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 ... Gas engine
10 ... Fuel gas supply line
11 ... Air supply line
12 ... Mixer
13 ... Throttle
14 ... Mixed gas supply line
15 ... Intake port
16 ... Exhaust pipe
17 ... Exhaust branch pipe
18 ... CO2 CO ₂ Collection tank
18a ... one tank
18b ... the other tank
20 ... Cooling moisture flow line
21 ... CO2 CO ₂ Collection line
22 ... Reactor
23 ... reformer
24 ... Hydrogen supply line
25 ... Storage tank
26 ... Liquid fuel supply line
27 ... Flow control valve

Claims (3)

  Hydrogen gas supply means (23) for extracting and supplying hydrogen gas by reforming from primary fuel, and carbon dioxide and hydrogen gas supply means (23) recovered and separated by a recovery means (18) for recovering carbon dioxide Reaction means (22) that reacts with the hydrogen supplied by (2) to produce secondary fuel, and mixes the primary fuel and air with the mixer (12) and flows into the intake port (15), In the internal combustion engine that supplies the secondary fuel from the storage tank (25) to the fuel injection device (28), the recovery means (18) is provided in an exhaust gas distribution pipe (17) branched from the exhaust pipe (16) to provide exhaust gas. Carbon dioxide is recovered from the fuel tank, a flow control valve (27) is provided in the fuel supply line (26) from the storage tank (25) to the fuel injection device (28), and the recovery means (18) Anti A carbon dioxide concentration sensor (SR2) is provided in the carbon dioxide recovery line (21) leading to the means (22), and a secondary fuel is received in response to signals from the load sensor (SR1) of the internal combustion engine and the carbon dioxide concentration sensor (SR2). A control unit (30) for controlling the supply amount of the engine, and when the control unit (30) reads the output signal of the load sensor (SR1) and the opening signal of the flow control valve (27), The secondary fuel supply amount is determined to be appropriate, and if it is determined that the secondary fuel supply amount is excessive, the secondary fuel supply amount or generation amount is decreased, A function to determine whether the amount of secondary fuel generated is the maximum if it is insufficient, and to increase the amount of secondary fuel generated if it is not maximum, and to increase the amount of primary fuel supplied if it is maximum Characterized by having Internal combustion engine.   Hydrogen gas supply means (23) for extracting and supplying hydrogen gas by reforming from the primary fuel, carbon dioxide recovered and separated from the exhaust gas, and hydrogen supplied by the hydrogen gas supply means (23) Reaction means (22) for reacting to produce secondary fuel, the primary fuel and air are mixed by a mixer (12) and flowed into an intake port (15), and the secondary fuel is stored in a storage tank ( 25) In the internal combustion engine that supplies fuel to the fuel injection device (28), the shunt pipe (17C) branched from the exhaust pipe (16) is connected to the inside via a three-way valve (VT) and an on-off valve (VC1) that open to the atmosphere. The reaction means (22) is connected to a carbon dioxide adsorption container (29) having a heater (34) and filled with an adsorbent (32), and further via a suction blower (36) and a carbon dioxide concentration sensor (SR2). Connected to A flow control valve (27) is provided in the fuel supply line (26) from the storage tank (25) to the fuel injection device (28), and the load sensor (SR1) of the internal combustion engine and the carbon dioxide concentration sensor (SR2) Is provided with a control unit (30) for controlling the supply amount of the secondary fuel, and the control unit (30) receives the octane number of the primary fuel and the octane number of the secondary fuel, and then the secondary fuel. When the engine is started using as a starting fuel, the output or ignition timing is detected by the load sensor (SR1), the on-off valve (VC1) provided in the shunt pipe (17C) is opened, and when a predetermined time has elapsed. Close the on-off valve (VC1), then determine whether the octane number of the primary fuel is greater than or equal to the octane number of the secondary fuel, and the octane number of the primary fuel is the octane number of the secondary fuel If it is higher, it is determined whether the ignition timing is late or whether the output is reduced. If YES, the flow control valve (27) is opened, and if NO, the flow control valve (27) is throttled. If the octane number of the primary fuel is lower than the octane number of the secondary fuel, it is determined whether the ignition timing is late / or whether the output is reduced. If YES, the flow control valve (27) is throttled. If it is NO, the internal combustion engine has a function of opening the flow control valve (27). Hydrogen gas supply means (23) for extracting and supplying hydrogen gas by reforming from the primary fuel, carbon dioxide recovered and separated from the exhaust gas, and hydrogen supplied by the hydrogen gas supply means (23) Reaction means (22) for reacting to produce secondary fuel, the primary fuel and air are mixed by a mixer (12) and flowed into an intake port (15), and the secondary fuel is stored in a storage tank ( 25) In the internal combustion engine supplied from 25) to the fuel injection device (28), the exhaust gas diverting pipe (17D) branched from the exhaust pipe (16) is provided with a separation membrane that allows only carbon dioxide to pass through the blower (46). A carbon recovery device (40) is provided, a flow control valve (27) is provided in a fuel supply line (26) from the storage tank (25) to the fuel injection device (28), and the carbon dioxide recovery device (40) in front A carbon dioxide concentration sensor (SR2) is provided in the carbon dioxide recovery line (21D) leading to the reaction means (22), and receives a signal from the load sensor (SR1) of the internal combustion engine and the carbon dioxide concentration sensor (SR2) to obtain a secondary. A control unit (30) for controlling the fuel supply amount is provided, and when the octane number of the primary fuel and the octane number of the secondary fuel are input, the control unit detects the output or ignition timing by the load sensor (SR1). Determine if the octane number of the secondary fuel is greater than or equal to the octane number of the secondary fuel. If the octane number of the primary fuel is greater than or equal to the octane number of the secondary fuel, determine whether the ignition is slow or whether the output is decreasing. If YES, the flow control valve (27) is opened, and if NO, the flow control valve (27) is throttled so that the octane number of the primary fuel is less than the secondary fuel. If it is below the Tan number, it is judged whether the ignition timing is late or the output is lowered. If YES, the flow control valve (27) is throttled, and if NO, the flow control valve (27) is opened. The function of increasing the rotational speed of the blower (46) after the flow control valve (27) is opened and reducing the rotational speed of the blower (46) after the flow control valve (27) is throttled. An internal combustion engine.

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