internal combustion engine

Abstract

To appropriately suppress release of unburned main fuel into the outside in an internal combustion engine that enables combined use of the main fuel and auxiliary fuel.SOLUTION: In an internal combustion engine, main fuel that is supplied from a fuel tank and auxiliary fuel that is obtained by decomposing the main fuel are supplied to a cylinder as fuel for operation. The internal combustion engine includes: a reactor generating the auxiliary fuel from the main fuel by applying voltage to an electrode; and a control device that adjusts the amount of auxiliary fuel to be generated from the main fuel by controlling frequency, pulse width or amplitude of the voltage to be applied to the electrode of the reactor, and when unburned main fuel discharged from the cylinder increases, increases a rate of the auxiliary fuel out of the fuel to be supplied to the cylinder, compared to when the unburned main fuel to be discharged is smaller.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an internal combustion engine that obtains power by burning a relatively inflammable fuel. [Background technology]

[0002] Reducing emissions of carbon dioxide, which has a greenhouse effect, is recognized as a global issue. Recently, attempts have been made to use carbon-free ammonia as fuel for internal combustion engines, which are used as various power sources, instead of carbon-containing fossil fuels (see the following patent document for an example). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-211155 Summary of the Invention [Problem to be solved by the invention]

[0004] Ammonia is relatively difficult to burn, and a large amount of unburned ammonia tends to remain in the cylinder. This leads to a decrease in the power and efficiency of the internal combustion engine, and raises concerns that unburned ammonia may be released to the outside.

[0005] To improve ammonia combustion, it is possible to supply easily combustible hydrogen as an auxiliary fuel to the cylinder along with the ammonia, which will allow the ammonia to be burned sufficiently and reduce the amount of unburned ammonia.

[0006] If two types of fuel, ammonia as the main fuel and hydrogen as the auxiliary fuel, are used, and a fuel tank for storing ammonia and a fuel tank for storing hydrogen are separately provided, it becomes necessary to separately replenish the ammonia and hydrogen to each fuel tank, which is troublesome from an operational standpoint.In addition, since a large amount of high-pressure hydrogen is to be stored in advance, safety measures such as explosion prevention are required, which has the disadvantage of increasing the overall weight and raising costs.

[0007] An intended object of the present invention is to appropriately suppress the release of unburned main fuel to the outside in an internal combustion engine that uses both main fuel and auxiliary fuel. [Means for solving the problem]

[0008] The present invention provides an internal combustion engine that operates by supplying, to cylinders, as fuel, main fuel supplied from a fuel tank and auxiliary fuel obtained by decomposing the main fuel, the engine comprising: a reactor that generates the auxiliary fuel from the main fuel by applying a voltage to electrodes; and a control device that adjusts the amount of the auxiliary fuel generated from the main fuel by manipulating the frequency, pulse width, or amplitude of the voltage applied to the electrodes of the reactor, so that when a large amount of unburned main fuel is discharged from the cylinders, the proportion of auxiliary fuel in the fuel supplied to the cylinders is increased compared to when a smaller amount of unburned main fuel is discharged. In a system in which a mixed fuel of main fuel and auxiliary fuel is injected from an injector into a cylinder, the opening time of the injector is corrected to be shorter as the proportion of auxiliary fuel in the fuel supplied to the cylinder increases. It constituted an internal combustion engine.

[0009] Further, the present invention provides an internal combustion engine that operates by supplying main fuel supplied from a fuel tank and auxiliary fuel obtained by decomposing the main fuel to cylinders as fuel, the engine comprising: a reactor that generates the auxiliary fuel from the main fuel by applying a voltage to electrodes; and a control device that adjusts the amount of auxiliary fuel generated from the main fuel by manipulating the frequency, pulse width, or amplitude of the voltage applied to the electrodes of the reactor, so that when a large amount of unburned main fuel is discharged from the cylinder, the proportion of auxiliary fuel in the fuel supplied to the cylinder is increased compared to when a smaller amount of unburned main fuel is discharged. The engine injects main fuel into the cylinder from one injector and auxiliary fuel from the other injector, and corrects the valve opening time of the one injector to be shorter and the valve opening time of the other injector to be longer as the proportion of auxiliary fuel in the fuel supplied to the cylinder increases. . [Effects of the Invention]

[0010] According to the present invention, in an internal combustion engine that uses both main fuel and auxiliary fuel, it is possible to appropriately prevent unburned main fuel from being released to the outside. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing the configuration of an internal combustion engine according to an embodiment of the present invention; [Figure 2] 1 is a diagram showing the configuration of an internal combustion engine according to an embodiment of the present invention; [Figure 3] 1 is a diagram showing the configuration of an internal combustion engine according to an embodiment of the present invention; [Figure 4] 1 is a diagram showing the structure of a plasma reactor according to an embodiment of the present invention; [Figure 5] FIG. 2 is a timing diagram showing a periodic pulse voltage applied to an electrode of a plasma reactor in one embodiment of the present invention. [Figure 6]FIG. 2 is a diagram showing the relationship between the frequency of the periodic pulse voltage applied to the electrodes of the plasma reactor and the amount of hydrogen produced by decomposition of ammonia. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will be described with reference to the drawings. Figures 1 to 3 show the configuration of an internal combustion engine according to an embodiment of the present invention. This internal combustion engine is a four-stroke spark-ignition reciprocating engine mounted on a vehicle as a power source, and has a plurality of cylinders 1 (one of which is shown in Figure 1).

[0013] This internal combustion engine uses a main fuel containing ammonia (which may be ammonia of extremely high purity) and an auxiliary fuel containing hydrogen (which may be hydrogen of extremely high purity) as fuel. The main fuel is stored in a fuel tank 13 before the internal combustion engine is operated. The main fuel is pressurized and in a liquid state when it is filled into the fuel tank 13.

[0014] In contrast, there is no fuel tank in which auxiliary fuel is stored prior to operation of the internal combustion engine. The only fuel that is replenished from outside into the fuel tank 13 is the main fuel, and there is no need to replenish the tank with auxiliary fuel. The auxiliary fuel is produced in a plasma reactor 16, which serves as a reactor, using the main fuel as a raw material. The plasma reactor 16 generates low-temperature plasma 164 and uses the energy of this plasma 164 to decompose ammonia and obtain hydrogen (and nitrogen). NH3 + e → (3 / 2)H2 + (1 / 2)N2 In known catalytic reaction methods, the ammonia decomposition reaction is initiated at high temperatures of 400°C to 800°C and requires the use of expensive precious metals such as ruthenium as catalysts. In contrast, the plasma reactor 16 can produce hydrogen from ammonia with high energy efficiency and low cost.

[0015] Fig. 4 shows an example of the structure of the plasma reactor 16. The plasma reactor 16 has a pair of thin plate-shaped electrodes 161 and 162 facing each other, and a plasma field 164 is formed between the electrodes 161 and 162 by applying a pulsating voltage (DC pulse voltage) or an AC voltage between the electrodes 161 and 162. Fig. 5 shows an example of the waveform of the pulse voltage applied between the electrodes 161 and 162.

[0016] The plasma reactor 16 in this embodiment generates low-temperature plasma 164 by a so-called dielectric barrier method. To this end, each of the electrodes 161 and 162 is covered with a dielectric (insulator) 163, which insulates one electrode 161 from the other electrode 162. The material of the dielectric 163 is typically ceramic or resin, and examples of materials that can be used include ceramic insulators such as alumina, zirconia, and silicon nitride, and polymer insulators such as polytetrafluoroethylene and polyimide.

[0017] Instead of covering the electrodes 161 and 162 with the dielectric 163, a porous dielectric may be disposed between the one electrode 161 and the other electrode 162.

[0018] 4, a plurality of pairs of electrodes 161, 162 are arranged in a stack. The main fuel discharged from the fuel tank 13 flows through the gap between the electrodes 161 and 162 and is exposed to plasma 164 in the process. At least a portion of the ammonia in the main fuel is decomposed into hydrogen and nitrogen.

[0019] The ratio of ammonia to hydrogen contained in the fuel that has passed through the plasma reactor 16 can be increased or decreased as desired. Specifically, the frequency F, pulse width (or duty ratio) or amplitude (absolute value of the peak of the applied voltage) V of the pulse voltage or AC voltage applied to the electrodes 161 and 162 can be adjusted. p By manipulating at least one of the above, the amount of hydrogen generated from ammonia in the plasma field 164 can be adjusted. The higher the frequency F of the applied voltage, the wider the pulse width (higher the duty ratio), or the higher the amplitude Vp The larger the F, the more energy the plasma field 164 gives to the ammonia in the main fuel, and the more ammonia is decomposed into hydrogen (and nitrogen). As a result, the amount of ammonia contained in the fuel that has passed through the plasma reactor 16 decreases, and the amount of hydrogen increases. It is not impossible to hydrogenate most or all of the ammonia in the main fuel. Figure 6 shows an example of the experimental results of the relationship between the frequency F of the pulse voltage or AC voltage applied to the electrodes 161 and 162 and the rate at which ammonia is decomposed and converted into hydrogen.

[0020] Naturally, when the main fuel is circulated without applying a pulsed or AC voltage to the electrodes 161 and 162, i.e., without generating the plasma field 164, a fuel mainly composed of ammonia and containing little or no hydrogen flows out downstream of the plasma reactor 16.

[0021] When the fuel that has passed through the plasma reactor 16 is supplied to each cylinder 1 of the internal combustion engine, the fuel may be injected from an injector 111 that is installed in the intake passage 3 connected to the cylinder 1 so as to be directed toward the intake port, as shown in Fig. 1, or from an injector 112 that is installed so as to face the combustion chamber of the cylinder 1, as shown in Fig. 2. Whether the former port injection type or the latter direct injection (direct injection into the cylinder) type is adopted, any of ammonia fuel containing little or no hydrogen, a mixed fuel of ammonia and hydrogen, or hydrogen fuel containing little or no ammonia is delivered to the injectors 111, 112 through fuel pipes 141, 142. When the former port injection type is adopted, ammonia is sufficiently mixed with the air flowing through the intake passage 3 toward the cylinder 1 before being drawn into the cylinder 1, which is expected to further stabilize the combustion of ammonia. When the latter direct injection system is adopted, backfire, which occurs when hydrogen unintentionally ignites and a flame occurs in the intake passage 3, can be reliably avoided.

[0022] As shown in Figure 3, it is also possible to install both the port injection injector 111 and the direct injection injector 112 side by side. In this case, the fuel that has passed through the plasma reactor 16 can simply be distributed to both injectors 111 and 112, and fuels with the same properties can be injected from each injector 111 and 112. However, it is also possible to separate the fuel that has passed through the plasma reactor 16 into ammonia fuel and hydrogen fuel using a separation membrane (not shown) that allows only hydrogen to pass through, and to send the ammonia fuel toward the port injection injector 111 and the hydrogen fuel toward the direct injection injector 112. In this case, it is possible to inject ammonia fuel from the injector 111 and hydrogen fuel from the injector 112. A volume (not shown) that serves as a buffer for temporarily storing hydrogen fuel may be provided on the fuel pipe 142.

[0023] 1 to 3, a pump (not shown) that pressurizes the fuel supplied to the injectors 111 and 112 and a pressure regulator (not shown) that adjusts the fuel pressure to a predetermined level may be installed in the fuel pipes 141 and 142 at locations upstream of the injectors 111 and 112. In place of or in addition to the pressure regulator, control valves 151 and 152 may be installed on the fuel pipes 141 and 142. The control valves 151 and 152 are flow control valves that can open and close the fuel pipes 141 and 142, or increase or decrease the flow rate of fuel flowing through the fuel pipes 141 and 142.

[0024] An ignition plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1 to ignite and burn fuel within the cylinder 1. The ignition plug 12 receives an induced voltage generated by an ignition coil and generates a spark discharge between its center electrode and ground electrode. The ignition coil is housed integrally in a coil case together with an igniter, which is a semiconductor switching element.

[0025] An intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. In the intake passage 3, an air cleaner 31, an electronically controlled throttle valve 32 which is an intake throttle valve, a surge tank 33, and an intake manifold 34 are arranged in this order from upstream.

[0026] An exhaust passage 4 for discharging exhaust gases guides exhaust gases generated as a result of fuel combustion in the cylinders 1 to the outside through the exhaust ports of each cylinder 1. An exhaust manifold 42 and an exhaust purification device 41 are arranged on this exhaust passage 4. The exhaust purification device 41 includes a catalyst that promotes the oxidation of unburned ammonia that has flowed into the exhaust passage 4, a three-way catalyst that promotes oxidation / reduction reactions of hydrocarbons, carbon monoxide, and nitrogen oxides, and a selective catalytic reduction (SCRED) device that reduces nitrogen oxides using a reducing agent such as urea water. In addition, an exhaust bypass passage 43 that bypasses the exhaust turbine 52 and a wastegate valve 44 that is a bypass valve that opens and closes the inlet of this bypass passage 43 are also provided.

[0027] The exhaust turbocharger 5 is configured such that an exhaust turbine 52 and a compressor impeller 51 are coaxially connected and interlocked via a shaft 53. The turbine 52 and impeller 51 are rotationally driven by the energy of the exhaust gas flowing through the exhaust passage 4. This rotational force causes the compressor 51 to perform a pumping action, thereby pressurizing and compressing (supercharging) the intake air flowing through the intake passage 3 and sending it into the cylinder 1.

[0028] The electronic control unit 0 that controls the operation of the internal combustion engine in this embodiment is a microcomputer system having a processor, a memory, an input interface, an output interface, etc. The ECU 0 may be configured by connecting a plurality of ECUs or controllers so that they can communicate with each other via an electric communication line such as a CAN (Controller Area Network).

[0029] The input interface of the ECU 0 includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed, a crank angle signal b output from a crank angle sensor that detects the rotation angle of the crankshaft, which is the output shaft of the internal combustion engine, and the engine speed, an accelerator opening signal c output from a sensor that detects the amount of depression of the accelerator pedal by the driver of the vehicle as the accelerator opening (in other words, the engine load rate or engine torque required for the internal combustion engine), and an intake air temperature / intake pressure sensor that detects the temperature and pressure of the intake air in the intake passage 3 (particularly, the surge tank 33 or the intake manifold 34) connected to the cylinder 1. The signals input to the exhaust gas purifier 41 include an intake air temperature / intake pressure signal d output from a water temperature sensor that detects the temperature of the coolant in the internal combustion engine, a fuel temperature / fuel pressure signal f output from a fuel temperature / fuel pressure sensor that detects the temperature and pressure of the main fuel in the fuel pipes 141, 142 connected to the injectors 111, 112 (particularly downstream of the control valves 151, 152 and immediately upstream of the injectors 111, 112), a cam angle signal g output from a cam angle sensor at multiple cam angles of the camshaft that drives the intake and exhaust valves to open and close, and a gas property signal h output from a sensor 45 that detects the property of the gas flowing through the exhaust purification device 41 in the exhaust passage 4. The sensor 45 includes an O2 sensor or linear A / F sensor that measures the oxygen concentration in the gas, an ammonia sensor that measures the ammonia concentration in the gas, a hydrogen sensor that measures the hydrogen concentration in the gas, etc.

[0030] The output interface of the ECU 0 outputs an ignition signal i to the igniter of the spark plug 12, fuel injection signals j1 and j2 to the injectors 111 and 112, an opening operation signal k to the throttle valve 32, opening operation signals l1 and l2 to the control valves 151 and 152, and a frequency F, pulse width (DUTY ratio) or amplitude V of the voltage applied to the electrodes 161 and 162 of the plasma reactor 16. p It outputs signals such as o that control

[0031] The processor of ECU0 interprets and executes programs stored in memory, calculates operating parameters, and controls the operation of the internal combustion engine. ECU0 acquires various pieces of information a, b, c, d, e, f, g, and h required for controlling the operation of the internal combustion engine via an input interface, and based on these, determines various operating parameters such as the required fuel injection amount, fuel injection timing (including the number of fuel injections per cycle of cylinder 1 (in a four-stroke engine, one cycle is defined as a series of intake stroke, compression stroke, expansion stroke, and exhaust stroke)), fuel injection pressure, ignition timing (including the number of spark ignitions per cycle of cylinder 1), and frequency F of the voltage applied to electrodes 161 and 162 of plasma reactor 16. ECU0 applies various control signals i, j1, j2, k, l1, l2, and o corresponding to the operating parameters via an output interface.

[0032] The internal combustion engine of this embodiment uses ammonia and hydrogen in combination as fuel for operation, with the intention of promoting the combustion of ammonia by adding hydrogen, which is highly flammable, to ammonia, which is relatively difficult to flammable.

[0033] The ECU0 determines the amounts of ammonia fuel and hydrogen fuel to be supplied to the cylinder 1 so as to generate a necessary and sufficient amount of heat (amount of energy) to output the required engine torque. First, the ECU0 sets a basic ratio of ammonia fuel and hydrogen fuel to be sent from the plasma reactor 16 to the injectors 111 and 112 of each cylinder 1 according to the current operating range of the internal combustion engine [engine speed, accelerator opening (or intake pressure or amount of air taken into the cylinder 1)], the coolant temperature, and other conditions.

[0034] As described above, the ratio of ammonia to hydrogen in the fuel can be adjusted to increase or decrease in the plasma reactor 16. In an operating range or under conditions where ammonia is relatively easily combusted in the combustion chamber of cylinder 1 (for example, a large amount of intake air, a high cooling water temperature (and therefore a high temperature inside the combustion chamber), etc.), the ratio of ammonia in the fuel supplied to cylinder 1 is increased and the ratio of hydrogen is reduced. In other words, the amount of ammonia decomposed into hydrogen by the plasma reactor 16 is reduced.

[0035] Conversely, in an operating range or under conditions where ammonia is difficult to burn in the combustion chamber of cylinder 1 (such as a small intake air amount or a low cooling water temperature), the proportion of ammonia in the fuel supplied to cylinder 1 is reduced and the proportion of hydrogen is increased. In other words, the amount of ammonia decomposed into hydrogen by plasma reactor 16 is increased.

[0036] In the embodiment shown in FIG. 3 in which the injector 111 for injecting ammonia and the injector 112 for injecting hydrogen are separated and independent, it is also possible to adjust the ratio of ammonia fuel and hydrogen fuel to be supplied to the cylinder 1 by individually adjusting the fuel injection amount from each of the injectors 111 and 112.

[0037] The memory of the ECU 0 stores in advance the operating range of the internal combustion engine (engine speed, accelerator opening), etc., and the frequency F (and / or pulse width, duty ratio, amplitude V) of the voltage to be applied to the electrodes 161 and 162 of the plasma reactor 16. p The ECU 0 searches the map using parameters such as the current operating range of the internal combustion engine as a key, and determines the frequency F (and / or pulse width, duty ratio, amplitude V) of the voltage to be applied to the electrodes 161, 162 of the plasma reactor 16. p ) to understand the basic quantities.

[0038] If the ammonia fuel supplied to cylinder 1 is always sufficiently burned in the combustion chamber of cylinder 1, it should be possible to generate the required engine torque by controlling the plasma reactor 16 and the injectors 111 and 112 in accordance with the above basic amounts. However, in reality, the ammonia does not burn sufficiently, and the unburned ammonia is sometimes discharged from cylinder 1 into the exhaust passage 4. This leads to a decrease in the output and fuel efficiency of the internal combustion engine and a deterioration in emissions.

[0039] Therefore, the ECU0 performs feedback control to correct the amounts of ammonia fuel and hydrogen combustion fuel supplied to the cylinder 1 from their basic amounts according to the concentration (or amount) of unburned ammonia discharged from the cylinder 1 into the exhaust passage 4. That is, when the concentration of ammonia discharged from the cylinder 1 exceeds a threshold value (or a target value) and is high (the amount of ammonia is large), the proportion of hydrogen in the fuel to be supplied to the cylinder 1 is increased and the proportion of ammonia is decreased, compared to when the concentration of ammonia discharged from the cylinder 1 is not high. Alternatively, the higher the concentration of ammonia discharged from the cylinder 1, the more the proportion of hydrogen in the fuel to be supplied to the cylinder 1 is increased and the proportion of ammonia is decreased. This allows the fuel to burn stably in the combustion chamber of the cylinder 1, and prevents unburned ammonia from being discharged from the cylinder 1.

[0040] The ECU 0 measures the ammonia concentration in the exhaust gas flowing through the exhaust passage 4 via a sensor 45 provided upstream of the exhaust purification device 41. Then, the ECU 0 corrects the ratio of ammonia fuel and hydrogen fuel sent from the plasma reactor 16 to the injectors 111 and 112 according to the ammonia concentration.

[0041] Specifically, when the concentration of ammonia in the exhaust gas exceeds a threshold and is high, the frequency F of the voltage applied to the electrodes 161 and 162 of the plasma reactor 16 is increased (and / or the pulse width, duty ratio, amplitude V p Correction is made to the basic amount of the frequency F of the applied voltage so that the frequency F of the applied voltage is increased, and the frequency F of the applied voltage etc. is finally determined.

[0042] The frequency F of the applied voltage may be manipulated to bring the deviation between the ammonia concentration in the exhaust gas and the threshold value (target value) closer to 0. If the ammonia concentration is lower than the threshold value, it means that the ammonia is burning well in the combustion chamber of cylinder 1. Therefore, the frequency F of the voltage applied to the electrodes 161 and 162 of the plasma reactor 16 may be lowered (and / or the pulse width, duty ratio, amplitude V p (smaller) to reduce power consumption in the plasma reactor 16.

[0043] However, if the ratio of ammonia to hydrogen supplied as fuel to cylinder 1 changes, the amount of heat generated in cylinder 1 may change even if the amount of main fuel supplied from fuel tank 13 and consumed remains the same. As a result, there is a risk that the engine torque output by the internal combustion engine will fluctuate to a non-negligible extent. Combustion of 1 mol of ammonia generates 91 kcal of heat. On the other hand, complete decomposition of 1 mol of ammonia in plasma reactor 16 produces 1.5 mol of hydrogen, and combustion of these 1.5 mol of hydrogen generates 102 kcal of heat. In other words, as the proportion of ammonia decreases and the proportion of hydrogen increases, the amount of heat generated increases.

[0044] The ECU 0 sets the amount of fuel injected from the injectors 111 and 112 to cylinder 1, in other words, the basic amount of the valve opening time of the injectors 111 and 112 (needless to say, the longer the valve opening time, the more fuel is injected), in proportion to the amount of air taken into cylinder 1. Then, when correcting (changing from the above basic amount) the ratio of ammonia fuel and hydrogen fuel sent from the plasma reactor 16 to the injectors 111 and 112, the ECU 0 corrects the basic amount of the valve opening time of the injectors 111 and 112, thereby finally determining the valve opening time of the injectors 111 and 112. This correction control makes it possible to generate in the combustion chamber of cylinder 1 an amount of heat corresponding to the required engine torque determined by the accelerator opening degree, etc., regardless of the ratio of ammonia and hydrogen, and thereby suppresses undesirable fluctuations in engine torque.

[0045] In a mode in which a mixed fuel of ammonia and hydrogen is injected from the injectors 111, 112, the valve opening time of the injectors 111, 112 is corrected to be shorter as the proportion of hydrogen increases, and the fuel injection amount from the injectors 111, 112 is reduced.

[0046] However, in the mode shown in FIG. 3 in which ammonia is injected from injector 111 and hydrogen is injected from injector 112, the valve opening time of the former injector 111 may be corrected to be shorter, and the valve opening time of the latter injector 112 may be corrected to be longer accordingly, and conversely, the valve opening time of the former injector 111 may be corrected to be longer, and the valve opening time of the latter injector 112 may be corrected to be shorter accordingly.

[0047] In the correction control, the ECU 0 may simultaneously correct the opening of the electronic throttle valve 32. Although the stoichiometric air-fuel ratio of ammonia and that of hydrogen are different, the oxygen required to burn (oxidize) 1 mol of ammonia is 0.75 mol, and the oxygen required to burn 1.5 mol of hydrogen obtained by decomposing 1 mol of ammonia is also 0.75 mol, so they are equal. However, the direct injection system shown in Figure 2 allows for stratified combustion (stratified combustion), not homogeneous combustion. In the system shown in Figure 3, in which ammonia and hydrogen are injected from separate injectors 111 and 112, the injection amounts of each can be controlled individually. Therefore, the amount of air taken into cylinder 1 may be increased or decreased. To do this, the opening of the throttle valve 32 must be corrected to increase or decrease from the basic opening determined by the accelerator position, etc. Furthermore, the harmful NOx generated in the combustion chamber of cylinder 1 is also controlled. x In order to reduce the amount of CO₂ released to the outside through the exhaust passage 4, it is also possible to correct the opening of the throttle valve 32.

[0048] Incidentally, during cranking for cold start of the internal combustion engine or immediately after cold start, most or all of the fuel injected from the injectors 111 and 112 and supplied to the cylinder 1 may be hydrogen.

[0049] According to this embodiment, in an internal combustion engine that uses fuel containing ammonia, it is possible to suppress the discharge of unburned ammonia components to the outside, and also to enable the internal combustion engine to stably output the required engine torque.

[0050] It should be noted that the present invention is not limited to the embodiment described above in detail. For example, in the above embodiment, the ammonia concentration in the exhaust gas discharged from cylinder 1 and flowing through exhaust passage 4 is measured by sensor 45. However, the concentration of ammonia discharged from cylinder 1 can also be estimated by measuring or estimating the temperature of the exhaust gas by a sensor, or by measuring or estimating the fluctuations in the engine speed or the output engine torque by a sensor.

[0051] Furthermore, the main fuel is not limited to ammonia, the auxiliary fuel is not limited to hydrogen, and the reactor for producing the auxiliary fuel from the main fuel is not limited to the plasma reactor 16 .

[0052] In addition, the specific configuration of each part can be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0053] 0...Control unit (ECU) 1...cylinder 111, 112...Injectors 13...Fuel tank 16...Reactor (plasma reactor) 161, 162...electrode 3...Intake passage 4...Exhaust passage 45...Main fuel (ammonia) concentration sensor h...Main fuel (ammonia) concentration signal j1, j2... Signals that control the opening of the injector valve o...Signal that controls the voltage applied to the electrodes of the reactor (plasma reactor)

Claims

1. An internal combustion engine that operates by supplying a main fuel supplied from a fuel tank and an auxiliary fuel obtained by decomposing the main fuel to a cylinder as fuel, a reactor for generating the auxiliary fuel from the main fuel by applying a voltage to electrodes; a control device that adjusts the amount of auxiliary fuel generated from the main fuel by manipulating a frequency, pulse width, or amplitude of a voltage applied to an electrode of the reactor, and increases the proportion of auxiliary fuel in the fuel supplied to the cylinder when a large amount of unburned main fuel is discharged from the cylinder compared to when a smaller amount of unburned main fuel is discharged; Equipped with An internal combustion engine in which a mixed fuel of main fuel and auxiliary fuel is injected into a cylinder from an injector, and the opening time of the injector is corrected to be shorter as the proportion of auxiliary fuel in the fuel supplied to the cylinder increases.

2. An internal combustion engine that operates by supplying a main fuel supplied from a fuel tank and an auxiliary fuel obtained by decomposing the main fuel to a cylinder as fuel, a reactor that generates the auxiliary fuel from the main fuel by applying a voltage to electrodes; a control device that adjusts the amount of auxiliary fuel generated from the main fuel by manipulating a frequency, pulse width, or amplitude of a voltage applied to an electrode of the reactor, and increases the proportion of auxiliary fuel in the fuel supplied to the cylinder when a large amount of unburned main fuel is discharged from the cylinder compared to when a smaller amount of unburned main fuel is discharged; Equipped with An internal combustion engine in which main fuel is injected from one injector and auxiliary fuel is injected from the other injector into a cylinder, and the valve opening time of the one injector is corrected to be shorter and the valve opening time of the other injector is corrected to be longer as the proportion of auxiliary fuel in the fuel supplied to the cylinder increases.

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