JP6319239B2 - Control device for gaseous fuel engine - Google Patents

Description

  The present invention belongs to a technical field related to a control device for a gaseous fuel engine mounted on a vehicle.

  Conventionally, when a gaseous fuel is used as an engine fuel, the gaseous fuel is supplied to the engine from a fuel tank that stores the fuel. In this case, when the fuel in the fuel tank is reduced and the pressure in the fuel tank is reduced, it is difficult to stably supply the fuel to the engine even if the fuel remains in the fuel tank.

  Therefore, in Patent Document 1, a main body part of a refrigerant recirculation device is provided outside the fuel tank, and a refrigerant pipe for recirculating (circulating) the refrigerant to the fuel tank is connected from the main body part, and the refrigerant pipe is provided inside the fuel tank. Is bent into a comb-like shape, fins are provided at the bent portion, and the refrigerant is flowed in the forward direction from the main body, thereby heating the gaseous fuel in the fuel tank and flowing the refrigerant in the reverse direction from the main body. It is disclosed that the gaseous fuel in the fuel tank is cooled, and when the pressure in the fuel tank is lowered, the refrigerant reflux device is driven to bring the gaseous fuel to high temperature and high pressure.

JP 2009-257286 A

  However, when the refrigerant recirculation device as in Patent Document 1 is provided, a space for the main body of the refrigerant recirculation device and the refrigerant piping is required, and the configuration in the fuel tank becomes complicated, which increases the size and cost of the vehicle. Will be invited.

  The present invention has been made in view of such a point, and an object of the present invention is to make it possible to use the gaseous fuel in the fuel tank as much as possible at low cost without increasing the size of the vehicle. It is in.

In order to achieve the above object, according to one aspect of the present invention , a fuel tank that is mounted on a vehicle and that stores gaseous fuel as fuel for the engine, and a fuel tank inside the fuel tank. Pressure detecting means for detecting the pressure of the fuel, temperature detecting means for detecting the temperature in the fuel tank, and control means for controlling the operation of the engine, wherein the control means comprises the fuel tank by the pressure detecting means. Exhaust heat increase control for increasing the exhaust heat of the engine is executed when the condition that the internal pressure is equal to or lower than the predetermined pressure and the temperature inside the fuel tank by the temperature detecting means is equal to or lower than the predetermined temperature is satisfied. in, the exhaust flow through the vicinity of the fuel tank is composed of the fuel tank so as to warm, further comprising an electric heater for heating the fuel tank, the exhaust The increase control is control for increasing the output of the engine, and the control means controls the operation of an electric heater control unit that controls the operation of the electric heater and a generator that is driven by the engine and generates electric power. A generator control unit, wherein the electric heater control unit is configured to operate the electric heater when the exhaust heat increase control is executed, and the generator control unit is configured to control the engine by the exhaust heat increase control. The configuration is such that the power generated by the generator is increased by at least the power consumption of the electric heater by increasing the output .

  With the above configuration, when the condition that the pressure in the fuel tank is equal to or lower than the predetermined pressure and the temperature in the fuel tank is equal to or lower than the predetermined temperature, that is, a certain amount of fuel remains in the fuel tank, When it is difficult to supply the fuel in the fuel tank to the engine, the fuel tank is heated by the exhaust flow passing near the fuel tank by executing the exhaust heat increase control. Temperature and pressure can be easily increased. Therefore, the gaseous fuel in the fuel tank can be used up as much as possible at low cost without increasing the size of the vehicle. If the exhaust pipe (exhaust path) of the engine is arranged so as to pass through the vicinity of the fuel tank, the fuel tank can be easily heated by the exhaust flow passing through the vicinity of the fuel tank. Alternatively, the exhaust path of the engine is configured with a proximity path that passes through the vicinity of the fuel tank and a remote path that passes through a position farther from the fuel tank than the proximity path, and when exhaust heat increase control is not executed, The exhaust flow may flow through the remote path, while the exhaust heat flow may be configured to flow through the proximity path when the exhaust heat increase control is performed.

Further, by increasing the engine output by the exhaust heat increase control, the fuel tank can be heated by the exhaust flow passing near the fuel tank, and the electric heater can be operated by the increase in the generated power by the generator. It is possible to increase the temperature and pressure in the fuel tank more effectively.

In the control device for a gaseous fuel engine according to the one aspect, the vehicle includes a generator that is driven by the engine to generate electric power, a battery that charges the electric power generated by the electric generator, and a vehicle that can be driven by the discharged electric power of the battery. A drive motor for driving, and a battery travel mode in which the battery travels with the discharge power of the battery, and a charge travel mode in which the engine is operated and the battery is charged with the output of the engine. The hybrid vehicle is further provided with battery remaining capacity detecting means for detecting the remaining capacity of the battery, and the control means has a first battery remaining capacity detected by the battery remaining capacity detecting means in the battery running mode. When it becomes lower than the predetermined value, the charging mode is switched to the charging mode. When the remaining battery capacity detected by the battery remaining capacity detecting means is higher than a second predetermined value set higher than the first predetermined value during the mode, the mode is switched to the battery running mode. A travel mode switching control unit, and configured to execute the exhaust heat increase control during the charge travel mode, wherein the electric heater control unit operates the electric heater during the exhaust heat increase control. In addition, in the battery running mode, a battery remaining capacity detected by the battery remaining capacity detecting means is set to a value higher than the first predetermined value and lower than the second predetermined value. 3 The electric heater may be configured to operate when the value is lower than a predetermined value and when the condition is satisfied.

  Thus, in the battery running mode, when the remaining capacity of the battery becomes lower than the third predetermined value, that is, shortly before the battery running mode is switched to the charging running mode, the electric heater is operated to The temperature and pressure in the tank can be raised, and the fuel in the fuel tank can be stably supplied to the engine immediately after switching to the charge running mode (immediately after starting the engine). .

A control device for a gaseous fuel engine according to another aspect of the present invention is a control device for a gaseous fuel engine mounted on a vehicle, the fuel tank storing gaseous fuel as fuel for the engine, Pressure detecting means for detecting pressure, temperature detecting means for detecting the temperature in the fuel tank, and control means for controlling the operation of the engine, wherein the control means is provided in the fuel tank by the pressure detecting means. When the condition that the pressure of the engine is equal to or lower than a predetermined pressure and the temperature inside the fuel tank by the temperature detecting means is equal to or lower than the predetermined temperature is satisfied, exhaust heat increase control for increasing the exhaust heat of the engine is executed. , by the exhaust flow through the vicinity of the fuel tank is composed of the fuel tank so as to warm, the vehicle includes a generator for power generation by being driven by the engine, A hybrid vehicle having a battery that charges the power generated by the generator and a drive motor for driving the vehicle that can be driven by the discharged power of the battery, and the exhaust heat increase control is a control that increases the output of the engine. And the control means includes a charge control unit that controls charging of the battery with the electric power generated by the generator, and the charge control unit is increased by an increase in output of the engine by the exhaust heat increase control. The increased amount of power generated by the generator is configured to charge the battery.

By doing so, the gaseous fuel in the fuel tank can be used up as much as possible at low cost without increasing the size of the vehicle. In addition, since the increased amount of power generated by the generator is charged to the battery, after the fuel is completely used up, the drive motor can be driven by the discharged power of the battery charged by the increased amount. Therefore, the cruising distance can be increased.

In the control apparatus for a gaseous fuel engine according to the other aspect, the vehicle is a series hybrid vehicle in which the drive motor is driven by at least one of the electric power discharged from the battery and the electric power generated by the generator. The engine uses, as the gaseous fuel, a first fuel and a second fuel having different calorific values per unit volume, and the fuel tank stores a first fuel tank. And a second fuel tank for storing the second fuel, wherein the pressure detection means is configured to detect pressures in the first fuel tank and the second fuel tank, respectively. The temperature detecting means is configured to detect temperatures in the first fuel tank and the second fuel tank, respectively, and the control means is configured to detect the first fuel tank. When the above conditions for the pressure and temperature in the fuel tank are satisfied, the exhaust fuel heat increase control is executed to heat the first fuel tank by the exhaust flow passing through the vicinity of the first fuel tank. When the above conditions are satisfied for the pressure and temperature of the second fuel tank, the exhaust heat increase control is executed, so that the second fuel tank is moved by the exhaust flow passing through the vicinity of the second fuel tank. The controller is configured to warm, and the control means supplies the first and second fuels to the engine at a predetermined ratio during steady engine operation in which the engine is operated at a predetermined rotation speed, and the exhaust When the heat increase control is performed, the fuel supply ratio with the higher calorific value is increased with respect to the predetermined ratio while the engine is operated at the predetermined rotation speed. It may be configured.

  Thus, the fuel efficiency can be improved during steady engine operation by setting the predetermined rotational speed to a rotational speed at which the engine efficiency is equal to or higher than a predetermined value. Even when the exhaust heat increase control is executed, the output of the engine can be easily increased while maintaining the predetermined rotational speed.

Alternatively, in the control apparatus for a gaseous fuel engine according to the other aspect , the vehicle is a series hybrid vehicle in which the drive motor is driven by at least one of the electric power discharged from the battery and the electric power generated by the generator. The engine uses a first fuel and a second fuel as the gaseous fuel, and the fuel tank contains a first fuel tank for storing the first fuel, and the second fuel. A second fuel tank to be stored, wherein the pressure detection means is configured to detect pressures in the first fuel tank and the second fuel tank, respectively, and the temperature detection means A remaining amount detection unit configured to detect the temperatures in the first fuel tank and the second fuel tank, respectively, and detects the remaining amounts of the first fuel and the second fuel, respectively. The control means further includes the control means, when the conditions for the pressure and temperature in the first fuel tank are satisfied, by executing the exhaust heat increase control and passing the vicinity of the first fuel tank. The first fuel tank is heated by the exhaust flow, and when the above condition is satisfied with respect to the pressure and temperature in the second fuel tank, the exhaust heat increase control is executed to execute the second fuel tank The second fuel tank is heated by an exhaust flow passing through the vicinity of the tank, and the control means further includes the first and second fuels during steady operation of the engine that operates the engine at a predetermined speed. Is supplied to the engine at a predetermined ratio, the combustion air-fuel ratio in the combustion chamber of the engine is set to a predetermined air-fuel ratio, and when the exhaust heat increase control is executed, the engine is While driving at a predetermined rotational speed, the amount of fuel supplied it is often remaining amount detected by the remaining amount detecting means may be configured to increase than when the engine steady operation.

  As a result, when the exhaust heat increase control is executed, the engine output can be easily increased while suppressing the consumption of the fuel having the smaller remaining amount while maintaining the predetermined rotational speed.

Alternatively, in the control apparatus for a gaseous fuel engine according to the other aspect , the vehicle is a series hybrid vehicle in which the drive motor is driven by at least one of the electric power discharged from the battery and the electric power generated by the generator. The engine uses, as the gaseous fuel, a first fuel and a second fuel having a low ignitability and a high calorific value per unit volume with respect to the first fuel. The fuel tank includes a first fuel tank that stores the first fuel, and a second fuel tank that stores the second fuel, and the pressure detection means includes the first fuel tank and the first fuel tank. And a temperature detecting means for detecting temperatures in the first fuel tank and the second fuel tank, respectively. The control means is configured to execute the exhaust heat increase control when the above conditions are satisfied with respect to the pressure and temperature in the first fuel tank, so that exhaust passing through the vicinity of the first fuel tank is performed. The first fuel tank is configured to be heated by the flow, and the control means further includes the first and second fuels at a predetermined ratio during steady engine operation in which the engine is operated at a predetermined speed. While supplying to the engine and executing the exhaust heat increase control, the second fuel supply ratio is configured to be higher than the predetermined ratio while operating the engine at the predetermined rotation speed. May be.

  That is, since the first fuel has higher ignitability than the second fuel, it is a fuel that should be used up as much as possible in order to reliably start the engine. From this, the pressure in the first fuel tank and By executing the exhaust heat increase control when the above condition is satisfied for the temperature, the effect of the present invention can be effectively exhibited. In addition, the fact that the above conditions are satisfied with respect to the pressure and temperature in the first fuel tank basically means that the remaining amount of the first fuel is low, but at the time of executing the exhaust heat increase control, Since the supply ratio of the second fuel is increased with respect to the predetermined ratio, the output of the engine can be easily increased while suppressing the consumption of the first fuel.

In the control device for the gaseous fuel engine according to the one aspect and the other aspect , the engine has an adjacent path that passes through the vicinity of the fuel tank as an exhaust path through which the exhaust flow flows, and is further away from the fuel tank than the adjacent path. An exhaust path switching device that switches the exhaust path between the proximity path and the remote path, and the control means is a switch that controls the operation of the exhaust path switching device. The switching device control unit switches the exhaust path to the proximity path when the exhaust heat increase control is executed, and switches the exhaust path to the remote path when the exhaust heat increase control is not executed. It is preferable to be configured to switch to

  Thus, when the exhaust heat increase control is executed, the fuel tank can be effectively heated to increase the temperature and pressure in the fuel tank, and when the exhaust heat increase control is not executed, the exhaust heat of the fuel tank can be increased. Can prevent heat damage.

As described above, according to the control device for a gaseous fuel engine according to one aspect and another aspect of the present invention, the condition that the pressure in the fuel tank is equal to or lower than the predetermined pressure and the temperature in the fuel tank is equal to or lower than the predetermined temperature. When the above is established, the exhaust tank heat increase control for increasing the exhaust heat of the engine is executed, so that the fuel tank is heated by the exhaust flow passing through the vicinity of the fuel tank, thereby increasing the size of the vehicle. Therefore, the gas fuel in the fuel tank can be used up as much as possible at low cost.

Further, according to the control device for the gaseous fuel engine according to one aspect of the present invention, the power generated by the generator is increased by at least the power consumption of the electric heater by increasing the output of the engine by the heat increase control. As a result, the temperature and pressure in the fuel tank can be increased more effectively.

Further, according to the control device for the gaseous fuel engine according to another aspect of the present invention, the battery is charged with the increased amount of the power generated by the generator, which is increased by the increase in the engine output by the exhaust heat increase control. As a result, after the fuel is completely used up, it becomes possible to run with the drive motor by the discharge power of the battery that is charged by the increase in the amount of power generation, and thus the cruising distance can be increased. it can.

It is the schematic of the vehicle carrying the gaseous fuel engine controlled by the control apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the engine of the said vehicle, and its control system. It is a graph which shows the relationship between the excess air ratio (lambda) and NOx discharge | emission amount from an engine when making it burn with an engine about hydrogen gas, natural gas, and these mixed gas A, B, and C. FIG. Regarding hydrogen gas, natural gas, and mixed gas A, B, and C thereof, the relationship between the excess air ratio λ and the engine output torque and the excess air ratio λ and the thermal efficiency of the engine when the engine is burned It is a graph which shows a relationship. It is a flowchart which shows the processing operation by a control unit. It is the schematic which shows another example which changed the structure of the exhaust path.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram of a vehicle 1 equipped with a gaseous fuel engine 10 (hereinafter referred to as an engine 10) controlled by a control device according to an embodiment of the present invention. The vehicle 1 is a so-called range extender EV vehicle (also referred to as a series hybrid vehicle), and includes an engine 10, a generator 20 driven by the engine 10 to generate electric power, and electric power generated by the generator 20. Motor 30 that is driven by at least one of the high-voltage / large-capacity battery 30 that is charged (charged), and the generated power of the generator 20 driven by the engine 10 and the stored power (discharged power) of the battery 30 40. In the present embodiment, the generator 20 is a motor generator having a function of a motor, and the engine 10 is driven (cranked) by the generator 20 as a motor to start the engine 10. .

  A first inverter 50 is provided between the generator 20 and the battery 30, and a second inverter 51 is provided between the battery 30 and the drive motor 40. The first inverter 50 and the second inverter 51 are connected to each other, and the battery 30 is connected to the connection line. The power generated by the generator 20 is supplied to the battery 30 via the first inverter 50 and also supplied to the drive motor 40 via the first and second inverters 50 and 51. Discharged power from the battery 30 is supplied to the drive motor 40 via the second inverter 51.

  The output of the drive motor 40 is transmitted to the drive wheels 61 (the left and right front wheels steered by the steering wheel 62) via the differential device 60, whereby the vehicle 1 travels.

  The drive motor 40 is capable of generating regenerative power and operates as a generator when the vehicle 1 is decelerated, and the generated power (regenerative power) is charged in the battery 30. In the charging travel mode described later, the engine 10 is started and the battery 30 is charged with the generated power of the generator 20. The battery 30 can be externally charged by a power source external to the vehicle 1.

  The engine 10 is a power generation engine used to drive the generator 20 to generate power. The engine 10 is a multi-fuel engine configured such that hydrogen gas stored in the hydrogen tank 70 and natural gas (CNG) stored in the CNG tank 71 can be supplied as gaseous fuels. Hydrogen gas is equivalent to the first fuel, and natural gas is equivalent to the second fuel having lower ignitability and higher calorific value per unit volume than the first fuel. The second fuel is not limited to natural gas but may be propane or butane, for example. The hydrogen tank 70 corresponds to the first fuel tank, and the CNG tank 71 corresponds to the second fuel tank.

  The hydrogen tank 70 (first fuel tank) and the engine 10 are connected by a hydrogen supply pipe 72, and hydrogen gas in the hydrogen tank 70 is passed through the hydrogen supply pipe 72 to the engine 10 (details will be described later). To the hydrogen port injection valve 17A and the hydrogen direct injection valve 18A). The CNG tank 71 (second fuel tank) and the engine 10 are connected by a CNG supply pipe 73, and the natural gas in the CNG tank 71 passes through the CNG supply pipe 73 to the engine 10 (in detail). , Supplied to a CNG port injection valve 17B and a CNG direct injection valve 18B, which will be described later.

  Two pressure reducing valves 74 and 75 are disposed in the hydrogen supply pipe 72. In a state where the hydrogen tank 70 is filled with hydrogen gas, the pressure in the hydrogen tank 70 (hydrogen gas pressure) is set to 35 MPa, for example. Then, when the hydrogen gas passes through the pressure reducing valve 74, the pressure of the hydrogen gas is reduced to, for example, 1.3 MPa, and when further passed through the pressure reducing valve 75, the pressure is reduced to, for example, 0.6 MPa, and passes through the pressure reducing valve 75. Hydrogen gas is supplied to the engine 10 at a later pressure.

  The CNG supply pipe 73 is also provided with two pressure reducing valves 76 and 77. In the state where the CNG tank 71 is filled with natural gas, the pressure in the CNG tank 71 (natural gas pressure) is set to 20 MPa, for example. When the natural gas passes through the pressure reducing valve 76, the pressure of the natural gas is reduced to, for example, 1.3 MPa, and when further passed through the pressure reducing valve 77, the pressure is reduced to, for example, 0.6 MPa, and passes through the pressure reducing valve 77. Natural gas is supplied to the engine 10 at a later pressure.

  In the present embodiment, the hydrogen tank 70 is provided with an electric heater 78 for hydrogen that heats the hydrogen tank 70 (hydrogen gas in the hydrogen tank 70), and the CNG tank 71 includes the CNG tank 71 (CNG tank 71). The CNG electric heater 79 is provided for heating the natural gas. The operation of the electric heaters 78 and 79 for hydrogen and CNG is controlled by a control unit 100 described later, and operates with electric power (discharge power) from the battery 30. The electric heaters 78 and 79 for hydrogen and CNG may be provided on the outer surfaces of the hydrogen tank 70 and the CNG tank 71, respectively, or may be provided inside the hydrogen tank 70 and the CNG tank 71, respectively. Note that the electric heaters 78 and 79 for hydrogen and CNG are not always necessary.

  As shown in FIG. 2, the engine 10 is a twin-rotor (two-cylinder) rotary piston engine, and is roughly arranged in a rotor housing chamber 11 a formed in two saddle-shaped rotor housings 11 (inside cylinders). Each of the triangular rotors 12 is accommodated. The two rotor housings 11 are integrated with the side housings so as to be sandwiched between three side housings (not shown), and each rotor housing chamber 11a is composed of each rotor housing 11 and the side housings on both sides thereof. Is formed. In FIG. 2, the two rotor housings 11 (two cylinders) are shown in an unfolded state, and the eccentric shafts 13 respectively drawn in the central portions in the two rotor housings 11 are the same.

  Each of the rotors 12 has apex seals (not shown) at the apexes of the triangles, and the apex seals are in sliding contact with the inner surface of the trochoid of the rotor housing 11. Three working chambers (corresponding to combustion chambers) are defined in 11a (each cylinder). Each rotor 12 rotates around the eccentric shaft 13 in a state where the three apex seals of the rotor 12 are in contact with the inner peripheral surface of the trochoid of the rotor housing 11, and around the axis of the eccentric shaft 13. To revolve around. While the rotor 12 makes one revolution, the working chambers formed between the tops of the rotor 12 move in the circumferential direction, and the intake, compression, expansion (combustion), and exhaust strokes are performed. The rotating force is output from the eccentric shaft 13 as the output shaft through the rotor 12.

  An intake passage 14 is connected to each of the rotor accommodating chambers 11a so as to communicate with an intake opening that opens to the working chamber in the intake stroke, and communicates with an exhaust opening that opens to the working chamber in the exhaust stroke. An exhaust passage 15 is connected to the front. There is one intake passage 14 on the upstream side, but on the downstream side, the intake passage 14 branches into two branch passages and communicates with each of the rotor accommodating chambers 11a. The cross-sectional area (valve opening degree) of the intake passage 14 is adjusted by being driven by a throttle valve actuator 90 such as a stepping motor on the upstream side of the branch portion of the intake passage 14 (downstream side of an intercooler 86 described later). A throttle valve 16 is provided. The throttle valve 16 adjusts the amount of intake air into each rotor accommodating chamber 11a (the working chamber in the intake stroke). In engine control described later in this embodiment, the throttle valve 16 is fully opened.

  In each branch passage downstream of the branch portion of the intake passage 14, hydrogen gas from the hydrogen tank 70 and natural gas from the CNG tank 71 are supplied to the intake passage 14 (especially the intake port or its vicinity). A hydrogen port injection valve 17A (second fuel port injection valve) and a CNG port injection valve 17B (first fuel port injection valve), which are respectively injected, are disposed in the (preferably). The hydrogen gas and natural gas injected by the hydrogen and CNG port injection valves 17A and 17B, respectively, are mixed with air and supplied to the working chamber in the intake stroke.

  The hydrogen and CNG port injection valves 17A and 17B are set in advance because the temperature of the cooling water of the engine 10 (hereinafter referred to as engine cooling water) is extremely low even when the engine 10 is extremely cold (even when the engine is cold). Used when starting at a temperature lower than the set temperature. In other cases, fuel (hydrogen gas and natural gas) is directly injected into the working chamber (combustion chamber) from hydrogen and CNG direct injection valves 18A and 18B described later. When the engine 10 is extremely cold, the fuel injection openings of the hydrogen and CNG direct injection valves 18A and 18B may be blocked by freezing of water generated by fuel combustion. Therefore, the fuel is exceptionally injected from the hydrogen and CNG port injection valves 17A and 17B. In addition, when the engine 10 is started and operated, fuel is injected only by the hydrogen and CNG port injection valves 17A and 17B, or the hydrogen and CNG direct injection valves 18A and 18B and the hydrogen and CNG are injected. It is also possible to inject fuel through the port injection valves 17A and 17B. Conversely, the hydrogen and CNG port injection valves 17A and 17B can be eliminated. In the following description, it is assumed that fuel (hydrogen gas and natural gas) is injected by the hydrogen and CNG direct injection valves 18A and 18B.

  Two exhaust passages 15 are provided on the upstream side so as to communicate with the respective rotor accommodating chambers 11a, but are joined together on the downstream side. A low temperature active three-way catalyst 81 and a NOx occlusion reduction catalyst 82 for purifying exhaust gas are disposed downstream of the merging portion of the exhaust passage 15. The low temperature active three-way catalyst 81 is a three-way catalyst having a catalyst activation temperature lower than that of the NOx storage reduction catalyst 82, and is disposed upstream of the NOx storage reduction catalyst 82. In FIG. 2, arrows shown in the intake passage 14 and the exhaust passage 15 indicate the flow of intake and exhaust.

  The NOx occlusion reduction catalyst 82 is configured, for example, by supporting a NOx occlusion agent such as barium (Ba) or potassium (K) on a carrier containing a noble metal such as platinum (Pt) or palladium (Pd). The NOx in the exhaust gas of the engine 10 is occluded in a lean air-fuel ratio atmosphere, and the occluded NOx is released in a rich air-fuel ratio atmosphere to cause the NOx to react with HC and CO in the exhaust gas. Have the function of reducing

  A portion of the exhaust passage 15 (exhaust pipe) on the downstream side of the NOx storage reduction catalyst 82 is shown in FIG. 1 (in FIG. 1, the low temperature active three-way catalyst 81, the NOx storage reduction catalyst 82, etc. are described. Pass through the vicinity of the hydrogen tank 70 and the CNG tank 71. That is, the exhaust flow flowing through the exhaust passage 15 passes through the vicinity of the hydrogen tank 70 and the CNG tank 71, and the exhaust heat is transmitted from the exhaust flow to the hydrogen tank 70 and the CNG tank 71, thereby heating the hydrogen tank 70 and the CNG tank 71. It is possible to do. It should be noted that the positions of the exhaust passage 15, the hydrogen tank 70, the CNG tank 71, etc. shown in FIG. For example, the hydrogen tank 70 and the CNG tank 71 may be arranged in the vehicle width direction, and the exhaust passage 15 may pass between the tanks 70 and 71 from the front side of the vehicle toward the rear side. The CNG tanks 71 may be arranged in the vehicle front-rear direction, and the exhaust passage 15 may pass through one side or the lower side in the vehicle width direction of the tanks 70, 71 from the vehicle front side toward the rear side.

  In each rotor housing 11 (each cylinder), a hydrogen direct injection valve 18A for directly injecting hydrogen gas from the hydrogen tank 70 into the working chamber (combustion chamber) in the compression stroke of the rotor accommodating chamber 11a; A CNG direct injection valve 18B for directly injecting natural gas from the CNG tank 71 into the working chamber (combustion chamber) in the compression stroke of the rotor accommodating chamber 11a is provided. In each rotor housing 11, two CNG direct injection valves 18B are provided, and these two CNG direct injection valves 18B are arranged in the width direction of the rotor 12 (the direction in which the eccentric shaft 13 extends). (In FIG. 2, the CNG direct injection valve 18B on the back side of the drawing is not visible). The number of the hydrogen direct injection valves 18A, the hydrogen port injection valves 17A, and the CNG port injection valves 17B are all one. In this embodiment, natural gas is always injected from the two CNG direct injection valves 18B.

  Each rotor housing 11 is provided with two spark plugs 19 for igniting hydrogen gas and natural gas respectively injected from hydrogen and CNG direct injection valves 18A and 18B. These spark plugs 19 are ignited in the order of the leading side and the trailing side in the vicinity of the compression top (TDC), and ignite the air-fuel mixture in the working chamber in the compression or expansion stroke.

The engine 10 is provided with an exhaust turbocharger 85 that supercharges intake air into the working chamber (combustion chamber) in the intake stroke in each rotor accommodating chamber 11a of the engine 10. The exhaust turbocharger 85 includes a compressor 85a disposed upstream of the throttle valve 16 in the intake passage 14 and a downstream side of the merging portion in the exhaust passage 15 and the low temperature active three-way catalyst 81. And a turbine 85b disposed on the upstream side. The turbine 85b is rotated by the exhaust gas flow, and the rotation of the turbine 85b activates the compressor 85a connected to the turbine 85b to compress the air taken into the intake passage 14. The compressed air is cooled by an intercooler 86 disposed downstream of the compressor 85a and upstream of the throttle valve 16 in the intake passage 14, and then accommodated in each rotor via each branch passage. Inhaled into the working chamber in the intake stroke of the chamber 11a.

  The vehicle 1 includes a battery current / voltage sensor 101 that detects a current flowing in and out of the battery 30 and a voltage of the battery 30, and an accelerator that detects an amount of depression of an accelerator pedal by an occupant of the vehicle 1 (accelerator opening by an occupant's operation). An opening sensor 102, a vehicle speed sensor 103 that detects the vehicle speed of the vehicle 1, a rotation angle sensor 104 that is provided on the eccentric shaft 13 and detects the rotation angle position of the eccentric shaft 13, and a low-temperature active three-way catalyst in the exhaust passage 15 An air-fuel ratio sensor 105 (configured by a linear O2 sensor in this embodiment) that is disposed between the turbine 81 and the turbine 85 b and detects the air-fuel ratio of the exhaust gas of the engine 10, and the rotor housing 11 It faces the formed water jacket (not shown) and flows through the water jacket. An engine water temperature sensor 106 for detecting the temperature of the engine coolant (engine water temperature) and a tank pressure sensor 107 for detecting the pressure in the hydrogen tank 70 and the pressure in the CNG tank 71 (into the hydrogen tank 70 and the CNG tank 71). Provided separately), an air flow sensor 108 for detecting the intake flow rate drawn into the intake passage 14, the temperature in the hydrogen tank 70 (the temperature of the hydrogen gas in the hydrogen tank 70), and the CNG tank 71 A tank temperature sensor 109 (provided separately for the hydrogen tank 70 and the CNG tank 71) for detecting the temperature (the temperature of the natural gas in the CNG tank 71), the operation control of the engine 10, and the first and first Control for performing operation control of the inverters 50 and 51 (that is, operation control of the generator 20 and the drive motor 40) Knit 100 and is provided. The rotation angle sensor 104 also serves as an engine rotation speed sensor that detects the rotation speed of the engine 10.

  The tank pressure sensor 107 constitutes pressure detection means for detecting the pressure in the hydrogen tank 70 and the CNG tank 71, respectively, and the remaining hydrogen gas in the hydrogen tank 70 and the remaining natural gas in the CNG tank 71, respectively. It also serves as a remaining amount detecting means for detection. The tank temperature sensor 109 constitutes temperature detection means for detecting the temperatures in the hydrogen tank 70 and the CNG tank 71, respectively.

  The control unit 100 is a controller based on a well-known microcomputer, and includes a central processing unit (CPU) that executes a program, a memory that is configured by, for example, a RAM or ROM, and stores a program and data, and an electrical signal An input / output (I / O) bus. The control unit 100 includes a battery current / voltage sensor 101, an accelerator opening sensor 102, a vehicle speed sensor 103, a rotation angle sensor 104, an air-fuel ratio sensor 105, an engine water temperature sensor 106, a tank pressure sensor 107, an air flow sensor 108, a tank temperature sensor. Various information signals from 109 etc. are input.

  The generator 20 transmits information on the voltage and current generated by the generator 20 to the control unit 100. The control unit 100 inputs the information and generates power generated by the generator 20 from the information. (Power generation amount) is detected.

  The drive motor 40 transmits information on the rotational speed of the drive motor 40 and information on the regenerative power generation voltage and regenerative power generation current generated by the drive motor 40 to the control unit 100, and the control unit 100 transmits the information. The input is used to control the operation of the drive motor 40.

  Then, based on the input signal, the control unit 100 controls the throttle valve actuator 90, the hydrogen port injection valve 17A, the CNG port injection valve 17B, the hydrogen direct injection valve 18A, the CNG direct injection valve 18B, and A control signal is output to the spark plug 19 to control the engine 10, and a control signal is output to the first and second inverters 50 and 51 to control the generator 20 and the drive motor 40. Control signals are output to drive circuits (not shown) for the hydrogen and CNG electric heaters 78 and 79 to control the hydrogen and CNG electric heaters 78 and 79, respectively. The control unit 100 constitutes a control means for controlling the operation of the engine 10, an electric heater controller for controlling the operation of the electric heaters 78 and 79 for hydrogen and CNG, and a generator for controlling the operation of the generator 20. And a control unit.

  The vehicle 1 is driven by the battery 30 in the battery running mode (at this time, the engine 10 is stopped), the engine 10 is operated, and the output of the engine 10 causes the battery to pass through the generator 20. And a charging travel mode in which the vehicle travels while charging 30. In the present embodiment, since the vehicle 1 is a series hybrid vehicle, in the charging travel mode, charging of the battery 30 and driving of the drive motor 40 are performed with electric power generated by the generator 20 that generates electric power from the output of the engine 10. Do.

  The control unit 100 detects the remaining capacity (SOC) of the battery 30 based on the current flowing into and out of the battery 30 and the voltage of the battery 30 detected by the battery current / voltage sensor 101. Thus, the battery current / voltage sensor 101 and the control unit 100 constitute a battery remaining capacity detecting means for detecting the remaining capacity of the battery 30.

  Then, when the detected SOC of the battery 30 is lower than a first predetermined value (for example, 30%) in the battery running mode, the control unit 100 switches to the charging running mode while the charging running mode Sometimes, when the detected SOC of the battery 30 becomes higher than a second predetermined value (for example, 70%) set to a value higher than the first predetermined value, the battery driving mode is switched. Thereby, the SOC of battery 30 can be maintained within a preferable range that is neither too low nor too high.

  In the battery running mode, the control unit 100 determines whether or not there is an operation request for the engine 10 based on the required output of the drive motor 40 and the SOC value of the battery 30 (in this embodiment, the same as the presence or absence of a power generation request). If there is an operation request (power generation request) for the engine 10, the engine 10 is cranked by the generator 20 as a motor to start the engine 10, and after that start, the generator 20 generates power. Therefore, the engine 10 is operated. That is, when the SOC of the battery 30 is lower than the first predetermined value or the required output of the drive motor 40 exceeds the maximum dischargeable power of the battery 30 in the battery running mode. Sometimes, the engine 10 is operated on the assumption that there is a request for operating the engine 10.

Here, the maximum dischargeable power varies depending on the temperature of the battery 30. The relationship between the temperature of the battery 30 and the maximum dischargeable electric power, as a map, is stored in the memory of the control unit 100, control unit 100 uses the map, the more the detection of the battery temperature sensor The maximum dischargeable power is detected from the temperature of the battery 30.

  In the charging travel mode, the control unit 100 basically operates the engine 10 at a predetermined rotational speed, and the engine rotational speed during the engine steady operation (the predetermined rotational speed) is the highest efficiency point of the engine 10. Is a value in an efficient region including 1800 rpm to 2200 rpm, for example, 2000 rpm in this embodiment. The engine load during the engine steady operation is a medium load or a high load larger than a predetermined load. At this time, the battery 30 is charged and the drive motor 40 is driven with the power generated by the generator 20 that generates power by the output of the engine 10 (the remaining power obtained by subtracting the required output of the drive motor 40 from the generated power). Is charged to the battery 30). Further, when the required output of the drive motor 40 becomes larger than the engine output (generated power) at 2000 rpm as in the case of the acceleration request of the vehicle 1 or more during the steady engine operation, the shortage is reduced. It is supplemented by the discharge power of the battery 30 (not charged). However, if the required output of the drive motor 40 cannot be satisfied even if the discharge power of the battery 30 reaches the maximum dischargeable power of the battery 30, the engine speed is exceptionally made higher than the predetermined speed. (Engine 10 is unsteady operation).

  The operation of the engine 10 when the required output of the drive motor 40 exceeds the maximum dischargeable power of the battery 30 in the battery running mode is also a steady operation at the predetermined rotational speed (2000 rpm), and the discharge power of the battery 30 is reduced. It adjusts so that the required output of the drive motor 40 may be satisfied.

  Hereinafter, the operation of the engine 10 when the exhaust heat increase control as described later is not executed (including the engine steady operation) is referred to as engine normal operation.

  The control unit 100 controls the hydrogen direct injection valve 18A and the CNG direct injection valve 18B to supply hydrogen gas and natural gas to the engine 10 at a predetermined ratio during the normal operation of the engine. In the present embodiment, during normal operation of the engine, hydrogen gas and natural gas are injected into the combustion chamber at substantially the same volume ratio (both 50%).

  Further, the control unit 100 sets the combustion air-fuel ratio in the combustion chamber of the engine 10 to a predetermined air-fuel ratio during the engine normal operation. The predetermined air-fuel ratio is a lean air-fuel ratio, and the NOx emission amount from the engine 10 (combustion chamber) is, for example, the NOx emission amount when only natural gas is combusted with the lean combustion air-fuel ratio. The air-fuel ratio becomes substantially the same.

  Here, FIG. 3 shows the excess air ratio λ and the engine 10 when hydrogen gas, natural gas, and mixed gas A, B, and C thereof are burned by the engine 10 (rotation speed 2000 rpm, throttle valve 16 fully opened). The relationship with the NOx emission amount from (combustion chamber) is shown. The mixed gas A has hydrogen gas and natural gas at substantially the same volume ratio (both are about 50%), and the mixed gas B has a larger volume ratio of hydrogen gas than the mixed gas A, The mixed gas C has a volume ratio of hydrogen gas larger than that of the mixed gas B. FIG. 4 shows the relationship between the excess air ratio λ and the output torque of the engine 10 when the above-mentioned gases shown in FIG. 3 are burned by the engine 10 (rotation speed 2000 rpm, throttle valve 16 fully opened), and air. The relationship between excess ratio (lambda) and the thermal efficiency of the engine 10 is shown. Here, natural gas is injected from the CNG direct injection valve 18B, and hydrogen gas is injected from the hydrogen port injection valve 17A. In this case, compared with the case where hydrogen gas and natural gas are respectively injected from the hydrogen and CNG direct injection valves 18A and 18B, the magnitude of the output torque and the like change, but the tendency of the above relationship does not change greatly.

  From FIG. 3 and FIG. 4, the lean air limit combustion air-fuel ratio (here, the excess air ratio λ) of natural gas is 1.6, and even if the excess air ratio λ is larger than this, stable ignition is achieved. I can't do it. 3 and 4, the excess air ratio λ is only up to 2.7, but the lean excess air excess ratio λ of hydrogen gas is about 3. In FIGS. 3 and 4, the results when the excess air ratio λ of hydrogen gas is lower than 1.8 are omitted.

  From FIG. 3, if the excess air ratio λ is the same, natural gas has a smaller NOx emission than hydrogen gas, and the mixed gas A, B, C has a larger volume ratio of natural gas (hydrogen gas It can be seen that the smaller the volume ratio), the smaller the NOx emissions. That is, when the volume ratio of hydrogen gas in the hydrogen gas or mixed gas is large, the NOx emission amount increases. However, when the volume ratio of hydrogen gas in the hydrogen gas or mixed gas is large, the lean combustion air-fuel ratio becomes high, so the NOx emission can be reduced by increasing the combustion air-fuel ratio in the combustion chamber. .

  In the present embodiment, during the engine steady operation, hydrogen gas and natural gas are injected into the combustion chamber at substantially the same volume ratio (both 50%). At this time, the combustion air-fuel ratio (excess air ratio λ) in the combustion chamber NOx emission amount from the engine 10 is, for example, a lean air-fuel ratio that is substantially the same as the NOx emission amount when only natural gas is burned with its lean-limit combustion air-fuel ratio (λ = 1.6). To do. In this embodiment, the lean air-fuel ratio is obtained at the point Q2 where the line parallel to the horizontal axis passing through the point Q1 of λ = 1.6 on the natural gas line in FIG. The value of λ (that is, λ = 1.9) is obtained.

  Here, if the fuel in the hydrogen tank 70 or the CNG tank 71 is reduced and the pressure in the hydrogen tank 70 or the CNG tank 71 is reduced, even if the fuel remains in the hydrogen tank 70 or the CNG tank 71, It becomes difficult to stably supply the fuel to the engine 10. In the present embodiment, the pressure in the hydrogen tank 70 or the CNG tank 71 is set to a pressure (for example, 1 MPa) slightly higher than the pressure (0.6 MPa in the above example) after the pressure is reduced by the pressure reducing valves 75 and 77. Then, it becomes difficult to stably supply the fuel to the engine 10. If the pressure in the hydrogen tank 70 (CNG tank 71) is 1 MPa, the pressure of the hydrogen gas (natural gas) is not limited even if the hydrogen gas (natural gas) passes through the pressure reducing valve 74 (pressure reducing valve 76). The pressure is 1 MPa as it is, and after passing through the pressure reducing valve 75 (pressure reducing valve 77), the pressure of hydrogen gas (natural gas) becomes 0.6 MPa.

  Therefore, in order to use up the fuel in the hydrogen tank 70 or the CNG tank 71 as much as possible, in the present embodiment, the control unit 100 causes the tank pressure sensor 107 to set the inside of the hydrogen tank 70 during the engine steady operation. Exhaust heat increase that increases the exhaust heat of the engine 10 when the first condition that the pressure in the hydrogen tank 70 is lower than the first predetermined pressure and the temperature in the hydrogen tank 70 by the tank temperature sensor 109 is lower than the first predetermined temperature is satisfied. By executing the control, the hydrogen tank 70 is heated by the exhaust flow passing through the vicinity of the hydrogen tank 70. In the present embodiment, since the exhaust flow also passes in the vicinity of the CNG tank 71, the CNG tank 71 is also heated by the execution of the exhaust heat increase control.

  Further, during the engine steady operation, the control unit 100 determines that the pressure in the CNG tank 71 by the tank pressure sensor 107 is equal to or lower than the second predetermined pressure, and the temperature in the CNG tank 71 by the tank temperature sensor 109 is equal to or lower than the second predetermined temperature. Even when the second condition is satisfied, the exhaust gas heat passing through the vicinity of the CNG tank 71 is heated by executing the exhaust heat increase control. In the present embodiment, the hydrogen tank 70 is also heated by executing the exhaust heat increase control when the second condition is satisfied.

  The first predetermined pressure is a value that makes it difficult to stably supply hydrogen gas to the engine 10 when the pressure in the hydrogen tank 70 becomes lower than the first predetermined pressure. It is the same. The first predetermined pressure and the second predetermined pressure may be the same value or different values.

  If the pressure in the hydrogen tank 70 is equal to or lower than the first predetermined pressure when the temperature in the hydrogen tank 70 is higher than the first predetermined temperature, almost no hydrogen gas remains in the hydrogen tank 70, and hydrogen Since the hydrogen gas can no longer be supplied to the engine 10 even when the tank 70 is heated, the temperature in the hydrogen tank 70 is added to the first condition above the first predetermined temperature. The same applies to the second condition. The first predetermined temperature and the second predetermined temperature may be the same value or different values.

  In the present embodiment, the exhaust heat increase control is executed when the first condition or the second condition is satisfied during the engine steady operation. However, during the engine normal operation, the first condition or the above is performed. The exhaust heat increase control may be executed when the second condition is satisfied. In other words, the exhaust heat increase control is executed when the first condition or the second condition is satisfied even during the unsteady operation of the engine 10 (when the engine speed is higher than the predetermined speed). You may make it do. However, when the engine 10 is in an unsteady operation, even if the exhaust heat increase control is not executed, the exhaust heat of the engine 10 increases more than in the engine steady operation. Therefore, it is not always necessary to execute the exhaust heat increase control. Absent.

  The exhaust heat increase control is control for increasing the output of the engine 10. In the present embodiment, in the exhaust heat increase control, the engine load (engine torque) is increased while maintaining the engine speed as compared with the engine steady operation. By increasing the output of the engine 10 by the exhaust heat increase control, the electric power generated by the generator 20 is increased, and the electric heater that heats the fuel tank corresponding to the satisfied condition by the increase (the first condition is satisfied). Sometimes it is a hydrogen electric heater 78 that heats the hydrogen tank 70, and when the second condition is satisfied, it is a CNG electric heater 79 that heats the CNG tank 71, hereinafter referred to as a specific electric heater). To cover. That is, when the exhaust heat increase control is performed, the specific electric heater is operated, and the power generated by the generator 20 is increased by at least the power consumption of the specific electric heater by the increase in the output of the engine 10 by the exhaust heat increase control. Increase. In addition, when the exhaust heat increase control is executed, not only the specific electric heater but also both the hydrogen heaters and the CNG electric heaters 78 and 79 may be operated.

  In the present embodiment, when the SOC of the battery 30 is lower than a preset value set to a value lower than the second predetermined value, the specific electric power is generated with respect to the power generated by the generator 20 during the engine steady operation. Electric power is generated by increasing the power consumption of the heater and the charge to the battery 30, and the battery 30 is charged with the generated power. Since a part of the charged increase in the generated power is consumed by the specific electric heater, the remaining amount of the increase and the charged power to the battery 30 among the generated power during the engine steady operation (the generated power) The value obtained by subtracting the required output of the drive motor 40 from the above) increases the SOC of the battery 30.

  The set value is a value close to the second predetermined value, and when the battery 30 is charged by adding the remainder of the increase to the generated power during the steady operation of the engine, the SOC of the battery 30 becomes the first value. 2 A value that may greatly exceed a predetermined value.

  On the other hand, when the SOC of the battery 30 is equal to or higher than the set value, power is generated by increasing the power consumption of the specific electric heater with respect to the power generated by the generator 20 during the steady engine operation. 30 is charged. Since all of the charged increase in the generated power is consumed by the specific electric heater, the SOC of the battery 30 is the amount of charge to the battery 30 (from the generated power in the generated power during the steady engine operation). The value increases by subtracting the required output of the drive motor 40).

  In the present embodiment, when the exhaust heat increase control is performed, the control unit 100 operates the engine 10 at the predetermined rotational speed (2000 rpm) and performs natural gas (relative to the first fuel) with respect to the predetermined ratio. Thus, the supply ratio of the second fuel having low ignitability and high calorific value per unit volume is increased. At this time, the combustion air-fuel ratio in the combustion chamber of the engine 10 may be the same as the predetermined air-fuel ratio. Even if the combustion air-fuel ratio in the combustion chamber is the same as the predetermined air-fuel ratio, the output of the engine 10 can be increased by increasing the supply ratio of natural gas having a higher calorific value. Alternatively, by increasing the supply amount of natural gas compared to that during steady operation of the engine, the supply ratio of natural gas is increased relative to the predetermined ratio, and the combustion air-fuel ratio in the combustion chamber of the engine 10 is set to the predetermined air-fuel ratio. It may be made richer.

  In addition, when the exhaust heat increase control is executed, instead of increasing the supply ratio of the natural gas with respect to the predetermined ratio, the tank pressure sensor 107 serving as the remaining amount detecting means has a larger remaining amount. The fuel supply amount may be increased as compared with the steady engine operation. As a result, the fuel supply ratio with the larger remaining amount becomes higher than the predetermined ratio, and the combustion air-fuel ratio in the combustion chamber of the engine 10 becomes richer than the predetermined air-fuel ratio.

  Next, the processing operation by the control unit 100 will be described based on the flowchart of FIG. Here, at the start of this flowchart, the battery running mode is set in a state where the engine 10 is stopped.

  In the first step S1, various input signals from various sensors are read, and in the next step S2, the required output of the drive motor 40 is calculated based on the signals from the accelerator opening sensor 102 and the vehicle speed sensor 103.

  In the next step S <b> 3, the presence or absence of an operation request for the engine 10 is confirmed based on the required output of the drive motor 40 and the SOC of the battery 30. That is, when the SOC of the battery 30 is lower than the first predetermined value, or when the required output of the drive motor 40 exceeds the maximum dischargeable power of the battery 30, there is a request for operation of the engine 10.

  In the next step S4, it is determined whether or not there is an operation request for the engine 10. When the determination in step S4 is NO, the process returns to step S1, while when the determination in step S4 is YES, the process proceeds to step S5, and the first condition or the second condition is satisfied during the steady engine operation. It is determined whether or not it is established.

  When the determination in step S5 is NO, the process proceeds to step S6 to perform the engine normal operation (basically, the engine steady operation), and then returns. On the other hand, when the determination in step S5 is YES, the process proceeds to step S7, the exhaust heat increase control is executed, and then the process proceeds to step S8.

  In step S8, it is determined whether the remaining capacity (SOC) of the battery 30 is lower than the set value. When the determination in step S8 is YES, the process proceeds to step S9, where the power consumption of the specific electric heater and the charge to the battery 30 are added to the power generated by the generator 20 during the engine steady operation. Therefore, the natural gas supply ratio is increased with respect to the predetermined ratio so that the process proceeds to step S11.

  On the other hand, when the determination in step S8 is NO, the process proceeds to step S10 so that the power generated by the generator 20 during the engine steady operation can be added with the power consumption of the specific electric heater to generate power. The supply ratio of natural gas is increased with respect to the predetermined ratio, and then the process proceeds to step S11.

  In step S11, the specific electric heater is operated in part (in the case of S9) or all (in the case of S10) of the extra part, and the remaining part of the extra part and the generated electric power during the steady engine operation of the battery The battery 30 is charged by the charge to 30 (from S9) or from the charge (from S10). Of the generated power during the engine steady operation, the required output of the drive motor 40 is supplied to the drive motor 40 to drive the drive motor 40.

  In the next step S12, various input signals are newly read and the presence or absence of the engine request operation is newly confirmed to determine whether or not the operation request for the engine 10 is lost. When the determination in step S12 is NO, the process returns to step S5. On the other hand, when the determination in step S12 is YES, that is, when the SOC of the battery 30 becomes higher than the second predetermined value, or the required output of the drive motor 40 becomes equal to or less than the maximum dischargeable power of the battery 30. If so, the routine proceeds to step S13, where the engine 10 is stopped and then the routine returns.

  Therefore, in the present embodiment, when the first condition is satisfied, that is, a certain amount of hydrogen gas remains in the hydrogen tank 70, it is difficult to supply the hydrogen gas in the hydrogen tank 70 to the engine 10. When the second condition is satisfied, that is, a certain amount of natural gas remains in the CNG tank 71, the natural gas in the CNG tank 71 may be supplied to the engine 10. When the exhaust heat increase control is executed in a difficult situation, the hydrogen tank 70 and the CNG tank 71 are heated by the exhaust flow passing through the vicinity of the hydrogen tank 70 and the CNG tank 71. The temperature and pressure in the tank 71 can be easily increased. Therefore, the hydrogen gas in the hydrogen tank 70 and the natural gas in the CNG tank 71 can be used up as much as possible without increasing the size of the vehicle 1 at a low cost.

  The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above embodiment, the exhaust passage 15 (exhaust passage) of the engine 10 passes through the vicinity of the hydrogen tank 70 and the CNG tank 71. However, as shown in FIG. The first branch path 15a that passes through the vicinity of the tank 70 (in the example of FIG. 6, the lower side of the hydrogen tank 70) and the vicinity of the CNG tank 71 (in the example of FIG. 6, the lower side of the CNG tank 71) pass. The second branch path 15b and a position farther from the hydrogen tank 70 than the first branch path 15a and farther from the CNG tank 71 than the second branch path 15b (in the example of FIG. You may make it branch to the 3rd branch path 15c which passes between the tank 70 and the CNG tank 71). The first branch path 15a corresponds to a proximity path to the hydrogen tank 70, the second branch path 15b corresponds to a proximity path to the CNG tank 71, and the third branch path 15c is a remote path to the hydrogen tank 70 and the CNG tank 71. Corresponds to the route. When only one type of fuel is used (when there is only one fuel tank), one of the first branch path 15a and the second branch path 15b is not necessary.

  In the first to third branch paths 15a, 15b, 15c, the exhaust path is switched to the first branch path 15a or the second branch path (proximity path) and the third branch path 15c (remote path). 1st-3rd switching valve 111-113 is each arrange | positioned. The first to third switching valves 111 to 113 are controlled to be opened and closed by the control unit 100, respectively. The first to third switching valves 111 to 113 correspond to an exhaust path switching device that switches the exhaust path between the proximity path and the remote path, and the control unit 100 is a switch that controls the operation of the exhaust path switching device. A device controller is included.

  The control unit 100 (switching device control unit) opens the third switching valve 113 and performs the first and second switching valves 111 and 112 during the normal operation of the engine (when the exhaust heat increase control is not executed). Is closed so that the exhaust flow flows through the third branch 15c. This prevents thermal damage caused by the exhaust heat of the hydrogen tank 70 and the CNG tank 71 when the exhaust heat increase control is not executed.

  On the other hand, when the first condition is satisfied and the exhaust heat increase control is executed, the control unit 100 (switching device controller) opens the first switching valve 111 and the second and third switching valves. 112 and 113 are closed so that the exhaust flow flows through the first branch 15a. Thereby, the hydrogen tank 70 is heated.

  When the second condition is satisfied and the exhaust heat increase control is executed, the control unit 100 (the switching device control unit) opens the second switching valve 112 and the first and third switching valves. 111 and 113 are closed so that the exhaust flow flows through the second branch 15b. Thereby, the CNG tank 71 is heated.

  In the example of FIG. 6, the electric heaters 78 and 79 for hydrogen and CNG are not provided, but these may be provided as in the above embodiment.

  In the above embodiment, the control unit 100 (electric heater control unit) operates the specific electric heater when the exhaust heat increase control is performed. However, the specific electric heater is activated when the exhaust heat increase control is performed. In addition to being operated, in the battery running mode, the SOC of the battery 30 is lower than a third predetermined value set to a value higher than the first predetermined value and lower than the second predetermined value. It is also possible to operate the specific electric heater when the first condition or the second condition is satisfied. The third predetermined value is a value close to the first predetermined value, and is a value that can sufficiently heat the fuel tank corresponding to the established condition immediately after switching to the charging travel mode. . In this way, in the battery running mode, when the SOC of the battery 30 becomes lower than the third predetermined value, that is, shortly before switching from the battery running mode to the charging running mode, the specific electric heater , The temperature and pressure in the fuel tank corresponding to the established condition can be increased, and immediately after switching to the charging travel mode (immediately after starting the engine 10), the fuel tank The fuel can be stably supplied to the engine 10.

  In the above embodiment, the exhaust heat increase control is executed when the first condition or the second condition is satisfied. However, in order to start the engine 10 reliably, the ignitability is higher. In order to use up hydrogen gas as much as possible, the exhaust heat increase control may be executed when only the first condition is satisfied. In this case, when the exhaust heat increase control is performed, the supply ratio of the natural gas having a higher calorific value per unit volume is made higher than the predetermined ratio while the engine 10 is operated at the predetermined rotation speed. If so, the output of the engine 10 can be easily increased while suppressing the consumption of the hydrogen gas whose remaining amount is low.

  Furthermore, in the above embodiment, the engine 10 is a power generation engine used to drive the generator 20 in a series hybrid vehicle to generate power. However, the engine of a parallel hybrid vehicle or a vehicle driven only by the engine is used. The present invention can also be applied to this engine. The engine applied to the present invention is not limited to a multi-fuel engine, and may be an engine using one kind of gaseous fuel or a reciprocating engine.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention is useful for a control device for a gaseous fuel engine mounted on a vehicle.

DESCRIPTION OF SYMBOLS 1 Vehicle 10 Engine 15 Exhaust passage 15a 1st branch path (close proximity path)
15b Second branch path (proximity path)
15c 3rd branch (remote route)
20 Generator 30 Battery 70 Hydrogen tank (first fuel tank)
71 CNG tank (second fuel tank)
78 Electric heater for hydrogen 79 Electric heater for CNG 100 Control unit (control means) (remaining battery capacity detection means)
101 Battery current / voltage sensor (Battery remaining capacity detection means)
107 Tank pressure sensor (pressure detection means) (remaining amount detection means)
109 Tank temperature sensor (temperature detection means)
111 1st switching valve (exhaust path switching device)
112 Second switching valve (exhaust path switching device)
113 3rd switching valve (exhaust path switching device)

Claims (7)

A control device for a gaseous fuel engine mounted on a vehicle,
A fuel tank for storing gaseous fuel as engine fuel;
Pressure detecting means for detecting the pressure in the fuel tank;
Temperature detecting means for detecting the temperature in the fuel tank;
Control means for controlling the operation of the engine,
When the condition that the pressure in the fuel tank by the pressure detecting means is equal to or lower than a predetermined pressure and the temperature in the fuel tank by the temperature detecting means is equal to or lower than a predetermined temperature is satisfied, By performing exhaust heat increase control for increasing exhaust heat, the fuel tank is configured to be heated by an exhaust flow passing through the vicinity of the fuel tank ,
An electric heater for heating the fuel tank;
The exhaust heat increase control is a control to increase the output of the engine,
Further, the control means includes an electric heater control unit that controls the operation of the electric heater, and a generator control unit that controls the operation of the generator that is driven by the engine to generate electric power,
The electric heater control unit is configured to operate the electric heater when executing the exhaust heat increase control,
The generator control unit is configured to increase the power generated by the generator by at least the power consumption of the electric heater by increasing the output of the engine by the exhaust heat increase control. Control device for gas fuel engine. In the control device of the gaseous fuel engine according to claim 1 ,
The vehicle has a generator that is driven by the engine to generate power, a battery that charges the power generated by the generator, and a drive motor for driving the vehicle that can be driven by the discharged power of the battery, A hybrid vehicle having a battery travel mode in which the battery is driven by the discharged power of the battery and a charge travel mode in which the engine is operated and the battery is charged by the output of the engine;
A battery remaining capacity detecting means for detecting the remaining capacity of the battery;
When the remaining battery capacity detected by the battery remaining capacity detecting means is lower than a first predetermined value during the battery running mode, the control means switches to the charging running mode, while in the charging running mode. The battery running mode is switched to the battery running mode when the remaining battery capacity detected by the battery remaining capacity detecting means is higher than a second predetermined value set to a value higher than the first predetermined value. Including a switching control unit and configured to execute the exhaust heat increase control during the charging travel mode,
In addition to operating the electric heater during execution of the exhaust heat increase control, the electric heater control unit determines whether the remaining battery capacity detected by the battery remaining capacity detecting means in the battery running mode is the first The electric heater is configured to operate when the condition is satisfied when the value is lower than a third predetermined value that is higher than one predetermined value and lower than the second predetermined value. A control device for a gaseous fuel engine. A control device for a gaseous fuel engine mounted on a vehicle,
A fuel tank for storing gaseous fuel as engine fuel;
Pressure detecting means for detecting the pressure in the fuel tank;
Temperature detecting means for detecting the temperature in the fuel tank;
Control means for controlling the operation of the engine,
When the condition that the pressure in the fuel tank by the pressure detecting means is equal to or lower than a predetermined pressure and the temperature in the fuel tank by the temperature detecting means is equal to or lower than a predetermined temperature is satisfied, By performing exhaust heat increase control for increasing exhaust heat, the fuel tank is configured to be heated by an exhaust flow passing through the vicinity of the fuel tank,
The vehicle is a hybrid vehicle having a generator that is driven by the engine to generate electric power, a battery that charges electric power generated by the generator, and a drive motor for driving the vehicle that can be driven by the discharged electric power of the battery. ,
The exhaust heat increase control is a control to increase the output of the engine,
The control means includes a charge control unit that controls charging of the battery with power generated by the generator,
The charge control unit is configured to charge the battery with the increased amount of power generated by the generator, which is increased by an increase in the output of the engine by the exhaust heat increase control. Control device for gaseous fuel engine. The control device for a gaseous fuel engine according to claim 3 ,
The vehicle is a series hybrid vehicle in which the drive motor is driven by at least one of the electric power discharged from the battery and the electric power generated by the generator.
The engine uses a first fuel and a second fuel having different calorific values per unit volume as the gaseous fuel,
The fuel tank includes a first fuel tank that stores the first fuel, and a second fuel tank that stores the second fuel,
The pressure detecting means is configured to detect pressures in the first fuel tank and the second fuel tank, respectively.
The temperature detecting means is configured to detect temperatures in the first fuel tank and the second fuel tank, respectively.
The control means executes the exhaust heat increase control when the above conditions are satisfied with respect to the pressure and temperature in the first fuel tank, thereby performing the exhaust flow through the vicinity of the first fuel tank. When the fuel tank is heated and the above conditions are satisfied with respect to the pressure and temperature of the second fuel tank, exhaust heat passing through the vicinity of the second fuel tank is performed by executing the exhaust heat increase control. Configured to heat the second fuel tank by a flow;
Further, the control means supplies the first and second fuels to the engine at a predetermined ratio at the time of engine steady operation in which the engine is operated at a predetermined rotation speed, and at the time of executing the exhaust heat increase control, A control device for a gaseous fuel engine, characterized in that, while operating the engine at the predetermined rotational speed, the supply ratio of the fuel having the higher calorific value is increased with respect to the predetermined ratio. . The control device for a gaseous fuel engine according to claim 3 ,
The vehicle is a series hybrid vehicle in which the drive motor is driven by at least one of the electric power discharged from the battery and the electric power generated by the generator.
The engine uses a first fuel and a second fuel as the gaseous fuel,
The fuel tank includes a first fuel tank that stores the first fuel, and a second fuel tank that stores the second fuel,
The pressure detecting means is configured to detect pressures in the first fuel tank and the second fuel tank, respectively.
The temperature detecting means is configured to detect temperatures in the first fuel tank and the second fuel tank, respectively.
Further comprising remaining amount detecting means for detecting the remaining amounts of the first fuel and the second fuel,
The control means executes the exhaust heat increase control when the above conditions are satisfied with respect to the pressure and temperature in the first fuel tank, thereby performing the exhaust flow through the vicinity of the first fuel tank. When one fuel tank is heated and the above conditions are satisfied with respect to the pressure and temperature in the second fuel tank, the exhaust heat increase control is executed to pass the vicinity of the second fuel tank. The second fuel tank is configured to be heated by the exhaust flow,
Further, the control means supplies the first and second fuels to the engine at a predetermined ratio and operates at a predetermined combustion air-fuel ratio in the combustion chamber of the engine when the engine is operated at a predetermined rotational speed. When the exhaust gas heat increase control is executed, the fuel supply amount of the fuel with the larger remaining amount detected by the remaining amount detecting means is set while the engine is operated at the predetermined rotational speed. A control device for a gaseous fuel engine, wherein the control device is configured to increase the amount of fuel during steady operation. The control device for a gaseous fuel engine according to claim 3 ,
The vehicle is a series hybrid vehicle in which the drive motor is driven by at least one of the electric power discharged from the battery and the electric power generated by the generator.
The engine uses, as the gaseous fuel, a first fuel and a second fuel having a low ignitability and a high calorific value per unit volume with respect to the first fuel,
The fuel tank includes a first fuel tank that stores the first fuel, and a second fuel tank that stores the second fuel,
The pressure detecting means is configured to detect pressures in the first fuel tank and the second fuel tank, respectively.
The temperature detecting means is configured to detect temperatures in the first fuel tank and the second fuel tank, respectively.
The control means executes the exhaust heat increase control when the above conditions are satisfied with respect to the pressure and temperature in the first fuel tank, thereby causing the exhaust flow to pass through the vicinity of the first fuel tank. Configured to heat the first fuel tank;
Further, the control means supplies the first and second fuels to the engine at a predetermined ratio at the time of engine steady operation in which the engine is operated at a predetermined rotation speed, and at the time of executing the exhaust heat increase control, A control device for a gaseous fuel engine, wherein the second fuel supply rate is increased with respect to the predetermined ratio while the engine is operated at the predetermined rotation speed. In the control apparatus of the gaseous fuel engine as described in any one of Claims 1-6 ,
The engine has, as an exhaust path through which the exhaust flow flows, a proximity path that passes through the vicinity of the fuel tank and a remote path that passes through a position farther from the fuel tank than the proximity path,
An exhaust path switching device that switches the exhaust path between the proximity path and the remote path;
The control means includes a switching device control unit that controls the operation of the exhaust path switching device,
The switching device control unit is configured to switch the exhaust path to the proximity path when the exhaust heat increase control is executed, and to switch the exhaust path to the remote path when the exhaust heat increase control is not executed. A control device for a gaseous fuel engine.

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