JP5447019B2 - Working gas circulation engine - Google Patents

Description

  The present invention relates to a working gas circulation engine.

  As a conventional engine, a working gas circulation type engine as a so-called closed cycle engine is known in which working gas is circulated from the exhaust side to the intake side of the combustion chamber and can be supplied to the combustion chamber again. As such a conventional working gas circulation engine, for example, Patent Document 1 discloses an internal combustion engine that burns hydrogen as a fuel in a combustion chamber and uses an inert gas as a working gas. This internal combustion engine removes water vapor as a product contained in the gas discharged from the combustion chamber by a moisture removing device, and recirculates the inert gas from which the water vapor has been removed to the combustion chamber through a circulation path and removes it. The inert gas molecules dissolved in the water are returned to the gaseous state by the degassing device and again supplied to the combustion chamber.

JP 2007-064092 A

  Incidentally, in the internal combustion engine described in Patent Document 1 as described above, it is desired that the temperature of gas exhausted from the combustion chamber is adjusted to a more appropriate temperature, for example, during the engine warm-up process. It was.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a working gas circulation engine capable of adjusting the temperature of gas exhausted from a combustion chamber to an appropriate temperature.

  In order to achieve the above object, a working gas circulation engine according to the present invention is provided with a combustion chamber in which a working gas having a higher specific heat ratio than fuel and air is supplied and the working gas can expand as the fuel burns. An engine body, a circulation path in which a gas containing the working gas is circulated from the exhaust side to the intake side of the combustion chamber and can be supplied to the combustion chamber again, and is provided in the circulation path and supplied to the combustion chamber An adjustment mechanism capable of adjusting the amount of the working gas, and at the time of warm-up operation for warming up the engine body, the control mechanism is controlled, and compared with the time of normal operation after the end of the warm-up, And a control device that performs warm-up control for reducing the amount of the working gas supplied to the combustion chamber.

  The working gas circulation engine includes a cooling medium circulation path that circulates a cooling medium between the engine body and a cooling device that is provided in the circulation path and cools the circulating gas. The amount of the working gas supplied to the combustion chamber can be reduced as the temperature of the cooling medium is lower.

  In the working gas circulation engine, the control device may adjust the amount of the working gas supplied to the combustion chamber based on the temperature of the gas exhausted from the combustion chamber.

  In the working gas circulation engine, the control device adjusts the amount of the working gas supplied to the combustion chamber so that the temperature of the gas exhausted from the combustion chamber does not exceed an upper limit temperature. It can be.

  In the working gas circulation engine, the adjustment mechanism may include a variable throttle mechanism that makes a passage sectional area of the circulation path variable.

  In the working gas circulation engine, the variable throttle mechanism is supplied with the fuel or an oxidant that burns the fuel with reference to the combustion chamber with respect to a circulation direction of the circulating gas in the circulation path. It can be provided upstream of the supply position.

  In the working gas circulation engine, the adjusting mechanism may include a valve operating mechanism capable of adjusting an opening / closing operation of an intake valve capable of opening / closing an intake port communicating with the combustion chamber.

  The working gas circulation engine according to the present invention controls the adjusting mechanism during the warm-up operation in which the control device warms up the engine body, and in the combustion chamber as compared with the normal operation after the warm-up ends. Since the warm-up control for reducing the amount of the working gas supplied is executed, the temperature of the gas exhausted from the combustion chamber can be adjusted to an appropriate temperature.

FIG. 1 is a schematic configuration diagram of an engine according to the first embodiment. FIG. 2 is a diagram illustrating engine warm-up control according to the first embodiment. FIG. 3 is a diagram illustrating engine warm-up control according to the second embodiment. FIG. 4 is a flowchart illustrating an example of control in the engine according to the second embodiment. FIG. 5 is an example of a control map in the engine according to the second embodiment. FIG. 6 is a schematic configuration diagram of an engine according to the third embodiment. FIG. 7 is a flowchart illustrating an example of control in the engine according to the third embodiment. FIG. 8 is an example of a control map in the engine according to the third embodiment. FIG. 9 is a flowchart illustrating an example of control in the engine according to the fourth embodiment. FIG. 10 is a schematic schematic configuration diagram of an engine according to the fifth embodiment. FIG. 11 is a schematic configuration diagram of an engine according to the sixth embodiment. FIG. 12 is a flowchart illustrating an example of control in the engine according to the sixth embodiment.

  Hereinafter, an embodiment of a working gas circulation engine according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram of an engine according to the first embodiment, and FIG. 2 is a diagram for explaining warm-up control of the engine according to the first embodiment.

  An engine 1 as a working gas circulation engine of the present embodiment shown in FIG. 1 is supplied with an oxidant, fuel, and working gas in a combustion chamber 11 of an engine body 10, and the combustion chamber 11 accompanies combustion of fuel. The working gas expands to generate power. The engine 1 circulates the working gas from the exhaust side of the combustion chamber 11 to the intake side via a circulation path 20 that connects the intake side and the exhaust side of the combustion chamber 11 and basically releases it to the atmosphere. This is a so-called closed cycle engine that can be supplied to the combustion chamber 11 again without being performed. The combustion chamber 11 and the circulation path 20 are both filled with working gas, and the working gas circulates between the combustion chamber 11 and the circulation path 20.

Here, the oxidant used in the engine 1 is oxygen (O ₂ ), and the fuel is hydrogen (H ₂ ). Further, the working gas used in the engine 1 has a specific heat ratio higher than that of air, and here is a monoatomic gas, argon (Ar). Argon expands in the combustion chamber 11 due to reaction heat generated by the reaction between oxygen and hydrogen, that is, combustion heat generated by hydrogen combustion (exothermic reaction). That is, the engine 1 burns hydrogen in the combustion chamber 11 and thermally expands argon as the hydrogen burns to generate power, thereby improving thermal efficiency.

  Specifically, as shown in FIG. 1, the engine 1 includes an engine body 10 provided with a combustion chamber 11 in which oxygen and hydrogen react, and a circulation path 20 that connects an exhaust side and an intake side of the combustion chamber 11. And an oxygen supply device 30 for supplying oxygen, a hydrogen supply device 40 for supplying hydrogen, a condenser 50, and an electronic control device 60 as a control device.

The engine body 10 is configured to include a combustion chamber 11 to which oxygen, hydrogen, and argon are supplied and in which argon can expand as hydrogen is burned. The combustion chamber 11 can exhaust argon and water vapor (H ₂ O) as a combustion product after the combustion of hydrogen. The engine body 10 has a plurality of combustion chambers 11 (cylinders) (not shown). The circulation path 20 is configured to circulate a circulating gas containing argon from the exhaust side to the intake side of the combustion chamber 11 and supply it to the combustion chamber 11 again. The circulation path 20 includes an intake port 12 and an exhaust port 13 formed in the cylinder head and communicating with the combustion chamber 11, and various pipes. The circulation path 20 connects the intake port 12 and the exhaust port 13 outside the combustion chamber 11. It comprises a passage 21 and basically forms a circulatory system that is sealed against the outside air as a whole. The circulation path 20 is provided with a condenser 50 as a removal device that removes water vapor, which is a product generated by combustion from the circulation gas.

  Here, the circulating gas is a gas that is circulated from the exhaust side to the intake side of the combustion chamber 11 via the circulation path 20, and in addition to argon as a working gas, the combustion chamber after combustion of hydrogen in the combustion chamber 11. 11 and the like which include exhaust gas exhausted from the exhaust gas. Here, the exhaust gas includes, for example, surplus oxygen remaining after the combustion of hydrogen in the combustion chamber 11, surplus gas composed of hydrogen, water vapor as a product generated by the combustion of hydrogen, and the like. . That is, the circulating gas here includes argon as working gas, surplus oxygen after combustion, surplus gas composed of hydrogen, etc., water vapor, and the like.

  The oxygen supply device 30 supplies high-pressure oxygen by injecting it into the circulation path 20 and supplies it to the combustion chamber 11 together with a circulation gas containing argon or the like. The hydrogen supply device 40 directly injects high-pressure hydrogen into the combustion chamber 11 and supplies it.

  The condenser 50 is provided in the circulation path 20 and removes most of the water vapor from the circulation gas circulating in the circulation path 20. The condenser 50 of the present embodiment includes a first condenser 50A as a cooling device provided on the upstream side with respect to the circulation direction of the circulating gas in the circulation path 20, and a first condenser provided on the downstream side. 2 condenser 50B. That is, the condenser 50 is provided with the first condenser 50A on the exhaust side of the combustion chamber 11 in the circulation path 20 and the second condenser 50B on the intake side. Here, the first condenser 50A and the second condenser 50B are connected to different cooling medium circulation systems different from each other.

  That is, the engine 1 includes a cooling water circulation path 51A as a cooling medium circulation path and a cooling water circulation path 51B. The cooling water circulation path 51A is connected to the first condenser 50A, the cooling water circulation path 51B is connected to the second condenser 50B, and the cooling water circulation path 51A and the cooling water circulation path 51B are independent from each other. It has become a route. Here, the cooling water circulation path 51 </ b> A serves as a cooling medium circulation system for the first condenser 50 </ b> A and also serves as a cooling medium circulation system for cooling the engine body 10. That is, the cooling water circulation path 51A circulates cooling water as a cooling medium between the engine body 10 and the first condenser 50A.

  More specifically, in the engine body 10, the cooling water pump 52A provided in the cooling water circulation path 51A is driven, so that the cooling water as the cooling medium cooled by the radiator 53A passes through the cooling water circulation path 51A. Supplied inside. The engine body 10 is cooled by circulating cooling water through a water jacket provided in the cylinder head or the cylinder block.

  In the first condenser 50A, the cooling water that has passed through the engine body 10 is supplied to the inside through the cooling water circulation path 51A. The first condenser 50A cools the circulating gas by exchanging heat between the cooling water and the circulating gas. Then, the circulating gas containing argon cooled by the first condenser 50A circulates in the circulation path 20 as it is and is introduced into the second condenser 50B at the subsequent stage.

  On the other hand, in the second condenser 50B, the cooling water pump 52B provided in the cooling water circulation path 51B is driven, so that the cooling water as the cooling medium cooled by the radiator 53B passes through the cooling water circulation path 51B. Supplied. The second condenser 50B cools the circulating gas by exchanging heat between the cooling water and the circulating gas, and liquefies and condenses the water vapor contained in the circulating gas into condensed water. Separate water vapor. Then, the circulating gas containing argon from which the water vapor has been separated by the second condenser 50B circulates in the circulation path 20 as it is, and the condensed water condensed by the first condenser 50A and the second condenser 50B is discharged from the discharge valve 54. And is discharged out of the circulation system of the circulation path 20.

  Here, the engine 1 is provided with a thermostat 55 configured in various well-known formats in a cooling water circulation path 51A that is a cooling medium circulation system for the first condenser 50A. The thermostat 55 switches the path through which the cooling water flows according to the temperature of the cooling water after passing through the condenser 50A. The thermostat 55 circulates the cooling water in a path that bypasses the radiator 53A in the cooling water circulation path 51A during the warm-up operation of the engine 1 in which the temperature of the cooling water is relatively low. As a result, the engine 1 is promoted to rise in temperature of the cooling water and to be warmed up. On the other hand, the thermostat 55 circulates the cooling water through a path passing through the radiator 53A in the cooling water circulation path 51A during normal operation after the warm-up of the engine 1 having a relatively high cooling water temperature. Thereby, the engine 1 appropriately cools the cooling water circulating through the cooling water circulation path 51A.

  The warm-up operation of the engine 1 is an operation state that promotes warm-up of the engine 1. Typically, cooling water for cooling the engine body 10 such as immediately after the engine 1 is started is set in advance. Is below the warm-up temperature, that is, when the engine 1 is cold. When the cooling water for cooling the engine body 10 becomes higher than a preset warm-up temperature, the engine 1 ends the warm-up operation and shifts to a normal warm operation.

  The electronic control device 60 is an electronic circuit mainly composed of a known microcomputer including a CPU, a ROM, a RAM, and an interface. The electronic control device 60 receives electrical signals corresponding to detection results detected by various sensors such as an accelerator opening sensor 61 that detects the accelerator opening and a crank angle sensor 62 that detects the crank angle. Here, the accelerator opening corresponds to the amount of operation of an accelerator pedal (not shown) provided at the driver's seat of the vehicle, and more specifically, the required engine load (required load factor) requested by the driver to the engine 1. ). The crank angle corresponds to the rotation angle of a crankshaft connected to the piston 16 via a connecting rod. For example, the electronic control unit 60 discriminates the intake stroke, compression stroke, expansion stroke, and exhaust stroke in each cylinder based on the crank angle detected by the crank angle sensor 62, and uses the engine speed (rpm) as the rotational speed of the engine 1. ) Is calculated. The electronic control unit 60 outputs drive signals to various parts of the engine 1 such as the oxygen supply unit 30, the hydrogen supply unit 40, the cooling water pumps 52 </ b> A and 52 </ b> B, the discharge valve 54, and the thermostat 55 according to the input detection results. Control the drive.

  The engine 1 configured as described above is exemplified as one that diffuses and burns hydrogen. In the engine 1, when the intake valve 14 provided in the intake port 12 is opened, the circulating gas circulating in the circulation path 20 is sucked (supplied) into the combustion chamber 11 together with oxygen from the oxygen supply device 30. The engine 1 injects high-pressure hydrogen from the hydrogen supply device 40 into a high-temperature compressed gas (oxygen and argon) formed in the combustion chamber 11 in accordance with the operation of the piston 16, thereby partially Ignites and burns while hydrogen and compressed gas (oxygen) are diffusely mixed. As a result, in the engine 1, steam is generated in the combustion chamber 11, and argon having a large specific heat ratio causes thermal expansion. As a result, the engine 1 can generate mechanical power by the piston 16 being pushed down by the combustion of hydrogen and the thermal expansion of argon, and the crankshaft rotating. When the exhaust valve 15 provided at the exhaust port 13 is opened, the engine 1 exhausts (exhausts) the exhaust gas after combustion of hydrogen from the combustion chamber 11 to the exhaust port 13 together with argon. And argon circulate through the circulation path 20 as a circulation gas and are again sucked into the combustion chamber 11. During this time, in the engine 1, most of the water vapor in the circulating gas is liquefied and condensed by the condenser 50 and separated. As a result, the engine 1 is not supplied with water vapor having a small specific heat ratio to the combustion chamber 11, and is again supplied with argon having a large specific heat ratio to the combustion chamber 11, so that the engine 1 can be operated with high thermal efficiency.

  During this time, the electronic control unit 60 determines the current engine load, engine speed, etc. based on the accelerator opening detected by the accelerator opening sensor 61, the crank angle detected by the crank angle sensor 62, etc. Oxygen and hydrogen supply amount (injection amount) and supply timing (injection timing) by the oxygen supply device 30 and the hydrogen supply device 40 so that the driving force (engine output) required by the driver can be obtained at the engine speed. ) To control. The electronic control device 60 basically has, for example, a supply amount map stored in advance in the storage unit in accordance with the driving state such as the accelerator opening and the engine speed corresponding to the amount of operation of the accelerator pedal by the driver. The supply amount and supply timing of hydrogen and oxygen that can obtain the required torque required at the current engine speed are determined from (not shown), and each part is controlled based on this.

  In addition, although this engine 1 was illustrated as a structure of the in-cylinder direct-injection self-ignition diffusion combustion type in which hydrogen is directly injected into the combustion chamber 11 to self-ignite and diffusely burn, it is not limited thereto. For example, the engine 1 may include a spark plug as an ignition device capable of igniting hydrogen supplied to the combustion chamber 11, and the spark plug may ignite hydrogen in the combustion chamber 11. Alternatively, a configuration may be adopted in which hydrogen is ignited with a spark plug to assist hydrogen self-ignition and diffuse combustion. Further, the engine 1 has, for example, an intake premixing configuration in which hydrogen is injected and supplied into the circulation path 20, here into the intake port 12, and supplied to the combustion chamber 11 together with a circulation gas containing argon or the like. Also good. The engine 1 may have a configuration in which oxygen is directly injected into the combustion chamber 11. Further, the engine 1 may have a so-called lean combustion type configuration.

  By the way, if it is assumed that the amount of argon supplied to the combustion chamber 11 is always constant, the engine 1 has a relatively high specific heat ratio with respect to the amount of argon having a relatively high specific heat ratio during a warm-up process or a light load. Since the amount of heat generated by the combustion of hydrogen is relatively small, the temperature of the gas exhausted from the combustion chamber 11 may be relatively lowered. This is because the argon circulation type engine 1 with high thermal efficiency has little exhaust loss, and the ratio of oxygen and hydrogen with respect to the amount of argon supplied to the combustion chamber 11 during the warm-up process or light load is high. This is because there is a possibility that it may become extremely low. When the cooling water circulation path 51A for circulating the cooling water is shared by the engine main body 10 and the first condenser 50A as described above, the temperature of the gas exhausted from the combustion chamber 11 is relatively low. If it decreases, for example, the temperature rise effect of the cooling water in the first condenser 50A by the gas exhausted from the combustion chamber 11 is reduced, and the completion of warming up of the engine 1 may be delayed.

  Therefore, the engine 1 according to the present embodiment executes the warm-up control in which the electronic control device 60 reduces the supply amount of argon (working gas) supplied to the combustion chamber 11 under a predetermined condition, so that the combustion chamber The temperature of the gas exhausted from 11 is adjusted to an appropriate temperature.

  Specifically, the engine 1 includes an adjustment mechanism 70, and the electronic control device 60 performs the warm-up control by controlling the adjustment mechanism 70 according to the operating state.

  The adjustment mechanism 70 is provided in the circulation path 20 and can adjust the amount of argon supplied to the combustion chamber 11, and has a variable throttle mechanism 71 here. The variable throttle mechanism 71 changes the cross-sectional area of the circulation path 20 and is electrically connected to the electronic control unit 60 to control its drive.

  The variable throttle mechanism 71 is located downstream of the supply position where hydrogen or oxygen is supplied, here the oxygen supply position where oxygen is supplied, with respect to the circulation direction of the circulating gas in the circulation path 20 with reference to the combustion chamber 11. Provided. The variable throttle mechanism 71 is provided between the oxygen supply position and the intake side of the combustion chamber 11.

  The variable throttle mechanism 71 adjusts the throttle amount of the passage between the oxygen supply position and the intake side of the combustion chamber 11 by driving a variable throttle valve provided in the circulation path 20, in other words, the circulation path 20. The amount of argon supplied to the combustion chamber 11 can be adjusted by adjusting the passage opening degree (passage cross-sectional area through which a fluid such as argon can pass). That is, the variable throttle mechanism 71 can reduce the amount of argon supplied to the combustion chamber 11 by relatively increasing the throttle amount and relatively reducing the passage opening degree of the circulation path 20. On the other hand, the variable throttle mechanism 71 can increase the amount of argon supplied to the combustion chamber 11 by relatively reducing the throttle amount and relatively increasing the passage opening degree of the circulation path 20.

  Then, as illustrated in FIG. 2, the electronic control unit 60 controls the adjustment mechanism 70 during the warm-up operation for warming up the engine body 10, and compared with the normal operation after the warm-up ends. Then, warm-up control for reducing the amount of argon supplied to the combustion chamber 11 is executed. FIG. 2 shows the ratio of the supply amounts of hydrogen, oxygen, and argon in the combustion chamber 11 when the warm-up control is performed in the warm-up process, and the combustion chamber 11 in the normal operation after the warm-up is completed. The ratio of the supply amounts of hydrogen, oxygen, and argon is schematically shown. FIG. 2 compares the case where the engine loads are equal, that is, the case where the supply amounts of oxygen and hydrogen into the combustion chamber 11 are equal.

  During the warm-up operation of the engine 1, the electronic control device 60 typically has a cooling water temperature equal to or lower than a preset warm-up temperature, and the cooling water is routed by the thermostat 55 bypassing the radiator 53A in the cooling water circulation path 51A. In the operation state in which the engine is circulated, the variable throttle mechanism 71 is controlled so that the throttle amount is relatively large and the passage opening degree of the circulation path 20 is relatively small. The amount of argon supplied is relatively reduced.

  Therefore, the engine 1 performs warm-up control that relatively reduces the amount of argon supplied to the combustion chamber 11 in the warm-up process or the like, so that the amount of heat generated by the combustion of hydrogen in the combustion chamber 11 is reduced. On the other hand, it is possible to suppress the amount of argon supplied to the combustion chamber 11 from being excessively increased. In other words, the ratio of oxygen and hydrogen to the amount of argon supplied to the combustion chamber 11 is significantly reduced. This can be suppressed. Thereby, the engine 1 can suppress the temperature of the gas exhausted from the combustion chamber 11 from being lowered. In other words, the engine 1 is combusted even if the amount of heat generated by the combustion of hydrogen in the combustion chamber 11 is equal. The temperature of the gas exhausted from the chamber 11 can be made relatively high. Therefore, the engine 1 can adjust the temperature of the gas exhausted from the combustion chamber 11 to an appropriate temperature, for example, can be adjusted to a suitable temperature according to the operating state.

  As a result, the engine 1 uses the gas exhausted from the combustion chamber 11 even when the cooling water circulation path 51A for circulating the cooling water is shared by the engine body 10 and the first condenser 50A as described above. It can suppress that the temperature rising effect of the cooling water in 50 A of 1st condensers falls. That is, the engine 1 can quickly raise the temperature of the cooling water, can improve the engine warm-up performance, and can complete the warm-up early.

  According to the engine 1 according to the embodiment of the present invention described above, an engine main body provided with a combustion chamber 11 in which hydrogen and argon having a higher specific heat ratio than air are supplied and in which argon can expand as the hydrogen burns. 10, a circulation path 20 in which a gas containing argon is circulated from the exhaust side to the intake side of the combustion chamber 11 and can be supplied again to the combustion chamber 11, and the amount of argon provided in the circulation path 20 and supplied to the combustion chamber 11 When the warming-up operation for warming up the engine main body 10 is controlled, the control mechanism 70 is controlled and supplied to the combustion chamber 11 as compared with the normal operation after the warm-up ends. And an electronic control unit 60 that performs warm-up control for reducing the amount of argon to be generated. Therefore, for example, the engine 1 can relatively increase the temperature of the gas exhausted from the combustion chamber 11 and can adjust the temperature of the gas exhausted from the combustion chamber 11 to an appropriate temperature.

[Embodiment 2]
FIG. 3 is a diagram for explaining warm-up control of the engine according to the second embodiment, FIG. 4 is a flowchart for explaining an example of control in the engine according to the second embodiment, and FIG. 5 is in the engine according to the second embodiment. It is an example of a control map. The working gas circulation engine according to the second embodiment is different from the working gas circulation engine according to the first embodiment in that the amount of the working gas is adjusted based on the temperature of the cooling water. In addition, about the structure, effect | action, and effect which are common in embodiment mentioned above, while overlapping description is abbreviate | omitted as much as possible, the same code | symbol is attached | subjected (the following embodiment is also the same).

  As illustrated in FIG. 3, the electronic control device 60 of the engine 201 as the working gas circulation engine of the present embodiment adjusts the temperature of the cooling water that cools the engine body 10 in the warm-up control during the warm-up operation. Based on this, the adjustment mechanism 70 is controlled to adjust the amount of argon supplied to the combustion chamber 11. Thereby, the engine 201 can adjust the temperature of the gas exhausted from the combustion chamber 11 to an appropriate temperature more efficiently, and can raise the temperature of the cooling water more efficiently, for example.

  Here, the cooling water that cools the engine main body 10 is the cooling water that circulates in the cooling water circulation path 51A described above. The electronic control device 60 controls the adjustment mechanism 70 based on the coolant temperature detection means, for example, the coolant temperature in the coolant circulation path 51 </ b> A detected by the temperature detector of the thermostat 55.

  Specifically, the electronic control unit 60 controls the variable throttle mechanism 71 to relatively increase the throttle amount and relatively reduce the passage opening degree of the circulation path 20 as the detected coolant temperature decreases. By doing so, the amount of argon supplied to the combustion chamber 11 is reduced. On the other hand, the electronic control unit 60 controls the variable throttle mechanism 71 to relatively reduce the throttle amount and relatively increase the passage opening of the circulation path 20 as the detected coolant temperature increases. The amount of argon supplied to the combustion chamber 11 is increased. As a result, the engine 201 increases the temperature of the gas exhausted from the combustion chamber 11 because the amount of argon supplied to the combustion chamber 11 decreases as the temperature of the cooling water that cools the engine body 10 decreases. For example, the temperature of the cooling water can be raised more quickly, the engine warm-up performance can be further improved, and the warm-up can be completed earlier.

  Next, an example of control in the engine 201 will be described with reference to the flowchart of FIG. Note that these control routines are repeatedly executed at a control cycle of several ms to several tens of ms.

  First, the electronic control unit 60 acquires, for example, the coolant temperature (engine coolant temperature) in the coolant circulation path 51A detected by the temperature detector of the thermostat 55 (ST21).

  Next, the electronic control unit 60 determines the amount of argon to be supplied to the combustion chamber 11 based on the coolant temperature acquired in ST21 (ST22), and adjusts the adjusting mechanism 70 based on the determined supply amount of argon. Control, end the current control cycle, and shift to the next control cycle.

  Here, the electronic control unit 60 obtains the amount of argon supplied to the combustion chamber 11 based on, for example, the control map illustrated in FIG. In this control map, the horizontal axis represents the cooling water temperature, and the vertical axis represents the argon amount. The control map describes the relationship between the cooling water temperature and the argon amount. In this control map, the argon amount increases as the cooling water temperature increases. The control map is stored in the storage unit of the electronic control unit 60 after the relationship between the cooling water temperature and the argon amount is set in advance. In ST22, the electronic control unit 60 obtains the amount of argon supplied to the combustion chamber 11 from the coolant temperature acquired in ST21 based on the control map of FIG. In the present embodiment, the electronic control unit 60 calculates the argon amount using the control map illustrated in FIG. 5, but the present embodiment is not limited to this. For example, the electronic control unit 60 may obtain the argon amount based on a mathematical expression corresponding to the control map illustrated in FIG. 5 (the same applies to the following description).

  According to the engine 201 according to the embodiment of the present invention described above, cooling is performed to the engine body 10 and the condenser 50 that is provided in the circulation path 20 and removes water vapor generated by hydrogen combustion from the circulating gas. A cooling water circulation path 51A for circulating water is provided, and the electronic control unit 60 reduces the amount of argon supplied to the combustion chamber 11 as the temperature of the cooling water is lower. Therefore, the engine 201 can increase the temperature of the gas exhausted from the combustion chamber 11 as the temperature of the cooling water that cools the engine body 10 is lower. For example, the temperature of the cooling water can be increased more quickly. it can.

[Embodiment 3]
6 is a schematic schematic configuration diagram of an engine according to the third embodiment, FIG. 7 is a flowchart illustrating an example of control in the engine according to the third embodiment, and FIG. 8 is a control map in the engine according to the third embodiment. It is an example. The working gas circulation engine according to the third embodiment is different from the working gas circulation engine according to the first embodiment in that the amount of the working gas is adjusted based on the temperature of the gas exhausted from the combustion chamber.

  The electronic control device 60 of the engine 301 as the working gas circulation engine of the present embodiment shown in FIG. 6 adjusts based on the temperature of the gas exhausted from the combustion chamber 11 in the warm-up control during the warm-up operation. The mechanism 70 is controlled to adjust the amount of argon supplied to the combustion chamber 11. Thereby, the engine 301 can adjust the temperature of the gas exhausted from the combustion chamber 11 to an appropriate temperature with higher accuracy. For example, the amount of argon supplied to the combustion chamber 11 is reduced too much, and the combustion chamber 11 It is possible to reliably prevent the temperature of the gas exhausted from becoming too high. Here, the electronic control unit 60 controls the adjusting mechanism 70 based on the temperature of the gas detected by the exhaust temperature detecting means, for example, the exhaust temperature sensor 362 provided near the exhaust port 13 of the circulation path 20.

  Specifically, the electronic control unit 60 controls the variable throttle mechanism 71 to relatively increase the throttle amount as the temperature of the gas exhausted from the combustion chamber 11 to be detected is lower, thereby opening the passage of the circulation path 20. By reducing the degree relatively, the amount of argon supplied to the combustion chamber 11 is reduced. On the other hand, as the temperature of the gas exhausted from the combustion chamber 11 detected is higher, the electronic control unit 60 controls the variable throttle mechanism 71 to reduce the throttle amount relatively, and the passage opening degree of the circulation path 20 is relatively set. Therefore, the amount of argon supplied to the combustion chamber 11 is increased. As a result, the engine 301 increases the amount of argon supplied to the combustion chamber 11 as the temperature of the gas exhausted from the combustion chamber 11 increases. For example, it is possible to prevent the heat load from becoming too high.

  Next, an example of control in the engine 301 will be described with reference to the flowchart of FIG.

  First, the electronic control unit 60 acquires, for example, the temperature (exhaust temperature) of the gas exhausted from the combustion chamber 11 detected by the exhaust temperature sensor 362 (ST31).

  Next, the electronic control unit 60 determines the amount of argon supplied to the combustion chamber 11 based on the exhaust gas temperature acquired in ST31 (ST32), and controls the adjusting mechanism 70 based on the determined supply amount of argon. The current control cycle is terminated, and the next control cycle is started.

  Here, the electronic control unit 60 determines the amount of argon supplied to the combustion chamber 11 based on, for example, the control map illustrated in FIG. In this control map, the horizontal axis indicates the exhaust temperature, and the vertical axis indicates the argon amount. The control map describes the relationship between the exhaust temperature and the argon amount. In this control map, the amount of argon increases as the exhaust temperature increases. The control map is stored in the storage unit of the electronic control unit 60 after the relationship between the exhaust temperature and the argon amount is set in advance. In ST32, the electronic control unit 60 obtains the amount of argon supplied to the combustion chamber 11 from the exhaust temperature acquired in ST31, based on the control map of FIG.

  According to the engine 301 according to the embodiment of the present invention described above, the electronic control device 60 adjusts the amount of argon supplied to the combustion chamber 11 based on the temperature of the gas exhausted from the combustion chamber 11. Therefore, the engine 301 can adjust the temperature of the gas exhausted from the combustion chamber 11 to an appropriate temperature with higher accuracy.

[Embodiment 4]
FIG. 9 is a flowchart illustrating an example of control in the engine according to the fourth embodiment. The working gas circulation engine according to the fourth embodiment is different from the working gas circulation engine according to the third embodiment in that the amount of the working gas is adjusted so that the temperature of the gas exhausted from the combustion chamber does not exceed the upper limit temperature. Different.

  The electronic control device 60 of the engine 401 as the working gas circulation engine of this embodiment described in FIG. 9 is configured so that the temperature of the gas exhausted from the combustion chamber 11 has an upper limit temperature in the warm-up control during the warm-up operation. The amount of argon supplied to the combustion chamber 11 is adjusted so as not to exceed.

  An example of control in the engine 401 will be described with reference to the flowchart of FIG.

  First, the electronic control unit 60 acquires, for example, the temperature (exhaust temperature) of the gas exhausted from the combustion chamber 11 detected by the exhaust temperature sensor 362 (ST41).

  Next, electronic control unit 60 determines whether or not the exhaust temperature acquired in ST41 is smaller than a predetermined value set in advance (ST42). Here, the predetermined value is set in advance according to the upper limit temperature of the exhaust temperature allowed by the engine 401, and is set as appropriate according to, for example, the strength and specifications of the engine 401.

  If the electronic control unit 60 determines that the exhaust temperature is smaller than a predetermined value set in advance (ST42: Yes), the electronic control unit 60 controls the variable throttle mechanism 71 to relatively increase the throttle amount, and the passage opening degree of the circulation path 20 Is reduced relatively, the amount of argon supplied to the combustion chamber 11 is reduced (ST43), the current control cycle is terminated, and the next control cycle is started. Thereby, the engine 401 can raise the temperature of the gas exhausted from the combustion chamber 11.

  When the electronic control unit 60 determines that the exhaust gas temperature is equal to or higher than a predetermined value set in advance (ST42: No), the electronic control unit 60 controls the variable throttle mechanism 71 to relatively reduce the throttle amount and open the passage of the circulation path 20. By increasing the degree relatively, the amount of argon supplied to the combustion chamber 11 is increased (ST44), the current control cycle is terminated, and the next control cycle is started. Thereby, the engine 401 can lower the temperature of the gas exhausted from the combustion chamber 11.

  Therefore, the engine 401 can maintain the temperature of the gas exhausted from the combustion chamber 11 at a high temperature within an allowable range, so that the temperature of the cooling water can be increased more quickly. As a result, the engine 401 can maintain the temperature of the gas exhausted from the combustion chamber 11 as high as possible within a range not exceeding the upper limit temperature.

  According to the engine 401 according to the embodiment of the present invention described above, the electronic control unit 60 is configured to supply argon supplied to the combustion chamber 11 so that the temperature of the gas exhausted from the combustion chamber 11 does not exceed the upper limit temperature. Adjust the amount. Therefore, the engine 401 can achieve both prevention of excessive heat load and improvement of warm-up performance.

[Embodiment 5]
FIG. 10 is a schematic schematic configuration diagram of an engine according to the fifth embodiment. The working gas circulation engine according to the fifth embodiment is different from the working gas circulation engine according to the first embodiment in the position of the variable throttle mechanism.

  An engine 501 as a working gas circulation engine of this embodiment shown in FIG. 10 includes an adjustment mechanism 70, and the adjustment mechanism 70 has a variable throttle mechanism 71.

  Then, the variable throttle mechanism 71 of the present embodiment is configured to supply a supply position of hydrogen or oxygen with respect to the circulation direction of the circulating gas in the circulation path 20 with reference to the combustion chamber 11, here oxygen supplied oxygen. Provided upstream from the supply position. The variable throttle mechanism 71 is provided between the oxygen supply position and the exhaust side of the combustion chamber 11. The variable throttle mechanism 71 is supplied to the combustion chamber 11 by driving a variable throttle valve provided in the circulation path 20 and adjusting the throttle amount of the passage between the oxygen supply position and the exhaust side of the combustion chamber 11. The amount of argon can be adjusted.

  In this case, the engine 501 is provided with the variable throttle mechanism 71 upstream of the oxygen supply position with respect to the circulation direction with respect to the combustion chamber 11, so that the variable throttle mechanism 71 supplies the engine 501 to the combustion chamber 11. It is not necessary to adjust the amount of oxygen to be produced, and only the amount of argon supplied to the combustion chamber 11 can be adjusted. Thereby, the engine 501 can improve the controllability of the engine control, and can improve the responsiveness at the time of engine output transition, for example. In other words, the engine 501 does not change the amount of oxygen supplied to the combustion chamber 11 even if the amount of argon supplied to the combustion chamber 11 by the variable throttle mechanism 71 is changed. Only the amount of argon supplied to the chamber 11 can be easily adjusted, and the pressure in the combustion chamber 11 can be easily adjusted to a suitable pressure corresponding to the operating state within an allowable range.

  According to the engine 501 according to the embodiment of the present invention described above, the variable throttle mechanism 71 burns hydrogen or hydrogen with reference to the combustion chamber 11 with respect to the circulation direction of the gas circulated in the circulation path 20. It is provided upstream from the supply position where oxygen is supplied. Therefore, the engine 501 can improve the controllability of engine control.

[Embodiment 6]
FIG. 11 is a schematic configuration diagram of an engine according to the sixth embodiment, and FIG. 12 is a flowchart illustrating an example of control in the engine according to the sixth embodiment. The working gas circulation engine according to the sixth embodiment is different from the working gas circulation engine according to the first embodiment in the configuration of the adjusting mechanism.

  An engine 601 as a working gas circulation engine of this embodiment shown in FIG. 11 includes an adjustment mechanism 670, and the adjustment mechanism 670 includes a valve mechanism 672. The valve mechanism 672 is capable of adjusting the opening / closing operation of the intake valve 14 that can open and close the intake port 12 communicating with the combustion chamber 11. The valve operating mechanism 672 adjusts the amount of gas sucked into the combustion chamber 11 by changing the lift amount and opening / closing timing of the intake valve 14 provided in the intake port 12 and changing them continuously. The valve mechanism 672 reduces the amount of argon supplied to the combustion chamber 11 by relatively retarding the closing timing of the intake valve 14 or relatively reducing the lift amount of the intake valve 14. can do. When the engine 601 relatively delays the closing timing of the intake valve 14, for example, the intake valve 14 is closed in the middle of the piston 16 passing the bottom dead center toward the top dead center. Thus, the amount of argon supplied to the combustion chamber 11 can be reduced. On the other hand, the valve operating mechanism 672 advances the valve closing timing of the intake valve 14 relatively, or relatively increases the lift amount of the intake valve 14 to increase the amount of argon supplied to the combustion chamber 11. Can be increased. The valve mechanism 672 is electrically connected to the electronic control unit 60 or connected via a hydraulic control circuit or the like, and its drive is controlled.

  Next, an example of control in the engine 601 will be described with reference to the flowchart of FIG. In the following description, the case where the amount of argon supplied to the combustion chamber 11 is reduced and the temperature of the gas exhausted from the combustion chamber 11 is increased will be described, and the amount of argon supplied to the combustion chamber 11 is increased and combustion is performed. The description about the case where the temperature of the gas exhausted from the chamber 11 is lowered is omitted.

  The electronic control unit 60 determines whether or not to reduce the amount of argon supplied to the combustion chamber 11 as described above according to the detection values of various sensors of the engine 601 and the driving state of each part, in other words, the combustion chamber 11. It is determined whether or not the temperature of the gas exhausted from the chamber is increased (ST61).

  If it is determined that the amount of argon supplied to the combustion chamber 11 is to be reduced (ST61: Yes), the electronic control unit 60 controls the valve mechanism 672 to relatively retard the valve closing timing of the intake valve 14. Alternatively, the lift amount of the intake valve 14 is made relatively small, or both are performed to reduce the amount of argon supplied to the combustion chamber 11 (ST62), the current control cycle is terminated, and the next Transition to the control cycle. If it is determined that the amount of argon supplied to the combustion chamber 11 is not reduced (ST61: No), the electronic control unit 60 skips the process of ST62, ends the current control cycle, and shifts to the next control cycle. .

  In this case, the engine 601 can adjust the amount of argon supplied to the combustion chamber 11 by the valve operating mechanism 672 without including the variable throttle mechanism 71 described above. The engine 601 adjusts the amount of argon with high accuracy and responsiveness because the amount of argon supplied is adjusted by the opening and closing operation of the intake valve 14 disposed closer to the combustion chamber 11. For example, the controllability and responsiveness of engine control during transient operation can be further improved.

  According to the engine 601 according to the embodiment of the present invention described above, the adjustment mechanism 670 includes the valve mechanism 672 that can adjust the opening / closing operation of the intake valve 14 that can open and close the intake port 12 communicating with the combustion chamber 11. Have. Therefore, the engine 601 can further improve the controllability of engine control.

  The working gas circulation engine according to the above-described embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the claims. The working gas circulation engine according to the embodiment of the present invention may be configured by combining a plurality of the embodiments described above.

  The working gas circulation engine described above includes a cooling medium circulation path that circulates the cooling medium between the engine main body and a removal device that is provided in the circulation path and removes a product generated by combustion from the circulating gas. There may be no configuration.

  The working gas circulation engine described above has been described on the assumption that the oxidant is oxygen and the fuel is hydrogen. However, the working gas is not limited to this, and the working gas may be expanded as the fuel is burned in the combustion chamber. Anything is possible. The working gas described above is not limited to argon, but may be a rare gas such as helium (He) which is a monoatomic gas.

  As described above, the working gas circulation engine according to the present invention is suitable for application to various working gas circulation engines capable of circulating the working gas from the exhaust side to the intake side of the combustion chamber and supplying the working gas to the combustion chamber again. .

1,201,301,401,501,601 engine (working gas circulation engine)
DESCRIPTION OF SYMBOLS 10 Engine body 11 Combustion chamber 12 Intake port 13 Exhaust port 14 Intake valve 15 Exhaust valve 20 Circulation path 30 Oxygen supply device 40 Hydrogen supply device 50 Condenser 50A 1st condenser (cooling device)
51A Cooling water circulation path (cooling medium circulation path)
55 Thermostat 60 Electronic control device (control device)
70, 670 Adjustment mechanism 71 Variable throttle mechanism 362 Exhaust temperature sensor 672 Valve mechanism

Claims (7)

An engine body provided with a combustion chamber in which a working gas having a specific heat ratio higher than that of air and air is supplied and in which the working gas can expand as the fuel burns;
A circulation path through which the gas containing the working gas is circulated from the exhaust side to the intake side of the combustion chamber and can be supplied to the combustion chamber again;
An adjusting mechanism provided in the circulation path and capable of adjusting the amount of the working gas supplied to the combustion chamber;
During the warm-up operation for warming up the engine body, the control mechanism is controlled to reduce the amount of the working gas supplied to the combustion chamber as compared with the normal operation after the warm-up is completed. And a control device that performs warm-up control,
Working gas circulation engine. A cooling medium circulation path for circulating a cooling medium between the engine main body and a cooling device provided in the circulation path for cooling the circulating gas;
The control device reduces the amount of the working gas supplied to the combustion chamber as the temperature of the cooling medium is lower.
The working gas circulation engine according to claim 1. The control device adjusts the amount of the working gas supplied to the combustion chamber based on the temperature of the gas exhausted from the combustion chamber.
The working gas circulation engine according to claim 1 or 2. The control device adjusts the amount of the working gas supplied to the combustion chamber so that the temperature of the gas exhausted from the combustion chamber does not exceed an upper limit temperature;
The working gas circulation engine according to any one of claims 1 to 3. The adjustment mechanism has a variable throttle mechanism that makes the cross-sectional area of the circulation path variable.
The working gas circulation engine according to any one of claims 1 to 4. The variable throttle mechanism is provided upstream of a supply position to which the fuel or an oxidant for burning the fuel is supplied with respect to the direction of circulation of the circulating gas in the circulation path with reference to the combustion chamber. ,
The working gas circulation engine according to claim 5. The adjusting mechanism has a valve operating mechanism capable of adjusting an opening / closing operation of an intake valve capable of opening / closing an intake port communicating with the combustion chamber.
The working gas circulation engine according to any one of claims 1 to 6.

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