JP2008133776A - Waste heat recovery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce frequency for driving a pressurization means of a working fluid of a waste heat recovery heat engine. <P>SOLUTION: The waste heat recovery device 10 recovers thermal energy of an exhaust gas discharged from an internal combustion engine 1 by a stirring engine 100. The waste heat recovery device 10 is provided with a pressure accumulation tank 12 for accumulating the working fluid of the stirring engine inside; a compressor 11 driven by the internal combustion engine 1, pressurizing the working fluid and feeding it to the pressure accumulation tank 12; and a clutch 16 arranged between the compressor 11 and the internal combustion engine 1. The clutch 16 is engaged or disengaged according to at least either of the loaded state of the internal combustion engine or the pressure in the pressure accumulation tank. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exhaust heat recovery apparatus that recovers exhaust heat of a heat engine.

  There is a technique for recovering exhaust heat of an internal combustion engine that is a heat engine mounted on a vehicle such as a passenger car, a bus, or a truck by using a heat engine for exhaust heat recovery that is a kind of heat engine. As a heat engine for exhaust heat recovery used for such applications, for example, there is a Stirling engine with excellent theoretical thermal efficiency. When using a Stirling engine as an exhaust heat recovery heat engine to recover exhaust heat from an internal combustion engine or the like, it is necessary to reduce the friction of the sliding portion as much as possible to improve the exhaust heat recovery efficiency. For this reason, a gas bearing is formed by interposing a working fluid of a Stirling engine between a piston and a cylinder, and there is a type that reduces friction between the two. When providing a gas bearing in a sliding part, a contact may generate | occur | produce in a sliding part for reasons, such as an overload and insufficient supply of gas. Patent Document 1 discloses a technique for determining contact between a bearing and a shaft by detecting electrical continuity between the bearing and the shaft in a gas bearing.

JP-A-8-93768

  When a gas bearing is configured by interposing a working fluid of a Stirling engine between the piston and the cylinder, thereby supporting the piston in the cylinder, it is important that the piston and the cylinder do not contact each other. In exhaust heat recovery, since the heat source is low quality, it is effective to pressurize the working fluid inside the crankcase of the Stirling engine and increase the output taken out from the Stirling engine. In order to exert the piston support function of the gas bearing and to extract a larger output from the Stirling engine, it is necessary to pressurize the working fluid of the Stirling engine.

  For this purpose, the pressure of the working fluid of the Stirling engine needs to be maintained at a predetermined value or more by the pressurizing means of the working fluid, and the pressurizing means must always be operated. It is conceivable that the working fluid pressurizing means is driven by the heat engine that is the exhaust heat recovery target. In this case, the fuel consumption of the heat engine that is the exhaust heat recovery target is increased or the working fluid pressurizing means is used. There is a risk of lowering the durability. Therefore, it is necessary to reduce as much as possible the frequency of driving the working fluid pressurizing means of the Stirling engine, which is a heat engine for exhaust heat recovery.

  Patent Document 1 discloses that in a gas bearing, the electrical continuity between the bearing and the shaft is detected to determine the contact between the bearing and the shaft. Problems such as an increase in fuel consumption and a decrease in durability of the pressurizing means for the working fluid are not mentioned, and there is room for improvement. Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide an exhaust heat recovery apparatus that can reduce the frequency of driving the pressurizing means of the working fluid of the exhaust heat recovery heat engine.

  In order to achieve the above object, an exhaust heat recovery apparatus according to the present invention includes an exhaust heat recovery heat engine that recovers exhaust heat of a heat engine, and a pressurized working fluid of the exhaust heat recovery heat engine. Accumulating means for storing inside and supplying the working fluid to the inside of the exhaust heat recovery heat engine; and pressurizing means driven by the heat engine to pressurize the working fluid and supply to the pressure accumulating means; Pressurizing control means for controlling supply of the working fluid to the pressure accumulating means by the pressurizing means in accordance with at least one of a load state of the heat engine or a pressure of the working fluid stored in the pressure accumulating means. It is characterized by including.

  The exhaust heat recovery device is configured to supply the working fluid to the exhaust heat recovery heat engine via the pressure accumulating means for storing the working fluid of the exhaust heat recovery heat engine. The supply of the working fluid to the pressure accumulating means by the pressurizing means is controlled according to at least one of the state or the pressure of the working fluid stored in the pressure accumulating means of the working fluid of the heat recovery heat recovery engine. As a result, it is not necessary to always drive the pressurizing means, so that the frequency of driving the pressurizing means for the working fluid of the exhaust heat recovery heat engine can be reduced.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, the pressurization control means applies at least one of a load state of the heat engine or a pressure of the working fluid stored in the pressure storage means. Accordingly, the supply of the working fluid to the pressure accumulating means by the pressurizing means may be executed or stopped.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, the pressurization control means requires the pressure of the working fluid stored in the pressure storage means in the exhaust heat recovery heat engine. It is preferable that the supply of the working fluid to the pressure accumulating means is stopped by the pressurizing means when the pressure of the heat engine is greater than a predetermined pressure and the load of the heat engine is not less than a predetermined value. . Thereby, for example, when the heat engine to be exhausted heat recovery is operated at a high load, the driving of the pressurizing means by the heat engine is stopped, so that the heat engine is generated by driving the pressurizing means. Power reduction can be suppressed.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, the pressurization control means has a margin for storing the working fluid in the pressure storage means, and the heat engine and the exhaust heat recovery apparatus. When the vehicle on which the heat recovery device is mounted is in a decelerating state, the working fluid is preferably supplied to the pressure accumulating means by the pressurizing means. As a result, when the output of the heat engine subject to exhaust heat recovery is not required, the pressurizing means can be driven and the working fluid can be stored in the pressure accumulating means, so that fuel consumption of the heat engine can be suppressed.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, when the deceleration acceleration of the vehicle is greater than a predetermined threshold value, the gear ratio between the heat engine and the drive wheels of the vehicle Is preferably smaller than the current state. As a result, it is possible to suppress the occurrence of excessive deceleration acceleration in a vehicle equipped with a heat engine that is an exhaust heat recovery target.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, as the pressure of the working fluid stored in the pressure accumulating means increases, the ratio for reducing the speed ratio becomes larger than the current state. It is preferable to do. As a result, it is possible to more effectively suppress the occurrence of excessive deceleration acceleration in a vehicle equipped with a heat engine that is an exhaust heat recovery target.

  An exhaust heat recovery apparatus according to the present invention includes an exhaust heat recovery heat engine that recovers exhaust heat of a heat engine, and pressurization that is driven by the heat engine to pressurize a working fluid of the exhaust heat recovery heat engine. Pressurized by the pressure means, a first working fluid supply passage connecting the pressure means and the pressure storage means, a power interrupt means provided between the heat engine and the pressure means, and the pressure means. And a pressure accumulating means for accumulating the working fluid therein, and a second working fluid supply passage connecting the pressure accumulating tank and the inside of the exhaust heat recovery heat engine.

  The exhaust heat recovery device is configured to supply the working fluid to the exhaust heat recovery heat engine via the pressure accumulating means for storing the working fluid of the exhaust heat recovery heat engine. The supply of the working fluid to the pressure accumulating means by the pressurizing means is executed or stopped according to at least one of the state or the pressure of the working fluid stored in the pressure accumulating means of the working fluid of the exhaust heat recovery heat engine. As a result, it is not necessary to always drive the pressurizing means, so that the frequency of driving the pressurizing means for the working fluid of the exhaust heat recovery heat engine can be reduced.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, the power intermittent means requires the pressure of the working fluid stored in the pressure accumulation means to be required for the exhaust heat recovery heat engine. When the pressure is greater than the pressure and the load of the heat engine is greater than or equal to a predetermined value, it is preferable to disconnect the heat engine and the pressurizing means. Thereby, for example, when the heat engine to be exhausted heat recovery is operated at a high load, the driving of the pressurizing means by the heat engine is stopped, so that the heat engine is generated by driving the pressurizing means. Power reduction can be suppressed.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, the pressurization control means has a margin for storing the working fluid in the pressure storage means, and the heat engine and the exhaust heat recovery apparatus. When the vehicle on which the heat recovery device is mounted is in a deceleration state, it is preferable to connect the heat engine and the pressurizing means. As a result, when the output of the heat engine subject to exhaust heat recovery is not required, the pressurizing means can be driven and the working fluid can be stored in the pressure accumulating means, so that fuel consumption of the heat engine can be suppressed.

  As in the exhaust heat recovery apparatus according to the present invention, in the exhaust heat recovery apparatus, when the deceleration acceleration of the vehicle is larger than a predetermined threshold, the power generated by the heat engine is transmitted to the drive wheels of the vehicle. It is preferable to make the gear ratio of the power transmission means to be smaller than the current state. As a result, it is possible to suppress the occurrence of excessive deceleration acceleration in a vehicle equipped with a heat engine that is an exhaust heat recovery target.

  As in the exhaust heat recovery apparatus according to the next aspect of the present invention, in the exhaust heat recovery apparatus, as the pressure of the working fluid stored in the pressure accumulating means increases, the ratio for reducing the speed ratio becomes larger than the current state. It is preferable to do. As a result, it is possible to more effectively suppress the occurrence of excessive deceleration acceleration in a vehicle equipped with a heat engine that is an exhaust heat recovery target.

  This invention can reduce the frequency which drives the pressurizing means of the working fluid of the heat engine for exhaust heat recovery.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the best mode for carrying out the invention (hereinafter referred to as an embodiment). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. In the following description, a case where a Stirling engine is used as the exhaust heat recovery heat engine and thermal energy is recovered from the exhaust gas of the internal combustion engine, which is a heat engine, is taken as an example. In addition to the Stirling engine, an exhaust heat recovery device using a Brayton cycle can be used as the exhaust heat recovery heat engine. Moreover, the kind of heat engine is not ask | required.

  The present embodiment is configured to supply the working fluid to the exhaust heat recovery heat engine via the pressure accumulating means for storing the working fluid of the exhaust heat recovery heat engine. A feature of controlling the supply of the working fluid to the pressure accumulating means by the pressurizing means of the working fluid according to at least one of the pressures of the working fluid stored in the pressure accumulating means of the working fluid of the heat engine for exhaust heat recovery There is. In the following description, the supply of the working fluid to the pressure accumulating means is controlled by executing or stopping the supply of the working fluid to the pressure accumulating means by the pressurizing means of the working fluid. However, the method of controlling is not limited to this. For example, the supply of the working fluid to the pressure accumulating means may be controlled by changing the supply amount of the working fluid by the pressurizing means in accordance with the load state of the heat engine to be exhausted heat recovery target.

  FIG. 1-1 is an overall view showing a configuration of an exhaust heat recovery apparatus according to the present embodiment. FIG. 1-2 is an explanatory diagram illustrating an example of a vehicle equipped with the exhaust heat recovery apparatus according to the present embodiment. As shown in FIG. 1B, in the present embodiment, the internal combustion engine 1 and the exhaust heat recovery device 10 that are heat engines are mounted on a vehicle 60 such as a passenger car or a truck, and serve as a power generation source of the vehicle 60. In the present embodiment, the exhaust heat recovery apparatus 10 includes a Stirling engine 100 as a heat engine for exhaust heat recovery, and is driven by receiving heat supply from the exhaust gas Ex flowing through the exhaust gas passage 3 of the internal combustion engine 1. As described above, the exhaust heat recovery apparatus 10 according to the present embodiment recovers the exhaust heat of the internal combustion engine 1 by the Stirling engine 100 that is an exhaust heat recovery heat engine.

  The power generated by the internal combustion engine 1 is input to the internal combustion engine transmission 4 as power transmission means via the internal combustion engine output shaft 1s. The internal combustion engine transmission 4 is a so-called automatic transmission that can automatically change the gear ratio according to the output of the internal combustion engine 1, the vehicle speed of the vehicle 60, and the like, and the engine ECU (Electronic Control Unit) 50 changes the gear ratio. Be changed. For the internal combustion engine transmission 4, a stepped gear ratio variable device, a belt-type CVT (Continuous Variable Transmission), or a toroidal CVT can be used.

  The internal combustion engine transmission 4 combines the power generated by the internal combustion engine 1 and the power of the Stirling engine 100 output from the exhaust heat recovery heat engine transmission 5 and outputs the resultant power to the transmission output shaft 9. . The transmission output shaft 9 is connected to the differential gear 6, and the differential gear 6 divides the output input from the transmission output shaft 9 into a first drive shaft 6S_A and a second drive shaft 6S_B. Output. Accordingly, the first drive wheel 7A attached to the first drive shaft 6S_A and the second drive wheel 7B attached to the second drive shaft 6S_B are driven, and the vehicle 60 shown in FIG.

  As described above, in the present embodiment, the power generated by the Stirling engine 100 is combined with the power generated by the internal combustion engine 1 and is coaxially extracted from the transmission output shaft 9. The heat energy recovered from the exhaust gas Ex of the internal combustion engine 1 may be converted into electric energy and used, for example, by driving a generator with the power generated by the Stirling engine 100, for example.

  The exhaust heat recovery heat engine transmission 5 that transmits the power generated by the Stirling engine 100 to the internal combustion engine transmission 4 has a function of changing the gear ratio. The Stirling engine 100 has low followability to a sudden change in the rotational speed. For this reason, for example, when the rotational speed of the internal combustion engine 1 changes abruptly, such as during acceleration, the change in the rotation of the Stirling engine 100 cannot follow, and the Stirling engine 100 is driven by the internal combustion engine 1. There is a risk that the engine 1 may become a load. As in the present embodiment, when the heat recovery gearbox 5 for exhaust heat recovery that can change the gear ratio is used, when the rotational speed of the internal combustion engine 1 changes abruptly and the change in the rotation of the Stirling engine 100 cannot follow. Is preferable because the Stirling engine 100 can be prevented from being driven by the internal combustion engine 1 by changing the gear ratio.

  For the heat engine transmission 5 for exhaust heat recovery, for example, a belt type CVT, a toroidal type CVT, or a stepped speed ratio variable device can be used. The exhaust heat recovery heat engine transmission 5 is controlled by the engine ECU 50. The exhaust heat recovery heat engine transmission 5 uses a gear whose gear ratio cannot be changed, and power is interrupted between the Stirling engine 100 and the exhaust heat recovery heat engine transmission 5 such as a clutch. Means may be provided. When the change in the rotation of the Stirling engine 100 cannot follow the change in the rotational speed of the internal combustion engine 1, the transmission of power generated by the Stirling engine 100 may be cut off by the power interrupting means.

  The thermal energy of the exhaust gas Ex recovered using the Stirling engine 100 is converted into kinetic energy by the Stirling engine 100 and taken out as output. A crankshaft 110, which is an output shaft of the Stirling engine 100, is connected to the input shaft 5 s of the exhaust heat recovery heat engine transmission device 5 through the coupling 8. As a result, the output generated by the Stirling engine 100 is transmitted to the exhaust heat recovery heat engine transmission 5 via the coupling 8. Even when the exhaust heat recovery heat engine transmission 5 has a function of changing the gear ratio, a clutch may be provided as a power interrupting means between the crankshaft 110 and the input shaft 5s. In this way, for example, when the exhaust gas temperature of the internal combustion engine 1 is not high enough to drive the Stirling engine 100, such as during cold start, the crankshaft 110 and the input shaft 5s are separated from each other. The Stirling engine 100 can be prevented from being driven by the internal combustion engine 1. Thus, the degree of freedom of control is improved by providing the power interrupting means between the crankshaft 110 and the input shaft 5s.

  In the Stirling engine 100 included in the exhaust heat recovery apparatus 10 according to the present embodiment, the working fluid is pressurized by a pressurizing unit driven by the internal combustion engine 1 in order to extract more output. In the present embodiment, air is used as the working fluid of the Stirling engine 100. In the present embodiment, the compressor 11 is used as the pressurizing means. The compressor 11 may be a piston type, an axial flow type, or a centrifugal type, and may be of any type.

  The compressor 11 is connected to the internal combustion engine via a belt 23 stretched between a driven pulley 22 attached to the compressor input shaft 2 and a drive pulley 21 attached to the internal combustion engine output shaft 1 s of the internal combustion engine 1. 1 driven. The compressor input shaft 2 is provided with a clutch 16 that is a power interrupting means, and interrupts power transmission between the internal combustion engine 1 and the compressor 11. Here, the operation of the clutch 16 is controlled by the pressure control device 30 provided in the ECU 50.

  When the clutch 16 is engaged, power is transmitted between the internal combustion engine 1 and the compressor 11. Then, the compressor 11 is driven by the internal combustion engine 1, and air, that is, the working fluid of the Stirling engine 100 is supplied to the pressure accumulation tank 12. On the other hand, if the clutch 16 is released, the internal combustion engine 1 and the compressor 11 are disconnected, and power transmission between the internal combustion engine 1 and the compressor 11 is not performed. Air is not supplied to the tank 12. As described above, the clutch 16 functions as a pressurization control unit that executes or stops the supply of the working fluid of the Stirling engine 100 that is a heat engine for exhaust heat recovery to the pressure accumulation tank 12 that is a pressure accumulation unit.

  For example, an electromagnetic clutch can be used as the clutch 16, and the clutch 16 may be incorporated in the compressor 11. In this way, the size can be reduced. Further, the clutch 16 serving as the power interrupting means may be arranged in the power transmission path between the internal combustion engine 1 and the compressor 11, and the arrangement place of the clutch 16 is limited between the driven pulley 22 and the compressor 11. Is not to be done. For example, the drive pulley 21 may incorporate a clutch 16 that is a power interrupting means.

  FIG. 1C is an explanatory diagram of another configuration example of the pressurization control unit. In the present embodiment, the pressurization control means only needs to have a function of executing or stopping the supply of the working fluid of the Stirling engine 100 that is the heat engine for exhaust heat recovery to the pressure accumulation tank 12 that is the pressure accumulation means. 1-3 pressurizes the compressor 11 directly by the internal combustion engine 1, that is, without interposing power interrupting means such as the clutch 16. Between the compressor 11 and the pressure accumulation tank 12, a three-way valve 24 controlled by a pressure control device 30 provided in the ECU 50 is provided as a working fluid discharge destination switching means. And by the three-way valve 24, the discharge destination of the air discharged from the compressor 11 is switched to either the pressure accumulation tank 12 or the atmosphere.

  The three-way valve 24 includes a working fluid inlet 24I into which air discharged from the compressor 11 flows, a working fluid supply port 24S connected to the pressure accumulation tank 12 and supplying air discharged from the compressor 11 to the pressure accumulation tank, And a working fluid discharge port 24E that discharges air discharged from the compressor 11 to the atmosphere. When air is not supplied to the pressure accumulation tank 12, the working fluid inlet 24I and the working fluid discharge port 24E are connected. Then, even if the compressor 11 is driven, the air discharged from the compressor 11 is released into the atmosphere, so that it is not supplied to the pressure accumulation tank 12. Further, since the air discharged from the compressor 11 is released into the atmosphere, there is almost no load on the internal combustion engine 1 even when the internal combustion engine 1 and the compressor 11 are directly connected. On the other hand, when supplying air to the pressure accumulation tank 12, the working fluid inlet 24I and the working fluid supply port 24S are communicated. Then, the air discharged from the compressor 11 is discharged from the working fluid supply port 24 </ b> S and supplied to the pressure accumulation tank 12.

  The air pressurized by the compressor 11 is supplied to the pressure accumulating tank 12 as the pressure accumulating means through the first working fluid supply passage 18. A first check valve 14 is attached to the first working fluid supply passage 18 in order to prevent a backflow of air from the pressure accumulation tank 12 to the compressor 11. A relief valve 17 is attached to the pressure accumulation tank 12 so that the internal pressure does not exceed a specified value.

  The pressure accumulating tank 12 and the Stirling engine 100 are connected by a second working fluid supply passage 19, and the air in the pressure accumulating tank 12 is supplied into the Stirling engine 100 through the second working fluid supply passage 19. . A second check valve 15 is attached to the second working fluid supply passage 19 in order to prevent the backflow of air from the Stirling engine 100 to the accumulator tank 12. The second working fluid supply passage 19 is provided with an on-off valve 13 as passage opening / closing means for opening and closing the second working fluid supply passage 19.

  The on-off valve 13 is opened and closed by a pressure control device 30 provided in the ECU 50. When the on-off valve 13 is opened, the pressure accumulation tank 12 and the inside of the Stirling engine 100 are communicated with each other by the second working fluid supply passage 19. When the pressure inside the pressure accumulating tank 12 is higher than the pressure inside the Stirling engine 100, the air inside the pressure accumulating tank 12 is supplied to the inside of the Stirling engine 100. When the on-off valve 13 is closed, the communication between the pressure accumulating tank 12 and the inside of the Stirling engine 100 is cut off, so that the supply of air to the inside of the Stirling engine 100 is stopped.

  A pressure accumulation tank pressure sensor 44 is attached to the pressure accumulation tank 12 as pressure accumulation means internal pressure detection means. The pressure of the air stored in the pressure accumulation tank 12 is detected by the pressure accumulation tank pressure sensor 44. In addition, a Stirling engine pressure sensor 45 is attached to the Stirling engine 100 as a heat engine internal pressure detection means for exhaust heat recovery. Then, the pressure of the working fluid filled in the Stirling engine 100 is detected by the Stirling engine pressure sensor 45.

  The detection signals of the accumulator tank pressure sensor 44 and the Stirling engine pressure sensor 45 are connected to the ECU 50. The detection signal is acquired by the pressure control device 30 provided in the ECU 50, and the pressure of the working fluid according to the present embodiment. Used for control. The engine ECU 50 is connected to sensors such as an accelerator opening sensor 40, an internal combustion engine speed sensor 41, a brake sensor 42, an air flow meter 43, and a vehicle speed sensor 46. The engine ECU 50 and the pressure control device 30 included in the engine ECU execute pressure control of the working fluid supplied to the Stirling engine 100 and control of the internal combustion engine transmission 4 based on information acquired from these sensors. Next, the configuration of a heat engine for exhaust heat recovery applied to the exhaust heat recovery apparatus according to the present embodiment will be described.

  FIG. 2 is a cross-sectional view showing a Stirling engine that is a heat engine for exhaust heat recovery according to the present embodiment. A Stirling engine 100 that is a heat engine for exhaust heat recovery according to this embodiment is a so-called α-type in-line two-cylinder Stirling engine. A high temperature side piston 103 that is a first piston housed in a high temperature side cylinder 101 that is a first cylinder, and a low temperature side piston 104 that is a second piston housed in a low temperature side cylinder 102 that is a second cylinder. Are arranged in series.

  The high temperature side cylinder 101 and the low temperature side cylinder 102 are supported or fixed directly or indirectly on a substrate 111 which is a reference body. In the Stirling engine 100 according to the present embodiment, the substrate 111 serves as a position reference for each component of the Stirling engine 100. By comprising in this way, the relative positional accuracy of each said component can be ensured. Further, as will be described later, the Stirling engine 100 according to the present embodiment supplies air, which is a working fluid, between the high temperature side cylinder 101 and the high temperature side piston 103 and between the low temperature side cylinder 102 and the low temperature side piston 104. The gas bearing GB is configured by interposing.

  By directly or indirectly attaching the high temperature side cylinder 101 and the low temperature side cylinder 102 to the substrate 111 which is the reference body, the clearance between the piston and the cylinder can be accurately maintained, so that the function of the gas bearing GB is achieved. It can be fully demonstrated. Further, the Stirling engine 100 can be easily assembled.

  Between the high temperature side cylinder 101 and the low temperature side cylinder 102, a heat exchanger 108 including a substantially U-shaped heater (heater) 105, a regenerator 106, and a cooler 107 is disposed. Thus, by making the heater 105 substantially U-shaped, the heater 105 can be easily arranged in a relatively narrow space such as in the exhaust gas passage of the internal combustion engine. Further, by arranging the high temperature side cylinder 101 and the low temperature side cylinder 102 in series as in the Stirling engine 100, the heater 105 can be relatively easily placed in a cylindrical space such as the heater case 3C of the internal combustion engine. Can be arranged.

  One end of the heater 105 is disposed on the high temperature side cylinder 101 side, and the other end is disposed on the regenerator 106 side. The regenerator 106 has one end disposed on the heater 105 side and the other end disposed on the cooler 107 side. One end of the cooler 107 is disposed on the regenerator 106 side, and the other end is disposed on the low temperature side cylinder 102 side.

  A working fluid is sealed in the high temperature side cylinder 101, the low temperature side cylinder 102, and the heat exchanger 108, and a Stirling engine is configured by heat supplied from the heater 105 and heat discharged from the cooler 107. 100 is driven. Here, for example, the heater 105 and the cooler 107 can be configured by bundling a plurality of tubes made of a material having high thermal conductivity and excellent heat resistance. Moreover, the regenerator 106 can be comprised with a porous heat storage body. Note that the configurations of the heater 105, the cooler 107, and the regenerator 106 are not limited to this example, and a suitable configuration can be selected depending on the heat conditions of the exhaust heat recovery target, the specifications of the Stirling engine 100, and the like.

  In the heat exchanger 108, at least the heater 105 is disposed in the hollow heater case 3C. The hollow heater case 3 </ b> C constitutes an exhaust passage through which the exhaust gas Ex discharged from the heat engine that is the exhaust heat recovery target passes. The heater 105 heats the working fluid flowing in the heater 105 by the heat energy from the exhaust gas Ex flowing in the heater case 3C. Note that the regenerator 106 of the heat exchanger 108 may be disposed in the heater case 3C.

  In the present embodiment, the exhaust gas Ex flows from the high temperature side cylinder 101 side toward the low temperature side cylinder 102 side. As a result, the exhaust gas Ex discharged from the heat engine is supplied to the heater 105 in a state in which the temperature drop is suppressed, so that the thermal energy of the exhaust gas Ex can be efficiently recovered.

  As described above, the high temperature side piston 103 and the low temperature side piston 104 are supported in the high temperature side cylinder 101 and the low temperature side cylinder 102 via the gas bearing GB. That is, the piston is supported in the cylinder without using a piston ring. Thereby, the friction between the piston and the cylinder can be reduced, and the thermal efficiency of the Stirling engine 100 can be improved. Further, by reducing the friction between the piston and the cylinder, for example, the Stirling engine 100 can be recovered by recovering thermal energy even under a low heat source and low temperature difference operating condition such as exhaust heat recovery of an internal combustion engine. .

  As shown in FIG. 1, the constituent elements such as the high temperature side cylinder 101, the high temperature side piston 103, the connecting rod 109, and the crankshaft 110 that constitute the Stirling engine 100 are stored in a housing 100C. Here, the casing 100C of the Stirling engine 100 includes a crankcase 114A and a cylinder block 114B.

  The casing 100C is filled with a working fluid, and the pressure of the working fluid in the casing 100C is pressurized higher than a predetermined value. This is because the working fluid in the high temperature side and low temperature side cylinders 101 and 102 and the heat exchanger 108 is pressurized to extract more output from the Stirling engine 100. When the pressure of the working fluid in the housing 100C becomes equal to or lower than a predetermined lower limit value, the on-off valve 13 shown in FIG. 1-1 is opened, and the air in the pressure accumulating tank 12 is supplied into the housing 100C. . Thereby, the pressure of the working fluid in the housing 100C is maintained at a value higher than a predetermined lower limit value.

  In the Stirling engine 100 according to the present embodiment, a seal bearing 116 is attached to the housing 100C, and the crankshaft 110 is supported by the seal bearing 116. The output of the crankshaft 110 is taken out of the housing 100C through a flexible coupling 118 such as an Oldham coupling. Next, the pressure control device 30 according to the present embodiment will be described.

  FIG. 3 is an explanatory diagram showing a configuration of a pressure control device used for pressure control of the working fluid according to the present embodiment. As shown in FIG. 3, the pressure control device 30 according to this embodiment is configured to be incorporated in an engine ECU 50. The engine ECU 50 includes a CPU (Central Processing Unit) 50p, a storage unit 50m, an input port 55, an output port 56, an input interface 57, and an output interface 58.

  In addition, separately from the engine ECU 50, the pressure control device 30 according to the present embodiment may be prepared and connected to the engine ECU 50. And in implement | achieving the pressure control of the working fluid which concerns on this embodiment, you may comprise so that the said pressure control apparatus 30 can utilize the control function with respect to the Stirling engine 100 etc. with which engine ECU50 is equipped.

  The pressure control device 30 includes a pressure determination unit 31, an operation condition determination unit 32, and a pressurization control unit 33. These are the parts that execute the pressure control of the working fluid according to the present embodiment. In the present embodiment, the pressure control device 30 is configured as a part of the CPU 50p configuring the engine ECU 50. The CPU 50p is provided with a general control unit 53h, which controls the operation of the internal combustion engine 1 and the operation of the internal combustion engine transmission 4 and the like.

The storage unit 50 m CPU 50p, are connected via a bus 54 _3. The pressure control device 30 and the general control unit 53h are connected via an input port 55, a bus 54 ₁ , an output port 56, and a bus 54 ₂ . Thereby, the pressure determination part 31, the operating condition determination part 32, and the pressurization control part 33 which comprise the pressure control apparatus 30 are comprised so that a control data can be mutually exchanged or a command can be issued to one side. . Further, the pressure control device 30 can obtain operation control data of the internal combustion engine 1 and the Stirling engine 100 included in the engine ECU 50 and can use them. Further, the pressure control device 30 can interrupt the pressure control of the working fluid according to the present embodiment into an operation control routine provided in advance in the engine ECU 50.

  An input interface 57 is connected to the input port 55. The input interface 57 includes an accelerator opening sensor 40, an internal combustion engine speed sensor 41, a brake sensor 42, an air flow meter 43, an accumulator tank pressure sensor 44, a Stirling engine pressure sensor 45, a vehicle speed sensor 46, and other working fluid pressures. Information detecting means for acquiring information necessary for control is connected. Signals output from these information detection means are converted into signals that can be used by the CPU 50 p by the A / D converter 57 a and the digital input buffer 57 d in the input interface 57 and sent to the input port 55. Thereby, CPU50p can acquire information required for operation control of internal-combustion engine 1, and pressure control of a working fluid.

An output interface 58 is connected to the output port 56. Control objects required for pressure control of the working fluid, such as the clutch 16 and the internal combustion engine transmission 4, are connected to the output interface 58. The output interface 58 includes control circuits 58 ₁ , 58 _{2 and the} like, and operates the control target based on a control signal calculated and generated by the CPU 50p. With such a configuration, the CPU 50p of the engine ECU 50 controls the internal combustion engine 1, the Stirling engine 100, the internal combustion engine transmission 4 or the exhaust heat recovery heat engine transmission 5 based on the output signals from the sensors. be able to.

  The storage unit 50m stores a computer program including a processing procedure for pressure control of the working fluid according to the present embodiment, a control map, or a control data map used for pressure control of the working fluid according to the present embodiment. Here, the storage unit 50m can be configured by a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory such as a flash memory, or a combination thereof.

  The computer program may be capable of realizing the processing procedure of the pressure control of the working fluid according to the present embodiment in combination with the computer program already recorded in the CPU 50p. Further, the pressure control device 30 may realize functions of the pressure determination unit 31, the operating condition determination unit 32, and the pressurization control unit 33 by using dedicated hardware instead of the computer program. Good. Next, an example of pressure control of the working fluid according to the present embodiment will be described. In the following description, please refer to FIGS.

(First control example)
FIG. 4 is a flowchart showing a procedure of a first control example in the pressure control of the working fluid according to the present embodiment. In executing the pressure control of the working fluid according to the present embodiment, in step S101, the pressure determination unit 31 of the pressure control device 30 uses the pressure accumulation tank pressure sensor 44 to store the pressure of air stored in the pressure accumulation tank 12 (hereinafter referred to as pressure accumulation). P) (referred to as tank internal pressure) is detected, and it is determined whether or not the pressure accumulation tank internal pressure P is smaller than the first working fluid pressure threshold P_A. Here, the first working fluid pressure threshold P_A is the pressure of the working fluid in the Stirling engine 100 necessary for the operation of the Stirling engine 100.

  Here, when the pressure of the working fluid in the Stirling engine 100 becomes equal to or lower than the first working fluid pressure threshold P_A, the on-off valve 13 shown in FIG. Is opened, and the air in the pressure accumulating tank 12 is supplied into the Stirling engine 100. Thereby, the pressure of the working fluid in the Stirling engine 100 is maintained at a value higher than the first working fluid pressure threshold P_A.

  When it is determined Yes in step S101, that is, when the pressure determination unit 31 determines that P <P_A, the pressure accumulation tank 12 cannot supply air with the minimum pressure necessary for the operation of the Stirling engine 100. . For this reason, when it determines with Yes at step S101, it is necessary to pressurize the pressure of the air in the pressure accumulation tank 12 more than 1st working fluid pressure threshold value P_A unconditionally. When it determines with Yes by step S101, it progresses to step S102, the pressurization control part 33 of the pressure control apparatus 30 engages the clutch 16 shown in FIG. 1-1, and drives the compressor 11 by the internal combustion engine 1. FIG. By doing so, the pressure of the air in the pressure accumulation tank 12 is pressurized more than 1st working fluid pressure threshold value P_A.

  When it is determined No in step S101, that is, when the pressure determination unit 31 determines that P ≧ P_A, the process proceeds to step S103. In step S103, the pressure determination unit 31 determines whether or not the pressure P in the accumulator tank acquired in step S101 is smaller than the second working fluid pressure threshold P_A. Here, the second working fluid pressure threshold P_B is a pressure that is larger than the second working fluid pressure threshold P_A and smaller than the allowable pressure P_D of the pressure accumulation tank 12. For example, the second working fluid pressure threshold value P_B is set to an intermediate size between the working fluid pressure threshold value P_A and the allowable pressure P_D.

  When it is determined Yes in step S103, that is, when the pressure determination unit 31 determines that P <P_B, there is a margin for the pressure required for the exhaust heat recovery heat engine, that is, the first working fluid pressure threshold P_A. However, in consideration of a margin for supplying air to the Stirling engine 100, it is preferable that the pressure of the air in the pressure accumulating tank 12 is set higher than the current level. In this case, if the compressor 11 is driven when a large output is required for the internal combustion engine 1 as when the vehicle 60 shown in FIG. 1-2 is accelerated, the requested acceleration performance may not be exhibited. is there. Therefore, when the internal combustion engine 1 is operated at a high load, the drive of the compressor 11 by the internal combustion engine 1 is stopped. Here, the high load means, for example, a load factor of 80% or more.

  In order to determine that the internal combustion engine 1 is operating at a high load, the current load on the internal combustion engine 1 may be obtained and determined. When it is determined Yes in step S103, in step S104, the operating condition determination unit 32 of the pressure control device 30 determines whether or not the current load of the internal combustion engine 1 is smaller than a predetermined load threshold K_C. judge. Here, the load of the internal combustion engine 1 can be obtained from the engine speed of the internal combustion engine 1 acquired from the internal combustion engine speed sensor 41 and the intake air amount acquired from the air flow meter 43. Further, it may be determined whether or not the internal combustion engine 1 is operated at a high load by using the accelerator opening detected by the accelerator opening sensor 40 instead of the current load of the internal combustion engine 1.

  If it is determined Yes in step S104, that is, if the operating condition determination unit 32 determines that the current load on the internal combustion engine 1 is smaller than a predetermined load threshold K_C, the process proceeds to step S102. And the pressurization control part 33 engages the clutch 16 shown to FIGS. 1-1, and drives the compressor 11 by the internal combustion engine 1, By this, the pressure of the air in the pressure accumulation tank 12 is made into the 1st working fluid. Pressurize to a pressure threshold P_B or higher.

  When it is determined No in step S103, that is, when the pressure determination unit 31 determines that P ≧ P_B, the pressure of the air in the pressure accumulation tank 12 is sufficient to pressurize the working fluid inside the Stirling engine 100. It can be judged that there is room. In this case, since pressurization of the air in the accumulator tank 12 by the compressor 11 is not necessary, the pressurization control unit 33 stops the pressurization of the air in the accumulator tank 12 in step S105. Stopping the pressurization of the air in the accumulator tank 12 can be realized by releasing the clutch 16 and disconnecting the internal combustion engine 1 and the compressor 11 (the same applies hereinafter). As a result, the internal combustion engine 1 is released from the drive of the compressor 11, and the fuel consumption of the internal combustion engine 1 is suppressed. Moreover, since the output for driving the compressor 11 by the internal combustion engine 1 can be used for the travel of the vehicle 60 shown in FIG. 1-2, for example, the acceleration performance is improved when the vehicle 60 is accelerated.

  When it is determined No in step S104, that is, the pressure determination unit 31 determines that P <P_B, and the operating condition determination unit 32 determines that the current load of the internal combustion engine 1 is a predetermined load threshold value K_C that is set in advance. If it is determined as above, the driving power of the internal combustion engine 1 for driving the vehicle 60 shown in FIG. 1-2 is reduced by the amount that the internal combustion engine 1 drives the compressor 11, so that drivability may be reduced. is there. In this case, in step S105, the pressurization control unit 33 stops the pressurization of the air in the pressure accumulation tank 12. As a result, the internal combustion engine 1 is released from the drive of the compressor 11, so that the output of the drive of the internal combustion engine 1 to the compressor 11 can be used for traveling the vehicle 60 shown in FIG. It is possible to suppress the deterioration of the ability.

  As described above, in the first control example in the pressure control of the working fluid according to the present embodiment, the pressure accumulation tank by the compressor 11 according to at least one of the load state of the internal combustion engine 1 or the pressure of the air stored in the pressure accumulation tank 12. The air supply to 12 is executed or stopped. Thereby, since it is not necessary to always drive the compressor 11, an increase in fuel consumption of the internal combustion engine 1 that drives the compressor 11 can be suppressed, and a decrease in durability of the compressor 11 can also be suppressed. Further, when the internal combustion engine 1 has a high load, the drive of the compressor 11 by the internal combustion engine 1 is stopped, so that all the power generated by the internal combustion engine 1 is driven to drive the vehicle 60 shown in FIG. Can be used.

(Second control example)
FIG. 5 is a flowchart showing a procedure of a second control example in the pressure control of the working fluid according to the present embodiment. Since step S201 and step S202 in the second control example are the same as step S101 and step S102 in the first control example described above, description thereof will be omitted.

  When it determines with No by step S201 in a 2nd control example, ie, when the pressure determination part 31 determines with P> = P_A, it progresses to step S203. When the compressor 11 is driven by the internal combustion engine 1 to pressurize the air in the accumulator tank 12, it is preferable to drive the compressor 11 in a range where the load for driving the compressor 11 by the internal combustion engine 1 is as small as possible. For this purpose, it is preferable to drive the compressor 11 when the internal combustion engine 1 is operated with no load or with a low load.

  In the second control example, for example, as shown in FIG. 1-2, whether or not the internal combustion engine 1 is operated with no load or low load depending on whether or not the vehicle 60 equipped with the internal combustion engine 1 is in a decelerating state. Determine. In addition to this, the internal combustion engine 1 can be used by using a so-called engine brake acting on a downhill or the like, using that the accelerator is OFF, or using the current load of the internal combustion engine 1. It is also possible to determine whether or not the vehicle is operating with no load or low load. Here, the low load means, for example, a load factor of 20% or less.

  In step S203, the driving condition determination unit 32 determines whether or not the vehicle 60 on which the internal combustion engine 1 is mounted as shown in FIG. This can be determined using, for example, a braking signal detected by the brake sensor 42, a deceleration acceleration obtained based on the vehicle speed of the vehicle 60 detected by the vehicle speed sensor 46, and the like. For example, when a braking signal is detected from the brake sensor 42, it is determined that the vehicle 60 is in a deceleration state.

  When it determines with Yes by step S203, it progresses to step S204. In step S <b> 204, the pressure determination unit 31 determines whether or not the pressure accumulation tank internal pressure P acquired in step S <b> 201 is smaller than the allowable pressure P_D of the pressure accumulation tank 12. When the pressure P in the pressure accumulation tank is lower than the allowable pressure P_D of the pressure accumulation tank 12, it is preferable to reduce the operating frequency of the compressor 11 by further increasing the pressure P in the pressure accumulation tank. When it determines with Yes by step S204, ie, when the pressure determination part 31 determines with P <P_D, it progresses to step S202. Then, the pressurization control unit 33 engages the clutch 16 shown in FIG. 1-1 and drives the compressor 11 by the internal combustion engine 1 to increase the pressure of the air in the pressure accumulating tank 12 to the allowable pressure P_D. Press.

  When it is determined No in step S203, that is, when the driving condition determination unit 32 determines that the vehicle 60 is not in a decelerating state, when the compressor 11 is driven by the internal combustion engine 1, the fuel consumption of the internal combustion engine 1 increases. Or the power generated by the internal combustion engine 1 may be reduced and drivability may be deteriorated. In this case, in step S205, the pressurization control unit 33 stops the pressurization of the air in the pressure accumulation tank 12. As a result, the internal combustion engine 1 is released from the drive of the compressor 11, and the fuel consumption of the internal combustion engine 1 is suppressed. Moreover, since the output for driving the compressor 11 by the internal combustion engine 1 can be used for traveling of the vehicle 60 shown in FIG. 1-2, the deterioration of drivability can be suppressed.

  When it is determined No in step S204, that is, when the driving condition determination unit 32 determines that the vehicle 60 is not in a decelerating state and the pressure determination unit 31 determines that P ≧ P_D, the pressure in the accumulator tank There is no room for further increase. In this case, in step S205, the pressurization control unit 33 stops the pressurization of the air in the pressure accumulation tank 12.

  Thus, in the second control example of the pressure control of the working fluid according to the present embodiment, the pressure accumulation tank by the compressor 11 according to at least one of the load state of the internal combustion engine 1 or the pressure of air stored in the pressure accumulation tank 12. The air supply to 12 is executed or stopped. When determining the supply of air to the pressure accumulation tank 12 according to the load state of the internal combustion engine 1, the air supply to the pressure accumulation tank 12 is executed when the internal combustion engine 1 is unloaded or lightly loaded. Thereby, since it is not necessary to always drive the compressor 11, an increase in fuel consumption of the internal combustion engine 1 that drives the compressor 11 can be suppressed, and a decrease in durability of the compressor 11 can also be suppressed. Further, when the internal combustion engine 1 has a high load, the drive of the compressor 11 by the internal combustion engine 1 is stopped, so that all the power generated by the internal combustion engine 1 is driven to drive the vehicle 60 shown in FIG. It can be used, and drivability deterioration can be effectively suppressed.

  Furthermore, the compressor 11 is driven when the output of the internal combustion engine 1 is not required, such as when the vehicle 60 shown in FIG. 1-2 is traveling downhill or when a so-called engine brake is operating. The working fluid is stored in the pressure accumulation tank 12. As a result, the fuel consumption of the internal combustion engine 1 can be suppressed, and the influence of the power reduction generated by the internal combustion engine 1 by driving the compressor 11 on the driving of the vehicle 60 can be reduced.

(Third control example)
FIG. 6 is an explanatory diagram showing the configuration of the pressure control device used in the third control example in the pressure control of the working fluid according to the present embodiment. FIG. 7 is a flowchart illustrating a procedure of a third control example in the pressure control of the working fluid according to the present embodiment. As shown in FIG. 6, the pressure control device 30a used in the third control example further includes a transmission ratio control unit 34 in addition to the pressure control device 30 used in the first and second control examples described with reference to FIG. It is a configuration. Other configurations are the same as those of the pressure control device 30 used in the first and second control examples, and the pressure control device 30a used in the third control example is provided in the ECU 50 shown in FIG. Next, the procedure of the third control example in the pressure control of the working fluid according to the present embodiment will be described.

  Since step S301 and step S302 in the third control example are the same as step S101, step S102, step S201, and step S202 in the first and second control examples described above, description thereof will be omitted. In step S302, the pressurization control unit 33 of the pressure control device 30a engages the clutch 16 shown in FIG. 1A and drives the compressor 11 by the internal combustion engine 1, whereby the air in the pressure accumulation tank 12 is increased. The pressure is increased to the first working fluid pressure threshold P_A or higher.

  When the compressor 11 is driven by the internal combustion engine 1, a part of the power generated by the internal combustion engine 1 is used for driving the compressor 11. Thereby, the vehicle 60 shown in FIG. 1-2 is decelerated, and the driver of the vehicle 60 is given a feeling of deceleration. If this feeling of deceleration increases, the driver of the vehicle 60 feels uncomfortable, so in the third control example, the gear ratio of the internal combustion engine transmission 4 is changed based on the deceleration acceleration generated in the vehicle 60. That is, as the deceleration acceleration increases, the transmission ratio of the internal combustion engine transmission 4 is decreased. Thereby, since the deceleration acceleration generated in the vehicle 60 can be suppressed, the uncomfortable feeling given to the driver of the vehicle 60 can be reduced.

  Here, the rotational speed of the input shaft of the internal combustion engine transmission 4, that is, the output shaft 1 s of the internal combustion engine is the input rotational speed, and the output shaft of the internal combustion engine transmission 4, that is, the rotational speed of the transmission output shaft 9 is the output rotational speed. Then, the gear ratio of the internal combustion engine transmission 4 is input rotational speed / output rotational speed. Note that changing the gear ratio of the internal combustion engine transmission 4 means that the internal combustion engine 1 and the drive wheels of the vehicle 60 shown in FIG. The gear ratio between the first drive wheel 7A and the second drive wheel 7B shown in FIG.

  In step S303, the operating condition determination unit 32 of the pressure control device 30a determines whether the deceleration acceleration (deceleration) of the vehicle 60 is greater than a predetermined first deceleration threshold G_E1. The deceleration acceleration of the vehicle 60 can be obtained based on the vehicle speed of the vehicle 60 detected by the vehicle speed sensor 46, for example. Further, the deceleration acceleration of the vehicle 60 may be detected using an acceleration sensor that can detect the acceleration in the front-rear direction of the vehicle 60.

  If it is determined Yes in step S303, that is, if the driving condition determination unit 32 determines that the deceleration acceleration (deceleration) of the vehicle 60 is greater than the predetermined first deceleration threshold G_E1, the process proceeds to step S304. In step S304, the gear ratio control unit 34 of the pressure control device 30a shifts up the internal combustion engine transmission 4 shown in FIG. That is, the gear ratio control unit 34 switches the gear position of the internal combustion engine transmission 4 to a gear position having a smaller gear ratio than the current gear ratio. As a result, the force with which the internal combustion engine 1 drives the drive wheels of the vehicle 60 can be reduced, so that the deceleration acceleration generated in the vehicle 60 can be suppressed. As a result, the uncomfortable feeling given to the driver of the vehicle 60 can be reduced.

  Here, as the pressure P in the accumulator tank increases, the compression work of the compressor 11 increases, and the power for the internal combustion engine 1 to drive the compressor 11 also increases. As a result, the deceleration acceleration generated by the vehicle 60 also increases. Therefore, it is preferable to change the ratio of changing the speed ratio of the internal combustion engine transmission 4 according to the pressure P in the accumulator tank. That is, it is preferable that the gear ratio of the internal combustion engine transmission 4 is set to a smaller value as the pressure in the accumulator tank increases. In this control example, as the pressure in the accumulator tank increases, the gear is shifted up to a gear stage having a smaller gear ratio. As a result, the deceleration acceleration generated in the vehicle 60 can be more appropriately reduced, so that the uncomfortable feeling given to the driver of the vehicle 60 can be more effectively reduced.

  If it is determined No in step S303, that is, if the driving condition determination unit 32 determines that the deceleration acceleration (deceleration) of the vehicle 60 is equal to or less than the predetermined first deceleration threshold G_E1, the process proceeds to step S305. In step S305, the gear ratio control unit 34 maintains the gear position of the internal combustion engine transmission 4 shown in FIG. When the deceleration acceleration (deceleration) of the vehicle 60 is equal to or less than a predetermined first deceleration threshold G_E1, the deceleration acceleration generated in the vehicle 60 is within the allowable range of the driver of the vehicle 60. This is because an uncomfortable feeling given to the driver is allowed.

  When it determines with No by step S301, ie, when the pressure determination part 31 determines with P> = P_A, it progresses to step S306. When the compressor 11 is driven by the internal combustion engine 1 to pressurize the air in the accumulator tank 12, it is preferable to drive the compressor 11 in a range where the load for driving the compressor 11 by the internal combustion engine 1 is as small as possible. For this purpose, it is preferable to drive the compressor 11 when the internal combustion engine 1 is operated with no load or with a low load.

  In the third control example, for example, as shown in FIG. 1-2, whether or not the internal combustion engine 1 is operated with no load or low load depending on whether or not the vehicle 60 equipped with the internal combustion engine 1 is in a braking state. Determine. In addition to this, the internal combustion engine 1 can be used by using a so-called engine brake acting on a downhill or the like, using that the accelerator is OFF, or using the current load of the internal combustion engine 1. It is also possible to determine whether or not the vehicle is operating with no load or low load.

  In step S306, the driving condition determination unit 32 determines whether or not the vehicle 60 on which the internal combustion engine 1 is mounted as shown in FIG. This can be determined using, for example, a braking signal detected by the brake sensor 42, a deceleration acceleration obtained based on the vehicle speed of the vehicle 60 detected by the vehicle speed sensor 46, and the like. For example, when a braking signal is detected from the brake sensor 42, it is determined that the vehicle 60 is in a deceleration state.

  When it determines with Yes by step S306, it progresses to step S307. In step S307, the pressure determination unit 31 of the pressure control device 30a determines whether the pressure P in the pressure accumulation tank acquired in step S301 is smaller than the allowable pressure P_D of the pressure accumulation tank 12. When the pressure P in the pressure accumulation tank is lower than the allowable pressure P_D of the pressure accumulation tank 12, it is preferable to reduce the operating frequency of the compressor 11 by further increasing the pressure P in the pressure accumulation tank.

  When it determines with Yes by step S307, ie, when the pressure determination part 31 determines with P <P_D, it progresses to step S308. In step S308, the pressurization control unit 33 engages the clutch 16 shown in FIG. 1-1 and drives the compressor 11 by the internal combustion engine 1, thereby pressurizing the air in the pressure accumulation tank 12. Start and go to step S309. In addition, the pressure of the air in the pressure accumulation tank 12 is pressurized to the allowable pressure P_D.

  In step S309, the driving condition determination unit 32 determines whether or not the deceleration acceleration (deceleration) of the vehicle 60 is greater than a predetermined first deceleration threshold G_E1. When it determines with Yes by step S309, ie, when the driving condition determination part 32 determines that the deceleration acceleration (deceleration) of the vehicle 60 is larger than the predetermined 1st deceleration threshold value G_E1, it progresses to step S304.

  In step S304, the gear ratio control unit 34 of the pressure control device 30a shifts up the internal combustion engine transmission 4 shown in FIG. That is, the gear ratio control unit 34 switches the gear position of the internal combustion engine transmission 4 to a gear position having a smaller gear ratio than the current gear ratio. As a result, the force with which the internal combustion engine 1 drives the drive wheels of the vehicle 60 can be reduced, so that it is possible to avoid the occurrence of a deceleration acceleration greater than that assumed by the driver of the vehicle 60.

  When it is determined No in step S309, that is, when the driving condition determination unit 32 determines that the deceleration acceleration (deceleration) of the vehicle 60 is equal to or less than the predetermined first deceleration threshold G_E1, the process proceeds to step S310. In step S310, the driving condition determination unit 32 determines whether or not the deceleration acceleration (deceleration) of the vehicle 60 is smaller than a predetermined second deceleration threshold G_E2. Here, the first deceleration threshold G_E1> the second deceleration threshold G_E2. When it determines with Yes by step S310, ie, when the driving condition determination part 32 determines with the deceleration acceleration (deceleration) of the vehicle 60 being smaller than the predetermined 2nd deceleration threshold value G_E2, it progresses to step S311.

  In step S311, the gear ratio control unit 34 shifts down the internal combustion engine transmission 4 shown in FIG. That is, the gear ratio control unit 34 switches the gear position of the internal combustion engine transmission 4 to a gear position with a larger gear ratio than the current state. In step S306 described above, it can be determined that the driver of the vehicle 60 shown in FIG. However, when the deceleration acceleration of the vehicle 60 is smaller than the predetermined second deceleration threshold G_E2, the deceleration acceleration requested by the driver may not be obtained. Therefore, by shifting down the internal combustion engine transmission 4 shown in FIG. As a result, by increasing the driving force of the internal combustion engine 1 to drive the drive wheels of the vehicle 60, it is possible to generate a larger deceleration acceleration in the vehicle 60 and to avoid that the deceleration acceleration required by the driver cannot be obtained.

  When it is determined No in step S310, that is, when the deceleration acceleration (deceleration) of the vehicle 60 is equal to or greater than a predetermined second deceleration threshold G_E2 and equal to or less than a predetermined first deceleration threshold G_E1, the driving condition determination unit 32 When it determines, it progresses to step S312. When the deceleration acceleration of the vehicle 60 is not less than the predetermined second deceleration threshold G_E2 and not more than the predetermined first deceleration threshold G_E1, it can be determined that an appropriate deceleration acceleration is generated in the vehicle 60. In this case, in step S312, the gear ratio control unit 34 maintains the gear position of the internal combustion engine transmission 4 shown in FIG.

  When it is determined No in step S306, that is, when the driving condition determination unit 32 determines that the vehicle 60 is not in a deceleration state, when the compressor 11 is driven by the internal combustion engine 1, the fuel consumption of the internal combustion engine 1 increases. Or the power generated by the internal combustion engine 1 may be reduced and drivability may be deteriorated. In this case, in step S313, the pressurization control unit 33 stops the pressurization of the air in the pressure accumulation tank 12. As a result, the internal combustion engine 1 is released from the drive of the compressor 11, and the fuel consumption of the internal combustion engine 1 is suppressed. Moreover, since the output for driving the compressor 11 by the internal combustion engine 1 can be used for traveling of the vehicle 60 shown in FIG. 1-2, the deterioration of drivability can be suppressed.

  When it is determined No in step S307, that is, when the driving condition determination unit 32 determines that the vehicle 60 is not in a decelerating state and the pressure determination unit 31 determines that P ≧ P_D, the pressure in the accumulator tank There is no room for further increase. In this case, in step S313, the pressurization control unit 33 stops the pressurization of the air in the pressure accumulation tank 12.

  Thus, in the third control example of the pressure control of the working fluid according to the present embodiment, the pressure accumulation tank by the compressor 11 according to at least one of the load state of the internal combustion engine 1 or the pressure of the air stored in the pressure accumulation tank 12. The air supply to 12 is executed or stopped. When air is supplied to the pressure accumulating tank 12, the speed ratio of the internal combustion engine transmission 4 is changed in accordance with the deceleration acceleration of the vehicle 60 shown in FIG. As a result, the deceleration acceleration of the vehicle 60 can be suppressed within an allowable range, so that the uncomfortable feeling given to the driver of the vehicle 60 can be reduced.

  As described above, in the present embodiment, the working fluid is supplied to the exhaust heat recovery heat engine via the pressure accumulating means for storing the working fluid of the exhaust heat recovery heat engine. Execute or stop the supply of the working fluid to the pressure accumulating means by the pressurizing means of the working fluid according to at least one of the state or the pressure of the working fluid stored in the pressure accumulating means of the working fluid of the heat engine for exhaust heat recovery To do. As a result, it is not necessary to always drive the pressurizing means, so that the frequency of driving the pressurizing means for the working fluid of the exhaust heat recovery heat engine can be reduced. And the fuel consumption of the heat engine which is an exhaust heat recovery object can be suppressed, and the durable fall of the pressurizing means of a working fluid can be suppressed. In addition, since the pressure of the working fluid inside the exhaust heat recovery heat engine can be maintained at an appropriate pressure, more power can be taken out from the exhaust heat recovery heat engine, and the function of the gas bearing can be sufficiently achieved. The contact between the piston and the cylinder can be suppressed.

  As described above, the exhaust heat recovery apparatus according to the present invention is useful for exhaust heat recovery of a heat engine, and in particular, drives a working fluid pressurizing means of an exhaust heat recovery heat engine provided in the exhaust heat recovery apparatus. Suitable for reducing frequency.

1 is an overall view showing a configuration of an exhaust heat recovery apparatus according to the present embodiment. It is explanatory drawing which shows an example of the vehicle carrying the waste heat recovery apparatus which concerns on this embodiment. It is explanatory drawing which shows the other structural example of a pressurization control means. It is sectional drawing which shows the Stirling engine which is a heat engine for waste heat recovery which concerns on this embodiment. It is explanatory drawing which shows the structure of the pressure control apparatus used for the pressure control of the working fluid which concerns on this embodiment. It is a flowchart which shows the procedure of the 1st control example in the pressure control of the working fluid which concerns on this embodiment. It is a flowchart which shows the procedure of the 2nd control example in the pressure control of the working fluid which concerns on this embodiment. It is explanatory drawing which shows the structure of the pressure control apparatus used for the 3rd control example in the pressure control of the working fluid which concerns on this embodiment. It is a flowchart which shows the procedure of the 3rd control example in the pressure control of the working fluid which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 1s Internal combustion engine output shaft 2 Compressor input shaft 3 Exhaust gas passage 4 Internal combustion engine transmission 5 Exhaust heat recovery heat engine transmission 6 Differential gear 7A, 7B Drive wheel 8 Coupling 9 Transmission output shaft 10 Waste heat recovery device 11 Compressor 12 Accumulation tank 13 On-off valve 14 First check valve 15 Second check valve 16 Clutch 17 Relief valve 18 First working fluid supply passage 19 Second working fluid supply passage 21 Drive pulley 22 Driven Pulley 23 Belt 30, 30a Pressure control device 31 Pressure determination unit 32 Operating condition determination unit 33 Pressurization control unit 34 Gear ratio control unit 40 Accelerator opening sensor 41 Internal combustion engine speed sensor 42 Brake sensor 43 Air flow meter 44 Accumulation tank pressure sensor 45 Pressure sensor for Stirling engine 46 Vehicle speed sensor 50 Engine ECU
100 Stirling engine

Claims (11)

A heat engine for exhaust heat recovery that recovers the exhaust heat of the heat engine;
A pressure accumulating means for storing the pressurized working fluid of the exhaust heat recovery heat engine inside, and supplying the working fluid into the exhaust heat recovery heat engine;
A pressurizing means driven by the heat engine to pressurize the working fluid and supply it to the pressure accumulating means;
A pressurizing control means for controlling supply of the working fluid to the pressure accumulating means by the pressurizing means according to at least one of a load state of the heat engine or a pressure of the working fluid stored in the pressure accumulating means;
An exhaust heat recovery apparatus comprising: The pressure control means includes
The supply of the working fluid to the pressure accumulating means by the pressurizing means is executed or stopped in accordance with at least one of a load state of the heat engine or a pressure of the working fluid stored in the pressure accumulating means. The exhaust heat recovery apparatus according to claim 1. The pressure control means includes
When the pressure of the working fluid stored in the pressure accumulating means is larger than the pressure required for the exhaust heat recovery heat engine and the load of the heat engine is not less than a predetermined value, the pressure is increased. The exhaust heat recovery apparatus according to claim 1 or 2, wherein supply of the working fluid to the pressure accumulating means by the pressure means is stopped. The pressure control means includes
When the pressure accumulating means has a margin for storing the working fluid, and when the vehicle equipped with the heat engine and the exhaust heat recovery device is in a decelerating state, the working fluid is supplied to the pressure accumulating means by the pressurizing means. The exhaust heat recovery device according to any one of claims 1 to 3, wherein the exhaust heat recovery device is supplied.   5. The exhaust heat recovery apparatus according to claim 4, wherein when a deceleration acceleration of the vehicle is larger than a predetermined threshold value, a speed change ratio between the heat engine and a drive wheel of the vehicle is made smaller than a current state. .   6. The exhaust heat recovery apparatus according to claim 5, wherein as the pressure of the working fluid stored in the pressure accumulating means increases, the ratio at which the speed ratio is reduced is increased as compared to the current state. A heat engine for exhaust heat recovery that recovers the exhaust heat of the heat engine;
Pressurizing means driven by the heat engine to pressurize the working fluid of the exhaust heat recovery heat engine;
A first working fluid supply passage connecting the pressurizing means and the pressure accumulating means;
Power intermittent means provided between the heat engine and the pressurizing means;
Pressure accumulating means for accumulating the working fluid pressurized by the pressurizing means;
A second working fluid supply passage connecting the pressure accumulation tank and the inside of the exhaust heat recovery heat engine;
An exhaust heat recovery apparatus comprising: The power intermittent means is
When the pressure of the working fluid stored in the pressure accumulating means is larger than the pressure required for the exhaust heat recovery heat engine and the load of the heat engine is equal to or higher than a predetermined value, the heat The exhaust heat recovery apparatus according to claim 7, wherein the engine and the pressurizing means are separated. The pressure control means includes
When the pressure accumulating means has room to store the working fluid and the vehicle on which the heat engine and the exhaust heat recovery device are mounted is in a decelerating state, the heat engine and the pressurizing means are connected. The exhaust heat recovery apparatus according to claim 7.   10. The gear ratio of the power transmission means for transmitting the power generated by the heat engine to the drive wheels of the vehicle when the deceleration acceleration of the vehicle is larger than a predetermined threshold value is smaller than the current state. The exhaust heat recovery device described in 1.   The exhaust heat recovery apparatus according to claim 10, wherein as the pressure of the working fluid stored in the pressure accumulating unit increases, a ratio of decreasing the speed change ratio is increased as compared with a current state.

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