JP2013151941A - Waste heat utilization system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste heat utilization system in which a Rankine circuit is constituted from a small-sized fluid machine provided with an expansion unit and a pump unit.SOLUTION: A waste heat utilization system includes a Rankine circuit (12) constituted by sequentially interposing, to a circulation path (13) for circulating working fluid: a pump unit (16) which boosts and ejects sucked working fluid; a heater (18); an expansion unit (20) which can convert thermal energy of the working fluid into torque to output the torque; and a condenser (22). A power transmission unit (30) for inputting and outputting the torque between the power transmission unit and the outside is connected to a driving shaft (72) with which the pump unit is connected. The Rankine circuit includes a check valve (102) interposed to a part of a circulation path extending between the pump unit and the heater, and a circulation path on-off valve (104) interposed on a part of the circulation path extending between the heater and the expansion unit.

Description

  The present invention relates to a waste heat utilization system, and more particularly, to a vehicle waste heat utilization system.

For example, a Rankine circuit constituting a waste heat utilization system of an internal combustion engine such as a vehicle engine has a circulation path through which a working fluid (heat medium) circulates, and the circulation path includes a pump, an evaporator (heat exchanger), An expander and a condenser are sequentially inserted.
The pump is driven by, for example, an electric motor and circulates the working fluid. As the working fluid passes through the evaporator, it receives waste heat and expands in the expander. At this time, the thermal energy of the working fluid is converted into torque and output to the outside, and is used, for example, to rotate a fan for air-cooling the condenser.

  Patent Document 1 discloses a fluid machine in which a pump, an expander, and a motor share one drive shaft as a compact and low-cost fluid machine suitable for such a Rankine circuit. In this fluid machine, the pump is started when the motor operates by receiving external power supply. When the pump is activated, the working fluid circulates, and the working fluid that has received the heat energy is expanded by the expander. After starting the motor, the power supply to the motor is stopped, the pump is operated by the torque output from the expander, and the motor is caused to function as a generator.

Japanese Unexamined Patent Publication No. 2005-30386

In the fluid machine of Patent Document 1 described above, since the motor that generates the rotational driving force has a power generation function, the power generation efficiency of the motor is lower than the power generation efficiency of the generator having only the power generation function.
Further, in the fluid machine of Patent Document 1, the motor is a DC motor. However, in general, a DC motor is heavier than an AC motor, has a low power generation efficiency when used as a generator, and in addition, brush maintenance. Is required.

Furthermore, in the fluid machine of Patent Document 1, the thermal energy recovered by the expander, in other words, the torque generated by the expander is once converted into electric power, and the recovered thermal energy cannot be output to the outside as torque.
The present invention has been made based on the above-described circumstances, and an object thereof is to provide a waste heat utilization system in which a Rankine circuit is configured from a small fluid machine including an expansion unit and a pump unit.

  In order to achieve the above object, according to the present invention, a pump unit that boosts and discharges the sucked working fluid to a circulation path for circulating the working fluid, a heater, and torque of the thermal energy of the working fluid The waste heat utilization system includes a Rankine circuit in which an expansion unit that can be converted into an output and a condenser are sequentially inserted, and the drive shaft to which the pump unit is connected is connected to the outside. Is connected to a power transmission unit for inputting and outputting torque, and the Rankine circuit includes a check valve inserted in a portion of the circulation path extending between the pump unit and the heater, A waste heat utilization system comprising a circulation path opening / closing valve interposed in a portion of the circulation path extending between a heater and the expansion unit is provided (Claim 1).

Preferably, a power generation unit is coupled to the expansion unit in addition to the pump unit.
Preferably, the expansion unit, the pump unit, and the power generation unit constitute a fluid machine, and the fluid machine has a first rotating body, and sucks a working fluid with the rotation of the first rotating body. The pump unit for boosting and discharging the sucked working fluid and the second rotating body, and receiving the working fluid and expanding the received working fluid while rotating the second rotating body. The power generation unit that has the expansion unit to be sent out later, and a third rotating body arranged coaxially with the first and second rotating bodies, and generates electric power as the third rotating body rotates. A unit, at least one of the first, second and third rotating bodies, the drive shaft integrally connected to the first rotating body, and the drive shaft connected to the drive shaft; The power transmission unit for transmitting Comprising (claim 3).

Preferably, when the circulation path opening / closing valve is closed, a pressure drop prevention for preventing a pressure drop in a portion of the circulation path extending between the circulation path opening / closing valve and the expansion unit with the operation of the expansion unit. A means is further provided (Claim 4).
Preferably, the pressure drop prevention means includes an external return path provided in parallel with the expansion unit in the circulation path, and a return path opening / closing valve that opens and closes the external return path (Claim 5).
Preferably, the pressure drop prevention means is provided in an expansion unit of the fluid machine, and an internal return path for returning the heat medium after the expansion process or expansion to the upstream side, and a return path opening / closing for opening and closing the internal return path. (Claim 6).

  In the waste heat utilization system according to claim 1 of the present invention, by closing the circulation path opening / closing valve, external power is stored as pressure energy in a portion of the circulation path extending from the check valve to the circulation path opening / closing valve. The stored pressure energy is converted into torque by the expansion unit by opening the circulation path on-off valve. That is, in this Rankine circuit, power from the outside can be stored in a form other than electric power depending on the situation.

  In the invention of claim 2, since the power generation unit is connected to the expansion unit in addition to the pump unit, the torque transmitted to the drive shaft is not only converted into electric power by the power generation unit, but also the pump. Used as unit power. For this reason, if the torque generated in the expansion unit is sufficiently large, the fluid machine can operate independently without receiving external power. Furthermore, the torque generated in the expansion unit can be output to the outside via the power transmission unit.

In the invention of claim 3, since the first, second and third rotating bodies of the pump unit, the expansion unit and the power generation unit are arranged on the same axis, the fluid machine can be reduced in size.
In this fluid machine, the drive shaft and the first rotating body of the pump unit are at least integrally connected, and a power transmission unit that transmits power from the outside is connected to the drive shaft. It can be started by external power. For this reason, a power generation unit does not need to have a function as an electric motor. Therefore, in this fluid machine, the power generation unit is configured to increase the power generation efficiency, and the power generation unit generates power with high efficiency.

Moreover, according to this fluid machine, the torque generated in the expansion unit can be output to the outside via the power transmission unit.
In the invention of claim 4, when the circulation path opening / closing valve is closed, the pressure drop prevention means prevents the pressure drop in the portion of the circulation path extending between the circulation path opening / closing valve and the expansion unit, thereby The unit does not operate like a vacuum pump. For this reason, even if the circulation path on-off valve is closed, an increase in power consumption of the expansion unit is suppressed, and power from the outside is preferentially converted into pressure and stored.

In the invention of claim 5, the pressure preventing means is configured with a simple configuration.
In the invention of claim 6, the pressure preventing means is configured with a simple configuration.

It is a figure showing roughly the composition of the waste heat utilization system of vehicles concerning a 1st embodiment. It is a schematic longitudinal cross-sectional view of the fluid machine applied to the system of FIG. It is a figure which shows roughly the structure of the waste heat utilization system of the vehicle which concerns on 2nd Embodiment. It is a figure which shows roughly the structure of the waste heat utilization system of the vehicle which concerns on 3rd Embodiment. It is a figure which shows roughly the structure of the waste heat utilization system of the vehicle which concerns on 4th Embodiment. It is a figure which shows roughly the structure of the waste heat utilization system of the vehicle which concerns on 5th Embodiment. It is a figure which shows the pressure drop prevention means of a modification. It is a figure which shows the outline of the pump unit of a modification. It is a figure which shows the outline of the electric power generation unit of a modification.

FIG. 1 shows a waste heat utilization system A for a vehicle according to the first embodiment, and the waste heat utilization system A recovers heat of exhaust gas discharged from an engine (internal combustion engine) 10 of the vehicle, for example. For this purpose, the waste heat utilization system A includes a Rankine circuit 12, and the Rankine circuit 12 has a circulation path 13 through which a working fluid (heat medium) circulates. The circulation path 13 is constituted by, for example, a pipe or a pipe.
A pump unit 16 of a fluid machine 14 is inserted in the circulation path 13 to allow the working fluid to flow. Further, a heater 18 and a fluid machine 14 are disposed downstream of the pump unit 16 in the direction in which the working fluid flows. The expansion unit 20 and the condenser 22 are sequentially inserted. That is, the pump unit 16 sucks the working fluid on the condenser 22 side, boosts the sucked working fluid, and then discharges the working fluid toward the heater 18. The working fluid discharged from the pump unit 16 is in a low-temperature and high-pressure liquid state.

  The heater 18 is a heat exchanger, and includes a low-temperature channel 18a that constitutes a part of the circulation path 13, and a high-temperature channel 18b that can exchange heat with the low-temperature channel 18a. The high temperature flow path 18b is inserted in an exhaust pipe 24 extending from the engine 10, for example. Accordingly, when passing through the heater 18, the low-temperature and high-pressure liquid working fluid receives the heat of the exhaust gas generated by the engine 10. As a result, the working fluid is heated to a high-temperature and high-pressure superheated steam state.

The expansion unit 20 of the fluid machine 14 expands the working fluid that has been in a superheated steam state, and thereby the working fluid is in a high-temperature and low-pressure superheated steam state.
The condenser 22 is a heat exchanger, which condenses the working fluid that has flowed out of the expansion unit 20 by heat exchange with the outside air to form a low-temperature and low-pressure liquid state. Specifically, an electric fan (not shown) is disposed in the vicinity of the condenser 22, and the working fluid is cooled by wind from the front of the vehicle or wind from the electric fan. The working fluid cooled by the condenser 22 is again sucked into the pump unit 16 and circulates in the circulation path 13.

  Here, the expansion unit 20 described above can not only expand the working fluid but also convert the thermal energy of the working fluid into torque (rotational force) and output the torque. In addition to the pump unit 16, a power generation unit 26 is connected to the expansion unit 20 so that torque output from the expansion unit 20 can be used. The power generation unit 26 is appropriately connected with an electrical load 28 such as a battery that uses or stores the generated power.

The fluid machine 14 has a power transmission unit 30 for inputting and outputting torque, and the power transmission unit 30 is, for example, an electromagnetic clutch. The electromagnetic clutch is operated by an ECU (electronic control unit) 31 and can transmit torque intermittently.
More specifically, as shown in FIG. 2, the expansion unit 20, the power generation unit 26, and the pump unit 16 are connected in series in this order.

The expansion unit 20 is, for example, a scroll type expander. The opening of the cup-shaped casing 32 (expansion unit casing) of the expansion unit 20 is substantially covered by the partition wall 34, and a through hole is formed at the center of the partition wall 34.
A fixed scroll 36 is fixed in the expansion unit casing 32, and a high-pressure chamber 38 is defined on the back side of the fixed scroll 36. The high pressure chamber 38 communicates with the heater 18 via an inlet port formed in the expansion unit casing 32 and a part of the circulation path 13 connected to the inlet port.

  On the front side of the fixed scroll 36, the movable scroll 40 is disposed so as to mesh. An expansion chamber 42 for expanding the working fluid is defined between the fixed scroll 36 and the movable scroll 40, and the periphery of the movable scroll 40 is defined as a low pressure chamber 44 for receiving the expanded working fluid. An introduction hole 46 is formed through substantially the center of the substrate of the fixed scroll 36, and the expansion chamber 42 and the high-pressure chamber 38 located at the center in the radial direction of the fixed and movable scrolls 36 and 40 communicate with each other through the introduction hole 46. To do.

  When the working fluid expands in the radially central expansion chamber 42, the volume of the expansion chamber 42 increases and the expansion chamber 42 moves radially outward along the spiral walls of the fixed and movable scrolls 36 and 40. The expansion chamber 42 finally communicates with the low pressure chamber 44, and the expanded working fluid flows into the low pressure chamber 44. The low pressure chamber 44 communicates with the condenser 22 through an outlet port (not shown) and a part of the circulation path 13 connected to the outlet port.

As the working fluid expands, the movable scroll 40 is swung with respect to the fixed scroll 36. This swiveling motion is converted into a rotating motion by the swivel mechanism.
That is, a boss is integrally formed on the rear surface of the substrate of the movable scroll 40, and an eccentric bush 50 is disposed in the boss via the needle bearing 48 so as to be relatively rotatable. A crankpin 52 is inserted into the eccentric bush 50, and the crankpin 52 protrudes eccentrically from the disk-shaped disk 54. From the opposite side of the disc 54 to the crankpin 52, a shaft portion 56 is integrally projected coaxially, and the shaft portion 56 is rotatably supported by the partition wall 34 via a radial bearing 58 such as a ball bearing. . That is, the turning motion of the movable scroll 40 is converted into the rotational motion of the shaft portion 56.

The turning mechanism has, for example, a ball coupling 60 in order to prevent rotation of the movable scroll 40 during the turning motion and to receive thrust pressure, and the ball coupling 60 is connected to the outer peripheral portion of the substrate of the movable scroll 40. The partition wall 34 is disposed between the outer peripheral portion and the opposing partition wall 34.
On the other hand, the pump unit 16 is, for example, a trochoid pump, but may be a gear pump. The pump unit 16 has a cylindrical casing (pump unit casing 62) that is open at both ends, and a pair of annular covers 64 are arranged in the pump unit casing 62 at a predetermined interval. Yes. Inner teeth 66 are rotatably disposed between these covers 64, and outer teeth 68 are fixedly disposed so as to surround the inner teeth 66.

  A pump chamber 70 is formed between the internal teeth 66 and the external teeth 68 to boost the working fluid as the internal teeth 66 rotate. The pump chamber 70 is connected to a suction port (not shown) and the suction port. The working fluid is sucked from the condenser 22 through a part of the circulation path 13. The working fluid pressurized in the pump chamber 70 is discharged toward the heater 18 through a discharge port (not shown) and a part of the circulation path 13 connected to the discharge port.

  In order to rotate the internal teeth 66, the internal teeth 66 are fixed to the drive shaft 72 so as to be integrally rotatable. The drive shaft 72 passes through the cover 64 and the pump unit casing 62, and also passes through the lid member 74 fixed to the opening end of the pump unit casing 62. The lid member 74 includes a cylindrical portion 76 and a flange portion 78, and the flange portion 78 is joined to the opening end of the pump unit casing 62.

Radial bearings 79 and 80 are disposed at both ends inside the cylindrical portion 76, and the cylindrical portion 76 rotatably supports the drive shaft 72 via the radial bearings 79 and 80. ing. Further, a shaft sealing member 81 such as a lip seal is disposed inside the cylinder portion 76, and the shaft sealing member 81 partitions the inside of the cylinder portion 76 in an airtight manner.
An electromagnetic clutch as the power transmission unit 30 is connected to one end of the drive shaft 72 protruding from the cylindrical portion 76.

  Specifically, the power transmission unit 30 includes a rotor 83 disposed on the outside of the cylindrical portion 76 via a radial bearing 82, and a pulley 84 is fixed to the outer peripheral surface of the rotor 83. A belt 86 is bridged between the pulley 84 and the pulley of the engine 10 as shown by a one-dot chain line, and the pulley 84 and the rotor 83 are rotatable by receiving power supply from the engine 10, for example. Further, a solenoid 86 is disposed inside the rotor 83, and the solenoid 86 generates a magnetic field by feeding power from the ECU 31.

  An annular armature 88 is disposed near the end face of the rotor 83, and the armature 88 is connected to the boss 92 via an elastic member 90 such as a leaf spring. The boss 92 is splined to one end of the drive shaft 72, so that the armature 88 can rotate integrally with the drive shaft 72. The armature 88 can be attracted to the end surface of the rotor 83 while resisting the urging force of the elastic member 90 by the magnetic field of the solenoid 86, and thus power can be transmitted between the rotor 83 and the armature 88. .

A cylindrical casing (power generation unit casing) 93 of the power generation unit 26 is sandwiched between the partition wall 34 and the pump unit casing 62. The expansion unit casing 32, the partition wall 34, the power generation unit casing 93, The pump unit casing 62 and the lid member 74 are connected to each other to constitute one housing for the fluid machine 14.
The other end of the drive shaft 72 reaches the through hole of the partition wall 34, and the other end of the drive shaft 72 is rotatably supported by the partition wall 34 via a needle bearing 94. Further, a one-way clutch 95 as a connecting member is fixed inside the other end of the drive shaft 72, and the other end of the drive shaft 72 and the shaft portion 56 of the turning mechanism are connected via the one-way clutch 95. .

  When the shaft 56 and the drive shaft 72 rotate in the same direction and the rotational speed of the shaft 56 is lower than the rotational speed of the drive shaft 72, the one-way clutch 95 is between the shaft 56 and the drive shaft 72. Shut off the power transmission. On the other hand, the one-way clutch 95 permits power transmission between the shaft portion 56 and the drive shaft 72 when the rotational speed of the shaft portion 56 is higher than the rotational speed of the drive shaft 72, and the shaft portion 56 and the drive shaft 72 And rotate together.

A rotor 96 is fixed to a portion of the drive shaft 72 extending in the power generation unit casing 93, and the rotor 96 is made of, for example, a permanent magnet. Therefore, the rotor 96 is arranged coaxially with the shaft portion 56 and the internal teeth 66.
A stator is fixed to the inner peripheral surface of the power generation unit casing 93 so as to surround the rotor 96. The stator includes a yoke 98 and, for example, three sets of coils 100 wound around the yoke 98. The coil 100 is wired so as to generate a three-phase alternating current as the rotor 96 rotates, and the generated alternating current is supplied to an external load 28 through a lead wire (not shown).

Since the power generation unit 26 does not have a function as an electric motor, the shape of the yoke 98, the number of turns of the coil 100, and the like are configured to increase power generation efficiency.
Hereinafter, a method of using the above-described vehicle waste heat utilization system A will be described focusing on the operations of the fluid machine 14 and the Rankine circuit 12.

<Startup>
When the ECU 31 turns on the power transmission unit 30 to activate the Rankine circuit 12, the power of the engine 10 is input to the drive shaft 72. As the drive shaft 72 rotates, the internal teeth 66 of the pump unit 16 rotate, and the pump unit 16 sucks the working fluid upstream, boosts the sucked working fluid, and discharges it downstream.

As a result, the working fluid circulates in the circulation path 13, and the working fluid is heated by the heater 18 and expanded by the expansion unit 20.
Immediately after the Rankine circuit 12 is started, the pressure of the working fluid in the circulation path 13 is low, so the rotational speed of the movable scroll 40, in other words, the rotational speed of the shaft portion 56 of the turning mechanism is smaller than the rotational speed of the drive shaft 72. Is also low. Therefore, the one-way clutch 95 blocks power transmission between the shaft portion 56 and the drive shaft 72.

<Autonomous operation and power generation>
When the pressure of the working fluid in the circulation path 13 is sufficiently increased after the Rankine circuit 12 is activated, the rotational speed of the shaft portion 56 of the turning mechanism tends to be higher than the rotational speed of the drive shaft 72. When the rotational speed of the shaft portion 56 of the turning mechanism in the free state becomes higher than the rotational speed of the drive shaft 72, the one-way clutch 95 is locked and the shaft portion 56 and the drive shaft 72 rotate integrally.

When the torque transmitted from the shaft portion 56 to the drive shaft 72 becomes large enough for the operation of the pump unit 16, the ECU 31 turns off the power transmission unit 30 and cuts off the power supply from the engine 10. Thereby, the fluid machine 14 shifts to an autonomous operation in which the pump unit 16 is operated using the torque generated in the expansion unit 20.
On the other hand, with the rotation of the drive shaft 72, the rotor 96 of the power generation unit 26 rotates, and the power generation unit 26 generates an alternating current. The alternating current is supplied to the load 28 and appropriately stored or consumed by the load 28. The load 28 may include a rectifier that converts alternating current into direct current.

<Regenerative brake>
After the fluid machine 14 shifts to autonomous operation, the load on the engine 10 is reduced. However, when the vehicle is braked or decelerated, the ECU 31 may turn on the power transmission unit 30, that is, connect an electromagnetic clutch. As a result, the fluid machine 14 functions as a regenerative brake, and not only an auxiliary load for deceleration is applied to the engine 10, but also the power generation unit 26 generates power, and the kinetic energy of the vehicle is converted into electric power.

<Others>
Further, the torque of the fluid machine 14 may be supplied to the engine 10 without shifting the fluid machine 14 to autonomous operation. That is, a portion of the torque generated by the expansion unit 20 that exceeds the torque consumed by the pump unit 16 and the power generation unit 26 may be output to the engine 10 via the power transmission unit 30.

As described above, the waste heat utilization system A for the vehicle according to the first embodiment converts the waste heat generated in the engine 10 of the vehicle into electric power by the fluid machine 14, so that the fuel efficiency of the vehicle is improved.
The waste heat utilization system A has a simple configuration because one fluid machine 14 has functions of a pump, a generator, and an expansion unit.
In particular, in the fluid machine 14, since the internal teeth 66 of the pump unit 16, the shaft portion 56 of the expansion unit 20, and the rotor 96 of the power generation unit 26 are coaxially arranged, the fluid machine 14 can be reduced in size. . For this reason, the fluid machine 14 is light weight and low in cost, and can be easily mounted on a vehicle.

  Further, in the fluid machine 14, the drive shaft 72 and the internal teeth 66 of the pump unit 16 are at least integrally connected, and the power transmission unit 30 that transmits power from the outside is connected to the drive shaft 72. The unit 16 can be activated by external power. For this reason, the power generation unit 26 may not have a function as an electric motor. Therefore, in the fluid machine 14, the power generation unit 26 is configured to increase the power generation efficiency, and the power transmitted by the drive shaft 72 is converted into electric power with high efficiency.

Furthermore, according to the fluid machine 14, the torque generated in the expansion unit 20 can be output to the outside and used depending on the situation, and the power of the engine 10 can be supplemented.
Further, in the above-described waste heat utilization system A, after the pump unit 16 of the fluid machine 14 is activated by external power, the shaft unit 56 of the expansion unit 20 is connected while the rotational speed is lower than the rotational speed of the drive shaft 72. A one-way clutch 95 as a member interrupts power transmission between the shaft portion 56 and the drive shaft 72. As a result, the load applied to the drive shaft 72 is reduced for a predetermined period after the pump unit 16 is started, and the power consumption of the fluid machine 14 is reduced.

The present invention is not limited to the first embodiment described above, and various modifications are possible.
For example, the waste heat utilization system A converts the heat of the exhaust gas into electric power, but may convert the heat of the cooling water of the engine 10 into electric power. Further, the waste heat utilization system A can be applied to other than the vehicle, but is suitable for the vehicle because the connection between the engine 10 and the power transmission device 30 is easy.

The power generation unit 26 of the fluid machine 14 generates an alternating current, but may generate a direct current. However, the power generation unit 26 that generates an alternating current is lighter than a direct current generator (direct current motor), has high power generation efficiency, and does not require a brush, so that maintenance is easy.
The drive shaft 72 of the fluid machine 14 is configured by a single member, but a plurality of members may be integrally connected by a joint or the like to configure the drive shaft.

In the fluid machine 14, the power transmission unit 30 is an electromagnetic clutch capable of interrupting power, but it may be a simple pulley that constantly transmits power. However, in the case of an electromagnetic clutch, torque input / output between the fluid machine 14 and the outside can be appropriately interrupted.
FIG. 3 shows a schematic configuration of a vehicle waste heat utilization system B according to the second embodiment. In addition, about the structure same as the waste heat utilization system A of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The waste heat utilization system B further includes a check valve 102 and a circulation path opening / closing valve 104. The check valve 102 is inserted in a part of the circulation path 13 extending between the pump unit 16 and the heater 18 of the fluid machine 14, and allows the working fluid to pass only in the direction from the pump unit 16 to the heater 18. To do. The circulation path opening / closing valve 104 is inserted in a portion of the circulation path 13 extending between the heater 18 and the expansion unit 20 of the fluid machine 14, and can open and close the circulation path 13 based on a signal from the ECU 31.

Moreover, the waste heat utilization system B has a pump bypass means. The pump bypass means includes an external bypass path 106 provided in the circulation path 13 in parallel with the pump unit 16 and a bypass path opening / closing valve 108 inserted in the external bypass path 106. The bypass path opening / closing valve 108 is an electromagnetic valve, and can open and close the external bypass path 106 based on a signal from the ECU 31.
In this waste heat utilization system B, the circulation path 13 is closed in front of the expansion unit 20 by the circulation path opening / closing valve 104, so that the power from the outside is applied to the part of the circulation path 13 extending from the check valve 102 to the circulation path opening / closing valve 104. Is stored as pressure energy. The stored pressure energy is converted into torque by the expansion unit 20 by opening the circulation path opening / closing valve 104, and then converted into electric power by the power generation unit 26 (accumulated pressure regeneration). That is, in this waste heat utilization system B, the power from the outside can be stored in a form other than electric power depending on the situation.

  In the waste heat utilization system B, the work of the pump unit 16 is reduced by bypassing the pump unit 16 by the pump bypass means. Accordingly, power input from the outside can be preferentially used for power generation in the power generation unit 16. In other words, depending on the situation, the fluid machine 14 can be used only as a generator, thereby reducing the number of external generators (alternators) and reducing the weight of the vehicle.

FIG. 4 shows a schematic configuration of a vehicle waste heat utilization system C according to the third embodiment. In addition, about the structure same as the waste heat utilization system A of 1st Embodiment, and the waste heat utilization system B of 2nd Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
In the fluid machine 110 applied to the waste heat utilization system C, the power transmission unit 30 and the internal teeth 66 of the pump unit 16 are integrally connected to the first drive shaft 112. The rotor 96 of the power generation unit 30 and the shaft portion 56 of the expansion unit 20 are integrally connected to the second drive shaft 114, and the first drive shaft 112 and the second drive shaft 114 are connected by a one-way clutch 116 as a connecting member. It is connected.

  The one-way clutch 116 has a first drive shaft 112 and a second drive shaft 114 when the rotation speed of the second drive shaft 114, that is, the rotation speed of the shaft portion 56 and the rotor 96 is lower than the rotation speed of the first drive shaft 112. And power transmission between the first drive shaft 112 and the first drive shaft 112 are interrupted. On the other hand, the one-way clutch 116 allows power transmission between the first drive shaft 112 and the second drive shaft 114 when the rotational speed of the second drive shaft 114 is higher than the rotational speed of the drive shaft 72. The first drive shaft 112 and the second drive shaft 114 rotate together.

Even in the waste heat utilization system C, power transmission from the first drive shaft 112 to the second drive shaft 114 is interrupted by the one-way clutch 116 for a predetermined period after the fluid machine 110 is started, and the power consumption of the fluid machine 110 is Is reduced.
On the other hand, the torque generated by the expansion unit 30 is not only converted into electric power by the power generation unit 26, but also when the rotational speed of the second shaft portion 114 is higher than the rotational speed of the first drive shaft 112, the one-way clutch 116. Is transmitted to the first drive shaft 112 via. The torque transmitted to the first drive shaft 112 is used as power for the pump unit 16, and if this torque is sufficiently large, the fluid machine 110 can operate without receiving external power. Furthermore, the torque generated in the expansion unit 20 can be output to the outside via the power transmission unit 30.

Also in the waste heat utilization system C, pressure energy can be stored by closing the circulation path on-off valve 104, and the stored pressure energy can be converted into electric power. Note that the check valve 102 and the circulation path opening / closing valve 104 may be deleted from the waste heat utilization system C as in the waste heat utilization system A.
FIG. 5 shows a schematic configuration of a vehicle waste heat utilization system D according to the fourth embodiment. In addition, about the structure same as waste-heat utilization system AC, the same code | symbol is attached | subjected and description is abbreviate | omitted.

In the fluid machine 120 applied to the waste heat utilization system D, the power transmission unit 30, the internal teeth 66 of the pump unit 16, the rotor 96 of the power generation unit 30, and the shaft portion 56 of the expansion unit 20 are one piece. The drive shaft 122 is integrally connected.
The waste heat utilization system D further includes an external return path 124 provided in the circulation path 13 in parallel with the expansion unit 20 and an electromagnetic valve 126 as a return path opening / closing valve inserted in the external return path 124. . The electromagnetic valve 126 can open and close the external return path 124 based on a signal from the ECU 31.

  Even in the fluid machine 120 of the waste heat utilization system D, the power is stored as pressure energy while the circulation path opening / closing valve 104 closes the circulation path 13, but the movable scroll 40 of the pump unit 20 is swung. doing. Therefore, in this waste heat utilization system D, when the circulation path opening / closing valve 104 closes the circulation path 13, the solenoid valve 126 is opened to open the external return path 124, thereby expanding the circulation path opening / closing valve 104 and the expansion path opening / closing valve 104. It suppresses that the pressure of the part of the circulation path 13 extended between the units 20 falls. Thus, the expansion unit 20 is prevented from operating like a vacuum pump, and an increase in load applied to the drive shaft 122 from the expansion unit 20 is suppressed.

Further, after the fluid machine 120 is started, until the pressure of the working fluid in the circulation path 13 sufficiently increases, even if the circulation path 13 is opened by opening the circulation path open / close valve 104, the electromagnetic valve 126 Is opened to open the external return path 124, thereby bypassing the expansion unit 20. As a result, the load applied to the drive shaft 122 from the expansion unit 20 is reduced for a predetermined period after activation.
After the fluid machine 120 is started, after the pressure of the working fluid has sufficiently increased, the solenoid valve 126 is closed and the external return path 124 is closed, so that the fluid machine 120 shifts to autonomous operation.

Note that the external return path 124 and the electromagnetic valve 126 may be deleted from the waste heat utilization system D, and the check valve 102 and the circulation path on-off valve 104 may be deleted.
FIG. 6 shows a schematic configuration of a vehicle waste heat utilization system E according to the fifth embodiment. In addition, about the structure same as waste heat utilization system AD, the same code | symbol is attached | subjected and description is abbreviate | omitted.
The waste heat utilization system E includes a check valve 128 as a return path opening / closing valve. The check valve 128 allows the working fluid to flow from downstream to upstream when the pressure immediately downstream of the expansion unit 20 becomes lower than the pressure immediately upstream. The check valve 128 autonomously suppresses the pressure in the portion of the circulation path 13 extending between the circulation path opening / closing valve 104 and the expansion unit 20 from decreasing. As a result, the check valve 128 reduces the burden on the drive shaft 122 from the expansion unit 20 when accumulating pressure energy or for a predetermined period after activation, like the solenoid valve 126.

In the waste heat utilization systems D and E described above, the external return path 124 and the return path opening / closing valve serve as means for preventing a pressure drop in the portion of the circulation path 13 extending between the circulation path opening / closing valve 104 and the expansion unit 20. Although functioning, the pressure drop prevention means is not limited to these.
For example, the pressure drop prevention means may be a capacity variable means of the expansion unit 20. For example, as shown in FIG. 7, the capacity varying means has a bypass hole 130 formed in the substrate of the fixed scroll 36. The bypass hole 130 communicates with the introduction hole 46 or the high-pressure chamber 38 through an internal flow path 132, and a capacity control valve 134 is inserted in the internal flow path 132. The ECU 31 can control the opening / closing operation of the capacity control valve 134, whereby the capacity of the expansion unit 20 is variable. In this case, by opening the capacity control valve 134 and opening the internal flow path 132, the same effect as opening the return path 124 by opening the return on-off valve can be obtained. When the capacity varying means is used as the pressure drop preventing means, the capacity control valve 134 corresponding to the return path opening / closing valve may be a check valve.

Furthermore, in the waste heat utilization systems B, D, and E described above, the external bypass passage 106 and the bypass passage opening / closing valve constitute the pump bypass means, but the pump bypass means is not limited to this.
For example, as shown in FIG. 8, an internal bypass passage 140 that connects the upstream pump chamber 70 and the downstream pump chamber 70 is provided, and a bypass passage opening / closing valve 142 is inserted into the internal bypass passage 140. Good. The opening / closing operation of the bypass passage opening / closing valve 142 is controlled by the ECU 31.

In this case, when the ECU 31 opens the internal bypass passage 140 by opening the bypass passage opening / closing valve 142, the working fluid in the pressure increasing process is released. As a result, work in the pump unit 16 can be reduced, and torque input from the outside can be used only for power generation in the power generation unit 26.
In the first to fifth embodiments, a permanent magnet is used as the rotor 96 of the power generation unit 26, but an electromagnet may be used. In this case, as shown in FIG. 9, if the amount of current supplied to the field coil (motor coil) 150 provided in the rotor is adjusted by the ECU 31, the amount of power generation can be controlled and consumed by the power generation unit 26. Torque can be adjusted. If this is utilized, the power from the outside can be appropriately distributed to the pump unit 16, the power generation unit 26 and the expansion unit 20 depending on the situation, or the torque generated in the expansion unit 20 can be distributed to the pump unit 16 and The power generation unit 26 can be appropriately distributed.

  Specifically, when the fluid machines 14 and 120 are started up, the power generation amount can be reduced to suppress the drive torque of the power generation unit 26, and after shifting to autonomous operation, the power generation amount can be increased. Further, when the pressure energy is stored, the drive torque of the power generation unit 26 can be suppressed by reducing the power generation amount. Further, at the time of braking or deceleration of the vehicle, the power generation amount may be increased to increase the driving torque of the power generation unit 26 to increase the braking force to the engine 10.

  In the first to fifth embodiments, the pump unit 16 is a trochoid type, but the type of the pump unit is not particularly limited. Further, although the expansion unit 20 is a scroll type, the type of the expansion unit is not particularly limited. For example, the expansion unit 20 may be reciprocating. In this case, the arrangement of the pump unit 16, the power generation unit 26, and the expansion unit 20 is not particularly limited.

A Vehicle waste heat utilization system
12 Rankine circuit
14 Fluid machinery
16 Pump unit
20 Expansion unit
26 Power generation unit
56 Shaft (second rotating body)
66 Internal teeth (first rotating body)
72 Drive shaft
96 rotor (third rotor)

Claims (6)

A pump unit that boosts and discharges the sucked working fluid into a circulation path for circulating the working fluid, a heater, an expansion unit that can convert the thermal energy of the working fluid into torque, and a condenser. And a waste heat utilization system having a Rankine circuit inserted sequentially.
A power transmission unit for inputting / outputting torque to / from the outside is connected to the drive shaft to which the pump unit is connected,
The Rankine circuit is
A check valve interposed in a portion of the circulation path extending between the pump unit and the heater;
A waste heat utilization system comprising: a circulation path opening / closing valve interposed in a portion of the circulation path extending between the heater and the expansion unit.   The waste heat utilization system according to claim 1, wherein a power generation unit is connected to the expansion unit in addition to the pump unit. The expansion unit, the pump unit, and the power generation unit constitute a fluid machine,
The fluid machine has a first rotating body, sucks the working fluid with the rotation of the first rotating body, pressurizes the sucked working fluid, and then discharges the working fluid.
An expansion unit that has a second rotating body, receives the working fluid while the second rotating body rotates, and expands the received working fluid and then delivers the working fluid;
The power generation unit having a third rotating body arranged coaxially with the first and second rotating bodies, and generating electric power with the rotation of the third rotating body;
The drive shaft integrally connected to at least the first rotating body among the first, second and third rotating bodies;
The waste heat utilization system according to claim 2, further comprising the power transmission unit coupled to the drive shaft and transmitting power from the outside to the drive shaft.   Pressure reduction preventing means for preventing a pressure drop in a portion of the circulation path extending between the circulation path on-off valve and the expansion unit when the expansion unit is operated when the circulation path on-off valve is closed; The waste heat utilization system according to any one of claims 1 to 3, further comprising: The pressure drop preventing means is
An external return path provided in parallel with the expansion unit in the circulation path;
The waste heat utilization system according to claim 4, further comprising a return path opening / closing valve that opens and closes the external return path. The pressure drop preventing means is
An internal return path that is provided in the expansion unit of the fluid machine and returns the heat medium after the expansion process or expansion to the upstream side;
The waste heat utilization system according to claim 4, further comprising a return path opening / closing valve that opens and closes the internal return path.

Images