JP2015068279A - Vehicle mounted with waste heat recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle mounted with a waste heat recovery device which has achieved improvement of travel fuel economy of a vehicle and reduction in cost by reducing driving of an alternator with a motor by an internal combustion engine, by alternator driving by power taken out by a waste heat recovery device and by starting the internal combustion engine by the alternator with a motor.SOLUTION: A vehicle mounted with a waste heat recovery device includes: an alternator with a motor 3; a first clutch 17 for performing connection/disconnection of an expander 23 and the alternator with a motor 3; a second clutch 33 for performing connection/disconnection of an internal combustion engine 1 and the alternator with a motor 3; a battery 7; and a control device 8 for performing connection/disconnection control of the first and the second clutches 17, 33. The control device 8 has: start means for connecting the second clutch 33 and starting the internal combustion engine 1; power generation means for connecting only the second clutch 33 and generating power by the alternator with a motor 3 while running down the slope; and generation means for generating power by a waste heat recovery device 2 by only connecting the first clutch 17 at the time other than on the downward slope.

Description

  The present invention relates to a vehicle having a waste heat recovery device and a motor-equipped alternator and equipped with a waste heat recovery device that performs efficient power generation.

In a vehicle equipped with an internal combustion engine, the heat efficiency of the internal combustion engine is improved by regenerating power from waste heat energy of the internal combustion engine by a waste heat recovery device (Rankine cycle circuit).
The Rankine cycle circuit is a circuit that recovers waste heat energy as power by passing a medium heated by waste heat energy of an internal combustion engine through an expander.
By driving the generator with this power, the waste heat energy can be recovered as electric power.

On the other hand, the internal combustion engine of the vehicle is provided with an alternator that generates electric power by the driving force of the internal combustion engine, and covers the electric power consumed by the vehicle.
Therefore, a vehicle equipped with a Rankine cycle circuit has two generators separately, but mounting components having the same function is disadvantageous from the viewpoints of mountability and cost.
A technique for solving such a situation is disclosed in Patent Document 1.

According to Patent Document 1, a generator that serves as both an alternator for an internal combustion engine and a generator for a Rankine cycle circuit, a first power transmission mechanism that transmits the power of the internal combustion engine to the generator via a first clutch, and a Rankine cycle A second power transmission mechanism for transmitting the power recovered by the circuit to the generator via the second clutch; and a clutch control means for controlling the engaged state of the first and second clutches.
Furthermore, when the amount of waste heat of the internal combustion engine enables power recovery by the Rankine cycle circuit, a technical disclosure is made in which the first clutch is disconnected and the second clutch is connected.

In this way, by controlling the engagement state of the first and second clutches, it is possible to switch whether to drive the generator using either the power of the internal combustion engine or the recovered power of the Rankine cycle circuit. .
When power recovery by the Rankine cycle circuit becomes possible, the alternator drive is switched from the internal combustion engine to recovery power by the Rankine cycle circuit to improve the thermal efficiency of the internal combustion engine.

JP 2009-278723 A

According to Patent Document 1, when the amount of waste heat of the internal combustion engine decreases, power is generated by the alternator by the driving force of the internal combustion engine.
Therefore, when the alternator drive source is frequently switched depending on the traveling state of the vehicle and the alternator drive is performed by the driving force of the internal combustion engine, the motive power of the internal combustion engine is consumed, so the traveling fuel consumption of the vehicle deteriorates. have.

  In view of the technical problem, the present invention reduces the drive of the motor-equipped alternator by the internal combustion engine, drives the alternator with the power extracted by the waste heat recovery device, and starts the internal combustion engine with the motor-equipped alternator. An object of the present invention is to provide a vehicle equipped with a waste heat recovery device that improves the driving fuel consumption and reduces the cost.

In order to solve this problem, the present invention recovers waste heat energy of an internal combustion engine as power, and in a vehicle equipped with a waste heat recovery device that drives a generator with the recovered power,
An alternator with a motor that is capable of connecting / disconnecting power with the expander of the waste heat recovery device and that generates power by the power of the expander;
A first clutch for connecting and disconnecting the power between the expander and the alternator with motor;
A second clutch for connecting and disconnecting power between the internal combustion engine and the alternator with motor;
A battery for storing electric power generated by the alternator with motor;
A control device for performing connection / disconnection control of the first clutch and the second clutch,
The control device connects the second clutch, drives the motor-equipped alternator with electric power from the battery, and starts the internal combustion engine; and
The alternator power generation means for generating power by driving the alternator by connecting the second clutch when the vehicle is going downhill, and disconnecting the second clutch and connecting the first clutch at times other than downhill Thus, it is possible to provide a vehicle equipped with a waste heat recovery device, characterized in that it has waste heat recovery power generation means for generating power with the waste heat recovery device.

According to this invention, since the internal combustion engine is started by the alternator with a motor, the starter of the internal combustion engine can be dispensed with, and the cost can be reduced.
In addition, when it is downhill without fuel injection, it is recovered by electricity with an alternator, and it is recovered only with a waste heat recovery device except during downhill, and the drive of the alternator by the internal combustion engine is stopped except during downhill. Fuel consumption can be improved.

  According to this invention, the driving of the alternator with a motor by the internal combustion engine is reduced, and the alternator is driven by the power extracted by the waste heat recovery device, and the internal combustion engine is started by the alternator with the motor, thereby improving the running fuel efficiency of the vehicle. It is possible to provide a vehicle equipped with a waste heat recovery device that reduces costs.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which represented typically the whole concerning embodiment of this invention is shown. The schematic block diagram of the electric power generating apparatus by the waste-heat recovery apparatus and alternator concerning embodiment of this invention is shown. The explanatory view of the power generation situation concerning the embodiment of the present invention is shown. The control flowchart which implements this invention is shown.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
However, the dimensions, materials, and relative arrangements of the components described in this embodiment are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Absent.

FIG. 1 is a configuration diagram schematically showing the whole according to an embodiment of the present invention.
FIG. 1 shows an internal combustion engine (hereinafter referred to as an engine) 1 mounted on a vehicle, and a waste heat recovery device (Rankine) that extracts waste heat of engine cooling water and exhaust gas, which is a waste heat recovery source of the engine 1, as electric power. Cycle circuit) 2 and motor-mounted alternator 3 that mechanically connects or disconnects the driving force of engine 1 via a clutch mechanism constitutes a power generator.
The electric power generated by the alternator with motor 3 and the waste heat recovery device 2 is used as a power source for various devices for the vehicle 6 to travel, and the battery 7 is charged with the surplus power source.

FIG. 2 is a schematic configuration diagram of a power generation device including a waste heat recovery device and an alternator.
An alternator 3 with a motor is attached to the engine 1.
The alternator with motor 3 is provided with a transmission 32 that is integrally assembled with the alternator with motor 3.
The transmission 32 transmits the driving force of the engine 1 to the alternator 3 with a motor via the second clutch 33.
When transmitting power from the engine 1 side, the transmission 32 transmits the rotational speed at an increased speed to the alternator 3 with motor, and transmits the rotational speed from the alternator 3 with motor to the second clutch side. Is supposed to slow down.
The clutch 33 is transmitted with power from the engine 1 by a drive belt 35 through a pulley 34 attached to the clutch 33 and a pulley 13 on the engine 1 side.
The motor-mounted alternator 3 can also start the engine 1 via the transmission 32 and the second clutch 33 (connection) by the electric power from the battery 7 when the engine is started. (Internal combustion engine starting means)

The waste heat recovery apparatus 2 uses the exhaust gas of the engine 1 introduced through the exhaust pipe 12 and the cooling water R of the engine 1 introduced through the cooling water passage 11 as heat sources, and the working fluid P and heat of the waste heat recovery apparatus 2 The evaporator 22 to be exchanged, the expander 23 that expands the working fluid P that has become high pressure and high temperature in the evaporator 22 to extract power, the condenser 24 that condenses the working fluid P operated by the expander 23, and the condensation The working fluid P is compressed and pressurized, and the working fluid pump 21 driven by an electric motor that is pumped to the evaporator 22 is connected to each device constituting the waste heat recovery device 2 to circulate the working fluid P. And a working fluid circulation path 25 to be made.
24 a is a blower fan that blows outside air to the condenser 24 and promotes condensation of the working fluid P.
The expander 23 is disposed so as to be connectable / disconnectable to the alternator 3 with a motor via the first clutch 17.
In addition, the cooling water R and exhaust gas used as a heat source heat the cooling water R discharged from the engine 1 with the exhaust gas, introduce the heated cooling water R into the evaporator 22, and cool the working fluid P and the exhaust gas. Heat exchange with water R is performed.
In the present embodiment, the cooling water R is heated as the heat source with the exhaust gas and introduced into the evaporator 22. However, either the cooling water R or the exhaust gas is directly introduced into the evaporator 22. Also good.
A radiator 14 cools the cooling water R when the temperature of the cooling water returned from the evaporator 22 to the cooling water channel 11 is high.

A control device 8 controls the operation of each device of the waste heat recovery device 2.
The control device 8 includes a power generation amount W from the motor-mounted alternator 3, a cooling water temperature Tr that is disposed in the cooling water passage in the engine 1 and detected by the temperature sensor 82, and a voltage from the battery sensor 83 that detects the charge capacity of the battery 7. V is input.
On the other hand, the control device 8 outputs to the battery 7 based on the connection / disconnection control signals C1 and C2 of the first and second clutches 17 and 33 and the power generation amount W from the motor-mounted alternator 3 based on the input signal. Vj (charging), the vehicle-side electric load Wo consumed by the devices 6 mounted on the vehicle, the drive control signal Wm of the working fluid pump 21 of the waste heat recovery apparatus 2, and the condenser 24 to cool the condenser 24 The rotation control signal Wf of the electric fan 24 that blows outside air to the container 24 is transmitted.

The power generation method will be described based on the vehicle power generation state explanatory diagram of FIG. 3 and the control flow of FIG.
In the present embodiment, when the vehicle stops due to a signal, traffic jam or the like, the engine 1 is stopped, and the engine 1 is automatically started by operating a brake pedal, a clutch pedal, or the like when starting traveling. An example of a vehicle equipped with an idle stop & start device (ISS) will be described.
In step S1, the control device 8 is started.
In step S2, the ISS device is started and the engine 1 is started by the electric power supplied from the battery 7 to the alternator 3 with motor. The vehicle travels in this state.
In step S3, it is determined whether the ISS stops or operates (operates) the engine 1.
When the ISS is turned on (stops the engine 1), YES is selected and the engine 1 is stopped in step S4.
When the engine 1 stops, the vehicle maintains a stopped state.
In step S5, it is determined whether the engine 1 is restarted or the stopped state is continued.
When the stop state is continued, the process returns to step S4 and the stop state of the engine 1 continues.
In step S5, when the driver operates the brake pedal, the clutch pedal, etc., it is determined that the engine is restarted, the process returns to step S2, and the ISS is turned on (starts the engine 1) to start the engine 1. .
Steps S1 to S5 represent ISS operation control.

When the engine 1 is started in step S2 and the vehicle starts to move in step S3, NO is selected and the process proceeds to step S6.
In step S6, it is determined whether the engine speed is engine speed N> specified speed No and fuel injection amount = 0 (no fuel injection state).
This detects a state in which the vehicle is descending and the engine 1 is not injecting fuel, as shown in region C of FIG.
When the running state of the vehicle is a flat road or climbing, if the rotational speed is No or higher and fuel injection is being performed, NO is selected and the process proceeds to step S7.
In step S7, disconnection of the second clutch 33 and connection control of the first clutch 17 are executed.
That is, the expander 23 of the waste heat recovery apparatus 2 and the motor-mounted alternator 3 are connected by the first clutch 17, while the motor-mounted alternator 3 and the second clutch that transmits the driving force from the engine 1 are disconnected (waste). Heat recovery power generation means).
When the waste heat recovery power generation means is executed, the process proceeds to step S8.

In step S8, power generation is performed only by the waste heat recovery apparatus 2.
This state shows the traveling state of the A region or the B region in FIG.
That is, the fuel is injected and the engine rotational speed N> Nw is the specified rotational speed, the cooling water temperature becomes high, and the amount of heat energy recovered in the waste heat recovery device 2 increases.
On the other hand, since the motor-mounted alternator 3 and the second clutch that transmits the driving force from the engine 1 are disconnected, the engine 1 can reduce the load for driving the motor-mounted alternator 3, and the vehicle running fuel efficiency can be improved. .

Proceed to step S9. In step S <b> 9, the waste heat power generation amount W ≧ vehicle-side electric load amount Wo of the waste heat recovery apparatus 2 is determined.
In step S9, if the waste heat power generation amount W of the waste heat recovery apparatus 2 is equal to or greater than the vehicle-side electric load Wo, YES is selected and the process proceeds to step S10.

In step S10, the waste heat power generation amount W of the waste heat recovery apparatus 2 is determined again as the vehicle-side electric load amount Wo. If YES in step S10, the process proceeds to step S11, and the entire amount of electric power generated by the waste heat recovery apparatus 2 is supplied to the electric load on the vehicle side.
The electric load on the vehicle side is electric devices that are necessary during traveling of the vehicle, such as lamps, audio, and air conditioner.
If NO is selected in step S10, that is, if the waste heat power generation amount W of the waste heat recovery device 2> the vehicle-side electric load amount Wo, the vehicle-side electric load amount Wo is set to the vehicle side in step S20. The battery 7 is charged with the difference between the waste heat power generation amount W and the vehicle-side electric load amount Wo = Δα.

In step S9, if the waste heat power generation amount W of the waste heat recovery device 2 <the vehicle-side electric load amount Wo, NO is selected and the process proceeds to step S12.
In step S12, the first and second clutches 17 and 33 are controlled to the connected state, and the process proceeds to step S13.
In step S13, the alternator with motor 3 generates power by the driving force from the waste heat recovery device 2 and the driving force from the engine 1, and the process proceeds to step S14.
Also in this case, the load of the engine 1 that drives the motor-mounted alternator 3 is reduced by the driving force of the waste heat recovery device 2, so that the engine 1 is in a fuel-saving operation.
In this state, when the waste heat power generation amount W of the waste heat recovery device 2 cannot cover the vehicle-side electrical load Wo, the cooperative power generation amount Wg by the waste heat energy of the waste heat recovery device and the engine load is used. 3 covers the vehicle-side electrical load Wo, and shows regions D and E in FIG.

In step S14, it is determined whether the cooperative power generation amount Wg ≧ the vehicle-side electric load Wo from the waste heat energy + the engine load.
When the vehicle-side electric load Wo is larger than the cooperative power generation amount Wg, NO is selected and the entire amount is used for the vehicle-side electric load Wo.
However, in the case of cooperative power generation amount Wg by waste heat energy + engine load <vehicle-side electric load Wo, the insufficient power is replenished from the battery 7.
In step S14, if cooperative power generation amount Wg ≧ vehicle-side electric load Wo, YES is selected and the process proceeds to step S15.
In step S15, the cooperative power generation amount Wg = vehicle-side electric load Wo is determined.
If the cooperative power generation amount Wg is equal to the vehicle-side electric load Wo, YES is selected, and the process proceeds to step S11 to use all the power generation amount for the vehicle-side electric load Wo.
On the other hand, if the cooperative power generation amount Wg> the vehicle-side electric load Wo is determined in step S15, the process proceeds to step S20.
In step S20, the vehicle-side electric load Wo is supplied to the vehicle side, and the battery 7 is charged with the difference between the cooperative power generation amount Wg and the vehicle-side electric load Wo = Δβ.

In step S6, when the engine speed N> No specified speed and the fuel injection amount = 0 (no fuel injection state), that is, the vehicle runs in a no-load operation state.
In this case, YES is selected and the process proceeds to step S16.
In step S16, an operation of connecting the second clutch 33 and disconnecting the first clutch 17 on the expander 23 side is executed (alternator power generation means).
When the alternator power generation means is executed, the process proceeds to step S17.
This corresponds to no-load running in step S17, that is, downhill in region C in FIG.
During downhill, the engine 1 is rotated by the downhill running energy of the vehicle in the order of the driving system (not shown), the drive system, the transmission clutch, and the engine 1, and the pulley 13 on the engine 1 side, the drive belt 35, the pulley 34 and the second clutch 33 are transmitted to the transmission 32 in this order.
Since the speed change device 32 increases the rotational speed from the second clutch side and transmits it to the alternator 3 with motor, the power generation efficiency of the alternator 3 with motor is improved.

In step S18, the no-load power generation amount Wf ≧ the vehicle-side electric load Wo is determined.
When the no-load power generation amount Wf <the vehicle-side electric load Wo, NO is selected and the total power generation amount is supplied to the vehicle-side electric load Wo.
However, when the no-load power generation amount Wf <the vehicle-side electric load Wo, the insufficient power is replenished from the battery 7.
On the other hand, if the no-load power generation amount Wf ≧ the vehicle-side electric load Wo, YES is selected and the process proceeds to step S19.
In step S19, the no-load power generation amount Wf = vehicle-side electric load Wo is determined again.
In the case of no-load power generation amount Wf = vehicle-side electric load Wo, YES is selected and the process proceeds to step S11, where the entire amount is supplied as the vehicle-side electric load Wo.
On the other hand, if the no-load power generation amount Wf> the vehicle-side electric load Wo, the process proceeds to step S20. In step S20, the vehicle-side electric load Wo is supplied to the vehicle side, and the no-load power generation amount Wf−the vehicle-side electric load Wo. = The difference of Δγ is charged in the battery 7.

By doing in this way, a starter motor can be abolished and cost reduction becomes possible.
When flat and uphill, the motor-driven alternator 3 is driven only with waste heat recovery energy to collect electricity, and when there is no fuel injection during downhill, the motor-driven alternator 3 is driven using the downhill energy of the vehicle. Since the control method is to perform the fuel consumption improvement effect.
Moreover, since the alternator 3 with a motor is not driven except when the waste heat power generation amount W is smaller than the load power generation amount Wg at a downhill, the durability of the motor alternator 3 is improved.

  In the present embodiment, the description is given in the case of a vehicle equipped with an idle stop & start device (ISS). Therefore, explanation is omitted.

  It can be used for a waste heat recovery device of an internal combustion engine using Rankine cycle.

1 engine (internal combustion engine)
DESCRIPTION OF SYMBOLS 2 Waste heat recovery apparatus 3 Motor alternator 6 Vehicle side electric load 7 Battery 8 Control apparatus 11 Cooling water path 12 Exhaust pipe 14 Radiator 17 1st clutch 21 Working fluid pump 22 Evaporator 23 Expander 24 Condenser 25 Working fluid circulation path 32 Transmission 33 Second clutch P Working fluid R Cooling water W Waste heat power generation amount Wf No-load power generation amount Wg Cooperative power generation amount Wo Vehicle-side electric load amount

Claims (1)

In a vehicle equipped with a waste heat recovery device that recovers waste heat energy of an internal combustion engine as power and drives a generator with the recovered power,
An alternator with a motor that is capable of connecting / disconnecting power with the expander of the waste heat recovery device and that generates power by the power of the expander;
A first clutch for connecting and disconnecting the power between the expander and the alternator with motor;
A second clutch for connecting and disconnecting power between the internal combustion engine and the alternator with motor;
A battery for storing electric power generated by the alternator with motor;
A control device for performing connection / disconnection control of the first clutch and the second clutch,
The control device connects the second clutch, drives the motor-equipped alternator with electric power from the battery, and starts the internal combustion engine; and
The alternator power generation means for generating power by driving the alternator by connecting the second clutch when the vehicle is going downhill, and disconnecting the second clutch and connecting the first clutch at times other than downhill And a waste heat recovery power generation means for generating power by the waste heat recovery device.

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