JPH11229867A - Exhaust heat generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a thermo electric element and the like by protecting the thermo electric element for exhaust heat generation from being heated so as not to exceed the limited temperature for use. SOLUTION: An exhaust heat generation system is composed of an exhaust heat generation unit 11 disposed at the intermediate position of an exhaust pipe 10 of an engine for generating power by collecting thermal energy of the exhaust heat flowing through the exhaust pipe 10, a bypass exhaust pipe 12 branched from the exhaust pipe 10 upstream of the exhaust heat generation unit 11 for bypassing, a flow control valve 13 for controlling flow rate of the exhaust gas passing through the exhaust heat generation unit 11, a controller 15 for reading temperature information output from the exhaust heat generation unit 11 and controlling the opening of the flow control valve 13, an engine control unit 16 for outputting control signals by detecting information on engine operation, and the like. The opening of the flow control valve 13 can also be controlled by the signal according to the opening of acceleration output from the engine control unit 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust heat power generator for recovering thermal energy of exhaust gas discharged from an engine mounted on an automobile or the like and generating power.

[0002]

2. Description of the Related Art Conventional exhaust heat power generators for automobiles include:
For example, there is one as shown in JP-A-6-81639.

[0003] As shown in FIG. 11, such an exhaust heat power generation device has an exhaust pipe 1 connected to an engine (not shown) for guiding exhaust gas to the outside, and an exhaust pipe provided in the middle of the exhaust pipe. A thermoelectric generation unit 2, a bypass exhaust pipe 3 branching off from the exhaust pipe 1 and bypassing the exhaust heat generation unit 2, and being provided upstream or downstream of the exhaust heat generation unit 2 and passing through the exhaust heat generation unit 2. Flow control valve 4 for adjusting the flow rate of exhaust gas to be exhausted, a muffler 5 provided at the rear end of the exhaust pipe 1, and a controller for detecting the temperature of the exhaust heat generation unit 2 and adjusting the opening of the flow control valve 4. 6 and the like.

The waste heat power generation unit uses a thermoelectric element that generates electric power by utilizing the Seebeck effect. The thermoelectric element can be used, for example, in a region where the temperature is low during idling and at low speeds during traffic congestion. In order to obtain a high power generation output, for example, Be-T
e and other thermoelectric elements are used.

During high-speed running, the flow rate of exhaust gas passing through the exhaust heat power generation unit 2 is adjusted so that the thermoelectric element will not be damaged, for example, at temperatures exceeding 300 ° C. or higher. That is, by detecting the temperature of the exhaust heat power generation unit 2 and inputting it to the controller 6, if the temperature of the thermoelectric element is high, the output of the controller 6 closes the flow control valve 4 provided in the exhaust pipe 1, The flow rate of the exhaust gas flowing through the exhaust heat power generation unit 2 is reduced to lower the temperature. On the other hand, when the temperature of the thermoelectric element falls below 300 ° C., the flow control valve 4 is opened to control so as to obtain the maximum power generation output within the upper limit of the operating temperature of the thermoelectric element.

[0006]

However, in such a conventional exhaust heat power generator, the exhaust temperature of the engine suddenly rises when the vehicle is rapidly accelerated or running on a mountainous road. The operation of the flow control valve 4 for bypassing the exhaust gas is delayed, and the temperature of the thermoelectric element rises by overshooting above the use limit temperature, and this overshoot is repeated for a long period of time. There was a problem of inviting.

That is, in the conventional exhaust heat power generator, as shown in FIG. 12, for example, when the accelerator is fully opened for rapid acceleration, the temperature of the exhaust gas first rises,
Accordingly, the power generation output of the exhaust heat power generation unit 2 increases.

Next, the controller 6 receives the output of the exhaust heat power generation unit 2, and the controller 6
By controlling the flow rate control valve 4 provided in the apparatus and adjusting the valve opening of the flow rate control valve 4, the flow rate of exhaust gas flowing to the exhaust heat power generation unit 2 is controlled. here,
For the first time, control is performed so that the temperature of the exhaust heat power generation unit 2 decreases.

In the case of full-open acceleration, as shown in FIG. 12, there is a time lag from the opening of the accelerator to the actuation of the flow control valve 4, so that the temperature of the exhaust gas becomes higher than the temperature upper limit of the exhaust heat power generation unit 2. Overshoot may occur, and the power generating element may be damaged while repeating this overshoot.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to reliably operate an exhaust heat power generation unit within a predetermined allowable temperature range so that a thermoelectric element can be used. An object of the present invention is to provide a waste heat power generation device capable of preventing damage and the like and performing desired waste heat power generation.

[0011]

According to a first aspect of the present invention, there is provided an exhaust heat power generator provided in a middle of an exhaust passage of an engine for recovering heat energy of exhaust flowing through the exhaust passage to generate electric power. A thermoelectric generation unit, a bypass exhaust passage branching from the exhaust passage at a position upstream of the exhaust heat generation unit and bypassing the exhaust heat generation unit, and adjusting a flow rate of exhaust gas passing through the exhaust heat generation unit. A flow control valve, and a controller that reads output information from the exhaust heat generation unit and controls an opening degree of the flow control valve,
An engine control unit that detects operation information of the engine and outputs a control signal, wherein the controller adjusts an opening degree of the flow control valve also by a signal output from the engine control unit. It is configured to be driven to control.

[0012] The exhaust heat power generator according to claim 2 of the present invention comprises:
2. The exhaust heat power generator according to claim 1, wherein an accelerator operation amount is detected as operation information of the engine, and when the accelerator operation amount is equal to or more than a predetermined value, the flow control valve is driven in a valve closing direction to perform the exhaust operation. The configuration is such that the flow rate of exhaust gas passing through the thermoelectric generator unit is set to a predetermined value or less.

According to a third aspect of the present invention, there is provided a waste heat power generator,
3. The exhaust heat power generator according to claim 1, further comprising a second flow control valve for adjusting a flow rate of exhaust gas passing through the bypass exhaust passage, wherein the controller reads output information from the exhaust heat power generation unit. 4. The opening of the second flow control valve is also controlled.

The exhaust heat power generator according to claim 4 of the present invention is
A low-temperature exhaust heat power generation unit that is provided in the middle of the exhaust passage of the engine and recovers thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage and generates electric power; A high-temperature exhaust heat power generation unit that is provided in the exhaust passage at a position and recovers thermal energy of high-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage to generate electric power; And a bypass exhaust passage that branches off from the exhaust passage at a position upstream of the low-temperature exhaust heat generation unit and bypasses the low-temperature exhaust heat generation unit, and a flow rate of exhaust gas that passes through the low-temperature exhaust heat generation unit. A flow control valve for adjusting the flow rate, a controller for reading output information from the high-temperature and low-temperature exhaust heat power generation units and controlling an opening degree of the flow control valve, and an operating condition of the engine. And an engine control unit that outputs a control signal by detecting the control signal, wherein the controller controls the opening of the flow control valve also by a signal output from the engine control unit. It is configured to be driven.

According to a fifth aspect of the present invention, there is provided a waste heat power generator,
5. The exhaust heat power generator according to claim 4, wherein an accelerator opening is detected as operation information of the engine, and when the accelerator opening is equal to or more than a predetermined value, the flow control valve is driven in a valve closing direction to reduce the low temperature. The flow rate of exhaust gas passing through the exhaust heat generation unit for use is set to a predetermined value or less.

The exhaust heat power generator according to claim 6 of the present invention is
The exhaust heat power generation device according to claim 4, further comprising a second flow control valve for adjusting a flow rate of exhaust gas passing through the bypass exhaust passage, wherein the controller is configured to control the high-temperature and low-temperature exhaust heat power generation units. Is read out to control the opening of the second flow control valve.

An exhaust heat power generator according to claim 7 of the present invention is
A low-temperature exhaust heat power generation unit that is provided in the middle of the exhaust passage of the engine and recovers thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage and generates electric power; A bypass exhaust passage branching from the exhaust passage at a position and bypassing the low-temperature exhaust heat generation unit, a first flow control valve for adjusting a flow rate of exhaust gas passing through the low-temperature exhaust heat generation unit, and the bypass. A high-temperature exhaust heat generation unit that is provided in the middle of the exhaust passage and collects thermal energy of high-temperature exhaust gas in a predetermined temperature range flowing through the bypass exhaust passage to generate electric power; and exhaust gas that passes through the high-temperature exhaust heat generation unit. And a controller for reading output information from the high-temperature and low-temperature exhaust heat power generation units and controlling opening degrees of the first and second flow control valves. And an engine control unit that detects an operation information of the engine and outputs a control signal, wherein the controller is configured to control the first and the second signals by a signal output from the engine control unit. It is configured to be driven so as to control the opening of the second flow control valve.

[0018] The exhaust heat power generator according to claim 8 of the present invention comprises:
8. The exhaust heat power generator according to claim 7, wherein an accelerator opening is detected as operation information of the engine, and when the accelerator opening is equal to or more than a predetermined value, the first flow control valve is driven in a valve closing direction. The flow rate of exhaust gas passing through the low-temperature exhaust heat generation unit is set to a predetermined value or less.

The exhaust heat power generator according to claim 9 of the present invention is
A low-temperature exhaust heat power generation unit that is provided in the middle of the exhaust passage of the engine and recovers thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage and generates electric power; A bypass exhaust passage branching from the exhaust passage at a position and bypassing the low-temperature exhaust heat generation unit, a first flow control valve for adjusting a flow rate of exhaust gas passing through the low-temperature exhaust heat generation unit, and the bypass. A high-temperature exhaust heat generation unit that is provided in the middle of the exhaust passage and collects thermal energy of high-temperature exhaust gas in a predetermined temperature range flowing through the bypass exhaust passage to generate electric power; and exhaust gas that passes through the high-temperature exhaust heat generation unit. A second flow control valve for adjusting the flow rate of the exhaust gas, and a high-temperature and low-temperature exhaust heat power generation unit that branches off from the exhaust passage at a position upstream of the high-temperature and low-temperature exhaust heat power generation unit. A second bypass exhaust passage for bypassing the exhaust gas, a third flow regulating valve for regulating a flow rate of exhaust gas passing through the second bypass exhaust passage, and reading output information from the high-temperature and low-temperature exhaust heat generation units. The first
A controller for controlling an opening degree of a third flow control valve, and an engine control unit for detecting operation information of the engine and outputting a control signal, wherein the controller includes the engine control unit Is driven so as to control the opening degree of the first to third flow control valves also by the signal output from the controller.

According to a tenth aspect of the present invention, in the exhaust heat power generator according to the ninth aspect, an accelerator opening is detected as the operation information, and when the accelerator opening is equal to or more than a predetermined value. The first flow control valve is driven in a valve closing direction to reduce the flow rate of exhaust gas passing through the low-temperature exhaust heat power generation unit to a predetermined value or less.

[0021]

According to the exhaust heat power generator according to the first aspect of the present invention, the output temperature from the engine control unit that detects the operation information of the engine and outputs the control signal causes the exhaust temperature to rise sharply. Predictably, before the exhaust heat power generation unit rises above the use limit temperature, the flow rate control valve can be driven in advance in the valve closing direction to reduce the flow rate of exhaust gas passing through the exhaust heat power generation unit.

Accordingly, it is possible to prevent the temperature of the exhaust heat power generation unit from rising beyond the use limit temperature, and to perform stable power generation without causing damage or the like.

According to the exhaust heat generator of the second aspect of the present invention, the accelerator opening is detected as the operation information of the engine, and the flow regulating valve is controlled based on the accelerator opening detection signal, ie, Since the flow control valve is controlled on the basis of information on a portion that is a starting source of the change when the operating state of the engine changes, the time lag due to the operation of the flow control valve can be further reduced, thereby reducing waste heat power generation. The unit can always be set within the allowable temperature range, and stable power generation can be performed.

According to the exhaust heat generator of the third aspect of the present invention, since the second flow rate regulating valve for regulating the flow rate of the exhaust gas passing through the bypass exhaust passage is provided, the exhaust gas is relatively exhausted immediately after the engine is started or the like. When the amount of heat is small, the exhaust gas can be positively flown into the exhaust heat generation unit by closing the second flow control valve.

[0025] Thus, in addition to the above effects, the heat energy of the exhaust gas can be more effectively recovered, and power can be efficiently generated from a low load region.

According to the exhaust heat power generator according to the fourth aspect of the present invention, a rapid rise in exhaust gas temperature is predicted by an output signal from an engine control unit which detects operation information of the engine and outputs a control signal. Before the low-temperature exhaust heat power generation unit rises above the usage limit temperature, the flow rate control valve is driven in advance in the valve closing direction to reduce the flow rate of exhaust gas passing through the low-temperature exhaust heat power generation unit. In addition, it is possible to prevent the temperature of the low-temperature exhaust heat power generation unit from rising beyond the usage limit temperature, and to perform stable power generation without causing damage or the like.

In addition to the low-temperature exhaust heat power generation unit, the high-temperature exhaust heat power generation unit is provided on the upstream side, so that the high-temperature exhaust heat power generation unit is provided on the upstream side where the temperature is high and in the high load region where the exhaust temperature is high. The unit can generate power, and the low-temperature exhaust heat generation unit can generate power in the low-load area where the exhaust temperature is low, such as on the downstream side where the temperature is low, and the thermal energy of the exhaust gas can be more efficiently recovered. Can be.

According to the exhaust heat power generator according to claim 5 of the present invention, the accelerator opening is detected as the operation information of the engine, and the flow regulating valve is controlled based on the detection signal of the accelerator opening. Since the flow control valve is controlled based on information of a portion that is a starting source of the change when the operation state of the engine changes, the time lag due to the operation of the flow control valve can be further reduced, and as a result, low-temperature exhaust gas can be reduced. By setting the thermoelectric power generation unit within the allowable temperature range at all times, stable power generation can be performed.

According to the exhaust heat power generator according to claim 6 of the present invention, since the second flow rate regulating valve for regulating the flow rate of the exhaust gas passing through the bypass exhaust passage is provided, the exhaust gas is relatively exhausted immediately after the engine is started or the like. When the amount of heat is small, the exhaust can be positively flown into the low-temperature exhaust heat power generation unit by closing the second flow control valve.

Thus, in addition to the above effects, the heat energy of the exhaust gas can be more effectively recovered, and power can be efficiently generated from a low load region.

According to the exhaust heat power generator according to claim 7 of the present invention, a rapid rise in exhaust gas temperature is predicted by an output signal from an engine control unit which detects operation information of the engine and outputs a control signal. Before the low-temperature exhaust power generation unit rises in temperature beyond the use limit temperature, the flow rate control valve is driven in advance in the valve closing direction to reduce the flow rate of exhaust gas passing through the low-temperature exhaust heat generation unit, It is possible to prevent the temperature of the low-temperature exhaust heat power generation unit from rising beyond the use limit temperature, and to perform stable power generation without causing damage or the like.

In addition to the low-temperature exhaust heat power generation unit, the high-temperature exhaust heat power generation unit arranged in parallel with the low-temperature exhaust heat power generation unit effectively recovers the heat energy of the exhaust gas in the high load region of the engine. In addition, the first flow control valve and the second flow control valve are appropriately adjusted to optimally control the flow rate of each exhaust gas flowing to the low-temperature exhaust heat power generation unit and the high-temperature exhaust heat power generation unit. Thus, more efficient power generation can be performed according to the changing load, that is, according to the calorific value of the exhaust gas.

According to the exhaust heat power generator according to claim 8 of the present invention, the accelerator opening is detected as the operation information of the engine, and the flow control valve is controlled based on the detection signal of the accelerator opening. Since the flow control valve is controlled based on information of a portion that is a starting source of the change when the operation state of the engine changes, the time lag due to the operation of the flow control valve can be further reduced, and as a result, low-temperature exhaust gas can be reduced. By setting the thermoelectric power generation unit within the allowable temperature range at all times, stable power generation can be performed.

According to the exhaust heat power generator according to the ninth aspect of the present invention, a rapid rise in exhaust gas temperature is predicted by an output signal from an engine control unit which detects operation information of the engine and outputs a control signal. Before the low-temperature exhaust heat power generation unit rises above the usage limit temperature, the flow rate control valve is driven in advance in the valve closing direction to reduce the flow rate of exhaust gas passing through the low-temperature exhaust heat power generation unit. In addition, it is possible to prevent the temperature of the low-temperature exhaust heat power generation unit from rising beyond the usage limit temperature, and to perform stable power generation without causing damage or the like.

In addition to the low-temperature exhaust heat power generation unit, the high-temperature exhaust heat power generation unit disposed in parallel with the low-temperature exhaust heat power generation unit effectively recovers the heat energy of the exhaust gas in the high load region of the engine. In addition, the first flow control valve and the second flow control valve are appropriately adjusted to optimally control the flow rate of each exhaust gas flowing to the low-temperature exhaust heat power generation unit and the high-temperature exhaust heat power generation unit. Thus, more efficient power generation can be performed according to the changing load, that is, according to the calorific value of the exhaust gas.

Further, a second bypass exhaust passage for bypassing both the high-temperature exhaust heat generation unit and the low-temperature exhaust heat generation unit, and a third flow control valve for adjusting the flow rate of exhaust gas passing through the second bypass exhaust passage. In the normal operation state, the third flow control valve is closed, and the exhaust gas flows through the high-temperature exhaust heat power generation unit and the low-temperature exhaust heat power generation unit. On the other hand, when the vehicle needs the sharpest acceleration, the third flow control valve is opened and the exhaust gas is caused to flow through the second bypass exhaust passage, so that the exhaust system can be controlled. Flow resistance can be reduced, and smooth acceleration at the time of sudden acceleration or the like can be performed.

According to the exhaust heat power generator according to claim 10 of the present invention, the accelerator opening is detected as the operation information of the engine, and the flow regulating valve is controlled based on the detection signal of the accelerator opening, that is, Since the flow control valve is controlled based on information of a portion that is a starting source of the change when the operation state of the engine changes, the time lag due to the operation of the flow control valve can be further reduced, and as a result, low-temperature exhaust gas can be reduced. By setting the thermoelectric power generation unit within the allowable temperature range at all times, stable power generation can be performed.

[0038]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of a waste heat power generator according to the present invention.
It is a schematic structure figure showing an example of. As shown in FIG. 1, this exhaust heat power generation device is provided in an exhaust passage of an engine (not shown), that is, in the exhaust pipe 10, and collects heat energy of exhaust flowing through the exhaust pipe 10 to generate electric power. A thermal power generation unit 11 and a branch from the exhaust pipe 10 at a position upstream of the waste heat power generation unit 11;
A bypass exhaust pipe 12 as a bypass exhaust passage for bypassing the exhaust gas; a flow control valve 13 for adjusting the flow rate of exhaust gas passing through the exhaust heat power generation unit 11;
The controller 15 includes a controller 15 that reads output information (temperature) from the controller and controls the opening degree of the flow control valve 13, an engine control unit 16 that detects operation information of the engine and outputs a control signal, and the like.

The bypass exhaust pipe 12 branches off from the exhaust pipe 10 at a position upstream of the exhaust heat generation unit 11.
Although it is formed so as to join the exhaust pipe 10 again at a position downstream of the flow control valve 13 and upstream of the muffler 14, it does not join the exhaust pipe 10 again but separates in a branched state. May be formed so as to be connected to a muffler (not shown) and open to the outside air.

Next, the operation of the exhaust heat power generator will be described. As shown in the flowchart of FIG. 2, the engine control unit 16 detects an accelerator opening signal as operation information, and then the engine control unit 16 outputs an output signal based on this detection information to the exhaust heat power generation unit (power generation). It is sent directly to the controller (power generation unit controller) 15 of the unit 11 and the controller 15 drives the flow regulating valve 13 based on this signal. Then, the flow rate of the exhaust gas flowing through the exhaust heat power generation unit 11 is adjusted, and the temperature of the exhaust heat power generation unit 11 is controlled to be within a predetermined allowable temperature range.

As described above, the signal from the engine control unit 16 predicts a sharp rise in the exhaust gas temperature.
Before the exhaust heat power generation unit 11 (particularly, thermoelectric element) rises in temperature, the flow rate control valve 13 is driven to adjust the flow rate of exhaust gas flowing through the exhaust heat power generation unit 11, as shown in FIG. There is no time lag between the opening operation and the actuation of the flow control valve 13, whereby the exhaust heat power generation unit 11 is exposed to exhaust gas having a temperature exceeding its use limit (upper limit) temperature and overshooting. Therefore, breakage of the thermoelectric element or the like due to heat is prevented.

In order to predict a sharp rise in the exhaust gas temperature, the engine control unit 16 or the controller 15
In addition to the change in the accelerator opening, the change in the engine speed, the change in the intake pressure, the set gear ratio, the vehicle speed, etc. are adopted as the operation information that is constantly detected, so that the temperature rise of the exhaust gas can be more accurately increased. Predictably, the flow control valve 13 can be driven.

Here, the control of the flow control valve 13 at the time of rapid acceleration will be described. First, during normal operation, the opening degree of the flow control valve 13 is adjusted by the controller 15 of the exhaust heat generation unit 11. When rapid acceleration is entered and the accelerator opening or the engine speed changes, for example, by ± 10% or more of the total load in, for example, 5 seconds, control by a signal from the engine control unit 16 is started before the exhaust gas temperature rises. change.

When the accelerator opening suddenly changes to the above value due to rapid acceleration, as shown in the flowchart of FIG.
The flow control valve 13 is driven in the valve closing direction to → according to the map shown in FIG. 4 (the opening degree adjustment map of the flow control valve 13) to reduce the flow rate of exhaust gas in the exhaust heat generation unit 11.

When the engine speed rises due to the depression of the accelerator, the flow control valve 13 is further driven in the valve closing direction to → to further reduce the flow rate of the exhaust gas in the exhaust heat generation unit 11.

At this time, the flow rate of the exhaust gas is reduced so that the surface temperature of the thermoelectric element constituting the exhaust heat generation unit 11 does not suddenly rise above the operating temperature upper limit.
Even if the exhaust gas temperature in the exhaust heat generation unit 11 rises, the surface temperature of the thermoelectric element does not rise above the operating temperature upper limit.

Thereafter, unless the accelerator opening and the engine speed change within, for example, ± 10% of the values at this time within, for example, 5 seconds, the control of the flow regulating valve 13 is performed by a signal from the controller 15. Control is switched (in FIG. 5).

At this time, since both the engine speed and the temperature of the exhaust gas have risen, even if the flow rate of the exhaust gas in the exhaust heat power generation unit 11 is reduced, the temperature of the exhaust heat power generation unit 11 (thermoelectric element) is maintained. It gradually rises. At this time, the controller 15 determines the surface temperature of the thermoelectric element based on the power generation output of the exhaust heat generation unit 11, and adjusts the valve opening of the flow control valve 13 so that the output becomes maximum within the upper limit of the operating temperature ( (In FIG. 5).

On the other hand, if the accelerator opening and the engine speed change within, for example, ± 10% or more of the values at this time within 5 seconds, the control of the flow regulating valve 13 is controlled by a signal from the engine control unit 16. Switch to

As described above, the control at the time of rapid acceleration is performed based on the opening degree adjustment map of the flow control valve based on the accelerator opening degree and the engine speed stored in the engine control unit 16.

Similarly, immediately after the start of the engine, the valve opening of the flow control valve 13 is basically controlled by the controller 15. In the case of the rapid acceleration described above, the output signal of the engine control unit 16 is used. Control.

On the other hand, when the vehicle is running slowly at low speed in a city where the temperature of exhaust gas does not change suddenly, or during steady running on a highway, as shown in FIG. 15, the opening of the flow control valve 13 is controlled, and the waste heat power generation unit 11 is controlled.
The maximum power generation output is obtained within the operating temperature upper limit of.

According to the exhaust heat power generator of the above embodiment, the accelerator opening is detected as the operation information of the engine, and a rapid change (rise) of the exhaust gas temperature is predicted based on the accelerator opening detection signal. Before the exhaust heat power generation unit 11 rises in temperature beyond the use limit temperature, the flow rate control valve 13 can be driven in advance in the valve closing direction to reduce the flow rate of exhaust gas passing through the exhaust heat power generation unit 11. In addition, it is possible to prevent the temperature of the exhaust heat power generation unit 11 from rising beyond the use limit temperature, and to perform stable power generation without particularly causing breakage of the thermoelectric element.

FIG. 7 shows a second embodiment of the exhaust heat power generator according to the present invention.
It is a schematic structure figure showing an example of. As shown in FIG. 7, this exhaust heat power generation device has a second flow rate that adjusts the flow rate of exhaust gas passing through the bypass exhaust pipe 12 in the middle of the bypass exhaust pipe 12 as compared with the first embodiment. The configuration is such that an adjustment valve 17 is added.

The operation of the exhaust heat power generator having the above-described configuration is basically the same as that of the first embodiment, and in addition, the amount of heat of the exhaust gas is relatively small immediately after the engine is started. In this case, the second flow control valve 17 is closed,
Exhaust gas is blocked from passing through the bypass exhaust pipe 12, and the exhaust gas is positively guided into the exhaust heat power generation unit 11.

As a result, the heat energy of the exhaust gas can be more effectively recovered from the low load region.

FIG. 8 shows a third embodiment of the exhaust heat power generator according to the present invention.
It is a schematic structure figure showing an example of. As shown in FIG. 8, the exhaust heat power generation device is provided in an exhaust passage of an engine (not shown),
A low-temperature exhaust heat power generation unit 11 ′ that recovers thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the inside and generates power, and is provided in the exhaust pipe 10 at a position upstream of the low-temperature exhaust heat power generation unit 11 ′. A high-temperature exhaust heat power generation unit 18 that recovers the heat energy of the high-temperature exhaust gas in a predetermined temperature range flowing through the exhaust heat pipe 10 to generate power, and a low-temperature exhaust heat power generation downstream of the high-temperature exhaust heat power generation unit 18 A bypass exhaust pipe 12 serving as a bypass exhaust passage that branches off from the exhaust pipe 10 and bypasses the low-temperature exhaust heat power generation unit 11 ′ at a position upstream of the unit 11 ′, and passes through the low-temperature exhaust heat power generation unit 11 ′. A flow control valve 13 for controlling the flow rate of the exhaust gas, a second flow control valve 17 for controlling the flow rate of the exhaust gas passing through the bypass exhaust pipe 12, and the high-temperature and low-temperature exhaust heat power generation units 18 and 11 ′. The force information (temperature) and the controller 15 for controlling the opening of reading the flow rate adjusting valve 13 includes an engine control unit 16 for outputting a control signal by detecting the operation information of the engine.

The bypass exhaust pipe 12 is formed so as to join the exhaust pipe 10 at a position upstream of the muffler 14 as in the first embodiment described above. Instead, it may be formed so as to be connected to a separate silencer (not shown) in a branched state and open to the outside air.

The bypass exhaust pipe 12 has a second
Although the flow rate adjusting valve 17 is provided to adjust the flow rate of the exhaust gas flowing in the bypass exhaust pipe 12, the configuration may be such that the second flow rate adjusting valve 17 is not provided.

The operation of the exhaust heat power generation apparatus having the structure shown in FIG. 8 is basically the same as that of the first embodiment, and additionally, the low temperature exhaust heat power generation unit 11 '.
In addition to the above, since a high-temperature exhaust heat power generation unit 18 is provided, power is generated by the high-temperature exhaust heat power generation unit 18 in a high-load area where the exhaust temperature is high, and a low-temperature exhaust heat Electric power is generated by the exhaust heat power generation unit 11 '.

Thus, the heat energy of the exhaust gas in the high load region can be effectively recovered.

FIG. 9 shows a fourth embodiment of the exhaust heat power generator according to the present invention.
It is a schematic structure figure showing an example of. As shown in FIG. 9, this exhaust heat power generation device is provided in an exhaust passage of an engine (not shown),
A low-temperature exhaust heat power generation unit 11 ′ that collects thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the inside and generates electric power, and branches from the exhaust pipe 10 at a position upstream of the low-temperature exhaust heat power generation unit 11 ′. Exhaust pipe 12 as a bypass exhaust passage for bypassing the low-temperature exhaust heat generation unit 11 ′
A first flow control valve 13 ′ provided in the exhaust pipe 10 for adjusting the flow rate of the exhaust gas passing through the low-temperature exhaust heat power generation unit 11 ′, and a bypass exhaust pipe provided in the middle of the bypass exhaust pipe 12. In order to adjust the flow rate of the exhaust heat power generation unit for high temperature 18 ′ which collects the thermal energy of the high temperature exhaust gas flowing in the predetermined temperature range and generates electric power, and the exhaust gas passing through the high temperature exhaust heat power generation unit 18 ′. The output information (temperature) from the second flow control valve 17 ′ provided in the bypass exhaust pipe 12 and the high-temperature and low-temperature exhaust heat power generation units 18 ′ and 11 ′ is read, and the first and second flow control valves 13 ′. , 17 '
And an engine control unit 16 that detects operation information of the engine and outputs a control signal.

The bypass exhaust pipe 12 is formed so as to join the exhaust pipe 10 at a position upstream of the muffler 14, as in the first embodiment. Instead, it may be formed so as to be connected to a separate silencer (not shown) in a branched state and open to the outside air.

The operation of the exhaust heat power generation device having the structure shown in FIG. 9 is basically the same as that of the first embodiment, and additionally, the low temperature exhaust heat power generation unit 11 '.
And the high-temperature exhaust heat power generation unit 18 ′ are arranged in parallel to the exhaust pipe 10, so that the high-temperature exhaust heat power generation unit 18 ′ generates electric power in a high load region where the exhaust temperature is high. And in the low-load region where the exhaust gas temperature is low, power is generated by the low-temperature exhaust heat power generation unit 11 ′, and the opening degree of the first flow control valve 13 ′ and the second flow control valve 17 ′ Is appropriately adjusted, and the flow rate of the exhaust gas flowing into the low-temperature exhaust heat power generation unit 11 ′ and the flow rate of the exhaust gas flowing into the high-temperature exhaust heat power generation unit 18 ′ are controlled so as to be optimal according to the operation state. .

As a result, the heat energy of the exhaust gas can be more efficiently recovered according to the changing load, that is, according to the heat amount of the exhaust gas, and high-efficiency power generation can be obtained.

FIG. 10 is a schematic configuration diagram showing a fifth embodiment of the exhaust heat power generator according to the present invention. As shown in FIG. 10, this exhaust heat power generation device is provided in an exhaust passage of an engine (not shown),
A low-temperature exhaust heat power generation unit 11 ′ that collects thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the inside and generates electric power, and branches from the exhaust pipe 10 at a position upstream of the low-temperature exhaust heat power generation unit 11 ′. Exhaust pipe 12 as a bypass exhaust passage for bypassing the low-temperature exhaust heat generation unit 11 ′
A first flow control valve 13 ′ for adjusting the flow rate of exhaust gas passing through the low-temperature exhaust heat generating unit 11 ′; and a predetermined temperature range provided in the middle of the bypass exhaust pipe 12 and flowing through the bypass exhaust pipe 12. A high-temperature exhaust heat power generation unit 18 ′ that collects thermal energy of the high-temperature exhaust gas to generate electric power, a second flow control valve 17 ′ that adjusts the flow rate of exhaust gas passing through the high-temperature exhaust heat power generation unit 18 ′, and , From the exhaust pipe 10 at a position upstream of the high-temperature and low-temperature exhaust heat power generation units 18 ′ and 11 ′.
, 11 ', a second bypass exhaust pipe 19 as a second bypass exhaust passage, a third flow control valve 20 for adjusting the flow rate of exhaust gas passing through the second bypass exhaust pipe 19, Low temperature waste heat power generation unit 18 ', 1
1 'to read the output information (temperature) from the first to third
It includes a controller 15 for controlling the opening of the flow regulating valves 13 ', 17', 20 and an engine control unit 16 for detecting operation information of the engine and outputting a control signal.

The bypass exhaust pipe 12 and the second bypass exhaust pipe 19 are formed so as to join the exhaust pipe 10 at a position upstream of the muffler 14 as in the first embodiment, but the exhaust gas is exhausted again. Instead of being joined to the pipe 10, each branch may be connected to a separate silencer (not shown) in a branched state, and each may be formed so as to open toward the outside air.

The operation of the exhaust heat power generator having the configuration shown in FIG. 10 is basically the same as that of the first embodiment, and in addition,
′ And the high-temperature exhaust heat power generation unit 18 ′ are arranged in parallel to the exhaust pipe 10, so that the high-temperature exhaust heat power generation unit 18 ′ generates electric power in a high load region where the exhaust gas temperature is high. And in the low-load region where the exhaust gas temperature is low, the low-temperature exhaust heat power generation unit 11 ′ generates power, and the first flow control valve 13 ′ and the second
The flow rates of the exhaust gas flowing into the low-temperature exhaust heat power generation unit 11 ′ and the exhaust gas flowing into the high-temperature exhaust heat power generation unit 18 ′ by appropriately adjusting the valve opening of the flow rate control valve 17 ′ and the third flow rate control valve 20. Is controlled so as to be optimal according to the operating condition.

As a result, the heat energy of the exhaust gas can be more efficiently recovered according to the changing load, that is, according to the calorific value of the exhaust gas, and highly efficient power generation can be obtained.

Further, a second bypass exhaust pipe 19 for bypassing both the high-temperature exhaust heat power generation unit 18 'and the low-temperature exhaust heat power generation unit 11', and the second bypass exhaust pipe 1
The third flow control valve 2 for controlling the flow rate of the exhaust gas passing through the inside 9
In the normal operation state, the third flow control valve 20 is closed, and the high-temperature exhaust heat power generation unit 18 'and the low-temperature exhaust heat power generation unit 11' are positively inserted. Control the exhaust to flow.

On the other hand, when the vehicle needs the sharpest acceleration, the third flow control valve 20 is opened and the second
The exhaust gas is controlled to flow positively into the bypass exhaust pipe 19.

Thus, in a normal operation state, desired power generation can be efficiently performed. On the other hand, in the case of sudden acceleration or the like, the flow resistance of the exhaust system is reduced to enable smooth acceleration. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a first embodiment of a waste heat power generation device according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the exhaust heat power generation device according to the present invention.

FIG. 3 is a time chart for explaining the operation of the exhaust heat power generation device according to the present invention.

FIG. 4 is an opening adjustment map of a flow control valve for explaining an operation of the exhaust heat power generation device according to the present invention.

FIG. 5 is a flowchart for explaining the operation of the exhaust heat power generation device according to the present invention.

FIG. 6 is a flowchart for explaining the operation of the exhaust heat power generation device according to the present invention.

FIG. 7 is a schematic configuration diagram showing a second embodiment of the waste heat power generation device according to the present invention.

FIG. 8 is a schematic configuration diagram showing a third embodiment of the waste heat power generation device according to the present invention.

FIG. 9 is a schematic configuration diagram showing a fourth embodiment of the waste heat power generation device according to the present invention.

FIG. 10 is a schematic configuration diagram showing a fifth embodiment of the exhaust heat power generator according to the present invention.

FIG. 11 is a schematic configuration diagram showing a conventional exhaust heat power generator.

FIG. 12 is a time chart for explaining the operation of a conventional exhaust heat power generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Exhaust pipe (exhaust passage) 11 Exhaust heat generation unit 11 'Exhaust heat generation unit for low temperature 12 Bypass exhaust pipe (Bypass exhaust passage) 13 Flow control valve 13' First flow control valve 14 Silencer 15 Controller 16 Engine control unit 17 , 17 ′ Second flow control valve 18, 18 ′ High-temperature exhaust heat power generation unit 19 Second bypass exhaust pipe (second bypass exhaust passage) 20 Third flow control valve

Claims (10)

[Claims] An exhaust heat generation unit provided in the middle of an exhaust passage of an engine for recovering thermal energy of exhaust flowing through the exhaust passage and generating electric power, and an exhaust heat generation unit at a position upstream of the exhaust heat generation unit. A bypass exhaust passage that branches off from an exhaust passage and bypasses the exhaust heat power generation unit, a flow control valve that adjusts a flow rate of exhaust gas that passes through the exhaust heat power generation unit, and reads output information from the exhaust heat power generation unit. A controller that controls the opening of the flow control valve and an engine control unit that detects an operation information of the engine and outputs a control signal, wherein the controller is output from the engine control unit. The exhaust heat power generator is driven so as to control the opening of the flow control valve also by a signal. 2. An accelerator opening is detected as operation information of the engine, and when the accelerator opening is equal to or more than a predetermined value, the flow control valve is driven in a valve closing direction to pass through the exhaust heat power generation unit. The exhaust heat power generator according to claim 1, wherein a flow rate of exhaust gas to be exhausted is set to a predetermined value or less. A second flow rate control valve for controlling a flow rate of exhaust gas passing through the bypass exhaust path, wherein the controller reads output information from the exhaust heat power generation unit and opens the second flow rate control valve. The exhaust heat power generator according to claim 1 or 2, wherein the temperature is also controlled. 4. A low-temperature exhaust heat power generation unit that is provided in the middle of an exhaust passage of an engine and recovers thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage and generates power. A high-temperature exhaust heat power generation unit that is provided in the exhaust passage at a position upstream of the unit and recovers thermal energy of high-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage to generate power; A bypass exhaust passage that branches off from the exhaust passage at a position downstream of the unit and upstream of the low-temperature exhaust heat power generation unit and bypasses the low-temperature exhaust heat power generation unit; A flow control valve for adjusting the flow rate of the exhaust gas passing therethrough, a controller for reading output information from the high-temperature and low-temperature exhaust heat power generation units and controlling an opening degree of the flow control valve; An engine control unit that detects operation information of the gin and outputs a control signal, wherein the controller adjusts an opening degree of the flow control valve also by a signal output from the engine control unit. An exhaust heat power generator driven to control. 5. An accelerator opening is detected as operation information of the engine, and when the accelerator opening is equal to or more than a predetermined value, the flow control valve is driven in a valve closing direction to allow the low-temperature exhaust heat power generation unit to operate. The exhaust heat power generation device according to claim 4, wherein the flow rate of exhaust gas passing through is set to a predetermined value or less. 6. A second flow control valve for controlling a flow rate of exhaust gas passing through the bypass exhaust passage, wherein the controller reads output information from the high-temperature and low-temperature exhaust heat power generation units and outputs the second information. The exhaust heat power generator according to claim 4 or 5, wherein the opening of the flow control valve is also controlled. 7. A low-temperature exhaust heat power generation unit that is provided in the middle of an exhaust passage of an engine and recovers thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage to generate power. A bypass exhaust passage that branches off from the exhaust passage at a position upstream of the unit and bypasses the low-temperature exhaust heat power generation unit; and a first flow rate adjustment that adjusts the flow rate of exhaust gas that passes through the low-temperature exhaust heat power generation unit. A valve, a high-temperature exhaust heat power generation unit provided in the middle of the bypass exhaust passage for recovering thermal energy of high-temperature exhaust gas in a predetermined temperature range flowing through the bypass exhaust passage and generating electric power, and the high-temperature exhaust heat power generation unit A second flow control valve for controlling a flow rate of exhaust gas passing through the inside, and reading output information from the high-temperature and low-temperature exhaust heat power generation units, the first and second flow rates.
A controller that controls the opening of the flow control valve and an engine control unit that detects an operation information of the engine and outputs a control signal, wherein the controller is output from the engine control unit. The exhaust heat power generator is driven to control the degree of opening of the first and second flow regulating valves also by a signal. 8. The low-temperature exhaust heat power generation device according to claim 1, wherein an accelerator opening is detected as operation information of the engine, and when the accelerator opening is equal to or more than a predetermined value, the first flow control valve is driven in a valve closing direction to cause the low-temperature exhaust heat generation. The exhaust heat power generator according to claim 7, wherein a flow rate of exhaust gas passing through the unit is set to a predetermined value or less. 9. A low-temperature exhaust heat power generation unit that is provided in the middle of an exhaust passage of an engine and recovers thermal energy of low-temperature exhaust gas in a predetermined temperature range flowing through the exhaust passage and generates power. A bypass exhaust passage that branches off from the exhaust passage at a position upstream of the unit and bypasses the low-temperature exhaust heat power generation unit; and a first flow rate adjustment that adjusts the flow rate of exhaust gas that passes through the low-temperature exhaust heat power generation unit. A valve, a high-temperature exhaust heat power generation unit provided in the middle of the bypass exhaust passage for recovering thermal energy of high-temperature exhaust gas in a predetermined temperature range flowing through the bypass exhaust passage and generating electric power, and the high-temperature exhaust heat power generation unit A second flow control valve for adjusting a flow rate of exhaust gas passing through the inside, and a branch from the exhaust passage at a position upstream of the high-temperature and low-temperature exhaust heat power generation units, and A second bypass exhaust passage for bypassing the exhaust heat generation unit for use, a third flow control valve for adjusting the flow rate of exhaust gas passing through the second bypass exhaust passage, and outputs from the high-temperature and low-temperature exhaust heat generation units. An exhaust heat power generator comprising: a controller that reads information and controls an opening degree of each of the first to third flow control valves; and an engine control unit that detects operation information of an engine and outputs a control signal. Is driven so as to control the degree of opening of the first to third flow control valves also by a signal output from the engine control unit. 10. An accelerator opening is detected as the operation information, and when the accelerator opening is equal to or more than a predetermined value, the first flow control valve is driven in a valve closing direction to allow the low-temperature exhaust heat power generation unit to operate. The exhaust heat power generation device according to claim 9, wherein a flow rate of exhaust gas passing through is set to a predetermined value or less.