JP4840202B2 - Waste heat recovery device - Google Patents

Description

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

  Conventionally, Patent Document 1 discloses a waste heat recovery device that recovers waste heat of an internal combustion engine to reduce driving power of the internal combustion engine.

  The waste heat recovery apparatus of Patent Document 1 includes an evaporator that heats water with waste heat of an internal combustion engine to generate high-pressure steam, an expander that expands high-pressure steam, and a condenser that liquefies low-pressure steam discharged from the expander The Rankine cycle includes a water pump that supplies water liquefied by the condenser to the evaporator again, and the recovered waste heat is converted into a rotational driving force by an expander and output.

Further, the output shaft of the expander and the output shaft of the internal combustion engine are connected via a planetary gear mechanism and a belt-type continuously variable transmission, and the rotational speed of the rotational driving force output from the expander and the rotational speed of the output shaft of the internal combustion engine. By controlling the gear ratio of the belt type continuously variable transmission so as to match the above, the recovered waste heat is used for reducing the driving power of the internal combustion engine.
JP 2001-227616 A

  However, in the waste heat recovery apparatus of Patent Document 1, since the rotational drive force whose rotational speed changes with a constant torque is output from the expander, the transmission capable of appropriately matching the rotational speed of the internal combustion engine and the rotational speed of the expander. Must be adopted. In other words, a transmission (for example, a belt-type continuously variable transmission) that can appropriately change the output speed even if the input speed changes fluctuates. The degree of freedom is reduced.

  That is, for example, in a belt-type continuously variable transmission, the rotation speed on the output side is controlled by changing the gear ratio by changing the groove width of the driving pulley and the driven pulley by a hydraulic mechanism or the like. In a waste heat recovery apparatus that employs a continuously variable transmission, the overall system becomes large and complicated. As a result, there is a problem that the degree of freedom of design of the entire system is lowered.

  An object of this invention is to provide the waste heat recovery apparatus which can utilize the collect | recovered waste heat effectively, without causing the fall of the design freedom of the whole system in view of the said point.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a waste heat recovery device for recovering waste heat of the heat engine (2), wherein the liquid working medium (30) is encapsulated in a flowable manner. A tubular container (31), a heating section (32) for heating the working medium (30) to steam by using waste heat of the heat engine (2) as a heat source, a cooling section (33) for cooling and condensing the steam, a tubular A steam engine (3) having an output unit (34) for converting the displacement of the liquid portion of the working medium (30) in the container (31) into mechanical energy and outputting the mechanical energy, and generating rotational driving force by the mechanical energy The rotational driving force generating mechanism (4) to be operated, the rotational speed adjusting means (9, 10) for adjusting the rotational speed (Ns) of the rotational driving force, and the rotational speed for controlling the operation of the rotational speed adjusting means (9, 10). and control means (8), the rotational driving force, the rotational load Is transmitted to 7,70), the rotational speed control means (8), as the efficiency of the steam engine (.eta.s) approaches the maximum value, waste heat recovery for controlling the operation of the rotational speed adjusting means (9, 10) Features the device.

  According to this, by adopting the steam engine (3), the rotational speed (Ns) of the rotational driving force output from the rotational driving force generating mechanism (4) can be made constant. Therefore, in order to match the rotational speed (Ns) of the rotational driving force output from the rotational driving force generation mechanism (4) with the rotational speed required for the rotational load (7, 70), a complicated transmission is employed. There is no need to do.

  As a result, since the system as a whole waste heat recovery apparatus is not enlarged and complicated, the recovered waste heat can be effectively used without causing a decrease in the degree of freedom in design of the entire system.

  Further, in the steam engine (3), the liquid part of the working medium (30) functions as a so-called liquid piston that directly receives the expansion pressure of the steam, so that there is a problem of corrosion and wear of parts subjected to the steam pressure. Absent. Therefore, the durability improvement effect and product life improvement effect as a whole waste heat recovery apparatus can also be obtained.

Further, with rotational driving force of the engine speed and the rotational speed adjusting means for adjusting (Ns) (9, 10), rotational speed control means for controlling the operation of the rotational speed adjusting means (9, 10) and (8) The rotation speed control means (8) controls the operation of the rotation speed adjustment means (9, 10) so that the efficiency (ηs) of the steam engine approaches the maximum value.

According to this, since the steam engine (3) can be operated with high efficiency, the waste heat recovered more effectively can be used.
The invention according to claim 2 is a waste heat recovery device that recovers waste heat of the heat engine (2), and is a tubular container (31) in which a liquid working medium (30) is encapsulated in a flowable manner. In the heating part (32) which heats the working medium (30) using the waste heat of the heat engine (2) as a heat source to make steam, the cooling part (33) which cools and condenses the steam, and the tubular container (31) A steam engine (3) having an output part (34) for converting the displacement of the liquid portion of the working medium (30) into mechanical energy and outputting the same, and a rotational driving force generating mechanism for generating rotational driving force by the mechanical energy (4) and a rotation stopping means (5a) for stopping the rotation of the output shaft (4e) of the rotation driving force generating mechanism (4), and the rotation driving force is transmitted to the rotation loads (7, 70). Features a waste heat recovery device.
According to this, similarly to the first aspect of the invention, the recovered waste heat can be effectively used without causing a decrease in the degree of freedom in design of the entire system. Furthermore, since the rotation stopping means (5a) is provided, generation of unnecessary rotational driving force can be stopped.

  More specifically, the rotation speed adjusting means is constituted by a transmission (9) for shifting the rotation speed (Ns) of the rotational driving force, and the rotation speed control means (8) is a transmission ratio of the transmission (9). By controlling the rotational speed (Ns) of the rotational driving force.

  Alternatively, the rotation speed adjustment means is connected to the output shaft (4e) of the rotation driving force generation mechanism (4) and is rotated by an electric motor (10) that is rotated by being supplied with electric power from the outside. The rotational speed control means (8) may be configured such that the rotational speed (Ns) of the rotational driving force is adjusted by controlling the rotational speed (Nm) of the electric motor (10).

  In the waste heat recovery apparatus having the above-described features, the rotational driving force may be transmitted to the output shaft (2a) of the heat engine (2). According to this, the driving power of the heat engine (2) can be reduced.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an overall configuration diagram of an engine-driven generator 1 to which a waste heat recovery apparatus of the present invention is applied. Therefore, the internal combustion engine is an engine 2 for driving a generator, and the rotational load is a generator 7 that is rotationally driven by the engine 2 to generate electric power. The rotational driving force output from the waste heat recovery device is transmitted to the output shaft 2 a of the engine 2 and used as an auxiliary driving force for the generator 7.

  As shown in FIG. 1, the waste heat recovery apparatus of the present embodiment has a steam engine 3 that converts thermal energy into mechanical energy and outputs it, and rotation that generates rotational driving force by mechanical energy output from the steam engine. It is comprised by the driving force generation mechanism 4 grade | etc.,.

  First, the steam engine 3 has become a tubular container 31 in which a working medium 30 in a liquid state is enclosed so as to flow, a heating unit 32 that heats the working medium 30 using the waste heat of the engine 2 as a heat source, and turns the steam into steam. A cooling unit 33 that cools and condenses the working medium 30, an output unit 34 that outputs the displacement of the liquid portion of the working medium 30 in the tubular container 31 as mechanical energy, and the like.

  The tubular container 31 is a pipe-shaped pressure container that encloses water as the working medium 30. The tubular container 31 has a first straight portion 31a extending in the vertical direction and a second straight portion 31b extending in the horizontal direction from the lower end of the first straight portion 31a, and is formed in a substantially L shape as a whole. Moreover, the gas chamber 35, the heating part 32, and the cooling part 33 are arrange | positioned in order from the upper side at the 1st linear part 31a.

  The gas chamber 35 is provided at the upper end portion in the first linear portion 31a, and is filled with an inert gas such as nitrogen or helium that does not react with water as the working medium 30. The compression reaction force of the gas filled in the gas chamber 35 causes a periodic excitation force (elastic force) to act on the working medium in the tubular container 31.

  The heating unit 32 is disposed below the gas chamber 35 so as to cover the outer peripheral side of the first linear portion 31a. Further, an exhaust gas passage (not shown) through which the exhaust gas of the engine 2 passes is formed inside the heating unit 32, and the heating unit 32 exchanges heat between the exhaust gas passing through the exhaust gas passage and the working medium 30, The working medium 30 is heated.

  The cooling unit 33 is disposed so as to cover the outer peripheral side of the first linear part 31a on the lower side (the first central part of the first linear part 31a) at the lower side of the heating part 32. Further, a cooling water passage (not shown) through which the cooling water of the engine 2 passes is formed inside the cooling portion 33, and the cooling portion 33 exchanges heat between the cooling water passing through the cooling water passage and the working medium 30. Then, the working medium 30 is cooled.

  As is well known, the cooling water of the engine 2 has a cooling water circulation circuit (not shown) configured to include a water pump for pumping the cooling water and a radiator (radiator) for radiating the heat of the cooling water to the atmosphere. It is in circulation.

  Therefore, in this embodiment, the cooling water absorbs the waste heat in the engine 2, further absorbs the heat amount of the working medium 30 in the cooling unit 33, and dissipates the heat amount absorbed in the radiator to the atmosphere. Of course, in addition to the cooling water circulation circuit for cooling the engine 2, a dedicated cooling water circulation circuit for circulating the cooling water only to the cooling unit 33 may be provided.

  Moreover, it is desirable that the tubular container 31 is made of a material having excellent heat insulating properties except for a portion where the heating unit 32 and the cooling unit 33 are disposed. Therefore, in the present embodiment, the tubular container 31 is made of stainless steel, and the portions corresponding to the heating unit 32 and the cooling unit 33 are made of copper or aluminum that has better thermal conductivity than stainless steel. In addition, you may integrally form the heater 32 and the cooling part 33 in the said site | part.

  An output portion 34 is provided at the end of the second straight portion 31 b of the tubular container 31. The output part 34 is connected to the rotational driving force generating mechanism 4 via the tube 5 having a diameter smaller than that of the second straight part 31b.

  The rotational driving force generating mechanism 4 includes a cylinder 4a into which a liquid portion flows in the working medium 30 through the tube 5, a piston 4b slidably disposed in the cylinder 4a, a crank mechanism 4c coupled to the piston 4b, It has a disk-shaped wheel 4d connected to the crank mechanism 4c.

  Further, the piston 4b is disposed so as to be able to reciprocate in the axial direction of the cylinder 4a under the pressure of the working medium 30 flowing into the cylinder 4a. When the piston 4b reciprocates, the reciprocating motion causes the crank mechanism 4c to move. Through the rotary motion of the wheel 4d. Then, the rotational motion of the wheel 4d is output as a rotational driving force from the output shaft 4e of the wheel 4d.

  Therefore, in the present embodiment, the displacement of the liquid portion of the working medium 30 is output from the output unit 34 as mechanical energy, and this mechanical energy is output as the rotational driving force by the rotational driving force generation mechanism 4. In other words, the rotational driving force generation mechanism 4 exhibits a function corresponding to the expander of Patent Document 1.

  The output shaft 4 e of the rotational driving force generation mechanism 4 is connected to the output shaft 2 a of the engine 2 via the power transmission device 6. The power transmission device 6 includes a clutch mechanism and a planetary gear mechanism (not shown), and transmits the rotational driving force of the output shaft 4 e of the rotational driving force generation mechanism 4 to the output shaft 2 a of the engine 2.

  Next, the operation of the present embodiment having the above configuration will be described. First, when the engine 2 is started, the output shaft 2a of the engine 2 rotates at a substantially constant rotational speed Ne. This rotational speed is a rotational speed determined in advance so that the generator 7 can be operated with high efficiency. At the same time, the cooling water in the cooling water circulation circuit also circulates.

  Thereby, the rotational driving force of the output shaft 2a of the engine 2 is transmitted to the generator 7, and the generator 7 starts power generation. The electric power generated by the generator 7 is supplied to various electric devices and stored in a storage battery or the like. Further, the exhaust gas of the engine 2 passes through the heating unit 32 of the steam engine 3, and the cooling water of the engine 2 passes through the cooling unit 33 of the steam engine 3. Thereby, the steam engine 3 also operates.

  Here, the operation of the steam engine 3 will be described. First, the working medium 30 in the tubular container 31 of the steam engine 3 is heated by exchanging heat with the exhaust gas in the heating unit 32 to become steam. And the liquid level of the working medium 30 in the 1st linear part 31a is pushed down with the expansion pressure of the vapor | steam of this working medium.

  Thereby, the liquid part of the working medium 30 is fluidly displaced from the first straight part 31a side to the second straight part 31b side. Then, the working medium 30 flows into the cylinder 4a of the rotational driving force generating mechanism 4 from the output unit 34 via the tube 5 and presses the piston 4b.

  Furthermore, when the steam of the working medium 30 generated by the heating unit 32 expands and reaches the cooling unit 33, the steam is cooled by exchanging heat with cooling water in the cooling unit 33 to be condensed and liquefied. Therefore, the expansion pressure that pushes down the liquid level of the working medium 30 in the first straight part 31a disappears, and the liquid level of the working medium 30 in the first straight part 31a rises.

  As a result, the liquid portion of the working medium 30 is fluidly displaced from the second straight portion 31 b side to the first straight portion 31 a side, so that the working medium 30 in the cylinder 4 a returns to the output portion 34 via the tube 5. . Further, the pressing force of the working medium 30 against the piston 4b disappears. Conversely, the piston 4b receives a force in the direction opposite to the pressing force due to the inertia (inertial force) of the wheel 4d.

  As a result, the working medium 30 in the tubular container 31 reciprocates in the axial direction of the cylinder 4a at a constant cycle while self-excited and displaced so that the liquid level of the working medium 30 in the first linear portion 31a rises and falls. Exercise.

  Furthermore, the reciprocating motion of the piston 4b is converted into the rotational motion of the wheel 4d via the crank mechanism 4c, and is output as a rotational driving force at a constant rotational speed Ns from the output shaft 4e at the center of the wheel 4d. That is, it is possible to output a rotational driving force that rotates at a constant rotational speed Ns while the torque changes from the output shaft 4e at the center of the wheel 4d.

  In this embodiment, the natural frequency determined by the heat transfer characteristics of the working medium in the heating unit 32 and the cooling unit 33 and the spring constant of the gas spring formed by the gas chamber 35, that is, the steam engine 3 is adapted to the rotational speed Ne of the output shaft 2 a of the engine 2.

  The rotational driving force output from the rotational driving force generation mechanism 4 is transmitted to the output shaft 2 a of the engine 2 to assist the driving of the engine 2.

  In the present embodiment, as described above, by adopting the steam engine 3, the rotational speed Ns of the rotational driving force output from the rotational driving force generating mechanism 4 is constant, so that a complicated transmission is not employed. The rotational speed Ns of the rotational driving force output from the rotational driving force generating mechanism 4 can be easily matched with the rotational speed Ne of the output shaft 2a of the engine 2.

  Accordingly, since the system as a whole waste heat recovery apparatus is not increased in size and complicated, the recovered waste heat can be effectively used without reducing the degree of freedom in design of the entire system.

  Further, in the steam engine 3, the liquid portion of the working medium 30 functions as a so-called liquid piston that directly receives the expansion pressure of the steam, so that there is no problem of corrosion and wear of components that receive the steam pressure. Therefore, the durability improvement effect and product life improvement effect as a whole waste heat recovery apparatus can also be obtained.

(Second Embodiment)
In this embodiment, an example in which the waste heat recovery apparatus of the present invention is applied to a waste heat recovery system 11 for a vehicle travel engine will be described. FIG. 2 is an overall configuration diagram of the waste heat recovery system 11 for the vehicle travel engine of the present embodiment. In FIG. 2, the same or equivalent parts as those in the first embodiment are denoted by the same reference numerals. The same applies to the following embodiments.

  Therefore, in the present embodiment, the internal combustion engine is the engine 2 for traveling the vehicle, and the rotational load is the transmission 70 that transmits power to the drive wheels. Similarly to the first embodiment, the rotational driving force output from the waste heat recovery device is transmitted to the output shaft 2 a of the engine 2 and used as an auxiliary driving force of the transmission 70.

  Further, the waste heat recovery apparatus according to the present embodiment includes a transmission 9 configured to be able to adjust a gear ratio by a control signal output from the control device 8. As the transmission 9, an electric multi-stage gear mechanism having a simple configuration can be adopted. This electric multi-stage gear mechanism can change the gear ratio by switching a combination of a plurality of gears having different diameters with the electric actuator 9a.

  Next, an outline of the electric control unit of the present embodiment will be described. The control device 8 shown in FIG. 2 includes a microcomputer and its peripheral circuits, and an electric actuator 9a of the transmission 9 is connected to the output side. Further, a detection signal of a rotation speed sensor 8a for detecting the rotation speed Ne of the engine 2 and a rotation speed sensor 8b for detecting the rotation speed Ns of the rotational driving force generating mechanism 4 are input to the input side of the control device 8. . Other configurations are the same as those of the first embodiment.

  Next, the operation of the present embodiment having the above configuration will be described. First, similarly to the first embodiment, when the engine 2 is operated, the exhaust gas of the engine 2 flows into the heating unit 32 of the steam engine 3 and the engine cooling water flows into the cooling unit 33 of the steam engine. Accordingly, the rotational driving force is transmitted from the output shaft 2 a of the engine 2 to the transmission 70, and the rotational driving force is output from the output shaft 4 e of the rotational driving force generation mechanism 4.

  Incidentally, the rotational speed Ne of the output shaft 2a of the vehicle engine 2 changes as the engine output changes. For this reason, as in the first embodiment, even if a rotational driving force having a constant rotational speed Ns is output from the output shaft 4e of the rotational driving force generation mechanism 4, the rotational speed Ns of the rotational driving force generation mechanism 4 and the rotation of the engine 2 are increased. Unless the number Ne is properly matched, the driving of the engine 2 cannot be assisted appropriately.

  The reason is that if the rotational speed Ne of the engine 2 and the rotational speed Ns of the rotational driving force generating mechanism 4 do not match, the rotational speed Ns of the rotational driving force generating mechanism 4 is forcibly synchronized with the rotational speed Ne of the engine 2. Because it will end up.

  If the rotational speed Ne of the rotational driving force generating mechanism 4 is forcibly changed in this way, the energy conversion efficiency ηs of the steam engine 3 (hereinafter simply referred to as the efficiency ηs of the steam engine 3) as shown in FIG. Decreases and the driving of the engine 2 cannot be assisted.

  FIG. 3 is a graph showing the relationship between the rotational speed Ns of the rotational driving force generating mechanism 4 and the efficiency ηs of the steam engine 3. Further, as is clear from FIG. 3, the efficiency ηs of the steam engine 3 exhibits a peak (maximum value) at a predetermined rotational speed of the rotational driving force generation mechanism 4. The rotation speed at which the efficiency ηs of the steam engine 3 reaches a peak is a value corresponding to the self-excited vibration frequency of the steam engine 3.

  Therefore, it is desirable to control the rotational speed Ns of the rotational driving force generating mechanism 4 so that the efficiency ηs of the steam engine 3 approaches the peak, that is, so that the rotational speed Ns falls within the high efficiency range shown in FIG.

  Therefore, in this embodiment, the control device 8 outputs a control signal to the electric actuator 9a of the transmission 9 so that the efficiency ηs of the steam engine 3 approaches a peak, and changes the gear ratio of the transmission 9, thereby The rotational speed Ns of the rotational driving force generating mechanism 4 is adjusted. Therefore, the transmission 9 of the present embodiment constitutes a rotation speed adjusting means for adjusting the rotation speed Ns of the rotational driving force generating mechanism 4, and the control device 8 has a rotation speed control means for controlling the operation of the rotation speed adjusting means. Constitute.

  More specifically, the control device 8 calculates a target gear ratio at which the efficiency ηs of the steam engine 3 approaches a peak based on the detection values of the rotation speed sensors 8a and 8b. This target gear ratio may be calculated from the ratio of the self-excited vibration frequency of the steam engine 3 and the detected value of the rotation sensor 8a (the rotation speed of the engine 2) stored in advance in the control device.

  And the control apparatus 8 controls the action | operation of the electric actuator 9a of the transmission 9, and changes the gear ratio of the transmission 9 so that it may become a target gear ratio. Thereby, the rotational speed Ns of the rotational driving force generating mechanism 4 is adjusted so that the efficiency ηs of the steam engine 3 approaches the peak.

  Since the present embodiment operates as described above, the rotational speed Ns of the rotational driving force output from the rotational driving force generation mechanism 4 and the rotational speed Ne of the output shaft 2a of the engine 2 can be achieved without employing the complicated transmission 9. And can be easily matched. As a result, even if it is mounted on a vehicle, the recovered waste heat can be used effectively without causing a reduction in the degree of design freedom of the entire waste heat recovery system.

  Furthermore, since the efficiency ηs of the steam engine 3 can be brought close to the peak, the recovered waste heat can be used more effectively.

(Third embodiment)
In the present embodiment, an example in which the waste heat recovery apparatus of the present invention is applied to a waste heat recovery system 21 for a vehicle running engine for a hybrid vehicle will be described. FIG. 4 is an overall configuration diagram of the waste heat recovery system 21 for the vehicle travel engine of the present embodiment. In the present embodiment, as shown in FIG. 4, the output shaft 2 a of the engine 2, the output shaft 4 e of the rotational driving force generating mechanism 4, and the rotational shaft 10 a of the motor generator 10 are connected via an operating gear device 12. .

  The motor generator 10 has the same structure as that of the DC motor. When the electric power is supplied from the control device 8, the rotating shaft 10a rotates. When the rotating shaft 10a is rotationally driven by an external driving force, the motor generator 10 generates electric power. It is an electric motor with a power generation function that outputs electric power to the control device 8. The electric power output from the motor generator 10 is stored in the battery 13 in addition to being supplied to various electric devices via the control device 8.

  Further, the rotational speed Nm of the rotating shaft 10 a of the motor generator 10 is detected by the rotational speed sensor 8 c, and the detection signal of the rotational speed sensor 8 c is input to the control device 8.

  The operating gear device 12 can transmit the rotation of the first rotating shaft to the other two rotating shafts having the same center (hereinafter referred to as second and third rotating shafts) at different rotational speeds. It is. Conversely, rotations of different rotational speeds of the second and third rotating shafts can be transmitted to the first rotating shaft. Further, the arithmetic average of the rotation speeds of the second and third rotation shafts is equal to the rotation speed of the first rotation shaft.

  In the present embodiment, the first rotating shaft is connected to the output shaft 2a of the engine 2, and the second and third rotating shafts are respectively connected to the output shaft 4e of the rotational driving force generating mechanism 4 and the rotating shaft 10a of the motor generator 10. It is linked to.

  Further, in the present embodiment, an on-off valve 5 a that opens and closes a tube 5 that connects the steam engine 3 and the rotational driving force generation mechanism 4 is provided. The on-off valve 5 a is an electromagnetic valve that is opened and closed by a control voltage of the control device 8. Other configurations are the same as those of the first embodiment.

  Next, the operation of the present embodiment having the above configuration will be described. In the hybrid vehicle according to the present embodiment, the motor generator 10 generates electric power by the assist operation mode in which the rotational driving force of the engine 2 is assisted by the rotational driving force of the motor generator 10 and the steam engine 3 and the rotational driving force of the engine 2. There is a power generation mode.

  First, the assist operation mode will be described. In the assist operation mode, the control device 8 opens the on-off valve 5 a and supplies power to the motor generator 10. Accordingly, the rotational driving force is output from the output shaft 4 e of the rotational driving force generation mechanism 4, and the rotational driving force is also output from the rotational shaft 10 a of the motor generator 10.

  Then, the rotational driving force on the rotational driving force generation mechanism 4 side and the rotational driving force on the motor generator 10 side are transmitted to the output shaft 2 a of the engine 2 via the operating gear mechanism 12. As described above, the operating gear mechanism 12 transmits to the output shaft 2 a of the engine 2 the rotational speed that is the arithmetic average of the rotational speed Ne of the rotational driving force generating mechanism 4 and the rotational speed Nm of the motor generator 10.

  Therefore, in the present embodiment, the control device 8 causes the rotational speed Ns of the rotational driving force generating mechanism 4 to reach the peak of the efficiency ηs of the steam engine 3 based on the detection values of the rotational speed sensors 8a, 8b, and 8c. The rotational speed Nm of the motor generator 10 is controlled. Therefore, the motor generator 10 according to the present embodiment functions as a rotation speed adjusting unit that adjusts the rotation speed Ns of the rotational driving force generating mechanism 4.

  More specifically, the control device 8 has a rotational driving force generating mechanism 4 in which the detected value of the rotational speed sensor 8c (the rotational speed Nm of the motor generator 10) and the efficiency of the steam engine 3 stored in the control device in advance reach a peak. The rotational speed of the motor generator 10 is controlled so that the arithmetic average of the rotational speed of the motor generator 10 approaches the rotational sensor 8a (the rotational speed Ne of the engine 2).

  Thereby, the rotation speed Ns of the rotational driving force generation mechanism 4 is adjusted so that the efficiency ηs of the steam engine 3 approaches the peak.

  On the other hand, in the power generation operation mode, the control device 8 closes the on-off valve 5a. Therefore, the rotational driving force is not output from the rotational driving force generation mechanism 4. Furthermore, since the working medium 30 in the cylinder 4a cannot flow out to the output part 34 side of the steam engine 3, the output shaft 4e of the rotational driving force generating mechanism 4 is in a fixed state. That is, the on-off valve 5a functions as rotation stop means.

  As described above, in the operating gear mechanism 12, the rotational speed Ne of the engine 2 is equal to the arithmetic average of the rotational speed Ns of the rotational driving force generation mechanism 4 and the rotational speed Nm of the motor generator 10. It is transmitted only to the motor generator 10 via the operating gear mechanism 12. Thereby, the rotational driving force of the engine 2 can be efficiently transmitted to the motor generator 10 to generate electric power.

  Since this embodiment operates as described above, in the assist operation mode, the rotational speed Ns of the rotational driving force generating mechanism 4 is set so that the efficiency ηs of the steam engine 3 approaches the peak without employing the complicated transmission 9. Can be adjusted. As a result, even if it is mounted on a vehicle, the recovered waste heat can be used effectively without causing a reduction in the degree of design freedom of the entire waste heat recovery system.

  On the other hand, in the power generation operation mode, the rotational driving force of the engine 2 can be efficiently transmitted to the motor generator 10, so that the rotational driving force of the engine 2 can be used effectively.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows.

  (1) In the above-described embodiment, the rotational driving force generation mechanism 4 is configured by the crank mechanism 4c, the wheel 4d, and the like, but the rotational driving force generation mechanism is not limited to this. That is, any mechanical energy may be used as long as the mechanical energy output from the output unit 34 of the steam engine 3 can be output as the rotational driving force. For example, the reciprocating motion of the piston may be converted into a rotational motion by a cam mechanism.

  (2) In the second embodiment described above, an electric multi-stage gear mechanism is employed as the transmission 9, but other mechanisms may be employed. For example, an electric multi-stage chain mechanism that changes a gear ratio by selecting a sprocket on which a chain is mounted from among a plurality of sprockets having different diameters by an electric actuator may be adopted.

  In addition, a belt type continuously variable transmission, a toroidal continuously variable transmission, a ring cone type continuously variable transmission, or the like may be employed within an allowable range of design flexibility of the entire system.

  (3) In the third embodiment described above, the rotation stopping means for stopping the rotation of the output shaft 4e of the rotational driving force generating mechanism 4 is configured by the on-off valve 5a, but the rotation stopping means is not limited to this. For example, a brake device that forcibly stops the rotation of the wheel 4d may be employed.

  (4) In the assist operation mode of the third embodiment described above, the rotational drive force of the engine 2 is assisted by the rotational drive force of the motor generator 10 and the steam engine 3, but the assist is performed only by the rotational drive force of the steam engine 3. May be. In this case, the motor generator 10 is allowed to act as a generator, and the rotational speed Ns of the rotational driving force generating mechanism 4 may be adjusted so that the efficiency ηs of the steam engine 3 approaches the peak by the driving torque.

  (5) In the above-described embodiment, the mechanical energy output from one steam engine 3 is output as the rotational driving force from the rotational driving force generating mechanism 4, but the mechanical energy output from the plurality of steam engines 3 is output. The energy may be output from the rotational driving force generation mechanism 4 as a rotational driving force.

It is a whole block diagram of the engine drive type generator of 1st Embodiment. It is a whole block diagram of the waste-heat recovery system of 2nd Embodiment. It is a graph which shows the relationship between the rotation speed Ns and the efficiency (eta) s of a steam engine. It is a whole block diagram of the waste heat recovery system of 3rd Embodiment.

Explanation of symbols

2 ... Engine, 2a ... Engine output shaft, 3 ... Steam engine,
4 ... Rotational driving force generating mechanism, 4e ... Output shaft of the rotational driving force generating mechanism, 5a ... Open / close valve,
7 ... Generator, 8 ... Control device, 9 ... Transmission, 10 ... Motor generator,
30 ... Working medium, 31 ... Tubular container, 32 ... Heating part, 33 ... Cooling part, 34 ... Output part,
70: Transmission.

Claims (5)

A waste heat recovery device for recovering waste heat of the heat engine (2),
A tubular container (31) in which a liquid working medium (30) is flowably enclosed, and a heating unit (32) that heats the working medium (30) using the waste heat of the heat engine (2) as a heat source to form steam. ), A cooling unit (33) that cools and condenses the vapor, and an output unit (34) that converts the displacement of the liquid portion of the working medium (30) in the tubular container (31) into mechanical energy and outputs the mechanical energy. A steam engine (3) having
A rotational driving force generating mechanism (4) for generating a rotational driving force by the mechanical energy ;
A rotational speed adjusting means (9, 10) for adjusting the rotational speed (Ns) of the rotational driving force;
A rotation speed control means (8) for controlling the operation of the rotation speed adjustment means (9, 10) ,
The rotational driving force is transmitted to the rotational load (7, 70) ;
The rotation speed control means (8) controls the operation of the rotation speed adjustment means (9, 10) so that the efficiency (ηs) of the steam engine approaches a maximum value. . A waste heat recovery device for recovering waste heat of the heat engine (2),
A tubular container (31) in which a liquid working medium (30) is flowably enclosed, and a heating unit (32) that heats the working medium (30) using the waste heat of the heat engine (2) as a heat source to form steam. ), A cooling unit (33) that cools and condenses the vapor, and an output unit (34) that converts the displacement of the liquid portion of the working medium (30) in the tubular container (31) into mechanical energy and outputs the mechanical energy. A steam engine (3) having
A rotational driving force generating mechanism (4) for generating a rotational driving force by the mechanical energy ;
Rotation stopping means (5a) for stopping the rotation of the output shaft (4e) of the rotational driving force generating mechanism (4) ,
The waste heat recovery apparatus, wherein the rotational driving force is transmitted to a rotational load (7, 70). The rotational speed adjusting means is constituted by a transmission (9) that changes the rotational speed (Ns) of the rotational driving force,
By the rotation speed control means (8) controls the transmission ratio of the transmission (9), according to claim 1 or 2, wherein the rotational driving force of the rotational speed (Ns) is adjusted Waste heat recovery equipment. The rotational speed adjusting means is constituted by an electric motor (10) that is connected to the output shaft (4e) of the rotational driving force generating mechanism (4) and rotates by being supplied with electric power from the outside.
By the rotation speed control means (8) controls the rotational speed (Nm) of the electric motor (10), according to claim 1 or 2, wherein the rotational driving force of the rotational speed (Ns) is adjusted The waste heat recovery device described in 1. The waste heat recovery apparatus according to any one of claims 1 to 4 , wherein the rotational driving force is transmitted to an output shaft (2a) of the heat engine (2).

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