JP2013076397A - Waste heat utilization device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste heat utilization device capable of achieving an improvement in temperature efficiency for an intake system fluid and enhancement in output of an internal combustion engine, as appropriate, while simplifying a structure of the waste heat utilization device.SOLUTION: The waste heat utilization device includes embodiment 1: a drive system 1a including an engine 5 and a turbocharger 7 for supplying the engine 5 with pressurized air; and a Rankine cycle 3a used in the drive system 1a. The Rankine cycle 3a includes a pump P1, a pressure air boiler 23, an expander 25, a condenser 27 and pipes 28 to 32. Furthermore, the Rankine cycle 3a is provided with a bypass 33 and a flow control valve 35. In the waste heat utilization device, the pump P1 and the expander 25 are connected through a drive shaft 37 to be capable of power transmission. Additionally, the pump P1 is connected to be capable of being driven by the engine 5 through an electromagnetic clutch 39 and a pulley 21.

Description

  The present invention relates to a waste heat utilization apparatus.

  Patent Document 1 and Patent Document 2 disclose conventional waste heat utilization devices. The waste heat utilization apparatus of Patent Document 1 is used in a drive system and includes a Rankine cycle that circulates a working fluid. The drive system includes an engine and a turbocharger that supplies pressurized air as an intake system fluid to the engine. Rankine cycle consists of a pump, a coolant boiler, a pressurized air boiler, an expander, a condenser, and a pipe that circulates the working fluid from the pump to the condenser through the coolant boiler, the pressurized air boiler, and the expander. And have. The coolant boiler heats the working fluid by exchanging heat between the coolant of the engine and the working fluid. The pressurized air boiler heats the working fluid by exchanging heat between the pressurized air and the working fluid.

  Moreover, the waste heat utilization apparatus of patent document 2 is used for a drive system, and is provided with the Rankine cycle which circulates a working fluid. The drive system has an engine as an internal combustion engine, and an exhaust gas recirculation passage for recirculating a part of exhaust gas generated in the engine as a recirculated exhaust gas as an intake system fluid. The Rankine cycle has a pump, a reflux exhaust boiler, an expander, a condenser, and piping. The reflux exhaust boiler heats the working fluid by exchanging heat between the reflux exhaust and the working fluid. The piping circulates the working fluid in the order of a pump, a reflux exhaust boiler, an expander, and a condenser.

  In these waste heat utilization devices, the working fluid can be heated by a coolant boiler and a pressurized air boiler, and the working fluid can be heated by a reflux exhaust boiler. For this reason, in these waste heat utilization apparatuses, it is possible to increase the pressure energy generated by the expansion and decompression of the working fluid. For this reason, in these waste heat utilization apparatuses, the amount of energy that can be recovered in the Rankine cycle increases, and the waste heat utilization apparatuses have high performance.

JP 2008-8224 A JP 2007-239513 A

  However, in each of the above waste heat utilization devices, the structure is complicated because the Rankine cycle pump and the expander cannot transmit power. For this reason, it is conceivable that the pump and the expander are coaxially connected to enable power transmission and the pump is connected by an internal combustion engine such as an engine and a pulley, a belt, and the like. In this case, the pump and the expander can be integrated. Further, since the pump can be driven by the internal combustion engine, it is not necessary to provide a drive device for driving the pump. For this reason, the structure of the waste heat utilization apparatus is simplified.

  In addition, intake system fluids such as the above-described pressurized air and recirculation exhaust are required to be taken in while being cooled by an internal combustion engine such as an engine. This is because by increasing the density of the intake system fluid by cooling and allowing the internal combustion engine to inhale in that state, the output and the like of the internal combustion engine are improved and its performance is improved.

  Therefore, in the Rankine cycle of each waste heat utilization device described above, if the working fluid that has passed through the pump flows directly into the pressurized air boiler or the reflux exhaust boiler, the intake system fluid (pressurized air and reflux exhaust) Heat can be transferred to the working fluid to effectively reduce the temperature of the intake system fluid. As a result, the internal combustion engine can be inhaled with the density of the intake fluid increased, and the performance of the internal combustion engine can be further improved.

  However, in that case, the temperature efficiency (the flow rate of the working fluid) for the intake system fluid depends on the operating state (the number of revolutions) of the internal combustion engine. Therefore, in some cases, the temperature efficiency with respect to the intake system fluid is low, and a situation may occur in which the output of the internal combustion engine is insufficient.

  The present invention has been made in view of the above-described conventional situation, and, while simplifying the structure of the waste heat utilization device, improves the temperature efficiency for the intake system fluid and improves the performance of the internal combustion engine as necessary. Providing a possible waste heat utilization device is a problem to be solved.

The waste heat utilization apparatus of the present invention is used in a drive system having an internal combustion engine, and includes a Rankine cycle for circulating a working fluid.
The Rankine cycle is a waste heat utilization apparatus having a pump, a boiler, an expander, a condenser, and a pipe for circulating the working fluid from the pump to the condenser through the boiler and the expander.
In the boiler, heat exchange between the working fluid and the intake system fluid that is sucked while being cooled with respect to the internal combustion engine is possible,
The pump and the expander are connected to transmit power,
The pump is connected to be driven by the internal combustion engine via a clutch,
A judging means for judging a required cooling amount for the intake system fluid;
And a control unit that disconnects the clutch when the requested cooling amount determined by the determining unit exceeds a first threshold value (Claim 1).

  The waste heat utilization apparatus of the present invention includes a Rankine cycle. This Rankine cycle is used for a drive system, and circulates a working fluid. The drive system has an internal combustion engine. On the other hand, the Rankine cycle has a pump, a boiler, an expander, a condenser, and piping. In the boiler, heat exchange between the intake fluid and the working fluid is possible, and the working fluid can be heated and the intake fluid can be cooled. Here, the intake system fluid refers to a fluid that is required to be sucked while being cooled with respect to the internal combustion engine as described above.

  In other words, in this waste heat utilization device, the heat of the intake system fluid becomes energy that can be recovered in the Rankine cycle, while the boiler functions as a cooling device for the intake system fluid, thereby effectively reducing the temperature of the intake system fluid. be able to. For this reason, in this waste heat utilization apparatus, it is possible to cause the internal combustion engine to intake air with the density of the intake system fluid increased. For this reason, this waste heat utilization apparatus can improve the performance of the internal combustion engine.

  Further, in this waste heat utilization device, the pump and the expander are connected so as to be able to transmit power, so that the pump and the expander can be integrated. Further, since the pump is connected to be driven by the internal combustion engine via the clutch, it is not necessary to provide a drive device for driving the pump. For this reason, the structure of the waste heat utilization apparatus is simplified.

  In this waste heat utilization device, if the internal combustion engine and the pump are connected by a clutch, the temperature efficiency with respect to the intake system fluid depends on the flow rate of the working fluid, that is, the operating state (rotation speed) of the internal combustion engine. Become. For this reason, this waste heat utilization apparatus is provided with a judgment means and a control means so that the connection by the clutch can be disconnected by the control means based on the required cooling amount for the intake system fluid judged by the judgment means.

  Specifically, when the determination means determines that the required cooling amount for the intake system fluid is equal to or less than the first threshold, the clutch is turned on and the internal combustion engine and the pump are connected by the clutch. . In this case, since the pump is in a normal operation state, the pump is driven by an internal combustion engine or an expander, the working fluid that has passed through the pump flows into the boiler as it is, and in the boiler, the heat of the intake system fluid is transferred to the working fluid, so that the intake system The temperature of the fluid can be lowered. As a result, the intake system fluid can be sucked into the internal combustion engine in a high density state, and the output of the internal combustion engine can be improved. At this time, the expander can return (regenerate) energy generated by the expander to the internal combustion engine by performing expansion work in the Rankine cycle. The expander can regenerate the internal combustion engine using the generated energy as power as it is, or convert the generated energy into electric power or the like.

  On the other hand, when the determination means determines that the required cooling amount for the intake fluid exceeds the first threshold, heat exchange in the boiler, that is, cooling of the intake fluid is prioritized, and the clutch is turned off. Thereby, the connection between the internal combustion engine and the pump by the clutch is disconnected. In this case, since the drive load of the expander is only the pump, in the Rankine cycle, the rotation speeds of the expander and the pump are increased, and the speed of the working fluid circulating in the piping is accelerated. For this reason, the flow volume of the working fluid which flows into a boiler increases. Thereby, in the boiler, the temperature of the intake system fluid can be further lowered, and the required cooling amount for the intake system fluid can be satisfied. In this case, the intake system fluid having a higher density can be sucked into the internal combustion engine. For this reason, in the waste heat utilization apparatus in this state, the performance of the internal combustion engine can be further enhanced. The acceleration of the working fluid stops when the power of the expander and the power consumption of the pump are balanced.

  Therefore, the waste heat utilization apparatus of the present invention can realize the improvement of the temperature efficiency with respect to the intake system fluid and the improvement of the performance of the internal combustion engine as required while simplifying the structure.

  In the Rankine cycle in the waste heat utilization apparatus of the present invention, in addition to the above-described boiler capable of heat exchange between the intake system fluid and the working fluid, for example, cooling capable of heat exchange between the waste heat of the internal combustion engine and the working fluid. You may have the oil boiler etc. which can exchange heat with the lubricating oil and working fluid with respect to a liquid boiler or an internal combustion engine. In this case, the working fluid can be heated by a plurality of boilers, and the waste heat utilization device has higher performance. However, while the clutch is in the OFF state, it is preferable to bypass the coolant boiler or the like so that the working fluid that has passed through the pump flows directly into the boiler that exchanges heat with the intake system fluid.

  In the waste heat utilization apparatus of the present invention, the determination means can determine the required cooling amount for the intake system fluid by various means. For example, the waste heat utilization apparatus of the present invention can include an output request detection means capable of detecting an output request to the internal combustion engine. The determining means preferably determines the required cooling amount for the intake fluid based on the detection value detected by the output request detecting means.

  Moreover, the waste heat utilization apparatus of this invention can be equipped with the 1st temperature detection means which can detect the temperature of the intake system fluid which flows out out of a boiler. The determining means preferably determines the required cooling amount for the intake system fluid based on the detected value detected by the first temperature detecting means.

  Moreover, the waste heat utilization apparatus of this invention can be equipped with the 2nd temperature detection means which can detect the temperature of the working fluid which flows in into a boiler. The determining means preferably determines the required cooling amount for the intake system fluid based on the detected value detected by the second temperature detecting means.

  Moreover, the waste heat utilization apparatus of this invention can be equipped with the 3rd temperature detection means which can detect the temperature of the working fluid which flows in into a pump. The determining means preferably determines the required cooling amount for the intake system fluid based on the detected value detected by the third temperature detecting means.

  Moreover, the waste heat utilization apparatus of this invention can be equipped with the 4th temperature detection means which can detect the temperature of the intake system fluid which flows in into a boiler. The determination means preferably determines the required cooling amount for the intake system fluid based on the detection value detected by the fourth temperature detection means.

  Moreover, the waste heat utilization apparatus of this invention can be equipped with the pressure detection means which can detect the pressure of the working fluid from the downstream of an expander to the upstream of a pump. The determining means preferably determines the required cooling amount for the intake system fluid based on the detected value detected by the pressure detecting means.

  As described above, in addition to the output request to the internal combustion engine, the temperature of the intake system fluid flowing out from the boiler or flowing into the boiler, the temperature of the working fluid flowing into the boiler or the pump, the working fluid from the downstream of the expander to the upstream of the pump Based on this pressure (condensation pressure), the determination means can accurately determine the required cooling amount for the intake system fluid. For this reason, in these waste heat utilization apparatuses, it becomes possible to more suitably realize improvement in temperature efficiency for the intake system fluid and improvement in performance of the internal combustion engine.

  In the waste heat utilization apparatus of the present invention, the pump and the expander are connected so as to be able to transmit power. For example, the pump and the expander may be integrated so as to be connected by a coaxial drive shaft. The expander may be integrated with a gear mechanism or the like. When the connection with the internal combustion engine is disconnected, the pump may be operated by electric power or the like in addition to the power of the expander.

  By the way, if it is determined only whether or not the required cooling amount for the intake system fluid exceeds the first threshold for the connection / disconnection between the pump and the internal combustion engine via the clutch, the regeneration of the energy generated in the expander to the internal combustion engine is reduced. Opportunities to perform may be reduced, and regeneration of energy generated in the expander with respect to the internal combustion engine may be insufficient. For this reason, in addition to determining that the required cooling amount for the intake fluid exceeds the first threshold, the control means preferably disconnects the clutch by a low-speed signal in which the rotation speed of the internal combustion engine falls below the second threshold. (Claim 8).

  In this case, in this waste heat utilization apparatus, the determination means determines that the required cooling amount for the intake system fluid has exceeded the first threshold value, and when there is a low speed signal, the clutch is turned off. The connection with the pump will be broken. On the other hand, not only when the determination unit determines that the required cooling amount for the intake system fluid is equal to or less than the first threshold value, but the determination unit determines that the required cooling amount for the intake system fluid exceeds the first threshold value as described above. Even in this case, when there is no low-speed signal, the clutch is in an ON state, and the internal combustion engine and the pump are connected by the clutch.

  When the clutch is ON, in the Rankine cycle, the flow rate of the pump, that is, the flow rate of the working fluid circulating in the pipe depends on the rotation speed of the internal combustion engine. There is a possibility that the flow rate of the working fluid in the cycle decreases and the cooling capacity for the intake system fluid in the boiler is insufficient. However, when the determination means determines that the required cooling amount for the intake system fluid has exceeded the first threshold value and the rotational speed of the internal combustion engine is lower than the second threshold value, the internal combustion engine and pump by the clutch are as described above. Is disconnected, and the drive load of the expander is only the pump. For this reason, in this waste heat utilization apparatus, the flow rate of the working fluid in the Rankine cycle increases, and the cooling capacity for the intake system fluid in the boiler increases.

  On the other hand, if the rotational speed of the internal combustion engine is greater than or equal to the second threshold value, the flow rate of the working fluid in the Rankine cycle is large even if the flow rate of the working fluid circulating in the pipe depends on the rotational speed of the internal combustion engine. The cooling capacity for the intake system fluid is sufficiently secured. In other words, even when the clutch is in the ON state, it is possible to satisfy the cooling request exceeding the first threshold value for the intake system fluid. For this reason, not only when the determination means determines that the required cooling amount for the intake system fluid is equal to or less than the first threshold value, but also when the determination means determines that the required cooling amount for the intake system fluid exceeds the first threshold value. However, when there is no low-speed signal, the clutch is in the ON state, so that it is possible to regenerate the energy generated in the expander for the internal combustion engine while satisfying the cooling requirement for the intake system fluid.

  Further, as described above, since the pump and the expander are connected so as to be able to transmit power, when the connection with the internal combustion engine is disconnected, the power generated by the expander is consumed for driving the pump. It becomes. Then, as described above, the circulation speed of the working fluid circulating in the pipe is accelerated to a point where the power of the expander and the power consumption of the pump are balanced. For this reason, there is a concern that the expander is excessively driven by the working fluid accelerated more than necessary.

  Therefore, the waste heat utilization apparatus of the present invention branches from the piping downstream of the boiler, bypasses the bypass to bypass the expander, joins the piping, the flow rate of the working fluid flowing into the expander, and the operation flowing into the bypass And a flow rate adjusting valve capable of adjusting the flow rate of the fluid. And it is preferable that a control means controls a flow regulating valve (Claim 9).

  In this case, the working fluid circulates in a bypass path that can bypass the expander, so that it is possible to prevent the working fluid from excessively driving the expander when the clutch is in an OFF state. Sex can be maintained.

  Moreover, in this waste heat utilization apparatus, it is possible to adjust the ratio between the flow rate of the working fluid flowing into the expander and the flow rate of the working fluid flowing into the bypass passage by the control means controlling the flow rate adjusting valve. is there. Thereby, the rotation speed of the expander and the pump when the power of the expander and the power consumption of the pump are balanced can be reduced, and these can be protected. On the other hand, by increasing the flow rate of the working fluid flowing into the expander than the flow rate of the working fluid flowing into the bypass passage, the energy that can be recovered by the Rankine cycle is increased while adjusting the rotation speed of the pump and the expander. It becomes possible to do.

  Furthermore, in the waste heat utilization apparatus of the present invention, the expander may be able to drive a generator. And it is preferable that a control means controls the load of a generator (Claim 10). In this case, in the Rankine cycle, the pressure energy generated by the expansion and decompression of the working fluid can be recovered as electric power, and this electric power can be regenerated to the internal combustion engine. Moreover, since the rotation speed of a pump and an expander can be adjusted also with the load by a generator, these can be protected.

  In the waste heat utilization apparatus of the present invention, various types of engines can be employed as the internal combustion engine of the drive system, in addition to gasoline engines, diesel engines, and the like. These engines may be hybrid engines combining motors. Furthermore, these engines may be air-cooled or water-cooled.

  Further, the drive system may include a supercharger that supplies pressurized air that is an intake system fluid to the internal combustion engine. The boiler may be a pressurized air boiler that exchanges heat between the pressurized air and the working fluid.

  In this case, the pressurized air is supplied to the internal combustion engine by the supercharger, thereby improving the output of the internal combustion engine. Here, since the compressed air is required to be sucked into the internal combustion engine while increasing its density by cooling, it corresponds to the intake system fluid. In this waste heat utilization device, it is possible to cool the pressurized air and increase its density by exchanging heat with the working fluid in the pressurized air boiler. Thereby, in this waste heat utilization apparatus, more pressurized air can be supplied to the internal combustion engine, and the performance of the internal combustion engine can be improved. As this supercharger, a turbocharger, a supercharger, or the like can be employed. There may be a plurality of superchargers.

  Further, the drive system may have an exhaust gas recirculation path that recirculates a part of the exhaust gas generated in the internal combustion engine to the internal combustion engine as recirculated exhaust gas that is an intake system fluid. The boiler may be a recirculation exhaust boiler that performs heat exchange between the recirculation exhaust and the working fluid.

  In this case, the exhaust gas recirculation path causes a part of the exhaust gas to be sucked (recirculated) into the internal combustion engine, thereby reducing the content of nitrogen oxides in the exhaust gas when it is finally released into the atmosphere. It becomes possible. Here, since the recirculated exhaust gas is required to be recirculated to the internal combustion engine while increasing its density by cooling, it corresponds to the intake system fluid. And in this waste heat utilization apparatus, it becomes possible to cool the recirculated exhaust gas and increase its density by exchanging heat with the working fluid in the recirculated exhaust boiler. Thereby, in this waste heat utilization apparatus, it becomes possible to recirculate | reflux exhaust gas suitably with respect to an internal combustion engine, and it becomes possible to improve the performance of an internal combustion engine.

  The waste heat utilization apparatus of the present invention can realize improvement in temperature efficiency with respect to the intake system fluid and improvement in performance of the internal combustion engine as required while simplifying the structure.

1 is a schematic structural diagram showing a waste heat utilization apparatus of Example 1. FIG. FIG. 3 is a schematic structural diagram illustrating a case where the clutch is in an ON state according to the waste heat utilization apparatus of the first embodiment. FIG. 3 is a schematic structural diagram illustrating a case where the clutch is in an OFF state according to the waste heat utilization apparatus of the first embodiment. FIG. 3 is a schematic structural diagram illustrating a state in which a working fluid flows into a condenser through a bypass path in the waste heat utilization apparatus of the first embodiment. FIG. 10 is a schematic structural diagram illustrating a case where the clutch is in an OFF state in the waste heat utilization apparatus of the second embodiment. FIG. 6 is a schematic structural diagram showing a waste heat utilization apparatus of Example 3. FIG. 6 is a schematic structural diagram illustrating a case where a clutch is in an ON state according to the waste heat utilization apparatus of the third embodiment. FIG. 10 is a schematic structural diagram illustrating a case where the clutch is in an OFF state in the waste heat utilization apparatus of the third embodiment. FIG. 6 is a schematic structural diagram illustrating a state in which a working fluid flows into a condenser through a bypass path in the waste heat utilization apparatus of the third embodiment. It is a schematic structure figure which shows the waste heat utilization apparatus of Example 4. FIG. 6 is a schematic structural diagram showing a waste heat utilization apparatus of Example 5. It is a schematic structure figure which shows the waste heat utilization apparatus of Example 6.

  Embodiments 1 to 6 embodying the present invention will be described below with reference to the drawings.

Example 1
The waste heat utilization apparatus of Example 1 is mounted on a vehicle and used in a drive system 1a of the vehicle as shown in FIG. The waste heat utilization apparatus includes a Rankine cycle 3a, an electromagnetic clutch 39, a bypass passage 33, a flow rate adjustment valve 35, and a control device 11a.

  The drive system 1a has an engine 5 as an internal combustion engine, a turbocharger 7 as a supercharger, and a radiator (not shown). The engine 5 is a known water-cooled gasoline engine. A water jacket (not shown) through which LLC (long life coolant) as a coolant can flow is formed inside the engine 5. The engine 5 is formed with an outlet and an inlet (both not shown) communicating with the water jacket.

  Further, the engine 5 is formed with an exhaust port 5a for exhausting exhaust gas and an intake port 5b for sucking pressurized air described later. The engine 5 is electrically connected to the control device 11a, and the number of revolutions of the engine 5 can be transmitted as an electric signal to the control device 11a. Specifically, the engine 5 transmits a low speed signal to the control device 11a when the rotational speed of the engine 5 falls below the second threshold value. In this waste heat utilization apparatus, 1500 rpm is set as the second threshold value.

  The turbocharger 7 is operated by exhaust generated from the engine 5 and supplies pressurized air as an intake system fluid to the engine 5.

  The engine 5 and the turbocharger 7 are connected by piping 8-10. Further, a pressurized air boiler 23 described later is connected to the pipe 9 and the pipe 10. The pipe 8 is capable of circulating exhaust gas and is connected to the exhaust port 5 a of the engine 5 and the turbocharger 7. On the other hand, the compressed air can flow through the pipe 9 and the pipe 10. The pipe 9 is connected to the turbocharger 7 and the first inlet 23 a of the pressurized air boiler 23. The pipe 10 is connected to the first outlet 23 b of the pressurized air boiler 23 and the inlet 5 b of the engine 5.

  Further, the turbocharger 7 is connected to one end sides of the pipes 12 and 13. The other end side of the pipe 12 is connected to a muffler (not shown). The other end of the pipe 13 is open to an air intake of a vehicle (not shown). The pipe 12 communicates with the pipe 8 through the turbocharger 7. Similarly, the pipe 13 communicates with the pipe 9 via the turbocharger 7.

  The engine 5 is connected to a known pulley 21 via a crankshaft 19. The pulley 21 includes a pair of pulley drums 21a and 21b, and a pulley belt 21c that couples the pulley drum 21a and the pulley drum 21b so that power can be transmitted. The crankshaft 19 is connected to a pulley drum 21a, and the pulley drum 21a can be rotated by the power of the engine 5.

  The Rankine cycle 3a includes a pump P1, a pressurized air boiler 23, an expander 25, a condenser 27, and pipes 28 to 32. The Rankine cycle 3a is integrally assembled with a bypass path 33 and a flow rate adjustment valve 35. An HFC 134a as a working fluid can be circulated through the pipes 28 to 32 and the bypass path 33.

  The pressurized air boiler 23 is formed with a first inlet 23a and a first outlet 23b, and a second inlet 23c and a second outlet 23d. Further, in the pressurized air boiler 23, a first passage 23e communicating with the first inflow port 23a and the first outflow port 23b on both ends, respectively, and a second inflow port 23c and a second outflow port 23d on both ends, respectively. And a second passage 23f communicating with the second passage 23f. In the pressurized air boiler 23, the pressurized air is cooled and the working fluid is heated by exchanging heat between the pressurized air in the first passage 23e and the working fluid in the second passage 23f.

  The expander 25 is formed with an inlet 25a through which a working fluid flows and an outlet 25b through which the working fluid flows out. The expander 25 generates a rotational driving force by expanding the working fluid heated through the pressurized air boiler 23. The expander 25 and the engine 5 are connected so as to be able to transmit power via a power transmission unit (not shown), and the engine 5 regenerates the rotational driving force generated by expanding the working fluid in the expander 25. .

  Further, a drive shaft 37 described later is connected to the expander 25. Furthermore, the expander 25 is electrically connected to the control device 11a. Thereby, the expander 25 can transmit the rotation speed in the expander 25 as an electric signal with respect to the control apparatus 11a.

  The condenser 27 is formed with an inlet 27a through which the working fluid flows and an outlet 27b through which the working fluid flows out. The condenser 27 exchanges heat between the working fluid flowing through the inside of the condenser 27 and air outside the vehicle, and cools and liquefies the working fluid decompressed by the expansion in the expander 25. An electric fan 27 c is provided in the vicinity of the condenser 27. The electric fan 27c is electrically connected to the control device 11a.

  The bypass path 33 causes the working fluid to bypass the expander 25 by circulating the working fluid therein. The flow rate adjustment valve 35 is a switching valve capable of adjusting the amount of the working fluid flowing into the expander 25 and the amount of the working fluid flowing into the bypass passage 33. The flow rate adjusting valve 35 is electrically connected to the control device 11a.

  The pump P1 and the expander 25 are connected by a drive shaft 37 so that power can be transmitted. Specifically, one end side of the drive shaft 37 is connected to the expander 25, and the other end side of the drive shaft 37 is connected to the pump P1. The pump P1 and the expander 25 are linked via the drive shaft 37, so that the pump P1 sucks the working fluid and discharges the sucked working fluid by the rotational driving force generated in the expander 25.

  The pump P1, the pressurized air boiler 23, the expander 25, the condenser 27, the bypass passage 33, and the flow rate adjustment valve 35 are connected by pipes 28 to 32. Specifically, the pump P1 and the second inlet 23c of the pressurized air boiler 23 are connected by a pipe 28. The second outlet 23 d of the pressurized air boiler 23 and the flow rate adjustment valve 35 are connected by a pipe 29. The flow rate adjustment valve 35 and the inlet 25a of the expander 25 are connected by a pipe 30. The outlet 25 b of the expander 25 and the inlet 27 a of the condenser 27 are connected by a pipe 31. The outlet 27b of the condenser 27 and the pump P1 are connected by a pipe 32. In addition, one end side of the bypass path 33 is connected to the flow rate adjustment valve 35, and the other end side is connected to the pipe 31.

  Further, the pump P1 can be driven by the engine 5 via the electromagnetic clutch 39. Specifically, the tip of the other end side of the drive shaft 37 is connected to a known electromagnetic clutch 39. The electromagnetic clutch 39 is electrically connected to the control device 11a. The electromagnetic clutch 39 has an electromagnetic solenoid (not shown). The electromagnetic clutch 39 can be connected to and disconnected from the pulley 21 by the operation of the electromagnetic solenoid. Then, when the electromagnetic clutch 39 comes into contact with the pulley drum 21b by the operation of the electromagnetic solenoid, the driving force of the engine 5 is transmitted to the pump P1 via the crankshaft 19, the pulley 21, the electromagnetic clutch 39, and the driving shaft 37. Pump P1 is driven. This electromagnetic clutch 39 corresponds to a clutch. Further, a one-way clutch (not shown) that allows rotation only in the direction in which the expander 25 drives the pump P1 is provided at an appropriate location between the pump P1 and the expander 25 on the drive shaft 37. Note that a multi-plate clutch or the like may be employed instead of the electromagnetic clutch 39.

  In this Rankine cycle 3a, by operating the pump P1, the working fluid reaches the condenser 27 from the pump P1 through the pressurized air boiler 23, the expander 25 or the bypass passage 33 as shown in FIGS. It circulates in the piping 28-32 in order. That is, in the flow direction of the working fluid in the Rankine cycle 3 a, the bypass path 33 branches off from the pipe 29 downstream of the pressurized air boiler 23 and merges with the pipe 31 upstream of the inlet 27 a of the condenser 27.

  As shown in FIG. 1, the control device 11a adjusts the amount of heat that the working fluid radiates to the outside air by controlling the operation of the electric fan 27c. Further, the control device 11a is configured to be able to detect the accelerator opening of the vehicle based on a signal received from the ECU or the like (not shown) of the vehicle, and can detect an output request to the engine 5 based on the accelerator opening. It has become. Then, the control device 11 a determines the required cooling amount for the pressurized air based on the output request for the engine 5. That is, the control device 11a functions as a determination unit and an output request detection unit.

  Further, the control device 11a also functions as a control unit, and performs connection / disconnection control between the electromagnetic clutch 39 and the pulley 21 based on the required cooling amount for the pressurized air and the rotational speed received from the engine 5. In addition, the control device 11a controls the flow rate adjustment valve 35 based on the rotation speed in the expander 25.

  The waste heat utilization apparatus configured as described above operates as follows by driving the vehicle.

  As shown in FIG. 2, when the vehicle is driven, the engine 5 operates in the drive system 1a. As a result, the exhaust discharged from the exhaust port 5a is discharged from the muffler to the outside of the vehicle through the pipe 8, the turbocharger 7 and the pipe 12 (see the one-dot chain line arrow in the figure). At this time, the turbocharger 7 is operated by the exhaust. Thereby, the air outside the vehicle is sucked into the turbocharger 7 from the pipe 13 and compressed. This air is sucked as pressurized air into the engine 5 from the intake port 5b of the engine 5 through the pipe 9, the first passage 23e of the pressurized air boiler 23 and the pipe 10 (see the broken line arrow in the figure). In addition, although illustration is abbreviate | omitted, a cooling fluid circulates between the engine 5 (an outflow port and an inflow port) and a radiator, and the engine 5 is also cooled.

  The control device 11a controls the flow rate adjustment valve 35. Here, the flow rate adjustment valve 35 is controlled so that the flow rate of the working fluid flowing into the expander 25 is maximized and the flow rate of the working fluid flowing into the bypass passage 33 is zero. The control device 11a operates the electric fan 27c.

  Further, the control device 11a operates the electromagnetic solenoid to bring the electromagnetic clutch 39 and the pulley drum 21b into contact with each other, thereby connecting the electromagnetic clutch 39 and the pulley 21 (the electromagnetic clutch 39 is turned on). Thereby, the pump P1 is driven by the engine 5 or the expander 25 (normal operation state).

  For this reason, in the Rankine cycle 3a, as shown by the solid line arrow in the figure, the working fluid discharged by the pump P1 passes through the pipe 28 and reaches the second passage 23f from the second inlet 23c of the pressurized air boiler 23. . The working fluid exchanges heat with the pressurized air in the pressurized air boiler 23. At this time, since the pressurized air flowing through the first passage 23e has a heat of about 150 ° C., the working fluid flowing through the second passage 23f is heated to a certain temperature. On the other hand, the pressurized air that circulates through the first passage 23e radiates heat to the working fluid that circulates through the second passage 23f, and therefore reaches the inside of the engine 5 from the suction port 5b while being cooled to a certain degree. .

  Thus, the working fluid heated in the pressurized air boiler 23 flows out of the second outlet 23d in a high temperature and high pressure state, and reaches the inside of the expander 25 from the inlet 25a of the expander 25 through the pipes 29 and 30. The high-temperature and high-pressure working fluid expands in the expander 25 and is depressurized. The rotational driving force generated by the pressure energy at this time is transmitted to the engine 5 through the power transmission means and regenerated by the engine 5.

  The working fluid depressurized in the expander 25 flows out from the outlet 25 b and reaches the condenser 27 through the pipe 31 from the inlet 27 a of the condenser 27. The working fluid of the condenser 27 is cooled by releasing heat to the air around the condenser 27. At this time, the control device 11a appropriately changes the operating amount of the electric fan 27c to suitably dissipate the working fluid and liquefy it. The cooled working fluid flows out from the outlet 27 b, is sucked into the pump P 1 through the pipe 32, and is discharged again toward the pipe 28 and eventually the pressurized air boiler 23.

  On the other hand, in this waste heat utilization device, as described above, the control device 11a operates the electromagnetic solenoid to release the connection between the electromagnetic clutch 39 and the pulley 21 (the electromagnetic clutch 39 is turned off). Is also possible (see FIG. 3).

  Thus, by releasing the connection between the electromagnetic clutch 39 and the pulley 21, the drive load of the expander 25 is only the pump P1. Thereby, in Rankine cycle 3a, the rotation speed of expander 25 and pump P1 increases, and the speed of the working fluid circulating in piping 28-32 is accelerated. In this case, the circulating speed of the working fluid circulating in the pipes 28 to 32 is accelerated to a point where the power of the expander 25 and the power consumed by the pump P1 are balanced. For this reason, compared with the case where the engine 5 and the pump P <b> 1 are connected via the electromagnetic clutch 39, the circulation speed of the working fluid circulating in the pipes 28 to 32 is increased and flows into the pressurized air boiler 23. The flow rate of the working fluid increases. For this reason, in the heat exchange in the pressurized air boiler 23, the working fluid receives more heat radiation from the pressurized air. As a result, the pressurized air is further cooled and sucked into the engine 5 in a higher density state. The working fluid heated by the pressurized air boiler 23 flows out from the second outlet 23d, and is expanded and depressurized by the expander 25 and then radiated by the condenser 27 as in the case shown in FIG. It will be.

  In this state (the electromagnetic clutch 39 is in the OFF state), the control device 11a controls the flow rate adjustment valve 35 when the rotational speed of the expander 25 exceeds a predetermined value. As a result, as shown in FIG. 4, the pipe 29 and the bypass path 33 are communicated, and a part of the working fluid flows into the bypass path 33 from the pipe 29.

  As a result, a part of the working fluid heated by the pressurized air boiler 23 flows into the bypass passage 33 as indicated by solid line arrows in FIG. The working fluid in the bypass passage 33 bypasses the expander 25 and reaches the inlet 27 a of the condenser 27 through the pipe 31. In this case, the flow rate of the working fluid flowing into the expander 25 decreases, and the high / low pressure difference between the front and rear of the expander 25 decreases, so the rotation speed of the expander 25 decreases.

  Thus, in this waste heat utilization apparatus, the working fluid can be heated by the pressurized air boiler 23. Here, the compressed air compressed by the turbocharger 7 has a higher temperature than the working fluid flowing into the pressurized air boiler 23. Then, by heat exchange with the working fluid, the heat of the pressurized air can be recovered in the Rankine cycle 3a, that is, a regenerative rotational driving force can be obtained. On the other hand, the temperature of the pressurized air can be effectively lowered by moving the heat of the pressurized air in the turbocharger 7 to the working fluid. For this reason, in this waste heat utilization apparatus, the pressurized air boiler 23 functions as an intercooler for the pressurized air, and supplies the engine 5 with high-density pressurized air, that is, a large amount of pressurized air. Is possible.

  Further, in this waste heat utilization apparatus, the pump P1 and the expander 25 are connected by the drive shaft 37 so as to be able to transmit power, so that the pump P1 and the expander 25 can be integrated. Further, since the pump P1 is connected by the engine 5 via the electromagnetic clutch 39 and the pulley 21, it is not necessary to provide a driving device for driving the pump P1. For this reason, the structure of the waste heat utilization apparatus is simplified.

  As shown in FIG. 2, the waste heat utilization apparatus has a temperature efficiency (flow rate of working fluid) with respect to pressurized air if the engine 5 and the pump P <b> 1 are connected by an electromagnetic clutch 39 and a pulley 21. It depends on the number of rotations of 5. For this reason, this waste heat utilization apparatus can cut | disconnect the connection by the electromagnetic clutch 39 as mentioned above by the control apparatus 11a.

  Specifically, (1) When the control device 11a determines that the required cooling amount for the pressurized air is equal to or less than the first threshold (as described above, the control device 11a makes an output request to the engine 5 based on the accelerator opening. At the same time, the cooling request amount for the pressurized air is determined based on the output request for the engine 5. If the accelerator opening is small and the output request for the engine 5 is small, the cooling request amount for the pressurized air is determined. And the control device 11a determines that the required cooling amount for the pressurized air is equal to or less than the first threshold value.) (2) If the required cooling amount for the pressurized air exceeds the first threshold value, the control device 11a 11a, the electromagnetic clutch 39 is in the ON state if it is any of the cases where there is no low speed signal in which the rotational speed of the engine 5 falls below 1500 rpm. It is.

  As described above, when the electromagnetic clutch 39 is in the ON state, the pump P1 is driven by the engine 5 or the expander 25, and the working fluid passing through the pump P1 and the pipe 28 is directly used as a pressurized air boiler. 23. And by the heat exchange in the pressurized air boiler 23, the heat of pressurized air can be moved to a working fluid, and the temperature of pressurized air can be lowered | hung. As a result, a large amount of pressurized air can be supplied to the engine 5 and the output of the engine 5 can be improved. At this time, in the waste heat utilization apparatus, the rotational driving force obtained by the pressure energy of the working fluid decompressed in the expander 25 is regenerated in the engine 5 as described above.

  Further, since the electromagnetic clutch 39 is in the ON state, the engine 5 and the pump P1 are connected via the electromagnetic clutch 39 in this waste heat utilization apparatus. Thereby, the cooling capacity of the pressurized air in the discharge air boiler 23 based on the discharge flow rate of the working fluid by the pump P1, that is, the flow rate of the working fluid in the Rankine cycle 3a depends on the rotational speed of the engine 5. However, when the low speed signal is not transmitted, that is, the rotational speed of the engine 5 is equal to or higher than the second threshold value (1500 rm), Since the flow rate of the working fluid in the Rankine cycle 3a increases, the cooling capacity for the pressurized air in the pressurized air boiler 23 is sufficiently ensured. In this way, by turning on the electromagnetic clutch 39, the waste heat utilization device can also regenerate the rotational driving force for the engine 5 as described above while satisfying the cooling requirement for the pressurized air. .

  On the other hand, when the output request for the engine 5 exceeds a predetermined value, that is, when the detected accelerator opening exceeds the predetermined value, the required cooling amount for the pressurized air increases. In order to increase the output of the engine 5, it is necessary to supply more pressurized air to the engine 5, and for that purpose, it is necessary to further cool the pressurized air and increase its density. In this case, it is required to further cool the pressurized air in the pressurized air boiler 23, that is, priority is given to cooling of the pressurized air in the pressurized air boiler 23. For these reasons, when the control device 11a determines that the required cooling amount for the pressurized air exceeds the first threshold based on the output request to the engine 5, the electromagnetic clutch 39 is turned off. Even when the low speed signal is present, the electromagnetic clutch 39 is turned off when the control device 11a determines that the required cooling amount for the pressurized air exceeds the first threshold value.

  Thereby, in the waste heat utilization apparatus, as shown in FIG. 3, the connection between the engine 5 and the pump P1 via the electromagnetic clutch 39 is released, and the load on the expander 25 is reduced. In this case, since the drive load of the expander 25 is only the pump P1, in the Rankine cycle 3a, the pipe 28 is more than in the case where the pump P1 and the engine 5 are connected via the electromagnetic clutch 39 (see FIG. 2). The speed of the working fluid circulating in ~ 32 is accelerated. For this reason, as shown in FIG. 3, the flow volume of the working fluid which flows into the pressurized air boiler 23 increases. Thereby, in the pressurized air boiler 23, the temperature of the pressurized air can be further lowered (the pressurized air is set to a temperature equal to or lower than the first threshold value), and more pressurized air can be supplied to the engine 5. It becomes. For this reason, it becomes possible to improve the output of the engine 5, and the output request | requirement with respect to the engine 5 can be satisfy | filled.

  Further, the waste heat utilization apparatus includes a bypass path 33 through which the working fluid can bypass the expander 25 and a flow rate adjustment valve 35. And the control apparatus 11a controls the flow regulating valve 35 because the rotation speed of the expander 25 becomes more than predetermined value. As a result, as shown in FIG. 4, a part of the working fluid circulates in the bypass passage 33, thereby reducing the flow rate of the working fluid flowing into the expander 25, and the difference between the high and low pressures before and after the expander 25 By reducing the value, the rotational speed of the expander 25 can be reduced. For this reason, in this waste heat utilization apparatus, even when the speed of the working fluid circulating in the pipes 28 to 32 is accelerated, the working fluid is prevented from excessively driving the expander 25, and the pump P1 and the expander The durability of 25 can be maintained.

  Furthermore, in this waste heat utilization apparatus, based on the output request | requirement with respect to the engine 5, it becomes possible for the control apparatus 11a to judge correctly the cooling request amount with respect to pressurized air.

  Therefore, the waste heat utilization apparatus according to the first embodiment can improve the temperature efficiency with respect to the pressurized air and improve the performance of the engine 5 as necessary while simplifying the structure.

  In this waste heat utilization device, the control device 11 a controls the flow rate adjustment valve 35 to adjust the ratio between the flow rate of the working fluid flowing into the expander 25 and the flow rate of the working fluid flowing into the bypass passage 33. It is possible. Thereby, when the power of the expander 25 and the power consumption of the pump P1 are balanced, the rotational speed of the expander 25 and the pump P1 can be appropriately changed.

(Example 2)
The waste heat utilization apparatus of the second embodiment is not provided with the bypass path 33 and the flow rate adjusting valve 35 as shown in FIG. A generator 41 is provided. The generator 41 is electrically connected to the control device 11a. The generator 41 generates electric power by a drive shaft 37 that is driven to rotate, and charges electric power to a battery (not shown). The other structure in this generator 41 is the same as that of a well-known generator. Further, the control device 11a controls the amount of power generated in the generator 41 and the like. Other configurations of the waste heat utilization apparatus are the same as those of the waste heat utilization apparatus of the first embodiment, and the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  Thus, in this waste heat utilization apparatus, since the generator 41 is provided on the drive shaft 37, the generator 41 can be driven by the expander 25, and the generator 41 is also driven by the engine 5. It is possible. Here, in this waste heat utilization device, since the generator 41 can be driven by the expander 25, when the electromagnetic clutch 39 is in the OFF state, the control device 11a controls the load on the generator 41, The flow rate of the working fluid circulating in the pipes 28 to 32 can be adjusted. For this reason, in this waste heat utilization apparatus, the control device 11a controls the load of the generator 41, thereby adjusting the rotational speeds of the pump P1 and the expander 25, and recovering the power in the Rankine cycle 3a and the output in the engine 5 The improvement can be suitably adjusted. Other functions and effects are the same as those of the waste heat utilization apparatus of the first embodiment.

  Therefore, the waste heat utilization apparatus of the second embodiment can also achieve an improvement in temperature efficiency with respect to pressurized air and an improvement in the performance of the engine 5 as necessary while simplifying the structure.

(Example 3)
The waste heat utilization apparatus of the third embodiment is also mounted on the vehicle, and is used in a vehicle drive system 1b as shown in FIG. This waste heat utilization apparatus includes a Rankine cycle 3b, a control device 11b, and a first temperature sensor 43a. The waste heat utilization apparatus also includes an electromagnetic clutch 39, a bypass path 33, and a flow rate adjustment valve 35, as in the waste heat utilization apparatus of the first embodiment.

  The drive system 1b includes an engine 2 as an internal combustion engine, a pipe 4 as an exhaust path, pipes 6a and 6b as exhaust recirculation paths, and a pipe 15 as an air introduction path. The piping 6b is provided with the first temperature sensor 43a and the variable valve 45 described above.

  The engine 2 is a known water-cooled diesel engine. The engine 2 is formed with an exhaust port 2a for discharging exhaust gas and an intake port 2b for sucking mixed air described later. Further, a water jacket (not shown) through which the coolant can flow is formed inside the engine 2. The engine 2 is formed with an outlet and an inlet (both not shown) communicating with the water jacket. The engine 2 is electrically connected to the control device 11b and can transmit the rotational speed of the engine 2 as an electric signal to the control device 11b. In this waste heat utilization apparatus as well, 1500 rpm is set as the second threshold value.

  Further, this engine 2 is also connected to a pulley 21 via a crankshaft 19 in the same manner as the engine 5 in the waste heat utilization apparatus of the first embodiment. Thereby, also in this waste heat utilization apparatus, it is possible to rotate the pulley drum 21a with the motive power of the engine 2. FIG.

  One end of the pipe 4 is connected to the exhaust port 2a, and the other end is connected to a muffler (not shown). Thereby, the piping 4 can guide | emit to the muffler by distribute | circulating the exhaust_gas | exhaustion produced in the engine 2 to the inside.

  One end of the pipe 6a is connected to the pipe 4, and the other end is connected to a first inlet 24a of a reflux exhaust boiler 24 described later. The pipe 6 b has one end connected to the first outlet 24 b of the recirculation exhaust boiler 24 and the other end connected to the intake 2 b of the engine 2. One end of the pipe 15 is connected to the pipe 6b, and the other end is connected to a vehicle air intake (not shown). Thereby, the pipe | tube 15 can be guide | induced to the pipe | tube 6b by distribute | circulating the air outside a vehicle to the inside. The pipes 6a and 6b serving as the exhaust gas recirculation path cause a part of the exhaust gas flowing through the pipe 4 to flow inside thereof, thereby returning the mixed air of the recirculated exhaust gas serving as the intake system fluid and the air to the engine 2. It is possible.

  The variable valve 45 is electrically connected to the control device 11b. The variable valve 45 can adjust the flow rate of the exhaust gas flowing into the pipe 6a from the pipe 4 by adjusting the opening degree thereof.

  The first temperature sensor 43a is electrically connected to the control device 11b. The first temperature sensor 43a functions as first temperature detection means, detects the temperature of the recirculated exhaust gas flowing out of the first outlet 24b of the recirculated exhaust boiler 24 and flowing through the pipe 6b, and controls the detected value. A call is sent to the device 11b.

  The Rankine cycle 3 b has a reflux exhaust boiler 24. Moreover, this Rankine cycle 3b has the pump P1, the expander 25, the condenser 27, and the piping 28-32 similarly to the Rankine cycle 3a in the waste heat utilization apparatus of Example 1. FIG. Furthermore, the bypass path 33 and the flow rate adjusting valve 35 are integrally assembled in the Rankine cycle 3b. Note that the pump P1, the expander 25, the electric fan 27c, and the flow rate adjustment valve 35 are all electrically connected to the control device 11b.

  The reflux exhaust boiler 24 is formed with a first inlet 24a and a second outlet 24b, and a second inlet 24c and a second outlet 24d. Further, in the recirculation exhaust boiler 24, a first passage 24e communicating with the first inlet 24a and the first outlet 24b at both ends, respectively, and a second inlet 24c and a second outlet 24d at both ends, respectively. A second passage 24f that communicates is provided. In the recirculation exhaust boiler 24, the recirculation exhaust is cooled and the working fluid is heated by exchanging heat between the recirculation exhaust in the first passage 24e and the working fluid in the second passage 24f.

  The pump P1 and the second inlet 24c of the recirculation exhaust boiler 24 are connected by a pipe 28. The second outlet 24 d of the recirculation exhaust boiler 24 and the flow rate adjustment valve 35 are connected by a pipe 29. The connection between the expander 25 and the condenser 27 in the Rankine cycle 3b is the same as that in the Rankine cycle 3a in the waste heat utilization apparatus of the first embodiment.

  Also in this waste heat utilization apparatus, the expander 25 and the pump P1 are connected by a drive shaft 37 so that power can be transmitted. Further, both the expander 25 and the engine 2 are connected so as to be able to transmit power via power transmission means (not shown), and the rotational driving force generated in the expander 25 is regenerated in the engine 2. The pump P1 can be driven by the engine 2 via the electromagnetic clutch 39. The electromagnetic clutch 39 is electrically connected to the control device 11b.

  In this Rankine cycle 3b, by operating the pump P1, the working fluid flows from the pump P1 to the condenser 27 through the recirculation exhaust boiler 24, the expander 25, or the bypass 33 as shown in FIGS. Circulates in the pipes 28-32. That is, in the flowing direction of the working fluid in the Rankine cycle 3 b, the bypass path 33 branches off from the pipe 29 downstream of the reflux exhaust boiler 24 and merges with the pipe 31 upstream of the inlet 27 a of the condenser 27.

  As shown in FIG. 6, the control device 11b adjusts the amount of heat that the working fluid radiates to the outside air by controlling the operation of the electric fan 27c. Further, the control device 11b determines the required cooling amount for the recirculated exhaust based on the temperature of the recirculated exhaust detected by the first temperature sensor 43a. Thereby, the control apparatus 11b functions as a determination means.

  Further, this control device 11b also functions as a control means, and performs connection / disconnection control between the electromagnetic clutch 39 and the pulley 21 based on the above-described cooling request amount for the recirculated exhaust and the rotational speed received from the engine 2. In addition, the control device 11b controls the flow rate adjustment valve 35 based on the rotation speed in the expander 25. Other configurations of the waste heat utilization apparatus are the same as those of the waste heat utilization apparatus of the first embodiment.

  The waste heat utilization apparatus configured as described above operates as follows by driving the vehicle.

  When the vehicle is driven, the engine 2 operates in the drive system 1b. As a result, as shown in FIG. 7, the exhaust discharged from the exhaust port 2a is discharged from the muffler through the pipe 4 to the outside of the vehicle (see the one-dot chain line arrow in FIG. 7). At this time, the control device 11b adjusts the opening degree of the variable valve 45 so that a part of the exhaust gas flowing through the pipe 4 flows into the pipe 6a. Exhaust gas that has flowed into the pipe 6a flows into the recirculation exhaust boiler 24 from the first inlet 24a as recirculation exhaust, flows through the first passage 24e, and reaches the pipe 6b from the first outlet 24b. At this time, the first temperature sensor 43a detects the temperature of the recirculated exhaust gas flowing out from the first outlet 24b, and transmits the temperature to the control device 11b. The recirculated exhaust gas flowing through the pipe 6b is mixed with the air outside the vehicle (see the broken arrow in the figure) via the pipe 15 and recirculates into the engine 2 from the intake port 2b as mixed air. In addition, although illustration is abbreviate | omitted, a cooling fluid circulates between the engine 2 (outflow port and inflow port) and a radiator, and the engine 2 is also cooled.

  Further, the control device 11b controls the flow rate adjustment valve 35 so that the flow rate of the working fluid flowing into the expander 25 is maximized and the flow rate of the working fluid flowing into the bypass passage 33 is zero. Furthermore, the control device 11b operates the electric fan 27c. When the control means 11b determines that the required cooling amount for the recirculated exhaust gas is equal to or less than the first threshold based on the detection value transmitted from the first temperature sensor 43a, the control device 11b turns on the electromagnetic clutch 39. As a result, the electromagnetic clutch 39 and the pulley 21 are connected. Even when the control device 11b determines that the required cooling amount for the recirculated exhaust gas exceeds the first threshold value, the control device 11b is electromagnetically controlled even when there is no low-speed signal with the engine 2 rotating below 1500 rpm. The clutch 39 is turned on.

  Accordingly, the waste heat utilization apparatus is also in a normal operation state, and the pump P1 is driven by the engine 5 or the expander 25. In the Rankine cycle 3b in the waste heat utilization apparatus, the working fluid discharged by the pump P1 passes through the pipe 28 and reaches the second passage 24f from the second inlet 24c of the recirculation exhaust boiler 24. At this time, the working fluid is heat-exchanged with the reflux exhaust in the reflux exhaust boiler 24. Here, since the recirculated exhaust gas flowing through the first passage 24e has a heat of about 500 ° C., the working fluid flowing through the second passage 24f is heated to a certain temperature. On the other hand, the recirculated exhaust gas that circulates through the first passage 24e radiates heat to the working fluid that circulates through the second passage 24f, and thus circulates through the suction port 6b in a state of being cooled to a certain degree (temperature below the first threshold). Then, after being mixed with the air that has passed through the pipe 15, it is returned to the engine 2 as mixed air.

  The working fluid heated in the reflux exhaust boiler 24 flows out from the second outlet 24d in a high temperature and high pressure state, expands in the expander 25, and is decompressed. At this time, as in the waste heat utilization apparatus of the first embodiment, regeneration of the rotational driving force for the engine 2 is performed. Further, the working fluid decompressed in the expander 25 flows out from the outlet 25b, reaches the condenser 27 through the pipe 31, and is cooled.

  Thus, in this waste heat utilization apparatus, the heat of the recirculated exhaust gas can be recovered in the Rankine cycle 3b, that is, it can be made a rotational driving force that can be regenerated. Further, in this waste heat utilization device, the reflux exhaust boiler 24 can function as a cooling device for the reflux exhaust. Thus, in this waste heat utilization apparatus, the nitrogen oxide in the exhaust discharged from the muffler to the outside of the vehicle is increased by suitably cooling the reflux exhaust to increase its density and increasing the ratio of the reflux exhaust in the mixed air. The content of can be reduced.

  Here, even if the control device 11b determines that the required cooling amount for the recirculated exhaust gas exceeds the first threshold value, the engine 2 has a rotation speed equal to or higher than the second threshold value (when there is no low speed signal). Even if the discharge flow rate of the working fluid by the pump P1 depends on the rotational speed of the engine 2, the flow rate of the working fluid in the Rankine cycle 3b increases. Thereby, in this waste heat utilization apparatus, the cooling capability with respect to the recirculation exhaust in the recirculation exhaust boiler 24 is fully ensured. For this reason, even when the control device 11b determines that the required cooling amount for the recirculated exhaust gas exceeds the first threshold value, the electromagnetic clutch 39 is in the ON state if the rotational speed of the engine 2 is equal to or higher than the second threshold value. By adopting (normal operation state), this waste heat utilization device can also regenerate the rotational driving force for the engine 2 as described above while satisfying the cooling requirement for the recirculated exhaust gas.

  On the other hand, when the detected value transmitted from the first temperature sensor 43a is large, the recirculation exhaust gas in the recirculation exhaust boiler 24 is not sufficiently cooled. For this reason, the control device 11b determines that the required cooling amount for the recirculated exhaust gas is large, that is, the required cooling amount for the recirculated exhaust gas has exceeded the first threshold. In this case, the control device 11b turns off the electromagnetic clutch 39. Even when the low speed signal is present, the electromagnetic clutch 39 is turned off when the control device 11b determines that the required cooling amount for the recirculated exhaust gas has exceeded the first threshold value.

  Thereby, as shown in FIG. 8, also in this waste heat utilization apparatus, the drive load of the expander 25 is only the pump P1, and the Rankine cycle 3b increases the rotation speed of the expander 25 and the pump P1. The speed of the working fluid circulating in the pipes 28 to 32 is accelerated. For this reason, in the Rankine cycle 3b, the flow rate of the working fluid flowing into the recirculation exhaust boiler 24 is increased, and the recirculation exhaust is further cooled, so that it is possible to satisfy the cooling request exceeding the first threshold value for the recirculation exhaust. . For this reason, in this waste heat utilization apparatus, it is possible to suitably cool the recirculated exhaust gas even when the required cooling amount for the recirculated exhaust gas is large.

  The waste heat utilization apparatus further includes a bypass path 33 through which the working fluid can bypass the expander 25 and a flow rate adjustment valve 35. For this reason, in this waste heat utilization apparatus, when the rotational speed of the expander 25 becomes a predetermined value or more when the electromagnetic clutch 39 is in the OFF state, the control device 11b controls the flow rate adjustment valve 35.

  As a result, as shown in FIG. 9, even in this waste heat utilization apparatus, the flow rate of the working fluid flowing into the expander 25 can be reduced by causing a part of the working fluid to flow into the bypass passage 33. . Thus, also in this waste heat utilization apparatus, it is possible to reduce the rotational speed of the expander 25 by reducing the high / low pressure difference between the front and rear of the expander 25. For this reason, also in this waste heat utilization apparatus, when the speed of the working fluid circulating in the pipes 28 to 32 is accelerated, the working fluid can be prevented from excessively driving the expander 25, and the pump P1 and the expansion can be prevented. The durability of the machine 25 can be maintained.

  Further, in this waste heat utilization device, the control device 11b can accurately determine the required cooling amount for the return exhaust gas based on the temperature of the return exhaust gas detected by the first temperature sensor 43a. Other functions and effects are the same as those of the waste heat utilization apparatus of the first embodiment.

  Therefore, the waste heat utilization apparatus according to the third embodiment can improve the temperature efficiency with respect to the recirculation exhaust and improve the performance of the engine 2 as necessary while simplifying the structure.

Example 4
In the waste heat utilization device of the fourth embodiment, a control device 11c and a second temperature sensor 43b shown in FIG. 10 are provided instead of the control device 11b and the first temperature sensor 43a in the waste heat utilization device of the third embodiment. . The expander 25, the electric fan 27c, the flow rate adjustment valve 35, the electromagnetic clutch 39, and the variable valve 45 are electrically connected to the control device 11c.

  The second temperature sensor 43 b is provided in the pipe 28. The second temperature sensor 43b is electrically connected to the control device 11c. The second temperature sensor 43b functions as second temperature detection means, and detects the temperature of the working fluid flowing through the pipe 28, that is, the temperature of the working fluid before flowing into the second inlet 24c of the recirculation exhaust boiler 24. At the same time, the detected value is transmitted to the control device 11c.

  Based on the temperature of the working fluid detected by the second temperature sensor 43b, the control device 11c determines the required cooling amount for the recirculated exhaust gas. That is, when the temperature of the working fluid is higher than a predetermined value, the cooling capacity of the recirculated exhaust gas in the recirculated exhaust boiler 24 is lowered, so that the required cooling amount for the recirculated exhaust gas is relatively increased. Thereby, the control device 11c also functions as a determination unit. Further, the control device 11c controls the operation of the electric fan 27c, thereby adjusting the amount of heat that the working fluid radiates to the outside air.

  Further, this control device 11c also functions as a control means, and controls connection / disconnection between the electromagnetic clutch 39 and the pulley 21 as well as the rotational speed of the expander 25, similarly to the control device 11b in the waste heat utilization apparatus of the third embodiment. The flow rate adjustment valve 35 is controlled based on the above. Other configurations of the waste heat utilization apparatus are the same as those of the waste heat utilization apparatus of the third embodiment.

  Also in this waste heat utilization device, as in the waste heat utilization device of the third embodiment, the control device 11c operates the electric fan 27c, the flow rate adjustment valve 35, the electromagnetic clutch 39, and the variable valve 45, respectively, when the vehicle is driven. Take control.

  Here, when the control unit 11c determines that the required cooling amount for the recirculated exhaust gas is equal to or less than the first threshold based on the detection value transmitted from the second temperature sensor 43b, the control device 11c turns on the electromagnetic clutch 39. State (normal operation state). The control device 11c controls the flow rate adjustment valve 35. In this waste heat utilization device, the other conditions for the control device 11c to turn on the electromagnetic clutch 39 and the control of the flow rate adjustment valve 35 when the electromagnetic clutch 39 is in the ON state are the same as those in the third embodiment. It is the same as the heat utilization device.

  On the other hand, when the detected value transmitted from the second temperature sensor 43b is large, that is, when the temperature of the working fluid before flowing into the recirculation exhaust boiler 24 is high, the control device 11c has a required cooling amount for the recirculation exhaust. Judge that it is big. When the control device 11c determines that the required cooling amount for the recirculated exhaust gas has exceeded the first threshold based on the detection value of the second temperature sensor 43b, the control device 11c turns off the electromagnetic clutch 39. In this waste heat utilization apparatus, other conditions for the control device 11c to turn off the electromagnetic clutch 39 are the same as those in the waste heat utilization apparatus of the third embodiment.

  Furthermore, also in this waste heat utilization apparatus, when the rotational speed of the expander 25 becomes a predetermined value or more when the electromagnetic clutch 39 is in the OFF state, the control device 11c controls the flow rate adjustment valve 35. In addition, about the control of the flow regulating valve 35 in this case, in the waste heat utilization apparatus of Example 3, it is the same as that when the rotation speed of the expander 25 becomes more than predetermined value.

  As a result, this waste heat utilization apparatus can achieve the same effects as the waste heat utilization apparatus of the third embodiment. Further, in this waste heat utilization device, the control device 11c can accurately determine the required cooling amount for the recirculated exhaust gas based on the temperature of the working fluid detected by the second temperature sensor 43b.

  Therefore, the waste heat utilization apparatus according to the fourth embodiment can also improve the temperature efficiency of the recirculated exhaust gas and improve the performance of the engine 2 as necessary while simplifying the structure.

(Example 5)
In the waste heat utilization device of the fifth embodiment, a control device 11d and a third temperature sensor 43c shown in FIG. 11 are provided instead of the control device 11b and the first temperature sensor 43a in the waste heat utilization device of the third embodiment. . The expander 25, the electric fan 27c, the flow rate adjusting valve 35, the electromagnetic clutch 39, and the variable valve 45 are electrically connected to the control device 11d.

  The third temperature sensor 43 c is provided in the pipe 32. The third temperature sensor 43c is electrically connected to the control device 11d. The third temperature sensor 43c functions as third temperature detection means, and detects the temperature of the working fluid flowing through the pipe 32, that is, the temperature of the working fluid before flowing into the pump P1. At the same time, the detected value is transmitted to the control device 11d.

  The control device 11d determines the required cooling amount for the recirculated exhaust gas based on the temperature of the working fluid detected by the third temperature sensor 43c. Thereby, the control device 11d also functions as a determination unit. Further, the control device 11d controls the operation of the electric fan 27c, thereby adjusting the amount of heat that the working fluid radiates to the outside air.

  Furthermore, this control device 11d also functions as a control means, and controls connection / disconnection between the electromagnetic clutch 39 and the pulley 21 as well as the rotational speed of the expander 25, similarly to the control device 11b in the waste heat utilization apparatus of the third embodiment. The flow rate adjustment valve 35 is controlled based on the above. Other configurations of the waste heat utilization apparatus are the same as those of the waste heat utilization apparatus of the third embodiment.

  Also in this waste heat utilization device, similarly to the waste heat utilization device of the third embodiment, the control device 11d operates the electric fan 27c, the flow rate adjustment valve 35, the electromagnetic clutch 39, and the variable valve 45, respectively, when the vehicle is driven. Take control.

  Here, when the control unit 11d determines that the required cooling amount for the recirculated exhaust gas is equal to or less than the first threshold value based on the detection value transmitted from the second temperature sensor 43c, the control device 11d turns on the electromagnetic clutch 39. State (normal operation state). In addition, the control device 11d controls the flow rate adjustment valve 35. In this waste heat utilization device, the other conditions for the control device 11d to turn on the electromagnetic clutch 39 and the control of the flow rate adjustment valve 35 when the electromagnetic clutch 39 is in the ON state are the same as those in the third embodiment. It is the same as the heat utilization device.

  On the other hand, the detected value detected by the third temperature sensor 43c increases as the temperature of the working fluid before flowing into the pump P1 increases. In this case, the control device 11d determines that the required cooling amount for the recirculated exhaust gas is large. This is because when the temperature of the working fluid flowing into the pump P1 is high, the working fluid is heated to a high temperature in the recirculation exhaust boiler 24, and it can be determined that the recirculation exhaust as a heat source is at a high temperature. When the control device 11d determines that the required cooling amount for the recirculated exhaust gas has exceeded the first threshold based on the detection value of the third temperature sensor 43c, the control device 11c turns off the electromagnetic clutch 39. In this waste heat utilization apparatus, other conditions for the control device 11d to turn off the electromagnetic clutch 39 are the same as those in the waste heat utilization apparatus of the third embodiment.

  Furthermore, also in this waste heat utilization apparatus, when the rotational speed of the expander 25 becomes a predetermined value or more when the electromagnetic clutch 39 is in the OFF state, the control device 11d controls the flow rate adjustment valve 35. Note that the control of the flow rate adjustment valve 35 in this case is the same as in the case where the rotational speed of the expander 25 becomes a predetermined value or more in the waste heat utilization apparatus of the third embodiment.

  As a result, this waste heat utilization apparatus can achieve the same effects as the waste heat utilization apparatus of the third embodiment. Further, in this waste heat utilization device, the control device 11d can accurately determine the required cooling amount for the recirculated exhaust gas based on the temperature of the working fluid detected by the third temperature sensor 43c.

  Therefore, the waste heat utilization apparatus according to the fifth embodiment can also improve the temperature efficiency of the recirculated exhaust gas and improve the performance of the engine 2 as necessary while simplifying the structure.

(Example 6)
In the waste heat utilization device of the sixth embodiment, a control device 11e and a pressure sensor 43d shown in FIG. 12 are provided instead of the control device 11b and the first temperature sensor 43a in the waste heat utilization device of the third embodiment. The expander 25, the electric fan 27c, the flow rate adjustment valve 35, the electromagnetic clutch 39, and the variable valve 45 are electrically connected to the control device 11e.

  The pressure sensor 43d is provided in the pipe 32. The pressure sensor 43d is electrically connected to the control device 11e. The pressure sensor 43d functions as pressure detection means, and detects the pressure of the working fluid flowing through the pipe 32, that is, the pressure of the working fluid from the downstream of the expander 25 to the upstream of the pump P1 (condensation pressure). The detected value is transmitted to the control device 11e.

  The control device 11e determines the required cooling amount for the recirculated exhaust gas based on the condensation pressure of the working fluid detected by the pressure sensor 43d. Thereby, the control device 11e also functions as a determination unit. Further, the control device 11e controls the operation of the electric fan 27c, thereby adjusting the amount of heat that the working fluid radiates to the outside air.

  Further, this control device 11e also functions as a control means, and controls connection / disconnection between the electromagnetic clutch 39 and the pulley 21 as well as the rotational speed of the expander 25, similarly to the control device 11b in the waste heat utilization apparatus of the third embodiment. The flow rate adjustment valve 35 is controlled based on the above. Other configurations of the waste heat utilization apparatus are the same as those of the waste heat utilization apparatus of the third embodiment.

  Also in this waste heat utilization device, similarly to the waste heat utilization device of the third embodiment, the control device 11e operates the electric fan 27c, the flow rate adjustment valve 35, the electromagnetic clutch 39, and the variable valve 45, respectively, when the vehicle is driven. Take control.

  Here, when the detected value transmitted from the pressure sensor 83d is small and the control unit 11e determines that the required cooling amount for the recirculated exhaust gas is equal to or less than the first threshold value, the control device 11e sets the electromagnetic clutch 39 in the ON state. (Normal operation) The control device 11e controls the flow rate adjustment valve 35. In this waste heat utilization apparatus, other conditions for the control device 11e to turn on the electromagnetic clutch 39 and the control of the flow rate adjustment valve 35 when the electromagnetic clutch 39 is in the ON state are the same as those in the third embodiment. It is the same as the heat utilization device.

  On the other hand, the detection value detected by the pressure sensor 43d increases as the condensation pressure of the working fluid increases from the downstream of the expander 25 to the upstream of the pump P1. As the condensing pressure of the working fluid increases in this way, the control device 11e determines that the required cooling amount for the recirculated exhaust gas is large. When the condensation pressure of the working fluid flowing through the pipe 32 is high even after passing through the condenser 27, the working fluid is heated to a high temperature in the reflux exhaust boiler 24, that is, a heat source for heating the working fluid in the reflux exhaust boiler 24. This is because it can be determined that the recirculated exhaust gas is at a high temperature. When the control device 11e determines that the required cooling amount for the recirculated exhaust gas exceeds the first threshold based on the detection value transmitted from the pressure sensor 43d, the control device 11e electromagnetic clutch 39 is turned off. In this waste heat utilization device, the other conditions for the control device 11e to turn off the electromagnetic clutch 39 are the same as those in the waste heat utilization device of the third embodiment.

  Furthermore, also in this waste heat utilization apparatus, when the rotational speed of the expander 25 becomes a predetermined value or more when the electromagnetic clutch 39 is in the OFF state, the control device 11e controls the flow rate adjustment valve 35. Note that the control of the flow rate adjustment valve 35 in this case is the same as in the case where the rotational speed of the expander 25 becomes a predetermined value or more in the waste heat utilization apparatus of the third embodiment.

  As a result, this waste heat utilization apparatus can achieve the same effects as the waste heat utilization apparatus of the third embodiment. Further, in this waste heat utilization device, the control device 11e can accurately determine the required cooling amount for the recirculated exhaust gas based on the condensation pressure of the working fluid detected by the pressure sensor 43d.

  Therefore, the waste heat utilization apparatus of the sixth embodiment can also improve the temperature efficiency with respect to the recirculated exhaust gas and improve the performance of the engine 2 as necessary while simplifying the structure.

  In the above, the present invention has been described with reference to the first to sixth embodiments. However, the present invention is not limited to the first to sixth embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, in the waste heat utilization apparatus of Examples 3 to 6, the generator 41 may be provided on the drive shaft 37 instead of the bypass passage 33 and the flow rate adjustment valve 35. In this case as well, the control devices 11b to 11e control the load on the generator 41 as in the waste heat utilization device of the second embodiment. Thereby, also in the waste heat utilization apparatus of Examples 3-6 in this case, it becomes possible to adjust the rotation speed of the pump P1 and the expander 25, and the recovery of electric power in the Rankine cycle 3b and the output improvement in the engine 2 are achieved. It becomes possible to adjust suitably.

  Moreover, in the waste heat utilization apparatus of Example 1, 2, while providing the 1st-3rd temperature sensors 43a-43c and the pressure sensor 43d, the control apparatus 11a is these 1st-3rd temperature sensors 43a-43c and the pressure sensor 43d. Based on the detected value, it is possible to determine the required cooling amount for the pressurized air.

  Further, for the control devices 11b to 11e in the waste heat utilization devices of Examples 3 to 6, the accelerator opening of the vehicle can be detected, and the output request to the engine 2 can be detected based on the accelerator opening. A configuration may be adopted in which the required cooling amount for the recirculated exhaust gas is determined based on the output request for the engine 2.

  Moreover, about the control apparatuses 11a-11e in the waste heat utilization apparatus of Examples 1-6, a vehicle speed may be detected and the cooling required amount with respect to pressurized air or recirculation | reflux exhaust may be judged based on this vehicle speed. Here, if the vehicle speed exceeds a certain speed, the working fluid is suitably radiated in the condenser 27. Thereby, the temperature of the working fluid flowing through the pipe 32 is lowered. In other words, the condensing pressure of the working fluid flowing through the pipe 32 becomes low. In this case, the pressurized air can be suitably cooled in the pressurized air boiler 23, and similarly, the reflux exhaust can be suitably cooled in the reflux exhaust boiler 24. For this reason, the control devices 11a to 11e can determine that the cooling request for the pressurized air or the reflux exhaust is small. On the other hand, if the vehicle speed is slower than a certain speed, the cooling capacity of the working fluid in the condenser 27 decreases, so the temperature (condensation pressure) of the working fluid flowing through the pipe 32 increases. In this case, the pressurized air cannot be sufficiently cooled in the pressurized air boiler 23, and similarly, the recirculated exhaust gas cannot be sufficiently cooled in the recirculated exhaust boiler 24. For this reason, it becomes possible for the control devices 11a to 11e to determine that the cooling request for the pressurized air and the reflux exhaust is large.

  Furthermore, in the waste heat utilization apparatus of the first to sixth embodiments, detection means that can detect the temperature of the pressurized air before flowing into the pressurized air boiler 23 and the temperature of the reflux exhaust before flowing into the reflux exhaust boiler 24 ( A temperature sensor corresponding to the fourth temperature detecting means), and the control devices 11a to 11e determine the required cooling amount for the pressurized air and the reflux exhaust based on the temperature of the pressurized air and the reflux exhaust. It is good also as a structure. In this case, if the temperature of the pressurized air before flowing into the pressurized air boiler 23 or the temperature of the reflux exhaust before flowing into the reflux exhaust boiler 24 is high, the temperature of the pressurized air flowing out from the pressurized air boiler 23 The temperature of the reflux exhaust flowing out from the reflux exhaust boiler 24 also increases. Therefore, the control devices 11a to 11e can determine that the required cooling amount for the pressurized air or the reflux exhaust is large.

  Moreover, about the control apparatuses 11a-11e in the waste heat utilization apparatus of Examples 1-6, the output request | requirement with respect to the engines 2 and 5, each detected value of the 1st-3rd temperature sensors 43a-43c and the pressure sensor 43d, vehicle speed, pressurization It is also possible to determine the required cooling amount for the pressurized air and the reflux exhaust by combining the temperature of the pressurized air before flowing into the air boiler 23 and the temperature of the reflux exhaust before flowing into the reflux exhaust boiler 24, respectively. good.

  Furthermore, you may provide a well-known receiver in the piping 31. FIG. In this case, since the working fluid is suitably liquefied by the receiver, the working fluid that has passed through the condenser 27 is suitably discharged by the pump P <b> 1 and circulates suitably through the pipes 28 to 32 and the bypass path 33.

  Moreover, in the waste heat utilization apparatus of Example 1, 2, in addition to the pressurized air boiler 23, you may provide the boiler etc. which can exchange heat with a cooling fluid and a working fluid. In this case, since the working fluid can be heated also by the heat of the coolant, that is, the waste heat of the engine 5, etc., the working fluid can be heated more suitably, and the amount of power that can be recovered in the Rankine cycle 3a is increased. It becomes possible to do. Further, since the coolant can be cooled by heat exchange with the working fluid, the engine 5 can be suitably cooled even if the radiator or the like is downsized. Similarly, in the waste heat utilization apparatus of Examples 3 to 6, in addition to the recirculation exhaust boiler 24, a boiler as described above that enables heat exchange between the waste heat and the like of the engine 2 and the working fluid may be provided. .

  The present invention is applicable to vehicles and the like.

1a, 1b ... Drive system 2 ... Engine (internal combustion engine)
3a, 3b ... Rankine cycle 5 ... Engine (internal combustion engine)
6a, 6b ... piping (exhaust gas recirculation path)
7 ... Turbocharger (supercharger)
11a ... Control device (determination means, control means, output request detection means)
11b to 11e ... Control device (determination means, control means)
DESCRIPTION OF SYMBOLS 23 ... Pressurized air boiler 24 ... Reflux exhaust boiler 25 ... Expander 27 ... Condenser 28-32 ... Piping 39 ... Electromagnetic clutch (clutch)
33 ... Bypass path 35 ... Flow control valve 41 ... Generator 43a ... 1st temperature sensor (1st temperature detection means)
43b ... second temperature sensor (second temperature detecting means)
43c ... 3rd temperature sensor (3rd temperature detection means)
43d ... Pressure sensor (pressure detection means)
P1 ... Pump

Claims (12)

Used in a drive system having an internal combustion engine, comprising a Rankine cycle for circulating a working fluid,
The Rankine cycle is a waste heat utilization apparatus having a pump, a boiler, an expander, a condenser, and a pipe for circulating the working fluid from the pump to the condenser through the boiler and the expander.
In the boiler, heat exchange between the working fluid and the intake system fluid that is sucked while being cooled with respect to the internal combustion engine is possible,
The pump and the expander are connected to transmit power,
The pump is connected to be driven by the internal combustion engine via a clutch,
A judging means for judging a required cooling amount for the intake system fluid;
A waste heat utilization apparatus comprising: a control unit that disconnects the clutch when the requested cooling amount determined by the determination unit exceeds a first threshold value. Comprising an output request detecting means capable of detecting an output request to the internal combustion engine;
The waste heat utilization apparatus according to claim 1, wherein the determination unit determines the required cooling amount for the intake fluid based on a detection value detected by the output request detection unit. First temperature detecting means capable of detecting the temperature of the intake system fluid flowing out of the boiler;
The waste heat utilization apparatus according to claim 1, wherein the determination unit determines the required cooling amount for the intake system fluid based on a detection value detected by the first temperature detection unit. A second temperature detecting means capable of detecting the temperature of the working fluid flowing into the boiler;
The waste heat utilization apparatus according to claim 1, wherein the determination unit determines the required cooling amount for the intake system fluid based on a detection value detected by the second temperature detection unit. A third temperature detecting means capable of detecting the temperature of the working fluid flowing into the pump;
The waste heat utilization apparatus according to claim 1, wherein the determination unit determines the required cooling amount for the intake fluid based on a detection value detected by the third temperature detection unit. A fourth temperature detecting means capable of detecting the temperature of the intake system fluid flowing into the boiler;
The waste heat utilization apparatus according to claim 1, wherein the determination unit determines the required cooling amount for the intake system fluid based on a detection value detected by the fourth temperature detection unit. Pressure detecting means capable of detecting the pressure of the working fluid from the downstream of the expander to the upstream of the pump;
The waste heat utilization apparatus according to claim 1, wherein the determination unit determines the required cooling amount for the intake system fluid based on a detection value detected by the pressure detection unit.   In addition to determining that the required cooling amount for the intake system fluid has exceeded the first threshold value, the control means disconnects the clutch by a low speed signal in which the rotational speed of the internal combustion engine falls below a second threshold value. The waste heat utilization apparatus of any one of Claim 1 thru | or 7. A bypass path that branches from the pipe downstream of the boiler, bypasses the expander and joins the pipe, a flow rate of the working fluid flowing into the expander, and a flow rate of the working fluid flowing into the bypass path And an adjustable flow rate adjustment valve,
The waste heat utilization apparatus according to any one of claims 1 to 8, wherein the control means controls the flow rate adjustment valve. The expander can drive a generator;
The waste heat utilization apparatus according to any one of claims 1 to 9, wherein the control means controls a load of the generator. The drive system has a supercharger that supplies pressurized air that is the intake system fluid to the internal combustion engine,
The waste heat utilization apparatus according to any one of claims 1 to 10, wherein the boiler is a pressurized air boiler that exchanges heat between the pressurized air and the working fluid. The drive system has an exhaust gas recirculation path for recirculating a part of exhaust gas generated in the internal combustion engine to the internal combustion engine as recirculated exhaust gas that is the intake system fluid,
The waste heat utilization apparatus according to any one of claims 1 to 10, wherein the boiler is a recirculation exhaust boiler that exchanges heat between the recirculation exhaust and the working fluid.

Images