JP2015200194A - vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control opening and closing of a grille shutter to effectively utilize a waste heat regeneration device in improving fuel consumption performance, in a vehicle including the waste heat regeneration device and the grille shutter.SOLUTION: A vehicle includes an internal combustion engine 2, and a waste heat regeneration device 31 regenerating waste heat of the internal combustion engine 2 as motive power or electric power. The vehicle includes a front face heat exchanger 38 disposed at a front side of an engine room at a vehicle body front portion and included in the waste heat regeneration device 31, an outside air introduction port 101 for introducing outside air from a frontmost portion of the engine room to the front face heat exchanger 38 in running, and adjusting means 100 capable of adjusting an outside air introduction amount from the outside air introduction port 101 by opening and closing the outside air introduction port 101. The adjusting means 100 reduces the outside air introduction amount when an outside air temperature is higher than a prescribed value, in comparison with a case when the outside air temperature is the prescribed value or less.

Description

  The present invention relates to a vehicle including a shutter capable of adjusting the amount of traveling wind introduced into an internal combustion engine housing provided at the front of a vehicle body.

  A general vehicle equipped with an internal combustion engine has a radiator for exchanging heat between cooling water and outside air at the front end of an engine room provided at the front of the vehicle body, and is used for introducing outside air so that traveling wind passes through the radiator. The grill is provided. By the way, as the amount of outside air introduced from the grill to the engine room increases, the cooling performance improves, but the fuel efficiency deteriorates due to the increase in air resistance. Therefore, Patent Document 1 discloses a vehicle that provides both a cooling performance and a fuel consumption performance by providing a grill shutter for opening and closing the grill and opening and closing the grill shutter according to the cooling water temperature.

JP 2010-111277 A

  However, the above document does not describe opening / closing control of the grill shutter in a vehicle including a waste heat regeneration device that regenerates waste heat of the internal combustion engine to generate electric power or power.

  By using the output generated by the waste heat regeneration device for assisting the internal combustion engine, fuel efficiency can be improved. However, since the performance (regeneration efficiency) of the waste heat regenerator depends on the amount of heat released from the outside air, in the case of a vehicle equipped with the waste heat regenerator, the cooling water temperature of the cooling system of the internal combustion engine or the hybrid high-voltage device as described above If the control for opening and closing the grill shutter according to the above is applied, the performance of the waste heat regeneration device cannot be fully exhibited.

  Therefore, an object of the present invention is to provide a vehicle that opens and closes a grill shutter so as to improve fuel efficiency by effectively using the output generated by the waste heat regeneration device.

  According to an aspect of the present invention, a vehicle including an internal combustion engine and a waste heat regeneration device that regenerates waste heat of the internal combustion engine as power or electric power is provided. The vehicle is disposed on the front side of the engine room provided in the front part of the vehicle body, and includes a front heat exchanger included in the waste heat regeneration device and outside air that introduces outside air from the frontmost part of the engine room to the front heat exchanger during traveling. And an adjusting means capable of adjusting the amount of outside air introduced from the outside air inlet by opening and closing the outside air inlet. The adjusting means adjusts the outside air introduction amount to be smaller when the outside air temperature is higher than a predetermined value, compared to when the outside air temperature is equal to or lower than the predetermined value.

  The fuel efficiency improvement effect by closing the grill shutter is constant regardless of the outside temperature, whereas the fuel efficiency improvement effect by operating the waste heat regeneration device is generally higher as the outside temperature is lower. According to the above aspect, when the outside air temperature is higher than the predetermined value, the adjusting means adjusts so that the introduction amount of the outside air is reduced compared to the case where the outside air temperature is equal to or lower than the predetermined value. The fuel efficiency improvement effect by driving the waste heat regeneration device is greater than the fuel efficiency improvement effect due to the above.

FIG. 1 is a schematic configuration diagram in an engine room of a vehicle (grill shutter open state). FIG. 2 is a schematic configuration diagram in the engine room of the vehicle (grill shutter closed state). FIG. 3 is a schematic configuration diagram showing the entire Rankine cycle system. FIG. 4 is a schematic cross-sectional view of an expander pump in which the pump and the expander are integrated. FIG. 5 is a characteristic diagram of the Rankine cycle operation region. FIG. 6 is a characteristic diagram of the Rankine cycle operation region. FIG. 7 is a schematic sectional view of the ejector. FIG. 8 is a schematic view showing Rankine cycle single operation. FIG. 9 is a schematic view showing the operation of the ejector air conditioner with torque assist. FIG. 10 is a schematic view showing the operation of the ejector air conditioner without torque assist. FIG. 11 is a schematic diagram showing the operation of the compressor air conditioner. FIG. 12 is a diagram illustrating an example of an opening / closing operation of the grill shutter according to the first embodiment. FIG. 13 is an open / closed state map of the grille shutter according to the first embodiment. FIG. 14 is an open / closed state map of the grill shutter for comparison. FIG. 15 is a diagram illustrating an example of an opening / closing operation of the grill shutter according to the second embodiment. FIG. 16 is a first diagram illustrating the operation of the grill shutter according to the third embodiment. FIG. 17 is a second diagram illustrating the operation of the grill shutter according to the third embodiment. FIG. 18 is a third diagram illustrating the operation of the grill shutter according to the third embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
1 and 2 are schematic configuration diagrams in the engine room of the vehicle 1 according to the present embodiment. This schematic configuration diagram is viewed from a direction orthogonal to the vehicle traveling direction.

  A condenser (front heat exchanger) 38, which is a component part of a Rankine cycle 31 as a waste heat regeneration device, which will be described later, is disposed in the foremost part of the engine room, and a radiator 11 for the internal combustion engine 1 is disposed immediately thereafter. Is done.

  At the front end of the vehicle body, a grill 101 for introducing outside air (also referred to as traveling wind) during traveling into the condenser 38 is opened. The grill 101 is provided with a grill shutter 100 that opens and closes the grill 101.

  The grill shutter 100 includes a plurality of plate-like members that can rotate around a rotation axis that extends in the horizontal direction, and an actuator such as an electric motor (not shown) that rotates the plate-like member. The plurality of plate-like members are arranged with a predetermined interval, and in the open state, the rotation angle is generated so that a gap is formed between the plate-like members as shown in FIG. 1, while in the closed state, each plate-like member is shown in FIG. The rotation angle is such that no gap is generated between the members.

  The structure of the grill shutter 100 described above is merely an example, and other structures may be used as long as the grill 101 can be opened and closed.

  Similarly to the radiator 11, the condenser 38 includes a core made of a tube having heat radiating fins, and cools the refrigerant flowing inside by exchanging heat with the air passing through the gap between the cores.

  In the state where the grill shutter 100 is opened as shown in FIG. 1, the traveling wind introduced from the grill 101 passes through the condenser 38 and the radiator 11. Since the air in the engine room is warmed by heat generated from the internal combustion engine 1 and other auxiliary machines, the amount of heat released from the condenser 38 to the outside air increases when the traveling wind is introduced, and waste heat is generated. Regeneration efficiency is improved. As described above, by introducing the outside air, the waste heat regeneration efficiency by the Rankine cycle 31 is increased, and the fuel efficiency performance is expected to be improved by the waste heat regeneration. However, introducing the traveling wind into the engine room may cause a decrease in aerodynamic performance due to an increase in air resistance, and may cause a decrease in fuel consumption performance.

  On the other hand, when the grill shutter 100 is closed as shown in FIG. 2, the traveling wind flows around the vehicle body without being introduced into the engine room. For this reason, although the effect which raises the waste heat regeneration efficiency by Rankine cycle 31 is not acquired, the improvement of the fuel consumption performance by the improvement of aerodynamic performance is anticipated. If the grill shutter 100 is closed to restrict the introduction of outside air into the engine room, effects such as shortening the warm-up time when starting the cold engine and preventing overcooling of the engine and the transmission can be obtained. Contributes to improved performance.

  In addition, as described above, the waste heat regeneration efficiency depends on the amount of heat released to the outside air. Therefore, the higher the outside air temperature, the smaller the cost for improving the fuel efficiency due to the waste heat regeneration.

  Therefore, the opening degree of the grill shutter 100 needs to be determined in consideration of the allowance for improving fuel efficiency due to waste heat regeneration and the allowance for improving fuel efficiency due to aerodynamic performance. Details of the opening control of the grill shutter 100 will be described later.

  Next, the Rankine cycle 31 used as a waste heat regeneration device in the present embodiment will be described.

  FIG. 3 is a schematic configuration diagram showing the entire Rankine cycle system as a premise of the present invention. The Rankine cycle 31 of FIG. 3 is configured to share the refrigerant and the condenser 38 with the refrigeration cycle 51, and a cycle in which the Rankine cycle 31 and the refrigeration cycle 51 are integrated is hereinafter expressed as an integrated cycle 30. The integrated cycle 30 includes a circuit (passage) through which the refrigerant of the Rankine cycle 31 and the refrigeration cycle 51 circulates and components such as a pump, an expander, and a condenser provided in the middle of the circuit, and a circuit for cooling water and exhaust. It shall refer to the entire system including (passage).

  The Rankine cycle 31 is operated when the vehicle speed shifts to a Rankine cycle operation region which will be described later. The internal combustion engine 2 includes an exhaust passage 3, and the exhaust passage 3 includes an exhaust manifold 4 and an exhaust pipe 5 connected to a collecting portion of the exhaust manifold 4. The exhaust pipe 5 branches off from the bypass exhaust pipe 6 on the way, and the exhaust pipe 5 in the section bypassed by the bypass exhaust pipe 6 has a waste heat recovery unit for exchanging heat between the exhaust and the cooling water. 22. The waste heat recovery unit 22 and the bypass exhaust pipe 6 are disposed between the underfloor catalyst 88 and the sub muffler 89 downstream thereof, for example, as a waste heat recovery unit 23 in which they are integrated.

  First, the engine coolant circuit will be described with reference to FIG. The cooling water that has exited the internal combustion engine 2 (approximately 80 to 90 ° C. in a warm-up state) flows separately into a cooling water passage 13 that passes through the radiator 11 and a bypass cooling water passage 14 that bypasses the radiator 11. Thereafter, the two flows are merged again by the thermostat valve 15 that determines the distribution of the flow rate of the cooling water flowing through both the passages 13 and 14, and then returns to the internal combustion engine 2 via the cooling water pump 16.

  The cooling water pump 16 is driven by the internal combustion engine 2 and its rotational speed is synchronized with the engine rotational speed. The thermostat valve 15 relatively increases the amount of cooling water passing through the radiator 11 by increasing the valve opening on the cooling water passage 13 side when the cooling water temperature is high, and on the cooling water passage 13 side when the cooling water temperature is low. The amount of cooling water passing through the radiator 11 is relatively reduced by reducing the valve opening. When the coolant temperature is particularly low, such as before warming up the internal combustion engine 2, the entire amount of coolant flows through the bypass coolant passage 14 side.

  On the other hand, the valve opening degree on the bypass cooling water passage 14 side is not fully closed. When the flow rate of the cooling water flowing through the radiator 11 is increased, the flow rate of the cooling water flowing through the bypass cooling water passage 14 is reduced as compared with the case where the entire amount of cooling water flows through the bypass cooling water passage 14 side. The thermostat valve 15 is configured so as not to stop completely.

  A bypass cooling water passage 14 that bypasses the radiator 11 is branched from the cooling water passage 13 and directly connected to a heat exchanger 36, which will be described later, and from the cooling water passage 13 to recover waste heat. The second bypass cooling water passage 25 connected to the heat exchanger 36 after passing through the vessel 22.

  The bypass cooling water passage 14 includes a heat exchanger 36 that exchanges heat with the refrigerant of the Rankine cycle 31. This heat exchanger 36 is an integrated heater and superheater. That is, two cooling water passages 36a and 36b are arranged in a row in the heat exchanger 36, and a refrigerant passage 36c through which the refrigerant of the Rankine cycle 31 flows so that heat can be exchanged between the refrigerant and the cooling water is a cooling water passage 36a, It is provided adjacent to 36b. Furthermore, the passages 36a, 36b, and 36c are configured so that the refrigerant and the cooling water of the Rankine cycle 31 flow in opposite directions when the entire heat exchanger 36 is looked down on.

  Specifically, one cooling water passage 36 a located on the upstream side (left side in FIG. 3) for the refrigerant of Rankine cycle 31 is interposed in the first bypass cooling water passage 24. The left side portion of the heat exchanger composed of the cooling water passage 36a and the refrigerant passage portion adjacent to the cooling water passage 36a directly introduces the cooling water from the internal combustion engine 2 into the cooling water passage 36a, thereby allowing the refrigerant passage 36c to be formed. It is a heater for heating the refrigerant of the flowing Rankine cycle 31.

  Cooling water that has passed through the waste heat recovery device 22 is introduced into the other cooling water passage 36b located on the downstream (right side in FIG. 3) side of the refrigerant in the Rankine cycle 31 via the second bypass cooling water passage 25. The right side portion of the heat exchanger (downstream side for the refrigerant of Rankine cycle 31) composed of the cooling water passage 36b and the refrigerant passage portion adjacent to the cooling water passage 36b is a cooling system in which the cooling water at the outlet of the internal combustion engine 2 is further heated by exhaust gas. The superheater superheats the refrigerant flowing through the refrigerant passage 36c by introducing water into the cooling water passage 36b.

  The cooling water passage 22 a of the waste heat recovery unit 22 is provided adjacent to the exhaust pipe 5. By introducing the cooling water at the outlet of the internal combustion engine 2 into the cooling water passage 22a of the waste heat recovery unit 22, the cooling water can be heated to, for example, about 110 to 115 ° C. by high-temperature exhaust. The cooling water passage 22a is configured such that the exhaust and cooling water flow in opposite directions when the entire waste heat recovery unit 22 is looked down on.

  A control valve 26 is interposed in the second bypass cooling water passage 25 provided with the waste heat recovery unit 22. Cooling of the outlet of the internal combustion engine 2 so that the engine water temperature indicating the temperature of the cooling water inside the internal combustion engine 2 does not exceed an allowable temperature (for example, 100 ° C.) for preventing deterioration of the efficiency and knocking of the internal combustion engine, for example. When the temperature detected by the water temperature sensor 74 becomes equal to or higher than a predetermined value, the opening degree of the control valve 26 decreases. As a result, when the engine water temperature approaches the allowable temperature, the amount of cooling water passing through the waste heat recovery device 22 decreases, so that the engine water temperature can be prevented from exceeding the allowable temperature.

  On the other hand, if the flow rate of the second bypass cooling water passage 25 decreases, the cooling water temperature rising by the waste heat recovery device 22 rises too much and the cooling water evaporates (boils). In addition to a decrease in efficiency, the flow of cooling water in the cooling water passage may deteriorate and the temperature may rise excessively. In order to avoid this, a bypass exhaust pipe 6 that bypasses the waste heat recovery unit 22, and a thermostat valve 7 that controls the exhaust passage amount of the waste heat recovery unit 22 and the exhaust passage amount of the bypass exhaust pipe 6 are provided in the bypass exhaust pipe 6. It is provided at the branch. In other words, the thermostat valve 7 is configured such that the valve opening degree of the cooling water exiting the waste heat recovery unit 22 is such that the temperature of the cooling water exiting the waste heat recovery unit 22 does not exceed a predetermined temperature (for example, a boiling temperature of 120 ° C.). Adjusted based on temperature.

  The heat exchanger 36, the thermostat valve 7, and the waste heat recovery unit 22 are integrated as a waste heat recovery unit 23, and are arranged in the middle of the exhaust pipe under the floor at the approximate center in the vehicle width direction. The thermostat valve 7 may be a relatively simple temperature-sensitive valve using bimetal or the like, or may be a control valve controlled by a controller to which a temperature sensor output is input. Adjustment of the amount of heat exchange from the exhaust gas to the cooling water by the thermostat valve 7 involves a relatively large delay. Therefore, if the thermostat valve 7 is adjusted alone, it is difficult to prevent the engine water temperature from exceeding the allowable temperature. However, since the control valve 26 of the second bypass cooling water passage 25 is controlled based on the engine water temperature (exit temperature), the heat recovery amount can be quickly reduced and the engine water temperature can be surely exceeded the allowable temperature. Can be prevented. Further, if the engine water temperature has a margin before the allowable temperature, heat exchange is performed until the temperature of the cooling water exiting the waste heat recovery unit 22 becomes high enough to exceed the allowable temperature of the engine water temperature (for example, 110 to 115 ° C.). To increase the amount of recovered waste heat. The cooling water that has exited the cooling water passage 36 b is joined to the first bypass cooling water passage 24 via the second bypass cooling water passage 25.

  If the temperature of the cooling water from the bypass cooling water passage 14 toward the thermostat valve 15 is sufficiently lowered, for example, by heat exchange in the heat exchanger 36, the valve opening on the cooling water passage 13 side of the thermostat valve 15 is reduced, The amount of cooling water passing through the radiator 11 decreases. Conversely, when the temperature of the cooling water from the bypass cooling water passage 14 toward the thermostat valve 15 becomes high due to the Rankine cycle 31 not being operated, the valve opening of the thermostat valve 15 on the cooling water passage 13 side increases, The amount of cooling water passing through the radiator 11 increases. Based on the operation of the thermostat valve 15, the cooling water temperature of the internal combustion engine 2 is appropriately maintained, and heat is appropriately supplied (recovered) to the Rankine cycle 31.

  Next, Rankine cycle 31 will be described. Here, Rankine cycle 31 is not a simple Rankine cycle, but is configured as a part of integrated cycle 30 integrated with refrigeration cycle 51. Hereinafter, the basic Rankine cycle 31 will be described first, and then the refrigeration cycle 51 will be referred to.

  The Rankine cycle 31 is a system that recovers the waste heat of the internal combustion engine 2 to a refrigerant through the cooling water of the internal combustion engine 2 and regenerates the recovered waste heat as power. The Rankine cycle 31 includes a refrigerant pump 32, a heat exchanger 36 as a superheater, an expander 37, and a condenser (condenser) 38, and each component is connected by refrigerant passages 41 to 44 through which a refrigerant (R134a and the like) circulates. Has been.

  The shaft of the refrigerant pump 32 is connected to the output shaft of the expander 37 on the same shaft, and the refrigerant pump 32 is driven by the output (power) generated by the expander 37 and the generated power is used as the output shaft of the internal combustion engine 2. It is the structure supplied to (crankshaft) (refer FIG. 4). That is, the refrigerant pump 32 shaft and the output shaft of the expander 37 are arranged in parallel with the output shaft of the internal combustion engine 2, and the belt 34 is interposed between the pump pulley 33 provided at the tip of the refrigerant pump 32 shaft and the crank pulley 2a. It is hung (see FIG. 3). In this embodiment, a gear type pump is used as the refrigerant pump 32 and a scroll type expander is used as the expander 37.

  An electromagnetic clutch (hereinafter referred to as “expander clutch”) 35 is provided between the pump pulley 33 and the refrigerant pump 32 so that the refrigerant pump 32 and the expander 37 and the internal combustion engine 2 can be connected and disconnected. (See FIG. 4). For this reason, by connecting the expander clutch 35 when the output generated by the expander 37 exceeds the driving force of the refrigerant pump 32 and the friction of the rotating body (when the predicted expander torque is positive), the expander 37 The rotation of the engine output shaft can be assisted by the generated output.

  Thus, the fuel efficiency can be improved by assisting the rotation of the engine output shaft using the energy obtained by the recovery of the waste heat. Further, the energy for driving the refrigerant pump 32 that circulates the refrigerant can also be covered by the recovered waste heat.

  The refrigerant exiting the refrigerant pump 32 is supplied to the heat exchanger 36 via the refrigerant passage 41. The heat exchanger 36 exchanges heat between the cooling water of the internal combustion engine 2 and the refrigerant, vaporizes the refrigerant and superheats it.

  The refrigerant leaving the heat exchanger 36 is supplied to the expander 37 through the refrigerant passage 42. The expander 37 is a steam turbine that converts heat into rotational energy by expanding the vaporized and superheated refrigerant. The power recovered by the expander 37 drives the refrigerant pump 32 and is transmitted to the internal combustion engine 2 via the belt transmission mechanism to assist the rotation of the internal combustion engine 2.

  The refrigerant exiting the expander 37 is supplied to the condenser 38 through the refrigerant passage 43. The condenser 38 exchanges heat between the outside air and the refrigerant, and cools and liquefies the refrigerant. For this reason, the condenser 38 is arranged in parallel with the radiator 11 so as to be cooled by the radiator fan 12.

  The refrigerant liquefied by the condenser 38 is returned to the refrigerant pump 32 via the refrigerant passage 44. The refrigerant returned to the refrigerant pump 32 is sent again to the heat exchanger 36 by the refrigerant pump 32 and circulates through each component of the Rankine cycle 31.

  Next, the refrigeration cycle 51 will be described. The refrigeration cycle 51 is integrated with the Rankine cycle 31 in order to share the refrigerant circulating in the Rankine cycle 31.

  The refrigeration cycle 51 includes a compressor (compressor) 52, a condenser 38, and an evaporator (evaporator) 55.

  The compressor 52 is a fluid machine that compresses the refrigerant of the refrigeration cycle 51 to a high temperature and a high pressure, and is driven by the internal combustion engine 2. That is, a compressor pulley is fixed to the drive shaft of the compressor 52, and the belt 34 is wound around the compressor pulley and the crank pulley 2a. The driving force of the internal combustion engine 2 is transmitted to the compressor pulley via the belt 34, and the compressor 52 is driven. Further, an electromagnetic clutch (hereinafter referred to as “compressor clutch”) 54 is provided between the compressor pulley and the compressor 52 so that the compressor 52 and the compressor pulley can be connected and disconnected.

  The refrigerant that has exited the compressor 52 joins the refrigerant passage 43 via the refrigerant passage 56 and is then supplied to the condenser 38. The condenser 38 condenses and liquefies the refrigerant by heat exchange with the outside air. The liquid refrigerant exiting the condenser 38 is supplied to an evaporator (evaporator) 55 through a refrigerant passage 57 branched from the refrigerant passage 44. The evaporator 55 is disposed in the case of the air conditioner unit in the same manner as a heater core (not shown). The evaporator 55 evaporates the liquid refrigerant exiting the condenser 38 and cools the conditioned air exiting the blower fan by the latent heat of evaporation at that time.

  The refrigerant evaporated by the evaporator 55 is returned to the compressor 52 through the refrigerant passage 58. Note that the mixing ratio of the conditioned air cooled by the evaporator 55 and the conditioned air heated by the heater core is adjusted to a temperature set by the occupant according to the opening of the air mix door.

  In the integrated cycle 30 including the Rankine cycle 31 and the refrigeration cycle 51, various valves are appropriately provided in the middle of the circuit in order to control the refrigerant flowing in the cycle. For example, in order to control the refrigerant circulating in the Rankine cycle 31, the expander upstream valve 62 is provided in the refrigerant passage 42 that connects the heat exchanger 36 and the expander 37. The refrigerant passage 41 that connects the refrigerant pump 32 and the heat exchanger 36 is provided with a check valve 63 to prevent the refrigerant from flowing backward from the heat exchanger 36 to the refrigerant pump 32. The refrigerant passage 43 that connects the expander 37 and the refrigeration cycle merge point 46 is also provided with a check valve 64 to prevent the refrigerant from flowing back from the refrigeration cycle merge point 46 to the expander 37. Further, an expander bypass passage 65 that bypasses the expander 37 from the upstream of the expander upstream valve 62 and merges upstream of the check valve 64 is provided, and a bypass valve 66 is provided in the expander bypass passage 65. Further, a pressure regulating valve 68 is provided in a passage 67 that bypasses the bypass valve 66. Also on the refrigeration cycle 51 side, an air conditioner circuit valve 69 is provided in the refrigerant passage 57 that connects the refrigeration cycle branch point 45 and the evaporator 55.

  The above valves 62, 66, and 69 are all electromagnetic on-off valves. An expander upstream pressure signal detected by the pressure sensor 72, a refrigerant pressure Pd signal at the outlet of the condenser 38 detected by the pressure sensor 73, a rotation speed signal of the expander 37, and the like are input to the engine controller 71. . The engine controller 71 controls the compressor 52 of the refrigeration cycle 51 and the radiator fan 12 and also controls the opening and closing of the valves 62, 66, and 69 based on these input signals in accordance with predetermined operating conditions. For example, the expander torque is predicted based on the expander upstream pressure detected by the pressure sensor 72 and the expander rotation speed, and when the predicted expander torque is positive, the expander clutch 35 is engaged, and the predicted expander When the torque is zero or negative, the expander clutch 35 is released. Based on the sensor detection pressure and the rotation speed of the expander, the expander torque can be predicted with higher accuracy than when the expander torque is predicted from the exhaust temperature. The mechanical clutch 35 can be appropriately engaged and disengaged (refer to Japanese Patent Application Laid-Open No. 2010-190185 for details).

  The valves 62, 66, 69 and the two check valves 63, 64 are refrigerant system valves. The functions of these refrigerant valves are shown again in FIG.

  The engine controller 71 includes a microcomputer having a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). It is also possible to configure the engine controller 71 with a plurality of microcomputers.

  In FIG. 3, the expander upstream valve 62 blocks the refrigerant passage 42 when the pressure of the refrigerant exiting the heat exchanger 36 is relatively low, and holds the refrigerant until the refrigerant exiting the heat exchanger 36 reaches a high pressure. Is to be able to. Thereby, even when the expander torque cannot be sufficiently obtained, the heating of the refrigerant is promoted, and for example, the time until the Rankine cycle 31 is restarted (regeneration can actually be performed) can be shortened. The bypass valve 66 is opened so that the refrigerant pump 32 can be operated after the expander 37 is bypassed when the amount of refrigerant existing on the Rankine cycle 31 side is insufficient when the Rankine cycle 31 is started. This is for shortening the startup time of the Rankine cycle 31. By operating the refrigerant pump 32 after the expander 37 is bypassed, the refrigerant temperature at the outlet of the condenser 38 or the inlet of the refrigerant pump 32 has a predetermined temperature difference (subcool degree SC) from the boiling point considering the pressure at that portion. ) If the state lowered as described above is realized, the Rankine cycle 31 is ready to supply a sufficient liquid refrigerant.

  The check valve 63 upstream of the heat exchanger 36 is for maintaining the refrigerant supplied to the expander 37 at a high pressure in cooperation with the bypass valve 66, the pressure adjusting valve 68, and the expander upstream valve 62. Under conditions where the regeneration efficiency of the Rankine cycle 31 is low, the operation of the Rankine cycle 31 is stopped and the circuit is closed over the front and rear sections of the heat exchanger 36 to increase the refrigerant pressure during the stop, It is used so that Rankine cycle 31 can be restarted promptly. The pressure regulating valve 68 functions as a relief valve that opens when the pressure of the refrigerant supplied to the expander 37 becomes too high and releases the refrigerant that has become too high.

  The check valve 64 downstream of the expander 37 is for preventing the bias of the refrigerant to the Rankine cycle 31. If the internal combustion engine 2 is not warmed immediately after the start of the operation of the vehicle 1, the Rankine cycle 31 has a lower temperature than the refrigeration cycle 51, and the refrigerant may be biased toward the Rankine cycle 31 side. Although the probability of being biased toward the Rankine cycle 31 is not so high, for example, immediately after the start of vehicle operation in summer, the cooling capacity is most demanded in the situation where it is desired to cool the interior quickly, so the slight uneven distribution of refrigerant is also eliminated. Therefore, there is a demand for securing the refrigerant for the refrigeration cycle 51. Therefore, a check valve 64 is provided to prevent uneven distribution of refrigerant to the Rankine cycle 31 side.

  The compressor 52 does not have a structure in which the refrigerant can freely pass when driving is stopped, but can prevent the refrigerant from being biased to the refrigeration cycle 51 in cooperation with the air conditioner circuit valve 69. This will be described. When the operation of the refrigeration cycle 51 stops, the refrigerant may move from the relatively high temperature Rankine cycle 31 side to the refrigeration cycle 51 side during steady operation, and the refrigerant circulating through the Rankine cycle 31 may be insufficient. In the refrigeration cycle 51, the temperature of the evaporator 55 is low immediately after the cooling is stopped, and the refrigerant tends to accumulate in the evaporator 55 having a relatively large volume and a low temperature. In this case, the movement of the refrigerant from the condenser 38 to the evaporator 55 is interrupted by stopping the driving of the compressor 52, and the air conditioner circuit valve 69 is closed to prevent the refrigerant from being biased to the refrigeration cycle 51.

  Incidentally, the refrigeration cycle 51 also includes a refrigerant passage 91 that bypasses the compressor 52. That is, a refrigerant passage 91 that branches from a refrigerant passage 58 that communicates the outlet of the evaporator 55 and the compressor 52 and joins the refrigeration cycle junction 46 is provided. An ejector 92 is interposed in the refrigerant passage 91. A check valve 99 that blocks the flow of the refrigerant from the ejector 92 to the branch point of the refrigerant passage 91 is interposed in the refrigerant passage 91 between the branch point of the refrigerant passage 91 and the ejector 92.

  The above-described ejector 92 is a device that can create a state close to a vacuum from a fluid without using a mechanical motion such as a pump. As shown in FIG. 7, the ejector 92 includes a chamber 93 surrounded by a periphery, a suction port 94 that opens to the chamber 93, a nozzle 95 that faces the chamber 93, and a diffuser 96. In the chamber 93, the nozzle 95 and the diffuser 96 face each other at an appropriate distance.

  The refrigerant passage is connected to the ejector 92 configured as described above as follows. That is, in FIG. 3, the refrigerant passage 97 is branched from the refrigerant passage 42 close to the outlet of the heat exchanger 36, and the branched refrigerant passage 97 is connected to the nozzle inlet 95a.

  An electromagnetic flow control valve 98 capable of adjusting a distribution ratio between the refrigerant flow rate flowing through the expander 37 and the refrigerant flow rate flowing through the ejector 92 is provided at a branch portion of the branch refrigerant passage 97. Here, “ejector side opening” and “expander side opening” are introduced as control amounts of the flow control valve 98.

  For example, when the ejector side opening is zero, all of the refrigerant that exits from the outlet of the heat exchanger 36 does not flow through the branch refrigerant passage 97, and when the ejector side opening is maximized, the refrigerant exits from the outlet of the heat exchanger 36. All of the refrigerant flows through the branch refrigerant passage 97. On the other hand, when the opening on the expander side is zero, all of the refrigerant at the outlet of the heat exchanger does not flow through the refrigerant passage 42, and when the opening on the expander side is maximized, the refrigerant flowing out from the outlet of the heat exchanger 36 All flows through the refrigerant passage 42. That is, when the ejector side opening is set to zero, the expander side opening is maximized, and when the ejector side opening is gradually increased from zero, the expander side opening is gradually decreased from the maximum. When the ejector side opening is maximized, the expander side opening is zero.

  As described above, the relationship between the two openings in the flow control valve 98 of the present embodiment is a relation in which the remaining opening is uniquely determined by setting one of the openings. Therefore, the flow control valve 98 may be controlled by either the ejector side opening or the expander side opening. Here, the ejector side opening degree is controlled. As described above, since the refrigerant circuit is configured so that the ejector 92 is in parallel with the expander 37, the refrigerant can be arbitrarily directed to the ejector side and the expander side. Drive as desired.

  The refrigerant passage 91 on the evaporator 55 side is connected to the suction port 94, and the refrigerant passage 91 on the side of the junction 46 with the refrigerant passage 43 is connected to the ejector outlet 96a.

  Next, a basic operation method of the Rankine cycle 31 will be described with reference to FIGS.

  5 and 6 are operation region diagrams of the Rankine cycle 31. FIG. FIG. 5 shows the operating range of the Rankine cycle 31 when the horizontal axis is the outside air temperature and the vertical axis is the engine water temperature (cooling water temperature). In FIG. 6, the horizontal axis is the engine rotation speed, and the vertical axis is the engine torque (engine The operating range of the Rankine cycle 31 is shown. However, FIG.5 and FIG.6 is an operation area | region figure on the assumption that the grill shutter 100 is being fixed in the open state.

  5 and 6, the Rankine cycle 31 is operated when a predetermined condition is satisfied, and the Rankine cycle 31 is operated when both of these conditions are satisfied. In FIG. 5, the operation of the Rankine cycle 31 is stopped in a region on the low water temperature side where priority is given to warming up the internal combustion engine 2 and a region on the high outside air temperature side where the load on the compressor 52 increases. During warm-up when the exhaust temperature is low and the recovery efficiency is poor, the Rankine cycle 31 is not operated, so that the coolant temperature is quickly raised. At a high outside air temperature where a high cooling capacity is required, the Rankine cycle 31 is stopped, and sufficient refrigerant and cooling capacity of the condenser 38 are provided to the refrigeration cycle 51. In FIG. 6, the operation of the Rankine cycle 31 is stopped in a region on the high rotational speed side where the friction of the expander 37 increases. Since it is difficult to make the expander 37 have a high-efficiency structure with little friction at all rotation speeds, in the case of FIG. 6, the expansion is performed so that the friction is small and the efficiency is high in the engine rotation speed range where the operation frequency is high. The machine 37 is configured (the dimensions of each part of the expander 37 are set).

  Next, the operation of the ejector 92 will be described.

  Generally, when sufficient waste heat of the internal combustion engine is obtained, energy is supplied from the outside to drive the pump to supply refrigerant to the heat exchanger, and drive the ejector by overheating due to waste heat to operate the refrigeration cycle . On the other hand, when the waste heat is insufficient, the pump is stopped and the compressor is driven by the internal combustion engine to operate the refrigeration cycle. However, in such a general apparatus, it is necessary to drive the pump by applying energy from the outside in order to obtain a high-pressure refrigerant for driving the ejector, and driving the pump deteriorates fuel consumption.

  Therefore, in this embodiment, in order to obtain a high-pressure refrigerant for driving the ejector, the pump need not be driven by applying energy from the outside. Hereinafter, this configuration will be described.

  When a high-pressure gas refrigerant is injected from the nozzle 95 toward the chamber 93 as a driving gas, the gas refrigerant becomes a low-pressure supersonic flow and proceeds to the inlet of the diffuser 96. Due to the flow of the gas refrigerant, a negative static pressure is generated in the chamber 93, and the inside of the chamber 93 is close to a vacuum. Due to the static pressure and the viscosity of the gas refrigerant, the gas refrigerant exiting the evaporator 55 is drawn into the gas refrigerant flow jumping into the inlet of the diffuser 96 as suction gas. The gas refrigerant supplied to the nozzle 95 and the gas refrigerant sucked from the suction port 94 are mixed in the front half of the diffuser 96, and in the latter half, the speed is reduced and the pressure is increased and discharged toward the diffuser outlet 96a.

  When the combined cycle 30 includes the ejector 92, if the Rankine cycle 31 is in operation, a part of the refrigerant flowing through the refrigerant passage of the Rankine cycle 31 is guided to the ejector 92 as a drive gas to drive the ejector 92 and the refrigeration cycle. 51 can be driven. With such a configuration, it is not necessary to drive the pump with energy from the outside in order to obtain a high-pressure refrigerant for driving the ejector. Here, “operating the refrigeration cycle 51” means that the refrigerant is circulated in the refrigerant passage of the refrigeration cycle 51 (as a result, the air conditioner is cooled).

  By providing the ejector 92 as described above, in this embodiment, <1> Rankine cycle independent operation, <2> Operation of an ejector air conditioner with torque assist, <3> Operation of an ejector air conditioner without torque assist, and <4> Compressor. It was possible to use four types of operation, namely air conditioner operation. Here, “operating the ejector air conditioner” means operating the refrigeration cycle 51 by driving the ejector 92 without using the compressor 52. Further, “operation of the compressor air conditioner” refers to operating the refrigeration cycle 51 by driving the compressor 52 without using the ejector 92. Hereinafter, each operation will be described.

<1> Rankine cycle independent operation

  Rankine cycle single operation is performed when there is no air conditioner request (cooling request). As shown in FIG. 8, the ejector side opening of the flow control valve 98 is set to zero (see the broken line), the gas refrigerant is not supplied to the ejector 92, and the drive of the ejector 92 is stopped.

  The heat exchanger 36 evaporates the refrigerant with waste heat of the internal combustion engine 2 and superheats it, and supplies all of the gas refrigerant that exits from the outlet of the heat exchanger 36 to the expander 37 via the refrigerant passage 42 (see thick solid line). ), And the expander 37 is rotationally driven by the pressure energy of the gas refrigerant. The refrigerant pump 32 is driven by the torque (output) generated by the expander 37 to circulate the refrigerant, and the Rankine cycle 31 is operated. Here, “operating Rankine cycle 31” means circulating the refrigerant in the refrigerant passage of Rankine cycle 31 (as a result, energy is recovered from waste heat). When the torque generated by the expander 37 exceeds the driving force of the refrigerant pump 32, the expander clutch 35 is connected, and the Rankine cycle 31 is operated to assist the rotation of the engine output shaft and improve the fuel efficiency.

<2> Operation of the ejector air conditioner with torque assist

  The ejector air conditioner with torque assist is operated when there is an air conditioner request and the torque generated by the expander 37 is sufficient because the torque generated by the expander 37 is sufficient, such as during a high-speed cruise mainly requiring an air conditioner. As shown in FIG. 9, the ejector side opening degree of the flow control valve 98 is controlled, and the gas refrigerant exiting from the outlet of the heat exchanger 36 is dividedly supplied to the expander 37 and the ejector 92 to rotate the expander 37. In addition to driving, the ejector 92 is driven.

  The refrigerant pump 32 is driven by the torque (output) of the expander 37 to circulate the refrigerant, and the Rankine cycle 31 is operated. A part of the refrigerant circulating in the refrigerant passage of the Rankine cycle 31 is guided to the ejector 92 to drive the ejector 92, and the refrigerant is also circulated through the refrigerant passage of the refrigeration cycle 51. The refrigeration cycle 51 is operated without driving the compressor 52, and the vehicle interior is air-conditioned. The driving of the compressor 52 becomes a load on the internal combustion engine 2 and the fuel efficiency is reduced accordingly. However, when the refrigeration cycle 51 is driven by driving the ejector 92 during the operation of the Rankine cycle 31, the driving of the compressor 52 is performed. The accompanying deterioration in fuel consumption can be suppressed.

  If the expander torque remains even after the refrigerant pump 32 is driven, the expander clutch 35 is connected, and the rotation of the engine output shaft is assisted by the remaining expander torque even if the refrigerant pump 32 is driven, thereby improving fuel efficiency. .

<3> Operation of ejector air conditioner without torque assist

  When there is an air conditioner request, such as during idling stop or low load, and the torque generated by the expander 37 is not sufficient and torque assist cannot be performed, the ejector air conditioner without torque assist is operated. The difference from the above-described operation of the ejector air conditioner with torque assist <2> is only that torque assist is not performed. That is, as shown in FIG. 10, the expander clutch 35 is disconnected, the ejector side opening degree of the flow control valve 98 is controlled, and the expander torque is driven only to drive the refrigerant pump 32 without torque assist. The Rankine cycle 31 is operated by using it. The refrigeration cycle 51 is operated by driving the ejector 92 with the gas refrigerant obtained by the operation of the Rankine cycle 31. The refrigeration cycle 51 can be operated only with engine waste heat without using power (compressor 52) for some time after shifting to idle stop or at low vehicle speeds.

<4> Operation of compressor air conditioner

  The compressor air conditioner is operated after the torque assist-free ejector air conditioner <3> cannot be operated during idle stop or low load. As shown in FIG. 11, the opening on the ejector side of the flow control valve 98 is set to zero, the supply of refrigerant to the expander 37 and the ejector 92 is stopped, and the operation of the Rankine cycle 31 and the drive of the ejector 92 are stopped. When idling stop is in progress, current is supplied to the motor and the compressor 52 is driven by the motor. When the load is low, the compressor clutch 54 is connected, and the compressor 52 is driven by the internal combustion engine 2 to operate the refrigeration cycle 51. Then, the passenger compartment is air-conditioned.

  Next, the opening / closing operation of the grill shutter 100 will be described.

  FIG. 12 is a diagram illustrating an example of the opening / closing operation of the grill shutter 100. This opening / closing operation is performed when the internal combustion engine 2 is in a warm-up state (cooling water temperature 80 ° C.) and the vehicle speed is 100 km / h. The “fuel efficiency improvement effect” on the vertical axis is the fuel efficiency improvement rate (%) with respect to the fuel efficiency when the Rankine cycle 31 is not operated and the grill shutter is opened under the same conditions as described above.

  The fuel efficiency improvement effect when the Rankine cycle 31 is operated with the grille shutter 100 fully opened (hereinafter also referred to as fuel efficiency improvement effect by the Rankine cycle 31) becomes smaller as the outside air temperature becomes higher as shown by the solid line. The temperature becomes zero at 35 ° C.

  On the other hand, the fuel efficiency improvement effect (hereinafter also referred to as the fuel efficiency improvement effect of the grill shutter 100) by fully closing the grill shutter 100 is constant regardless of the outside air temperature as shown by the broken line. Note that when the Rankine cycle 31 is operated with the grille shutter 100 fully closed, as shown by the alternate long and short dash line, the fuel efficiency improvement effect is hardly obtained. That is, the fuel efficiency improvement effect by the grill shutter 100 is due to the improvement of aerodynamic performance.

  As shown in FIG. 12, when the outside air temperature is 30 ° C., the fuel efficiency improvement effect by Rankine cycle 31 and the fuel efficiency improvement effect by grill shutter 100 are equal. Therefore, in this embodiment, when the outside air temperature is 30 ° C. or lower, the Rankine cycle 31 is operated with the grill shutter 100 opened, and when the outside air temperature is higher than 30 ° C., the grill shutter 100 is not operated without operating the Rankine cycle 31. Close. That is, according to the outside air temperature, the one having the larger fuel efficiency improvement effect is selected from among the waste heat regeneration by the Rankine cycle 31 or the aerodynamic performance improvement by closing the grill shutter 100. Thereby, fuel consumption performance can be improved in a wide range of outside air temperatures.

  In addition, the numbers of 30 ° C. and 35 ° C. used in the above description are used as typical ones, and actually have some widths before and after due to individual differences and the like.

  FIG. 13 is an open / closed state map of the grille shutter 100 including operating conditions other than those described above. The engine controller 71 performs opening / closing control of the grill shutter 100 based on this map. FIG. 14 is an open / closed state map of the grille shutter when the waste heat regeneration device (Rankine cycle 31) is not provided.

  When the engine coolant temperature is 90 ° C. or higher, the grille shutter 100 is open in the entire outside air temperature range in both FIGS. This is due to the cooling request of the internal combustion engine 2. That is, it is for introducing outside air into the radiator 11 in order to suppress an increase in the cooling water temperature. The presence / absence of a cooling request is determined by the engine controller 71 based on the cooling water temperature detected by the cooling water temperature sensor. For example, when the cooling water temperature reaches 90 ° C., it is determined that there is a cooling request.

  When the cooling water temperature at which the internal combustion engine 2 is not required to be cooled is 60 ° C. or lower, the grille shutter 100 is closed in the entire outside air temperature region in both FIGS. This is because priority is given to setting the internal combustion engine 2 to a warm-up state (cooling water temperature of 80 ° C. or higher).

  At the cooling water temperature of 80 ° C. immediately after the internal combustion engine 2 is warmed up, when the Rankine cycle 31 is provided, the above-described open / closed state is established. This is because if the cooling water temperature is 80 ° C., an output can be obtained by operating the Rankine cycle 31, and a fuel efficiency improvement effect greater than the fuel efficiency improvement effect obtained by closing the grill shutter 100 can be obtained.

  Note that the grill shutter 100 may be opened even when the outside air temperature is −20 ° C., but in FIG. 13, the grill shutter 100 is closed when the outside air temperature is −20 ° C. This is because at an extremely low temperature such as −20 ° C., the low-pressure side pressure of the Rankine cycle 31 is excessively lowered, the regeneration efficiency is deteriorated, and output cannot be performed. As described above, when the waste heat regeneration cannot be performed, the grill shutter 100 is closed, and the fuel efficiency improvement effect by the grill shutter 100 can be obtained.

  On the other hand, when the waste heat regeneration device is not provided, the grill shutter 100 is closed in the entire outside air temperature region even when the cooling water temperature is 80 ° C. This is because if the cooling water temperature is 80 ° C., there is no request for cooling the internal combustion engine 2 and priority is given to improving aerodynamic performance.

  As described above, when the Rankine cycle 31 is not provided, the grill shutter 100 is closed until the cooling water temperature reaches 90 ° C., whereas when the Rankine cycle 31 is provided, the internal combustion engine 2 is warmed up. The grill shutter 100 is opened from the cooling water temperature (80 ° C.) immediately after.

  According to this embodiment described above, the following effects can be obtained.

  (1) A vehicle 1 according to this embodiment includes an internal combustion engine 2 and a Rankine cycle (waste heat regeneration device) 31 that regenerates waste heat of the internal combustion engine 2 as power or electric power. The vehicle 1 includes a condenser (front heat exchanger) 38 disposed on the front side of the engine room, and a grill (outside air introduction port) 101 for introducing outside air from the foremost part of the engine room to the condenser 38 during traveling. And a grille shutter (adjusting means) 100 that can adjust the amount of outside air introduced from the grille 101 by opening and closing the grille 101. When the outside air temperature is higher than the predetermined value, the grill shutter 100 adjusts the outside air introduction amount to be smaller than that when the outside air temperature is equal to or lower than the predetermined value. Thereby, the fuel consumption improvement effect is acquired in a wide outside temperature range.

  (2) The above-mentioned predetermined temperature is equivalent to the fuel consumption improvement allowance due to driving the Rankine cycle 31 with the grille shutter 100 fully open and the fuel consumption improvement allowance due to running with the grill shutter 100 fully closed. The outside air temperature. The grill shutter 100 is fully closed when the outside air temperature is higher than a predetermined temperature, and fully opened when the outside air temperature is lower than the predetermined temperature. Thereby, a greater fuel efficiency improvement effect can be obtained in a wide range of outside air temperatures.

  (3) The vehicle 1 according to the present embodiment includes an engine controller 71 (engine cooling request determination unit) that determines whether or not there is a cooling request for the internal combustion engine 2 based on the coolant temperature. When there is a cooling request, the grill shutter 100 adjusts the outside air introduction amount to be the same as when the outside air temperature is equal to or lower than the predetermined value even if the outside air temperature is higher than the predetermined value. Thereby, the cooling request | requirement of the internal combustion engine 2 can be satisfied.

  (4) When the exhaust gas temperature is so low that output due to waste heat regeneration is impossible, the grill shutter 100 is closed. Thereby, the fuel efficiency can be improved by the fuel efficiency improvement effect of the grill shutter 100.

  The waste heat regeneration device is not limited to the Rankine cycle 31, and may be, for example, a Stirling cycle, or a device that generates electric power that regenerates waste heat, such as a thermoelectric element. In addition, since the refrigeration cycle 51 can be operated without using a pump by driving the ejector 92 using a part of the refrigerant flowing through the refrigerant passage of the Rankine cycle 31, the ejector 92 is also used as a waste heat regeneration device. Can be included.

(Second Embodiment)
Although this embodiment has the same system configuration as the first embodiment, the operation of the grill shutter 100 is different. Hereinafter, the operation of the grill shutter 100 will be mainly described.

  FIG. 15 is a diagram illustrating an opening / closing operation of the grill shutter 100 in the present embodiment. The traveling conditions are the same as in the first embodiment.

  When the outside air temperature is 30 ° C. or lower and when it is higher than 35 ° C., the opening degree of the grill shutter 100 is the same as that of the first embodiment. However, when the outside air temperature is between 30 ° C. and 35 ° C., the higher the outside air temperature is, the smaller the opening degree of the grill shutter 100 is.

  The effects of the above opening / closing operation will be described.

  If the fuel efficiency improvement effect by the grill shutter 100 is FE1, and the fuel efficiency improvement effect by the Rankine cycle 31 when the outside air temperature is between 30 ° C. and 35 ° C. is FE2, the fuel efficiency improvement effect FEtotal as a whole is expressed by the equation (1). ).

    FEtotal = FE1 × k1 + FE2 × k2 (1)

  However, k1 is a coefficient which corrects the fuel consumption improvement effect by the grill shutter 100 according to the opening degree of the grill shutter 100. The fuel efficiency improvement effect FE1 by the grill shutter 100 is based on the premise that the grill shutter 100 is fully closed, and the effect decreases as the opening degree increases. Therefore, the coefficient k1 is used to calculate the fuel efficiency improvement effect according to the opening degree. Is used. k2 is a coefficient for correcting the fuel efficiency improvement effect of the Rankine cycle 31 according to the opening degree of the grill shutter 100. The fuel efficiency improvement effect FE2 by Rankine cycle 31 is based on the premise that the grille shutter 100 is fully open, and the effect decreases as the opening becomes smaller. Therefore, in order to calculate the fuel efficiency improvement effect according to the opening, the coefficient k2 is set. Use.

  That is, the expression (1) shows the fuel efficiency improvement effect that combines the fuel efficiency improvement effect by the Rankine cycle 31 and the fuel efficiency improvement effect by the grill shutter 100 at the opening degree (intermediate opening degree) where the grill shutter 100 is not fully opened or fully closed. Is to be calculated.

  When the opening degree of the grille shutter 100 is made smaller as the outside air temperature is higher in the outside air temperature range of 30 ° C. to 35 ° C., the fuel efficiency improvement effect FEtotal is calculated by the equation (1), as shown by the thick line in FIG. An upwardly convex characteristic is obtained with respect to the improvement effect FE1. That is, when the outside air temperature is between 30 ° C. and 35 ° C., driving with the grill shutter 100 fully closed or driving the Rankine cycle 31 has a greater fuel efficiency improvement effect than when executing alone. It is done.

Further, the upper limit of the outside air temperature at which the grill shutter 100 is fully opened may be set to 30 ° C. or less.
Specifically, the grill shutter 100 reaches a temperature at which the fuel efficiency improvement effect FEtotal obtained by the expression (1) is equal to the fuel efficiency improvement effect by the Rankine cycle 31 when the grill shutter 100 is fully opened (outside air temperature T0 ° C. in FIG. 16). Fully open. And the opening degree of the grille shutter 100 is made small, so that outside temperature is high in the range of T0 degreeC-35 degreeC.

  Accordingly, as shown by a thick line in FIG. 16, either running with the grill shutter 100 fully closed or driving the Rankine cycle 31 in the range of the outside air temperature T0 ° C. to 35 ° C. alone. Greater fuel efficiency can be achieved than is possible.

  As described above, according to this embodiment, in addition to the same effects as those of the first embodiment, the following effects can be obtained.

  (5) From the outside temperature at which the fuel consumption improvement cost by driving the Rankine cycle 31 with the grill shutter 100 fully opened and the fuel consumption improvement cost by driving with the grill shutter 100 fully closed are equal to each other. Until the outside air temperature at which the fuel efficiency improvement effect by driving the Rankine cycle 31 is fully opened, the opening degree of the grill shutter 100 becomes smaller as the outside air temperature becomes higher. That is, in the above example, when the outside air temperature is between 30 ° C. and 35 ° C., the opening degree of the grill shutter 100 becomes smaller as the outside air temperature becomes higher. As a result, when the outside air temperature is in the range of 30 ° C. to 35 ° C., driving with the grill shutter 100 fully closed or driving the Rankine cycle 31 has a greater fuel efficiency improvement effect than when performing alone. can get.

  (6) The fuel consumption improvement allowance which combines the fuel consumption improvement allowance by the Rankine cycle 31 when the grille shutter 100 is at the intermediate opening and the fuel consumption improvement allowance by the grille shutter 100 when the grille shutter 100 is at the intermediate opening is fully opened. In the state, the grill shutter 100 is fully opened at an outside temperature equal to or less than the fuel efficiency improvement by the Rankine cycle 31. From the outside temperature to the outside temperature at which the fuel efficiency improvement effect is eliminated when the Rankine cycle 31 is operated with the grill shutter 100 fully opened, the opening degree of the grill shutter 100 becomes smaller as the outside temperature increases. That is, in the above example, the grill shutter 100 is fully opened at the outside air temperature T0 ° C. or less where the fuel economy improving effect FEtotal calculated by the equation (1) and the fuel economy improving effect FE2 by the Rankine cycle 31 are equal, and the outside air temperature T0 to 35 ° C. In this range, the opening degree of the grill shutter 100 becomes smaller as the outside air temperature becomes higher. Thereby, when the outside air temperature is in the range of T0 ° C. to 35 ° C., the fuel efficiency improvement effect is greater than when either running with the grill shutter 100 fully closed or driving the Rankine cycle 31 alone. can get.

(Third embodiment)
The vehicle 1 to which this embodiment is applied has the same configuration as that of the first embodiment, and the opening / closing operation of the grill shutter 100 is basically the same. However, the difference is that when the change rate of the outside air temperature is equal to or higher than a predetermined value, the opening / closing operation of the grill shutter 100 is delayed. Hereinafter, this difference will be mainly described.

  The case where the change rate of the outside air temperature is equal to or higher than a predetermined value means a case where the outside air temperature changes suddenly. Although the predetermined value here can be set arbitrarily, it is set to, for example, about 1 to 2 ° C./second.

  As a case where the outside air temperature changes suddenly, for example, there are a case where the outside air temperature rapidly rises as in the case of entering a tunnel, and a case where the outside air temperature rapidly drops as in the case of exiting from a tunnel.

  First, let us consider a case where the outside air temperature rapidly rises to a temperature at which the grill shutter 100 is closed by entering a tunnel or the like while the grill shutter 100 is opened and the Rankine cycle 31 is being operated. For example, referring to the map of FIG. 13, when traveling in an environment with an outside air temperature of 20 ° C. at a cooling water temperature of 80 ° C., a tunnel with an air temperature of 30 ° C. is entered.

  In this case, for example, according to the map of FIG. 13, when entering the tunnel, the grill shutter 100 is closed. However, since the temperature of the refrigerant in Rankine cycle 31 does not increase immediately even if the outside air temperature rises rapidly, there is a delay from when the tunnel enters the tunnel until waste heat regeneration by Rankine cycle 31 becomes impossible. In other words, even after entering the tunnel, there is time to recover waste heat.

  Therefore, in this embodiment, when the outside air temperature rapidly increases, a delay time (between T31 and T32) is provided until the grill shutter 100 is closed as shown in FIG. The delay time is set so that the fuel efficiency is further improved by comparing the decrease in the waste heat regeneration capability accompanying the temperature rise of the refrigerant with the fuel efficiency improvement effect of the grill shutter 100. Accordingly, it is possible to avoid the situation that the grill shutter 100 is closed despite the fact that the fuel efficiency improvement effect due to waste heat regeneration is greater than the fuel efficiency improvement effect due to the grill shutter 100, and the fuel efficiency performance can be improved.

  Next, in contrast to the above, consider a case where the outside air temperature suddenly drops to a temperature at which the grill shutter 100 is opened, such as by exiting a tunnel, while traveling with the grill shutter 100 closed.

  In this case, according to the map of FIG. 13, the grill shutter 100 is opened after exiting the tunnel. However, since the temperature of the refrigerant in the Rankine cycle 31 does not immediately decrease even if the outside air temperature rapidly decreases, there is a delay until the Rankine cycle 31 can recover waste heat. In other words, waste heat regeneration is not possible immediately after exiting the tunnel.

  Therefore, in the present embodiment, when the outside air temperature rapidly decreases, a delay time (between T31 and T32) is provided until the grill shutter 100 is opened as shown in FIG. The delay time is set so that the fuel efficiency is further improved by comparing the increase in the waste heat regeneration capability accompanying the temperature decrease of the refrigerant with the fuel efficiency improvement effect of the grill shutter 100. Accordingly, it is possible to avoid a situation in which the grill shutter 100 is opened to reduce the aerodynamic performance and the fuel consumption performance is deteriorated even though the waste heat regeneration cannot be performed.

  According to this embodiment described above, the following effects can be obtained.

  (7) When the change rate of the outside air temperature exceeds a predetermined value, that is, when the outside air temperature changes suddenly, the grill shutter 100 adjusts the outside air introduction amount with a delay with respect to the change of the outside air temperature. Thereby, the fall of the fuel consumption performance resulting from the response delay of Rankine cycle 31 with respect to external temperature change can be avoided.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.

1 Vehicle 2 Internal Combustion Engine 30 Combined Cycle 31 Rankine Cycle 32 Refrigerant Pump 33 Pump Pulley 34 Belt 35 Expander Clutch (Clutch)
36 heat exchanger 37 expander 51 refrigeration cycle 52 compressor 54 compressor clutch 55 evaporator 71 engine controller 92 ejector 100 grill shutter 101 grill

Claims (7)

An internal combustion engine;
A waste heat regeneration device for regenerating waste heat of the internal combustion engine as power or electric power;
In a vehicle comprising:
A front heat exchanger disposed on the front side of the engine room provided at the front of the vehicle body and included in the waste heat regeneration device;
An outside air introduction port for introducing outside air from the frontmost part of the engine room to the front heat exchanger during traveling;
Adjusting means capable of adjusting the amount of outside air introduced from the outside air inlet by opening and closing the outside air inlet;
With
The vehicle characterized in that the adjusting means reduces the amount of outside air introduced when the outside air temperature is higher than a predetermined temperature compared to when the outside air temperature is equal to or lower than the predetermined temperature. The vehicle according to claim 1,
The predetermined temperature is an outside temperature at which a fuel consumption improvement allowance when performing waste heat regeneration with the adjustment means fully open and a fuel consumption improvement allowance when traveling with the adjustment means fully closed are equivalent. Yes,
The adjusting device is fully closed when the outside air temperature is higher than the predetermined temperature, and fully opened when the outside air temperature is equal to or lower than the predetermined temperature. The vehicle according to claim 1,
The predetermined temperature is an outside temperature at which a fuel consumption improvement allowance when performing waste heat regeneration with the adjustment means fully open and a fuel consumption improvement allowance when traveling with the adjustment means fully closed are equivalent. Yes,
From the predetermined temperature to the outside air temperature at which the fuel efficiency improvement effect is eliminated when waste heat regeneration is performed in a state where the adjusting device is fully opened, the opening degree of the adjusting device decreases as the outside air temperature increases. Vehicle. The vehicle according to claim 1,
The predetermined temperature is a combination of a fuel consumption improvement allowance when performing waste heat regeneration with the adjustment means at an intermediate opening and a fuel consumption improvement allowance when traveling with the adjustment means at an intermediate opening. The fuel consumption improvement allowance is an outside air temperature that is equal to the fuel consumption improvement allowance when performing waste heat regeneration with the adjustment means fully opened.
From the predetermined temperature to the outside air temperature at which the fuel efficiency improvement effect is eliminated when waste heat regeneration is performed in a state where the adjusting device is fully opened, the opening degree of the adjusting device decreases as the outside air temperature increases. Vehicle. The vehicle according to any one of claims 1 to 4,
Engine cooling request determining means for determining whether or not there is a cooling request for the internal combustion engine based on the coolant temperature of the internal combustion engine;
When there is an engine cooling request, the adjusting means adjusts the outside air introduction amount to be equal to the outside air introduction amount even when the outside air temperature is higher than the predetermined temperature. vehicle. The vehicle according to any one of claims 1 to 5,
The vehicle adjusts the outside air introduction amount with a delay with respect to a change in the outside air temperature when the outside air temperature rapidly changes at a changing speed equal to or higher than a predetermined speed. The vehicle according to any one of claims 1 to 6,
When the outside air temperature is low enough to regenerate the waste heat of the internal combustion engine, the adjusting means closes the outside air inlet.

Images