JP4941445B2 - Exhaust heat recovery device - Google Patents

Description

  The present invention makes it possible to promote the temperature rise of a catalyst provided in an exhaust passage of an internal combustion engine by utilizing the exhaust heat of the internal combustion engine and to promote the temperature rise of cooling water once taken out from the internal combustion engine. The present invention relates to a heat recovery apparatus.

  Conventionally, the heat of exhaust gas from an internal combustion engine mounted on a vehicle such as an automobile is recovered with a heat pipe to promote activation of the catalyst, promote warm-up operation of the internal combustion engine, and heat early. It is known that it is used for making it possible (see, for example, Patent Documents 1 and 2).

  In the conventional example according to Patent Document 1, one end of the heat pipe is attached to the downstream side of the catalyst device in the exhaust passage of the internal combustion engine as a heating unit (corresponding to a heat receiving unit), and the other end of the heat pipe is connected to the exhaust passage. In this configuration, a cooling unit (corresponding to a heat radiating unit) is attached upstream from the catalyst device, and the temperature of the catalyst device is indirectly raised by heating and heating the exhaust gas upstream from the catalyst device. ing.

  The heat pipe shown in this conventional example encloses a working fluid such as pure water in its internal space, heats one end side to evaporate the working fluid, sends it to the other end side, and operates with steam on the other end side The structure is such that the heat of the fluid is released to condense and return to the one end side.

  The conventional example according to Patent Document 2 includes an evaporation unit (corresponding to a heat receiving unit) that recovers exhaust heat of an exhaust passage of an internal combustion engine and evaporates the working fluid, and a condensing unit (heat dissipation unit) that condenses the evaporated working fluid. In the state of being arranged next to each other, and connecting them in a closed loop, and by connecting a part of the cooling water flow path of the internal combustion engine close to the condensing part, Heat is exchanged between the cooling water and the gaseous working fluid.

  In this conventional example, an exhaust heat recovery device having a configuration in which an evaporation unit and a condensation unit are integrated side by side is used, and the evaporation unit of the exhaust heat recovery device is arranged so as to cross the exhaust passage. ing.

  In addition, for example, Patent Document 3 is known as an exhaust heat recovery device in which a heat receiving unit and a condensing unit (corresponding to a heat radiating unit) of a loop heat pipe are spaced apart.

In the conventional example according to Patent Document 3, a heat receiving portion of a loop heat pipe is installed downstream of the catalyst in the exhaust passage of the internal combustion engine, and installed in the middle of the cooling water passage that draws out the cooling water of the internal combustion engine and returns it. The condensing part of the loop heat pipe is installed in the vicinity of the heater core of the hot air heater.
Japanese Utility Model Publication No. 63-22321 JP 2008-14304 A Japanese Utility Model Publication 2-76508

  The exhaust heat recovery device of the conventional example uses a heat circulation path for raising the temperature of a catalyst installed in an exhaust passage of an internal combustion engine using exhaust gas discharged from the internal combustion engine, and cooling water for the internal combustion engine. Only one of the heat circulation paths for raising the temperature is provided, and none of them has both.

  The inventor of the present application has been diligently researching to develop an exhaust heat recovery apparatus having two heat circulation paths with different heating targets as described above, but the use in the case where two heat circulation paths are provided. We thought that there was room for ingenuity about the form and came to propose the present invention.

  In view of such circumstances, the present invention provides an exhaust heat recovery device for an internal combustion engine, which uses exhaust heat from the internal combustion engine to increase the temperature of the catalyst provided in the exhaust passage of the internal combustion engine and to cool the internal combustion engine. Emission reduction at the time of cold start of an internal combustion engine, etc., by enabling the temperature increase promotion process of the water to be performed with priority over the temperature increase promotion process of the cooling water. It aims to make it possible.

An exhaust heat recovery apparatus according to the present invention recovers exhaust heat of an internal combustion engine and recovers exhaust heat of the internal combustion engine, a first heat circulation path for promoting temperature rise of a catalyst provided in an exhaust passage of the internal combustion engine. And a second heat circulation path for promoting the temperature rise of the cooling water once taken out from the internal combustion engine, and the first heat circulation path is formed by exhaust heat downstream of the catalyst in the exhaust passage of the internal combustion engine. A heat receiving part that vaporizes the working fluid enclosed therein, and a heat exchange between the working fluid transferred from the heat receiving part and the catalyst or an area near the inlet of the catalyst in the exhaust passage condenses the working fluid. A first heat dissipating part, a first transfer path for transferring the working fluid from the heat receiving part to the first heat dissipating part, and a first reflux path for returning the working fluid from the first heat dissipating part to the heat receiving part And the second thermal circulation path The heat receiving portion, a second heat radiating portion for condensing the working fluid by exchanging heat between the working fluid transferred from the heat receiving portion and the cooling water once taken out from the internal combustion engine, and the heat receiving portion from the heat receiving portion. A second transfer path for transferring the working fluid to the second heat dissipating part, and a second reflux path for returning the working fluid from the second heat dissipating part to the heat receiving part, and the heat receiving part, The working fluid is enclosed and the liquid level of the working fluid is lowered as the gas is vaporized, and the first transfer path is connected to the upper side in the vertical direction from the liquid level of the working fluid at a low temperature in the container of the heat receiving unit. The second transfer path is connected to a lower side in the vertical direction than the connection position of the first transfer path in the container of the heat receiving part, and the heat circulation in the first heat circulation path is the second heat circulation path. Configured to start before heat circulation in It is characterized in that.

  In this configuration, by providing a time lag from the start of heat circulation in the first heat circulation path to the start of heat circulation in the second heat circulation path, the heat of the catalyst is heated using the heat of the exhaust gas discharged from the internal combustion engine. While preferentially accelerating the engine, the temperature of the cooling water taken out from the internal combustion engine is raised using the heat of the exhaust gas to promote the warm-up operation of the internal combustion engine.

  Thus, for example, when the internal combustion engine is cold-started, the catalyst is warmed up preferentially, so that the catalyst can be activated as quickly as possible to reduce emissions. Is advantageous.

In particular, in the above-described configuration, the working fluid vaporized in the single heat receiving part is first transferred to the first heat radiating part through the first transfer path, and then appropriately delayed through the second transfer path. It is transferred to the second heat radiation part. That is, the vaporization of the working fluid enclosed in the container of the heat receiving unit proceeds and the internal pressure rises, so that the liquid level of the working fluid in the container of the heat receiving unit decreases, thereby opening the second transfer path. In other words, the working fluid functions as a valve for adjusting the opening of the second transfer path.

  Moreover, for the time lag, for example, a switch, a valve device and a controller are not used at all, and a single heat receiving part is commonly used as an exhaust heat recovery part of two heat circulation paths. It is possible to simplify the configuration of the exhaust heat recovery device and suppress the equipment cost.

  By the way, it is possible to start the heat circulation in the second heat circulation path when the temperature of the catalyst reaches the activation temperature. The temperature of the catalyst serving as a reference for starting thermal circulation can be set to a value obtained by adding an appropriate plus / minus margin to the activation temperature. Therefore, various conditions are set so that when the temperature of the catalyst reaches the activation temperature, the liquid level of the working fluid in the heat receiving portion is set to a position where the second transfer path is opened.

The exhaust heat recovery apparatus according to the present invention also includes a first thermal circulation path for recovering the exhaust heat of the internal combustion engine and promoting the temperature rise of the catalyst provided in the exhaust passage of the internal combustion engine, and the exhaust heat of the internal combustion engine. And a second thermal circulation path for accelerating the temperature rise of the cooling water once taken out from the internal combustion engine, and the first thermal circulation path is an exhaust downstream of the catalyst in the exhaust passage of the internal combustion engine. Heat exchange is performed between the first heat receiving portion that vaporizes the working fluid enclosed therein by heat, the working fluid transferred from the first heat receiving portion, and the catalyst or the exhaust passage area near the inlet of the catalyst. A first heat radiating portion for condensing the working fluid, a first transfer path for transferring the working fluid from the first heat receiving portion to the first heat radiating portion, and from the first heat radiating portion to the first heat receiving portion. Formed with a first return path for returning the working fluid The second heat circulation path includes a second heat receiving portion that vaporizes the working fluid enclosed inside by an exhaust heat downstream of the catalyst in the exhaust passage of the internal combustion engine, and a working fluid transferred from the second heat receiving portion. And a second heat radiating portion for condensing the working fluid by exchanging heat between the cooling water once taken out from the internal combustion engine and a second heat radiating portion for transferring the working fluid from the second heat receiving portion to the second heat radiating portion. 2 transfer paths and a second reflux path for returning the working fluid from the second heat radiating part to the second heat receiving part, and the first heat receiving part is more exhaust gas than the second heat receiving part. It is arranged on the upstream side in the discharge direction, and is characterized in that the heat circulation in the first heat circulation path is started before the heat circulation in the second heat circulation path. .

  Here, after specifying the configuration of the first and second heat circulation paths, the installation location of the first and second heat receiving parts is specified, so that the second heat circulation from the start of the heat circulation in the first heat circulation path. A time lag is provided before the start of heat circulation in the route.

  In this configuration, the heat of the exhaust gas flowing through the exhaust pipe is first recovered by the first heat receiving part, and then the heat of the exhaust gas that could not be recovered by the first heat receiving part is the second heat receiving part. Will be collected.

  As a result, the amount of heat received by the first heat receiving portion increases and the amount of heat received by the second heat receiving portion decreases, so that the working fluid in the first heat receiving portion is vaporized before the working fluid in the second heat receiving portion. As a result, the heat circulation in the first heat circulation path is started before the heat circulation in the second heat circulation path.

  Moreover, for the time lag, for example, no switch, valve device, controller, or the like is used, so that the configuration of the exhaust heat recovery device can be simplified and the equipment cost can be reduced.

  By the way, it is possible to start the heat circulation in the second heat circulation path when the temperature of the catalyst reaches the activation temperature. The temperature of the catalyst serving as a reference for starting thermal circulation can be set to a value obtained by adding an appropriate plus / minus margin to the activation temperature. Therefore, various conditions necessary for the vaporization are set so that the working fluid in the second heat receiving portion starts to vaporize when the temperature of the catalyst reaches the activation temperature.

Furthermore, the exhaust heat recovery apparatus according to the present invention includes a first thermal circulation path for recovering exhaust heat of the internal combustion engine and promoting temperature rise of the catalyst provided in the exhaust passage of the internal combustion engine, and exhaust heat of the internal combustion engine. And a second thermal circulation path for accelerating the temperature rise of the cooling water once taken out from the internal combustion engine, and the first thermal circulation path is an exhaust downstream of the catalyst in the exhaust passage of the internal combustion engine. Heat exchange is performed between the first heat receiving portion that vaporizes the working fluid enclosed therein by heat, the working fluid transferred from the first heat receiving portion, and the catalyst or the exhaust passage area near the inlet of the catalyst. A first heat radiating portion for condensing the working fluid, a first transfer path for transferring the working fluid from the first heat receiving portion to the first heat radiating portion, and from the first heat radiating portion to the first heat receiving portion. Formed with first return path to return working fluid The second heat circulation path includes a second heat receiving portion that vaporizes a working fluid enclosed in the exhaust passage downstream of the catalyst in the exhaust passage of the internal combustion engine, and an operation that is transferred from the second heat receiving portion. A second heat radiating portion for condensing the working fluid by exchanging heat between the fluid and the cooling water once taken out from the internal combustion engine; and for transferring the working fluid from the second heat receiving portion to the second heat radiating portion. A large-diameter portion is formed in the second transfer path and a second reflux path for returning the working fluid from the second heat radiating section to the second heat receiving section, and in a region downstream of the catalyst in the exhaust passage. A small diameter pipe is inserted into the large diameter portion, a flow rate control valve is provided at the inlet of the small diameter pipe, and the first heat receiving portion crosses the exhaust gas inside the small diameter pipe. And the second heat receiving portion is configured with the large diameter portion. The annular space is provided so that the exhaust gases traverse between the diameter tube, configured as heat circulation in the first heat circulation path is started before the heat circulation in the second heat circulation path It is characterized by being .

  Here, the configuration of the first and second heat circulation paths is specified. And, by controlling the inflow timing of the exhaust gas to the first and second heat receiving parts by opening and closing the flow control valve, from the start of thermal circulation in the first thermal circulation path to the start of thermal circulation in the second thermal circulation path A time lag is provided.

  In this configuration, when the flow control valve is opened, the exhaust gas that has passed through the catalyst in the exhaust passage flows into the small-diameter pipe, whereby the heat of the exhaust gas is recovered by the first heat receiving portion. On the other hand, when the flow control valve is closed, the exhaust gas flows into the annular space between the large diameter portion and the small diameter tube, whereby the heat of the exhaust gas is recovered by the second heat receiving portion.

  That is, for example, at the time of cold start of the internal combustion engine, the heat of the exhaust gas discharged from the internal combustion engine is recovered by the first heat receiving portion, and then after a predetermined time delay, the exhaust gas is separated from the large diameter portion. The heat of the exhaust gas can be recovered by the second heat receiving part so as to flow into the annular space between the small diameter pipe.

  In this way, the first heat receiving part recovers the exhaust heat at the second heat receiving part with a predetermined time delay after the exhaust heat is recovered, so that the working fluid in the first heat receiving part is in the second heat receiving part. As a result, the heat circulation in the first heat circulation path is started before the heat circulation in the second heat circulation path.

  By the way, the timing for starting the heat circulation in the second heat circulation path, that is, the timing for closing the flow rate control valve is to control the flow rate control valve by, for example, a controller when the temperature of the catalyst reaches the activation temperature. It is possible to The temperature of the catalyst serving as a reference for starting thermal circulation can be set to a value obtained by adding an appropriate plus / minus margin to the activation temperature.

Preferably , the thermal circulation start timing in the second thermal circulation path is when the temperature of the catalyst reaches the activation temperature. The temperature of the catalyst serving as a reference value for starting the heat circulation includes a case where an appropriate plus / minus margin is added to the activation temperature. Such specification facilitates reduction of emissions during the warm-up operation of the internal combustion engine. Preferably , non-condensable gas is enclosed in the second heat circulation path .

  In this configuration, since the non-condensable gas does not evaporate, the non-condensed gas is transferred to the second heat radiating portion by the working fluid vaporized in the second heat receiving portion after the internal combustion engine is started.

  Here, in a situation where the amount of heat received by the second heat receiving part is small and the steam pressure is low, the non-condensable gas in the second heat radiating part is difficult to be compressed, so the proportion of the non-condensed gas in the second heat radiating part is large. The heat radiation area of the working fluid in the gas phase is small. For this reason, the amount of the working fluid in the gas phase that is exchanged in heat and condensed in the second heat radiating portion is reduced, so that the cooling water heating ability of the internal combustion engine by the second heat radiating portion is lowered.

  On the other hand, as the amount of heat received by the second heat receiving portion increases with the passage of time and the vapor pressure increases, the non-condensable gas in the second heat radiating portion is compressed. The proportion of gas compression is reduced. Therefore, the amount of the working fluid in the gas phase that is exchanged in the second heat radiating portion is increased by heat exchange, and the cooling water heating capability of the internal combustion engine by the second heat radiating portion is increased.

  As described above, when the heating capacity of the second heat radiating portion is gradually increased with the passage of time by using the non-condensable gas, the second heat circulation is started from the start of the heat circulation in the first heat circulation path. It is possible to set the time lag until the start of heat circulation in the route as long as possible.

  The gradual increase rate of the cooling water heating capacity by the second heat radiating unit can be arbitrarily adjusted according to the amount of the non-condensed gas enclosed, and for this reason, the cooling water warm-up start timing of the internal combustion engine, The time required from the start to the end of warm-up can be adjusted as necessary.

  Preferably, at least one of the first transfer path and the first return path and the second transfer path and the second return path is a heat pipe in which a wick having a capillary structure is provided on the inner peripheral surface of the cylindrical member. The

  With this configuration, the piping structure that connects the heat receiving portion and the heat radiating portion in communication is simplified, and the degree of freedom of installation is increased.

  Preferably, vibration transmission attenuation means is provided at a position near the internal combustion engine in the exhaust passage, and the second heat radiating portion is attached to a region between the vibration transmission attenuation means and the catalyst.

  Here, in short, vibration transmission from the internal combustion engine to the exhaust passage is attenuated by the vibration transmission attenuation means, and the heat receiving portion (first and second) is disposed in the exhaust passage in the region downstream of the vibration transmission attenuation means. The heat receiving portion) and the first and second heat radiating portions are installed.

  In other words, when the downstream region of the exhaust passage vibrates in the exhaust passage, the heat receiving portion and the first and second heat radiating portions all move substantially synchronously. This means that the bending stress due to the vibration hardly acts on the roots of the second transfer path and the first and second reflux paths.

  For this reason, the first and second transfer paths and the first and second reflux paths are less likely to cause fatigue damage over time, so that it is possible to achieve a long life. Here, in the case where the bending stress is applied, the plate thickness and outer diameter size of the first and second transfer paths and the first and second reflux paths are increased to increase the rigidity, or Although measures such as forming the first and second transfer paths and the first and second reflux paths with flexible pipes are necessary, in the case of the present invention, such measures are unnecessary.

  In the exhaust heat recovery apparatus of the present invention, the exhaust heat of the internal combustion engine can be used to perform the temperature increase promotion process for the catalyst provided in the exhaust passage of the internal combustion engine and the temperature increase promotion process for the cooling water of the internal combustion engine. In addition, the catalyst temperature increase promotion process can be performed preferentially over the cooling water temperature increase promotion process. As a result, it is possible to reduce as much as possible the emission during cold start of the internal combustion engine.

The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.
(First embodiment)
1 to 4 show a first embodiment of the present invention. In this embodiment, an exhaust heat recovery device applied to an internal combustion engine mounted on a vehicle is taken as an example.

  A schematic configuration of the exhaust heat recovery apparatus will be described with reference to FIG. In the figure, reference numeral 1 denotes a water-cooled internal combustion engine. The internal combustion engine 1 uses an air-fuel mixture obtained by mixing air supplied from an intake system and fuel supplied from a fuel supply system at an appropriate air-fuel ratio. After being supplied to the combustion chamber of the engine 1 and burning, the exhaust gas in the combustion chamber is released from the exhaust system to the atmosphere.

  The exhaust system has at least an exhaust manifold 2 attached to the internal combustion engine 1 and an exhaust pipe 4 connected to the exhaust manifold 2 via a spherical joint 3. The exhaust manifold 2 and the exhaust pipe 4 constitute an exhaust passage.

  As shown in FIG. 2, the spherical joint 3 includes a radially outward flat flange 3 a provided at the downstream opening end of the exhaust manifold 2 and a hemispherical flange 3 b provided at the upstream opening end of the exhaust pipe 4. A gasket 3c sandwiched between the flat flange 3a and the hemispherical flange 3b, a bolt 3d and a nut 3e for fastening the flat flange 3a and the hemispherical flange 3b, and a bolt 3d and the flat flange 3a. A coil spring 3f interposed in a compressed state is included.

  The gasket 3c has a flat surface on the side that contacts the flat flange 3a, and a hemispherical surface that conforms to the side that contacts the inner surface of the hemispherical flange 3b. The gasket 3c seals the contact surface with the flat flange 3a and the contact surface with the hemispherical flange 3b by the elastic restoring force of the coil spring 3f. When an external force is applied that causes the exhaust manifold 2 and the exhaust pipe 4 to swing around the swing center 3g, the swing is forced by sliding between the gasket 3c and the hemispherical flange 3b. It has come to allow. In other words, the spherical joint 3 transmits vibrations and movements of the internal combustion engine 1 to the exhaust pipe 4 without being transmitted or attenuates them, and functions as vibration transmission attenuation means.

  Two catalysts 5 and 6 are installed in the exhaust pipe 4 in series, and the exhaust gas is purified by the two catalysts 5 and 6.

  Among these catalysts 5, 6, the catalyst 5 installed upstream in the exhaust gas flow direction in the exhaust pipe 4 is called a so-called start catalyst (S / C), and is called an upstream catalyst. On the other hand, the catalyst 6 installed on the downstream side in the exhaust gas flow direction in the exhaust pipe 4 is a so-called main catalyst (M / C) or underfloor catalyst (U / F). I will say.

  Both of these catalysts 5 and 6 can be called, for example, a three-way catalyst. This three-way catalyst exhibits a purifying action in which carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx) are collectively changed to harmless components by a chemical reaction.

  In this embodiment, the upstream catalyst 5 is formed in a tapered shape whose outer case (reference number omitted) is cylindrical and whose outer diameters at one end side and the other end side gradually decrease toward the end edge. Although not shown, a catalyst carrier is accommodated in the cylindrical part of the outer case.

  In the internal combustion engine 1, a refrigerant called a long life coolant (LLC) (hereinafter simply referred to as “cooling water”) enclosed in the internal combustion engine 1 is once taken out from the cooling water take-out passage 8 and supplied to the radiator 7. To the internal combustion engine 1 through the cooling water recirculation passage 9. The radiator 7 cools the cooling water circulated by the water pump 10 by heat exchange with the outside air.

  The amount of cooling water flowing through the radiator 7 and the amount of cooling water flowing through the bypass passage 12 are adjusted by the thermostat 11. For example, at the time of warming up, the amount of cooling water on the bypass flow path 12 side is increased, warming up is promoted, and overcooling of the cooling water by the radiator 7 is prevented.

  A heater core 14 is provided in the middle of the heater flow path 13 branched from the cooling water take-out path 8 and connected to the upstream side of the water pump 10 in the cooling water recirculation path 9. The heater core 14 is a heat source for heating the passenger compartment using the cooling water. The air heated by the heater core 14 is introduced into the vehicle compartment 17 by the blower fan 15. The heater core 14 and the blower fan 15 constitute a warm air heater 16. In the heater flow path 13, the temperature of the cooling water flowing in the downstream area from the heater core 14 becomes low due to heat radiation from the heater core 14.

  An exhaust heat recovery device 18 is attached to the exhaust system of the internal combustion engine 1 having such a configuration.

  The exhaust heat recovery device 18 takes in the heat of the exhaust gas discharged from the internal combustion engine 1 and promotes, for example, the temperature rise of the upstream catalyst 5, or takes in the heat of the upstream catalyst 5 and takes in the internal combustion engine from the heater core 14. It is possible to perform a process for promoting the temperature rise of the cooling water to be returned to 1. Mainly, the single heat receiving portion 21, the first heat radiating portion 22, the second heat radiating portion 23, the first transfer path 24, the first The first reflux path 25, the second transfer path 26, and the second reflux path 27 are included.

  The heat receiving part 21, the first heat radiating part 22, the first transfer path 24, and the first reflux path 25 form a first heat circulation path 40 (see solid line arrows in FIGS. 1 and 3), and the heat receiving part 21, the second heat radiating portion 23, the second transfer path 26, and the second reflux path 27 form a second heat circulation path 50 (see the dashed line arrows in FIGS. 1 and 3).

  Thus, the single heat receiving part 21 is commonly used for the two heat circulation paths 40 and 50.

  Although these main components will be described in detail later, the working fluid is sealed in a vacuum state. This working fluid is, for example, pure water. The boiling point of water is 100 ° C. at 1 atm, but the boiling point is 5 to 10 ° C., for example, because the main components are depressurized (eg, 0.01 atm). The working fluid can be, for example, alcohol, fluorocarbon, chlorofluorocarbon or the like in addition to pure water. Moreover, these main components are formed, for example with the stainless steel provided with high corrosion resistance.

  Next, main components will be described in detail with reference to FIG.

  The heat receiving portion 21 is installed downstream of the downstream catalyst 6 in the exhaust pipe 4 and is configured to take in heat as vaporization heat when the liquid working fluid sealed inside receives the exhaust heat and evaporates. Has been.

  Specifically, the heat receiving portion 21 is installed in a direction orthogonal to the exhaust gas passage direction with respect to the exhaust pipe 4, and has a plurality of vertically long through windows 21b in the rectangular tank 21a. Are provided, and fins 21c... Are joined and disposed in the through window 21b.

  The through windows 21b... Serve as exhaust gas flow passages that circulate in the exhaust pipe 4. The fins 21c arranged in the facing gap are of a corrugated type so as to expand the heat exchange area with the exhaust gas passing through the facing gap. The corrugated fin 21c is formed, for example, by forming a thin strip plate into a corrugated shape by roller processing. In short, the heat of the exhaust gas is absorbed by the fins 21c so that the working fluid in the tank 21a is heated and vaporized.

  The first heat radiating section 22 is attached to the outer diameter side of the upstream catalyst 5, and is condensed with the working fluid made of steam transferred from the heat receiving section 21 by heating the upstream catalyst 5. It is configured as follows.

  Specifically, the first heat radiating portion 22 surrounds the upstream catalyst 5 and forms a single internal annular space on the outer diameter side of the exhaust gas introducing portion 5d of the upstream catalyst 5. It can be set as the structure containing fin 22b ... provided.

  The case 22a has a shape in which the inner diameter side of the hollow sleeve is opened. The fins 22b are joined to the outer diameter side of the outer case 5b of the upstream catalyst 5 so as to protrude outward in the radial direction.

  In this embodiment, the fin 22b is a corrugated type so as to expand the heat exchange area with the working fluid made of steam passing through the internal space of the case 22a. The corrugated fins 22b are formed by, for example, forming a thin strip plate into a waveform in the circumferential direction by roller processing.

  The second heat radiating portion 23 is provided near the spherical joint 3 between the upstream catalyst 5 and the spherical joint 3, and is a working fluid composed of steam transferred from the first heat radiating portion 22, and is connected from the heater core 14 to the internal combustion engine. The working fluid is condensed by heating the cooling water returned to the engine 1.

  Specifically, the second heat dissipating part 23 is configured such that the downstream end of the second transfer path 26 and the upstream end of the second return path 27 are connected to a case 23 a whose inside is sealed. A region downstream of the heater core 14 in the heater flow path 13 is inserted into the internal space of the case 23a.

  The region inserted into the case 23a in the heater flow path 13 is provided with fins 13a on the outer periphery thereof, and the heat exchange area is expanded. In short, when the working fluid vaporized in the heat receiving part 21 is transferred to the second heat radiating part 23 via the second transfer path 26, the heat of the working fluid is absorbed by the fins 13a. The absorbed heat heats the cooling water flowing through the heater flow path 13.

  The first transfer path 24 is a pipe for transferring the working fluid vaporized in the heat receiving part 21 to the first heat radiating part 22.

  The first reflux path 25 is a pipe for returning the working fluid condensed in the first heat radiating unit 22 to the heat receiving unit 21.

  The second transfer path 26 is a pipe for transferring the working fluid vaporized in the heat receiving part 21 to the second heat radiating part 23.

  The second reflux path 27 is a pipe for returning the working fluid condensed in the second heat radiating unit 23 to the heat receiving unit 21.

  In addition, the 1st transfer path 24 is arrange | positioned through appropriate clearance so that the vicinity of the exhaust passage (the exhaust pipe 4, the upstream catalyst 5, and the downstream catalyst 6) may be followed.

  Specifically, the separation distance between the first transfer path 24 and the exhaust path (the exhaust pipe 4, the upstream catalyst 5 and the downstream catalyst 6) is the working fluid composed of steam transferred in the first transfer path 24. It can be a dimension required to maintain a temperature at which no condensation occurs. The dimensions are preferably determined experimentally and empirically according to the overall length of the first transfer path 24, the material, the wall thickness, the facing area, and the like.

  In order to realize such an arrangement of the first transfer path 24, a plurality of locations (two locations in this embodiment) in the middle of the first transfer path 24 are connected to the outer wall or the like of the downstream catalyst 6 via the bracket 29. To support. The bracket 29 is preferably made of a material having high thermal conductivity (for example, stainless steel).

  In contrast to the first transfer path 24 described above, the first return path 25 has an exhaust path (exhaust pipe 4, upstream side) so that the liquid working fluid flowing through the first return path 25 is not vaporized again. The catalyst 5 and the downstream catalyst 6) and the first transfer path 24 are arranged as far away as possible. Moreover, the first recirculation path 25 is provided with an appropriate downward gradient so that the working fluid that has been condensed and turned into a liquid state can be easily recirculated to the heat receiving portion 21.

  Specifically, the separation distance between the first reflux path 25 and the exhaust passage (the exhaust pipe 4, the upstream catalyst 5 and the downstream catalyst 6) is a liquid state flowing through the first reflux path 25 by radiant heat from the exhaust passage side. The dimensions can be as required to keep the working fluid from re-evaporating. The dimensions are preferably determined experimentally and empirically according to the overall length of the first reflux path 25, the material, the wall thickness, the facing area, and the like. Further, the downward gradient can be set to about 6 degrees, for example, but is arbitrary.

  However, similarly to the first transfer path 24, the second transfer path 26 can be arranged so as to be close to the exhaust pipe 4, but in this embodiment, the second heat dissipation part 23 is replaced with the first heat dissipation part. Therefore, it is not disposed so as to be particularly close to the exhaust pipe 4 because of the relationship of being disposed at a position close to 22.

  Further, like the first reflux path 25, the second reflux path 27 is disposed at a position as far away from the exhaust pipe 4 as possible. In addition, the second recirculation path 27 is provided with an appropriate downward gradient (for example, about 6 degrees) in order to facilitate the recirculation of the condensed working fluid into the heat receiving part 21.

  In this embodiment, first, heat circulation in the first heat circulation path 40 is preferentially started, and then the heat circulation in the second heat circulation path 50 is started after a predetermined time has elapsed. Yes. Specifically, first, the upstream catalyst 5 is warmed up by performing heat circulation in the first heat circulation path 40, and after the upstream catalyst 5 has been warmed up, the second heat circulation path. By performing the heat circulation at 50, the temperature of the cooling water taken out from the internal combustion engine 1 is raised to end the warm-up operation of the internal combustion engine 1, and early heating by the warm air heater 16 is enabled. .

  In order to shift the start timing of the heat circulation in the two heat circulation paths 40 and 50 in this way, the connection positions of the first transfer path 24 and the second transfer path 26 with respect to the heat receiving part 21 are set as follows. Yes.

  Specifically, the first transfer path 24 is connected to the ceiling of the tank 21 a of the heat receiving unit 21, and the second transfer path 26 is connected to the middle of the tank 21 a of the heat receiving unit 21 in the vertical direction. The first reflux path 25 and the second reflux path 27 are both connected to the bottom of the tank 21a of the heat receiving portion 21.

  Here, the operation of the exhaust heat recovery device 18 described above will be described.

  For example, when the internal combustion engine 1 is cold-started, all of the upstream catalyst 5, the downstream catalyst 6, and the cooling water of the internal combustion engine 1 are at a low temperature, but from the internal combustion engine 1 to the exhaust pipe 4 through the exhaust manifold 2. For example, exhaust gas of 300 to 400 ° C. is exhausted, and the two catalysts 5 and 6 are heated from the inside by the exhaust gas, while the cooling water does not pass through the radiator 7 and bypass channel 12. The engine is warmed up by being returned to the internal combustion engine 1 through the above.

  In the cold start of the internal combustion engine, in the initial stage, the working fluid in the heat receiving portion 21 is heated by the exhaust gas, but the amount of vaporization (evaporation) of the working fluid in the heat receiving portion 21 is small. The surface remains high.

  Here, for example, as shown in FIG. 3, the connection port with the heat receiving unit 21 is exposed from the liquid surface of the working fluid in the first transfer path 24, and the connection with the heat receiving unit 21 is performed in the second transfer path 26. If the mouth is immersed in the working fluid and blocked, the working fluid vaporized in the heat receiving portion 21 is transferred to the first heat radiating portion 22 only through the first transfer path 24.

  Thereby, in the 1st thermal radiation part 22, heat exchange will be performed between the working fluid of a gaseous state, and the upstream catalyst 5, and the upstream catalyst 5 will be heated from the outside.

  In short, in this state, the upstream catalyst 5 is heated from the inside by the exhaust gas, and at the same time, the heat of the exhaust gas that has passed through the downstream catalyst 6 is recovered and the upstream catalyst 5 is heated from the outside. Therefore, the temperature increase of the upstream catalyst 5 is promoted and activated as soon as possible. As the temperature of the upstream catalyst 5 increases, the temperature of the downstream catalyst 6 on the downstream side also increases due to the purification action of the exhaust gas.

  As a result of such heat exchange, the working fluid is condensed in the first heat radiating section 22, and this condensed working fluid is returned from the first heat radiating section 22 to the heat receiving section 21 through the first reflux path 25. It is.

  By the way, when the connection port with the heat receiving part 21 is immersed in the working fluid and blocked in the second transfer path 26 as in the initial stage, the heat receiving part 21 is vaporized to the second heat radiating part 23. Since the working fluid is not transferred, the cooling water of the internal combustion engine 1 is not heated.

  Therefore, the heat circulation in the first heat circulation path 40 (refer to the solid line arrows in FIGS. 1 and 3) such as the heat receiving part 21 → the first transfer path 24 → the first heat radiation part 22 → the first reflux path 25 → the heat receiving part 21 is performed. Again, in the second heat circulation path 50 (refer to the one-dot chain line arrows in FIGS. 1 and 3) such as the heat receiving part 21 → the second transfer path 26 → the second heat radiating part 23 → the second reflux path 27 → the heat receiving part 21. There is no thermal circulation.

  Then, by continuing the heating of the upstream catalyst 5 as described above, the temperature of the upstream catalyst 5 rises to the activation temperature (for example, 300 to 400 ° C.), and the exhaust on the downstream side of the downstream catalyst 6. When the temperature of the gas rises, the amount of vaporization (evaporation) of the working fluid in the heat receiving unit 21 increases, and the liquid level of the working fluid in the heat receiving unit 21 decreases.

  As the working fluid level decreases, for example, as shown in FIG. 4, when the connection port with the heat receiving unit 21 is exposed upward from the working fluid level in the heat receiving unit 21 in the second transfer path 26, the heat receiving unit 21 receives heat. The working fluid vaporized in the part 21 is transferred to the second heat radiating part 23 through the second transfer path 26.

  As a result, heat exchange is performed between the working fluid in the gas phase state and the cooling water flowing through the heater flow path 13 in the second heat radiating portion 23, so that the cooling water taken out from the internal combustion engine is the first. 2 Heated by the heat dissipating unit 23 and returned to the internal combustion engine, the warm-up operation of the internal combustion engine is promoted, and the warm air heater 16 can be used at an early stage.

  As a result of such heat exchange, the working fluid is condensed in the second heat radiating section 23, and this condensed working fluid is returned from the second heat radiating section 23 to the heat receiving section 21 through the second reflux path 27. It is.

  That is, the heat circulation in the second heat circulation path 50 (refer to the one-dot chain line arrows in FIGS. 1 and 3) such as the heat receiving part 21 → the second transfer path 26 → the second heat radiation part 23 → the second reflux path 27 → the heat receiving part 21. Will be repeated.

  By the way, since the connection port with the heat receiving part 21 remains exposed on the liquid level of the working fluid in the heat receiving part 21 in the first transfer path 24, the heat circulation by the first heat circulation path 40 is continued. .

  Here, if the upstream catalyst 5 exceeds its activation temperature and the temperature of the upstream catalyst 5 becomes higher than the temperature of the exhaust gas reaching the installation location of the heat receiving portion 21, the upstream side The gas-phase working fluid transferred into the first heat radiating section 22 is heated by the heat generated from the catalyst 5 and the internal pressure rises. Therefore, the gas-phase working fluid is transferred to the first reflux path 25. After that, it is returned to the heat receiving part 21.

  In such a case, the heat generated from the upstream catalyst 5 is consumed for maintaining the working fluid in a gas phase, and the working fluid in the gas phase is transferred from the first heat radiating unit 22 to the heat receiving unit 21. It is transferred to the second heat radiation part 23 via Therefore, the upstream catalyst 5 does not need to be heated excessively, and it is possible to avoid a deterioration in the function of the upstream catalyst 5.

  As described above, in the first embodiment to which the present invention is applied, the working fluid vaporized in the single heat receiving part 21 is first transferred to the first heat radiating part 22, thereby enabling the first heat circulation path. After the thermal circulation at 40 is started, the thermal circulation in the second thermal circulation path 50 is started by allowing the transfer to the second heat radiating portion 23 with an appropriate delay.

  As a result, it is possible to prioritize and efficiently perform the warm-up of the upstream catalyst 5 and the downstream catalyst 6 attached to the internal combustion engine 1 and the warm-up of the cooling water of the internal combustion engine 1. This is advantageous in reducing emissions during cold start of the internal combustion engine 1.

In addition, for the time lag, for example, no switch, valve device, controller or the like is used, and the single heat receiving portion 21 is commonly used as the exhaust heat recovery portion of the two heat circulation paths 40 and 50. In addition, the configuration of the exhaust heat recovery device 18 can be simplified and the facility cost can be suppressed.
(Second Embodiment)
5 to 7 show a second embodiment of the present invention. The difference between the second embodiment and the first embodiment is that the dedicated heat receiving portions 21A and 21B are used for the two heat circulation paths 40 and 50, respectively, while the heat circulation in the first heat circulation path 40 is the first. This is to start before the heat circulation in the two heat circulation path 50.

  Specifically, in this embodiment, a first heat receiving portion 21A dedicated to the first heat circulation path 40 is provided on the upstream side in the downstream region of the upstream catalyst 5, and the second heat is provided on the downstream side of the first heat receiving portion 21A. A second heat receiving portion 21B dedicated to the circulation path 50 is provided.

  The first heat receiving part 21A and the second heat receiving part 21B are substantially the same as the configuration exemplified in the first embodiment, as shown in FIGS.

  In addition to this, the vaporization start temperature of the working fluid in the first heat receiving portion 21A can be set to the second by adjusting the kind and amount of the working fluid sealed in the two heat circulation paths 40 and 50 individually. The temperature is set lower than the vaporization start temperature of the working fluid in the heat receiving portion 21B.

  In such a configuration, after the exhaust heat is preferentially recovered by the first heat receiving part 21A installed upstream in the exhaust gas discharge direction, the exhaust gas that could not be recovered by the first heat receiving part 21A. The heat is recovered by the second heat receiving portion 21B installed on the downstream side in the exhaust gas discharge direction. As a result, the amount of heat received by the first heat receiving portion 21A increases, and the amount of heat received by the second heat receiving portion 21B decreases.

  And since the vaporization start temperature of the working fluid in the 1st heat receiving part 21A is set lower than the vaporization start temperature of the working fluid in the 2nd heat receiving part 21B, it operates in the 1st heat receiving part 21A. The fluid is vaporized (evaporated) before the working fluid in the second heat receiving portion 21B.

  For these reasons, the working fluid in the first heat receiving portion 21A is vaporized (evaporated) before the working fluid in the second heat receiving portion 21B. However, the working fluid is vaporized in the second heat receiving portion 21B ( It takes time to evaporate).

  As a result, the heat circulation in the first heat circulation path 40 is started before the heat circulation in the second heat circulation path 50. That is, as the operation of the internal combustion engine 1 starts, the upstream catalyst 5 is first warmed up. After the upstream catalyst 5 is warmed up, the cooling water of the internal combustion engine 1 is warmed up. In addition, a time lag can be provided.

  As described above, in the second embodiment to which the present invention is applied, the heat in the second heat circulation path 50 is started after the heat circulation in the first heat circulation path 40 is started, as in the first embodiment. By providing a time lag before the circulation is started, the heat of the exhaust gas discharged from the internal combustion engine 1 is used to preferentially promote the warm-up of the upstream catalyst 5, and the heat of the exhaust gas is used. Thus, the temperature of the cooling water taken out from the internal combustion engine 1 is raised to promote the warm-up operation of the internal combustion engine 1.

  In this way, it is possible to efficiently carry out the prioritization with respect to the warming up of the upstream catalyst 5 and the downstream catalyst 6 attached to the internal combustion engine 1 and the warming up of the cooling water of the internal combustion engine 1, This is advantageous in reducing emissions during cold start of the internal combustion engine 1.

Moreover, for the time lag, for example, no switch, valve device, controller, or the like is used, so that the configuration of the exhaust heat recovery device 18 can be simplified and the equipment cost can be reduced.
(Third embodiment)
8 and 9 show a third embodiment of the present invention. The third embodiment is different from the first embodiment in that the dedicated heat receiving portions 21A and 21B are used for the two heat circulation paths, and the second heat circulation is performed in the first heat circulation path 40. This is to start before the heat circulation in the path 50.

  In this embodiment, as shown in FIG. 8, the downstream region of the downstream catalyst 6 in the exhaust pipe 4 is a large diameter portion 4a, and a small diameter tube 4b is inserted into the large diameter portion 4a. In this way, the exhaust pipe 4 has a so-called double pipe structure, and in order to selectively distribute the exhaust gas to either the large diameter portion 4a or the small diameter pipe 4b, An electromagnetic flow control valve 31 is provided. The opening degree of the flow control valve 31 is controlled by the controller 32.

  The small diameter pipe 4b is provided with a first heat receiving part 21A dedicated to the first heat circulation path 40, and the large diameter part 4a is provided with a second heat receiving part 21B dedicated to the second heat circulation path 50. . Thus, the second heat receiving portion 21B is installed on the outer diameter side of the first heat receiving portion 21A so as to surround it.

  As shown in FIG. 9, the first heat receiving part 21A and the second heat receiving part 21B have the same configuration as that shown in the first embodiment in principle.

  First, the first heat receiving part 21A is installed in a direction perpendicular to the exhaust gas passage direction with respect to the small diameter pipe 4b of the exhaust pipe 4, and has a plurality of vertically long through windows in the rectangular tank 21a. 21b... Are provided and fins 21c... Are joined and disposed in the through window 21b. A working fluid is sealed in the tank 21a.

  On the other hand, the second heat receiving portion 21B is provided with a plurality of vertically long through windows 21e in a tank 21d having an outer shape like a square ring, and fins 21f are joined and arranged in the through windows 21b. It has a configuration like this. A working fluid is sealed in the tank 21d.

  The first heat receiving part 21A is fitted and mounted in the central hole of the second heat receiving part 21B. The through windows 21b and 21e serve as exhaust gas flow passages that circulate in the large diameter portion 4a and the small diameter tube 4b of the exhaust pipe 4. The fins 21c and 21f are of a corrugated type so as to expand the heat exchange area with the exhaust gas passing through the through windows 21b and 21e.

  The first transfer path 24 is connected near the ceiling of the tank 21a of the first heat receiving part 21A, and the first reflux path 25 is connected near the bottom of the tank 21a of the first heat receiving part 21A. The second transfer path 26 is connected near the ceiling of the tank 21d of the second heat receiving part 21B, and the second reflux path 27 is connected near the bottom of the tank 21d of the second heat receiving part 21B.

  In addition, since the small diameter tube 4b is interposed between the first heat receiving portion 21A and the second heat receiving portion 21B, a material that can serve as a heat capacity member for appropriately delaying heat conduction in the small diameter tube 4b, for example, It can be formed of stainless steel or the like. Further, although not shown, a heat capacity member for appropriately delaying heat conduction may be separately provided on the outer diameter side or the inner diameter side of the small diameter tube 4b. The delay time due to the heat capacity member can be arbitrarily adjusted depending on the material, thickness, and the like. For this reason, the time lag can be adjusted as necessary.

  The operation in such a configuration will be described.

  First, in the cold start of the internal combustion engine, in the initial stage, the controller 32 controls to open the flow control valve 31. As a result, most of the exhaust gas that has passed through the downstream side catalyst 6 in the exhaust pipe 4 flows into the small diameter pipe 4b, so that the working fluid in the first heat receiving portion 21A is heated by the exhaust gas. become.

  With the passage of time in this state, the working fluid in the first heat receiving portion 21A is vaporized (evaporated), and this vaporized working fluid is transferred to the first heat radiating portion 22 via the first transfer path 24. Thus, the upstream catalyst 5 is heated from the outer diameter side, and the temperature rise of the upstream catalyst 5 is promoted.

  Here, when the temperature of the upstream catalyst 5 rises to the activation temperature, the controller 32 detects this and controls the flow control valve 31 to be closed.

  As a result, most of the exhaust gas that has passed through the downstream side catalyst 6 in the exhaust pipe 4 flows in the space between the large diameter portion 4a and the small diameter tube 4b, and the exhaust gas causes the inside of the second heat receiving portion 21B. The working fluid is heated.

  With the passage of time in this state, the working fluid in the second heat receiving portion 21B is vaporized (evaporated), and this vaporized working fluid is transferred to the second heat radiating portion 23 via the second transfer path 26. As a result, the cooling water in the heater flow path 13 is heated, so that the warm-up of the internal combustion engine 1 is promoted, and the warm air heater 16 can be used early.

  Thus, the heat of the exhaust gas flowing through the exhaust pipe 4 is first recovered by the first heat receiving part 21A and then recovered by the second heat receiving part 21B. Therefore, the working fluid in the first heat receiving part 21A is vaporized (evaporated) before the working fluid in the second heat receiving part 21B, but the working fluid is vaporized (evaporated) in the second heat receiving part 21B. It will take time to complete. Therefore, the heat circulation in the first heat circulation path 40 is started before the heat circulation in the second heat circulation path 50. That is, as the operation of the internal combustion engine 1 starts, the upstream catalyst 5 is first warmed up. After the upstream catalyst 5 is warmed up, the cooling water of the internal combustion engine 1 is warmed up. In addition, a time lag can be provided.

  As described above, in the third embodiment to which the present invention is applied, the second thermal circulation path 50 is started after the thermal circulation in the first thermal circulation path 40 is started, as in the first and second embodiments. By providing a time lag until the heat circulation in the engine is started, the heat of the exhaust gas is preferentially promoted to warm up the upstream catalyst 5 using the heat of the exhaust gas discharged from the internal combustion engine 1. The temperature of the cooling water taken out from the internal combustion engine 1 is increased by using this to promote the warm-up operation of the internal combustion engine 1.

  In this way, it is possible to efficiently carry out the prioritization with respect to the warming up of the upstream catalyst 5 and the downstream catalyst 6 attached to the internal combustion engine 1 and the warming up of the cooling water of the internal combustion engine 1, This is advantageous in reducing emissions during cold start of the internal combustion engine 1.

  However, in this embodiment, for example, the flow rate control valve 31 and the controller 32 are used for the time lag. Therefore, although the equipment cost is higher than the first and second embodiments described above, the time lag is reduced. It is excellent in that it can be managed more accurately.

  In addition, this invention is not limited only to the said embodiment, All the deformation | transformation and application included in the range equivalent to the claim and the said range are possible. Examples are given below.

  (1) In each said embodiment, although the example which attached the 2nd thermal radiation part 23 between the spherical joint 3 and the upstream catalyst 5 is given, the installation place of the 2nd thermal radiation part 23 is specifically limited. Instead, the second heat dissipating part 23 can be installed at a location away from the exhaust passage (2, 4), for example, in the vicinity of the vehicle compartment 17, as shown in FIG.

  In this case, the separation distance between the second heat radiating unit 23 and the heat receiving unit 21 can be set short, and therefore, the working fluid vaporized in the heat receiving unit 21 is condensed in the transfer process to the second heat radiating unit 23. This is advantageous in preventing the occurrence of the damage.

  (2) In each of the above embodiments, instead of the first transfer path 24 and the first return path 25, or the second transfer path 26 and the second return path 27, for example, as shown in FIGS. It is possible to use a type of heat pipe 31, 32.

  The wick type heat pipes 31 and 32 are known as shown in, for example, Japanese Patent Application Laid-Open Nos. 4-148193 and 2002-195023, but as shown in FIGS. Wicks 31b and 32b are provided on the inner diameter side of the cylindrical members 31a and 32a to transfer the liquid in one direction by capillary action.

  That is, in the case of the heat pipes 31 and 32, the inner holes of the cylindrical members 31a and 32a serve as the first and second transfer paths 24 and 26, and the wicks 31b and 32b serve as the first and second reflux paths 25 and 27, respectively. Become. Therefore, one end side of the inner holes of the cylindrical members 31a and 32a is connected to the heat receiving portion 21 (21A, 21B), and the other end sides of the inner holes of the cylindrical members 31a and 32a are the first and second heat radiating portions 22 and 23. It is connected to the communication. Furthermore, one end side of the wicks 31b and 32b is connected to the first and second heat radiating units 22 and 23, and the other end side of the wicks 31b and 32b is connected to the heat receiving unit 21 (21A and 21B).

  The inner peripheral surfaces of the wicks 31b and 32b in the heat pipes 31 and 32 are flattened in the circumferential direction as shown in FIG.

  In addition, as shown in FIG. 14, for example, the inner peripheral surfaces of the wicks 31b and 32b can form grooves 31c and 32c along the axial direction at several places on the circumference. The cross-sectional shape in the vertical direction of the grooves 31c and 32c is not particularly limited, and can be various shapes.

  In this case, since the surface area of the wicks 31b and 32b on the inner diameter side of the wick type heat pipes 31 and 32 is increased, the reflux efficiency of the condensed working fluid is improved.

  (3) Non-condensable gas can be sealed in the second heat circulation path 50 shown in the second and third embodiments. As this non-condensable gas, it is publicly known, and examples thereof include hydrogen gas.

  In this configuration, since the non-condensable gas does not evaporate, the non-condensable gas is transferred to the second heat radiating unit 23 by the working fluid vaporized in the second heat receiving unit 21B after the internal combustion engine 1 is started.

  Here, in a situation where the amount of heat received by the second heat receiving part 21B is small and the steam pressure is low, the non-condensable gas in the second heat radiating part 23 is difficult to be compressed. It is large and the heat radiation area of the working fluid in the gas phase is small. Therefore, the amount of the working fluid in the vapor phase that is heat-exchanged and condensed in the second heat radiating portion 23 is reduced, and the cooling water heating ability of the internal combustion engine 1 by the second heat radiating portion 23 is reduced.

  On the other hand, as the amount of heat received by the second heat receiving portion 21B increases with the passage of time and the vapor pressure increases, the non-condensed gas in the second heat radiating portion 23 is compressed, so the second heat radiating portion The proportion of non-condensable gas in 23 is reduced. As a result, the amount of the working fluid in the vapor phase that is heat-exchanged and condensed in the second heat radiating section 23 increases, and the cooling water heating capability of the internal combustion engine 1 by the second heat radiating section 23 is increased.

  Thus, when it is made into the form which gradually increases the heating capability by the 2nd thermal radiation part 23 according to passage of time by utilizing non-condensable gas, it is 2nd heat from the start of thermal circulation in the 1st thermal circulation path 40. It is possible to set the time lag until the start of thermal circulation in the circulation path 50 as long as possible.

  The gradual increase rate of the cooling water heating capacity by the second heat radiating unit 23 can be arbitrarily adjusted according to the amount of the non-condensed gas enclosed, and so on. The start timing and the time required from the start to the end of the process can be adjusted as necessary.

  (4) In each of the above embodiments, an example is given in which the second heat radiating portion 23 is used to heat the cooling water that is returned from the heater core 14 of the warm air heater 16 to the internal combustion engine 1. It is not limited to that.

  For example, it is possible to use cooling water introduced into the heater core 14 for an object to be heated by the second heat radiating unit 23. In this case, in the situation where the warm air heater 16 is operated during the warm-up operation of the internal combustion engine 1, it is possible to promote the temperature rise of the cooling water introduced into the heater core 14, so the warm air heater is also used during the warm-up operation. 16 enables early heating.

  Moreover, it is also possible to use the cooling water flowing through the bypass channel 12 for the object to be heated by the second heat radiating unit 23. The bypass flow path 12 is a flow path that is used when it is necessary to raise the temperature of the cooling water, for example, when the internal combustion engine 1 is warmed up. Therefore, the temperature of the cooling water flowing through the bypass passage 12 can be accelerated by the second heat radiating unit 23, so that the warm-up operation of the internal combustion engine 1 can be quickly terminated.

  (5) In each said embodiment, the internal combustion engine used as the connection object of the automatic transmission 1 is not limited to a gasoline engine, a diesel engine, and another engine. In the case of a diesel engine, the catalysts 5 and 6 can be, for example, DPF (Diesel Particulate Filter), DPNR (Diesel Particulate-NOx Reduction system), or the like.

  In the case of a diesel engine, the upstream catalyst 5 can be a NOx storage reduction catalyst (NSR), and the downstream catalyst 6 can be a NOx selective reduction catalyst (SCR).

  (6) In each of the above embodiments, an example in which two catalysts 5 and 6 are provided is given, but the number of catalysts is not limited, and may be, for example, one or three or more. .

  (7) In each said embodiment, the structure of the 1st, 2nd thermal radiation part 22 and 23 is not specifically limited. For reference, in each of the above embodiments, for example, the first heat radiating portion 22 is configured to use, for example, a case 22a in which the inner diameter side of the hollow sleeve is opened, but the present invention is not limited to this, for example, Although not shown, a hollow sleeve can be used as the case 22a. In that case, the fins 22b may be provided on the outer diameter side of the inner peripheral wall of the hollow sleeve.

  (8) In each of the above embodiments, an example in which the outer shape of the first heat radiating portion 22 attached to the upstream catalyst 5 is an annular shape surrounding the upstream catalyst 5 is given. The shape is not particularly limited.

  For reference, the outer shape of the first heat radiating portion 22 may be a curved shape so as to be attached to a partial region on the outer wall surface of the upstream catalyst 5, for example.

  (9) In each of the above embodiments, although not shown, a valve device can be provided in a predetermined region of the first return path 25 or the second return path 27, and further, the first return path 25 or the second return path 27 can be provided. It is also possible to provide a tank for storing the working fluid upstream of the valve device in the reflux direction in the reflux path 27.

  The valve device is an on-off valve that can be switched between an open state and a closed state, or a flow rate control valve that can adjust the opening degree in a stepless manner, such as an electromagnetic operation type or a self-operation type.

  In this case, when the corresponding valve device is closed, the working fluid condensed by the first heat radiating portion 22 and the second heat radiating portion 23 can be stored in the corresponding tank. Thus, when a predetermined time elapses after the valve device is closed, the heat transfer from the heat receiving portion 21 (21A, 21B) to the first and second heat radiating portions 22, 23 is stopped, and the upstream catalyst 5 The temperature increase promotion and the temperature increase promotion of the cooling water for the internal combustion engine 1 are stopped.

  Therefore, for example, when the temperature of the upstream catalyst 5 or the water temperature of the internal combustion engine 1 is likely to rise excessively, the valve device is closed to reduce the function due to excessive heating of the upstream catalyst 5, One overheating can be avoided.

1 is a schematic configuration diagram illustrating a first embodiment of an exhaust heat recovery apparatus according to the present invention. It is sectional drawing which shows the spherical joint of FIG. FIG. 2 is a partial cross-sectional view showing a specific configuration of the exhaust heat recovery apparatus of FIG. 1, showing a state where only catalyst warm-up is performed. FIG. 4 is a diagram showing a state where catalyst warm-up and cooling water warm-up of the internal combustion engine are performed simultaneously in FIG. 3. FIG. 3 is a schematic configuration diagram corresponding to FIG. 1 in the second embodiment of the exhaust heat recovery apparatus according to the present invention. It is a fragmentary sectional view which shows the specific structure of the 1st heat circulation path | route in the exhaust heat recovery apparatus of FIG. It is a fragmentary sectional view which shows the specific structure of the 2nd heat circulation path | route in the exhaust heat recovery apparatus of FIG. FIG. 3 is a schematic configuration diagram corresponding to FIG. 1 in a third embodiment of the exhaust heat recovery apparatus according to the present invention. It is an arrow view of the (9)-(9) line cross section of FIG. FIG. 4 is a schematic configuration diagram corresponding to FIG. 1 in the fourth embodiment of the exhaust heat recovery apparatus according to the present invention. FIG. 6 is a schematic configuration diagram corresponding to FIG. 1 in a fifth embodiment of the exhaust heat recovery apparatus according to the present invention. It is sectional drawing which shows the wick type heat pipe of FIG. It is an arrow view of the (13)-(13) line cross section of FIG. It is a figure which shows the modification of the heat pipe of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Exhaust manifold 3 Spherical joint 4 Exhaust pipe 5 Upstream catalyst 6 Downstream catalyst 7 Radiator 8 Cooling water extraction path 9 Cooling water recirculation path 10 Water pump 13 Heater flow path 14 Heater core 16 Hot air heater 18 Exhaust heat recovery device 21 heat receiving part 22 first heat radiating part 23 second heat radiating part 24 first transfer path 25 first reflux path 26 second transfer path 27 second reflux path 40 first thermal circulation path 50 second thermal circulation path

Claims (7)

A first heat circulation path for recovering exhaust heat of the internal combustion engine and promoting a temperature rise of the catalyst provided in the exhaust passage of the internal combustion engine; and cooling water temporarily recovered from the internal combustion engine by recovering the exhaust heat of the internal combustion engine A second heat circulation path for promoting the temperature rise of
The first heat circulation path includes a heat receiving portion that vaporizes a working fluid sealed inside by exhaust heat downstream of the catalyst in an exhaust passage of the internal combustion engine, a working fluid transferred from the heat receiving portion, the catalyst, A first heat dissipating part for condensing the working fluid by exchanging heat with a region near the inlet of the catalyst in the exhaust passage; and a first transfer path for transferring the working fluid from the heat receiving part to the first heat dissipating part. And a first reflux path for returning the working fluid from the first heat radiating portion to the heat receiving portion,
The second heat circulation path includes a second heat radiating portion that condenses the working fluid by exchanging heat between the heat receiving portion and the working fluid transferred from the heat receiving portion and the cooling water once taken out from the internal combustion engine. And a second transfer path for transferring the working fluid from the heat receiving part to the second heat radiating part, and a second reflux path for returning the working fluid from the second heat radiating part to the heat receiving part,
And the said heat receiving part has a container by which a working fluid is enclosed and the liquid level of a working fluid falls with vaporization,
The first transfer path is connected vertically above the liquid surface of the working fluid at a low temperature in the container of the heat receiving part, and the second transfer path is a connection position of the first transfer path in the container of the heat receiving part. Connected to the lower vertical direction than
The exhaust heat recovery apparatus is configured such that heat circulation in the first heat circulation path is started before heat circulation in the second heat circulation path. A first heat circulation path for recovering exhaust heat of the internal combustion engine and promoting a temperature rise of the catalyst provided in the exhaust passage of the internal combustion engine; and cooling water temporarily recovered from the internal combustion engine by recovering the exhaust heat of the internal combustion engine A second heat circulation path for promoting the temperature rise of
The first heat circulation path includes a first heat receiving portion that vaporizes a working fluid sealed inside by exhaust heat downstream of the catalyst in an exhaust passage of the internal combustion engine, and a working fluid transferred from the first heat receiving portion. A first heat radiating portion that condenses the working fluid by exchanging heat with the catalyst or an area near the inlet of the catalyst in the exhaust passage, and the working fluid is transferred from the first heat receiving portion to the first heat radiating portion. And a first return path for returning the working fluid from the first heat dissipating part to the first heat receiving part,
The second heat circulation path includes a second heat receiving portion that vaporizes a working fluid sealed inside by exhaust heat downstream of the catalyst in an exhaust passage of the internal combustion engine, and a working fluid transferred from the second heat receiving portion. A second heat radiating portion for condensing the working fluid by exchanging heat with the cooling water once taken out from the internal combustion engine, and a second for transferring the working fluid from the second heat receiving portion to the second heat radiating portion. Formed by a transfer path and a second reflux path for returning the working fluid from the second heat radiating section to the second heat receiving section;
And the said 1st heat receiving part is arrange | positioned rather than the said 2nd heat receiving part in the upstream of an exhaust gas discharge direction,
The exhaust heat recovery apparatus is configured such that heat circulation in the first heat circulation path is started before heat circulation in the second heat circulation path . A first heat circulation path for recovering exhaust heat of the internal combustion engine and promoting a temperature rise of the catalyst provided in the exhaust passage of the internal combustion engine; and cooling water temporarily recovered from the internal combustion engine by recovering the exhaust heat of the internal combustion engine A second heat circulation path for promoting the temperature rise of
The first heat circulation path includes a first heat receiving portion that vaporizes a working fluid sealed inside by exhaust heat downstream of the catalyst in an exhaust passage of the internal combustion engine, and a working fluid transferred from the first heat receiving portion. A first heat radiating portion that condenses the working fluid by exchanging heat with the catalyst or an area near the inlet of the catalyst in the exhaust passage, and the working fluid is transferred from the first heat receiving portion to the first heat radiating portion. And a first return path for returning the working fluid from the first heat dissipating part to the first heat receiving part,
The second heat circulation path includes a second heat receiving portion that vaporizes a working fluid sealed inside by exhaust heat downstream of the catalyst in an exhaust passage of the internal combustion engine, and a working fluid transferred from the second heat receiving portion. A second heat radiating portion for condensing the working fluid by exchanging heat with the cooling water once taken out from the internal combustion engine, and a second for transferring the working fluid from the second heat receiving portion to the second heat radiating portion. Formed by a transfer path and a second reflux path for returning the working fluid from the second heat radiating section to the second heat receiving section;
In the exhaust passage, a large diameter portion is provided in a region downstream from the catalyst, a small diameter pipe is inserted inside the large diameter portion, and a flow rate control valve is provided at the inlet of the small diameter pipe,
The first heat receiving part is provided so that exhaust gas traverses the inside of the small diameter pipe, and the second heat receiving part is provided so that exhaust gas traverses the annular space between the large diameter part and the small diameter pipe. And
The exhaust heat recovery apparatus is configured such that heat circulation in the first heat circulation path is started before heat circulation in the second heat circulation path . In the exhaust heat recovery device according to any one of claims 1 to 3 ,
The exhaust heat recovery apparatus according to claim 1, wherein the heat circulation start time in the second heat circulation path is set when the temperature of the catalyst reaches an activation temperature. The exhaust heat recovery apparatus according to claim 2 or 3 ,
An exhaust heat recovery apparatus, wherein the second heat circulation path is filled with a non-condensable gas . In the exhaust heat recovery device according to any one of claims 1 to 5,
At least one of the first transfer path and the first return path and the second transfer path and the second return path is a heat pipe in which a wick having a capillary structure is provided on the inner peripheral surface of the cylindrical member. An exhaust heat recovery device characterized by. The exhaust heat recovery apparatus according to any one of claims 1 to 6,
Vibration transmission attenuation means is provided at a position near the internal combustion engine in the exhaust passage, and the second heat radiating portion is provided in a region between the vibration transmission attenuation means and the catalyst. Exhaust heat recovery device.

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