JP2020128841A - Heat exchange structure body and heat storage heating device - Google Patents

Abstract

To provide a heat exchange structure body and a heat storage heating device capable of utilizing waste heat of exhaust gas with high heat transfer efficiency through a simple configuration.SOLUTION: A heat exchange structure body 11 which absorbs heat from exhaust gas G flowing in an exhaust pipe L21 of an engine and radiates the heat to cooling water W, comprises: piping L11 which forms a flow passage of the cooling water W along a portion of the exhaust pipe L21; and a heat storage section which encases the exhaust pipe L21 and the piping L11 and is filled with a solid-solid phase transition heat storage material 21. The cooling water W heated through heat radiation of the heat storage section heats a rear seat heater. The exhaust pipe L21 introduced into the heat storage section is branched piping branched from an exhaust pipe L20 before the same is introduced into the heat storage section. The heat storage section has a heat storage container 20 which is filled with the solid-solid phase transition heat storage material 21 and a heat transfer medium 22.SELECTED DRAWING: Figure 3

Description

The present invention relates to a heat exchange structure and a heat storage heating device that utilize exhaust heat of exhaust gas with good heat transfer efficiency.

A vehicle equipped with an engine that is an internal combustion engine uses cooling water to cool the engine. Further, a vehicle equipped with an engine includes a heater that heats the inside of the vehicle by utilizing cooling water heated by heat generated by the engine. Here, in Patent Document 1, when a solid solid phase transition heat storage material is used, heat energy is stored by absorbing heat from the cooling water when the heated cooling water exceeds the phase transition temperature, and the cooling water is cooled to form a phase. When the temperature becomes equal to or lower than the transition temperature, the stored heat energy is released to the cooling water, and the heated cooling water is used to warm the inside of the vehicle by the heater. As a result, the heat storage device having the solid-solid phase transition heat storage material stores heat when the engine is operating in steady operation and radiates heat when the engine is not operating due to idling stop etc. to warm the interior of the vehicle with the heater. be able to. It should be noted that Patent Document 1 describes a heat storage unit that stores exhaust heat of an exhaust pipe and returns cooling water heated by heat radiation of the stored heat to the engine side.

JP, 2016-31187, A

Here, there is a demand for a technique for more effectively utilizing the heat of exhaust gas described in Patent Document 1.

The present invention has been made in view of the above, and an object of the present invention is to provide a heat exchange structure and a heat storage heating device with a simple configuration that can utilize exhaust heat of exhaust gas with higher heat transfer efficiency. To do.

In order to solve the above problems and achieve the object, a heat exchange structure according to the present invention is a heat exchange structure that radiates heat absorbed from exhaust gas flowing through an exhaust pipe of an engine of a moving body to a cooling heat medium. And, a pipe that forms a flow path of the cooling heat medium along a part of the exhaust pipe, and a heat storage unit that is filled with a solid-solid phase transition heat storage material that surrounds the exhaust pipe and the pipe, It is characterized by being provided.

Further, the heat exchange structure according to the present invention is, in the above-mentioned invention, the exhaust pipe introduced into the heat storage section is a branch pipe branched from a part of the exhaust pipe before being introduced into the heat storage section. It is characterized by being.

Further, the heat exchange structure according to the present invention is characterized in that, in the above-mentioned invention, the heat storage part is filled with the solid-solid phase transition heat storage material and the heat transfer medium in a heat storage container.

Further, the heat exchange structure according to the present invention is characterized in that, in the above-mentioned invention, the heat transfer medium is liquid or grease-like.

Further, in the heat exchange structure according to the present invention, in the above invention, the cooling heat medium is cooling water, and the phase transition temperature of the solid-solid phase transition heat storage material is higher than a predetermined temperature from the predetermined temperature. It is characterized in that it is up to the boiling point of the cooling water.

Further, the heat exchange structure according to the present invention is characterized in that, in the above-mentioned invention, the solid-solid phase transition heat storage material is a strongly correlated electron compound.

Further, the heat exchange structure according to the present invention is characterized in that, in the above-mentioned invention, the exhaust pipe and the pipe have a double pipe structure in which the exhaust pipe is provided inside the pipe.

Further, the heat exchange structure according to the present invention is characterized in that, in the above-mentioned invention, each side surface of the exhaust pipe and the pipe are in contact with each other.

Further, the heat storage heating device according to the present invention is a heat storage heating device in which the heat absorbed from the exhaust gas flowing through the exhaust pipe is received by the cooling heat medium, and the received heat is used to warm the moving body by the heater. Then, the heat exchange structure according to any one of the above inventions is provided in the exhaust pipe.

In the heat storage heating device according to the present invention, in the above invention, the cooling heat medium is cooling water for cooling the engine, and the pipe introduces cooling water for the engine.

Further, a heat storage heating device according to the present invention is characterized in that, in the above-mentioned invention, the heater is provided on a rear seat side of the moving body.

According to the present invention, exhaust heat of exhaust gas can be efficiently used with a simple configuration.

FIG. 1 is a schematic diagram showing a schematic configuration of a system including a heat storage heating device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the arrangement of the heat exchange structure with respect to the exhaust pipe. FIG. 3 is a perspective view showing the configuration of the heat exchange structure. FIG. 4 is a cross-sectional view of the heat exchange structure. FIG. 5: is a figure which shows the heat absorption characteristic and heat dissipation characteristic accompanying a phase transition of a solid-solid phase transition heat storage material. FIG. 6 is a perspective view showing the configuration of the heat exchange structure of Modification 1. FIG. 7 is a cross-sectional view of the heat exchange structure of Modification Example 1. 8: is a perspective view which shows the structure of the heat exchange structure of the modification 2. FIG. FIG. 9 is a cross-sectional view of the heat exchange structure of Modification 2. FIG. 10: is a schematic diagram which shows the structure of the system containing the thermal storage heating apparatus of the modification 3. As shown in FIG. FIG. 11: is a cross-sectional view which shows an example of the heat exchange structure of the modification 4 applied to the EGR cooler of an exhaust gas recirculation (EGR:Exhaust Gas Recirculation) system.

Embodiments for carrying out the present invention will be described below with reference to the accompanying drawings. In addition, below, the example utilized for the seat heater which warms a seat is demonstrated. In recent years, heaters have been installed in the back seats of vehicles and the like, and the demand for them is increasing. Therefore, it is conceivable to supply the cooling water heated by the engine to the heater arranged on the rear seat side. However, providing the cooling water pipe between the engine and the heater on the rear seat side requires a large device configuration and a long pipe length, which causes a problem of poor heat transfer efficiency. According to the present invention, for example, exhaust heat of exhaust gas can be efficiently used for heat theta such as a rear seat. The present invention is not limited to the seat heater and may be used for heating the inside of the vehicle.

<Device configuration>
FIG. 1 is a schematic diagram showing a schematic configuration of a system including a heat storage heating device 10 according to an embodiment of the present invention. The present system uses the exhaust heat of the engine 3 to heat the front seat heater 4 on the front seat side in the vehicle and the heating device 1 that uses the exhaust heat of exhaust gas G to the rear seat heater on the rear seat side. A heat storage heating device 10 for heating 14 is mounted on the vehicle.

<Configuration of heating device 1>
As shown in FIG. 1, the heating device 1 cools the engine 3 with the cooling water W that is a cooling heat medium, cools the heated cooling water W with the radiator 2, and cools the cooling water W heated with the engine 3. Is introduced into the front seat heater 4 to heat the front seat heater 4. The piping system L has two piping systems for cooling the engine and heating the front seat heater.

The pump 6 is a pump that pumps the cooling water W to the engine 3 side. Into the pump 6, the cooling water W cooled by the radiator 2 and the cooling water W that has been heat-exchanged by the front heater 4 and cooled are introduced. The flow rate flow control valve 5 is, for example, a thermostat valve, and when the introduced cooling water W exceeds a certain temperature, the piping on the radiator 2 side is opened and the cooling water W is cooled by the radiator 2 and introduced. When the cooling water W is at a certain temperature or lower, the pipe side bypassing the radiator 2 is closed, and the cooling water W is led to the pump 6 side as it is to perform the warm-up operation. Strictly speaking, the flow rate flow control valve 5 adjusts the opening of the pipe on the radiator 2 side and the opening of the pipe bypassing the radiator 2 according to the temperature.

<Configuration of heat storage heating device 10>
An exhaust pipe L20 for exhausting exhaust gas of the engine 3 is laid around the lower part of the vehicle and extends to the rear part of the vehicle. The heat storage heating device 10 arranges the heat exchange structure 11 on the rear side of the exhaust pipe L20, for example, near the muffler. The pump 12 pumps the cooling water W to the heat exchange structure 11. The heat exchange structure 11 has a heat storage part that encloses the exhaust pipe L20 and the cooling water W and is filled with a solid-solid phase transition heat storage material. The heat exchange structure 11 stores the exhaust heat of the exhaust gas G from the exhaust pipe L20 and radiates the stored thermal energy to the cooling water W. The heat exchange structure 11 has a heat storage function when the engine 3 is stopped in an idling stop vehicle, a hybrid vehicle, or the like, the exhaust heat amount of exhaust gas becomes small, and the temperature of the cooling water W becomes low, This is because the cooling water W is heated by radiating the heat stored in the heat exchange structure 11, and the rear seat heater 14 is heated by the heated cooling water W.

The piping system L10 has piping L11 and L12. The cooling water W that has received the radiated heat is heated. The heated cooling water W is led to the rear seat heater 14 side via the pipe L11. The cooling water W introduced into the rear seat heater 14 is cooled by heat exchange with the rear seat heater 14 and returned to the pump 12 via the pipe L12.

<Arrangement of heat exchange structure>
As shown in FIG. 2, the heat exchange structure 11 has an exhaust pipe L21 that is a branch pipe that branches a part of the exhaust gas G passing through the exhaust pipe L20. The flow rate of the exhaust gas G to the exhaust pipe L21 is adjusted by the flow rate adjusting valve 13 provided in the exhaust pipe L20.

<Structure of heat exchange structure>
FIG. 3 is a perspective view showing the configuration of the heat exchange structure 11. Further, FIG. 4 is a cross-sectional view of the heat exchange structure 11. As shown in FIGS. 3 and 4, the heat exchange structure 11 includes a pipe L11 that passes through the heat storage container 20 and passes the cooling water W and an exhaust pipe L21 that passes the exhaust gas G. Then, the heat storage container 20 is filled with a solid-solid phase transition heat storage material 21 that encloses the pipe L11 and the exhaust pipe L21. Further, the heat storage container 20 may be filled with a heat transfer medium 22 that fills a gap between the solid-solid phase transition heat storage materials 21. The solid-solid phase transition heat storage material 21 is in the form of particles, granules, or a sintered body. The heat transfer medium 22 is a grease-like or liquid one having a high thermal conductivity which improves heat transfer efficiency between the pipe L11 and the exhaust pipe L21 and the solid-solid phase transition heat storage material 21. The heat transfer medium 22 is, for example, silicone grease or molybdenum grease.

The solid-solid phase transition heat storage material 21 changes to a solid first phase state when the temperature is equal to or lower than the phase transition temperature, and changes to a solid second phase state when the temperature exceeds the phase transition temperature. .. Then, as shown in FIG. 5, the solid-solid phase transition heat storage material 21 absorbs heat during a phase change at a phase transition temperature (for example, around 65° C.) when heated, and conversely, when cooled, the phase is changed. Dissipates heat during a phase change at the transition temperature.

The solid-solid phase transition heat storage material 21 is a strongly correlated electron compound, and is, for example, vanadium dioxide (VO ₂ ) or vanadium oxide in which VO ₂ is doped with W, Re, Ru, Nb, Ta, or the like.

When the heat transfer medium 22 is in the form of grease, a filler of a heat conducting member may be included in the grease. Examples of the heat conductive member include aluminum oxide, aluminum hydroxide, magnesium oxide, silicon oxide, silicon carbide, zinc oxide, boron nitride, aluminum nitride, silicon nitride, silicon carbide and diamond.

In the present embodiment, the phase transition temperature of the solid-solid phase transition heat storage material 21 is 65° C., but the phase transition may be between a predetermined temperature (for example, 40° C.) and the boiling point of the cooling water W, For example, it may be 90°C. The phase transition temperature can be changed depending on the mixing ratio of the doping material of the solid/solid phase transition heat storage material 21.

The specific solid-solid phase transition heat storage material 21 is VO ₂ and is 50% by weight with respect to the heat storage container 20. Further, the heat conductive member included in the heat transfer medium 22 is boron nitride, and is 20% by weight with respect to the heat storage container 20. Further, the heat transfer medium 22 is silicone-based grease, and is 30% by weight with respect to the heat storage container 20. With such a composition, the heat storage container 20 has a heat storage density of 110 J/cc, a heat storage temperature of 90° C., a thermal conductivity of 2.8 W/mK, a specific heat of 2.2 J/gK, and a density of 3.2 g/cm ^3. Exhibit the characteristics of.

<Modification 1>
FIG. 6 is a perspective view showing the configuration of the heat exchange structure 11 of Modification 1. Further, FIG. 7 is a cross-sectional view of the heat exchange structure 11 of Modification 1. As shown in FIGS. 6 and 7, in the first modification, the exhaust pipe L21 is provided in the pipe L11 to have a double pipe structure. Accordingly, the heat exchange structure 11 of Modification 1 has a heat storage function and can directly exchange heat between the exhaust pipe L21 and the pipe L11.

<Modification 2>
8: is a perspective view which shows the structure of the heat exchange structure 11 of the modification 2. As shown in FIG. Further, FIG. 9 is a cross-sectional view of the heat exchange structure 11 of Modification 2. As shown in FIGS. 8 and 9, in the second modification, the exhaust pipe L21 and the pipe L11 are in contact with each other at their side surfaces. As a result, the heat exchange structure 11 of Modification 2 has a simple structure, has a heat storage function, and can improve the heat exchange efficiency between the exhaust pipe L21 and the pipe L11.

<Modification 3>
FIG. 10: is a schematic diagram which shows the structure of the system containing the thermal storage heating apparatus 10a of the modification 3. As shown in FIG. As shown in FIG. 10, in the heat storage heating device 10a of Modification 3, a pipe system L10a corresponding to the pipe system L10 is connected to the pipe system L via an opening/closing valve 15. That is, in the heat storage heating device 10 shown in FIG. 1, the pipe system L10 is independent of the pipe system L of the heating device 1 and two pipe systems are provided in the vehicle, but the heat storage heating device 10a shown in FIG. It is connected to the piping system L of the heating device 1 so as to form one piping system in the vehicle.

In addition to water pumps such as pumps 6 and 12, it is necessary to provide electric components such as a reservoir tank with a water level gauge (not shown) and a flow passage switching electromagnetic valve such as a flow passage adjusting valve 5 in one piping system. There is. Therefore, a vehicle having the heating device 1 and the heat storage heating device 10 shown in FIG. 1 needs to be provided with two sets of electric components, but the heating device 1 and the heat storage heating device 10a shown in FIG. The vehicle that has been completed requires only one set of electric parts.

As a result, when importance is attached to the installation property of the pipe and the warm air speed, the heat storage heating device 10 shown in FIG. Although it falls off, it is preferable to adopt the configuration of the heat storage heating device 10a shown in FIG. 10 when the cost reduction of the electric parts, especially the reduction of the number of pumps is emphasized.

<Modification 4>
FIG. 11 is a cross-sectional view showing an example of the heat exchange structure 31 of Modification 4 applied to the EGR cooler of the exhaust gas recirculation (EGR) system. In the heat exchange structure 31, a plurality of exhaust pipes L31 that pass the exhaust gas G and make it turbulent are arranged in the pipe L30 of the EGR cooler. The cooling water W passes through the flow path between the exhaust pipe L31 and the pipe L30. Therefore, it is similar to the double tube structure of the first modification. The heat storage container 20 is filled with the solid-solid phase transition heat storage material 21 so as to penetrate the exhaust pipe L31 and the pipe L30 and wrap the pipe L30. Further, the heat storage container 20 may be filled with a heat transfer medium 22 that fills a gap between the solid-solid phase transition heat storage materials 21. The solid-solid phase transition heat storage material 21 and the heat transfer medium 22 are the same as those in the above-described embodiment and modifications 1 to 3. The cooling water W flowing through the pipe L30 heats the rear seat heater 14, but may heat the front seat heater 4.

In the modified example 4, the heat of the exhaust gas G recirculated to the EGR cooler is also stored, and the stored heat can be used for heating the vehicle interior, so that the effective use of the exhaust gas G can be further increased.

Although the embodiment and the modified example to which the invention made by the present inventors is applied have been described above, the present invention is not limited by the description and the drawings which form part of the disclosure of the present invention according to the present embodiment. Absent. That is, all other embodiments, examples, operation techniques and the like made by those skilled in the art based on the present embodiment are included in the scope of the present invention.

1 Heating Device 2 Radiator 3 Engine 4 Front Heater 5 Flow Rate Flow Control Valve 6,12 Pump 10, 10a Heat Storage Heating Device 11,31 Heat Exchange Structure 13 Flow Rate Control Valve 14 Rear Seat Heater 15 Open/Close Valve 20 Heat Storage Container 21 Solid Solid phase transition heat storage material 22 Heat transfer medium G Exhaust gas L, L10 Piping system L11, L12, L30 Piping L20, L21, L31 Exhaust pipe W Cooling water

Claims (11)

A heat exchange structure that radiates heat absorbed from exhaust gas flowing through an exhaust pipe of an engine of a moving body to a cooling heat medium,
A pipe forming a flow path of the cooling heat medium along a part of the exhaust pipe,
A heat storage part that is filled with a solid-solid phase transition heat storage material that surrounds the exhaust pipe and the pipe,
A heat exchange structure comprising: The heat exchange structure according to claim 1, wherein the exhaust pipe introduced into the heat storage unit is a branch pipe that branches a part of the exhaust pipe before being introduced into the heat storage unit. The heat storage structure according to claim 1 or 2, wherein the heat storage unit has a heat storage container filled with the solid-solid phase transition heat storage material and a heat transfer medium. The heat exchange structure according to claim 3, wherein the heat transfer medium is liquid or grease-like. The cooling heat medium is cooling water,
The phase transition temperature of the solid-solid phase transition heat storage material is between a predetermined temperature and a boiling point of the cooling water higher than the predetermined temperature, according to any one of claims 1 to 4. Heat exchange structure. The heat exchange structure according to any one of claims 1 to 5, wherein the solid-solid phase transition heat storage material is a strongly correlated electron compound. The heat exchange structure according to any one of claims 1 to 6, wherein the exhaust pipe and the pipe have a double pipe structure in which the exhaust pipe is provided inside the pipe. The heat exchange structure according to any one of claims 1 to 6, wherein the exhaust pipe and the pipe are in contact with each other at their side surfaces. A heat storage heating device in which heat absorbed from exhaust gas flowing through the exhaust pipe is received by a cooling heat medium, and the moving body is warmed by a heater using the received heat.
A heat storage heating device, wherein the exhaust pipe is provided with the heat exchange structure according to any one of claims 1 to 7. The cooling heat medium is cooling water for cooling the engine,
The heat storage heating device according to claim 9, wherein the pipe introduces cooling water for the engine. The heat storage heating device according to claim 9 or 10, wherein the heater is provided on a rear seat side of the moving body.

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