Device for recovering exhaust heat using a dual-pipe system

Abstract

This invention relates to a device for recovering exhaust heat using a dual-pipe system. The device is installed in a vehicle for recovering exhaust heat. The device includes a housing, a first pipe, and a second pipe. The housing has a heat exchanger inside and includes a front through-hole and a rear through-hole. Exhaust gas is introduced through the front through-hole and discharged through the rear through-hole. The first pipe is mounted to the housing and has a dual-pipe structure. The second pipe is connected to the first pipe and also has a dual-pipe structure. Coolant introduced through the second pipe passes through the first pipe and exchanges heat with the exhaust gas in the heat exchanger within the housing. The heat-exchanged coolant is discharged to the engine through both the first and second pipes.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0144188, filed on November 2, 2020, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a device installed in a vehicle for recovering exhaust heat. The device includes a housing with a heat exchanger inside, and has a front through-hole and a rear through-hole. Exhaust gas is introduced through the front through-hole and discharged through the rear through-hole. The device also includes a first pipe with a double-pipe structure installed in the housing and a second pipe with a double-pipe structure connected to the first pipe. Coolant introduced through the second pipe passes through the first pipe and exchanges heat with the exhaust gas in the heat exchanger within the housing. The heat-exchanged coolant is discharged to the engine through the first and second pipes. Background Technology

[0004] Typically, exhaust heat recovery devices are installed to improve vehicle fuel economy, and their principle is as follows.

[0005] More specifically, when a vehicle's engine is started, it is kept at a high RPM until the engine heats up to a predetermined temperature, resulting in a warm-up state with high levels of soot and smoke, which leads to poorer fuel economy.

[0006] Therefore, the principle of exhaust heat recovery devices is to shorten the engine's warm-up time. By using a heat exchanger to exchange heat with the exhaust gases emitted from the engine during startup, the temperature of the coolant is increased, thereby shortening the warm-up time. This principle can improve vehicle fuel economy and reduce emissions of soot and smoke.

[0007] Figure 1 This is a structural diagram of an exhaust heat recovery device 10 in the related art. Device 10 includes: an exhaust pipe 11 and a housing 12; exhaust gases from the engine are introduced through the exhaust pipe 11; the housing 12 is configured to increase the temperature of the coolant by exchanging heat with the exhaust gases introduced through the exhaust pipe 11 using a heat exchanger. The exhaust heat recovery device 10 also includes: an inlet pipe 13, an outlet pipe 14, and a through-hole 15; coolant enters the housing 12 through the inlet pipe 13 for heat exchange; the coolant, whose temperature has increased by heat exchange with the exhaust gases in the housing 12, is discharged through the outlet pipe 14; the exhaust gases that have been introduced into the housing 12 through the exhaust pipe 11 and exchanged heat with the coolant are discharged through the through-hole 15 into a muffler connected to the rear end of the housing 12.

[0008] However, because the exhaust heat recovery device 10 in the related technology constructed as described above is shaped such that the inlet pipe 13 and the outlet pipe 14 extend along the shape or structure of the vehicle body, it is difficult to design the shape of the pipes. Furthermore, the number of brackets used to fix the pipes to the vehicle body increases. Therefore, the efficiency of the assembly process decreases.

[0009] When the exhaust heat recovery device 10 is installed in the vehicle body, components used to enhance body rigidity are removed to ensure clearance between the exhaust heat recovery device 10 and surrounding components. As a result, there is a problem of deterioration in the vehicle's noise, vibration, and harshness (NVH) performance. Summary of the Invention

[0010] This invention aims to provide a simple tubular device for recovering exhaust heat. The device can be easily installed in a vehicle body, thereby improving the efficiency of the assembly process. Furthermore, it minimizes the gap between the device and surrounding components, thus eliminating limitations when installing components used to enhance vehicle body rigidity.

[0011] An embodiment of the present invention provides a device for recovering exhaust heat. The device includes a housing, a first pipe, and a second pipe. The housing has a heat exchanger inside and includes a front through-hole and a rear through-hole. Exhaust gas is introduced through the front through-hole and discharged through the rear through-hole. The first pipe is mounted on the housing and has a double-pipe structure. The second pipe is connected to the first pipe and also has a double-pipe structure. Coolant introduced through the second pipe passes through the first pipe and exchanges heat with the exhaust gas in the heat exchanger within the housing. The cooled coolant, after heat exchange, is discharged to the engine through the first and second pipes.

[0012] In the device for recovering exhaust heat according to the invention, constructed as described above, the pipes for recovering exhaust heat (which are used for introducing and discharging coolant) are designed with a simple shape through the application of a dual-pipe structure. Therefore, the efficiency of the assembly process can be improved because the device can be easily installed in the vehicle body. Furthermore, the clearance between the device for recovering exhaust heat and the surrounding components can be minimized, thereby eliminating factors that restrict the installation of components used to enhance vehicle body rigidity. As a result, the vehicle's NVH (noise, vibration, and harshness) performance can be improved.

[0013] A channel can be formed to regulate the amount of coolant to be introduced by utilizing the wax in the cap of the wax supply unit. Therefore, all coolant heated by the heat exchanger of the device for recovering exhaust heat is discharged to the outside. As a result, abnormal noises (different types of noise) generated when residual coolant is heated by the heat exchanger are eliminated, and the durability of the device for recovering exhaust heat is properly maintained. Attached Figure Description

[0014] Figure 1 This is a structural diagram of an exhaust heat recovery device based on related technologies.

[0015] Figure 2 This is a partial front perspective view of an apparatus for recovering exhaust heat according to the present invention.

[0016] Figure 3 This is a partial bottom perspective view of an apparatus for recovering exhaust heat according to the present invention.

[0017] Figure 4 This is a partial bottom perspective view of the housing of the device for recovering exhaust heat according to the present invention.

[0018] Figures 5a to 5d A detailed view of the housing of the device for recovering exhaust heat according to the present invention, wherein Figure 5a This is a partial side perspective view of the shell. Figure 5b This is a 3D view of the first tube. Figure 5c It is along Figure 5b A cross-sectional view taken from line B-B'. Figure 5d It is along Figure 4 A cross-sectional view taken from line A-A'.

[0019] Figure 6 This is a cross-sectional view of the first tube of the device for recovering exhaust heat according to the present invention.

[0020] Figure 7 This is a perspective view showing the state of the second pipe connection of the device for recovering exhaust heat according to the present invention.

[0021] Figure 8 This is a longitudinal cross-sectional view of the second pipe of the device for recovering exhaust heat according to the present invention.

[0022] Figure 9a and Figure 9b This is a longitudinal cross-sectional view of the second pipe of the device for recovering exhaust heat according to the present invention, wherein... Figure 9a It is along Figure 7 The longitudinal section diagram taken from line C-C'. Figure 9b It is along Figure 7 The longitudinal section diagram taken from line D-D'.

[0023] Figure 10a , Figure 10b and Figure 10c A view showing the operation of the U-shaped tube of the device for recovering exhaust heat according to the present invention is provided.

[0024] Figure 11 This is a perspective view of the engine cooling module side connector of the device for recovering exhaust heat according to the present invention.

[0025] Figure 12 It is along Figure 11 The diagram shows a cross-sectional view taken along line F-F', and also shows a cross-section of the connector of the device for recovering exhaust heat according to the present invention. Detailed Implementation

[0026] The structure and operation of the apparatus for recovering exhaust heat using a dual-pipe system according to the present invention will be described in detail below with reference to the accompanying drawings.

[0027] The accompanying drawings are provided as examples to fully convey the spirit of the invention to those skilled in the art. Therefore, the invention is not limited to the drawings and the embodiments described below, and may be specified in other aspects and embodiments.

[0028] Furthermore, unless otherwise specified, the terminology used in this specification has the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the following description and drawings, detailed descriptions of well-known functions and structures will be omitted so as not to unnecessarily obscure the subject matter of the invention.

[0029] Figure 2 This is a partial front perspective view of an apparatus for recovering exhaust heat according to the present invention. Figure 3 This is a partial bottom perspective view of an apparatus for recovering exhaust heat according to the present invention.

[0030] First, refer to Figure 2 The device 100 for recovering exhaust heat according to the present invention includes a housing 110 configured to define the appearance of the recovery device. Inside the housing is a heat exchanger 150 and a first pipe 120 mounted outside the housing 110 and having a double-pipe structure. A front through-hole 111 is formed on one side of the housing 110, through which exhaust gas discharged from the engine is introduced. A rear through-hole 112 is formed on the other side of the housing 110, through which the exhaust gas after heat exchange is discharged to the outside of the housing 110.

[0031] Reference Figure 3 The partial bottom perspective view shows that the device 100 for recovering exhaust heat according to the present invention includes a second pipe 130 connected to a first pipe 120. A U-shaped pipe 131 is connected to the second pipe 130.

[0032] Both the first pipe 120 and the second pipe 130 have a double-pipe structure and are configured to allow coolant to be introduced and discharged through the double-pipe structure.

[0033] In the device 100 for recovering exhaust heat according to the invention, constructed as described above, coolant introduced through the second pipe 130 passes through the first pipe 120 and through a heat exchanger 150 installed within the housing 110. The coolant is then discharged to the outside through the first pipe 120 and the second pipe 130. In this case, the coolant passing through the heat exchanger 150 is heated using the temperature of the exhaust gas introduced through the front through-hole 111 of the housing 110. The exhaust gas is then discharged from the housing 110 through the rear through-hole 112 and delivered to a muffler (not shown) connected to the rear end of the device 100 for recovering exhaust heat. The noise of the exhaust gas delivered to the muffler is reduced, and then the exhaust gas is discharged to the outside of the vehicle.

[0034] The apparatus for recovering exhaust heat according to the invention, constructed as described above, will now be described in more detail.

[0035] Figure 4 This is a partial bottom perspective view of the housing of the device for recovering exhaust heat according to the present invention. Figures 5a to 5d This is a detailed view of the housing of the device for recovering exhaust heat according to the present invention. Figure 5a This is a partial side perspective view of the shell. Figure 5b This is a 3D view of the first tube. Figure 5c It is along Figure 5b A cross-sectional view taken from line B-B'. Figure 5d It is along Figure 4 A cross-sectional view taken from line A-A'.

[0036] The apparatus for recovering exhaust heat according to the present invention is shown in detail below. Figure 4 and Figure 5a The first pipe 120 installed outside the housing 110 of the device 100 for recovering exhaust heat according to the present invention has a double pipe structure, including an outer pipe 121 and an inner pipe 122 installed inside the outer pipe 121.

[0037] The wax supply unit 140 is mounted on the outside of the housing 110.

[0038] The wax supply unit 140 is configured to supply wax that expands or contracts according to the temperature of coolant introduced through a U-shaped tube 131 connected to a second tube 130. The wax supply unit 140 includes a container 142 connected via a bracket 113 (mounted externally to the housing 110). The container 142 is open on one side and has a space for containing wax. The wax supply unit 140 has a cap 141 configured to close the opening on one side of the container 142 and allow the wax contained in the container 142 to be supplied. The wax supply unit 140 also includes a valve 144 mounted on the other side of the container 142 and configured to regulate the amount of wax contained in the cap 141 and the container 142 by the spring force of a spring 143 cooperating with the valve 144.

[0039] The cover 141 has a lower hole 141a and an upper hole 141b through which coolant introduced from the U-shaped tube 131 flows.

[0040] The inlet port 114 and the outlet port 115 through which the coolant flows are formed on one side of the housing 110.

[0041] Reference Figure 5b and Figure 5c The inner tube 122 is installed inside the outer tube 121 of the first tube 120, and the coolant outlet 123 and inlet 124 are formed in the bottom surface of the outer tube 121. The inlet 124 communicates with the coolant outlet port 115 formed in the housing 110, and the outlet 123 communicates with the coolant inlet port 114 formed in the housing 110.

[0042] The internal space of the inner pipe 122 defines a coolant discharge path 125 through which coolant introduced into the coolant inlet 124 flows to the second pipe 130. The space between the outer pipe 121 and the inner pipe 122 defines a coolant inflow path 126 through which coolant introduced from the second pipe 130 flows to the coolant outlet 123.

[0043] Therefore, as Figure 5d As shown in the cross-sectional view along line A-A', in the apparatus for recovering exhaust heat according to the invention constructed as described above, coolant introduced from the second pipe 130 is introduced into the heat exchanger 150 via coolant inflow path 126 and coolant inflow port 114. In the heat exchanger 150, the coolant exchanges heat with the high-temperature exhaust gas introduced into the heat exchanger 150 through the front through-hole 111, causing the coolant temperature to rise. The coolant is discharged into the second pipe 130 via the coolant discharge path 125 of the first pipe 120 through the coolant outlet port 115.

[0044] Figure 6This is a cross-sectional perspective view of the first tube 120 of the device for recovering exhaust heat according to the present invention. The inner tube 122 is securely supported within the interior space of the outer tube 121 by a support member 127, one side of which is attached to the inner circumferential surface of the outer tube 121 and the other side of which is attached to the outer circumferential surface of the inner tube 122. Multiple supports 127 with appropriate gaps can be installed in the first tube 120.

[0045] Next, the construction of the second tube 130 of the device 100 for recovering exhaust heat according to the present invention will be described in detail.

[0046] Figure 7 This is a perspective view showing the state of the second pipe connection of the device for recovering exhaust heat according to the present invention. Figure 8 This is a longitudinal cross-sectional view of the second pipe of the device for recovering exhaust heat according to the present invention. Figure 9a and Figure 9b This is a longitudinal cross-sectional view of the second pipe of the device for recovering exhaust heat according to the present invention. Figure 9a It is along Figure 7 The longitudinal section diagram taken from line C-C'. Figure 9b It is along Figure 7 The longitudinal section diagram taken from line DD'. Figure 8 This is a longitudinal cross-sectional view of the second pipe of the device for recovering exhaust heat according to the present invention.

[0047] First, refer to Figure 7 According to the invention, the second pipe 130 of the device 100 for recovering exhaust heat is configured to allow coolant to be introduced into or discharged from the first pipe 120. The second pipe 130 includes an outer pipe 132 communicating with an outer pipe 121 of the first pipe 120 and an inner pipe 133 communicating with an inner pipe 122 of the first pipe 120.

[0048] Specifically, the diameter of the outer tube 121 of the first tube 120 and the diameter of the outer tube 133 of the second tube 130 can be equal to each other. Similarly, the diameter of the inner tube 122 of the first tube 120 and the diameter of the inner tube 133 of the second tube 130 can also be equal to each other.

[0049] The U-shaped tube 131 is installed on one side of the second tube 130. The U-shaped tube 131 is formed by integrally connecting one tube member 131a and another tube member 131b into a U-shape.

[0050] In this case, such as Figure 9a and Figure 9bAs shown, the internal space of the inner tube 133 of the second tube 130 defines a coolant discharge path 135, through which coolant introduced from the inner tube 122 of the first tube 120 is discharged into the coolant tank. The space between the inner tube 133 and the outer tube 132 of the second tube 130 defines a coolant inflow path 136, through which coolant introduced from the coolant tank flows into the first tube 120.

[0051] One pipe member 131a of the U-shaped pipe 131 is connected to the U-shaped pipe inlet 137 of the second pipe 130, so that coolant introduced into the coolant inflow path 136 is introduced into the U-shaped pipe 131. Another pipe member 131b of the U-shaped pipe 131 is connected to the U-shaped pipe outlet 138 of the second pipe 130, so that coolant introduced into the coolant inflow path 136 is discharged from the U-shaped pipe 131 and introduced into the coolant inflow path 126 of the first pipe 120.

[0052] In this case, such as Figure 8 , Figure 9a and Figure 9b As shown in the detailed cross-sectional view, in order to allow the coolant introduced into the second pipe 130 in the coolant inflow path 136 to flow into the U-shaped pipe 131, a first baffle 134 is installed on the rear side of the location of the U-shaped pipe inlet 137 of the second pipe 130, shielding the coolant inflow path 136 between the outer pipe 132 and the inner pipe 133. A second baffle 134' is installed on the front side of the location of the U-shaped pipe outlet 138 of the second pipe 130, shielding the coolant inflow path 136 between the outer pipe 132 and the inner pipe 133.

[0053] When the coolant introduced into the coolant inflow path 136 is introduced into the U-tube 131 as described above, the wax contained in the cap 141 (which is connected to another pipe member 131b of the U-tube 131) expands or contracts according to the temperature of the coolant flowing in the U-tube 131, thereby regulating the amount of coolant to be introduced.

[0054] In other words, such as Figure 10aThe diagram illustrates the operation of a U-shaped tube in an apparatus for recovering exhaust heat according to the invention, wherein wax is supplied from a container 142 of a wax supply unit 140 to a cap 141. A lower orifice 141a and an upper orifice 141b of the cap 141 are connected to another tube member 131b of the U-shaped tube 131. A channel T, configured to connect the lower orifice 141a and the upper orifice 141b, is installed in the cap 141. The channel T has a core 160 formed at its center and a wax layer 163 formed at a predetermined distance from the core 160 and formed as wax is introduced from and contained in the container 142 of the wax supply unit 140. The inner circumferential surface of the wax layer 163 is shielded by a membrane 162, and a coolant flow path 161 is formed between the core 160 and the membrane 162 of the wax layer 163, through which coolant introduced into the U-shaped tube 131 flows.

[0055] In this case, the core 160 is made of a material with high heat resistance to prevent thermal deformation, and the film 162 is a material with excellent thermal conductivity.

[0056] The operation performed based on the temperature of the coolant passing through channel T (which is formed in the cover 141 constructed as described above) is described below. As the device for recovering exhaust heat according to the invention operates, the temperature of the coolant introduced into the second pipe 130 gradually increases. Therefore, as... Figure 10b As shown, the wax layer 163 expands due to the temperature of the coolant flowing through the coolant flow path 161 of the channel T, causing the width of the wax layer 163 to increase to a first width a. When the temperature of the coolant further increases, the wax layer 163 expands further, causing the width of the wax layer 163 to increase to a second width b, as shown. Figure 10c As shown. As a result, the inflow of coolant through coolant flow path 161 is almost blocked, and all coolant heated by heat exchanger 150 in housing 110 is discharged to the outside. Therefore, abnormal noise (different types of noise) generated when residual coolant is heated by heat exchanger is eliminated, and the durability of the device for recovering exhaust heat is properly maintained.

[0057] Figure 11 This is a perspective view of the engine cooling module side connector of the device for recovering exhaust heat according to the present invention. Figure 12 It is along Figure 11 The diagram shows a cross-sectional view taken along line F-F', and also shows a cross-section of the connector of the device for recovering exhaust heat according to the present invention.

[0058] The connecting pipe 170 is a component connected to both the coolant drain pipe and the coolant inlet pipe. Coolant already used to cool the engine flows back through the coolant drain pipe, and coolant is supplied to the engine through the coolant inlet pipe. The connecting pipe 170 is connected to a second pipe 130 of the device for recovering exhaust heat according to the invention, to introduce coolant into or receive coolant from the second pipe 130.

[0059] Reference Figure 11 and Figure 12 The connecting pipe 170 includes an outer pipe 171 shielded on one side by a flat plate 171a. An inner pipe 172 is installed inside the outer pipe 171 and has an opening 172a formed on one side. An inlet pipe 173 is connected to the outer pipe 171, and coolant used to cool the engine flows into the inlet pipe 173 for return. The interior of the inner pipe 172 defines a discharge path 174 through which coolant is discharged to the engine's coolant inlet pipe. The space between the outer pipe 171 and the inner pipe 172 defines an inflow path 175 through which coolant introduced from the engine's coolant discharge pipe and introduced through the inlet path 176 of the inlet pipe 173 flows to the second pipe 130.

Claims

1. An apparatus for recovering heat from exhaust gas, the apparatus comprising: The housing has a heat exchanger inside and has a front through hole and a rear through hole. Exhaust gas is introduced through the front through hole and discharged through the rear through hole. The first tube, which is mounted on the housing, has a double-tube structure; and The second pipe, which connects to the first pipe, has a double-pipe structure. The coolant introduced through the second pipe passes through the first pipe and exchanges heat with the exhaust gas in a heat exchanger inside the casing. The coolant that has undergone heat exchange is discharged to the engine through the first and second pipes. The first tube includes: outer tube; and The inner tube is installed inside the outer tube. The coolant outlet and inlet are formed in the outer pipe, the internal space of the inner pipe defines the coolant discharge path, the coolant introduced into the inlet flows to the second pipe through the coolant discharge path, and the space between the outer pipe and the inner pipe defines the coolant inlet path, the coolant introduced from the second pipe flows to the outlet through the coolant inlet path; The second tube includes: The outer tube, which is connected to the outer tube of the first tube; and The inner tube is connected to the inner tube of the first tube. The internal space of the inner tube of the second tube defines the coolant discharge path of the second tube. The coolant introduced from the inner tube of the first tube is discharged through the coolant discharge path of the second tube. The space between the outer tube and the inner tube of the second tube defines the coolant inflow path of the second tube. The coolant flows to the first tube through the coolant inflow path of the second tube.

2. The apparatus for recovering exhaust heat according to claim 1, wherein, The inlet is connected to the coolant outlet port formed in the housing, and the outlet is connected to the coolant inlet port formed in the housing.

3. The apparatus for recovering exhaust heat according to claim 1, wherein, The first tube has a support member for supporting an inner tube installed in the internal space of the outer tube. One side of the support member is attached to the inner circumferential surface of the outer tube, and the other side is attached to the outer circumferential surface of the inner tube.

4. The apparatus for recovering exhaust heat according to claim 1, wherein, A U-shaped tube is installed on one side of the second tube. The U-shaped tube is formed by integrally connecting one tube component and another tube component into a U-shape. The pipe member is connected to the U-shaped inlet of the second pipe, so that the coolant flowing into the second pipe is introduced into the U-shaped pipe. The other pipe component is connected to the U-shaped outlet of the second pipe, such that the coolant introduced into the coolant inflow path of the second pipe is discharged from the U-shaped pipe and introduced into the coolant inflow path of the first pipe.

5. The apparatus for recovering exhaust heat according to claim 4, comprising: A wax supply unit is mounted outside the housing and configured to supply wax that expands or contracts according to the temperature of the coolant introduced through a U-shaped tube connected to a second tube.

6. The apparatus for recovering exhaust heat according to claim 5, wherein, The wax supply unit includes: A container, which is connected by a bracket mounted on the outside of the shell, has an opening on one side and has a space for holding wax; A lid, configured to close an opening on one side of the container and allow the wax contained within the container to be supplied; and A valve, mounted on the other side of the container, is configured to regulate the amount of wax contained in the lid and container by means of the spring force of a spring that operates in conjunction with the valve.

7. The apparatus for recovering exhaust heat according to claim 4, wherein, To allow the coolant in the flow path of the second pipe to flow into the U-shaped pipe, a first baffle is installed behind the inlet of the second pipe to shield the coolant flow path between the outer and inner pipes, and a second baffle is installed in front of the outlet of the second pipe to shield the coolant flow path between the outer and inner pipes.

8. The apparatus for recovering exhaust heat according to claim 6, wherein, The lower and upper holes of the cap are connected to another tubular component of the U-shaped tube, and the cap has a channel configured to connect the lower and upper holes. The channel has a core formed at its center and a wax layer formed at a predetermined distance from the core, and is formed as wax is introduced and contained from the container of the wax supply unit. The inner circumferential surface of the wax layer is shielded by a film. A coolant flow path is formed between the core and the wax layer film, and the coolant introduced into the U-shaped tube flows through the coolant flow path.

9. The apparatus for recovering exhaust heat according to claim 1, comprising: A connecting pipe, which connects to the second pipe, to introduce coolant into or receive coolant from the second pipe.

10. The apparatus for recovering exhaust heat according to claim 9, wherein, The connecting pipe includes; The outer tube is shielded on one side by a flat plate; The inner tube is installed inside the outer tube and has an opening on one side; as well as An inlet pipe, which connects to the outer pipe of the connecting pipe, is used to cool the engine; the coolant flows into the inlet pipe and returns. The inner tube of the connecting pipe defines the discharge path of the connecting pipe, through which the coolant is discharged to the engine's coolant inlet pipe. The space between the outer and inner pipes of the connecting pipe defines the inflow path of the connecting pipe. Coolant introduced from the engine's coolant drain pipe and through the inlet path of the inlet pipe flows through the inflow path of the connecting pipe to the second pipe.

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