Engine exhaust heat recovery device, exhaust system, heat exchange system and vehicle

Abstract

The application discloses an engine exhaust waste heat recovery device, an exhaust system, a heat exchange system and a vehicle, and belongs to the technical field of thermal management. The engine exhaust waste heat recovery device comprises an exhaust pipe. A pipe cavity of the exhaust pipe is used for circulating exhaust gas of an engine. A heat exchange flow channel is formed in a pipe wall of the exhaust pipe. The heat exchange flow channel is used for circulating a heat exchange medium, so that the heat exchange medium and the exhaust gas in the pipe cavity perform heat exchange through the pipe wall. The heat exchange medium and the exhaust gas perform heat exchange through the pipe wall by arranging the heat exchange flow channel in the pipe wall of the exhaust pipe. The structure is simple, and no additional exhaust resistance is generated.

Description

Technical Field

[0001] This application relates to the field of thermal management technology, and in particular to an engine exhaust waste heat recovery device, an exhaust system, a heat exchange system, and a vehicle. Background Technology

[0002] During operation, engines generate a large amount of high-temperature exhaust gas, which typically reaches temperatures of 400°C to 700°C and contains considerable heat energy. To improve the overall energy efficiency of the vehicle, existing technologies often incorporate waste heat recovery devices to recover exhaust heat, which is then used to heat onboard fluids such as coolant, engine oil, or air conditioning refrigerant. This supports functions such as rapid engine warm-up, improved cold-start emissions, or providing heating for the passenger compartment.

[0003] Currently, there are two main types of exhaust waste heat recovery solutions: one type involves connecting an independent heat exchanger (such as a shell-and-tube or plate-fin structure) in series in the exhaust pipe, with the heat exchange element placed directly inside the exhaust flow channel; the other type involves adding a jacket or sleeve to the outside of the exhaust pipe, forming a heat exchange chamber between the jacket and the exhaust pipe. Although the former has higher heat exchange efficiency, the heat exchange structure occupies the exhaust channel, resulting in a reduced flow cross-section and increased flow resistance, thereby raising the exhaust back pressure and affecting the engine's pumping efficiency and power performance. Although the latter does not directly affect the exhaust flow, it requires additional sleeves, sealing end caps, and support structures, resulting in a large overall size and many parts, making it difficult to arrange in the space-constrained engine compartment, and it is prone to leakage or failure under high temperature and vibration conditions. Utility Model Content

[0004] This application provides an engine exhaust waste heat recovery device, an exhaust system, a heat exchange system, and a vehicle to at least partially solve the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, an engine exhaust waste heat recovery device is provided, comprising an exhaust pipe, wherein the cavity of the exhaust pipe is used for the flow of engine exhaust, and a heat exchange channel is formed in the wall of the exhaust pipe for the flow of a heat exchange medium, so that the heat exchange medium and the exhaust in the cavity exchange heat through the pipe wall.

[0006] Optionally, the engine exhaust waste heat recovery device further includes a heat exchange structure, which is disposed in the heat exchange channel and is thermally connected to the pipe wall.

[0007] Optionally, the engine exhaust waste heat recovery device further includes a pressure relief valve, which is connected to the heat exchange channel.

[0008] Optionally, the engine exhaust waste heat recovery device further includes a pressure relief pipe, one end of which is connected to the heat exchange channel through the pressure relief valve, and the other end of which is used to connect to the heat exchange medium storage device.

[0009] According to a second aspect of this application, an exhaust system is provided, including an engine exhaust waste heat recovery device as described in any of the above claims.

[0010] Optionally, the exhaust system further includes: A catalytic converter, wherein the air inlet of the catalytic converter is connected to the exhaust port of the engine, and the exhaust port of the catalytic converter is connected to one end of the cavity of the exhaust pipe of the engine exhaust waste heat recovery device; A muffler, wherein the air inlet of the muffler is connected to the other end of the cavity of the exhaust pipe.

[0011] According to a third aspect of this application, a heat exchange system is also provided, including a heat exchange component and an engine exhaust waste heat recovery device as described in any of the above claims, wherein the heat exchange system has a heat exchange circuit, and the heat exchange component and the heat exchange flow channel of the engine exhaust waste heat recovery device are disposed in the heat exchange circuit.

[0012] Optionally, the heat exchange system further includes an on / off device, which is located in the heat exchange circuit and is used to control the opening or closing of the heat exchange channel.

[0013] Optionally, the on / off device includes a first shut-off valve and a second shut-off valve, and the heat exchange circuit includes: Hot dry road; The first heat exchange branch is connected to the heat exchange main branch; The second heat exchange branch is arranged in parallel with the first heat exchange branch and is connected to the heat exchange main branch; The heat exchange component is located in the first heat exchange branch, the first shut-off valve, the second shut-off valve and the heat exchange flow channel are located in the second heat exchange branch, and the heat exchange flow channel is located between the first shut-off valve and the second shut-off valve.

[0014] According to a fourth aspect of this application, a vehicle is also provided, including the exhaust system as described above or the heat exchange system as described above.

[0015] In the engine exhaust waste heat recovery device of this application embodiment, the cavity of the exhaust pipe serves as the exhaust flow channel of the engine. When the exhaust flows within the cavity, its heat can be transferred outward through the pipe wall. A heat exchange channel is provided inside the pipe wall for the flow of the heat exchange medium, allowing the heat exchange medium to exchange heat with the exhaust through the pipe wall. Since the heat exchange channel is located inside the pipe wall, it does not occupy or alter the flow space of the cavity, the exhaust flow path remains intact, and no additional resistance is generated, thus not affecting the normal exhaust of the engine. Furthermore, by utilizing the pipe wall itself as the heat exchange structure, no additional components are required, resulting in a simple overall structure. In summary, by setting a heat exchange channel inside the exhaust pipe wall, the heat exchange medium and exhaust exchange heat through the pipe wall, resulting in a simple structure and no additional exhaust resistance.

[0016] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0018] Figure 1 This is a three-dimensional structural schematic diagram of the engine exhaust waste heat recovery device provided in an exemplary embodiment of this disclosure; Figure 2 yes Figure 1 A cross-sectional schematic diagram of the engine exhaust waste heat recovery device; Figure 3 yes Figure 1 An exploded schematic diagram of the engine exhaust waste heat recovery device; Figure 4 This is a schematic diagram of the structural principle of the heat exchange system provided in an exemplary embodiment of this disclosure; Figure 5 yes Figure 4 A schematic diagram of the heat exchange system in the first working mode; Figure 6 yes Figure 4 A schematic diagram of the heat exchange system in the second working mode; Figure 7 yes Figure 4 A schematic diagram of the heat exchange system in the third working mode; Figure 8 yes Figure 4A schematic diagram of the heat exchange system in the fourth operating mode; Figure 9 yes Figure 4 A schematic diagram of the heat exchange system in the fifth working mode; Figure 10 This is a schematic diagram of another structural principle of the heat exchange system provided in an exemplary embodiment of this disclosure; Figure 11 This is another schematic diagram of the structural principle of the heat exchange system provided in the exemplary embodiments of this disclosure.

[0019] Explanation of reference numerals in the attached figures: 100. Heat exchange system; 10. Heat exchange loop; 101. Heat exchange trunk line; 102. First heat exchange branch line; 103. Second heat exchange branch line; 1. Engine exhaust waste heat recovery device; 11. Exhaust pipe; 111. Pipe cavity; 1111. Pipe cavity inlet; 1112. Pipe cavity outlet; 112. Pipe wall; 1121. Heat exchange flow channel; 113. Heat exchange structure; 114. Third flange; 115. Fourth flange; 12. Pressure relief valve; 13. Pressure relief pipe; 14. Heat exchange medium inlet pipe; 15. Heat exchange medium outlet pipe; 16. First connecting pipe; 161. First flange; 17. Second connecting pipe; 171. Second flange; 18. Seal; 2. Heat exchange components; 21. 21. Cylinder block and cylinder head; 22. Heat exchanger; 23. EGR cooler; 24. Oil cooler; 25. Battery cold plate; 3. On / off device; 31. First shut-off valve; 32. Second shut-off valve; 41. Water pump; 42. Cooling medium power unit; 51. First thermostat; 52. Second thermostat; 61. First radiator; 62. Second radiator; 71. First expansion tank; 72. Second expansion tank; 81. Third shut-off valve; 82. Fourth shut-off valve; 83. Fifth shut-off valve; 84. Sixth shut-off valve; 85. Three-way valve. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0021] Please see Figure 1 , Figure 2 and Figure 3This application provides an engine exhaust waste heat recovery device 1, including an exhaust pipe 11, the cavity 111 of the exhaust pipe 11 for the flow of engine exhaust, and a heat exchange channel 1121 formed in the pipe wall 112 of the exhaust pipe 11 for the flow of heat exchange medium, so that the heat exchange medium and the exhaust in the cavity 111 can exchange heat through the pipe wall 112.

[0022] In the technical solution of this application, the cavity 111 of the exhaust pipe 11 serves as the exhaust flow channel of the engine. When the exhaust flows within the cavity 111, its heat can be transferred outward through the pipe wall 112. A heat exchange channel 1121 is provided inside the pipe wall 112 for the flow of the heat exchange medium, allowing the heat exchange medium to exchange heat with the exhaust through the pipe wall 112. Since the heat exchange channel 1121 is located inside the pipe wall 112, it does not occupy or alter the flow space of the cavity 111, the exhaust flow path remains intact, and no additional resistance is generated, thus not affecting the normal exhaust of the engine. Simultaneously, utilizing the pipe wall 112 itself as the heat exchange structure 113 eliminates the need for additional components, resulting in a simple overall structure. In summary, by providing a heat exchange channel 1121 within the pipe wall 112 of the exhaust pipe 11, the heat exchange medium and exhaust exchange heat through the pipe wall 112, resulting in a simple structure without generating additional exhaust resistance.

[0023] In some embodiments, the pipe wall 112 is made of metal, alloy or other high thermal conductivity materials with strong temperature resistance and excellent thermal conductivity, such as stainless steel, aluminum alloy, copper alloy, etc., to ensure long-term stable operation in high-temperature exhaust environment and to effectively transfer heat.

[0024] This disclosure does not limit the overall shape of the exhaust pipe 11, which can be cylindrical, rectangular or any other form. The specific design can be adapted according to the heat exchange requirements, exhaust flow characteristics and the layout space around the exhaust system, so as to meet the structural strength and heat exchange efficiency while taking into account the flexibility of the overall vehicle layout.

[0025] Please see Figure 1 , Figure 2 and Figure 3 In some embodiments, the engine exhaust waste heat recovery device 1 further includes a heat exchange medium inlet pipe 14 and a heat exchange medium outlet pipe 15. The heat exchange medium inlet pipe 14 and the heat exchange medium outlet pipe 15 are connected to the outside of the exhaust pipe 11 and are respectively connected to the heat exchange flow channel 1121 in the pipe wall 112, for guiding the heat exchange medium into and out of the heat exchange flow channel 1121.

[0026] Please see Figure 1 , Figure 2 and Figure 3In some embodiments, the heat exchange channel 1121 is arranged around the cavity 111 in a spiral, annular or multi-channel parallel form within the pipe wall 112; the heat exchange medium inlet pipe 14 and the heat exchange medium outlet pipe 15 are respectively close to the two ends of the exhaust pipe 11 in the axial direction and located on both sides of the exhaust pipe 11 in the radial direction, so that the heat exchange medium flows from one end to the other along the pipe wall 112 within the heat exchange channel 1121, forming a longer heat exchange path, thereby extending the heat exchange time and improving the heat exchange efficiency.

[0027] Please see Figure 2 In some embodiments, along the axial direction of the exhaust pipe 11, the heat exchange medium inlet pipe 14 and the cavity outlet 1112 are located at the same end, and the heat exchange medium outlet pipe 15 and the cavity inlet 1111 are located at the same end. This arrangement can form counter-current heat exchange: the high-temperature exhaust (near the cavity inlet 1111) exchanges heat with the already heat-exchanged, higher-temperature heat exchange medium (near the heat exchange medium outlet), while the low-temperature exhaust (near the cavity outlet 1112) exchanges heat with the newly entered low-temperature heat exchange medium (near the heat exchange medium inlet), thereby maintaining a large average temperature difference throughout the heat exchange path and improving heat exchange efficiency.

[0028] Please see Figure 2 In some embodiments, the engine exhaust waste heat recovery device 1 further includes a heat exchange structure 113, which is disposed within the heat exchange channel 1121 and is thermally connected to the pipe wall 112. In these embodiments, the heat exchange structure 113 is configured to increase the effective heat exchange area within the heat exchange channel 1121 and / or disturb the flow state of the heat exchange medium, thereby enhancing the heat conduction and convection heat transfer effect between the heat exchange medium and the pipe wall 112. Simultaneously, since the heat exchange structure 113 is directly thermally connected to the pipe wall 112, it can efficiently transfer the heat absorbed by the pipe wall 112 from the exhaust side to the heat exchange medium, further improving the waste heat recovery efficiency.

[0029] This disclosure does not limit the specific form of the heat exchange structure 113. The heat exchange structure 113 may be a porous medium, fins, baffles, or other structural forms that can increase the heat exchange area and disturb the fluid flow to enhance the heat exchange performance.

[0030] Please see Figure 1 , Figure 2 and Figure 3 In some embodiments, the engine exhaust waste heat recovery device 1 further includes a pressure relief valve 12, which is connected to the heat exchange channel 1121. In these embodiments, when the pressure of the heat exchange medium in the heat exchange channel 1121 rises to a set threshold due to thermal expansion or abnormal operating conditions, the pressure relief valve 12 automatically opens to release part of the medium to reduce the system pressure, thereby preventing damage to the pipe wall 112 or the connection parts due to overpressure and ensuring the safety and reliability of the device operation.

[0031] Please see Figure 1 and Figure 3 In some embodiments, the engine exhaust waste heat recovery device 1 further includes a pressure relief pipe 13. One end of the pressure relief pipe 13 is connected to the heat exchange channel 1121 via a pressure limiting valve 12, and the other end of the pressure relief pipe 13 is used to connect to a heat exchange medium storage device. In these embodiments, when the pressure inside the heat exchange channel 1121 exceeds the opening threshold of the pressure limiting valve 12, the excess heat exchange medium is discharged into the pressure relief pipe 13 through the pressure limiting valve 12 and flows back to the heat exchange medium storage device (such as an expansion tank, oil pan, etc.), avoiding direct leakage of the medium and causing losses or environmental pollution.

[0032] According to a second aspect of this application, an exhaust system is provided, including an engine exhaust waste heat recovery device 1. The structure of the engine exhaust waste heat recovery device 1 is as described above. Since the exhaust system includes the aforementioned engine exhaust waste heat recovery device 1, the exhaust system has all the beneficial effects of the aforementioned engine exhaust waste heat recovery device 1, which will not be repeated here.

[0033] In some embodiments, the exhaust system further includes a catalytic converter and a muffler. The catalytic converter's intake port is connected to the engine's exhaust port, and the catalytic converter's exhaust port is connected to one end (i.e., the inlet 1111) of the exhaust pipe 11 of the engine exhaust waste heat recovery device 1. The muffler's intake port is connected to the other end (i.e., the outlet 1112) of the exhaust pipe 11. In these embodiments, the exhaust pipe 11 of the engine exhaust waste heat recovery device 1 is connected in series between the catalytic converter and the muffler. In this case, the exhaust gas, after being converted into harmful gases by the catalytic converter, still maintains a relatively high temperature (typically 300°C to 600°C) and enters the engine exhaust waste heat recovery device 1 for heat exchange. This avoids the adverse effects on catalytic efficiency that may be caused by temperature loss due to the introduction of the heat exchange structure 113 at the front of the catalytic converter, and effectively captures the high-temperature exhaust energy that still has recovery value in the rear of the catalytic converter, achieving synergistic optimization of waste heat utilization and emission control.

[0034] Please see Figure 1 , Figure 2 and Figure 3 In some embodiments, the engine exhaust waste heat recovery device 1 further includes a first connecting pipe 16 with one end connected to the catalytic converter exhaust port and a second connecting pipe 17 with one end connected to the muffler intake port; the other end of the first connecting pipe 16 is connected to a first flange 161, the other end of the second connecting pipe 17 is connected to a second flange 171, and the two ends of the exhaust pipe 11 are respectively provided with a third flange 114 and a fourth flange 115; the first flange 161 is mated with the third flange 114, the second flange 171 is mated with the fourth flange 115, and a sealing element 18 is provided between each mating flange to seal the connection interface and prevent exhaust leakage.

[0035] Please see Figure 5 According to a third aspect of this application, a heat exchange system 100 is also provided, including a heat exchange component 2 and an engine exhaust waste heat recovery device 1. The structure of the engine exhaust waste heat recovery device 1 is as described above. The heat exchange system 100 has a heat exchange circuit 10, and the heat exchange component 2 and the heat exchange flow channel 1121 of the engine exhaust waste heat recovery device 1 are disposed in the heat exchange circuit 10. Since the heat exchange system 100 includes the aforementioned engine exhaust waste heat recovery device 1, the heat exchange system 100 has all the beneficial effects of the aforementioned engine exhaust waste heat recovery device 1, which will not be repeated here. Furthermore, since the engine exhaust waste heat recovery device 1 and the heat exchange component 2 are integrated in the same heat exchange circuit 10, the heat exchange medium can directly flow through the heat exchange flow channel 1121 to absorb exhaust waste heat without additional pumping or intermediate heat exchangers, and then immediately enter the heat exchange component 2 to release heat, thereby achieving efficient and direct heat transfer. This structure not only simplifies the system piping layout and reduces energy consumption and cost, but also significantly improves the response speed of waste heat utilization and the flexibility of thermal management.

[0036] Please see Figure 5 In some embodiments, the heat exchange system 100 further includes an on / off device 3, which is disposed in the heat exchange circuit 10 and is used to control the opening or closing of the heat exchange channel 1121. In these embodiments, when the vehicle is in a cold start, high load, or specific thermal management requirement condition, the on / off device 3 can open the heat exchange channel 1121, allowing the heat exchange medium to flow through the engine exhaust waste heat recovery device 1 to absorb exhaust heat; while in conditions where waste heat recovery is not required (such as when the system is overheated, the heat exchange component 2 has met the temperature requirements, or the exhaust temperature is too low), the on / off device 3 can close the heat exchange channel 1121, allowing the heat exchange medium to bypass or stop flowing through the device, thereby avoiding unnecessary heat exchange or energy loss and improving the flexibility and energy efficiency of the vehicle's thermal management.

[0037] It is understandable that when the on / off device 3 disconnects the heat exchange channel 1121, residual liquid heat exchange medium (such as engine coolant, battery coolant, or high-temperature heat transfer oil) may still remain in the heat exchange channel 1121. When the engine continues to exhaust and the temperature of the pipe wall 112 rises, this residual medium may be heated and vaporized, causing the internal pressure of the heat exchange channel 1121 to rise. At this time, if the system is equipped with a pressure limiting valve 12 and a pressure relief pipe 13, the vapor can be released by opening the pressure limiting valve 12, and the gaseous heat exchange medium can be diverted to the corresponding heat exchange medium storage device (such as an expansion tank or a liquid storage tank) through the pressure relief pipe 13. The gaseous medium can gradually condense and flow back to the storage device during the transportation process, thereby avoiding pipeline deformation or leakage caused by pressure accumulation, and realizing the recycling of the medium.

[0038] Please see Figure 5In some embodiments, the on / off device 3 includes a first shut-off valve 31 and a second shut-off valve 32, and the heat exchange circuit 10 includes a heat exchange main line 101, a first heat exchange branch line 102 and a second heat exchange branch line 103. The first heat exchange branch line 102 is connected to the heat exchange main line 101; the second heat exchange branch line 103 is arranged in parallel with the first heat exchange branch line 102 and is connected to the heat exchange main line 101. The heat exchange component 2 is disposed in the first heat exchange branch line 102, and the first shut-off valve 31, the second shut-off valve 32 and the heat exchange flow channel 1121 are disposed in the second heat exchange branch line 103, and the heat exchange flow channel 1121 is disposed between the first shut-off valve 31 and the second shut-off valve 32. In these embodiments, by simultaneously closing the first shut-off valve 31 and the second shut-off valve 32, the pipe section containing the heat exchange channel 1121 can be completely isolated from the heat exchange circuit 10, achieving a complete cut-off of that channel. When the waste heat recovery function needs to be activated, the first shut-off valve 31 and the second shut-off valve 32 are opened simultaneously, allowing the heat exchange medium to flow through the heat exchange channel 1121 for heat exchange. This dual-valve clamping layout not only reliably controls the opening and closing of the heat exchange channel 1121, but also seals the heat exchange channel 1121 during maintenance or failure to prevent medium leakage, and ensures that the heat exchange component 2 in the first heat exchange branch 102 can still operate independently, thereby improving the flexibility, safety, and reliability of system operation.

[0039] In the heat exchange system 100, the heat exchange medium can be engine coolant, battery coolant, high-temperature heat transfer oil, refrigerant, or other fluid media; the heat exchange circuit 10 can include at least one of the following: engine coolant main circulation path, engine oil heat exchange path, battery temperature control path, and passenger compartment heating path, or any combination thereof forming an integrated thermal management circuit; the heat exchange component 2 is configured to use the heat exchange medium heated by the exhaust waste heat of the engine to heat or regulate the temperature of the target object, and it can include specially designed heat exchangers (such as heater heat exchanger 22, engine oil cooler 24, battery cold plate 25, EGR cooler 23, etc.), or it can include parts of the engine body that participate in heat exchange, such as the cylinder block and cylinder head 21 (the cylinder block is equipped with a cooling water jacket, through which the coolant can absorb or release heat, thereby achieving temperature regulation of the engine).

[0040] It should be noted that the heat exchange trunk line 101, the first heat exchange branch line 102, and the second heat exchange branch line 103 in this article do not specifically refer to physically isolated or structurally fixed pipes, but rather to the dynamic flow paths formed by the actual flow of the heat exchange medium under the control of various flow path switching devices during system operation. For example, according to different thermal management needs (such as cold start warm-up, battery heating, waste heat recovery, or heat dissipation conditions), the control system can open or close corresponding valves to allow the heat exchange medium to selectively flow through different components, thereby logically forming the trunk line and each branch line.

[0041] The working principle of the heat exchange system 100 is explained below with reference to several specific implementation methods.

[0042] like Figure 4 The diagram illustrates the working principle of an example scheme for heating engine coolant and oil via exhaust gas. The engine coolant flow path is shown by solid lines in the diagram. Water pump 41 provides coolant circulation pressure. EGR cooler 23 is connected in parallel across cylinder block / cylinder head 21 and heater core 22, forming the main coolant circulation path together with first thermostat 51, second thermostat 52, first radiator 61, and first expansion tank 71. Heat exchange passages 1121 of exhaust pipe 11 are connected in parallel across the main circulation path (across EGR cooler 23, cylinder block / cylinder head 21, and heater core 22, or any other suitable location).

[0043] like Figure 5 The diagram shows the workflow of exhaust heating of engine coolant. When the engine coolant needs to absorb exhaust heat, the first shut-off valve 31 and the second shut-off valve 32 open, while the third shut-off valve 81 and the fourth shut-off valve 82 close. After being pressurized by the main flow pump 41, a portion of the coolant flow is drawn out to form a branch, entering the heat exchange channel 1121 of the exhaust pipe 11 through the heat exchange medium inlet pipe 14. After fully absorbing exhaust heat through the heat exchange structure 113 within the heat exchange channel 1121, the coolant flows out through the heat exchange medium outlet pipe 15 and then returns to the main circulation path. At this time, the engine is in a rapid warm-up phase, the first radiator 61 is not working, and the coolant in the main circulation path operates in a small circulation mode, playing a role in heating the engine body.

[0044] like Figure 6 The diagram shows the workflow of exhaust heating of engine oil. Due to the high viscosity of the engine oil, after the oil exchanges heat with the exhaust, the channels of the first shut-off valve 31 and the second shut-off valve 32 are completely closed. The remaining oil in the heat exchange channel 1121 is too viscous to be discharged in time and is easily decomposed by the continuous high temperature from the exhaust. This not only damages the durability and lifespan of the engine exhaust waste heat recovery device 1 but also reduces the amount of lubricating oil in the engine system. Therefore, the engine oil cannot directly exchange heat with the exhaust in the exhaust pipe 11. Therefore, engine coolant is used as a medium to transfer exhaust heat to the engine oil. When the engine oil needs to absorb exhaust heat, the first shut-off valve 31 and the third shut-off valve 81 open, while the second shut-off valve 32 and the fourth shut-off valve 82 close. The coolant sequentially passes through the water pump 41, the first shut-off valve 31, the exhaust pipe 11, the third shut-off valve 81, and the oil cooler 24, finally returning to the water pump 41 to complete the circulation. Heat exchange between the coolant and the engine oil is completed in the oil cooler 24. At this time, the coolant plays the role of heating the engine oil.

[0045] like Figure 7The diagram illustrates the process of simultaneously heating the engine coolant and engine oil via exhaust. When both the engine coolant and engine oil need to absorb heat from the exhaust, the first shut-off valve 31, the second shut-off valve 32, and the third shut-off valve 81 open, while the fourth shut-off valve 82 closes. After passing through the exhaust pipe 11, a portion of the coolant flows through the second shut-off valve 32 to the main coolant circulation path, while the other portion flows through the third shut-off valve 81 to the oil cooler 24, achieving simultaneous heating of both the engine oil and the coolant. At this time, the coolant functions to heat both the engine oil and the engine block.

[0046] like Figure 8 The diagram illustrates another method for simultaneously heating engine coolant and oil via exhaust. First shut-off valve 31 and second shut-off valve 32 are open, third shut-off valve 81 is closed, and fourth shut-off valve 82 is open. After passing through exhaust pipe 11, the coolant returns to the main coolant circulation path. After being pressurized by water pump 41, a portion flows through fourth shut-off valve 82 to oil cooler 24, achieving simultaneous heating of both oil and coolant. At this time, the coolant also functions to heat the engine oil and the engine itself.

[0047] like Figure 9 The diagram shows the workflow when neither the engine coolant nor the engine oil needs heating, i.e., when the engine is in a warm-up state. At this time, the first shut-off valve 31, the second shut-off valve 32, and the third shut-off valve 81 are all closed. The coolant, in addition to flowing in the main coolant circulation path, is diverted at the outlet of the water pump 41, entering the oil cooler 24 through the fourth shut-off valve 82, and finally returning to the water pump 41. Meanwhile, the second thermostat 52 switches the flow path to the first radiator 61, and the coolant in the main circulation path operates in a large circulation mode, effectively cooling the engine oil and the engine itself.

[0048] A pressure relief pipe 13 and a pressure limiting valve 12 are located at the top center of the exhaust pipe 11. When the engine reaches a warm-up state, the first shut-off valve 31 and the second shut-off valve 32 close simultaneously, leaving a large amount of residual coolant in the space between the two shut-off valves, including inside the exhaust pipe 11, which does not return to the main circulation path. As exhaust continues to pass through the exhaust pipe 11, the residual coolant is continuously heated and gradually evaporates, causing the temperature and pressure inside the cavity to rise continuously. When the temperature and pressure inside the cavity reach a set value, the pressure limiting valve 12 opens to discharge the steam. Figures 4 to 9 The dashed line in the middle indicates the degassing path. During the discharge process, the coolant vapor gradually condenses in the degassing pipeline and eventually returns to the first expansion tank 71 to be collected again. The uncondensed vapor is discharged to the outside of the system as the pressure relief valve 12 opens after the pressure in the first expansion tank 71 reaches the limit.

[0049] Figure 10This is a schematic diagram illustrating the working principle of heating the battery cooling medium using exhaust gas. The battery cold plate 25, cooling medium power unit 42, second radiator 62, and second expansion tank 72 form the battery cooling medium circulation loop. The battery cooling medium can be coolant, refrigerant, or other media. Correspondingly, the cooling medium power unit 42 can be a water pump 41, a compressor, or other equipment. When the battery cooling medium needs to absorb exhaust heat, the first shut-off valve 31 and the second shut-off valve 32 open simultaneously. After being pressurized by the water pump 41, a portion of the cooling medium is drawn out to form a branch and enter the heat exchange channel 1121 of the exhaust pipe 11. When the battery cooling medium does not need to absorb exhaust heat, the first shut-off valve 31 and the second shut-off valve 32 close simultaneously. The heat exchange and degassing processes of heating the battery cooling medium using exhaust gas are similar to those of heating engine coolant using exhaust gas. The battery cooling medium can return to the second expansion tank 72.

[0050] Please see Figure 11 When the battery coolant and engine coolant have the same composition, the engine coolant flow path and the battery coolant flow path can be integrated through valves and pipes, with the exhaust pipe 11 as the node. When the exhaust pipe 11 is used to heat the engine coolant, the first shut-off valve 31 and the second shut-off valve 32 are open, the fifth shut-off valve 83 and the sixth shut-off valve 84 are closed, and the three-way valve 85 switches to the first expansion tank 71; when the exhaust pipe 11 is used to heat the battery coolant, the first shut-off valve 31 and the second shut-off valve 32 are closed, the fifth shut-off valve 83 and the sixth shut-off valve 84 are open, and the three-way valve 85 switches to the second expansion tank 72; when the exhaust pipe 11 is not working, the first shut-off valve 31, the second shut-off valve 32, the fifth shut-off valve 83, and the sixth shut-off valve 84 are all closed.

[0051] When the engine coolant needs to be heated by the waste heat of the engine exhaust: The control system first determines whether the engine needs to run based on the driving conditions and battery status, and determines whether the motor has entered normal operating condition by checking the motor circulating coolant temperature, i.e., the motor parameters. When it is confirmed that the motor operating temperature is normal and the engine needs to run, the engine body temperature TE and the motor circulating coolant temperature TMC are collected to determine whether the motor circulating coolant needs to heat the engine coolant. When the difference between TMC and TE satisfies TMC - TE = ΔT > ΔTsat, the engine relies on the waste heat of the motor to heat up; when 0 < ΔT < ΔTsat (ΔTsat is a set value), the engine is started, and after the engine runs smoothly, the heat exchange between the motor coolant and the engine coolant is cut off, and the first shut-off valve 31 and the second shut-off valve 32 are opened at the same time, allowing the engine coolant to exchange heat with the high-temperature exhaust through the exhaust pipe 11. When the engine coolant temperature TEC and the engine body temperature both reach the set value TE-sat, the first shut-off valve 31 and the second shut-off valve 32 are closed at the same time, and the electronic thermostat is controlled to start the large circulation.

[0052] When it is required to heat engine oil by means of engine exhaust waste heat: the control system first determines whether the engine needs to operate according to driving conditions and battery status, and determines whether the motor has entered a normal working state according to the temperature of the motor circulating coolant. After confirming that the working temperature of the motor is normal and the engine needs to operate, the engine body temperature TE, the oil temperature TO and the motor circulating coolant temperature TMC are collected to determine whether the motor circulating coolant is required to heat the engine oil. When TMC - TE>ΔTsat or TMC - TO>ΔTsat, the motor coolant is used to heat the engine oil; when 0<TMC - TE<ΔTsat and 0<TMC - TO<ΔTsat, the engine is controlled to start, and after the engine operates stably, the heat exchange between the motor coolant and the engine oil is cut off. Since the viscosity of the oil is relatively high, if the oil still remains in the heat exchanger after the heat exchange between the oil and the exhaust gas, it is easily decomposed by high temperature, resulting in loss of lubricating oil amount in the engine system, so the oil cannot directly exchange heat with the exhaust gas in the exhaust pipe 11. Therefore, engine coolant is used as a medium to transfer exhaust heat to the oil, the heat exchange between the motor coolant and the engine oil is cut off, and at the same time, the first stop valve 31 and the second stop valve 32 are opened, so that the engine coolant exchanges heat with high-temperature exhaust gas through the exhaust pipe 11. The heated coolant transfers heat to the engine oil through the oil cooler 24. After both the engine oil temperature and the engine body temperature reach the set value TE-sat, the first stop valve 31 and the second stop valve 32 are closed at the same time, and the electronic thermostat is controlled to open the large circulation, at which time the coolant cools the oil through the oil cooler 24.

[0053] When it is required to heat the battery by means of engine exhaust waste heat: when the engine is in an operating state, the control system receives a start signal and a temperature signal from the battery system. When the battery is started and the battery temperature value is lower than the set normal operating temperature value of the battery, the first stop valve 31 and the second stop valve 32 are opened at the same time, and the battery cooling medium is introduced into the cooling medium flow channel of the exhaust pipe 11 to exchange heat with the exhaust gas. After both the battery cooling medium temperature TBC and the battery temperature TB reach the set value TB-sat, the first stop valve 31 and the second stop valve 32 are closed at the same time, a degassing process is performed, and the discharged steam flows through the pipeline, condenses and returns to the second expansion tank 72.

[0054] Degassing process: After the exhaust pipe 11 completes heat exchange and the first shut-off valve 31 and the second shut-off valve 32 are closed, a significant amount of cooling medium remains in the heat exchange channel 1121 and is not discharged in time. As the engine continues to operate and exhaust continues to flow through the exhaust pipe 11, the cooling medium in the heat exchange channel 1121 is continuously heated. The control system constantly monitors the temperature and pressure status in the heat exchange channel 1121. When the gas pressure P in the heat exchange channel 1121 exceeds the pressure relief valve 12's pressure relief setting value Psat, the pressure relief valve 12 opens, and high-pressure steam is discharged along the pressure relief pipe 13 to the liquid storage structure (first expansion tank 71 and / or second expansion tank 72). As the steam is discharged, the pressure inside the cavity decreases to below the pressure relief valve 12's pressure relief setting value Psat, and the pressure relief valve 12 closes.

[0055] According to the fourth aspect of this application, a vehicle is also provided, including an exhaust system or heat exchange system 100, the structure of which is as described above. Since the vehicle includes the exhaust system or heat exchange system 100, the vehicle has all the beneficial effects of the exhaust system or heat exchange system 100, which will not be repeated here.

[0056] The vehicle may be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc., and this disclosure does not make any specific restrictions.

[0057] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0058] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0059] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0060] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. An engine exhaust waste heat recovery device, characterized in that, The device includes an exhaust pipe, the cavity of which is used to circulate engine exhaust, and a heat exchange channel is formed inside the pipe wall of the exhaust pipe, the heat exchange channel being used to circulate a heat exchange medium so that the heat exchange medium and the exhaust in the cavity exchange heat through the pipe wall.

2. The engine exhaust waste heat recovery device according to claim 1, characterized in that, The engine exhaust waste heat recovery device also includes a heat exchange structure, which is disposed in the heat exchange channel and is thermally connected to the pipe wall.

3. The engine exhaust waste heat recovery device according to claim 1, characterized in that, The engine exhaust waste heat recovery device also includes a pressure relief valve, which is connected to the heat exchange channel.

4. The engine exhaust waste heat recovery device according to claim 3, characterized in that, The engine exhaust waste heat recovery device also includes a pressure relief pipe. One end of the pressure relief pipe is connected to the heat exchange channel through the pressure limiting valve, and the other end of the pressure relief pipe is used to connect to the heat exchange medium storage device.

5. An exhaust system, characterized in that, Includes the engine exhaust waste heat recovery device as described in any one of claims 1 to 4.

6. The exhaust system according to claim 5, characterized in that, The exhaust system also includes: A catalytic converter, wherein the air inlet of the catalytic converter is connected to the exhaust port of the engine, and the exhaust port of the catalytic converter is connected to one end of the cavity of the exhaust pipe of the engine exhaust waste heat recovery device; A muffler, wherein the air inlet of the muffler is connected to the other end of the cavity of the exhaust pipe.

7. A heat exchange system, characterized in that, The system includes a heat exchange component and an engine exhaust waste heat recovery device as described in any one of claims 1 to 4, wherein the heat exchange system has a heat exchange circuit, and the heat exchange component and the heat exchange flow channel of the engine exhaust waste heat recovery device are disposed in the heat exchange circuit.

8. The heat exchange system according to claim 7, characterized in that, The heat exchange system also includes an on / off device, which is located in the heat exchange circuit and is used to control the opening or closing of the heat exchange channel.

9. The heat exchange system according to claim 8, characterized in that, The on / off device includes a first shut-off valve and a second shut-off valve, and the heat exchange circuit includes: Hot dry road; The first heat exchange branch is connected to the heat exchange main branch; The second heat exchange branch is arranged in parallel with the first heat exchange branch and is connected to the heat exchange main branch; The heat exchange component is located in the first heat exchange branch, the first shut-off valve, the second shut-off valve and the heat exchange flow channel are located in the second heat exchange branch, and the heat exchange flow channel is located between the first shut-off valve and the second shut-off valve.

10. A vehicle, characterized in that, This includes the exhaust system as described in claim 5 or 6, or the heat exchange system as described in any one of claims 7 to 9.

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