EGR cooler with changeable heat structure

Abstract

This invention discloses an EGR cooler with a variable heat structure, relating to the field of engine exhaust gas recirculation cooling technology. The invention involves arranging a wave-gradient fin assembly within the exhaust gas flow channel cavity, with gently corrugated fins, deeply corrugated fins, and finely corrugated fins arranged sequentially along the exhaust gas flow direction. This allows the exhaust gas to pass through a low-resistance pre-cooling zone, an enhanced heat exchange zone, and a supplementary cooling zone during its straight-through flow. The gently corrugated fins reduce inlet flow resistance, the deeply corrugated fins enhance mid-section heat exchange capacity, and the finely corrugated fins improve outlet supplementary cooling effect. This improves the overall heat exchange efficiency and outlet exhaust gas temperature stability of the EGR cooler without significantly increasing exhaust gas flow resistance. Furthermore, the first, second, and third zone water jackets are respectively configured to correspond to the gently corrugated fins, deeply corrugated fins, and finely corrugated fins, allowing different heat exchange zones to selectively participate in cooling according to engine operating conditions.

Description

Technical Field

[0001] This invention relates to the field of engine exhaust gas recirculation cooling technology, specifically to an EGR cooler with a variable thermal structure. Background Technology

[0002] EGR system is one of the important technologies for reducing nitrogen oxide emissions in engines. It reduces the combustion temperature by reintroducing some of the high-temperature exhaust gas from the engine into the intake system, thereby reducing the generation of nitrogen oxides. In order to improve the cycle efficiency of EGR system, it is usually necessary to use EGR cooler to cool the recirculated exhaust gas to ensure engine combustion stability and emission performance.

[0003] Most existing EGR coolers adopt a fixed heat exchange structure, and their internal fin structure and coolant flow channels are usually of a single form. It is difficult to flexibly adjust the heat exchange intensity under different engine operating conditions. When the engine is under high load, the exhaust gas temperature is high, and traditional coolers are prone to insufficient heat exchange capacity. On the other hand, under low load or cold start conditions, if the cooling intensity is too high, it is easy to cause excessive cooling of the exhaust gas, which will affect the combustion stability of the engine.

[0004] Meanwhile, existing EGR coolers mostly employ a uniform corrugated fin structure, which, while enhancing heat exchange, can increase exhaust gas flow resistance, leading to higher pressure drop and increasing the risk of carbon buildup in localized areas. Furthermore, traditional coolant channels typically use a continuous, uninterrupted structure, making it impossible to provide zoned coolant supply according to the needs of different heat exchange zones. This can easily result in uneven cooling, unreasonable flow distribution, and pressure fluctuations, thus affecting the overall heat exchange efficiency and operational stability of the EGR cooler. Summary of the Invention

[0005] To address the problems of low heat exchange efficiency, high flow resistance, and unadjustable cooling intensity in existing EGR coolers, this invention provides an EGR cooler with a variable thermal structure.

[0006] The present invention is achieved through the following technical solution: an EGR cooler with a changeable heat structure, comprising a cooler shell, one end of which is provided with an exhaust gas inlet shell, and the other end of which is provided with an exhaust gas outlet shell. A plurality of heat exchange cores are provided inside the cooler shell, each of the plurality of heat exchange cores having an exhaust gas flow channel cavity, and each of the plurality of exhaust gas flow channel cavities being provided with a wave-gradient fin assembly. The wave-gradient fin assembly includes gently corrugated fins, deeply corrugated fins, and finely corrugated fins arranged sequentially along the exhaust gas flow direction. A partitioned water jacket type changeable heat exchanger is provided on the outside of several heat exchange cores. The partitioned water jacket type changeable heat exchanger includes a first partitioned water jacket, a second partitioned water jacket, a third partitioned water jacket, and two sealing partitions. The first partitioned water jacket, the second partitioned water jacket, and the third partitioned water jacket are respectively provided for gently corrugated fins, deeply corrugated fins, and finely corrugated fins, and adjacent partitioned water jackets are separated by sealing partitions. The cooler housing is provided with a partitioned water inlet assembly and three water outlet pipes. The partitioned water inlet assembly is connected to the first partitioned water jacket, the second partitioned water jacket and the third partitioned water jacket respectively. The three water outlet pipes are connected to the first partitioned water jacket, the second partitioned water jacket and the third partitioned water jacket respectively.

[0007] Furthermore, the gently corrugated fins are disposed on the side of the exhaust gas flow channel cavity near the exhaust gas inlet end shell, the deep corrugated fins are disposed between the gently corrugated fins and the fine corrugated fins, and the fine corrugated fins are disposed on the side of the exhaust gas flow channel cavity near the exhaust gas outlet end shell, so that the exhaust gas passes through the gently corrugated fins, the deep corrugated fins and the fine corrugated fins in sequence in the exhaust gas flow channel cavity.

[0008] Furthermore, the crest height of the gently corrugated fins is smaller than that of the deeply corrugated fins, and the corrugation pitch of the finely corrugated fins is smaller than that of both the gently corrugated and deeply corrugated fins. The junction of the gently corrugated and deeply corrugated fins forms a gradually deepening transition zone with increasing crest height, which is used to allow the exhaust gas to smoothly enter the enhanced heat exchange zone from the low-resistance pre-cooling zone. The junction of the deeply corrugated and finely corrugated fins forms a refined transition zone with gradually decreasing corrugation pitch, which is used to allow the exhaust gas to smoothly enter the supplementary cooling heat exchange zone from the enhanced heat exchange zone.

[0009] Furthermore, the waveform gradient fin assembly also includes a fin limiting plate and a fin supporting plate. The fin limiting plate is disposed at the junction of the gently corrugated fin and the deeply corrugated fin to maintain the waveform docking position between the gently corrugated fin and the deeply corrugated fin and to maintain the flow gap in the gradient transition zone. The fin supporting plate is disposed at the junction of the deeply corrugated fin and the finely corrugated fin to support the fin structure in the refined transition zone and to maintain the straight-through state of the exhaust gas flow channel cavity between the deeply corrugated fin and the finely corrugated fin.

[0010] Furthermore, the first partition water jacket covers the outer side of the heat exchange core corresponding to the gently corrugated fins, the second partition water jacket covers the outer side of the heat exchange core corresponding to the deeply corrugated fins, and the third partition water jacket covers the outer side of the heat exchange core corresponding to the finely corrugated fins. The sealing partition is connected between the cooler shell and the heat exchange core to restrict the flow of coolant between adjacent partition water jackets.

[0011] Furthermore, the length of the second partition water jacket along the exhaust gas flow direction is greater than the lengths of the first partition water jacket and the third partition water jacket along the exhaust gas flow direction, so that the second partition water jacket and the deep corrugated fins correspond to form the main heat exchange area.

[0012] Furthermore, the partitioned water inlet assembly includes a first water inlet pipe, a second water inlet pipe, and a third water inlet pipe. The first water inlet pipe is connected to the first partitioned water jacket, the second water inlet pipe is connected to the second partitioned water jacket, and the third water inlet pipe is connected to the third partitioned water jacket, so that the first partitioned water jacket, the second partitioned water jacket, and the third partitioned water jacket can be independently inlet.

[0013] Furthermore, the partitioned water inlet assembly also includes a pressure-stabilizing and replenishing pipe one, a pressure-stabilizing connecting cavity, a pressure-stabilizing connecting plate, a one-way valve, and a pressure-stabilizing and replenishing pipe two. The cooler housing has a pressure-stabilizing connecting cavity inside. The pressure-stabilizing and replenishing pipe one and the pressure-stabilizing and replenishing pipe two are both connected to the pressure-stabilizing connecting cavity. The pressure-stabilizing connecting cavity is connected to the first partition water jacket, the second partition water jacket, and the third partition water jacket respectively through three pressure-stabilizing connecting plates.

[0014] Furthermore, a one-way valve is installed inside the first pressure-stabilizing and replenishing pipe, and three pressure-stabilizing connecting plates are correspondingly arranged between the pressure-stabilizing connecting cavity and the first, second, and third partition water jackets. The pressure-stabilizing connecting plates are provided with connecting holes corresponding to the first, second, and third partition water jackets, so that the coolant in the pressure-stabilizing connecting cavity can be replenished into the first, second, and third partition water jackets respectively, and the pressure of the three partition water jackets can be balanced during the partition water inlet process.

[0015] The present invention has the following beneficial effects: This EGR cooler with a variable heat structure incorporates a wave-gradient fin assembly within the exhaust gas flow channel. The arrangement of gently corrugated fins, deeply corrugated fins, and finely corrugated fins along the exhaust gas flow direction allows the exhaust gas to sequentially pass through a low-resistance pre-cooling zone, an enhanced heat transfer zone, and a supplementary cooling zone during its straight-through flow. The gently corrugated fins reduce inlet flow resistance, the deeply corrugated fins enhance mid-section heat transfer, and the finely corrugated fins improve outlet supplementary cooling. This enhances the overall heat transfer efficiency and outlet exhaust gas temperature stability of the EGR cooler without significantly increasing exhaust gas flow resistance.

[0016] This EGR cooler with a variable heat structure uses three water jackets—the first, second, and third—to correspond to gently corrugated fins, deeply corrugated fins, and finely corrugated fins, respectively. Liquid is supplied through the first, second, and third inlet pipes, allowing different heat exchange zones to selectively participate in cooling according to engine operating conditions. Simultaneously, the pressure-stabilizing and replenishing pipe one, the pressure-stabilizing connecting chamber, the pressure-stabilizing connecting plate, the one-way valve, and the pressure-stabilizing and replenishing pipe two work together to provide auxiliary replenishment and pressure balance for the three water jackets, reducing localized liquid shortages, crossflow, and pressure fluctuations during the zoned liquid supply process, thereby improving the stability of the variable heat regulation.

[0017] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the cooler housing of the present invention; Figure 2 This is a schematic diagram of the internal structure of the cooler housing of the present invention; Figure 3 This is a schematic diagram of the internal structure of the cooler housing from another perspective. Figure 4 This is a schematic diagram of the overall structure of the heat exchange core of the present invention; Figure 5 This is a schematic diagram of the overall structure of the heat exchange core of the present invention from another perspective; Figure 6 This is a schematic diagram of the overall structure of the waveform gradient fin assembly of the present invention; Figure 7 This is a schematic diagram of the internal structure of the partitioned water inlet component of the present invention.

[0019] In the diagram: 1. Cooler shell; 101. Exhaust gas inlet shell; 102. Exhaust gas outlet shell; 2. Heat exchange core; 201. Exhaust gas flow channel cavity; 3. Waveform gradient fin assembly; 301. Gentle corrugated fins; 302. Deep corrugated fins; 303. Fine corrugated fins; 304. Fin limiting plate; 305. Fin support plate; 4. Zoned water jacket type changeable heat exchange assembly; 401. First zone water jacket; 402. Second zone water jacket; 403. Third zone water jacket; 404. Sealing partition; 5. Zoned water inlet assembly; 501. First water inlet pipe; 502. Second water inlet pipe; 503. Third water inlet pipe; 504. Pressure stabilizing and replenishing liquid pipe one; 505. Pressure stabilizing connecting cavity; 506. Pressure stabilizing connecting plate; 507. One-way valve; 508. Pressure stabilizing and replenishing liquid pipe two; 6. Water outlet pipe. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0022] Please see Figures 1-7 The present invention provides a technical solution: an EGR cooler with a changeable heat structure, including a cooler shell 1, one end of the cooler shell 1 is provided with an exhaust gas inlet shell 101, the other end of the cooler shell 1 is provided with an exhaust gas outlet shell 102, a plurality of heat exchange cores 2 are provided inside the cooler shell 1, each of the plurality of heat exchange cores 2 has an exhaust gas flow channel cavity 201, and each of the plurality of exhaust gas flow channel cavities 201 is provided with a wave-gradient fin assembly 3, the wave-gradient fin assembly 3 including a gently corrugated fin 301, a deeply corrugated fin 302 and a finely corrugated fin 303 arranged sequentially along the exhaust gas flow direction; A partitioned water jacket type changeable heat assembly 4 is provided on the outside of several heat exchange cores 2. The partitioned water jacket type changeable heat assembly 4 includes a first partitioned water jacket 401, a second partitioned water jacket 402, a third partitioned water jacket 403 and two sealing partitions 404. The first partitioned water jacket 401, the second partitioned water jacket 402 and the third partitioned water jacket 403 are respectively provided for the gently corrugated fins 301, the deeply corrugated fins 302 and the finely corrugated fins 303, and adjacent partitioned water jackets are separated by sealing partitions 404. The cooler housing 1 is equipped with a partitioned water inlet assembly 5 and three water outlet pipes 6. The partitioned water inlet assembly 5 is connected to the first partitioned water jacket 401, the second partitioned water jacket 402 and the third partitioned water jacket 403 respectively. The three water outlet pipes 6 are connected to the first partitioned water jacket 401, the second partitioned water jacket 402 and the third partitioned water jacket 403 respectively. Through the cooperation of the cooler housing 1, the heat exchange core 2, the waveform gradient fin assembly 3 and the partitioned water jacket type convertible heat exchange assembly 4, the exhaust gas flows directly in the exhaust gas flow channel cavity 201, and the first partitioned water jacket 401, the second partitioned water jacket 402 and the third partitioned water jacket 403 respectively perform partitioned cooling of different fin areas.

[0023] The gently corrugated fins 301 are disposed on the side of the exhaust gas flow channel cavity 201 near the exhaust gas inlet end shell 101. The deeply corrugated fins 302 are disposed between the gently corrugated fins 301 and the finely corrugated fins 303. The finely corrugated fins 303 are disposed on the side of the exhaust gas flow channel cavity 201 near the exhaust gas outlet end shell 102, so that the exhaust gas passes through the gently corrugated fins 301, the deeply corrugated fins 302 and the finely corrugated fins 303 in sequence in the exhaust gas flow channel cavity 201. The gently corrugated fins 301, the deeply corrugated fins 302 and the finely corrugated fins 303 are arranged in sequence along the exhaust gas flow direction, so that the exhaust gas passes through the inlet precooling zone, the main heat exchange zone and the outlet make-up cooling zone in sequence.

[0024] The peak height of the gently corrugated fin 301 is smaller than that of the deeply corrugated fin 302, and the corrugation pitch of the finely corrugated fin 303 is smaller than that of both the gently corrugated fin 301 and the deeply corrugated fin 302. At the junction of the gently corrugated fin 301 and the deeply corrugated fin 302, a gradually increasing peak height transition zone is formed, which is used to smoothly transfer the exhaust gas from the low-resistance pre-cooling zone to the enhanced heat exchange zone. At the junction of the deeply corrugated fin 302 and the finely corrugated fin 303, a gradually decreasing corrugation pitch refinement transition zone is formed, which is used to smoothly transfer the exhaust gas from the enhanced heat exchange zone to the supplementary cooling heat exchange zone. Through the waveform differences of the gently corrugated fin 301, the deeply corrugated fin 302, and the finely corrugated fin 303, as well as the gradually increasing and refinement transition zones, the exhaust gas smoothly transitions between different heat exchange zones, reducing abrupt flow changes.

[0025] The waveform gradient fin assembly 3 also includes a fin limiting plate 304 and a fin support plate 305. The fin limiting plate 304 is disposed at the junction of the gently corrugated fin 301 and the deeply corrugated fin 302 to maintain the waveform docking position between the gently corrugated fin 301 and the deeply corrugated fin 302 and to maintain the flow gap in the gradient transition zone. The fin support plate 305 is disposed at the junction of the deeply corrugated fin 302 and the finely corrugated fin 303 to support the fin structure in the refined transition zone and to maintain the straight-through state of the exhaust gas flow channel cavity 201 between the deeply corrugated fin 302 and the finely corrugated fin 303. The fin limiting plate 304 is used to maintain the docking stability of the gently corrugated fin 301 and the deeply corrugated fin 302. The fin support plate 305 is used to support the junction area of ​​the deeply corrugated fin 302 and the finely corrugated fin 303 to ensure the straight-through stability of the exhaust gas flow channel cavity 201.

[0026] The first partition water jacket 401 covers the outer side of the heat exchange core 2 corresponding to the gently corrugated fins 301, the second partition water jacket 402 covers the outer side of the heat exchange core 2 corresponding to the deeply corrugated fins 302, and the third partition water jacket 403 covers the outer side of the heat exchange core 2 corresponding to the finely corrugated fins 303. The sealing partition 404 is connected between the cooler housing 1 and the heat exchange core 2 to limit the flow of coolant between adjacent partition water jackets. The first partition water jacket 401, the second partition water jacket 402 and the third partition water jacket 403 are respectively set for the three types of fin areas. The sealing partition 404 is used to separate adjacent water jackets and reduce the flow of coolant.

[0027] The length of the second partition water jacket 402 along the exhaust gas flow direction is greater than that of the first partition water jacket 401 and the third partition water jacket 403 along the exhaust gas flow direction, so that the second partition water jacket 402 and the deep corrugated fins 302 correspond to form the main heat exchange area. The second partition water jacket 402 is longer and is set to correspond with the deep corrugated fins 302, so that the central area forms the main heat exchange area and improves the overall cooling efficiency.

[0028] The partitioned water inlet assembly 5 includes a first water inlet pipe 501, a second water inlet pipe 502, and a third water inlet pipe 503. The first water inlet pipe 501 is connected to the first partitioned water jacket 401, the second water inlet pipe 502 is connected to the second partitioned water jacket 402, and the third water inlet pipe 503 is connected to the third partitioned water jacket 403, so that the first partitioned water jacket 401, the second partitioned water jacket 402, and the third partitioned water jacket 403 can be independently inletted with water. The first water inlet pipe 501, the second water inlet pipe 502, and the third water inlet pipe 503 supply liquid to the three partitioned water jackets respectively, so that the first partitioned water jacket 401, the second partitioned water jacket 402, and the third partitioned water jacket 403 can independently participate in heat exchange.

[0029] The partitioned water inlet assembly 5 also includes a pressure-stabilizing and replenishing pipe 1 504, a pressure-stabilizing connecting cavity 505, a pressure-stabilizing connecting plate 506, a one-way valve 507, and a pressure-stabilizing and replenishing pipe 2 508. The cooler housing 1 has a pressure-stabilizing connecting cavity 505 inside. The pressure-stabilizing and replenishing pipe 1 504 and the pressure-stabilizing and replenishing pipe 2 508 are both connected to the pressure-stabilizing connecting cavity 505. The pressure-stabilizing connecting cavity 505 is connected to the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403 respectively through the three pressure-stabilizing connecting plates 506. The pressure-stabilizing and replenishing pipe 1 504 and the pressure-stabilizing and replenishing pipe 2 508 are connected to the pressure-stabilizing connecting cavity 505. The pressure-stabilizing connecting cavity 505 is connected to the three partition water jackets through the pressure-stabilizing connecting plate 506 for auxiliary replenishment and pressure equalization.

[0030] The pressure-stabilizing and replenishing pipe 504 is equipped with a one-way valve 507. Three pressure-stabilizing connecting plates 506 are respectively arranged between the pressure-stabilizing connecting cavity 505 and the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403. The pressure-stabilizing connecting plates 506 are provided with connecting holes corresponding to the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403, so that the coolant in the pressure-stabilizing connecting cavity 505 can be replenished into the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403, and the pressure of the three partition water jackets can be balanced during the partition water inlet process. The one-way valve 507 is arranged in the pressure-stabilizing and replenishing pipe 504 to restrict the backflow of coolant. The connecting holes on the pressure-stabilizing connecting plates 506 are used to replenish the coolant in the pressure-stabilizing connecting cavity 505 into each partition water jacket.

[0031] The specific working process of this invention is as follows: When the EGR cooler is working, part of the high-temperature exhaust gas discharged from the engine first enters the exhaust gas inlet end housing 101. The exhaust gas inlet end housing 101 guides the high-temperature exhaust gas into several heat exchange cores 2 inside the cooler housing 1. After entering the heat exchange cores 2, the high-temperature exhaust gas flows directly along each exhaust gas flow channel cavity 201. During the flow process, the exhaust gas does not need to make large-angle detours or bypasses inside the cooler, thus reducing the overall flow resistance of the exhaust gas when passing through the cooler.

[0032] After the exhaust gas enters the exhaust gas flow channel cavity 201, it first passes through the gently corrugated fins 301 in the waveform gradient fin assembly 3. The gently corrugated fins 301 are located on the side of the housing 101 near the exhaust gas inlet end. Their waveform undulations are small and the flow gap is relatively smooth. They can smoothly guide and pre-cool the high-temperature exhaust gas that has just entered the cooler, avoiding the exhaust gas from being suddenly subjected to strong turbulence in the inlet section, which would lead to an increase in pressure drop. At the same time, it reduces the risk of local carbon accumulation in the inlet area due to the direct impact of high-temperature exhaust gas.

[0033] Subsequently, the exhaust gas continues to enter the area where the deep corrugated fin 302 is located. The deep corrugated fin 302 is located between the gently corrugated fin 301 and the finely corrugated fin 303, and the peak height of the deep corrugated fin 302 is greater than that of the gently corrugated fin 301. When the exhaust gas flows through this area, the deep corrugated fin 302 can increase the contact area between the exhaust gas and the fin surface and enhance the local disturbance of the exhaust gas in the exhaust gas flow channel cavity 201, so that the heat in the exhaust gas can be more fully transferred to the heat exchange core 2 and the coolant area on its outside. Therefore, this area mainly undertakes the task of enhancing the heat exchange of the exhaust gas.

[0034] After passing through the deep corrugated fins 302, the exhaust gas enters the area where the fine corrugated fins 303 are located. The fine corrugated fins 303 are located on the side near the exhaust gas outlet end housing 102, and the corrugation pitch of the fine corrugated fins 303 is smaller than that of the gentle corrugated fins 301 and the deep corrugated fins 302. Since the fins of the fine corrugated fins 303 are more densely distributed per unit length, the effective heat exchange area of ​​the outlet section can be increased, and the exhaust gas that has already been cooled in the front section can be further cooled, so that the temperature of the exhaust gas is more stable before it is discharged. After the exhaust gas is cooled, it is discharged from the exhaust gas outlet end housing 102 and flows back to the engine intake system to participate in combustion.

[0035] As the exhaust gas flows through the three types of fins in sequence, a gradually deepening transition zone with increasing wave crest height is formed at the junction of the gently corrugated fin 301 and the deeply corrugated fin 302. This allows the exhaust gas to smoothly enter the enhanced heat transfer zone from the low-resistance pre-cooling zone, reducing the local flow abrupt changes that occur when suddenly transitioning from a shallow corrugated structure to a deep corrugated structure. At the junction of the deeply corrugated fin 302 and the finely corrugated fin 303, a refined transition zone with gradually decreasing corrugation pitch is formed, allowing the exhaust gas to smoothly enter the make-up cooling heat transfer zone from the enhanced heat transfer zone. To reduce the risk of sudden changes in local resistance and deposition when exhaust gas enters the fine corrugated area, the fin limiting plate 304 is set at the junction of the gently corrugated fin 301 and the deeply corrugated fin 302 to maintain the waveform docking position between the two and maintain the flow gap in the gradually deepening transition zone. The fin support plate 305 is set at the junction of the deeply corrugated fin 302 and the fine corrugated fin 303 to support the fin structure in the refined transition zone and ensure that the exhaust gas flow channel cavity 201 remains straight at this junction position.

[0036] When the coolant side is working, the first inlet pipe 501, the second inlet pipe 502, and the third inlet pipe 503 in the partitioned water inlet assembly 5 supply coolant to the first partitioned water jacket 401, the second partitioned water jacket 402, and the third partitioned water jacket 403, respectively. The first partitioned water jacket 401 covers the outer side of the gently corrugated fins 301 corresponding to the heat exchange core 2 and is used to cool the inlet low-resistance pre-cooling area. The second partitioned water jacket 402 covers the outer side of the deeply corrugated fins 302 corresponding to the heat exchange core 2 and is used to cool the middle enhanced heat exchange area. The third partitioned water jacket 403 covers the outer side of the finely corrugated fins 303 corresponding to the heat exchange core 2 and is used to cool the outlet make-up cooling heat exchange area. Adjacent partitioned water jackets are separated by a sealing partition 404. The sealing partition 404 is connected between the cooler shell 1 and the heat exchange core 2 and can restrict the direct flow of coolant between adjacent partitioned water jackets, so that the three partitioned water jackets form relatively independent heat exchange areas.

[0037] Under different engine operating conditions, the three-section water jackets can supply coolant to different degrees according to cooling requirements. When the engine is in a cold start, low load, or no-strong-cooling condition, coolant can be mainly supplied to the first inlet pipe 501, allowing the first section water jacket 401 to participate in heat exchange. At this time, the exhaust gas mainly undergoes mild pre-cooling in the area corresponding to the gently corrugated fins 301, which can appropriately reduce the exhaust gas temperature and avoid over-cooling of the exhaust gas. When the engine is in a normal warm-up or medium-load condition, coolant can be supplied to the first inlet pipe 501 and the second inlet pipe 502, allowing the first section water jacket 401 and the second section water jacket 502 to participate in heat exchange. The two-section water jacket 402 jointly participate in heat exchange. The exhaust gas first undergoes low-resistance pre-cooling in the area of ​​the gently corrugated fins 301, and then undergoes main cooling in the area of ​​the deeply corrugated fins 302. When the engine is under high load, high exhaust temperature, or requires strong EGR cooling, coolant can be supplied to the first water inlet pipe 501, the second water inlet pipe 502, and the third water inlet pipe 503 at the same time, so that the first section water jacket 401, the second section water jacket 402, and the third section water jacket 403 all participate in heat exchange. This allows the exhaust gas to pass through inlet pre-cooling, mid-section enhanced heat exchange, and outlet make-up cooling in sequence, thereby obtaining a higher cooling effect and a more stable outlet temperature.

[0038] During the three-zone water jacket partitioned liquid supply process, both the first pressure-stabilizing liquid supply pipe 504 and the second pressure-stabilizing liquid supply pipe 508 are connected to the pressure-stabilizing connecting cavity 505. The pressure-stabilizing connecting cavity 505 is connected to the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403 respectively through three pressure-stabilizing connecting plates 506. When the first partition water jacket 401, the second partition water jacket 402, or the third partition water jacket 403 experiences local pressure fluctuations, insufficient liquid supply, or uneven flow during independent water intake, the coolant can enter the pressure-stabilizing connecting cavity 505 through the first pressure-stabilizing liquid supply pipe 504, and then replenish the corresponding partition water jacket through the connecting holes on the pressure-stabilizing connecting plate 506 to balance the pressure difference between the three partition water jackets and reduce problems such as local liquid shortage, air resistance, or uneven heat exchange.

[0039] The pressure-stabilizing liquid supply pipe 504 is equipped with a one-way valve 507. The one-way valve 507 is used to allow coolant to be supplied unidirectionally towards the pressure-stabilizing connecting chamber 505, and to restrict the coolant in the pressure-stabilizing connecting chamber 505 from flowing back to the pressure-stabilizing liquid supply pipe 504. Thus, when the three partition water jackets are supplied with liquid at different flow rates, the pressure-stabilizing connecting chamber 505 can provide auxiliary liquid supply and pressure equalization for the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403, thereby improving the stability of the partition liquid supply process and ensuring that each heat exchange area maintains good cooling consistency under the condition of heat exchange.

[0040] After heat exchange, the coolant flows from the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403 to the corresponding outlet pipes 6, and is discharged from the cooler shell 1 through the three outlet pipes 6. During the flow of the coolant, the heat of the high-temperature exhaust gas is first transferred to the gently corrugated fins 301, the deeply corrugated fins 302, and the finely corrugated fins 303, and then transferred to the coolant in the corresponding partition water jackets via the heat exchange core 2. Finally, the coolant is carried out of the cooler through the outlet pipes 6, thus completing the exhaust gas cooling process. The gently corrugated fins 301, the deeply corrugated fins 302, and the finely corrugated fins are used to achieve this. 303 forms a waveform-gradual heat exchange structure that changes progressively along the direction of exhaust gas flow. At the same time, the first partition water jacket 401, the second partition water jacket 402, and the third partition water jacket 403 correspond to the three fin heat exchange areas for partitioned liquid supply, so that the gas-side heat exchange capacity and the water-side cooling intensity are matched accordingly. In addition, the pressure stabilizing liquid supply pipe 1 504, the pressure stabilizing connecting cavity 505, the pressure stabilizing connecting plate 506, the one-way valve 507, and the pressure stabilizing liquid supply pipe 2 508 are used to achieve pressure balance and auxiliary liquid supply. Thus, while maintaining the direct low-resistance flow of exhaust gas, partitioned participation, staged heat exchange, and variable adjustment of cooling intensity are achieved.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An EGR cooler with a changeable heat structure, comprising a cooler shell (1), wherein one end of the cooler shell (1) is provided with an exhaust gas inlet shell (101), and the other end of the cooler shell (1) is provided with an exhaust gas outlet shell (102), wherein a plurality of heat exchange cores (2) are provided inside the cooler shell (1), and each of the plurality of heat exchange cores (2) forms an exhaust gas flow channel cavity (201), characterized in that: Each of the several exhaust gas flow channels (201) is provided with a wave-gradient fin assembly (3), which includes a gently corrugated fin (301), a deeply corrugated fin (302), and a finely corrugated fin (303) arranged sequentially along the exhaust gas flow direction. A partitioned water jacket type changeable heat assembly (4) is provided on the outside of several heat exchange cores (2). The partitioned water jacket type changeable heat assembly (4) includes a first partitioned water jacket (401), a second partitioned water jacket (402), a third partitioned water jacket (403) and two sealing partitions (404). The first partitioned water jacket (401), the second partitioned water jacket (402) and the third partitioned water jacket (403) are respectively provided with gently corrugated fins (301), deeply corrugated fins (302) and finely corrugated fins (303), and adjacent partitioned water jackets are separated by sealing partitions (404). The cooler housing (1) is provided with a partitioned water inlet assembly (5) and three water outlet pipes (6). The partitioned water inlet assembly (5) is connected to the first partitioned water jacket (401), the second partitioned water jacket (402) and the third partitioned water jacket (403) respectively. The three water outlet pipes (6) are connected to the first partitioned water jacket (401), the second partitioned water jacket (402) and the third partitioned water jacket (403) respectively.

2. The EGR cooler with a changeable thermal structure according to claim 1, characterized in that: The gently corrugated fins (301) are disposed on the side of the exhaust gas flow channel cavity (201) near the exhaust gas inlet end shell (101), the deeply corrugated fins (302) are disposed between the gently corrugated fins (301) and the finely corrugated fins (303), and the finely corrugated fins (303) are disposed on the side of the exhaust gas flow channel cavity (201) near the exhaust gas outlet end shell (102), so that the exhaust gas passes through the gently corrugated fins (301), the deeply corrugated fins (302) and the finely corrugated fins (303) in sequence in the exhaust gas flow channel cavity (201).

3. The EGR cooler with a changeable thermal structure according to claim 2, characterized in that: The peak height of the gently corrugated fin (301) is less than that of the deep corrugated fin (302), and the corrugation pitch of the fine corrugated fin (303) is less than that of the gently corrugated fin (301) and the deep corrugated fin (302). The junction of the gently corrugated fin (301) and the deep corrugated fin (302) forms a gradually increasing transition zone with a gradually increasing peak height, which is used to allow the exhaust gas to smoothly enter the enhanced heat exchange zone from the low-resistance pre-cooling zone. The junction of the deep corrugated fin (302) and the fine corrugated fin (303) forms a refined transition zone with a gradually decreasing corrugation pitch, which is used to allow the exhaust gas to smoothly enter the supplementary cooling heat exchange zone from the enhanced heat exchange zone.

4. The EGR cooler with a changeable thermal structure according to claim 3, characterized in that: The waveform gradient fin assembly (3) further includes a fin limiting plate (304) and a fin support plate (305). The fin limiting plate (304) is disposed at the junction of the gently corrugated fin (301) and the deeply corrugated fin (302) to maintain the waveform docking position between the gently corrugated fin (301) and the deeply corrugated fin (302) and to maintain the flow gap in the gradient transition zone. The fin support plate (305) is disposed at the junction of the deeply corrugated fin (302) and the finely corrugated fin (303) to support the fin structure in the refined transition zone and to maintain the straight-through state of the exhaust gas flow channel cavity (201) between the deeply corrugated fin (302) and the finely corrugated fin (303).

5. The EGR cooler with a changeable thermal structure according to claim 1, characterized in that: The first partition water jacket (401) covers the outer side of the heat exchange core (2) corresponding to the gently corrugated fins (301), the second partition water jacket (402) covers the outer side of the heat exchange core (2) corresponding to the deeply corrugated fins (302), the third partition water jacket (403) covers the outer side of the heat exchange core (2) corresponding to the finely corrugated fins (303), and the sealing partition (404) is connected between the cooler housing (1) and the heat exchange core (2) to restrict the flow of coolant between adjacent partition water jackets.

6. An EGR cooler with a changeable thermal structure according to claim 5, characterized in that: The length of the second partition water jacket (402) along the exhaust gas flow direction is greater than the length of the first partition water jacket (401) and the third partition water jacket (403) along the exhaust gas flow direction, so that the second partition water jacket (402) and the deep corrugated fins (302) correspond to form the main heat exchange area.

7. The EGR cooler with a changeable thermal structure according to claim 1, characterized in that: The partitioned water inlet assembly (5) includes a first water inlet pipe (501), a second water inlet pipe (502), and a third water inlet pipe (503). The first water inlet pipe (501) is connected to the first partitioned water jacket (401), the second water inlet pipe (502) is connected to the second partitioned water jacket (402), and the third water inlet pipe (503) is connected to the third partitioned water jacket (403), so that the first partitioned water jacket (401), the second partitioned water jacket (402), and the third partitioned water jacket (403) can be independently inlet.

8. An EGR cooler with a changeable thermal structure according to claim 7, characterized in that: The partitioned water inlet assembly (5) also includes a pressure-stabilizing liquid supply pipe one (504), a pressure-stabilizing connecting cavity (505), a pressure-stabilizing connecting plate (506), a one-way valve (507), and a pressure-stabilizing liquid supply pipe two (508). The cooler housing (1) has a pressure-stabilizing connecting cavity (505) inside. The pressure-stabilizing liquid supply pipe one (504) and the pressure-stabilizing liquid supply pipe two (508) are both connected to the pressure-stabilizing connecting cavity (505). The pressure-stabilizing connecting cavity (505) is connected to the first partition water jacket (401), the second partition water jacket (402), and the third partition water jacket (403) respectively through three pressure-stabilizing connecting plates (506).

9. An EGR cooler with a changeable thermal structure according to claim 8, characterized in that: The pressure-stabilizing and replenishing pipe (504) is equipped with a one-way valve (507). The three pressure-stabilizing connecting plates (506) are respectively arranged between the pressure-stabilizing connecting cavity (505) and the first partition water jacket (401), the second partition water jacket (402) and the third partition water jacket (403). The pressure-stabilizing connecting plate (506) is provided with connecting holes corresponding to the first partition water jacket (401), the second partition water jacket (402) and the third partition water jacket (403) respectively, so that the coolant in the pressure-stabilizing connecting cavity (505) is replenished into the first partition water jacket (401), the second partition water jacket (402) and the third partition water jacket (403) respectively, and the pressure of the three partition water jackets is balanced during the partition water inlet process.

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