CN201420626Y - An Exhaust Gas Recirculation Cooler for Medium and Heavy Duty Vehicles with Ridge Ring - Google Patents

Abstract

The utility model relates to an exhaust gas recirculation cooler for medium and heavy vehicles with a ridge ring. Including: tube shell, tube sheets installed at both ends of the tube shell and water inlet and outlet pipes on the side of the tube shell. Multiple heat exchange tubes for circulating exhaust gas are installed between the two tube sheets at both ends of the tube shell. The two tube sheets are respectively connected to Inlet and exhaust pipe boxes are connected. The pipe shell is surrounded by metal plates with a thickness of less than 2mm. The cross-section of the pipe shell is rectangular and the shape is also rectangular. The shell is still a multi-segment tube shell whose total length is greater than 1 times the width or height, and the tube shell and the intake pipe box or exhaust pipe box, and the tube shells of the multi-section tube shells are connected by ridge rings. In the cooler described in the utility model, the split tube shells and the tube shell and the tube box are all connected by ridge rings, so that the strength of the cooler is increased, the structural design is more compact, and the overall performance is also improved. Since the cooler has a ridge ring, the difficulty of assembling the cooler is reduced, and the machining accuracy is improved at the same time.

Description

An Exhaust Gas Recirculation Cooler for Medium and Heavy Duty Vehicles with Ridge Ring

technical field

The utility model relates to an exhaust gas recirculation cooler for medium and heavy vehicles with a ridge ring, which is a heat exchanger used in the engine exhaust gas recirculation cooling system of medium and heavy vehicles.

Background technique

In the field of automobiles, the coolers for the engine exhaust gas recirculation cooling system are constantly improving to meet the increasingly stringent automobile exhaust emission standards; for medium and heavy diesel engines, the cost of exhaust gas recirculation coolers is higher than that of light diesel engines. Therefore, when designing and processing coolers for customers, not only their performance and reliability must be fully considered, but also the difficulty and cost of processing must be taken into consideration.

The application of exhaust gas recirculation cooling technology is one of the effective measures to reduce vehicle exhaust emissions in the automotive industry. Exhaust gas recirculation cooling technology is to add a cooler to the exhaust gas recirculation system. Part of the recycled exhaust gas emitted by the automobile engine is first cooled by the exhaust gas recirculation cooler, and then returned to the combustion chamber of the engine for fresh air. A technique in which combustion is carried out after thorough mixing. This technology utilizes the characteristic that the waste gas contains a large amount of chemically inert gases (CO ₂ , N ₂ , H ₂ O) and has a high specific heat to reduce the formation of _NOx . Because the NO _x generation condition is high temperature oxygen-enriched, and the introduction of lower temperature exhaust gas increases the heat capacity of the mixture, so that the same amount of mixture increases and the heat required for the same temperature increases, thereby effectively reducing the maximum combustion temperature , which deviates from the high-temperature generation zone of NO _x ; on the other hand, the dilution of exhaust gas to fresh air also reduces the concentration of oxygen correspondingly, thereby effectively inhibiting the formation of NO _x . Therefore, in the exhaust gas recirculation system, setting up an efficient exhaust gas recirculation cooler can make the exhaust emission of the vehicle meet the requirements of strict regulations.

At present, there are two types of coolers used in the exhaust gas recirculation system of automobile engines. One is the plate-fin cooler, and the other is the shell-and-tube cooler, among which the shell-and-tube cooler is the most widely used. Since the addition of the exhaust gas recirculation cooler will affect the operation of the entire cooling system of the engine, and even affect the entire engine, it is not only required that the cooler be compact and efficient, but more importantly, its reliability must be guaranteed. At the same time, considering the cost, it is necessary Use the most practical technology to manufacture high-reliability products, save costs for customers and ensure the mass supply of products.

Due to the harsh operating environment of medium and heavy vehicles, the reliability of the exhaust gas recirculation cooler is very important. If the cooler leaks during operation, it will directly cause destructive damage to the engine. Since the exhaust gas recirculation cooler is divided into two channels, the gas side and the water side, the high-temperature gas passes through the heat exchange tube, and the coolant of the engine passes through the tube shell. If there is leakage on the gas side, the coolant enters the heat exchange tube, thereby cooling If the filter enters the exhaust system, it will destroy the normal operation of the air circuit, resulting in damage to the engine; if there is a leak on the coolant side, that is, the coolant leaks into the environment through the connection between the tube shell and the water pipe, it will cause coolant leakage. The continuous loss of the engine will eventually cause the entire cooling system of the engine to lose its function, which will also cause great damage to the engine. Therefore, in order to avoid this from happening, the overall strength and reliability of the cooler must be guaranteed.

At present, in the exhaust gas recirculation coolers for medium and heavy diesel locomotives designed and produced in China, the tube shells are mostly made of castings, which makes the overall structure of the cooler relatively cumbersome and takes up a large space of the engine. The power density of this type of cooler Low, the heat exchange effect of the cooler per unit volume is not fully utilized, and the ability of this cooler to be upgraded is poor.

Contents of the invention

In order to solve this problem, the utility model proposes an exhaust gas recirculation cooler for medium and heavy diesel locomotives with a ridge ring. Make full use of space, make full use of the space in the tube shell, and arrange the heat exchange tube bundles compactly, so that the performance of the cooler can meet the requirements, and it has the ability to be upgraded; One-piece design, and the split tube shells are connected by ridge rings, which reduces the processing difficulty, improves the machining accuracy, and can effectively ensure the reliability of the tube shells; at the same time, the tube shells and the end tube boxes are also connected by ridge rings Connection, the tube sheet is fixed between the tube shell and the tube box, so that the overall reliability of the cooler is improved, and it can meet the requirements of the engine in terms of performance and reliability, and meet the requirements of increasingly stringent emission regulations.

The purpose of this utility model is achieved in the following way: a medium and heavy-duty vehicle exhaust gas recirculation cooler with a ridge ring, including: the tube shell as the main body, the tube plate installed at both ends of the tube shell and the water inlet pipe on the side of the tube shell and A plurality of heat exchange tubes for circulating exhaust gas are installed between the two tube plates at both ends of the tube shell, and the two tube plates are respectively connected with the intake pipe box and the exhaust pipe box. The tube shell is composed of thickness Surrounded by metal plates less than 2 mm, the section of the shell is rectangular, and the shape is also rectangular. The shell can be a single segment or connected by multiple segments, whether it is a single segment or a multi-segment The overall length of the tube shell is greater than 1 times the width or height, and the tube shell and the intake pipe box or the exhaust pipe box, and the tube shells of the multi-section tube shells are connected by ridge rings.

The beneficial effects produced by the utility model are: the exhaust gas recirculation cooler for medium and heavy vehicles with a ridge ring can realize the one-time welding and forming of the cooler after adding the ridge ring, while most of the exhaust gas recirculation coolers for medium and heavy vehicles currently use It is welded two or more times, so the design method of the cooler in the utility model can improve the production efficiency of the cooler, and is especially suitable for mass production.

The split design of the rectangular shell of the exhaust gas recirculation cooler for medium and heavy vehicles with a ridge ring, compared with the generally used integral casting of the shell, on the one hand can ensure that the overall design of the cooler is more compact on the basis of the same shape and space. The space in the tube shell is effectively used, and the arrangement of the tube bundle is more reasonable, thereby improving the overall performance of the cooler. The cooler tube shell adopts split design, which greatly reduces the processing difficulty of the longer cooler tube shell, and the split tube shell is connected by a ridge ring, which improves the strength of the tube shell; at the end of the cooler, the tube shell and The tube box is connected by a ridge ring, and the tube sheet is a flanged structure, which is fixed between the tube shell and the tube box to increase the connection strength between the three and improve the overall reliability of the heat exchanger.

Since the cooler is used on medium and heavy diesel locomotives, the structure is generally longer. In order to reduce the thermal stress caused by thermal expansion and contraction, an expansion joint is arranged at the end of the cooler tube shell, and the split design is adopted, so that the tube can be installed in a shorter tube. The expansion joints are processed on the shell, which greatly reduces the difficulty of processing, and at the same time can improve the accuracy of processing, improve the reliability of the tube shell connection, and also improve the overall reliability of the cooler. The cooler meets both reliability requirements and performance requirements, thereby effectively reducing the temperature of the recirculated exhaust gas, reducing the emission of nitrogen oxides in the exhaust gas, and making due contributions to environmental protection.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 The waste gas recirculation cooler described in Embodiments 1 and 3 of the utility model;

Fig. 2 Partial view of the exhaust gas recirculation cooler described in Embodiment 1 of the utility model;

Fig. 3 is a schematic diagram of the tube sheet described in Embodiment 1 of the utility model;

Fig. 4 The dual-channel waste gas recirculation cooler using flat groove heat exchange tubes described in Embodiments 1 and 7 of the utility model;

Fig. 5 is a schematic diagram of the ridge ring described in the second embodiment of the utility model;

Fig. 6 is a schematic diagram of the ridge ring described in Embodiment 4 of the utility model;

Fig. 7 is a schematic diagram of the exhaust gas recirculation cooler with the ridge ring described in the fourth embodiment of the utility model installed;

Fig. 8 is an exhaust gas recirculation cooler with a three-section shell with an expansion joint and a circular groove heat exchange tube as described in Embodiments 5 and 7 of the utility model;

Fig. 9 is the exhaust gas recirculation cooler described in the sixth embodiment of the utility model;

Fig. 10 is a schematic diagram of the flat grooved heat exchange tube described in the eighth embodiment of the utility model.

Detailed ways

Embodiment one:

This embodiment is an exhaust gas recirculation cooler for medium and heavy vehicles with a ridge ring, as shown in Figures 1 and 2 . The cooler includes: tube shells 1, 2 as the main body, tube sheets 9 installed at both ends of the tube shell, and water inlet pipes 5 and outlet pipes 6 on the side of the tube shell, and installed between the two tube sheets at both ends of the tube shell. There are a plurality of heat exchange tubes 4 for circulating exhaust gas, and two tube sheets are respectively connected with the intake pipe box 7 and the exhaust pipe box 8. The tube shell is surrounded by a metal plate with a thickness less than 2 mm. The cross-section of the shell is rectangular, and the shape is also rectangular. The shell can be a single section, or it can be formed by connecting multiple sections. High, between the pipe shell and the intake pipe box or the exhaust pipe box, and between the pipe shells of the multi-section pipe shells are connected by a ridge ring 3 .

It is not a simple substitution to replace the integral casting shell with the shell made of metal sheet. The integral casting shell type can meet the requirements in the period when the emission regulations are not high, but as the emission regulations become more and more stringent, this kind of cooler with a cast shell has great disadvantages in upgrading. Due to the limited space for installing the cooler on the engine and the large thickness of the casting, it is difficult to expand the space inside the casting under the same space volume, thus limiting the increase of the effective heat exchange area of the tube bundle in the tube shell. Under the condition of the same arrangement of heat exchange tube bundles, the space outside the heat exchange tubes of the tube shell surrounded by metal sheets is larger, which reduces the flow resistance of the coolant through the cooler, which is beneficial to the EGR (exhaust gas recirculation) system. Or due to the larger space, more coolant can pass through the cooler, so that the overall heat exchange effect of the cooler can be improved. Since the shape of the exhaust gas recirculation cooler for medium and heavy vehicles is usually rectangular, its length is much larger than its width and height, so the strength in the length direction must be relatively large, so as to withstand the deformation of the shell when the cold and heat alternately appear Too large to damage the case.

Since the outer shape of the tube shell in this embodiment is a strip shape with a rectangular cross-section, the tube shell in this embodiment can be designed as a single section or multiple sections. The so-called single-section shell means that the shell has an integral metal sheet, and the so-called multi-segment shell means that the shell is truncated into multiple short shells in the long direction, and each section is connected by a ridge ring 3, as shown in Figures 1, 2, 4, 6, and 9 are two-stage designs, and Figure 8 is a three-stage design. This method of segmented manufacturing and then connecting together can effectively solve the manufacturing process problem of the overly long shell.

The tube shell adopts a split design, which greatly reduces the processing difficulty of the long cooler tube shell and improves the machining accuracy; due to the long structure of the cooler, in order to solve the problem of thermal expansion and cold contraction of the long tube shell, the upper tube shell Set expansion joints to reduce thermal stress caused by thermal expansion and contraction.

The pipe shell is provided with collar holes 13, 23, the water pipes 5, 6 are directly inserted into the pipe shell, and the position of the water pipes is fixed by the annular protrusions 51, 61. The water pipes shown in this embodiment are straight pipes, and the water pipes can be It is in the form of a curved pipe.

As shown in FIG. 3 , the tube sheet used in the first embodiment has a flanged structure, and the heat exchange tubes pass through the through holes 93 on the tube sheet, and are connected with the tube sheet after welding. The bend 92 is inserted into the through hole of the ridge ring, and the flange 91 is connected with the ridge ring and the pipe box on one side, and is fixed between the pipe box and the ridge ring, thereby improving the connection strength.

This embodiment can be a single-channel cooler, which uses a shell made of bent metal sheet, which is different from the cast shell of the traditional exhaust gas recirculation cooler for medium and heavy vehicles. The shell made of metal sheet has many advantages over the cast shell: the manufacturing process is simple, the production process has less pollution, it is easy to realize automatic production, and the quality is easy to guarantee. If a segmented tube shell design is adopted, the length of a single tube shell is shorter, easier to process, and can guarantee quality, which is suitable for the manufacture of batch products.

This embodiment can also be a dual-channel cooler, as shown in FIG. 4 . When a multi-cylinder engine (such as a six-cylinder engine) is divided into two groups and a common turbocharger is used, it is generally considered to use a dual-channel cooler, and the pipe box has two channels 72, 73; The gas pulse realizes the exhaust gas recirculation function. In this embodiment, the cooler also adopts a split design, and is divided into two parts, the left shell 1 and the right shell 2, and the effect of the split design of the shell is the same as that of Example 1.

The shell of the cooler adopts a split design, so that the expansion joint can be processed on the shell with a short end, which greatly reduces the difficulty of processing, and at the same time can improve the precision of processing, which also improves the reliability of the shell connection. The overall reliability of the cooler is improved. This split design can improve production efficiency and is suitable for mass production of products. The design of the rectangular tube shell of the cooler can effectively use the space inside the tube shell and make the arrangement of the tube bundle more compact. The cooler meets both the reliability requirements and the performance requirements, thereby effectively reducing the temperature of the recirculated exhaust gas and reducing the nitrogen in the exhaust gas. The emission of oxygen compounds meets the increasingly stringent environmental protection requirements.

Because the ridge ring is used in the cooler, the overall strength of the cooler is strengthened, making the cooler more suitable for medium and heavy trucks, because trucks are generally used in harsh environments, not only with heavy loads, but also on very bumpy roads, so this The cooler is suitable as an exhaust gas recirculation cooler for medium and heavy vehicles.

Embodiment two:

This embodiment is an improvement of the first embodiment, and is a refinement of the embodiment about the ridge ring. The ridge ring described in this embodiment is a rectangular metal ring. There is a circular raised ridge in the middle of the outer surface of the rectangular metal ring, and two annular surfaces for inserting pipe shells or intake pipe boxes and exhaust pipe boxes are formed on both sides of the raised ridge.

As shown in FIG. 5 , the ridge ring in this embodiment includes an annular protrusion 32 and two annular surfaces 31 , 33 . The ridge ring has the following functions: first, the ridge ring is the connection between the split shells; second, the ridge ring is the connection between the shell and the tube box; third, the split shell passes through the ridge After the rings are connected as a whole, the overall strength of the tube shell can be enhanced; fourth, the protrusions in the ridge ring facilitate the assembly of the ridge ring, and play the role of positioning and limiting, and the planes on both sides are inserted into the tube shell or tube box; fifth , the end tube sheet is located between the tube box and the ridge ring, and the ridge ring plays the role of fixing the tube sheet after being connected with the tube box; sixth, since the cooler is equipped with multiple ridge rings, the support strength of the overall structure of the cooler Increase to improve the shock resistance of the cooler; in addition, when the tube shell is long, it is necessary to add baffles to increase the flow length of the cooler. For the overall tube shell, the baffles are very difficult to assemble. The baffle can be fixed on the ridge ring by adding the ridge ring, and the baffle can be fixed on the tube shell before assembling the tube bundle, which is convenient for assembly. After the ridge ring is added, the overall assembly difficulty of the medium and heavy vehicle cooler is reduced, and it can be welded and formed at one time; at present, most of the medium and heavy vehicle coolers are formed through two or more welding processes. The number of times of welding can be reduced, the production efficiency can be improved, and the needs of mass production can be met.

Embodiment three:

This embodiment is a refinement of the previous embodiment, and is concerned with the refinement of the end of the package using a ridge ring. The tube shell described in this embodiment is plugged into the annular surface of the ridge ring after being flared at the end.

In order to strengthen the connection strength between the ridge ring and the shell, the ends of the split shell are flared, as shown in 11, 12, 21, and 22 in Figure 1, to facilitate the connection of the two; similarly, the ridge ring is directly Insert the connection ends 71, 81 of the tube box to make the overall connection of the cooler more firm.

Embodiment four:

This embodiment is an adaptation of Embodiment 1, and is concerned with the refinement of the ridge ring, as shown in FIG. 6 . The ridge ring is a rectangular metal ring. There is a circular raised ridge in the middle of the inner surface of the rectangular metal ring. Two annular surfaces 34, 35 are formed on both sides of the raised ridge. The tube shell is directly inserted into the ridge ring. The raised ridge It acts as a limiter; when the ridge ring is used to connect the tube shell and the tube box at the end of the tube, one side of the ridge ring is the inner annular surface, and the other side is the outer annular surface, and the tube shell is inserted into the inner annular surface of the ridge ring. The outer annular surface of the ridge ring is inserted into the inner edge of the end tube box; in addition, the ridge ring used to connect the tube shell and the tube box at the end of the tube can also be the same as the ridge ring connecting the tube shell. The above method of using the ridge ring to connect the components can enhance the overall strength of the cooler.

The inner surface of the ridge ring in this embodiment has a boss, which facilitates the insertion of the tube shell and accurate positioning, as shown in FIG. 7 . The tube shell is inserted into the interior of the ridge ring, avoiding the process of tube shell flaring and reducing the processing links.

Embodiment five:

This embodiment is an improvement of the above embodiments with respect to the shell. Expansion joints are arranged on the shell, and the expansion joints are continuous arc-shaped protrusions arranged along the width and height directions of the shell, as shown in FIG. 8 .

This embodiment adopts a facility for expansion joints 14 and 24, which are arranged on the shell and are a continuous arc-shaped protrusion, that is, an arc-shaped raised edge is processed on the thin-walled metal shell as an expansion joint. , can play the role of thermal expansion and contraction. The expansion joint can effectively absorb the amount of deformation caused by thermal expansion and contraction. Due to the harsh environment in which the exhaust gas recirculation cooler is applied, high-temperature exhaust gas flows through the heat exchange tubes, and low-temperature coolant flows through the tube shell, so different thermal expansions occur between the tube bundle and the tube shell, resulting in thermal stress. , compressive stress is generated on the heat exchange tube, tensile stress is generated on the tube shell, bending stress is generated on the tube sheet, and the tube bundle, tube sheet and tube shell form a closed force flow. Due to the stress generated by the different expansion of each component, it may cause failure of a single component or damage at the joint of the tube sheet, causing leakage of the cooler, and may destroy the normal operation of the engine in severe cases.

As shown in Figure 8, there are expansion joints on the left and right tube shells. Especially when the exhaust gas recirculation cooler is applied to medium and heavy vehicles, in order to meet the heat exchange efficiency of the cooler, the length of the cooler is generally longer. The thermal stress caused by the difference in thermal expansion between these components cannot be ignored. Therefore, in the split shell of this embodiment, expansion joints are provided on both the left shell and the right shell, which can effectively absorb the heat caused by the tube bundle and the tube The different expansions caused by the different heating of the shell reduce the generation of thermal stress and prevent the damage of the cooler components. Likewise, the right tubular shell is of the same design, has an expansion joint, and serves the same purpose.

Embodiment six:

This embodiment is an improvement of the above-mentioned embodiment. The water inlet pipe and the water outlet pipe are connected to the pipe shell by an elbow, and a branch pipe is arranged on the water outlet pipe; the air inlet pipe box includes: an air inlet pipe flange, which is connected to the air inlet pipe flange What is connected with the decoupler is the head of the intake pipe box, and the head of the intake pipe box is connected with the ridge ring on one side of the intake pipe box. The outlet pipe box includes: an outlet pipe flange, the outlet pipe flange is connected to the head of the outlet pipe box, and the head of the outlet pipe box is connected to the ridge ring on one side of the outlet pipe box.

This embodiment, as shown in Figure 9, includes split tube shells 1, 2, water pipes 5, 6, ridge ring 3, brackets 110, 120, end tube boxes 7, 8, heat exchange tubes and tube sheets (not shown) part. The heat exchange tubes used in this embodiment can use circular spiral groove heat exchange tubes or flat groove heat exchange tubes according to different discharge requirements; between the tube box and the shell, between the shell and the shell The role played by the ridge ring 3 is the same as that played by the ridge ring in Embodiment 1; wherein the water inlet pipe 5 and the water outlet pipe 6 are all bent pipe designs, which are directly determined by the arrangement of the cooler in the engine, and the water pipe 6 The main function of the branch pipe 62 on the top is to exhaust steam. During the heat exchange process of the cooler, the temperature of the coolant rises, which may cause local vaporization, which is very unfavorable to the heat exchange of the cooler. When the water side pressure increases To a certain extent, the vaporized coolant will be discharged from the branch pipe 62, so that the cooler can function normally; the intake pipe box 7 is not an integrated design, and consists of several parts: the intake pipe flange 75, the decoupler 74, and the intake pipe head 76. Composition, this combination design can make the structure of the cooler more compact, the intake pipe flange is directly connected to the engine, and the decoupler is directly connected to the intake pipe head, reducing the EGR pipeline connecting the engine and the EGR cooler, This design effectively utilizes the limited space of the engine. Exhaust pipe box 8 is an integrated design, because after the cooler needs to be connected with devices such as regulating valves, it is not necessary to be designed into the form of an air intake pipe box according to the layout of the engine. The design of the tube and shell in the cooler is the same as that of Embodiment 1. The overall design of this embodiment is more compact, not only can the engine meet the strict emission requirements, but also can effectively save space, and the overall strength of the cooler is high, and the reliability is high. The cooler can be formed by one-time welding, which improves production efficiency and meets the needs of mass production.

Embodiment seven:

This embodiment is an improvement on the heat exchange tubes of the above embodiments. The heat exchange tube described in this embodiment is a circular spiral groove heat exchange tube.

The heat exchange tube described in this embodiment is a circular spiral groove heat exchange tube. As shown in Figures 2 and 8, the heat exchange tube 8 of the exhaust gas recirculation cooler passes through the high-temperature exhaust gas, and the split tube shell and the heat exchange tube The area in between is the coolant channel. When the high-temperature gas passes through the circular spiral groove heat exchange tube, it encounters the obstruction of the spiral protrusion, the flow direction changes, and a complex secondary flow vortex flow is generated. At the same time, a vortex is also formed behind the spiral protrusion. The swirling increases the turbulence of the exhaust gas, especially increases the disturbance to the boundary layer near the wall, destroys or thins the fluid boundary layer, thereby enhancing the heat transfer; at the same time, the enhancement of the fluid disturbance reduces the critical Reynolds number , that is, the transition from laminar flow to turbulent flow occurs early, and the strong turbulent flow makes the dirt in the tube severely eroded, which is not easy to scale and easy to clean.

The cooler adopts circular spiral grooved tubes, which can meet the emission standards of Euro 3 or even Euro 4; on this basis, without changing the shape of the cooler, the shape and bundle of the heat exchange tubes can be changed to improve the efficiency of the heat exchange tubes. efficiency to meet higher emission requirements.

Embodiment eight:

This embodiment is an improvement on the heat exchange tubes of the first to fifth embodiments above. The heat exchange tube described in this embodiment is a flat grooved heat exchange tube.

This embodiment adopts flat grooved heat exchange tube 4, as shown in Figure 4 and 10, grooves and bulges are arranged on the upper and lower surfaces where the long side of the heat exchange tube section is located, wherein the grooves are connected to the axis of the bulge It is an equidistant helix line together, and the heat exchange performance of the flat grooved tube is better than that of the circular spiral grooved tube; the advantages of the flat cross-section spiral heat exchange tube are: Under the premise that the volume of the device and the exhaust gas flow rate are constant, that is, when the cross-sectional area of the heat exchange tube is constant, the cross-sectional perimeter of the flat tube must be greater than that of the round tube, so the heat transfer area of the flat tube is larger than that of the round tube. The heat exchange area of the round tube increases the heat exchange area of the entire cooler, so that the cooler achieves a higher heat exchange effect; The role of the heat pipe, while preventing the deformation of the heat exchange tube due to thermal expansion and contraction, the exhaust gas recirculation cooler using the flat heat exchange tube can meet the emission requirements above Euro IV.

The above only shows the connection modes of several typical exhaust gas recirculation coolers for medium and heavy duty diesel engines of the utility model. The shape of the cooler tube shell, the number of tube shell segments, etc. The split structure of the shell effectively reduces the processing difficulty of the longer cooler and improves the processing accuracy, thereby ensuring the overall welding strength of the cooler and is suitable for mass production. This design improves the reliability of the cooler and ensures The cooler fulfills its function, enabling the car engine to meet increasingly stringent emission regulations.

Finally, it should be noted that the above is only used to illustrate the technical solution of the utility model without limitation. Although the utility model has been described in detail with reference to the preferred layout scheme, those of ordinary skill in the art should understand that the technical solutions of the utility model can be The scheme (such as the shape of the shell, the shape of the water pipe, the shape of the end pipe box, the setting of the inner and outer inserting annular surfaces of the ridge ring, etc.) is modified or equivalently replaced without departing from the spirit and scope of the technical solution of the utility model.

Claims (8)

1. medium and heavy Vehicular waste gas recycle cooler with the ridge ring, comprise: as the shell of main body be installed in the tube sheet at shell two ends and the intake pipe and the outlet pipe of shell side, many heat exchanging tubes of circulation waste gas are installed between two tube sheets at described shell two ends, two tube sheets are connected with the exhaust bobbin carriage with the air inlet bobbin carriage respectively, it is characterized in that, described shell is to be surrounded by the sheet metal of thickness less than 2 millimeters, described shell cross section is a rectangle, external form also is a rectangle, described shell can be a single hop, also can be formed by connecting by multistage, no matter what be its total contour length of single hop shell or multistage shell greater than 1 times is wide or high, between described shell and air inlet bobbin carriage or the exhaust bobbin carriage, connect by the ridge ring between each section shell of multistage shell.

2. cooler according to claim 1 is characterized in that, described ridge ring is a rectangular metal ring, and there is a belt convex ridge at the outer side surface middle part of rectangular metal ring, forms the ring surface of two grafting shells or air inlet bobbin carriage, exhaust bobbin carriage in the both sides of convex ridge.

3. cooler according to claim 2 is characterized in that, described shell is plugged on the ring surface of ridge ring after by expanding end.

4. cooler according to claim 1 is characterized in that, described ridge ring is a rectangular metal ring, and there is a belt convex ridge at the inner side surface middle part of rectangular metal ring, forms the ring surface of two grafting shells or air inlet bobbin carriage, exhaust bobbin carriage in the both sides of convex ridge.

5. according to claim 3 or 4 described coolers, it is characterized in that, arrange expansion joint on the described shell, described expansion joint is along the set continuous arc convex of the wide and high direction of shell.

6. cooler according to claim 5 is characterized in that, what described intake pipe and outlet pipe were connected with shell is a bend pipe, and described outlet pipe is provided with a branched pipe; Described suction tude case comprises: the suction tude flange, and what be connected with described suction tude flange is to subtract the coupling device, is air inlet bobbin carriage end socket with what subtract that the coupling device is connected, described air inlet bobbin carriage end socket is connected with the ridge ring of air inlet bobbin carriage one side; Described steam outlet pipe case comprises: the steam outlet pipe flange, and described steam outlet pipe flange is connected with the bobbin carriage end socket of giving vent to anger, and the described bobbin carriage end socket of giving vent to anger is connected with the ridge ring of bobbin carriage one side of giving vent to anger.

7. cooler according to claim 6 is characterized in that, described heat exchanging tube is the round screw thread groove heat exchange tube.

8. cooler according to claim 6 is characterized in that, described heat exchanging tube is flat-shaped groove heat exchange tube.

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