An evaporator
By optimizing the structure of the evaporator's manifold and flat tubes, the problem of uneven refrigerant flow was solved, improving the cooling effect and heat exchange efficiency, and reducing the difficulty of processing and assembly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHIYAN TIANYA AUTO TECH
- Filing Date
- 2024-01-12
- Publication Date
- 2026-07-10
AI Technical Summary
Uneven flow of refrigerant in the evaporator affects the cooling effect.
The system employs a first upper manifold, a second upper manifold, a first lower manifold, and a second lower manifold arranged in parallel, with baffles inside to divide them into multiple half-pipes. The refrigerant enters and exits from the middle, and the contact area is increased through flat tubes and fins to optimize the refrigerant flow path.
It improves the uniformity of refrigerant flow and cooling effect, enhances heat exchange efficiency, and reduces processing and assembly difficulty.
Smart Images
Figure CN117847849B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of air conditioning for new energy vehicles, and in particular to an evaporator. Background Technology
[0002] New energy vehicles refer to automobiles that use unconventional vehicle fuels as their power source and integrate advanced technologies in vehicle power control and drive, resulting in vehicles with advanced technical principles and new technologies and structures. Due to their energy-saving and environmentally friendly characteristics, new energy vehicles have experienced rapid development in recent years.
[0003] Automotive air conditioning is an important component of new energy vehicles, and the evaporator is a crucial part of it, primarily responsible for cooling. The evaporator is installed in an evaporator box, which is located inside the passenger-side dashboard. The evaporator consists of a row of winding pipes and numerous metal fins for heat dissipation. Through heat exchange, it transfers heat from the low-temperature condensate to the outside air, vaporizing and absorbing heat to achieve a cooling effect.
[0004] In related technologies, a heat exchange device for electric vehicles has been proposed, including an evaporator. The evaporator includes a first lower manifold and a second lower manifold arranged side by side, and a first upper manifold and a second upper manifold arranged parallel above the first lower manifold and the second lower manifold. The first upper manifold and the second upper manifold are interconnected. An array of evaporator flat tubes is provided between the first lower manifold and the first upper manifold, and between the second lower manifold and the second upper manifold. Evaporator fins are provided between adjacent evaporator flat tubes. A liquid inlet pipe is connected to the end of the first lower manifold, and a gas return pipe is connected to the end of the second lower manifold.
[0005] The liquid inlet pipe is used to introduce liquid refrigerant. After the refrigerant flows into the first lower manifold, it flows upward through each evaporator flat tube to the first upper manifold, and then through the second upper manifold and the corresponding evaporator flat tube to the second lower manifold. During the flow, the refrigerant gradually vaporizes. The vaporized refrigerant gas is discharged through the return gas pipe connected to the front end of the second lower manifold for circulation.
[0006] The aforementioned technologies have the following drawbacks: the refrigerant enters the first lower manifold from the end of the first lower manifold and only enters the evaporator flat tube after filling the entire first lower manifold; the vaporized refrigerant gathers at the end of the second lower manifold before passing through the return pipe for distribution, resulting in poor uniformity of refrigerant flow and distribution, which affects the cooling effect. Summary of the Invention
[0007] To improve the problem of poor refrigerant flow uniformity, this application provides an evaporator.
[0008] The evaporator provided in this application adopts the following technical solution:
[0009] An evaporator includes: a first upper manifold, a second upper manifold, a first lower manifold, a second lower manifold, and a plurality of flat tubes. The first upper manifold and the second upper manifold are arranged side by side, the first lower manifold and the second lower manifold are arranged side by side, the first upper manifold and the first lower manifold correspond to each other, the second upper manifold and the second lower manifold correspond to each other, a portion of the plurality of flat tubes is connected between the first lower manifold and the first upper manifold, the first upper manifold and the second upper manifold are connected in communication, another portion of the plurality of flat tubes is connected between the second upper manifold and the second lower manifold, and a liquid inlet pipe is provided in the middle of one side of the first lower manifold.
[0010] By adopting the above technical solution, the refrigerant enters the first lower manifold from the middle and exits the second lower manifold from the middle, making the refrigerant flow smoother, improving the uniformity of the refrigerant flow, and enhancing the cooling effect.
[0011] Optionally: Each of the first lower manifold, the first upper manifold, the second upper manifold, and the second lower manifold is provided with a baffle plate. The baffle plate divides the first lower manifold into a first half-pipe and an eighth half-pipe, the baffle plate divides the first upper manifold into a second half-pipe and a seventh half-pipe, the baffle plate divides the second upper manifold into a third half-pipe and a sixth half-pipe, and the baffle plate divides the second lower manifold into a fourth half-pipe and a fifth half-pipe. The first half-pipe, the second half-pipe, the third half-pipe, the fourth half-pipe, the fifth half-pipe, the sixth half-pipe, the seventh half-pipe, and the eighth half-pipe are connected in sequence. The inlet pipe is located in the middle of one side of the first half-pipe, and the outlet pipe is located in the middle of one side of the eighth half-pipe.
[0012] By adopting the above technical solution, the liquid inlet pipe and the liquid outlet pipe are integrated on the first lower manifold, which reduces the processing and assembly difficulty of the first lower manifold, the first upper manifold, the second upper manifold, and the second lower manifold. In addition, the refrigerant flows through the first half-pipe, the second half-pipe, the third half-pipe, the fourth half-pipe, the fifth half-pipe, the sixth half-pipe, the seventh half-pipe, and the eighth half-pipe in sequence, which extends the flow path of the refrigerant within a limited space and improves the cooling effect.
[0013] Optionally, the plurality of the baffles are located in the middle of the first lower manifold, the first upper manifold, the second upper manifold, and the second lower manifold, respectively.
[0014] By adopting the above technical solution, the first half-pipe, the second half-pipe, the third half-pipe, the fourth half-pipe, the fifth half-pipe, the sixth half-pipe, the seventh half-pipe, and the eighth half-pipe have the same volume, which further improves the uniformity of refrigerant flow and further enhances the cooling effect.
[0015] Optionally: the plurality of flat tubes include a first flat tube, a second flat tube, a third flat tube, and a fourth flat tube. The first half-tube and the second half-tube are connected by the plurality of first flat tubes. The plurality of first flat tubes are arranged alternately along the length direction of the first half-tube and the second half-tube. The third half-tube and the fourth half-tube are connected by the plurality of second flat tubes. The plurality of second flat tubes are arranged alternately along the length direction of the third half-tube and the fourth half-tube. The fifth half-tube and the sixth half-tube are connected by the plurality of third flat tubes. The plurality of third flat tubes are arranged alternately along the length direction of the fifth half-tube and the sixth half-tube. The seventh half-tube and the eighth half-tube are connected by the plurality of fourth flat tubes. The plurality of fourth flat tubes are arranged alternately along the length direction of the seventh half-tube and the eighth half-tube.
[0016] By adopting the above technical solution, the first half-pipe, second half-pipe, third half-pipe, fourth half-pipe, fifth half-pipe, sixth half-pipe, seventh half-pipe, and eighth half-pipe are connected by an array of first flat tubes, second flat tubes, third flat tubes, and fourth flat tubes, which reduces the difficulty of processing and assembly. In addition, the first flat tube, second flat tube, third flat tube, and fourth flat tube are all flat, which increases the contact area between the refrigerant and the air, improves the heat exchange efficiency, and enhances the cooling effect.
[0017] Optionally: the first flat tube is provided with a first fin, the second flat tube is provided with a second fin, the third flat tube is provided with a third fin, and the fourth flat tube is provided with a fourth fin.
[0018] By adopting the above technical solution, the contact area between the first, second, third, and fourth flat tubes and the air is further increased, thereby further improving the heat exchange efficiency and the cooling effect.
[0019] Optionally: the first fin is located on the side of the first flat tube near the second flat tube, and the second fin is located on the side of the second flat tube near the first flat tube.
[0020] By adopting the above technical solution, the refrigerant flows sequentially through the first flat tube and the second flat tube. After entering the first and second flat tubes, the refrigerant exchanges heat with the outside air and then vaporizes. Therefore, the refrigerant temperature in the first and second flat tubes is different. The first fin is located on the side of the first flat tube closer to the second flat tube, and the second fin is located on the side of the second flat tube closer to the first flat tube. This increases the distance between the first and second flat tubes, reduces the possibility of mutual influence between the refrigerants in the first and second flat tubes, and improves the cooling effect.
[0021] Optionally: the third fin is located on the side of the third flat tube close to the fourth flat tube, and the fourth fin is located on the side of the fourth flat tube close to the third flat tube.
[0022] By adopting the above technical solution, the refrigerant flows sequentially through the third and fourth flat tubes. After entering the third and fourth flat tubes, the refrigerant exchanges heat with the outside air and then vaporizes. Therefore, the refrigerant temperature in the third and fourth flat tubes is different. The third fin is located on the side of the third flat tube closer to the fourth flat tube, and the fourth fin is located on the side of the fourth flat tube closer to the third flat tube. This increases the distance between the third and fourth flat tubes, reduces the possibility of mutual influence between the refrigerants in the third and fourth flat tubes, and improves the cooling effect.
[0023] Optionally: The second half-tube and the third half-tube are connected by a plurality of first through holes, the plurality of first through holes being arranged sequentially at intervals along the length direction of the second half-tube and the third half-tube; the sixth half-tube and the seventh half-tube are connected by a plurality of second through holes, the plurality of second through holes being arranged sequentially at intervals along the length direction of the sixth half-tube and the seventh half-tube.
[0024] By adopting the above technical solution, the first through holes are arranged at intervals along the length direction of the second half tube and the third half tube, and the second through holes are arranged at intervals along the length direction of the sixth half tube and the seventh half tube. Under the premise of ensuring the strength of the second half tube, the third half tube, the sixth half tube and the seventh half tube, the connection between the second half tube and the third half tube and the connection between the sixth half tube and the seventh half tube are realized. Moreover, the processing is simple and saves raw materials.
[0025] Optionally: the end of the inlet pipe near the first half-pipe is flattened, and the end of the outlet pipe near the eighth half-pipe is flattened.
[0026] By adopting the above technical solution, the contact area between the liquid inlet pipe and the first half-pipe, and the contact area between the liquid outlet pipe and the eighth half-pipe are increased. Furthermore, the extension direction of the flat opening is the same as the length direction of the first half-pipe and the eighth half-pipe, which further improves the uniformity of refrigerant flow and further enhances the cooling effect.
[0027] Optionally, the outer sides of the first upper manifold, the second upper manifold, the first lower manifold, and the second lower manifold are all provided with protective shells.
[0028] By adopting the above technical solution, the first upper manifold, the second upper manifold, the first lower manifold, and the second lower manifold are protected, reducing the possibility of damage to the first upper manifold, the second upper manifold, the first lower manifold, and the second lower manifold, and improving the service life of the first upper manifold, the second upper manifold, the first lower manifold, and the second lower manifold.
[0029] In summary, this application has the following beneficial effects:
[0030] Both the inlet and outlet pipes are integrated in the middle of the first lower manifold. The refrigerant flows into the first half-pipe from the middle and flows out of the eighth half-pipe from the middle, making the refrigerant flow smoother, improving the uniformity of the refrigerant flow, and enhancing the cooling effect. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;
[0032] Figure 2 This is a partial structural diagram from a first-view perspective of an embodiment of this application;
[0033] Figure 3 This is a partial structural diagram from a second perspective of an embodiment of this application;
[0034] Figure 4 This is a first-view partial structural cross-sectional view of an embodiment of this application.
[0035] Explanation of reference numerals in the attached figures:
[0036] 1. First upper manifold; 11. Second half-pipe; 12. Seventh half-pipe; 13. First through hole; 14. Second through hole; 2. Second upper manifold; 21. Third half-pipe; 22. Sixth half-pipe; 3. First lower manifold; 31. First half-pipe; 32. Eighth half-pipe; 4. Second lower manifold; 41. Fourth half-pipe; 42. Fifth half-pipe; 51. Inlet pipe; 52. Outlet pipe; 6. Baffle; 71. First flat pipe; 72. Second flat pipe; 73. Third flat pipe; 74. Fourth flat pipe; 75. First fin; 76. Second fin; 77. Third fin; 78. Fourth fin; 8. Protective shell; 9. Connector. Detailed Implementation
[0037] The present application will be further described in detail below with reference to the accompanying drawings.
[0038] This embodiment: an evaporator, as shown in the following example. Figure 1 It includes: a first upper manifold 1, a second upper manifold 2, a first lower manifold 3, and a second lower manifold 4. The first upper manifold 1 and the second upper manifold 2 are arranged side by side and fixedly connected together, and the first lower manifold 3 and the second lower manifold 4 are arranged side by side and fixedly connected together. In the vertical direction, the first upper manifold 1 corresponds to the first lower manifold 3, and the second upper manifold 2 corresponds to the second lower manifold 4. The first upper manifold 1, the second upper manifold 2, the first lower manifold 3, and the second lower manifold 4 are parallel. A protective shell 8 is installed on the outside of the first upper manifold 1, the second upper manifold 2, the first lower manifold 3, and the second lower manifold 4.
[0039] Reference Figure 2 and Figure 3Each of the first lower manifold 3, the first upper manifold 1, the second upper manifold 2, and the second lower manifold 4 is equipped with a baffle 6. The four baffles 6 are located in the middle of the first lower manifold 3, the first upper manifold 1, the second upper manifold 2, and the second lower manifold 4, respectively. The baffle 6 divides the first lower manifold 3 into a first half-pipe 31 and an eighth half-pipe 32, the first upper manifold 1 into a second half-pipe 11 and a seventh half-pipe 12, the second upper manifold 2 into a third half-pipe 21 and a sixth half-pipe 22, and the second lower manifold 4 into a fourth half-pipe 41 and a fifth half-pipe 42. The baffles 6 in the second lower manifold 4 are perforated.
[0040] The first half-pipe 31, the second half-pipe 11, the third half-pipe 21, the fourth half-pipe 41, the fifth half-pipe 42, the sixth half-pipe 22, the seventh half-pipe 12, and the eighth half-pipe 32 are connected in sequence. An inlet pipe 51 is fixedly connected to the middle of the side of the first half-pipe 31 furthest from the fourth half-pipe 41, and the inlet pipe 51 is connected to the first half-pipe 31. An outlet pipe 52 is fixedly connected to the middle of the side of the eighth half-pipe 32 furthest from the fifth half-pipe 42, and the outlet pipe 52 is connected to the fifth half-pipe 42. The end of the inlet pipe 51 furthest from the first half-pipe 31 and the end of the outlet pipe 52 furthest from the eighth half-pipe 32 are fixed together by a connector 9.
[0041] It should be noted that the end of the inlet pipe 51 near the first half-pipe 31 is flattened, and the end of the outlet pipe 52 near the eighth half-pipe 32 is also flattened, with the extension direction of the flattened ends being the same as the length direction of the first lower manifold 3. This arrangement increases the contact area between the inlet pipe 51 and the first half-pipe 31, and the contact area between the outlet pipe 52 and the eighth half-pipe 32, resulting in a smoother refrigerant flow and improved uniformity of refrigerant flow.
[0042] During cooling, the refrigerant flows sequentially through the inlet pipe 51, the first half-pipe 31, the second half-pipe 11, the third half-pipe 21, the fourth half-pipe 41, the fifth half-pipe 42, the sixth half-pipe 22, the seventh half-pipe 12, the eighth half-pipe 32, and the outlet pipe 52. The refrigerant flows into the first half-pipe 31 from the middle and exits the eighth half-pipe 32 from the middle. This not only makes the refrigerant flow smoother and improves its uniformity but also increases the length of the refrigerant flow path within a limited space, thus enhancing the cooling effect.
[0043] The first half-tube 31 and the second half-tube 11 are connected by a plurality of arrayed first flat tubes 71. The plurality of first flat tubes 71 are arranged at intervals along the length direction of the first half-tube 31 and the second half-tube 11, and are parallel to each other and perpendicular to the first half-tube 31. The third half-tube 21 and the fourth half-tube 41 are connected by a plurality of second flat tubes 72. The plurality of second flat tubes 72 are arranged at intervals along the length direction of the third half-tube 21 and the fourth half-tube 41, and are parallel to each other and perpendicular to the third half-tube 21.
[0044] The fifth half-tube 42 and the sixth half-tube 22 are connected by multiple third flat tubes 73. These third flat tubes 73 are arranged alternately along the length of the fifth half-tube 42 and the sixth half-tube 22, and are parallel to each other and perpendicular to the fifth half-tube 42. The seventh half-tube 12 and the eighth half-tube 32 are connected by multiple fourth flat tubes 74. These fourth flat tubes 74 are arranged alternately along the length of the seventh half-tube 12 and the eighth half-tube 32, and are parallel to each other and perpendicular to the seventh half-tube 12.
[0045] Reference Figure 4 The second half-tube 11 and the third half-tube 21 are connected by a plurality of first through holes 13, which are arranged alternately along the length of the second half-tube 11 and the third half-tube 21. The sixth half-tube 22 and the seventh half-tube 12 are connected by a plurality of second through holes 14, which are arranged alternately along the length of the sixth half-tube 22 and the seventh half-tube 12.
[0046] During cooling, the refrigerant sequentially passes through the inlet pipe 51, the first half-pipe 31, the first flat pipe 71, the second half-pipe 11, the first through hole 13, the third half-pipe 21, the second flat pipe 72, the fourth half-pipe 41, the baffle 6, the fifth half-pipe 42, the third flat pipe 73, the sixth half-pipe 22, the second through hole 14, the seventh half-pipe 12, the fourth flat pipe 74, the eighth half-pipe 32, and the outlet pipe 52. This improves the uniformity of refrigerant flow and the length of the flow path, thereby enhancing the cooling effect.
[0047] A first fin 75 is fixedly connected to a first flat tube 71, and the first fin 75 is located on the side of the first flat tube 71 near the second flat tube 72. A second fin 76 is fixedly connected to a second flat tube 72, and the second fin 76 is located on the side of the second flat tube 72 near the first flat tube 71. A third fin 77 is fixedly connected to a third flat tube 73, and the third fin 77 is located on the side of the third flat tube 73 near the fourth flat tube 74. A fourth fin 78 is fixedly connected to a fourth flat tube 74, and the fourth fin 78 is located on the side of the fourth flat tube 74 near the third flat tube 73.
[0048] The first fin 75, the second fin 76, the third fin 77, and the fourth fin 78 increase the contact area between the first flat tube 71, the second flat tube 72, the third flat tube 73, and the fourth flat tube 74 and the air, thereby increasing the contact area between the refrigerant and the air, improving heat exchange efficiency, and enhancing the cooling effect. Furthermore, the first fin 75 and the second fin 76 are located on adjacent sides of the first flat tube 71 and the second flat tube 72, respectively, and the third fin 77 and the fourth fin 78 are located on adjacent sides of the third flat tube 73 and the fourth flat tube 74, respectively. This increases the spacing between the first flat tube 71 and the second flat tube 72, and between the third flat tube 73 and the fourth flat tube 74, reducing the mutual influence of the refrigerant within these tubes and further improving cooling efficiency.
[0049] The implementation principle of an evaporator according to an embodiment of this application is as follows: During refrigeration, the refrigerant sequentially passes through the inlet pipe 51, the first half-pipe 31, the first flat pipe 71, the second half-pipe 11, the first through hole 13, the third half-pipe 21, the second flat pipe 72, the fourth half-pipe 41, the baffle 6, the fifth half-pipe 42, the third flat pipe 73, the sixth half-pipe 22, the second through hole 14, the seventh half-pipe 12, the fourth flat pipe 74, the eighth half-pipe 32, and the outlet pipe 52. The inlet pipe 51 is located in the middle of the first half-pipe 31, and the outlet pipe 52 is located in the middle of the eighth half-pipe 32. This not only makes the refrigerant flow smoother and improves the uniformity of the refrigerant flow, but also increases the length of the refrigerant flow path within a limited space, thereby improving the refrigeration effect. The first fin 75, the second fin 76, the third fin 77, and the fourth fin 78 increase the contact area between the refrigerant and the air, further improving the heat exchange efficiency and the refrigeration effect.
[0050] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. An evaporator, characterized in that, include: The system comprises a first upper manifold (1), a second upper manifold (2), a first lower manifold (3), a second lower manifold (4), and multiple flat tubes. The first upper manifold (1) and the second upper manifold (2) are arranged side by side, the first lower manifold (3) and the second lower manifold (4) are arranged side by side, the first upper manifold (1) corresponds to the first lower manifold (3), the second upper manifold (2) corresponds to the second lower manifold (4), a portion of the multiple flat tubes is connected between the first lower manifold (3) and the first upper manifold (1), the first upper manifold (1) is connected to the second upper manifold (2), another portion of the multiple flat tubes is connected between the second upper manifold (2) and the second lower manifold (4), and an inlet pipe (51) is provided in the middle of one side of the first lower manifold (3). Each of the first lower manifold (3), the first upper manifold (1), the second upper manifold (2), and the second lower manifold (4) is provided with a baffle (6). The baffle (6) divides the first lower manifold (3) into a first half-pipe (31) and an eighth half-pipe (32). The baffle (6) divides the first upper manifold (1) into a second half-pipe (11) and a seventh half-pipe (12). The baffle (6) divides the second upper manifold (2) into a third half-pipe (21) and a sixth half-pipe (22). The partition (6) divides the second lower manifold (4) into a fourth half-pipe (41) and a fifth half-pipe (42). The first half-pipe (31), the second half-pipe (11), the third half-pipe (21), the fourth half-pipe (41), the fifth half-pipe (42), the sixth half-pipe (22), the seventh half-pipe (12), and the eighth half-pipe (32) are connected in sequence. The inlet pipe (51) is located in the middle of one side of the first half-pipe (31), and the outlet pipe (52) is located in the middle of one side of the eighth half-pipe (32). The plurality of flat tubes include a first flat tube (71), a second flat tube (72), a third flat tube (73), and a fourth flat tube (74). The first half-tube (31) and the second half-tube (11) are connected by the plurality of first flat tubes (71). The plurality of first flat tubes (71) are arranged sequentially at intervals along the length direction of the first half-tube (31) and the second half-tube (11). The third half-tube (21) and the fourth half-tube (41) are connected by the plurality of second flat tubes (72). The plurality of second flat tubes (72) are arranged along the length direction of the third half-tube (21) and the fourth half-tube (41). 1) The fifth half-tube (42) and the sixth half-tube (22) are arranged alternately along the length direction of the fourth half-tube (41). The fifth half-tube (42) and the sixth half-tube (22) are connected by multiple third flat tubes (73). The multiple third flat tubes (73) are arranged alternately along the length direction of the fifth half-tube (42) and the sixth half-tube (22). The seventh half-tube (12) and the eighth half-tube (32) are connected by multiple fourth flat tubes (74). The multiple fourth flat tubes (74) are arranged alternately along the length direction of the seventh half-tube (12) and the eighth half-tube (32). The first flat tube (71) is provided with a first fin (75), the second flat tube (72) is provided with a second fin (76), the third flat tube (73) is provided with a third fin (77), and the fourth flat tube (74) is provided with a fourth fin (78). The first fin (75) is located on the side of the first flat tube (71) near the second flat tube (72), and the second fin (76) is located on the side of the second flat tube (72) near the first flat tube (71).
2. An evaporator according to claim 1, characterized in that: The multiple baffles (6) are located in the middle of the first lower manifold (3), the first upper manifold (1), the second upper manifold (2) and the second lower manifold (4).
3. An evaporator according to claim 1, characterized in that: The third fin (77) is located on the third flat tube (73) on the side close to the fourth flat tube (74), and the fourth fin (78) is located on the fourth flat tube (74) on the side close to the third flat tube (73).
4. An evaporator according to claim 1, characterized in that: The second half-tube (11) and the third half-tube (21) are connected by a plurality of first through holes (13), and the plurality of first through holes (13) are arranged alternately along the length direction of the second half-tube (11) and the third half-tube (21). The sixth half-tube (22) and the seventh half-tube (12) are connected by a plurality of second through holes (14), and the plurality of second through holes (14) are arranged alternately along the length direction of the sixth half-tube (22) and the seventh half-tube (12).
5. An evaporator according to claim 1, characterized in that: The inlet pipe (51) is flattened at one end near the first half-pipe (31), and the outlet pipe (52) is flattened at one end near the eighth half-pipe (32).
6. An evaporator according to claim 1, characterized in that: The outer sides of the first upper manifold (1), the second upper manifold (2), the first lower manifold (3), and the second lower manifold (4) are all provided with protective shells (8).