Tank-dividing cooling method for micro-channel aluminum flat pipe

Abstract

The invention discloses a sub-groove cooling method for a micro-channel aluminum flat pipe, which comprises the following steps: S1, replacing an aluminum bar, extruding a flat pipe by an extruder, and moving the flat pipe towards a cooling device; s2, measuring the moving distance of the flat tube by a meter counter, and calculating the moving speed of the flat tube; s3, when the moving speed of the flat pipe reaches a set value, the water pump conveys cooling water in the water storage tank into the lower water tank; s4, when the moving distance of the flat pipe reaches a set value, the cooling water in the lower water tank enters a water tank corresponding to the upper water tank, and the flat pipe is cooled; and S5, when the moving distances of the other flat pipes reach the set values respectively, cooling water in the lower water tank enters the corresponding water tanks of the upper water tank to cool the other flat pipes respectively. According to the invention, each flat pipe is independently cooled through a split-groove cooling method, so that cooling water is prevented from entering an inner hole of the flat pipe from a crack to cause oxidation in the flat pipe to generate badness, the loss of the high-temperature flat pipe to a tool is reduced, and the automation of the cooling operation of the flat pipe is also realized.

Description

Technical Field

[0001] The present invention relates to a grooving cooling method for microchannel aluminum flat tubes. Background Art

[0002] In order to improve production efficiency and reduce production costs, the extrusion of microchannel aluminum flat tubes has been gradually increased from "one-out-one" to "one-out-six", that is, the extrusion of one microchannel aluminum flat tube by one extrusion die has been optimized to the extrusion of six microchannel aluminum flat tubes by one extrusion die. The time required to extrude an aluminum rod into a microchannel aluminum flat tube is approximately 5 - 8 minutes. Each time an aluminum rod is replaced, a crack will occur at the joint of the microchannel aluminum flat tubes. When the crack at the joint of the microchannel aluminum flat tube passes through the water tank, if the water tank is in working condition, the cooling water will enter the inner hole of the flat tube from the crack of the microchannel aluminum flat tube, thereby causing oxidation in the inner hole of the microchannel aluminum flat tube and generating a large number of defects.

[0003] Since one extrusion die needs to distribute six cavities to simultaneously extrude six microchannel aluminum flat tubes, the frictional resistances of the six cavities are inconsistent. The microchannel aluminum flat tube in the cavity with small frictional force moves fast, while the microchannel aluminum flat tube in the cavity with large frictional force moves slowly. Therefore, the moving speeds of the six microchannel aluminum flat tubes are inconsistent. If we wait for the slowest moving microchannel aluminum flat tube with a crack to pass through the water tank and then start the water cooling operation of the water tank, at this time, the fastest moving microchannel aluminum flat tube with a crack has moved a long distance. The uncooled microchannel aluminum flat tube is in a high-temperature state, and the high-temperature microchannel aluminum flat tube will scald the tooling it contacts, which will reduce the service life of the tooling. As a result, the tooling needs to be frequently replaced during production, leading to an increase in the line stop time of the production line. The existing cooling method cannot solve this contradiction, so there is an urgent need for a grooving cooling method for microchannel aluminum flat tubes. Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title. However, such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] The technical problem to be solved by the present invention is how to effectively cool the microchannel aluminum flat tubes with different moving speeds just extruded.

[0006] To solve the above technical problem, the present invention provides the following technical solution: A grooving cooling method for microchannel aluminum flat tubes, comprising the following steps:

[0007] S1: Replace an aluminum bar, and the extruder extrudes a flat tube, which moves towards the cooling device;

[0008] S2: The length counter measures the moving distance of the flat tube, uploads it to the PLC control board, and calculates the moving speed of the flat tube;

[0009] S3: When the moving speed of the fastest moving flat tube reaches the set value, the PLC control board starts the water pump to convey the cooling water in the water storage tank to the lower water tank;

[0010] S4: When the moving distance of the fastest moving flat tube reaches the set value, the PLC control board opens the corresponding water inlet switch, so that the cooling water in the lower water tank enters the corresponding water groove in the upper water tank to cool the flat tube;

[0011] S5: When the moving distances of the remaining flat tubes respectively reach the set values, the PLC control board opens the corresponding water inlet switches, so that the cooling water in the lower water tank enters the corresponding water grooves in the upper water tank to cool the remaining flat tubes respectively;

[0012] S6: The flat tube after cooling is purged by a compressed air purging device, and then dried in an oven and wound on a coiling machine.

[0013] As a preferred embodiment of the method for slot-cooling of the micro-channel aluminum flat tube of the present invention, wherein: the cooling device includes a cooling water tank, a water storage tank, a plate cooler and a water pump. The water pump conveys the cooling water in the water storage tank to the cooling water tank after cooling it through the plate cooler. The water grooves are arranged on the top of the cooling water tank for separately cooling each flat tube, and the water inlet switches are arranged at the bottom of the water grooves so that the cooling water in the lower water tank can directly enter the water grooves in the upper water tank through the water inlet switches.

[0014] As a preferred embodiment of the method for slot-cooling of the micro-channel aluminum flat tube of the present invention, wherein: the opening of the water inlet switch in each water groove needs to meet two conditions simultaneously. One is that the moving speed of the flat tube passing through this water groove is greater than or equal to the set value of the moving speed, and the other is that the moving distance of the flat tube passing through this water groove is greater than or equal to the set value of the moving distance, so as to prevent the water inlet switch from opening to cool the flat tube when the crack of the flat tube has not moved out of the cooling area of the cooling water tank, resulting in the cooling water entering the inner hole of the flat tube through the crack.

[0015] As a preferred embodiment of the method for slot-cooling of the micro-channel aluminum flat tube of the present invention, wherein: the water inlet switch is connected to a pneumatic solenoid valve through a push rod, and the pneumatic solenoid valve is connected to the PLC control board, and the PLC control board controls each water inlet switch in the water groove separately.

[0016] As a preferred embodiment of the method for slot-cooling of the micro-channel aluminum flat tube of the present invention, wherein: the set value of the moving speed of the flat tube in S3 is 3 m / min to achieve the best cooling effect.

[0017] As a preferred embodiment of the slot-dividing cooling method for the micro-channel aluminum flat tube of the present invention, wherein: the set value of the moving distance of the flat tube in S4 is 6m. Under the condition of preventing cooling water from entering the inner hole of the flat tube, the rest of the flat tube is cooled as much as possible.

[0018] The beneficial effects are as follows: The present invention realizes the separate cooling of each extruded flat tube through the slot-dividing cooling method, which not only avoids the poor quality caused by the oxidation inside the flat tube due to the cooling water entering the inner hole from the crack, but also reduces the loss of the tooling caused by the high-temperature flat tube, and also realizes the automation of the flat tube cooling operation. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0020] Figure 1 It is a schematic diagram of the overall structure of the slot-dividing cooling device for the micro-channel aluminum flat tube.

[0021] Figure 2 It is a schematic diagram of the position structure of the cooling device of the slot-dividing cooling method for the micro-channel aluminum flat tube.

[0022] Figure 3 It is a schematic diagram of the position structure of the water tank and the flat tube of the slot-dividing cooling method for the micro-channel aluminum flat tube.

[0023] Figure 4 It is a schematic diagram of the position structure of the crack of the flat tube in actual production.

[0024] In the figure: 100, extruder; 110, PLC control board; 200, cooling device; 210, first relay; 220, cooling water tank; 221, upper water tank; 2211, water tank; 222, lower water tank; 223, overflow water tank; 224, through hole; 225, first overflow port; 226, second overflow port; 230, water pump; 240, water storage tank; 250, plate cooler; 260, water pipe; 270, water inlet switch; 280, ejector rod; 290, pneumatic solenoid valve; 300, compressed air purging device; 310, control valve; 320, compressed air nozzle; 330, air pressure pipe; 400, oven; 410, second relay; 500, coiler; 510, length counter; 600, flat tube; 610, crack. Detailed Embodiments

[0025] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given in conjunction with the accompanying drawings of the specification.

[0026] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0027] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that may be included in at least one implementation manner of the present invention. The "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or selectively exclusive embodiment from other embodiments.

[0028] Embodiment 1

[0029] Referring to Figures 1 to 3 , which is the first embodiment of the present invention. This embodiment provides a grooving cooling device for microchannel aluminum flat tubes, including an extruder 100, a cooling device 200, a compressed air purging device 300, an oven 400 and a coiler 500. The extruder 100 is used for the extrusion molding of the microchannel aluminum flat tubes 600. The extrusion die used in this embodiment is a "one-out-six" die, that is, through the extruder 100, one aluminum rod can be extruded into six microchannel aluminum flat tubes 600. A PLC control board 110 is installed on the extruder 100, which serves as the central control processing unit in this embodiment. A cooling device 200 is installed on the right side of the extruder 100 for the individual water cooling of each flat tube 600. A compressed air purging device 300 is installed on the right side of the cooling device 200 for purging the liquid droplets on the outer surface of the cooled flat tube 600. An oven 400 is installed on the right side of the compressed air purging device 300 for drying the cooled flat tube 600. And a second relay 410 is installed at the bottom of the oven 400. The second relay 410 serves as a fan control unit and is electrically connected to the PLC control board 110 and is controlled by the PLC control board 110. Six coilers 500 corresponding to the number of flat tubes 600 are installed on the right side of the oven 400 for coiling six flat tubes 600 into coils.

[0030] Specifically, the cooling device 200 mainly includes a cooling water tank 220, a water storage tank 240, and a water pump 230. The distance between the cooling water tank 220 and the outlet end of the extruder 100 is 5 m. The cooling water tank 220 includes an overflow water tank 223, a lower water tank 222, and an upper water tank 221. The overflow water tank 223 has the largest size. The lower water tank 222 is installed inside the overflow water tank 223, and a first overflow port 225 is provided at the right bottom of the lower water tank 222 so that the cooling water in the lower water tank 222 can enter the overflow water tank 223 through the first overflow port 225. The upper water tank 221 is installed on the top of the lower water tank 222. Six water troughs 2211 corresponding to the number of flat tubes 600 are evenly arranged on the upper water tank 221 through partitions for separately water-cooling the six flat tubes 600. It should be noted that through holes 224 for the six flat tubes 600 to pass through are provided on both the overflow water tank 223 and the upper water tank 221 so that the six flat tubes 600 can penetrate the corresponding six water troughs 2211. The water storage tank 240 is installed at the bottom of the cooling water tank 220. A second overflow port 226 is provided at the bottom of the overflow water tank 223 so that the cooling water in the overflow water tank 223 can flow into the water storage tank 240 through the second overflow port 226 to realize the recycling of the cooling water. The left side of the water storage tank 240 is connected to the water pump 230 through a water pipe 260. The outlet end of the water pump 230 is connected to the lower water tank 222 through a water pipe 260. A first relay 210 is also installed on the water pump 230. The water pump 230 is connected to the PLC control board 110 through the first relay 210. The PLC control board 110 controls the water pump 230 to deliver the cooling water in the water storage tank 240 to the lower water tank 222 for water-cooling the flat tubes 600 passing through the water troughs 2211.

[0031] Furthermore, a water inlet switch 270 is installed at the bottom of each water trough 2211 so that the cooling water in the lower water tank 222 can enter the water troughs 2211 in the upper water tank 221 through the water inlet switch 270. A push rod 280 is installed on the water inlet switch 270, and a pneumatic solenoid valve 290 is installed at the top of the push rod 280. The six pneumatic solenoid valves 290 are all connected to the PLC control board 110 so that the PLC control board 110 can separately control the water inlet switches 270 in each water trough 2211, thereby realizing the separate water-cooling of each flat tube 600.

[0032] Furthermore, a plate cooler 250 is installed on the connecting water pipe 260 between the water pump 230 and the lower water tank 222, so that the outlet end of the water pump 230 is connected to the plate cooler 250 through the water pipe 260, and the outlet end of the plate cooler 250 is connected to the lower water tank 222 through the water pipe 260. The plate cooler 250 can cool down the conveyed cooling water to improve the water-cooling efficiency of the flat tubes 600.

[0033] Specifically, the compressed air purging device 300 includes a compressed air pipe 330 connected to an air compressor and a compressed air nozzle 320 installed on the compressed air pipe 330. The compressed air nozzle 320 is arranged on the upper and lower sides of the climbing route of the flat tube 600, and the compressed air nozzle 320 is used to spray compressed air toward the flat tube 600. The spraying direction of the compressed air nozzle 320 faces the upstream direction of the movement of the flat tube 600, and the spraying direction of the compressed air nozzle 320 forms a 30° angle with the length direction of the flat tube 600, so as to achieve a better purging effect. A control valve 310 is installed on the compressed air pipe 330 for opening or closing the compressed air. In this embodiment, the control valve 310 is a solenoid valve. The solenoid valve is used as the control unit of the compressed air, and the control end of the solenoid valve is connected to the PLC control board 110, so that the solenoid valve is controlled by the PLC control board 110.

[0034] Further, a length meter 510 is installed on each of the six coiling machines 500 for measuring the moving distance of the flat tube 600 in real time. The six length meters 510 are all connected to the PLC control board 110, so as to synchronously upload the moving distances of the six flat tubes 600 measured in real time to the PLC control board 110, thereby realizing the real-time monitoring of the moving distances of the six flat tubes 600. The PLC control board 110 can also calculate the moving speeds of the six flat tubes 600 through the uploaded data to realize the real-time monitoring of the moving speeds of the six flat tubes 600, so as to realize the individual water cooling of the six flat tubes 600. It should be noted that since the "one-out-six" extrusion die is adopted in this embodiment, that is, there are six die cavities distributed in one die, and six flat tubes 600 are extruded simultaneously. The frictional resistances of the six die cavities are inconsistent. The flat tube 600 with a small frictional force moves fast, and the flat tube 600 with a large frictional force moves slowly.

[0035] Embodiment 2

[0036] Refer to Figures 1 to 4 , which is the second embodiment of the present invention. Based on the previous embodiment, a method for slot cooling of the microchannel aluminum flat tube 600 is provided, including the following steps:

[0037] S1: When the previous aluminum rod is about to be extruded completely, replace it with a new aluminum rod. At this time, the flat tube 600 extruded by the previous aluminum rod is in a static state until the extruder 100 extrudes six new flat tubes 600. The six new flat tubes 600 are connected to the six flat tubes 600 extruded by the previous aluminum rod, and a crack 610 will appear at the connection. The extruder 100 continues to extrude, so that the six flat tubes 600 with the crack 610 move toward the cooling device 200. During this process, the moving speeds of the six flat tubes 600 gradually increase from 0.

[0038] S2: During the process of the six flat tubes 600 with slits 610 moving towards the cooling device 200, the counters 510 on the six coiling machines 500 respectively measure the moving distances of the six flat tubes 600 and synchronously upload them to the PLC control board 110. The PLC control board 110 monitors the moving distances of the six flat tubes 600 in real time, and the PLC control board 110 calculates the moving speeds of the six flat tubes 600;

[0039] S3: When the PLC control board 110 monitors that the moving speed of the fastest moving flat tube 600 among the six flat tubes 600 reaches the set value of 3 m / min, the PLC control board 110 controls the water pump 230 to start through the first relay 210, and conveys the cooling water in the water storage tank 240 to the lower water tank 222 through the plate heat exchanger 250 in order to achieve the best cooling effect. It should be noted that at this time, the water inlet switch 270 corresponding to the bottom of the water tank 2211 penetrated by the flat tube 600 is not opened;

[0040] S4: When the PLC control board 110 monitors that the moving distance of the fastest moving flat tube 600 reaches the set value of 6 m, the PLC control board 110 controls the corresponding pneumatic solenoid valve 290 to open the water inlet switch 270 at the bottom of the water tank 2211 corresponding to the flat tube 600 through the ejector rod 280. And the water inlet speed of the cooling water entering the lower water tank 222 is greater than the overflow speed of the cooling water flowing out of the first overflow port 225 in the lower water tank 222, so that the cooling water entering the lower water tank 222 can enter the corresponding water tank 2211 in the upper water tank 221 until the cooling water overflows the flat tube 600 to realize water cooling of the flat tube 600. The overflowing cooling water can directly flow into the overflow water tank 223 through the through holes 224 on both sides of the water tank 2211 of the upper water tank 221, and finally enter the water storage tank 240 through the second overflow port 226 at the bottom of the overflow water tank 223. Since the flat tube 600 in any water tank 2211 may be the fastest moving one, the opening of the water inlet switch 270 in each water tank 2211 in this embodiment needs to meet two conditions at the same time. One is that the moving speed of the flat tube 600 passing through the water tank 2211 is greater than or equal to the set value of the moving speed, and the other is that the moving distance of the flat tube 600 passing through the water tank 2211 is greater than or equal to the set value of the moving distance, so as to avoid the water inlet switch 270 being opened to cool the flat tube 600 when the crack 610 of the flat tube 600 has not moved out of the cooling area of the cooling water tank 220, resulting in the cooling water entering the inner hole of the flat tube 600 through the crack 610. It should be noted that the size of the crack 610 on the flat tube 600 is less than 1 cm. About 5 m of the 6 m of the flat tube 600 not water-cooled is formed by the extrusion of the previous aluminum rod, and the distance between the outlet end of the extruder 100 and the cooling water tank 220 is about 5 m. When the flat tube 600 contacts the water, the moving distance of the flat tube 600 has reached 6 m, and the crack 610 of the flat tube 600 has passed about 1 m beyond the cooling water tank 220, that is, the crack 610 of the flat tube 600 has moved out of the cooling area of the water tank 2211. At this time, water cooling the flat tube 600 can avoid the cooling water entering the inner hole of the flat tube 600 from the crack 610, causing oxidation and defects inside the flat tube 600, and water cooling the rest of the flat tube 600 as much as possible. At the same time, it takes about 30 s to replace a new aluminum rod. The 5 m long flat tube 600 extruded by the previous aluminum rod will be naturally cooled for 30 s, and the temperature will be greatly reduced. That is, only about 1 m of the 6 m of the flat tube 600 not water-cooled is still in a high-temperature state, thereby reducing the loss of the high-temperature flat tube 600 to the tooling;

[0041] S5: After the water cooling of the fastest moving flat tube 600 is completed, when the moving distances of the other five flat tubes 600 reach the set value of 6 m respectively, the PLC control board 110 controls the corresponding pneumatic solenoid valve 290 to open the water inlet switch 270 at the bottom of the water tank 2211 corresponding to the other five flat tubes 600 through the ejector rod 280, so that the cooling water in the lower water tank 222 enters the water tanks 2211 corresponding to the five flat tubes 600 respectively, and cools the other five flat tubes 600 respectively, thereby realizing the separate water cooling of the six flat tubes 600, so as to prevent the cooling water from flowing into the inner hole of the flat tube 600 from the crack 610 during the water cooling process of the flat tube 600;

[0042] S6: The six flat tubes 600 after water cooling climb at an angle of 20° to the horizontal plane and pass through the compressed air purging device 300. During this process, the PLC control board 110 controls the control valve 310 to open, so that the compressed air is ejected from the compressed air nozzle 320 through the air pressure pipe 330 to realize the purging of the upper and lower sides of the flat tube 600. After the purging is completed, it passes through the oven 400. During this process, the PLC control board 110 controls the oven 400 to open through the second relay 410 to dry the outer surface of the flat tube 600. The six flat tubes 600 after drying are respectively wound on the corresponding six coiling machines 500 until the extrusion of this new aluminum rod is exhausted. After the extrusion of this aluminum rod is completed, the moving speeds of the six flat tubes 600 return to zero. When the PLC control board 110 monitors that the moving speed of the fastest moving flat tube 600 is less than 3 m / min, the PLC control board 110 controls the water pump 230 to close, and the cooling water in the water tanks 2211 of all the upper water tanks 221 flows back to the lower water tank 222 under the action of gravity through the water inlet switch 270, and finally flows into the water storage tank 240 through the overflow water tank 223. After about 5 s, all the cooling water in the water tanks 2211 has completely flowed out, and the PLC control board 110 controls all the water inlet switches 270 to close, waiting to replace the new aluminum rod to realize the automation of the cooling operation of the flat tube 600.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A slotting cooling method for a microchannel aluminum flat tube, characterized in that, It includes the following steps: S1: Replace an aluminum rod, and the extruder extrudes a flat tube, which moves towards the cooling device; S2: The length counter measures the moving distance of the flat tube, uploads it to the PLC control board, and calculates the moving speed of the flat tube; S3: When the moving speed of the fastest moving flat tube reaches the set value, the PLC control board starts the water pump to convey the cooling water in the water storage tank to the lower water tank; S4: When the moving distance of the fastest moving flat tube reaches the set value, the PLC control board opens the corresponding water inlet switch, so that the cooling water in the lower water tank enters the corresponding water trough in the upper water tank to cool the flat tube; S5: When the moving distances of the remaining flat tubes reach the set values respectively, the PLC control board opens the corresponding water inlet switches, so that the cooling water in the lower water tank enters the corresponding water troughs in the upper water tank to cool the remaining flat tubes respectively; S6: The flat tube after cooling is blown by a compressed air blowing device, and then dried in an oven and wound on a coiling machine.

2. The grooving cooling method of the microchannel aluminum flat tube according to claim 1, characterized in that: The cooling device includes a cooling water tank, a water storage tank, a plate cooler and a water pump. The water pump conveys the cooling water in the water storage tank to the cooling water tank after cooling by the plate cooler. The water trough is arranged at the top of the cooling water tank, and the water inlet switch is arranged at the bottom of the water trough.

3. The grooving cooling method for the microchannel aluminum flat tube according to claim 2, wherein: The opening of the water inlet switch in each water trough needs to meet two conditions simultaneously. One is that the moving speed of the flat tube passing through this water trough is greater than or equal to the set value of the moving speed, and the other is that the moving distance of the flat tube passing through this water trough is greater than or equal to the set value of the moving distance.

4. The slot cooling method of the microchannel aluminum flat tube according to claim 1, characterized in that: The water inlet switch is connected to the pneumatic solenoid valve through a push rod, and the pneumatic solenoid valve is connected to the PLC control board. The PLC control board controls the water inlet switch in each water trough individually.

5. The slotting cooling method of the microchannel aluminum flat tube according to claim 1, characterized in that: The set value of the moving speed of the flat tube in S3 is 3 m / min.

6. The grooving cooling method of the microchannel aluminum flat tube according to claim 5, characterized in that: The set value of the moving distance of the flat tube in S4 is 6 m.

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