Pre-volatilization method for zinc spraying part of heat exchanger, pre-volatilization zinc spraying part and heat exchanger

Abstract

The invention provides a pre-volatilization method for a heat exchanger zinc-sprayed component, a pre-volatilization zinc-sprayed component and a heat exchanger, and relates to the technical field of heat exchanger manufacturing, the pre-volatilization method comprises the following steps: carrying out zinc pre-volatilization treatment on the heat exchanger zinc-sprayed component through a brazing furnace to obtain the pre-volatilization zinc-sprayed component; the temperature of the pre-volatilization treatment is 400-550 DEG C; and the conveying net speed of a zinc spraying part in the brazing furnace is 150 mm / min to 300 mm / min. The technical problem that excessive accumulation of Zn affects the welding quality and causes local corrosion when a zinc (Zn) spraying component of a heat exchanger is directly welded in the prior art is solved, and the technical effects of reducing Zn accumulation in a welding seam area, reducing the potential difference of a welding seam part, improving the corrosion resistance of the heat exchanger and improving the welding quality are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchanger manufacturing, and in particular to a pre-volatilization method for a zinc spraying component of a heat exchanger, a pre-volatilization zinc spraying component, and a heat exchanger. Background Art

[0002] As an important heat exchange device, condensers are widely used in air conditioning, refrigeration, and automobile engine systems. In the production process of condensers, zinc (Zn) spraying is often used to improve the corrosion resistance of the pipe. However, during the welding process, excessive Zn accumulation often leads to an increase in the potential difference at the weld, which affects the corrosion resistance of the condenser and even reduces the service life of the equipment.

[0003] If the welding is carried out directly after zinc spraying, the excessive accumulation of zinc will not only affect the welding quality, but also cause local corrosion. Therefore, how to effectively control the distribution of Zn during welding and reduce its accumulation in the weld area is a technical problem that needs to be solved in condenser manufacturing.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] One of the purposes of the present invention is to provide a pre-volatilization method for zinc spraying parts of a heat exchanger, which can make the zinc volatilization speed moderate and uniform, and can avoid excessive accumulation of Zn in the weld area during welding.

[0006] The second object of the present invention is to provide a pre-volatilization zinc spraying component, which can effectively reduce the Zn aggregation in the weld area during welding, reduce the potential difference in the weld area, and avoid corrosion problems caused by excessive Zn.

[0007] A third object of the present invention is to provide a heat exchanger with good corrosion resistance, high welding quality and long service life.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0009] In a first aspect, a method for pre-volatilization of a zinc spraying component of a heat exchanger comprises the following steps:

[0010] Obtain zinc spraying parts for heat exchangers;

[0011] The zinc-sprayed parts of the heat exchanger are subjected to a pre-volatilization treatment of zinc through a brazing furnace to obtain pre-volatilized zinc-sprayed parts;

[0012] The temperature of the pre-volatilization treatment is 400°C-550°C;

[0013] The conveying net speed of the zinc spraying parts in the brazing furnace is 150mm / min-300mm / min.

[0014] Furthermore, the pre-volatilization treatment time is 60 min-90 min.

[0015] Furthermore, the heat exchanger zinc spraying component includes a zinc spraying pipe.

[0016] Furthermore, the zinc-sprayed pipe comprises a zinc-sprayed flat pipe.

[0017] Furthermore, the material of the zinc-sprayed flat tube includes at least one of 1 series aluminum alloy and 3 series aluminum alloy.

[0018] Furthermore, the flat tube is surface treated by a Zn spraying method to form a zinc layer, thereby obtaining the zinc-sprayed flat tube.

[0019] Furthermore, the amount of zinc sprayed on the flat tube by the Zn spraying method is 5g / m 2 -10g / m 2 .

[0020] In a second aspect, a pre-volatilization zinc sprayed component is manufactured by any of the pre-volatilization methods described above.

[0021] In a third aspect, a heat exchanger comprises a fin and a pre-volatilization zinc spraying tube, wherein the pre-volatilization zinc spraying tube is made by any of the pre-volatilization methods described above;

[0022] The fins and the pre-volatilized zinc spraying pipe are connected by welding.

[0023] Furthermore, the zinc content on the surface of the pre-volatilized zinc spraying tube is 2 g / m 2 -4g / m 2 .

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] The pre-volatilization method for zinc-sprayed components of a heat exchanger provided by the present invention controls the pre-volatilization temperature and the transmission net speed in a brazing furnace, so that the volatilization speed of zinc is moderate and the volatilization is uniform, thereby being able to reduce excessive accumulation of Zn in the weld area during welding, being beneficial to reducing the potential difference in the weld area, and improving corrosion resistance and welding quality.

[0026] The pre-volatilization zinc spraying component provided by the present invention can reduce Zn aggregation in the weld area during welding and reduce the potential difference in the weld area.

[0027] The heat exchanger provided by the invention has good corrosion resistance, high welding quality and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A diagram showing the surface Zn distribution of the zinc-sprayed flat tube before and after pre-volatilization treatment provided in Example 1 of the present invention;

[0030] Figure 2 A diagram showing the welding quality of the zinc-sprayed flat tube and the fins before and after the pre-volatilization treatment provided in Example 1 of the present invention;

[0031] Figure 3 This is a diagram of the Zn content in the weld of the zinc-sprayed flat tube before and after pre-volatilization treatment provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] According to a first aspect of the present invention, a method for pre-volatilization of a zinc spraying component of a heat exchanger is provided, comprising the following steps:

[0034] Obtain zinc spraying parts for heat exchangers;

[0035] The zinc-sprayed parts of the heat exchanger are subjected to a pre-volatilization treatment of zinc through a brazing furnace to obtain pre-volatilized zinc-sprayed parts;

[0036] The temperature of the pre-volatilization treatment is 400°C-550°C, and typical but non-limiting temperatures are, for example, 400°C, 420°C, 440°C, 460°C, 480°C, 500°C, 510°C, 520°C, 530°C, 540°C, and 550°C;

[0037] It should be noted that the appropriate temperature can ensure a moderate volatilization rate of zinc, which is beneficial to reduce the accumulation of Zn in the weld area;

[0038] The conveying mesh speed of the zinc-sprayed parts in the brazing furnace is 150 mm / min-300 mm / min, and its typical but non-limiting conveying mesh speed is, for example, 150 mm / min, 160 mm / min, 170 mm / min, 180 mm / min, 190 mm / min, 200 mm / min, 220 mm / min, 240 mm / min, 260 mm / min, 280 mm / min, 300 mm / min;

[0039] It should be noted that an appropriate transmission speed can ensure uniform volatilization of zinc, while too fast or too slow transmission speed will cause uneven volatilization.

[0040] The pre-volatilization method for zinc-sprayed components of a heat exchanger provided by the present invention controls the pre-volatilization temperature and the transmission net speed in a brazing furnace, so that the volatilization speed of zinc is moderate and the volatilization is uniform, thereby being able to reduce excessive accumulation of Zn in the weld area during welding, being beneficial to reducing the potential difference in the weld area, and improving corrosion resistance and welding quality.

[0041] In a preferred embodiment, the pre-volatilization treatment time can be 60min-90min, and its typical but non-limiting time is, for example, 60min, 65min, 70min, 75min, 80min, 85min, and 90min, which is more conducive to further controlling the zinc (Zn) content, reducing the Zn content in the weld area, ensuring a smoother welding process, improving the weld quality, and significantly improving the corrosion resistance.

[0042] In a preferred embodiment, the zinc spraying component includes but is not limited to a zinc spraying pipe.

[0043] The surface of the heat exchanger components is treated by a Zn spraying method to form a thin zinc layer, thereby obtaining a zinc-sprayed component. The zinc layer can improve the corrosion resistance of the component.

[0044] In a preferred embodiment, the zinc-sprayed pipe may be a zinc-sprayed flat pipe; wherein the flat pipe may be made of 1 series aluminum alloy and / or 3 series aluminum alloy, but is not limited thereto.

[0045] The flat tube is surface treated by a Zn spraying method to form a zinc layer to obtain a zinc sprayed flat tube.

[0046] In a preferred embodiment, the amount of zinc sprayed on the flat tube by the Zn spraying method is 5g / m 2 -10g / m 2 , a typical but non-limiting zinc content of 5 g / m 2 , 6g / m 2 , 7g / m 2 , 8g / m 2 , 9g / m 2 , 10g / m2 .

[0047] According to a second aspect of the present invention, there is provided a pre-volatilization zinc spraying component manufactured by any of the pre-volatilization methods described above.

[0048] The pre-volatilization zinc spraying component provided by the present invention can reduce Zn aggregation in the weld area during welding and reduce the potential difference in the weld area.

[0049] According to a third aspect of the present invention, there is provided a heat exchanger comprising fins and a pre-volatilization zinc spraying tube;

[0050] Wherein, the pre-volatilized zinc spraying pipe is made by any of the pre-volatilization methods described above;

[0051] The fins and the pre-volatile zinc sprayed pipes are connected by welding.

[0052] When the pre-volatilized zinc spray pipe is welded to manufacture the heat exchanger, due to the low Zn content, excessive Zn accumulation in the weld area is avoided, the surface Zn is evenly distributed, and the potential difference is effectively reduced, thereby improving the corrosion resistance of the heat exchanger and the welding quality.

[0053] In addition, the fins can also be pre-volatilized after zinc spraying. The pre-volatilized zinc sprayed fins are also helpful in avoiding excessive accumulation of Zn in the weld area when welding and manufacturing heat exchangers, which helps to reduce the potential difference.

[0054] In a preferred embodiment, the zinc content on the surface of the pre-volatile zinc spray pipe can be 2g / m 2 -4g / m 2 , a typical but non-limiting zinc content of 2 g / m 2 , 3g / m 2 , 4g / m 2 .

[0055] The heat exchanger provided by the invention has good corrosion resistance, high welding quality and long service life.

[0056] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0057] Example 1

[0058] A heat exchanger is manufactured by the following method:

[0059] (a) The flat tube is surface treated by zinc spraying (Zn), with a zinc spraying amount of 6.0g / m 2 , forming a zinc layer with a thickness of about 0.85μm to obtain a zinc-sprayed flat tube;

[0060] The zinc layer can improve the corrosion resistance of the pipe, and the flat pipe is made of 1 series aluminum alloy;

[0061] (b) The zinc-sprayed flat tube obtained in step (a) is sent into a brazing furnace for pre-volatilization treatment of zinc to obtain a pre-volatilized zinc-sprayed flat tube having a surface zinc content of 3.2 g / m 2 ;

[0062] The temperature of the brazing furnace is 480°C, and the pre-volatilization treatment time is 75 minutes;

[0063] In the brazing furnace, the conveying speed of the zinc-sprayed flat tube is 230mm / min;

[0064] The surface Zn distribution of zinc spray flat tube before and after pre-volatilization treatment is shown in Figure 1 Figure a shows the Zn distribution on the surface of the zinc-sprayed flat tube before pre-volatilization. It can be seen that the surface of the zinc-sprayed flat tube is covered with an uneven zinc layer, which is dense in some areas and sparse in other areas; Figure b shows the Zn distribution on the surface of the zinc-sprayed flat tube after pre-volatilization. It can be seen that after pre-volatilization treatment, the zinc layer distribution on the surface of the flat tube becomes more continuous and uniform, which helps to improve the performance and corrosion resistance of the zinc-sprayed flat tube;

[0065] (c) welding the pre-volatilized zinc-sprayed flat tube obtained in step (b) to obtain a heat exchanger;

[0066] The welding quality of the zinc-sprayed flat tube and the fins before and after pre-volatilization treatment is shown in the figure. Figure 2 Figure a shows the welding quality of the zinc-sprayed flat tube and the fin before pre-volatilization, and figure b shows the welding quality of the zinc-sprayed flat tube and the fin after pre-volatilization. By comparison, it can be seen that after pre-volatilization treatment, the welding quality of the flat tube and the fin has been significantly improved, the weld width has been reduced, the surface has become smoother, the combination has become tighter, the weld filling has become fuller, and the overall welding effect has been better;

[0067] The Zn content of the weld before and after pre-volatilization treatment of zinc spray flat tube is shown in Figure 3 Figure a shows the Zn content of the weld before pre-volatilization of the zinc-sprayed flat tube, and figure b shows the Zn content of the weld after pre-volatilization of the zinc-sprayed flat tube. By comparison, it can be seen that after pre-volatilization treatment, the Zn content in the weld area has been significantly reduced and the color has become lighter. It can be seen that the pre-volatilization treatment can effectively reduce the Zn content in the weld area.

[0068] Example 2

[0069] The difference between this embodiment and embodiment 1 is that in step (b), the temperature of the brazing furnace is 400°C, and the surface zinc content of the obtained pre-volatilized zinc sprayed flat tube is 3.9 g / m 2 ;

[0070] The rest is the same as in Example 1 to obtain a heat exchanger.

[0071] Example 3

[0072] The difference between this embodiment and embodiment 1 is that in step (b), the temperature of the brazing furnace is 550°C, and the surface zinc content of the obtained pre-volatilized zinc sprayed flat tube is 2.4 g / m 2 ;

[0073] The rest is the same as in Example 1 to obtain a heat exchanger.

[0074] Example 4

[0075] The difference between this embodiment and embodiment 1 is that in step (b), the pre-volatilization treatment time is 60 minutes, and the surface zinc content of the obtained pre-volatilized zinc sprayed flat tube is 3.5g / m 2 ;

[0076] The rest is the same as in Example 1 to obtain a heat exchanger.

[0077] Example 5

[0078] The difference between this embodiment and embodiment 1 is that in step (b), the pre-volatilization treatment time is 90 minutes, and the surface zinc content of the obtained pre-volatilized zinc sprayed flat tube is 2.9 g / m 2 ;

[0079] The rest is the same as in Example 1 to obtain a heat exchanger.

[0080] Example 6

[0081] The difference between this embodiment and embodiment 1 is that in step (b), the conveying speed of the zinc-sprayed flat tube is 150 mm / min, and the surface zinc content of the obtained pre-volatilized zinc-sprayed flat tube is 3.0 g / m 2 ;

[0082] The rest is the same as in Example 1 to obtain a heat exchanger.

[0083] Example 7

[0084] The difference between this embodiment and embodiment 1 is that in step (b), the conveying speed of the zinc-sprayed flat tube is 300 mm / min, and the surface zinc content of the obtained pre-volatilized zinc-sprayed flat tube is 3.4 g / m 2 ;

[0085] The rest is the same as in Example 1 to obtain a heat exchanger.

[0086] Comparative Example 1

[0087] The difference between this comparative example and Example 1 is that the zinc-sprayed flat tube is not subjected to the pre-volatilization treatment of step (b), that is, the zinc-sprayed flat tube is directly welded;

[0088] The rest is the same as in Example 1 to obtain a heat exchanger.

[0089] Compared with Example 1, the defect in this comparative example is that the zinc content on the surface of the zinc-sprayed flat tube is too high, resulting in zinc aggregation in the weld and excessive potential difference, which affects the corrosion resistance.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 1 is that in step (b), the temperature of the brazing furnace is 350°C;

[0092] The rest is the same as in Example 1 to obtain a heat exchanger.

[0093] Compared with Example 1, the defect in this comparative example is that the zinc content on the surface of the zinc-sprayed flat tube is still too high, resulting in zinc aggregation in the weld and excessive potential difference, which affects the corrosion resistance.

[0094] Comparative Example 3

[0095] The only difference between this comparative example and Example 1 is that in step (b), the temperature of the brazing furnace is 600°C;

[0096] The rest is the same as in Example 1 to obtain a heat exchanger.

[0097] Compared with Example 1, the defect in this comparative example is that the zinc content on the surface of the zinc-sprayed flat tube is too low, resulting in a small amount of zinc diffusion into the interior of the flat tube, affecting the corrosion resistance.

[0098] Comparative Example 4

[0099] The difference between this comparative example and Example 1 is that in step (b), the conveying speed of the zinc-sprayed flat tube is 100 mm / min;

[0100] The rest is the same as in Example 1 to obtain a heat exchanger.

[0101] Compared with Example 1, the defect in this comparative example is that the zinc content on the surface of the zinc-sprayed flat tube is too low, resulting in a small amount of zinc diffusion into the interior of the flat tube, affecting the corrosion resistance.

[0102] Comparative Example 5

[0103] The difference between this comparative example and Example 1 is that in step (b), the conveying speed of the zinc-sprayed flat tube is 350 mm / min;

[0104] The rest is the same as in Example 1 to obtain a heat exchanger.

[0105] Compared with Example 1, the defect in this comparative example is that the zinc content on the surface of the zinc-sprayed flat tube is still too high, resulting in zinc aggregation in the weld and excessive potential difference, which affects the corrosion resistance.

[0106] Test example

[0107] The heat exchangers obtained in Examples 1-7 and Comparative Examples 1-5 were tested, and the test results are shown in Table 1.

[0108] (1) Zn accumulation in the weld area: electron probe;

[0109] (2) Potential difference at weld site: electrochemical workstation;

[0110] (3) Corrosion resistance: salt spray corrosion test;

[0111] (4) Welding quality: metallographic observation.

[0112] Table 1

[0113]

[0114] As can be seen from Table 1, the present invention controls the temperature and the conveying network speed in the brazing furnace, the zinc volatilization rate is moderate and uniform, the Zn content in the weld area is effectively controlled, the accumulation of Zn in the weld area is significantly reduced, and the potential difference is significantly reduced, thereby significantly improving the corrosion resistance and welding quality of the heat exchanger and extending the service life.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for pre-volatilization of zinc spraying parts of a heat exchanger, characterized in that: The following steps are involved: Obtain zinc spraying parts for heat exchangers; The zinc-sprayed parts of the heat exchanger are subjected to a pre-volatilization treatment of zinc through a brazing furnace to obtain pre-volatilized zinc-sprayed parts; The temperature of the pre-volatilization treatment is 400°C-550°C; The conveying net speed of the zinc spraying parts in the brazing furnace is 150mm / min-300mm / min.

2. The pre-volatilization method according to claim 1, characterized in that: The time of the pre-volatilization treatment is 60 min-90 min.

3. The pre-volatilization method according to claim 1 or 2, characterized in that: The heat exchanger zinc spraying component comprises a zinc spraying pipe.

4. The pre-volatilization method according to claim 3, characterized in that: The zinc-sprayed pipe comprises a zinc-sprayed flat pipe.

5. The pre-volatilization method according to claim 4, characterized in that: The material of the zinc-sprayed flat tube includes at least one of a 1-series aluminum alloy and a 3-series aluminum alloy.

6. The pre-volatilization method according to claim 4, characterized in that: The flat tube is surface treated by a Zn spraying method to form a zinc layer, thereby obtaining the zinc sprayed flat tube.

7. The pre-volatilization method according to claim 6, characterized in that: The amount of zinc sprayed on the flat tube by the Zn spraying method is 5g / m 2 -10g / m 2 .

8. A pre-volatilized zinc sprayed component manufactured by the pre-volatilization method according to any one of claims 1 to 7.

9. A heat exchanger, comprising fins and a pre-volatilization zinc spraying tube, characterized in that: The pre-volatilization zinc spraying pipe is made by the pre-volatilization method according to any one of claims 1 to 7; The fins and the pre-volatilized zinc spraying pipe are connected by welding.

10. The heat exchanger according to claim 9, characterized in that The zinc content on the surface of the pre-volatile zinc spray pipe is 2g / m 2 -4g / m 2 .

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