Stainless steel heat exchanger, gas water heating device and manufacturing method of heat exchanger

Abstract

The application discloses a stainless steel heat exchanger, a gas water heater and a manufacturing method of the heat exchanger, and relates to the heat exchanger field.The stainless steel heat exchanger comprises a mounting plate, a plurality of heat exchange pipes, a first welding part, a communication structure and a cover plate.The heat exchange pipes are fixedly connected to the mounting plate through the first welding part.The communication structure has a communication space.The communication space connects the pipe ends of two or more heat exchange pipes to form a flow channel.The communication structure is connected to the mounting plate and / or the heat exchange pipes.The cover plate is provided with a protruding part protruding away from the mounting plate and a second connecting part around the protruding part.The interior of the protruding part forms the communication space.The second connecting part is connected to the mounting plate through a third welding part to seal around the protruding part.A fourth welding part is arranged around the protruding part, and the fourth welding part separates the third welding part from the flow channel.The stainless steel heat exchanger and the gas water heater can prevent the heat exchange pipe welding part from being corroded, and improve the service life.

Description

[0001] This application is a divisional application of application No. "201810320306.3", with a filing date of "April 11, 2018", and with the title of "Stainless steel heat exchanger, gas water heater and manufacturing method of heat exchanger". TECHNICAL FIELD

[0002] The present application relates to the field of heat exchangers, in particular to a stainless steel heat exchanger, a gas water heater and a manufacturing method of a heat exchanger. BACKGROUND

[0003] The gas water heater is a gas appliance that uses gas as fuel to heat the cold water flowing through the heat exchanger by burning to achieve the purpose of preparing hot water. At present, the heat exchanger used in the gas water heater mainly includes a surrounding frame, a plurality of heat exchange pipes provided in the surrounding frame and provided with fins, and a "U" type joint provided outside the surrounding frame to connect the end heads of the heat exchange pipes two by two. The "U" type joint makes all the heat exchange pipes form a continuous flow channel. However, in the processing process, each joint is separately connected with the end head of the heat exchange pipe by brazing, which is complicated to operate and time-consuming. With the extension of the use time, the brazing welded part will be corroded and leaked, which reduces the service life of the heat exchanger.

[0004] There is also a heat exchanger structure in the prior art that uses a water collecting box to connect the heat exchange pipes of the heat exchanger. The heat exchange pipes are connected by a sealing cover plate provided with a convex bump to form a flow channel. This structure covers the sealing cover plate on the mounting plate on one side of the heat exchanger, and connects the ports of the heat exchange pipes to be connected through the connecting channel of the convex bump structure. However, it is found that the brazing welded part of the port position of the heat exchange pipe contacting water is easily corroded and damaged during use, which affects the service life of the heat exchanger. SUMMARY

[0005] Through long-term research by the inventor, it is found that the material of the solder of the end welding part of the heat exchange pipe of the heat exchanger in the above form is different from the material of the heat exchanger itself, which causes a potential difference between the two metal materials when the welding part (welding seam) contacts the heat exchange medium (water), and further causes electrochemical corrosion. Especially in the case of a stainless steel heat exchanger and the use of copper solder or nickel solder, the corrosion phenomenon is more prominent, and the welding part is corroded and damaged with long-term use.

[0006] In addition, the heat exchanger in the gas water heater exchanges heat with the high-temperature flue gas formed by the burner to heat the water inside the heat exchange pipe. After the user stops (such as stopping using hot water with the water end), the water in the heat exchange pipe stops flowing, but there is still high-temperature flue gas in the gas water heater, which will continue to heat the water remaining in the heat exchange pipe. Since the water in the heat exchange pipe is in a static state at this time, it cannot take away the heat transferred by the high-temperature flue gas, so the water in the heat exchange pipe will be heated to an excessively high temperature, and the above-mentioned welding part is accelerated to be corroded and damaged under the action of the excessively high temperature water.

[0007] To solve the above problems, the present application provides a stainless steel heat exchanger, a gas water heater and a manufacturing method of the heat exchanger.

[0008] A stainless steel heat exchanger, comprising:

[0009] A mounting plate;

[0010] A plurality of heat exchange pipes; the heat exchange pipes are fixedly connected to the mounting plate through a first welding part;

[0011] A communication structure having a communication space; the communication space communicates the pipe ends of two or more heat exchange pipes to form a flow channel; the communication structure is connected to the mounting plate and / or the heat exchange pipes;

[0012] An isolation part; the isolation part isolates the first welding part from the flow channel.

[0013] Preferably, the isolation part includes a second welding part connecting the mounting plate and the heat exchange pipes; the welding mode of the second welding part is different from that of the first welding part.

[0014] Preferably, the second welding part is formed by laser welding or argon arc welding, and the first welding part is formed by brazing.

[0015] Preferably, the brazing filler metal is copper or nickel.

[0016] Preferably, the communication structure is connected to the mounting plate and / or the heat exchange pipes through a third welding part.

[0017] Preferably, the communication structure includes a cover plate arranged on one side of the mounting plate; the cover plate is provided with a protruding part protruding away from the mounting plate and a second connecting part located around the protruding part; the inside of the protruding part forms the communication space; and the second connecting part is connected to the mounting plate through the third welding part to seal around the protruding part.

[0018] Preferably, the mounting plate has a first connecting portion sleeved on the heat exchange pipe; the first welding portion connects the first connecting portion with the outer wall of the heat exchange pipe; and the second welding portion is closer to the pipe end of the heat exchange pipe than the first welding portion, so as to separate the first welding portion from the flow channel.

[0019] Preferably, the first connecting portion extends away from the communication structure; and the first connecting portion is a flange formed on a mounting hole of the mounting plate.

[0020] Preferably, the second welding portion is arranged around the heat exchange pipe and seals between the flange wall and the wall of the heat exchange pipe.

[0021] Preferably, the first welding portion is formed between the flange and the pipe wall of the heat exchange pipe.

[0022] Preferably, the length of the second welding portion along the axial direction of the heat exchange pipe is less than the length of the first welding portion.

[0023] Preferably, the second welding portion is formed by melting part of the mounting plate and / or part of the heat exchange pipe.

[0024] Preferably, the second welding portion is formed by laser welding on the pipe end of the heat exchange pipe.

[0025] Preferably, the third welding portion is formed by brazing; a fourth welding portion is arranged around the protruding portion, and the fourth welding portion separates the third welding portion from the flow channel.

[0026] Preferably, the fourth welding portion is formed by melting part of the cover plate and / or the mounting plate.

[0027] Preferably, the first welding portion and / or the third welding portion are made of a material different from that of the mounting plate and the heat exchange pipe.

[0028] Preferably, the material of the isolation portion is different from that of the first welding portion and the third welding portion.

[0029] Preferably, the first welding portion and the third welding portion are made of a material other than stainless steel, and the material of the isolation portion is stainless steel.

[0030] Preferably, the isolation portion includes a waterproof coating applied to the surface of the first welding portion and / or the third welding portion exposed in the flow channel.

[0031] A gas water heater, comprising: the stainless steel heat exchanger according to any one of the above.

[0032] A manufacturing method of a heat exchanger, comprising:

[0033] welding the outer wall of the heat exchange pipe and the mounting portion of the mounting plate to form a welding portion;

[0034] An isolation portion is arranged between the outer wall of the heat exchange pipe and the mounting portion to isolate the welding portion from water.

[0035] Preferably, the isolation portion is formed prior to the welding portion.

[0036] Preferably, the temperature for forming the welding portion is lower than the melting point of the heat exchange pipe and the mounting plate.

[0037] Preferably, the heat exchange pipe and the mounting plate are made of stainless steel.

[0038] Preferably, part of the heat exchange pipe and / or part of the mounting plate is melted to form the isolation portion.

[0039] Preferably, the isolation portion is formed by laser welding or argon arc welding.

[0040] Preferably, the welding method for forming the welding portion is different from the welding method for forming the isolation portion.

[0041] Preferably, the mounting portion comprises a mounting hole formed on the mounting plate; and the manufacturing method of the heat exchanger comprises:

[0042] laser welding the pipe end of the heat exchange pipe extending into the mounting hole to form the isolation portion.

[0043] Preferably, the welding portion is formed by brazing.

[0044] Preferably, the mounting hole is provided with a flange, and the brazing welding portion is formed between the flange and the outer wall of the heat exchange pipe to seal and connect the mounting plate and the heat exchange pipe.

[0045] Beneficial effects:

[0046] The stainless steel heat exchanger provided by the application isolates the first welding portion from the flow channel by the isolation portion, so that the first welding portion cannot directly contact the heat exchange medium (preferably water) in the flow channel, and the first welding portion cannot be corroded by the heat exchange medium, thereby effectively protecting the first welding portion between the heat exchange pipe and the mounting plate and prolonging the service life.

[0047] Meanwhile, the isolation portion isolates the first welding portion from the flow channel, so that even if the material of the first welding portion is different from the materials of the mounting plate and the heat exchange pipe, electrochemical corrosion cannot be formed, and the first welding portion cannot be corroded and damaged, thereby effectively improving the service life of the welding portion between the heat exchange pipe and the mounting plate.

[0048] The particular embodiments of the application will be described in relation to the enclosed drawings and the following description, indicating the way in which the principles of the application can be applied. It is understood that the embodiments of the application are not limited in scope so as to encompass only the specific embodiments described. Embodiments of the application encompass many alternatives, modifications, and equivalents within the scope of the claims and criteria indicated below.

[0049] Features described and / or illustrated with respect to one embodiment can be used in the same or similar manner in one or more other embodiments in combination with or in place of features in the other embodiments.

[0050] It should be emphasized that the term "comprises / comprising" when used in this specification is taken to mean the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0052] Figure 1 is a schematic diagram of a structure of a stainless steel heat exchanger provided in an embodiment of the present application;

[0053] Figure 2 is a partial exploded view of Figure 1 ;

[0054] Figure 3 is a schematic diagram of an isolation part structure of Figure 1 ;

[0055] Figure 4 is a schematic diagram of a manufacturing method step of a heat exchanger provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to make the person skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0057] It is to be understood that when an element such as a layer, region or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, it is to be understood that when a layer is referred to as being "connected", "coupled" or "supported" to another layer, it can be directly connected, coupled or supported to the other layer, or intervening layers can also be present. As used herein, the term "vertical", "horizontal", "left", "right", and the like, are merely used for the purpose of illustration and are not intended to be limiting.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0059] Please refer to Figures 1 to 3 The stainless steel heat exchanger 100 provided in the embodiments of the present application comprises: a mounting plate 3; a plurality of heat exchange tubes 4; the heat exchange tubes 4 are fixedly connected to the mounting plate 3 through a first welding portion 8; a communication structure having a communication space 6; the communication space 6 connects the tube ends of two or more heat exchange tubes 4 to form a flow channel; the communication structure is connected to the mounting plate 3 and / or the heat exchange tubes 4; an isolation portion; the isolation portion separates the first welding portion 8 from the flow channel.

[0060] The stainless steel heat exchanger 100 provided in the embodiments of the present application separates the first welding portion 8 from the flow channel through the isolation portion, so that the first welding portion 8 cannot directly contact the heat exchange medium (preferably water) in the flow channel, and thus the first welding portion 8 cannot be corroded by the heat exchange medium, and the first welding portion 8 between the heat exchange tubes 4 and the mounting plate 3 can be effectively protected, prolonging the service life.

[0061] Meanwhile, the isolation portion separates the first welding portion 8 from the flow channel, so that even if the material of the first welding portion 8 is different from the materials of the mounting plate 3 and the heat exchange tubes 4, electrochemical corrosion cannot be formed, and thus the first welding portion 8 cannot be corroded and damaged, effectively improving the service life of the welding portion between the heat exchange tubes 4 and the mounting plate 3.

[0062] In addition, the isolation portion separates the first welding portion 8 from the flow channel, so that even if the high-temperature flue gas remaining in the heat exchanger after shutdown is heated to a too high temperature in the heat exchange tubes 4, the first welding portion 8 cannot contact the water due to the presence of the isolation portion, and also cannot be accelerated corrosion.

[0063] In an embodiment, the isolation portion can be a coating structure, which can be arranged on the surface of the first welding portion 8 exposed to the flow channel to avoid direct contact between the first welding portion 8 and the heat exchange medium in the flow channel. Preferably, the isolation portion is formed by laser welding or argon arc welding.

[0064] In the present embodiment, the second welding portion 7 formed by laser welding or argon arc welding separates the brazing-formed welding portion from the water in the flow channel. Since the second welding portion 7 is formed by melting the base material of the stainless steel heat exchanger, the second welding portion 7 is basically consistent with the material of the stainless steel heat exchanger itself and has strong corrosion resistance, thereby avoiding the corrosion damage problem caused by the direct contact between the brazing-formed first welding portion 8 and the water and improving the service life of the heat exchanger.

[0065] Meanwhile, the heat exchange pipes 4 are mainly connected to the mounting plate 3 through the first welding portion 8, which reduces the requirement for the connection performance of the second welding portion 7, and only the second welding portion 7 needs to separate the first welding portion 8 from the flow channel.

[0066] In an embodiment, the isolation portion can completely separate the first welding portion 8 from the flow channel, or can separate part of the first welding portion 8. Preferably, the isolation portion completely separates the first welding portion 8 from the flow channel to ensure that the first welding portion 8 cannot contact the water and cause corrosion. The isolation portion can be in contact with the first welding portion 8, or can not be in contact with the first welding portion 8, as long as the isolation portion can separate the first welding portion 8 from the flow channel.

[0067] Considering that the heat exchange medium is usually water, the isolation portion can also be a water isolation portion in some embodiments. The water isolation portion separates the first welding portion 8 from the water in the flow channel to avoid the contact between the first welding portion 8 and the water. In a preferred embodiment, the isolation portion can seal and connect the mounting plate 8 and the heat exchange pipe 4, and completely separate the first welding portion 8 from the flow channel.

[0068] In order to separate the first welding portion 8 from the flow channel, the isolation portion can be located on the side of the first welding portion 8 close to the flow channel to avoid the direct contact between the first welding portion 8 and the inside of the flow channel. As shown in Figure 3 , the isolation portion is located on the side of the first welding portion 8 close to the communication structure.

[0069] As shown in the embodiment of Figure 1 , Figure 2 , the mounting plate 3 is located on one side of the heat exchanger 100, and a plurality of heat exchange pipes 4 are installed on the mounting plate 3 in parallel. The outer side of each mounting plate 3 is provided with the communication structure to connect the plurality of heat exchange pipes 4 in series to form the flow channel. The heat exchange pipe 4 can be in the shape of a circular tube, and fins 9 for increasing the heat exchange area can be arranged on the heat exchange pipe 4. In the present embodiment, the heat exchange pipe 4 heats the heat exchange medium (preferably water) in the inside by heat exchange with the flue gas generated by the burner.

[0070] like Figure 3 As shown, the mounting plate 3 has multiple flanged holes 10, and multiple heat exchange tubes 4 are arranged in parallel, with the tube ends of the heat exchange tubes 4 passing through the flanged holes 10. To separate the first welded part 8 from the flow channel, the isolation part can be annular in shape, surrounding the tube ends of the heat exchange tubes 4.

[0071] In this embodiment, the isolation section includes a second welded section 7 connecting the mounting plate 3 to the heat exchange tube 4. The second welded section 7 and the first welded section 8 are welded using different methods to form second welded sections 7 and first welded sections 8 made of different materials. Preferably, the second welded section 7 can be formed by laser welding or argon arc welding. The first welded section 8 is formed by brazing. Specifically, the brazing filler metal is copper or nickel.

[0072] In this embodiment, the second welded part 7 formed by laser welding or argon arc welding isolates the brazed part from the water phase in the flow channel. Since laser welding and argon arc welding are formed by melting the stainless steel heat exchanger base material to form the second welded part 7, the material of the second welded part 7 is basically the same as that of the stainless steel heat exchanger itself, which reduces the risk of electrochemical corrosion and has strong corrosion resistance. This avoids the corrosion damage caused by direct contact between the first welded part 8 formed by brazing and water, and improves the service life of the heat exchanger.

[0073] Meanwhile, the heat exchange tube 4 is mainly connected to the mounting plate 3 through the first welding part 8, which reduces the requirements for the connection performance of the second welding part 7. It is only necessary for the second welding part 7 to isolate the first welding part 8 from the flow channel.

[0074] In practice, the second welded part 7 can be formed first, prior to the first welded part 8, using laser welding or argon arc welding. The heat exchange tube 4 and the mounting plate 3 are then fixed together by the second welded part 7, thereby positioning the heat exchange tube 4. After positioning, a space for brazing filler material is formed between the heat exchange tube 4 and the mounting plate 3. The filler material (such as copper or nickel) forms the first welded part 8.

[0075] In one embodiment, the mounting plate 3 has a first connecting portion sleeved on the heat exchange tube 4. A first welding portion 8 connects the first connecting portion to the outer wall of the heat exchange tube 4. A second welding portion 7 is closer to the tube end of the heat exchange tube 4 than the first welding portion 8, thereby isolating the first welding portion 8 from the flow channel.

[0076] Specifically, the first connecting portion extends in a direction away from the communicating structure; the first connecting portion is the flange of the flanged hole 10 on the mounting plate 3. This flange can form a fitting gap with the tube end of the heat exchange tube 4, and this fitting gap can be filled with solder to form a first welded portion 8.

[0077] Similar to the first welding portion 8, in the embodiment, the second welding portion 7 is arranged around the heat exchange tube 4 and seals between the flange wall and the wall of the heat exchange tube 4. Specifically, the first welding portion 8 is formed between the flange and the tube wall of the heat exchange tube 4. Meanwhile, the second welding portion 7 is closer to the communication space 6 relative to the first welding portion 8.

[0078] As shown in FIG. 1, the second welding portion 7 is located in the cooperation gap between the flange and the heat exchange tube 4. The first welding portion 8 is located in the cooperation gap to connect the heat exchange tube 4 and the flange and to seal the heat exchange tube 4 and the mounting plate 3. The second welding portion 7 also connects the flange and the heat exchange tube 4 and can be formed before the first welding portion 8 to position the welding of the first welding portion 8. As shown in FIG. 1, the length of the second welding portion 7 along the axial length of the heat exchange tube 4 is less than the length of the first welding portion 8. Figure 3 Figure 3 As shown in FIG. 1, the length of the second welding portion 7 along the axial length of the heat exchange tube 4 is less than the length of the first welding portion 8.

[0079] In the embodiment, the material of the second welding portion 7 can be the same as or different from the material of the mounting plate 3 and the heat exchange tube 4. To avoid the formation of electrochemical corrosion of the second welding portion 7 and protect the second welding portion 7 from being corroded and damaged, the material of the second welding portion 7 is preferably stainless steel.

[0080] To avoid the formation of electrochemical corrosion of the second welding portion 7 and ensure that the second welding portion 7 is not damaged, the material of the second welding portion 7 can be the same as the material of the mounting plate 3 and the heat exchange tube 4. Specifically, the material of the second welding portion 7 can be stainless steel. The second welding portion 7 with stainless steel material has better corrosion resistance. Further, the second welding portion 7 can be formed by melting part of the mounting plate 3 and / or part of the heat exchange tube 4.

[0081] To facilitate the formation of the second welding portion 7, when the second welding portion 7 is formed by welding, the second welding portion 7 can be formed by laser welding on the tube end of the heat exchange tube 4. Of course, the second welding portion 7 is not limited to being formed by the tube end of the heat exchange tube 4, but can also be formed by laser welding on the side wall of the heat exchange tube 4 or by laser welding on the mounting plate 3.

[0082] The second welding portion 7 formed by laser welding separates the brazed first welding portion from the water in the flow channel. Since the second welding portion 7 is formed by melting the base material, the material of the second welding portion 7 is basically the same as the material of the stainless steel heat exchanger itself, which reduces the risk of electrochemical corrosion and has strong corrosion resistance. Thus, the problem of corrosion damage caused by the direct contact of the brazing portion with water is avoided, and the service life of the heat exchanger is improved.

[0083] ​In this embodiment, the connecting structure can be mounted on the mounting plate 3 and connect the plurality of heat exchange pipes 4 through the connecting space 6. The present application does not limit the shape of the connecting space 6, as long as it can connect the pipe ends of the plurality of heat exchange pipes 4. The connecting structure can be formed with a plurality of connecting spaces 6, and each connecting space 6 is sealed and spaced from each other (not directly connected).

[0084] Specifically, the periphery of each connecting space 6 can be sealingly connected with the mounting plate 3, so that each connecting space 6 remains independent, thereby connecting the plurality of heat exchange pipes 4 in series to form a heat exchange flow channel. The connecting structure can be mounted on the mounting plate 3 by bolt connection and clamping of a sealing gasket, or by riveting or other forms. As a preferred solution, the connecting structure can be connected to the mounting plate 3 and / or the heat exchange pipe 4 by a third welding portion.

[0085] As shown in the embodiment, Figure 1 Figure 2 The connecting structure includes a cover plate 1 arranged on one side of the mounting plate 3. The cover plate 1 is provided with a protruding portion 2 protruding away from the mounting plate 3, and a second connecting portion located around the protruding portion 2. The interior of the protruding portion 2 forms the connecting space 6. The second connecting portion is connected to the mounting plate 3 by the third welding portion to seal around the protruding portion 2.

[0086] In this embodiment, the protruding portion 2 of the connecting structure can connect two or more heat exchange pipes 4. As shown in Figure 2 To connect the plurality of heat exchange pipes 4 in series to form a flow channel, the pipe ends of the two heat exchange pipes 4 are connected to the interior of the protruding portion 2 (connecting space 6).

[0087] Specifically, the third welding portion can be formed by brazing. To avoid corrosion and damage of the third welding portion by water, a fourth welding portion 5 can be arranged around the protruding portion 2. The fourth welding portion 5 isolates the third welding portion from the flow channel. The fourth welding portion 5 can be formed by melting part of the cover plate 1 and / or the mounting plate 3.

[0088] In the embodiment, to facilitate manufacturing and form a sealing structure between the heat exchange pipe 4, the mounting plate 3, and the connecting structure, the first welding portion 8 and the third welding portion can be formed by brazing. The first welding portion 8 and / or the third welding portion are made of different materials from the mounting plate 3 and the heat exchange pipe 4.

[0089] ​In an embodiment, the material of the isolation portion is different from the first welding portion 8 and the third welding portion. Specifically, the first welding portion 8 and the third welding portion are made of a material other than stainless steel, such as copper (including copper alloy) or nickel (including nickel alloy). The material of the isolation portion is stainless steel.

[0090] In an embodiment, the isolation portion is not limited to the above-mentioned welding structure formed by welding. In one embodiment, the isolation portion can include a waterproof coating applied to the surface of the first welding portion 8 and / or the third welding portion exposed in the flow channel. The waterproof coating can be applied after the first welding portion 8 and / or the third welding portion is formed.

[0091] In an embodiment, the application also provides a gas water heating device, which includes the above-mentioned stainless steel heat exchanger 100. The gas water heating device can include, but is not limited to, a gas water heater or a wall-mounted boiler. Specifically, the gas water heating device can be provided with a burner (not shown), and the flue gas formed by the burner exchanges heat with the stainless steel heat exchanger 100 to heat the water in the stainless steel heat exchanger 100.

[0092] It should be noted that the gas water heating device provided in the present embodiment can have any suitable existing structure for the combustion portion and other portions (e.g., control portion, display portion). For the sake of clarity and brevity, the above-mentioned portions will not be described in detail, and the accompanying drawings will also be simplified. However, it should be understood that the present embodiment is not limited in scope by this.

[0093] As shown in Figure 4 In an embodiment, the application also provides a method for manufacturing a heat exchanger. The method for manufacturing a heat exchanger can be used to manufacture the above-mentioned stainless steel heat exchanger 100 in any embodiment or example. In this embodiment, the method for manufacturing a heat exchanger includes:

[0094] S1, welding and sealing between the outer wall of the heat exchange pipe 4 and the mounting portion of the mounting plate 3 to form a welding portion;

[0095] S2, providing an isolation portion between the outer wall of the heat exchange pipe 4 and the mounting portion for isolating the welding portion from water.

[0096] The steps S1 and S2 in the present embodiment are not limited in the order of execution, and step S1 can be executed before step S2, that is, the welding portion is formed before the isolation portion. Step S2 can also be executed before step S1, that is, the isolation portion is formed before the welding portion.

[0097] In the step S1, the temperature for forming the welding part is lower than the melting point of the heat exchange tube 4 and the mounting plate 3. The welding part can be formed by solder, which can be copper or nickel. Specifically, the welding part is formed by brazing. Of course, the welding part can also refer to the description of the welding part, or the first welding part 8 and / or the third welding part in the stainless steel heat exchanger 100 of the above-mentioned embodiments, which will not be repeated here.

[0098] In the step S2, part of the heat exchange tube 4 and / or part of the mounting plate 3 are melted to form the isolation part. Specifically, the isolation part is formed by laser welding or argon arc welding. The welding method for forming the welding part and the welding method for forming the isolation part can be different.

[0099] The mounting part is a mounting hole formed on the mounting plate 3. Specifically, the mounting hole is a flange hole 10, and the welding part formed by brazing is formed between the flange of the flange hole 10 and the outer wall of the heat exchange tube 4 to seal and connect the mounting plate 3 and the heat exchange tube 4.

[0100] In the step S2, the tube end of the heat exchange tube 4 extending into the mounting hole is laser welded to form the isolation part. The isolation part formed by laser welding separates the brazing part from the water in the flow channel. Since the isolation part is formed by melting the base material, the material of the isolation part is basically the same as that of the stainless steel heat exchanger itself, which has strong corrosion resistance. Thus, the problem of corrosion damage caused by direct contact between the brazing part and the water is avoided, and the service life of the heat exchanger is improved.

[0101] It should be noted that the mounting plate 3, the welding part, the mounting hole, and the isolation part in the present embodiment can refer to the description of the mounting plate 3, the welding part (the first welding part 8 and / or the third welding part), the mounting hole, and the isolation part in the stainless steel heat exchanger 100 of the above-mentioned embodiments, which will not be repeated here.

[0102] Any numerical value recited herein includes all values from the lower value and up to the upper value in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value. As an example, if a numerical value is recited as from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, it is intended that all values and subranges between the lower value and the upper value are also disclosed. For values which are less than one, one unit is considered to be 0.0001, 0.001, 0.01, or 0.1, as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application.

[0103] Unless otherwise stated, all ranges include endpoints and all numerical values contained therein are "approximate" means that the value + / - 10% of the stated value. Unless otherwise stated, the use of "about" or "approximately" in connection with a range applies to both ends of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0104] All articles and references, including patent applications and publications, disclosed below are incorporated herein by reference for all purposes. The term "consisting essentially of to describe combinations shall include the elements, ingredients, components or steps identified, and such other elements ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, ingredients, components or steps herein also is taken to mean that other elements, ingredients, components or steps that do not materially affect the basic and novel characteristics of the combinations are optionally present. The use of the term "can" in the context of "can include" or "can consist of" is taken to mean possibly, possibly can, possibly might or possibly may.

[0105] Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps. To "comprise" or "comprising" means to include, without necessarily being limited to the content, elements, ingredients, components or steps listed or similar elements, ingredients, components or steps.

[0106] It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the technology should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The omission of any aspect of the subject matter disclosed herein does not preclude coverage of that aspect, nor does it relinquish any right to use such subject matter under the field of patent novelty grace period.

Claims

1. A stainless steel heat exchanger, characterized by, The stainless steel heat exchanger comprises: a mounting plate; a plurality of heat exchange tubes; the heat exchange tubes are fixedly connected to the mounting plate by a first welding portion; a communication structure having a communication space; the communication space connects the tube ends of two or more heat exchange tubes to form a flow channel; the communication structure is connected to the mounting plate and / or the heat exchange tubes; the communication structure comprises a cover plate arranged on one side of the mounting plate; the cover plate is provided with a protruding portion protruding away from the mounting plate and a second connecting portion around the protruding portion; the interior of the protruding portion forms the communication space; the second connecting portion is connected to the mounting plate by a third welding portion to seal the space around the protruding portion; a fourth welding portion is arranged around the protruding portion, which separates the third welding portion from the flow channel.

2. The stainless steel heat exchanger of claim 1, wherein: The third welding portion is formed by brazing.

3. The stainless steel heat exchanger of claim 1, wherein: The fourth welding portion is formed by melting part of the cover plate and / or the mounting plate.

4. The stainless steel heat exchanger of claim 1, wherein: The first welding portion and / or the third welding portion are made of a material different from that of the mounting plate and the heat exchange tubes.

5. The stainless steel heat exchanger of claim 1, wherein: The third welding portion is made of a non-stainless steel material.

6. The stainless steel heat exchanger of claim 1, wherein: The stainless steel heat exchanger further comprises: an isolation portion separating the first welding portion from the flow channel.

7. The stainless steel heat exchanger of claim 6, wherein: The isolation portion comprises a second welding portion connecting the mounting plate and the heat exchange tubes, which is formed by melting part of the mounting plate and / or part of the heat exchange tubes.

8. The stainless steel heat exchanger of claim 7, wherein: The second welding portion is formed by a welding method different from that of the first welding portion.

9. The stainless steel heat exchanger of claim 8, wherein: The second welding portion is formed by laser welding or argon arc welding, and the first welding portion is formed by brazing.

10. The stainless steel heat exchanger of claim 9, wherein: The brazing filler metal is copper or nickel.

11. The stainless steel heat exchanger as claimed in claim 8 or 9 or 10 wherein: The mounting plate has a first connecting portion sleeved on the outer wall of the heat exchange tube; the first welding portion connects the first connecting portion and the outer wall of the heat exchange tube; the second welding portion is closer to the tube end of the heat exchange tube than the first welding portion, so as to separate the first welding portion from the flow channel.

12. The stainless steel heat exchanger of claim 11, wherein: The first connecting portion extends away from the communication structure; the first connecting portion is formed by flanging a mounting hole on the mounting plate.

13. The stainless steel heat exchanger of claim 12, wherein: The second welding portion is arranged around the heat exchange tube and seals the space between the flanged wall and the wall of the heat exchange tube.

14. The stainless steel heat exchanger of claim 13, wherein: The first welding portion is formed between the flange and the tube wall of the heat exchange tube.

15. The stainless steel heat exchanger of claim 14, wherein: The length of the second welding portion along the axial direction of the heat exchange tube is smaller than that of the first welding portion.

16. The stainless steel heat exchanger of claim 11, wherein: The second welding portion is formed by laser welding on the tube end of the heat exchange tube.

17. The stainless steel heat exchanger of claim 6, wherein: The material of the isolation portion is different from that of the first welding portion and the third welding portion.

18. The stainless steel heat exchanger of claim 17, wherein: The first welding portion and the third welding portion are made of a non-stainless steel material, and the material of the isolation portion is a stainless steel material.

19. The stainless steel heat exchanger of claim 6, wherein: The isolation portion comprises a waterproof coating coated on the surface of the first welding portion and / or the third welding portion exposed in the flow channel.

20. A gas water heating apparatus characterised by The stainless steel heat exchanger comprises: The stainless steel heat exchanger of any one of claims 1-19.

21. A method of manufacturing a stainless steel heat exchanger as claimed in claim 6, wherein, The stainless steel heat exchanger comprises: a welding portion formed by welding and sealing the outer wall of the heat exchange tube and the mounting portion of the mounting plate; an isolation portion arranged between the outer wall of the heat exchange tube and the mounting portion to separate the welding portion from water.

22. The method of claim 21, wherein the heat exchanger is formed by a process comprising: The isolation portion is formed before the welding portion.

23. The method of claim 21, wherein the heat exchanger is formed by a process comprising: The temperature for forming the welding part is lower than the melting point of the heat exchange tube and the mounting plate.

24. The method of claim 21, wherein the heat exchanger is formed by a process comprising: The heat exchange tube and the mounting plate are made of stainless steel.

25. The method for manufacturing the heat exchanger as described in claim 21, characterized in that, Part of the heat exchange tube and / or part of the mounting plate is melted to form the isolation part.

26. The method for manufacturing the heat exchanger as described in claim 25, characterized in that, The isolation part is formed by laser welding or argon arc welding.

27. The method of claim 21, wherein the heat exchanger is formed by a process comprising: The welding method for forming the welding part is different from the welding method for forming the isolation part.

28. The method of claim 21, wherein the heat exchanger is formed by a process comprising: The mounting part includes a mounting hole formed on the mounting plate; the manufacturing method of the heat exchanger includes: The tube end of the heat exchange tube extending into the mounting hole is laser welded to form the isolation part.

29. The method of manufacturing a heat exchanger of any one of claims 21-28, wherein, The welding part is formed by brazing.

30. The method of claim 29, wherein the heat exchanger is formed by a process comprising: The mounting hole is provided with a flange, and the brazing welding part is formed between the flange and the outer wall of the heat exchange tube to seal and connect the mounting plate and the heat exchange tube.

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