A PTC heater for SPA and a manufacturing method thereof

Abstract

The application discloses a PTC heater for SPA and a manufacturing method thereof. The PTC heater comprises a heating core, a heat conduction component and an anticorrosion layer. The heating core is a heating unit for converting electric energy into heat energy. The heat conduction component is arranged outside the heating core and comprises heat conduction pipes and sealing plugs. The inner diameters of the two or more heat conduction pipes are different, and the heat conduction pipes are arranged outside the heating core layer by layer from small to large in inner diameter. The sealing plugs are arranged at two ends of the heating core. The anticorrosion layer is sprayed on the surface of the outermost heat conduction pipe in contact with the outside. The application sets two or more heat conduction pipes with different inner diameters in the heat conduction component, and the heat conduction pipes are arranged layer by layer to form multi-layer protection for the heating core and to reduce the thermal resistance caused by the gap as much as possible. The setting of the sealing plugs effectively improves the insulation performance of the PTC heater. In addition, the anticorrosion layer significantly improves the corrosion resistance of the PTC heating pipe. The dn heat conduction pipe does not need to be shrunk or pressed, and the surface of the dn heat conduction pipe will not have micro cracks, thereby effectively preventing water from being immersed and corroded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heaters, in particular to a PTC heater for SPA and a manufacturing method thereof. BACKGROUND

[0002] Due to the special positive temperature coefficient resistance temperature characteristic of PTC ceramic elements, PTC heater products are widely used in the field of heating technology, and have been widely used in the field of household appliances for air heating, such as air conditioner auxiliary heating, hair dryer, bath heater, etc.; defrosting and heating of traditional fuel vehicles; in-vehicle heating and battery thermal management of new energy vehicles.

[0003] Compared with traditional electric heating wires, electric heating tubes, and far-infrared quartz heaters, PTC heaters use PTC ceramics as the core heating element, have the advantages of automatic temperature control, wide voltage range, no open flame, safety and reliability, long service life, etc. In the field of high-power heating, the application range of PTC heaters is still expanding. In addition to the field of air heating, PTC heaters have also been widely used in water heating applications such as swimming pools (SPA), floor heating, electric water heaters, and new energy vehicle battery thermal management, for rapid heating of water or automobile antifreeze.

[0004] The insulation performance requirement of PTC heaters used in water is higher than that of air heating heaters, especially for SPA water PTC heaters. People will stay in the water for a long time, and the safety requirement is extremely high. In addition, a small amount of chlorine tablets will be added to the SPA water for disinfection, and seawater may also be used. Therefore, PTC heaters that come into contact with water also need to have certain corrosion resistance, otherwise safety hazards may also occur (water corrodes the heater shell and penetrates into the heating core body, causing poor insulation, resulting in water electrification).

[0005] In the prior art, there are usually two structures for SPA PTC heaters: one is to place a rectangular PTC heating pipe in a water-through aluminum shell to emit heat, and the heat is transmitted to the water channel of the water-through aluminum shell through electrode sheets, insulating films, and metal pipes, thereby heating the water in the water channel; the other is to insert a PTC heating core into a metal pipe for pipe shrinking to form a heating metal pipe, and then insert the heating metal pipe into a stainless steel pipe with a slightly larger inner diameter and perform pipe shrinking again to form a PTC heater.

[0006] In the long time use process, especially the family leisure water pool (SPA), the water needs to be disinfected by the chlorine tablet, and there is a certain concentration of chloride ion in the water, and sometimes sea water is also used, which is more corrosive. The water channel and the sealing surface of the aluminum shell of the former structure will be corroded due to poor corrosion resistance, resulting in sealing failure, and in severe cases, the shell will be perforated, and water will penetrate into the PTC heating pipe, thereby causing the safety problem of electric leakage. The corrosion resistance of the outer layer of the stainless steel heating pipe of the latter structure is better, and the internal metal pipe and the external stainless steel pipe are both in the shrink pipe structure, and the thermal resistance is small. However, this structure has the following fatal defects:

[0007] 1) Although the corrosion resistance of stainless steel is better than that of aluminum, the chloride ion corrosion resistance is poor, and it is not suitable for SPA water pool heating;

[0008] 2) The outer layer of stainless steel is pressed and shrunk, and there are microcracks and defects on the surface. In the long-term use process in water, the microcracks and defects are weak points that are corroded first, causing the crack to expand, water to penetrate into the stainless steel, and then to penetrate into the heating core in the metal pipe (the metal pipe is shrunk, and the surface also has microcracks), thereby causing poor insulation and causing great safety hazards;

[0009] 3) The thermal conductivity of the outer layer of the stainless steel pipe is much lower than that of the inner layer of the metal aluminum pipe, the thermal resistance is large, and the heating efficiency is low.

[0010] Therefore, there is an urgent need in the technical field to provide a PTC heater suitable for SPA, which has simple structure, strong corrosion resistance, high heat conduction efficiency. SUMMARY

[0011] In order to solve the above technical problems, the present application provides a PTC heater suitable for SPA, which has simple structure, strong corrosion resistance, good insulation and high heat conduction efficiency.

[0012] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0013] In one aspect, the present application discloses a PTC heater for SPA, comprising a heating core, a heat conduction component and an anticorrosion layer, the heating core is a heating unit for converting electric energy into heat energy, the heating core comprises a PTC ceramic element, metal electrodes and insulating paper; the PTC ceramic element is arranged in the middle, the number of the metal electrodes is two, the two metal electrodes are respectively attached to the two sides of the PTC ceramic element, forming a heating combination with a circular cross section, and the insulating paper is wrapped around the outer periphery of the heating combination; the heat conduction component is arranged outside the heating core and comprises heat conduction pipes and sealing plugs, the heat conduction pipes are two or more, the inner diameters of the two or more heat conduction pipes are different, and the inner diameters are d1, d2 to dn in order from small to large, wherein n is an integer greater than or equal to 2, the d1 heat conduction pipe is sleeved outside the heating core, and the inner wall of the d1 heat conduction pipe is in close contact with the outer surface of the heating core, and the d2 to dn heat conduction pipes are sequentially sleeved outside the d1 heat conduction pipe in order from small to large; the sealing plugs are respectively arranged at both ends of the heating core to form a sealed space with the heat conduction pipes; and the anticorrosion layer is sprayed on the surface of the dn heat conduction pipe in contact with the outside.

[0014] The beneficial effects of the above technical solution are that the problems of poor corrosion resistance, poor insulation, high risk of electric leakage and low heat transfer efficiency of the PTC heater for SPA in the prior art are fully considered, two or more heat conduction pipes with different inner diameters are arranged in the heat conduction component, the heating core is protected by layering, the d1 heat conduction pipe in the innermost layer is in close contact with the outer surface of the heating core to reduce the thermal resistance caused by the gap as much as possible; the sealing plugs are arranged to form a sealed space for the heating core, preventing external water from entering, which effectively improves the insulation performance of the PTC heater, and the anticorrosion layer is sprayed on the surface of the dn heat conduction pipe in contact with the outside, which significantly improves the corrosion resistance of the PTC heating pipe; the dn heat conduction pipe is not heat-shrunk or compressed, and the surface will not have micro-cracks, effectively preventing the water in the SPA from entering and corroding.

[0015] As a further improvement of the technical solution of the present application, the heat conduction component is also provided with a filling sealant, which is filled in the gap between the d1 heat conduction pipe, the d2 heat conduction pipe to the dn heat conduction pipe.

[0016] The beneficial effects of the above technical solution are that the filling sealant is arranged to fill the gap between different layers of heat conduction pipes, effectively reducing the thermal resistance caused by the gap and improving the heating efficiency.

[0017] As a further improvement of the technical solution of the present application, the gap between the d1 heat conduction pipe, the d2 heat conduction pipe to the dn heat conduction pipe ranges from 0.1 mm to 1 mm.

[0018] The beneficial effect of the above technical solution is that the gap between the heat pipes of different layers is in the preferred range, which is conducive to the rapid assembly of the heat pipes, improves the production efficiency of the PTC heater, and is also conducive to the injection of the potting glue, and keeps a low thermal resistance.

[0019] As a further improvement of the technical solution of the application, the thickness of the d1 heat pipe is in the range of 0.2mm-1.5mm.

[0020] The beneficial effect of the above technical solution is that practice has proved that when the thickness of the innermost d1 heat pipe is in the range of 0.2mm-1.5mm, it can maintain appropriate strength and facilitate close contact with the heating core through pressing or pipe shrinking.

[0021] As a further improvement of the technical solution of the application, the thickness of the dn heat pipe is in the range of 0.2mm-2.5mm.

[0022] The beneficial effect of the above technical solution is that to avoid micro-cracks on the surface, the outermost dn heat pipe is not shrunk, therefore, the dn heat pipe requires higher strength, and its thickness needs to be appropriately thickened compared to other layers of heat pipes. Practice has proved that when the thickness of the dn heat pipe is in the range of 0.2mm-2.5mm, it can maintain sufficient strength while having good economy.

[0023] As a further improvement of the technical solution of the application, the heat pipe is an aluminum round pipe.

[0024] The beneficial effect of the above technical solution is that the aluminum round pipe is used as the heat pipe, which fully utilizes the excellent heat conductivity, light weight, and plasticity of the aluminum round pipe, and is easy to process, which helps to further improve the heat conductivity of the heat pipe and prolong the service life of the PTC heater.

[0025] As a further improvement of the technical solution of the application, the potting glue is silicone.

[0026] The beneficial effect of the above technical solution is that silicone is used as the potting glue, which fully utilizes the high heat conductivity and thermal stability of silicone, maintains a good filling state at high temperature, and as much as possible reduces the thermal resistance of the potting glue itself, further improving the heat conduction efficiency from the heating core to the outside.

[0027] As a further improvement of the technical solution of the application, the corrosion-resistant layer is one of iron fluoride, epoxy resin, fluorocarbon resin, anodic oxidation, and electrophoretic paint.

[0028] The beneficial effects of the above technical solution are that the above material is used as the anticorrosive layer, which fully plays the roles of resisting acid, alkali and various organic solvents, and has the characteristics of resisting high temperature, effectively preventing the corrosion of the disinfectant water containing chlorine ions or the seawater containing various corrosive substances, further prolonging the service life of the PTC heater and reducing the replacement frequency.

[0029] As a further improvement of the technical solution of the application, the heating core further comprises an aluminum foil, and the insulating paper is at least two layers, and the aluminum foil is arranged between the at least two layers of insulating paper.

[0030] The beneficial effects of the above technical solution are that the number of layers of the insulating paper is set to at least two, and the aluminum foil is arranged between the two layers of insulating paper, which can effectively absorb and block impurity particles, thereby playing a role in protecting the insulating layer.

[0031] On the other hand, the application further discloses a manufacturing method of the PTC heater for SPA, comprising the following steps:

[0032] S1: two semicircular metal electrodes are respectively attached to the two sides of the PTC ceramic element, and the insulating paper is wrapped to form a heating core with a circular cross section;

[0033] S2: the heating core is inserted into the d1 heat conducting pipe, and the pipe is shrunk by pressing to form a circular heating pipe;

[0034] S3: the circular heating pipe is inserted into the d2 heat conducting pipe, one end of the circular heating pipe is sealed with a sealing plug, the gap between the d2 heat conducting pipe and the circular heating pipe is injected with potting glue, and the other end of the circular heating pipe is sealed with a sealing plug;

[0035] S4: repeating step S3 until the assembly of the dn heat conducting pipe is completed;

[0036] S5: spraying an anticorrosive layer on the surface of the dn heat conducting pipe in contact with the outside.

[0037] The beneficial effects of the above technical solution are that the PTC heater manufacturing method is formulated, which is convenient for standardizing the manufacturing process of the PTC heater, is conducive to improving the production efficiency, maintaining the stability of the production quality, and is conducive to realizing standardized mass production. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these accompanying drawings without creative effort.

[0039] Figure 1 A schematic view of a front cross-section of a PTC heater according to the present application;

[0040] Figure 2 A schematic view of a cross-section of a PTC heater according to the present application;

[0041] Figure 3 A schematic view of a cross-section of another PTC heater according to the present application;

[0042] The corresponding component names represented by the numbers in the figures are as follows:

[0043] Heating core 1; PTC ceramic element 11; metal electrode 12; insulating paper 13; aluminum foil 14; heat conducting assembly 2; heat conducting pipe 21; d1 heat conducting pipe 211; d2 heat conducting pipe 212; dn heat conducting pipe 213; sealing plug 22; tail sealing plug 221; head sealing plug 222; potting glue 23; corrosion protection layer 3. DETAILED DESCRIPTION

[0044] In order to facilitate the understanding of the present application, the present application will be described more fully and completely by means of the accompanying drawings and preferred embodiments. However, the scope of protection of the present application is not limited to the following specific embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0045] In order to achieve the purpose of the present application, the technical solutions provided by the present application are as follows:

[0046] On the one hand, in some embodiments of the present application, such as Figure 1,3 shown, discloses a PTC heater for SPA, comprising a heating core 1, a heat conduction component 2 and an anticorrosion layer 3, the heating core 1 is a heating unit for converting electric energy into heat energy, the heater core comprises a PTC ceramic element 11, a metal electrode 12 and an insulating paper 13; the PTC ceramic element 11 is arranged in the middle, the metal electrode 12 is two pieces, the two pieces of metal electrode 12 are respectively attached to the two sides of the PTC ceramic element 11, forming a heating combination with a circular cross section, and the insulating paper 13 is wrapped around the outer periphery of the heating combination; the heat conduction component 2 is arranged outside the heating core 1, comprising a heat conduction pipe 21 and a sealing plug 22, the heat conduction pipe 21 is two or more, the inner diameters of the two or more heat conduction pipes 21 are different, and the inner diameters are d1 heat conduction pipe 211, d2 heat conduction pipe 212 to dn heat conduction pipe 213 in turn from small to large, wherein n is an integer greater than or equal to 2, d1 heat conduction pipe 211 is sleeved outside the heating core 1, and the inner wall of d1 heat conduction pipe 211 is in close contact with the outer surface of the heating core 1, d2 heat conduction pipe 212 to dn heat conduction pipe 213 are sequentially sleeved outside d1 heat conduction pipe 211 in turn from small to large; the sealing plug 22 comprises a tail sealing plug 221 and a head sealing plug 222, the tail sealing plug 221 and the head sealing plug 222 are respectively arranged at the tail port and the head port of the heating core 1, and are used to construct a sealed space with the heat conduction pipe 21 for the heating core 1; the anticorrosion layer 3 is sprayed on the surface of dn heat conduction pipe 213 in contact with the outside.

[0047] The beneficial effects of the above technical scheme are: fully considering the poor corrosion resistance, poor insulation, high risk of electric leakage and low heat transfer efficiency of the PTC heater for SPA in the prior art, two or more heat conduction pipes 21 with different inner diameters are arranged in the heat conduction component 2, which provides multi-layer protection for the heating core 1 by layer-by-layer sleeving, the innermost d1 heat conduction pipe 211 is in close contact with the outer surface of the heating core 1 to minimize the thermal resistance caused by the gap; the sealing plug 22 is arranged to construct a sealed space for the heating core 1, preventing external water from entering, which effectively improves the insulation performance of the PTC heater, and the anticorrosion layer 3 is sprayed on the surface of the outermost dn heat conduction pipe 213 in contact with the outside, which significantly improves the corrosion resistance of the PTC heating pipe; dn heat conduction pipe 213 is not heat-shrunk or compressed, and the surface will not have micro-cracks, effectively preventing the immersion and corrosion of SPA water.

[0048] In some other embodiments of the present application, as shown in Figures 1-3 the heat conduction component 2 is also provided with a potting glue 23, which is filled in the gap between d1 heat conduction pipe 211, d2 heat conduction pipe 212 to dn heat conduction pipe 213.

[0049] The beneficial effects of adopting the above technical solution are: the setting of potting compound 23, by filling the gap between different layers of heat-conducting pipes 21, effectively reduces the thermal resistance caused by the gap and improves the heating efficiency.

[0050] In some other embodiments of the present invention, the gap between heat pipe d1 211, heat pipe d2 212 and heat pipe dn 213 is in the range of 0.1mm-1mm.

[0051] The beneficial effects of adopting the above technical solution are: the gap range between the heat pipes 21 in different layers is within the preferred range, which is conducive to the rapid assembly of the heat pipes 21 and improves the production efficiency of the PTC heater, and also facilitates the injection of potting compound 23 and maintains a low thermal resistance.

[0052] In some other embodiments of the present invention, the thickness of the heat pipe 211 d1 ranges from 0.2 mm to 1.5 mm.

[0053] The beneficial effects of adopting the above technical solution are: as proven by practice, when the thickness of the innermost d1 heat pipe 211 is set in the range of 0.2mm-1.5mm, it can maintain appropriate strength and facilitate close contact with the heating core 1 through compression or tube shrinking.

[0054] In some other embodiments of the present invention, the thickness of the dn heat pipe 213 ranges from 0.2 mm to 2.5 mm.

[0055] The beneficial effects of adopting the above technical solution are as follows: In order to avoid micro-cracks on the surface, the outermost DN heat pipe 213 is not reduced in thickness. Therefore, the DN heat pipe 213 has higher requirements in terms of strength. Compared with the heat pipes 21 in other layers, its thickness needs to be appropriately increased. Practice has proven that the thickness range of DN heat pipe 213 is 0.2mm-2.5mm, which can maintain sufficient strength while also being economical.

[0056] In some other embodiments of the present invention, the heat pipe 21 is an aluminum circular tube.

[0057] The beneficial effects of adopting the above technical solution are: using an aluminum round tube as the heat conduction tube 21 fully utilizes the excellent thermal conductivity, light weight and strong plasticity of the aluminum round tube, and it is easy to process. While ensuring further improvement of the thermal conductivity of the heat conduction tube 21, it helps to extend the service life of the PTC heater.

[0058] In some other embodiments of the present invention, the potting compound 23 is silicone.

[0059] The beneficial effects of adopting the above technical solution are: using silicone as potting compound 23, the high thermal conductivity and thermal stability of silicone are fully utilized. At high temperature, while maintaining a good filling state, the thermal resistance of the potting compound 23 itself is reduced as much as possible, further improving the thermal conductivity from the heating core 1 to the outside.

[0060] In some other embodiments of the present invention, the anti-corrosion layer 3 is one of Teflon, epoxy resin, fluorocarbon resin, anodizing and electrophoretic paint.

[0061] The beneficial effects of adopting the above technical solution are as follows: using the above material as the anti-corrosion layer 3 fully utilizes its resistance to acids, alkalis, and various organic solvents, and also has high-temperature resistance, effectively preventing corrosion from disinfectants containing chloride ions or seawater containing various corrosive substances, further extending the service life of the PTC heater and reducing the replacement frequency. In addition, other anti-corrosion materials with similar characteristics can also be used as the anti-corrosion layer 3 of the PTC heater, thereby effectively improving the anti-corrosion performance of the PTC heater.

[0062] In other embodiments of the invention, such as Figure 3 As shown, the heating core 1 also includes an aluminum foil 14, and the insulating paper 13 consists of at least two layers, with the aluminum foil 14 disposed between the at least two layers of insulating paper 13.

[0063] The beneficial effects of adopting the above technical solution are: the number of insulating paper 13 layers is at least two, and aluminum foil 14 is placed between the two insulating paper layers 13, which can effectively absorb and block impurity particles, thereby playing a role in protecting the insulating layer.

[0064] In other embodiments of the present invention, a method for manufacturing a PTC heater for SPA is further disclosed, comprising the following steps:

[0065] S1: Two semi-circular metal electrodes 12 are attached to both sides of the PTC ceramic element 11 and wrapped with insulating paper 13 to form a heating core 1 with a circular cross-section.

[0066] S2: Insert the heating core 1 into the heat pipe 211 of d1, and shrink it by pressing to make a circular heating pipe;

[0067] S3: Insert the circular heating tube into the d2 heat pipe 212, seal one end of the circular heating tube with the sealing plug 22, inject potting compound 23 into the gap between the d2 heat pipe 212 and the circular heating tube, and then seal the other end of the circular heating tube with the sealing plug 22.

[0068] S4: Repeat step S3 until the assembly of dn heat pipe 213 is completed;

[0069] S5: Spray an anti-corrosion layer 3 onto the surface of the dn heat pipe 213 that is in contact with the outside.

[0070] The beneficial effects of adopting the above technical solution are: the formulation of the PTC heater manufacturing method facilitates the standardization of the PTC heater manufacturing process, which helps to improve production efficiency, maintain the stability of production quality, and facilitates standardized mass production.

[0071] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A PTC heater for SPA, characterized in that, Includes heating core, heat-conducting components, and anti-corrosion layer. The heating core is a heating unit used to convert electrical energy into heat energy. The heating core includes a PTC ceramic element, metal electrodes, and insulating paper. The PTC ceramic element is located in the middle, and there are two metal electrodes. The two metal electrodes are respectively attached to both sides of the PTC ceramic element to form a heating assembly with a circular cross-section. The insulating paper is wrapped around the outer periphery of the heating assembly. The heat-conducting assembly, located outside the heating core, includes heat-conducting pipes and sealing plugs. There are two or more heat-conducting pipes, each with a different inner diameter, arranged in ascending order of inner diameter as d1, d2, to dn, where n is an integer greater than or equal to 2. The d1 heat-conducting pipe is fitted over the heating core, with its inner wall in close contact with the outer surface of the heating core. The d2 to dn heat-conducting pipes are fitted over the d1 heat-conducting pipe in ascending order of inner diameter. The sealing plugs are located at both ends of the heating core, forming a sealed space for the heating core together with the heat-conducting pipes. The anti-corrosion layer is sprayed onto the surface of the DN heat pipe that contacts the outside. The heat-conducting component is also provided with potting compound, which fills the gap between the d1 heat-conducting pipe, the d2 heat-conducting pipe and the dn heat-conducting pipe. The heating core also includes aluminum foil, and the insulating paper consists of at least two layers, with the aluminum foil disposed between the at least two layers of insulating paper.

2. The PTC heater for SPA according to claim 1, characterized in that, The gap between heat pipes d1, d2, and dn is 0.1 mm. 1mm.

3. The PTC heater for SPA according to claim 1, characterized in that, The thickness of the d1 heat pipe is 0.2 mm. 1.5mm.

4. The PTC heater for SPA according to claim 1, characterized in that, The thickness of the DN heat pipe is in the range of 0.2mm. 2.5mm.

5. The PTC heater for SPA according to claim 1, characterized in that, The heat pipe is an aluminum round tube.

6. The PTC heater for SPA according to claim 1, characterized in that, The potting compound is silicone.

7. The PTC heater for SPA according to claim 1, characterized in that, The anti-corrosion layer is one of Teflon, epoxy resin, fluorocarbon resin, anodizing, and electrophoretic paint.

8. A method for manufacturing a PTC heater for SPA, characterized in that, Includes the following steps: S1: Attach two semi-circular metal electrodes to both sides of the PTC ceramic element and wrap them with insulating paper to form a heating core with a circular cross-section. S2: Insert the heating core into the d1 heat pipe and shrink it by pressing to make a circular heating pipe; S3: Insert the circular heating tube into the d2 heat pipe, seal one end of the circular heating tube with a sealing plug, inject potting compound into the gap between the d2 heat pipe and the circular heating tube, and then seal the other end of the circular heating tube with a sealing plug. S4: Repeat step S3 until the assembly of the dn heat pipe is completed; S5: Apply an anti-corrosion layer to the surface of the dn heat pipe that comes into contact with the outside.

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