Manufacturing method of a surface-oriented exposed low-voltage high-current heating device

Abstract

The present application relates to a manufacturing method for a surface-oriented, exposed low-voltage, high-current heating device. The method is characterized by comprising the following steps: (1) determining a low-voltage value (1 V to 110 V) based on the required heating power and the available heating area; then determining the parameters of the resistance heating element, such as thickness, length, and width, according to the specified voltage value, and fabricating a matching isolation transformer; (2) designing and preparing a drawing of the heating element based on the calculation results; (3) manufacturing the heating element by cutting the plate according to the created drawing; (4) insulating the heating element while mounting it on the available heating area of ​​the heat treatment device.Compared to the prior art, the heater manufactured according to the present invention enables a reduction in thermal resistance, an increase in heat transfer area, and an increase in thermal efficiency, thereby reducing energy consumption by at least 30%. Furthermore, the service life of the heater can be significantly extended. Furthermore, the present invention contributes to improving the working environment of the heater and lowering the working temperature in the production hall.

Description

Technical area

[0001] The present application relates to the field of heating technology, in particular to a method of manufacturing a labyrinth-shaped low-voltage high-current heating device. Background technology

[0002] Currently, electrical heating in industrial applications such as surface heating, asphalt melting, metal melting, maintaining the molten state of materials, air heating for material drying, and temperature control is primarily achieved using resistance heating tubes and heating plates. These resistance heating tubes and heating plates are typically based on heating wires with operating voltages of 380 V or 220 V. Heating wires are heated through thick insulation layers and transfer heat indirectly to the material to be heated via the outer metallic shell. This indirect heating method has high thermal resistance, a small effective heating surface of the heating wires, and low heat transfer efficiency, which is not energy-efficient. Traditional resistance heating methods have the following disadvantages in particular: 1. High heat losses: In existing equipment such as asphalt machines and lead melting furnaces, heating is provided by heating wires that generate heat on both the inside and outside of pipes or plates. While the heat generated on the inside (in direct contact with the object to be heated) is transferred to the object, most of the heat generated on the outside is lost to the surrounding air, resulting in significant energy losses and wasted electrical energy. 2. Increased ambient temperature: Due to significant heat loss, the ambient temperature rises significantly, severely impacting production conditions, especially during the summer months. On-site working temperatures often exceed 40°C, forcing some companies to use air conditioning to reduce temperatures, which in turn leads to additional energy consumption and thus further energy waste. 3. Short service life and high maintenance costs: Since conventional heating systems rely on heating wires, these are prone to aging, deformation, and burnout due to the high operating temperatures. Replacement after a failure is often difficult. The typical service life of heating tubes and heating plates is about six months, which causes frequent failures and thus production interruptions. This results in correspondingly high maintenance costs. 4. The power density is low and not suitable for applications requiring higher temperatures; 5. Large thermal inertia, strong temperature fluctuations.

[0003] Another improved heating device uses electromagnetic induction, the operating principle of which is based on the generation of eddy currents through magnetic induction. The body of the electromagnetic induction heating coil itself does not heat up. In practical applications, the cylinder is additionally covered on the outside with a certain thickness of insulating material. The surface temperature of the electromagnetic induction heating coil thus remains below 60°C, and only a small amount of the heat generated inside the cylinder is radiated into the environment. This significantly reduces heat loss and significantly increases heating efficiency, leading to significant energy savings. However, the high-frequency current generated during operation of the coil generates a rapidly changing magnetic field, which, when a certain field strength is reached, can pose a threat to the human central nervous system.Currently, China only has specific regulations for electromagnetic devices used in household and similar applications, while corresponding standards for electromagnetic devices developed for industrial purposes are still lacking. Manufacturers of electromagnetic induction heaters currently only conduct EMF (electromagnetic field) tests around individual heaters based on EU standards. However, under real-world operating conditions, the electromagnetic radiation intensity of these devices remains relatively high, resulting in an undetermined risk. In addition, the service life of electromagnetic induction heaters is short, typically only 2 to 3 years. Contents of the invention

[0004] The aim of the present application is to provide a manufacturing method of a low-voltage, high-current heating device that has a maximum heat transfer area, high thermal efficiency, low heat losses and a long service life, so that the heating performance can be reliably ensured while increasing energy savings.

[0005] The present application discloses a manufacturing method of a surface-oriented exposed low-voltage high-current heating device, the manufacturing method comprising the following steps: (1) Design of the heating device, comprising the following sub-steps: 1-1: Determination of the heating power and the available heating surface of the heat treatment plant on which the heating device is to be installed; First, the power to be used for heating is determined based on the specified power requirements of the heat treatment plant. Next, the available heating area of ​​the heating chamber is determined, where the heating chamber refers to the interior of the heat treatment plant used for the heating process. The available heating area is the sum of the areas that can be used for heat exchange. Based on the determined heating power and the available area, and with reference to a comprehensive data table developed from experience, a specific value for the low voltage to be used is provisionally determined. The low voltage range is between 1 V and 110 V. 1-2: Determination of the material of the heating element of the heating device and the heat transfer surface; The material of the heating element of the heater is then selected based on the maximum temperature requirements or the specific heating characteristics of the interior of the heat treatment facility. Various high-temperature-resistant alloy plates such as high-temperature Hastelloy plates, nickel-based alloys, titanium-based alloys, tungsten-based alloys, copper-based alloys, as well as various high-temperature-resistant stainless steel plates such as 2520, 800H, or stainless steels such as 9041, 310S, 309S, 304, 316L, as well as aluminum and copper plates, are considered. The heating element consists of individual heating modules, each constructed of a coiled, continuous resistor. The effective heat transfer area is then determined based on the thermal conductivity of the selected material.This heat transfer area refers to the actual contact area through which heat exchange takes place between the heating module and the respective available area of ​​the heating chamber. The ratio of the sum of all heat transfer areas to the total available heating area is more than 40%, preferably more than 60%. 1-3: Determination of the specific parameters of the individual heating module based on the heating output, the available heating surface of the boiler room and the provisionally determined low voltage value (1 V to 110 V), After determining the heating power, available heating surface, and low voltage, the optimal specific parameters for each heating module can be determined based on empirical values ​​and calculation formulas. These specific parameters include: the current of the heating element resistance, the current-carrying capacity, the length, thickness, width, and the spacing between the conductor tracks of each heating module. (2) Design and preparation of a drawing of the heating element based on the calculation results Based on the calculated values ​​for the thickness, length, width, and pitch of the individual heating module's resistor, the shape of the heating module is designed. This shape consists of a resistor arranged continuously in a zigzag pattern, spread over the required area. The structure resembles a labyrinth and is formed from N winding straight lines to maximize the available heating surface. (3) Manufacturing of the heating element by cutting the plate according to the drawing prepared; According to the drawing, a metal plate of the required thickness is used and cut to the required area and shape of a single-zone heating module using a cutting device. Screw holes are cut at both ends of the electrical resistance of the single-zone heating module to allow for the connection of cables to the transformer. The cutting device comprises a laser cutting machine. (4) When fixing the heating module to the available heating surface of the heat treatment plant, an insulation treatment shall be carried out;

[0006] The areas where the heating element comes into contact with or is attached to the heat treatment system or to non-insulated objects are separated from each other by an insulating layer, whereby the insulating layer has a thickness and no metallic sheath is required on the outside.

[0007] In a preferred embodiment, the design step (1) additionally comprises sub-step 1-4, wherein step 1-4 consists of customizing a transformer according to the specified values ​​for the power, the low voltage and the high current of the heating device.

[0008] In a preferred embodiment, the number of individual heating modules may be greater than one depending on the available heating area.

[0009] In a preferred embodiment, if the number of individual heating modules is greater than one, several of these individual heating modules are connected to one another either in parallel or in series.

[0010] In a preferred embodiment, steps 1-3 further comprise: adjusting the number of individual heating modules and adaptively adjusting the width, length, thickness, spacing and current carrying capacity of the resistors of the individual heating modules, wherein several calculations are performed to determine the number of individual heating modules that ensures the highest efficiency.

[0011] In a preferred embodiment, steps 1-3 also include recording the specific parameters obtained in each calculation in order to continuously update the empirical formulas.

[0012] In a preferred embodiment, the heating device further comprises a temperature-controlled zone control system adapted according to the parameters of the transformer, wherein the number of zone control systems is less than or equal to the number of transformers. The heating device can be used in the following operating modes: area-direct contact heating, external contact-based indirect heating, internal radiant heating, convection heating, and indirect heating by means of a medium. Indirect heating by means of a medium involves the heater heating a medium such as a liquid or a gas, and the heated medium is subsequently used to heat the object to be heated.

[0013] In a preferred embodiment, direct surface contact heating includes both solids and fluids.

[0014] In a preferred embodiment, direct surface contact heating, indirect external contact heating, internal radiant heating, convection heating, and indirect heating by means of a medium may be used in combination depending on the actual work requirements.

[0015] In a preferred embodiment, the two power terminals of the resistor of the individual low-voltage, high-current heating module are each connected to the two input and output terminals of an isolation transformer using two matching sets of cables. The 220V or 380V power supply is then connected to the isolation transformer using matching cables. The temperature system controls the transformer in real time by monitoring temperature changes of the object being heated to ensure precise temperature control.

[0016] In a preferred embodiment, the two power terminals of several low-voltage, high-current heating modules are each connected in parallel or series with several matching cable sets and then connected together to the two input and output terminals of an isolation transformer. The 220V or 380V power supply is then connected to the isolation transformer via matching cables. The temperature system controls the transformer in real time by monitoring temperature changes of the object to be heated, ensuring high temperature accuracy. Compared to the prior art, the heating device of the present invention manufactured according to the invention has the following advantages: 1) Compared with conventional heating elements using a heating wire, the heating element of the present invention has a larger heat transfer area. Its exposed design reduces thermal resistance, increases heat efficiency, and significantly saves energy, with a savings rate of at least 30%. This is due to the fact that the invention uses area-oriented low-voltage heating, which allows for a maximum expansion of the heat transfer area. The insulating materials used can be made very thin, resulting in low thermal resistance, a large heat transfer area, and high heat transfer efficiency.This allows the temperature of the heating section to approach the operating temperature, heat transfer occurs quickly, and the amount of heat generated is at least 1:0.9 to the amount of heat absorbed by the object being heated, thus minimizing energy loss during the heat transfer process. Furthermore, the use of a low-voltage isolation transformer ensures high safety, so even in the event of a current leak, there is no risk of electric shock. Low-voltage heating increases heat utilization efficiency and reduces energy costs, making the solution economical and cost-effective. 2) The heating device of the present invention manufactured according to the invention ensures that the current load of the resistor is 10 A / mm 2 which can significantly extend the service life of the heater. 3) The design method of the present invention is area-oriented and provides for the adjustment of low voltage and high current parameters to ensure the heat transfer area, thereby making full use of the available heating area and achieving maximum heat transfer efficiency. 4) The invention also contributes to improving the working environment of the heater and reducing the temperature in the workshop. Due to the characteristics of conventional heating technologies, tight thermal insulation is not possible, resulting in significant heat loss and significantly deteriorating working conditions in workshops, especially in summer. In the present heater, however, the low-voltage characteristics, increased heat transfer surface, and high heat transfer efficiency enable tight thermal insulation with minimal heat radiation, thus avoiding a drastic increase in the ambient temperature in the workshop.

[0017] This description lists numerous technical features distributed across various technical embodiments. A complete listing of all possible combinations of these technical features (i.e., all technical solutions) would unnecessarily overload the description. To avoid this problem, all technical features described in the above disclosure of the present invention, all technical features disclosed in the following embodiments and examples, and all technical features illustrated in the accompanying drawings may be arbitrarily combined to form various new technical solutions (all of which technical solutions are deemed to be disclosed in this description), unless such a combination would be technically impracticable.For example, in one embodiment, the feature combination A+B+C is disclosed, while in another embodiment, the combination A+B+D+E is disclosed. Since features C and D represent technically equivalent means that serve the same purpose and can be used individually but not simultaneously, the combination A+B+C+D is not technically feasible and is therefore considered undisclosed. The combination A+B+C+E, on the other hand, is technically feasible and is considered disclosed in the present description. Figures Fig. Figure 1 shows a schematic overall view of the heating device manufactured by the manufacturing method disclosed in the present invention; Fig. 2 shows a schematic diagram of the structure of a heating element according to the first embodiment of the present invention; Fig. 3 shows a schematic diagram of the structure of a heating element according to the second embodiment of the present invention; Fig. 4 shows a schematic diagram of the structure of a heating element according to the third embodiment of the present invention; Fig. 5 is a schematic diagram showing the structure of a heating element according to the fourth embodiment of the present invention; Fig. 6 shows a schematic diagram of the structure of a heating element according to the fifth embodiment of the present invention.

[0018] 1 - Available heating surface; 2 - Heating element; 3 - Temperature control device; 4 - Heat treatment system; 5 - Isolation transformer; Specific embodiments

[0019] After intensive research and extensive selection, the inventors of the present application have developed a manufacturing method for a surface-oriented, exposed, low-voltage, high-current heating device. Compared with the prior art, the present application adapts the design of the low-voltage, high-current heating module according to the available heating area of ​​the heat treatment equipment used to maximize the heat transfer area. This significantly improves both heat exchange efficiency and energy savings. Furthermore, due to the low-voltage, high-current, and exposed heating method used, thick, dielectric-resistant insulation and additional metallic sheaths are eliminated, thereby reducing thermal resistance and increasing thermal efficiency.

[0020] In the following, numerous technical details are provided to facilitate the reader's understanding of the present application. However, it will be understood by those skilled in the art that the claimed technical solution of the present application can also be implemented without these technical details, as well as with various modifications and variations based on the following embodiments.

[0021] The surface-oriented exposed low-voltage high-current heating device described in the present invention is Fig. 1 and comprises: heating element 2, temperature control device 3, heat treatment system 4, and isolation transformer 5. The length, width, and spacing of the heating element 2 are determined empirically based on the available heating surface of the heat treatment system 4 and the designed voltage. The heating element 2 is mounted on the heat treatment system 4, with the connection points being treated with insulation. The heat treatment system 4 is connected to the isolation transformer 5, which is specifically designed according to the low-voltage value used for the heat treatment system 4. The isolation transformer 5, in turn, is connected to the temperature control device 3, which serves to monitor the specific heating values ​​of the heating element 2 to ensure the safety and stability of the heating process. Example 1

[0022] The design of the heating element of the surface-oriented exposed low voltage high current heating device of the present invention is shown in Fig. 2. The construction steps are as follows: 1-1: Determination of the required heating power and the available heating surface of the heat treatment plant on which the heating device is to be installed; First, based on the specified power requirements of the heat treatment system 4, the power to be used for heating and the available heating area are determined in order to establish the actual low-voltage and high-current values ​​to be used. In the present exemplary embodiment, the specified power of the heat treatment system is 5.6 kW, and based on empirical values, 20 V was selected as the low-voltage value to be used in this example. After determining the low-voltage value, the available heating area of ​​the heating chamber is determined. In the present exemplary embodiment, the available heating area is approximately 0.29 m 2 ; 1-2: Determination of the material of the heating element 2 of the heating device and the heat transfer surface; Subsequently, the material of the heating element (hereinafter also referred to as individual heating element 2) is selected based on the maximum achievable temperature or the heating properties inside the heat treatment system. Since in the present embodiment, the maximum heating temperature can reach up to 280 °C, a high-temperature Hastelloy plate is selected as the material. Subsequently, the heat transfer area on each available surface of the heating chamber is determined, taking into account the thermal conductivity of the selected material. The heat transfer area refers to the area over which the heating element is in thermal contact with the available surface of the heating chamber during the actual heat exchange process. The ratio of the total of all heat transfer surfaces to the total available heating surface is more than 40%, preferably more than 60%. In the present embodiment, the ratio of the heat transfer area is approximately 65%. 1-3: Determination of the specific parameters of the individual heating element 2 based on the heating power, the available heating surface of the boiler room and the provisionally determined low voltage value (1 V to 110 V). After determining the available heating area, the optimal specific parameters of the individual heating element 2 can be determined based on the heating power, the available heating area, and the low-voltage value using empirical values ​​and calculation formulas. In the present embodiment, the following specific values ​​​​are obtained for the heating element 2: the thickness of the heating element 2 is 2.8 mm, and the width of the wound continuous resistance strip is 10 mm. According to the calculations, an energy saving rate of approximately 40% can be achieved in the present embodiment by using the low-voltage high-current heating device manufactured using the manufacturing method of the present invention. Example 2

[0023] The design of the heating element 2 of the surface-oriented exposed low-voltage high-current heating device of the present invention is shown in Fig. 3. The construction steps are as follows: 1-1: Determination of the required heating power and the available heating surface of the heat treatment plant on which the heating device is to be installed; First, the power to be used for heating is determined based on the specified power requirements of the heat treatment system 4 in order to establish the actual low-voltage and high-current values ​​to be used. In the present exemplary embodiment, the specified power of the heat treatment system is 25 kW. Based on empirical values, 45 V was selected as the low-voltage used in this example. After determining the low-voltage value, the available heating area of ​​the heating room is determined, which in the present exemplary embodiment is approximately 6.64 m 2 amounts; 1-2: Determination of the material of the heating element 2 of the heating device and the heat transfer surface; The material of the heating element (hereinafter also referred to as individual heating element 2) is then selected based on the maximum achievable heating temperature or the heating properties inside the heat treatment system. Since in the present embodiment, the maximum heating temperature can reach up to 550 °C, a 2520 stainless steel, which can withstand temperatures of up to 1500 °C, is selected as the material. The heat transfer area on each available surface of the heating chamber is then determined, taking into account the thermal conductivity of the selected material. The heat transfer area refers to the area over which the heating element 2 comes into thermal contact with the available surface of the heating chamber during the actual heat exchange process. The ratio of the total of all heat transfer surfaces to the total available heating surface is more than 40%, preferably more than 60%.In the present embodiment, the ratio of the heat transfer area is approximately 70%. 1-3: Determination of the specific parameters of the individual heating element 2 based on the heating power, the available heating surface of the boiler room and the provisionally determined low voltage value (1 V to 110 V). After determining the available heating area, the optimal specific parameters of the individual heating element 2 can be determined based on the heating power, the available heating area, and the low-voltage value, using empirical values ​​and calculation formulas. In the present embodiment, the heat treatment system 4 has a ring-shaped structure. Therefore, three individual heating elements 2 connected in parallel were selected as the final design. The specific values ​​calculated for the heating element 2 in the present embodiment after substituting the parameters are: the thickness of the heating element 2 is 3.9 mm, and the width of the coiled resistor is 27 mm. According to the calculations, an energy saving rate of approximately 50% can be achieved in the present embodiment by using the low-voltage high-current heating device manufactured by the manufacturing method of the present invention. Example 3

[0024] The design of the heating element 2 of the surface-oriented exposed low-voltage high-current heating device of the present invention is shown in Fig. 4. The construction steps are as follows: 1-1: Determination of the required heating power and the available heating surface of the heat treatment plant on which the heating device is to be installed.

[0025] First, the power to be used for heating is determined based on the specified power requirements of the heat treatment system 4 in order to establish the actual low-voltage and high-current values ​​to be used. In the present exemplary embodiment, the heat treatment system has an irregular shape, which is why a separate design was created for the center and the two sides: The intended power for the center individual heating element 2 is 6 kW, with 40 V chosen as the low-voltage value based on empirical values. The intended power for the two side individual heating elements 2 is 17.3 kW each, with 60 V chosen as the low-voltage value. After determining the low-voltage values, the available heating area of ​​the heating room is determined, which in the present exemplary embodiment is approximately 5.5 m 2 amounts; 1-2: Determination of the material of the heating element 2 of the heating device and the heat transfer surface; Subsequently, the material of the heating element (hereinafter also referred to as individual heating element 2) is selected based on the maximum achievable heating temperature or the heating properties inside the heat treatment system. Since in the present embodiment, the maximum heating temperature can reach up to 200°C, 904L stainless steel is selected as the material. Subsequently, the heat transfer area on each available surface of the heating chamber is determined, taking into account the thermal conductivity of the selected material. The heat transfer area refers to the area over which the heating element comes into thermal contact with the available surface of the heating chamber during the actual heat exchange process. The ratio of the total of all heat transfer surfaces to the total available heating surface is more than 40%, preferably more than 60%. In the present embodiment, the ratio of the heat transfer area is approximately 50%. 1-3: Determination of the specific parameters of the individual heating element 2 based on the heating power, the available heating surface of the boiler room and the provisionally determined low voltage value (1 V to 110 V).

[0026] After determining the available heating area, the optimal specific parameters of the individual heating element 2 can be determined based on the heating power, the available heating area, and the low-voltage value using empirical values ​​and calculation formulas. In the present embodiment, the specific values ​​of the individual heating element 2 obtained by calculation are as follows: For the individual heating element 2 in the central region, the thickness is 8 mm and the width of the coiled resistor is 36 mm. For the individual heating elements 2 on both sides, the thickness is 10 mm and the width of the coiled resistor is 18.8 mm. According to the calculations, in the present embodiment, an energy saving rate of approximately 50% can be achieved by using the low-voltage high-current heating device manufactured by the manufacturing method of the present invention. Example 4

[0027] The design of the heating element of the surface-oriented exposed low voltage high current heating device of the present invention is shown in Fig. 5. The construction steps are as follows: 1-1: Determination of the required heating power and the available heating surface of the heat treatment plant on which the heating device is to be installed; First, the power to be used for heating is determined based on the specified power requirements of the heat treatment system 4 in order to establish the actual values ​​to be used for low voltage and high current. In the present exemplary embodiment, the heat treatment system has a cuboid shape with a total specified heating power of 90 kW. Since the interior of the heating chamber also consists of three small cuboid-shaped areas, one side of each of these small cuboids is used as the available heating surface and designed accordingly. The heating power of each of the three individual heating elements 2 is set to 30 kW. Based on empirical values, 35 V is selected as the low voltage value used in the present exemplary embodiment. After determining the low voltage value, the available heating surface is determined, which in the present exemplary embodiment is approximately 9 m 2 amounts; 1-2: Determination of the material of the heating element 2 of the heating device and the heat transfer surface; The material of the heating element (hereinafter also referred to as individual heating element 2) is then selected based on the maximum achievable heating temperature or the heating properties inside the heat treatment system. Since in the present embodiment, the maximum heating temperature can reach up to 450 °C, a bare (uncoated) alloy is selected as the material. Subsequently, the heat transfer area on each available surface of the heating chamber is determined, taking into account the thermal conductivity of the selected material. The heat transfer area refers to the area over which the heating element comes into thermal contact with the available surface of the heating chamber during the actual heat exchange process. The ratio of the total of all heat transfer surfaces to the total available heating surface is more than 40%, preferably more than 60%.In the present embodiment, the ratio of the heat transfer area is approximately 80%. 1-3: Determination of the specific parameters of the individual heating element 2 based on the heating power, the available heating surface of the boiler room and the provisionally determined low voltage value (1 V to 110 V). After determining the available heating area, the optimal specific parameters of the individual heating element 2 can be determined based on the heating power, the available heating area, and the low-voltage value using empirical values ​​and calculation formulas. In the present embodiment, the following specific values ​​are obtained for all three individual heating elements 2 according to the calculations: the thickness of the individual heating element 2 is 8 mm, and the width of the wound resistance strip is 50 mm. In the present embodiment, the calculations show that an energy saving rate of approximately 40% can be achieved by using the low-voltage high-current heating device manufactured using the manufacturing method of the present invention. Example 5

[0028] The design of the heating element of the surface-oriented exposed low voltage high current heating device of the present invention is shown in Fig. 6. The construction steps are as follows: 1-1: Determination of the required heating power and the available heating surface of the heat treatment plant on which the heating device is to be installed; First, the power to be used for heating is determined based on the specified power requirements of the heat treatment system 4 in order to establish the actual values ​​to be used for low voltage and high current. In the present exemplary embodiment, the heat treatment system has the shape of a cuboid, with a total specified heating power of 200 kW. Since the interior of the heating chamber is also cuboid-shaped, the bottom of the cuboid is used as the available heating surface for the construction. The heating element 2 at the bottom consists of a single resistance module, whose heating power was set at 203 kW. Based on empirical values, 85 V was selected as the low voltage value used in the present exemplary embodiment. After determining the low voltage value, the available heating surface is determined, which in the present exemplary embodiment is approximately 12.8 m 2 amounts. 1-2: Determination of the material of the heating element 2 of the heating device and the heat transfer surface; Subsequently, the material of the heating element (hereinafter also referred to as the individual resistance heating element 2) is selected based on the maximum achievable heating temperature or the heating properties inside the heat treatment system. Since the maximum heating temperature in the present embodiment is 80°C, a 310S stainless steel plate is selected as the material. Subsequently, the effective heat transfer area on the available heating surface of the heating chamber is determined, taking into account the thermal conductivity of the selected material. The heat transfer area refers to the area over which the heating element comes into thermal contact with the available heating surface of the heating chamber during the actual heat exchange process. The ratio of the total of all heat transfer areas to the total available heating area is more than 40%, preferably more than 60%.In the present embodiment, the ratio of the heat transfer area is approximately 60%. 1-3: Determination of the specific parameters of the individual heating element 2 based on the heating power, the available heating surface of the boiler room and the provisionally determined low voltage value (1 V to 110 V). After determining the available heating area, the optimal specific parameters of the individual heating element 2 can be determined based on the heating power, the available heating area, and the low-voltage value using empirical values ​​and calculation formulas. In the present embodiment, the following specific values ​​are obtained for the individual resistance heating element 2 according to the calculations: the thickness of the individual resistance heating element 2 is 1 mm, and the width of the individual resistance module is 450 mm. In the present embodiment, the calculations show that an energy saving rate of approximately 45% can be achieved by using the low-voltage high-current heating device manufactured using the manufacturing method of the present invention.

[0029] It should be noted that in the application documents for this patent application, terms such as "first" and "second" are used merely to distinguish one element or act from another element or act, without necessarily requiring or implying any actual relationship or order between the recited elements or acts. Furthermore, the term "comprise," "include," or any other variation thereof should be construed as a non-exclusive list. This means that a process, method, article, or apparatus that includes a series of elements includes not only those expressly recited elements, but also additional elements not expressly listed or elements that are inherent in the process, method, article, or apparatus.Without further limitation, language such as "comprises a" element does not exclude the possibility that other identical elements may be present in the process, method, article, or apparatus comprising that element. In the application documents of this patent application, a reference to performing an act "based on" a particular element means that the act is performed at least with reference to that element. This includes both the case where the act is performed based solely on that element and the case where the act is performed based on that element and other elements. The terms "multiple", "multiple", "different", etc. include two, twice, or two kinds, as well as more than two, more than twice, or more than two kinds.

[0030] All documents cited in this application are considered to be fully incorporated into the disclosure of this application, so that they may be used as a basis for amendments if necessary. Furthermore, it is understood that, after reading the above disclosure of this application, those skilled in the art may make various changes or modifications to this application, and such equivalent embodiments will also fall within the scope of this application.

Claims

[1] Manufacturing method of a surface-oriented exposed low-voltage high-current heating device, characterized by that the manufacturing method includes the following steps: (1) Design of the heating device, comprising the following sub-steps: 1-1: Determine the required heating power and the available heating area of ​​the heat treatment plant on which the heating device is to be installed; First, determining the power to be used for heating based on the specified power requirements of the heat treatment plant, and then determining the available heating area of ​​the heating chamber, where the heating chamber refers to the interior of the heat treatment plant used for the heating process, with the available heating area being the sum of the areas that can be used for heat exchange; provisionally determining the specific low-voltage value based on the determined heating power and the available area, with reference to a comprehensive data table developed from experience, with the low-voltage range being between 1 V and 110 V; 1-2: Determine the material of the heating element of the heater and the heat transfer surface; Then, selecting the material of the heating element of the heating device based on the maximum temperature that can be reached during heating inside the heat treatment equipment or the specific heating characteristics, where: high-temperature resistant alloy plates such as high-temperature Hastelloy plates, nickel-based alloy plates, titanium-based alloy plates, tungsten-based alloy plates, copper-based alloy plates; high-temperature resistant stainless steel plates such as 2520, 800H, as well as stainless steel plates such as 9041, 310s, 309S, 304, 316L; or aluminum plates and copper plates can be used as materials; characterized bythat the heating element consists of individual heating modules, whereby the heating module can be designed either as the area of ​​a single resistance strip or as the area of ​​a wound continuous resistance strip; and then the heat transfer area on each available area of ​​the heating space is determined taking into account the thermal conductivity of the material, whereby: the heat transfer area denotes the actual area over which, in the heat exchange process, the heating module is in thermal contact with the respective available area of ​​the heating space; the ratio of the sum of all heat transfer areas to the total available heating area is greater than 40% and preferably greater than 60%; 1-3: Determine the specific parameters of the individual heating module based on the heating power, the available heating area of ​​the heating room and the preliminarily determined low voltage value (1 V to 110 V), After determining the heating output, the available heating area and the low voltage value, determining the optimal design of the specific parameters of the individual heating module based on the heating output, the available heating area and the low voltage value using empirical values ​​and calculation formulas, whereby the specific parameters include: the current of the heating module resistor; the current carrying capacity (conductor cross-section); the length; the thickness; the width and the distance (gap) of the conductor tracks; (2) Design and preparation of a drawing of the heating element based on the calculation results; Designing the shape of the heating module based on the calculated thickness, length, width and pitch of the resistor of the individual heating module, the shape consisting of a continuously wound resistor pattern spread over the required area to maximize the available heating area; (3) Manufacturing of the heating element by cutting the plate according to the drawing prepared; Using a metal plate of the required thickness and cutting it to the desired area and shape of the individual heating module using a cutting device according to the drawing prepared, screw holes are cut out at both ends of the heating resistor to allow connection of the cables to the transformer, the cutting device comprising a laser cutting machine; (4) Carrying out an insulation treatment when fixing the heating module on the available heating surface of the heat treatment plant; Separating and insulating the contact or attachment areas of the heating element where it comes into contact with the heat treatment equipment or with non-insulated objects by means of an insulating layer, the thickness of the insulating layer being 1 mm to 10 mm and no additional outer metal sheath being required. [2] Manufacturing method according to claim 1, characterized by that step (1) of the design method further comprises step 1-4, wherein step 1-4 consists in adjusting the transformer based on the specified values ​​of the heater power, the low voltage and the high current. [3] Manufacturing method according to claim 1, characterized by that the number of single-zone heating modules can be greater than one depending on the available heating area. [4] Manufacturing method according to claim 3, characterized bythat if the number of single-zone heating modules is greater than one, several of the single-zone heating modules are connected in parallel or in series. [5] Manufacturing method according to claim 3, characterized by that steps 1-3 further comprise: adjusting the number of single-zone heating modules and adaptively adjusting the width, length, thickness, spacing and resistance current carrying capacity of the single-zone heating modules through multiple calculations to determine the number of single-zone heating modules with the highest efficiency. [6] Manufacturing method according to claim 5, characterized by that step 1-3 further includes logging the specific parameters obtained in each calculation in order to update the empirical formula. [7] Heating device manufactured according to a manufacturing method of claims 1 to 6, characterized byin that the heating device further comprises a temperature-controlled system for area control which is adapted according to the parameters of the transformer, the number of temperature-controlled area control systems being less than or equal to the number of transformers, the heating device being usable for: direct surface contact heating, external contact heating, internal radiant heating, convection heating and indirect heating by means of a medium, the indirect heating by means of a medium consisting in that the heating device heats a medium such as a liquid or a gas and the heated medium is in turn used to heat the object to be heated. [8] Heating device according to claim 7, characterized by that the object of surface direct contact heating includes both solid bodies and liquids. [9] Heating device according to claim 7, characterized bythat surface direct contact heating, external contact heating, internal radiant heating, convection heating and indirect heating by means of a medium can be used in combination depending on the actual work requirements. [10] Assembly method for a heating device manufactured according to a manufacturing method of claims 1 to 6, characterized byAccording to the design, the two ends of the low-voltage high-current single-zone heating module are connected with two sets of matching cables, or individually connected to the two inputs and outputs of an isolation transformer, or the two ends of multiple single-zone heating modules are wired in parallel or series with multiple sets of matching cables and then connected to the two input and output terminals of the isolation transformer, and finally the 220V or 380V power supply is connected to the isolation transformer with matching cables; then the temperature control system monitors the temperature change inside the heat treatment equipment and controls the transformer in real time to ensure a precise temperature.

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