An electromagnetic induction electric heater

Abstract

The present invention discloses an electromagnetic induction electric heater, which is applied to the field of electric heaters and includes a spiral coil thermocouple, an insulating layer, an inlet pipe thermocouple, an inlet pipe mass flow controller, an inlet pipe, an outlet pipe, an outlet pipe mass flow controller, an outlet pipe thermocouple, an electromagnetic induction coil, an electromagnetic controller, an inner spiral coil and an outer spiral coil; the present invention is used in a solid oxide electrolysis cell system and can heat water, hydrogen, air, etc. to 600-800°C. The electric heater generates heat by electromagnetic induction, reduces thermal resistance, and improves the economic efficiency of the electric heater. The fluid of the present invention flows in the tube, reduces the risk of leakage, increases insulation, and increases the safety of the electric heater.

Description

Technical Field

[0001] The present invention relates to the technical field of electric heaters, and in particular to an electromagnetic induction electric heater. Background Art

[0002] Reversible solid oxide fuel cells (RSOFCs) are fuel cells that combine power generation and electrolysis. When electricity is needed, RSOFCs consume hydrogen to generate electricity. When hydrogen is needed, RSOFCs consume electricity and electrolyze water vapor to produce hydrogen. RSOFCs are high-temperature fuel cells. Compared to other electrolytic cells, solid oxide electrolyzers offer advantages such as high efficiency and a fully solid-state structure, making them highly promising.

[0003] In reversible solid oxide fuel cell systems, electric heaters are required to heat water, hydrogen, and air to temperatures between 600 and 800°C, posing significant performance challenges. Traditional electric heaters consist of a heating wire made of iron, chromium, and aluminum, coated with magnesium oxide powder, then encased in a protective metal shell. Due to the high thermal conductivity of the magnesium oxide powder and the low temperature tolerance of the iron, chromium, and aluminum materials over extended periods of operation, heating media like water and gas to temperatures above 500°C is difficult, and there are risks of overheating and electrical leakage. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide an electromagnetic induction electric heater. The electric heater uses an induction coil and a spiral coil to achieve the heating of fluids that undergo phase change during the heating process, such as high-temperature water vapor, and fluids that do not undergo phase change during the heating process, such as hydrogen. The electric heater generates heat through electromagnetic induction, reduces thermal resistance, improves insulation, and has the advantages of high efficiency and safety.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An electromagnetic induction electric heater, comprising: a spiral coil thermocouple 1, an insulating layer 2, an inlet pipe thermocouple 3, an inlet pipe mass flow controller 4, an inlet pipe 5, an outlet pipe 6, an outlet pipe mass flow controller 7, an outlet pipe thermocouple 8, an electromagnetic induction coil 9, an electromagnetic controller 10, an inner spiral coil 11, and an outer spiral coil 12;

[0007] Among them, the electromagnetic induction coil 9, the inner spiral coil 11, the outer spiral coil 12 and the electromagnetic controller 10 constitute an electromagnetic heater; the insulating layer 2 is located between the inner spiral coil 11, the outer spiral coil 12 and the electromagnetic induction coil 9, and the electromagnetic induction coil 9 is tightly wound around the outside of the inner spiral coil 11 and the outer spiral coil 12; the electromagnetic controller 10 is located at the bottom of the electromagnetic induction coil 9, the inner spiral coil 11 and the outer spiral coil 12 and is connected to the electromagnetic induction coil 9. This arrangement is conducive to improving the compactness of the electromagnetic heater; the spiral coil thermocouple 1 is arranged on the inner spiral coil 11 and the outer spiral coil 12 and is connected to the electromagnetic controller 10. It is a protective device of the electromagnetic heater. When the wall temperature of the spiral coil is too high, the electromagnetic controller 10 will reduce or cut off the current, thereby reducing the power or shutting down the electromagnetic heater.

[0008] The inlet pipe 5 is connected to the outer spiral coil 12 via the inlet pipe mass flow controller 4 and the inlet pipe thermocouple 3. The inner spiral coil 11 and the outer spiral coil 12 have different pipe diameters. The inner spiral coil 11 is connected to the outlet pipe 6 via the outlet pipe thermocouple 8 and the outlet pipe mass flow controller 7.

[0009] The electromagnetic controller 10 generates an alternating current and passes it into the electromagnetic induction coil 9. The electromagnetic induction coil 9 generates an alternating magnetic field to cut the inner spiral coil 11 and the outer spiral coil 12. The inner spiral coil 11 and the outer spiral coil 12 will generate an induced electromotive force and thus generate an induced current. Due to the generation of the induced current, the inner spiral coil 11 and the outer spiral coil 12 generate Joule heat, which is transferred to the gas inside the inner spiral coil 11 and the outer spiral coil 12 through fluid convection, thereby increasing the gas temperature.

[0010] The electromagnetic induction coil (9) is wound axially along the inner side of the inner spiral coil 11 and the outer side of the outer spiral coil 12; not only does the electromagnetic induction coil (9) enable the inner spiral coil 11 and the outer spiral coil 12 to be heated uniformly, but it also provides a basis for configuring the double-layer spiral coil, thereby enhancing the structural compactness of the electromagnetic induction heater.

[0011] The inner spiral coil 11 and the outer spiral coil 12 have different tube diameters. The outer diameter of the inner spiral coil 11 is D, D is 8mm to 20mm, and the tube wall thickness is 0.1D to 0.2D, and the outer diameter of the outer spiral coil 12 is 2D. When heating a fluid without phase change during the heating process, the fluid flows into the outer spiral coil 12 and flows out of the inner spiral coil 11, and the heating tube diameter changes from 2D to D, the gas flow rate increases and the convective heat transfer thermal resistance decreases. When the same heat power is transmitted, the reduction in convective thermal resistance reduces the wall temperature of the spiral coil, thereby improving the safety of the electromagnetic heater. When heating a fluid with phase change during the heating process, the fluid flows into the inner spiral coil 11 and flows out of the outer spiral coil 12, and the heating tube diameter changes from D to 2D, reducing the flow rate, reducing the resistance loss along the flow, reducing the pipeline pressure, reducing the pump work, and improving the safety of the electromagnetic heater.

[0012] The fluid that undergoes phase change during the heating process is high-temperature water vapor, and the fluid that does not undergo phase change during the heating process is hydrogen, air, nitrogen, or methane.

[0013] Since the flow controller can only measure and control the flow of low-temperature fluid, flow controllers are arranged on the inlet pipe 5 and the outlet pipe 6, namely the inlet pipe mass flow controller 4 and the outlet pipe mass flow controller 7. Therefore, no matter whether the fluid flows into from the inlet pipe 5 or the outlet pipe 6, the fluid flow can be measured and controlled; the inlet pipe thermocouple 3 and the outlet pipe thermocouple 8 are both working, and the inlet pipe mass flow controller 4 and the outlet pipe mass flow controller 7 work selectively; through the cooperation of the inlet pipe thermocouple 3, the outlet pipe thermocouple 8, the inlet pipe mass flow controller 4, the outlet pipe mass flow controller 7 and the electromagnetic controller 10, the control of the electromagnetic heater power, fluid flow and fluid outlet temperature is achieved.

[0014] The spiral coil thermocouple 1 is welded to the inner spiral coil 11 and the outer spiral coil 12 .

[0015] The insulating and heat-preserving layer 2 plays the role of insulation and heat preservation. When the electromagnetic heater is working, the temperature of the outer spiral coil 12 is high, and the insulating and heat-preserving layer 2 protects the electromagnetic induction coil 9 from overheating.

[0016] The inner spiral coil 11 and the outer spiral coil 12 are connected by welding.

[0017] The present invention has the following advantages and beneficial effects:

[0018] 1. The present invention provides an electromagnetic induction electric heater, which realizes the new function of ultra-high temperature heating of fluids with phase change during heating, such as water vapor, and fluids without phase change during heating, such as hydrogen, through induction coils and spiral coils.

[0019] 2. The present invention provides an electromagnetic induction electric heater, which generates heat through electromagnetic induction, reduces thermal resistance, improves the heating efficiency of the electric heater, and improves economy.

[0020] 3. The present invention provides an electromagnetic induction electric heater, which generates heat through electromagnetic induction, does not require an intermediate heat-conducting medium, and improves insulation. The fluid flows in the tube without leakage risk, thereby improving the safety of the electric heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an overall schematic diagram of the electromagnetic induction electric heater.

[0022] Figure 2 This is the working principle diagram of the electromagnetic induction electric heater.

[0023] Figure 3 Schematic diagram of electromagnetic induction coil.

[0024] Figure 4 Schematic diagram of the electromagnetic induction heater spiral coil.

[0025] Figure 5 This is the schematic diagram of the bidirectional spiral coil heating.

[0026] In the figure: 1- spiral coil thermocouple, 2- insulation layer, 3- inlet pipe thermocouple, 4- inlet pipe mass flow controller, 5- inlet pipe, 6- outlet pipe, 7- outlet pipe mass flow controller, 8- outlet pipe thermocouple, 9- electromagnetic induction coil, 10- electromagnetic controller, 11- inner spiral coil, 12- outer spiral coil DETAILED DESCRIPTION

[0027] The present invention will be described in further detail below with reference to the accompanying drawings.

[0028] like Figure 1As shown, the electromagnetic induction electric heater of the present invention includes: a spiral coil thermocouple 1, an insulating layer 2, an inlet pipe thermocouple 3, an inlet pipe mass flow controller 4, an inlet pipe 5, an outlet pipe 6, an outlet pipe mass flow controller 7, an outlet pipe thermocouple 8, an electromagnetic induction coil 9, an electromagnetic controller 10, an inner spiral coil 11, and an outer spiral coil 12. The electromagnetic heater is composed of the electromagnetic induction coil 9, the inner spiral coil 11, the outer spiral coil 12, and the electromagnetic controller 10. The electromagnetic induction coil 9 is wound around the outer side of the insulating layer 2, and the insulating layer 2 is tightly wound around the outer sides of the inner spiral coil 11 and the outer spiral coil 12. The insulating and heat-preserving layer 2 is located between the inner spiral coil 11 and the outer spiral coil 12 and the electromagnetic induction coil 9, and the electromagnetic induction coil 9 is tightly wound around the outer side of the inner spiral coil 11 and the outer spiral coil 12, playing the role of insulation and heat preservation. When the electromagnetic heater is working, the temperature of the outer spiral coil 12 is relatively high, and the insulating and heat-preserving layer 2 can protect the electromagnetic induction coil 9 from overheating. The electromagnetic controller 10 is located at the bottom of the electromagnetic induction coil 9, the inner spiral coil 11, the outer spiral coil 12, etc. This arrangement is conducive to improving the compactness of the electric heater. The spiral coil thermocouple 1 is welded to the inner spiral coil 11 and the outer spiral coil 12 and connected to the electromagnetic controller 10. It is a protective device for the electric heater. When the wall temperature of the spiral coil is too high, the electromagnetic controller 10 will reduce or cut off the current, thereby reducing the power or shutting down the electromagnetic heater.

[0029] like Figure 2 The electromagnetic controller 10 generates an alternating current and passes it into the electromagnetic induction coil 9. The electromagnetic induction coil 9 generates an alternating magnetic field to cut the inner spiral coil 11 and the outer spiral coil 12. The inner spiral coil 11 and the outer spiral coil 12 will generate an induced electromotive force and thus generate an induced current. Due to the generation of the induced current, the inner spiral coil 11 and the outer spiral coil 12 generate Joule heat, which is transferred to the gas inside the inner spiral coil 11 and the outer spiral coil 12 through fluid convection, thereby increasing the gas temperature.

[0030] like Figure 3 , unlike the conventional electromagnetic induction coil 9 which is wound circumferentially on the outside of the outer spiral coil 12, the electromagnetic induction coil 9 of the present invention is wound axially along the inside of the inner spiral coil 11 and the outside of the outer spiral coil 12. This winding method enables the electromagnetic induction coil 9 to uniformly heat the inner spiral coil 11 and the outer spiral coil 12, making it possible to arrange the inner spiral coil 11 and the outer spiral coil 12 in two layers, thereby improving the compactness of the electromagnetic induction heater. On the other hand, the axially wound electromagnetic induction coil 9 can generate a uniform and stable electromagnetic field inside the electromagnetic induction coil 9, which can uniformly heat the inner spiral coil 11 and the outer spiral coil 12.

[0031] like Figure 4 The inlet pipe 5 is connected to the outer spiral coil 12 via the inlet pipe mass flow controller 4 and the inlet pipe thermocouple 3. The inner spiral coil 11 is welded to the outer spiral coil 12. The inner spiral coil 11 is connected to the outlet pipe 6 via the outlet pipe thermocouple 8 and the outlet pipe mass flow controller 7. The inner spiral coil 11 and the outer spiral coil 12 have different diameters. The outer diameter of the inner spiral coil 11 is D, which ranges from 8 mm to 20 mm, and the wall thickness is 0.1D to 0.2D. The diameter of the outer spiral coil 12 is 2D.

[0032] like Figure 4 Since the flow controller can only measure and control the flow of low-temperature fluid, flow controllers are arranged on both the inlet pipe 5 and the outlet pipe 6, namely the inlet pipe mass flow controller 4 and the outlet pipe mass flow controller 7. Therefore, no matter whether the fluid flows into the inlet pipe 5 or the outlet pipe 6, the fluid flow can be measured and controlled. The inlet pipe thermocouple 3 and the outlet pipe thermocouple 8 are both working. The inlet pipe mass flow controller 4 and the outlet pipe mass flow controller 7 work selectively. Whether they work depends on the temperature measured by the thermocouples near them. For example, when the temperature measured by the inlet pipe thermocouple 3 is less than 50°C, the inlet pipe mass flow controller 4 works and the outlet pipe mass flow controller 7 does not work. Through the coordination of the inlet pipe thermocouple 3, the outlet pipe thermocouple 8, the inlet pipe mass flow controller 4, the outlet pipe mass flow controller 7, and the electromagnetic controller 10, the electromagnetic heater power, fluid flow, and fluid outlet temperature can be controlled.

[0033] like Figure 5 When heating a fluid such as hydrogen that does not change phase during the heating process, the fluid flows from the outer spiral coil 12 with a tube diameter of 2D into the inner spiral coil 11 with a tube diameter of D. The gas mass flow rate remains unchanged during the heating process, but as the tube diameter changes from 2D to D, the gas flow rate increases and the convective heat transfer thermal resistance decreases. When the same heat power is transmitted, the reduction in convective heat resistance can reduce the wall temperature of the spiral coil and improve the safety of the electromagnetic heater.

[0034] When heating a fluid that undergoes a phase change during heating, such as water, the fluid flows from the inner spiral coil 11, with a diameter of D, into the outer spiral coil 12, with a diameter of 2D. During the heating process, the fluid undergoes a phase change. Although the fluid mass flow rate remains unchanged, the volume flow rate increases hundreds or thousands of times, leading to a rapid increase in flow velocity. Changing the pipe diameter from D to 2D reduces the flow velocity, reduces the resistance loss along the flow path, lowers pipeline pressure, reduces pump work, and improves the safety of the electromagnetic heater.

[0035] The electromagnetic induction electric heater of the present invention can be used in a solid oxide electrolysis cell system to heat water, hydrogen, air, and other materials to 600-800°C. This electric heater generates heat through electromagnetic induction, reducing thermal resistance and improving the heater's economic efficiency. The fluid flows within the tube, reducing the risk of leakage, improving insulation, and enhancing the heater's safety.

Claims

1. An electromagnetic induction electric heater, characterized in that: include: A spiral coil thermocouple (1), an insulating layer (2), an inlet pipe thermocouple (3), an inlet pipe mass flow controller (4), an inlet pipe (5), an outlet pipe (6), an outlet pipe mass flow controller (7), an outlet pipe thermocouple (8), an electromagnetic induction coil (9), an electromagnetic controller (10), an inner spiral coil (11), and an outer spiral coil (12); The electromagnetic induction coil (9), the inner spiral coil (11), the outer spiral coil (12) and the electromagnetic controller (10) constitute an electromagnetic heater; the insulating layer (2) is located between the inner spiral coil (11), the outer spiral coil (12) and the electromagnetic induction coil (9), and the electromagnetic induction coil (9) is tightly wound around the outer sides of the inner spiral coil (11) and the outer spiral coil (12); the electromagnetic controller (10) is located at the bottom of the electromagnetic induction coil (9), the inner spiral coil (11) and the outer spiral coil (12) and is connected to the electromagnetic induction coil (9), and this arrangement is conducive to improving the compactness of the electromagnetic heater; the spiral coil thermocouple (1) is arranged on the inner spiral coil (11) and the outer spiral coil (12) and is connected to the electromagnetic controller (10), and is a protective device of the electromagnetic heater. When the wall temperature of the spiral coil is too high, the electromagnetic controller (10) will reduce or cut off the current, thereby achieving power reduction or shutdown of the electromagnetic heater; The inlet pipe (5) is connected to the outer spiral coil (12) via the inlet pipe mass flow controller (4) and the inlet pipe thermocouple (3); the inner spiral coil (11) and the outer spiral coil (12) have different pipe diameters; the inner spiral coil (11) is connected to the outlet pipe (6) via the outlet pipe thermocouple (8) and the outlet pipe mass flow controller (7); The electromagnetic controller (10) generates an alternating current and passes it into the electromagnetic induction coil (9). The electromagnetic induction coil (9) generates an alternating magnetic field to cut the inner spiral coil (11) and the outer spiral coil (12). The inner spiral coil (11) and the outer spiral coil (12) generate an induced electromotive force and thus generate an induced current. Due to the generation of the induced current, the inner spiral coil (11) and the outer spiral coil (12) generate Joule heat. The Joule heat is transferred to the gas inside the inner spiral coil (11) and the outer spiral coil (12) by fluid convection, thereby increasing the temperature of the gas. The inner spiral coil (11) and the outer spiral coil (12) have different tube diameters. The outer diameter of the inner spiral coil (11) is D, which is 8 mm to 20 mm, and the tube wall thickness is 0.1D to 0.2D. The outer diameter of the outer spiral coil (12) is 2D. When heating a fluid without phase change during the heating process, the fluid flows from the outer spiral coil (12) and flows out of the inner spiral coil (11). The heating tube diameter changes from 2D to D, the gas flow rate increases, the convective heat transfer thermal resistance decreases, and the same heat power is transmitted. The reduction in convective heat resistance reduces the wall temperature of the spiral coil, thereby improving the safety of the electromagnetic heater. When heating a fluid with phase change during the heating process, the fluid flows from the inner spiral coil (11) and flows out of the outer spiral coil (12). The heating tube diameter changes from D to 2D, reducing the flow rate, reducing the flow resistance loss along the way, reducing the pipeline pressure, reducing the pump work, and improving the safety of the electromagnetic heater.

2. The electromagnetic induction electric heater according to claim 1, characterized in that: The electromagnetic induction coil (9) is wound axially along the inner side of the inner spiral coil (11) and the outer side of the outer spiral coil (12); not only does the electromagnetic induction coil (9) enable the inner spiral coil (11) and the outer spiral coil (12) to be uniformly heated, but it also provides a basis for configuring the double-layer spiral coil, thereby enhancing the structural compactness of the electromagnetic induction heater.

3. The electromagnetic induction electric heater according to claim 1, characterized in that: The fluid that undergoes phase change during the heating process is high-temperature water vapor, and the fluid that does not undergo phase change during the heating process is hydrogen, air, nitrogen, or methane.

4. The electromagnetic induction electric heater according to claim 1, characterized in that: Since the flow controller can only measure and control the flow of the cryogenic fluid, flow controllers are arranged on both the inlet pipe (5) and the outlet pipe (6), namely, the inlet pipe mass flow controller (4) and the outlet pipe mass flow controller (7). Therefore, when the fluid flows in from the inlet pipe (5) or the outlet pipe (6), the fluid flow can be measured and controlled; the inlet pipe thermocouple (3) and the outlet pipe thermocouple (8) are both in operation, and the inlet pipe mass flow controller (4) and the outlet pipe mass flow controller (7) work selectively; The electromagnetic heater power, fluid flow rate and fluid outlet temperature are controlled by cooperating with an inlet pipe thermocouple (3), an outlet pipe thermocouple (8), an inlet pipe mass flow controller (4), an outlet pipe mass flow controller (7) and an electromagnetic controller (10).

5. The electromagnetic induction electric heater according to claim 1, characterized in that: The spiral coil thermocouple (1) is welded to the inner spiral coil (11) and the outer spiral coil (12).

6. The electromagnetic induction electric heater according to claim 1, characterized in that: The insulating and heat-preserving layer (2) plays an insulating and heat-preserving role. When the electromagnetic heater is working, the temperature of the outer spiral coil (12) is high, and the insulating and heat-preserving layer (2) protects the electromagnetic induction coil (9) from overheating.

7. The electromagnetic induction electric heater according to claim 1, characterized in that: The inner layer spiral coil (11) and the outer layer spiral coil (12) are connected by welding.

Images