Multi-section temperature control electromagnetic heating system for hydrogen production through methanol reforming

Abstract

The invention relates to the technical field of methanol reforming devices, and discloses a multi-section temperature control electromagnetic heating system for hydrogen production through methanol reforming. Comprising an electromagnetic induction inner heating piece, an electromagnetic induction outer heating piece, a temperature equalizing pipe arranged on the outer wall of the electromagnetic induction outer heating piece and an electromagnetic coil arranged on the outer wall of the temperature equalizing pipe which are sequentially arranged from inside to outside, and a distance is reserved between the electromagnetic induction inner heating piece and the electromagnetic induction outer heating piece to define a reaction space; a connecting piece is connected between the electromagnetic induction inner heating piece and the electromagnetic induction outer heating piece, and catalyst particles are loaded on the outer wall of the connecting piece. According to the application, the uniformity of the temperature in the reaction space can be improved, and cold spots are reduced, so that the efficiency of the catalyst and the overall reaction efficiency are improved.

Description

Technical Field

[0001] The present application relates to the technical field of methanol reforming devices, and in particular to a multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen. Background Art

[0002] Hydrogen energy is the most ideal clean energy in the world, with the advantages of high energy density, high calorific value, renewable, zero pollution, zero carbon emission, wide sources and rich application scenarios. Compared with traditional natural gas hydrogen production, methanol steam reforming hydrogen production has the advantages of low investment, simple equipment, easy storage and transportation, high hydrogen content in product gas, and methanol raw materials can be produced from renewable resources. It can provide a reliable hydrogen source for fuel cells and has great application potential in distributed energy storage, new energy vehicles, communication stations and other fields.

[0003] The methanol steam reforming reaction is a highly endothermic reaction, which requires a constant supply of heat to maintain the reaction. Therefore, the reaction device needs to maintain a suitable high reaction temperature and have a good response speed to meet the integrated application of hydrogen production and use.

[0004] The traditional tubular reactor provides heat for the methanol reforming hydrogen production reaction through high-temperature fluid heat exchange. Due to the heat transfer limitation of the reactor, the endothermic heat of the reaction cannot be supplied enough, so the endothermic reaction causes the temperature to drop, forming a cold spot, and a temperature gradient appears in the entire bed. Under the action of this temperature gradient, the temperature of some catalysts or even most catalysts cannot reach the optimal operating temperature. The catalyst activity cannot be fully exerted, further reducing the effective utilization rate of the catalyst, thereby affecting the hydrogen production efficiency. Therefore, there is still a lot of room for improvement in the current methanol steam reforming hydrogen production device. Summary of the invention

[0005] In order to reduce the reduction in catalyst efficiency caused by uneven temperature in the reactor, the present application provides a multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen.

[0006] This application adopts the following technical solutions: A multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen comprises an electromagnetic induction inner heating element, an electromagnetic induction outer heating element, a temperature-equalizing tube arranged on the outer wall of the electromagnetic induction outer heating element, and an electromagnetic coil arranged on the outer wall of the temperature-equalizing tube, which are arranged in sequence from the inside to the outside; a distance is left between the electromagnetic induction inner heating element and the electromagnetic induction outer heating element to enclose a reaction space; a connecting element is connected between the electromagnetic induction inner heating element and the electromagnetic induction outer heating element, and the outer wall of the connecting element is loaded with catalyst particles.

[0007] By adopting the above technical scheme, under the action of the electromagnetic coil, the electromagnetic induction inner heating element and the electromagnetic induction outer heating element can generate eddy current effect and heat up. The electromagnetic induction inner heating element and the electromagnetic induction outer heating element are connected by a connecting piece, and a reaction space is formed, so that heat can be provided for methanol reforming, and uniform heating can be performed along the axial direction of the electromagnetic induction inner heating element and the electromagnetic induction outer heating element, thereby reducing the problem of uneven temperature during the reaction process, so that the catalyst can catalyze the reaction more effectively.

[0008] Optionally, it also includes a magnetic isolation shell, which is coated on the electromagnetic coil.

[0009] By adopting the above technical solution, the magnetic isolation housing can ensure that no magnetic field loss occurs in the non-working direction of the electromagnetic coil, thereby ensuring the maximum utilization of the induction heating efficiency and further improving the heating effect.

[0010] Optionally, the outer wall of the magnetic isolation shell is provided with a heat isolation shell.

[0011] By adopting the above technical solution, the heat-insulating shell is located at the outermost layer, and the heat-insulating shell can keep the entire device warm and reduce heat loss.

[0012] Optionally, the electromagnetic induction inner heating element and the electromagnetic induction outer heating element are both hollow tubular structures.

[0013] By adopting the above technical scheme, the electromagnetic induction inner heating element and the electromagnetic induction outer heating element are tubular structures, and adopt a sleeve-type structure. The electromagnetic induction inner heating element and the electromagnetic induction outer heating element can provide heat for the methanol reforming reaction, which is beneficial to reducing the radial temperature difference of the reactor; and the electromagnetic induction inner heating element is a hollow structure, so that its cavity part can have a better insulation effect, and can better supplement heat when the temperature difference of the reaction space changes.

[0014] Optionally, the electromagnetic coil is provided with at least three sections on the outer wall of the temperature equalizing tube, and the electromagnetic coils are independent of each other. The inner wall of the electromagnetic induction internal heating element and the inner wall of the electromagnetic induction external heating element are both provided with temperature sensors, and the temperature sensor corresponds to each section of the electromagnetic coil. The temperature sensor is connected to a control power supply of the electromagnetic coil to adjust the output power of the electromagnetic coil by detecting the temperature.

[0015] By adopting the above technical solution, both the electromagnetic induction internal heating element and the electromagnetic induction external heating element are provided with temperature sensors, which can control the output power of the corresponding electromagnetic coil according to the temperature feedback unit, adjust the temperature of the electromagnetic induction internal and external heating tubes, and keep the overall temperature of the system consistent.

[0016] Optionally, the temperature control step is: S1: collect the temperature Ti of each electromagnetic coil through the temperature sensor; S2: Calculate the system average temperature Tave; S3: Calculate the difference ∆T between the temperature corresponding to each electromagnetic coil and the average temperature of the system, ∆T=Tave-Ti; S4: Determine whether ∆T is greater than Ta, where Ta is a preset temperature difference threshold. If ∆T is greater than Ta, increase the power output of the electromagnetic coil in this section until the temperature difference is less than the set temperature difference threshold Ta. If it is less than Ta, do not adjust the output power of the electromagnetic coil in this section.

[0017] Optionally, a plurality of the connecting members are arranged at intervals along the circumferential direction of the electromagnetic induction internal heating member, and a plurality of the connecting members are arranged at intervals along the length direction of the electromagnetic induction internal heating member.

[0018] By adopting the above technical solution, multiple connectors are provided, and catalyst microparticles are evenly fixed on the outer wall of the connector. When the reaction fluid flows through the connector, a reforming reaction occurs, which reduces the mass transfer distance and mass transfer resistance and improves the effective utilization rate of the catalyst.

[0019] Optionally, the connecting piece is a tubular structure with a hollow interior.

[0020] In summary, the present application includes at least one of the following beneficial effects: 1. The multi-stage electromagnetic coil heating structure is adopted. Under the action of electromagnetic induction, both the electromagnetic induction inner heating element and the electromagnetic induction outer heating element will generate eddy current effect to provide heat for the methanol reforming reaction. The surface of the electromagnetic induction outer heating element is provided with a temperature-averaging tube, which can reduce the temperature difference of each part more quickly and make the temperature more uniform. In addition, since induction heating can generate heat uniformly in the axial direction of the heating part, the axial temperature difference of the reformer will be greatly reduced. 2. The sleeve-type structure is adopted. Both the electromagnetic induction internal heating element and the electromagnetic induction external heating element can provide heat for the methanol reforming reaction, which is beneficial to reduce the radial temperature difference of the reactor; (3) Both the electromagnetic induction internal heating element and the electromagnetic induction external heating element are equipped with temperature sensors, which can control the output power of the corresponding electromagnetic coils according to the temperature feedback unit, adjust the heating temperature of the electromagnetic induction, and keep the overall temperature of the system consistent; (4) The catalyst microparticles are evenly fixed on the surface of the connector. When the reaction fluid flows through the membrane pores, a reforming reaction occurs, which reduces the mass transfer distance and mass transfer resistance and improves the effective utilization of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of an embodiment of the present application; Figure 2 is a cross-sectional schematic diagram of an embodiment of the present application; Figure 3 It is a logical schematic diagram of the temperature sensor in the embodiment of the present application.

[0022] Explanation of the accompanying drawings: 1. Electromagnetic induction internal heating element; 2. Electromagnetic induction external heating element; 3. Temperature equalizing tube; 4. Electromagnetic coil; 5. Connecting piece; 6. Magnetic insulation shell; 7. Thermal insulation shell; 8. Temperature sensor. DETAILED DESCRIPTION

[0023] The following is combined with Figure 1-3 This application is described in further detail.

[0024] The present application embodiment discloses a multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen. Figure 1 and Figure 2 The heating system of the present application includes an electromagnetic induction inner heating element 1, an electromagnetic induction outer heating element 2, a temperature-averaging tube 3 arranged on the outer wall of the electromagnetic induction outer heating element 2, and an electromagnetic coil 4 arranged on the outer wall of the temperature-averaging tube 3, which are arranged in sequence from the inside to the outside. The electromagnetic induction inner heating element 1 and the electromagnetic induction inner and outer heating elements are both hollow cylindrical structures, and the two are coaxially arranged.

[0025] A connector 5 is connected between the electromagnetic induction inner heating element 1 and the electromagnetic induction outer heating element 2, and there is a certain distance between the electromagnetic induction inner heating element 1 and the electromagnetic induction outer heating element 2, so that the two enclose a reaction space. The connector 5 is a tubular structure, and multiple connectors 5 are arranged at intervals along the circumference of the electromagnetic induction inner heating element 1, and multiple connectors are arranged along the axial direction of the electromagnetic induction inner heating element 1. One end of the connector 5 is welded to the surface of the electromagnetic induction inner heating element 1, and the other end is welded to the inner wall of the electromagnetic induction outer heating element 2. Furthermore, the outer wall of the connector 5 is provided with micro-channels penetrating the tube wall, and the catalyst particles are filled in the micro-channels. When the reactants enter the reaction space, a catalytic reaction can be carried out by the catalyst.

[0026] The electromagnetic induction inner heating element 1 and the electromagnetic induction outer heating element 2 are both made of metal materials that can generate heat under the action of electromagnetic induction. Through the joint heating action of the electromagnetic induction inner heating element 1 and the electromagnetic induction outer heating element 2, the uniformity of heating is improved and the radial temperature difference in the reaction space is reduced. Furthermore, the temperature-averaging tube 3 is sleeved on the outer wall of the electromagnetic induction outer heating element 2 and fits closely with the outer wall of the electromagnetic induction outer heating element 2, so that the temperature difference of each part is rapidly reduced, thereby making the temperature more uniform.

[0027] In the present embodiment, the electromagnetic coil 4 is connected to an external variable frequency induction heating circuit, and the operation of the electromagnetic coil 4 is controlled by the variable frequency induction heating circuit. The variable frequency induction heating circuit mainly includes a three-phase AC power supply, a rectifier circuit, a filter, an inverter, and a load circuit. The rectifier circuit can convert the three-phase AC power supply into DC power. The rectifier circuit adopts a three-phase bridge uncontrolled rectifier circuit, which can reduce the complexity of power regulation. The filter adopts a large capacitor to stabilize the DC voltage. The inverter can convert DC power into AC power. The inverter adopts a series resonant circuit, which can convert DC power into AC power, can reduce switching losses, is suitable for frequent startup, and is convenient for adjusting the inverter output power through the inverter side power regulation.

[0028] In a further embodiment, the heating system further comprises a magnetic-insulating shell 6, which is a cylindrical structure, and is sleeved on the outer wall of the electromagnetic coil 4 and wraps the electromagnetic coil 4. The magnetic-insulating shell 6 is selected from magnetic-insulating materials, and the magnetic-insulating shell 6 can ensure that the non-working direction of the electromagnetic coil 4 does not generate magnetic field loss, thereby ensuring the maximum utilization of the induction heating efficiency. Furthermore, the outer wall of the magnetic-insulating shell 6 is sleeved with a heat-insulating shell 7, which is located at the outermost layer of the overall device and can insulate and keep the overall device warm.

[0029] In a further embodiment, at least three sections of electromagnetic coils 4 are provided on the outer wall of the temperature-averaging tube 3, and the electromagnetic coils 4 are independent of each other to control the output power therein respectively. In this embodiment, three sections of electromagnetic coils 4 are used for illustration. Temperature sensors 8 are provided on the inner walls of the electromagnetic induction internal heating element 1 and the electromagnetic induction external heating element 2, and the temperature sensors 8 correspond to the electromagnetic coils 4 of each section. The temperature sensor 8 is connected to the control power supply of the corresponding electromagnetic coil 4, and the output power of the electromagnetic coil 4 is adjusted by detecting the temperature of the corresponding position through the temperature sensor 8, so as to facilitate the control of the temperature.

[0030] Combination Figure 3 , the temperature control steps are: S1: collecting the temperature Ti of each electromagnetic coil 4 through the temperature sensor 8; S2: Determine the system average temperature Tave; S3: Calculate the difference ∆T between the temperature corresponding to each section of the electromagnetic coil 4 and the average temperature of the system, ∆T=Tave-Ti; S4: Determine whether ∆T is greater than Ta, where Ta is a preset temperature difference threshold. If ∆T is greater than Ta, increase the power output of the electromagnetic coil 4 in this section until the temperature difference is less than the set temperature difference threshold Ta. If it is less than Ta, do not adjust the output power of the electromagnetic coil 4 in this section. After increasing the power of the electromagnetic coil 4, continue to perform cyclic detection after a certain delay, such as 30s, 60s, 120s, etc. In this embodiment, 120s is selected.

[0031] The implementation principle of a multi-stage temperature-controlled electromagnetic heating system for methanol reforming hydrogen production in the embodiment of the present application is as follows: a multi-stage electromagnetic coil 4 heating structure is adopted. Under the action of electromagnetic induction, the electromagnetic induction inner heating element 1 and the electromagnetic induction outer heating element 2 will generate eddy current effect to provide heat for the methanol reforming reaction; the surface of the electromagnetic induction outer heating tube is provided with a temperature-equalizing tube 3, which can reduce the temperature difference of each part more quickly so that the temperature is more uniform, and because the induction heating can realize the uniform generation of heat in the axial direction of the membrane tube, the axial temperature difference of the reformer will be greatly reduced. The magnetic induction inner heating element and the electromagnetic induction outer heating element 2 are coaxially arranged structures, and both can provide heat, thereby reducing the radial temperature difference during the reaction. Both the electromagnetic induction inner heating element and the electromagnetic induction outer heating element are provided with temperature sensors, which can control the output power of the corresponding electromagnetic coils according to the temperature feedback unit, adjust the heating temperature of the electromagnetic induction, and keep the overall temperature of the system consistent.

[0032] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen, characterized in that: The invention comprises an electromagnetic induction inner heating element (1), an electromagnetic induction outer heating element (2), a temperature-averaging tube (3) arranged on the outer wall of the electromagnetic induction outer heating element (2), and an electromagnetic coil (4) arranged on the outer wall of the temperature-averaging tube (3), wherein a distance is left between the electromagnetic induction inner heating element (1) and the electromagnetic induction outer heating element (2) to enclose a reaction space, and a connecting element (5) is connected between the electromagnetic induction inner heating element (1) and the electromagnetic induction outer heating element (2), and the outer wall of the connecting element (5) is loaded with catalyst particles.

2. A multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen according to claim 1, characterized in that: It also comprises a magnetic isolation shell (6), wherein the magnetic isolation shell (6) covers the electromagnetic coil (4).

3. A multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen according to claim 2, characterized in that: The outer wall of the magnetic isolation shell (6) is provided with a heat isolation shell (7).

4. A multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen according to claim 2, characterized in that: The electromagnetic induction inner heating element (1) and the electromagnetic induction outer heating element (2) are both hollow tubular structures.

5. The multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen according to claim 2, characterized in that: The electromagnetic coil (4) is provided with at least three sections on the outer wall of the temperature-averaging tube (3), and the electromagnetic coils (4) are independent of each other. The inner wall of the electromagnetic induction internal heating element (1) and the inner wall of the electromagnetic induction external heating element (2) are both provided with temperature sensors (8), and the temperature sensors (8) correspond to each section of the electromagnetic coil (4). The temperature sensors (8) are connected to a control power supply of the electromagnetic coil (4) so ​​as to adjust the output power of the electromagnetic coil (4) by detecting the temperature.

6. A multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen according to claim 5, characterized in that: The temperature control step is: S1: collecting the temperature Ti corresponding to each electromagnetic coil (4) through a temperature sensor (8); S2: Calculate the system average temperature Tave; S3: Calculate the difference ∆T between the temperature corresponding to each electromagnetic coil (4) and the average temperature of the system, ∆T=Tave-Ti; S4: determining whether ∆T is greater than Ta, where Ta is a preset temperature difference threshold value. If ∆T is greater than Ta, the power output of the electromagnetic coil (4) in this section is increased until the temperature difference is less than the preset temperature difference threshold value Ta. If the temperature difference is less than the preset temperature difference threshold value Ta, the output power of the electromagnetic coil (4) in this section is not adjusted.

7. A multi-stage temperature-controlled electromagnetic heating system for methanol reforming to produce hydrogen according to claim 6, characterized in that: A plurality of the connecting members (5) are arranged at intervals along the circumference of the electromagnetic induction internal heating member (1), and a plurality of the connecting members (5) are arranged at intervals along the length direction of the electromagnetic induction internal heating member (1).

8. A multi-stage temperature-controlled electromagnetic heating system for hydrogen production by methanol reforming according to claim 7, characterized in that: The connecting piece (5) is a tubular structure with a hollow interior.

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