A helical heat matching reactor based on the increase of flow channel volume

Abstract

The application discloses a spiral heat matching reactor based on flow channel volume increase, and relates to the technical field of solar thermochemical technology.The application comprises a parabolic solar heat collector and a spiral heat matching reactor, wherein the spiral heat matching reactor is internally provided with an annular reaction flow channel, and the flow channel cross section gradually increases to adapt to the feature of the volume increase of the methane reforming reaction gas.The parabolic solar heat collector forms a circular non-uniform temperature light spot, and the multiple turns of the annular reaction flow channel are matched with the shape of the circular non-uniform temperature light spot to utilize the heat of the non-uniform temperature light spot.The application can directly utilize the non-uniform heat generated by the parabolic solar heat collector, and fully utilize the heat on the reactor for the methane reforming reaction, so that the methane conversion rate is improved.

Description

Technical Field

[0001] This invention discloses a spiral thermal matching reactor based on increased flow channel volume, belonging to the field of solar thermochemical technology, and particularly relating to solar thermal system reaction devices. Background Technology

[0002] With the development of the world economy, the consumption of fossil fuels has risen sharply, and energy and environmental problems have become increasingly serious. Therefore, the demand for a clean energy source to replace fossil fuels is constantly increasing. Hydrogen energy, as a high-calorific-value, renewable energy source, has received widespread attention from the global energy sector. Increasing the use of hydrogen energy can effectively alleviate the environmental and resource problems caused by fossil fuels.

[0003] Methane steam reforming is the most mature industrial hydrogen production technology, accounting for approximately 48% of the world's annual hydrogen production. It is a crucial pathway for hydrogen energy production. Multi-energy complementary technologies are an important method for addressing energy shortages. Combining solar energy and biogas with hydrogen production through methane steam reforming has broad application prospects.

[0004] The optimal reaction temperature for methane steam reforming is 850K-1000K. When solar energy is chosen to heat the reaction, a parabolic dish collector is preferable to collect solar radiation. However, parabolic dish collectors produce circular, non-uniform temperature spots, characterized by a high temperature in the center and a gradually decreasing temperature around the edges. This non-uniform heating can lead to problems such as localized overheating, shortening the reactor's lifespan.

[0005] A solar-driven gas reactor, published in Chinese Document No. CN117680048A, addresses the issue of circular, non-uniform temperature spots generated by dish solar collectors. It designs a spiral reactor whose temperature matches the spot temperature, allowing gas to flow in from the periphery and gradually utilize the spot temperature for reaction. However, this reactor does not consider the inherent characteristics of the methane steam reforming reaction, making it prone to pressure drop issues that can lead to flow channel blockage.

[0006] Methane steam reforming is a reaction in which the volume of gas increases. As the reaction proceeds, the number of moles of gas gradually increases. According to Le Chatelier's principle, under the same volume, an increase in the number of moles will lead to an increase in pressure, forcing the reaction equilibrium to shift to the left.

[0007] A solar-driven variable volume flow channel reactor (Chinese document publication number CN117772117A) incorporates the characteristics of methane steam reforming by designing a spiral reactor with gradually increasing flow channels to utilize the circular, non-uniform temperature and light spots generated by a dish collector. However, the reactor has large gaps between the flow channels, preventing the utilization of solar energy at these gaps, resulting in inefficient energy utilization.

[0008] Therefore, how to provide a reactor that can efficiently utilize solar energy and reduce the impact of the increase in gas volume during methane steam reforming on the reaction is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a spiral heat-matching reactor based on increased flow channel volume. This reactor is designed with an annular flow channel that gradually increases in volume according to the circular non-uniform temperature spot generated by the dish collector, which can make full use of the circular non-uniform temperature spot to improve the conversion rate of methane.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0011] A spiral heat-matching reactor based on increased flow channel volume, comprising:

[0012] Parabolic solar collectors provide energy for spiral heat-matching reactors;

[0013] The spiral heat matching reactor has an annular reaction channel inside. The annular reaction channel is composed of multiple interconnected channels, and the diameter of the multiple channels gradually increases from the periphery of the reactor to the center. The outermost ring of the annular reaction channel is connected to the feed pipe, and the innermost ring of the annular reaction channel is connected to the discharge pipe.

[0014] The parabolic solar collector forms a circular non-uniform temperature spot, which is composed of multiple rings with different temperatures. The multi-circulation flow channel of the annular reaction channel is matched with the shape of the circular non-uniform temperature spot to utilize the heat of the non-uniform temperature spot. Therefore, any design that utilizes the non-uniform temperature spot by matching the structure is within the scope of protection of this application.

[0015] Furthermore, the parabolic solar collector 1 generates a temperature range of 600K to 1300K to drive the methane reforming reaction in the spiral heat matching reactor; this collector can be replaced by a tower-type or trough-type collector.

[0016] Furthermore, the cross-section of the annular reaction channel gradually increases from the outer ring to the inner ring to mitigate the impact of increased gas volume and pressure on the methane reforming reaction and improve the methane conversion rate. Therefore, any design that improves the reaction conversion rate by changing the reactor channel space is within the scope of protection of this application.

[0017] Furthermore, the annular reaction channel is composed of five annular baffles with gradually increasing diameters connected together, and the circular non-uniform temperature spot is composed of multiple rings with different temperatures. The two are matched with each other to utilize the heat of the non-uniform temperature spot.

[0018] Furthermore, the spiral heat matching reactor includes a reactor shell and a set of annular baffles with different diameters inside it. The annular baffles divide the space inside the reactor shell to form an annular reaction channel. The annular baffles have 5 rings and together with the shell form an annular reaction channel.

[0019] Furthermore, the annular baffle includes a first ring plate, a second ring plate, a third ring plate, a fourth ring plate, a fifth ring plate, and a central component, arranged from the outside in. A connecting plate is radially arranged and sequentially connected to one end of the first ring plate, the second ring plate, the third ring plate, the fourth ring plate, and the fifth ring plate. The other end of each ring plate forms an opening from the adjacent outer ring to the inner ring with the connecting plate. The opening between the first ring plate and the connecting plate is a feed inlet connected to the feed pipe. The innermost ring is formed inside the fifth ring plate, and the innermost ring is connected to the discharge pipe.

[0020] Furthermore, the connecting plate extends to the innermost end and connects to the central component. The central component has a cylindrical structure and its side wall opening communicates with the innermost ring. The reactant enters the discharge pipe outward through the middle space of the central component.

[0021] Furthermore, the reactor shell is cylindrical to withstand greater hot gas pressure, and the annular baffle is 2mm thick and made of nickel-iron alloy 625, which has excellent thermal conductivity. This means that all the heat reflected to the bottom of the reactor shell can be used for the reaction, reducing heat waste. Therefore, the operation of reducing the volume of the baffle and using materials with better thermal conductivity to improve heat utilization efficiency is within the scope of protection of this patent.

[0022] Furthermore, a nickel-based alumina catalyst is uniformly arranged within the annular reaction channel.

[0023] Furthermore, the inlets of each channel in the annular reaction channel are angled at 8°, 8°, 12°, 14°, 25°, and 40° from the centerline of the spiral thermal matching reactor, respectively, so that the inlet width can match the channel width.

[0024] Compared with existing technologies, the present invention has the following advantages:

[0025] 1. The present invention provides a spiral heat matching reactor based on increased flow channel volume. By designing an annular flow channel that matches the circular non-uniform light spot generated by the dish collector, the reaction gas gradually flows from the lower temperature flow channel at the periphery into the higher temperature flow channel at the center, realizing the direct utilization of non-uniform temperature, homogenizing the temperature on the reactor, and extending the life of the reactor.

[0026] 2. The present invention provides a spiral heat-matching reactor based on increased flow channel volume. By using a baffle with negligible thickness, an annular gas reaction flow channel is designed, which makes full use of the space inside the reactor shell and can effectively improve the utilization efficiency of solar energy and the conversion rate of methane.

[0027] 3. The present invention provides a spiral heat-matching reactor based on the increase of flow channel volume. According to the fact that the methane reforming reaction is a reaction in which the gas volume increases, and the pressure increase in a fixed volume flow channel will force the equilibrium to shift to the left, the reactor is designed with a flow channel cross-section that gradually increases, thereby reducing the influence of pressure on the reaction equilibrium and further improving the methane conversion rate.

[0028] In summary, this invention provides a spiral thermal matching reactor based on increased flow channel volume. Addressing the issues of insufficient solar energy utilization and low methane conversion rates in current solar reactors, this invention combines the characteristics of a circular, non-uniform temperature spot with the methane reforming reaction to design a variable cross-section annular reaction flow channel. This significantly improves the reactor's solar energy utilization efficiency and methane conversion rate, making it worthy of widespread application in the field of methane reforming for hydrogen production. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the solar-heated reactor of the present invention.

[0030] Figure 2 This is a schematic diagram of the concentration ratio of the parabolic dish solar collector of the present invention.

[0031] Figure 3 This is a schematic diagram of the bottom surface temperature of the reactor before the reaction occurs, according to the present invention.

[0032] Figure 4 This is a schematic diagram of the reactor centerline temperature after biogas and water vapor react at an inlet temperature of 800K, an inlet velocity of 0.5m / s, and a water-to-carbon ratio of 2.

[0033] Figure 5 This is a cloud map showing the distribution of methane in the flow channel after biogas with an inlet temperature of 800K, an inlet velocity of 0.5m / s, and a water-to-carbon ratio of 2 reacts with water vapor, according to the present invention.

[0034] Figure 6 This is a three-dimensional schematic diagram of an annular partition according to an embodiment of the present invention.

[0035] Figure 7 This is a top view of the annular partition of the present invention along the center line. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings:

[0037] Example: Please refer to Figures 1 to 7A spiral heat-matching reactor based on increased flow channel volume is disclosed, comprising a parabolic solar collector 1 and a spiral heat-matching reactor. The parabolic solar collector 1 provides energy to the spiral heat-matching reactor. The spiral heat-matching reactor contains an annular reaction channel 4, which consists of multiple interconnected concentric channels. The diameter of these concentric channels gradually increases from the periphery to the center of the reactor. The outermost concentric channel of the annular reaction channel 4 connects to a feed pipe 3, and the innermost concentric channel connects to a discharge pipe 5. The parabolic dish-type solar collector forms a circular non-uniform temperature spot, which is composed of multiple rings with different temperatures. The shape of the multiple concentric channels of the annular reaction channel matches the shape of the circular non-uniform temperature spot to utilize its heat. The parabolic solar collector has a dish structure and is hereinafter referred to as a parabolic dish-type solar collector.

[0038] In this invention, the parabolic solar collector 1, i.e., the parabolic dish collector, generates a temperature range of 600K to 1300K to drive the methane reforming reaction within the spiral heat-matching reactor; this collector can be replaced by a tower-type or trough-type collector. The annular reaction channel 4 has a gradually increasing cross-section from the outer to the inner ring to mitigate the impact of increased gas volume and pressure on the methane reforming reaction and improve the methane conversion rate. The annular reaction channel is composed of five interconnected annular baffles with gradually increasing diameters. The circular non-uniform temperature spot is composed of multiple rings with different temperatures, which are matched to utilize the heat from the non-uniform temperature spot. A nickel-based alumina catalyst is uniformly arranged within the annular reaction channel 4.

[0039] In one embodiment of the present invention, as Figure 1 and Figure 6 As shown, the spiral heat matching reactor includes a reactor shell 2 and a set of annular baffles with different diameters inside. The annular baffles divide the space inside the reactor shell 2 to form an annular reaction channel 4. The annular baffles have 5 rings and together with the shell form an annular reaction channel. The annular baffles include a first annular plate 401, a second annular plate 402, a third annular plate 403, a fourth annular plate 404, a fifth annular plate 405, and a central member 406, arranged from the outside to the inside. A connecting plate 407 is radially arranged and sequentially connected to one end of the first annular plate 401, the second annular plate 402, the third annular plate 403, the fourth annular plate 404, and the fifth annular plate 405. The other end of each annular plate forms an opening or inlet from the adjacent outer ring to the inner ring with the connecting plate 406. The opening 41 between the first annular plate 401 and the connecting plate 406 is a feed inlet connected to the feed pipe 3. The innermost ring is formed inside the fifth annular plate 405, and the innermost ring is connected to the discharge pipe 5. The connecting plate 406 extends to the innermost end and connects to the central component. The central component has a cylindrical structure and its side wall opening communicates with the innermost ring. The reactant enters the discharge pipe 5 through the space in the middle of the central component 407. The aforementioned annular partition can be integrally formed or assembled from multiple components.

[0040] A spiral heat-matching reactor based on increased flow channel volume includes a parabolic dish solar collector (parabolic solar collector 1), a reactor shell 2, a feed pipe 3, an annular variable cross-section gas reaction channel (annular reaction channel 4), and a discharge pipe 5. The parabolic dish solar collector is located below the reactor and is used to collect solar radiation to provide heat to the reactor. The reactor shell 2 is cylindrical, with holes designed at the center of its side and upper surface to match the feed pipe 3 and the discharge pipe 5. The feed pipe 3 has a rectangular cross-section and does not contain a catalyst. The annular variable cross-section gas reaction channel is composed of a set of annular baffles of different diameters dividing the space inside the reactor shell. The cross-section of the channel gradually increases from the outside to the inside to accommodate the increased gas volume in the methane reforming reaction. Nickel-based alumina catalyst is uniformly arranged in different concentric layers of the annular variable cross-section gas reaction channel. The discharge pipe 5 has a circular cross-section and does not contain a catalyst. In one embodiment, the reactor shell diameter can be designed to be 185mm and the height to be 10mm; the rectangular cross-section of the feed pipe has a length of 12mm and a width of 8mm, and the length of the feed pipe is 20mm.

[0041] In one embodiment of the present invention, the parabolic solar collector has a focal length of 0.55m, an edge angle of 35°, a radiation absorption coefficient of 0.1, and a maximum central concentration ratio of 48; preferably, when the input solar irradiance is 1000W / m² 2 At that time, the maximum solar radiation produced by the parabolic dish collector was 4.9 × 10⁴ W / m². 2 The minimum solar radiation is 2.97 × 10³ W / m². 2 Preferably, the annular variable cross-section gas reaction channel has a total of 5 concentric channels with different cross-sections, the cross-sectional width gradually increasing from the outside to the inside, with widths of 5mm, 10mm, 15mm, 20mm, and 25mm respectively. The annular variable cross-section gas reaction channel is composed of a set of annular baffles of different diameters dividing the space inside the reactor shell. The thickness of these baffles is 2mm-3mm, negligible compared to the internal space of the reactor shell, and the material is nickel-iron alloy 625, which has good thermal conductivity, indicating that the channel can utilize all the heat inside the reactor shell for the reaction occurring within the reactor. Preferably, the inlets of the annular variable cross-section gas reaction channel are at angles to the reactor centerline of 8°, 8°, 12°, 14°, 25°, and 40° respectively, so that the inlet width matches the channel width. Figure 7 As shown in the figure, β is the angle between the inlet formed by the fifth ring plate of the annular reaction channel and the line connecting it to the center of the reactor.

[0042] like Figure 2As shown, the parabolic solar collector is a parabolic dish collector. The concentration ratio gradually decreases from the center of the disk to the periphery, from 48 to 24. The limitation of the concentration accuracy will lead to uneven distribution of reflected sunlight, resulting in uneven temperature spots on the reflective plane. This is the essential reason for the uneven temperature spots produced by dish collectors.

[0043] like Figure 3 As shown, when the parabolic solar collector collects solar radiation and reflects it to the bottom surface of the reactor, it will form a non-uniform temperature field on the bottom surface. This temperature field has the characteristics of "high temperature at the center and gradually decreasing temperature around the perimeter". The highest temperature at the center of the bottom surface is 1250K and the lowest temperature is 800K.

[0044] like Figures 4-5 The figure shows the changes in the concentration and temperature of various substances inside the spiral heat-matching reactor under the boundary conditions of an inlet temperature of 800K, an inlet velocity of 0.5m / s, and a water-to-carbon ratio of 2.

[0045] This invention relates to a spiral heat-matching reactor based on increased flow channel volume, primarily involving methane reforming chemical reactions, with the specific equations as follows:

[0046] Reforming reaction:

[0047] Transformation reaction:

[0048] To verify the feasibility of the reactor design, the following assumptions were made about the reaction process:

[0049] 1. In the simulation software parameter settings, the raw gas entering from the reactor inlet is thoroughly mixed and treated as an ideal gas, and the gas is incompressible.

[0050] 2. Since the catalyst has a very small particle size, it can be assumed that it is completely adhered to the porous structure, so it is suitable to use a uniform porous media model for analysis.

[0051] 3. The porosity of the packed bed remains consistent throughout its entire length.

[0052] 4. The effect of the dry methane reforming (DRM) reaction on the results is not considered in the biogas reforming process.

[0053] 5. The effect of reactant body forces on fluid dynamics is not considered during the reaction process.

[0054] The operating principle of this reactor is as follows:

[0055] Parabolic solar collector 1 collects solar radiation and reflects it onto the lower surface of the reactor shell 2, providing energy for the reaction occurring within the annular reaction channel 4. Gas is introduced through the inlet pipe 3 and then enters the annular reaction channel 4 connected to the inlet pipe to react. In the outer ring of the annular reaction channel 4, the heating temperature is lower, the gas reaction rate is slower, and the endothermic reaction causes a small decrease in the temperature of the reactor's heat-absorbing surface. As the gas enters the inner ring of the reaction channel, the heating temperature gradually increases, the gas reaction rate accelerates, and the endothermic reaction increases, leading to a gradual and larger decrease in the temperature of the reactor's heat-absorbing surface. This achieves the effect of utilizing and homogenizing the circular, non-uniform temperature spot of the solar radiation. Since the methane reforming reaction involves an increase in gas volume, the gas velocity gradually increases as the reaction proceeds in the same channel. However, upon entering the next channel, the gas velocity decreases due to the expansion of the channel cross-section, increasing the residence time of the gas in the higher-temperature layer. This allows the gas to fully utilize the high-temperature energy of the inner ring, improving the methane conversion rate.

[0056] like Figure 4 As shown, when the boundary conditions are an inlet temperature of 800K, an inlet velocity of 0.5m / s, and a water-to-carbon ratio of 2, after the reaction occurs, the temperature of the bottom surface of the reactor will decrease overall. The highest temperature at the center drops from 1250K before the reaction to 1010K, and the lowest temperature drops from 800K to 728K. The maximum temperature difference between the reactor shell and the ground surface drops from 450K to 282K. This indicates that the reactor can utilize the circular non-uniform temperature spot generated by the homogenized parabolic solar collector 1.

[0057] like Figure 5 As shown, when the boundary conditions are an inlet temperature of 800 K, an inlet velocity of 0.5 m / s, and a water-to-carbon ratio of 2, the methane conversion rate is 99.2%.

[0058] The above description is merely an embodiment of the invention's technical content. Any modifications or variations made by those skilled in the art using this invention are within the scope of the invention's claims, and are not limited to those disclosed in the embodiments.

Claims

1. A spiral heat-matching reactor based on increased flow channel volume, characterized in that... include: Parabolic solar collectors provide energy for spiral heat-matching reactors; The spiral heat matching reactor has an annular reaction channel inside. The annular reaction channel is composed of multiple interconnected channels, and the diameter of the multiple channels gradually increases from the periphery of the reactor to the center. The outermost ring of the annular reaction channel is connected to the feed pipe, and the innermost ring of the annular reaction channel is connected to the discharge pipe. The parabolic solar collector forms a circular non-uniform temperature spot, which is composed of multiple rings with different temperatures. The multi-circulation flow channel of the annular reaction channel matches the shape of the circular non-uniform temperature spot to utilize the heat of the non-uniform temperature spot. The spiral heat-matching reactor includes a reactor shell and a set of annular baffles with different diameters inside it. The annular baffles divide the space inside the reactor shell to form an annular reaction channel.

2. The spiral heat-matching reactor based on increased flow channel volume according to claim 1, characterized in that: Parabolic solar collectors generate temperatures ranging from 600K to 1300K to drive methane reforming reactions within a spiral heat-matching reactor; this collector can be replaced by tower or trough collectors.

3. A spiral heat-matching reactor based on increased flow channel volume according to claim 1, characterized in that: The annular baffle has 5 rings and forms an annular reaction channel with the outer shell.

4. A spiral heat-matching reactor based on increased flow channel volume according to claim 1, characterized in that: The annular baffle includes a first ring plate, a second ring plate, a third ring plate, a fourth ring plate, a fifth ring plate, and a central component, arranged from the outside in. A connecting plate is radially arranged and sequentially connected to one end of the first ring plate, the second ring plate, the third ring plate, the fourth ring plate, and the fifth ring plate. The other end of each ring plate forms an opening from the adjacent outer ring to the inner ring with the connecting plate. The opening between the first ring plate and the connecting plate is a feed inlet connected to the feed pipe. The innermost ring is formed inside the fifth ring plate, and the innermost ring is connected to the discharge pipe.

5. A spiral heat-matching reactor based on increased flow channel volume according to claim 4, characterized in that: The connecting plate extends to the innermost end and connects to the central component. The central component is a cylindrical structure with side wall openings that communicate with the innermost ring. The reactant enters the discharge pipe through the middle space of the central component.

6. A spiral heat-matching reactor based on increased flow channel volume according to claim 4 or 5, characterized in that: The reactor shell is cylindrical to withstand greater hot gas pressure. The annular baffle is 2mm thick and made of nickel-iron alloy 625, which has excellent thermal conductivity. This means that all the heat reflected to the bottom of the reactor shell can be used for the reaction, reducing heat waste.

7. A spiral heat-matching reactor based on increased flow channel volume according to claim 1, characterized in that: Nickel-based alumina catalyst is uniformly arranged in the annular reaction channel.

8. A spiral heat-matching reactor based on increased flow channel volume according to claim 4, 5, or 7, characterized in that: The inlets of the annular reaction channel are angled at 8°, 8°, 12°, 14°, 25°, and 40° from the centerline of the spiral heat-matching reactor, respectively, so that the inlet width can match the channel width.

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