Fuel reformer

Abstract

One embodiment of the present invention provides a fuel reformer comprising: a combustion gas supply pipe disposed in the internal center of the fuel reformer and forming a space in which a heat source can be disposed; a combustion gas flow path pipe formed to be longer than the length of the combustion gas supply pipe and through which combustion gas generated from the heat source flows into the interior through a lower portion that is in communication with the combustion gas supply pipe; a reforming reaction pipe having a larger diameter than the combustion gas flow path pipe and having a catalyst layer provided inside; and a corrugated pipe located above the reforming reaction pipe, formed in a double spiral shape, receiving raw material gas and raw material water together, and discharging the preheated raw material gas and raw material water in a divided manner to the reforming reaction pipe.

Description

Technology Field

[0001] The present invention relates to a fuel reformer, and more specifically, to a fuel reformer having a double-coil type corrugated tube and a plurality of distribution plates. Background Technology

[0003] As one example of the application of the present invention, a reforming reaction device (hereinafter referred to as a reformer) that produces hydrogen through a natural gas-steam reforming reaction can be cited. The reformer is a reactor that produces hydrogen using natural gas, which is mainly composed of methane, as a raw material. The raw material gas and steam are converted into a reformed gas, which is a mixture of hydrogen, carbon monoxide, and carbon dioxide, on a catalyst; since this causes a strongly endothermic reaction, a separate supply of reaction heat is required.

[0004] In a concentric fuel reformer, the combustion chamber is located in the center and preheats the reaction feedstocks—water and natural gas—through the combustion of fuel, while simultaneously supplying the heat required for the fuel reforming reaction. A cylindrical catalyst layer is positioned around the outer edge of the combustion chamber, and due to the central location of the combustion chamber, the outlet for the reformed gas is located on the side rather than the center.

[0005] The fuel reformer consists of a connected steam generator required for the reaction and a preheater for preheating the reactants, forming the entire process. In this case, the heat for the steam generator and preheater can be supplied by recovering waste heat from combustion flue gas emitted after heating the catalyst bed or from the produced reformed gas. Accordingly, it is required to increase the heat exchange efficiency to enhance the efficiency of the entire process, including the steam reformer.

[0006] Conventional industrial reformers utilize tubular reactors, primarily employing radiation heat transfer for heat exchange. In this configuration, the heat flux from the reaction heat generated in the combustor to the reaction tubes is very high, which is advantageous for maximizing processing capacity; however, this poses a risk of localized heating within the tubes due to direct contact with the flame. Consequently, uneven reactions occur, leading to reduced reaction stability and conversion efficiency. Furthermore, significant variation in reaction rates between reactors makes operation, maintenance, and management difficult, and the system presents the problem of requiring expensive heat-resistant materials.

[0007] This poses a significant obstacle to device miniaturization. In small reformers, heat exchange primarily utilizes convective heat transfer. To minimize device volume while maximizing heat exchange efficiency within the fuel reformer, concentric reactors are being used. Consequently, there is a need for research and development on technologies to enhance feedstock distribution efficiency and thermal efficiency in small reformers. The problem to be solved

[0009] The technical problem to be solved by the present invention is to provide a fuel reformer that improves the distribution efficiency and thermal efficiency of the reforming reactant by providing a double-coil type corrugated tube and a plurality of distribution plates.

[0010] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0012] To achieve the above technical objective, one embodiment of the present invention provides a fuel reformer comprising: a combustion gas supply pipe positioned at the internal center of the fuel reformer and forming a space in which a heat source can be positioned; a combustion gas flow path pipe formed to be longer than the length of the combustion gas supply pipe, through which combustion gas generated from the heat source flows into the interior via a lower portion that is in communication with the combustion gas supply pipe; a reforming reaction pipe having a larger diameter than the combustion gas flow path pipe and having a catalyst layer provided therein; and a corrugated pipe located above the reforming reaction pipe, formed in a double spiral shape, which receives raw material gas and raw material water together and divides and discharges the preheated raw material gas and raw material water to the reforming reaction pipe.

[0013] In an embodiment of the present invention, the corrugated pipe is formed in a double helical shape surrounding the combustion gas flow path pipe and may include raw gas inlets provided at the upper portions of opposing positions and raw gas outlets provided at the lower portions of opposing positions.

[0014] In an embodiment of the present invention, the heat exchanger may further include a space in which the corrugated pipe can be disposed and a passage in which combustion gas introduced from the combustion gas passage pipe can pass.

[0015] In an embodiment of the present invention, the heat exchanger may have a ventilation hole formed on the lower inner side through which combustion gas passing through the combustion gas flow path can flow in, and a combustion gas discharge port formed on the upper outer side.

[0016] In an embodiment of the present invention, a distribution plate may be further provided inside the reforming reaction tube and formed on a flow path leading to the catalyst layer for the raw material gas and raw material water discharged from the corrugated tube, and guiding the preheated raw material gas and raw material water supplied to the catalyst layer to be supplied uniformly.

[0017] In an embodiment of the present invention, the distribution plate comprises a first distribution plate, a second distribution plate located below the first distribution plate, and a third distribution plate located below the second distribution plate, and the second distribution plate may be arranged at an angle rotated axially by 15° to 30° with respect to the first and third distribution plates.

[0018] In an embodiment of the present invention, to supply heat to the catalyst layer formed between the combustion gas flow path and the reforming reaction tube, a heat transfer fin formed in the form of a partition on the outer surface of the combustion gas flow path may be further included.

[0019] In an embodiment of the present invention, the heat transfer fins include a plurality of heat transfer fins arranged spaced apart along the outer surface of the combustion gas flow path, and each of the heat transfer fins may be formed spaced apart from an adjacent heat transfer fin in the height direction by a predetermined distance.

[0020] In an embodiment of the present invention, a reforming gas discharge pipe may be further included, which is formed in a shape surrounding the reforming reaction pipe, and has a reforming gas discharge port formed on the upper outer side through which reforming gas is discharged and reforming gas is introduced into the interior through a lower portion that is in communication with the reforming reaction pipe. Effects of the invention

[0022] According to an embodiment of the present invention, the distribution efficiency and thermal efficiency of the modified reactant can be improved by providing a double coil-shaped corrugated tube and a plurality of distribution plates.

[0023] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the composition of the invention described in the description or claims of the present invention. Brief explanation of the drawing

[0025] FIG. 1 is a schematic diagram illustrating the overall configuration of a fuel reformer according to one embodiment of the present invention. FIG. 2 is a drawing showing a corrugated pipe installed according to one embodiment of the present invention. FIG. 3 is a drawing illustrating the installation of a distribution plate according to one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating the installation of a heat transfer fin according to one embodiment of the present invention. Specific details for implementing the invention

[0026] The present invention will be described below with reference to the attached drawings. However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0027] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0028] The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0029] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0030] FIG. 1 is a schematic diagram illustrating the overall configuration of a fuel reformer according to one embodiment of the present invention, FIG. 2 is a diagram illustrating the installation of a corrugated pipe according to one embodiment of the present invention, and FIG. 3 is a diagram illustrating the installation of a distribution plate according to one embodiment of the present invention.

[0031] Referring to FIG. 1, the fuel reformer of the present invention may include a heat source (100), a combustion gas supply pipe (200), a combustion gas flow path pipe (300), a reforming reaction pipe (400), a reformed gas discharge pipe (500), a heat exchange pipe (600), a corrugated pipe (700), and a distribution plate (800).

[0032] The fuel reformer of the present invention may include at least one reaction conduit (tube) for reforming raw gas. A heat source (100) may be disposed in the internal center of the fuel reformer.

[0033] The heat source (100) supplies the reaction heat required for the reforming reaction and can generate combustion gas in the inner center of the fuel reformer by burning air and fuel supplied from the outside. The heat source (100) according to the present invention (hereinafter referred to as a combustor) may be implemented, for example, as a burner. Here, the combustion fuel supplied to the heat source (100) may be natural gas (NG) identical to the raw material of the reformer.

[0034] The combustion gas supply pipe (200) is positioned at the inner center of the fuel reformer and can form a space where a combustor (100) can be positioned. The combustor (100) provided inside the combustion gas supply pipe (200) can be positioned at the upper center of the combustion gas supply pipe (200).

[0035] The combustion gas flow path (300) is arranged concentrically with the combustion gas supply pipe (200) and can be formed with a larger diameter than the combustion gas supply pipe (200). That is, the combustion gas flow path (300) can be formed in a shape that surrounds the combustion gas supply pipe (200).

[0036] Referring to FIG. 1, the combustion gas flow path (300) may be formed to be longer than the length of the combustion gas supply pipe (200). Here, the length of the combustion gas flow path (300) may refer to the length from the bottom surface of the fuel reformer to the top of the fuel reformer where the raw gas inlets (711, 713) are located.

[0037] Accordingly, the open lower portion of the combustion gas supply pipe (200) can be provided in a form that allows it to communicate with the combustion gas flow path (300). The combustion gas generated from the combustion device (100) can move downward to the lower portion of the combustion gas supply pipe (200), then flow into the lower portion of the combustion gas flow path (300), and then move along an upward path toward the upper portion of the combustion gas flow path (300).

[0038] That is, the donut-shaped space formed between the combustion gas supply pipe (200) and the combustion gas flow path pipe (300) becomes a combustion gas flow path through which combustion gas (exhaust gas) flows. In order to discharge the combustion gas (EG), the lower end of the combustion gas supply pipe (200) is spaced apart from the bottom surface of the fuel reformer and is not in contact with it, so the combustion gas supply pipe (200) may have a structure that is open to the bottom.

[0039] The combustion gas (EG) generated in the combustion device (100) passes through the combustion gas path and provides the necessary reaction heat to the reforming reaction tube (400) formed on one side, and after overheating the raw material mixture (raw material gas and raw material water) supplied to the reforming reaction tube (400), passes through the heat exchange tube (600) provided on one side of the upper part of the combustion gas path (300), preheats the raw material mixture injected through the corrugated tube (700), and then can be exhausted through the combustion gas outlet (630).

[0040] The reforming reaction tube (400) is arranged concentrically with the combustion gas flow path (300), but can be formed in a shape that surrounds the combustion gas flow path (300) as its diameter is larger than that of the combustion gas flow path (300). As shown in FIG. 1, a catalyst layer (410) for the reforming reaction can be provided in the lower region of the reforming reaction tube (400).

[0041] The reforming gas discharge pipe (500) is arranged concentrically with the reforming reaction pipe (400) and can be formed in a shape that surrounds the reforming reaction pipe (400).

[0042] Referring to FIG. 1, the lower portion of the reforming gas reaction tube (400) is formed in an open shape, and, similar to the combustion gas supply tube (200), the lower portion of the reforming gas reaction tube (400) is not attached to the bottom surface of the fuel reformer but is spaced apart and can be connected to the reforming gas discharge tube (500). Accordingly, the reforming gas generated as the raw material mixture passes through the catalyst layer (410) can pass through the open lower portion of the reforming gas reaction tube (400), flow into the reforming gas discharge tube (500), move upward, and then be discharged through the reforming gas discharge port (510).

[0043] The reformed gas outlet (510) can be formed on the upper outer side of the reformed gas outlet pipe (500).

[0044] The heat exchanger (600) is arranged concentrically with the combustion gas flow path (300) and can be provided in a form that surrounds the upper part of the combustion gas flow path (300). The heat exchanger (600) can form a space inside which a corrugated tube (700) can be placed.

[0045] A ventilation hole (610) may be provided on the lower inner side of the heat exchanger tube (600), and a combustion gas outlet (630) may be provided on the upper outer side. Combustion gas passing through the combustion gas flow path (300) flows into the interior of the heat exchanger tube (600) through the ventilation hole (610), and can be exhausted to the outside through the combustion gas outlet (630) after passing through the flow path between the corrugated tubes (700).

[0046] The corrugated pipe (700) is a heat exchange conduit that forms an injection path for a raw material mixture containing raw material gas and raw material water to be injected into the fuel reformer, and heat exchange between the combustion gas (EG) flowing outside the corrugated pipe (700) and the raw material mixture flowing inside the corrugated pipe (700) can be performed.

[0047] The corrugated tube (700) is located in the internal space of the heat exchange tube (600) and can be formed in a double spiral shape to increase the heat exchange area. Raw gas inlets (711, 713) may be provided at opposing positions on the upper part of the corrugated tube (700), and raw gas outlets (731, 733) may be provided at opposing positions on the lower part (see FIG. 1).

[0048] According to one embodiment, the corrugated pipe (700) may be formed in a coil shape that wraps around the combustion gas flow path (300) several times, and a first raw gas inlet (711) may be provided at the upper part of the corrugated pipe (700) which is formed in a circular shape, and a second raw gas inlet (713) may be provided at a position at an angle of 170 to 190 degrees from the position of the first raw gas inlet (711). Likewise, a first raw gas outlet (731) may be provided at the lower part of the corrugated pipe (700), and a second raw gas outlet (733) may be provided at a position at an angle of 170 to 190 degrees from the position of the first raw gas outlet (731).

[0049] As the raw material mixture injected through the raw material gas inlet (711, 713) undergoes heat exchange, the preheated raw material mixture (raw material gas and raw material water) can be discharged to the reforming reaction tube (400) through the raw material gas outlet (731, 733). At this time, the raw material mixture supplied into the fuel reformer can be injected in a predetermined amount, and it is preferable that half of the said amount of raw material mixture is injected into the first raw material gas inlet (711) and the second raw material gas inlet (713), respectively, and that half of the total amount of the preheated raw material mixture is discharged through the first raw material gas outlet (731) and the second raw material gas outlet (733), respectively.

[0050] Referring to FIG. 1, the lower end of the raw gas outlet (731, 733) may be provided in a form inserted inside the reforming reaction tube (400).

[0051] In one embodiment, the total length of the corrugated pipe (700) may be 5 to 15 m, preferably 8.2 m, and may be formed in a shape that wraps the combustion gas flow path (300) in two rows, but the length of the corrugated pipe (700) is not limited thereto and may be provided with a length corresponding to the diameter of the combustion gas flow path (300) being implemented.

[0052] A distribution plate (800) may be provided inside the reforming reaction tube (400). Specifically, the distribution plate (800) may be placed on the flow path leading to the catalyst layer (410) for the preheated raw material mixture discharged from the corrugated tube (700).

[0053] The distribution plate (800) can serve to ensure that the preheated raw material mixture is uniformly supplied to the catalyst layer (410). As shown in FIG. 1, the distribution plate (800) can be formed in the shape of a flat ring with distribution holes formed at equal intervals.

[0054] A distribution plate (800) according to one embodiment of the present invention may include a first distribution plate (810), a second distribution plate (830), and a third distribution plate (850). The first distribution plate (810) may be located at the top of the distribution plates and may be positioned adjacent to the corrugated pipe (700). The second distribution plate (830) may be located below the first distribution plate (810), and the third distribution plate (850) may be located below the second distribution plate (830).

[0055] At this time, the second distribution plate (830) may be positioned at an axial rotation angle of 15° to 30° relative to the first distribution plate (810) and the third distribution plate (850). For example, the second distribution plate (830) may be positioned at an axial rotation angle of 18° relative to the first and third distribution plates (810, 850). At this time, the first distribution plate (810) and the third distribution plate (850) may be positioned at the same angle so that the positions of the ventilation holes coincide. For example, each of the first to third distribution plates may include 10 ventilation holes, and the 10 ventilation holes may be positioned at equal intervals.

[0056] As the second distribution plate (830) is positioned at an angle rotated by a predetermined angle with respect to the first and third distribution plates (810, 850), the ventilation holes formed in the second distribution plate (830) and the ventilation holes formed in the first and third distribution plates (810, 850) can be positioned to be staggered from each other.

[0057] As the first to third distribution plates (810, 830, 850) as described above are placed between the corrugated pipe (700) and the catalyst layer (410), the raw material mixture (raw material gas and raw material water) that has passed through the first to third distribution plates (810, 830, 850) after being divided and discharged from the corrugated pipe (700) can be supplied to the catalyst layer (410) with a uniform distribution.

[0058] FIG. 3 shows a distribution plate installed according to one embodiment of the present invention, wherein the first distribution plate (810), the second distribution plate (830), and the third distribution plate (850) of the present invention can each be implemented with a diameter of 1Φ. Although the present invention has been described as having three distribution plates (800), the number of distribution plates is not limited thereto and can be varied as needed.

[0059] The raw material gas injected into the corrugated pipe (700) may be a hydrocarbon raw material (LNG, LPG, etc.), and the hydrocarbon raw material may have sulfur components removed. The raw material gas and raw material water are injected together into the corrugated pipe (700) and, as they are heat-exchanged with the combustion gas, the raw material gas and raw material water, which are preheated, can be supplied to the catalyst layer (410) in a uniform distribution through the distribution plate (800). The raw material mixture is supplied to the catalyst layer (410), and hydrocarbons such as ethane, propane, and isobutane are converted into methane, and then a reformed gas mainly containing hydrogen can be formed through a steam reforming reaction. At this time, the catalyst layer (410) may include a catalyst such as a nickel-based or ruthenium-based catalyst.

[0060] The reformed gas generated through the catalyst layer (410) flows into the reformed gas discharge pipe (500), moves upward, and can be discharged to the outside through the reformed gas discharge port (510) provided on one side of the upper part of the reformed gas discharge pipe (500).

[0061] A fuel reformer according to another embodiment of the present invention may further include heat transfer fins (900). FIG. 4 is a schematic diagram illustrating the installation of heat transfer fins according to an embodiment of the present invention.

[0062] The heat transfer fins (900) can be formed in the form of partitions on the outer surface of the combustion gas flow path (300) to better supply heat to the catalyst layer (410) located between the combustion gas flow path (300) and the reforming reaction tube (400).

[0063] As shown in FIG. 4, the heat transfer fins (900) may include a plurality of heat transfer fins arranged in a spaced-apart manner along the outer surface of the combustion gas flow path (300). Each of the plurality of heat transfer fins may be formed at a predetermined distance from an adjacent heat transfer fin in the height direction.

[0064] The reason for providing a gap between the heat transfer fins formed along the height direction of the combustion gas flow path (300) is to minimize thermal deformation of the heat transfer fins caused by the combustion gas flowing through the combustion gas supply pipe (200) and the combustion gas flow path (300). If thermal deformation occurs in the heat transfer fins due to the combustion gas, the shape of the heat transfer fins becomes deformed, which may cause a problem in that it becomes difficult to maintain the gap between the combustion gas flow path (300) and the reforming reaction pipe (400). Consequently, this may result in uneven distribution of the reactants and make it difficult to ensure reproducibility of operating performance.

[0065] As described above, the fuel reformer of the present invention can significantly reduce the outlet temperature deviation of the reforming reaction tube (400) compared to the conventional one by providing a corrugated tube (700) and a plurality of distribution plates.

[0066] As an experimental example, a conventional fuel reformer having a heat exchange section and composed of a single distribution plate was compared with a fuel reformer according to the present invention. As a result, it was confirmed that the outlet temperature deviation of the reforming reaction tube in the conventional fuel reformer was 55°C, and the outlet temperature deviation of the reforming reaction tube in the fuel reformer according to the present invention was 20°C. In this experiment, the temperature deviation was measured using four thermometers installed at 90° intervals at the bottom of the cylindrical reforming reaction tube (400).

[0067] Also, the degree of equilibrium attainment (△T RIn the case of *), the equilibrium attainment of the fuel reformer according to the present invention was measured at 7°C, whereas that of the conventional fuel reformer was 57°C. According to numerous existing research results, designing the fuel reformer so that the equilibrium attainment reaches 5 to 20°C is advantageous in terms of fuel efficiency.

[0068] In addition, the thermal efficiency of the existing fuel reformer was confirmed to be 75.7% based on LHV (Lower Heat Value), whereas the thermal efficiency of the fuel reformer according to the present invention was 77.1%, which is an increase of about 1.4% compared to the existing one.

[0069] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0070] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0072] 100: Heat source, combustor 200: Combustion gas supply pipe 300: Combustion gas flow pipe 400: Reforming reaction tube 500: Reformed gas exhaust pipe 600: Heat exchange tube 700: Corrugated tube 800: Distribution board 900: Heat transfer fins

Claims

Claim 1 A fuel reformer comprising: a combustion gas supply pipe positioned at the internal center of the fuel reformer and forming a space in which a heat source can be positioned; a combustion gas flow path pipe formed longer than the length of the combustion gas supply pipe, through which combustion gas generated from the heat source flows into the interior via a lower portion that is in communication with the combustion gas supply pipe; a reforming reaction pipe having a larger diameter than the combustion gas flow path pipe and having a catalyst layer provided inside; a heat exchange pipe located above the reforming reaction pipe; and a corrugated pipe positioned in a double helix shape inside the heat exchange pipe, which receives raw material gas and raw material water together through an internal flow path, preheats them, and then discharges them to the reforming reaction pipe; wherein a ventilation hole is formed in a partition wall forming the boundary between the combustion gas flow path pipe and the heat exchange pipe, so that the combustion gas passing through the combustion gas flow path pipe flows directly into the interior of the heat exchange pipe and exchanges heat with the outer surface of the corrugated pipe. Claim 2 A fuel reformer according to claim 1, wherein the corrugated pipe is formed in a double spiral shape surrounding the combustion gas flow path pipe, and includes raw gas inlets provided at the upper portions of opposing positions and raw gas outlets provided at the lower portions of opposing positions. Claim 3 delete Claim 4 A fuel reformer according to claim 1, wherein the heat exchange tube is characterized by having a combustion gas outlet formed on the upper outer side. Claim 5 A fuel reformer according to claim 1, further comprising a distribution plate provided inside the reforming reaction tube, formed on a flow path toward the catalyst layer for the raw gas and raw water discharged from the corrugated tube, and guiding the preheated raw gas and raw water supplied to the catalyst layer to be supplied uniformly. Claim 6 A fuel reformer according to claim 5, wherein the distribution plate comprises a first distribution plate, a second distribution plate located below the first distribution plate, and a third distribution plate located below the second distribution plate, and wherein the second distribution plate is arranged at an angle rotated axially by 15° to 30° with respect to the first and third distribution plates. Claim 7 A fuel reformer according to claim 1, further comprising a heat transfer fin formed in the form of a partition on the outer surface of the combustion gas flow path to supply heat to the catalyst layer formed between the combustion gas flow path and the reforming reaction path. Claim 8 A fuel reformer according to claim 7, wherein the heat transfer fins comprise a plurality of heat transfer fins arranged spaced apart along the outer surface of the combustion gas flow path, and each of the heat transfer fins is formed spaced apart from an adjacent heat transfer fin in the height direction by a predetermined distance. Claim 9 A fuel reformer according to claim 1, further comprising a reforming gas discharge pipe formed in a shape surrounding the reforming reaction pipe, wherein reforming gas is introduced into the interior through a lower portion communicating with the reforming reaction pipe, and a reforming gas discharge port is formed on the upper outer side for discharging the reforming gas.

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