Steam generator for operating soec

Abstract

The present invention relates to a steam generator for operating an SOEC. The present invention comprises: a chamber that extends vertically and provides a sealed space; a water spray part that is installed in the upper end portion of the chamber and sprays water into the chamber; a heater that heats the water sprayed from the water spray part to generate steam; a heat transfer medium that is filled into the chamber, is heated by receiving the heat from the heater, and transfers the heat to descending water; and a steam discharge part that discharges the steam generated in the chamber to the outside of the chamber.

Description

Steam generator for SOEC operation

[0001] The present invention relates to a steam generator for generating steam to be supplied to an SOEC stack, and more specifically, to a steam generator for driving an SOEC that stably and continuously generates steam and supplies a precise amount to the SOEC stack, thereby maintaining the performance of the SOEC stack at its best.

[0002] A Solid Oxide Electrolysis Cell (SOEC) is a device that decomposes water into hydrogen and oxygen through an electrochemical reaction opposite to that of a Solid Oxide Fuel Cell (SOFC), which operates at high temperatures. Since SOECs utilize steam at high temperatures to induce the water splitting reaction, the temperature and amount of steam directly affect the efficiency of the electrolysis reaction. For this reason, a steam supply of constant temperature and flow rate is essential in SOEC systems, and the performance of the steam generator is critical to this.

[0003] Conventional steam generators have a simple structure in which water is placed in a tank equipped with a heater, and the heater is operated to boil the water and generate steam. However, this type of steam generator has the problem that the temperature and amount of generated steam are inconsistent. This is because the heater repeatedly turns on and off depending on the water temperature. In other words, when the heater is on, the water is heated and the amount of steam generated increases, but when the heater is turned off, the water temperature drops and the amount of steam generated decreases.

[0004] Such fluctuations in steam generation volume make it difficult to maintain consistency in steam temperature and supply volume, ultimately having a negative impact on the performance of the SOEC device. Therefore, there is a need for a steam generator capable of improving the performance of the SOEC device through a stable steam supply.

[0005] As prior art related to SOEC, Korean Registered Patent Publication No. 10-2481707 (SOEC system having heating capability) has been disclosed.

[0006] The present invention was created to resolve the above-mentioned problems and aims to provide a steam generator for driving an SOEC that can optimize the performance of the SOEC device by stably generating a constant amount of steam, has a very fast heating speed, and excellent energy efficiency.

[0007] The steam generator for driving an SOEC according to the present invention, as a means of solving the problem for achieving the above objective, comprises: a chamber that extends vertically and provides a sealed space; a water injection unit installed at the upper end of the chamber and injecting water into the chamber; a heater that generates steam by heating the water injected from the water injection unit; a heat transfer medium that fills the chamber, receives heat from the heater to heat it, and transfers heat to the descending water; and a steam discharge unit that discharges the steam generated inside the chamber to the outside of the chamber.

[0008] In addition, the water injection unit includes a spray tube located at the center of the upper part of the chamber and having a plurality of water injection holes.

[0009] In addition, the water spraying unit comprises an inlet pipe that receives water supplied from the outside and guides it into the chamber, and a spray bar connected to the inlet pipe, extending longitudinally within the chamber and having a plurality of water spray holes.

[0010] In addition, the above-mentioned inlet tube is installed vertically at the center of the upper part of the chamber, and multiple spray bars are applied, extending radially from the inlet tube and forming symmetry.

[0011] In addition, the heaters have the shape of a round bar, and a number of them are arranged symmetrically with respect to the central axis of the chamber.

[0012] In addition, the heat transfer medium takes the form of a powder and heats water that is sprayed from a water sprayer and descends due to gravity by passing it through the pores.

[0013] In addition, the heat transfer medium includes silicon carbide (SiC).

[0014] In addition, the interior of the chamber is further provided with a spacing member that maintains the spacing of the heaters.

[0015] In addition, the above-mentioned gap-maintaining member includes a support disc having the shape of a disc, with its peripheral portion fixed to the inner circumference of the chamber, and having a plurality of heater passage holes for passing a heater and a steam passage for passing steam downward to guide it to a steam discharge portion.

[0016] In addition, the heater is equipped with a heat transfer area expander that expands the heat dissipation area of ​​the heater.

[0017] The steam generator for driving an SOEC according to the present invention, as described above, converts all of the quantitatively supplied water into steam as it passes through, thereby stably generating a constant amount of steam and optimizing the performance of the SOEC device.

[0018] In addition, the chamber is filled with silicon carbide powder as a heat transfer medium, so water supplied from the top spreads through the pores of the powder and is heated by the powder, resulting in a very fast heating speed and excellent energy efficiency.

[0019] FIG. 1 is a schematic diagram of an SOEC device to which a steam generator according to one embodiment of the present invention is applied.

[0020] FIG. 2 is a drawing illustrating the steam generator shown in FIG. 1 in more detail.

[0021] FIG. 3 is a cross-sectional view illustrating the internal configuration of the steam generator of FIG. 2.

[0022] Figure 4 is a cross-sectional view along line AA of Figure 3.

[0023] Figure 5 is a drawing showing the water spraying unit illustrated in Figure 3 separately.

[0024] FIG. 6 is a perspective view showing the heater of FIG. 3 separately.

[0025] FIG. 7 is a cutaway perspective view showing the support disc illustrated in FIG. 3.

[0026] FIG. 8 is a drawing for explaining a configuration in which a heat transfer area expansion body is applied to the heater of FIG. 6.

[0027] FIG. 9 is a plan view illustrating a modified example of the water spray unit shown in FIG. 3.

[0028] Hereinafter, one embodiment according to the present invention will be described in more detail with reference to the attached drawings.

[0029] FIG. 1 is a schematic diagram of an SOEC device (100) to which a steam generator (20) according to one embodiment of the present invention is applied.

[0030] As described above, the steam generator (20) according to the present embodiment is a component included in the SOEC device (100). The steam generator (20) generates steam by heating water supplied from the water metering supply device (10) as it passes through its interior, and supplies the generated steam to the SOEC unit (40). The SOEC unit (40) can generate hydrogen using the delivered steam as a raw material. The interior of the SOEC unit (40) includes an SOEC stack.

[0031] FIG. 2 is a drawing showing the steam generator (20) illustrated in FIG. 1 in more detail, and FIG. 3 is a cross-sectional view for explaining the internal configuration of the steam generator of FIG. 2.

[0032] As described above, the steam generator (20) can be fixed to the side of the SOEC unit (40) via a fixing bracket (24). The steam generator (20) is installed vertically.

[0033] The steam generator (20) includes a chamber (21), a water injection section, a plurality of heaters (27), a heat transfer medium, and a steam discharge section.

[0034] The chamber (21) takes the shape of a cylinder, extends vertically, and provides a sealed space. The chamber (21) includes a main body (21a) of a certain diameter and a cap (21b) that seals the upper and lower ends of the main body.

[0035] The main body (21a) has the shape of a cylinder extended in the vertical direction and has service ports (47) at two locations on the side. The service ports (47) are ports that open the internal space of the chamber (21) to the outside and can be used for various purposes. For example, a pressure gauge (38) or a thermometer (39) can be mounted and operated on the service ports (47).

[0036] The cap (21b) is a plate-shaped member that is bolted to the upper and lower parts of the main body (21a). When the cap (21b) is removed, maintenance can be performed on the components inside the chamber (21).

[0037] Meanwhile, the water injection unit (25) is installed at the top of the chamber (21) and serves to inject water into the chamber. The water injection unit (25) is connected to the water metering supply unit (10) through the water supply pipe (11). The water metering supply unit (10) supplies a volume of water determined by the manager to the water injection unit. This allows for the accurate calculation of the volume of water supplied to the chamber (21). Since all the water introduced into the chamber (21) is converted into steam, the amount of steam supplied can also be accurately predicted.

[0038] FIG. 5 is a drawing showing the water spraying unit (25) shown in FIG. 3 separately.

[0039] The water spray unit (25) illustrated in FIG. 5 is a spray tube (25a) having an upper end screw-coupled to the water supply pipe (11) and a lower end closed. A plurality of spray holes (25b) are formed in the spray tube (25a). The spray holes (25b) are nozzle-shaped holes that spray water introduced through the water supply pipe (11) in a radial direction and downward. The inner diameter of the spray holes (25b) narrows from the inside to the outside of the spray tube (25a). As the water passes through the spray holes (25b), it is accelerated and can reach further.

[0040] As long as water can be supplied inside the chamber (21), the water sprayer can have various structures. FIG. 9 is a plan view illustrating a modified example of the water sprayer (26) shown in FIG. 3.

[0041] The water spray unit (26) illustrated in FIG. 9 includes an inlet pipe (26a) and a plurality of spray bars (26c).

[0042] The inlet pipe (26a) is a vertical pipe connected to the water supply pipe (11) and receives water supplied through the water supply pipe (11) and directs it into the chamber (21). The inlet pipe (26a) is installed vertically at the center of the upper part of the chamber (21).

[0043] Additionally, the spray bar (26c) is a member connected to the lower end of the inlet pipe (26a) and extending longitudinally within the chamber, and has a plurality of water spray holes (26d). The spray bar (26c) extends radially from the inlet pipe (26a) and is symmetrical. In this embodiment, six spray bars (26c) are applied, but the number of spray bars (26c) applied may vary. The sum of the flow cross-sectional areas of the spray bars (26c) is equal to the flow cross-sectional area of ​​the inlet pipe (26a).

[0044] Water introduced through the inlet pipe (26a) splits at the bottom of the inlet pipe (26a) and flows into the spray bar (26c). Additionally, the water flowing into the spray bar (26c) spreads widely as it moves along the longitudinal direction of the spray bar (26c) in the radial direction of the chamber and is ejected through the spray hole (26d). When the spray bar (26c) is applied, water can be ejected more widely.

[0045] The water ejected through the above-mentioned water spraying unit (25, 26) descends by passing through the pores of the powder-type heat transfer medium (29) described later due to the action of gravity. In particular, as the descending water passes through the pores, it is repeatedly split and broken into very small 'fine water droplets'. As the size of the water droplets decreases, the surface area per unit volume increases, so heat transfer occurs more quickly and heating occurs faster. The finely divided water droplets receive direct heat generated by the heater (27) and indirect heat from the heat transfer medium (29) heated by the heater, and are converted into steam at a very high speed.

[0046] The heater (27) serves to generate steam by heating the water sprayed from the water spraying section (25, 26). The heater (27) takes the shape of a vertically extended cylindrical rod, and a number of them are arranged symmetrically with respect to the central axis of the chamber (21).

[0047] FIG. 6 is a separate perspective view of the heater (27) of FIG. 3.

[0048] As described above, the heater (27) includes a heater case (27a), a heating element (27c), and a head (27e). The heater case (27a) is a pipe-shaped hollow member with a closed bottom and accommodates the heating element (27c). The heating element (27c) generates heat by power applied through an external heater drive unit (36 in FIG. 2). The head (27e) is fixed to the top of the heater case (27a) and connects the heating element (27c) to a power line (27f).

[0049] As illustrated in FIG. 2 or FIG. 3, the head (27e) is exposed to the upper part of the chamber (21) and is covered by a housing (22). The housing (22) protects the head (27e) while housing it. Additionally, a connecting module (23) is mounted on the housing (22). The connecting module (23) is an electrical element connected to the power line (27f) of each heater (27). Additionally, a heater driving unit (36) is connected to the connecting module (23). The heater driving unit (36) is connected to the heater (27) through the connecting module (23) and drives the heater (27). For example, it turns the heater (27) on or off or controls the heating temperature of the heater. For example, it causes the heater (27) to output heat of 100°C to 350°C.

[0050] In addition, the heaters (27) are symmetrically arranged inside the chamber (21). FIG. 4 is a cross-sectional view along line AA of FIG. 3. Referring to FIG. 4, it can be seen that six heaters (27) are arranged equilaterally with respect to the central axis of the chamber (21), which is filled with a heat transfer medium (29).

[0051] In addition, as shown in FIG. 8, a heat transfer area extension body (28) may be additionally applied to the heater (27). FIG. 8 is a drawing for explaining an example configuration in which a heat transfer area extension body (28) is applied to the outside of the heater (27).

[0052] The heat transfer area expansion body (28) serves to expand the heat dissipation area of ​​the heater (27). The heat transfer area expansion body (28) can be made of aluminum or copper and accommodates a heater case (27a) inside it. The outer surface of the heater case (27a) and the inner surface of the heat transfer area expansion body (28) are in close contact. Additionally, an uneven surface (28a) is formed on the outer surface of the heat transfer area expansion body (28).

[0053] The heat transfer area can be expanded by applying the uneven surface (28a). By additionally installing the heat transfer area expansion body (28) in this manner, the heat dissipation area of ​​heat generated from the heater increases, thereby further improving energy efficiency. As long as the heat transfer area can be expanded, the configuration of the heat transfer area expansion body can be varied.

[0054] Meanwhile, the heat transfer medium (29) is a powder-type element filled inside the chamber (21). The heat transfer medium (29) receives heat from the heater inside the chamber and is heated, and transfers heat to the descending water to heat and vaporize the water. That is, it generates steam by passing water, which is sprayed from the water spraying unit (25, 26) and descends due to the action of gravity, through the air gaps while being heated, in a state where it is heated itself.

[0055] The heat transfer medium in this embodiment is silicon carbide (SiC). The particle size of the silicon carbide can be varied, for example, it may have a particle size of 20 μm to 100 μm.

[0056] As is known, silicon carbide has high thermal conductivity and a very high melting point, which provides excellent thermal stability and allows it to maintain its physical and chemical properties stably even in high-temperature environments. In particular, it has a low coefficient of thermal expansion, so it hardly expands or contracts with changes in temperature. Since there is no concern about expansion, the heat transfer medium (29) can be filled inside the chamber (21). Of course, the more heat transfer medium (29) is added, the larger the heating surface area for the water becomes.

[0057] Since the heat transfer medium (29) itself has thermal conductivity, the heat emitted from the heater (27) is first transferred to the heat transfer medium (29) in direct contact with the heater (27), and then transferred sequentially to the surrounding heat transfer medium (29). Since the heat transfer medium (29) completely fills the interior of the chamber (21), the temperature inside the chamber (21) can be maintained uniformly. Eventually, the water sprayed from the water sprayer gradually descends due to the action of gravity, is heated by the heat transfer medium (29), and changes into steam.

[0058] The generated steam initially rises through the air gaps inside the chamber and fills the chamber's internal space from the top. Once the chamber is filled with steam, the steam then descends, passes downward through the support disc (31), and is discharged to the outside through the steam discharge tube (33). The discharged steam is supplied to the SOEC unit (40) through the steam transfer pipe (34).

[0059] Meanwhile, a spacing member is further provided inside the chamber (21). The spacing member maintains the spacing of the heater (27) and also serves to guide steam to the steam discharge tube (33). In this embodiment, the spacing member includes a support disc (31).

[0060] FIG. 7 is a cutaway perspective view showing the support disc (31) together with the steam discharge tube (33).

[0061] The support disc (31) is a disc-shaped member having a certain thickness. The periphery, or edge, of the support disc (31) is welded and fixed to the inner circumference of the chamber body (21a). In addition, six heater passage holes (31a) are formed in the support disc (31). The heater passage holes (31a) are holes through which heaters (27) pass. As the heaters (27) are fitted into the heater passage holes (31a), the spacing between the heaters (27) can be maintained at a constant level.

[0062] Additionally, a plurality of steam passages (31c) are provided in the main portion of the support disc (31). The steam passages (31c) are passages for sending steam generated inside the chamber downward. The steam guided downward through the steam passages (31c) passes through the lower space of the support disc (31) and exits through the discharge hole (33a) of the steam discharge tube (33).

[0063] The steam discharge tube (33) is a steam discharge section that discharges steam generated inside the chamber to the outside of the chamber. The steam discharge tube (33) is a vertical pipe of a certain diameter, the upper end is fixed to the bottom surface of the support disc (31), and the lower end extends to the bottom of the chamber (21). A plurality of discharge holes (33a) are formed in the steam discharge tube (33). Steam passes through the discharge holes (33a), flows through the steam discharge tube (33), and flows into the steam transfer pipe (34).

[0064] The steam generator (20) according to the present embodiment, as described above, can enable the SOEC unit (40) to produce hydrogen more stably by rapidly converting a quantitatively supplied water into steam through a heater and a heat transfer medium and delivering it to the SOEC unit (40).

[0065] Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical concept of the present invention.

Claims

1. A chamber that extends vertically and provides a sealed space; A water spray unit installed at the top of the chamber and spraying water into the chamber; A heater that heats water sprayed from a water spray unit to generate steam; A heat transfer medium that is filled inside a chamber, heats up by receiving heat from a heater, and transfers heat to descending water; A steam discharge unit comprising a steam discharge unit that discharges steam generated inside the chamber to the outside of the chamber, Steam generator for SOEC driving.

2. In Paragraph 1, In the above water spray unit, A spray tube having a plurality of water spray holes located at the center of the upper part of the chamber, Steam generator for SOEC driving.

3. In Paragraph 1, The above water spray unit is, An inlet tube that receives water supplied from the outside and guides it into the chamber, and Having a spray bar connected to an inlet tube, extending longitudinally within a chamber, and having a plurality of water spray holes, Steam generator for SOEC driving.

4. In Paragraph 3, The above-mentioned inlet tube is installed vertically in the center of the upper part of the chamber, and Multiple spray bars are applied, extending radially from the inlet tube and forming a symmetrical structure. Steam generator for SOEC driving.

5. In Paragraph 1, The above heater takes the shape of a round bar, and a plurality of them are symmetrical with respect to the central axis of the chamber. Steam generator for SOEC driving.

6. In Paragraph 5, The above heat transfer medium is, It takes the form of a powder and heats water that is sprayed from a water sprayer and descends due to the action of gravity by passing it through the pores. Steam generator for SOEC driving.

7. In Paragraph 6, The above heat transfer medium includes silicon carbide (SiC). Steam generator for SOEC driving.

8. In Paragraph 5, Inside the above chamber, a spacing member for maintaining the spacing of the heaters is further provided. Steam generator for SOEC driving.

9. In Paragraph 8, In the above spacing member, A support disc having the shape of a disc, with a peripheral portion fixed to the inner circumference of a chamber, and comprising a plurality of heater passage holes for passing a heater, and a steam passage for passing steam downward and guiding it to a steam discharge portion. Steam generator for SOEC driving.

10. In Paragraph 5, In the above heater, Equipped with a heat transfer surface area expander that expands the heat dissipation surface area of ​​the heater, Steam generator for SOEC driving.

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