WO2025239513A1 - Steam generation unit and solid oxide electrolyzer system - Google Patents

Abstract

Disclosed are a steam generation unit and a solid oxide electrolyzer system. The disclosed steam generation unit comprises: a pre-heater for heating low-temperature supply water to convert same into high-temperature supply water; and an evaporator for heating the high-temperature supply water to convert same into supply steam.

Description

Steam generation unit and solid oxide water electrolysis system

A steam generation unit and a solid oxide electrolysis system are disclosed. More specifically, a steam generation unit and a solid oxide electrolysis system are disclosed that are configured to increase space efficiency and price competitiveness and enable mass production.

Existing high-temperature water electrolysis systems have the problem that waste heat transfer of the product is limited and a lot of energy is required for cooling to separate water and hydrogen.

Additionally, cooling through the air cooler, energy consumption due to the water and hydrogen separation process, and waste heat generation due to high-temperature exhaust air (since the waste heat of the exhaust air is transferred through the already heated feed water as it passes through the product/water exchanger, the exhaust air discharged to the outside of the system inevitably becomes high temperature) all reduce energy efficiency.

Additionally, irreversible energy loss occurs during the process of cooling the product and then recirculating and reheating it.

Additionally, the separation of the separator and buffer vessel incurs additional CAPEX (Capital ExpenditurPD), and additional costs are incurred due to structural limitations that require the separator to be positioned on top of the buffer vessel for fluid flow from the separator to the buffer vessel.

In addition, existing solid oxide electrolysis systems have unsatisfactory problems in terms of space efficiency, price competitiveness, and mass production.

One embodiment of the present invention provides a steam generation unit configured to increase space efficiency and price competitiveness and to enable mass production.

Another embodiment of the present invention provides a solid oxide electrolysis system comprising the steam generation unit.

One aspect of the present invention is:

A preheater configured to heat low-temperature feed water and convert it into high-temperature feed water; and

A steam generation unit is provided, which includes an evaporator configured to heat the high temperature feed water and convert it into feed steam.

The above preheater may include a heat exchanger.

The above preheater may further include a supply water inlet, an internal supply water path, and a supply water outlet in this order, which are in fluid communication with each other.

The above preheater is fluidly connected to each other, but fluidly isolated from the supply water inlet, the internal supply water passage, and the supply water outlet, and may further include an exhaust inlet, an internal exhaust passage, and an exhaust outlet in that order.

The above evaporator may include a water heater in fluid communication with a supply water outlet of the preheater and a supply steam path in fluid communication with the water heater.

The above water heater may include a heating coil.

The above steam generating unit may further include an external supply water path disposed between the supply water outlet of the preheater and the water heater and in fluid communication therewith.

The water heaters may be a plurality, and the steam generation unit may further include a supply water manifold configured to distribute high-temperature supply water discharged from the external supply water path to the plurality of water heaters.

It may further include a supply steam manifold configured to transfer the supply steam generated from the plurality of water heaters to the supply steam path.

The above supply water manifold and the above supply steam manifold can be arranged spaced apart from each other by a predetermined height.

Another aspect of the present invention is:

A solid oxide electrolysis system including the above steam generation unit is provided.

The above solid oxide electrolysis system may further include a stack including a fuel electrode, an electrolyte, and an air electrode; an anode recuperator configured to heat-exchange a product discharged from the fuel electrode and steam supplied to the fuel electrode; a recycle blower configured to recirculate a portion of the product discharged from the fuel electrode recuperator to the fuel electrode recuperator; an air blower configured to supply supply air to the air electrode; and an air electrode recuperator configured to heat-exchange exhaust discharged from the air electrode and supply air supplied to the air electrode.

The above solid oxide electrolysis system can be configured to discharge the remainder of the product discharged from the fuel electrode recuperator to the outside.

It may further include a fuel electrode heater configured to heat steam discharged from the fuel electrode recuperator and supply it to the fuel electrode.

It may further include an air electrode heater configured to heat the supply air discharged from the air electrode recuperator and supply it to the air electrode.

The above solid oxide electrolysis system may further include an air dryer configured to dry the supply air discharged from the air blower.

The above solid oxide electrolysis system may further include an air preheater configured to heat the supply air discharged from the air blower.

The above solid oxide electrolysis system may further include a filter configured to remove impurities in the supply air and supply it to the air blower.

The steam generation unit and solid oxide electrolysis system according to one embodiment of the present invention have the advantages of increasing space efficiency and price competitiveness and enabling mass production.

FIG. 1 is a side perspective view of a steam generating unit according to one embodiment of the present invention.

FIG. 2 is a side view of a steam generating unit according to one embodiment of the present invention.

FIG. 3 is a perspective view of the other side of a steam generating unit according to one embodiment of the present invention.

FIG. 4 is a schematic diagram of a solid oxide electrolysis system according to one embodiment of the present invention.

Hereinafter, a steam generation unit and a solid oxide electrolysis system according to one embodiment of the present invention will be described in detail with reference to the drawings.

In this specification, “supply air” means all air existing between the supply air inlet and the stack, and “exhaust” means all air existing between the stack and the exhaust outlet.

Also, in this specification, “fluid communication” means that two or more members are connected so that a fluid can flow through the interior thereof.

Also, in this specification, "fluid separation" means that two or more members are configured so that fluid does not flow from one member to the other.

Also in this specification, "product" means hydrogen, steam, water or a combination thereof.

FIG. 1 is a one-side perspective view of a steam generating unit (SGU) according to one embodiment of the present invention, FIG. 2 is a one-side perspective view of a steam generating unit (SGU) according to one embodiment of the present invention, and FIG. 3 is a another-side perspective view of a steam generating unit (SGU) according to one embodiment of the present invention.

Referring to FIGS. 1 to 3, a steam generation unit (SGU) according to one embodiment of the present invention includes a preheater (PH) and an evaporator (EVP).

The preheater (PH) can be configured to heat the low temperature feed water (CSW) and convert it into high temperature feed water (HSW).

The preheater (PH) may include a heat exchanger (HEXP).

Additionally, the preheater (PH) may further include a feed water inlet (SWi), an internal feed water path (not shown), and a feed water outlet (SWo) in that order.

The above internal supply water paths may be multiple and may be arranged inside the heat exchanger (HEXP).

The supply water inlet (SWi), the internal supply water path, and the supply water outlet (SWo) may be in fluid communication with each other.

Additionally, the preheater (PH) may further include an exhaust inlet (EAi), an internal exhaust path (not shown), and an exhaust outlet (EAo) in that order.

The above internal exhaust paths may be multiple and may be arranged inside the heat exchanger (HEXP).

The exhaust inlet (EAi), the internal exhaust path and the exhaust outlet (EAo) may be in fluid communication with each other, but may be fluidly isolated from the supply water inlet (SWi), the internal supply water path and the supply water outlet (SWo).

The evaporator (EVP) can be configured to heat high temperature feed water (HSW) and convert it into feed steam (SS).

The evaporator (EVP) may include a water heater (WEH) and a supply steam path (SSP).

The water heater (WEH) may be in fluid communication with the supply water outlet (SWo) of the preheater (PH).

The supply steam flow (SSP) may be in fluid communication with the water electric heater (WEH).

The water heater (WEH) may have a cylindrical structure. However, the present invention is not limited thereto.

Additionally, the water heater (WEH) may include a heating coil (HC).

Although not shown in the drawing, the heating coil (HC) may include a cylindrical sheath, an electrical insulating material filling an inner cavity of the cylindrical sheath, and a wire embedded in the electrical insulating material.

The above outer shell is in direct contact with high-temperature feed water (HSW) and serves to heat the high-temperature feed water (HSW) and convert it into feed steam (SS). Therefore, the outer shell may include a metal with excellent corrosion resistance and thermal conductivity.

The electrical insulating material serves to block electrical conduction between the wire and the outer covering and promote thermal conduction. For example, the electrical insulating material may include magnesium oxide (MgO).

The above wire serves to convert electrical energy into thermal energy. For example, the above wire may include an alloy of nickel and chromium.

Additionally, the steam generation unit (SGU) may further include an external feed water path (SWP).

An external supply water path (SWP) may be arranged between a supply water outlet (SWo) of a preheater (PH) and a water heater (WEH) and may be in fluid communication with them. Specifically, one end of the external supply water path (SWP) may be in fluid communication with the supply water outlet (SWo) of the preheater (PH), and the other end of the external supply water path (SWP) may be in fluid communication with one side of the water heater (WEH).

There may be multiple water heaters (WEH). For example, there may be three or four water heaters (WEH), but the present invention is not limited thereto. In this case, the steam generation unit (SGU) may further include a feedwater manifold (SWM). Additionally, the multiple water heaters (WEH) may be arranged radially.

A feedwater manifold (SWM) may be configured to distribute high temperature feedwater (HSW) discharged from an external feedwater path (SWP) to a plurality of water heaters (WEH). Additionally, the feedwater manifold (SWM) may have a radial configuration.

Additionally, the steam generation unit (SGU) may further include a supply steam manifold (SSM).

A supply steam manifold (SSM) may be configured to transfer supply steam (SS) generated from multiple water heaters (WEH) to a supply steam path (SSP). For example, the supply steam manifold (SSM) may have a radial configuration.

The feed water manifold (SWM) and the feed steam manifold (SSM) can be arranged to be spaced apart from each other by a predetermined height (i.e., the height between the position where high temperature feed water (HSW) flows into the water heater (WEH) and the position where the high temperature feed water (HSW) is converted to feed steam (SS) by more than 95 wt%).

A steam generation unit (SGU) according to one embodiment of the present invention having the above configuration has the advantages of increasing space efficiency and price competitiveness and enabling mass production.

FIG. 4 is a schematic diagram of a solid oxide electrolysis system (SOEC) according to one embodiment of the present invention.

Referring to FIG. 4, a solid oxide electrolysis system (SOEC) according to one embodiment of the present invention includes the steam generation unit (SGU) described above.

Also, referring to FIG. 4, a solid oxide electrolysis system (SOEC) according to one embodiment of the present invention may further include a stack (ST), a fuel electrode recuperator (FR), a recycle blower (RB), and an air electrode recuperator (AR).

A stack (ST) may include a fuel electrode (FE), an electrolyte (EL), and an air electrode (AE).

At the fuel electrode (FE), the reaction of the following reaction formula 1 occurs, and at the air electrode (AE), the reaction of the following reaction formula 2 occurs, and the overall reaction can be expressed as in the following reaction formula 3.

[Reaction Formula 1]

H ₂ O + 2e ^- → H ₂ + O ^2-

[Reaction Formula 2]

2O ^2- → O ₂ + 4e ^-

[Reaction Formula 3]

2H ₂ O → 2H ₂ + O ₂

Additionally, the fuel electrode (FE) may include Ni-doped yttrium-stabilized zirconia (YSZ), perovskite lanthanum strontium manganese (LSM), lanthanum strontium manganese chromate (LSCM), scandium-doped LCSM, or a combination thereof.

The electrolyte (EL) may include 8 mol% Y ₂ O ₃ doped ZrO ₂ (YSZ), scandia stabilized zirconia (ScSZ), a ceria-based electrolyte, a lanthanum gallate material, or a combination thereof.

The air electrode (AE) may include LSM, a material obtained by impregnating LSM with Gd-doped CeO ₂ (GDC) nanoparticles, or a combination thereof.

Additionally, the stack (ST) can be operated at high temperatures of 600 to 850°C.

The fuel electrode recuperator (FR) may be configured to heat-exchange the product discharged from the fuel electrode (FE) with the steam supplied to the fuel electrode (FE). Specifically, the fuel electrode recuperator (FR) may be configured to heat-exchange the product discharged from the fuel electrode (FE) with the steam supplied to the fuel electrode (FE), thereby cooling the product and heating the steam. At this time, the waste heat in the product may be transferred to the steam and transported (primary transport of product waste heat).

In addition, the fuel electrode recuperator (FR), stack (ST) and air electrode recuperator (AR) described below are devices that constitute a high-temperature section that operates at 300°C or higher, and can be packaged with a high-temperature insulating material (not shown) to minimize heat loss.

Additionally, the fuel electrode recuperator (FR) can be configured to transfer as much waste heat from the product as possible to the feed water (SW) to minimize the temperature of hydrogen (H ₂ ) discharged to the outside of the solid oxide electrolysis system (SOEC), and also to minimize heat loss in the piping.

The supply water (SW) may be demineralized water.

Additionally, the fuel electrode recuperator (FR), stack (ST), and air electrode recuperator (AR) described below can be configured to minimize volume and weight and maximize high-temperature durability.

A recycle blower (RB) may be configured to recirculate a portion (the first portion) of the product discharged from the fuel electrode recuperator (FE) to the fuel electrode recuperator (FE). At this time, waste heat in the product (i.e., the first portion) may be transferred and transported to the fuel electrode recuperator (FR) (secondary transport of the product waste heat). The recycle blower (RB) may be configured to withstand a high temperature of 200°C or higher based on the discharge temperature, and accordingly, due to the product (i.e., the first portion) recirculated to the fuel electrode recuperator (FR), the fluid heat capacity of the fuel electrode recuperator (FR) and the stack (ST), which constitute the high temperature section, increases, thereby increasing temperature homeostasis, which may help extend the life of the stack (ST).

Additionally, the solid oxide electrolysis system (SOEC) can be configured to discharge the remainder (i.e., the second portion) of the products discharged from the fuel electrode recuperator (FR) to the outside.

Additionally, the solid oxide electrolysis system (SOEC) may further include a fuel electrode heater (FH).

The fuel electrode heater (FH) may be configured to additionally heat the steam and/or unevaporated residual water discharged from the fuel electrode recuperator (FR) and supply them to the fuel electrode (FE) of the stack (ST).

An air electrode recuperator (AR) may be configured to heat-exchange exhaust air (EA) discharged from an air electrode (AE) of a stack (ST) and supply air (SA) supplied to the air electrode (AE). Specifically, the air electrode recuperator (AR) may be configured to heat-exchange exhaust air (EA) discharged from an air electrode (AE) of a stack (ST) and supply air (SA) supplied to the air electrode (AE), thereby cooling the exhaust air (EA) and heating the supply air (SA) (primary transfer of exhaust air (EA) waste heat).

Additionally, the air electrode recuperator (AR) can be configured to transfer as much waste heat as possible in the exhaust (EA) to the supply air (SA) to minimize the temperature of the exhaust (EA) discharged to the outside of the solid oxide electrolysis system (SOEC), and also to minimize heat loss in the piping.

A steam generation unit (SGU) may be configured to heat feedwater (SW) and convert it into feed steam (SS).

Specifically, the steam generation unit (SGU) may include a preheater (PH) and an evaporator (EVP), as described above with reference to FIGS. 1 to 3.

A preheater (PH) may be configured to heat-exchange the feed water (SW) and the exhaust air (EA) discharged from the air cathode recuperator (AR). Specifically, the preheater (PH) may be configured to heat-exchange the feed water (SW) and the exhaust air (EA) discharged from the air cathode recuperator (AR) to heat the feed water (SW) and cool the exhaust air (EA) discharged from the air cathode recuperator (AR). At this time, waste heat in the exhaust air (EA) discharged from the air cathode recuperator (AR) may be transferred to the feed water (SW) (secondary transfer of exhaust air (EA) waste heat).

The evaporator (EVP) can be configured to secondarily heat the feed water (SW) that has been primarily heated in the preheater (PH).

Additionally, the solid oxide electrolysis system (SOEC) may further include an air electrode heater (AH).

The air electrode heater (AH) can be configured to heat the supply air (SA) discharged from the air electrode recuperator (AR) and supply it to the air electrode (AE) of the stack (ST).

Additionally, the solid oxide electrolysis system (SOEC) may further include an air blower (AB).

The air blower (AB) can be configured to supply supply air (SA) to the air electrode (AE) of the stack (ST).

Additionally, the solid oxide electrolysis system (SOEC) may further include an air dryer (AD).

The air dryer (AD) can be configured to dry the supply air (SA) discharged from the air blower (AB).

Additionally, the solid oxide electrolysis system (SOEC) may further include a filter (FT).

The filter (FT) can be configured to remove impurities in the supply air (SA) and supply it to the air blower (AB).

The above impurities may include dust, sulfur-containing compounds, or a combination thereof.

Additionally, the solid oxide electrolysis system (SOEC) may further include an air preheater (APH).

The air preheater (APH) can be configured to heat the supply air (SA) discharged from the air blower (AB) and supply it to the air electrode recuperator (AR).

In addition, the solid oxide electrolysis system (SOEC) can be configured to supply supply air (SA) discharged from an air blower (AB) to an air electrode recuperator (AR) during normal operation (V5: open, V6: closed), and to discharge supply air (SA) discharged from the air blower (AB) to the outside for moisture removal during maintenance (V5: closed, V6: open).

A solid oxide electrolysis system (SOEC) according to one embodiment of the present invention having the above configuration has the advantages of being able to increase space efficiency and price competitiveness and being capable of mass production.

While the present invention has been described with reference to the drawings, these are merely exemplary, and those skilled in the art will appreciate that various modifications and equivalent implementations are possible. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the appended claims.

[Explanation of symbols]

SGU: Steam Generation Unit FRM: Frame

PH: Preheater EAi: Exhaust inlet

EAo: Exhaust outlet HEA: High temperature exhaust

CEA: Low Temperature Exhaust HEXP: Heat Exchanger

SWi: Supply water inlet SWo: Supply water outlet

CSW: Low Temperature Feedwater HSW: High Temperature Feedwater

EVP: Evaporator WEH: Water Heater

HC: Heating Coil SSP: Supply Steam Euro

SWP: Feed Water Euro SSM: Feed Steam Manifold

SWM: Feedwater Manifold FR: Fuel Anode Recuperator

FH: Fuel electrode heater AR: Air electrode recuperator

AH: Air electrode heater ST: Stack

SOEC: Solid Oxide Electrolysis System SW: Feedwater

RB: Recycle blower FE: Fuel electrode

EL: Electrolyte AE: Air electrode

SA: Supply air FT: Filter

AB: Air blower AD: Air dryer

APH: Air Preheater EA: Exhaust

V1~V6: Valves

Claims (18)

A preheater configured to heat low-temperature feed water and convert it into high-temperature feed water; and A steam generating unit comprising an evaporator configured to heat the high temperature feed water and convert it into feed steam. In the first paragraph, The above preheater is a steam generating unit including a heat exchanger. In the first paragraph, The above preheater is a steam generating unit further comprising a feed water inlet, an internal feed water path, and a feed water outlet in this order, which are in fluid communication with each other. In the third paragraph, A steam generating unit in which the preheaters are fluidly connected to each other, but fluidly isolated from the supply water inlet, the internal supply water passage, and the supply water outlet, and further includes an exhaust inlet, an internal exhaust passage, and an exhaust outlet in that order. In paragraph 4, The above evaporator is a steam generating unit including a water heater in fluid communication with the supply water outlet of the preheater and a supply steam path in fluid communication with the water heater. In paragraph 5, The above water heater is a steam generating unit including a heating coil. In paragraph 5, A steam generation unit further comprising an external supply water path disposed between the supply water outlet of the above preheater and the water heater and in fluid communication therewith. In paragraph 6, A steam generation unit further comprising a plurality of water heaters and a supply water manifold configured to distribute high-temperature supply water discharged from the external supply water path to the plurality of water heaters. In paragraph 8, A steam generation unit further comprising a supply steam manifold configured to transfer the supply steam generated from the plurality of water heaters to the supply steam path. In paragraph 9, A steam generating unit in which the above supply water manifold and the above supply steam manifold are spaced apart from each other by a predetermined height. A solid oxide electrolysis system comprising a steam generation unit according to any one of claims 1 to 10. In Article 11, A stack comprising a fuel electrode, an electrolyte and an air electrode; A fuel electrode recuperator configured to heat-exchange the product discharged from the fuel electrode and the steam supplied to the fuel electrode; A recycle blower configured to recirculate a portion of the products discharged from the fuel electrode recuperator to the fuel electrode recuperator; An air blower configured to supply supply air to the air electrode; and A solid oxide electrolysis system further comprising an air electrode recuperator configured to heat-exchange exhaust air discharged from the air electrode and supply air supplied to the air electrode. In Article 12, A solid oxide electrolysis system configured to discharge the remainder of the products discharged from the above fuel electrode recuperator to the outside. In Article 12, A solid oxide water electrolysis system further comprising a fuel electrode heater configured to heat steam discharged from the fuel electrode recuperator and supply the heated steam to the fuel electrode. In Article 12, A solid oxide water electrolysis system further comprising an air electrode heater configured to heat the supply air discharged from the air electrode recuperator and supply it to the air electrode. In Article 12, A solid oxide electrolysis system further comprising an air dryer configured to dry the supply air discharged from the air blower. In Article 12, A solid oxide electrolysis system further comprising an air preheater configured to heat the supply air discharged from the air blower. In Article 12, A solid oxide electrolysis system further comprising a filter configured to remove impurities in the supply air and supply the removed air to the air blower.