SOEC water supply system and control method thereof

Abstract

The invention relates to the technical field of hydrogen production, in particular to an SOEC water supply system and a control method thereof. A water evaporator is communicated with a water tank; an input port and an output port of the filter are communicated with the water evaporator and the electric pile respectively, and a pressure monitoring assembly is arranged on the filter and used for detecting the pressure difference between the input port and the output port of the filter in real time; the cleaning device is communicated with the water evaporator and is used for washing the filter; the controller is in signal connection with the cleaning device and the pressure monitoring assembly, and the controller is used for driving the cleaning device to flush the filter or stop flushing according to the pressure difference data. The pressure monitoring component monitors the pressure difference between the inlet and the outlet of the filter before entering the electric pile, judges whether scale accumulation occurs or not according to the pressure difference, and performs backwashing by using the cleaning device if scale accumulation occurs, so that automatic washing is realized, the maintenance time is shortened, the system shutdown time is reduced, and non-shutdown maintenance is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production, and in particular to a SOEC water supply system and a control method thereof. Background Art

[0002] The Solid Oxide Electrolysis Cell (SOEC) is a high-temperature electrochemical device that uses electricity to efficiently convert water vapor (H2O) or carbon dioxide (CO2) into hydrogen (H2), oxygen (O2), or synthesis gas (CO + H2). Its core technology is the opposite of the solid oxide fuel cell (SOFC). While the latter generates electricity through the hydrogen-oxygen reaction, the SOEC uses electricity to drive the chemical reaction, achieving green energy storage and conversion.

[0003] In the related art, the operation of the SOEC system requires the use of a water evaporator to convert liquid water into water vapor. However, the operating characteristics of the SOEC system will cause its equipment to be in a high-temperature environment for a long time. The high temperature will cause mineral ions such as calcium and magnesium in the liquid water to combine with carbonate and sulfate ions to form water-insoluble precipitates such as calcium carbonate and calcium sulfate. At the same time, the high temperature will reduce the solubility of these salts and accelerate the evaporation of water, which will increase the ion concentration, causing crystal precipitation and adhesion to the metal surface, eventually forming a hard scale layer, and finally forming scale in the water evaporator. The scale may enter the stack through the pipes under the erosion of water flow and high-temperature steam flow. Once the scale enters the SOEC stack, its performance will be seriously affected: the sediment will block the electrode pores and hinder gas diffusion, cover the active sites of the catalyst and reduce the reaction efficiency, and induce thermal stress to damage the electrolyte layer at high temperature, ultimately leading to a decrease in electrolysis efficiency, an increase in ohmic loss and a shortened stack life. Summary of the Invention

[0004] Regarding the related technology, SOEC system equipment is prone to scale generation in a high-temperature environment. The scale may enter the fuel cell stack through the pipeline under the flushing of water flow and high-temperature steam flow, seriously affecting its performance.

[0005] In a first aspect, an embodiment of the present application provides a SOEC water supply system, which includes: a water tank, a water evaporator, a filter, a cleaning device and a controller; wherein, a water evaporator in communication with the water tank; A filter, whose input and output ports are respectively connected to the water evaporator and the fuel cell stack, and the filter is provided with a pressure monitoring component, which is used to detect the pressure difference between the input and output ports of the filter in real time; a cleaning device, which is in communication with the water evaporator, and is used to flush the filter; a controller connected to the cleaning device and the pressure monitoring component by signal, the controller being configured to drive the cleaning device to flush or stop flushing the filter based on pressure difference data; When the pressure difference between the filter input and output ports meets the preset range, the cleaning device does not take action; When the pressure difference between the filter input port and the filter output port does not meet the preset range, the controller drives the cleaning device to flush and clean the filter until the pressure difference between the filter input port and the filter output port meets the preset range.

[0006] In combination with the first aspect, in one embodiment, the cleaning device includes: a first stop valve, which is provided on the delivery pipeline between the water evaporator and the filter, and the first stop valve is connected to the controller signal; a water delivery pipeline, one end of which is connected to the water tank, and the other end of which is connected to the water outlet of the filter and the battery stack; A second stop valve is provided on the delivery pipeline between the water evaporator and the fuel cell stack. The second stop valve is used to open the delivery pipeline to allow the liquid water in the water delivery pipeline to flow to the fuel cell stack, or to cut off the delivery pipeline to allow the liquid water in the water delivery pipeline to flow to the filter to flush the filter.

[0007] In combination with the first aspect, in one embodiment, the cleaning device further includes: a reflux circuit, a water outlet of which is connected to the water tank, and a water inlet of the reflux circuit is provided on the delivery pipeline between the first stop valve and the filter.

[0008] In combination with the first aspect, in one embodiment, the reflux circuit includes: a return line, one end of which is connected to the water tank and the other end of which is arranged between the first stop valve and the filter; A bypass valve is provided on the return line and is connected to the controller signal.

[0009] In combination with the first aspect, in one embodiment, a filter element is detachably provided on the return line.

[0010] In combination with the first aspect, in one embodiment, a manual valve is provided on the return line.

[0011] In conjunction with the first aspect, in one embodiment, the pressure monitoring component includes: a first pressure sensor, which is provided at the filter input port; The second pressure sensor is arranged at the filter output port.

[0012] In combination with the first aspect, in one embodiment, a water pump is provided on the delivery pipeline between the water tank and the water evaporator.

[0013] In combination with the first aspect, in one embodiment, a deionizer is provided on the delivery pipeline between the water tank and the water evaporator.

[0014] In a second aspect, an embodiment of the present application provides a control method for a water supply system using the SOEC described in any one of the above items, comprising the following steps: driving the water tank to transport water to the water evaporator, and using the water evaporator to convert liquid water into water vapor; Use the pressure monitoring component to monitor the pressure difference between the filter input and output in real time, and use the controller to judge the pressure difference data; When the pressure difference between the filter input and output ports meets the preset range, the cleaning device does not take action; When the pressure difference between the filter input port and the filter output port does not meet the preset range, the controller drives the cleaning device to flush and clean the filter until the pressure difference between the filter input port and the filter output port meets the preset range.

[0015] The beneficial effects of the technical solutions provided in the embodiments of the present application include: This application uses a pressure monitoring component to monitor the pressure difference between the inlet and outlet of the filter before entering the fuel cell stack, and determines whether scale accumulation occurs based on the pressure difference. If scale accumulation occurs, a cleaning device is used for backwashing to achieve automatic flushing, shorten maintenance time, reduce system downtime, and achieve maintenance without stopping the machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 This is a schematic diagram of the SOEC water supply system in an embodiment of the present application; Figure 2 This is a flow chart of the control method of the SOEC water supply system in the embodiment of the present application.

[0018] In the figure: 1. Water tank; 11. Liquid level sensor; 12. Temperature sensor; 2. Water evaporator; 3. Filter; 4. Fuel cell stack; 51. First stop valve; 52. Second stop valve; 53. Water supply pipeline; 6. Return pipeline; 61. Bypass valve; 62. Filter element; 63. Hand valve; 71. First pressure sensor; 72. Second pressure sensor; 8. Water pump; 81. Flow meter; 9. Deionizer; 91. Conductivity sensor. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] Regarding the related technology, SOEC system equipment is prone to scale generation in a high-temperature environment. The scale may enter the fuel cell stack through the pipeline under the flushing of water flow and high-temperature steam flow, seriously affecting its performance.

[0021] In a first aspect, the present application provides a SOEC water supply system, which comprises: a water tank 1, a water evaporator 2, a filter 3, a cleaning device and a controller; wherein, A water evaporator 2 is connected to the water tank 1; a filter 3 has an input and output port connected to the water evaporator 2 and the fuel cell stack 4, respectively; the filter 3 is provided with a pressure monitoring component for detecting the pressure difference between the input and output ports of the filter 3 in real time; a cleaning device is connected to the water evaporator 2 and is used to flush the filter 3; a controller is connected to the cleaning device and the pressure monitoring component by signal, and is used to drive the cleaning device to flush or stop flushing the filter 3 based on pressure difference data; When the pressure difference between the input and output ports of the filter 3 meets the preset range, the cleaning device does not take action; When the pressure difference between the input port and the output port of the filter 3 does not meet the preset range, the controller drives the cleaning device to flush and clean the filter 3 until the pressure difference between the input port and the output port of the filter 3 meets the preset range.

[0022] It should be noted that due to the high temperature operating characteristics of the SOEC system, the water evaporator 2 operates in a high-temperature environment for a long time. The high temperature causes mineral ions such as calcium and magnesium in the water to combine with carbonate and sulfate ions, forming water-insoluble precipitates such as calcium carbonate and calcium sulfate. At the same time, high temperature reduces the solubility of these salts and accelerates water evaporation, which increases the ion concentration, causing crystal precipitation and adhesion to the metal surface, eventually forming a hard scale layer. The present application adds a filter 3 to filter the medium discharged from the water evaporator 2 before entering the fuel cell stack. However, the filter will block most impurities and particulate matter on the filter inlet side. Over time, the filter will become clogged and the flow resistance will increase until it is completely clogged. To solve this problem, the present application arranges pressure sensors at the inlet and outlet of the filter 3 to monitor the inlet and outlet pressure difference. Once it is found to be clogged, it is cleaned immediately to prevent scale clogging and reduce the working efficiency of the SOEC system equipment.

[0023] In some preferred embodiments, the cleaning device includes: a first stop valve 51, a second stop valve 52 and a water supply pipeline 53; wherein, A first stop valve 51 is provided on the delivery pipeline between the water evaporator 2 and the filter 3, and the first stop valve 51 is connected to the controller signal; a water delivery pipeline 53, one end of which is connected to the water tank 1, and the other end is connected to the water outlet of the filter 3 and the fuel cell stack 4; a second stop valve 52 is provided on the delivery pipeline between the water evaporator 2 and the fuel cell stack 4, and the second stop valve 52 is used to open the delivery pipeline so that the liquid water in the water delivery pipeline 53 flows to the fuel cell stack 4, or to cut off the delivery pipeline so that the liquid water in the water delivery pipeline 53 flows to the filter 3 to flush the filter 3.

[0024] Furthermore, when the SOEC water supply system is operating, if it is determined that filter 3 does not need to be cleaned, the first and second stop valves 51, 52 can be simultaneously opened. At this time, water in the water tank 1 flows through the water pipeline 53 and the second stop valve 52 into the fuel cell stack 4 for reaction. When it is determined that filter 3 needs to be cleaned, the first and second stop valves 51, 52 are simultaneously closed. At this time, water in the water tank 1 flows through the water pipeline 53 and into the water outlet of the filter 3 to backwash the filter 3.

[0025] It is worth noting that the cleaning device in the preferred embodiment described above does not include an additional cleaning device to flush the filter. Instead, two shutoff valves are used in conjunction with the water supply line 53 to backwash the filter 3. This application, based on the steam pressure difference between the inlet and outlet of the filter 3, backwashes the filter 3 via the first shutoff valve 51 and the second shutoff valve 52 if the pressure difference does not meet the required level. Furthermore, the liquid water used for backwashing rinses the filter 3 and then flows back into the water tank 1, completing the cycle.

[0026] In some preferred embodiments, the cleaning device further comprises: a reflux circuit, a water outlet of which is connected to the water tank 1 , and a water inlet of the reflux circuit is provided on the delivery pipeline between the first stop valve 51 and the filter 3 .

[0027] It is worth noting that the reflux circuit cooperates with the first stop valve 51 and the second stop valve 52 to guide the liquid water after backwashing into the water tank 1. On the one hand, it does not affect the water vapor flow channel generated by the functional components of the water evaporator 2, and on the other hand, it does not increase water consumption.

[0028] Specifically, the reflux circuit includes: a reflux line 6 and a bypass valve 61; wherein, The return line 6 has one end connected to the water tank 1 and the other end arranged between the first stop valve 51 and the filter 3; the bypass valve 61 is arranged on the return line 6, and the bypass valve 61 is connected to the controller signal.

[0029] Furthermore, the bypass valve 61 is connected to the controller signal. When the controller determines that the pressure difference between the inlet and outlet of the filter 3 does not meet the requirements, it will open the bypass valve 61 to allow the backwash liquid water to flow into the return pipe 6 through the bypass valve 61.

[0030] In some preferred embodiments, a filter element 62 is detachably provided on the return line 6 .

[0031] It's worth noting that scale accumulated in the filter 3 will enter the return line after backwashing. If left untreated, it will flow through the return line into the water tank 1. Therefore, a removable and replaceable filter element 62 is provided on the return line 6. This not only allows the filter element 62 to filter out scale, but also makes it easy for operators to replace it at any time.

[0032] Optionally, the filter element 62 is a deionizer filter element.

[0033] It is worth noting that the deionizer filter element can adsorb ions in the supplied water to reduce the conductivity of the water.

[0034] In some optional implementations, a manual valve 63 is provided on the return line 6 .

[0035] It is understandable that the manual valve 63 is used for an operator to manually operate the opening and closing of the return line 6 .

[0036] In some specific implementations, the pressure monitoring assembly includes: a first pressure sensor 71 and a second pressure sensor 72; wherein, The first pressure sensor 71 is provided at the input port of the filter 3 ; the second pressure sensor 72 is provided at the output port of the filter 3 .

[0037] It is understood that the controller can receive pressure information from the first pressure sensor 71 and the second pressure sensor 72 and calculate the pressure difference, and then determine whether the filter 3 is clogged based on the pressure difference.

[0038] In some optional embodiments, a water pump 8 is provided on the delivery pipeline between the water tank 1 and the water evaporator 2. Furthermore, a deionizer 9 is provided on the delivery pipeline between the water tank 1 and the water evaporator 2.

[0039] It is worth noting that the water pump 8 is used to adjust the water supply rate of the water tank 1.

[0040] Second, as Figure 2 As shown, the present application provides a control method for the SOEC water supply system using any of the above items, which comprises the following steps: Step S1: The system issues a power command and powers on the components.

[0041] Step S2: Use the water tank level sensor 11 to monitor the liquid level of the water tank 1 and execute according to the settings.

[0042] Specifically, when the liquid level in water tank 1 is lower than 30%, the system issues a yellow warning to remind you to add water. When the liquid level in water tank 1 is lower than 10%, the system issues a red warning to remind you to add water and limits power operation until the machine shuts down.

[0043] Step S3: If the liquid level of the water tank 1 is normal, the water pump 8 is controlled to start as required. At the same time, the temperature sensor 12 reads the water temperature and feeds it back to the controller. The controller adjusts the power of the water evaporator 2 according to the fed-back water temperature information.

[0044] Step S4: Use the flow meter 81 to determine whether the flow in the flow pipeline meets the demand. If it is less, adjust the power of the water pump 8. If it is more, open the bypass valve 61 to allow the excess water to flow back to the water tank 1. If it is normal, it flows into the ionizer 9.

[0045] Step S5: The conductivity sensor 91 monitors the conductivity at the outlet of the deionizer 9 in real time, and prompts the system to replace the filter element 62 under certain circumstances.

[0046] Specifically, the filter element 62 is a deionizer filter element.

[0047] It is worth noting that the deionizer filter element can adsorb ions in the supplied water to reduce the conductivity of the water.

[0048] Step S6: supply water to the water evaporator 2, and use the water evaporator 2 to convert liquid water into water vapor.

[0049] Specifically, the water vapor generated by the water evaporator 2 enters the filter 3 through the first stop valve 51 .

[0050] Step S7: Use the first pressure sensor 71 and the second pressure sensor 72 to monitor the pressure difference between the input port and the output port of the filter 3 in real time, and use the controller to judge the pressure difference data; wherein, Case A: If the pressure difference between the input port and the output port of the filter 3 satisfies a preset range, the controller drives the first stop valve 51 and the second stop valve 52 to maintain the conducting state.

[0051] It can be understood that the first stop valve 51 and the second stop valve 52 remain in an on state, and the gas enters the fuel cell stack 4 through the second stop valve 52 to react.

[0052] Case B: If the pressure difference between the input and output ports of the filter 3 does not meet the preset range, the controller drives the first stop valve 51 and the second stop valve 52 to be closed, and the water in the water supply pipeline 53 is diverted to the outlet of the filter 3 to backwash the filter 3. The liquid water after flushing flows into the water tank 1 through the bypass valve 61 and the reflux circuit.

[0053] To summarize, this application uses a pressure monitoring component to monitor the pressure difference between the inlet and outlet of the filter before entering the fuel cell stack, and determines whether scale accumulation occurs based on the pressure difference. If scale accumulation occurs, a cleaning device is used for backwashing to achieve automatic flushing, shorten maintenance time, reduce system downtime, and achieve maintenance without stopping the machine.

[0054] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0055] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0056] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A SOEC water supply system, characterized in that: include: Water tank (1); a water evaporator (2), which is in communication with the water tank (1); A filter (3), the input port and the output port of which are respectively connected to the water evaporator (2) and the fuel cell stack (4), and the filter (3) is provided with a pressure monitoring component, the pressure monitoring component being used to detect the pressure difference between the input port and the output port of the filter (3) in real time; a cleaning device, which is in communication with the water evaporator (2), and is used to flush the filter (3); a controller connected to the cleaning device and the pressure monitoring component signal, the controller being used to drive the cleaning device to flush or stop flushing the filter (3) according to pressure difference data; When the pressure difference between the input port and the output port of the filter (3) satisfies a preset range, the cleaning device does not take action; When the pressure difference between the input port and the output port of the filter (3) does not meet the preset range, the controller drives the cleaning device to flush and clean the filter (3) until the pressure difference between the input port and the output port of the filter (3) meets the preset range.

2. The SOEC water supply system according to claim 1, characterized in that The cleaning device comprises: A first stop valve (51) is provided on the delivery pipeline between the water evaporator (2) and the filter (3), wherein the first stop valve (51) is connected to the controller signal; A water delivery pipeline (53), one end of which is in communication with the water tank (1), and the other end of which is in communication with both the water outlet of the filter (3) and the battery stack (4); A second stop valve (52) is provided on the delivery pipeline between the water evaporator (2) and the fuel cell stack (4), and the second stop valve (52) is used to open the delivery pipeline to allow the liquid water in the water delivery pipeline (53) to flow to the fuel cell stack (4), or to close the delivery pipeline to allow the liquid water in the water delivery pipeline (53) to flow to the filter (3) to flush the filter (3).

3. The SOEC water supply system according to claim 2, wherein: The cleaning device further comprises a reflux circuit, the water outlet of which is in communication with the water tank (1), and the water inlet of the reflux circuit is arranged on the delivery pipeline between the first stop valve (51) and the filter (3).

4. The SOEC water supply system according to claim 3, wherein: The reflux circuit comprises: a return line (6), one end of which is in communication with the water tank (1) and the other end of which is disposed between the first stop valve (51) and the filter (3); A bypass valve (61) is provided on the return line (6), and the bypass valve (61) is connected to the controller signal.

5. The SOEC water supply system according to claim 4, wherein: A filter element (62) is detachably provided on the return line (6).

6. The SOEC water supply system according to claim 4, wherein: A hand valve (63) is provided on the return line (6).

7. The SOEC water supply system according to claim 1, wherein: The pressure monitoring component includes: a first pressure sensor (71), which is provided at the input port of the filter (3); A second pressure sensor (72) is provided at the output port of the filter (3).

8. The SOEC water supply system according to claim 1, wherein: A water pump (8) is provided on the delivery pipeline between the water tank (1) and the water evaporator (2).

9. The SOEC water supply system according to claim 1, wherein: A deionizer (9) is provided on the delivery pipeline between the water tank (1) and the water evaporator (2).

10. A control method using the SOEC water supply system according to claim 1, characterized in that: It includes the following steps: driving the water tank (1) to transport water to the water evaporator (2), and using the water evaporator to convert liquid water into water vapor; The pressure monitoring component is used to monitor the pressure difference between the input port and the output port of the filter (3) in real time, and the controller is used to judge the pressure difference data; wherein, When the pressure difference between the input port and the output port of the filter (3) satisfies a preset range, the cleaning device does not take action; When the pressure difference between the input port and the output port of the filter (3) does not meet the preset range, the controller drives the cleaning device to flush and clean the filter (3) until the pressure difference between the input port and the output port of the filter (3) meets the preset range.

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