A steam generation system based on SOEC and its control method

Abstract

The invention discloses a steam generation system based on SOEC and a control method thereof, comprising a water storage tank, a magnetic pump, a pressure-resistant water tank, a liquid mass flowmeter and a steam generator; the water storage tank, the magnetic pump, the pressure-resistant water tank, the liquid mass flowmeter and the steam generator are connected in sequence through pipelines; the steam outlet of the steam generator is connected to a steam delivery pipeline to deliver the generated steam to a subsequent steam-using unit; an electromagnetic regulating valve a for regulating flow is provided between the magnetic pump and the pressure-resistant water tank; a coupling electromagnetic valve for regulating flow is provided between the liquid mass flowmeter and the steam generator; the steam delivery pipeline is respectively connected to the steam-using unit and the exhaust pipeline, and a cut-off valve a and a cut-off valve b for opening and closing the pipeline are respectively provided at the connection points.

Description

Technical Field

[0001] The present invention relates to the field of solid oxide electrolysis technology (SOEC), and in particular to a steam generation system based on SOEC and a control method thereof. Background Art

[0002] Hydrogen has attracted more and more attention due to its advantages such as cleanliness, high calorific value, large raw material reserves, and rich application scenarios. It has become a carrier for my country to develop new energy. The premise of its large-scale utilization is to first solve the problem of hydrogen preparation. The products and processes of hydrogen production by electrolysis of water do not contain any pollutants, making it a clean method of hydrogen production.

[0003] At present, the main technologies for hydrogen production and energy storage by water electrolysis include alkaline electrolysis technology, solid polymer electrolysis technology (SPE) and solid oxide electrolysis technology (SOEC). Alkaline electrolysis technology is the most mature and has the lowest cost. It has been applied in large-scale hydrogen production, but its efficiency is relatively low. SPE water electrolysis is suitable for applications in fluctuating power supply occasions, but its cost is relatively high. Solid oxide water electrolysis technology (SOEC) uses solid oxide as electrolyte material and performs electricity-to-hydrogen conversion at high temperature. It has the advantages of high energy conversion efficiency, no need for precious metal catalysts, and low electrolysis voltage. It is currently the most promising water electrolysis technology.

[0004] At present, foreign companies conducting research in the field of SOEC include Germany's Sunfire, the US Idaho National Laboratory, Bloom Energy, Denmark's Topsoe Fuel Cell Company, the Korea Institute of Energy Research, and the EU Relhy high-temperature electrolysis technology development project. The research direction has gradually shifted from electrolytic cell material research to electrolytic cell stacks and system integration. From the research results in recent years, it is known that the SOEC stack power of the US Idaho National Laboratory project has reached 15kW. Germany's Sunfire launched initial products in 2017, and hydrogen refueling stations have begun demonstrations. In China, the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Tsinghua University, China University of Mining and Technology, State Grid Corporation of China, and University of Science and Technology of China have carried out SOEC-related research based on solid oxide fuel cell research. Since SOEC has very strict requirements on materials, its research direction is also targeted. For example, the attenuation mechanism and microstructure regulation of Ni in Ni / YSZ hydrogen electrode, which is easily oxidized and deactivated under high temperature and high humidity conditions during water electrolysis; the oxygen electrode of conventional materials has serious anodic polarization and is prone to delamination in the electrolysis mode, and the voltage loss of the oxygen electrode is much higher than the loss of the hydrogen electrode and the electrolyte. The development of new materials and new oxygen electrodes to reduce polarization loss. In terms of battery stack integration, new glass or glass-ceramic sealing materials are studied to increase the service life of materials. However, there is still little research on the electrolytic cell system level, especially in the invention and innovation of each module unit in the SOEC system.

[0005] Generally, the SOEC system mainly includes an electrolytic cell stack unit, a gas supply unit, a water vapor preparation unit, a gas preheating unit, an electrolytic cell charge and discharge unit, an exhaust gas treatment unit, etc. In the working mode of hydrogen production of the SOEC hydrogen production system, the intake gas is generally a mixture of hydrogen and water vapor, and the products are pure hydrogen and pure oxygen. A sufficiently high content of water vapor is required in the intake gas to ensure the smooth progress of electrolysis. Whether the high-temperature water vapor can be supplied continuously, accurately and stably is one of the key factors affecting the smooth operation of the SOEC system, and it is also a difficult problem that needs to be overcome urgently. At the same time, since the high-temperature steam generated by the steam unit is generally around 700°C, it is a high-temperature hazard source. How to improve the safety performance of the system unit under the premise of continuous and stable output of high-temperature steam is also a key point of research. At present, the patents related to the SOEC system that have been published include CN101067209A "High-temperature steam electrolysis hydrogen production electrode test device", CN101216495A "High-temperature water vapor electrolysis hydrogen production online test system and test method", CN105449250A "A kilowatt-level reversible solid oxide fuel cell-electrolyzer test system", CN208955118U "A solid oxide fuel cell exhaust gas treatment system based on a solid oxide electrolyzer", etc., but there are no relevant reports on the steam unit control method in the SOEC system. Summary of the invention

[0006] Purpose of the invention: The technical problem to be solved by the present invention is to provide a steam generation system based on SOEC and a control method thereof in view of the deficiencies in the prior art, so as to realize a continuous, accurate and stable supply of water vapor and ensure the smooth operation of the steam generation system in SOEC.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A steam generation system based on SOEC includes a water storage tank, a magnetic pump, a pressure-resistant water tank, a liquid mass flow meter and a steam generator;

[0009] The water storage tank, magnetic pump, pressure-resistant water tank, liquid mass flow meter and steam generator are connected in sequence through pipelines;

[0010] The steam outlet of the steam generator is connected to a steam delivery pipeline to deliver the generated steam to a subsequent steam-using unit;

[0011] An electromagnetic regulating valve a for regulating flow is provided between the magnetic pump and the pressure-resistant water tank;

[0012] A coupling solenoid valve for adjusting flow is provided between the liquid mass flow meter and the steam generator;

[0013] The steam delivery pipeline is connected to the steam using unit and the exhaust pipeline respectively, and a shut-off valve a and a shut-off valve b for opening and closing the pipeline are respectively provided at the connection points.

[0014] Furthermore, the tops of the pressure-resistant water tank and the steam generator are respectively connected back to the water storage tank through exhaust pipes, and the exhaust pipes are respectively provided with automatic exhaust valves and safety valves.

[0015] Furthermore, the magnetic pump and the electromagnetic regulating valve a are connected back to the water storage tank through a circulation pipeline, and the circulation pipeline is provided with an electromagnetic regulating valve b for adjusting the flow rate.

[0016] Furthermore, a drain outlet is provided at the bottom of the water storage tank, which is connected to an emptying pipe through a hand valve a, and the water in the water storage tank is drained through the emptying pipe; a hand valve b is provided at the water outlet of the emptying pipe.

[0017] Furthermore, a check valve is provided between the coupling solenoid valve and the steam generator.

[0018] Furthermore, the water tank is provided with a level gauge L1 for monitoring the water level in the water tank; the pressure-resistant water tank is provided with a pressure gauge P1 for monitoring the pressure in the pressure-resistant water tank; and the steam generator is provided with a temperature gauge T1 for monitoring the temperature in the steam generator.

[0019] Furthermore, a pressure gauge P2 and a temperature gauge T2 are provided on the steam delivery pipeline.

[0020] Furthermore, it also includes a PLC control system, the pins of which are respectively connected to the liquid level meter L1, the magnetic pump, the electromagnetic regulating valve b, the electromagnetic regulating valve a, the pressure gauge P1, the liquid mass flow meter, the coupling electromagnetic valve, the temperature gauge T1, the pressure gauge P2, the temperature gauge T2, the cut-off valve a and the cut-off valve b, and the buzzer.

[0021] The present invention also provides a control method for the steam generation system based on SOEC, comprising the following steps:

[0022] S1: The liquid level meter L1 monitors the water level signal of the water storage tank and sends it to the PLC control system. The PLC control system determines whether the water level signal is normal. If it is abnormal, the PLC control system sends a signal to the buzzer, and the buzzer alarms. If it is normal, it goes to step S2;

[0023] S2: The PLC control system sends a start signal to the electromagnetic regulating valve a and the electromagnetic regulating valve b, and the electromagnetic regulating valve a and the electromagnetic regulating valve b perform the action. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the PLC control system display screen. At the same time, a signal is sent to the buzzer, and the buzzer alarms. If it is normal, it goes to step S3;

[0024] S3: The PLC control system sends a start signal to the magnetic pump, and the magnetic pump executes the action. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the PLC control system display screen. At the same time, a signal is sent to the buzzer, and the buzzer alarms. If it is normal, the automatic exhaust valve automatically controls the exhaust, and enters step S4;

[0025] S4: The pressure gauge P1 monitors the pressure signal in the pressure-resistant water tank and sends the signal to the PLC control system. The PLC control system determines whether the pressure signal is normal. If it is abnormal, the PLC control system sends a regulating signal to the electromagnetic regulating valve a and the electromagnetic regulating valve b to adjust the corresponding opening. If the pressure signal is normal, it goes to step S5;

[0026] S5: The PLC control system sends a start signal to the liquid mass flow meter, the coupling solenoid valve and the cut-off valve b, and the liquid mass flow meter, the coupling solenoid valve and the cut-off valve b perform the action. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the PLC control system display screen. At the same time, a signal is sent to the buzzer, and the buzzer alarms. If it is normal, it goes to step S6;

[0027] S6: The PLC control system sends a start signal to the steam generator, and the steam generator executes the action. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the PLC control system display screen. At the same time, a signal is sent to the buzzer, and the buzzer alarms. If it is normal, it goes to step S7;

[0028] S7: The temperature meter T1 monitors the temperature signal in the steam generator and sends it to the PLC control system. The PLC control system determines whether the temperature signal is normal. If it is abnormal, the PLC control system display screen pops up an abnormal window and sends a signal to the buzzer at the same time. The buzzer alarms. If it is normal, it goes to step S8;

[0029] S8: The pressure gauge P2 and the temperature gauge T2 monitor the pressure signal and temperature signal of the steam in the steam delivery pipeline and send them to the PLC control system, which determines whether the temperature signal and the pressure signal meet the set conditions; if both meet, it proceeds to step S9; if at least one of the temperature signal and the pressure signal does not meet, the PLC control system sends a temperature increase signal to the steam generator until both the temperature signal and the pressure signal meet the set conditions;

[0030] S9: The PLC control system sends a signal to the terminal control system to determine whether to execute steam delivery, and waits for signal feedback from the terminal control system; after receiving the signal feedback from the terminal control system, the PLC control system sends a signal to the shut-off valve a and the shut-off valve b, the shut-off valve a opens, the shut-off valve b closes, and steam is delivered to the steam-using unit; if the shut-off valve a and the shut-off valve b are abnormally started, a signal is fed back to the PLC control system, an abnormal window pops up on the PLC control system display, and a signal is sent to the buzzer at the same time, and the buzzer alarms.

[0031] Beneficial effects:

[0032] (1) The steam generation system of the present invention adopts a pressure-resistant water tank to avoid the flow fluctuation generated at the input end from affecting the output end, and provides a continuous and stable delivery pressure for the liquid mass flowmeter. At the same time, the liquid mass flowmeter and the coupled solenoid valve interlock control realize the precise control of the liquid flow, providing accurate flow for the steam generator.

[0033] (2) The steam generating system of the present invention integrates a pressure-resistant water tank, a liquid mass flow meter, an air evaporator, and a plurality of functional valves and instruments. According to the process sequence in the technical solution, it is assisted by a PLC control program to control its instructions, thereby realizing continuous and stable operation in the process from water supply to the air evaporator and finally to the next unit, and also realizing high-precision flow control.

[0034] (3) The control method of the steam generation system of the present invention adopts four logical control modes, namely, the startup mode, the normal operation mode, the failure mode and the shutdown mode. It not only performs all-round command control on the startup mode, the normal operation mode and the shutdown mode, but also performs all-round control and analysis on various equipment, valves and key instruments mentioned in the failure mode (abnormal mode). It realizes multi-angle monitoring and troubleshooting for abnormal problems occurring during the operation of the steam unit, thereby ultimately ensuring the stable operation of the process.

[0035] (4) The high-temperature steam generated by the steam generation system is generally around 700°C, which belongs to a high-temperature environment with a high risk factor. During operation, the PLC control system performs a detailed failure logic analysis and is assisted by hardware monitoring such as safety valves, solenoid shut-off valves and instruments to ensure the safe operation of the steam unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0037] Figure 1 Schematic diagram of the overall structure of the SOEC-based steam generation system.

[0038] Among them, the figures represent: 1 water tank; 2 magnetic pump; 3 electromagnetic regulating valve a; 4 pressure-resistant water tank; 5 liquid mass flow meter; 6 coupling electromagnetic valve; 7 check valve; 8 steam generator; 9 electromagnetic shut-off valve b; 10 electromagnetic shut-off valve a; 11 electromagnetic regulating valve b; 12 automatic exhaust valve; 13 safety valve; 14 steam unit; 15 buzzer; 16 water filling port; 17 pressure gauge P1; 18 pressure gauge P2; 19 temperature gauge T2; 20 temperature gauge T1; 21 manual valve a; 22 manual valve b; 23 liquid level gauge L1. DETAILED DESCRIPTION

[0039] The present invention can be better understood with reference to the following examples.

[0040] like Figure 1 As shown, the steam generation system based on SOEC is mainly composed of a PLC control system and various instruments, valves, flow meters, and auxiliary equipment in the schematic diagram. It includes a water storage tank 1, a magnetic pump 2, a pressure-resistant water tank 4, a liquid mass flow meter 5, and a steam generator 8; the water storage tank 1, the magnetic pump 2, the pressure-resistant water tank 4, the liquid mass flow meter 5, and the steam generator 8 are connected in sequence through pipelines; the steam outlet of the steam generator 8 is connected to the steam delivery pipeline to deliver the generated steam to the subsequent steam unit 14; between the magnetic pump 2 and the pressure-resistant water tank 4, there is an electromagnetic regulating valve a3 for regulating the flow; between the liquid mass flow meter 5 and the steam generator 8, there is a coupling electromagnetic valve 6 for regulating the flow; the steam delivery pipeline is respectively connected to the steam unit 14 and the exhaust pipeline, and the connection is respectively provided with an electromagnetic shut-off valve a10 and an electromagnetic shut-off valve b9 for opening and closing the pipeline.

[0041] The tops of the pressure-resistant water tank 4 and the steam generator 8 are respectively connected back to the water tank 1 through exhaust pipes, and the exhaust pipes are respectively provided with automatic exhaust valves 12 and safety valves 13. The magnetic pump 2 and the electromagnetic regulating valve a3 are connected back to the water tank 1 through a circulation pipe, and the circulation pipe is provided with an electromagnetic regulating valve b11 for adjusting the flow rate. A drain port is provided at the bottom of the water tank 1, which is connected to the emptying pipe through a hand valve a21, and the water in the water tank 1 is emptied through the emptying pipe; a hand valve b22 is provided at the water outlet of the emptying pipe. A check valve 7 is provided between the coupling electromagnetic valve 6 and the steam generator 8. A liquid level gauge L123 for monitoring the water level in the water tank is provided on the water tank 1; a pressure gauge P117 for monitoring the pressure in the pressure-resistant water tank is provided on the pressure-resistant water tank 4; and a temperature gauge T120 for monitoring the temperature in the steam generator 8 is provided on the steam generator 8. The steam delivery pipeline is equipped with a pressure gauge P218 and a temperature gauge T219. The pins of the PLC control system (6ES7288) are respectively connected to the level gauge L1 (RLT-1000) 23, the magnetic pump (HPP / HPF 100) 2, solenoid control valve b (ZQ-16P-DN10*3) 11, solenoid control valve a (ZQ-16P-DN10) 3, pressure gauge P1 (BST6600-20BB) 17, liquid mass flow meter (M13-AAD-22-KS) 5, coupling solenoid valve 6, temperature gauge T1 (T32 / TIF50S) 20, pressure gauge P2 (EJA530E-JBS9N-012EN / NF2) 18, temperature gauge T2 (T32 / TIF50S) 19, solenoid cut-off valve a (ZSB311-16P-G-DN10) 10 and solenoid cut-off valve b (ZSB311-16P-G-DN10) 9, and buzzer (0905 passive 12V) 15.

[0042] The operation process of the steam generation system is as follows: the water in the water storage tank is transported to the pressure water tank through a magnetic pump, and the pressure water tank is transported to the steam generator after being interlocked with the liquid mass flow meter and the coupled solenoid valve. Finally, the steam generated by the steam generator is transported to the next steam unit (SOEC stack system). The steam transmission pipeline from the steam generator outlet to the next steam unit is equipped with a pressure gauge P2, a temperature gauge T2 and a solenoid shut-off valve; the pressure water tank outlet pipeline is equipped with an automatic exhaust valve to form a loop with the water storage tank, and a safety valve is installed between the steam generator and the water storage tank. The PLC system performs command control on each valve, instrument and equipment.

[0043] The water storage tank is used as a water supply source, the magnetic pump provides the conveying power, and the electromagnetic regulating valve a controls the water supply. The pressure-resistant water tank and the automatic exhaust valve are used in combination. The advantage is that the bubble entrainment generated by the magnetic pump during startup or abnormality will not affect the liquid supply pressure, and provide a continuous and stable conveying pressure for the subsequent liquid mass flowmeter. The liquid mass flowmeter is interlocked with the coupled electromagnetic valve and controlled by the PLC system to provide accurate liquid flow for the steam generator, so that the amount of steam generated per unit time is within a controllable range. A safety valve is provided on the pipeline from the steam generator back to the water storage tank, which also ensures that the steam is released in time when an abnormality occurs, ensuring that the steam outlet pressure is always within the control range. A pressure gauge P2, a temperature gauge T2 and an electromagnetic shut-off valve are installed on the pipeline from the outlet of the steam generator to the steam unit (SOEC stack system) to achieve the purpose of final monitoring and response of the conveyed steam. A buzzer is installed in the PLC control system, and an alarm will be sounded when the system is in an abnormal mode. The above valves, instruments and equipment are all monitored, responded and operated by the PLC control program instructions according to the control method of the present invention. The specific control method adopted in its control system includes the following steps:

[0044] 1. Pre-settings:

[0045] First, the system is powered on, the water storage tank is filled with water through the water injection port 16, the system is turned on, and the pure water is delivered by the magnetic pump. After the process parameters are set, the PLC control system automatically detects the control point position, and the electric heating of the steam outlet pipeline is turned on.

[0046] 2. Boot mode:

[0047] Step 1: L1 level gauge checks the liquid level in the water tank and feeds back to the PLC control system. The PLC determines whether the liquid level is normal. If it is abnormal, the PLC sends a signal and the buzzer alarms. If it is normal, go to step 2.

[0048] Step 2: PLC sends a start signal to electric control valve a and electric control valve b, and electric control valve a and electric control valve b execute the action. If the start is abnormal, PLC sends a signal, the buzzer alarms, and the display pops up an abnormal window; if it is normal, go to step 3.

[0049] Step 3: PLC sends a signal to start the magnetic pump, and the magnetic pump executes the action. If the feedback signal is abnormal, PLC sends a signal, the buzzer alarms, and the abnormal window pops up on the display. If it is normal, the automatic exhaust valve automatically controls the exhaust, and the PLC control system enters step 4.

[0050] Step 4: PLC outputs pressure check signal, the pressure tank pressure P2 is executed, feedback signal, PLC controls and determines the pressure, if the pressure is abnormal, PLC sends a signal to adjust the opening of electric regulating valve a and electric regulating valve b. If the pressure is normal, go to step 5.

[0051] Step 5: PLC outputs the liquid mass flow meter start-up, coupling solenoid valve start-up, and solenoid shut-off valve b open signals. The liquid mass flow meter, coupling solenoid valve, and solenoid shut-off valve b execute actions. If the feedback signal is abnormal, the PLC sends a signal, the buzzer alarms, and an abnormal window pops up on the display screen, and the process goes to step 6 normally.

[0052] Step 6: PLC sends a steam generator start signal, the steam generator executes the action, if the feedback signal is abnormal, PLC sends a signal, the buzzer alarms, the display pops up an abnormal window, and goes to step 7 normally.

[0053] Step 7: PLC sends out T1 temperature detection and collection signal, steam generator temperature T1 detection, if the feedback signal is abnormal, PLC sends out a signal, buzzer alarms, and the display pops up an abnormal window, if normal, go to step 8.

[0054] Step 8: PLC sends out steam outlet pressure P2 detection and temperature T2 detection signals, P2 and T2 perform actions and feedback signals, at this time PLC receives signal judgment. If the judgment result is that P2 and T2 meet the conditions, then go to step 9; if the judgment result is that P2 meets the conditions but T2 does not meet the conditions or T2 meets the conditions but P2 does not meet the conditions, the system will delay the response, at this time T2 and P2 will continue to be monitored, if the monitoring result is that P2 and T2 meet the conditions, then go to step 9, if P2 and T2 still do not meet the conditions, then PLC sends out a signal to increase the temperature of the steam generator, at this time the steam generator will perform a temperature increase action.

[0055] Step 9: The PLC sends a signal that the conditions for normal steam delivery are met, and requests the terminal control system whether to execute steam delivery. If not, the status quo is maintained and instructions are awaited. If steam delivery is executed, the PLC sends a signal to start the solenoid shut-off valve a and close the solenoid shut-off valve b, and the solenoid shut-off valve executes the action. If the feedback signal is abnormal, the PLC sends a signal, the buzzer alarms, and an abnormal window pops up on the display. If normal, the PLC control system reminds the steam generating unit to operate normally.

[0056] 3. Normal operation mode:

[0057] There are 8 steps that need to be monitored in the normal operation mode, Step 1: Monitor the liquid level of the water storage tank; Step 2: Monitor the pressure of the pressure-resistant water tank; Step 3: Monitor the temperature of the steam generator; Step 4: Monitor the outlet pressure of the steam generator; Step 5: Monitor the outlet temperature of the steam generator; Step 6: Monitor the changes of the pressure gauge P2 and the temperature gauge T2, and the PLC control system automatically fine-tunes the steam generator temperature control system; Step 7: Monitor the changes of the pressure gauge P1, and the PLC control system automatically fine-tunes the opening of the electromagnetic regulating valve a and the electromagnetic regulating valve b; Step 8: According to the changes in monitoring L1, the PLC control system emits an alarm buzzer to remind water injection.

[0058] 4. Failure mode:

[0059] L1 level gauge abnormality:

[0060] (1) When the liquid level gauge suddenly stops displaying the liquid level, the PLC control automatically emits a buzzer and a dialog box pops up on the control screen to confirm whether the system continues to run. If it continues to run, the abnormal point is manually checked and handled; if it stops running, the PLC control system executes emergency stop mode 1.

[0061] (2) When the liquid level in the liquid level gauge fluctuates greatly, the PLC control automatically emits a buzzer sound, and the PLC monitors the pressure of the pressure tank P1 to confirm. If it does not exceed the pressure control range, the liquid level gauge L1 is manually checked for abnormalities and special care is performed. If it exceeds the pressure control range, a dialog box pops up on the control screen, and the operator manually determines whether to continue to run. If it continues to run, the abnormality is handled and special care is performed. If the operation stops, the PLC control system executes emergency stop mode 1.

[0062] Electric regulating valve 4 is abnormal:

[0063] (1) If the regulating valve does not perform an action or receive no signal, the PLC control will automatically emit a buzzer and monitor the pressure P1 of the pressure-resistant water tank. If it does not exceed the pressure control range, it will perform special care operation. If it exceeds the pressure control range, a dialog box will pop up on the control screen and manual judgment will be made whether to continue operation. If it continues to operate, the abnormality will be handled and special care operation will be performed. If it stops operating, the PLC control system will execute emergency stop mode 1.

[0064] (2) The regulating valve is suddenly closed, and the PLC control system automatically emits a buzzer sound. After a certain delay, the PLC executes emergency stop mode 1.

[0065] Electric control valve 1 is abnormal:

[0066] (1) If the regulating valve does not perform an action or receive no signal, the PLC control will automatically emit a buzzer. The PLC monitors the pressure P1 of the pressure-resistant water tank. If it does not exceed the pressure control range, it will perform special care operation. If it exceeds the pressure control range, a dialog box will pop up on the control screen, and the operator will manually determine whether to continue the operation. If it continues to operate, the abnormality will be handled and special care operation will be performed. If it stops operating, the PLC control system will execute emergency stop mode 1.

[0067] (2) The regulating valve is suddenly closed, and the PLC control system automatically emits a buzzer sound. After a certain delay, the PLC executes emergency stop mode 2.

[0068] Pressure water tank P1 abnormality:

[0069] (1) The pressure gauge suddenly displays no pressure, the PLC control system automatically emits a buzzer, and the liquid mass flow meter 1 detects flow changes. If the flow rate does not exceed the flow control range, the abnormal point is processed and special care is performed. If the flow rate exceeds the flow control range, a dialog box pops up on the control screen to manually determine whether to continue running. If it continues to run, the abnormality is processed and special care is performed. If it stops running, the PLC control system executes emergency stop mode 2.

[0070] (2) If the pressure gauge fluctuates greatly, the PLC control system will automatically emit a buzzer sound and the liquid mass flow meter 1 will detect the flow change. If the pressure does not exceed the pressure control range, the abnormal point will be processed and special care will be performed. If the flow control range is exceeded, a dialog box will pop up on the control screen to manually determine whether to continue running. If it continues to run, the abnormality will be processed and special care will be performed. If it stops running, the PLC control system will execute emergency stop mode 2.

[0071] Magnetic pump abnormality: The magnetic pump suddenly stops running, and the PLC control system executes emergency stop mode 1.

[0072] Liquid mass flow control abnormality:

[0073] (1) If there is no flow display suddenly, the PLC control system will automatically emit a buzzer sound and monitor the pressure change of P1. If it does not exceed the pressure control range, the abnormal point will be processed and special care will be performed. If it exceeds the pressure control range (is lower than), a dialog box will pop up on the control screen to manually determine whether to continue running. If it continues to run, the abnormality will be processed and special care will be performed. If it stops running, the PLC control system will execute emergency stop mode 1.

[0074] (2) If the flow fluctuation exceeds the control range, the PLC control system will automatically emit a buzzer sound, and the PLC will monitor the change of pressure P1. If it exceeds the pressure control range, a dialog box will pop up on the control screen, and a manual decision will be made whether to continue to run. If it continues to run, the abnormality will be handled and special care will be taken. If it stops running, the PLC control system will execute emergency stop mode 1; if it does not exceed the pressure control range, the steam generator outlet pressure P2 or steam generator outlet temperature T2 will be monitored. If the steam generator outlet pressure P2 or steam generator outlet temperature T2 exceeds the control range, a dialog box will pop up on the control screen, and a manual decision will be made whether to continue to run. If it continues to run, the abnormality will be handled and special care will be taken. If it stops running, the PLC control system will execute emergency stop mode 1.

[0075] Steam generator abnormality:

[0076] (1) T1 temperature suddenly stops displaying, the PLC control system automatically emits a buzzer, and the PLC monitors the changes in the steam generator outlet pressure P2 and the steam generator outlet temperature T2. If it does not exceed the control range, the abnormal point is processed and special care is performed. If it exceeds the control range, a dialog box pops up on the control screen, and a manual decision is made whether to continue to run. If it continues to run, the abnormality is processed and special care is performed. If it stops running, the PLC control system executes emergency stop mode 3.

[0077] (2) If the temperature T1 suddenly exceeds the control range, the PLC control system will automatically emit a buzzer sound. The PLC monitors the changes in the steam generator outlet pressure P2 and the steam generator outlet temperature T2. If it does not exceed the control range, the abnormal point is processed and special care is performed. If it exceeds the control range, a dialog box will pop up on the control screen to manually determine whether to continue running. If it continues to run, the abnormality is processed and special care is performed. If it stops running, the PLC control system will execute emergency stop mode 3.

[0078] Steam outlet temperature T2 is abnormal: T2 temperature suddenly does not display or T2 temperature suddenly exceeds the control range, and the PLC control system automatically emits a buzzer. The PLC monitors the steam generator temperature T1, liquid mass flow control 1 flow and steam generator outlet pressure P2. If the PLC determines that all three data are within the control range, it will process the abnormal point and perform special care operation; if at least one of the three items is not within the control range, the PLC control system will execute emergency shutdown mode 3.

[0079] Steam outlet pressure P2 is abnormal: P2 temperature suddenly does not display or P2 temperature suddenly exceeds the control range, and the PLC control system automatically emits a buzzer. The PLC monitors the steam generator temperature T1, liquid mass flow control 1 flow, and steam generator outlet temperature T2. If the PLC determines that all three data are within the control range, it will process the abnormal point and perform special care operation; if at least one of the three items is not within the control range, the PLC control system will execute emergency shutdown mode 3.

[0080] Abnormality of the steam outlet electromagnetic shut-off valve a: If the electromagnetic shut-off valve does not perform an action, does not receive a signal or closes suddenly, the PLC control automatically emits a buzzer, and the PLC executes emergency stop mode 4 after a certain delay; if the electromagnetic shut-off valve a suddenly opens, the PLC control system automatically emits a buzzer, and the PLC executes emergency stop mode 5 after a certain delay.

[0081] Abnormality of the steam outlet electromagnetic shut-off valve b: If the shut-off valve does not execute an action, does not receive a signal, or the shut-off valve is suddenly closed, the PLC control automatically emits a buzzer, and the PLC will execute emergency stop mode 5 after a certain delay; if the electromagnetic shut-off valve b is suddenly opened, the PLC control system automatically emits a buzzer, and the PLC will execute emergency stop mode 4 after a certain delay.

[0082] 5. Stop mode:

[0083] There are 5 emergency shutdown modes and 1 normal shutdown mode in the shutdown mode. These 6 shutdown modes all include the settings in which the PLC issues a steam supply stop request and requests the terminal control system to execute it, so they will not be repeated in the following examples of each mode.

[0084] Emergency stop mode 1: PLC automatically issues instructions, the magnetic pump stops, the electric control valve b is fully opened, the electric control valve a is fully opened, the steam generator stops, the electromagnetic cut-off valve b is opened, and the electromagnetic cut-off valve a is closed.

[0085] Emergency stop mode 2: PLC automatically issues a command, the electric control valve b is fully opened, the steam generator is shut down, the electromagnetic shut-off valve b is opened, and the electromagnetic shut-off valve a is closed.

[0086] Emergency stop mode 3: PLC automatically issues a command, electric control valve b is fully opened, steam generator is shut down, electromagnetic shut-off valve b is opened, electromagnetic shut-off valve a is closed, and electromagnetic control valve a is closed.

[0087] Emergency stop mode 4: PLC automatically issues a command, the electric control valve b is fully opened, the steam generator is shut down, the electromagnetic shut-off valve b is opened, and the electromagnetic control valve a is closed.

[0088] Emergency stop mode 5: PLC automatically issues a command, the electric control valve b is fully opened, the steam generator is shut down, the electromagnetic control valve a is closed, and when the internal pressure of the steam generator reaches the safety valve trip pressure, the safety valve trips and releases the pressure.

[0089] Normal shutdown mode: PLC automatically issues a command, the steam generator stops, the electromagnetic shut-off valve a is closed, and the electromagnetic shut-off valve b is opened. At this time, when the steam generator temperature T1 drops to the set value, the magnetic pump stops, the electric control valve a is closed, and the electric control valve b is closed.

[0090] The present invention provides a steam generation system based on SOEC and a control method thereof. There are many methods and approaches to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A control method for a steam generation system based on SOEC, characterized in that: The steam generation system comprises a water storage tank (1), a magnetic pump (2), a pressure-resistant water tank (4), a liquid mass flow meter (5) and a steam generator (8); The water storage tank (1), the magnetic pump (2), the pressure-resistant water tank (4), the liquid mass flow meter (5) and the steam generator (8) are connected in sequence via pipelines; The steam outlet of the steam generator (8) is connected to a steam delivery pipeline to deliver the generated steam to a subsequent steam-using unit (14); An electromagnetic regulating valve a (3) for regulating flow is provided between the magnetic pump (2) and the pressure-resistant water tank (4); A coupling solenoid valve (6) for adjusting flow rate is provided between the liquid mass flow meter (5) and the steam generator (8); The steam delivery pipeline is connected to the steam using unit (14) and the exhaust pipeline respectively, and a shut-off valve a (10) and a shut-off valve b (9) for opening and closing the pipeline are respectively provided at the connection points; The tops of the pressure-resistant water tank (4) and the steam generator (8) are respectively connected back to the water storage tank (1) through exhaust pipes, and the exhaust pipes are respectively provided with automatic exhaust valves (12) and safety valves (13); The magnetic pump (2) and the electromagnetic regulating valve a (3) are connected back to the water storage tank (1) via a circulation pipeline, and the circulation pipeline is provided with an electromagnetic regulating valve b (11) for regulating flow; The water storage tank (1) is provided with a liquid level gauge L1 (23) for monitoring the water level in the water storage tank; the pressure-resistant water tank (4) is provided with a pressure gauge P1 (17) for monitoring the pressure in the pressure-resistant water tank; the steam generator (8) is provided with a temperature gauge T1 (20) for monitoring the temperature in the steam generator (8); The steam delivery pipeline is provided with a pressure gauge P2 (18) and a temperature gauge T2 (19); It also includes a PLC control system, wherein the pins of the PLC control system are respectively connected to the liquid level meter L1 (23), the magnetic pump (2), the electromagnetic regulating valve b (11), the electromagnetic regulating valve a (3), the pressure gauge P1 (17), the liquid mass flow meter (5), the coupling electromagnetic valve (6), the temperature gauge T1 (20), the pressure gauge P2 (18), the temperature gauge T2 (19), the cut-off valve a (10) and the cut-off valve b (9), and the buzzer (15); The control method comprises the following steps: S1: The liquid level meter L1 (23) monitors the water level signal of the water storage tank (1) and sends it to the PLC control system. The PLC control system determines whether the water level signal is normal. If it is abnormal, the PLC control system sends a signal to the buzzer (15), and the buzzer (15) alarms. If it is normal, it goes to step S2; S2: The PLC control system sends a start signal to the electromagnetic control valve a (3) and the electromagnetic control valve b (11), and the electromagnetic control valve a (3) and the electromagnetic control valve b (11) perform an action. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the display screen of the PLC control system. At the same time, a signal is sent to the buzzer (15), and the buzzer (15) alarms. If it is normal, the process goes to step S3; S3: The PLC control system sends a start signal to the magnetic pump (2), and the magnetic pump (2) executes an action. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the display screen of the PLC control system. At the same time, a signal is sent to the buzzer (15), and the buzzer (15) alarms. If it is normal, the automatic exhaust valve (12) automatically controls the exhaust, and the process goes to step S4; S4: The pressure gauge P1 (17) monitors the pressure signal in the pressure-resistant water tank (4) and sends the signal to the PLC control system. The PLC control system determines whether the pressure signal is normal. If it is abnormal, the PLC control system sends a regulating signal to the electromagnetic regulating valve a (3) and the electromagnetic regulating valve b (11) to adjust the corresponding opening. If the pressure signal is normal, the process goes to step S5. S5: the PLC control system sends a start signal to the liquid mass flow meter (5), the coupling solenoid valve (6) and the cut-off valve b (9), and the liquid mass flow meter (5), the coupling solenoid valve (6) and the cut-off valve b (9) perform actions. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the display screen of the PLC control system. At the same time, a signal is sent to the buzzer (15), and the buzzer (15) alarms. If it is normal, the process goes to step S6; S6: the PLC control system sends a start signal to the steam generator (8), and the steam generator (8) executes an action. If the start is abnormal, a signal is fed back to the PLC control system, and an abnormal window pops up on the display screen of the PLC control system. At the same time, a signal is sent to the buzzer (15), and the buzzer (15) alarms. If it is normal, the process goes to step S7; S7: The temperature meter T1 (20) monitors the temperature signal in the steam generator (8) and sends it to the PLC control system. The PLC control system determines whether the temperature signal is normal. If it is abnormal, an abnormal window pops up on the PLC control system display screen and sends a signal to the buzzer (15). The buzzer (15) alarms. If it is normal, the process goes to step S8; S8: The pressure gauge P2 (18) and the temperature gauge T2 (19) monitor the pressure signal and the temperature signal of the steam in the steam delivery pipeline and send them to the PLC control system. The PLC control system determines whether the temperature signal and the pressure signal meet the set conditions. If both meet the conditions, the process proceeds to step S9. If at least one of the temperature signal and the pressure signal does not meet the conditions, the PLC control system sends a temperature increase signal to the steam generator (8) until both the temperature signal and the pressure signal meet the set conditions. S9: The PLC control system sends a signal to the terminal control system to determine whether to execute steam delivery, and waits for a signal feedback from the terminal control system. After receiving the signal feedback from the terminal control system, the PLC control system sends a signal to the cut-off valve a (10) and the cut-off valve b (9), and the cut-off valve a (10) is opened and the cut-off valve b (9) is closed, and steam is delivered to the steam-using unit (14). If the cut-off valve a (10) and the cut-off valve b (9) are abnormally started, a signal is fed back to the PLC control system, and an abnormal window pops up on the display screen of the PLC control system. At the same time, a signal is sent to the buzzer (15), and the buzzer (15) alarms.

2. The control method of the steam generation system based on SOEC according to claim 1, characterized in that: The bottom of the water storage tank (1) is provided with a drain outlet, which is connected to a drain pipe via a hand valve a (21), and the water in the water storage tank (1) is drained via the drain pipe; a hand valve b (22) is provided at the water outlet of the drain pipe.

3. The control method of the steam generation system based on SOEC according to claim 1, characterized in that: A check valve (7) is provided between the coupling solenoid valve (6) and the steam generator (8).

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