A molten salt steam generation system

Abstract

The application relates to the technical field of molten salt energy storage steam, in particular to a molten salt steam generation system which comprises a control unit, a water circulation unit and a molten salt circulation unit; the water circulation unit comprises an evaporator, a primary heater and a preheater which are communicated with each other through circulation pipelines; the molten salt circulation unit is communicated with the evaporator through a molten salt circulation pipeline; a water circulation pump is arranged on the circulation pipeline between the evaporator and the primary heater, and a molten salt circulation valve is arranged on the molten salt circulation pipeline; temperature sensors and pressure sensors are arranged in the evaporator; the control unit is used for acquiring temperature data and pressure data in real time and sending water heating instructions to the water circulation pump; when it is determined that the temperature data in the evaporator reaches a safety temperature threshold value, a first control instruction is sent to the molten salt circulation valve, and when it is determined that the pressure data in the evaporator reaches a pre-set pressure threshold value, steam is put into use. The molten salt steam generation system guarantees the stable and continuous supply of steam and prolongs the overall service life of the equipment.

Description

Technical Field

[0001] This application relates to the field of molten salt energy storage steam technology, and more particularly to a molten salt steam generation system. Background Technology

[0002] Molten salt steam generation systems are core thermal systems in the fields of solar thermal power generation, industrial steam supply, and energy storage and peak shaving. Relying on the excellent heat transfer and heat storage characteristics of molten salt, they achieve stable steam production through energy exchange between the molten salt exothermic cycle and the water / steam heat exchange cycle. The safety and stability of their operation directly determine the equipment life, steam quality, and operating efficiency of the entire system.

[0003] Existing molten salt steam generation systems generally consist of a molten salt circulation unit, a water circulation unit, and a steam application unit. They achieve water vaporization and steam output through heat exchange between molten salt and water. However, due to the characteristics of molten salt being prone to solidification (e.g., the solidification point of ternary nitrate molten salt is about 142℃) and the high energy matching requirements of the heat exchange process between high-temperature molten salt and water, the structural design and control logic of traditional systems have obvious defects. This leads to multiple safety risks during system startup and operation, and poor energy coordination control, making it difficult to achieve stable and efficient operation.

[0004] Furthermore, traditional systems do not provide comprehensive and uniform preheating control for the water medium in the evaporator and connected pipes. Some systems only involve a single heating device for preheating, which can easily lead to uneven temperature distribution on the heat exchanger walls of the evaporator. When high-temperature molten salt (approximately 390°C) enters the evaporator, if the walls are in a "cold wall" state, the molten salt will rapidly cool down and solidify locally inside the heat exchange tubes, causing blockage and damage to the pipes and equipment. Moreover, the solidified molten salt is extremely difficult to clear, which seriously affects the system's start-up and shutdown efficiency and the equipment's service life. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, this application provides a molten salt steam generation system, which solves the technical problems of existing molten salt steam generation systems not performing uniform preheating control over the entire evaporator and connected pipelines, resulting in uneven temperature of the evaporator heat exchange wall surface during system startup and operation, and local solidification of high-temperature molten salt after contact with the cold wall causing blockage and damage to pipelines and equipment, as well as safety risks such as thermal shock and water hammer, and poor energy coordination control effect, making it difficult to achieve stable steam production and smooth and efficient operation.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the main technical solutions adopted in this application include:

[0009] In a first aspect, embodiments of this application provide a molten salt steam generation system, including: a control unit, a water circulation unit, a molten salt circulation unit, and a steam application unit; wherein, the water circulation unit includes an evaporator, a preliminary heater, and a preheater connected in pairs through circulation pipelines; the steam application unit is connected to the evaporator through a steam application pipeline, and the molten salt circulation unit is connected to the evaporator through a molten salt circulation pipeline;

[0010] A water circulation pump is installed on the circulation pipeline between the evaporator and the primary heater, a steam application valve is installed on the steam application pipeline, and a molten salt circulation valve is installed on the molten salt circulation pipeline; a temperature sensor for real-time monitoring of the temperature data inside the evaporator and a pressure sensor for real-time monitoring of the pressure data inside the evaporator are installed inside the evaporator.

[0011] The water circulation pump, steam application valve, molten salt circulation valve, temperature sensor, and pressure sensor are all electrically connected to the control unit;

[0012] The control unit is used to acquire temperature and pressure data in real time after determining that the system initialization process is completed, and send a water heating command to the water circulation pump to start the water circulation pump to circulate and heat the water in the evaporator.

[0013] In addition, when the temperature data inside the evaporator is determined to reach the preset safe temperature threshold, a first control command is sent to the molten salt circulation valve to control the molten salt circulation between the molten salt circulation unit and the evaporator.

[0014] Additionally, when the pressure data inside the evaporator reaches a preset pressure threshold, a steam application command is sent to the steam application valve to open the steam application valve and supply steam to the steam application unit for use.

[0015] Optionally, in one specific embodiment, the molten salt circulation valve includes: a molten salt outlet regulating valve, a molten salt inlet regulating valve, and a molten salt bypass regulating valve;

[0016] The molten salt circulation unit is connected to the molten salt inlet of the evaporator via the molten salt inlet pipe, and the molten salt circulation unit is connected to the molten salt outlet of the evaporator via the molten salt outlet pipe. The molten salt inlet pipe and the molten salt outlet pipe are connected by a molten salt bypass pipe.

[0017] The molten salt bypass regulating valve is installed on the molten salt bypass pipeline, the molten salt inlet regulating valve is installed between the molten salt bypass regulating valve and the molten salt inlet of the evaporator, and the molten salt outlet regulating valve is installed between the molten salt bypass regulating valve and the molten salt outlet of the evaporator;

[0018] The molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve are all electrically connected to the control unit;

[0019] The control unit, upon determining that the temperature data within the evaporator has reached a preset safe temperature threshold, sends a first control command to the molten salt circulation valve to control the molten salt circulation between the molten salt circulation unit and the evaporator, including:

[0020] When the temperature data inside the evaporator reaches a preset safe temperature threshold, a first control command is sent to the molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve to control the molten salt circulation between the molten salt circulation unit and the evaporator. The first control command is used to control the molten salt outlet regulating valve and the molten salt inlet regulating valve to open based on a preset valve opening speed, and to control the molten salt bypass regulating valve to close based on a preset valve closing speed.

[0021] Optionally, in one specific embodiment, the control unit determines that the system initialization process is complete by:

[0022] Send a second control command to the molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve. The second control command is used to control the molten salt outlet regulating valve and the molten salt inlet regulating valve to be completely closed, and to control the opening degree of the molten salt bypass regulating valve to be greater than the preset initial opening degree threshold.

[0023] In addition, a third control command is sent to the water circulation pump, wherein the third control command is used to control the water circulation pump to shut down.

[0024] Optionally, in one specific embodiment, the control unit is further configured to:

[0025] After sending the first control command to the molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve, the heating rate and pressure rate within the evaporator are obtained based on real-time temperature and pressure data. When the heating rate exceeds a preset heating rate threshold or the pressure rate exceeds a preset pressure rate threshold, a shut-off speed regulation command is sent to the molten salt bypass regulating valve. The heating rate is the ratio of the difference between the current temperature data and the previous temperature data to a preset unit time; the pressure rate is the ratio of the difference between the current pressure data and the previous pressure data to a preset unit time.

[0026] The closing speed adjustment command is used to adjust the closing speed of the molten salt bypass regulating valve to control the heating rate in the evaporator to be less than or equal to a preset heating rate threshold, and to control the pressure rate in the evaporator to be less than or equal to a preset pressure rate threshold.

[0027] Optionally, in one specific embodiment, the system further includes a water supply unit, which is connected to a circulation pipeline between the preheater and the primary heater via a water supply pipeline;

[0028] A water supply regulating valve is installed on the water supply pipeline, and the water supply regulating valve is electrically connected to the control unit;

[0029] The control unit is also used for:

[0030] Based on the current temperature and pressure data, as well as the pre-set water supply circulation algorithm, a fourth control command is sent to the water supply regulating valve, which is used to adjust the opening degree of the water supply regulating valve.

[0031] Optionally, in a specific embodiment, the control unit sends a fourth control command to the water supply regulating valve based on the current temperature data and pressure data, as well as a pre-set water supply circulation algorithm, including: obtaining the corresponding temperature deviation based on the current temperature data and a pre-set target temperature, and obtaining the corresponding pressure deviation based on the current pressure data and a pre-set target pressure;

[0032] Based on the current temperature and pressure deviations, as well as the pre-set heat exchange power, corresponding coefficients, specific heat capacity at constant pressure, and water density at constant pressure, the corresponding theoretical water supply rate is obtained; where the heat exchange power is the heat exchange power between molten salt and water per unit flow rate, and the corresponding coefficient is the coefficient between steam pressure and water saturation temperature.

[0033] The theoretical water supply rate is corrected based on the current pressure increase rate and temperature increase rate, as well as the preset temperature increase rate threshold and pressure increase rate threshold.

[0034] Based on the corrected theoretical water supply rate, as well as the preset fully open water supply rate and linear matching coefficient, the basic water supply opening of the water supply regulating valve at the current moment is determined.

[0035] Based on the current basic water supply opening of the water supply regulating valve, a fourth control command is sent to the water supply regulating valve to control the water supply regulating valve to open based on the basic water supply opening.

[0036] Optionally, in one specific embodiment, the control unit obtains the corresponding theoretical water supply rate based on the current temperature and pressure deviations, as well as preset constant-pressure specific heat capacity and constant-pressure water density, including:

[0037] Based on the current temperature and pressure deviations, and pre-set heat exchange power, corresponding coefficients, isobaric specific heat capacity, isobaric water density, molten salt anti-condensation safety margin coefficient, and Formula 1, the corresponding theoretical feedwater rate is obtained; Formula 1 is:

[0038] ;

[0039] Where Q1 is the theoretical water supply rate, q 熔 T represents the heat transfer efficiency, k is the corresponding coefficient, and T represents the heat transfer power.偏 For temperature deviation, P 偏 For pressure deviation, c 水 For the specific heat capacity at constant pressure, ρ 水 K is the density of water under constant pressure, and k3 is the safety margin coefficient for molten salt anti-condensation.

[0040] Optionally, in one specific embodiment, the control unit corrects the theoretical water supply rate based on the current pressure increase rate and temperature increase rate, as well as preset temperature increase rate thresholds and pressure increase rate thresholds, including:

[0041] Based on the current boost rate and the preset boost rate threshold, obtain the boost rate constraint value corresponding to the current time; where the boost rate constraint value is the absolute value of the difference between the ratio of boost rate to boost rate threshold and 1.

[0042] Based on the current heating rate and the preset heating rate threshold, obtain the heating rate constraint value corresponding to the current time; the heating rate constraint value is the absolute value of the difference between the ratio of heating rate to heating rate threshold and 1.

[0043] Based on the pressure rise rate constraint value and the temperature rise rate constraint value, as well as the pre-set temperature rise rate constraint coefficient and pressure rise rate constraint coefficient, the theoretical water supply rate is corrected; wherein, the corrected theoretical water supply rate is the product of the pressure rise rate constraint value, the temperature rise rate constraint value, the temperature rise rate constraint coefficient, the pressure rise rate constraint coefficient and the theoretical water supply rate.

[0044] Optionally, in one specific embodiment, the control unit determines the basic water supply opening of the water supply regulating valve at the current moment based on the corrected theoretical water supply rate, and a preset fully open water supply rate and linear matching coefficient, including:

[0045] Based on the corrected theoretical water supply rate, and the preset fully open water supply rate and linear matching coefficient, the basic water supply opening of the water supply regulating valve at the current moment is determined; wherein, the basic water supply opening is the ratio of the corrected theoretical water supply rate to the product of the fully open water supply rate and the linear matching coefficient.

[0046] Optionally, in one specific embodiment, the control unit sends a fourth control command to the water supply regulating valve based on the current basic water supply opening, to control the water supply regulating valve to open based on the basic water supply opening, including:

[0047] Based on the baseline water supply opening, safe temperature threshold, target temperature, and current temperature data, as well as a pre-set temperature safety margin correction strategy, the baseline water supply opening is corrected; the temperature safety margin correction strategy is as follows:

[0048] ;

[0049] Where, θ 基 Based on water supply opening degree, θ 修 For the corrected basic water supply opening, T 安 For the safe temperature threshold, T 标 For the target temperature, T 实 This is the temperature data at the current moment.

[0050] (III) Beneficial Effects

[0051] This application discloses a molten salt steam generation system. It comprises a control unit, a water circulation unit (including an evaporator, a preliminary heater, and a preheater), a molten salt circulation unit, and a steam application unit. Water circulation pumps, steam application valves, and molten salt circulation valves are installed in corresponding pipelines. Temperature and pressure sensors are installed within the evaporator and electrically linked to the control unit. After system initialization, the control unit drives the water circulation pump to circulate and heat the water. Molten salt circulation is initiated once the temperature reaches a safe threshold, and steam is supplied to the steam application unit once the pressure reaches the threshold. This system achieves uniform preheating of the water medium throughout the evaporator and connected pipelines through the coordinated circulation heating of the evaporator, preliminary heater, and preheater, fundamentally preventing solidification and pipeline blockage caused by high-temperature molten salt contacting cold walls. Furthermore, real-time monitoring by temperature and pressure sensors and step-by-step command control by the control unit enable precise timing synchronization of water circulation, molten salt circulation, and steam application. This effectively avoids safety risks such as thermal shock and water hammer, ensuring a stable and continuous steam supply while extending the overall service life of the equipment. Attached Figure Description

[0052] Figure 1 A schematic diagram of a molten salt steam generation system provided in this application embodiment;

[0053] Figure 2 This is a schematic diagram of the operation process of a molten salt steam generation system provided in an embodiment of this application.

[0054] [Explanation of Labels in the Attached Image]

[0055] 1: Evaporator; 2: Preheater; 3: Preliminary heater; 11: Molten salt outlet regulating valve; 12: Molten salt inlet regulating valve; 13: Molten salt bypass regulating valve; 14: Water circulation pump; 41: Steam application valve; 42: Feedwater regulating valve. Detailed Implementation

[0056] To better explain and facilitate understanding of this application, the following detailed description of the application is provided in conjunction with the accompanying drawings and specific embodiments.

[0057] Molten salt steam generation systems are core thermal systems in fields such as concentrated solar power (CSP) and industrial steam supply. Relying on the excellent heat transfer and storage properties of molten salt, steam is produced through heat exchange between molten salt and water / steam. The safety and stability of their operation directly affect equipment lifespan, steam quality, and system efficiency. While existing systems of this type are equipped with molten salt circulation, water circulation, and steam application units, they suffer from drawbacks due to the molten salt's tendency to solidify, the high energy matching requirements for heat exchange between molten salt and water, defects in structural design and control logic, and the lack of uniform preheating of the evaporator and pipeline water medium. Single-mode heating easily leads to uneven temperature distribution on the heat exchange walls, causing localized solidification of the high-temperature molten salt upon contact with the cold walls, resulting in blockage and damage to pipelines and equipment. This severely impacts system start-up and shutdown efficiency and equipment lifespan, poses multiple safety risks, and exhibits poor energy coordination control.

[0058] The molten salt steam generation system of this application constructs a supporting structure consisting of a control unit, a water circulation unit with multiple heating devices, a molten salt circulation unit, and a steam application unit. Various pumps and valves are installed in the pipelines, and temperature and pressure sensors are configured in the evaporator 1 to link with the control unit. The control unit drives the water circulation pump 14 according to the process to circulate and heat the water. Once the temperature reaches the target, the molten salt circulation is activated; once the pressure reaches the target, steam is supplied. This system achieves uniform preheating of the water medium throughout the entire process through coordinated circulation heating of multiple devices, fundamentally preventing molten salt solidification. Furthermore, relying on sensor monitoring and stepped command control, it achieves precise timing linkage between each unit, avoiding the risks of thermal shock and water hammer, ensuring a stable steam supply, and extending the service life of the equipment.

[0059] To better understand the above technical solutions, exemplary embodiments of this application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application can be understood more clearly and thoroughly, and that the scope of this application can be fully conveyed to those skilled in the art.

[0060] This application provides a molten salt steam generation system, such as... Figure 1 and Figure 2 As shown, it includes: a control unit, a water circulation unit, a molten salt circulation unit, and a steam application unit; wherein, the water circulation unit includes an evaporator 1, a preliminary heater 3, and a preheater 2 connected in pairs through circulation pipelines; the steam application unit is connected to the evaporator 1 through a steam application pipeline, and the molten salt circulation unit is connected to the evaporator 1 through a molten salt circulation pipeline;

[0061] A water circulation pump 14 is installed on the circulation pipeline between the evaporator 1 and the primary heater 3, a steam application valve 41 is installed on the steam application pipeline, and a molten salt circulation valve is installed on the molten salt circulation pipeline; a temperature sensor for real-time monitoring of the temperature data inside the evaporator 1 and a pressure sensor for real-time monitoring of the pressure data inside the evaporator 1 are installed inside the evaporator 1.

[0062] The water circulation pump 14, steam application valve 41, molten salt circulation valve, temperature sensor, and pressure sensor are all electrically connected to the control unit.

[0063] The control unit is used to acquire temperature and pressure data in real time after determining that the system initialization process is completed, and send a water heating command to the water circulation pump 14 to start the water circulation pump 14 to circulate and heat the water in the evaporator 1.

[0064] In addition, when it is determined that the temperature data in the evaporator 1 reaches the preset safe temperature threshold, a first control command is sent to the molten salt circulation valve to control the molten salt circulation between the molten salt circulation unit and the evaporator 1.

[0065] Furthermore, when the pressure data within the evaporator 1 is determined to reach a preset pressure threshold, a steam application command is sent to the steam application valve 41 to open the steam application valve 41 and introduce steam into the steam application unit for use.

[0066] This application provides a molten salt steam generation system. It comprises a control unit, a water circulation unit (including an evaporator 1, a preliminary heater 3, and a preheater 2), a molten salt circulation unit, and a steam application unit. A water circulation pump 14, a steam application valve 41, and a molten salt circulation valve are installed in the corresponding pipelines. Temperature and pressure sensors are installed in the evaporator 1 and electrically linked to the control unit. After system initialization, the control unit drives the water circulation pump 14 to circulate and heat the water. Molten salt circulation is initiated once the temperature reaches a safe threshold, and steam is supplied to the steam application unit once the pressure reaches the threshold. This system achieves uniform preheating of the water medium in the evaporator 1 and connected pipelines through the coordinated circulation heating of the evaporator 1, preliminary heater 3, and preheater 2, fundamentally preventing solidification and pipeline blockage caused by high-temperature molten salt contacting cold walls. Furthermore, real-time monitoring by temperature and pressure sensors and step-by-step command control by the control unit enable precise timing linkage between water circulation, molten salt circulation, and steam application. This effectively avoids safety risks such as thermal shock and water hammer, ensuring a stable and continuous steam supply while extending the overall service life of the equipment.

[0067] Furthermore, the molten salt steam generation system provided in this application is applied to the cross-technology field of molten salt thermal energy storage and thermal power generation, focusing on industrial-grade thermal application scenarios such as solar thermal power generation, flexible transformation of thermal power plants, integrated energy supply for industrial parks, and steam supply for compressed air energy storage. It is the core execution link for the implementation of molten salt thermal energy storage technology.

[0068] This application differs from conventional water circulation heating in that it has fundamental differences in application scenarios, technical parameters, and core requirements. Specifically: First, the water circulation heating in the molten salt steam generation system is a cross-medium heat exchange intermediary between molten salt and water. The core objective is to generate high-temperature, high-pressure industrial steam through the heating and vaporization of water. Water is the heat exchange carrier, and the final conversion into steam is necessary to achieve energy output, serving core production needs such as power generation and industrial steam supply. Conventional air conditioning water circulation heating only uses water as a heat medium to regulate indoor temperature, without any medium phase change requirements. It only has a single function of heat transfer and does not involve secondary energy conversion. Second, the water circulation heating in this application needs to be adapted to high temperatures (water-side preheating temperature exceeding 100℃, molten salt-side heat exchange temperature reaching...). The proposed solution requires industrial-grade parameters including temperatures above 390℃, high pressure (steam pressure within evaporator 1 reaches industrial-grade threshold), and high flow rate, with long-term continuous and stable operation and a load scale reaching megawatt / gigawatt levels. In contrast, conventional water circulation heating operates at ambient temperature (water temperature mostly between 0-60℃), ambient pressure, and low flow rate, typical for civilian / commercial use. Its load scale is small and allows for intermittent and variable load adjustments. Finally, the water circulation heating in this application needs to be deeply coordinated with molten salt circulation, with the core objective of avoiding industrial safety risks such as molten salt solidification, thermal shock, and water hammer. It also has strict quantitative control requirements for heating / pressurization rates and wall temperature uniformity. Conventional water circulation heating lacks cross-media coordination constraints, requires only simple temperature start-stop control, and has no industrial-grade safety risk prevention and control requirements.

[0069] Optionally, in one specific embodiment, the molten salt circulation valve includes: a molten salt outlet regulating valve 11, a molten salt inlet regulating valve 12, and a molten salt bypass regulating valve 13;

[0070] The molten salt circulation unit is connected to the molten salt inlet of the evaporator 1 via the molten salt inlet pipe, and the molten salt circulation unit is connected to the molten salt outlet of the evaporator 1 via the molten salt outlet pipe. The molten salt inlet pipe and the molten salt outlet pipe are connected by a molten salt bypass pipe.

[0071] Molten salt bypass regulating valve 13 is installed on the molten salt bypass pipeline, molten salt inlet regulating valve 12 is installed between molten salt bypass regulating valve 13 and molten salt inlet of evaporator 1, and molten salt outlet regulating valve 11 is installed between molten salt bypass regulating valve 13 and molten salt outlet of evaporator 1.

[0072] The molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13 are all electrically connected to the control unit;

[0073] The control unit, upon determining that the temperature data within the evaporator 1 has reached a preset safe temperature threshold, sends a first control command to the molten salt circulation valve to control the molten salt circulation between the molten salt circulation unit and the evaporator 1, including:

[0074] When the temperature data inside the evaporator 1 is determined to reach the preset safe temperature threshold, a first control command is sent to the molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13 to control the molten salt circulation between the molten salt circulation unit and the evaporator 1; wherein, the first control command is used to control the molten salt outlet regulating valve 11 and the molten salt inlet regulating valve 12 to open based on a preset valve opening speed, and to control the molten salt bypass regulating valve 13 to close based on a preset valve closing speed.

[0075] Specifically, the molten salt circulation valve includes a molten salt outlet regulating valve 11, a molten salt inlet regulating valve 12, and a molten salt bypass regulating valve 13; that is, the molten salt output end of the molten salt circulation unit is sealed and connected to the molten salt inlet on the evaporator 1 shell through the molten salt inlet pipe, and the molten salt return end of the molten salt circulation unit is sealed and connected to the molten salt outlet on the evaporator 1 shell through the molten salt outlet pipe. Furthermore, the middle section of the molten salt inlet pipe and the middle section of the molten salt outlet pipe are also sealed and connected across the circuit through the molten salt bypass pipe, forming a dual molten salt circulation path of "molten salt main circuit (molten salt inlet pipe - evaporator 1 - molten salt outlet pipe) + molten salt bypass (molten salt bypass pipe)".

[0076] The molten salt bypass regulating valve 13 is sealed and connected in series with the molten salt bypass pipeline to regulate the molten salt flow rate in the molten salt bypass pipeline; the molten salt inlet regulating valve 12 is sealed and connected in series with the molten salt inlet pipeline between the molten salt bypass regulating valve 13 and the molten salt inlet of the evaporator 1 to regulate the molten salt flow rate entering the evaporator 1; the molten salt outlet regulating valve 11 is sealed and connected in series with the molten salt outlet pipeline between the molten salt bypass regulating valve 13 and the molten salt outlet of the evaporator 1 to regulate the molten salt flow rate exiting the evaporator 1.

[0077] Molten salt outlet regulating valve 11, molten salt inlet regulating valve 12 and molten salt bypass regulating valve 13 are all electrically connected to the control unit, and can receive electrical signal commands from the control unit and execute corresponding valve opening adjustment actions.

[0078] Correspondingly, the control unit collects the water-side temperature data in the evaporator 1 in real time through a temperature sensor and compares it with a pre-stored safe temperature threshold (molten salt freezing point +20℃, such as 160℃ for ternary nitrate molten salt). When the temperature data is determined to continuously and stably reach the safe temperature threshold, a first control command is immediately generated and sent. This command consists of three independent electrical signal regulation commands, which are synchronously transmitted to the molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13, respectively. Among them, the electrical signal commands sent to the molten salt outlet regulating valve 11 and the molten salt inlet regulating valve 12 are used to control the two regulating valves according to... The molten salt main circuit is gradually opened at a pre-set uniform and slow opening speed (e.g., the opening degree increases by 1% every 30 seconds) to achieve slow on / off control. An electrical signal command is sent to the molten salt bypass regulating valve 13 to control the regulating valve to gradually close at a pre-set uniform and slow closing speed (e.g., the opening degree decreases by 1-3% per minute). Through the slow flow restriction of the molten salt bypass, the high-temperature molten salt output from the molten salt circulation unit is forced to gradually divert from the molten salt bypass pipeline to the molten salt main circuit, so that the high-temperature molten salt enters the evaporator 1 slowly at a controllable flow rate to exchange heat with the preheated water medium in the evaporator 1, thereby avoiding the risk of thermal shock, water hammer and molten salt solidification caused by a sudden increase in molten salt flow rate from the source.

[0079] The opening speed of the molten salt outlet regulating valve 11 and the molten salt inlet regulating valve 12 and the closing speed of the molten salt bypass regulating valve 13 are pre-calibrated matching values ​​to ensure that the rate of increase of the flow rate of the molten salt main pipeline is matched with the rate of decrease of the flow rate of the molten salt bypass, thereby stabilizing the overall molten salt flow rate of the molten salt circulation unit and avoiding pressure fluctuations in the molten salt circulation system due to sudden changes in pipeline flow.

[0080] This embodiment refines the molten salt circulation valve into molten salt outlet, inlet regulating valves, and molten salt bypass regulating valve 13, and establishes a dual circulation path for the molten salt main path and bypass path. With the electrical connection between each valve and the control unit, it realizes refined zone control of the molten salt circulation. The control unit only controls the molten salt inlet and outlet regulating valves to open slowly and uniformly at a preset speed and the molten salt bypass regulating valve 13 to close slowly and uniformly at a preset speed when the water side temperature of evaporator 1 continuously and stably reaches the safety threshold. At the same time, the opening and closing speeds of each valve are calibrated and matched so that the rate of increase of molten salt flow in the main path is matched with the rate of decrease of flow in the bypass path. This achieves a smooth diversion of high-temperature molten salt from the bypass path to the main path and allows it to slowly enter evaporator 1 at a controllable flow rate to exchange heat with the preheated water medium. This avoids the risks of molten salt solidification, thermal shock, and water hammer caused by a sudden increase in molten salt flow rate from the source, and ensures the stability of the overall molten salt flow rate of the molten salt circulation unit. It also avoids pressure fluctuations in the molten salt circulation system caused by sudden changes in pipeline flow rate, further improving the safety and controllability of the molten salt steam generation system startup process.

[0081] Optionally, in one specific embodiment, the control unit determines that the system initialization process is complete, including:

[0082] Send a second control command to the molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13. The second control command is used to control the molten salt outlet regulating valve 11 and the molten salt inlet regulating valve 12 to be completely closed, and to control the opening degree of the molten salt bypass regulating valve 13 to be greater than the preset initial opening degree threshold.

[0083] In addition, a third control command is sent to the water circulation pump 14, wherein the third control command is used to control the water circulation pump 14 to shut down.

[0084] Specifically, the control unit first sends a second control command to the molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13. This command issues specific opening control instructions to the three valves. For the molten salt outlet regulating valve 11 and the molten salt inlet regulating valve 12, the command controls them to completely close, cutting off the connection between the molten salt main line and the evaporator 1, preventing molten salt from entering the evaporator 1 during the system initialization phase. For the molten salt bypass regulating valve 13, the command controls it to open and reach an opening degree greater than the preset initial opening threshold (e.g., if the initial opening threshold is set to 80%, then the opening degree of the molten salt bypass regulating valve 13 is adjusted to 80%). (Above), ensure that the molten salt circulation unit can form an independent molten salt circulation path through the molten salt bypass pipeline, and complete the initialization preparation of the molten salt side; at the same time, the control unit sends a third control command to the water circulation pump 14, and controls the water circulation pump 14 to perform a shut-off action, so that the water circulation unit is in a stopped state, and the water medium in the evaporator 1 and the connected circulation pipeline remains static, so as to prepare for the circulation heating of the subsequent water side preheating stage. After the molten salt side and the water circulation side have completed the status adjustment of the above-mentioned initialization valves and equipment, the control unit determines that the initialization process of the molten salt steam generation system is completed, and can enter the next stage of the water side preheating process.

[0085] This application sends a second control command to the molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13 to achieve full closure of the molten salt main pipeline valve and exceed the initial threshold opening of the bypass valve. Simultaneously, a third control command is sent to the water circulation pump 14 to shut it down. After the molten salt side and the water circulation side complete the corresponding state regulation, the system initialization is determined to be complete. This not only cuts off the molten salt main pipeline and opens the molten salt bypass pipeline to form an independent circulation path for the molten salt circulation unit, avoiding the risk of molten salt entering the evaporator 1 and causing solidification during the initialization stage, but also shuts down the water circulation pump 14 to keep the water medium static, preparing for uniform preheating of the entire water side. Furthermore, through standardized equipment and valve state regulation, precise control of the initialization of the molten salt side and the water circulation side is achieved, ensuring that each unit is in a safe and standardized preset state before system startup. This avoids safety hazards caused by equipment malfunctions from the start-up source, improving the controllability and safety of the system startup preparation stage.

[0086] Optionally, in one specific embodiment, the control unit is further configured to:

[0087] After sending the first control command to the molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13, the heating rate and pressure rate within the evaporator 1 are obtained based on real-time acquired temperature and pressure data. When the heating rate exceeds a preset heating rate threshold or the pressure rate exceeds a preset pressure rate threshold, a shut-off speed regulation command is sent to the molten salt bypass regulating valve 13. The heating rate is the ratio of the difference between the current temperature data and the previous temperature data to a preset unit time. The pressure rate is the ratio of the difference between the current pressure data and the previous pressure data to a preset unit time.

[0088] The closing speed adjustment command is used to adjust the closing speed of the molten salt bypass regulating valve 13, so as to control the heating rate in the evaporator 1 to be less than or equal to the preset heating rate threshold, and to control the pressure rate in the evaporator 1 to be less than or equal to the preset pressure rate threshold.

[0089] Specifically, after sending the first control command, the control unit continues to perform rate monitoring and dynamic adjustment operations during the molten salt introduction process. This includes: after sending the first control command to the molten salt outlet regulating valve 11, the molten salt inlet regulating valve 12, and the molten salt bypass regulating valve 13 to initiate the molten salt introduction process (main circuit open, bypass closed), the control unit continuously and in real-time collects water-side temperature data and steam-side pressure data within the evaporator 1 using temperature and pressure sensors. Based on the continuously collected time-series data, the control unit obtains the heating rate and pressure rate within the evaporator 1 according to preset calculation rules. The heating rate is the ratio of the difference between the temperature data collected at the current moment and the temperature data collected at the previous moment to a preset unit time; the pressure rate is the ratio of the difference between the pressure data collected at the current moment and the pressure data collected at the previous moment to a preset unit time. The real-time calculated heating rate and pressure rate are compared with the pre-stored heating rate threshold and pressure rate threshold, respectively. If it is determined that the heating rate is greater than the heating rate threshold or the pressure rate is greater than the pressure rate threshold, a closing speed adjustment command is immediately generated and sent to the molten salt bypass regulating valve 13. This closing speed adjustment command carries a new valve closing speed parameter, which is used to control the molten salt bypass regulating valve 13 to slow down the current closing speed. By reducing the flow restriction rate of the molten salt bypass pipeline, the flow rate of molten salt to the main pipeline is reduced, thereby reducing the flow rate of molten salt entering the evaporator 1. This achieves precise control of the water-side heating rate and steam-side pressure rate in the evaporator 1, ensuring that the heating rate drops quickly and stabilizes to less than or equal to the heating rate threshold, and the pressure rate drops quickly and stabilizes to less than or equal to the pressure rate threshold, avoiding safety risks such as thermal shock, water hammer, and molten salt solidification caused by excessive rates.

[0090] This embodiment continuously collects data using temperature and pressure sensors and calculates the heating and pressurization rates of evaporator 1 according to rules. When either rate exceeds a preset threshold, a closing speed adjustment command is promptly sent to the molten salt bypass regulating valve 13 to slow down its closing speed, thereby reducing the flow of molten salt entering evaporator 1. This achieves real-time monitoring and dynamic closed-loop control of the heating / pressurization rate, ensuring that the rate never exceeds the preset threshold. This effectively avoids safety risks such as molten salt solidification, thermal shock, and water hammer caused by excessive rate. At the same time, it keeps the energy exchange during the molten salt introduction process under control, ensuring the refined coordination between molten salt circulation and water / steam circulation. This improves the stability, controllability, and safety of the molten salt steam generation system during the start-up phase, allowing the system to smoothly transition to the design operating conditions.

[0091] Optionally, in one specific embodiment, the system further includes a water supply unit, which is connected to the circulation pipeline between the preheater 2 and the primary heater 3 via a water supply pipeline;

[0092] A water supply regulating valve 42 is installed on the water supply pipeline, and the water supply regulating valve 42 is electrically connected to the control unit;

[0093] The control unit is also used for:

[0094] Based on the current temperature and pressure data, as well as the pre-set water supply circulation algorithm, a fourth control command is sent to the water supply regulating valve 42, wherein the fourth control command is used to adjust the opening degree of the water supply regulating valve 42.

[0095] Furthermore, based on the current temperature and pressure data, and the pre-set water supply circulation algorithm, a fourth control command is sent to the water supply regulating valve 42, including: obtaining the corresponding temperature deviation based on the current temperature data and the pre-set target temperature, and obtaining the corresponding pressure deviation based on the current pressure data and the pre-set target pressure.

[0096] Based on the current temperature and pressure deviations, as well as the pre-set heat exchange power, corresponding coefficients, specific heat capacity at constant pressure, and water density at constant pressure, the corresponding theoretical water supply rate is obtained; where the heat exchange power is the heat exchange power between molten salt and water per unit flow rate, and the corresponding coefficient is the coefficient between steam pressure and water saturation temperature.

[0097] The theoretical water supply rate is corrected based on the current pressure increase rate and temperature increase rate, as well as the preset temperature increase rate threshold and pressure increase rate threshold.

[0098] Based on the corrected theoretical water supply rate, as well as the preset fully open water supply rate and linear matching coefficient, the basic water supply opening of the water supply regulating valve 42 at the current moment is determined.

[0099] Based on the current basic water supply opening of the water supply regulating valve 42, a fourth control command is sent to the water supply regulating valve 42 to control the water supply regulating valve 42 to open based on the basic water supply opening.

[0100] Furthermore, the control unit, based on the current temperature and pressure deviations, as well as the pre-set isobaric specific heat capacity and isobaric water density, obtains the corresponding theoretical water supply rate, including:

[0101] Based on the current temperature and pressure deviations, and pre-set heat exchange power, corresponding coefficients, isobaric specific heat capacity, isobaric water density, molten salt anti-condensation safety margin coefficient, and Formula 1, the corresponding theoretical feedwater rate is obtained; Formula 1 is:

[0102] ;

[0103] Where Q1 is the theoretical water supply rate, q 熔 T represents the heat transfer efficiency, k is the corresponding coefficient, and T represents the heat transfer power. 偏For temperature deviation, P 偏 For pressure deviation, c 水 For the specific heat capacity at constant pressure, ρ 水 K is the density of water under constant pressure, and k3 is the safety margin coefficient for molten salt anti-condensation.

[0104] Furthermore, based on the current pressure increase rate and temperature increase rate, as well as the preset temperature increase rate threshold and pressure increase rate threshold, the theoretical feedwater rate is corrected, including:

[0105] Based on the current boost rate and the preset boost rate threshold, obtain the boost rate constraint value corresponding to the current time; where the boost rate constraint value is the absolute value of the difference between the ratio of boost rate to boost rate threshold and 1.

[0106] Based on the current heating rate and the preset heating rate threshold, obtain the heating rate constraint value corresponding to the current time; the heating rate constraint value is the absolute value of the difference between the ratio of heating rate to heating rate threshold and 1.

[0107] Based on the pressure rise rate constraint value and the temperature rise rate constraint value, as well as the pre-set temperature rise rate constraint coefficient and pressure rise rate constraint coefficient, the theoretical water supply rate is corrected; wherein, the corrected theoretical water supply rate is the product of the pressure rise rate constraint value, the temperature rise rate constraint value, the temperature rise rate constraint coefficient, the pressure rise rate constraint coefficient and the theoretical water supply rate.

[0108] Furthermore, based on the corrected theoretical water supply rate, and the pre-set fully open water supply rate and linear matching coefficient, the basic water supply opening of the water supply regulating valve 42 at the current moment is determined, including:

[0109] Based on the corrected theoretical water supply rate, and the preset fully open water supply rate and linear matching coefficient, the basic water supply opening of the water supply regulating valve 42 at the current moment is determined; wherein, the basic water supply opening is the ratio of the corrected theoretical water supply rate to the product of the fully open water supply rate and the linear matching coefficient.

[0110] Furthermore, based on the current basic water supply opening of the water supply regulating valve 42, a fourth control command is sent to the water supply regulating valve 42 to control the water supply regulating valve 42 to open based on the basic water supply opening, including:

[0111] Based on the baseline water supply opening, safe temperature threshold, target temperature, and current temperature data, as well as a pre-set temperature safety margin correction strategy, the baseline water supply opening is corrected; the temperature safety margin correction strategy is as follows:

[0112] ;

[0113] Where, θ 基 Based on water supply opening degree, θ修 For the corrected basic water supply opening, T 安 For the safe temperature threshold, T 标 For the target temperature, T 实 This is the temperature data at the current moment.

[0114] Specifically, in this embodiment, a water supply unit is provided to connect with the circulation pipeline between the preheater 2 and the primary heater 3 in the water circulation unit through the water supply pipeline, thereby supplementing the water circulation unit with water medium; a water supply regulating valve 42 is connected in series on the water supply pipeline, which is electrically connected to the control unit and can receive the fourth control command issued by the control unit to perform the corresponding opening adjustment action, thereby regulating the water supply rate from the water supply unit to the water circulation unit.

[0115] First, the control unit will display the current temperature data (T) of the water side of evaporator 1. 实 ) and the preset target temperature (T) 标 The difference is calculated to obtain the temperature deviation (T). 偏 ), that is, T 偏 =T 实 -T 标 .

[0116] The current pressure data (P) on the evaporator side 1 is used. 实 ) and preset target pressure (P) 标 The difference is calculated to obtain the pressure deviation (P). 偏 ), that is, P 偏 =P 实 -P 标 .

[0117] The control unit, based on the obtained temperature and pressure deviations, combined with the pre-set heat exchange power (q) per unit flow rate of molten salt and water, 熔 ), the coefficient of correspondence between steam pressure and water saturation temperature (k), and the specific heat capacity of water at constant pressure (c) 水 ), the isobaric density of water (ρ) 水 The molten salt anti-condensation safety margin factor (k3) is substituted into Formula 1 to calculate the theoretical feed rate (unit: m). 3 / h);

[0118] The standard formula is: ;

[0119] Where Q1 is the theoretical water supply rate, q 熔 T represents the heat transfer efficiency, k is the corresponding coefficient, and T represents the heat transfer power. 偏 For temperature deviation, P 偏 For pressure deviation, c 水 For the specific heat capacity at constant pressure, ρ 水Where k is the density of water under constant pressure, and k3 is the safety margin factor for molten salt anti-condensation. The addition of 0.01 to the formula avoids a denominator of 0 and ensures the validity of the calculation; k·P 偏 • 1000 represents the conversion of pressure deviation into thermal power equivalent, achieving unified matching of thermal power for both temperature and pressure parameters. The isobaric specific heat capacity and isobaric water density mentioned above are generally taken as constant values, i.e., c. 水 It is 4.2 kJ / (kg·℃), ρ 水 1000 kg / m 3 The pressure does not change with the real-time pressure and temperature of evaporator 1. The steam side pressure of evaporator 1 in the molten salt steam generation system is under medium-low pressure conditions (considering the characteristic of molten salt heat exchange temperature ≤565℃, the system design pressure is generally ≤10MPa). Within this pressure range, although the isobaric specific heat capacity and density of the water / steam-water mixture change, the change is extremely small (usually <5%), and the impact on the calculation results of feedwater rate and valve opening is negligible.

[0120] The control unit first calculates the boost rate (V) at the current moment. p ) and preset boost rate threshold (V pmax The ratio of ) to 1, and then the absolute value of the difference, yields the boost rate constraint value (K). p ), that is, K p =|1-(V p / V pmax )|;

[0121] Similarly, calculate the current heating rate (V) t ) and preset heating rate threshold (V tmax The ratio of ) to 1, with the absolute value of the difference, yields the heating rate constraint value (K). t ), that is, K t =|1-(V t / V tmax )|.

[0122] The control unit multiplies the two rate constraint values ​​mentioned above with the preset pressure rise rate constraint coefficient and temperature rise rate constraint coefficient to correct the theoretical water supply rate and obtain the corrected water supply rate (Q2). The pressure rise rate and temperature rise rate constraint coefficients are both industrial empirical values ​​of 0-1, which are used to further hard-constrain the temperature rise rate and pressure rise rate to avoid exceeding the standard.

[0123] The control unit is based on the corrected water supply rate (Q2), combined with the pre-calibrated fully open water supply rate (Q) when the water supply regulating valve 42 is fully open. max The linear matching coefficient (S) between the opening degree of the water supply regulating valve 42 and the water supply rate is used to calculate the basic water supply opening degree (in %); that is, the calculation formula is: basic water supply opening degree θbase = Q2 / (Qbase) max•S). The linear matching coefficient S is set to 1 by default (the regulating valve is a linear valve, and the opening degree is proportional to the water supply rate). If it is a non-linear valve, it can be calibrated in advance and then entered.

[0124] The control unit combines the safe temperature threshold (T) 安 Based on the molten salt freezing point +20℃, target temperature, and current temperature data, the basic water supply opening is corrected a second time according to the preset temperature safety margin correction strategy to obtain the final target opening (θ) of the water supply regulating valve 42. 修 ), and send it as the core parameter of the fourth control command to the water supply regulating valve 42; the temperature safety margin correction strategy is:

[0125] ;

[0126] Where, θ 基 Based on water supply opening degree, θ 修 For the corrected basic water supply opening, T 安 For the safe temperature threshold, T 标 For the target temperature, T 实 This is the temperature data at the current moment.

[0127] This embodiment achieves precise water replenishment control for the water circulation unit by adding a water supply unit and a water supply regulating valve 42 electrically connected to the control unit. Simultaneously, the control unit, based on real-time temperature and pressure data from the evaporator 1, performs a complete calculation process involving temperature and pressure deviation calculation, theoretical water supply rate derived through formula quantification, hard constraint correction of heating / pressurization rate, basic opening conversion, and secondary correction of temperature safety margin. This process determines the final target opening of the water supply regulating valve 42 and sends a fourth control command. Thus, through quantitative calculation combining temperature and pressure parameters with the molten salt heat transfer characteristics, precise matching of the water supply rate and the molten salt heat transfer power is achieved. This system ensures the energy balance of the molten salt-water / steam dual-cycle system. It also relies on the hard constraints of the heating / pressurization rate constraints and empirical coefficients, combined with the dual protection of the molten salt anti-condensation safety margin coefficient and the temperature safety margin correction strategy. This avoids the risks of molten salt solidification, thermal shock, and water hammer from the feedwater side. Furthermore, the use of engineering-defined values ​​for the thermal properties of water simplifies calculations without affecting control accuracy. The fully quantitative calculation logic makes feedwater regulation more precise and controllable, further improving the stability, safety, and automation level of the molten salt steam generation system during startup and steady-state operation, and ensuring steam quality and system operating efficiency.

[0128] Furthermore, before introducing molten salt, the water medium in the evaporator 1 and its connected water supply pipeline must be preheated uniformly to a safe temperature threshold using a preliminary heater 3 (such as an electric heater). This temperature threshold is generally about 20°C higher than the freezing point of molten salt. The safe temperature for ternary molten salt can be 160°C.

[0129] Ensure that the shut-off valve of the molten salt main line (evaporator 1 inlet and outlet) is closed, while the regulating valve on the molten salt bypass line is pre-opened to a large degree (e.g., 80%) to establish circulation in the molten salt system.

[0130] Open the molten salt inlet / outlet passage of evaporator 1: Slowly open the switch valves at the molten salt inlet and outlet of evaporator 1. At this time, due to the large opening of the bypass valve, most of the high-temperature molten salt still flows through the bypass, and only a very small flow or static molten salt exists at the inlet of evaporator 1.

[0131] Close the molten salt bypass regulating valve of evaporator 1 at an extremely slow rate (reducing the opening by 1-3% per minute). This operation forces a portion of the high-temperature molten salt to slowly flow into the heat exchange tubes of evaporator 1.

[0132] Heating rate control: By adjusting the closing speed of the bypass valve, the heating rate of the water side medium in evaporator 1 is strictly controlled to ≤20℃ / h. Pressure rise rate control: The pressure rise rate of the steam side in evaporator 1 is synchronously controlled to ≤0.05MPa / min. These two rates are the core of coordinated control and are achieved through real-time monitoring.

[0133] When the pressure of evaporator 1 rises to a pressure sufficient to supply steam to users, each steam user is slowly connected according to preset logic, and the feedwater flow rate is adjusted synchronously to establish a stable steam-feedwater cycle. Dual-cycle steady-state coordination: When the system approaches the design operating condition, the molten salt bypass regulating valve 13 is put into automatic control mode, which automatically fine-tunes the opening degree according to the deviation between the steam pressure or temperature at the outlet of evaporator 1 and the set value, thereby precisely controlling the flow rate of molten salt entering evaporator 1 to ensure the dynamic balance of steam user demand.

[0134] Furthermore, the safe temperature threshold can be optimized according to the specific type of molten salt and the system design, for example, set to "molten salt freezing point + 30℃".

[0135] Furthermore, the speed of the high-temperature molten salt pump can be finely adjusted simultaneously, but the control logic is more complex. It is necessary to ensure that the adjustment of the bypass valve is the primary method and frequency adjustment is secondary, so as to avoid adverse effects on the pump.

[0136] Furthermore, for the control of the pressure rise rate, the saturation temperature change rate of evaporator 1 can be introduced as an indirect monitoring parameter to provide dual protection along with the pressure rise rate.

[0137] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0138] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0139] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0140] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0141] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A molten salt steam generation system, characterized in that, include: The system comprises a control unit, a water circulation unit, a molten salt circulation unit, and a steam application unit; wherein the water circulation unit includes an evaporator, a preliminary heater, and a preheater connected in pairs via circulation pipelines; the steam application unit is connected to the evaporator via a steam application pipeline, and the molten salt circulation unit is connected to the evaporator via a molten salt circulation pipeline; A water circulation pump is installed on the circulation pipeline between the evaporator and the primary heater, a steam application valve is installed on the steam application pipeline, and a molten salt circulation valve is installed on the molten salt circulation pipeline; a temperature sensor for real-time monitoring of the temperature data inside the evaporator and a pressure sensor for real-time monitoring of the pressure data inside the evaporator are installed inside the evaporator. The water circulation pump, steam application valve, molten salt circulation valve, temperature sensor, and pressure sensor are all electrically connected to the control unit; The molten salt circulation valve includes: a molten salt outlet regulating valve, a molten salt inlet regulating valve, and a molten salt bypass regulating valve; The molten salt circulation unit is connected to the molten salt inlet of the evaporator via the molten salt inlet pipe, and the molten salt circulation unit is connected to the molten salt outlet of the evaporator via the molten salt outlet pipe. The molten salt inlet pipe and the molten salt outlet pipe are connected by a molten salt bypass pipe. The molten salt bypass regulating valve is installed on the molten salt bypass pipeline, the molten salt inlet regulating valve is installed between the molten salt bypass regulating valve and the molten salt inlet of the evaporator, and the molten salt outlet regulating valve is installed between the molten salt bypass regulating valve and the molten salt outlet of the evaporator; The molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve are all electrically connected to the control unit; The control unit is used to acquire temperature and pressure data in real time after determining that the system initialization process is completed, and send a water heating command to the water circulation pump to start the water circulation pump to circulate and heat the water in the evaporator. Furthermore, when the temperature data inside the evaporator is determined to reach a preset safe temperature threshold, a first control command is sent to the molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve to control the molten salt circulation between the molten salt circulation unit and the evaporator; wherein, the first control command is used to control the molten salt outlet regulating valve and the molten salt inlet regulating valve to open based on a preset valve opening speed, and to control the molten salt bypass regulating valve to close based on a preset valve closing speed; Additionally, when the pressure data inside the evaporator reaches a preset pressure threshold, a steam application command is sent to the steam application valve to open the steam application valve and supply steam to the steam application unit for use.

2. The molten salt steam generating system according to claim 1, characterized in that, The control unit determines that the system initialization process is complete, including: Send a second control command to the molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve. The second control command is used to control the molten salt outlet regulating valve and the molten salt inlet regulating valve to be completely closed, and to control the opening degree of the molten salt bypass regulating valve to be greater than the preset initial opening degree threshold. In addition, a third control command is sent to the water circulation pump, wherein the third control command is used to control the water circulation pump to shut down.

3. The molten salt steam generating system according to claim 1, characterized in that, The control unit is also used for: After sending the first control command to the molten salt outlet regulating valve, the molten salt inlet regulating valve, and the molten salt bypass regulating valve, the heating rate and pressure rate inside the evaporator are obtained based on the real-time acquired temperature and pressure data. When the heating rate is greater than a preset heating rate threshold or the pressure rate is greater than a preset pressure rate threshold, a shut-off speed regulation command is sent to the molten salt bypass regulating valve. The heating rate is the ratio of the difference between the temperature data at the current moment and the temperature data at the previous moment to a preset unit time. The pressure increase rate is the ratio of the difference between the pressure data at the current moment and the pressure data at the previous moment to a preset unit time. The closing speed adjustment command is used to adjust the closing speed of the molten salt bypass regulating valve to control the heating rate in the evaporator to be less than or equal to a preset heating rate threshold, and to control the pressure rate in the evaporator to be less than or equal to a preset pressure rate threshold.

4. The molten salt steam generating system according to claim 3, characterized in that, The system further includes a water supply unit, which is connected to the circulation pipeline between the preheater and the primary heater via a water supply pipeline; A water supply regulating valve is installed on the water supply pipeline, and the water supply regulating valve is electrically connected to the control unit; The control unit is also used for: Based on the current temperature and pressure data, as well as the pre-set water supply circulation algorithm, a fourth control command is sent to the water supply regulating valve, which is used to adjust the opening degree of the water supply regulating valve.

5. The molten salt steam generating system according to claim 4, characterized in that, The control unit, based on the current temperature and pressure data and a pre-set water supply circulation algorithm, sends a fourth control command to the water supply regulating valve, including: Based on the current temperature data and the preset target temperature, obtain the corresponding temperature deviation; based on the current pressure data and the preset target pressure, obtain the corresponding pressure deviation. Based on the current temperature and pressure deviations, as well as the pre-set heat exchange power, corresponding coefficients, specific heat capacity at constant pressure, and water density at constant pressure, the corresponding theoretical water supply rate is obtained; where the heat exchange power is the heat exchange power between molten salt and water per unit flow rate, and the corresponding coefficient is the coefficient between steam pressure and water saturation temperature. The theoretical water supply rate is corrected based on the current pressure increase rate and temperature increase rate, as well as the preset temperature increase rate threshold and pressure increase rate threshold. Based on the corrected theoretical water supply rate, as well as the preset fully open water supply rate and linear matching coefficient, the basic water supply opening of the water supply regulating valve at the current moment is determined. Based on the current basic water supply opening of the water supply regulating valve, a fourth control command is sent to the water supply regulating valve to control the water supply regulating valve to open based on the basic water supply opening.

6. The molten salt steam generating system according to claim 5, characterized in that, The control unit, based on the current temperature and pressure deviations, and pre-set constant-pressure specific heat capacity and constant-pressure water density, obtains the corresponding theoretical water supply rate, including: Based on the current temperature and pressure deviations, and pre-set heat exchange power, corresponding coefficients, isobaric specific heat capacity, isobaric water density, molten salt anti-condensation safety margin coefficient, and Formula 1, the corresponding theoretical feedwater rate is obtained; Formula 1 is: ； Where Q1 is the theoretical water supply rate, q 熔 T represents the heat transfer efficiency, k is the corresponding coefficient, and T represents the heat transfer power. 偏 For temperature deviation, P 偏 For pressure deviation, c 水 For the specific heat capacity at constant pressure, ρ 水 K is the density of water under constant pressure, and k3 is the safety margin coefficient for molten salt anti-condensation.

7. The molten salt steam generating system according to claim 5, characterized in that, The control unit, based on the current pressure increase rate and temperature increase rate, as well as preset temperature increase rate thresholds and pressure increase rate thresholds, corrects the theoretical water supply rate, including: Based on the current boost rate and the preset boost rate threshold, obtain the boost rate constraint value corresponding to the current time; where the boost rate constraint value is the absolute value of the difference between the ratio of boost rate to boost rate threshold and 1. Based on the current heating rate and the preset heating rate threshold, obtain the heating rate constraint value corresponding to the current time; the heating rate constraint value is the absolute value of the difference between the ratio of heating rate to heating rate threshold and 1. Based on the pressure rise rate constraint value and the temperature rise rate constraint value, as well as the pre-set temperature rise rate constraint coefficient and pressure rise rate constraint coefficient, the theoretical water supply rate is corrected; wherein, the corrected theoretical water supply rate is the product of the pressure rise rate constraint value, the temperature rise rate constraint value, the temperature rise rate constraint coefficient, the pressure rise rate constraint coefficient and the theoretical water supply rate.

8. The molten salt steam generating system according to claim 5, characterized in that, The control unit, based on the corrected theoretical water supply rate and the preset fully open water supply rate and linear matching coefficient, determines the basic water supply opening of the water supply regulating valve at the current moment, including: Based on the corrected theoretical water supply rate, and the preset fully open water supply rate and linear matching coefficient, the basic water supply opening of the water supply regulating valve at the current moment is determined; wherein, the basic water supply opening is the ratio of the corrected theoretical water supply rate to the product of the fully open water supply rate and the linear matching coefficient.

9. The molten salt steam generating system according to claim 5, characterized in that, The control unit, based on the current basic water supply opening of the water supply regulating valve, sends a fourth control command to the water supply regulating valve to control the water supply regulating valve to open based on the basic water supply opening, including: Based on the baseline water supply opening, safe temperature threshold, target temperature, and current temperature data, as well as a pre-set temperature safety margin correction strategy, the baseline water supply opening is corrected; the temperature safety margin correction strategy is as follows: ； Where, θ 基 Based on water supply opening degree, θ 修 For the corrected basic water supply opening, T 安 For the safe temperature threshold, T 标 For the target temperature, T 实 This is the temperature data at the current moment.

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