Parallel molten salt heating superheated steam generation system and control method thereof

Abstract

The embodiment of the present application provides a parallel type fused salt heating superheated steam generation system and a control method thereof, and belongs to the technical field of oilfield steam injection. The system comprises: an evaporator system and a superheater system connected in sequence, which are combined to process oilfield produced water into corresponding steam required for steam injection; a control module for constructing a corresponding salt supply linkage model based on real-time operation conditions, generating an optimal fused salt supply device linkage control scheme under the condition of meeting the steam injection demand based on the salt supply linkage model; and an execution module arranged on the salt supply pipeline of the fused salt supply device of the evaporator system and the superheater system, respectively, for adjusting the fused salt supply amount based on the optimal fused salt supply device linkage control scheme. The present application not only reduces the consumption of fused salt, but also solves the problem of uncoordinated salt supply ratio and steam quality fluctuation in the prior art, greatly improves the dynamic response capability of the steam injection system, and provides a more efficient solution for heavy oil exploitation.

Description

Technical Field

[0001] This invention relates to the field of oilfield steam injection technology, specifically to a parallel molten salt heating superheated steam generation system and a control method for the parallel molten salt heating superheated steam generation system. Background Technology

[0002] In heavy oilfield steam injection production, the precise generation of wet saturated steam and superheated steam is a key step in achieving efficient oil recovery. However, existing steam injection systems generally adopt a separate design, where the evaporator system and the superheater system operate independently, each receiving its own heat source from a separate molten salt supply unit. Although this design can meet basic requirements under certain specific operating conditions, it has significant shortcomings in terms of overall system energy efficiency optimization and stability.

[0003] First, the existing scheme lacks coordinated control of the molten salt supply process between the evaporator and superheater systems. Because the two systems operate independently, their molten salt supply can only be adjusted using separate control algorithms. This makes it difficult to dynamically optimize the salt supply ratio according to actual operating needs, often resulting in situations where the superheated steam temperature or wet saturated steam dryness cannot simultaneously meet target requirements. This separate control method limits the overall dynamic response capability of the system, increases molten salt consumption, and consequently reduces operating efficiency.

[0004] Secondly, the existing scheme lacks centralized management of cold salt recovery and hot salt distribution. The reheating process after cold salt recovery lacks stability due to fluctuations in the return salt flow rate, which further affects the stability of steam quality. Especially when there are large load fluctuations or complex produced water quality, a separate molten salt supply unit is difficult to coordinate the salt supply needs of the evaporator and superheater, which can easily lead to fluctuations in steam quality or system overload operation.

[0005] To address the above issues, a new superheated steam generation scheme needs to be proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a parallel molten salt heating superheated steam generation system and its control method, so as to at least solve the problems of insufficient operating efficiency and difficulty in guaranteeing steam effect in existing solutions.

[0007] To achieve the above objectives, the first aspect of the present invention provides a parallel molten salt heating superheated steam generation system, the system comprising: an evaporator system and a superheater system connected in sequence, combined for treating oilfield produced water into steam for corresponding steam injection requirements; wherein, both the evaporator system and the superheater system have separate molten salt supply devices, the molten salt supply devices being used to provide a heat source for the operation of the evaporator system and the superheater system; the cold salt from the molten salt supply devices of the evaporator system and the superheater system is collected into a single cold salt recovery device; a control module is used to construct a corresponding salt supply linkage model based on real-time operating conditions, and to generate an optimal molten salt supply device linkage control scheme based on the salt supply linkage model to meet the steam injection requirements; an execution module is respectively installed on the salt supply pipelines of the molten salt supply devices of the evaporator system and the superheater system, and is used to adjust the molten salt supply based on the optimal molten salt supply device linkage control scheme.

[0008] Optionally, the evaporator system includes multiple heat exchangers connected in series to allow the produced water after heat exchange in the previous heat exchanger to flow into the current heat exchanger for secondary heat exchange.

[0009] Optionally, the system further includes: a preheating system connected to the front end of the evaporator system; the preheating system is used to preheat the produced water and supply the preheated produced water to the preheating system.

[0010] Optionally, the superheater system includes: a steam-water separator connected to the output pipe of the evaporator system for separating the wet saturated steam output from the evaporator system to obtain dry steam and saturated water respectively; a superheater connected to the pipe outputting dry steam from the steam-water separator for heat exchange between the dry steam and the hot molten salt in the molten salt supply device of the superheater system to convert the dry steam into superheated dry steam; and a mixer that incorporates the superheated dry steam and the saturated water for generating the steam required for steam injection based on the mixing of the superheated dry steam and the saturated water.

[0011] Optionally, the molten salt supply device of the superheater system includes: a second salt supply pipe arranged in the opposite direction to the dry steam output direction of the steam-water separator, the second salt supply pipe being arranged along the same path as the dry steam conveying pipe in the superheater; the execution module arranged on the superheater system includes: a second hot salt pump for pumping hot salt into the second salt supply pipe; a second three-way regulating valve arranged on the second salt supply pipe between the superheater and the second hot salt pump for controlling the flow rate of hot salt flowing into the corresponding second salt supply pipe of the superheater; the molten salt supply device of the superheater system further includes: a second hot salt return pipe arranged at the third end of the second three-way regulating valve for returning excess hot salt in the total hot salt flow rate output by the second hot salt pump that does not flow to the superheater system to the hot salt storage system.

[0012] Optionally, the molten salt supply device of the evaporator system includes: a first salt supply pipe arranged from the last heat exchanger of the evaporator system to the first heat exchanger; the execution module arranged on the evaporator system includes: a first hot salt pump for pumping hot salt into the first salt supply pipe; a first three-way regulating valve arranged on the first salt supply pipe between the last heat exchanger and the first hot salt pump for controlling the flow rate of hot salt flowing into the first salt supply pipe corresponding to the evaporator system; the molten salt supply device of the evaporator system further includes: a first hot salt return pipe arranged at the third end of the first three-way regulating valve for returning excess hot salt in the total hot salt flow rate output by the first hot salt pump that does not flow to the evaporator system to the hot salt storage system.

[0013] Optionally, the control module is configured to: collect steam demand information for steam injection, and use the steam demand information for steam injection as a basic constraint; construct a corresponding optimization model based on the basic constraint and the artificial immune algorithm, wherein the optimization objective of the optimization model is the minimum thermal salt consumption; perform iterative solution on the optimization model until the iteration termination condition is triggered, and output the optimal control scheme of the molten salt supply device of the evaporator system and the superheater system as the optimal molten salt supply device joint control scheme.

[0014] Optionally, the step of constructing the corresponding optimization model based on the basic constraints and the artificial immune algorithm includes: taking the valve openings of the first hot salt pump, the second hot salt pump, the first three-way regulating valve on the evaporator system side, and the second three-way regulating valve on the superheater system side as antibody structures; constructing corresponding fitness functions to evaluate the fitness of each antibody; specifying corresponding mutation frequencies, and constructing corresponding optimization models based on antibody structures, fitness functions, and mutation frequencies.

[0015] Optionally, the fitness function is expressed as:

[0016]

[0017] in, This is the fitness value; Total heat salt consumption; This indicates the error between the quality of the steam used for steam injection and the target steam quality. and These are the target wet steam dryness and the actual wet steam dryness, respectively. and These are the target superheated steam temperature and the actual superheated steam temperature, respectively. and These are the preset weights for total heat and salt consumption and steam quality error, respectively.

[0018] Optionally, the iterative solution of the optimization model until the iteration termination condition is triggered, and the optimal control scheme of the molten salt supply device for the evaporator system and the superheater system is output as the optimal molten salt supply device joint control scheme, includes: performing model initialization, randomly generating multiple antibodies within the design range of the preset operating frequency of the preset molten salt supply device and the opening and closing degree of each valve as an initial antibody population; calculating the fitness of each antibody in the initial antibody population, and selecting antibodies with fitness greater than a preset fitness threshold to perform mutation in the optimization direction to obtain mutated antibodies; selecting antibodies with fitness greater than a preset fitness threshold from the mutated antibodies to perform mutation in the optimization direction again, and repeating the mutation multiple times until the iteration number is reached or the fitness function reaches the convergence condition, stopping the iteration, and outputting the optimal control scheme of the molten salt supply device for the evaporator system and the superheater system as the optimal molten salt supply device joint control scheme.

[0019] Optionally, the optimization direction is determined by the following rule: introducing PID control logic, determining the control action point of the PID, and determining the optimization direction based on the control action point of the PID; wherein, the control action point of the PID for the valve opening of the first hot salt pump and the first three-way regulating valve on the evaporator system side is confirmed based on the dryness of the wet saturated steam; the control action point of the PID for the valve opening of the second hot salt pump and the second three-way regulating valve on the superheater system side is confirmed based on the temperature of the superheated steam.

[0020] Optionally, the PID control action point of the valve opening on the evaporator system side of the first hot salt pump and the first three-way regulating valve is based on the confirmation rule of the wet saturated steam dryness:

[0021]

[0022] in, The combined control output for the valve opening of the first hot salt pump and the first three-way regulating valve on the evaporator system side; This represents the dryness error of wet saturated steam. , and These are proportional gain, integral gain, and derivative gain, respectively.

[0023] Optionally, the PID control action point of the valve opening on the superheater system side of the second hot salt pump and the second three-way regulating valve is based on the temperature of the superheated steam, and the confirmation rule is as follows:

[0024]

[0025] in, The combined control output for the valve opening of the second hot salt pump and the second three-way regulating valve on the superheater system side; This is to account for the temperature error of the superheated steam used for steam injection; , and These are proportional gain, integral gain, and derivative gain, respectively.

[0026] Optionally, PID control logic is introduced to determine the control action point of the PID, and the optimization direction is determined based on the control action point of the PID. This includes: dynamically correcting the variables of the antibody solution through the PID control logic to optimize steam quality; calculating the fitness value using the PID-adjusted variables, and determining the optimal control action point based on the fitness evaluation results; and performing antibody mutation based on the optimal control point as the corresponding optimization direction.

[0027] Optionally, the optimal control scheme for the molten salt supply device of the evaporator system and the superheater system, as the optimal molten salt supply device joint control scheme, includes: a joint control output of the valve opening of the first hot salt pump and the first three-way regulating valve on the evaporator system side based on the PID control logic of the final iteration round, and a joint control output of the valve opening of the second hot salt pump and the second three-way regulating valve on the superheater system side. The control strategies of each joint control output are decoupled to obtain the target power of the first hot salt pump, the target valve opening of the first three-way regulating valve on the evaporator system side, the target power of the second hot salt pump, and the target valve opening of the second three-way regulating valve on the superheater system side, respectively, so as to generate the corresponding control scheme as the optimal molten salt supply device joint control scheme.

[0028] A second aspect of the present invention provides a control method for a parallel molten salt heating superheated steam generation system, characterized in that the method is applied to the aforementioned parallel molten salt heating superheated steam generation system, and the method includes: collecting steam demand information for steam injection, using the steam demand information for steam injection as a basic constraint; constructing a corresponding optimization model based on the basic constraint and an artificial immune algorithm, wherein the optimization objective of the optimization model is the minimum hot salt consumption; performing iterative solution on the optimization model until the iteration termination condition is triggered, and outputting the optimal control scheme of the molten salt supply device for the evaporator system and the superheater system as the optimal molten salt supply device joint control scheme.

[0029] Optionally, the step of constructing the corresponding optimization model based on the basic constraints and the artificial immune algorithm includes: taking the valve openings of the first hot salt pump, the second hot salt pump, the first three-way regulating valve on the evaporator system side, and the second three-way regulating valve on the superheater system side as antibody structures; constructing corresponding fitness functions to evaluate the fitness of each antibody; specifying corresponding mutation frequencies, and constructing corresponding optimization models based on antibody structures, fitness functions, and mutation frequencies.

[0030] Optionally, the iterative solution of the optimization model until the iteration termination condition is triggered, and the optimal control scheme of the molten salt supply device for the evaporator system and the superheater system is output as the optimal molten salt supply device joint control scheme, includes: performing model initialization, randomly generating multiple antibodies within the design range of the preset operating frequency of the preset molten salt supply device and the opening and closing degree of each valve as an initial antibody population; calculating the fitness of each antibody in the initial antibody population, and selecting antibodies with fitness greater than a preset fitness threshold to perform mutation in the optimization direction to obtain mutated antibodies; selecting antibodies with fitness greater than a preset fitness threshold from the mutated antibodies to perform mutation in the optimization direction again, and repeating the mutation multiple times until the iteration number is reached or the fitness function reaches the convergence condition, stopping the iteration, and outputting the optimal control scheme of the molten salt supply device for the evaporator system and the superheater system as the optimal molten salt supply device joint control scheme.

[0031] Optionally, the optimization direction is determined by the following rule: introducing PID control logic, determining the control action point of the PID, and determining the optimization direction based on the control action point of the PID; wherein, the control action point of the PID for the valve opening of the first hot salt pump and the first three-way regulating valve on the evaporator system side is confirmed based on the dryness of the wet saturated steam; the control action point of the PID for the valve opening of the second hot salt pump and the second three-way regulating valve on the superheater system side is confirmed based on the temperature of the superheated steam.

[0032] Optionally, the optimal control scheme for the molten salt supply device of the evaporator system and the superheater system, as the optimal molten salt supply device joint control scheme, includes: a joint control output of the valve opening of the first hot salt pump and the first three-way regulating valve on the evaporator system side based on the PID control logic of the final iteration round, and a joint control output of the valve opening of the second hot salt pump and the second three-way regulating valve on the superheater system side. The control strategies of each joint control output are decoupled to obtain the target power of the first hot salt pump, the target valve opening of the first three-way regulating valve on the evaporator system side, the target power of the second hot salt pump, and the target valve opening of the second three-way regulating valve on the superheater system side, respectively, so as to generate the corresponding control scheme as the optimal molten salt supply device joint control scheme.

[0033] On the other hand, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described control method for a parallel molten salt heating superheated steam generation system.

[0034] Through the above technical solution, this invention achieves coordinated optimization of the molten salt supply process for the evaporator and superheater systems by introducing a salt supply linkage model and a real-time control mechanism. By equipping each system with an independent molten salt supply device and integrating their cold salt recovery into a single cold salt recovery device, the centralization of cold salt management and reheating efficiency are enhanced, significantly improving the overall system operational stability and energy efficiency. The control module can dynamically generate a salt supply linkage scheme based on real-time operating conditions and precisely adjust the molten salt supply in the salt supply pipeline through the execution module to ensure that the steam quality (wet steam dryness and superheated steam temperature) meets the steam injection requirements. This solution not only reduces molten salt consumption but also solves the problems of inconsistent salt supply ratios and steam quality fluctuations in existing technologies, significantly improving the dynamic response capability of the steam injection system and providing a more efficient solution for heavy oil extraction.

[0035] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0036] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0037] Figure 1 This is a system structure diagram of a parallel molten salt heating superheated steam generation system provided in one embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the specific structure of a parallel molten salt heating superheated steam generation system provided in one embodiment of the present invention;

[0039] Figure 3 This is a flowchart of the steps of a control method for a parallel molten salt heating superheated steam generation system provided by one embodiment of the present invention.

[0040] Explanation of reference numerals in the attached figures

[0041] 1-Water supply pipeline; 2-Evaporator system; 3-Wet steam pipeline; 4-Dryness online monitoring device; 5-First signal line; 6-First control system; 7-Superheater system; 8-Superheated steam pipeline; 9-Temperature online monitoring device; 10-Second signal line; 11-Second-2nd hot salt pipeline; 12-Second control system; 13-Second hot salt pump; 14-Second-1st hot salt pipeline; 15-Second three-way regulating valve; 16-Second return salt pipeline; 17-First hot salt pump; 18-First-1st hot salt pipeline; 19-First three-way regulating valve; 20-First return salt pipeline; 21-First-2nd hot salt pipeline; 22-Second cold salt pipeline; 23-First cold salt pipeline. Detailed Implementation

[0042] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0043] Figure 1 This is a system structure diagram of a parallel molten salt heating superheated steam generation system provided in one embodiment of the present invention. Figure 1 As shown, this invention provides a parallel molten salt heating superheated steam generation system. The system includes: an evaporator system 2 and a superheater system 7 connected in sequence, combined to process oilfield produced water into steam for corresponding injection requirements; wherein, both the evaporator system 2 and the superheater system 7 have separate molten salt supply devices, which provide a heat source for the operation of the evaporator system 2 and the superheater system 7; the cold salt from the molten salt supply devices of the evaporator system 2 and the superheater system 7 is collected into a single cold salt recovery device; a control module is used to construct a corresponding salt supply linkage model based on real-time operating conditions, and to generate an optimal molten salt supply device linkage control scheme that meets the steam injection requirements based on the salt supply linkage model; an execution module is respectively installed on the salt supply pipelines of the molten salt supply devices of the evaporator system 2 and the superheater system 7, and is used to adjust the molten salt supply based on the optimal molten salt supply device linkage control scheme.

[0044] Preferably, the evaporator system 2 includes multiple heat exchangers connected in series to allow the extracted water after heat exchange in the previous heat exchanger to flow into the current heat exchanger for secondary heat exchange.

[0045] In this embodiment of the invention, the produced water first enters the primary heat exchanger, where it undergoes preliminary heat exchange with hot salt to raise its temperature. It then flows into the next primary heat exchanger, where it continues to undergo deeper heat exchange with the hot salt, gradually increasing the water temperature until it reaches the design requirements. This multi-stage series heat exchange method effectively improves the utilization efficiency of the hot salt and avoids energy loss caused by excessive temperature differences in single-stage heat exchange. Multi-stage heat exchange also reduces the risk of localized scaling, as the gradual temperature increase design reduces the probability of scaling in high-silica water under high-temperature conditions, thereby extending the service life of the heat exchangers. Furthermore, this design optimizes the series connection of the heat exchangers, allowing the evaporator system 2 to flexibly adapt to changes in produced water temperature and flow rate under different operating conditions. The primary heat exchanger is mainly responsible for heating the produced water to a lower range of saturation temperature, while subsequent heat exchangers complete the wet steam generation process according to the design load. This ensures the operational stability of the entire system and provides high-quality wet steam under both low and high load conditions.

[0046] Furthermore, the system also includes a preheating system connected to the front end of the evaporator system 2; the preheating system is used to preheat the produced water and supply the preheated produced water to the preheating system.

[0047] In this embodiment of the invention, the main function of the preheating system is to preheat the produced water using a low-grade heat source, raising the water temperature from ambient temperature to an initial heating level. The preheated produced water is then transported to the evaporator system 2 for further heating and steam generation. The preheating system can utilize waste heat, a residual heat recovery system, or low-temperature hot salt as a heat source, fully utilizing the remaining heat energy resources in the system and effectively reducing the consumption of high-grade hot salt.

[0048] By adding a preheating stage before evaporator system 2, not only is the overall system thermal efficiency improved, but the heat load on the heat exchanger in evaporator system 2 is also reduced. Specifically, the preheating system raises the temperature of the extracted water to near the lower limit of the saturation temperature, thereby reducing the heat required for heat exchange in the evaporator. This design not only shortens the heating time of evaporator system 2, but also reduces the amount of hot salt transported and the workload of the pumps, significantly improving the system's operational economy.

[0049] Preferably, the superheater system 7 includes: a steam-water separator connected to the output pipe of the evaporator system 2, used to separate the wet saturated steam output from the evaporator system 2 to obtain dry steam and saturated water respectively; a superheater connected to the pipe outputting dry steam from the steam-water separator, used to perform heat exchange between the dry steam and the hot molten salt in the molten salt supply device of the superheater system 7 to convert the dry steam into superheated dry steam; and a mixer that incorporates the superheated dry steam and the saturated water, used to generate the steam required for steam injection based on the mixing of the superheated dry steam and the saturated water.

[0050] In this embodiment of the invention, the superheater system 7 operates as follows: First, wet saturated steam is output from the evaporator system 2 and enters the steam-water separator. The steam-water separator uses efficient separation technology to separate the wet steam into dry steam and saturated water. The dry steam is transported to the superheater through connecting pipes and exchanges heat with hot molten salt from the molten salt supply device of the superheater system 7, further heating it into superheated dry steam. Subsequently, the superheated dry steam and the saturated water separated by the steam-water separator are mixed in a mixer at a set ratio to generate steam that meets the steam injection requirements. This design fully considers the different requirements for the dryness and temperature of wet saturated steam. Through the separation treatment of the steam-water separator and the precise heating of the superheater, the steam quality is adjusted to a suitable range. At the same time, the addition of the mixer further enhances flexibility, enabling the system to adapt to different steam injection requirements by adjusting the mixing ratio without changing the front-end production process.

[0051] Based on this invention, a steam-water separator separates wet saturated steam into dry steam and saturated water, eliminating the influence of droplets in the wet steam and ensuring the stability and efficiency of the subsequent superheating process. The superheater uses high-temperature molten salt to heat the dry steam, enabling it to reach a precise superheating temperature range to meet the needs of different steam injection processes. The blender allows the system to adjust the final steam temperature and dryness according to steam injection requirements by mixing superheated dry steam and saturated water, adapting to the requirements of different heavy oil blocks. The recycling of saturated water reduces energy waste, while the blending process avoids superheated steam waste, achieving efficient system operation. The application of the steam-water separator reduces corrosion and scaling in the superheater caused by droplet scouring, lowering equipment maintenance costs and extending service life. The multi-stage process of separation-heating-blending optimizes the dynamic response capability of steam generation, enabling the system to maintain stable operation even under load fluctuations or changes in produced water conditions.

[0052] Preferably, the molten salt supply device of the superheater system 7 includes: a second salt supply pipe arranged in the opposite direction to the dry steam output direction of the steam-water separator, the second salt supply pipe being arranged along the same path as the dry steam conveying pipe in the superheater; the execution module arranged on the superheater system 7 includes: a second hot salt pump 13 for pumping hot salt into the second salt supply pipe; a second three-way regulating valve 15 arranged on the second salt supply pipe between the superheater and the second hot salt pump 13 for controlling the flow rate of hot salt flowing into the corresponding second salt supply pipe of the superheater; the molten salt supply device of the superheater system 7 further includes: a second hot salt return pipe arranged at the third end of the second three-way regulating valve 15 for returning excess hot salt in the total hot salt flow rate output by the second hot salt pump 13 that does not flow to the superheater system 7 to the hot salt storage system.

[0053] In this embodiment of the invention, the molten salt supply device of the superheater system 7 consists of modules such as a second salt supply pipe, a second hot salt pump 13, a second three-way regulating valve 15, and a second hot salt return pipe, forming a closed-loop molten salt flow control system. The second salt supply pipe is arranged along the same path as the dry steam conveying pipe in the superheater, and its design fully considers maximizing the heat exchange efficiency between hot salt and dry steam. Driven by the second hot salt pump 13, high-temperature molten salt is transported to the superheater through the second salt supply pipe, where it exchanges heat with the dry steam and further heats it to the preset superheated temperature. At the same time, the second three-way regulating valve 15 is installed between the second hot salt pump 13 and the superheater to regulate the flow rate of hot salt to the superheater, ensuring that the system can stably output high-quality superheated dry steam under different load conditions.

[0054] Furthermore, to avoid molten salt waste and further optimize energy efficiency, the third end of the second three-way regulating valve 15 is connected to the second hot salt return pipe. Through this return mechanism, excess hot salt not consumed by the superheater is quickly recovered to the hot salt storage system and recycled again. This design not only reduces energy consumption but also dynamically optimizes the hot salt distribution ratio through the return regulation mechanism, thereby reducing the operating pressure of the superheater system 7.

[0055] Preferably, the molten salt supply device of the evaporator system 2 includes: a first salt supply pipe arranged from the last heat exchanger of the evaporator system 2 to the first heat exchanger; the execution module arranged on the evaporator system 2 includes: a first hot salt pump 17 for pumping hot salt into the first salt supply pipe; a first three-way regulating valve 19 arranged on the first salt supply pipe between the last heat exchanger and the first hot salt pump 17 for controlling the flow rate of hot salt flowing into the first salt supply pipe corresponding to the evaporator system 2; the molten salt supply device of the evaporator system 2 further includes: a first hot salt return pipe arranged at the third end of the first three-way regulating valve 19 for returning excess hot salt in the total hot salt flow rate output by the first hot salt pump 17 that does not flow to the evaporator system 2 to the hot salt storage system.

[0056] In this embodiment of the invention, the first salt supply pipe is arranged along the heat exchangers within the evaporator system 2, extending from the last heat exchanger towards the first. This counter-current arrangement design ensures that the hot salt first contacts the higher-temperature heat exchanger region and then flows sequentially through the lower-temperature heat exchangers, maximizing the heat transfer efficiency of the hot salt. In this way, the thermal energy of the hot salt is gradually released, allowing each stage of the evaporator system 2 to absorb heat in the most efficient manner. The first hot salt pump 17 is responsible for pumping hot salt from the hot salt storage system into the first salt supply pipe, providing the required heat to the evaporator system 2. The operating frequency of the hot salt pump can be dynamically adjusted according to the system load to meet the hot salt demand under different operating conditions, thereby achieving energy saving and efficient operation.

[0057] Furthermore, a first three-way regulating valve 19, located between the last heat exchanger and the first hot salt pump 17, has a flow regulation function. By adjusting the valve opening, the flow rate of hot salt entering the evaporator system 2 is controlled, ensuring that the hot salt supply matches the current heat exchange demand of the evaporator system 2. The three-way valve design provides high flexibility in hot salt supply, enabling rapid response to changes in the operation of the evaporator system 2. Excess hot salt that does not flow to the evaporator system 2 is transported through the third end of the first three-way regulating valve 19 to the first hot salt return pipe, directly returning to the hot salt storage system. This design enables rapid recovery and reuse of excess hot salt, effectively reducing hot salt waste, while also lightening the load on the hot salt pump and optimizing the energy efficiency of the entire heating system.

[0058] Preferably, the control module is configured to: collect steam demand information for steam injection, and use the steam demand information for steam injection as a basic constraint; construct a corresponding optimization model based on the basic constraint and the artificial immune algorithm, wherein the optimization objective of the optimization model is the minimum thermal salt consumption; perform iterative solution on the optimization model until the iteration termination condition is triggered, and output the optimal control scheme of the molten salt supply device of the evaporator system 2 and the superheater system 7 as the optimal molten salt supply device joint control scheme.

[0059] In this embodiment of the invention, the control module first collects the steam demand information for steam injection, including target steam parameters (pressure, temperature, dryness) and real-time operating data (produced water flow rate, inlet water temperature, etc.). This information serves as the basic constraint for the optimization process, providing clear objectives and limitations for the control scheme of the molten salt supply device.

[0060] Based on the aforementioned fundamental constraints, the control module utilizes an artificial immune algorithm to construct a corresponding optimization model. Inspired by the biological immune system, the artificial immune algorithm employs mechanisms such as selection, cloning, mutation, and memory to achieve efficient global optimization and adaptability. The optimization model aims to minimize hot salt consumption, thereby maximizing system energy efficiency and reducing operating costs while meeting steam quality requirements. Through iterative solutions using the artificial immune algorithm, the model can dynamically adjust the control parameters of the evaporator and superheater molten salt supply devices, including the hot salt pump frequency and the three-way valve opening.

[0061] During the iteration process, the control module evaluates the optimal solution in real time based on the actual operating conditions and ensures the convergence and computational efficiency of the optimization process by setting reasonable iteration termination conditions (error threshold or maximum number of iterations). When the iteration termination condition is triggered, the control module outputs the optimal control scheme, namely the joint control strategy of the evaporator and superheater system 7 molten salt supply unit.

[0062] Furthermore, the construction of the corresponding optimization model based on the basic constraints and the artificial immune algorithm includes: taking the valve openings of the first hot salt pump 17, the second hot salt pump 13, the first three-way regulating valve 19 on the evaporator system 2 side, and the valve openings of the second three-way regulating valve 15 on the superheater system 7 side as antibody structures; constructing corresponding fitness functions to evaluate the fitness of each antibody; specifying corresponding mutation frequencies, and constructing corresponding optimization models based on antibody structures, fitness functions, and mutation frequencies.

[0063] In this embodiment of the invention, key control variables of the system (including the frequency of the first hot salt pump 17, the frequency of the second hot salt pump 13, the valve opening of the first three-way regulating valve 19 on the evaporator side, and the valve opening of the second three-way regulating valve 15 on the superheater side) are incorporated as components of the antibody structure. These variables directly affect the flow distribution of molten salt supply and the thermal efficiency of the system, and are core parameters for achieving precise control. In the model, the fitness function is a key indicator for evaluating the quality of each antibody. The fitness function comprehensively considers steam quality errors (such as deviations in dryness and temperature from target values) and hot salt consumption. To achieve dynamic optimization of the model, a reasonable mutation frequency is specified, and new antibodies are generated through the mutation mechanism of an artificial immune algorithm. The mutation mechanism introduces small perturbations to simulate adjustments in the hot salt pump frequency or valve opening, thereby enhancing the diversity of the antibody population and avoiding getting trapped in local optima. At the same time, antibodies with higher fitness are preferentially cloned to accelerate the global optimization process. Finally, through antibody screening, cloning, and mutation iteration, the model can output a set of control parameters with the highest fitness, forming the optimal molten salt supply control scheme.

[0064] Preferably, the fitness function is expressed as:

[0065]

[0066] in, This is the fitness value; Total heat salt consumption; This indicates the error between the quality of the steam used for steam injection and the target steam quality. and These are the target wet steam dryness and the actual wet steam dryness, respectively. and These are the target superheated steam temperature and the actual superheated steam temperature, respectively. and These are the preset weights for total heat and salt consumption and steam quality error, respectively.

[0067] In this embodiment of the invention, the fitness function mainly consists of two parts: total heat salt consumption and steam quality error. Total heat salt consumption reflects the energy usage of the system and is an important indicator for measuring system energy efficiency. By reducing the amount of heat salt used, not only can operating costs be reduced, but energy utilization efficiency can also be improved, thereby achieving the goal of energy conservation and emission reduction.

[0068] Steam quality error is another key component of the fitness function, used to quantify the deviation between the actual and target parameters of the injected steam. Specifically, steam quality error includes deviations in wet steam dryness and superheated steam temperature. The magnitude of dryness and temperature deviations directly affects the effectiveness of steam use, especially in heavy oil extraction where steam quality requirements are extremely stringent. Therefore, by strictly controlling steam quality error, the dryness and temperature of the output steam can be kept stable, meeting the steam injection needs of different oilfields.

[0069] To achieve a balance between total heat and salt consumption and steam quality error, a weighting parameter is introduced into the fitness function to adjust the degree of influence of the two components. This design allows for flexible adjustment of the optimization objective based on actual needs. For example, in scenarios prioritizing energy conservation, the weight of heat and salt consumption can be increased, while in scenarios with high steam quality requirements, the weight of steam quality error can be increased.

[0070] Preferably, the iterative solution of the optimization model until the iteration termination condition is triggered, and the optimal control scheme of the molten salt supply device of the evaporator system 2 and the superheater system 7 is output as the optimal molten salt supply device joint control scheme, includes: performing model initialization, randomly generating multiple antibodies within the design range of the preset operating frequency of the preset molten salt supply device and the opening and closing degree of each valve, as an initial antibody population; calculating the fitness of each antibody in the initial antibody population, and selecting antibodies with fitness greater than a preset fitness threshold to perform mutation in the optimization direction to obtain mutated antibodies; selecting antibodies with fitness greater than a preset fitness threshold from the mutated antibodies to perform mutation in the optimization direction again, and repeating the mutation multiple times until the iteration number is reached or the fitness function reaches the convergence condition, stopping the iteration, and outputting the optimal control scheme of the molten salt supply device of the evaporator system 2 and the superheater system 7 as the optimal molten salt supply device joint control scheme.

[0071] Preferably, the optimization direction is determined by the following rule: introducing PID control logic, determining the control action point of the PID, and determining the optimization direction based on the control action point of the PID; wherein, the control action point of the PID for the valve opening of the first hot salt pump 17 and the first three-way regulating valve 19 on the evaporator system 2 side is confirmed based on the dryness of the wet saturated steam; the control action point of the PID for the valve opening of the second hot salt pump 13 and the second three-way regulating valve 15 on the superheater system 7 side is confirmed based on the temperature of the superheated steam.

[0072] In this embodiment of the invention, the solution combines steam quality control requirements and the goal of minimum heat and salt consumption during the initialization, optimization, and convergence / termination phases, effectively improving the operating efficiency and steam quality stability of the steam injection system. Specifically, it includes the following steps:

[0073] 1) Model initialization:

[0074] During the initialization phase, multiple antibodies are randomly generated within the preset operating frequency range and valve opening / closing range of the molten salt supply device. These antibodies represent possible combinations of control parameters, including the frequencies of the first hot salt pump 17 and the second hot salt pump 13, and the opening degrees of the first three-way regulating valve 19 and the second three-way regulating valve 15. These antibodies constitute the initial antibody population, serving as the initial solution space for optimization. The fitness value of each antibody is calculated using a fitness function, which integrates the system's hot salt consumption and steam quality errors (including deviations in wet steam dryness and superheated steam temperature). A higher fitness value indicates that the corresponding antibody is closer to the optimization target.

[0075] 2) Mutation and optimization stage:

[0076] During the optimization phase, antibodies with fitness greater than a preset threshold in the initial population are mutated. The purpose of mutation is to generate a new solution space by partially adjusting the antibody structure, in order to explore better combinations of control parameters. The mutation operation is based on the following rules:

[0077] PID control logic is introduced to dynamically adjust the optimization direction. The control point of the PID is confirmed through real-time steam parameter feedback: the optimization direction of the first hot salt pump 17 and the first three-way regulating valve 19 is determined by the wet steam dryness control point. By monitoring the wet steam dryness in real time, the PID control logic adjusts the frequency of the first hot salt pump 17 and the opening of the first three-way regulating valve 19 to stabilize the wet steam dryness within the target range. The optimization direction of the second hot salt pump 13 and the second three-way regulating valve 15 is determined by the superheated steam temperature control point. By monitoring the superheated steam temperature, the PID control logic dynamically adjusts the frequency of the second hot salt pump 13 and the opening of the second three-way regulating valve 15 to ensure that the superheated steam temperature meets the steam injection requirements.

[0078] Mutation rules: Antibodies with higher fitness are preferentially selected for mutation. In each round of mutation, small perturbations are introduced (such as fine-tuning the upper and lower limits of the pump frequency or changing the valve opening) to generate new antibodies.

[0079] 3) Iterative solution:

[0080] After the mutant antibody is generated, its fitness value is recalculated, and antibodies with a fitness value greater than the threshold are included in the next round of optimization iteration. This process is repeated until one of the following conditions is met:

[0081] Reaching the preset number of iterations indicates that the algorithm's optimization exploration has been fully underway.

[0082] The fitness function converges, meaning that the optimal combination of control parameters for the system has been determined.

[0083] When the iteration stops, the antibody with the highest fitness is output as the final control scheme, forming the optimal molten salt supply device joint control scheme for evaporator system 2 and superheater system 7.

[0084] Based on the present invention, through iterative optimization of the artificial immune algorithm and the introduction of PID control logic, the system can achieve real-time joint control optimization under dynamic operating conditions. The PID control logic provides a dynamic adjustment basis for the optimization direction, ensuring that the optimization scheme always aims at a balance between steam quality and thermal salt consumption. The PID control point design based on wet steam dryness and superheated steam temperature ensures that steam quality meets injection requirements. During optimization, real-time adjustments to dryness and temperature make steam output more stable, adapting to injection requirements under different oilfield conditions. With minimum thermal salt consumption as the optimization objective, the molten salt supply is dynamically adjusted to reduce unnecessary energy waste, improve molten salt utilization efficiency, and thus reduce system operating costs. By introducing the mutation mechanism of the artificial immune algorithm, the system can explore a wider solution space, avoiding getting trapped in local optima. Simultaneously, the algorithm can flexibly adapt to load fluctuations and changes in operating conditions, enhancing the system's adaptability and robustness. Without manual intervention, the entire process from model initialization to final optimization scheme output is completed automatically, simplifying the operation process and improving the intelligence level of the control system. The optimized molten salt supply unit control scheme significantly reduces hot salt consumption and equipment operating load, lowering operation and maintenance costs. Simultaneously, reduced energy consumption helps reduce carbon emissions, aligning with the requirements of green and low-carbon development.

[0085] Preferably, the PID control action point of the valve opening on the evaporator system 2 side of the first hot salt pump 17 and the first three-way regulating valve 19 is based on the confirmation rule for the wet saturated steam dryness:

[0086]

[0087] in, The combined control output for the valve opening of the first hot salt pump 17 and the first three-way regulating valve 19 on both sides of the evaporator system; This represents the dryness error of wet saturated steam. , and These are proportional gain, integral gain, and derivative gain, respectively.

[0088] In this embodiment of the invention, the PID control logic monitors the dryness of the wet saturated steam in real time, using the deviation between the actual dryness and the target dryness as the control input, and calculates the joint control output based on the proportional, integral, and derivative gains. This control output directly affects the frequency adjustment of the first hot salt pump 17 and the opening adjustment of the first three-way regulating valve 19, thereby dynamically adjusting the flow rate of hot salt entering the evaporator system 2 to achieve precise control of the steam dryness. The proportional gain is mainly used to respond to real-time dryness errors, providing rapid adjustment force to ensure that compensation measures are taken quickly when the dryness deviates from the target value. The integral gain corrects the long-term deviation of the system by accumulating historical errors, avoiding steady-state errors during system operation; the derivative gain improves the dynamic response capability of the system by predicting the changing trend of dryness errors, reducing adjustment lag caused by excessively rapid changes in dryness.

[0089] Preferably, the PID control action point of the valve opening on the superheater system 7 side of the second hot salt pump 13 and the second three-way regulating valve 15 is based on the confirmation rule for the superheated steam temperature:

[0090]

[0091] in, The combined control output for the valve opening of the second hot salt pump 13 and the second three-way regulating valve 15 on the superheater system 7 side; This is to account for the temperature error of the superheated steam used for steam injection; , and These are proportional gain, integral gain, and derivative gain, respectively.

[0092] In this embodiment of the invention, the control logic monitors the actual temperature of the superheated steam and compares it with the target temperature to obtain the temperature error as input. The PID controller generates a combined control output based on the calculation rules of proportional, integral, and derivative parameters. This output is used to dynamically adjust the operating frequency of the second hot salt pump 13 and the opening of the second three-way regulating valve 15, thereby regulating the flow rate of hot salt entering the superheater system 7. The proportional control section responds quickly to the current temperature error, providing immediate adjustment to ensure rapid compensation measures are taken when the temperature deviates from the target value. The integral control section corrects the deviation of the system over long-term operation by accumulating the temperature error, avoiding the accumulation of steady-state error. The derivative control section predicts the changing trend of the temperature error and responds in advance to possible rapid temperature fluctuations, thereby enhancing the dynamic adjustment capability of the system.

[0093] Preferably, PID control logic is introduced to determine the control action point of the PID, and the optimization direction is determined based on the control action point of the PID, including: dynamically correcting the variables of the antibody solution through the PID control logic to optimize steam quality; calculating the fitness value using the PID-adjusted variables, and determining the optimal control action point based on the fitness evaluation results; and performing antibody mutation based on the optimal control point as the corresponding optimization direction.

[0094] In this embodiment of the invention, the PID control logic uses the deviation between the target value and the actual value as input, based on real-time feedback of steam quality parameters (wet steam dryness and superheated steam temperature), and dynamically corrects the variables of the solution through proportional, integral, and derivative calculations. These variables typically include the frequency of the hot salt pump and the opening degree of the three-way valve, which are core factors affecting molten salt flow rate and steam quality. After correction by the PID logic, the variables can more accurately meet the steam quality requirements, forming an optimized preliminary control scheme.

[0095] Based on this, fitness values ​​are calculated using the corrected variables. The fitness value assessment reflects not only the heat and salt consumption of the current control scheme but also the error in steam quality (dryness and temperature deviations). The fitness assessment results are used to further screen for optimal control action points, which represent the best regulation strategy for the system under the current operating conditions. After determining the optimal control action point, antibody mutation is performed based on this point. Mutation, by applying small perturbations to the variables, generates new antibody solutions, thereby expanding the solution space and exploring better control schemes. The mutated antibody solutions have clear directions and are more aligned with the goal of steam quality optimization.

[0096] Preferably, the optimal control scheme for the molten salt supply device of the evaporator system 2 and the superheater system 7, as the optimal molten salt supply device joint control scheme, includes: a joint control output of the valve opening of the first hot salt pump 17 and the first three-way regulating valve 19 on the evaporator system 2 side under the PID control logic of the final iteration round, and a joint control output of the valve opening of the second hot salt pump 13 and the second three-way regulating valve 15 on the superheater system 7 side; decoupling the control strategies of each joint control output; obtaining the target power of the first hot salt pump 17, the target valve opening of the first three-way regulating valve 19 on the evaporator system 2 side, the target power of the second hot salt pump 13, and the target valve opening of the second three-way regulating valve 15 on the superheater system 7 side, respectively, to generate the corresponding control scheme as the optimal molten salt supply device joint control scheme.

[0097] In this embodiment of the invention, the present invention utilizes PID control logic to jointly optimize the key control parameters of the evaporator system 2 and the superheater system 7, and decouples them based on the control output in the final iteration round to generate specific target values ​​for each control device, including the target power of the first hot salt pump 17, the target valve opening of the first three-way regulating valve 19 on the evaporator system 2 side, the target power of the second hot salt pump 13, and the target valve opening of the second three-way regulating valve 15 on the superheater system 7 side.

[0098] By decoupling the control strategies, the control objectives of each device can be optimized independently, thereby eliminating interference between devices and ensuring that each device can work together in the most efficient way during operation. The control of the first hot salt pump 17 and the first three-way regulating valve 19 is mainly based on the wet steam dryness target of the evaporator system 2. By dynamically adjusting the hot salt flow rate and distribution ratio, the stability of the wet steam dryness is maintained. The second hot salt pump 13 and the second three-way regulating valve 15 are based on the superheated steam temperature target of the superheater system 7. By precisely adjusting the hot salt supply, the temperature of the superheated steam is ensured to meet the steam injection requirements.

[0099] In one possible implementation, such as Figure 2 A schematic diagram of a parallel molten salt heating superheated steam generation system is provided. Specifically, it comprises: a water pipe 1, an evaporator system 2, a wet steam pipe 3, a dryness online monitoring device 4, a first signal line 5, a first control system 6, a superheater system 7, a superheated steam pipe 8, a temperature online monitoring device 9, a second signal line 10, a second-second hot salt pipe 11, a second control system 12, a second hot salt pump 13, a second-first hot salt pipe 14, a second three-way regulating valve 15, a second return salt pipe 16, a first hot salt pump 17, a first-first hot salt pipe 18, a first three-way regulating valve 19, a first return salt pipe 20, a first-first hot salt pipe 21, a second cold salt pipe 22, and a first cold salt pipe 23. The control module includes the first control system 6 and the second control system 12. The specific operating principles and processes of each part of the system are as follows, in conjunction with the embodiment.

[0100] 1. The main equipment of this invention consists of an evaporator system 2, a superheater system 7, a first hot salt pump 17, a second hot salt pump 13, a first three-way regulating valve 19, and a second three-way regulating valve 15.

[0101] 2. Oilfield produced water is connected to evaporator system 2 through water supply pipeline 1; the silicon content of oilfield produced water can be <250mg / L, and the water supply temperature can be 40-70℃; evaporator system 2 can be composed of heat exchangers such as preheater, heater, and evaporator.

[0102] 3. Oilfield produced water exchanges heat with hot salt through evaporator system 2 to generate wet saturated steam. In order to reduce the scaling rate of each heat exchange surface in evaporator system 2 under the water quality conditions of high silica content in oilfield produced water, the dryness of wet saturated steam can be controlled below 75%.

[0103] 4. The wet saturated steam produced by the evaporator system 2 is connected to the superheater system 7 through the wet steam pipeline 3, and then connected to the steam injection wellhead through the hot steam pipeline 8; the wet steam pressure can be 8MPa, the temperature is 295℃, and the dryness is 75%; the superheated steam temperature can be 310℃; the material of the wet steam pipeline 3 and the superheated steam pipeline 8 can be 20G carbon steel.

[0104] 5. Install an online steam dryness monitoring device 4 on the wet steam pipe 3 at the outlet of evaporator system 2.

[0105] 6. Install an online steam temperature monitoring device 9 on the superheated steam pipe 8 at the outlet of the superheater system 7.

[0106] 7. A portion of the hot salt in the system is pressurized by the first hot salt pump 17, connected to the first three-way regulating valve 19 through the first-1 hot salt pipeline 18, and then connected to the evaporator system 2 through the first-2 hot salt pipeline 21. After heat exchange in the evaporator system 2, the hot salt becomes cold salt and is connected to the first cold salt pipeline 23. The molten salt can be a binary salt, the hot salt temperature can be 560℃, the first hot salt pump 17 is a variable frequency pump, and the materials of the first-1 hot salt pipeline 18 and the first-2 hot salt pipeline 21 can be 347H stainless steel.

[0107] 8. Hot salt can be connected to the first return salt pipeline 20 through the first three-way regulating valve 19.

[0108] 9. The first hot salt pump 17, the first three-way regulating valve 19, and the dryness online monitoring device 4 connect to the first control system 6 via the first signal line 5. Automatic control of the dryness of the wet steam at the outlet of the evaporator system 2 is achieved by adjusting the motor frequency of the first hot salt pump 17 and the opening degree of the first three-way regulating valve 19. To ensure stable hot salt flow, the frequency range of the first hot salt pump 17 is 25-50 Hz, corresponding to a load adjustment of 50%-100%. At this time, the first three-way regulating valve 19 is fully open (i.e., all molten salt flows through the first-1 hot salt pipe 21). When the dryness value displayed by the dryness online monitoring device 4 is higher than the set value, the first control system 6 reduces the frequency of the first hot salt pump 17 through the pre-set PID calculation logic, causing the dryness value of the dryness online monitoring device 4 to return to the set value. Conversely, when the dryness value displayed by the dryness online monitoring device 4 is lower than the set value, the first control system 6 increases the frequency of the first hot salt pump 17 through the pre-set PID calculation logic, causing the dryness value of the dryness online monitoring device 4 to rise to the set value. The system achieves stepless control of the evaporator system's load range from 250% to 100%. When the system load is below 50%, the frequency of the first hot salt pump 17 stabilizes at 25Hz. At this time, the first control system 6 interlocks the dryness signal from the online dryness monitoring device 4 with the opening of the first three-way regulating valve 19. When the steam dryness displayed by the online dryness monitoring device 4 is higher than the set value, the first control system 6 adjusts the first three-way regulating valve 19 through the pre-set PID calculation logic, increasing the molten salt flow rate in the first return salt pipeline 20 and decreasing the molten salt flow rate in the first-1 hot salt pipeline 21. This causes the steam dryness of the online dryness monitoring device 4 to return to the set value; conversely, when the steam dryness displayed by the online dryness monitoring device 4 is lower than the set value, the first control system 6 adjusts the first three-way regulating valve 19 through the pre-set PID calculation logic, reduces the molten salt flow rate of the first return salt pipeline 20, and increases the molten salt flow rate of the first hot salt pipeline 21, so that the steam dryness of the online dryness monitoring device 4 is adjusted up to the set value, thereby achieving stable control of steam dryness in the system's 0%-50% load range, and ultimately achieving stepless regulation of the evaporator system's 20%-50% load range.

[0109] 10. Another part of the hot salt in the system is pressurized by the second hot salt pump 13, connected to the second three-way regulating valve 15 through the second-1 hot salt pipeline 14, and then connected to the superheater system 7 through the second-2 hot salt pipeline 11. After heat exchange in the superheater system 7, the hot salt becomes cold salt and is connected to the second cold salt pipeline 22, and then mixed with the cold salt from the first cold salt pipeline 23. The temperature of the cold salt after heat exchange can be 285-300℃.

[0110] 11. The other portion of hot salt can be connected to the second return salt pipeline 16 through the second three-way regulating valve 15.

[0111] 12. The second hot salt pump 13, the second three-way regulating valve 15, and the online temperature monitoring device 9 are connected to the second control system 12 via the second signal line 10. Automatic control of the superheated steam temperature at the outlet of the superheater system 7 is achieved by adjusting the motor frequency of the second hot salt pump 13 and the opening degree of the second three-way regulating valve 15. To ensure stable hot salt flow, the frequency conversion range of the second hot salt pump 13 is 25-50 Hz, corresponding to a load adjustment of 50%-100%. At this time, the second three-way regulating valve 15 is fully open (i.e., all molten salt flows through the second-second hot salt pipe 11). If the temperature value displayed by the online temperature monitoring device 9 is higher than the set value, the second control system 12 reduces the frequency of the second hot salt pump 13 through the pre-set PID calculation logic, causing the temperature value displayed by the online temperature monitoring device 9 to return to the set value. Conversely, if the temperature value displayed by the online temperature monitoring device 9 is lower than the set value, the second control system 12 increases the frequency of the second hot salt pump 13 through the pre-set PID calculation logic, causing the temperature value displayed by the online temperature monitoring device 9 to rise to the set value. The superheater system 7 can be steplessly controlled within a load range of 50%-100%. When the system load is below 50%, the frequency of the second hot salt pump 13 stabilizes at 25Hz. At this time, the temperature signal of the online temperature monitoring device 9 is interlocked with the opening of the second three-way regulating valve 15 through the second control system 12. If the steam temperature displayed by the online temperature monitoring device 9 is higher than the set value, the second control system 12 adjusts the second three-way regulating valve 15 through the pre-set PID calculation logic, increasing the molten salt flow rate of the second return salt pipeline 16 and decreasing the molten salt flow rate of the second-2 hot salt pipeline 11, so that the steam temperature of the online temperature monitoring device 9 returns to the set value. Conversely, if the steam temperature displayed by the online temperature monitoring device 9 is lower than the set value, the second control system 12 adjusts the second three-way regulating valve 15 through the pre-set PID calculation logic, decreasing the molten salt flow rate of the second return salt pipeline 16 and increasing the molten salt flow rate of the second-2 hot salt pipeline 11, so that the steam temperature of the online temperature monitoring device 9 is raised to the set value, realizing stable steam temperature control within the system load range of 0%-50%, and ultimately achieving stepless regulation of the superheater system within the load range of 70%-50%.

[0112] Figure 3 This is a flowchart of a method for controlling a parallel molten salt heating superheated steam generation system according to one embodiment of the present invention. Figure 3 As shown, an embodiment of the present invention provides a control method for a parallel molten salt heating superheated steam generation system, the method comprising:

[0113] Step S10: Collect the demand information for steam for steam injection, and use the demand information for steam for steam injection as the basic constraint.

[0114] Step S20: Construct a corresponding optimization model based on the basic constraints and the artificial immune algorithm. The optimization objective of the optimization model is to minimize the amount of heat salt consumed.

[0115] Step S30: Perform iterative solution on the optimization model until the iteration termination condition is triggered, and output the optimal control scheme of the molten salt supply device of the evaporator system and the superheater system as the optimal molten salt supply device joint control scheme.

[0116] Preferably, the step of constructing the corresponding optimization model based on the basic constraints and the artificial immune algorithm includes: taking the valve openings of the first hot salt pump, the second hot salt pump, the first three-way regulating valve on the evaporator system side, and the second three-way regulating valve on the superheater system side as antibody structures; constructing corresponding fitness functions to evaluate the fitness of each antibody; specifying corresponding mutation frequencies, and constructing corresponding optimization models based on antibody structures, fitness functions, and mutation frequencies.

[0117] Preferably, the iterative solution of the optimization model until the iteration termination condition is triggered, and the optimal control scheme of the molten salt supply device for the evaporator system and the superheater system is output as the optimal molten salt supply device joint control scheme, includes: performing model initialization, randomly generating multiple antibodies within the design range of the preset operating frequency of the molten salt supply device and the opening and closing degree of each valve, as an initial antibody population; calculating the fitness of each antibody in the initial antibody population, and selecting antibodies with fitness greater than a preset fitness threshold to perform mutation in the optimization direction to obtain mutated antibodies; selecting antibodies with fitness greater than a preset fitness threshold from the mutated antibodies to perform mutation in the optimization direction again, and repeating the mutation multiple times until the iteration number is reached or the fitness function reaches the convergence condition, stopping the iteration, and outputting the optimal control scheme of the molten salt supply device for the evaporator system and the superheater system as the optimal molten salt supply device joint control scheme.

[0118] Preferably, the optimization direction is determined by the following rule: introducing PID control logic, determining the control action point of the PID, and determining the optimization direction based on the control action point of the PID; wherein, the control action point of the PID for the valve opening of the first hot salt pump and the first three-way regulating valve on the evaporator system side is confirmed based on the dryness of the wet saturated steam; the control action point of the PID for the valve opening of the second hot salt pump and the second three-way regulating valve on the superheater system side is confirmed based on the temperature of the superheated steam.

[0119] Preferably, the optimal control scheme for the molten salt supply device of the evaporator system and the superheater system, as the optimal molten salt supply device joint control scheme, includes: a joint control output of the valve opening of the first hot salt pump and the first three-way regulating valve on the evaporator system side based on the PID control logic of the final iteration round, and a joint control output of the valve opening of the second hot salt pump and the second three-way regulating valve on the superheater system side; decoupling the control strategies of each joint control output; obtaining the target power of the first hot salt pump, the target valve opening of the first three-way regulating valve on the evaporator system side, the target power of the second hot salt pump, and the target valve opening of the second three-way regulating valve on the superheater system side, respectively, to generate the corresponding control scheme as the optimal molten salt supply device joint control scheme.

[0120] The present invention also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described control method for a parallel molten salt heating superheated steam generation system.

[0121] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0122] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0123] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A parallel flow molten salt heated superheated steam generating system characterized by, The system comprises: A vaporizer system and a superheater system connected in sequence, combined for treating oilfield produced water into corresponding steam injection demand steam; wherein, Both the vaporizer system and the superheater system have a separate molten salt supply device for providing a heat source for the operation of the vaporizer system and the superheater system; The cold salt collection of the molten salt supply devices of the vaporizer system and the superheater system is collected into the same cold salt recovery device; A control module is configured to build a corresponding salt supply linkage model based on real-time operating conditions, to generate an optimal molten salt supply device linkage control scheme under the condition of meeting the steam injection demand based on the salt supply linkage model; wherein, The control module is configured to collect the demand information of steam for steam injection, to take the demand information of steam for steam injection as a basic constraint; to build a corresponding optimization model based on the basic constraint and an artificial immune algorithm, the optimization target of the optimization model being the minimum heat salt consumption; to perform iterative solution on the optimization model until the iteration termination condition is triggered, and to output the optimal control scheme of the molten salt supply device of the vaporizer system and the superheater system as the optimal molten salt supply device linkage control scheme; An execution module is arranged on the salt supply pipeline of the molten salt supply device of the vaporizer system and the superheater system, respectively, for adjusting the molten salt supply amount based on the optimal molten salt supply device linkage control scheme.

2. The system of claim 1, wherein, The vaporizer system comprises a plurality of heat exchangers connected in series, so that the produced water after heat exchange in the previous heat exchanger flows into the current heat exchanger to perform secondary heat exchange.

3. The system of claim 1, wherein, The system further comprises: A preheating system connected at the front end of the vaporizer system; The preheating system is used for preheating the produced water and supplying the preheated produced water to the vaporizer.

4. The system of claim 1, wherein, The superheater system comprises: A steam-water separator connected with the output pipeline of the vaporizer system, for performing steam-water separation on the wet saturated steam output by the vaporizer system to obtain dry steam and saturated water respectively; A superheater connected with the pipeline outputting dry steam from the steam-water separator, for realizing heat exchange between the dry steam and the hot molten salt in the molten salt supply device of the superheater system, so as to convert the dry steam into superheated dry steam; A blender that inputs the superheated dry steam and the saturated water, for mixing the superheated dry steam and the saturated water to generate steam demand steam.

5. The system of claim 4, wherein, The molten salt supply device of the superheater system comprises: A second salt supply pipeline arranged in the opposite direction of the dry steam output direction of the steam-water separator, the second salt supply pipeline being arranged in the same path as the dry steam conveying pipeline in the superheater; The execution module arranged on the superheater system comprises: A second hot salt pump for pumping hot salt into the second salt supply pipeline; A second three-way regulating valve arranged on the second salt supply pipeline between the superheater and the second hot salt pump, for controlling the flow of hot salt into the superheater corresponding to the second salt supply pipeline; The molten salt supply device of the superheater system further comprises: A second hot salt return pipeline arranged on the third end of the second three-way regulating valve, for returning the excess hot salt in the total hot salt flow output by the second hot salt pump to the hot salt storage system.

6. The system of claim 5, wherein, The molten salt supply device of the vaporizer system comprises: A first salt supply pipe is arranged from the last heat exchanger to the first heat exchanger of the evaporator system; The execution module arranged on the evaporator system comprises: A first hot salt pump for pumping hot salt into the first salt supply pipe; A first three-way regulating valve arranged on the first salt supply pipe between the last heat exchanger and the first hot salt pump, for controlling the flow of hot salt into the evaporator system corresponding to the first salt supply pipe; The molten salt supply device of the evaporator system further comprises: A first hot salt return pipe arranged on the third end of the first three-way regulating valve, for returning the excess hot salt in the total hot salt flow output by the first hot salt pump and not flowing to the evaporator system to the hot salt storage system.

7. The system of claim 6, wherein, The construction of the corresponding optimization model based on the basic constraints and the artificial immune algorithm comprises: The first hot salt pump, the second hot salt pump, the valve opening degree of the first three-way regulating valve on the evaporator system side, and the valve opening degree of the second three-way regulating valve on the superheater system side are taken as the antibody structure; A corresponding fitness function is constructed for evaluating the fitness of each antibody; A corresponding mutation frequency is specified, and a corresponding optimization model is constructed based on the antibody structure, the fitness function, and the mutation frequency.

8. The system of claim 7, wherein, The fitness function is expressed as: wherein, fitness value; Total heat salt consumption; represents an error in the steam quality of the steam for steam injection from the target steam quality; and x and y are the target and actual wet steam dryness, respectively; and Tsh and Tsh, respectively, are the target and actual superheated steam temperatures; and are preset weights of total heat salt consumption and steam quality error, respectively.

9. The system of claim 7, wherein, The iterative solution of the optimization model is performed until the iteration termination condition is triggered, and the optimal control scheme of the molten salt supply device of the evaporator system and the superheater system is output as the optimal molten salt supply device joint control scheme, comprising: Model initialization is performed, and a plurality of antibodies are randomly generated as an initial antibody population within the design range of the preset working frequency of the preset molten salt supply device, the opening and closing degree of the first three-way regulating valve, and the second three-way regulating valve; The fitness of each antibody in the initial antibody population is calculated respectively, and the antibody with a fitness greater than a preset fitness threshold is selected to perform mutation in the optimization direction to obtain a mutated antibody; The antibody with a fitness greater than the preset fitness threshold is selected from the mutated antibody to perform mutation in the optimization direction again, and the mutation is repeated for multiple times until the number of iterations is reached or the fitness function reaches the convergence condition, and the iteration is stopped, and the optimal control scheme of the molten salt supply device of the evaporator system and the superheater system is output as the optimal molten salt supply device joint control scheme.

10. The system of claim 9, wherein, The determination rule of the optimization direction is: PID control logic is introduced to determine the control action point of PID, and the optimization direction is determined based on the control action point of PID; wherein The control action point of PID of the valve opening degree of the first hot salt pump and the first three-way regulating valve on the evaporator system side is confirmed based on the dryness of wet saturated steam; The control action point of PID of the valve opening degree of the second hot salt pump and the second three-way regulating valve on the superheater system side is confirmed based on the temperature of superheated steam.

11. The system of claim 10, wherein, The confirmation rule of the control action point of PID of the valve opening degree of the first hot salt pump and the first three-way regulating valve on the evaporator system side based on the dryness of wet saturated steam is that: wherein, is a joint control output for the valve opening of the first thermal-salt pump and the first three-way control valve evaporator system side; Dryness error for wet saturated vapor; , and are proportional, integral and derivative gains, respectively.

12. The system of claim 11, wherein, The confirmation rule of the control action point of PID of the valve opening degree of the second hot salt pump and the second three-way regulating valve on the superheater system side based on the temperature of superheated steam is that: wherein, is a combined control output for the valve opening degree of the second heat pump and the second three-way control valve heater system side; Terror for superheated steam for steam injection; , and are proportional, integral and derivative gains, respectively.

13. The system of claim 12, wherein, Introducing PID control logic, determining the control point of PID, determining the optimization direction based on the control point of PID, including: Through the PID control logic, dynamically correct the antibody solution variables to optimize the steam quality; Using the PID adjusted variable to calculate the fitness value, and determining the optimal control point according to the fitness evaluation result; Based on the optimal control point, execute antibody mutation as the corresponding optimization direction.

14. The system of claim 13, wherein, Output the optimal control scheme of the molten salt supply device of the evaporator system and the superheater system as the optimal molten salt supply device joint control scheme, including: Based on the joint control output of the valve opening degree of the first hot salt pump and the first three-way regulating valve evaporator system side and the joint control output of the valve opening degree of the second hot salt pump and the second three-way regulating valve superheater system side under the PID control logic of the final iteration round, execute the control strategy decoupling of each joint control output, respectively obtain the first hot salt pump target power, the first three-way regulating valve evaporator system side target valve opening degree, the second hot salt pump target power and the second three-way regulating valve superheater system side target valve opening degree, to generate the corresponding control scheme as the optimal molten salt supply device joint control scheme.

15. A control method for a parallel molten salt heating superheated steam generation system, characterized by, The method is applied to the parallel molten salt heating superheated steam generation system in any one of claims 1-14, the parallel molten salt heating superheated steam generation system comprising a molten salt supply device, the molten salt supply device comprising: a first salt supply pipeline arranged from the last heat exchanger to the first heat exchanger of the evaporator system; the execution module arranged on the evaporator system comprises: a first hot salt pump for pumping hot salt into the first salt supply pipeline; a first three-way regulating valve arranged on the first salt supply pipeline between the last heat exchanger and the first hot salt pump, for controlling the flow of hot salt into the corresponding first salt supply pipeline of the evaporator system; the molten salt supply device of the evaporator system further comprises: a first hot salt return pipeline arranged on the third end of the first three-way regulating valve, for returning the excess hot salt in the total hot salt flow output by the first hot salt pump to the hot salt storage system without flowing to the evaporator system; a second salt supply pipeline arranged in the opposite direction of the dry steam output direction of the steam-water separator, the second salt supply pipeline being arranged in the same path as the dry steam conveying pipeline in the superheater; the execution module arranged on the superheater system comprises: a second hot salt pump for pumping hot salt into the second salt supply pipeline; a second three-way regulating valve arranged on the second salt supply pipeline between the superheater and the second hot salt pump, for controlling the flow of hot salt into the corresponding second salt supply pipeline of the superheater; the molten salt supply device of the superheater system further comprises: a second hot salt return pipeline arranged on the third end of the second three-way regulating valve, for returning the excess hot salt in the total hot salt flow output by the second hot salt pump to the hot salt storage system without flowing to the superheater system; the method comprises: Collecting the demand information of steam for injection, and taking the demand information of steam for injection as a basic constraint; Based on the basic constraint and the artificial immune algorithm, a corresponding optimization model is constructed, and the optimization target of the optimization model is the minimum hot salt consumption. The optimization model is solved iteratively until an iteration termination condition is triggered, and an optimal control scheme of the molten salt supply device of the evaporator system and the superheater system is output as an optimal molten salt supply device joint control scheme.

16. The method of claim 15, wherein, The corresponding optimization model is constructed based on the basic constraints and the artificial immune algorithm, which includes: The first hot salt pump, the second hot salt pump, the valve opening degree of the first three-way regulating valve on the evaporator system side, and the valve opening degree of the second three-way regulating valve on the superheater system side are taken as the antibody structure; A corresponding fitness function is constructed for evaluating the fitness of each antibody; A corresponding mutation frequency is specified, and a corresponding optimization model is constructed based on the antibody structure, the fitness function, and the mutation frequency.

17. The method of claim 15, wherein, The optimization model is solved iteratively until an iteration termination condition is triggered, and an optimal control scheme of the molten salt supply device of the evaporator system and the superheater system is output as an optimal molten salt supply device joint control scheme, which includes: Model initialization is performed, and a plurality of antibodies are randomly generated within the design range of the preset working frequency of the preset molten salt supply device, the opening and closing degree of the first three-way regulating valve, and the second three-way regulating valve as an initial antibody population; The fitness of each antibody in the initial antibody population is calculated, and the antibodies with fitness greater than a preset fitness threshold are selected to perform mutation in the optimization direction to obtain mutated antibodies; In the mutated antibodies, the antibodies with fitness greater than the preset fitness threshold are selected to perform mutation in the optimization direction again to repeat the mutation for multiple times until the number of iterations is reached or the fitness function reaches the convergence condition, the iteration is stopped, and an optimal control scheme of the molten salt supply device of the evaporator system and the superheater system is output as an optimal molten salt supply device joint control scheme.

18. The method of claim 17, wherein, The determination rule of the optimization direction is: PID control logic is introduced to determine the control action point of PID, and the optimization direction is determined based on the control action point of PID; wherein The control action point of PID of the first hot salt pump and the valve opening degree of the first three-way regulating valve on the evaporator system side is confirmed based on the dryness of wet saturated steam; The control action point of PID of the second hot salt pump and the valve opening degree of the second three-way regulating valve on the superheater system side is confirmed based on the temperature of superheated steam.

19. The method of claim 18, wherein, The optimal control scheme of the molten salt supply device of the evaporator system and the superheater system is output as an optimal molten salt supply device joint control scheme, which includes: Based on the joint control output of the first hot salt pump and the valve opening degree of the first three-way regulating valve on the evaporator system side under the PID control logic of the final iteration round, and the joint control output of the second hot salt pump and the valve opening degree of the second three-way regulating valve on the superheater system side, the control strategy decoupling of each joint control output is performed to obtain the first hot salt pump target power, the target valve opening degree of the first three-way regulating valve on the evaporator system side, the second hot salt pump target power, and the target valve opening degree of the second three-way regulating valve on the superheater system side, respectively, to generate a corresponding control scheme as an optimal molten salt supply device joint control scheme.

20. A computer-readable storage medium, characterized in that, The computer readable storage medium stores instructions which, when executed on the computer, cause the computer to perform the parallel molten salt heating superheated steam generation system control method of any one of claims 15-19.

Images