Staged heating superheated steam generation system and control method thereof

Abstract

This invention provides a cascade heating superheated steam generation system and its control method, belonging to the field of energy engineering and thermal technology. The system includes: an evaporator with multiple heat exchangers, used to process preheated produced water into wet saturated steam; wherein the series and parallel connections between the heat exchangers in the evaporator are adjusted based on real-time heating demand information; a steam conversion device for converting the wet saturated steam into superheated steam for injection; a control device for determining the sequence number of the heat exchangers participating in the heat exchange and the series and parallel connections of the heat exchangers based on real-time heating demand information; and a molten salt transfer device that sequentially passes through the steam conversion device and the evaporator to provide heat to the steam conversion device and the evaporator. This invention adapts to complex heating demand scenarios, thus providing an efficient, flexible, and intelligent solution for heavy oil steam injection.

Description

Technical Field

[0001] This invention relates to the fields of energy engineering and thermal technology, specifically to a cascade heating superheated steam generation system and a control method for the cascade heating superheated steam generation system. Background Technology

[0002] Steam injection technology is a crucial means to improve the efficiency of heavy oil extraction. Currently, the widely used steam injection technology requires heating produced water into wet saturated steam or superheated steam before injecting it into the reservoir to reduce the viscosity of the crude oil. However, in existing technologies, the heat exchange efficiency and system flexibility of the steam generator still have significant problems.

[0003] First, existing evaporation devices typically consist of multiple heat exchangers, but their configuration (e.g., series or parallel) is usually fixed, lacking flexibility. When heating demand fluctuates, the operating status and connection method of the heat exchangers cannot be dynamically adjusted according to actual demand. This can lead to energy waste under low-demand conditions and insufficient heat exchange capacity under high-demand conditions, failing to meet steam production efficiency requirements. This fixed pattern significantly limits the system's adjustability and adaptability.

[0004] Secondly, existing technologies lack precise control methods to manage the operating status of multiple heat exchangers. Although some systems attempt to introduce simple on / off control, they fail to optimize the configuration of the number of heat exchangers in operation and their series-parallel relationships based on real-time heating demand. This lack of dynamic control capability easily leads to uneven heat load distribution among heat exchangers, further reducing the overall energy efficiency of the system. In addition, heat exchanger overload or prolonged inefficient operation will accelerate equipment aging and increase operating costs.

[0005] In summary, existing technologies have significant shortcomings in terms of flexibility and intelligent control of multi-heat exchanger evaporation units, making it difficult to simultaneously meet the requirements of high-efficiency heat exchange and dynamic heating. These issues have become key bottlenecks limiting further improvements in the efficiency and economy of heavy oil steam injection technology. Summary of the Invention

[0006] The purpose of this invention is to provide a cascade heating superheated steam generation system and its control method, so as to at least solve the problem that the prior art has obvious deficiencies in terms of flexibility and intelligent control of multi-heat exchanger evaporation devices.

[0007] To achieve the above objectives, a first aspect of the present invention provides a cascade heating superheated steam generation system, the system comprising: an evaporation device equipped with multiple heat exchangers, the evaporation device being used to process preheated produced water into wet saturated steam; wherein the series-parallel connection relationship between the heat exchangers in the evaporation device is adjusted based on real-time heating demand information; a steam conversion device connected to the rear end of the evaporation device, used to convert the wet saturated steam into superheated steam for injection; a control device communicatively connected to each heat exchanger, used to determine the sequence number of the heat exchangers participating in the heat exchange, and the series-parallel connection relationship of the heat exchangers participating in the heat exchange, based on real-time heating demand information; and a molten salt transfer device that sequentially passes through the steam conversion device and the evaporation device, used to transfer molten salt that provides a heat source to the steam conversion device and the evaporation device.

[0008] Optionally, the evaporator is provided with two flow pipes, and each heat exchanger is located between the two flow pipes and connected to the flow pipes through a three-way valve.

[0009] Optionally, when the current heat exchanger is involved in evaporation, the valves at the two ports connected to the heat exchanger corresponding to the two ends of the heat exchanger are opened; when the current heat exchanger involved in evaporation is connected in series with the next adjacent heat exchanger involved in evaporation, the outflow water from the current heat exchanger is channeled into the next adjacent heat exchanger involved in evaporation through the three-way valve on the same side as the outlet end of the current heat exchanger; when the current heat exchanger involved in evaporation is connected in parallel with the next adjacent heat exchanger involved in evaporation, the outflow water from the current heat exchanger involved in evaporation and the next adjacent heat exchanger involved in evaporation converges on the same side, and the outflow water after heat exchange between the current heat exchanger involved in evaporation and the next adjacent heat exchanger involved in evaporation is merged through the three-way valve on the other side.

[0010] Optionally, determining the heat exchanger serial number and the series-parallel connection relationship of each heat exchanger based on real-time heating demand information includes: constructing a corresponding genetic algorithm optimization model with the optimization objectives of maximizing evaporation efficiency and minimizing molten salt consumption; performing iterative optimization based on the genetic algorithm optimization model until the iteration termination rule is triggered, and outputting the heat exchanger serial number and the series-parallel connection relationship of each heat exchanger under the optimal evaporation state.

[0011] Optionally, the constraints of the genetic algorithm optimization model include: the dryness of the wet saturated steam at the evaporator outlet is greater than a preset dryness threshold; the total pressure drop of the evaporator is less than a preset pressure drop threshold; and the load of the evaporator is less than the maximum design load.

[0012] Optionally, the chromosome structure of the genetic algorithm optimization model includes the heat exchanger participation state and the series-parallel relationship matrix of the participating heat exchangers;

[0013] The participation status of the heat exchanger is represented as follows:

[0014]

[0015] in, The participation status of the Nth heat exchanger is 0, where 0 means not participating in evaporation and 1 means participating in evaporation. The rule for determining the series-parallel relationship matrix of participating heat exchangers is that if the relationship between the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation is in series, it is represented as 1; if it is in parallel, it is represented as 0.

[0016] Optionally, the iterative optimization based on the genetic algorithm optimization model, until the iteration termination rule is triggered, outputting the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, and the series-parallel connection relationship of each heat exchanger participating in heat exchange, includes: randomly generating a preset number of individuals with different chromosome structures to form an initial population, and calculating the fitness of each individual in the initial population; determining the selection probability of each individual based on the fitness of each individual, performing the corresponding genetic operation to obtain a progeny population, and performing fitness calculation for the corresponding progeny population, performing the next round of genetic operation based on the fitness of the progeny population, until a preset number of iterations is reached, or the change value of the optimal fitness for a consecutive preset number of iterations is less than a preset change value threshold, stopping the iteration, and outputting the individual with the optimal fitness; determining the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, and the series-parallel connection relationship of each heat exchanger participating in heat exchange based on the chromosome structure of the individual with the optimal fitness.

[0017] Optionally, the fitness of the individual is calculated as follows: the objective function of the genetic algorithm optimization model is calculated based on the current individual to obtain the objective function value; the objective function value is penalized based on the constraints to obtain the penalized objective function value; the penalized objective function value is normalized to obtain the fitness of the current individual.

[0018] Optionally, the objective function of the genetic algorithm optimization model is:

[0019]

[0020] in, , indicating evaporation efficiency; P represents the molten salt consumption; P represents the heat exchanger assembly. and These are the evaporation efficiency and molten salt consumption of the i-th heat exchanger, respectively.

[0021] Optionally, the rule for normalizing the penalized objective function value is as follows:

[0022]

[0023] in, For individual fitness; This represents the objective function value after the current individual has been punished. and These are the minimum and maximum values ​​of the objective function for each individual after the penalty.

[0024] Optionally, the genetic operations include: crossover and / or mutation; the crossover rule is: select two parent individuals based on roulette wheel selection, and perform random position swapping on the chromosomes of the two parent individuals to obtain two offspring individuals; the mutation rule is: select any individual based on roulette wheel selection, and perform a state flip on any position in the chromosome structure of that individual to obtain the corresponding offspring individual.

[0025] Optionally, the control module is configured to: generate a valve control scheme for the three-way valves connected to each heat exchanger based on the determined heat exchanger serial number and the series-parallel relationship of each heat exchanger; if the current heat exchanger is not selected, the valves of the three-way valves at both ends of the current heat exchanger that point to the current heat exchanger will be closed; if the current heat exchanger is selected, the inlet and outlet directions of the current heat exchanger will be determined based on the series-parallel relationship between the current heat exchanger and the selected heat exchangers before and after it, and the opening and closing scheme of the valves at each port of the current three-way valve will be determined based on the determined inlet and outlet directions.

[0026] Optionally, the system further includes a preheating module connected to the front end of the evaporator for preheating the produced water and then channeling the preheated produced water into the evaporator.

[0027] Optionally, the steam conversion device includes: a steam-water separation device connected to the evaporator output port for separating wet saturated steam into dry steam and saturated water; the dry steam is introduced into a superheater for converting the dry steam into superheated dry steam; the superheated dry steam and saturated water are introduced into a mixer for mixing the superheated dry steam and saturated water to obtain superheated steam for steam injection.

[0028] A second aspect of the present invention provides a control method for a cascade heating superheated steam generation system. The method is used for controlling the aforementioned cascade heating superheated steam generation system. The method includes: constructing a corresponding genetic algorithm optimization model with the optimization objectives of maximizing evaporation efficiency and minimizing molten salt consumption; performing iterative optimization based on the genetic algorithm optimization model until an iteration termination rule is triggered; and outputting the sequence number of the heat exchangers participating in heat exchange under the optimal evaporation state, as well as the series and parallel connection relationship of each heat exchanger participating in heat exchange.

[0029] Optionally, the chromosome structure of the genetic algorithm optimization model includes the heat exchanger participation state and the series-parallel relationship matrix of the participating heat exchangers; wherein, the heat exchanger participation state is represented as:

[0030]

[0031] in, The participation status of the Nth heat exchanger is 0, where 0 means not participating in evaporation and 1 means participating in evaporation. The rule for determining the series-parallel relationship matrix of participating heat exchangers is that if the relationship between the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation is in series, it is represented as 1; if it is in parallel, it is represented as 0.

[0032] Optionally, the iterative optimization based on the genetic algorithm optimization model, until the iteration termination rule is triggered, outputting the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, and the series-parallel connection relationship of each heat exchanger participating in heat exchange, includes: randomly generating a preset number of individuals with different chromosome structures to form an initial population, and calculating the fitness of each individual in the initial population; determining the selection probability of each individual based on the fitness of each individual, performing the corresponding genetic operation to obtain a progeny population, and performing fitness calculation for the corresponding progeny population, performing the next round of genetic operation based on the fitness of the progeny population, until a preset number of iterations is reached, or the change value of the optimal fitness for a consecutive preset number of iterations is less than a preset change value threshold, stopping the iteration, and outputting the individual with the optimal fitness; determining the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, and the series-parallel connection relationship of each heat exchanger participating in heat exchange based on the chromosome structure of the individual with the optimal fitness.

[0033] Optionally, the fitness of the individual is calculated as follows: the objective function of the genetic algorithm optimization model is calculated based on the current individual to obtain the objective function value; the objective function value is penalized based on the constraints to obtain the penalized objective function value; the penalized objective function value is normalized to obtain the fitness of the current individual.

[0034] Optionally, the objective function of the genetic algorithm optimization model is:

[0035]

[0036] in, , indicating evaporation efficiency; P represents the molten salt consumption; P represents the heat exchanger assembly. and These are the evaporation efficiency and molten salt consumption of the i-th heat exchanger, respectively.

[0037] 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 stepped heating superheated steam generation system.

[0038] Through the above technical solution, this invention significantly improves the flexibility and thermal efficiency of the evaporation device by setting up an evaporation unit with multiple heat exchangers and dynamically adjusting the series and parallel connections of each heat exchanger based on real-time heating demand. By determining the number of heat exchangers participating in heat exchange and their connection method in real time, energy waste or insufficient heat exchange capacity caused by fluctuations in heating demand can be effectively avoided, ensuring the high efficiency and stability of the steam production process. In addition, the control device is communicatively connected to each heat exchanger, realizing intelligent dynamic regulation, which not only optimizes the system's heat load distribution and extends equipment life, but also reduces operating costs. With the cooperation of the steam conversion device, this solution can further convert wet saturated steam into superheated steam that meets the steam injection requirements, enhancing steam quality and applicability. Through the efficient transfer of heat source by the molten salt transfer device, the system can more stably realize energy input and conversion, adapting to complex heating demand scenarios, thus providing an efficient, flexible, and intelligent solution for heavy oil steam injection.

[0039] 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

[0040] 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:

[0041] Figure 1 This is a system structure diagram of a cascade heating superheated steam generation system provided in one embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the specific structure of a cascade heating superheated steam generation system provided in one embodiment of the present invention;

[0043] Figure 3 This is a flowchart of the steps of a step-by-step control method for a cascade heating superheated steam generation system provided in one embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures

[0045] 1-Oilfield produced water supply pipeline; 2-Electric heating solid thermal storage preheater; 3-Preheated water pipeline; 4-Evaporator; 5-Wet steam pipeline; 6-Second hot salt pipeline; 7-Steam-water separator; 8-Separated water pipeline; 9-Dry steam pipeline; 10-Superheater; 11-First superheated steam pipeline; 12-Mixer; 13-Second superheated steam pipeline; 14-First hot salt pipeline; 15-Cold salt pipeline. Detailed Implementation

[0046] 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.

[0047] Figure 1 This is a system structure diagram of a cascade heating superheated steam generation system provided in one embodiment of the present invention. Figure 1 As shown, an embodiment of the present invention provides a cascade heating superheated steam generation system. The system includes: an evaporation device equipped with multiple heat exchangers, the evaporation device being used to process preheated produced water into wet saturated steam; wherein the series and parallel connection relationship between the heat exchangers in the evaporation device is adjusted based on real-time heating demand information; a steam conversion device connected to the rear end of the evaporation device, used to convert the wet saturated steam into superheated steam for injection; a control device communicatively connected to each heat exchanger, used to determine the sequence number of the heat exchangers participating in the heat exchange, and the series and parallel connection relationship of each heat exchanger participating in the heat exchange, based on real-time heating demand information; and a molten salt transfer device that sequentially passes through the steam conversion device and the evaporation device, used to transfer molten salt that provides a heat source to the steam conversion device and the evaporation device.

[0048] Preferably, the evaporator is provided with two flow pipes, and each heat exchanger is located between the two flow pipes and connected to the flow pipes through a three-way valve.

[0049] Preferably, when the current heat exchanger participates in evaporation, the valves of the two three-way valves at the beginning and end of the corresponding heat exchanger, corresponding to the two ports connected to the heat exchanger, are opened; when the current heat exchanger participating in evaporation is connected in series with the next adjacent heat exchanger participating in evaporation, the outflow water output from the current heat exchanger flows into the next adjacent heat exchanger participating in evaporation through the three-way valve on the same side as the outlet end of the current heat exchanger; when the current heat exchanger participating in evaporation is connected in parallel with the next adjacent heat exchanger participating in evaporation, the outflow water from the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation flows into the same side, and the outflow water after heat exchange between the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation is merged through the three-way valve on the other side.

[0050] In this embodiment of the invention, each heat exchanger is equipped with two three-way valves at both ends, which are connected to two flow pipes at the inlet and outlet ends of the heat exchanger, respectively. When the current heat exchanger is involved in evaporation, the relevant ports of the two three-way valves connected to it are opened, allowing fluid to enter the heat exchanger and complete the heat exchange process. For heat exchangers not involved in evaporation, the three-way valves remain closed, isolating the heat exchanger and avoiding unnecessary energy loss.

[0051] Furthermore, when two adjacent heat exchangers involved in evaporation are connected in series, the output port of the previous heat exchanger is directly connected to the input port of the next heat exchanger via a three-way valve. The fluid passes through each heat exchanger sequentially, thereby gradually improving thermal efficiency, suitable for operating conditions with low flow rates and high heat exchange demands. The advantage of this mode is that it can progressively increase the fluid temperature or steam quality, reducing heat loss between heat exchangers. When two adjacent heat exchangers involved in evaporation are connected in parallel, the inlet and outlet of each heat exchanger are connected to two separate flow pipes via three-way valves. The fluid is distributed to each heat exchanger and completes heat exchange in parallel before merging again via a three-way valve on the other side. The parallel mode is suitable for operating conditions with high flow rates and low heat exchange demands, improving heat exchange efficiency and reducing the overall system pressure drop.

[0052] Furthermore, the system adjusts the participation status and series-parallel connection of heat exchangers in real time based on heating demand. The control system dynamically calculates the optimal combination of heat exchangers by monitoring key parameters such as flow rate, temperature, and pressure, optimizing evaporator operating efficiency. Through flexible series-parallel configuration, the system can select the optimal heat exchange path according to real-time demand, maximizing the utilization of the heat transfer medium's thermal energy and avoiding unnecessary energy loss. The step-by-step heating in series mode significantly improves steam quality, especially suitable for high-quality steam production; while the split-flow operation in parallel mode enhances system processing capacity and adapts to high-flow-rate scenarios.

[0053] In series mode, the fluid passes through multiple heat exchangers sequentially, with each heat exchanger gradually heating the fluid, resulting in a significant increase in the outlet fluid temperature. This concentrated heat utilization is suitable for applications requiring multi-stage heating of the fluid. It is applicable to the production of high-temperature, high-pressure superheated steam (e.g., applications requiring high outlet steam dryness). Furthermore, at lower flow rates, the fluid has a longer heat exchange time within each heat exchanger, allowing for more efficient heat absorption. However, in series mode, the fluid must flow through each heat exchanger sequentially, leading to a large system pressure drop and limited flow rate. A failure in a single heat exchanger can disrupt the entire series heat exchange path, resulting in lower reliability.

[0054] In parallel operation, fluid is simultaneously diverted into multiple heat exchangers, each completing heating in parallel, with the outlet fluids converging at the end of the parallel path. The heat exchanger capacity is evenly distributed, resulting in a smaller fluid temperature rise. This is suitable for scenarios with high flow rate requirements but relatively low temperature rise or quality requirements. It is also suitable for meeting multi-point heating needs or rapidly increasing evaporation capacity. However, parallel operation has lower thermal efficiency and limited improvement in outlet fluid quality. It also requires a higher number of heat exchangers, potentially increasing initial investment costs.

[0055] Therefore, in actual operation, the system's heating demand may fluctuate due to external conditions (such as ambient temperature, load changes, steam injection requirements, etc.). When the heating demand is high, the parallel mode can activate multiple heat exchangers simultaneously, increasing flow handling capacity and quickly meeting large flow demands. When the heating demand is low and high-quality outlet steam is required, the series mode fully utilizes thermal energy through staged heating, improving the outlet steam temperature and dryness.

[0056] The water inlet direction of the heat exchanger in this invention can be modified to adjust the series and parallel connection between the heat exchangers, thereby enabling adaptive state adjustment in various scenarios.

[0057] Preferably, determining the heat exchanger serial number participating in heat exchange and the series-parallel relationship of each heat exchanger based on real-time heating demand information includes: constructing a corresponding genetic algorithm optimization model with the optimization objectives of maximizing evaporation efficiency and minimizing molten salt consumption; performing iterative optimization based on the genetic algorithm optimization model until the iteration termination rule is triggered, and outputting the heat exchanger serial number participating in heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in heat exchange.

[0058] In this embodiment of the invention, the genetic algorithm is an optimization method that simulates the mechanisms of natural selection and genetic evolution, suitable for solving complex multi-objective problems. In this system, the genetic algorithm is used to dynamically optimize the operating configuration of heat exchangers. Its optimization process uses the participation state and connection method of the heat exchangers as core variables, and generates multiple heat exchanger combination schemes based on system operating data, such as heating demand, temperature, pressure, and flow rate. Through multiple iterative screenings, the heat exchanger configuration that achieves the best evaporation efficiency and lowest energy consumption under the current operating conditions is finally selected.

[0059] Furthermore, the optimization process begins with initialization, first generating multiple heat exchanger configuration schemes. Each scheme includes which heat exchangers participate in operation and their connection methods. Then, the system evaluates the performance of each scheme under current operating conditions, judging its advantages and disadvantages in terms of steam production efficiency and molten salt energy consumption. Through inheritance, improvement, and mutation of the preferred scheme, the genetic algorithm gradually optimizes the number of heat exchangers involved and their connection relationships, ultimately outputting the optimal configuration. The dynamic optimization mechanism ensures that the system can adjust its operating mode according to real-time changes in heating demand. During peak heating demand, the system automatically selects more heat exchangers to participate in operation and configures them in parallel mode as needed to meet high flow rate demands. During low heating demand, the system reduces the number of operating heat exchangers and tends to use series mode to improve the quality of the outlet steam.

[0060] Furthermore, the dynamic control of the heat exchanger is executed by a control system combined with a genetic algorithm. The system periodically collects data such as temperature, pressure, and flow rate at the evaporator inlet and outlet, and recalculates the heat exchanger's participation status and connection method based on this real-time information. The start-up, shutdown, and series-parallel switching of the heat exchanger are achieved through intelligent valves, and all control is directed by a central system to ensure that the system can operate continuously with optimal configuration.

[0061] The reason this invention requires determining the heat exchanger serial numbers for heat exchange is that the configuration and operating status of the heat exchangers directly affect the system's efficiency, reliability, and lifespan. Therefore, determining which heat exchangers participate in operation (i.e., their serial numbers) and dynamically adjusting their status is crucial for optimizing system performance. If some heat exchangers operate at high loads for extended periods while others remain idle or at low loads, the high-load heat exchangers will age prematurely, increasing maintenance frequency and replacement costs. By dynamically determining the heat exchanger serial numbers, heat exchangers can be used in rotation during different heat exchange cycles, distributing the heat load evenly and extending the overall system's lifespan. This approach not only reduces equipment maintenance costs but also improves the long-term operational reliability of the system.

[0062] Furthermore, due to variations in pipe length and layout, the distance between heat exchangers and heat sources or outlets will differ. Heat exchangers located further away may experience reduced heat exchange efficiency due to pipe heat loss, potentially leading to energy waste during operation. When determining heat exchanger serial numbers, priority should be given to heat exchangers that are closer to the heat source and have higher efficiency to maximize the overall thermal energy utilization of the system. Simultaneously, the operating time of distant heat exchangers can be rationally scheduled based on current operating conditions to reduce heat energy waste caused by pipe length.

[0063] Therefore, the heating demand in the system may exhibit localized concentrations. For example, certain heat exchangers may bear higher heat loads due to their location or fluid characteristics, leading to localized overheating or overload. By determining the heat exchanger serial numbers and dynamically adjusting them, the distribution of heat load can be optimized, avoiding localized overload problems and improving overall operating efficiency. This adjustment method can also effectively reduce the risk of scaling inside the heat exchangers, maintaining long-term stable system operation.

[0064] Furthermore, the operating efficiency of each heat exchanger can be affected by temperature gradients, flow distribution, and differences in equipment performance. Failure to selectively choose heat exchangers for operation may result in underutilization of high-efficiency heat exchangers and a decline in overall performance due to the use of inefficient heat exchangers. Dynamically determining the sequence of heat exchangers for operation helps prioritize the use of high-efficiency heat exchangers, thereby improving the overall system's heat exchange efficiency. This selection can also optimize the heat exchanger combination based on operating data, maximizing energy savings and reducing consumption.

[0065] Furthermore, multi-heat exchanger systems typically incorporate redundancy to address equipment failures or maintenance needs. Without dynamically adjusting heat exchanger numbers, redundant heat exchangers may remain idle for extended periods, making it difficult for the system to quickly switch to backup equipment in the event of a sudden failure. Determining heat exchanger numbers allows for the reasonable scheduling of redundant heat exchanger operation, preventing performance degradation due to prolonged idleness. Simultaneously, it enables the rapid deployment of backup heat exchangers in the event of existing heat exchanger failures or maintenance, ensuring the continuity and reliability of system operation.

[0066] Furthermore, heating demand is dynamic, with peak and off-peak periods. If the operation status of heat exchangers is fixed, the heating capacity may be insufficient to meet the demand during peak or off-peak periods, resulting in energy waste. By dynamically determining the heat exchanger sequence, the number of heat exchangers in operation can be selected based on real-time heating demand. This satisfies peak demand while reducing unnecessary heat exchanger operation during off-peak periods, thereby reducing system energy consumption.

[0067] Preferably, the constraints of the genetic algorithm optimization model include: the dryness of the wet saturated steam at the evaporator outlet is greater than a preset dryness threshold; the total pressure drop of the evaporator is less than a preset pressure drop threshold; and the load of the evaporator is less than the maximum design load.

[0068] Specifically, the chromosome structure of the genetic algorithm optimization model includes the heat exchanger participation state and the series-parallel relationship matrix of the participating heat exchangers; wherein, the heat exchanger participation state is represented as:

[0069]

[0070] in, The participation status of the Nth heat exchanger is 0, where 0 means not participating in evaporation and 1 means participating in evaporation. The rule for determining the series-parallel relationship matrix of participating heat exchangers is that if the relationship between the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation is in series, it is represented as 1; if it is in parallel, it is represented as 0.

[0071] In this embodiment of the invention, in the evaporator optimization model based on a genetic algorithm, several optimization constraints are set to ensure that the system can operate in the most efficient and stable manner. These constraints include: the wet saturated steam at the evaporator outlet and the dryness of the steam must be greater than preset critical values ​​to ensure that the steam quality meets the steam injection requirements; the total pressure drop of the system must be less than a preset upper limit to reduce energy loss and pipeline load in fluid transmission; in addition, the operating load of each heat exchanger participating in evaporation must not exceed its maximum design load to ensure the reliability and lifespan of the equipment.

[0072] In the specific genetic algorithm optimization model, the chromosome structure is designed to include the participation states of heat exchangers and the connections between them. The participation states of heat exchangers are represented in binary form, with each heat exchanger corresponding to a state value. A state value of 1 indicates that the heat exchanger participates in evaporation, while a state value of 0 indicates that it does not participate in evaporation. Furthermore, to describe the connections between participating heat exchangers, the model also employs a matrix representation rule for series and parallel connections. If two adjacent heat exchangers are connected in series, the corresponding value in the matrix is ​​marked as 1; if they are connected in parallel, it is marked as 0. This design clearly expresses the operational configuration state of the entire system and provides a foundation for the optimization process of the genetic algorithm.

[0073] By iteratively optimizing the participation status and connection relationships of heat exchangers using a genetic algorithm, the model can find the optimal evaporator configuration under the current operating conditions. For example, when higher steam quality is required, the algorithm will prioritize selecting more heat exchangers and operating them in series; while when a larger flow rate needs to be processed, it may select more heat exchangers to operate in parallel to improve the overall processing capacity.

[0074] Preferably, the iterative optimization based on the genetic algorithm optimization model, until the iteration termination rule is triggered, and the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, as well as the series-parallel connection relationship of each heat exchanger participating in heat exchange, includes: randomly generating a preset number of individuals with different chromosome structures to form an initial population, and calculating the fitness of each individual in the initial population; determining the selection probability of each individual based on the fitness of each individual, performing the corresponding genetic operation to obtain a progeny population, and performing fitness calculation for the corresponding progeny population, and performing the next round of genetic operation based on the fitness of the progeny population, until a preset number of iterations is reached, or the change value of the optimal fitness for a consecutive preset number of iterations is less than a preset change value threshold, stopping the iteration, and outputting the individual with the optimal fitness; and determining the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, as well as the series-parallel connection relationship of each heat exchanger participating in heat exchange, based on the chromosome structure of the individual with the optimal fitness.

[0075] In this embodiment of the invention, in the evaporation system based on a genetic algorithm optimization model, dynamically adjusting the sequence number of the heat exchangers involved in heat exchange and their series-parallel connection is the core of achieving efficient system operation. Therefore, through iterative optimization using a genetic algorithm, the optimal evaporation configuration under the current operating conditions can be intelligently found, ensuring that the system achieves its best state in terms of energy utilization and operating efficiency. Specifically, this includes the following rules:

[0076] 1) Initial Population Generation: The optimization process begins with the random generation of an initial population. Each individual in the population represents an operating configuration of a heat exchanger, including which heat exchangers are involved in operation and their series-parallel connections. The structure of each individual (i.e., chromosome) encodes the state and connection method of the heat exchangers. By randomly generating multiple individuals, the initial population can cover the widest possible configuration space, laying the foundation for subsequent optimization.

[0077] 2) Fitness Calculation: For each individual in the initial population, its fitness is calculated. Fitness is a key indicator of an individual's quality, typically determined by objectives such as system efficiency and resource consumption. For example, a high-fitness individual corresponds to a configuration that maximizes evaporation efficiency while minimizing energy consumption. Fitness calculation provides guidance for genetic operations, prioritizing the retention of better individuals.

[0078] 3) Selection Operation: Based on the fitness of each individual, the probability of its selection is determined. Individuals with higher fitness have a greater probability of being selected. This selection mechanism mimics the survival of the fittest in natural selection, preserving better-performing configurations for the next generation while eliminating individuals with lower fitness.

[0079] 4) Genetic Operations: Genetic operations include two main steps: crossover and mutation. Crossover combines the chromosomal structures of two parent individuals to generate new offspring, thus exploring more configuration possibilities. Mutation randomly modifies some genes of an individual, such as changing the participation status of certain heat exchangers or adjusting the series-parallel connection of heat exchangers. Through genetic operations, the population can continuously evolve, gradually approaching the optimal configuration.

[0080] 5) Fitness calculation of offspring population: The fitness of the offspring population generated by genetic operations is recalculated to ensure that the next round of genetic operations can continue to optimize the population structure. As iterations proceed, the overall fitness of the population continuously improves, resulting in increased system operating efficiency and reduced energy consumption.

[0081] 6) Iteration Termination Rules: The termination conditions for the optimization process include two cases: first, reaching the preset maximum number of iterations; second, the change in the optimal fitness value is lower than a preset threshold in consecutive iterations. This design ensures that the algorithm can find a solution close to the global optimum within a sufficient computation time, while avoiding unnecessary excessive iterations.

[0082] 7) Output Optimal Configuration: After optimization, the individual with the highest fitness is output. Based on the chromosome structure of this individual, the optimal heat exchanger sequence and its series-parallel connection relationship can be determined, thereby achieving the best evaporation state under the current operating conditions.

[0083] Preferably, the fitness of the individual is calculated as follows: the objective function of the genetic algorithm optimization model is calculated based on the current individual to obtain the objective function value; the objective function value is penalized based on the constraints to obtain the penalized objective function value; the penalized objective function value is normalized to obtain the fitness of the current individual.

[0084] In this embodiment of the invention, the fitness of an individual is a key indicator for measuring its quality in the genetic algorithm, directly affecting the execution of subsequent selection, crossover, and mutation operations. To accurately evaluate the quality of individuals, a fitness calculation method based on an objective function and constraints is employed. This method ensures that the fitness comprehensively reflects the quality of individuals and effectively guides the optimization process by calculating, penalizing, and normalizing the objective function value.

[0085] First, the objective function value of the genetic algorithm optimization model is calculated for each individual's running configuration. The objective function value is the core indicator for measuring the performance of the current configuration, and it is usually derived from a combination of multiple optimization objectives (such as maximizing evaporation efficiency and minimizing energy consumption). The result of the objective function can directly reflect the performance of the current configuration, but without considering system constraints, the result may not be entirely reasonable.

[0086] To ensure that individual configuration schemes comply with system operating constraints, a penalty is applied to the objective function value. This penalty is a negative evaluation mechanism applied to individuals that violate constraints; for example, when steam quality is below the set value or equipment load exceeds the design limit, the objective function value of that individual is reduced. This approach effectively prevents configurations that do not meet actual operational requirements from entering the next generation of the population, thereby improving the efficiency and practicality of the optimization process.

[0087] Finally, to facilitate the comparison and manipulation of fitness values, the penalized objective function value is normalized. The normalized fitness value is confined to a uniform range, making it easier to use directly in genetic operations. Simultaneously, the normalization process also improves the algorithm's convergence, ensuring that optimization can quickly find the optimal solution.

[0088] Specifically, the objective function of the genetic algorithm optimization model is:

[0089]

[0090] in, , indicating evaporation efficiency; P represents the molten salt consumption; P represents the heat exchanger assembly. and These are the evaporation efficiency and molten salt consumption of the i-th heat exchanger, respectively.

[0091] Specifically, the rule for normalizing the penalized objective function value is as follows:

[0092]

[0093] in, For individual fitness; This represents the objective function value after the current individual has been punished. and These are the minimum and maximum values ​​of the objective function for each individual after the penalty.

[0094] Specifically, the genetic operations include: crossover and / or mutation; the crossover rule is: select two parent individuals based on roulette wheel selection, and perform random position swapping on the chromosomes of the two parent individuals to obtain two offspring individuals; the mutation rule is: select any individual based on roulette wheel selection, and perform a state flip on any position in the chromosome structure of that individual to obtain the corresponding offspring individual.

[0095] Specifically, the control module is configured to: generate a valve control scheme for the three-way valves connected to each heat exchanger based on the determined heat exchanger serial number and the series-parallel relationship of each heat exchanger; if the current heat exchanger is not selected, the valves of the three-way valves at both ends of the current heat exchanger that point to the current heat exchanger will be closed; if the current heat exchanger is selected, the inlet and outlet directions of the current heat exchanger will be determined based on the series-parallel relationship between the current heat exchanger and the selected heat exchangers before and after it, and the opening and closing scheme of the valves at each port of the current three-way valve will be determined based on the determined inlet and outlet directions.

[0096] In this embodiment of the invention, for heat exchangers not selected for operation in the current optimization results, the control module closes the three-way valves at both ends of the heat exchanger. Closing the three-way valves isolates the fluid within the flow pipes, preventing fluid from entering the heat exchanger, thereby reducing ineffective energy consumption and system pressure loss. By isolating unselected heat exchangers, system operating efficiency can be ensured, while unnecessary equipment load is reduced, effectively protecting the heat exchangers from long-term impact from high pressure and high temperature. For heat exchangers selected for operation in the optimization results, the control module generates inlet and outlet water direction schemes based on their connection relationships with the preceding and following heat exchangers. The inlet and outlet water directions of the heat exchangers are determined by the series-parallel relationships in the optimization results:

[0097] 1) Series connection: The outlet water of the current heat exchanger directly enters the inlet of the next heat exchanger. Based on this flow path, the control module directs the outlet valve of the current heat exchanger to the next heat exchanger, while ensuring that the inlet valve is connected to the previous heat exchanger.

[0098] 2) Parallel Connection: The inlet and outlet fluids of the current heat exchanger are respectively connected to the flow pipes and mixed with the fluids of other parallel heat exchangers before being transported together. The control module directs the inlet and outlet valves of the current heat exchanger to the flow pipes to achieve fluid diversion and merging.

[0099] Each heat exchanger's inlet and outlet are connected to two flow pipes via three-way valves. The control module generates specific control commands for each three-way valve based on the current operating status and connection relationships of the heat exchangers, including the on / off status of each port. For heat exchangers in series, the control module ensures that fluid enters and exits in a predetermined direction; for heat exchangers in parallel, the control module ensures that fluid can be effectively split and merged. Regardless of the mode, the control module dynamically adjusts the state of the three-way valves based on real-time operating data, ensuring the system's flexibility and efficiency.

[0100] Through the three-way valve management of the control module, the system can achieve highly flexible heat exchanger operation configuration to meet the needs of different operating conditions. For example, when high steam quality requirements are needed, the system can select more heat exchangers to operate in series to improve the temperature and dryness of the outlet steam; while when high flow rate requirements are needed, more heat exchangers can be selected to operate in parallel to quickly increase processing capacity. In addition, the dynamic adjustment of the three-way valve enables the system to continue operating stably even when some heat exchangers fail or require maintenance, demonstrating high fault tolerance.

[0101] Preferably, the system further includes a preheating module connected to the front end of the evaporator, used to preheat the produced water and to collect the preheated produced water into the evaporator.

[0102] Preferably, the steam conversion device includes: a steam-water separation device connected to the evaporator output port for separating wet saturated steam into dry steam and saturated water; the dry steam is introduced into a superheater for converting the dry steam into superheated dry steam; the superheated dry steam and saturated water are introduced into a mixer for mixing the superheated dry steam and saturated water to obtain superheated steam for steam injection.

[0103] In this embodiment of the invention, a preheating module is configured at the front end of the evaporator to preheat the produced water. The produced water temperature is typically low, and direct entry into the evaporator may lead to decreased heat exchange efficiency and increased evaporator load. Through the preheating module, the produced water temperature is raised to near its saturation temperature, which not only reduces the evaporator's heat load but also significantly improves its heat exchange efficiency. Furthermore, the preheating module can utilize recovered waste heat or low-quality heat sources for heating, further reducing the system's energy consumption. This design ensures that the produced water enters the evaporator at a higher temperature, thereby accelerating the evaporation process and improving the overall system efficiency.

[0104] Furthermore, the steam conversion unit includes a steam-water separator, a superheater, and a mixer, responsible for separating wet saturated steam, superheating dry steam, and conditioning the final superheated steam, respectively. This modular design allows the system to flexibly adjust steam quality to adapt to different steam injection requirements. Specifically, it includes:

[0105] 1) Steam-water separation unit: Wet saturated steam enters the steam-water separation unit from the evaporator outlet, where it is separated into dry steam and saturated water. The dry steam has high steam quality (close to 100% dryness), while the saturated water can be reintroduced into the system as a water source for blending or other purposes. The steam-water separation process ensures heat exchange efficiency in subsequent superheating processes while reducing the potential impact of wet steam on the superheater's heat exchange surface.

[0106] 2) Superheater: Dry steam enters the superheater from the steam-water separator, where it is further heated into high-temperature, high-pressure superheated dry steam. The superheater utilizes high-temperature molten salt or other heat sources to provide heat, ensuring that the temperature and quality of the dry steam meet the standards required for steam injection wells. Superheated dry steam has higher heat content and transport efficiency, making it suitable for applications such as heavy oil steam injection where high steam quality is required.

[0107] 3) Blender: Superheated dry steam and saturated water are remixed in the blender to adjust the final steam superheat. This design allows for flexible adjustment of steam quality according to injection requirements; for example, reducing the amount of saturated water when a higher superheat is required, and increasing the proportion of saturated water when a lower superheat is required. The blender's function is to precisely control steam parameters so that the output superheated steam fully meets the injection requirements.

[0108] In one possible implementation, such as Figure 2 The present invention provides a specific structure of a cascade heating superheated steam generation system, which is exemplified by a series configuration and includes a produced water supply pipeline 1, an electrically heated solid thermal storage preheater 2, a preheated water pipeline 3, an evaporator 4, a wet steam pipeline 5, a second hot salt pipeline 6, a steam-water separator 7, a separated water pipeline 8, a dry steam pipeline 9, a superheater 10, a first superheated steam pipeline 11, a mixer 12, a second superheated steam pipeline 13, a first hot salt pipeline 14, and a cold salt pipeline 15.

[0109] The working principles and processes of each part of the system are as follows, in conjunction with the embodiments.

[0110] 1. The main equipment of this invention consists of an electrically heated solid heat storage preheater 2, an evaporator 4, a steam-water separator 7, a superheater 10, and a mixer 12;

[0111] 2. Oilfield produced water is connected to the electrically heated solid-state thermal storage preheater 2 via the oilfield produced water supply pipeline 1. After being heated in the electrically heated solid-state thermal storage preheater 2, the oilfield produced water is connected to the evaporator 4 via the preheated water pipeline 3. Taking binary molten salt as an example, the freezing point of the binary molten salt is 220℃, the oilfield produced water supply temperature is 40-70℃, and the preheated water temperature is 230-250℃. The silicon content of the oilfield produced water can be <250mg / L. The electrically heated solid-state thermal storage 2 can use solid magnesium bricks as the heat storage medium, and use green electricity to heat the solid magnesium bricks, continuously extracting heat from the solid magnesium bricks to heat the oilfield produced water.

[0112] 3. Evaporator 4 can be composed of one or more heat exchangers connected in series or in parallel; if intermediate adjustment is not considered, the evaporator can be equipped with only one heat exchanger, and if intermediate adjustment is considered, the evaporator can be equipped with two or more heat exchangers.

[0113] 4. Oilfield produced water is heated by molten salt in evaporator 4 to become wet saturated steam. The wet saturated steam is connected to steam-water separator 7 through wet steam pipeline 5. The parameters of the wet saturated steam produced by evaporator 4 can be 8MPa, 295℃, and dryness 75%. The dryness of the wet steam must not exceed 75%, otherwise it will cause rapid scaling on the heat exchange surface of evaporator 4 and affect the heat exchange effect.

[0114] 5. The wet saturated steam connected to the steam-water separator 7 is partially converted into dry steam and partially into saturated water.

[0115] 6. The wet saturated steam connected to the steam-water separator 7 is partially converted into dry steam and partially into saturated water. The dry steam parameters can be 99%-100% dryness, 75% dry steam by mass, and 25% saturated water by mass.

[0116] 7. The saturated water separated from the steam-water separator 7 is connected to the mixer 12 via the separated water pipeline 8;

[0117] 8. The dry steam separated from the steam-water separator 7 is connected to the superheater 10 via the dry steam pipe 9. In the superheater 10, the dry steam is heated by high-temperature molten salt to become superheated steam with a high degree of superheat; the superheat of the superheated steam with a high degree of superheat can be 135℃.

[0118] 9. The superheated steam with high superheat generated in the superheater 10 is connected to the mixer 12 via the first superheated steam pipe 11.

[0119] 10. In the mixer 12, high-superheated superheated steam and saturated water are mixed to become low-superheated superheated steam, which is then transported to the steam injection well through the second superheated steam pipeline 13; the superheat of the low-superheated superheated steam can be 15-20℃.

[0120] 11. Molten salt serves as the heat source medium for the system. High-temperature molten salt is connected to the superheater 10 via the first hot salt pipe 14 to heat dry steam into superheated steam with a high degree of superheat. Then, it is connected to the evaporator 2 via the second hot salt pipe 6 to heat preheated water into wet saturated steam. Finally, it is discharged from the system via the cold salt pipe 15. Taking binary molten salt as an example, the high-temperature molten salt temperature can be 560℃, and the low-temperature molten salt temperature after heat exchange can be 285℃.

[0121] Figure 3 This is a flowchart of a method for controlling a cascade 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 cascade heating superheated steam generation system, the method comprising:

[0122] Step S10: With the optimization objectives of maximizing evaporation efficiency and minimizing molten salt consumption, construct the corresponding genetic algorithm optimization model.

[0123] Step S20: Perform iterative optimization based on the genetic algorithm optimization model until the iteration termination rule is triggered, and output the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, as well as the series and parallel connection relationship of each heat exchanger participating in heat exchange.

[0124] Preferably, the chromosome structure of the genetic algorithm optimization model includes the heat exchanger participation state and the series-parallel relationship matrix of the participating heat exchangers; wherein, the heat exchanger participation state is represented as:

[0125]

[0126] in, The participation status of the Nth heat exchanger is 0, where 0 means not participating in evaporation and 1 means participating in evaporation. The rule for determining the series-parallel relationship matrix of participating heat exchangers is that if the relationship between the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation is in series, it is represented as 1; if it is in parallel, it is represented as 0.

[0127] Preferably, the iterative optimization based on the genetic algorithm optimization model, until the iteration termination rule is triggered, and the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, as well as the series-parallel connection relationship of each heat exchanger participating in heat exchange, includes: randomly generating a preset number of individuals with different chromosome structures to form an initial population, and calculating the fitness of each individual in the initial population; determining the selection probability of each individual based on the fitness of each individual, performing the corresponding genetic operation to obtain a progeny population, and performing fitness calculation for the corresponding progeny population, and performing the next round of genetic operation based on the fitness of the progeny population, until a preset number of iterations is reached, or the change value of the optimal fitness for a consecutive preset number of iterations is less than a preset change value threshold, stopping the iteration, and outputting the individual with the optimal fitness; and determining the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, as well as the series-parallel connection relationship of each heat exchanger participating in heat exchange, based on the chromosome structure of the individual with the optimal fitness.

[0128] Preferably, the fitness of the individual is calculated as follows: the objective function of the genetic algorithm optimization model is calculated based on the current individual to obtain the objective function value; the objective function value is penalized based on the constraints to obtain the penalized objective function value; the penalized objective function value is normalized to obtain the fitness of the current individual.

[0129] Preferably, the objective function of the genetic algorithm optimization model is:

[0130]

[0131] in, , indicating evaporation efficiency; P represents the molten salt consumption; P represents the heat exchanger assembly. and These are the evaporation efficiency and molten salt consumption of the i-th heat exchanger, respectively.

[0132] 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 stepped heating superheated steam generation system.

[0133] 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.

[0134] 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.

[0135] 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 stepped heating superheated steam generation system, characterized in that, The system includes: An evaporation unit equipped with multiple heat exchangers is used to process preheated produced water into wet saturated steam; wherein... The series and parallel connections between the heat exchangers in the evaporation unit are adjusted based on real-time heating demand information. A steam conversion device connected to the rear end of the evaporator is used to convert the wet saturated steam into superheated steam for injection. A control device that communicates with each heat exchanger is used to determine the sequence number of the heat exchanger participating in the heat exchange, as well as the series and parallel connection relationship of each heat exchanger participating in the heat exchange, based on real-time heating demand information. A molten salt transfer device that sequentially passes through a steam conversion unit and an evaporation unit is used to transfer molten salt that provides a heat source to the steam conversion unit and the evaporation unit.

2. The system according to claim 1, characterized in that, The evaporation device is equipped with two flow pipes, and each heat exchanger is located between the two flow pipes and connected to the flow pipes through a three-way valve.

3. The system according to claim 2, characterized in that, When the current heat exchanger participates in evaporation, the two three-way valves corresponding to the beginning and end of the current heat exchanger and the valves of the two ports connected to the heat exchanger are opened; When the current heat exchanger participating in evaporation is connected in series with the next heat exchanger participating in evaporation, the overflow water output from the current heat exchanger flows into the next heat exchanger participating in evaporation through the three-way valve on the same side as the outlet end of the current heat exchanger. When the current heat exchanger participating in evaporation is connected in parallel with the next adjacent heat exchanger participating in evaporation, the outflow water of the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation merges on the same side, and the outflow water of the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation merges through the three-way valve on the other side.

4. The system according to claim 1, characterized in that, The determination of the heat exchanger serial number participating in heat exchange based on real-time heating demand information, and the series-parallel connection relationship of each heat exchanger participating in heat exchange, includes: With the optimization objectives of maximizing evaporation efficiency and minimizing molten salt consumption, a corresponding genetic algorithm optimization model is constructed. Based on the genetic algorithm optimization model, iterative optimization is performed until the iteration termination rule is triggered, and the sequence number of the heat exchanger participating in heat exchange under the optimal evaporation state, as well as the series and parallel connection relationship of each heat exchanger participating in heat exchange, are output.

5. The system according to claim 4, characterized in that, The constraints of the genetic algorithm optimization model include: The dryness of the wet saturated steam at the evaporator outlet is greater than the preset dryness threshold. The total pressure drop of the evaporator is less than the preset pressure drop threshold; The evaporator load is less than the maximum design load.

6. The system according to claim 4, characterized in that, The chromosome structure of the genetic algorithm optimization model includes the heat exchanger participation state and the series-parallel relationship matrix of the participating heat exchangers; The participation status of the heat exchanger is represented as follows: in, This represents the participation status of the Nth heat exchanger, where 0 indicates no participation in evaporation and 1 indicates participation in evaporation. The rule for determining the series-parallel relationship matrix of the heat exchangers is as follows: if the relationship between the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation is in series, it is represented as 1; if it is in parallel, it is represented as 0.

7. The system according to claim 6, characterized in that, The iterative optimization based on the genetic algorithm optimization model continues until the iteration termination rule is triggered, outputting the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, and the series-parallel connection relationship of each heat exchanger participating in heat exchange, including: A predetermined number of individuals with different chromosome structures are randomly generated to form an initial population, and the fitness of each individual in the initial population is calculated. Based on the fitness of each individual, the probability of selection of each individual is determined to perform the corresponding genetic operation, obtain the offspring population, and perform fitness calculation of the corresponding offspring population. Then, the next round of genetic operation is performed based on the fitness of the offspring population until the preset number of iterations is reached, or the change value of the optimal fitness for the preset number of consecutive iterations is less than the preset change value threshold, at which point the iteration stops and the individual with the optimal fitness is output. Based on the chromosome structure of individuals with optimal fitness, the sequence number of heat exchangers participating in heat exchange under optimal evaporation conditions is determined, as well as the series and parallel connections of each heat exchanger participating in heat exchange.

8. The system according to claim 7, characterized in that, The fitness of the individual is calculated according to the following rules: Based on the objective function of the current individual calculation genetic algorithm optimization model, the objective function value is obtained; The objective function value is penalized based on the constraints to obtain the penalized objective function value. Normalize the penalized objective function value to obtain the fitness of the current individual.

9. The system according to claim 8, characterized in that, The objective function of the genetic algorithm optimization model is: in, , indicating evaporation efficiency; This refers to the amount of molten salt consumed. P represents the heat exchanger assembly; and These are the evaporation efficiency and molten salt consumption of the i-th heat exchanger, respectively.

10. The system according to claim 8, characterized in that, The rule for normalizing the penalized objective function value is as follows: in, For individual fitness; This represents the objective function value after the current individual has been punished. and These are the minimum and maximum values ​​of the objective function for each individual after the penalty.

11. The system according to claim 7, characterized in that, The genetic operations include: Crossover and / or variation; The rules for intersection are: Two parent individuals are selected based on roulette wheel selection, and their chromosomes are randomly swapped to obtain two offspring individuals. The rules for mutation are: Based on a roulette wheel, any individual is selected, and the state of any position in the chromosome structure of that individual is flipped to obtain the corresponding offspring individual.

12. The system according to claim 1, characterized in that, The control device is configured to: Based on the determined heat exchanger serial numbers and the series-parallel connections of the heat exchangers, a valve control scheme for the three-way valves connected to each heat exchanger is generated. If the current heat exchanger is not selected, the valves pointing to the current heat exchanger side of the three-way valves at both ends of the current heat exchanger will be closed. If the current heat exchanger is selected, the inlet and outlet directions of the current heat exchanger are determined based on the series and parallel connection relationship between the current heat exchanger and the selected heat exchangers before and after it. Based on the determined inlet and outlet directions, the opening and closing schemes of the valves at each port of the current three-way valve are determined.

13. The system according to claim 1, characterized in that, The system also includes: The preheating module connected to the front end of the evaporator is used to preheat the produced water and then draw the preheated produced water into the evaporator.

14. The system according to claim 1, characterized in that, The steam conversion device includes: A steam-water separator connected to the evaporator output port is used to separate wet saturated steam into dry steam and saturated water; The dry steam is introduced into a superheater, which is used to convert the dry steam into superheated dry steam. The superheated dry steam and saturated water are introduced into a mixer for mixing the superheated dry steam and saturated water to obtain superheated steam for injection.

15. A control method for a cascade heating superheated steam generation system, characterized in that, The method is used for controlling the cascade heating superheated steam generation system according to any one of claims 1-14, the method comprising: With the optimization objectives of maximizing evaporation efficiency and minimizing molten salt consumption, a corresponding genetic algorithm optimization model is constructed. Based on the genetic algorithm optimization model, iterative optimization is performed until the iteration termination rule is triggered, and the sequence number of the heat exchanger participating in heat exchange under the optimal evaporation state, as well as the series and parallel connection relationship of each heat exchanger participating in heat exchange, are output.

16. The method according to claim 15, characterized in that, The chromosome structure of the genetic algorithm optimization model includes the heat exchanger participation state and the series-parallel relationship matrix of the participating heat exchangers; The participation status of the heat exchanger is represented as follows: in, This represents the participation status of the Nth heat exchanger, where 0 indicates no participation in evaporation and 1 indicates participation in evaporation. The rule for determining the series-parallel relationship matrix of the heat exchangers is as follows: if the relationship between the current heat exchanger participating in evaporation and the next adjacent heat exchanger participating in evaporation is in series, it is represented as 1; if it is in parallel, it is represented as 0.

17. The method according to claim 16, characterized in that, The iterative optimization based on the genetic algorithm optimization model continues until the iteration termination rule is triggered, outputting the heat exchanger sequence number participating in heat exchange under the optimal evaporation state, and the series-parallel connection relationship of each heat exchanger participating in heat exchange, including: A predetermined number of individuals with different chromosome structures are randomly generated to form an initial population, and the fitness of each individual in the initial population is calculated. Based on the fitness of each individual, the probability of selection of each individual is determined to perform the corresponding genetic operation, obtain the offspring population, and perform fitness calculation of the corresponding offspring population. Then, the next round of genetic operation is performed based on the fitness of the offspring population until the preset number of iterations is reached, or the change value of the optimal fitness for the preset number of consecutive iterations is less than the preset change value threshold, at which point the iteration stops and the individual with the optimal fitness is output. Based on the chromosome structure of individuals with optimal fitness, the sequence number of heat exchangers participating in heat exchange under optimal evaporation conditions is determined, as well as the series and parallel connections of each heat exchanger participating in heat exchange.

18. The method according to claim 17, characterized in that, The fitness of the individual is calculated according to the following rules: Based on the objective function of the current individual calculation genetic algorithm optimization model, the objective function value is obtained; The objective function value is penalized based on the constraints to obtain the penalized objective function value. Normalize the penalized objective function value to obtain the fitness of the current individual.

19. The method according to claim 18, characterized in that, The objective function of the genetic algorithm optimization model is: in, , indicating evaporation efficiency; This refers to the amount of molten salt consumed. P represents the heat exchanger assembly; and These are the evaporation efficiency and molten salt consumption of the i-th heat exchanger, respectively.

20. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the control method for a cascade heating superheated steam generation system as described in any one of claims 15-19.

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