Stepped heating superheated steam generation system and control method thereof

Abstract

The embodiment of the invention provides a cascade heating superheated steam generation system and a control method thereof, and belongs to the technical field of energy engineering and thermal power. The system comprises: an evaporation device provided with a plurality of heat exchangers, wherein the evaporation device is used for treating preheated produced water into wet saturated steam; wherein the series-parallel connection relation between the heat exchangers in the evaporation device is adjusted based on real-time heat supply demand information; the steam conversion device is used for converting the wet saturated steam into superheated steam for steam injection; the control device is used for determining the serial numbers of the heat exchangers participating in heat exchange and the series-parallel connection relation of the heat exchangers participating in heat exchange based on the real-time heat supply demand information; the fused salt conveying device sequentially passes through the steam conversion device and the evaporation device and is used for providing a heat source for the steam conversion device and the evaporation device. According to the scheme, the method adapts to complex heat supply demand scenes, and therefore an efficient, flexible and intelligent solution is provided for thick oil steam injection.

Description

Technical Field

[0001] The present invention relates to the field of energy engineering and thermal technology, and in particular to a step-heating superheated steam generating system and a step-heating superheated steam generating system control method. Background Art

[0002] Steam injection technology in heavy oil fields is one of the important means to improve the efficiency of heavy oil production. The currently widely used steam injection technology requires heating the produced water into wet saturated steam or superheated steam and then injecting it into the oil reservoir to reduce the viscosity of the crude oil. However, in the existing technology, there are still significant problems with the heat exchange efficiency and system flexibility of the steam generation device.

[0003] First, the evaporation device in the prior art is usually composed of multiple heat exchangers, but the configuration of these heat exchangers (such as series or parallel) is usually fixed and lacks flexibility. When the heating demand fluctuates, the working state and connection mode of the heat exchanger cannot be dynamically adjusted according to the actual demand, resulting in energy waste in the system under low demand conditions, and insufficient heat exchange capacity under high demand conditions, which cannot meet the requirements of steam production efficiency. This fixed mode significantly limits the system's adjustment ability and adaptability.

[0004] Secondly, the existing technology lacks precise control methods to manage the operating status of multiple heat exchangers. Although some systems have tried to introduce simple switch control, they have failed to optimize the number of heat exchangers and their series and parallel relationships based on real-time heating demand. This design lacking dynamic control capabilities can easily lead to uneven distribution of heat load in the heat exchanger, further reducing the overall energy efficiency of the system. In addition, overloading the heat exchanger or operating inefficiently for a long time will accelerate equipment aging and increase operating costs.

[0005] In summary, the existing technology has obvious deficiencies in the flexibility and intelligent control of multi-heat exchanger evaporation devices, and it is difficult to simultaneously meet the requirements of efficient heat exchange and dynamic heating demand. These problems have become the key bottleneck restricting the further improvement of the efficiency and economy of heavy oil steam injection technology. Summary of the invention

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

[0007] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a step-heating superheated steam generation system, the system comprising: an evaporation device provided with a plurality of heat exchangers, the evaporation device being used to process preheated produced water into wet saturated steam; wherein the series-parallel 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, being used to convert the wet saturated steam into superheated steam for steam injection; a control device communicatively connected to each heat exchanger, being used to determine the serial number of the heat exchanger involved in the heat exchange and the series-parallel relationship of each heat exchanger involved in the heat exchange based on real-time heating demand information; and a molten salt transmission device passing through the steam conversion device and the evaporation device in turn, being used to flow molten salt to provide 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 arranged between the two flow pipes and connected to the flow pipes through a three-way valve.

[0009] Optionally, when the current heat exchanger participates in evaporation, the valves corresponding to the two three-way valves at the head and tail of the heat exchanger and the two ports connected to the heat exchanger are opened; when the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are connected in series, the overflow water output by the current evaporation heat exchanger passes through the three-way valve of the adjacent next heat exchanger participating in evaporation on the same side as the outlet end of the current evaporation heat exchanger and is merged into the adjacent next heat exchanger participating in evaporation; when the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are connected in parallel, the overflow water of the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are merged on the same side, and the overflow water after heat exchange between the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation is merged through the three-way valve on the other side.

[0010] Optionally, the serial numbers of the heat exchangers involved in the heat exchange and the series-parallel relationships of the heat exchangers involved in the heat exchange are determined based on the real-time heating demand information, including: constructing a corresponding genetic algorithm optimization model with maximizing evaporation efficiency and minimizing molten salt consumption as optimization goals; performing iterative optimization based on the genetic algorithm optimization model until the iteration termination rule is triggered, and outputting the serial numbers of the heat exchangers involved in the heat exchange under the optimal evaporation state, as well as the series-parallel relationships of the heat exchangers involved in the heat exchange.

[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 participating states of the heat exchangers and the series-parallel relationship matrix of the participating heat exchangers; Among them, the heat exchanger participation state is expressed as:

[0013] in, is the participation state of the Nth heat exchanger, 0 means not participating in evaporation, and 1 means participating in evaporation; the determination rule of the series-parallel relationship matrix of the 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.

[0014] Optionally, the iterative optimization is performed based on the genetic algorithm optimization model until the iteration termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of the heat exchangers participating in the heat exchange are output, including: randomly generating a preset number of individuals with different chromosome structures to constitute an initial population, and calculating the fitness of each individual in the initial population respectively; determining the selection probability of each individual based on the fitness of each individual, so as to perform the corresponding genetic operation, obtain the offspring population, and perform the fitness calculation of the corresponding offspring population, so as to perform the next round of genetic operation 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 a consecutive preset number of times is less than the preset change value threshold, the iteration is stopped, and the individual with the optimal fitness is output; based on the chromosome structure of the individual with the optimal fitness, the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of the heat exchangers participating in the heat exchange are determined.

[0015] Optionally, the calculation rule of the fitness of the individual is: calculate the objective function of the genetic algorithm optimization model based on the current individual to obtain the objective function value; perform penalty on the objective function value based on constraint conditions to obtain the objective function value after penalty; perform normalization processing on the objective function value after penalty to obtain the fitness of the current individual.

[0016] Optionally, the objective function of the genetic algorithm optimization model is:

[0017] in, , represents the evaporation efficiency; is, which represents the consumption of molten salt; P is the set of heat exchangers; and are the evaporation efficiency and molten salt consumption of the i-th heat exchanger respectively.

[0018] Optionally, the rule for normalizing the penalized objective function value is:

[0019] in, is the fitness of the individual; is the objective function value after the current individual penalty; and are the minimum and maximum values ​​of the objective function of each individual after penalty.

[0020] Optionally, the genetic operation includes: crossover and / or mutation; the rule of crossover is: based on roulette wheel, two parent individuals are selected, and the chromosomes of the two parent individuals are randomly exchanged to obtain two offspring individuals; the rule of mutation is: based on roulette wheel, any individual is selected, and the state of any bit in the chromosome structure of the individual is flipped to obtain the corresponding offspring individual.

[0021] 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 serial numbers of the heat exchangers involved in the heat exchange and the series-parallel relationships of the heat exchangers involved in the heat exchange; if the current heat exchanger is not selected, the three-way valves at the head and tail of the current heat exchanger will all point to the valves of the three-way valve on the current heat exchanger side being closed; if the current heat exchanger is selected, the water inlet direction and the water outlet direction of the current heat exchanger are determined based on the series-parallel relationship determined by the current heat exchanger and the front and rear selected heat exchangers, and the switching scheme of the valves at each port of the current three-way valve is determined based on the determined water inlet direction and water outlet direction.

[0022] Optionally, the system further includes: a preheating module connected to the front end of the evaporator, for preheating the produced water and flowing the preheated produced water into the evaporator.

[0023] Optionally, the steam conversion device includes: a steam-water separation device connected to the evaporator output port, used to separate wet saturated steam into dry steam and saturated water; the dry steam is introduced into a superheater, and the superheater is used to convert dry steam into superheated dry steam; the superheated dry steam and saturated water are introduced into a mixer, and the mixer is used to mix the superheated dry steam and saturated water to obtain superheated steam for steam injection.

[0024] A second aspect of the present invention provides a control method for a cascade-heated superheated steam generation system, which is used for controlling the above-mentioned cascade-heated superheated steam generation system. The method comprises: taking maximizing evaporation efficiency and minimizing molten salt consumption as optimization objectives, constructing a corresponding genetic algorithm optimization model; performing iterative optimization based on the genetic algorithm optimization model until an iteration termination rule is triggered, and outputting the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state, as well as the series-parallel relationship of each heat exchanger participating in the heat exchange.

[0025] Optionally, the chromosome structure of the genetic algorithm optimization model includes a heat exchanger participation state and a series-parallel relationship matrix of the participating heat exchangers; wherein the heat exchanger participation state is expressed as:

[0026] in, is the participation state of the Nth heat exchanger, 0 means not participating in evaporation, and 1 means participating in evaporation; the determination rule of the series-parallel relationship matrix of the 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.

[0027] Optionally, the iterative optimization is performed based on the genetic algorithm optimization model until the iteration termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of the heat exchangers participating in the heat exchange are output, including: randomly generating a preset number of individuals with different chromosome structures to constitute an initial population, and calculating the fitness of each individual in the initial population respectively; determining the selection probability of each individual based on the fitness of each individual, so as to perform the corresponding genetic operation, obtain the offspring population, and perform the fitness calculation of the corresponding offspring population, so as to perform the next round of genetic operation 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 a consecutive preset number of times is less than the preset change value threshold, the iteration is stopped, and the individual with the optimal fitness is output; based on the chromosome structure of the individual with the optimal fitness, the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of the heat exchangers participating in the heat exchange are determined.

[0028] Optionally, the calculation rule of the fitness of the individual is: calculate the objective function of the genetic algorithm optimization model based on the current individual to obtain the objective function value; perform penalty on the objective function value based on constraint conditions to obtain the objective function value after penalty; perform normalization processing on the objective function value after penalty to obtain the fitness of the current individual.

[0029] Optionally, the objective function of the genetic algorithm optimization model is:

[0030] in, , represents the evaporation efficiency; is, which represents the consumption of molten salt; P is the set of heat exchangers; and are the evaporation efficiency and molten salt consumption of the i-th heat exchanger respectively.

[0031] On the other hand, the present invention provides a computer-readable storage medium having instructions stored thereon, which, when executed on a computer, enables the computer to execute the above-mentioned step-heating superheated steam generation system control method.

[0032] Through the above technical scheme, the scheme of the present invention significantly improves the flexibility and thermal energy utilization efficiency of the evaporation device by setting an evaporation device with multiple heat exchangers and dynamically adjusting the series-parallel relationship of each heat exchanger based on the real-time heating demand. By determining the number of heat exchangers involved in heat exchange and their connection methods in real time, it is possible to effectively avoid energy waste or insufficient heat exchange capacity caused by fluctuations in heating demand, thereby ensuring the efficiency and stability of the steam production process. In addition, the control device is connected to each heat exchanger in communication, realizing intelligent dynamic regulation, which not only optimizes the system's heat load distribution and extends the service life of the equipment, but also reduces operating costs. With the cooperation of the steam conversion device, this scheme can further convert wet saturated steam into superheated steam that meets the steam injection demand, thereby enhancing the steam quality and applicability. By efficiently transferring the heat source through the molten salt transmission device, the system can more stably realize energy input and conversion, adapt to complex heating demand scenarios, and thus provide an efficient, flexible and intelligent solution for heavy oil steam injection.

[0033] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 It is a system structure diagram of a step-heating superheated steam generating system provided by one embodiment of the present invention; Figure 2 It is a specific structural schematic diagram of a step-heating superheated steam generating system provided by one embodiment of the present invention; Figure 3 It is a flow chart of the steps of a step-heating superheated steam generation system control method provided by one embodiment of the present invention.

[0035] Description of Reference Numerals 1-Oilfield produced water supply pipeline; 2-Electrically heated solid heat storage preheater; 3-Preheated water pipeline; 4-Evaporator; 5-Wet steam pipeline; 6-Second hot salt pipeline; 7-Steam-water separator; 8-Separation 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 DESCRIPTION

[0036] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0037] Figure 1 1 is a system structure diagram of a step-heating superheated steam generation system provided by an embodiment of the present invention. Figure 1 As shown, an embodiment of the present invention provides a step-heating superheated steam generating system, the system comprising: an evaporation device provided with a plurality of heat exchangers, the evaporation device being used to process preheated produced water into wet saturated steam; wherein the series-parallel 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, being used to convert the wet saturated steam into superheated steam for steam injection; a control device communicatively connected to each heat exchanger, being used to determine the serial number of the heat exchanger involved in the heat exchange and the series-parallel relationship of each heat exchanger involved in the heat exchange based on real-time heating demand information; and a molten salt transmission device passing through the steam conversion device and the evaporation device in turn, being used to flow molten salt to provide a heat source to the steam conversion device and the evaporation device. Preferably, the evaporator is provided with two flow pipes, and each heat exchanger is arranged between the two flow pipes and connected to the flow pipes through a three-way valve.

[0038] Preferably, when the current heat exchanger participates in evaporation, the valves of the two ports connected to the heat exchanger corresponding to the two three-way valves at the head and tail of the heat exchanger are opened; when the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are connected in series, the overflow water output by the current evaporation heat exchanger passes through the three-way valve of the adjacent next heat exchanger participating in evaporation on the same side as the outlet end of the current evaporation heat exchanger and is merged into the adjacent next heat exchanger participating in evaporation; when the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are connected in parallel, the overflow water of the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are merged on the same side, and the overflow water after heat exchange between the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation is merged through the three-way valve on the other side.

[0039] In the embodiment of the present invention, two three-way valves are installed at the head and tail of each heat exchanger, and are respectively connected to the inlet and outlet ends of the heat exchanger and the two flow pipes. When the front heat exchanger participates in evaporation, the relevant ports of the two three-way valves connected to it are opened, allowing the fluid to enter the heat exchanger and complete the heat exchange process through it. The three-way valve of the heat exchanger that does not participate in evaporation remains closed, isolating the heat exchanger to avoid unnecessary energy loss.

[0040] Furthermore, when two adjacent heat exchangers participating in evaporation are in a series relationship, the output port of the upper heat exchanger is directly connected to the input port of the lower heat exchanger through a three-way valve. The fluid passes through each heat exchanger in turn, thereby gradually improving the thermal energy utilization rate, which is suitable for operating conditions with low flow and high heat exchange requirements. The advantage of this mode is that it can gradually increase the temperature of the fluid or the steam quality and reduce the heat loss between the heat exchangers. When two adjacent heat exchangers participating in evaporation are in a parallel relationship, the inlets and outlets of the two heat exchangers are respectively merged into two flow pipes through three-way valves. After the fluid is distributed to each heat exchanger and completes the heat exchange in parallel, it is merged through the three-way valve on the other side. The parallel mode is suitable for working conditions with high flow and low heat exchange requirements, which can improve the heat exchange efficiency and reduce the total pressure drop of the system.

[0041] Furthermore, the participation status and series-parallel relationship of the heat exchanger are adjusted in real time based on the heating demand. The control system dynamically calculates the best combination of heat exchangers and optimizes the operating efficiency of the evaporator by monitoring key parameters such as flow, temperature, and pressure. Through flexible series-parallel configuration, the system can select the optimal heat exchange path according to real-time needs, maximize the thermal energy of the heat transfer medium, and avoid unnecessary energy loss. The step-by-step heating in the series mode can significantly improve the quality of steam, which is especially suitable for high-quality steam production needs; while the diversion operation in the parallel mode can improve the system processing capacity and adapt to high-flow scenarios.

[0042] In the series mode, the fluid passes through multiple heat exchangers in sequence, and each heat exchanger gradually heats the fluid, and the outlet fluid temperature is significantly increased. The thermal energy utilization is relatively concentrated, which is suitable for the need to heat the fluid in multiple stages. It is suitable for the production of high-temperature and high-pressure superheated steam (such as working conditions with high outlet steam dryness requirements). And when the flow rate is small, the heat exchange time of the fluid in each heat exchanger is longer, and the heat energy can be absorbed more fully. However, in the series mode, the fluid needs to flow through each heat exchanger step by step, the system pressure drop is large, and the flow rate is limited. The failure of a single heat exchanger will interrupt the entire series heat exchange path, and the reliability is low.

[0043] In parallel mode, the fluid is divided into multiple heat exchangers at the same time, each heat exchanger completes heating in parallel, and the outlet fluid converges at the end of the parallel path. The heat exchanger processing capacity is evenly distributed, and the fluid temperature rise is small. It is suitable for scenarios with high flow requirements but relatively low temperature rise or quality requirements. It is suitable for conditions that meet multi-point heating needs or quickly increase evaporation capacity. However, the parallel mode has low thermal energy utilization efficiency and limited improvement in the quality of the outlet fluid. It requires a high number of heat exchangers, and the initial investment cost may increase.

[0044] Based on this, 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 enable multiple heat exchangers at the same time to improve the flow handling capacity and quickly meet the large flow demand. When the heating demand is low and the outlet steam quality is required to be high, the series mode fully utilizes the thermal energy through step-by-step heating to increase the outlet steam temperature and dryness.

[0045] The water inlet direction of the heat exchanger provided in the solution of the present invention can be modified, so as to adjust the series-parallel relationship between the heat exchangers, so as to achieve adaptive state adjustment in various scenarios.

[0046] Preferably, the determining the serial numbers of the heat exchangers involved in the heat exchange and the series-parallel relationships of the heat exchangers involved in the heat exchange based on the real-time heating demand information includes: constructing a corresponding genetic algorithm optimization model with maximizing evaporation efficiency and minimizing molten salt consumption as optimization objectives; performing iterative optimization based on the genetic algorithm optimization model until an iteration termination rule is triggered, and outputting the serial numbers of the heat exchangers involved in the heat exchange and the series-parallel relationships of the heat exchangers involved in the heat exchange under the optimal evaporation state.

[0047] In the embodiment of the present invention, the genetic algorithm is an optimization method that simulates the mechanism of natural selection and genetic evolution, and is suitable for solving complex multi-objective problems. In this system, the genetic algorithm is used to dynamically optimize the operating configuration of the heat exchanger. The optimization process uses the participation state and connection mode of the heat exchanger as the core variables, and generates a variety of heat exchanger combination schemes based on system operation data, such as heating demand, temperature, pressure and flow. Through multiple iterative screening, the heat exchanger configuration that can achieve the best evaporation efficiency and the lowest energy consumption under the current working conditions is finally selected.

[0048] Furthermore, the optimization process starts with initialization, and first generates multiple heat exchanger configuration schemes. Each scheme includes which heat exchangers are involved in the operation and how they are connected. Then, the system evaluates each scheme based on its performance under the current operating conditions to determine its pros and cons in terms of steam production efficiency and molten salt energy consumption. By inheriting, improving and mutating the preferred scheme, the genetic algorithm gradually optimizes the number of heat exchangers involved and the connection relationship, and finally outputs the optimal configuration. The dynamic optimization mechanism ensures that the system can adjust the operating mode according to the real-time changing heating demand. During peak heating demand, the system will automatically select more heat exchangers to participate in the operation, and configure them in parallel mode as needed to meet large flow requirements. When the heating demand is low, the system will reduce the number of heat exchangers in operation and tend to adopt a series mode to improve the quality of the outlet steam.

[0049] Furthermore, the dynamic control of the heat exchanger is performed by a control system combined with a genetic algorithm. The system regularly collects data such as temperature, pressure, flow rate, etc. at the inlet and outlet of the evaporator, and recalculates the participation status and connection mode of the heat exchanger based on this real-time information. The start and stop and series-parallel switching of the heat exchanger are achieved through intelligent valves, and all controls are directed by the central system to ensure that the system can continue to operate with the optimal configuration.

[0050] The reason why the scheme of the present invention needs to determine the serial number of the heat exchanger involved in the heat exchange is that the configuration and operating status of the heat exchanger directly affect the efficiency, reliability and service life of the system. Therefore, determining which heat exchangers are involved in the operation (i.e., the serial number of the heat exchanger) and dynamically adjusting their status is the key to optimizing system performance. If some heat exchangers are running at high load for a long time, while other heat exchangers are idle or at low load, the heat exchangers running at high load will age prematurely, increasing the maintenance frequency and replacement cost. By dynamically determining the serial number of the heat exchanger, the heat exchanger can be used in turn in different heat exchange cycles, evenly distributing the heat load and extending the service life of the overall system. This approach not only reduces the maintenance cost of the equipment, but also improves the long-term operating reliability of the system.

[0051] Furthermore, due to differences in pipeline length and pipeline layout, the distance between the heat exchanger and the heat source or outlet will vary. A heat exchanger farther away may have reduced heat exchange efficiency due to pipeline heat loss, and may even cause energy waste in actual operation. When determining the sequence number of the heat exchanger, it is necessary to give priority to heat exchangers that are closer to the heat source and more efficient to maximize the overall thermal energy utilization of the system. At the same time, the operating time of the remote heat exchanger can be reasonably arranged according to the current working conditions to reduce the heat energy waste caused by the length of the pipeline.

[0052] Based on this, the heating demand in the system may be locally concentrated. For example, some specific heat exchangers bear higher heat loads due to their location or fluid characteristics, which can cause local overheating or overload of the heat exchanger. By determining the sequence number of the heat exchanger and adjusting it dynamically, the distribution of the heat load can be optimized, the overload problem of local heat exchangers can be avoided, and the overall operating efficiency can be improved. This adjustment method can also effectively reduce the risk of scaling in the heat exchanger and maintain the long-term stable operation of the system.

[0053] Furthermore, the operating efficiency of each heat exchanger may be affected by temperature gradient, flow distribution and equipment performance differences. If the heat exchangers are not selected for operation in a targeted manner, high-efficiency heat exchangers may not be fully utilized, and low-efficiency heat exchangers may participate in the operation, resulting in a decrease in overall performance. Dynamically determining the sequence number of the heat exchangers involved in the operation helps to give priority to the use of high-efficiency heat exchangers, thereby improving the heat exchange efficiency of the overall system. This selection can also optimize the combination of heat exchangers based on operating data to maximize energy saving and consumption reduction.

[0054] Furthermore, a multi-heat exchanger system usually includes a certain redundancy design to cope with equipment failure or maintenance needs. If the heat exchanger serial number is not adjusted dynamically, the redundant heat exchanger may be idle for a long time, and the system cannot quickly switch to the backup device when a sudden failure occurs during operation. When determining the heat exchanger serial number, the operation time of the redundant heat exchanger can be reasonably arranged to avoid its long-term idleness and performance degradation. At the same time, when the existing heat exchanger fails or is under maintenance, the backup heat exchanger can be quickly called to ensure the continuity and reliability of the system operation.

[0055] Furthermore, the heating demand is dynamic, and there may be peak and valley periods. If the participation status of the heat exchanger is fixed, the heating capacity may not be able to meet the peak demand or energy waste during low demand. By dynamically determining the sequence number of the heat exchanger, the number of heat exchangers participating in the operation can be selected according to the real-time heating demand, which can not only meet the peak demand, but also reduce unnecessary participation of heat exchangers during valley periods, thereby reducing the energy consumption of system operation.

[0056] 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; the load of the evaporator is less than the maximum design load.

[0057] 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 expressed as:

[0058] in, is the participation state of the Nth heat exchanger, 0 means not participating in evaporation, and 1 means participating in evaporation; the determination rule of the series-parallel relationship matrix of the 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.

[0059] In the embodiment of the present invention, in the evaporator optimization model based on genetic algorithm, several optimization constraints are set to ensure that the system can operate in the most efficient and stable manner. These conditions include: the wet saturated steam and steam dryness at the evaporator outlet must be greater than the preset critical value to ensure that the steam quality meets the steam injection requirements; the total pressure drop of the system must be less than the preset upper limit value to reduce the energy loss and pipeline load in fluid transmission; in addition, the operating load of each heat exchanger involved in evaporation must not exceed its maximum design load to ensure the reliability and life of the equipment operation.

[0060] In the specific genetic algorithm optimization model, the chromosome structure is designed to include the participation status of the heat exchanger and the connection relationship between the participating heat exchangers. The participation status of the heat exchanger is represented in binary form, and each heat exchanger corresponds to a state value. A state value of 1 indicates that the heat exchanger participates in the evaporation work, while a state value of 0 indicates that it does not participate in the evaporation work. In addition, in order to describe the connection mode between the participating heat exchangers, the model also adopts the matrix representation rule of series-parallel relationship. If the connection between two adjacent heat exchangers is in series, the corresponding value in the matrix is ​​marked as 1; if it is in parallel, it is marked as 0. This design can clearly express the operating configuration status of the entire system and provide a basis for the optimization process of the genetic algorithm.

[0061] By iteratively optimizing the participation status and connection relationship of the heat exchangers through genetic algorithms, the model can find the optimal evaporator configuration solution under the current operating conditions. For example, when higher steam quality is required, the algorithm will give priority to more heat exchangers and work in series; when a larger flow rate needs to be processed, more heat exchangers may be selected to operate in parallel to improve the overall processing capacity.

[0062] Preferably, the iterative optimization is performed based on the genetic algorithm optimization model until the iterative termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are output, including: randomly generating a preset number of individuals with different chromosome structures to constitute an initial population, and calculating the fitness of each individual in the initial population respectively; determining the selection probability of each individual based on the fitness of each individual, so as to perform the corresponding genetic operation, obtain the offspring population, and perform the fitness calculation of the corresponding offspring population, so as to perform the next round of genetic operation 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 a consecutive preset number of times is less than the preset change value threshold, the iteration is stopped, and the individual with the optimal fitness is output; based on the chromosome structure of the individual with the optimal fitness, the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are determined.

[0063] In the embodiment of the present invention, in the evaporation system based on the genetic algorithm optimization model, dynamically adjusting the sequence number of the heat exchangers involved in heat exchange and the series-parallel relationship of the heat exchangers is the core of achieving efficient operation of the system. To this end, through the iterative optimization of the genetic algorithm, it is possible to intelligently find the optimal evaporation configuration under the current working conditions to ensure that the system reaches the best state in terms of energy utilization and operating efficiency. Specifically, the following rules are included: 1) Generation of the initial population: The optimization process starts with randomly generating the initial population. Each individual in the population represents an operating configuration of a heat exchanger, including which heat exchangers are involved in the operation and their series and parallel relationships. The structure of each individual (i.e., chromosome) represents the state and connection mode of the heat exchanger in an encoded manner. By randomly generating multiple individuals, the initial population can cover the widest possible configuration space, laying the foundation for subsequent optimization.

[0064] 2) Fitness calculation: For each individual in the initial population, calculate its fitness. Fitness is a key indicator to measure the quality of an individual, and is usually determined by objectives such as system operation efficiency and resource consumption. For example, a high-fitness individual corresponds to a configuration that maximizes evaporation efficiency and minimizes energy consumption. Fitness calculation can provide guidance for genetic operations and give priority to retaining better individuals.

[0065] 3) Selection operation: Based on the fitness of each individual, determine its probability of being selected. The higher the fitness of the individual, the greater the probability of being selected. This selection mechanism imitates the survival of the fittest in natural selection, which can retain the configuration with better performance to the next generation, while eliminating individuals with lower fitness.

[0066] 4) Genetic operation: Genetic operation includes two main steps: crossover and mutation. The crossover operation generates new offspring individuals by combining the chromosome structures of two parent individuals, thereby exploring more configuration possibilities. The mutation operation randomly modifies some genes of individuals, such as changing the participation status of certain heat exchangers or adjusting the series-parallel relationship of heat exchangers. Through genetic operations, the population can continue to evolve and gradually approach the optimal configuration.

[0067] 5) Calculation of fitness of offspring population: Recalculate the fitness of offspring population generated by genetic operation to ensure that the next round of genetic operation can continue to optimize the population structure. As the iteration proceeds, the overall fitness of the population continues to improve, which is reflected in the improvement of system operation efficiency and the reduction of energy consumption.

[0068] 6) Iteration termination rule: The termination conditions of the optimization process include two situations: one is that the preset maximum number of iterations is reached; the other is that the optimal fitness value changes below the preset threshold in multiple consecutive iterations. This design ensures that the algorithm can find a solution close to the global optimal solution within sufficient computing time while avoiding meaningless excessive iterations.

[0069] 7) Output the optimal configuration: After the optimization is completed, the individual with the highest fitness is output. Based on the chromosome structure of the individual, the optimal heat exchanger sequence number and its series-parallel relationship can be determined to achieve the best evaporation state under the current working conditions.

[0070] Preferably, the calculation rule of the individual's fitness is: calculate the objective function of the genetic algorithm optimization model based on the current individual to obtain the objective function value; perform penalty on the objective function value based on the constraint condition to obtain the objective function value after penalty; perform normalization processing on the objective function value after penalty to obtain the fitness of the current individual.

[0071] In the embodiment of the present invention, in the genetic algorithm, the fitness of an individual is a key indicator to measure its quality, which directly affects the execution of subsequent selection, crossover and mutation operations. In order to accurately evaluate the quality of an individual, a fitness calculation method based on an objective function and constraints is adopted. This method ensures that the fitness can fully reflect the quality of an individual and effectively guide the optimization process by calculating, penalizing and normalizing the objective function value.

[0072] First, the objective function value of the genetic algorithm optimization model is calculated for each individual running configuration. The objective function value is the core indicator to measure the performance of the current configuration, which is usually obtained by combining multiple optimization goals (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 the system constraints, the result may not be completely reasonable.

[0073] In order to ensure that the individual configuration scheme meets the constraints of system operation, the objective function value is penalized. Penalty processing is a negative evaluation mechanism for individuals that violate constraints. For example, when the steam quality is lower than the set value or the equipment load exceeds the design upper limit, the individual will be penalized by reducing the objective function value. This processing method effectively prevents configurations that do not meet actual operating requirements from entering the next generation of populations, thereby improving the efficiency and practicality of the optimization process.

[0074] Finally, in order to facilitate the comparison and operation of fitness values, the penalized objective function value is normalized. The normalized fitness value is limited to a unified range, which is convenient for direct use in genetic operations. At the same time, the normalization process can also improve the convergence of the algorithm and ensure that the optimization can quickly find the optimal solution.

[0075] Specifically, the objective function of the genetic algorithm optimization model is:

[0076] in, , represents the evaporation efficiency; is, which represents the consumption of molten salt; P is the set of heat exchangers; and are the evaporation efficiency and molten salt consumption of the i-th heat exchanger respectively.

[0077] Specifically, the rule for normalizing the objective function value after penalty is:

[0078] in, is the fitness of the individual; is the objective function value after the current individual penalty; and are the minimum and maximum values ​​of the objective function of each individual after penalty.

[0079] Specifically, the genetic operation includes: crossover and / or mutation; the rule of crossover is: based on roulette, two parent individuals are selected, and the chromosomes of the two parent individuals are randomly exchanged to obtain two offspring individuals; the rule of mutation is: based on roulette, any individual is selected, and the state of any bit in the chromosome structure of the individual is flipped to obtain the corresponding offspring individual.

[0080] 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 serial number of the heat exchanger involved in the heat exchange and the series-parallel relationship of the heat exchangers involved in the heat exchange; if the current heat exchanger is not selected, the three-way valves at the head and tail of the current heat exchanger will all point to the valves of the three-way valve on the current heat exchanger side to be closed; if the current heat exchanger is selected, the water inlet direction and the water outlet direction of the current heat exchanger are determined based on the series-parallel relationship determined by the current heat exchanger and the front and rear selected heat exchangers, and the switching scheme of the valves at each port of the current three-way valve is determined based on the determined water inlet direction and water outlet direction.

[0081] In an embodiment of the present invention, for the heat exchangers that are not selected to participate in the work in the current optimization results, the control module will close the three-way valves at both ends of the heat exchanger. The closing operation of the three-way valve isolates the fluid in the flow pipe to prevent the fluid from entering the heat exchanger, thereby reducing invalid energy consumption and system pressure loss. By isolating the unselected heat exchangers, the operating efficiency of the system can be ensured, while unnecessary equipment loads can be reduced, and the heat exchanger can be effectively protected from long-term impacts of high pressure and high temperature. For the heat exchangers selected to participate in the work in the optimization results, the control module will generate a water inlet and outlet direction plan based on its connection relationship with the front and rear heat exchangers. The water inlet and outlet directions of the heat exchanger are determined by the series-parallel relationship in the optimization results: 1) Series relationship: The outlet fluid of the current heat exchanger directly enters the water 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.

[0082] 2) Parallel relationship: The inlet and outlet fluids of the current heat exchanger are respectively merged into the flow pipe, mixed with the fluids of other parallel heat exchangers and transported uniformly. The control module points the inlet and outlet valves of the current heat exchanger to the flow pipe respectively to achieve fluid diversion and confluence.

[0083] The water inlet and outlet of each heat exchanger are connected to two flow pipes through a three-way valve. The control module generates specific control instructions for each three-way valve, including the switch status of each port, based on the current operating status and connection relationship of the heat exchanger. For heat exchangers in series mode, the control module ensures that the fluid enters and flows out in the predetermined direction; for heat exchangers in parallel mode, the control module ensures that the fluid can be effectively divided and merged. Regardless of the mode, the control module will dynamically adjust the status of the three-way valve based on real-time operating data to ensure the flexibility and efficiency of system operation.

[0084] 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 working conditions. For example, when high steam quality is required, the system can select more heat exchangers to work in series to increase the temperature and dryness of the outlet steam; when high flow is required, more heat exchangers can be selected to work in parallel to quickly improve processing capacity. In addition, the dynamic adjustment of the three-way valve enables the system to operate stably when some heat exchangers fail or need maintenance, and has a high fault tolerance.

[0085] Preferably, the system further comprises: a preheating module connected to the front end of the evaporator, for preheating the produced water and flowing the preheated produced water into the evaporator.

[0086] Preferably, the steam conversion device includes: a steam-water separation device connected to the output port of the evaporator, used to separate the wet saturated steam into dry steam and saturated water; the dry steam is introduced into a superheater, and the superheater is used to convert the dry steam into superheated dry steam; the superheated dry steam and saturated water are introduced into a mixer, and the mixer is used to mix the superheated dry steam and saturated water to obtain superheated steam for steam injection.

[0087] In an embodiment of the present invention, a preheating module is configured at the front end of the evaporator to preheat the produced water. The temperature of produced water is usually low, and directly entering the evaporator may cause a decrease in heat exchange efficiency and increase the load of the evaporator. Through the processing of the preheating module, the temperature of the produced water is raised to a level close to the saturation temperature, which can not only reduce the heat load of the evaporator, but also significantly improve the heat exchange efficiency of the evaporator. In addition, the preheating module can use recycled waste heat or low-quality heat sources for heating, thereby further reducing the energy consumption of the system. This design ensures that the produced water enters the evaporator at a higher temperature, thereby accelerating the evaporation process and improving the overall efficiency of the system.

[0088] Furthermore, the steam conversion device includes a steam-water separator, a superheater and a mixer, which are responsible for the separation of wet saturated steam, the superheating of dry steam and the modulation of superheated steam. This modular design enables the system to flexibly adjust the steam quality to meet different steam injection requirements. Specifically, it includes: 1) Steam-water separation device: Wet saturated steam enters the steam-water separation device from the evaporator outlet, and the device separates it into dry steam and saturated water. Dry steam has a higher steam quality (close to 100% dryness), while saturated water can re-enter the system as a water source for mixing or other purposes. The steam-water separation process can ensure the heat exchange efficiency in the subsequent superheating process, while reducing the possible impact of wet steam on the superheater heat exchange surface.

[0089] 2) Superheater: Dry steam enters the superheater from the steam-water separation device and is further heated into high-temperature and high-pressure superheated dry steam. The superheater uses high-temperature molten salt or other heat sources to provide heat to ensure that the temperature and quality of the dry steam meet the standards required by the steam injection well. Superheated dry steam has higher heat content and transmission efficiency, and is suitable for application scenarios with high requirements for steam quality, such as heavy oil steam injection.

[0090] 3) Blender: Superheated dry steam and saturated water are remixed in the blender to adjust the final steam superheat. This design allows the quality of steam to be flexibly adjusted according to the steam injection requirements, such as 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 role of the blender is to accurately control the steam parameters so that the output superheated steam fully meets the steam injection requirements.

[0091] In a possible implementation, Figure 2 , provides a specific structure of a step-heating superheated steam generating system, which is exemplified in a series state, including a produced water feed pipeline 1, an electrically heated solid heat 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 separation 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, a cold salt pipeline 15, etc.

[0092] In combination with the embodiment, the working principles and processes of each part of the system are specifically as follows.

[0093] 1. The main equipment of the invention is composed of an electrically heated solid heat storage preheater 2, an evaporator 4, a steam-water separator 7, a superheater 10 and a blender 12; 2. The produced water from the oilfield is connected to the electrically heated solid thermal storage preheater 2 through the produced water supply pipeline 1. The produced water from the oilfield is heated in the electrically heated solid thermal storage preheater 2 and then connected to the evaporator 4 through the preheating water pipeline 3. Taking the use of binary molten salt as an example, the freezing point of the binary molten salt is 220°C, the produced water supply temperature of the oilfield is 40-70°C, and the preheating water temperature is 230-250°C. The silicon content of the produced water from the oilfield can be <250mg / L. The electrically heated solid thermal storage 2 can use solid magnesium bricks as the thermal storage medium, use green electricity to heat the solid magnesium bricks, and continuously take heat from the solid magnesium bricks to heat the produced water from the oilfield.

[0094] 3. The evaporator 4 can be composed of one or more heat exchangers connected in series or in parallel; if the need for intermediate regulation is not considered, the evaporator can be equipped with only one heat exchanger; if the need for intermediate regulation is considered, the evaporator can be equipped with two or more heat exchangers; 4. The produced water from the oil field is heated by molten salt in the evaporator 4 to become wet saturated steam, and the wet saturated steam is connected to the steam-water separator 7 through the wet steam pipeline 5; the parameters of the wet saturated steam produced by the evaporator 4 can be 8MPa, 295℃, and 75% dryness; the wet steam dryness shall not exceed 75%, otherwise it will cause rapid scaling of the heat exchange surface of the evaporator 4, affecting the heat exchange effect.

[0095] 5. The wet saturated steam connected to the steam-water separator 7, part of which becomes dry steam, and the other part becomes saturated water; 6. A part of the wet saturated steam connected to the steam-water separator 7 becomes dry steam, and the other part is called saturated water; the dry steam parameters can be 99%-100% dryness, with dry steam accounting for 75% of the mass and saturated water accounting for 25% of the mass; 7. The saturated water separated from the steam-water separator 7 is connected to the blender 12 via the separation water pipeline 8; 8. The dry steam separated from the steam-water separator 7 is connected to the superheater 10 through the dry steam pipeline 9. In the superheater 10, the dry steam is heated by the high-temperature molten salt to become highly superheated superheated steam; the highly superheated superheated steam may have a superheat of 135°C; 9. The highly superheated steam generated in the superheater 10 is connected to the mixer 12 via the first superheated steam pipeline 11; 10. In the mixer 12, the high superheated steam and saturated water are mixed to become low superheated steam, which is then transported to the steam injection well through the second superheated steam pipeline 13; the superheat of the low superheated steam can be 15-20°C; 11. Molten salt is used as the heat source medium of the system. The high-temperature molten salt is connected to the superheater 10 through the first hot salt pipeline 14 to heat the dry steam into highly superheated superheated steam, and then connected to the evaporator 2 through the second hot salt pipeline 6 to heat the preheated water into wet saturated steam, and then discharged from the system through the cold salt pipeline 15. Taking binary molten salt as an example, the temperature of the high-temperature molten salt can be 560°C, and the temperature of the low-temperature molten salt after heat exchange can be 285°C.

[0096] Figure 3 1 is a flow chart of a method for controlling a step-heating superheated steam generation system provided by an embodiment of the present invention. Figure 3 As shown, an embodiment of the present invention provides a control method for a step-heating superheated steam generation system, the method comprising: Step S10: Taking maximizing evaporation efficiency and minimizing molten salt consumption as optimization objectives, a corresponding genetic algorithm optimization model is constructed.

[0097] Step S20: performing iterative optimization based on the genetic algorithm optimization model until the iteration termination rule is triggered, and outputting the sequence number of the heat exchanger participating in the heat exchange under the optimal evaporation state, and the series-parallel relationship of each heat exchanger participating in the heat exchange.

[0098] 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 expressed as:

[0099] in, is the participation state of the Nth heat exchanger, 0 means not participating in evaporation, and 1 means participating in evaporation; the determination rule of the series-parallel relationship matrix of the 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.

[0100] Preferably, the iterative optimization is performed based on the genetic algorithm optimization model until the iterative termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are output, including: randomly generating a preset number of individuals with different chromosome structures to constitute an initial population, and calculating the fitness of each individual in the initial population respectively; determining the selection probability of each individual based on the fitness of each individual, so as to perform the corresponding genetic operation, obtain the offspring population, and perform the fitness calculation of the corresponding offspring population, so as to perform the next round of genetic operation 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 a consecutive preset number of times is less than the preset change value threshold, the iteration is stopped, and the individual with the optimal fitness is output; based on the chromosome structure of the individual with the optimal fitness, the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are determined.

[0101] Preferably, the calculation rule of the individual's fitness is: calculate the objective function of the genetic algorithm optimization model based on the current individual to obtain the objective function value; perform penalty on the objective function value based on the constraint condition to obtain the objective function value after penalty; perform normalization processing on the objective function value after penalty to obtain the fitness of the current individual.

[0102] Preferably, the objective function of the genetic algorithm optimization model is:

[0103] in, , represents the evaporation efficiency; is, which represents the consumption of molten salt; P is the set of heat exchangers; and are the evaporation efficiency and molten salt consumption of the i-th heat exchanger respectively.

[0104] The embodiment of the present invention further provides a computer-readable storage medium, on which instructions are stored, which, when executed on a computer, enable the computer to execute the above-mentioned step-heating superheated steam generation system control method.

[0105] Those skilled in the art will understand that all or part of the steps in the method for implementing the above-mentioned embodiments can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions for making a single-chip microcomputer, a chip or a processor execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0106] The optional embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, the technical scheme of the embodiments of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to 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. In order to avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0107] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A step-heating superheated steam generation system, characterized in that: The system comprises: An evaporation device is provided with multiple heat exchangers, and the evaporation device is used to process the preheated produced water into wet saturated steam; wherein, The series-parallel 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 for converting the wet saturated steam into superheated steam for steam injection; A control device in communication with each heat exchanger, used to determine the serial number of the heat exchanger involved in the heat exchange and the series-parallel relationship of each heat exchanger involved in the heat exchange based on real-time heat demand information; The molten salt transmission device sequentially passes through the steam conversion device and the evaporation device, and is used to flow the molten salt that provides a heat source to the steam conversion device and the evaporation device.

2. The system according to claim 1, characterized in that The evaporator is provided with two flow pipes, and each heat exchanger is arranged 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 front heat exchanger participates in evaporation, the valves of the two three-way valves corresponding to the two ports connected to the heat exchanger at the head and tail of the heat exchanger are opened; When the current evaporation heat exchanger and the next adjacent evaporation heat exchanger are connected in series, the overflow water output by the current evaporation heat exchanger flows into the next adjacent evaporation heat exchanger through the three-way valve of the next adjacent evaporation heat exchanger on the same side as the outlet end of the current evaporation heat exchanger; When the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are connected in parallel, the overflow water of the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation are merged on the same side, and the overflow water of the current heat exchanger participating in evaporation and the adjacent next heat exchanger participating in evaporation after heat exchange is merged through the three-way valve on the other side.

4. The system according to claim 1, characterized in that The determining of the sequence number of the heat exchanger involved in the heat exchange and the series-parallel relationship of the heat exchangers involved in the heat exchange based on the real-time heat demand information includes: Taking maximizing evaporation efficiency and minimizing molten salt consumption as the optimization objectives, a corresponding genetic algorithm optimization model is constructed; Iterative optimization is performed based on the genetic algorithm optimization model until the iteration termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the 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 a preset dryness threshold; The total pressure drop of the evaporator is less than the preset pressure drop threshold; The load on the evaporator 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 participating states of the heat exchangers and the series-parallel relationship matrix of the participating heat exchangers; Among them, the heat exchanger participation state is expressed as: in, is the participation status of the Nth heat exchanger, 0 means not participating in evaporation, 1 means participating in evaporation; The determination rule of the series-parallel relationship matrix of the heat exchangers involved is that if the relationship between the current heat exchanger involved in evaporation and the next adjacent heat exchanger involved in evaporation is in series, it is represented as 1, and if it is in parallel, it is represented as 0.

7. The system according to claim 6, characterized in that The iterative optimization is performed based on the genetic algorithm optimization model until the iterative termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are output, including: Randomly generate a preset number of individuals with different chromosome structures to form an initial population, and calculate the fitness of each individual in the initial population; Based on the fitness of each individual, the probability of selection of the corresponding individual is determined to perform the corresponding genetic operation, obtain the offspring population, and perform the fitness calculation of the corresponding offspring population, so as to perform the next round of genetic operation based on the fitness of the offspring population, until a preset number of iterations is reached, or the change value of the optimal fitness for a consecutive preset number of times is less than a preset change value threshold, the iteration is stopped, and the individual with the optimal fitness is output; Based on the chromosome structure of the individual with the best fitness, the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are determined.

8. The system according to claim 7, characterized in that The calculation rule of the individual's fitness is: Calculate the objective function of the genetic algorithm optimization model based on the current individual and obtain the objective function value; Penalizing the objective function value based on the constraint condition to obtain a penalized objective function value; The objective function value after penalty is normalized 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, , represents the evaporation efficiency; is, which represents the molten salt consumption; P is the heat exchanger set; and 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 objective function value after penalty is: in, is the fitness of the individual; is the objective function value after the current individual penalty; and are the minimum and maximum values ​​of the objective function of each individual after penalty.

11. The system according to claim 7, characterized in that The genetic manipulation comprises: Crossover and / or mutation; The rules for crossover are: Select two parent individuals based on roulette, and perform random position exchange on the chromosomes of the two parent individuals to obtain two offspring individuals; The mutation rules are: Based on the roulette wheel, any individual is selected and the state of any bit in the chromosome structure of the individual is flipped to obtain the corresponding offspring individual.

12. The system according to claim 1, characterized in that The control module is configured to: Based on the determined serial numbers of the heat exchangers involved in the heat exchange and the series-parallel relationship of the heat exchangers involved in the heat exchange, a valve control scheme for the three-way valves connected to the heat exchangers is generated; If the current heat exchanger is not selected, the three-way valves at the head and tail of the current heat exchanger will all point to the three-way valve on the current heat exchanger side and close; If the current heat exchanger is selected, the water inlet and outlet directions of the current heat exchanger are determined based on the series-parallel relationship between the current heat exchanger and the previously selected heat exchangers, and the switching scheme of the valves at each port of the current three-way valve is determined based on the determined water inlet and outlet directions.

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

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

15. A control method for a step-heating superheated steam generation system, characterized in that: The method is used for controlling the step-heating superheated steam generation system according to any one of claims 1 to 14, and the method comprises: Taking maximizing evaporation efficiency and minimizing molten salt consumption as the optimization objectives, a corresponding genetic algorithm optimization model is constructed; Iterative optimization is performed based on the genetic algorithm optimization model until the iteration termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the 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 participating states of the heat exchangers and the series-parallel relationship matrix of the participating heat exchangers; Among them, the heat exchanger participation state is expressed as: in, is the participation status of the Nth heat exchanger, 0 means not participating in evaporation, 1 means participating in evaporation; The determination rule of the series-parallel relationship matrix of the heat exchangers involved is that if the relationship between the current heat exchanger involved in evaporation and the next adjacent heat exchanger involved in evaporation is in series, it is represented as 1, and if it is in parallel, it is represented as 0.

17. The method according to claim 16, characterized in that The iterative optimization is performed based on the genetic algorithm optimization model until the iterative termination rule is triggered, and the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are output, including: Randomly generate a preset number of individuals with different chromosome structures to form an initial population, and calculate the fitness of each individual in the initial population; Based on the fitness of each individual, the probability of selection of the corresponding individual is determined to perform the corresponding genetic operation, obtain the offspring population, and perform the fitness calculation of the corresponding offspring population, so as to perform the next round of genetic operation based on the fitness of the offspring population, until a preset number of iterations is reached, or the change value of the optimal fitness for a consecutive preset number of times is less than a preset change value threshold, the iteration is stopped, and the individual with the optimal fitness is output; Based on the chromosome structure of the individual with the best fitness, the serial number of the heat exchanger participating in the heat exchange under the optimal evaporation state and the series-parallel relationship of each heat exchanger participating in the heat exchange are determined.

18. The method according to claim 17, characterized in that The calculation rule of the individual's fitness is: Calculate the objective function of the genetic algorithm optimization model based on the current individual and obtain the objective function value; Penalizing the objective function value based on the constraint condition to obtain a penalized objective function value; The objective function value after penalty is normalized 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, , represents the evaporation efficiency; is, which represents the molten salt consumption; P is the heat exchanger set; and 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, which, when executed on a computer, enable the computer to execute the step-heating superheated steam generation system control method described in any one of claims 1-14.

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