Operation control method and device for direct current furnace unit

Abstract

The invention discloses an operation control method and device for a direct current furnace unit, relates to the technical field of electric power, and mainly aims to improve the operation control safety of the direct current furnace unit. According to the main technical scheme, the method comprises the steps that a target load instruction, a current main steam pressure set value, a main steam pressure actual value, a main steam temperature actual value sequence and a unit actual load sequence are obtained; when it is determined that the unit is in the dry-wet state conversion stage based on the actual load sequence of the unit, the newest power limiting rate is calculated based on the characteristics of the conversion stage and the deviation between the main steam pressure set value and the main steam pressure actual value; calculating a newest transition load instruction value of the next control period according to the newest power limiting rate and the target load instruction; generating a main steam pressure set value of the next control period based on the latest transition load instruction value and the main steam temperature actual value sequence; and according to the newest transition load instruction value, the main steam pressure set value and the combustion characteristic parameters, the running state of the direct current furnace unit is adjusted.

Description

Technical Field

[0001] The present invention relates to the field of power technology, and in particular, to an operation control method and device for a once-through boiler unit. Background Art

[0002] A once-through boiler unit is a form of thermal power generation, which realizes power production by converting thermal energy into electrical energy. The whole process is automatically managed by a coordinated control system. Specifically, when the coordinated control system receives a load instruction issued by the power grid dispatching system, it will set a corresponding main steam pressure set value according to this instruction, and regulate the operation control of the once-through boiler unit according to the main steam pressure set value and the target load instruction. In order to avoid damage to the equipment caused by rapid adjustment, the coordinated control system gradually adjusts the working state of the once-through boiler unit according to a preset power limit rate to smoothly reach the target load required by the power grid dispatching system, rather than making abrupt changes.

[0003] However, there is a significant problem with the existing method: the adopted power limit rate is fixed, which means that the once-through boiler unit is adjusted at the same rate at all times to reach the target load instruction. During the wet-dry state conversion process, this control strategy may have an adverse impact on the equipment. The wet-dry state conversion refers to the phase change between liquid and gas of the working medium (such as water and steam) in the boiler of a coal-fired unit during operation. During this process, as the properties of the working medium (water / steam) change and parameters such as the main steam pressure change, the power that the unit can safely and efficiently output will also change. If, in this case, the actual power output capacity of the unit is low, but the fixed-rate control still requires a rapid increase in load, it may lead to overloading of the unit, accelerating equipment wear and even causing failures. On the other hand, if the actual power output capacity of the unit increases, and the control system still adjusts at a fixed rate, it may lead to a lag in power regulation, unable to fully utilize the equipment potential, and may also affect the safe operation of the equipment. Summary of the Invention

[0004] In view of the above problems, the present invention provides an operation control method and device for a once-through boiler unit, and the main purpose is to improve the safety of the operation control of the once-through boiler unit.

[0005] To solve the above technical problems, the present invention proposes the following solutions:

[0006] In a first aspect, the present invention provides an operation control method for a once-through boiler unit, and the method includes:

[0007] Obtain a target load instruction issued by the power grid dispatching, the current main steam pressure set value and the actual main steam pressure value, the sequence of actual main steam temperature values within a preset time window, and the sequence of actual unit loads within a preset time window;

[0008] When it is determined that the current operation state of the unit is in the wet-dry conversion stage based on the actual load sequence of the unit, based on the characteristics of the conversion stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value, calculate the latest power limit rate;

[0009] According to the latest power limit rate and the target load instruction, calculate the latest transition load instruction value for the next control cycle;

[0010] Based on the latest transition load instruction value for the next control cycle and the actual main steam temperature value sequence, generate the main steam pressure set value for the next control cycle;

[0011] According to the latest transition load instruction value for the next control cycle, the main steam pressure set value for the next control cycle and the combustion characteristic parameters, adjust the operation control state of the once-through boiler unit.

[0012] In a second aspect, the present invention provides an operation control device for a once-through boiler unit, and the device includes:

[0013] An information acquisition unit, configured to acquire a target load instruction issued by the power grid dispatching, the current main steam pressure set value and the actual main steam pressure value, the actual main steam temperature value sequence within a preset time window, and the actual load sequence of the unit within a preset time window;

[0014] A rate calculation unit, configured to calculate the latest power limit rate based on the characteristics of the conversion stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value when it is determined that the current operation state of the unit is in the wet-dry conversion stage based on the actual load sequence of the unit acquired by the information acquisition unit;

[0015] An instruction calculation unit, configured to calculate the latest transition load instruction value for the next control cycle according to the latest power limit rate calculated by the rate calculation unit and the target load instruction;

[0016] A pressure calculation unit, configured to generate the main steam pressure set value for the next control cycle based on the latest transition load instruction value for the next control cycle calculated by the instruction calculation unit and the actual main steam temperature value sequence;

[0017] An operation control unit, which adjusts the operation control state of the once-through boiler unit according to the latest transition load instruction value for the next control cycle calculated by the instruction calculation unit, the main steam pressure set value for the next control cycle calculated by the pressure calculation unit, and the combustion characteristic parameters.

[0018] To achieve the above object, according to the third aspect of the present invention, there is provided a storage medium, the storage medium including a stored program, wherein when the program runs, it controls the device where the storage medium is located to execute the operation control method of the once-through boiler unit in the first aspect above.

[0019] To achieve the above object, according to the fourth aspect of the present invention, there is provided a processor, the processor being used to run a program, wherein when the program runs, it executes the operation control method of the once-through boiler unit in the first aspect above.

[0020] By means of the above technical solution, an operation control method and device for a once-through boiler unit provided by the present invention first obtain a target load instruction, a current main steam pressure set value, an actual main steam pressure value, an actual main steam temperature value sequence issued by the power grid dispatching, and a unit actual load sequence within a preset time window. Then, when it is determined that the current unit operation state is in the wet-dry state conversion stage based on the unit actual load sequence, based on the characteristics of the conversion stage and in combination with the deviation between the current main steam pressure set value and the actual main steam pressure value, the latest power limit rate is calculated instead of using a fixed rate. Subsequently, according to the latest power limit rate and the target load instruction, the latest transition load instruction value for the next control cycle is determined. Furthermore, according to the next control cycle and the actual main steam temperature value sequence, the corresponding main steam pressure set value is generated. Finally, comprehensively considering the latest transition load instruction value, the main steam pressure set value, and the combustion characteristic parameters for the next control cycle, the operation control state of the once-through boiler unit is precisely adjusted. Compared with the prior art, the present invention continuously adjusts the power limit rate dynamically according to the real-time operation data of the unit, including the output load and the main steam pressure, and optimizes the load and main steam pressure set values in real time. Through this feedforward regulation method, the operation control of the once-through boiler unit is more closely adapted to the wet-dry state conversion working condition, effectively avoiding overloading regulation and equipment safety risks.

[0021] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following specifically describes the embodiments of the present invention. Description of the Drawings

[0022] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0023] Figure 1Shows a flowchart of an operation control method for a once-through boiler unit provided by an embodiment of the present invention;

[0024] Figure 2 Shows a flowchart of another operation control method for a once-through boiler unit provided by an embodiment of the present invention;

[0025] Figure 3 Shows a block diagram of the composition of an operation control device for a once-through boiler unit provided by an embodiment of the present invention;

[0026] Figure 4 Shows a block diagram of the composition of another operation control device for a once-through boiler unit provided by an embodiment of the present invention. Detailed implementation manners

[0027] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0028] In view of the problems existing in the existing operation methods of once-through boiler units, such as inflexible regulation and potential safety hazards caused by using a fixed power limit rate during the dry-wet state conversion process, etc., the inventors, through continuous innovative efforts, have proposed a new operation method for once-through boiler units applicable to the dry-wet state conversion working condition. This method abandons the practice of using a fixed power limit rate in the traditional method and instead adopts a method of dynamically adjusting the power limit rate based on real-time data.

[0029] The specific steps are as follows: First, obtain the target load instruction, the current main steam pressure set value, the actual value, and the sequence of actual main steam temperature values issued by the power grid dispatching system, and collect the sequence of actual unit loads within a preset time window. Then, identify the current dry-wet state conversion stage based on these data and calculate the latest power limit rate. Based on this latest rate and the target load instruction, recalculate the transition load instruction value for the next control cycle.

[0030] Subsequently, use the transition load instruction value for the next control cycle and the sequence of actual main steam temperature values to generate the main steam pressure set value for the next control cycle. Finally, perform feedforward regulation on the once-through boiler unit based on the updated main steam pressure set value and the transition load instruction value to ensure that its operation can better adapt to the specific characteristics of the dry-wet state conversion, thereby avoiding overloading regulation and ensuring equipment safety.

[0031] The core execution entity of the present invention is the coordinated control system. Once receiving the target load instruction issued by the power grid dispatching system, the coordinated control system will guide the once-through boiler unit according to the power limit rate calculated in real time, and gradually meet the requirements of the target load instruction on the premise of ensuring safety. This method not only improves the response speed and flexibility of the system, but also enhances the overall operation safety and efficiency.

[0032] Suppose the target load instruction is 400MW (the current load is 300MW), and the latest calculated power limit rate is 5MW / min. The current unit is in the conversion stage from wet state to dry state, and the power rising rate needs to be concerned. The coordinated control system accurately generates the load instruction value for the next control cycle based on this rate. Specifically, at T = 0min, the load instruction is 300MW; at T = 1min, the load instruction increases to 305MW. In other words, the load instruction for the next control cycle is set to 305MW. In this example, the control cycle is one minute to ensure the accuracy and smoothness of load adjustment.

[0033] Next, combined with Figure 1 describe an operation control method for a once-through boiler unit provided by the present invention, and its specific implementation steps are as Figure 1 shown, including:

[0034] 101. Obtain the target load instruction issued by the power grid dispatching, the current main steam pressure set value and the actual main steam pressure value, the actual main steam temperature value sequence within a preset time window, and the actual unit load sequence within a preset time window.

[0035] 102. When it is determined based on the actual unit load sequence that the current unit operation state is in the wet-dry state conversion stage, calculate the latest power limit rate based on the characteristics of the conversion stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value.

[0036] In step 101, first obtain the target load instruction issued by the power grid dispatching, the set value and the actual value of the main steam pressure in the current control cycle, the actual main steam temperature value sequence within a preset time window, and the actual unit load sequence within a preset time window. These data will serve as the basis for subsequent calculations and adjustments.

[0037] Specifically, the main steam pressure set value refers to the target pressure value set in the current control cycle, and the actual main steam pressure value is the pressure value actually measured in the current cycle. Based on these real-time data, the embodiments of the present invention aim to perform feedforward adjustment on the operation of the next control cycle according to the actual situation of the unit in the current cycle, so as to optimize the operation parameters and improve the response speed and accuracy of the system.

[0038] In addition, the time range of the actual main steam temperature value sequence and the actual unit load sequence within the preset time window is from a specific start time to the current time. Herein, the "current time" refers to the data acquisition moment or the time point of the most recent update, while the "start time" is determined according to the quantity of the actual temperature values and load values to be obtained. For example, if it is necessary to analyze the data of the past 10 minutes, the start time is the moment 10 minutes before the current time. This method ensures that the data used not only contains sufficient historical information to reflect trend changes but also can timely reflect the latest operating status.

[0039] Through the above steps, the system can dynamically adjust the power limit rate and other key parameters according to the latest operating data, thereby achieving more precise control of the once-through boiler unit, ensuring that its operation is more in line with the actual conditions of the wet-dry state conversion, and improving the overall efficiency and safety.

[0040] It should be noted that the present invention is particularly applicable to large newly-built supercritical once-through boiler units with a capacity of more than 300MW. The load range of such units during the wet-dry state conversion is 25% to 35% of the rated load (Pe). Specifically, by monitoring the actual load sequence output by the unit (the actual unit load sequence), it can be determined whether it is within this specific load range.

[0041] Once it is confirmed that the actual load of the unit is between 25%Pe and 35%Pe, it is then necessary to further analyze the change direction of the load sequence. For example, if the unit load sequence shows a gradual increase from 25%Pe to 35%Pe, it indicates that the current is in the conversion stage from the wet state to the dry state; on the contrary, if the load sequence shows a gradual decrease from 35%Pe to 25%Pe, it means that the system is undergoing the process of dry state to wet state.

[0042] In this way, the wet-dry state conversion stage can be accurately identified according to the actual load and its change trend. Subsequently, based on the characteristics of the wet-dry state conversion stage, combined with the main steam pressure set value and the actual main steam pressure value, the latest power limit rate is calculated.

[0043] When calculating the latest power limit rate based on the characteristics of the wet-dry state conversion stage, combined with the main steam pressure set value and the actual value, various methods can be adopted.

[0044] One effective method is to use a preset relationship table to determine the power limit rate:

[0045] First, a preset relationship table is established in advance for the relationship between the difference between the main steam pressure set value and the actual value and the power limit rate. This table lists the recommended power limit rates corresponding to different difference intervals. Then, calculate the deviation between the main steam pressure set value and the actual value within the current control cycle. Using the calculated deviation, look up the corresponding power limit rate in the preset relationship table. Determine the found power limit rate as the latest power limit rate for subsequent load adjustment calculations.

[0046] For example, if the calculated deviation between the main steam pressure set value and the actual value falls within a certain specific interval, then according to the preset relationship table, directly select the corresponding power limit rate as the latest power limit rate. This method greatly improves the determination rate of the power limit rate.

[0047] It should be particularly noted that during the wet-to-dry state transition, the power limit rate shows an increasing rate; on the contrary, during the dry-to-wet state transition, it shows a decreasing rate.

[0048] In addition, the present invention also adopts the method of a dynamic calculation model to optimize the determination of the power limit rate. This method directly calculates the power limit rate based on real-time data by establishing a mathematical model, thus getting rid of the dependence on the pre-set relationship table. The specific implementation steps are as follows:

[0049] 1. Construct a dynamic calculation model:

[0050] First, based on the historical data and experimental results of the unit operation, construct a dynamic calculation model. This model takes the deviation (ΔP) between the main steam pressure set value and the actual value as the core input variable, and at the same time comprehensively considers the characteristics of the wet / dry state transition stage (such as wet-to-dry state or dry-to-wet state), the unit load change trend, and other relevant operation parameters (such as main steam temperature, etc.). The model can adopt linear regression, non-linear functions or other appropriate mathematical expressions, for example:

[0051] R = f(ΔP, S, T)

[0052] Where, R represents the power limit rate, ΔP is the deviation between the main steam pressure set value and the actual value, S represents the characteristics of the wet / dry state transition stage (positive for wet-to-dry state, negative for dry-to-wet state), and T represents other auxiliary parameters (such as the change rate of main steam temperature).

[0053] 2. Calculate the deviation in real time:

[0054] Within the current control cycle, according to the obtained main steam pressure set value and the actual value, calculate the deviation between the two:

[0055] ΔP = P_set - P_actual

[0056] Subsequently, the calculated deviation ΔP, the characteristics S of the current wet-dry state conversion stage, and auxiliary parameters (such as the main steam temperature change rate) are substituted into the dynamic calculation model to calculate the latest power limit rate R in real time.

[0057] For example, in the wet-to-dry state stage, if the set value of the main steam pressure is higher than the actual value, the model will output a positive power limit rate (i.e., the load increase rate); while in the dry-to-wet state stage, if the set value of the main steam pressure is lower than the actual value, the model will output a negative power limit rate (i.e., the load decrease rate).

[0058] 3. Determine and apply the power limit rate:

[0059] After the calculation is completed, the obtained power limit rate R is determined as the latest power limit rate and is used for subsequent calculation of the transitional load command value and adjustment of the unit operation state.

[0060] Compared with the preset relationship table, the dynamic calculation model can adaptively adjust according to real-time data and is applicable to more complex and changeable operating conditions. By comprehensively considering various factors (such as the characteristics of the wet-dry state conversion stage, the main steam temperature change rate, etc.), the model can more accurately reflect the actual operating requirements and reduce errors caused by fixed relationships. In addition, the dynamic model can be continuously optimized and updated according to new operating data to ensure its long-term applicability and accuracy. However, the efficiency of this method may be slightly lower than that of the preset relationship table.

[0061] 103. Calculate the latest transitional load command value for the next control cycle according to the latest power limit rate and the target load command.

[0062] 104. Generate the set value of the main steam pressure for the next control cycle based on the latest transitional load command value for the next control cycle and the actual value sequence of the main steam temperature.

[0063] 105. Adjust the operation control state of the once-through boiler unit according to the latest transitional load command value for the next control cycle, the set value of the main steam pressure for the next control cycle, and the combustion characteristic parameters.

[0064] In the present invention, the coordinated control system precisely controls the once-through boiler unit according to the transitional load command value in each control cycle, aiming to gradually guide the unit to reach the target load command issued by the power grid dispatching system. For this purpose, after obtaining the latest power limit rate and the target load command, the system will calculate the latest transitional load command value for the next control cycle. Subsequently, based on this transitional load command value and the actual value sequence of the main steam temperature, the set value of the main steam pressure for the next control cycle is generated.

[0065] It should be particularly noted that the present invention has achieved significant improvements compared with the prior art in the above steps:

[0066] The prior art usually directly determines the corresponding target main steam pressure setting value based on the target load instruction issued by the power grid dispatching system and combines it with the sliding pressure curve, and adopts independent rate control strategies for adjustment. However, the present invention adopts a more refined and dynamic control method:

[0067] First, after receiving the target load instruction, the system will comprehensively consider the current operating state and the latest power limit rate, and calculate the latest transitional load instruction value required to achieve the target load instruction. This process deeply considers the actual operating conditions and the characteristics of the dry-wet state conversion stage, ensuring that the transitional load instruction value not only meets the target requirements but also guarantees safe implementation.

[0068] Then, the system uses the obtained latest transitional load instruction value to generate the corresponding main steam pressure setting value through the sliding pressure curve. This method not only focuses on the final target load but also emphasizes the transitional process from the current state to the target state, achieving smoother and more efficient load adjustment.

[0069] The above approach of the present invention has the following prominent advantages compared with the prior art:

[0070] By calculating the corresponding main steam pressure setting value based on the transitional load instruction value, it ensures the precise matching of the main steam pressure and the current load demand in each control cycle, effectively optimizes the combustion process, improves the energy utilization efficiency, and reduces fuel consumption.

[0071] In addition, considering that there are differences in the optimal operating parameters (such as temperature, pressure, etc.) of the boiler under different load levels, the present invention dynamically adjusts the main steam pressure setting value based on the transitional load, enabling the system to always maintain at a working point close to the optimal, thereby significantly improving the overall thermal efficiency.

[0072] Especially during the dry-wet state conversion process, the requirements for the main steam pressure are different in different load stages. The present invention can dynamically adjust the main steam pressure setting value according to the transitional load, better adapting to the requirements in this special process and ensuring the safety and efficiency of operation.

[0073] Finally, the operating control state of the once-through boiler unit can be adjusted according to the latest transitional load instruction value of the next control cycle, the main steam pressure setting value of the next control cycle, and the combustion characteristic parameters. Among them, the combustion characteristic parameters include the differential feedforward of the main steam pressure control deviation and the total fuel quantity, etc.

[0074] Based on the above Figure 1From the implementation method, it can be seen that a method for operating and controlling a once-through boiler unit provided by the present invention obtains a target load instruction issued by the power grid dispatching, the current main steam pressure set value, the actual main steam pressure value, the actual main steam temperature value sequence, and the actual unit load sequence within a preset time window. Then, when it is determined based on the actual unit load sequence that the current unit operating state is in the wet-dry conversion stage, based on the characteristics of the conversion stage, combined with the deviation between the main steam pressure set value and the actual main steam pressure value, the latest power limit rate is calculated instead of using a fixed rate. Subsequently, according to the latest power limit rate and the target load instruction, the latest transition load instruction value for the next control cycle is determined. Furthermore, according to the next control cycle and the actual main steam temperature value sequence, the corresponding main steam pressure set value is generated. Finally, comprehensively considering the latest transition load instruction value, the main steam pressure set value, and the combustion characteristic parameters of the next control cycle, the operating control state of the once-through boiler unit is precisely adjusted. Compared with the prior art, the present invention continuously adjusts the power limit rate dynamically according to the real-time operating data of the unit, including the output load and the main steam pressure, and optimizes the load and the main steam pressure set value in real time. Through this feedforward regulation method, the operating control of the once-through boiler unit is more closely adapted to the wet-dry conversion working condition, effectively avoiding overloading regulation and equipment safety risks.

[0075] Further, as a refinement and extension of the Figure 1 embodiment shown, the embodiment of the present invention also provides another method for operating and controlling a once-through boiler unit, as Figure 2 shown, and its specific steps are as follows:

[0076] 201. Obtain the target load instruction issued by the power grid dispatching, the current main steam pressure set value and the actual main steam pressure value, the actual main steam temperature value sequence within a preset time window, and the actual unit load sequence within a preset time window.

[0077] Among them, the implementation method of step 201 is the same as that of step 101, and the same technical effects can be achieved and the same technical problems can be solved, so it will not be repeated here.

[0078] 202. When it is determined based on the actual unit load sequence that the current unit operating state is in the wet-dry conversion stage, based on the characteristics of the conversion stage, combined with the deviation between the main steam pressure set value and the actual main steam pressure value, calculate the latest power limit rate.

[0079] In this step, if several wet-state conversion stages are from wet state to dry state, the first updated power limit rate is calculated based on the difference between the actual main steam pressure value and the set main steam pressure value. The first updated power limit rate is the load increase rate; conversely, if several wet-state conversion stages are from dry state to wet state, the second updated power limit rate is calculated based on the difference between the actual main steam pressure value and the set main steam pressure value. The second updated power limit rate is the load decrease rate.

[0080] Among them, when the difference between the actual main steam pressure value and the set main steam pressure value > a, the power limit rate can be c * 1.2; when -a < the difference between the actual main steam pressure value and the set main steam pressure value < a, the power limit rate can be c; when the difference between the actual main steam pressure value and the set main steam pressure value < -a, the power limit rate can be c * 0.8.

[0081] Among them, when the difference between the actual main steam pressure value and the set main steam pressure value > a, the power limit rate can be c * 0.8; when -a < the difference between the actual main steam pressure value and the set main steam pressure value < a, the power limit rate can be c; when the difference between the actual main steam pressure value and the set main steam pressure value < -a, the power limit rate can be c * 1.2.

[0082] 203. Calculate the latest transition load command value for the next control cycle according to the latest power limit rate and the target load command.

[0083] In this step, the total change required to reach the target load command from the transition load command value of the current control cycle can be calculated first. Then, according to the latest power limit rate and the cycle duration of the current control cycle, the maximum allowable load change is determined. Subsequently, the smaller value of the total change and the maximum load change can be used as the actual load change allowed for the current control cycle. Because if the total change is less than the maximum allowable load change, it may prove that the once-through boiler unit has almost reached the target load command issued by the grid dispatching system.

[0084] Finally, the latest transition load command value for the next control cycle can be obtained according to the transition load command value of the current control cycle and the actual load change, combined with the conversion characteristics of the wet-dry state conversion stage. Specifically:

[0085] If several wet-state conversion stages are from wet state to dry state, the difference between the load command value of the current control cycle and the actual load change is used as the latest transition load command value for the next control cycle; if several wet-state conversion stages are from dry state to wet state, the sum of the load command value of the current control cycle and the actual load change is used as the latest transition load command value for the next control cycle.

[0086] Exemplarily, the transitional load instruction value for the current control cycle is 300 MW, and the target load instruction value is 350 MW; the latest power limit rate is 5 MW / min, and the control cycle duration is 1 minute.

[0087] Calculation process:

[0088] Total change = Target load instruction value - Current transitional load instruction value = 350 MW - 300 MW = 50 MW

[0089] Maximum load change = Latest power limit rate × Control cycle duration = 5 MW / min × 1 minute = 5 MW

[0090] Since the total change (50 MW) is greater than the maximum load change (5 MW), the actual load change takes the smaller value, which is 5 MW.

[0091] Assume that the current is in the wet state to dry state stage:

[0092] The latest transitional load instruction value for the next control cycle = Current transitional load instruction value + Actual load change = 300 MW + 5 MW = 305 MW

[0093] Assume that the current is in the dry state to wet state stage:

[0094] The latest transitional load instruction value for the next control cycle = Current transitional load instruction value - Actual load change = 300 MW - 5 MW = 295 MW

[0095] 204. Based on the latest transitional load instruction value for the next control cycle, determine the target main steam pressure setting value within the next control cycle according to the specified sliding pressure curve.

[0096] 205. Based on the actual main steam temperature value sequence, calculate the pressure setting rate, and determine each transitional main steam pressure setting value corresponding to the target main steam pressure setting value for the next control cycle according to the pressure setting rate.

[0097] 206. Adjust the operation control state of the once-through boiler unit according to the latest transitional load instruction value for the next control cycle, each transitional main steam pressure setting value for the next control cycle, and the combustion characteristic parameters.

[0098] In steps 204 - 206, first, based on the latest transitional load instruction value for the next control cycle, determine the target main steam pressure setting value within the next control cycle according to the specified sliding pressure curve. Then, based on the actual main steam temperature value sequence, calculate the pressure setting rate. Finally, according to the pressure setting rate, generate the main steam pressure setting values for each sub-cycle in the next control cycle, where the main steam pressure setting values for each sub-cycle are the intermediate values to reach the latest main steam pressure setting value for the next control cycle, that is, the transitional main steam pressure setting values.

[0099] Among them, based on the actual main steam temperature sequence, the following method can be used to calculate the pressure setting rate. Specifically:

[0100] If it is determined from the actual main steam temperature sequence that the wet-dry state conversion stage is from wet state to dry state, then determine the rising rate of the main steam temperature according to the actual main steam temperature sequence, and determine the latest pressure setting rate according to the rising rate of the main steam temperature;

[0101] If it is determined from the actual main steam temperature sequence that the wet-dry state conversion stage is from dry state to wet state, then determine the falling rate of the main steam temperature according to the actual main steam temperature sequence, and determine the latest pressure setting rate according to the falling rate of the main steam temperature.

[0102] Among them, the latest pressure setting rate is the rate determined according to the preset relationship between the falling rate or rising rate of the main steam temperature and the pressure setting rate.

[0103] The preset relationship for the wet state to dry state conversion is:

[0104] The rising rate of the main steam temperature > a, pressure rate = d * 1.2;

[0105] b < the rising rate of the main steam temperature < a, pressure rate = d;

[0106] The rising rate of the main steam temperature < b, pressure rate = d * 0.8

[0107] The preset relationship for the dry state to wet state conversion is:

[0108] The rising rate of the main steam temperature > a, pressure rate = d * 0.8;

[0109] b < the rising rate of the main steam temperature < a, pressure rate = d;

[0110] The rising rate of the main steam temperature < b, pressure rate = d * 1.1

[0111] Among them, generating the main steam pressure setting value for each sub-cycle in the next control cycle according to the pressure setting rate includes:

[0112] Next control cycle duration: 10 minutes, target main steam pressure setting value: 12 MPa, pressure setting rate: 0.4 MPa / min

[0113] Current main steam pressure: 8 MPa, steps for generating the main steam pressure setting value for each sub-cycle:

[0114] 1. Determine the sub-cycle division

[0115] Divide the next 10-minute control cycle into 5 sub-cycles, and the duration of each sub-cycle is 2 minutes.

[0116] 2. Calculate the set value of the main steam pressure for each sub-cycle

[0117] According to the pressure setting rate and the current main steam pressure, calculate the set value of the main steam pressure at the end of each sub-cycle (i.e., at the start of the next sub-cycle) in sequence:

[0118] The 1st sub-cycle:

[0119] Time range: 0 - 2 minutes, pressure set value: P1 = 8 + 0.4×2 = 8.8 MPa

[0120] The 2nd sub-cycle:

[0121] Time range: 2 - 4 minutes, pressure set value: P2 = 8.8 + 0.4×2 = 9.6 MPa

[0122] The 3rd sub-cycle:

[0123] Time range: 4 - 6 minutes

[0124] Pressure set value: P3 = 9.6 + 0.4×2 = 10.4 MPa

[0125] The 4th sub-cycle:

[0126] Time range: 6 - 8 minutes

[0127] Pressure set value: P4 = 10.4 + 0.4×2 = 11.2 MPa

[0128] The 5th sub-cycle:

[0129] Time range: 8 - 10 minutes

[0130] Pressure set value: P5 = 11.2 + 0.4×2 = 12 MPa

[0131] Furthermore, as an implementation of the above Figure 1 shown method, the embodiment of the present invention also provides an operation control device for a once-through boiler unit, which is used to implement the above Figure 1 shown method. This device embodiment corresponds to the foregoing method embodiment. For the convenience of reading, the details of the foregoing method embodiment will not be repeated one by one in this device embodiment. However, it should be clear that the device in this embodiment can correspondingly implement all the contents of the foregoing method embodiment. As Figure 3 shown, the device includes:

[0132] An information acquisition unit 301, configured to acquire a target load instruction issued by the grid dispatching, the current set value of the main steam pressure and the actual value of the main steam pressure, the sequence of actual main steam temperature values within a preset time window, and the sequence of actual unit loads within a preset time window;

[0133] A rate calculation unit 302, configured to, when determining that the current operating state of the unit is in the wet-dry state transition stage based on the actual load sequence of the unit obtained by the information acquisition unit 301, calculate the latest power limit rate based on the characteristics of the transition stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value;

[0134] An instruction calculation unit 303, configured to calculate the latest transition load instruction value for the next control cycle according to the latest power limit rate calculated by the rate calculation unit 302 and the target load instruction;

[0135] A pressure calculation unit 304, configured to generate the main steam pressure set value for the next control cycle based on the latest transition load instruction value for the next control cycle calculated by the instruction calculation unit 303 and the actual main steam temperature value sequence;

[0136] An operation control unit 305, configured to adjust the operation control state of the once-through boiler unit according to the latest transition load instruction value for the next control cycle calculated by the instruction calculation unit 303, the main steam pressure set value for the next control cycle calculated by the pressure calculation unit 304, and the combustion characteristic parameters.

[0137] Further, as an implementation of the above Figure 2 shown method, an embodiment of the present invention further provides another operation control device for a once-through boiler unit, configured to implement the above Figure 2 shown method. This device embodiment corresponds to the foregoing method embodiment. For the convenience of reading, details of the foregoing method embodiment will not be described one by one in this device embodiment. However, it should be clear that the device in this embodiment can correspondingly implement all the contents of the foregoing method embodiment. As Figure 4 shown, the device includes:

[0138] An information acquisition unit 301, configured to acquire the target load instruction issued by the grid dispatching, the current main steam pressure set value and the actual main steam pressure value, the actual main steam temperature value sequence within a preset time window, and the actual load sequence of the unit within a preset time window;

[0139] A rate calculation unit 302, configured to, when determining that the current operating state of the unit is in the wet-dry state transition stage based on the actual load sequence of the unit obtained by the information acquisition unit 301, calculate the latest power limit rate based on the characteristics of the transition stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value;

[0140] An instruction calculation unit 303, configured to calculate the latest transition load instruction value for the next control cycle according to the latest power limit rate calculated by the rate calculation unit 302 and the target load instruction;

[0141] A pressure calculation unit 304, configured to generate a main steam pressure set value for the next control cycle based on the latest transition load instruction value for the next control cycle calculated by the instruction calculation unit 303 and the actual main steam temperature value sequence.

[0142] An operation control unit 305, configured to adjust the operation control state of the once-through boiler unit according to the latest transition load instruction value for the next control cycle calculated by the instruction calculation unit 303, the main steam pressure set value for the next control cycle calculated by the pressure calculation unit 304, and the combustion characteristic parameters.

[0143] In an alternative embodiment, the rate calculation unit 302 includes:

[0144] A first rate calculation module 3021, configured to calculate a first latest power limit rate according to the difference between the actual main steam pressure value and the main steam pressure set value if the wet-dry state conversion stage is from the wet state to the dry state, and the first latest power limit rate is the load increase rate.

[0145] A second rate calculation module 3022, configured to calculate a second latest power limit rate according to the difference between the actual main steam pressure value and the main steam pressure set value if the wet-dry state conversion stage is from the dry state to the wet state, and the second latest power limit rate is the load decrease rate.

[0146] In an alternative embodiment, the instruction calculation unit 303 is specifically configured to:

[0147] Calculate the total change amount required for the transition load instruction value of the current control cycle to reach the target load instruction.

[0148] Based on the latest power limit rate and the cycle duration of the current control cycle, determine the maximum allowable load change amount.

[0149] Take the smaller value of the total change amount and the maximum load change amount as the actual load change amount allowed for the current control cycle.

[0150] According to the transition load instruction value of the current control cycle and the actual load change amount, and in combination with the conversion characteristics of the wet-dry state conversion stage, obtain the latest transition load instruction value for the next control cycle.

[0151] In an alternative embodiment, when the instruction calculation unit 303 obtains the latest transition load instruction value for the next control cycle according to the transition load instruction value of the current control cycle and the actual load change amount, and in combination with the conversion characteristics of the wet-dry state conversion stage, it is specifically configured to:

[0152] If the dry-wet state conversion stage is from the wet state to the dry state, the difference between the transitional load command value of the current control period and the actual load change amount is used as the latest transitional load command value of the next control period;

[0153] If the dry-wet state conversion stage is from the dry state to the wet state, the sum value of the transitional load command value of the current control period and the actual load change amount is used as the latest transitional load command value of the next control period.

[0154] In an optional implementation manner, the pressure calculation unit 304 is specifically configured to:

[0155] Based on the latest transitional load command value of the next control period, determine the target main steam pressure setting value within the next control period according to the specified sliding pressure curve;

[0156] Based on the actual main steam temperature value sequence, calculate the pressure setting rate;

[0157] According to the pressure setting rate, generate the main steam pressure setting values of each sub-period in the next control period, and the main steam pressure setting values of each sub-period are intermediate values for reaching the main steam pressure setting value of the next control period.

[0158] In an optional implementation manner, for calculating the pressure setting rate based on the actual main steam temperature value sequence in the pressure calculation unit 304, it is specifically configured to:

[0159] If it is determined from the actual main steam temperature value sequence that the dry-wet state conversion stage is from the wet state to the dry state, determine the main steam temperature rising rate according to the actual main steam temperature value sequence, and determine the latest pressure setting rate according to the main steam temperature rising rate;

[0160] If it is determined from the actual main steam temperature value sequence that the dry-wet state conversion stage is from the dry state to the wet state, determine the main steam temperature falling rate according to the actual main steam temperature value sequence, and determine the latest pressure setting rate according to the main steam temperature falling rate.

[0161] In an optional implementation manner, the latest pressure setting rate is a rate determined according to a preset relationship between the main steam temperature falling rate or the main steam temperature rising rate and the pressure setting rate.

[0162] Furthermore, an embodiment of the present invention further provides a storage medium for storing a computer program, wherein when the computer program runs, it controls the device where the storage medium is located to execute the above Figure 1-2 operation control method of the once-through boiler unit described.

[0163] Further, an embodiment of the present invention further provides a processor for running a program, wherein when the program runs, it executes the above-mentioned Figure 1-2 operation control method of the once-through boiler unit described in

[0164] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0165] It can be understood that the relevant features in the above methods and devices can be referred to each other. In addition, the "first", "second", etc. in the above embodiments are used to distinguish the respective embodiments, and do not represent the advantages or disadvantages of the respective embodiments.

[0166] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0167] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The structure required to construct such systems is obvious from the above description. In addition, the present invention is not directed to any particular programming language. It should be understood that the content of the present invention described herein can be implemented using various programming languages, and the description of the specific language above is to disclose the best mode of the present invention.

[0168] In addition, the memory may include non-permanent memory in a computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0169] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0170] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and combinations of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general purpose computers, special purpose computers, embedded processors, or other programmable data processing devices to produce a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices produce means for implementing the functions specified in one or more of the flows Figure 1 one or more of the flows and / or blocks Figure 1 or means for implementing the functions specified in one or more of the blocks.

[0171] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including instruction means that implement the functions specified in one or more of the flows Figure 1 one or more of the flows and / or blocks Figure 1 or means for implementing the functions specified in one or more of the blocks.

[0172] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are performed on the computer or other programmable device to produce a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more of the flows Figure 1 one or more of the flows and / or blocks Figure 1 or means for implementing the functions specified in one or more of the blocks.

[0173] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0174] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of computer-readable media.

[0175] A computer-readable medium includes both permanent and non-permanent, removable and non-removable media and can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information accessible by a computing device. As defined herein, a computer-readable medium does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0176] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0177] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0178] The above are only the embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A method for operating and controlling a once-through boiler unit, characterized in that, The method includes: Obtaining a target load instruction issued by the power grid dispatching, the current main steam pressure set value and the actual main steam pressure value, the actual main steam temperature value sequence within a preset time window, and the actual unit load sequence within a preset time window; When it is determined based on the actual unit load sequence that the current unit operation state is in the wet-dry state conversion stage, calculate the latest power limit rate based on the characteristics of the conversion stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value; Calculate the latest transition load instruction value for the next control cycle according to the latest power limit rate and the target load instruction; Generate the main steam pressure set value for the next control cycle based on the latest transition load instruction value for the next control cycle and the actual main steam temperature value sequence; Adjust the operation state of the once-through boiler unit according to the latest transition load instruction value for the next control cycle, the main steam pressure set value for the next control cycle, and the combustion characteristic parameters.

2. The method according to claim 1, characterized in that, Calculating the latest power limit rate based on the characteristics of the conversion stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value includes: If the wet-dry state conversion stage is from wet state to dry state, calculate the first latest power limit rate according to the difference between the actual main steam pressure value and the main steam pressure set value, and the first latest power limit rate is the load increase rate; If the wet-dry state conversion stage is from dry state to wet state, calculate the second latest power limit rate according to the difference between the actual main steam pressure value and the main steam pressure set value, and the second latest power limit rate is the load decrease rate.

3. The method according to claim 1, wherein Calculating the latest transition load instruction value for the next control cycle according to the latest power limit rate and the target load instruction includes: Calculating the total change amount required for the transition load instruction value of the current control cycle to reach the target load instruction; Determine the maximum allowable load change amount based on the latest power limit rate and the cycle duration of the current control cycle; Take the smaller value of the total change amount and the maximum load change amount as the actual load change amount allowed for the current control cycle; Obtain the latest transition load instruction value for the next control cycle according to the transition load instruction value of the current control cycle and the actual load change amount, in combination with the conversion characteristics of the wet-dry state conversion stage.

4. The method according to claim 3, characterized in that, Obtaining the latest transition load instruction value for the next control cycle according to the transition load instruction value of the current control cycle and the actual load change amount, in combination with the conversion characteristics of the wet-dry state conversion stage includes: If the wet-dry state conversion stage is from wet state to dry state, take the difference between the transition load instruction value of the current control cycle and the actual load change amount as the latest transition load instruction value for the next control cycle; If the wet-dry state conversion stage is from dry state to wet state, take the sum of the transition load instruction value of the current control cycle and the actual load change amount as the latest transition load instruction value for the next control cycle.

5. The method according to claim 1, characterized in that Generating the main steam pressure set value for the next control cycle based on the latest transition load instruction value for the next control cycle and the actual main steam temperature value sequence includes: Based on the latest transition load command value for the next control period, determine the target main steam pressure set value within the next control period according to the specified sliding pressure curve; Based on the actual main steam temperature value sequence, calculate the pressure setting rate; According to the pressure setting rate, generate the main steam pressure set values for each sub-period in the next control period, and the main steam pressure set values for each sub-period are intermediate values to reach the main steam pressure set value for the next control period.

6. The method according to claim 5, wherein Based on the actual main steam temperature value sequence, calculating the pressure setting rate includes: If it is determined according to the actual main steam temperature value sequence that the dry-wet state conversion stage is from wet state to dry state, determine the main steam temperature rising rate according to the actual main steam temperature value sequence, and determine the latest pressure setting rate according to the main steam temperature rising rate; If it is determined according to the actual main steam temperature value sequence that the dry-wet state conversion stage is from dry state to wet state, determine the main steam temperature falling rate according to the actual main steam temperature value sequence, and determine the latest pressure setting rate according to the main steam temperature falling rate.

7. The method according to claim 6, wherein The latest pressure setting rate is a rate determined according to a preset relationship between the main steam temperature falling rate or the main steam temperature rising rate and the pressure setting rate.

8. An operating control device for a once-through boiler unit, characterized in that, The device includes: An information acquisition unit, configured to acquire a target load command issued by the grid dispatching, the current main steam pressure set value and the actual main steam pressure value, the actual main steam temperature value sequence within a preset time window, and the actual unit load sequence within a preset time window; A rate calculation unit, configured to, when it is determined based on the actual unit load sequence acquired by the information acquisition unit that the current unit operation state is in the dry-wet state conversion stage, calculate the latest power limit rate based on the characteristics of the conversion stage and in combination with the deviation between the main steam pressure set value and the actual main steam pressure value; An instruction calculation unit, configured to calculate the latest transition load command value for the next control period according to the latest power limit rate calculated by the rate calculation unit and the target load command; A pressure calculation unit, configured to generate the main steam pressure set value for the next control period based on the latest transition load command value for the next control period calculated by the instruction calculation unit and the actual main steam temperature value sequence; An operation control unit, adjusts the operation state of the once-through boiler unit according to the latest transition load command value for the next control period calculated by the instruction calculation unit, the main steam pressure set value for the next control period calculated by the pressure calculation unit, and the combustion characteristic parameters.

9. A storage medium, characterized in that, The storage medium includes a stored program, wherein when the program runs, it controls the device where the storage medium is located to execute the operation control method of the once-through boiler unit as described in any one of claims 1 to 7.

10. A processor, characterized in that, The processor is used to run the program, wherein when the program runs, it executes the operation control method of the once-through boiler unit as described in any one of claims 1 to 7.

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