Method and related device for evaluating energy efficiency of variable load process of coal-fired boiler

Abstract

The application discloses a coal-fired boiler variable load process energy efficiency evaluation method and related device, relates to the technical field of boiler energy efficiency evaluation, and comprises the following steps: acquiring real-time monitoring data in a transient variable load process of a boiler and performing pretreatment; based on the pretreated real-time monitoring data, further determining a main steam outlet enthalpy, a feedwater enthalpy, a reheated steam outlet enthalpy and a reheated steam inlet enthalpy; then, according to each group of data at different moments in the transient variable load process of the boiler, determining a load-instantaneous efficiency curve and a load-time average efficiency curve; finally, calculating a deviation area of the load-time average efficiency curve and a load-efficiency curve under a stable working condition of the boiler, and calculating a fluctuation degree of the load-instantaneous efficiency curve, and evaluating the energy efficiency of the boiler in the transient variable load process based on the deviation area and the fluctuation degree. The application can realize energy efficiency evaluation of the transient variable load process of the boiler.

Description

Technical Field

[0001] This application relates to the field of boiler energy efficiency evaluation technology, and in particular to a method and related apparatus for evaluating the energy efficiency of a coal-fired boiler during variable load processes. Background Technology

[0002] To accommodate the integration of high proportions of renewable energy into the grid, traditional coal-fired power generation is gradually shifting from baseload power to peak-shaving power, resulting in boilers frequently operating under variable load conditions, where the load continuously increases or decreases at a certain rate. Currently, boiler energy efficiency testing and evaluation rules, whether for positive or negative balance, apply only to steady-state operating conditions and lack evaluation methods for boiler energy efficiency during transient load changes. Summary of the Invention

[0003] The purpose of this application is to provide a method and related apparatus for evaluating the energy efficiency of a coal-fired boiler during a variable load process, which can realize the energy efficiency evaluation of the boiler during a transient process of variable load.

[0004] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a method for evaluating the energy efficiency of a coal-fired boiler during variable load processes, including: Acquire real-time monitoring data during the transient load change process of the boiler; the real-time monitoring data includes real-time collected load, coal consumption, main steam flow rate, main steam pressure, main steam temperature, economizer inlet feedwater pressure and feedwater temperature, reheat steam flow rate, reheater outlet steam pressure and steam temperature, high-pressure cylinder exhaust pressure, and exhaust temperature. The real-time monitoring data is preprocessed to obtain preprocessed real-time monitoring data; The enthalpy of the main steam outlet is determined based on the pretreated main steam pressure and main steam temperature. The feedwater enthalpy is determined based on the pretreated economizer inlet feedwater pressure and feedwater temperature. The reheat steam outlet enthalpy is determined based on the pretreated reheater outlet steam pressure and outlet steam temperature. The inlet enthalpy of reheat steam is determined based on the pre-treated high-pressure cylinder exhaust pressure and exhaust temperature. Based on the pre-treated coal consumption, pre-treated main steam flow rate, main steam outlet enthalpy, feedwater enthalpy, pre-treated reheat steam flow rate, reheat steam outlet enthalpy, and reheat steam inlet enthalpy at different times during the boiler transient load change process, determine the instantaneous efficiency and time-averaged efficiency at each time point. Based on the instantaneous efficiency, average efficiency, and pre-processed load at each time point, determine the load-instantaneous efficiency curve and the load-average efficiency curve. Calculate the area of ​​deviation between the load-time average efficiency curve and the load-efficiency curve under stable boiler operating conditions, and calculate the degree of fluctuation of the load-instantaneous efficiency curve; The energy efficiency of the boiler during transient load changes is evaluated based on the deviation area and the degree of fluctuation.

[0005] In a second aspect, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for evaluating the energy efficiency of a coal-fired boiler under varying loads as described in the first aspect.

[0006] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the energy efficiency evaluation method for variable load processes of coal-fired boilers described in the first aspect.

[0007] Fourthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the energy efficiency evaluation method for variable load processes of coal-fired boilers described in the first aspect.

[0008] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a method and related apparatus for evaluating the energy efficiency of a coal-fired boiler during a transient load change process. First, real-time monitoring data during the boiler's transient load change process is acquired and preprocessed. Based on the preprocessed real-time monitoring data, the enthalpy of the main steam outlet, feedwater, reheat steam outlet, and reheat steam inlet are further determined. Then, based on the preprocessed coal consumption, preprocessed main steam flow rate, main steam outlet enthalpy, feedwater enthalpy, preprocessed reheat steam flow rate, reheat steam outlet enthalpy, and reheat steam inlet enthalpy at different times during the transient load change process, the instantaneous efficiency and time-averaged efficiency at each time point are determined. Then, combined with the load at each time point, the load-instantaneous efficiency curve and the load-time-averaged efficiency curve are determined. Finally, the area of ​​deviation between the load-time-averaged efficiency curve and the load-efficiency curve under stable boiler conditions is calculated, as is the degree of fluctuation of the load-instantaneous efficiency curve. Based on the area of ​​deviation and the degree of fluctuation, the energy efficiency of the boiler during the transient load change process is evaluated. Using the above methods, this application constructs evaluation indicators in two dimensions: deviation area and fluctuation degree. This enables the evaluation of the energy efficiency of the boiler during the load change process from both the energy efficiency level and energy efficiency stability aspects, thus making up for the shortcomings of the existing technology. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is an application environment diagram of an energy efficiency evaluation method for a coal-fired boiler during variable load processes, as described in one embodiment of this application. Figure 2 A flowchart illustrating an embodiment of the energy efficiency evaluation method for a coal-fired boiler under varying loads provided in this application. Figure 3 A flowchart illustrating a method for evaluating the energy efficiency of a coal-fired boiler during variable load processes, provided in another embodiment of this application; Figure 4 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0011] Unlike steady-state operation, the overall thermodynamic state of a boiler undergoes continuous changes during transient load changes (hereinafter referred to as the load change process), causing boiler operating parameters to deviate from the steady-state condition. Taking coal consumption as an example, during steady-state operation, the unit's operating parameters are basically stable. Based on energy conservation, the coal consumption under different load conditions can be calculated, representing the coal consumption that should be expected if the unit could instantly reach the steady-state load. However, the transient load change process may cause an increase or decrease in coal consumption under the same load conditions. This is mainly due to two factors: First, changes in the unit's thermodynamic state (changes in working fluid and metal temperature, bed material, etc.) are caused by the inherent heat storage characteristics of the unit. When the load increases, heating the metal pipes and increasing the steam temperature and pressure requires additional coal consumption, thus increasing coal consumption. When the load decreases, the coal consumption decreases as the system continues to release stored heat. Second, the control system (combustion control, steam temperature control, feedwater control, etc.) cannot keep up in time during load change operations, leading to control deviations (such as parameter fluctuations), which cause changes in coal consumption. This reflects the level of operation and the quality of the control system. If not properly controlled, significant fluctuations in parameters such as steam temperature and pressure during load increases / decreases, and a severe deviation of combustion organization from design conditions, can lead to increased coal consumption. Similarly, other operating parameters are also affected by transient load changes. Therefore, the boiler's instantaneous efficiency also deviates from its steady-state efficiency. These deviations are caused by the transient load change process and can be used for boiler energy efficiency evaluation during transient load changes.

[0012] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] This application provides an energy efficiency evaluation method for coal-fired boilers during variable load processes, which can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be set up independently, integrated into server 104, or placed in the cloud or on other servers. Terminal 102 can send real-time monitoring data during boiler transient load changes to server 104. After receiving the real-time monitoring data, server 104 preprocesses the data to obtain preprocessed real-time monitoring data; determines the main steam outlet enthalpy based on the preprocessed main steam pressure and temperature; determines the feedwater enthalpy based on the preprocessed economizer inlet feedwater pressure and temperature; determines the reheat steam outlet enthalpy based on the preprocessed reheater outlet steam pressure and temperature; determines the reheat steam inlet enthalpy based on the preprocessed high-pressure cylinder exhaust pressure and temperature; and determines the reheat steam inlet enthalpy based on the boiler transient load changes. During the load process, the instantaneous efficiency and time-averaged efficiency are determined by measuring the pre-treated coal consumption, pre-treated main steam flow rate, main steam outlet enthalpy, feedwater enthalpy, pre-treated reheat steam flow rate, reheat steam outlet enthalpy, and reheat steam inlet enthalpy at different times for each group of pre-treated components. Based on the instantaneous efficiency, time-averaged efficiency, and pre-treated load at each time point, load-instantaneous efficiency curves and load-time-averaged efficiency curves are determined. The area of ​​deviation between the load-time-averaged efficiency curve and the load-efficiency curve under stable boiler operating conditions is calculated, as well as the degree of fluctuation of the load-instantaneous efficiency curve. Based on the area of ​​deviation and the degree of fluctuation, the energy efficiency of the boiler during the transient load change process is evaluated. Server 104 can feed back the obtained energy efficiency evaluation results of the boiler during the transient load change process to terminal 102. In addition, in some embodiments, the energy efficiency evaluation method for the variable load process of a coal-fired boiler can also be implemented by the server 104 or the terminal 102 separately. For example, the terminal 102 can directly process the real-time monitoring data during the transient load change process of the boiler, or the server 104 can obtain the real-time monitoring data during the transient load change process of the boiler from the data storage system and process it.

[0015] The terminal 102 can be, but is not limited to, various desktop computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, and smart in-vehicle devices. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted devices. The server 104 can be implemented using a standalone server or a server cluster composed of multiple servers, or it can be a cloud server.

[0016] In one exemplary embodiment, such as Figure 2 As shown, a method for evaluating the energy efficiency of a coal-fired boiler during variable load processes is provided. This method is executed by computer equipment, specifically by a terminal or server alone, or by both a terminal and a server. In this embodiment, the method is applied to... Figure 1 Taking server 104 as an example, the explanation includes the following steps 201 to 210. Wherein: Step 201: Obtain real-time monitoring data during the transient load change process of the boiler; the real-time monitoring data includes real-time collected load, coal consumption, main steam flow rate, main steam pressure, main steam temperature, economizer inlet feedwater pressure and feedwater temperature, reheat steam flow rate, reheater outlet steam pressure and steam temperature, high-pressure cylinder exhaust pressure, and exhaust temperature.

[0017] Step 202: Preprocess the real-time monitoring data to obtain preprocessed real-time monitoring data.

[0018] Step 203: Determine the main steam outlet enthalpy based on the pretreated main steam pressure and main steam temperature.

[0019] Step 204: Determine the feedwater enthalpy based on the pretreated economizer inlet feedwater pressure and feedwater temperature.

[0020] Step 205: Determine the reheat steam outlet enthalpy based on the pretreated reheater outlet steam pressure and outlet steam temperature.

[0021] Step 206: Determine the inlet enthalpy of reheat steam based on the pre-treated high-pressure cylinder exhaust pressure and exhaust temperature.

[0022] Step 207: Based on the pre-treated coal consumption, pre-treated main steam flow rate, main steam outlet enthalpy, feedwater enthalpy, pre-treated reheat steam flow rate, reheat steam outlet enthalpy, and reheat steam inlet enthalpy of each group at different times during the boiler transient load change process, determine the instantaneous efficiency and time-averaged efficiency at each time.

[0023] Step 208: Determine the load-instantaneous efficiency curve and the load-average efficiency curve based on the instantaneous efficiency, average efficiency, and pre-processed load at each time point.

[0024] Step 209: Calculate the area of ​​deviation between the load-time average efficiency curve and the load-efficiency curve under stable boiler operating conditions, and calculate the degree of fluctuation of the load-instantaneous efficiency curve.

[0025] Step 210: Evaluate the energy efficiency of the boiler during transient load changes based on the deviation area and the degree of fluctuation.

[0026] As an optional implementation, the process of determining the load-efficiency curve under stable boiler operating conditions specifically includes: 1-1) Obtain the steady-state efficiency of the boiler under stable operating conditions corresponding to different loads; each steady-state efficiency is determined by using the inverse balance method based on the corresponding energy efficiency test of the boiler.

[0027] 1-2) Based on the steady-state efficiency under different loads, the load-efficiency curve under the steady-state operating conditions of the boiler is obtained by fitting.

[0028] As an optional implementation, the instantaneous efficiency is determined according to the instantaneous efficiency calculation formula, which is: ; in, Indicates instantaneous efficiency; The coal consumption is expressed in kg / s and is based on the cumulative value of the feeder belt scale. When the belt scale drifts for a long time or the coal flow fluctuates, causing large fluctuations in coal consumption, it is necessary to use an algorithm for data preprocessing. This indicates the lower heating value of the coal sample, expressed in kJ / kg. It is assumed that the calorific value of the coal sample remains stable during periods of variable load, and the value measured at the sampling point is the standard. This indicates the main steam flow rate, in kg / h. This represents the enthalpy of the main steam outlet, in kJ / kg. It can be obtained by looking up the enthalpy-entropy table based on the main steam pressure and temperature. This represents the feedwater enthalpy, expressed in kJ / kg. It is obtained by referring to the enthalpy-entropy table based on the feedwater pressure and temperature at the economizer inlet. This indicates the reheat steam flow rate, in kg / h. When measurement conditions are complex, the main steam flow rate can be subtracted from the high-pressure cylinder extraction steam flow rate. This represents the enthalpy of the reheat steam outlet, in kJ / kg. It can be obtained by looking up the enthalpy-entropy table based on the reheater outlet pressure and temperature. This represents the inlet enthalpy of reheat steam, in kJ / kg. It is obtained by referring to the enthalpy-entropy table based on the exhaust pressure and temperature of the high-pressure cylinder.

[0029] As an optional implementation, the time-averaged efficiency is determined according to the time-averaged efficiency calculation formula, which is: ; in, Indicates time-average efficiency; Indicates the start time of the transient load change process. It represents any moment in the transient load change process.

[0030] As an optional implementation, the area of ​​deviation between the calculated load-time average efficiency curve and the load-efficiency curve under stable boiler operating conditions specifically includes: The absolute value of the difference between the load-time average efficiency curve and the load-efficiency curve under stable boiler operating conditions is integrated to obtain the deviation area.

[0031] As an optional implementation, the energy efficiency of the boiler during transient load changes is evaluated based on the deviation area and the degree of fluctuation, specifically including: Based on the deviation area and the degree of fluctuation, the energy efficiency of the boiler during the transient load change process is evaluated using preset evaluation rules. The preset rules include: the smaller the deviation area, the higher the energy efficiency level of the boiler during the transient load change process; the smaller the degree of fluctuation, the stronger the energy efficiency stability of the boiler during the transient load change process.

[0032] As an optional implementation, the preprocessing includes: outlier removal, filtering and noise reduction, resampling, and time alignment.

[0033] To aid understanding by those skilled in the art, the following embodiments further illustrate the points.

[0034] Since current boiler energy efficiency testing and evaluation rules apply to steady-state operating conditions, there is a lack of a boiler energy efficiency evaluation system for transient load changes. This embodiment, based on the steady-state deviation concept, constructs a boiler energy efficiency evaluation method for transient load changes from the perspectives of positive balance and negative balance. This includes: firstly, conducting performance tests under wide-load stable operating conditions, calculating boiler efficiency based on negative balance, and fitting a load-efficiency curve under steady-state operation as a benchmark reference system; during the load change process, calculating the boiler's instantaneous efficiency and time-averaged efficiency based on positive balance, plotting the load-instantaneous efficiency curve and the load-time-averaged efficiency curve, and evaluating the energy efficiency of the load change process through the analysis of these three curves.

[0035] This embodiment provides a method for evaluating the energy efficiency of a coal-fired boiler during variable load processes based on steady-state deviation, which mainly consists of the following steps: (1) Establish a steady-state energy efficiency reference system: Boiler performance tests were conducted under multiple steady load conditions, and the steady-state efficiency of the boiler under each load was calculated based on the inverse balance method. Fitting the boiler load-steady-state efficiency curve This serves as a benchmark for energy efficiency comparison during variable load processes.

[0036] (2) Real-time operation data acquisition: During the boiler's variable load operation, boiler operation data is collected from the control system in real time. The data includes at least coal consumption, boiler load (hereinafter referred to as load), main steam flow, main steam temperature, main steam pressure, feedwater parameters (economizer inlet feedwater pressure and feedwater temperature) and reheat steam parameters (reheater outlet steam pressure and outlet steam temperature).

[0037] (3) Data processing: The collected data is subjected to outlier removal, filtering and noise reduction, resampling, and time alignment. First, based on the dynamic characteristics of historical data on boiler fuel input and steam output, a suitable algorithm is selected for outlier removal and filtering and noise reduction, and the time lag data τ is calculated using cross-correlation. Then, the real-time monitored coal consumption and steam parameters are processed and automatically shifted and aligned to match the boiler input energy and output energy under a unified time reference.

[0038] Since the steam quantity signal lags behind the coal feed quantity signal, the coal feed quantity signal can be aligned with the steam quantity signal by calculating the delay time for subsequent calculations. Therefore, the time lag compensation involves determining the dynamic time delay by calculating the correlation between the coal feed quantity signal and the steam signal, and then performing time shift correction on the coal consumption data.

[0039] Among them, filtering and noise reduction are performed using algorithms such as moving average filtering, weighted filtering, or Kalman filtering.

[0040] (4) Transient efficiency calculation: Based on the positive balance concept, the instantaneous thermal efficiency of the boiler is calculated using the processed real-time data. And form a load-instantaneous efficiency curve. .

[0041] (5) Calculation of time-averaged efficiency: During the load change time interval, the time-averaged efficiency of the boiler during the load change process is obtained by integrating the cumulative fuel input and cumulative steam output. And form a load-hour average efficiency curve. .

[0042] (6) Calculation of energy efficiency deviation and energy efficiency evaluation: The time-averaged efficiency is calculated. Steady-state reference efficiency under the same load The comparison was performed, and the energy efficiency deviation area during boiler load variation was obtained by integration. Based on energy efficiency deviation area Based on the fluctuation characteristics of the transient efficiency curve, the energy efficiency of the boiler during the load change process is quantitatively or qualitatively evaluated. In this paper, the energy efficiency deviation area is the same as the deviation area.

[0043] This method is applicable to pulverized coal boilers and circulating fluidized bed boilers.

[0044] This embodiment provides a method for evaluating the energy efficiency of a coal-fired boiler during load changes. Its key feature is the calculation of steady-state efficiency through inverse balance and transient efficiency through forward balance. By comparing and analyzing these two methods, the energy efficiency of the boiler during load changes can be calculated and evaluated. See also... Figure 3 The specific steps are explained below: Step 1: Boiler Performance Test. From an anti-balance perspective, conduct boiler energy efficiency tests under wide load stable operating conditions. Select different unit load rates (including at least 4 load rates, such as 30%, 50%, 75%, and 100%), and test the boiler steady-state efficiency according to the specific requirements of national standard GB 10184-2025. Simultaneously, the load-efficiency curve under steady-state operation (i.e., steady operating condition) is fitted. As a comparable benchmark reference system.

[0045] Step 2: Collect real-time monitoring data required for positive balance calculation. During the boiler's transient load change process, collect real-time monitoring data (coal consumption, steam parameters, load, feedwater parameters, etc.) from the DCS (Distributed Control System) or SIS (Safety Instrumented System).

[0046] Step 3: Align, denoise, and resample the real-time monitoring data. Due to the time lag between boiler coal feeding and steam production (potassium pulverized coal boilers may have a lag of 10-20 seconds, while circulating fluidized bed boilers may have a lag of 300 seconds), it is necessary to first select an appropriate algorithm for outlier removal and noise reduction based on the dynamic characteristics of historical boiler fuel input and steam output data, and then automatically calculate the time delay τ using cross-correlation. Next, the raw data of real-time monitored coal consumption and steam parameters are processed (e.g., denoising and resampling) and automatically shifted and aligned to match the boiler's input and output energy under a unified time reference.

[0047] Coal consumption and feedwater parameters change almost simultaneously (similar to the supply side), and load and steam parameters change almost simultaneously (similar to the response side). The alignment method between feedwater and steam parameters can be found in the section on "Alignment Methods for Coal Consumption and Steam Parameters".

[0048] For cross-correlation calculation, algorithms from the existing field of signal analysis can be used.

[0049] Step 4: Calculate the instantaneous efficiency and plot the curve. Boiler instantaneous efficiency See the previous text for the calculation formula.

[0050] Instantaneous efficiency Plot the load-efficiency curves corresponding to the boiler load during the transient load change process. .

[0051] During load changes, the heat storage capacity of the boiler's metal walls and working fluid changes drastically. Therefore, in the initial stage of load increase, The efficiency curve may drop sharply (at which point instantaneous coal consumption increases and steam parameters respond with lag), forming a trough, after which it may rebound but fluctuate. Conversely, in the initial stage of load reduction, the efficiency curve may first rise sharply (at which point instantaneous coal consumption decreases), forming a peak, and then may gradually decline as the load decreases.

[0052] Step 5: Calculate the time-averaged efficiency. The time-averaged efficiency is obtained based on the cumulative coal consumption and cumulative steam consumption. And plotted as a curve of variation with boiler load. The formula for calculating the time-averaged efficiency is given above.

[0053] Average efficiency This represents the overall energy conversion efficiency of the boiler as an energy conversion device during variable load processes, comprehensively reflecting combustion efficiency, heat transfer efficiency, and control quality.

[0054] Step 6: During the boiler load change process, plot the above three thermal efficiency curves, based on the boiler load-efficiency curve during the load change process. , Boiler load-steady-state efficiency curve under stable operating conditions To further analyze the deviation from the target, the energy efficiency characteristics of the boiler during load changes are examined from the following dimensions: ① Boiler load-time average efficiency curve during variable load process Boiler load-steady-state efficiency curve Area of ​​deviation: ; in, This indicates the initial load corresponding to the load change process. This represents the target load corresponding to the load change process. (This area value) The smaller the value, the smaller the "energy loss + heat storage impact" during the entire load change process, and the higher the energy efficiency level of the load change process.

[0055] Here, "size" and "height" are relative terms, referring to boilers with the same parameters, or to different load variations of the same boiler. The smaller the value, the higher the energy efficiency level during the variable load process.

[0056] Regarding starting load and target load, let's illustrate with an example: Due to the influence of renewable energy power generation, boilers typically have a low load rate at midday and a high load rate at night. This means that the boiler may undergo a load-changing process, gradually increasing the load from a low load state at midday (starting load) to a high load state at night (target load). Any time in between midday and night is considered the starting load. .

[0057] ② Boiler load-instantaneous efficiency curve The greater the fluctuation, the more drastic the fluctuations in fuel and steam parameters during the load change process. In this case, it is important to optimize the control system (such as optimizing the coal feeding system, air supply system, steam temperature and pressure control system, etc.).

[0058] The degree of fluctuation can be quantified by the standard deviation of instantaneous efficiency throughout the entire load change process. The larger the standard deviation, the more severe the efficiency fluctuation.

[0059] Relationship with energy efficiency: In addition to the level (or high or low), energy efficiency also involves stability. Especially during variable load processes, energy efficiency stability can reflect whether the overall operating state of the boiler is stable. The closer the overall operating state is to stability, the better the control is, and the easier it is for the boiler to reach the ideal combustion conditions.

[0060] Similarly, energy efficiency stability here is also relative.

[0061] ③ Boiler load-instantaneous efficiency curve The overall change was stable, and the load response was significantly lower than the steady-state reference curve during the load increase process and significantly higher than the steady-state reference curve during the load decrease process, indicating that the load response process is greatly affected by the boiler's heat storage capacity.

[0062] The following situations may also occur: ④ During load increase, the instantaneous efficiency is higher than the steady-state reference curve, while during load decrease, the instantaneous efficiency is lower than the steady-state reference curve. This situation violates the thermodynamic laws of boilers, indicating that the data alignment may be incorrect or there may be a measurement problem. The validity of the data needs to be checked.

[0063] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 4As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores real-time monitoring data during the transient load change process of the boiler. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for evaluating the energy efficiency of a coal-fired boiler during load change.

[0064] Those skilled in the art will understand that Figure 4 The structures shown are merely block diagrams of some structures related to the present application and do not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than shown in the figures, or combine certain components, or have different component arrangements. In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0065] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0066] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0067] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Moreover, the collection, use and processing of the relevant data are carried out in compliance with the relevant data protection laws and policies of the country where the location is located, and with the authorization granted by the owner of the corresponding device.

[0068] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0069] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0070] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for evaluating the energy efficiency of a coal-fired boiler during variable load processes, characterized in that, include: Acquire real-time monitoring data during the boiler's transient load change process; The real-time monitoring data includes real-time collected load, coal consumption, main steam flow rate, main steam pressure, main steam temperature, economizer inlet feedwater pressure and temperature, reheat steam flow rate, reheater outlet steam pressure and temperature, high-pressure cylinder exhaust pressure, and exhaust temperature. The real-time monitoring data is preprocessed to obtain preprocessed real-time monitoring data; The enthalpy of the main steam outlet is determined based on the pretreated main steam pressure and main steam temperature. The feedwater enthalpy is determined based on the pretreated economizer inlet feedwater pressure and feedwater temperature. The reheat steam outlet enthalpy is determined based on the pretreated reheater outlet steam pressure and outlet steam temperature. The inlet enthalpy of reheat steam is determined based on the pre-treated high-pressure cylinder exhaust pressure and exhaust temperature. Based on the pre-treated coal consumption, pre-treated main steam flow rate, main steam outlet enthalpy, feedwater enthalpy, pre-treated reheat steam flow rate, reheat steam outlet enthalpy, and reheat steam inlet enthalpy at different times during the boiler transient load change process, determine the instantaneous efficiency and time-averaged efficiency at each time point. Based on the instantaneous efficiency, average efficiency, and pre-processed load at each time point, determine the load-instantaneous efficiency curve and the load-average efficiency curve. Calculate the area of ​​deviation between the load-time average efficiency curve and the load-efficiency curve under stable boiler operating conditions, and calculate the degree of fluctuation of the load-instantaneous efficiency curve; The energy efficiency of the boiler during transient load changes is evaluated based on the deviation area and the degree of fluctuation.

2. The method for evaluating the energy efficiency of a coal-fired boiler during variable load processes according to claim 1, characterized in that, The process of determining the load-efficiency curve under stable boiler operating conditions specifically includes: The steady-state efficiency of the boiler under stable operating conditions corresponding to different loads is obtained; each steady-state efficiency is determined by using the inverse balance method based on the corresponding energy efficiency test of the boiler. Based on the steady-state efficiency under different loads, the load-efficiency curves of the boiler under stable operating conditions are obtained by fitting.

3. The method for evaluating the energy efficiency of a coal-fired boiler during variable load processes according to claim 1, characterized in that, The instantaneous efficiency is determined according to the instantaneous efficiency calculation formula, which is as follows: ； in, Indicates instantaneous efficiency; Indicates coal consumption; This indicates the lower heating value of the coal sample; Indicates the main steam flow rate; Indicates the enthalpy of the main steam outlet; Indicates the enthalpy of water supply; Indicates the reheat steam flow rate; Indicates the enthalpy of the reheat steam outlet; This indicates the inlet enthalpy of the reheat steam.

4. The method for evaluating the energy efficiency of a coal-fired boiler during variable load processes according to claim 3, characterized in that, The average time efficiency is determined according to the formula for calculating the average time efficiency, which is as follows: ； in, Indicates time-average efficiency; Indicates the start time of the transient load change process. It represents any moment in the transient load change process.

5. The method for evaluating the energy efficiency of a coal-fired boiler during variable load processes according to claim 1, characterized in that, The area of ​​deviation between the calculated load-time average efficiency curve and the load-efficiency curve under stable boiler operating conditions specifically includes: The absolute value of the difference between the load-time average efficiency curve and the load-efficiency curve under stable boiler operating conditions is integrated to obtain the deviation area.

6. The method for evaluating the energy efficiency of a coal-fired boiler during variable load processes according to claim 1, characterized in that, Based on the deviation area and the degree of fluctuation, the energy efficiency of the boiler during transient load changes is evaluated, specifically including: Based on the deviation area and the degree of fluctuation, the energy efficiency of the boiler during the transient load change process is evaluated using preset evaluation rules. The preset rules include: the smaller the deviation area, the higher the energy efficiency level of the boiler during the transient load change process; the smaller the degree of fluctuation, the stronger the energy efficiency stability of the boiler during the transient load change process.

7. The method for evaluating the energy efficiency of a coal-fired boiler during variable load processes according to claim 1, characterized in that, The preprocessing includes outlier removal, filtering and noise reduction, resampling, and time alignment.

8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that the processor executes the computer program to implement the energy efficiency evaluation method for a coal-fired boiler under varying loads as described in any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the method for evaluating the energy efficiency of a coal-fired boiler under varying loads as described in any one of claims 1-7.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the method for evaluating the energy efficiency of a coal-fired boiler under varying loads as described in any one of claims 1-7.

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