An energy-saving control method for economizer based on load adaptation

Abstract

The application discloses a kind of based on load self-adapting economizer energy-saving control method, it is related to industrial process control technical field, including, load advance control program is hung to the corresponding acquisition period of economizer heat exchange state information, extraction flue gas import and export temperature change and feedwater import and export temperature change, and with economizer heat exchange response record is time sequence and is compared, determines heat exchange response deviation, corrects the adjustment direction and execution order of control program section, generates load compensation execution program;Load compensation execution program is split into circulation flow, flue gas flow and feedwater flow control program section, according to adjustment direction and execution order segmented execution, acquisition corresponding period flue gas import and export temperature change and feedwater import and export temperature change, according to response direction and change degree switch execution mode of control program section, forms economizer energy-saving control information.The application improves economizer energy-saving process control precision and operation reliability.

Description

Technical Field

[0001] This invention relates to the field of industrial process control technology, and in particular to an economizer energy-saving control method based on load adaptation. Background Technology

[0002] As coal-fired boilers evolve towards wider load operation, rapid peak shaving, and lower energy consumption, economizer control is gradually shifting from fixed parameter adjustment to process control based on operating conditions. Related technologies typically collect data on boiler load, flue gas inlet and outlet temperatures, feedwater inlet and outlet temperatures, and flow rates. These data are then combined with historical operating curves to establish a correlation between load changes and heat exchange response. The control system adjusts flue gas flow rate, circulating flow rate, and feedwater flow rate to coordinate flue gas waste heat recovery, feedwater heat absorption, and boiler operational stability.

[0003] Existing economizer process control systems often rely on current load values ​​or single temperature differences for regulation, failing to adequately address issues such as misaligned acquisition timings of different operating information, variations in continuous operation stages, and lag in heat exchange response. This can lead to control commands lagging behind actual heat exchange changes when boiler load fluctuates rapidly. Furthermore, multi-flow regulation typically employs a fixed execution sequence or synchronous correction method, lacking differentiation between reverse response, intermittent response, attenuation propagation, and continuous propagation. This makes it difficult to switch control program segments based on actual temperature propagation status, easily causing mutual interference in flow regulation and decreased stability of energy-saving control. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a load-adaptive economizer energy-saving control method to solve the problems of inaccurate connection between load changes and heat exchange response, as well as untimely switching between multiple flow control programs.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a load-adaptive economizer energy-saving control method, comprising: collecting boiler load operation information, economizer heat exchange status information, and equipment historical operation information; aligning timestamps and merging continuous operation segments according to the collection sequence; extracting the load change direction, change rate, and duration; and extracting corresponding economizer heat exchange response records from the equipment historical operation information to generate load program scheduling basic data; combining the load program scheduling basic data with the economizer heat exchange response records; dividing continuous change segments according to the load change direction; and verifying the connection between the continuous change segments and the start and end times of the heat exchange response records to obtain the flue gas temperature difference change trend and heat exchange response lag; and simultaneously combining the circulating flow rate, flue gas flow rate, and feedwater flow rate... The adjustment direction and sequence are arranged into control program segments to form a load advance control program. The load advance control program is then linked to the corresponding acquisition period of the economizer heat exchange status information. The changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures are extracted and compared with the economizer heat exchange response records in time sequence to determine the deviation in heat exchange response. The adjustment direction and execution sequence of the control program segments are then corrected to generate a load compensation execution program. The load compensation execution program is then divided into circulating flow, flue gas flow rate, and feedwater flow rate control program segments. These segments are executed according to the adjustment direction and execution sequence. The changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in the corresponding time periods are collected. The execution mode of the control program segments is switched according to the response direction and degree of change to form economizer energy-saving control information.

[0007] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the steps of performing timestamp alignment and merging continuous operation segments are as follows: Based on the collection time and recording order of boiler load operation information, economizer heat exchange status information and equipment historical operation information, duplicate records are eliminated, and information within the same operating period is linked to a unified time position to form a time-aligned operation sequence. Based on the time-series aligned operation sequence, the continuous acquisition of data and the continuous operation of the boiler are checked at adjacent time positions. The acquisition disconnection, boiler start-up and shutdown switching and operation phase separation positions are marked. The continuous records between the segment boundaries are merged to form a set of continuous operation segments.

[0008] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the steps for generating the basic data for load program scheduling are as follows: The boiler load changes in the continuous operation segment set are sorted according to the acquisition time, the time position of the load change direction change is located, the continuous records with the same change direction are divided into load change segments, the load change direction is extracted, the load change rate is calculated, and the continuity of the load change segment is determined to form the load change succession segment. Based on the load change direction and duration in the load change segment, the corresponding historical load segments and economizer heat exchange response records are extracted from the equipment's historical operating information. The start time of the economizer heat exchange change is then linked back to the corresponding load change segment. The load change direction, change rate, duration, and economizer heat exchange response records are collected to generate basic data for load program scheduling.

[0009] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the step of dividing the continuously changing segment according to the direction of load change is as follows: Based on the load program arrangement of basic data, the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in the economizer heat exchange response record are linked to a unified acquisition time axis to form a load heat exchange time sequence. Based on the load heat exchange time series, load change segments are divided according to the load change direction, change rate and collection continuity. The segment boundaries are checked and short-term boundaries formed by instantaneous sampling fluctuations are removed to generate a set of continuous change segments.

[0010] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the step of obtaining the flue gas temperature difference change trend is as follows: Around the start and end times of the continuously changing range, locate the starting time of the continuous change of flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures, exclude temperature fluctuations at individual collection times, and mark the heat exchange response frontier according to the order of the starting times to form a load heat exchange receiving window. Organize the temperature change trajectory in the load heat exchange receiving window according to the transfer sequence from the flue gas inlet side to the flue gas outlet side, calculate the temperature difference between the flue gas inlet and outlet, mark the direction of increase or decrease, the magnitude of change and the location of continuous pauses of the temperature difference between the flue gas inlet and outlet, and form the trend of flue gas temperature difference change.

[0011] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the steps for forming the load advance control program are as follows: Following the transmission sequence of load change, flue gas side response, economizer heat exchange, and feedwater side response, the starting time of each change is compared and the pause marks caused by single sampling deviation are eliminated to determine the lag in flue gas side response, heat transfer lag, and feedwater side response, and heat exchange response lag information is generated. By combining the flue gas temperature difference change trend and heat exchange response lag information, the adjustment direction and execution sequence of flue gas flow rate, circulation flow rate and feedwater flow rate are determined. Control program segments are arranged according to the corresponding continuously changing sections. The control program segments corresponding to the lag links are moved forward and written into the lag mark to form the load advance control program.

[0012] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the steps for extracting the changes in flue gas inlet and outlet temperatures and the changes in feedwater inlet and outlet temperatures are as follows: Extract the continuously changing section, control program segment, adjustment direction, execution sequence and lag mark from the load advance control program. Locate the corresponding collection time period in the economizer heat exchange status information according to the start and end time of the continuously changing section. Link the control program segment with the flue gas inlet and outlet temperature records and the feedwater inlet and outlet temperature records to form an adjustment heat exchange receiving window. The temperature changes of flue gas inlet and outlet and feedwater inlet and outlet in the regulating heat exchange receiving window are continuously processed according to the collection time. Single-point temperature jumps that are not sustained are eliminated. The start and end times, direction of change and duration of each temperature change are calibrated. The temperature change receiving relationship is established according to the transmission sequence from the flue gas side to the feedwater side, forming a regulating temperature response sequence.

[0013] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the steps for generating the load compensation execution program are as follows: The temperature response sequence is compared with the economizer heat exchange response record according to the load change direction and continuous change section. The positions of delayed temperature change start, inconsistent change direction and interrupted temperature transmission are marked. The marked positions are then attached to the corresponding control program segments of flue gas flow rate, circulation flow rate and feedwater flow rate to generate heat exchange response deviation marks. Based on the heat transfer response deviation marker, the adjustment direction and execution sequence of the control program segments in the load advance control program are corrected. The control program segments with delayed start are moved forward, the adjustment direction of control program segments with inconsistent change directions is adjusted, and the control program segments corresponding to the temperature transfer interruption position are executed in advance. The corrected control program segments, execution sequence, continuous change sections and heat transfer response deviation markers are collected to generate the load compensation execution program.

[0014] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the steps for collecting the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures within the corresponding time period are as follows: Extract the adjustment direction, execution sequence, continuous change section and heat exchange response deviation mark corresponding to the circulating flow, flue gas flow and feedwater flow from the load compensation execution program. Divide the program into circulating flow control program segment, flue gas flow control program segment and feedwater flow control program segment according to the flow type, and divide the program into continuous execution segments according to the execution sequence to form a segmented program execution sequence. The circulating flow rate, flue gas flow rate, and feedwater flow rate are changed sequentially according to the segmented program execution sequence. The changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in each continuous execution segment are collected simultaneously. Single-point temperature jumps that are not continuously maintained are eliminated, and the start and end times, direction of change, magnitude of change, rate of change, and duration of each temperature change are linked to the corresponding continuous execution segment to form a segmented program response record.

[0015] As a preferred embodiment of the economizer energy-saving control method based on load adaptation described in this invention, the steps for forming economizer energy-saving control information are as follows: According to the heat transfer sequence of flue gas inlet, flue gas outlet, feedwater inlet and feedwater outlet, the temperature change direction, change amplitude and duration in the segmented program response records are connected in series and compared with the economizer heat transfer response records of the corresponding continuous change section. Records with inconsistent directions are classified as reverse response records, records with consistent directions and change amplitude less than the heat transfer response amplitude threshold are classified as attenuated transfer records, and records with consistent directions, continuous transfer and change amplitude not less than the heat transfer response amplitude threshold are classified as continuous transfer records, thus forming segmented program response classification information. Based on the segmented program response classification information, the execution mode of the corresponding control program segment is switched, the flow value of the control program segment corresponding to the continuous transmission record is maintained, the execution period of the control program segment corresponding to the attenuation transmission record is extended, the next control program segment associated with the intermittent response record is moved forward, and the control program segment corresponding to the reverse response record is stopped. The corresponding flow is restored to the flow value corresponding to the most recent continuous transmission record of the same flow type. If no continuous transmission record is formed, it is restored to the initial flow value before the segmented program execution, thus forming economizer energy-saving control information.

[0016] The beneficial effects of this invention are as follows: by verifying the load change section and the heat exchange response time, the lag in the heat exchange link is identified and the control program segment is moved forward, thereby realizing the load advance process control, which is used to reduce the adjustment lag under variable load and improve the timeliness and stability of waste heat recovery; by classifying the temperature response of the continuous execution segment and switching the execution mode of the control program segment, the multi-flow regulation is realized according to the heat exchange state, which is used to suppress mutual interference of control and improve the control accuracy and operational reliability of the economizer energy-saving process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a flowchart of an economizer energy-saving control method based on load adaptation.

[0019] Figure 2 A flowchart for constructing basic data for multi-source operation information calibration and load program scheduling.

[0020] Figure 3 This is a flowchart illustrating the formation of load change receiving segments and the historical heat exchange response re-hanging process.

[0021] Figure 4 A flowchart is generated for the heat exchange response deviation identification and load compensation execution procedure. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0025] Reference Figures 1-4 This is one embodiment of the present invention, which provides an economizer energy-saving control method based on load adaptation, comprising the following steps: S1: Collect boiler load operation information, economizer heat exchange status information, and equipment historical operation information. Perform timestamp alignment and merge continuous operation segments according to the collection time sequence. Extract the load change direction, change rate, and duration. Extract the corresponding economizer heat exchange response records from the equipment historical operation information to generate basic data for load program scheduling.

[0026] S1.1: Based on the collection time and recording order of boiler load operation information, economizer heat exchange status information and equipment historical operation information, duplicate records are eliminated, and information within the same operating period is linked to a unified time position to form a time-aligned operation sequence.

[0027] Furthermore, regarding the collection time and recording order of boiler load operation information, economizer heat exchange status information, and equipment historical operation information, the records from each source are arranged chronologically, and the operation stage and original sequence are retained. For duplicate items with the same collection source, the same collection time, and the same recorded content, only one is retained. For records with the same collection time but different recorded content, the valid items are determined based on the continuity of change between adjacent records. A unified time position is set based on the collection time of boiler load operation information, and the economizer heat exchange status information and equipment historical operation information within the same operating period are linked to the corresponding time position to form an initial time sequence linking relationship.

[0028] The initial time sequence connection relationship is used to verify the adjacency of the boiler start-up and shutdown phase, load operation phase, and data acquisition time, eliminating records connected across operating phases. For records that do not coincide with a unified time position, they are connected to the time position consistent with the operating phase according to the proximity of the acquisition time, and the correspondence between the original acquisition time and the unified time position is preserved. The order of records from each source is checked along the unified time position, and positions with missing corresponding records are reserved as vacant positions to avoid using records from other operating phases to fill in the gaps. Boiler load operation information, economizer heat exchange status information, and equipment historical operation information are collected according to the unified time position to form a time-aligned operation sequence.

[0029] S1.2: Based on the time-series aligned operation sequence, check the acquisition continuity and boiler operation continuity of adjacent time positions, mark the acquisition disconnection, boiler start-up and shutdown switching and operation phase separation positions, merge the continuous records between the segment boundaries to form a continuous operation segment set.

[0030] Furthermore, adjacent records are compared item by item along the time-aligned operation sequence at the same time position to verify the acquisition interval, record continuity, and boiler operation stage between the previous and next time positions. Adjacent records with continuous acquisition intervals and no change in boiler operation stage are maintained in their original connection. Acquisition disconnection positions are set for positions where there are gaps in the same time position, abnormal time spans of adjacent records, or where the record sequence cannot be continuously connected. Combining the boiler start-up and shutdown status and load operation stage, boiler start-up and shutdown switching positions and operation stage separation positions are set for positions where the boiler changes from shutdown to operation, from operation to shutdown, and where there are cross-segment changes in load operation stage, forming the operation segment boundary.

[0031] Using the boundaries of operating segments as dividing points, the connection relationships between each time position are re-organized along the time sequence alignment. Records with continuous acquisition at adjacent time positions, continuous boiler operation, and no segment boundaries are grouped into the same operating segment, while records on both sides of the segment boundary are grouped into different operating segments to avoid cross-segment mixing of records before and after boiler start-up and shutdown and records at different load operation stages. The time positions within the operating segment are corrected sequentially, vacant positions and corresponding disconnection relationships are retained, and the start time position, end time position, and recording order within the segment are registered for each operating segment. The operating segments are then collected according to the order of operation to form a set of continuous operating segments.

[0032] S1.3: Organize the boiler load changes in the continuous operation segment set according to the acquisition time, locate the time position where the load change direction changes, divide the continuous records with the same change direction into load change segments, extract the load change direction, calculate the load change rate, and determine the duration of the load change segment to form a load change succession segment.

[0033] Furthermore, the boiler load records in the continuous operation segment set are arranged sequentially according to the acquisition time, while keeping the segment boundaries between each continuous operation segment unchanged. The boiler load corresponding to adjacent acquisition times is compared item by item along each continuous operation segment. Positions where the load at the later acquisition time is higher than the load at the earlier acquisition time are classified as increasing load direction, positions where the load at the later acquisition time is lower than the load at the earlier acquisition time are classified as decreasing load direction, and positions where the load does not show a continuous increase or decrease are classified as stable direction. Load change boundaries are set around the transition positions of increasing load direction, decreasing load direction, and stable direction, and short-term transitions that only last for a single acquisition interval and are not carried over by subsequent changes in the same direction are merged, retaining the directional transition positions that can reflect the continuous changes in boiler load.

[0034] The records between adjacent load change boundaries are considered as a load change segment. Boiler load records with the same change direction and continuous acquisition time are merged into the corresponding load change segment. The load change rate is calculated according to the boiler load difference and time span corresponding to the start and end times of the load change segment, and the abnormal rate is corrected by combining the load increase and decrease at adjacent acquisition times within the load change segment. The duration is determined by the start and end times of the load change segment, while retaining the number of acquisition positions that maintain continuous change direction. The load change direction, load change rate, start and end times, and duration are linked to the corresponding load change segment to form a load change connection segment.

[0035] The formula for calculating the rate of load change is: ; ; in, Indicates the rate of load change. This indicates the boiler load corresponding to the start time of the load change segment. This indicates the boiler load corresponding to the end time of the load change segment. Indicates the start time of the load change section. Indicates the end time of the load change section. Indicates the load-bearing coefficient in the direction of load. This indicates the correction factor. Indicates the first [unit] within the load change zone The boiler load corresponding to each data collection location Indicates the first The boiler load corresponding to the previous data collection location. Indicates the data collection location. This indicates the total number of data collection points within the load variation zone. This represents a very small positive number, used to prevent the denominator from being zero. This represents the natural exponential function.

[0036] It should be noted that the load direction continuity factor (example range: 0 to 1) is determined based on the proportion of the load difference between the beginning and end of the load change section to the cumulative value of the adjacent load changes within the section. The closer the value is to 1, the more continuous the load change direction is.

[0037] The bearing correction factor (example range: 0.1 to 1.0) is calibrated based on the correspondence between the degree of load fluctuation and the degree of deviation of the actual heat exchange response in the equipment's historical operating information. The larger the value is when the fluctuation effect is more obvious.

[0038] The formula calculates the rate of change of the basic load using the difference between the first and last loads of a section and the time span, and introduces a load direction carrying capacity coefficient for exponential correction. This is mainly because using only the difference between the first and last loads is insufficient to reflect the cyclical fluctuations within a section. When the load change within a section continues to change in the same direction, the difference between the first and last loads is close to the cumulative value of the absolute values ​​of the load changes at each adjacent sampling location, and the rate of change of the basic load remains basically constant. When multiple reverse fluctuations occur within a section, the load direction carrying capacity coefficient decreases accordingly. The exponential correction term nonlinearly compresses the rate of change of the basic load to avoid artificially inflated rates of change caused by short-term fluctuations, while retaining the positive and negative directions and original dimensions corresponding to load increases and decreases.

[0039] The load direction carrying coefficient is determined based on the boiler load records within the current load change segment. The total number of collection points is determined by the number of valid collection records between the start and end times of the segment. The boiler load corresponding to each collection point participates in the adjacent difference accumulation according to the order of collection. The carrying correction coefficient is calibrated based on the correspondence between the degree of load cyclical fluctuation and the degree of heat exchange response deviation in the equipment's historical operating information. It is used to control the correction strength of the load direction carrying coefficient on the basic load change rate. The minimum positive number is set to a value significantly lower than the normal load change amount. It is only used to prevent the denominator from being zero when the cumulative load change value is close to zero, and it does not have a substantial impact within the normal load change segment.

[0040] S1.4: Based on the load change direction and duration in the load change segment, extract the corresponding historical load segments and economizer heat exchange response records from the equipment's historical operating information, reattach the start time of the economizer heat exchange change to the corresponding load change segment, and collect the load change direction, change rate, duration, and economizer heat exchange response records to generate basic data for load program scheduling.

[0041] Furthermore, using the load change direction and duration within the load change segment as historical retrieval criteria, historical records with consistent operating phases, identical load change directions, and durations covering the corresponding load change segments are filtered from the equipment's historical operating information. Candidate historical load segments are defined around each historical record, and the corresponding load change rate, load direction carrying coefficient, and duration are extracted. The overall similarity between each candidate historical load segment and the current load change segment is calculated and sorted from largest to smallest based on the overall similarity. Historical records of boiler start-up / shutdown switching, data acquisition disconnection, and mid-term load direction reversal are excluded. The actual values, adjustment directions, action times, and execution status of the circulating flow rate, flue gas flow rate, and feedwater flow rate within the corresponding time period of the historical load segment are retained and continuously arranged with the flue gas inlet / outlet temperature changes and feedwater inlet / outlet temperature changes according to the acquisition time to form an economizer heat exchange response record.

[0042] Based on the load change start time of historical load segments, locate the time position where the flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures begin to change continuously along the economizer heat exchange response record; exclude temperature fluctuations that only appear at a single acquisition time and are not carried over by subsequent changes in the same direction, determine the time position where the continuous change first occurs as the economizer heat exchange change start time, and link it back to the corresponding load change segment; collect the load change direction, load change rate, duration, comprehensive proximity, economizer heat exchange response record and corresponding start time according to the load change segment, maintain the linkage relationship between each item and the load change segment, and generate the basic data for load program arrangement.

[0043] It should be noted that the basic data for load program scheduling specifically includes load change segments, load change direction, load change rate, duration, economizer heat exchange response records, and the corresponding start time of heat exchange changes, while retaining the connection relationship between each item and the load change segment. The economizer heat exchange response records also include the actual values ​​of circulation flow rate, flue gas flow rate, feedwater flow rate, adjustment direction, action time, execution status, and changes in flue gas inlet and outlet and feedwater inlet and outlet temperatures.

[0044] The formula for calculating the degree of closeness is: ; in, Indicates the first The degree of similarity between historical load segments and current load change segments. Indicates the number of the historical load segment, Indicates the first The rate of load change for each historical load segment Indicates the first Load direction bearing capacity of a historical load segment Indicates the duration of a historical load segment. Indicates the duration of the current load change segment. It represents a very small positive number.

[0045] S2: Combine the load program arrangement basic data with the economizer heat exchange response record, divide the continuous change section according to the load change direction, and verify the connection between the continuous change section and the start and end times of the heat exchange response record to obtain the flue gas temperature difference change trend and heat exchange response lag. At the same time, arrange the adjustment direction and sequence of the circulation flow, flue gas flow rate and feedwater flow rate into control program segments to form the load advance control program.

[0046] S2.1: Based on the load program arrangement of basic data, the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in the economizer heat exchange response record are linked to a unified acquisition time axis to form a load heat exchange time sequence.

[0047] Furthermore, taking the load change segments in the load program arrangement basic data as the attachment objects, a unified acquisition time axis is set according to the start and end times of the load change segments, and the load change direction, change rate and duration are written into the corresponding time range; around each load change segment, temperature records with mutually overlapping time ranges are located in the economizer heat exchange response record, and the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures are arranged to the unified acquisition time axis according to the original acquisition time; temperature records whose acquisition time completely coincides with the time position of the unified acquisition time axis are directly attached, and temperature records whose acquisition time is between adjacent time positions are assigned to the corresponding time positions according to the adjacent relationship, while retaining the original acquisition time.

[0048] The operation stages and time sequence of the load change sections and economizer heat exchange response records are checked along a unified acquisition time axis. Temperature records that cross section boundaries, boiler start-up and shutdown positions, and acquisition disconnection positions are excluded. In cases where multiple similar temperature records exist at the same time position, temperature records that can be continuously connected are retained according to the acquisition continuity and the direction of change. For time positions where no corresponding temperature record is formed, a blank mark is retained, and temperature records from adjacent load change sections are not used to fill the gap. The load change direction, change rate, duration, and changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures corresponding to each time position are sequentially connected in series to form a load heat exchange time sequence.

[0049] It should be noted that the time range (example range: 1-3 minutes before the start of the load change section to 5-10 minutes after the end of the section) is determined based on the boiler load sampling cycle, the economizer thermal inertia, and the heat exchange response lag time in the equipment's historical operating information.

[0050] S2.2: Based on the load heat exchange time sequence, load change segments are divided according to the load change direction, change rate and collection continuity. The segment boundaries are checked and short-term boundaries formed by instantaneous sampling fluctuations are eliminated to generate a set of continuous change segments.

[0051] Furthermore, the load change direction and rate of change are compared item by item along the unified acquisition time axis in the load heat exchange time sequence. Records with continuously increasing load, continuously decreasing load, and no increase or decrease in load at multiple consecutive acquisition times are connected in series. When the load change direction of adjacent records is consistent and the rate of change does not show continuous reverse change, they are classified into the same candidate segment. When the load change direction changes, the rate of change deviates continuously from the original change direction, or the acquisition time loses continuity, candidate segment boundaries are set. The direction change is checked around the candidate segment boundaries to see if it can be continuously inherited by subsequent records in the same direction, and candidate segment boundaries that can distinguish different load change processes are retained.

[0052] For candidate segment boundaries that are continuously sampled for a single interval and have the same load change direction before and after the boundary, the records inside the boundary are incorporated into the original continuous change process. For direction reversal caused by instantaneous sampling fluctuations, the corresponding candidate segment boundaries are removed when the load returns to its original change direction. Segment boundaries are retained for sampling disconnection locations, locations where the load change direction continuously changes, and locations where the change rate cannot be continuously carried along the original direction. Load change segments are redefined according to the retained segment boundaries, and the start and end times of the segments, the load change direction, the change rate, and the continuous sampling relationship are linked to the corresponding segments to generate a set of continuous change segments.

[0053] S2.3: Based on the start and end times of the continuously changing range set, locate the starting time of the continuous change of flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures, exclude temperature fluctuations at individual acquisition times, and mark the heat exchange response frontier according to the order of the starting times to form a load heat exchange receiving window.

[0054] Furthermore, using the start and end times of the segments in the set of continuously changing segments as the positioning benchmark, the temperature change direction at adjacent acquisition times of the flue gas inlet, flue gas outlet, water supply inlet, and water supply outlet is compared along the axial boundary of the segment during unified acquisition. The position where the temperature begins to deviate from the stable state before the segment boundary is taken as the candidate response position, and the temperature change is checked along the candidate response position to see if it can maintain the same direction of increase or decrease. Temperature records that only show an increase or decrease at a single acquisition time and resume the original change trajectory at the next acquisition time are treated as instantaneous fluctuations and are not included in the continuous change process. For temperature records that maintain the same direction of change at multiple consecutive acquisition times, the earliest change position is retained as the starting time of the continuous change.

[0055] The temporal continuity between temperature changes and corresponding continuous change segments is verified around the start time of each continuous change. Continuous change records that are located after the start time of a segment and do not cross the end time of the segment are linked to the corresponding segment. For temperature records that continue to change in the same direction after the end time of a segment, the linkage range is extended along the original direction of change until the temperature reaches a stable state or changes in the opposite direction. The start times of each continuous change are arranged according to the heat transfer sequence from the flue gas side to the feedwater side. The temperature position that first forms a continuous change and its subsequent records of changes in the same direction are marked as the heat transfer response frontier. The heat transfer response frontier, the corresponding continuous change segment, and the time continuity range are collected to form the load heat transfer continuity window.

[0056] It should be noted that multiple consecutive sampling times can be set as three consecutive sampling times, meaning that from the candidate response position, the temperature changes in three consecutive valid samples maintain the same direction of increase or decrease, the sampling process is uninterrupted, and the cumulative temperature change is greater than the minimum resolution of the temperature sensor. This is determined based on the temperature sampling period, the economizer's thermal inertia, and the on-site noise level, and is used to eliminate single-point fluctuations and short-term disturbances.

[0057] S2.4: Organize the temperature change trajectory in the load heat exchange receiving window according to the transfer sequence from the flue gas inlet side to the flue gas outlet side, calculate the temperature difference between the flue gas inlet and outlet, mark the direction of increase or decrease, the magnitude of change and the position of continuous pause of the temperature difference between the flue gas inlet and outlet, and form the trend of flue gas temperature difference change.

[0058] Furthermore, according to the flow sequence of flue gas from the inlet side to the outlet side within the economizer, the flue gas inlet temperature records and flue gas outlet temperature records in the load heat exchange receiving window are arranged in chronological order; a correspondence between the inlet temperature records and outlet temperature records is established using the same acquisition time on a unified acquisition time axis, and the flue gas outlet temperature records are aligned with the heat exchange response frontier; for temperature records that cannot form a corresponding position, a blank mark is retained, and the aligned flue gas inlet temperature, flue gas outlet temperature, and corresponding temperature change are substituted into the flue gas inlet and outlet temperature difference formula to calculate the flue gas inlet and outlet temperature difference at each acquisition time, and then attached to the corresponding continuous change section and heat exchange response frontier.

[0059] The temperature differences between adjacent flue gas inlets and outlets are compared sequentially along the acquisition time. Records with continuously increasing temperature differences are marked as temperature increase, and records with continuously decreasing temperature differences are marked as temperature decrease. The change range is determined by the temperature difference difference between the first and last positions of records with the same direction of change. When the change in adjacent temperature differences is not greater than the temperature difference change corresponding to the temperature acquisition resolution and is maintained for multiple consecutive acquisition times, a continuous pause mark is set. When the same direction of change does not continue in subsequent acquisition times, the stop position is marked as the change interruption position. The direction of increase or decrease in temperature difference, the change range, the continuous pause position, and the change interruption position are collected according to the acquisition sequence to form the flue gas temperature difference change trend.

[0060] The formula for calculating the temperature difference between the flue gas inlet and outlet is:

[0061] in, This indicates the temperature difference between the flue gas inlet and outlet. This indicates the flue gas inlet temperature at the current sampling moment. This indicates the flue gas outlet temperature after response hysteresis alignment. This indicates the change in flue gas inlet temperature relative to the previous data collection time. This represents the change in flue gas outlet temperature after response hysteresis alignment relative to the previous corresponding data acquisition time. This represents the correction factor for the direction of temperature change. This represents a very small positive number, used to prevent the denominator from being zero. This represents the hyperbolic tangent function.

[0062] The temperature change direction correction factor (example range: 0.1 to 0.8) is calibrated based on the correspondence between the consistency of flue gas inlet and outlet temperature change directions in the equipment's historical operating information and the actual heat exchange intensity.

[0063] The formula uses the difference between the flue gas inlet temperature and the flue gas outlet temperature after response lag alignment as the base temperature difference. It then uses the product of the temperature changes on both sides to determine if the directions of change are consistent, and finally performs dimensionless normalization through the sum of squares to avoid the magnitude of temperature changes interfering with the determination of the directional relationship. When the flue gas inlet temperature change is in the same direction as the flue gas outlet temperature change, the correction factor increases to highlight the temperature difference formed by stable heat transfer; when the temperatures on both sides change in opposite directions, the correction factor decreases to suppress spurious temperature difference amplification caused by local fluctuations. The hyperbolic tangent function limits the correction amplitude within the stable range, balancing dynamic response sensitivity and computational stability.

[0064] The flue gas inlet temperature change and flue gas outlet temperature change are the differences between the current temperature and the previous corresponding temperature, respectively. The flue gas outlet temperature and flue gas outlet temperature change are aligned with the heat transfer response front before calculation. The temperature change direction correction coefficient is calibrated based on the correspondence between the consistency of flue gas inlet and outlet temperature changes and the actual heat transfer intensity in the equipment's historical operating information. It is used to adjust the degree of correction of the basic temperature difference by the consistency of direction. The minimum positive number is set according to the temperature acquisition resolution. It is the product of the square of the smallest resolvable temperature change and the zero-division prevention coefficient less than one. It is added to the normalized denominator to avoid division by zero when the temperature changes on both sides are zero, and to keep the magnitude relationship between non-zero temperature changes unchanged.

[0065] S2.5: Following the transmission sequence of load change, flue gas side response, economizer heat exchange, and feedwater side response, the initial moment of each change is compared and the pause marks caused by single sampling deviation are eliminated to determine the lag in flue gas side response, heat transfer lag, and feedwater side response, and heat exchange response lag information is generated.

[0066] Furthermore, taking the start time of load change in the load change transition segment as the starting point of transmission, and following the sequential relationship of load change, flue gas side response, economizer heat exchange, and feedwater side response, the transition comparison is performed sequentially on the start time of load change, the start time of continuous flue gas side change in the heat exchange response front, the start time of continuous change of flue gas temperature difference, and the start time of continuous change of feedwater temperature. It is checked whether the start times of adjacent changes maintain a progressive relationship, and records with inverted start times, those that cross continuous change segments, and those that do not form a transition with the preceding changes are set as positions to be reviewed. Pauses caused only by a single sampling deviation and subsequent changes revert to the original transmission direction are removed, and transition intervals that persist and affect subsequent temperature changes are retained.

[0067] The time intervals between each transmission link are determined sequentially according to the retained start time of the change; the time interval between the start time of the load change and the start time of the continuous change on the flue gas side is marked as the flue gas side response lag, the time interval between the start time of the continuous change on the flue gas side and the start time of the continuous change in flue gas temperature difference is marked as the heat transfer lag, and the time interval between the start time of the continuous change in flue gas temperature difference and the start time of the continuous change in feedwater temperature is marked as the feedwater side response lag; the occurrence of each lag is checked along the corresponding continuous change segment, and occasional intervals that are not carried over by subsequent similar changes are excluded. All types of lags, corresponding start times, carrying order, and continuous change segments are collected to generate heat transfer response lag information.

[0068] S2.6: Combining the flue gas temperature difference change trend and heat exchange response lag information, determine the adjustment direction and execution sequence of flue gas flow rate, circulation flow rate and feedwater flow rate, arrange control program segments according to the corresponding continuously changing sections, move the control program segment corresponding to the lag link forward and write it into the lag mark to form the load advance control program.

[0069] Furthermore, the flue gas temperature difference change trend and heat exchange response lag information are linked according to continuous change segments. The direction of temperature difference increase / decrease, the location of continuous pauses, and the lag markers of each link are checked along the flow of flue gas, the heat exchange of economizer, and the transmission relationship of feedwater. Historical flow regulation records under the same load change direction, flue gas temperature difference change trend, and lag type are extracted from the economizer heat exchange response records. The historical regulation direction that can form continuous heat exchange transmission is taken as the current regulation direction. When the historical incremental regulation forms a reverse response, the decrement regulation is adopted. When the historical decrement regulation forms a reverse response, the incremental regulation is adopted. When no stable correspondence is formed, the corresponding flow rate is kept unchanged. The regulation directions of flue gas flow rate, circulation flow rate, and feedwater flow rate are determined respectively.

[0070] The execution order is determined based on the direction of each flow regulation. Flue gas flow rate regulation with a delayed response on the flue gas side is placed first, followed by circulating flow rate regulation with a delayed heat transfer response. Feedwater flow rate regulation with a delayed response on the feedwater side is placed at the point where heat transfer begins. Control program segments are set up according to continuously changing sections. Each control program segment contains the regulation object, regulation direction, execution order, and corresponding section, as well as the initial flow rate before execution, single regulation step size, allowable rate of change, execution time window, flow upper and lower limits, and stop conditions. The single regulation step size and execution time window are determined based on the corresponding historical flow regulation records, while the allowable rate of change and flow upper and lower limits are determined based on the allowable operating range of the economizer recirculation pump, flue gas regulating damper, and feedwater regulating valve. The control program segment corresponding to a longer lag time is moved forward, and the lag marker is attached to the adjusted execution position, forming a load advance control program.

[0071] It should be noted that the load advance control program is a control scheme that pre-arranges the timing and execution sequence of adjusting flue gas flow rate, circulation flow rate and feedwater flow rate based on the load change trend and the lag of each heat exchange link. It is used to start the corresponding adjustment before the actual heat exchange response occurs, thereby reducing the control lag caused by load changes.

[0072] S3: Connect the load advance control program to the corresponding acquisition period of the economizer heat exchange status information, extract the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures, and compare them with the economizer heat exchange response record in time sequence to determine the heat exchange response deviation, correct the adjustment direction and execution sequence of the control program segment, and generate the load compensation execution program.

[0073] S3.1: Extract the continuously changing section, control program segment, adjustment direction, execution sequence and lag mark from the load advance control program. Locate the corresponding collection time period in the economizer heat exchange status information according to the start and end time of the continuously changing section. Link the control program segment with the flue gas inlet and outlet temperature records and the feedwater inlet and outlet temperature records to form a regulation heat exchange receiving window.

[0074] Furthermore, taking the continuously changing segments in the load advance control program as the attachment objects, the corresponding acquisition time period is located in the economizer heat exchange status information according to the start and end times of each continuously changing segment; the execution position of the control program segment falls into the corresponding acquisition time period, and the original relationship between the adjustment direction, execution order, and lag mark and the control program segment is maintained; when the control program segment moves forward to before the start time of the continuously changing segment, the corresponding acquisition time period is synchronously adjusted according to the forward execution position to avoid attaching temperature records at the original execution position; when the control program segment crosses adjacent continuously changing segments, the acceptance boundary is determined by the execution start position and execution end position respectively to prevent temperature records under different load change processes from being mixed into the same program segment.

[0075] Along the execution sequence of each control program segment, the flue gas inlet and outlet temperature records and the feedwater inlet and outlet temperature records are sequentially linked to the corresponding acquisition time period. Temperature records whose acquisition time falls within the execution period of the control program segment are directly associated. Temperature records located at the boundary of adjacent control program segments are assigned to the control program segment that first takes effect according to the actual execution order. For acquisition disconnection, boiler start-up / shutdown switching, and operation phase separation positions, the acceptance boundary is retained, and the temperature records on both sides of the boundary are not used to fill in each other. Each acquisition position is connected in series according to the time correspondence between the control program segment, the continuously changing section, and the temperature record, and the adjustment direction, execution order, and lag mark are written to form the adjustment heat exchange acceptance window.

[0076] S3.2: Continuously organize the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in the regulating heat exchange receiving window according to the acquisition time, eliminate single-point temperature jumps that are not sustained, calibrate the start and end times, direction of change and duration of each temperature change, and establish the temperature change receiving relationship according to the transmission sequence from the flue gas side to the feedwater side to form a regulating temperature response sequence.

[0077] Furthermore, the temperature changes of flue gas inlet and outlet and feedwater inlet and outlet are arranged sequentially along the acquisition time in the heat exchange receiving window to maintain the connection between each temperature record and the control program segment, continuous change segment, and execution position; the increase and decrease status of adjacent acquisition time at the same temperature position are compared item by item, and the temperature records of continuous increase, continuous decrease, and continuous stability are connected in series respectively; a single-point jump mark is set for records that only show a sudden increase or decrease at a single acquisition time and return to the original change direction at the next acquisition time and are excluded; records that maintain the continuous temperature change direction and are continuously received at acquisition time are classified into the same temperature change segment, and the starting time is marked by the position where the earliest continuous change occurs, and the ending time is marked by the position where the change direction changes, the temperature stabilizes, or the acquisition continuity is interrupted.

[0078] Arrange the temperature change sections according to the heat transfer sequence of flue gas inlet, flue gas outlet, feedwater inlet, and feedwater outlet. Take the start time of the flue gas inlet temperature change as the starting point of the transfer on the flue gas side, and check the relationship between the direction of change and the start and end times along the subsequent temperature positions. Establish a forward succession relationship for temperature change sections with mutually successive change directions and sequentially shifted start times. Retain independent marks for temperature change sections with reversed start times, conflicting change directions, and those that cross the execution boundary of the control program segment. Connect the start and end times, change directions, duration sections, and corresponding control program segments of each temperature change section in series according to the transfer sequence to form a temperature regulation response sequence.

[0079] S3.3: The temperature response sequence is compared with the economizer heat exchange response record according to the load change direction and continuous change segment. The positions where the temperature change start is delayed, the change direction is inconsistent, and the temperature transfer is interrupted are marked. The marked positions are then attached to the corresponding control program segments for flue gas flow rate, circulation flow rate, and feedwater flow rate to generate heat exchange response deviation marks.

[0080] Furthermore, according to the direction of load change and continuous change segments, the regulating temperature response sequence and the economizer heat exchange response record are linked to the same acquisition time axis, and the comparison segment is defined by the start and end times of the corresponding continuous change segments. Along the heat transfer sequence of flue gas inlet, flue gas outlet, feedwater inlet, and feedwater outlet, the start time, direction of change, and connection status of the same temperature position in both are aligned item by item. When the start time of change in the regulating temperature response sequence is later than the corresponding start time in the economizer heat exchange response record, the delayed start position of the temperature change is marked. When the two show opposite directions of increase or decrease at the same temperature position, the position where the direction of change is inconsistent is marked.

[0081] Check whether temperature changes can be continuously transmitted from the flue gas side to the feedwater side along the forward connection between each temperature position; if the previous temperature position has formed a continuous change but the next temperature position does not show the same forward connection, or if there is a situation where the temperature is continuously collected but the temperature change is not continued to be transmitted between adjacent temperature positions, mark the temperature transmission interruption position; according to the heat transfer link where the marked position is located and the corresponding execution time, respectively link back to the flue gas flow control program segment, circulation flow control program segment and feedwater flow control program segment that are responsible for flue gas side regulation, heat transfer connection regulation and feedwater side regulation, and write the deviation type, corresponding continuous change segment and marking time to generate heat transfer response deviation mark.

[0082] S3.4: Based on the heat transfer response deviation flag, correct the adjustment direction and execution sequence of the control program segments in the load advance control program, move the control program segments with delayed start forward, adjust the adjustment direction of control program segments with inconsistent change directions, and advance the execution of the control program segments corresponding to the temperature transmission interruption position. Collect the corrected control program segments, execution sequence, continuous change sections and heat transfer response deviation flags to generate the load compensation execution program.

[0083] Furthermore, based on the continuous change segment and control program segment corresponding to the heat exchange response deviation mark, the original execution position is located in the load advance control program, and the continuity relationship between the flue gas flow rate, circulation flow rate, and feedwater flow rate control program segments is maintained. For the temperature change start delay mark, the forward shift amount is determined by the time difference between the mark time and the corresponding change start time in the economizer heat exchange response record, and the execution start point of the corresponding control program segment is adjusted to the start side of the continuous change segment. For the change direction inconsistency mark, the relationship between the original adjustment direction of the control program segment and the temperature change direction is checked, and the incremental adjustment that causes the temperature to deviate in the opposite direction is changed to the decremental adjustment, and the decremental adjustment is changed to the incremental adjustment, and the continuity order of adjacent control program segments is corrected simultaneously.

[0084] Tracing back to the point where temperature transmission is interrupted, for heat exchange links that have not yet formed a subsequent temperature connection, the corresponding control program segment is moved to be executed before the interruption point, avoiding execution overlap with the already moved control program segment; when multiple heat exchange response deviation markers point to the same control program segment, the forward movement requirements and direction corrections are merged according to the temperature transmission order, with the earliest execution position as the program segment starting point, and the connection relationship between each deviation marker and the correction content is preserved; the corrected control program segments are rearranged along the continuously changing sections, the sequential connection between flue gas flow rate, circulation flow rate, and feedwater flow rate regulation is checked, and the control program segments, execution order, continuously changing sections, and heat exchange response deviation markers are collected to generate a load compensation execution program.

[0085] It should be noted that the load compensation execution program is a control scheme formed by correcting the adjustment direction and execution timing of the original load advance control program based on the deviation of the actual temperature response from the historical heat exchange response. It is used to compensate for the delay in heat exchange response, deviation in direction, and interruption of temperature transmission, and to ensure that each flow regulation can adapt to the current heat exchange state of the economizer.

[0086] S4: The load compensation execution program is divided into circulating flow, flue gas flow and feedwater flow control program segments. The segments are executed according to the adjustment direction and execution sequence. The flue gas inlet and outlet temperature changes and feedwater inlet and outlet temperature changes are collected for the corresponding time period. The execution mode of the control program segment is switched according to the response direction and degree of change to form economizer energy-saving control information.

[0087] S4.1: Extract the adjustment direction, execution sequence, continuous change section and heat exchange response deviation mark corresponding to the circulating flow, flue gas flow and feedwater flow from the load compensation execution program, split it into circulating flow control program segment, flue gas flow control program segment and feedwater flow control program segment according to the flow type, and divide it into continuous execution segments according to the execution sequence to form a segmented program execution sequence.

[0088] Furthermore, taking the control program segments in the load compensation execution procedure as the processing object, the adjustment content of circulating flow, flue gas flow, and feedwater flow is identified according to the corresponding adjustment object, and the original adjustment direction, execution position, continuous change section, and heat exchange response deviation mark of each control program segment are retained; the adjustment content acting on different flow types in the same control program segment is separated and assigned to the circulating flow control program segment, flue gas flow control program segment, and feedwater flow control program segment respectively; the execution start point and end position of the separated control program segments are checked, and the forward processing, direction correction, and early execution content are kept unchanged to avoid changing the control relationship already determined in the load compensation execution procedure during the separation process.

[0089] Various control program segments are arranged in the execution order of the load compensation execution procedure. Control program segments with continuous execution time, consistent adjustment direction, and belonging to the same continuous change zone are grouped into the same continuous execution segment. When the flow type of a control program segment changes, the adjustment direction changes, the execution time is interrupted, or the boundary of the continuous change zone is crossed, an execution segment separation position is set. When there are multiple flow control program segments at the same execution position, the order of execution within the segment is determined according to the original execution order, and the heat exchange response deviation mark is attached to the corresponding control program segment. The flow control program segments are sequentially connected in series according to the start and end positions of the execution segment to form a segmented program execution sequence.

[0090] S4.2: Change the circulating flow rate, flue gas flow rate and feedwater flow rate sequentially according to the segmented program execution sequence, and simultaneously collect the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in each continuous execution segment. Eliminate single-point temperature jumps that are not continuously maintained, and attach the start and end times, direction of change, magnitude of change, rate of change and duration of each temperature change to the corresponding continuous execution segment to form a segmented program response record.

[0091] Furthermore, following the execution order in the segmented program execution sequence, the boiler controller sequentially calls the circulating flow control program segment, the flue gas flow control program segment, and the feedwater flow control program segment. Specifically, the circulating flow control program segment controls the economizer recirculation pump to change the circulating flow according to the corresponding adjustment direction; the flue gas flow control program segment controls the flue gas regulating damper to change the flue gas flow according to the corresponding adjustment direction; and the feedwater flow control program segment controls the feedwater regulating valve to change the feedwater flow according to the corresponding adjustment direction. Each actuator changes the corresponding flow rate sequentially according to the single adjustment step size in the control program segment, limiting the rate of flow change within the allowable range. When the temperature change reaches the corresponding historical value... The current control program segment stops when the response amplitude, execution time reaches the execution time window, and the actual flow reaches the upper and lower limits of the flow. When each control program segment enters the execution state, the actual value of the corresponding flow and the execution state are collected. The actual flow before execution is registered as the initial flow of the current continuous execution segment. The start time of the continuous execution segment is marked synchronously. The flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures are continuously collected along the execution process. Each temperature record is attached to the current continuous execution segment. The temperature record ownership remains unchanged until the previous continuous execution segment ends. Execution boundaries are set at the locations where the flow type changes, the adjustment direction changes, and the execution sequence is interrupted to avoid the temperature changes of adjacent continuous execution segments from mixing with each other.

[0092] The system compares adjacent temperature records one by one along the acquisition time of each continuous execution segment, and concatenates the temperature records that are continuously rising, continuously falling, and continuously stable. Records that show a sudden rise or fall only at a single acquisition time and then return to the original trajectory in subsequent acquisition times are marked with a single-point jump mark and removed. The starting time of the change is marked by the position where the temperature begins to continuously deviate from the state before execution, and the ending time is marked by the position where the change direction changes, the temperature returns to stability, and the end of the continuous execution segment. The change amplitude is determined according to the temperature difference between the start and end, and the change rate is determined according to the temperature change and the corresponding time span. The start and end times, change direction, change amplitude, change rate, duration, initial flow, actual flow, and execution status are linked to the corresponding continuous execution segment to form a segmented program response record.

[0093] S4.3: According to the heat transfer sequence of flue gas inlet, flue gas outlet, feedwater inlet, and feedwater outlet, the temperature change direction, change amplitude, and duration in the segmented program response records are connected in series and compared with the economizer heat transfer response records of the corresponding continuous change sections. Records with inconsistent directions are classified as reverse response records, records with consistent directions and change amplitudes less than the heat transfer response amplitude threshold are classified as attenuated transfer records, and records with consistent directions, continuous transfer, and change amplitudes not less than the heat transfer response amplitude threshold are classified as continuous transfer records, thus forming segmented program response classification information.

[0094] Furthermore, following the heat transfer sequence of flue gas inlet, flue gas outlet, feedwater inlet, and feedwater outlet, the temperature change records in the segmented program response records are sequentially connected in series, maintaining the connection between the temperature change records and the continuous execution segment and control program segment; the direction, magnitude, and duration of change are checked along adjacent temperature positions, and the economizer heat exchange response records of the corresponding continuous change segments are linked to the same acquisition time axis; using the same temperature position and change stage as the comparison benchmark, the direction of change of the segmented program response records and the economizer heat exchange response records are checked item by item. When the direction of temperature change is opposite to the direction of economizer heat exchange response, the corresponding temperature change record is classified as a reverse response record.

[0095] The continuity between adjacent temperature positions is checked along the heat transfer sequence. If the preceding temperature has changed continuously but the subsequent temperature has not changed accordingly, and the temperature transfer stops midway and is not picked up by the subsequent change in the same direction, the corresponding temperature change record is classified as an intermittent response record. If the temperature change direction is consistent and the transfer is continuous, the actual change amplitude is compared with the heat transfer response amplitude threshold. If the actual change amplitude is less than the heat transfer response amplitude threshold, it is classified as an attenuated transfer record. If the actual change amplitude is not less than the heat transfer response amplitude threshold, it is classified as a continuous transfer record. Temperature change records, continuous execution segments, and control program segments are collected according to response category to form segmented program response classification information.

[0096] It should be noted that the heat exchange response amplitude threshold (example range: 70% to 90% of the historical continuous transfer variation amplitude) is calibrated based on the lower limit of the variation amplitude recorded in the historical continuous transfer under the same load change direction and flow control program segment.

[0097] Intermittent response records refer to response records where, during the transmission of temperature changes from the flue gas side to the feedwater side, the preceding temperature has already formed a continuous change, but the subsequent temperature fails to continue the transition, and no further transmission in the same direction occurs after the interruption. These records are used to identify the interruption point in the heat transfer chain, providing a basis for subsequently moving the corresponding control program segment forward and adjusting the execution timing.

[0098] S4.4: Based on the segmented program response classification information, switch the execution mode of the corresponding control program segment, maintain the flow value of the control program segment corresponding to the continuous transmission record, extend the execution period of the control program segment corresponding to the attenuation transmission record, move the next control program segment associated with the intermittent response record forward, stop the control program segment corresponding to the reverse response record, restore the corresponding flow to the flow value corresponding to the most recent continuous transmission record of the same flow type, and restore the initial flow value before the segmented program execution when no continuous transmission record is formed, thus forming economizer energy-saving control information.

[0099] Furthermore, based on the segmented program response classification information, the continuously executed segments and control program segments associated with the continuous transmission records, attenuated transmission records, intermittent response records, and reverse response records are located, and the flow type, execution location, and adjustment direction are verified. When the continuous transmission record indicates that the temperature change has formed a stable connection along the heat exchange transmission sequence, the current flow value of the control program segment is maintained, and the subsequent execution sequence remains unchanged. When the attenuated transmission record indicates that the temperature change direction is correct but the transmission degree is insufficient, the execution period of the associated control program segment is extended so that the flow regulation effect continues until the temperature change reaches the corresponding response level in the economizer heat exchange response record.

[0100] For intermittent response records, the temperature transfer stop position is located along the heat transfer sequence, the next control program segment to take over the subsequent heat transfer is moved forward to the transfer stop position, and the execution start point of the subsequent control program segments is rearranged. For reverse response records, the execution of the associated control program segment is stopped, and the most recent continuous transfer record is traced back according to the same flow type, and the flow is restored to the actual stable flow recorded in the most recent continuous transfer record. If no continuous transfer record of the same flow type is formed, the flow is restored to the initial flow recorded in the current continuous execution segment. The execution status, flow hold value, extended time period, forward position, and restored flow value of each control program segment are collected to form economizer energy-saving control information.

[0101] In summary, this invention achieves load advance process control by: verifying the load change segment and heat exchange response time, identifying the lag in the heat exchange link and advancing the control program segment, thereby reducing the adjustment lag under variable load and improving the timeliness and stability of waste heat recovery; and by classifying the temperature response of the continuous execution segment and switching the execution mode of the control program segment, it achieves multi-flow regulation according to the heat exchange state, thereby suppressing mutual interference of control and improving the energy-saving process control accuracy and operational reliability of the economizer.

[0102] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A load-adaptive economizer energy-saving control method, characterized in that, include: Collect boiler load operation information, economizer heat exchange status information and equipment historical operation information, align timestamps and merge continuous operation segments according to the collection time sequence, extract load change direction, change rate and duration, and extract corresponding economizer heat exchange response records from equipment historical operation information to generate basic data for load program scheduling. The load program arrangement data is combined with the economizer heat exchange response record. The continuous change section is divided according to the load change direction. The start and end times of the continuous change section and the heat exchange response record are checked to obtain the flue gas temperature difference change trend and heat exchange response lag. At the same time, the adjustment direction and sequence of the circulating flow, flue gas flow and feedwater flow are arranged into control program segments to form the load advance control program. The load advance control program is attached to the corresponding acquisition period of the economizer heat exchange status information. The changes in flue gas inlet and outlet temperature and feedwater inlet and outlet temperature are extracted and compared with the economizer heat exchange response record in time sequence to determine the heat exchange response deviation. The adjustment direction and execution sequence of the control program segment are corrected to generate the load compensation execution program. The load compensation execution program is divided into control program segments for circulating flow, flue gas flow, and feedwater flow. These segments are executed in stages according to the adjustment direction and execution sequence. The changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures are collected for the corresponding time periods. The execution mode of the control program segments is switched according to the response direction and degree of change to form economizer energy-saving control information.

2. The economizer energy-saving control method based on load adaptation as described in claim 1, characterized in that, The steps for timestamp alignment and merging of consecutive running segments are as follows: Based on the collection time and recording order of boiler load operation information, economizer heat exchange status information and equipment historical operation information, duplicate records are eliminated, and information within the same operating period is linked to a unified time position to form a time-aligned operation sequence. Based on the time-series aligned operation sequence, the continuous acquisition of data and the continuous operation of the boiler are checked at adjacent time positions. The acquisition disconnection, boiler start-up and shutdown switching and operation phase separation positions are marked. The continuous records between the segment boundaries are merged to form a set of continuous operation segments.

3. The economizer energy-saving control method based on load adaptation as described in claim 2, characterized in that, The steps for generating the basic data for load balancing are as follows: The boiler load changes in the continuous operation segment set are sorted according to the acquisition time, the time position of the load change direction change is located, the continuous records with the same change direction are divided into load change segments, the load change direction is extracted, the load change rate is calculated, and the continuity of the load change segment is determined to form the load change succession segment. Based on the load change direction and duration in the load change segment, the corresponding historical load segments and economizer heat exchange response records are extracted from the equipment's historical operating information. The start time of the economizer heat exchange change is then linked back to the corresponding load change segment. The load change direction, change rate, duration, and economizer heat exchange response records are collected to generate basic data for load program scheduling.

4. The economizer energy-saving control method based on load adaptation as described in claim 1, characterized in that, The steps for dividing the continuously changing sections according to the direction of load change are as follows: Based on the load program arrangement of basic data, the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in the economizer heat exchange response record are linked to a unified acquisition time axis to form a load heat exchange time sequence. Based on the load heat exchange time series, load change segments are divided according to the load change direction, change rate and collection continuity. The segment boundaries are checked and short-term boundaries formed by instantaneous sampling fluctuations are removed to generate a set of continuous change segments.

5. The economizer energy-saving control method based on load adaptation as described in claim 4, characterized in that, The steps for obtaining the trend of flue gas temperature difference change are as follows: Around the start and end times of the continuously changing range, locate the starting time of the continuous change of flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures, exclude temperature fluctuations at individual collection times, and mark the heat exchange response frontier according to the order of the starting times to form a load heat exchange receiving window. Organize the temperature change trajectory in the load heat exchange receiving window according to the transfer sequence from the flue gas inlet side to the flue gas outlet side, calculate the temperature difference between the flue gas inlet and outlet, mark the direction of increase or decrease, the magnitude of change and the location of continuous pauses of the temperature difference between the flue gas inlet and outlet, and form the trend of flue gas temperature difference change.

6. The economizer energy-saving control method based on load adaptation as described in claim 5, characterized in that, The steps for establishing the load advance control procedure are as follows: Following the transmission sequence of load change, flue gas side response, economizer heat exchange, and feedwater side response, the starting time of each change is compared and the pause marks caused by single sampling deviation are eliminated to determine the lag in flue gas side response, heat transfer lag, and feedwater side response, and heat exchange response lag information is generated. By combining the flue gas temperature difference change trend and heat exchange response lag information, the adjustment direction and execution sequence of flue gas flow rate, circulation flow rate and feedwater flow rate are determined. Control program segments are arranged according to the corresponding continuously changing sections. The control program segments corresponding to the lag links are moved forward and written into the lag mark to form the load advance control program.

7. The economizer energy-saving control method based on load adaptation as described in claim 6, characterized in that, The steps for extracting the changes in flue gas inlet and outlet temperatures and the changes in feedwater inlet and outlet temperatures are as follows: Extract the continuously changing section, control program segment, adjustment direction, execution sequence and lag mark from the load advance control program. Locate the corresponding collection time period in the economizer heat exchange status information according to the start and end time of the continuously changing section. Link the control program segment with the flue gas inlet and outlet temperature records and the feedwater inlet and outlet temperature records to form an adjustment heat exchange receiving window. The temperature changes of flue gas inlet and outlet and feedwater inlet and outlet in the regulating heat exchange receiving window are continuously processed according to the collection time. Single-point temperature jumps that are not sustained are eliminated. The start and end times, direction of change and duration of each temperature change are calibrated. The temperature change receiving relationship is established according to the transmission sequence from the flue gas side to the feedwater side, forming a regulating temperature response sequence.

8. The economizer energy-saving control method based on load adaptation as described in claim 1 or 7, characterized in that, The steps for generating the load compensation execution program are as follows: The temperature response sequence is compared with the economizer heat exchange response record according to the load change direction and continuous change section. The positions of delayed temperature change start, inconsistent change direction and interrupted temperature transmission are marked. The marked positions are then attached to the corresponding control program segments of flue gas flow rate, circulation flow rate and feedwater flow rate to generate heat exchange response deviation marks. Based on the heat transfer response deviation marker, the adjustment direction and execution sequence of the control program segments in the load advance control program are corrected. The control program segments with delayed start are moved forward, the adjustment direction of control program segments with inconsistent change directions is adjusted, and the control program segments corresponding to the temperature transfer interruption position are executed in advance. The corrected control program segments, execution sequence, continuous change sections and heat transfer response deviation markers are collected to generate the load compensation execution program.

9. The economizer energy-saving control method based on load adaptation as described in claim 8, characterized in that, The steps for collecting the changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures within the corresponding time period are as follows: Extract the adjustment direction, execution sequence, continuous change section and heat exchange response deviation mark corresponding to the circulating flow, flue gas flow and feedwater flow from the load compensation execution program. Divide the program into circulating flow control program segment, flue gas flow control program segment and feedwater flow control program segment according to the flow type, and divide the program into continuous execution segments according to the execution sequence to form a segmented program execution sequence. The circulating flow rate, flue gas flow rate, and feedwater flow rate are changed sequentially according to the segmented program execution sequence. The changes in flue gas inlet and outlet temperatures and feedwater inlet and outlet temperatures in each continuous execution segment are collected simultaneously. Single-point temperature jumps that are not continuously maintained are eliminated, and the start and end times, direction of change, magnitude of change, rate of change, and duration of each temperature change are linked to the corresponding continuous execution segment to form a segmented program response record.

10. The economizer energy-saving control method based on load adaptation as described in claim 9, characterized in that, The steps for generating economizer energy-saving control information are as follows: According to the heat transfer sequence of flue gas inlet, flue gas outlet, feedwater inlet and feedwater outlet, the temperature change direction, change amplitude and duration in the segmented program response records are connected in series and compared with the economizer heat transfer response records of the corresponding continuous change section. Records with inconsistent directions are classified as reverse response records, records with consistent directions and change amplitude less than the heat transfer response amplitude threshold are classified as attenuated transfer records, and records with consistent directions, continuous transfer and change amplitude not less than the heat transfer response amplitude threshold are classified as continuous transfer records, thus forming segmented program response classification information. Based on the segmented program response classification information, the execution mode of the corresponding control program segment is switched, the flow value of the control program segment corresponding to the continuous transmission record is maintained, the execution period of the control program segment corresponding to the attenuation transmission record is extended, the next control program segment associated with the intermittent response record is moved forward, and the control program segment corresponding to the reverse response record is stopped. The corresponding flow is restored to the flow value corresponding to the most recent continuous transmission record of the same flow type. If no continuous transmission record is formed, it is restored to the initial flow value before the segmented program execution, thus forming economizer energy-saving control information.

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