A method for dynamic modeling of a heating network

Abstract

The present application relates to the technical field of central heating pipe network operation and regulation, and discloses a kind of dynamic modeling method of heating pipe network.The method, first according to pipe section attribute, measuring point position and valve pump operating state determine pipe network actual flow relationship, carry out time alignment and effectiveness verification to pressure, flow, temperature, environmental data and operation and maintenance event;Combined with the hydraulic, thermal and environmental changes in different cycle observation period, distinguish the parameter changes caused by scale formation, insulation layer damp and soil humidity change;According to the differential pressure and flow of pipe section, correct the resistance coefficient along the line, determine the temperature propagation time delay, and align the inlet temperature and outlet temperature corresponding to the same batch of heat medium, to correct the comprehensive heat transfer coefficient;According to parameter identification level, update pipe section parameter, and use field observation data to check pipe network model, thereby improve the accuracy of pipe section parameter dynamic updating, make pipe network model consistent with actual operating state.

Description

Technical Field

[0001] This invention relates to the field of centralized heating network operation and control technology, specifically a dynamic modeling method for heating networks. Background Technology

[0002] As the scale of centralized heating networks continues to expand, these networks are increasingly characterized by a large number of nodes, long transmission distances, frequent changes in operating conditions, and the interaction between hydraulic and thermal processes. Existing heating network models are typically established based on design drawings, pipe length, diameter, material, and insulation structure. Before the heating season begins, historical operating data is used to calibrate the pipe friction coefficient and heat transfer parameters. During subsequent operation, the model boundary conditions are usually adjusted only based on changes in heat source output, pump and valve status, and user load, while the resistance and heat transfer parameters of each pipe section remain fixed or uniform. Correction values; for example, authorized Chinese invention patent application CN115238499B discloses a system and method for realizing steady-state and dynamic simulation of the entire process of intelligent decision-making in heating systems. It establishes steady-state and dynamic models of heating systems through a component model library and corrects relevant parameters based on model verification errors. Another example is authorized Chinese invention patent application CN110287509B, which discloses a method and system for flexible analysis and structural defect diagnosis and location of urban heating networks. It establishes a thermal-hydraulic mapping model through structural mechanism modeling and operational data identification to achieve flexible analysis and structural defect location of heating networks.

[0003] However, during the long-term operation of heating pipe networks, scaling inside the pipes, aging of the insulation layer due to moisture, and changes in the water content of the surrounding soil have different causes and cycles, leading to varying degrees of dynamic changes in the friction coefficient and overall heat transfer coefficient of different pipe sections. Existing technologies struggle to accurately distinguish the impact of different factors on pipe section parameter changes by combining pump and valve operating status with the actual connectivity of the pipe network. Furthermore, since the temperature change of the heat medium takes time to travel from the pipe section inlet to the outlet, directly comparing the inlet and outlet temperatures at the same moment can easily misinterpret the time difference caused by temperature propagation as pipe heat loss. For pipe sections with insufficient measurement point coverage, missing data, or abnormal data, parameter identification errors may also propagate to adjacent pipe sections, causing model parameters to deviate from actual values. This results in inconsistencies between the model calculation results and the actual operating state of the heating pipe network, reducing the model's calculation accuracy, stability, and reliability. Therefore, existing technologies urgently need to address the problems of coupling different influencing factors, temperature propagation time differences, and the difficulty in accurately updating parameters of different pipe sections under conditions of insufficient measurement point coverage. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a dynamic modeling method for heating pipe networks, which solves the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A dynamic modeling method for heating pipe networks, comprising:

[0007] S1. Establish the current connection relationship based on the pipe section attributes, measuring point locations, and valve / pump status, and set the friction resistance coefficient and overall heat transfer coefficient for each pipe section.

[0008] S2. Perform time alignment and validity verification on pressure, flow, temperature, environmental data and operation and maintenance events; determine parameter identification level based on measurement point coverage and pipeline constraints; and establish observation periods with different cycles at multiple times.

[0009] S3. Based on the temporal pattern, spatial distribution, and correlation of hydraulic and thermal parameters during each observation period, distinguish the parameter changes caused by scaling, insulation layer dampness, and soil moisture changes.

[0010] S4. Correct the friction coefficient based on the pipe section pressure difference and flow rate, determine the temperature propagation delay according to the flow rate, and correct the comprehensive heat transfer coefficient after aligning the inlet and outlet temperatures.

[0011] S5. Update the parameters of each pipe section according to the parameter identification level, and verify the pipeline network model with field observation data; if the verification does not meet the preset conditions, suspend the update of the corresponding pipe section or restore the previous valid parameters.

[0012] Preferably, S1 includes:

[0013] Pipe sections are divided according to pipe diameter, material, laying method, and the location of valves, pumps, branch interfaces, and junction interfaces. The current inlet node and current outlet node of each pipe section are determined according to the direction of heat medium flow, and the correspondence between measuring points, nodes, and pipe sections is established.

[0014] The actual flow path is determined based on valve status, pump status, flow direction, node pressure, and maintenance records, and the corresponding operational connectivity version is generated.

[0015] Based on the commissioning data, stable operation data, or design data, determine the baseline values ​​and historical effective ranges of the friction coefficient and the overall heat transfer coefficient, and re-determine the corresponding parameter baseline values ​​after pipe cleaning, replacement, or insulation maintenance.

[0016] Preferably, S2 includes:

[0017] The data sampling period is determined based on the instrument refresh cycle, the monitoring system polling cycle, and the shortest effective operating condition duration.

[0018] Data time is corrected based on acquisition time, timing error, timestamp resolution error, and communication delay.

[0019] The data is verified for range, rate of change, continuity, physical relationship and source integrity, and abnormal data, conflicting data and short-term missing data are marked and processed respectively.

[0020] The parameter identification level is determined based on the coverage of the measuring points and the hydraulic and thermal relationships that can be formed.

[0021] Based on the daily load cycle, environmental change process and operation and maintenance events, different periodic observation periods are divided, and direct identification, joint identification or maintaining the previous effective parameter is determined according to the proportion of effective data.

[0022] Preferably, the parameter identification level is determined based on the coverage of the measuring points and the hydraulic and thermal relationships that can be formed, including:

[0023] When a pipe section has inlet pressure, outlet pressure, flow rate, inlet temperature, and outlet temperature observations, it is determined to be of the direct identification level;

[0024] If some measurement points are missing, but can be supplemented by nodal flow balance, loop pressure relationship or regional boundary observation, and the number of independent relationships is not less than the number of parameters to be determined, it is determined as a joint identification level;

[0025] The remaining pipe segments are constrained and inferred based on the parameters of adjacent pipe segments, the physical properties of the pipe segments, and the historical effective range. If a complete relationship cannot be formed or there is a lack of reference pipe segments that meet the conditions, the previous effective parameters are maintained.

[0026] Preferably, S3 includes:

[0027] The impact of scaling was determined based on pressure difference, flow rate changes, and water quality records under similar operating conditions during a long-term observation period.

[0028] The impact of moisture on the insulation layer is determined based on changes in the comprehensive heat transfer coefficient, rainfall, groundwater level, and changes in adjacent pipe sections during the medium-period observation period.

[0029] The soil environmental impact is determined based on the correlation between the comprehensive heat transfer coefficient and soil moisture content, soil temperature and freeze-thaw state during the short-period observation period.

[0030] The parameter changes were allocated in the order of scaling, insulation layer dampness, and soil environment influence, and the consistency between the allocation results and the actual parameter changes was verified.

[0031] Preferably, the parameter changes are allocated in the order of scaling, insulation layer dampness, and soil environmental influence, and the consistency between the allocation results and the actual parameter changes is verified, including:

[0032] First, determine the change in friction coefficient corresponding to scaling, and then determine the change in overall heat transfer coefficient when calibration data before and after cleaning is available.

[0033] After deducting this part from the total change in the overall heat transfer coefficient, determine the changes corresponding to the moisture content of the insulation layer and the soil moisture in turn.

[0034] Compare the sum of all changes with the actual observed changes. If the deviation exceeds the sum of the instrument's overall error and the upper limit of historical normal fluctuations, or if the judgment conditions conflict with each other, retain the previous valid parameter and mark it as pending verification.

[0035] Preferably, S4 includes:

[0036] Based on the current operational connectivity, pipe segment geometry parameters, local components, pressure and flow data, the friction coefficient is determined after deducting static pressure and local pressure drop.

[0037] The basic temperature propagation delay is determined based on the effective flow area, pipe section length, and time-varying flow rate, and corrected using the co-directional changes in inlet and outlet temperatures.

[0038] The inlet and outlet temperatures of the same batch of heat medium are matched, and the comprehensive heat transfer coefficient is determined by combining mass flow rate, specific heat capacity, effective heat exchange area and ambient temperature. Candidate parameters are then selected based on the design range, historical effective range and event consistency.

[0039] Preferably, the base temperature propagation delay is determined based on the effective flow area, pipe section length, and time-varying flow rate, and corrected using the co-directional changes in inlet and outlet temperatures, including:

[0040] When the flow rate is stable, the internal heat medium volume is determined based on the effective flow area and length of the pipe section, and the initial time delay is determined in combination with the volumetric flow rate.

[0041] When the flow rate changes, the heat medium entering the pipe section at each time period is accumulated according to the sampling order. The initial time delay is determined when the accumulated value reaches the heat medium volume inside the pipe section.

[0042] The temperature propagation delay is corrected based on the difference between the corresponding characteristic times, matching the heating, cooling, peak or valley characteristics of the inlet and outlet temperatures near the initial time delay.

[0043] Preferably, S5 includes:

[0044] Reference pipe sections are selected based on pipe diameter, material, laying method, insulation structure, and historical parameters;

[0045] The update ratio and single change magnitude are determined based on the parameter identification level, data completeness, and candidate parameter source, and the parameters to be updated are written into the model to be verified.

[0046] The key pressure, flow rate and temperature are checked using the boundary conditions of heat source, valve, water pump and heat exchange station during the same observation period. If the check fails, the previous valid parameters of the relevant pipe section or corresponding area are restored. If the check fails continuously, the update is suspended.

[0047] Preferably, the update ratio and single change magnitude are determined based on the parameter identification level, data completeness, and candidate parameter source, and the parameters to be updated are written into the model to be verified, including:

[0048] The update ratio is set by combining the parameter identification level, the proportion of effective data and the source of candidate parameters. The update ratio of directly identified pipe sections is higher than that of jointly identified pipe sections, and the update ratio of jointly identified pipe sections is higher than that of constraint-inferred pipe sections.

[0049] The update is written to the model to be verified step by step, starting with a smaller update ratio, and the update ratio that passes the verification is selected based on the changes in the overall deviation and local deviation.

[0050] The magnitude of a single change is limited based on the historical normal change limit, instrument error, and model stability. If the magnitude is exceeded, the update is written in multiple update cycles or the update is paused.

[0051] Compared with the prior art, the present invention provides a dynamic modeling method for heating pipe networks, which has the following beneficial effects:

[0052] 1. This invention determines the actual flow path of the pipeline network by comprehensively considering valve status, pump status, flow direction, node pressure, and maintenance records. It also performs correlation analysis on hydraulic parameters, thermal parameters, environmental data, and operation and maintenance events according to different periodic observation periods, identifying parameter changes caused by scaling, insulation layer dampness, and soil moisture variations. Furthermore, it determines the temperature propagation delay based on the internal heat medium volume and time-varying flow rate of the pipe section, and matches the inlet and outlet temperatures corresponding to the same batch of heat medium. By classifying parameter identification levels according to the coverage of measuring points, setting parameter update ranges based on data completeness and candidate parameter sources, and combining on-site pressure, flow, and temperature data for model verification, it pauses updates or rolls back parameters that fail verification. This improves the accuracy of dynamic parameter identification and updating of the heating pipeline network, making the pipeline model more consistent with actual operating conditions.

[0053] 2. This invention classifies, labels, and processes abnormal data, conflicting state data, and short-term missing data, and determines pipe segment parameters using direct identification, joint identification, and constraint inference methods based on the coverage of measurement points. By writing the parameters to be updated into a verification model that is independent of the current valid model, the pressure of key nodes, the flow rate of key branches, and the temperature at key locations are verified under the same field boundary conditions. Based on the verification results, the previous valid parameters of the pipe segments or corresponding areas that failed the verification are restored, or the parameter updates of the relevant pipe segments are paused. This reduces the transmission of local measurement point anomalies and parameter deviations to adjacent pipe segments and other areas, and maintains the continuous availability and operational stability of the heating network model under conditions of incomplete data or changes in operating status. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the process of a dynamic modeling method for heating pipe networks according to the present invention;

[0055] Figure 2 This is a schematic diagram illustrating the actual flow relationship of the heating pipe network according to the present invention;

[0056] Figure 3 This is a flowchart of the data processing and parameter identification level determination process of the present invention;

[0057] Figure 4 This is a schematic diagram illustrating the determination of the causes of parameter changes during different observation periods in this invention;

[0058] Figure 5 This is a schematic diagram illustrating the determination of the friction coefficient in this invention.

[0059] Figure 6 This is a schematic diagram of temperature propagation delay correction and temperature alignment according to the present invention;

[0060] Figure 7 This is a flowchart of the parameter hierarchical update and model verification rollback process of the present invention. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Example 1: Figure 1 - Figure 7 A dynamic modeling method for heating pipe networks is presented, including:

[0063] This embodiment uses the primary hot water pipe network of a centralized urban heating system as the application object, and is applicable to single-heat-source branched pipe networks, multi-heat-source ring pipe networks, and mixed pipe networks with connecting pipes. The pipe network includes heat source nodes, branch nodes, junction nodes, heat exchange station nodes, pipe sections, valves, and water pumps. Pressure transmitters, flow meters, temperature transmitters, valve position feedback devices, and water pump operation feedback devices are installed on site. This method can be executed by a heating dispatch center server, heat source control equipment, heat exchange station edge computing equipment, or other electronic devices with data processing and information interaction capabilities. Input data includes pipe network geographic information, asset ledgers, measuring point ledgers, on-site pressure, etc. The data includes flow and temperature data, valve and pump status, meteorological data, soil condition data, water quality testing records, and operation and maintenance event records. The processing results include friction coefficient, comprehensive heat transfer coefficient, parameter source, update time, effective status, and model version corresponding to the actual operating status of the pipeline network. The sampling period, time tolerance, observation period length, effective data ratio, temperature deviation, and parameter update range appearing in this embodiment are all determined according to the instrument error, field test results, and historical operating data recorded in the corresponding paragraph. When the measurement error, refresh cycle, or communication conditions of the field equipment do not meet the example range, the corresponding values ​​are re-determined based on the actual field test results.

[0064] Specifically, such as Figure 2 As shown: When the heating season starts, the pipeline structure changes, the heat source is switched, valves are operated, pipeline section maintenance is completed, or the model verification cycle is reached, the electronic equipment reads the pipeline geographic information data and asset ledger. The model verification cycle is determined according to the heating company's operation and maintenance plan, the rate of change of historical parameters, and the pipeline model verification records. The pipeline geographic information data includes at least pipeline route, node location, pipeline connection relationship, and node elevation, and the asset ledger includes at least pipeline length, nominal diameter, inner diameter, wall thickness, material, laying method, insulation material, insulation thickness, commissioning time, maintenance records, soil type, and groundwater conditions.

[0065] Electronic equipment divides a pipeline into two adjacent network nodes into a single segment if the pipe diameter, material, and laying method are continuous and there are no valves, pumps, branch interfaces, merging interfaces, or other control components in between. When valves, pumps, branch interfaces, merging interfaces, or changes occur in the pipe diameter, material, or laying method, a new segment is divided at the corresponding location. Each segment is assigned a unique segment number and two end nodes. When the physical structure of the network remains unchanged, the segment number and the two end nodes remain unchanged.

[0066] The current inlet and outlet nodes of the pipe section are determined based on the actual flow direction of the heat medium. The end node located upstream along the flow direction of the heat medium is designated as the current inlet node, and the end node located downstream is designated as the current outlet node. When the flow direction of the heat medium in the pipe section reverses, only the markings of the current inlet and outlet nodes are exchanged, without changing the pipe section number or the physical connection relationship between the two end nodes. This ensures that the inlet pressure, outlet pressure, inlet temperature, and outlet temperature used subsequently are consistent with the actual flow direction of the heat medium.

[0067] After the pipe segment division is completed, the electronic equipment establishes the correspondence between measuring points, nodes, and pipe segments based on the measuring point ledger and on-site installation records; pressure measuring points are mapped to the nodes corresponding to the actual installation locations, flow measuring points are mapped to the pipe segments or branches corresponding to the actual installation locations, and temperature measuring points are mapped to the end nodes corresponding to the actual installation locations; when a measuring point can reflect the common state of multiple adjacent pipe segments, the sharing relationship between the measuring point and each related pipe segment is recorded, and the same measurement value is not reused as multiple independent observation values.

[0068] When the measurement point log is inconsistent with the on-site installation record, both the location recorded in the log and the location confirmed on-site are retained, and the relevant measurement points are marked as locations pending confirmation. Before the on-site verification is completed, the data of the measurement point is only used for monitoring the operating status and is not used for the automatic updating of the friction coefficient or the overall heat transfer coefficient. When the asset log lacks key data affecting parameter determination, such as the inner diameter, length, material, or insulation structure of the pipe section, the relevant pipe section only participates in the establishment of the current operating connection relationship and is not automatically updated with pipe section parameters.

[0069] Electronic equipment determines the current operational connectivity based on valve status, pump status, flow direction in pipe sections, pressure relationships at nodes, and maintenance and isolation records.

[0070] For valves with continuous opening feedback, the valve state is divided into closed state, transition state, and conducting state; the valve closing boundary is determined based on the valve shut-off test; as the valve opening gradually decreases, when the flow rate of the corresponding branch decreases to within the effective resolution range of the flowmeter, the upper limit of the corresponding opening is taken as the closing boundary; the effective resolution range of the flowmeter is determined based on the flowmeter accuracy class, minimum measurable flow rate, and the results of zero flow calibration on site.

[0071] The valve conduction boundary is determined based on the field calibration relationship between the valve opening and the branch flow rate. As the valve opening gradually increases, when the valve has entered the stable flow region and the flow rate change caused by further increasing the opening does not exceed the comprehensive measurement error of the flow meter, the corresponding minimum opening is taken as the conduction boundary. The opening range between the closing boundary and the conduction boundary is taken as the transition state.

[0072] For valves that only have open and closed signals, the valve status is determined based on the open, closed, and fault signals. When the valve is in a transitional state, lacks position feedback, or the valve opening is inconsistent with the branch flow, the corresponding connection is not directly determined to be connected or disconnected. Instead, the connection is checked in conjunction with the branch flow and node pressure.

[0073] When the valve is closed and the corresponding branch flow is within the effective resolution range of the flow meter, the corresponding connection is determined to be disconnected; when the valve is open and the branch flow direction is consistent with the node pressure, the corresponding connection is determined to be valid; when the valve status is inconsistent with the relationship between the branch flow and the node pressure, the corresponding connection is marked as pending confirmation.

[0074] The pump's operating status is determined based on start / stop signals, operating frequency, motor current, pump inlet pressure, pump outlet pressure, and corresponding branch flow rate. When the start / stop signal indicates that the pump is running, the pump outlet pressure is higher than the pump inlet pressure, and there is flow rate in the corresponding branch that conforms to the delivery direction, the pump is considered to be in effective operating status. When the start / stop signal indicates that the pump is running, but the motor current, pump outlet pressure, or branch flow rate is lower than the equipment's lower operating limit and continues to reach the status confirmation time, the pump status is marked as pending confirmation.

[0075] The lower limit of equipment operation shall be preferentially adopted from the minimum stable operating current, minimum effective differential pressure, and minimum stable flow rate recorded in the pump product manual or the completion and commissioning record; if the corresponding record is missing, it shall be determined through on-site startup test; the pump status confirmation time shall be determined based on the time required for the pump to form a stable differential pressure from startup, the data sampling period, and the communication delay, taking the maximum value of the three and adding one sampling period; the pump startup time shall be adopted from the product manual or the on-site startup test record, and the communication delay shall be adopted from the upper limit of normal delay in the historical communication log; when the pump is stopped or in maintenance isolation state, the corresponding pressurization path shall not be used as the current valid path.

[0076] For parallel pump sets, the operating status of each pump is recorded separately, and the pump set is judged to maintain normal flow in the corresponding branch based on the pressure and flow of the common pipeline. The period from the start of pump switching to the recovery of the pressure and flow of the common pipeline to the historical normal fluctuation range is called the transition period. The data during the transition period is only used for monitoring the operating status and is not used for updating the pipeline parameters.

[0077] The flow direction of a pipe section is determined primarily based on the direction information output by the flow meter, and then verified by the pressure relationship between the two ends of the pipe section. When the flow direction is consistent with the pressure relationship, the direction output by the flow meter is adopted. When the flow is within the effective resolution range of the flow meter, the valve and pump status has not changed but the flow direction is continuously reversed, or the flow direction contradicts the pressure relationship, the flow direction of the pipe section is marked as pending confirmation.

[0078] For single-heat-source branched pipe networks, a basic connection relationship is established based on the actual heating path from the heat source to each heat exchange station, and then verified using valve status, pipe section flow direction, and node pressure. For multi-heat-source ring pipe networks, the path that can actually flow is determined by combining the status of connecting valves, the outlet pressure of each heat source, the flow direction of the ring network branches, and maintenance and isolation records. For connecting pipes that can experience flow reversal, at least the current flow direction, the effective time of the flow direction, and the corresponding valve and pump status are recorded.

[0079] When valve status, flow direction, and node pressure are consistent, the corresponding connection is effective. When two of them are consistent, but the other one experiences a short-term data loss, the corresponding connection is marked as temporarily valid and will be rechecked in subsequent sampling periods. The allowable duration of short-term data loss is determined based on the duration of occasional packet loss in historical communication records and must not span valve operation, pump switching, heat source adjustment, or changes in pipeline operation status. When the three statuses conflict with each other, or when the conflict involves heat source outlets, main pipes, and critical connecting pipes, no new parameter update task is generated, and the most recently confirmed valid current operating connection continues to be used.

[0080] When emergency repairs, pipe section replacements, pipeline flushing, valve disassembly or insulation replacement occur, the pipe section involved in the incident is set to an isolation or maintenance state. After the operation is completed, the valve status, flow direction and node pressure are rechecked. Once it is confirmed that the corresponding pipe section has been restored to normal flow, it is then included in the current operational connectivity.

[0081] The electronic equipment establishes parameter records for each pipe section. The parameter records include at least the current value of the friction coefficient, the reference value of the friction coefficient, the current value of the comprehensive heat transfer coefficient, the reference value of the comprehensive heat transfer coefficient, the parameter source, the update time, the effective status, the time of the last cleaning, the time of the last insulation maintenance, the soil zoning, the groundwater impact status, and the historical effective range.

[0082] The reference value for the friction coefficient should preferably be the data from the final commissioning or the parameters verified on-site during the stable operation at the beginning of the heating season. If on-site commissioning data is lacking, the initial parameters should be determined based on the pipe section's inner diameter, length, material, design flow rate, and heat medium properties, and the source of the parameters should be recorded as the design calculation.

[0083] The benchmark value of the comprehensive heat transfer coefficient should be determined primarily using the as-built thermal test data or the flow rate, inlet temperature, outlet temperature, and ambient temperature during the stable operation period at the beginning of the heating season. If on-site thermal test data is lacking, the initial parameters should be determined based on the pipe section inner diameter, insulation material, insulation thickness, laying method, and environmental conditions, and the source of the parameters should be recorded as the design calculation.

[0084] Stable operation refers to a continuous operating period in which the current operational connectivity remains unchanged, valves and pumps are not switched, pressure, flow rate, and temperature are all within the historical normal fluctuation range, and there are no maintenance, flushing, or other events that change the physical state of the pipeline section.

[0085] After the pipe section is replaced, cleaned, or the insulation structure is replaced, the parameter change records before the maintenance are terminated; after the event ends, a new parameter baseline is determined from the newly formed stable operation period, and the parameter change trend before the event is not continued to be used for the pipe section after the event.

[0086] The historical effective range is determined primarily based on parameters that have been verified and approved during multiple stable operating periods of the same pipe section. When sufficient historical data is lacking, pipe sections with the same or similar pipe diameter, material, laying method, insulation structure, and environmental conditions can be selected to determine the initial reasonable range. The range formed by the reference pipe section is only used to constrain the parameters of the target pipe section and does not directly replace the on-site observation results of the target pipe section.

[0087] Once the current operational connectivity is determined, the electronic equipment generates a corresponding version record. The version record includes at least the version number, the connected pipe segment, the isolated pipe segment, the flow direction of each pipe segment, the valve status, the pump status, the version effective time, and the triggering event. Subsequent pressure, flow, temperature, environmental data, and maintenance events are all associated with the corresponding version to prevent the mixing of data from different operational connectivity relationships.

[0088] Pipe segment number, end node, measurement point mapping relationship, current operating connectivity relationship, parameter benchmark, and version record are used together for subsequent data time alignment, data validity check, parameter identification, and pipeline network model update.

[0089] Specifically, such as Figure 3 As shown: Electronic equipment receives operational data, environmental data, and maintenance data from the heating network; operational data includes at least pressure, flow rate, supply water temperature, return water temperature, valve position, pump operating frequency, and equipment operating status; environmental data includes at least outdoor temperature, precipitation, soil temperature, soil moisture content, and groundwater level; maintenance data includes at least water quality test results, valve operation records, pump switching records, pipe cleaning records, pipe repair records, and pipe replacement records.

[0090] The sampling period for pressure, flow, and temperature data is determined based on the effective refresh period of the field instruments, the polling period of the monitoring system, and the duration of the shortest effective operating condition to be identified. The sampling period is not shorter than the larger of the effective refresh period of the instruments and the polling period of the monitoring system, and is shorter than the duration of the shortest effective operating condition, so that continuous sampling data can reflect the operation process after valve regulation, pump switching, and changes in heat source load. Communication delay is not directly used as the sampling period, but is used to determine the data reception waiting time, time alignment tolerance, and late data processing method.

[0091] For example, the sampling period for pressure, flow, and temperature data can be selected from 30 seconds to 120 seconds; this range is suitable for urban centralized heating networks where the instrument refresh cycle and monitoring system polling cycle are in the range of seconds to minutes; the specific sampling period can be determined through instrument product information, data acquisition equipment configuration, monitoring system polling settings, and historical communication records; when the refresh cycle of the field instrument exceeds 120 seconds, the sampling period should be extended accordingly; when the duration of the operating condition change to be identified is short, and the instrument and communication conditions allow, the sampling period can be shortened accordingly.

[0092] Each data record should include at least the following fields: data source, measurement point number, corresponding node or pipe section, data type, acquisition time, reception time, observed value, unit of measurement, and data status. Acquisition devices with unified time synchronization should use a unified time to record the acquisition time. Acquisition devices without unified time synchronization should correct the acquisition time based on the device clock deviation, timestamp resolution, and communication delay test results, while retaining the original time and the corrected time.

[0093] The time alignment tolerance is determined based on the upper limit of timing error, timestamp resolution error, and communication delay fluctuation. When the data contains a reliable acquisition timestamp, the time alignment tolerance shall not be less than the sum of the upper limit of timing error and the timestamp resolution error. When the data lacks a reliable acquisition timestamp and it is necessary to reconstruct the acquisition time based on the reception time, communication delay fluctuation shall also be taken into account.

[0094] For example, when using a unified time synchronization, and the sum of time synchronization error, timestamp resolution error, and communication delay fluctuation does not exceed 2 seconds, the time alignment tolerance can be selected to be within 2 seconds; when the sum of the above errors exceeds 2 seconds, the time alignment tolerance is expanded according to the upper limit of the error obtained from actual testing; data with a time difference exceeding the corresponding tolerance is not used as data at the same sampling time, but the original record is retained and re-paired or marked as time-inconsistent data according to adjacent sampling times.

[0095] After time alignment is completed, the data is checked for range, rate of change, continuity, physical relationship, and source integrity.

[0096] Range checks are based on instrument range, pipeline design pressure, design flow rate, and allowable operating temperature. When an observed value exceeds the effective range of the instrument or the allowable operating range of the pipeline, the observed value is marked as out-of-limit data. The effective range of the instrument is the range recorded in the product data or on-site calibration record. The allowable operating range of the pipeline is the pressure, flow rate, and temperature range specified in the design documents, commissioning records, or operating procedures.

[0097] The rate of change check is used to determine whether the data changes at adjacent sampling times conform to normal operating conditions; a stable operating period refers to a continuous operating period in which the current operating connectivity has not changed, valves and pumps have not been switched, heat source output and circulation flow are within the historical normal fluctuation range, and there are no maintenance, cleaning or pipe section replacement events; the upper limit of historical normal change can be determined based on the amount of change of adjacent sampling values ​​within multiple stable operating periods.

[0098] In the absence of records of valve operation, pump switching, or heat source adjustment, when the change in adjacent observation values ​​exceeds the sum of the instrument's maximum permissible error and the historical upper limit of normal change, the corresponding data will be marked as abrupt change data. By using instrument error and historical operating records to jointly determine the judgment boundary, it is possible to avoid misjudging instrument fluctuations as changes in pipeline status.

[0099] The continuity check is used to identify measurement point freezing; when the measurement point value remains unchanged for a longer period than the maximum duration of no change during the historical stable operation period of the measurement point, and the status of adjacent measurement points or related equipment has changed during the same period, the measurement point is marked as suspected freezing.

[0100] When sufficient historical data is lacking, for example, keeping the measurement point value exactly the same for three or more consecutive sampling cycles can be used as an initial freezing condition, and then the changes of adjacent measurement points and equipment status can be verified. Three sampling cycles are used to exclude short-term value invariance caused by low instrument resolution. The actual number of cycles used can be adjusted according to the instrument resolution, normal fluctuation range and historical data records.

[0101] The physical relationship check is used to verify whether the data from different measuring points conform to the basic operating relationship of the heating network; the flow direction of the pipe section should be consistent with the pressure relationship at both ends of the pipe section; the inflow and outflow of each branch at the same node should be balanced within the allowable range of the comprehensive measurement error of the flow meter; when the valve is closed, the flow of the corresponding branch should be reduced to within the effective resolution range of the flow meter; after the temperature at the heat source outlet changes, the downstream temperature measuring point should show a consistent change in direction after the temperature propagation through the corresponding pipe section.

[0102] The allowable deviation for flow balance is determined based on the maximum allowable error of each flow meter involved in the calculation. For example, when a node connects to multiple branches, the maximum allowable error of each branch flow meter can be converted to the same unit of measurement, and the converted comprehensive error can be used as the allowable deviation for flow balance of the node. When the difference between the inflow and outflow of the node exceeds this allowable deviation, the relevant flow data is marked as pending verification.

[0103] When the valve status, flow direction, or node pressure relationship reflected in the collected data is inconsistent with the current operational connectivity, the relevant data is marked as status conflict data, and the current operational connectivity is not changed directly based on a single conflict; when the status conflict continues to reach the status confirmation time, or involves heat source outlets, main pipes, and key connecting pipes, the valve status, pump status, flow direction, and node pressure are re-verified, and the current operational connectivity is updated based on the verification results.

[0104] The status confirmation time is determined based on the time required for the valve to complete its action, the time required for the water pump to start or switch and form a stable differential pressure, the data sampling period, and the normal communication delay. The maximum value of the above times can be taken and an additional sampling period can be added. The valve action time and water pump start time are based on the equipment product data or on-site commissioning records, and the communication delay is based on the upper limit of the normal delay in the historical communication records.

[0105] Source integrity checks are used to confirm whether data can be mapped to specific measurement points, nodes, or pipe sections. Data with unknown sources, unidentifiable measurement point numbers, missing units of measurement, missing acquisition times, or that cannot be mapped to specific nodes and pipe sections will not be used for subsequent parameter identification. When multiple data sources provide conflicting observations for the same object, data that has been verified on-site, is in normal equipment condition, and has a high historical operational stability will be given priority. The remaining data will be retained and marked as pending verification.

[0106] The allowable duration for short-term data loss is determined based on the duration of occasional packet loss in historical communication records, and is shorter than the duration of the shortest valid operating condition that needs to be identified; short-term data loss must not span the time of valve operation, pump switching, heat source adjustment, pipe section isolation, or change in the current operating connectivity.

[0107] For example, the allowable duration for short-term data loss can be selected as one to three sampling periods; when historical communication records show that most occasional interruptions can be recovered within one sampling period, one sampling period can be used; when there are two or three consecutive packet losses, but no change in operating status occurs during the data loss period, two or three sampling periods can be used.

[0108] When the data loss time of a single measuring point does not exceed the allowable duration, the most recent valid value before the loss or the backup measuring point value verified on-site can be used to maintain the continuous display of the operating status; the data used for temporary replacement should at least record the original measuring point number, the source of the replacement data, the start time of the replacement, the end time of the replacement, and the replacement status; the temporary replacement data is not used for judging long-term parameter changes, nor is it used as the main data for the formal update of the friction coefficient and the overall heat transfer coefficient.

[0109] If the data loss time exceeds the allowable duration, or if multiple adjacent key measuring points are missing at the same time, parameter updates that rely on the missing measuring points will be suspended, and the parameter identification level of the corresponding pipe section will be adjusted according to whether the remaining measuring points can form a complete hydraulic or thermal relationship. Key measuring points include at least those used to determine the heat source boundary, main pipe flow rate, treatment area boundary pressure, pipe section inlet temperature, or pipe section outlet temperature.

[0110] After completing the data validity check, the parameter identification level of each pipe segment is determined based on the coverage of the measuring points and the physical relationship of the pipeline network. The parameter identification level may include the direct identification level, the joint identification level, and the constraint inference level.

[0111] When a pipe segment has corresponding inlet pressure, outlet pressure, flow rate, inlet temperature, and outlet temperature observations, and can form independent hydraulic and thermal relationships, the pipe segment is identified as a direct identification level.

[0112] If a pipe section lacks some independent measuring points, but the missing conditions can be supplemented by the flow balance relationship between adjacent nodes, the loop pressure relationship, or the boundary observations of the inlet and outlet of the treatment area, and the number of independent relationships formed is not less than the number of parameters to be determined, then the pipe section is identified as a joint identification level.

[0113] If a pipe segment lacks the observations required to form an independent hydraulic or thermal relationship, and can only form candidate parameters based on the parameters of adjacent pipe segments, the physical properties of the pipe segment, and the historical effective range, then the pipe segment is determined to be of the constraint inference level. If a complete physical relationship cannot be formed, and a reference pipe segment that meets the requirements of pipe diameter, material, laying method, and insulation structure cannot be found, then the previous effective parameters are retained and no automatic update is performed.

[0114] The importance of the pipe section and the parameter identification level are recorded separately; even if the heat source outlet pipe, main pipe or critical connecting pipe has a significant impact on the heating operation, it will not be directly identified as the direct identification level when there are insufficient measuring points; the parameter identification record shall include at least the following fields: pipe section number, identification level, available measuring points, missing measuring points, physical relationship used, corresponding operating connection relationship version and identification status.

[0115] Electronic devices establish long-cycle, medium-cycle, and short-cycle observation periods based on data that has passed validity checks.

[0116] Long-term observation periods are used to observe slow parameter changes related to scaling and long-term deposition in pipes. The length of a long-term observation period should cover at least seven complete daily load cycles and should not span events such as pipe cleaning, pipe replacement, or changes in the pipe network structure. For example, a long-term observation period can be selected as 10 to 14 days, and the shift interval can be selected as 1 to 3 days. This range is determined based on the daily load change cycle of the heating pipe network, the water quality testing cycle, and historical parameter change records before and after cleaning. It only indicates the data observation time range and does not indicate the actual scaling formation cycle.

[0117] The medium-cycle observation period is used to observe parameter changes caused by moisture absorption of the insulation layer, changes in groundwater level, and natural drying processes. The length of the medium-cycle observation period should cover at least one continuous process of environmental change occurrence, pipe section thermal state response, and gradual parameter stabilization. For example, the medium-cycle observation period can be selected from 3 to 7 days, and the shift interval can be selected from 12 hours to 1 day. This range is determined based on the local continuous rainfall time, groundwater level change records, the duration of temperature changes after the insulation layer becomes damp, and insulation structure maintenance records.

[0118] Short-cycle observation periods are used to observe short-term parameter changes caused by soil moisture content, soil temperature, and freeze-thaw conditions. The length of a short-cycle observation period should cover at least one process of environmental condition rise and fall. For example, the short-cycle observation period can be selected from 12 hours to 48 hours, and the shift interval can be selected from 1 hour to 4 hours. This range is determined based on the response time of the soil moisture sensor, the record of soil moisture content changes after rainfall, and the duration of the local freeze-thaw process.

[0119] An observation period record is established for each observation period. The observation period record shall include at least the following fields: observation period category, start time, end time, corresponding running connectivity version, effective data ratio, stable running period, associated environmental events, and associated operation and maintenance events.

[0120] The effective data ratio is the ratio of the actual number of observations that have passed time alignment, range checks, rate of change checks, continuity checks, physical relationship checks, and source integrity checks within the observation period to the total number of observations that should be obtained according to the sampling period; temporary substitute data are not included in the actual number of observations.

[0121] The minimum requirement for the effective data ratio is determined based on the historical data completeness rate, the number of effective measurement points, and the minimum number of observations required to form hydraulic and thermal relationships. For example, the minimum effective data ratio can be selected as 80%. Historical operating data can be used to test the parameter stability and model verification results under different data completeness levels. The minimum ratio that can continuously form hydraulic and thermal relationships without causing abnormal parameter fluctuations is taken as the actual adopted value.

[0122] When the proportion of valid data is lower than the corresponding minimum requirement, no direct parameter update is performed; when the remaining valid data can still form a complete joint constraint relationship, it can be processed according to the joint identification method; when a complete constraint relationship cannot be formed, the previous valid parameter is retained.

[0123] When continuous rainfall occurs, observation periods are formed for the stable operating period before rainfall, the rainfall process, and the recovery period after rainfall. When pipeline cleaning or pipe section replacement occurs, the original long-cycle observation period is terminated, and a new long-cycle observation period is established from the stable operating period after the event ends. When heat source switching, large-scale valve operation, or changes in the current operating connectivity occur, the observation period spanning the time of change is terminated, and the data before and after the change are respectively assigned to different cycle observation periods.

[0124] After the above processing, operational data that has been completed and validated is generated, along with parameter identification levels for each pipe section and long-cycle, medium-cycle, and short-cycle observation periods. These data are used to subsequently determine changes in pipe section parameters caused by scaling, moisture absorption of the insulation layer, and changes in soil moisture.

[0125] Specifically, such as Figure 4 As shown: The electronic device calls the established long-term, medium-term, and short-term observation periods, and combines them with historical parameters of the pipe section, water quality test records, environmental data, and operation and maintenance events to determine the impact of scaling, insulation layer dampness, and soil moisture changes on pipe section parameters in the order of long-term hydraulic changes, medium-term thermal changes, and short-term environmental changes.

[0126] During the long-term observation period, select at least two stable operating periods where the observation data do not completely overlap, and compare the pipe section pressure difference, flow rate, and inlet and outlet temperatures after temperature propagation delay correction when the operating conditions are similar. The stable operating period should meet the following conditions: the current operating connection relationship has not changed, the valves and pumps have not been switched, the heat source output and circulation flow rate are within the historical normal fluctuation range, and there are no maintenance, cleaning, or pipe section replacement events.

[0127] Selecting at least two stable operating periods is to eliminate accidental changes caused by single load adjustments, instrument fluctuations, or short-term operational disturbances. When historical operating fluctuations are large, the number of stable operating periods for comparison can be increased. The differences in heat source output, circulation flow rate, and outdoor temperature between different stable operating periods should be within their respective historical stable fluctuation ranges to ensure the comparability of different observation data.

[0128] When the same pipe section exhibits a gradual increase in differential pressure under the same flow rate or a gradual decrease in flow rate under the same differential pressure during at least two stable operating periods, and there are no pipe cleaning, pipe flushing, pipe section replacement, or high-velocity scouring events during the corresponding period, it is preliminarily determined that the pipe section has scaling or long-term deposition effects.

[0129] Water quality test results can be used to further verify scaling judgments; when water hardness, turbidity, or iron content exceeds the upper limit of water quality control implemented by the heating company or the historical normal range of the pipeline network for two or more consecutive testing cycles, the reliability of scaling judgments is improved; two consecutive testing cycles are used to exclude accidental exceedances caused by single sampling errors and laboratory errors, and the testing cycle is determined according to the actual water quality testing plan implemented by the heating company; when historical water quality fluctuations are large, the number of consecutive testing cycles can be increased.

[0130] After confirming that the friction coefficient along the pipe is changing slowly and continuously, the direction and range of the impact of scaling on the overall heat transfer coefficient are determined based on the historical test records before and after cleaning of the target pipe section or similar pipe sections. The historical test records should at least include data such as parameters before cleaning, parameters after cleaning, corresponding flow rate, inlet temperature, outlet temperature, and ambient temperature. If historical data that can reflect the differences before and after cleaning is lacking, only the impact of scaling on the friction coefficient along the pipe is determined, and the amount of change in the overall heat transfer coefficient caused by scaling is not automatically determined.

[0131] During the medium-period observation period, check whether the overall heat transfer coefficient changes continuously throughout the observation period, and make a judgment based on precipitation, groundwater level, damage to the outer insulation layer, repair of insulation joints, and drainage records. When the overall heat transfer coefficient changes continuously, the friction coefficient does not increase accordingly, and the change occurs after continuous rainfall, rising groundwater level, or damage to the outer insulation layer, it is preliminarily determined that the pipe section is affected by moisture in the insulation layer.

[0132] The spatial range of moisture in the insulation layer is determined based on the parameter changes of adjacent pipe sections. When two or more directly connected pipe sections are located in the same groundwater-affected area, low-lying waterlogged area, or construction-affected area, and show consistent changes in the comprehensive heat transfer coefficient within the same medium-period observation period, it is determined that the corresponding area may be continuously damp. Two pipe sections are the minimum number required to form an adjacent spatial continuity relationship. When there are many branches in the pipe network or significant differences in environmental conditions, the number of adjacent pipe sections involved in the judgment should be increased.

[0133] When the overall heat transfer coefficient of only one pipe segment changes, while the adjacent pipe segments remain within the historical normal range, further check the insulation outer protective layer, insulation interface, drainage conditions and nearby construction records of that pipe segment to avoid misjudging a single-point measurement anomaly as regional dampness.

[0134] After the insulation layer is drained, dried, or the insulation structure is replaced, the continuous assessment of moisture changes before maintenance is terminated; data after the event ends are collected separately, and a new comprehensive heat transfer coefficient benchmark is determined after stable operating conditions are re-established, without carrying over the parameter change trend before maintenance to after maintenance.

[0135] Within a short-period observation period, the portion of the comprehensive heat transfer coefficient that has a short duration and can rise or fall with environmental conditions is extracted and correlated with soil moisture content, soil temperature, precipitation, and freeze-thaw conditions over time.

[0136] When two or more directly adjacent pipe sections within the same soil zone show a consistent change in the overall heat transfer coefficient during the same short-period observation period, and the parameter change no longer expands after the soil moisture content stabilizes, or partially falls back after the soil moisture content decreases, it is determined that the change is related to the change in soil moisture. Using two or more adjacent pipe sections for judgment is to distinguish between the common influence of the environment and the anomaly of a single pipe section or a single measuring point.

[0137] In areas where soil moisture sensors are not installed, meteorological station precipitation records, groundwater level records, soil type, and parameter changes under similar historical weather conditions can be used as alternative information. When using alternative information, the data source, data collection location, distance from the target pipe section, and corresponding soil zone should be recorded, and the update range should be lower than that of the on-site soil moisture measurement data in subsequent parameter updates.

[0138] For areas with freeze-thaw processes, the comprehensive heat transfer coefficients before freezing, during freezing, and after thawing are compared separately. When parameter changes only occur during freezing or thawing and return to the historical effective range after the soil condition recovers, the change is determined as a short-term impact caused by the freeze-thaw environment and is not considered permanent insulation damage. The freezing and thawing periods are determined based on local meteorological records, soil temperature records, or underground pipeline environmental monitoring records.

[0139] The causes of parameter changes are determined in the following order: first, long-term hydraulic changes; then, medium-term thermal changes; and finally, short-term environmental changes. First, the changes in friction coefficient caused by scaling or long-term deposition are determined based on long-term observation periods. If historical test records before and after cleaning are available, the changes in the comprehensive heat transfer coefficient corresponding to scaling are determined. Subsequently, the portion that can be explained by scaling is deducted from the total change in the comprehensive heat transfer coefficient, and the impact of moisture on the insulation layer is determined based on damping events, changes in adjacent pipe sections, and groundwater conditions. Among the remaining changes, the short-term portion that is synchronous with soil moisture content, soil temperature, or freeze-thaw conditions is determined to be the impact caused by changes in the soil environment.

[0140] To check the judgment results for different causes, the parameter changes corresponding to scaling, insulation layer dampness and soil moisture changes were added together and compared with the actual observed parameter changes. The absolute difference between the two was taken as the residual deviation.

[0141] The allowable range of residual deviation is determined based on the instrument's overall error and the normal fluctuation range of parameters during historical stable operation. The instrument's overall error is formed by the maximum allowable error of the pressure transmitter, flow meter, temperature transmitter, and data acquisition channel involved in parameter determination. The normal fluctuation range of parameters is determined based on the parameter change records of the same pipe section during multiple stable operation periods. When the residual deviation exceeds the sum of the upper limit of the instrument's overall error and the upper limit of the normal fluctuation range of parameters, the corresponding pipe section is marked as a cause of change pending verification.

[0142] When the same parameter change meets contradictory judgment conditions, the corresponding pipe section will also be marked as the cause of the change and await verification. For example, if the friction coefficient and the overall heat transfer coefficient change abruptly at the same time, and there is valve throttling and continuous rainfall during the corresponding period, it is necessary to re-examine the local resistance of the valve, the current operating connection relationship, the status of the measuring point and the environmental data, and not directly determine the parameter change as scaling or insulation layer dampness.

[0143] For pipe sections where the cause of change needs to be verified, the previous valid parameters will be maintained, and automatic parameter updates will not be performed until new stable operating data is obtained, on-site inspections are completed, or data conflicts are eliminated.

[0144] After determining the cause of parameter changes, a record of the cause of parameter changes is generated for each pipe segment. The record of the cause of parameter changes includes at least the pipe segment number, the cause of parameter change, the amount of parameter change, the corresponding observation period, the data source used, the associated environmental events, the associated operation and maintenance events, the scope of impact, the remaining deviation, and the verification status. The record of the cause of parameter changes is used to subsequently determine the candidate values ​​for the friction coefficient and the overall heat transfer coefficient.

[0145] Specifically, such as Figure 5 and Figure 6 As shown: The electronic device reads the current operating connectivity, pipe segment length, pipe segment inner diameter, pipe segment elevation, local component information, pressure data, flow data, inlet temperature, outlet temperature and ambient temperature. First, it determines the friction coefficient of the pipe segment, then determines the time required for the heat medium to travel from the pipe segment inlet to the pipe segment outlet, and finally determines the comprehensive heat transfer coefficient after the inlet temperature and outlet temperature correspond to the same batch of heat medium.

[0146] The current operational connectivity is used to determine the pipe segments involved in the calculation, the direction of heat medium flow, and the current inlet and outlet nodes of the pipe segments; the pipe segment length, inner diameter, and elevation are preferably obtained from the as-built data or the asset ledger verified on-site; the local component information includes at least the fields such as the type, installation location, and operating status of valves, elbows, tees, reducers, and other components that can generate local pressure loss; the pressure, flow, and temperature data are observation data that have been time-aligned and validated.

[0147] For pipe sections whose parameters can be determined using their own measuring points, the electronic equipment first obtains the difference between the current inlet node pressure and the current outlet node pressure, and then subtracts the static pressure change caused by the elevation difference between the inlet node and the outlet node, as well as the pressure loss caused by local components such as valves, elbows, and reducers, to obtain the pressure loss caused by friction along the pipeline.

[0148] The static pressure change caused by the elevation difference is determined based on the heat medium density, gravitational acceleration, and the elevation difference between the inlet and outlet nodes; the heat medium density is determined based on the type of heating medium and the corresponding temperature, and can be obtained from the heat medium physical property data; when the supply water temperature and return water temperature differ greatly, the corresponding heat medium density can be determined by the average value of the inlet and outlet temperatures of the pipe section.

[0149] Pressure loss caused by local components is primarily determined using equipment product data, as-built commissioning records, or on-site flow and pressure differential test results. When the valve is fully open, the local resistance data corresponding to the fully open state is used. When the valve is in the regulating state, the local pressure loss is determined based on the current opening degree and the relationship between the opening degree and flow and pressure differential formed by the valve on-site calibration.

[0150] When on-site calibration results are unavailable, the corresponding local resistance coefficients can be obtained from equipment data or heating pipeline design data based on the structural form of valves, elbows, tees, and reducers. The local pressure loss can then be determined by combining the density of the heat medium and the average flow velocity within the pipe section. If the type, condition, or local pressure loss of the main local components cannot be determined, the corresponding operating period should not be used for the direct determination of the friction coefficient to avoid incorrectly including pressure losses caused by valve throttling or abnormal local components in the pipeline friction resistance.

[0151] The average flow velocity within the pipe section is determined based on the pipe section volumetric flow rate and the effective flow area; the effective flow area is determined based on the pipe section inner diameter; when there is an inner lining, significant sedimentation, or other conditions that reduce the actual flow area, the actual effective inner diameter obtained from the test should be used first; when the actual effective inner diameter is missing, the pipe section inner diameter in the asset ledger can be used temporarily, and the parameter source should be recorded as ledger data.

[0152] Electronic equipment determines the friction coefficient based on the physical relationship between the pressure loss along the heating pipeline and the length, inner diameter, density of the heating medium, and average flow velocity. The greater the pressure loss along the pipeline, the shorter the length of the pipeline, or the lower the average flow velocity, the greater the corresponding friction coefficient. During the determination process, the units of measurement for pressure, flow rate, length, and inner diameter should be kept consistent.

[0153] When the pipeline network model uses equivalent resistance to represent the hydraulic characteristics of the pipe section, the equivalent resistance can be determined based on the relationship between the pressure loss along the pipe section and the square of the volumetric flow rate. Both the friction coefficient and the equivalent resistance are used to represent the hydraulic characteristics of the pipe section. The same parameter representation method is used in the same pipeline network model update and verification process to avoid mixing different parameter forms.

[0154] When the pressure or flow rate fluctuates significantly at a single sampling moment, instead of directly using a single observation value to determine the friction coefficient, multiple operating segments with the same operational connectivity, stable valve and pump status, and heat source output and circulating flow rate within the historical normal fluctuation range are selected, and the corresponding friction coefficients are determined separately. After removing out-of-limit data, frozen data, and data with conflicting status, the median of the remaining parameters can be taken as a candidate value to reduce the impact of a single instrument fluctuation on the parameter results.

[0155] When using the median, the number of valid parameters involved in the processing should not be less than three; three valid parameters are the minimum number required to form an intermediate sorting result; when there is a large amount of stable running data, the number of parameters involved in the processing can be increased; the specific number is determined based on the number of valid observation periods and the completeness of the data.

[0156] For pipe segments whose parameters cannot be determined using only a single pipe segment measurement point, but whose complete hydraulic relationship can be formed using observations of adjacent nodes and regional boundaries, adjacent pipe segments should be included in the same treatment area. The scope of the treatment area should be the smallest area that can form a complete hydraulic relationship, with at least one of the following effective observations: regional inlet flow, regional outlet flow, or boundary pressure, and the missing conditions can be supplemented using node flow balance relationships or loop pressure relationships.

[0157] The number of parameters that need to be determined within the processing area shall not exceed the number of independent conditions that can be provided by effective boundary observations, nodal flow relationships, and loop pressure relationships. If clear parameter results cannot be formed, the observation period can be extended, boundary measuring points can be added, or the pipe segment range of the parameters to be determined can be narrowed. If a complete hydraulic relationship still cannot be formed, parameter values ​​that are indistinguishable from each other will not be output. Instead, the previous effective parameter of the relevant pipe segment will be maintained, or the processing method of referring to the parameters of adjacent pipe segments will be adopted.

[0158] After the candidate values ​​of the friction coefficient are generated, the electronic equipment checks whether the candidate values ​​are within the design range of the pipe section and the historical effective range, and checks whether the direction of change of the candidate values ​​is consistent with the operation and maintenance events. If the friction coefficient shows a significant decrease beyond the historical normal change range within an update cycle without cleaning, flushing, pipe section replacement or valve adjustment, it will not be automatically updated.

[0159] The historical normal variation range is determined based on the records of friction coefficient changes in the same pipe section during multiple stable operating periods. If the historical records of the pipe section are missing, pipe sections with similar pipe diameter, material, laying method and commissioning years can be selected to determine the initial reference range. The reference range is only used to determine whether the candidate value is obviously abnormal and does not directly replace the observation results of the target pipe section.

[0160] If the friction coefficient continues to increase and the increase exceeds the range that can be explained by historical scaling changes, further check whether there is siltation, local blockage, valve not fully open, or flow meter malfunction in the pipe section. Do not uniformly attribute all increases in hydraulic resistance to scaling.

[0161] After the hydraulic parameters are determined, the electronic equipment determines the temperature propagation delay based on the heat medium volume and volumetric flow rate inside the pipe section. The heat medium volume inside the pipe section is determined based on the effective flow area and length of the pipe section. When the flow rate of the pipe section is basically stable, the basic time for the heat medium to propagate from the current inlet node to the current outlet node is obtained by dividing the heat medium volume inside the pipe section by the volumetric flow rate during stable operation.

[0162] "Basically stable flow" means that the flow rate change during the processing period does not exceed the sum of the flow meter's comprehensive measurement error and the historical stable flow rate fluctuation limit for that pipe section. The comprehensive measurement error of the flow meter is determined based on the flow meter's accuracy class and the data acquisition channel error, while the historical stable flow rate fluctuation limit is determined based on the flow rate records of multiple stable operating periods under the same operating connectivity.

[0163] When the flow rate in the pipe section changes over time, the average flow rate of the entire observation period is not used to directly determine the temperature propagation delay. Instead, the heat medium volume entering the pipe section is accumulated according to the sampling order. The heat medium volume entering the pipe section in each sampling period is determined by the volumetric flow rate and duration of that period. When the accumulated heat medium volume first reaches or exceeds the heat medium volume inside the pipe section, the time from the start of the accumulation to the sampling time is taken as the basic temperature propagation delay.

[0164] Near the base temperature propagation delay, the electronic device uses the change characteristics of the inlet and outlet temperatures to correct for the delay. The inlet temperature change characteristics may include the start time of continuous heating, the start time of continuous cooling, the local peak time, and the local trough time. Within the time range corresponding to the base temperature propagation delay, the electronic device searches for temperature characteristics with the same change direction from the outlet temperature sequence.

[0165] The inlet temperature change amplitude used for time delay correction should be greater than the sum of the temperature sensor resolution and the upper limit of normal temperature fluctuation during stable operation, and the corresponding change duration should not be less than two sampling periods; two sampling periods are used to exclude abnormalities of individual sampling points and instantaneous measurement fluctuations; the actual duration can be adjusted according to the sampling period, temperature sensor response time and historical temperature fluctuation records.

[0166] When the inlet and outlet temperatures change continuously in the same direction, the time difference between the inlet temperature characteristic moment and the corresponding outlet temperature characteristic moment is used to correct the base temperature propagation delay. When multiple temperature features can form a corresponding relationship, multiple delay results can be obtained. After removing the results that deviate significantly from the base temperature propagation delay, the median of the remaining results is used as the actual temperature propagation delay.

[0167] After temperature propagation time delay correction is completed, the outlet temperature is mapped to the inlet temperature when the same batch of heat medium enters the pipe section; the comprehensive heat transfer coefficient is determined based on the mass flow rate of the heat medium, the specific heat capacity of the heat medium, the effective heat exchange area of ​​the pipe section, the inlet and outlet temperatures after time delay alignment, and the ambient temperature.

[0168] The mass flow rate of the heat medium is determined based on the volumetric flow rate and the density of the heat medium. The specific heat capacity of the heat medium is obtained from the physical property data based on the type of heat medium and the corresponding temperature. The effective heat exchange area of ​​the pipe section is determined based on the outer diameter and length of the pipe section. When there is a clearly defined heat insulation structure and outer protective layer size, the effective heat exchange area can be determined in combination with the actual heat transfer boundary.

[0169] During operation when the heat transfer medium flow rate and ambient temperature remain stable, the electronic equipment determines the heat dissipation of the pipe section based on the degree of temperature reduction of the heat transfer medium before and after it flows through the pipe section, and then determines the comprehensive heat transfer coefficient based on the effective heat exchange area of ​​the pipe section and the difference between the heat transfer medium temperature and the ambient temperature. The greater the temperature difference between the inlet temperature and the outlet temperature, the greater the corresponding comprehensive heat transfer coefficient under the same conditions.

[0170] When using the above relationship, both the inlet and outlet temperatures should be higher than or lower than the ambient temperature to ensure that the heat transfer direction is consistent. The difference between the inlet temperature and the ambient temperature, and the difference between the outlet temperature and the ambient temperature, should also be greater than the comprehensive uncertainty range of the temperature measurement link. When the temperature difference is lower than this range, the measurement error will have a greater impact on the calculation results, and the corresponding operating segment will not be used for the direct determination of the comprehensive heat transfer coefficient.

[0171] For directly buried pipelines, the soil temperature near the pipeline is used as the ambient temperature. For overhead pipelines, the outdoor temperature is used, and the representative ambient temperature is determined by combining wind speed and shielding conditions. For pipelines laid in trenches, the air temperature in the trench or the representative ambient temperature obtained by on-site testing is used. When no environmental measuring points are set up near the target pipeline section, representative measuring points are selected according to soil zoning, laying method, burial depth, and distance between environmental measuring points and the target pipeline section.

[0172] When using environmental measuring points far from the target pipe section, the environmental measuring point number, installation location, corresponding soil zone, distance from the target pipe section, and validity status of environmental data should be recorded. When the target pipe section and the environmental measuring point belong to different soil zones, different laying methods, or different groundwater-affected areas, the data from the environmental measuring point should not be used to determine the comprehensive heat transfer coefficient.

[0173] When the flow rate in the pipe section is lower than the reliable measurement limit of the flow meter, the temperature measuring point freezes, the change in inlet temperature cannot be found in the outlet temperature, the temperature propagation delay spans two different versions of the operating connection relationship, or the difference between the inlet temperature and the ambient temperature is lower than the comprehensive uncertainty range of the temperature measurement link, the corresponding operating segment is not used for the direct determination of the comprehensive heat transfer coefficient.

[0174] The lower limit of reliable flow meter measurement is determined by the flow meter product data or the results of on-site small flow calibration. The comprehensive uncertainty range of the temperature measurement link is determined by the maximum permissible error of the inlet temperature sensor, the maximum permissible error of the outlet temperature sensor, the error of the data acquisition channel, the temperature deviation caused by time alignment, and the upper limit of normal temperature fluctuation during stable operation.

[0175] The allowable deviation for temperature calibration shall not be less than the comprehensive uncertainty range of the temperature measurement link; for example, when the comprehensive error formed by the accuracy of the temperature sensor, the acquisition channel error and the time alignment error does not exceed 0.3 degrees Celsius to 0.8 degrees Celsius, the allowable deviation for temperature calibration may be selected as 0.3 degrees Celsius to 0.8 degrees Celsius.

[0176] When the temperature sensor has high accuracy, the pipe section is short, the temperature propagation delay is small, and the timing conditions are good, an allowable deviation of close to 0.3 degrees Celsius can be used; when the pipe section is long, the environment changes significantly, or the temperature measurement error is high, an allowable deviation of close to 0.8 degrees Celsius can be used; when the overall error of the temperature measurement link exceeds 0.8 degrees Celsius, the allowable deviation should be increased according to the actual overall error, and the above range should not be used.

[0177] After generating candidate values ​​for the friction coefficient and the overall heat transfer coefficient, check whether the parameters are within the design allowable range and the historical valid range, whether the data used is complete and valid, whether the parameter changes are consistent with events such as cleaning, flushing, maintenance, rainfall or groundwater changes, and whether the physical relationship between pressure, flow rate and temperature can be maintained after the candidate parameters are substituted into a single pipe section.

[0178] Candidate parameters that fail the above checks will not be used for pipeline model updates. After passing the checks, a candidate parameter record will be generated for each pipeline segment. The candidate parameter record will include at least the following fields: pipeline segment number, candidate value of friction coefficient, candidate value of comprehensive heat transfer coefficient, parameter identification level, observation period used, corresponding operating connectivity version, effective data ratio, temperature propagation delay, reason for parameter change, and check results. The candidate parameter record will be used for subsequent pipeline model verification and parameter updates.

[0179] Specifically, such as Figure 7 As shown: The electronic equipment determines the update range of the friction coefficient and the overall heat transfer coefficient based on the parameter identification level of each pipe section, the source of candidate parameters, the completeness of observation data, and the parameter check results, and writes the parameters to be updated into the model to be checked; the model to be checked is independent of the current effective model, and does not replace the currently effective model before the on-site observation and verification are completed;

[0180] For pipe segments with directly identified grades, candidate parameters are determined by observational data such as pressure, flow rate, inlet temperature, and outlet temperature of the pipe segment itself; for pipe segments with jointly identified grades, candidate parameters are jointly determined by boundary pressure, boundary flow rate, nodal flow balance relationship, and loop pressure relationship of the treatment area; for pipe segments with constrained inference grades, candidate parameters are determined based on the parameters of reference pipe segments that meet the conditions, the physical properties of the target pipe segment, and the historical effective range of the target pipe segment.

[0181] When selecting reference pipe sections, first exclude pipe sections that are under maintenance, have abnormal data, have missing data, or whose parameter changes are pending verification. Then select pipe sections with the same or similar pipe diameter, material, laying method, and insulation structure as the target pipe section. The reference order is determined according to the connection distance between the pipe section and the target pipe section, the difference in commissioning time, soil zoning, and the stability of historical parameters.

[0182] The same or similar pipe diameter means that the difference in pipe diameter is within the allowable range of the design specifications of similar pipelines; pipe sections with completely identical materials and laying methods should be selected first; the insulation structure should at least compare the insulation material, insulation thickness and outer protective structure; when candidate reference pipe sections belong to different soil zones, different groundwater-affected areas or different laying environments, they should not be used as the same group of reference pipe sections.

[0183] When there are multiple reference pipe segments that meet the conditions, first remove abnormal parameters that exceed the historical stable range of each reference pipe segment, and then use the median of the remaining parameters to form the initial inference value. When using the median, the number of valid reference parameters shall not be less than three. When there are fewer than three valid reference parameters, the reference pipe segment parameters that are closest to the physical conditions of the target pipe segment can be used, but the corresponding candidate parameters are only used as low-confidence inference results.

[0184] The inference results must not exceed the common range of the target pipe section's design allowable range, the target pipe section's historical effective range, and the reference pipe section's stable parameter range; if a common range cannot be formed, or if the parameter differences between reference pipe sections exceed their respective historical normal fluctuation ranges, candidate parameters for the target pipe section will not be automatically generated, and the previous effective parameter will continue to be used while waiting for supplementary observation data;

[0185] The reference pipe section record should include at least the target pipe section number, reference pipe section number, pipe diameter, material, laying method, insulation structure, connection distance, commissioning time, soil zoning, reference parameters, screening results, and data validity status, so as to facilitate subsequent verification of the source of the inferred parameters;

[0186] When updating parameters, instead of directly replacing the previous valid parameter with a candidate parameter, the previous valid parameter is gradually modified towards a candidate parameter according to the update ratio. The update ratio represents the degree to which the candidate parameter accounts for in this parameter modification, and its value is greater than zero and not greater than one.

[0187] The update ratio is determined based on the parameter identification level, the proportion of effective data, the fluctuation degree of candidate parameters, and the deviation change of the model to be verified. Directly identified parameters are formed using the observation data of the pipe segment itself, and their update ratio is higher than that of the joint identified parameters. Jointly identified parameters are formed using regional boundary observations and inter-pipe segment relationships, and their update ratio is higher than that of the constrained inference parameters. Candidate parameters formed using environmental substitute data, temporary recovery data, or low-completeness data use a lower update ratio.

[0188] The specific update ratio is determined starting from a smaller value; the electronic equipment first corrects the parameters according to the smaller update ratio, writes the corrected parameters into the model to be verified, and compares the deviations of key pressure, flow and temperature measurement points before and after the update; when the overall deviation decreases and the local deviation does not exceed the corresponding allowable range, the update ratio can be increased step by step; when the overall deviation no longer decreases, or the local deviation of any key measurement point exceeds the corresponding allowable range, the update ratio is stopped from being increased, and the update ratio of the previous verification is adopted;

[0189] The adjustment interval for the update ratio is determined based on the rate of change of historical parameters and the model's sensitivity to parameter changes. Pipe sections with slower parameter changes and stable historical operation can use a smaller adjustment interval. Pipe sections with faster parameter changes and complete field observation can appropriately increase the adjustment interval. When historical operation data is lacking, a smaller update ratio should be used first to avoid writing too many candidate parameters at once, which could cause a sudden change in the model state.

[0190] Each parameter update is also limited by the magnitude of a single change; the magnitude of a single change is determined based on the upper limit of the historical normal parameter changes of the same pipe section between adjacent effective observation periods, the instrument errors involved in the parameter determination, and the stability test results of the model to be verified.

[0191] For example, when there is a continuous operating record and the parameter change within adjacent historical effective observation periods does not exceed 10% to 20% of the previous effective parameter, the single change range can be selected as 10% to 20% of the previous effective parameter; before adopting this range, it should also be confirmed that the model to be verified will not cause an increase in the pressure of key nodes, the flow of key branches, or the downstream temperature deviation within the corresponding change range.

[0192] Historical operation records show that when the normal parameter change is less than 10%, the single change amplitude should be reduced accordingly; when a confirmed cleaning, insulation dampness or environmental change occurs, and the on-site observation can support a large parameter change, the single change amplitude can be appropriately increased after the model to be verified passes the verification; when the difference between the candidate parameter and the previous effective parameter exceeds the single change amplitude, it should be gradually corrected in multiple update cycles, or the update should be paused and the data and parameter change causes should be re-examined.

[0193] Changes in the friction coefficient caused by scaling or long-term deposition are corrected using a continuous and slow, limited-amplitude correction method. In the absence of cleaning, flushing, pipe section replacement, or prolonged high-flow-rate scouring, the friction coefficient is not allowed to decrease significantly beyond the historical normal range within a single update cycle.

[0194] The change in the overall heat transfer coefficient caused by moisture in the insulation layer is corrected according to the process of moisture occurrence, moisture duration, and drainage recovery; after completing the drainage and drying treatment of the insulation layer or replacing the insulation structure, the parameter change process before maintenance is terminated, and the parameter benchmark is re-determined based on the stable operation data after maintenance.

[0195] Changes in the overall heat transfer coefficient caused by soil moisture content, soil temperature, or freeze-thaw conditions can be corrected bidirectionally within the historical effective range and the calibration range under the corresponding environmental conditions. After the environmental conditions recover, the overall heat transfer coefficient gradually returns to the normal range with the observation data, without solidifying short-term environmental changes into permanent changes in pipe section parameters.

[0196] Before writing the parameters to be updated into the model to be verified, save the parameter status of the current effective model; the parameter saving record shall include at least the following fields: the current running connectivity version, pipe segment number, previous effective friction coefficient, previous effective comprehensive heat transfer coefficient, candidate parameters, reason for parameter change, parameter identification level, corresponding observation period, update ratio, single change magnitude and saving time;

[0197] The model to be verified is operated using the same heat source water supply temperature, heat source flow rate, valve status, water pump status and heat exchange station boundary conditions corresponding to the same observation period on site. The calculated key node pressure, key branch flow rate and key location temperature are compared with the on-site observation results.

[0198] Key measuring points are determined based on the pipeline network structure and the degree of impact on heating operation, and include at least the pressure measuring point at the heat source outlet, the flow measuring point on the main pipeline, the measuring point on the key connecting pipeline, the pressure measuring point at the boundary of the treatment area, and the temperature measuring point at the downstream heat exchange station; in the same verification, the same key measuring points and the same field boundary conditions are used before and after the parameter update.

[0199] The pressure allowable deviation is the larger of the maximum allowable error of the pressure measuring point and the upper limit of the normal pressure deviation of the measuring point during the historical stable operation period; the flow allowable deviation is the larger of the maximum allowable error of the flow meter and the upper limit of the normal flow deviation of the corresponding branch during the historical stable operation period; the temperature allowable deviation is the allowable range determined based on the temperature sensor error, acquisition channel error, time alignment error and historical temperature fluctuations.

[0200] The upper limit of historical normal deviation is determined based on multiple operating periods with the same current operating connectivity, stable valve and pump status, and no maintenance events. When sufficient historical data is lacking, the maximum permissible error of the instrument can be used as the basic permissible range, and then corrected after accumulating stable operating data.

[0201] The overall deviation is compared by comparing the observation deviations of the same set of key measuring points before and after the parameter update; the overall deviation can be the average of the absolute deviations of each key measuring point or the maximum value among them, but the same statistical method should be used before and after the same parameter update;

[0202] Local deviations are represented by the observation deviations of the nodes at both ends of the updated pipe section, the directly adjacent pipe section, and the downstream heat exchange station. When the overall deviation of the model to be checked is less than the overall deviation before the parameter update, and the local deviations of each affected area do not exceed the corresponding allowable range, the parameter update is deemed to have passed the check, and the model to be checked is switched to the new currently valid model.

[0203] When only a few pipe sections fail the verification, and these pipe sections are not directly connected to each other, do not involve heat source outlets, main pipes, or critical connecting pipes, restore the previous valid parameters of the pipe sections that failed the verification, and retain the parameters of the other pipe sections that passed the verification; after restoration, check the pressure, flow rate, and temperature relationship at the boundary of the treatment area again to confirm that the local restoration has not disrupted the hydraulic balance and thermal continuity of the area.

[0204] If two or more directly connected pipe sections fail the verification, or if the pressure, flow rate, or temperature deviation at the inlet and outlet of the treatment area increases simultaneously, the parameter update for that area is deemed to have failed the verification, and the previous valid parameters for all relevant pipe sections in that area are restored.

[0205] If the overall deviation after the update is greater than the overall deviation before the update, or if the deviation of any key measuring point exceeds the corresponding allowable range, the parameter update is also deemed to have failed the verification; candidate parameters that fail the verification are not written into the current valid model.

[0206] When the verification anomaly involves only a few measuring points, the temperature propagation delay is close to the upper limit of the allowable error, or the proportion of effective data cannot support direct identification but can still form a complete joint identification relationship, the observation data can be re-screened, the temperature propagation delay can be re-determined, the parameter identification level can be reduced, or the observation period can be extended before processing again.

[0207] If the same pipe section fails to pass the verification for two or more consecutive valid update cycles, restore the parameter status of the most recent verification and suspend the automatic update of the pipe section; two consecutive update cycles are used to distinguish between single operating condition disturbances and continuous anomalies; when the parameter update cycle is short or the field fluctuation is large, the number of consecutive cycles can be increased according to the historical false alarm situation and anomaly response requirements.

[0208] If the heat source boundary cannot be confirmed, the status of key connecting pipes is conflicting, a large number of key measuring points fail, or the model to be verified cannot maintain stable operation, no local parameter update will be performed. Instead, the confirmed safety parameters at the beginning of the heating season will be restored, or the model status of the most recent time when all key measuring points have passed verification and the version record is complete will be restored.

[0209] During communication interruptions, incomplete data is not used to update parameters; only the currently valid model is retained and the received data is cached. After communication is restored, the data acquisition time, the current running connectivity version, and the missing time period are checked. If no changes in the running connectivity occurred during the missing period and the data completeness meets the processing requirements, the observation data can be re-collected. If valve operation, pump switching, heat source adjustment, or pipe section isolation occurs during the missing period, the data before and after the interruption are not included in the same observation time period.

[0210] Candidate parameters generated under the old operating connectivity version must not cover parameters that have already taken effect under the new version; when the valve status cannot be confirmed, the flow direction and pressure relationship continue to conflict, or key measuring points fail for a long time, freeze the relevant pipe section parameters and wait for on-site inspection or new valid observation data;

[0211] Before resuming automatic updates, at least one observation period must be obtained that meets the corresponding requirements, does not cross the time of change in operational connectivity, and includes stable operational data, and a verification of the model to be verified must be completed once; the first update after the anomaly is resolved uses an update ratio lower than that under normal operation; after passing the verification consecutively, the normal update ratio is gradually restored.

[0212] For each parameter update, pause, resumption, partial undo, and parameter rollback, a processing record should be established. The processing record should include at least the following fields: trigger reason, affected pipe segment, previous valid parameter, candidate parameter, actual written parameter, running connectivity version, verification result, resumption condition, processing time, and operation status.

[0213] Through the above processing, the friction coefficient and the overall heat transfer coefficient are gradually updated according to the actual flow state of the pipeline network, the observation data of the pipe section, and the physical state. Candidate parameters that have not passed the pressure, flow and temperature observation verification are prevented from entering the current effective model, thereby reducing the impact of temperature propagation delay, environmental changes and local abnormal data on the heating pipeline network model.

[0214] Example 2: Based on Example 1, the specific application process of a dynamic modeling method for heating pipe networks is further explained:

[0215] The application focuses on the primary hot water pipeline network of a city's centralized heating system. This network supplies hot water from a heat source plant to three heat exchange stations. The heat source plant is equipped with two parallel circulating water pumps, with the first circulating water pump in operation and the second circulating water pump in standby mode. The network includes a main pipeline, three branch lines to the heat exchange stations, and a connecting pipeline. The main pipeline and the branch lines to the heat exchange stations all use pre-insulated direct-buried pipes, and the medium being transported is treated hot water.

[0216] Dynamic parameter processing was performed on the first pipe section of the main pipeline, the second pipe section of the branch line of the first heat exchange station, and the third pipe section of the branch line of the second heat exchange station. The first pipe section is 820 meters long, with a nominal diameter of 400 mm and an actual inner diameter of 392 mm, and has been in operation for 8 years. The second pipe section is 1600 meters long, with a nominal diameter of 250 mm and an actual inner diameter of 245 mm, and has been in operation for 6 years. The third pipe section is 900 meters long, with a nominal diameter of 200 mm and an actual inner diameter of 194 mm, and has been in operation for 5 years. The pipe section length, nominal diameter, and actual inner diameter were obtained from the as-built data verified on-site, and the commissioning time was obtained from the records in the heating company's asset ledger.

[0217] Pressure and temperature measuring points are set at the inlet and outlet of the first pipe section, respectively, and a flow meter is set at the inlet of the pipe section. The pressure, flow and temperature data of the pipe section itself can be used to form a complete hydraulic and thermodynamic relationship. Therefore, the first pipe section is identified as the direct identification level.

[0218] The second pipe section did not have an independent outlet pressure measurement point, but its branch had an inlet flow measurement point, a branch outlet flow measurement point, and pressure measurement points at adjacent nodes. The missing outlet pressure conditions could be supplemented by the branch boundary observation data and the node flow balance relationship. Therefore, the second pipe section was identified as a joint identification level.

[0219] Since no outlet temperature measuring point was set in the third pipe section, a complete thermodynamic relationship could not be formed solely based on the measuring point in this pipe section. It is necessary to combine the adjacent pipe sections of the same specification, the historical effective range of the target pipe section, and the boundary data of the branch where it is located to determine the candidate parameters. Therefore, the third pipe section was determined as the constraint inference level.

[0220] After the heating season starts, the electronic equipment reads the pipeline geographic information, asset ledger and measuring point ledger, divides the pipeline into sections according to the location of pipe diameter changes, valve installation location, branch interface location and confluence interface location, and sets a unique pipe section number and two end nodes for each pipe section; according to the actual flow direction of the heat medium, the electronic equipment marks the end node located upstream as the current inlet node and the end node located downstream as the current outlet node.

[0221] Under this operating condition, the connecting pipe valve is closed, the first circulating water pump operates at a frequency of 42 Hz, and the second circulating water pump is in standby mode. The start / stop signal of the first circulating water pump indicates that it is in operation, its motor current is within the stable operating range of the equipment, the pump outlet pressure is higher than the pump inlet pressure, and there is a flow in the main pipe in the same direction as the water pump's delivery. Therefore, it is determined that the first circulating water pump is in an effective operating state.

[0222] The valves on the main pipeline and the three heat exchange station branches are all in the conducting state. The flow direction of each branch is consistent with the pressure relationship of the corresponding node. Based on this, the pipe sections and branches that actually participate in the heating operation are determined, and the current operation connection relationship is formed.

[0223] Electronic devices generate version numbers for the current connectivity relationships; the corresponding version record includes at least the version number, the connected pipe segment, the isolated pipe segment, the flow direction of each pipe segment, the valve status, the pump status, the version effective time, and the version trigger event; the pressure data, flow data, temperature data, environmental data, and operation and maintenance events collected subsequently are all associated with this version number.

[0224] When a connecting valve is operated, a circulating water pump is switched, or a pipe section is isolated during heating operation, the data collection under the original operational connectivity version is terminated, and a new operational connectivity version is generated after the valve, water pump, pressure, and flow rate reach a stable state again. Data before and after the version change are processed separately, and data under different operational connectivity versions are not included in the same observation period.

[0225] The effective refresh cycle of the on-site pressure, flow, and temperature measuring equipment is 10 seconds, and the monitoring system polling cycle is 30 seconds. On-site records show that the shortest time required to reach a stable operating state after valve adjustment or pump switching is greater than 5 minutes. Based on the effective refresh cycle of the instruments, the polling cycle of the monitoring system, and the shortest effective operating condition duration, the sampling cycle for pressure, flow, and temperature data is set to 60 seconds. The 60-second sampling cycle is greater than the polling cycle of the monitoring system and significantly less than the shortest effective operating condition duration after valve adjustment or pump switching. This can continuously reflect the main operational changes in the pipeline network while reducing a large amount of duplicate data caused by excessively short sampling intervals.

[0226] The on-site data acquisition equipment uses a unified time synchronization mechanism with a time synchronization error limit of 0.5 seconds, a timestamp resolution error of 0.1 seconds, and historical communication records show a normal communication delay fluctuation limit of 0.8 seconds, totaling 1.4 seconds. Therefore, the time alignment tolerance is set to 2 seconds. When the difference in acquisition time between different measurement points does not exceed 2 seconds, it is used as data from the same sampling time. When the difference in acquisition time exceeds 2 seconds, the original acquisition time is retained, and data is re-paired based on adjacent sampling times. Data that cannot form a valid correspondence is marked as time-inconsistent data and is not used for parameter determination. The electronic equipment performs range checks, rate of change checks, continuity checks, physical relationship checks, and source integrity checks on continuously acquired pressure, flow, temperature, and equipment status data.

[0227] The maximum permissible error for the inlet and outlet pressure transmitters of the first pipeline section is 0.005 MPa, the maximum permissible error for the flow meter is 0.5% of the measured value, and the maximum permissible error for the temperature transmitter is 0.2 degrees Celsius. The above errors are based on the values ​​in the instrument product data and the most recent field calibration record.

[0228] Historical stable operation data shows that the normal pressure change between adjacent sampling times in the first pipe section does not exceed 0.004 MPa, the normal flow rate change does not exceed 1.5% of the measured value, and the normal temperature change does not exceed 0.15 degrees Celsius. In the absence of records of valve operation, pump switching, or heat source adjustment, if the pressure change exceeds 0.009 MPa, the flow rate change exceeds 2.0% of the measured value, or the temperature change exceeds 0.35 degrees Celsius between adjacent sampling times, the corresponding data will be marked as abrupt change data. The judgment ranges for pressure, flow rate, and temperature are determined jointly by the maximum permissible error of the corresponding instrument and the upper limit of normal changes during historical stable operation. Historical communication records show that after occasional data loss in the communication link, it can usually be recovered within two sampling cycles, and the two minutes corresponding to the two sampling cycles are significantly shorter than the shortest effective operating condition duration to be identified. Therefore, the allowable duration for short-term data loss is set to two sampling cycles.

[0229] If the data loss time for a single measuring point does not exceed two sampling cycles, and no valve operation, water pump switching, heat source adjustment, or change in operational connectivity occurs during the data loss period, the most recent valid value before the data loss can be used to maintain the continuous display of the operating status. Temporary replacement data is only used for the display of operating status, is not included in the actual valid observation quantity, and is not used for the formal update of friction coefficient and comprehensive heat transfer coefficient.

[0230] During a long-term observation period of 12 days, each measuring point should obtain 17,280 data points with a sampling period of 60 seconds. After time alignment and data validity checks, the first pipe section retained 16,850 valid data points, with a valid data ratio of approximately 97.5%; the second pipe section retained 16,720 valid data points, with a valid data ratio of approximately 96.8%; and the third pipe section retained 16,210 valid data points, with a valid data ratio of approximately 93.8%. The valid data ratios of all three pipe sections are higher than the minimum requirement of 80%, allowing for further investigation into the causes of parameter changes and the determination of candidate parameters. The minimum valid data ratio of 80% was determined through historical operational data testing of the pipeline network. The results show that when the effective data ratio is below 80%, stable operating data is easily fragmented by missing data periods and temporary substitute data, making it difficult to continuously form complete hydraulic and thermal relationships. When the effective data ratio reaches above 80%, sufficient pressure, flow, and temperature data can be obtained, and the resulting parameters remain stable during model verification. Therefore, this processing uses 80% as the minimum requirement for the effective data ratio. The observation period for the long-term observation period is set to 12 days, and the observation period update interval is set to 2 days. 12 days can cover multiple complete daily load change processes and can include the weekly water quality test results of heating companies, which can be used to judge slow hydraulic changes caused by scaling or long-term deposition.

[0231] The observation period for the medium-term observation period is set to 5 days, and the update interval for the observation period is set to 12 hours. This observation period can cover the process of continuous rainfall, rising groundwater level, changes in the thermal state of the pipe section and the gradual recovery after the rain, and is used to determine the changes in thermal parameters caused by moisture in the insulation layer.

[0232] The observation duration for the short-period observation period is set to 24 hours, and the update interval for the observation period is set to 2 hours. This observation duration can cover the process of soil moisture content and soil temperature rising and falling before and after rainfall, and is used to determine short-term thermal changes caused by changes in the soil environment.

[0233] During the long-term observation period, three stable operating periods with non-overlapping observation data were selected from the operating data of the first pipe section. During the three stable operating periods, the flow rate of the first pipe section was between 640 cubic meters and 660 cubic meters per hour, the difference between the heat source water supply temperatures did not exceed 1 degree Celsius, the difference between the outdoor temperatures did not exceed 2 degrees Celsius, and the valve status, pump status, and operational connectivity remained unchanged.

[0234] During the first stable operating period, the pressure difference between the inlet and outlet of the first pipe section was 0.071 MPa when the flow rate was approximately 650 cubic meters per hour; during the second stable operating period, the pressure difference between the inlet and outlet was 0.076 MPa under similar flow conditions; and during the third stable operating period, the pressure difference between the inlet and outlet was 0.081 MPa under similar flow conditions.

[0235] After deducting the static pressure changes caused by the elevation difference between the inlet and outlet nodes, as well as the pressure losses caused by local components such as valves and elbows, the frictional pressure loss along the pipe section caused by pipe wall friction in the first pipe section shows a continuous increasing trend.

[0236] During the aforementioned period, no cleaning, flushing, replacement, or valve adjustment of the first pipe section occurred; the heating company's two consecutive water quality tests showed that the hardness of the circulating water was 0.68 mmol / L and 0.71 mmol / L, respectively, both exceeding the company's water quality control record upper limit of 0.60 mmol / L.

[0237] Based on the continuous increase in pressure loss along the pipe under similar flow conditions, the water hardness continuously exceeding the company's control limit, and the absence of maintenance events that could significantly reduce resistance during the corresponding period, it was determined that the changes in hydraulic parameters of the first pipe section were related to scaling or long-term deposition.

[0238] The first pipe section lacks historical test records that can reflect the changes in the overall heat transfer coefficient before and after cleaning of similar pipe sections. Therefore, it only determines the impact of scaling or long-term deposition on the friction coefficient and does not automatically determine the change in the overall heat transfer coefficient caused by scaling.

[0239] During the medium-term observation period, the target area experienced continuous rainfall for about 36 hours, and the groundwater level rose by about 0.35 meters. The friction coefficients of the second pipe section and its downstream adjacent pipe section remained within their respective historical normal ranges, but the overall heat transfer coefficient continued to increase from the second day after the rainfall began and gradually decreased after the rainfall ended.

[0240] The second pipe section and its downstream adjacent pipe section are both located in the same low-lying groundwater-affected area. The inspection record also shows that construction disturbances occurred near the second pipe section. Since the two directly adjacent pipe sections showed consistent changes in the comprehensive heat transfer coefficient during the same medium-cycle observation period, while the friction coefficient did not increase synchronously, it was determined that the changes in the corresponding thermal parameters were related to the moisture absorption of the insulation layer.

[0241] Subsequent on-site inspection revealed that one of the insulation interfaces in the second pipe section was not properly sealed, and the on-site inspection results were consistent with the judgment based on parameter changes.

[0242] During the short-period observation period, the soil moisture content in the soil zone where the third pipe section is located increased from 18% to 26% after rainfall, and then dropped back to 21% within 24 hours after the rainfall ended. The third pipe section and two adjacent pipe sections in the same soil zone all showed a short-term increase in the comprehensive heat transfer coefficient, and the direction of parameter change was consistent with the direction of soil moisture content change, and it partially dropped back after the soil moisture content decreased. During the corresponding period, there was no increase in the friction coefficient, and no damage was found to the outer insulation layer or insulation interface. Therefore, it was determined that the change in this part of the thermal parameters was caused by the short-term change in soil moisture.

[0243] After determining the cause of parameter changes, the electronic equipment determines the candidate value of the friction coefficient of the first pipe section; the length, inner diameter and elevation of the first pipe section are based on the asset ledger data verified on site, and the pressure loss caused by local components is based on valve product information and as-built commissioning records.

[0244] Based on the inlet pressure, outlet pressure, and flow rate during three stable operating periods, the friction coefficient of the first pipe section was determined, and the results were 0.030, 0.031, and 0.032, respectively. All three results were within the design allowable range and historical effective range of the first pipe section, and the median value of 0.031 was taken as the candidate value of the friction coefficient.

[0245] The effective friction coefficient of the first pipe section was 0.027, and the candidate value increased by about 14.8% compared with the previous effective value. This change is consistent with the situation where long-term scaling or deposition causes an increase in pipe resistance.

[0246] The internal heat transfer medium volume of the first pipe section is determined based on the actual inner diameter and pipe section length, and is approximately 99 cubic meters. Under the condition that the flow rate is approximately 650 cubic meters per hour, the basic time required for the heat transfer medium to travel from the pipe section inlet to the pipe section outlet is approximately 9.1 minutes.

[0247] The inlet temperature of the first pipe section began to rise continuously at 10:12, and the outlet temperature began to rise continuously in the same direction at 10:22. Therefore, the actual temperature propagation delay of the pipe section was corrected to 10 minutes, and the outlet temperature at 10:22 was matched with the inlet temperature at 10:12.

[0248] Because the flow rate of the first pipe section is relatively large, the temperature drop of the heat medium in the pipe section is small. After the time delay alignment is completed, the difference between the inlet temperature and the outlet temperature is close to the comprehensive uncertainty range of the temperature measurement link. Therefore, this operating period is not used for the direct update of the comprehensive heat transfer coefficient of the first pipe section, and the first pipe section continues to use the previous effective comprehensive heat transfer coefficient.

[0249] The flow rate of the second pipe section is approximately 120 cubic meters per hour, and the volume of the heat transfer medium inside the pipe section is approximately 75 cubic meters. The resulting basic temperature propagation delay is approximately 37.5 minutes. By comparing the continuous heating time, continuous cooling time, and local peak time of the inlet and outlet temperatures, the actual temperature propagation delay of the second pipe section is corrected to 39 minutes.

[0250] After temperature propagation delay correction, the inlet temperature of the second pipe section is 82.6 degrees Celsius, the outlet temperature of the same batch of heat medium is 81.8 degrees Celsius, and the soil temperature near the pipe is 8.5 degrees Celsius.

[0251] The electronic equipment determines the candidate value of the comprehensive heat transfer coefficient of the second pipe section based on the heat medium flow rate, specific heat capacity of the heat medium, effective heat exchange area of ​​the pipe section, inlet and outlet temperatures after time delay alignment, and soil temperature. This candidate value is about 12% higher than the baseline value of the comprehensive heat transfer coefficient before rainfall, and the direction of change is consistent with the enhanced heat dissipation of the pipe section after the insulation layer becomes damp.

[0252] The candidate value of the comprehensive heat transfer coefficient of the second pipe section is within the historical effective range of the pipe section and the parameter range before and after insulation maintenance of similar pipe sections. It is also consistent with events such as continuous rainfall, rising groundwater level and poor sealing of insulation interface. Therefore, it passes the parameter check.

[0253] The third pipe segment belongs to the constraint inference level; the electronic equipment selects three reference pipe segments from the current operating connectivity relationship that are the same as or similar to the third pipe segment in terms of pipe diameter, material, laying method, insulation structure and soil zoning.

[0254] One of the reference pipe sections was under maintenance and was therefore excluded; the electronic equipment used the stable parameters of the remaining two reference pipe sections and combined them with the inlet temperature, branch flow rate and historical effective range of the third pipe section to form a comprehensive heat transfer coefficient candidate value.

[0255] Since there are fewer than three valid reference pipe segments, the candidate parameters for the third pipe segment are used only as inferences with lower reliability, and the update magnitude is smaller than that for directly identified pipe segments and jointly identified pipe segments.

[0256] After the candidate parameters for the first, second, and third pipe sections are formed, the electronic equipment writes the corresponding candidate parameters into the model to be verified, without directly replacing the current valid model.

[0257] The first pipe section belongs to the direct identification level, with complete observation data and clear reasons for parameter changes. Its candidate value for friction coefficient has increased by approximately 14.8% compared to the previous effective value. Historical operation records show that the normal parameter changes between adjacent effective observation periods for this pipe section do not exceed 10% to 20% of the previous effective parameter. Furthermore, historical test results of the model to be verified indicate that corrections within this range will not cause an increase in critical pressure and flow deviations. Therefore, the parameter update range for the first pipe section this time adopts the actual difference between the candidate value and the previous effective value.

[0258] The second pipe section belongs to the joint identification level. Its candidate value of comprehensive heat transfer coefficient is determined by regional boundary observation, parameter changes of adjacent pipe sections and environmental events. Therefore, a lower update range than that of the first pipe section is adopted to gradually correct the previous effective comprehensive heat transfer coefficient towards the candidate value.

[0259] The third pipe segment belongs to the constraint inference level, and the number of effective reference pipe segments is less than three. Therefore, the smaller update range among the three identification levels is adopted, and only the previous effective comprehensive heat transfer coefficient is slightly modified.

[0260] The model to be verified is operated using the same observation period as the heat source water supply temperature, heat source flow rate, valve status, water pump status, and heat exchange station boundary conditions. The key measurement points used for model verification include at least the heat source outlet pressure measurement point, the main pipe flow rate measurement point, the connecting pipe pressure or flow rate measurement point, the three heat exchange station inlet pressure measurement points, and the heat exchange station inlet temperature measurement point.

[0261] The pressure tolerance is determined based on the maximum permissible error of the pressure transmitter and the normal pressure deviation during historical stable operation, and is set at 0.008 MPa; the flow tolerance is determined based on the maximum permissible error of the flow meter and the normal flow deviation during historical stable operation, and is set at 2.5% of the measured value; the temperature tolerance is determined based on the inlet temperature sensor error, outlet temperature sensor error, data acquisition channel error, time alignment error, and the normal fluctuation range of historical temperature, and is set at 0.6 degrees Celsius.

[0262] Before the parameters were updated, the maximum deviation of the key pressure measurement points in the area to be checked was 0.017 MPa, the maximum deviation of the key flow measurement points was 6.4%, and the maximum deviation of the key temperature measurement points was 0.9 degrees Celsius.

[0263] After incorporating the friction coefficient of the first pipe section and the combined heat transfer coefficient of the second pipe section into the model to be verified, the maximum deviation of the key pressure measurement point was reduced to 0.006 MPa, the maximum deviation of the key flow measurement point was reduced to 2.1%, and the maximum deviation of the key temperature measurement point was reduced to 0.4 degrees Celsius. Since none of the above deviations exceeded the corresponding allowable range, the parameter updates of the first and second pipe sections passed the verification.

[0264] After the candidate value of the comprehensive heat transfer coefficient of the third pipe section was written into the model to be verified, the temperature deviation of its downstream heat exchange station increased from 0.5 degrees Celsius to 0.9 degrees Celsius, exceeding the allowable temperature deviation of 0.6 degrees Celsius. Since the third pipe section belongs to the constraint inference level and the number of effective reference pipe sections is insufficient, the previous effective comprehensive heat transfer coefficient of the third pipe section is restored, and the parameter update results of the first and second pipe sections that have passed the verification are retained.

[0265] After restoring the previous effective parameters of the third pipe section, the flow relationship between the inlet and outlet of the processing area, the pressure at the boundary node, and the temperature of the downstream heat exchange station were checked again. The verification results showed that the inlet flow and outlet flow of the area remained balanced within the comprehensive measurement error range of the flow meter, and the deviations of the key pressure and temperature measuring points did not exceed the corresponding allowable range. Therefore, the model to be verified, which included the updated parameters of the first and second pipe sections, was switched to the new current effective model.

[0266] During subsequent operation, the friction coefficient of the first pipe section will continue to be updated with limited amplitude based on stable operating data during long-term observation periods.

[0267] After the insulation interface of the second pipe section is repaired, the continuous judgment of the change in the comprehensive heat transfer coefficient before the repair is terminated, and the benchmark value of the comprehensive heat transfer coefficient is re-determined from the stable operation data after the repair is completed, so as not to carry over the moisture change trend before the repair to the post-repair period.

[0268] The third pipe section continues to maintain the previous effective parameters until an outlet temperature measurement point is added, or after obtaining more than three pipe section parameters that meet the reference conditions, candidate parameters are re-formed and the model to be checked is verified.

[0269] An operation record is generated for this parameter processing. The operation record includes at least the following fields: pipe segment number, operation connectivity version, parameter identification level, corresponding observation period, effective data ratio, reason for parameter change, temperature propagation delay, previous effective parameter, candidate parameter, actual written parameter, model verification result, parameter recovery status, and processing time.

[0270] Through the above treatment, pipe sections with complete measuring points, partially missing measuring points, and insufficient measuring point coverage can be treated separately in the same heating network. Based on long-term hydraulic changes, medium-term thermal changes, and short-term environmental changes, the effects of scaling or long-term deposition, insulation layer dampness, and soil moisture changes on pipe section parameters can be distinguished.

[0271] Before determining the overall heat transfer coefficient, the temperature propagation delay is first determined based on the heat medium volume inside the pipe section and the actual flow rate, so that the inlet temperature and outlet temperature correspond to the same batch of heat medium. Candidate parameters can only be written into the current effective model after being verified by the verification model, thereby preventing the pipe network model parameters from deviating from the actual operating state due to data anomalies, temperature propagation time differences, or improper selection of reference pipe sections.

[0272] It should be noted that this invention can be deployed on the device itself to realize embedded applications, or it can run on a PC or other terminal with a user interface, thereby meeting various hardware environments and usage requirements.

[0273] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any other combination. When implemented in software, the above embodiments can be implemented in whole or in part by a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions of the embodiments of this application are implemented in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted wirelessly or wiredly from one website, computer, server, or data center to another website, computer, server, or data center. Wired methods include optical fiber, twisted pair, coaxial cable, etc. Wireless methods include infrared, microwave, etc. Available media include any available media that can be accessed by a computer or data storage devices such as servers and data centers that contain one or more sets of available media. Available media can be magnetic media (floppy disks, hard disks, magnetic tapes), optical media (DVDs), or semiconductor media. Semiconductor media can be solid-state drives.

[0274] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0275] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for dynamic modeling of heating pipe networks, characterized in that, include: S1. Establish the current connection relationship based on the pipe section attributes, measuring point locations, and valve / pump status, and set the friction resistance coefficient and overall heat transfer coefficient for each pipe section. S2. Perform time alignment and validity verification on pressure, flow, temperature, environmental data and operation and maintenance events; determine parameter identification level based on measurement point coverage and pipeline constraints; and establish observation periods with different cycles at multiple times. S3. Based on the temporal pattern, spatial distribution, and correlation of hydraulic and thermal parameters during each observation period, distinguish the parameter changes caused by scaling, insulation layer dampness, and soil moisture changes. S4. Correct the friction coefficient based on the pipe section pressure difference and flow rate, determine the temperature propagation delay according to the flow rate, and correct the comprehensive heat transfer coefficient after aligning the inlet and outlet temperatures. S5. Update the parameters of each pipe section according to the parameter identification level, and verify the pipeline network model with field observation data; if the verification does not meet the preset conditions, suspend the update of the corresponding pipe section or restore the previous valid parameters.

2. The dynamic modeling method for heating pipe networks according to claim 1, characterized in that, S1 includes: Pipe sections are divided according to pipe diameter, material, laying method, and the location of valves, pumps, branch interfaces, and junction interfaces. The current inlet node and current outlet node of each pipe section are determined according to the direction of heat medium flow, and the correspondence between measuring points, nodes, and pipe sections is established. The actual flow path is determined based on valve status, pump status, flow direction, node pressure, and maintenance records, and the corresponding operational connectivity version is generated. Based on the commissioning data, stable operation data, or design data, determine the baseline values ​​and historical effective ranges of the friction coefficient and the overall heat transfer coefficient, and re-determine the corresponding parameter baseline values ​​after pipe cleaning, replacement, or insulation maintenance.

3. The dynamic modeling method for heating pipe networks according to claim 1, characterized in that, S2 includes: The data sampling period is determined based on the instrument refresh cycle, the monitoring system polling cycle, and the shortest effective operating condition duration. Data time is corrected based on acquisition time, timing error, timestamp resolution error, and communication delay. The data is verified for range, rate of change, continuity, physical relationship and source integrity, and abnormal data, conflicting data and short-term missing data are marked and processed respectively. The parameter identification level is determined based on the coverage of the measuring points and the hydraulic and thermal relationships that can be formed. Based on the daily load cycle, environmental change process and operation and maintenance events, different periodic observation periods are divided, and direct identification, joint identification or maintaining the previous effective parameter is determined according to the proportion of effective data.

4. The dynamic modeling method for heating pipe networks according to claim 3, characterized in that, The parameter identification level is determined based on the coverage of the measuring points and the hydraulic and thermal relationships that can be established, including: When a pipe section has inlet pressure, outlet pressure, flow rate, inlet temperature, and outlet temperature observations, it is determined to be of the direct identification level; If some measurement points are missing, but can be supplemented by nodal flow balance, loop pressure relationship or regional boundary observation, and the number of independent relationships is not less than the number of parameters to be determined, it is determined as a joint identification level; The remaining pipe segments are constrained and inferred based on the parameters of adjacent pipe segments, the physical properties of the pipe segments, and the historical effective range. If a complete relationship cannot be formed or there is a lack of reference pipe segments that meet the conditions, the previous effective parameters are maintained.

5. The dynamic modeling method for heating pipe networks according to claim 1, characterized in that, S3 includes: The impact of scaling was determined based on pressure difference, flow rate changes, and water quality records under similar operating conditions during a long-term observation period. The impact of moisture on the insulation layer is determined based on changes in the comprehensive heat transfer coefficient, rainfall, groundwater level, and changes in adjacent pipe sections during the medium-period observation period. The soil environmental impact is determined based on the correlation between the comprehensive heat transfer coefficient and soil moisture content, soil temperature and freeze-thaw state during the short-period observation period. The parameter changes were allocated in the order of scaling, insulation layer dampness, and soil environment influence, and the consistency between the allocation results and the actual parameter changes was verified.

6. The dynamic modeling method for heating pipe networks according to claim 5, characterized in that, The parameter changes were allocated in the order of scaling, insulation layer dampness, and soil environmental influence, and the consistency between the allocation results and the actual parameter changes was verified, including: First, determine the change in friction coefficient corresponding to scaling, and then determine the change in overall heat transfer coefficient when calibration data before and after cleaning is available. After deducting this part from the total change in the overall heat transfer coefficient, determine the changes corresponding to the moisture content of the insulation layer and the soil moisture in turn. Compare the sum of all changes with the actual observed changes. If the deviation exceeds the sum of the instrument's overall error and the upper limit of historical normal fluctuations, or if the judgment conditions conflict with each other, retain the previous valid parameter and mark it as pending verification.

7. The dynamic modeling method for heating pipe networks according to claim 1, characterized in that, S4 includes: Based on the current operational connectivity, pipe segment geometry parameters, local components, pressure and flow data, the friction coefficient is determined after deducting static pressure and local pressure drop. The basic temperature propagation delay is determined based on the effective flow area, pipe section length, and time-varying flow rate, and corrected using the co-directional changes in inlet and outlet temperatures. The inlet and outlet temperatures of the same batch of heat medium are matched, and the comprehensive heat transfer coefficient is determined by combining mass flow rate, specific heat capacity, effective heat exchange area and ambient temperature. Candidate parameters are then selected based on the design range, historical effective range and event consistency.

8. The dynamic modeling method for heating pipe networks according to claim 7, characterized in that, The base temperature propagation delay is determined based on the effective flow area, pipe section length, and time-varying flow rate, and corrected using the co-directional changes in inlet and outlet temperatures, including: When the flow rate is stable, the internal heat medium volume is determined based on the effective flow area and length of the pipe section, and the initial time delay is determined in combination with the volumetric flow rate. When the flow rate changes, the heat medium entering the pipe section at each time period is accumulated according to the sampling order. The initial time delay is determined when the accumulated value reaches the heat medium volume inside the pipe section. The temperature propagation delay is corrected based on the difference between the corresponding characteristic times, matching the heating, cooling, peak or valley characteristics of the inlet and outlet temperatures near the initial time delay.

9. The dynamic modeling method for heating pipe networks according to claim 1, characterized in that, S5 includes: Reference pipe sections are selected based on pipe diameter, material, laying method, insulation structure, and historical parameters; The update ratio and single change magnitude are determined based on the parameter identification level, data completeness, and candidate parameter source, and the parameters to be updated are written into the model to be verified. The key pressure, flow rate and temperature are checked using the boundary conditions of heat source, valve, water pump and heat exchange station during the same observation period. If the check fails, the previous valid parameters of the relevant pipe section or corresponding area are restored. If the check fails continuously, the update is suspended.

10. A dynamic modeling method for heating pipe networks according to claim 9, characterized in that, The update ratio and single change magnitude are determined based on the parameter identification level, data completeness, and candidate parameter source, and the parameters to be updated are written into the model to be verified, including: The update ratio is set by combining the parameter identification level, the proportion of effective data and the source of candidate parameters. The update ratio of directly identified pipe sections is higher than that of jointly identified pipe sections, and the update ratio of jointly identified pipe sections is higher than that of constraint-inferred pipe sections. The update is written to the model to be verified step by step, starting with a smaller update ratio, and the update ratio that passes the verification is selected based on the changes in the overall deviation and local deviation. The magnitude of a single change is limited based on the historical normal change limit, instrument error, and model stability. If the magnitude is exceeded, the update is written in multiple update cycles or the update is paused.

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