A method for evaluating comprehensive energy efficiency and two-network balance state of a heat supply system

Abstract

This invention relates to the field of heating energy efficiency assessment technology, specifically to a method for assessing the comprehensive energy efficiency and secondary network balance of a heating system. The method includes the following steps: screening reference evaluation units from various similar evaluation groups that are not affected by adjacent oversupply, generating a corresponding classification benchmark set; using the classification benchmark set as a reference, performing joint deviation analysis on the operating status of heat exchange stations and the operating status of each branch, distinguishing multiple categories of deviations, and generating an integrated station-network assessment result for the heating system; combining the transmission and distribution side resistance correction results to output the comprehensive energy efficiency level, secondary network balance level, heat saving potential, electricity saving potential, renovation priority, and investment payback period, forming an assessment report. This invention effectively eliminates false differences caused by building variations, regulatory instability, and adjacent oversupply, improving the authenticity of energy efficiency evaluation and balance analysis.

Description

Technical Field

[0001] This invention relates to the field of heating energy efficiency assessment technology, and in particular to a method for assessing the comprehensive energy efficiency and secondary network balance of a heating system. Background Technology

[0002] Central heating systems typically consist of heat exchange stations and secondary pipe networks, and their operational status directly impacts heating efficiency and user-side thermal comfort. Currently, engineering projects often use indicators such as supply and return water temperature difference, circulation flow rate, or energy consumption per unit area to evaluate system operation, and optimize them through simple hydraulic balance adjustments or heat source-side adjustments. However, due to significant differences in building envelopes, terminal configurations, and actual heat consumption behaviors among different buildings, there are inherent inconsistencies in heat demand between branches within the same heating system. This makes it difficult to establish a unified and comparable benchmark using existing evaluation methods based on network-wide averages or single indicators. Consequently, evaluation results are easily affected by building differences and local anomalies, making it difficult to accurately reflect the true operating status of the system.

[0003] During the operation of heating systems, multiple factors often coexist and interact, such as imbalances in the hydraulic distribution of the secondary network, insufficient or excessive heat exchange capacity, excessive circulation and distribution, and differences in the heat demand of individual buildings. This results in complex and difficult-to-distinguish causes of heating anomalies. Existing technologies typically analyze problems from a single dimension, such as judging heat exchange efficiency through temperature difference or judging hydraulic balance through flow rate. However, they lack a unified breakdown and quantitative description of different sources of deviation. This can easily lead to misjudging normal deviations caused by building differences as system problems, or misattributing hydraulic distribution problems to the heat source side, thus affecting the accuracy of regulation decisions.

[0004] In addition, existing heating assessment methods mostly remain at the level of condition diagnosis, lacking the ability to directly derive optimized operating parameters and renovation strategies from the assessment results. They are difficult to quantify the potential for heat and electricity savings, and even more difficult to conduct correlation analysis between energy-saving effects and investment costs, resulting in a lack of effective connection between operation management and energy-saving renovation. Summary of the Invention

[0005] This invention provides a method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system. It establishes a comparable evaluation benchmark in complex heating systems, distinguishes the causes of multi-source coupling deviations, and further realizes an integrated analysis from diagnosis to optimization and investment decision-making.

[0006] A method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system includes the following steps: S1. Perform terminal homogeneity discrimination and reference qualification screening on each heating unit in the heating area. Group heating units with similar terminal structures, similar thermal properties and stable operation response into the same evaluation group. Screen out reference evaluation units that are not affected by neighboring over-supply from each of the same evaluation groups and generate the corresponding classification benchmark set. S2. Using the aforementioned classification benchmark set as a reference, perform joint deviation decomposition on the operating status of the heat exchange station and the operating status of each branch, distinguishing multiple categories of deviations, including: Natural deviations caused by differences in building heat demand; Hydraulic deviation caused by imbalance in the distribution of the secondary network; Thermal deviation caused by insufficient or excessive heat exchange; And pumping deviation caused by excessive circulation and distribution; Generate integrated evaluation results for the heating system's station-network integration; S3. Based on the integrated evaluation results of the station network, reconstruct the target flow rate of the branch road and the target total flow rate of the heat exchange station according to the same evaluation group, and output the comprehensive energy efficiency level, the balance level of the secondary network, the heat saving potential, the power saving potential, the renovation priority and the investment payback period in combination with the correction results of the transmission and distribution side resistance, and form an evaluation report.

[0007] Optionally, the process of performing end-point homogeneity discrimination and reference qualification screening on each heating unit within the heating area includes: Collect the terminal type, comprehensive heat transfer coefficient of the building envelope and design heat load per unit area of ​​each heating unit, construct feature vectors and calculate the weighted Euclidean distance between each pair of units, and classify heating units whose distance is within the preset threshold into the same candidate homogeneous group. Within the candidate homogeneous group, the room temperature or return water temperature sequence of each unit at daily or hourly intervals during the evaluation period is obtained, the standard deviation and autocorrelation coefficient of the sequence are calculated, and unstable units whose standard deviation exceeds the first threshold or whose autocorrelation coefficient deviates from the second threshold range are removed. The remaining units constitute the same evaluation group.

[0008] Optionally, the selection of the reference evaluation unit includes obtaining the physical adjacency relationship of each unit, and performing the following judgment for each unit to be judged: calculating the first partial correlation coefficient between the room temperature sequence of the unit to be judged and its own heating sequence, and the maximum value of the second partial correlation coefficient between the room temperature sequence of the unit to be judged and the heating sequences of each adjacent unit; if the first partial correlation coefficient is greater than the maximum value of the second partial correlation coefficient, and the average heating intensity of all adjacent units during the time period does not exceed a preset multiple of the average heating intensity of the same evaluation group, then the unit to be judged is determined as a reference evaluation unit that is not affected by the over-supply of neighboring units.

[0009] Optionally, the generation of the classification benchmark set includes using the statistical values ​​of the average supply and return water temperature, average supply and return water temperature difference, and average flow rate per unit area of ​​all reference evaluation units within the same evaluation group as the classification benchmark set.

[0010] Optionally, it also includes obtaining the actual total supply water temperature, total return water temperature, total circulation flow rate, total heat supply, and circulation pump power consumption of the heat exchange station, while obtaining the actual flow rate, return water temperature, and heating area of ​​each branch; calculating the difference between the actual total heat supply of the heat exchange station and the benchmark total heat supply calculated based on the benchmark operating parameters and total heating area, as the total heat supply deviation; calculating the flow difference between the actual total circulation flow rate and the benchmark total flow rate, and the power consumption difference between the actual circulation pump power consumption and the benchmark power consumption calculated based on the benchmark total flow rate and the resistance characteristics of the transmission and distribution pipeline.

[0011] Optionally, the total deviation of heating supply can be combined and decomposed to obtain: Natural deviation component: Under the assumption of hydraulic balance between the two networks and that the supply water temperature is equal to the reference supply temperature, the change in heat supply caused by the inherent difference in the heat demand characteristics of each building relative to the reference heat demand level of the same type. Hydraulic deviation component: The change in heat supply caused by the dispersion of return water temperature in each branch due to the deviation of the flow distribution of each branch from the area-weighted balanced flow under the actual supply water temperature and actual total circulation flow of the heat exchange station. Thermal deviation component: Based on the actual total circulation flow rate, the change in heat supply caused only by the deviation of the actual water supply temperature of the heat exchange station from the reference water supply temperature; Pumping deviation component, including the heat supply deviation calculated from the flow rate difference and the power consumption difference; The total heating deviation is calculated by subtracting the heating deviation from the hydraulic deviation component, thermal deviation component, and pumping deviation component, and the remaining value is taken as the natural deviation component.

[0012] Optionally, the integrated evaluation results of the station network shall include at least the absolute values ​​of four types of deviation components, their percentages relative to the total heating deviation, and the attribution of the energy efficiency and balance bottlenecks based on the percentage values. The benchmark operating parameters include: the average supply and return water temperature, the average supply and return water temperature difference, and the average flow rate per unit area of ​​the classification benchmark centralized reference evaluation unit.

[0013] Optionally, based on the integrated evaluation results of the station network, the average flow rate per unit area of ​​the classification benchmark for each evaluation group, the average temperature of the benchmark supply and return water, the temperature difference of the benchmark supply and return water, and the natural deviation component and hydraulic deviation component of each branch are obtained. For each branch, under the condition that the branch only has natural deviation and hydraulic distribution is balanced within the same evaluation group, the target flow rate of the branch is reconstructed, so that the target return water temperature of the branch is equal to the average return water temperature of the reference plus the return water temperature deviation caused by natural deviation, and the target supply and return water temperature difference is equal to the reference supply and return water temperature difference. The target flow rate of the branch is then calculated by combining the heating area of ​​the branch. The return water temperature deviation caused by natural deviation is obtained by back-calculation of the natural deviation component and the actual flow rate of the branch. The total target flow of the heat exchange station is obtained by summing the target flow rates of all branches under the jurisdiction of the same heat exchange station.

[0014] Optionally, it also includes performing transmission and distribution side resistance correction: based on the pipeline topology and the current valve status, the target opening degree of each branch regulating valve is redistributed according to the target flow of the branch, the required circulating pump head and power consumption to achieve the distribution are calculated, the target pumping power consumption is obtained, and the power consumption difference in the current pumping deviation component is combined with the target pumping power consumption to output the power saving potential after transmission and distribution correction. The system outputs a comprehensive energy efficiency rating and a secondary network balance rating. The comprehensive energy efficiency rating is determined based on the ratio of heat-saving potential to the actual total heat supply of the heat exchange station. The heat-saving potential is determined by the sum of the absolute value of the thermal deviation component and the recoverable superheated component in the hydraulic deviation component. The secondary network balance rating is determined based on the percentage of the hydraulic deviation component to the total heat supply deviation and the expected improvement value of the branch return water temperature dispersion.

[0015] Optionally, based on the heat-saving potential and the power-saving potential after transmission and distribution correction, the annualized cost savings are calculated, and combined with the preset investment quotas for balance regulation, heat exchange station renovation and pump unit frequency conversion renovation, the renovation priority and investment payback period are output to form the evaluation report.

[0016] The beneficial effects of this invention are: This invention performs end-point homogeneity discrimination and operational stability screening on heating units, and further introduces a reference evaluation unit screening mechanism based on partial correlation and adjacent oversupply suppression. It constructs a classification benchmark set that is not affected by adjacent heat interference, so that heating units with different buildings, different end-point forms and different operating conditions have a unified comparable basis. Compared with the existing technology of directly averaging or simply comparing data from the entire network, this invention effectively eliminates spurious differences caused by building differences, unstable regulation and adjacent oversupply, and improves the authenticity of energy efficiency evaluation and balance analysis.

[0017] This invention, using the aforementioned classification benchmark set as a reference, decomposes the total heating deviation into four components: natural deviation, hydraulic deviation, thermal deviation, and pumping deviation. Through a joint deviation decomposition model, it separates the originally coupled heating anomalies according to their formation mechanisms. Compared to existing technologies that rely on a single indicator for judgment, this invention can clearly distinguish different causes such as differences in building heat demand, hydraulic distribution imbalance, heat exchange capacity deviation, and excessive distribution, transforming system operation problems from abnormal results into traceable causes. This mechanism-level decomposition method improves diagnostic accuracy and avoids mistaking hydraulic problems for heat source problems or misjudging load differences as system imbalance.

[0018] This invention, based on the completed deviation decomposition, further reconstructs the flow rates of each branch with the goal of retaining only natural deviations and achieving complete hydraulic balance. It then performs transmission and distribution side resistance correction based on the pipeline network resistance characteristics to obtain the target operating parameters and target pumping power consumption of the heat exchange station, thereby forming an optimized system operation plan. Simultaneously, by converting thermal deviations and recyclable hydraulic deviations into heat-saving potential, and pumping deviations into power-saving potential, and combining annualized costs with investment quotas, it outputs the priority of renovation and the investment payback period. This invention achieves a closed-loop process from operational status assessment to energy-saving potential quantification and renovation decision output. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention; Figure 2 This is a schematic diagram of step S3 in an embodiment of the present invention. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. For some well-known technologies, those skilled in the art may also use other alternative methods to implement the invention. Moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0022] like Figures 1-2 As shown, a method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system includes the following steps: S1. Perform terminal homogeneity discrimination and reference qualification screening on each heating unit in the heating area. Group heating units with similar terminal structures, similar thermal properties and stable operation response into the same evaluation group. Screen out reference evaluation units that have not been affected by neighboring over-supply from each of the same evaluation groups to generate the corresponding classification benchmark set.

[0023] S11. For each heating unit within the heating area, collect its terminal type, comprehensive heat transfer coefficient of the building envelope, and design heat load per unit area, and construct a feature vector for each heating unit based on this. Specifically, this is represented as: ;in, Indicates the first The feature vector of each heating unit Numerical encoding representing the end type, Indicates the overall heat transfer coefficient of the building envelope. This represents the design heat load per unit area.

[0024] The numerical coding of terminal types is obtained by classifying and mapping the actual heat dissipation terminal forms used in the heating unit. Based on design drawings, equipment ledgers, or on-site verification results, the terminal forms of each heating unit are identified, including radiator type, floor radiant type, fan coil type, and air heater type. Then, a unified type coding table is established, mapping different terminal types to discrete or ordered numerical values. A unique heat coding method can be used, mapping each type of terminal to an independent 0 / 1 identifier.

[0025] The overall heat transfer coefficient of the building envelope is obtained by weighted summation of the heat transfer performance of each component of the building envelope. First, based on building design data or energy-saving assessment reports, the individual heat transfer coefficients and corresponding areas of the exterior walls, roof, doors, windows, and floors are obtained. Then, the heat transfer coefficients of each component are weighted and averaged according to their area proportions to obtain the overall heat transfer coefficient of the building envelope. For cases with significant thermal bridging or localized insulation defects, a correction factor can be introduced to compensate, ensuring that this parameter accurately reflects the overall heat dissipation capacity and heat loss level of the building. Specifically, the overall heat transfer coefficient of the building envelope is calculated as follows: ;in, Indicates the first The overall heat transfer coefficient of each heating unit Indicates the type and quantity of enclosure components. Indicates the first The first unit The heat transfer coefficient of the building envelope, This indicates the area of ​​the corresponding enclosure structure. This represents the correction factor for thermal bridging or insulation defects, ranging from 1.0 to 1.3. For conventional buildings, it ranges from 1.05 to 1.15. If there are obvious thermal bridging or old insulation defects, it can be taken as 1.15 to 1.30.

[0026] The design heat load per unit area is obtained directly from the original heating design documents. In addition, under the condition of multi-period data, the 95th percentile of the high load can be selected as an approximate substitute value for the design load.

[0027] After obtaining the feature vectors of each heating unit, calculate the weighted Euclidean distance between any two heating units: ; in, Indicates the first The and the first Weighted Euclidean distance between heating units These represent the weighting coefficients corresponding to the terminal type, heat transfer coefficient, and design heat load, respectively.

[0028] when At that time, the corresponding heating units will be grouped into the same candidate homogeneous group. Among them, This represents the homogeneity discrimination distance threshold. It is obtained using an adaptive method based on data distribution, which can be achieved by calculating the statistical distribution of the weighted Euclidean distances between all heating units and selecting the 15th percentile value as the initial threshold.

[0029] Through the above, the initial homogeneous clustering of heating units is completed, forming several candidate homogeneous groups.

[0030] S12. Within the candidate homogeneous group, further obtain the room temperature sequence or return water temperature sequence of each heating unit at daily or hourly intervals during the evaluation period, and screen their operational stability.

[0031] Let the first The temperature sequence for each heating unit is as follows: ; Calculate the standard deviation of the sequence: ; in, Indicates the first Standard deviation of the temperature series of each heating unit Indicates the first The temperature value at that moment. This represents the mean of the temperature series. Indicates the sequence length.

[0032] Further calculation of the first-order autocorrelation coefficient of the temperature series: ; in, Indicates the first The first-order autocorrelation coefficient of the temperature sequence of each heating unit.

[0033] A heating unit will be classified as an unstable unit and removed if the following conditions are met: ;in, Indicates the standard deviation threshold. This indicates the allowable range of the autocorrelation coefficient. Take 0.5℃~1.5℃ (room temperature series) or 1℃~3℃ (return water temperature series); take [0.6, 0.95], and tighten to [0.7, 0.9] in highly stable systems.

[0034] After removing unstable units, the remaining heating units constitute the aforementioned evaluation group.

[0035] S13. Within the same evaluation group, further screen reference evaluation units that are not affected by neighboring over-supply. First, obtain the physical adjacency relationships between each heating unit, and perform the following judgment on each unit to be judged: S131. Calculate the first partial correlation coefficient between the room temperature sequence of the unit to be judged and its own heat supply sequence: ;in, This represents the first partial correlation coefficient. Indicates the first Room temperature sequence of each heating unit This indicates the heat supply sequence of the unit. This represents the set of control variables used to eliminate the influence of common disturbance factors; pcorr represents the partial correlation coefficient.

[0036] S132. Calculate the second partial correlation coefficient between the room temperature sequence of the unit to be judged and the heating sequence of each adjacent unit, and take the maximum value: ; in, This indicates the maximum value of the second partial correlation coefficient. Indicates the relationship with the first A set of adjacent heating units. Indicates adjacent units The heat supply sequence.

[0037] S133. Calculate the average heating intensity of each adjacent unit over a time period: ; And the average heating intensity of similar evaluation groups: ; in, Indicates adjacent units The average heating intensity, Indicates time heating intensity This represents the average heating intensity of similar evaluation groups. This represents a set of evaluation group units of the same type. This indicates the number of elements in the set.

[0038] S134. When the following conditions are met, the unit to be judged is determined as a reference evaluation unit that is not affected by neighboring over-supply: ; in, It generates its own heat. The neighbor provides the heat. This indicates that the current temperature variation in the unit is primarily determined by its own heating capacity, rather than by the influence of its neighbors. This indicates that the surrounding neighbors cannot be units with abnormally high heating levels. This indicates the preset multiple threshold, with a value ranging from 1.15 to 1.25.

[0039] S14. After completing the selection of reference evaluation units, summarize the operational statistical characteristics of all reference evaluation units within the same evaluation group to generate a classification benchmark set. The classification benchmark set includes the average supply water temperature, average return water temperature, average supply and return water temperature difference, and average flow rate per unit area, where: Average water supply temperature: ; Average return water temperature: ; Average supply and return water temperature difference: ; Average flow rate per unit area: ; in, Indicates the number of reference evaluation units. Indicates the first The average water supply temperature of each reference unit, Indicates the first The average return water temperature of each reference unit, Indicates the first The flow rate of each reference unit, This indicates the corresponding heating area.

[0040] Based on the above statistical results, a set of classification benchmarks for corresponding evaluation groups of the same type is formed for subsequent integrated evaluation of the station network.

[0041] S2. Using the aforementioned classification benchmark set as a reference, perform joint deviation decomposition on the operating status of the heat exchange station and the operating status of each branch, distinguishing between natural deviations caused by differences in building heat demand, hydraulic deviations caused by imbalances in the distribution of the secondary network, thermal deviations caused by insufficient or excessive heat exchange, and pumping deviations caused by excessive circulation and distribution, thereby generating an integrated evaluation result of the heating system.

[0042] S21. The statistical results of the reference evaluation units in the classification benchmark set are used as benchmark operating parameters, including: ;in, Indicates the reference water supply temperature. Indicates the reference return water temperature. Indicates the reference supply and return water temperature difference. This represents the baseline flow rate per unit area.

[0043] Simultaneously, the actual operating parameters of the heat exchange station and each branch are obtained, including: On the heat exchange station side: , , , , ;in, Indicates the actual total water supply temperature. This indicates the actual total return water temperature. This represents the actual total circulation flow. This indicates the actual total heat supply. This indicates the power consumption of the circulating pump.

[0044] Side of the branch road: , , ;in, Indicates the first Actual traffic flow of the branch road Indicates the first The return water temperature of the branch circuit This indicates the corresponding heating area.

[0045] S22, Benchmark conversion and total deviation calculation.

[0046] S221. Calculate the baseline total flow rate and baseline total heating capacity based on the baseline operating parameters and the total heating area: The baseline total flow rate is: ;in, Indicates the baseline total flow rate. This indicates the total heating area.

[0047] The baseline total heating supply is: ;in, Indicates the baseline total heat supply. This indicates the density of water. This indicates the specific heat capacity of water.

[0048] Calculate the total deviation of heating supply: ;in, This indicates that the heating supply deviates from the total amount.

[0049] S222, Calculate the difference in flow rate and the difference in power consumption: The flow difference is: ;in, This indicates the difference in total circulation flow.

[0050] Based on the resistance characteristics of transmission and distribution pipelines, the baseline power consumption is calculated according to the flow rate: ;in, Indicates the baseline power consumption. This represents the proportional coefficient of pipeline resistance, determined by the pipeline resistance characteristics.

[0051] The power consumption difference is: ;in, This indicates poor power consumption of the circulating pump.

[0052] The scaling factor is obtained as follows: 1. Under different operating conditions, collect actual operating data of the circulating pumps in the heat exchange station, including total circulating flow and corresponding pump power consumption data, and select data from time periods when the system is running stably without frequent adjustment interference as valid samples; at the same time, remove non-steady-state data such as start-up and shutdown phases and speed change phases to ensure that the data represents the true resistance characteristics of the pipeline network.

[0053] 2. Based on the collected data of multiple sets of "flow rate - power consumption", a functional relationship model is constructed. According to the similarity law of circulating pumps, a cubic function is used for fitting, that is, it is assumed that power consumption and flow rate approximately satisfy a cubic relationship. The relationship curve is obtained by fitting the curve using the least squares method or regression analysis.

[0054] 3. In the fitted cubic function relationship of power consumption versus flow rate, normalize the function form to: The coefficient before the cubic term is the proportionality coefficient. This coefficient reflects the degree to which a change in unit flow rate amplifies power consumption under the current pipeline structure and resistance conditions.

[0055] 4. Substitute the fitted proportional coefficient k into the typical operating conditions for back calculation, and compare the error between the calculated power consumption and the actual power consumption; if the error exceeds the preset range, the sample data is re-screened until the proportional coefficient can stably reflect the pipeline resistance characteristics.

[0056] S23, Joint Deviation Split Calculation: S231, Hydraulic deviation component: First, calculate the area-weighted equilibrium flow: ;in, Indicates the first Balanced flow of the branch.

[0057] The change in heat supply caused by hydraulic deviation can be expressed as: ;in, This indicates the hydraulic deviation component.

[0058] S232, Thermal Deviation Component: Assuming the actual total circulation flow remains constant, only the supply water temperature deviation is considered: ;in, This indicates the thermal deviation component.

[0059] S233, Pumping deviation component: Heat supply deviation calculated from flow difference: ;in, This indicates the deviation in heat supply caused by pumping; Simultaneously retain power consumption deviation: ; as an energy consumption indicator for pumping deviation.

[0060] S234, Natural Deviation Component: After deducting other deviation components, the remaining part is taken as the natural deviation component: ;in, This indicates the natural deviation component.

[0061] S24. Generation of integrated station-network assessment results.

[0062] Take the absolute value of each deviation component: ; And calculate its proportion of the total heating deviation: ; in, Indicates the first Class deviation component proportion; .

[0063] S3. Based on the integrated evaluation results of the station network, reconstruct the target flow rate of the branch road and the target total flow rate of the heat exchange station according to the same evaluation group, and output the comprehensive energy efficiency level, the balance level of the secondary network, the heat saving potential, the power saving potential, the renovation priority and the investment payback period in combination with the correction results of the transmission and distribution side resistance, and form an evaluation report.

[0064] The core idea of ​​Part S3 is: based on the identification of various deviations, instead of directly evaluating the current situation, it constructs an ideal operating state. Specifically, using the benchmark parameters of similar evaluation groups as a reference, each branch is assumed to have only its own heat demand difference, i.e., natural deviation, and the hydraulic distribution is already balanced. Under this condition, the return water temperature and supply-return water temperature difference that the branch should achieve are recalculated, thereby deriving the target flow rate that the branch should be configured with. The obtained target flow rate actually represents the reasonable flow distribution that each branch should have under a state of fair allocation and meeting its own needs.

[0065] Based on this, the target flow rates of all branches are aggregated to obtain the total target flow rate of the heat exchange station. Combining this with the pipeline topology and valve status, the pump head and power consumption required to achieve this flow distribution are further calculated, resulting in an optimized transmission and distribution operation. Subsequently, the recoverable portions of the current system's thermal and hydraulic deviations are converted into heat-saving potential, and the pumping deviation is converted into power-saving potential. Based on this, the system's energy efficiency level and secondary network balance level are assessed. Finally, the energy-saving benefits are combined with the retrofit costs to calculate the investment payback period and prioritize retrofits, thus transforming problem identification into actionable optimization and investment decisions.

[0066] The specific plan is as follows: S31. Based on the integrated evaluation results of the station network, extract the classification benchmark set parameters for each evaluation group of the same type: ; Simultaneously, the natural deviation component and hydraulic deviation component of each branch are obtained: ;in, Indicates the first The branch naturally deviates from the component. Indicates the first Hydraulic deviation component of branch road.

[0067] S32, Branch Target Flow Reconstruction.

[0068] For each branch, under the assumption that only natural deviation exists and hydraulic distribution is balanced, the return water temperature deviation is first calculated from the natural deviation component: ; in, This indicates the return water temperature deviation caused by natural deviation. Indicates the natural deviation component. Indicates the first Actual traffic flow of the branch road This indicates the density of water. This indicates the specific heat capacity of water.

[0069] The target return water temperature is: ;in, This indicates the target return water temperature.

[0070] The target supply and return water temperature difference is taken as the baseline value: ; Based on this, the target water supply temperature can be obtained: ; in, Indicates the target water supply temperature.

[0071] Further calculate the target flow rate by combining the heating area of ​​the branch circuit: ; in, Indicates the first Target traffic flow for each branch road This indicates the target heat supply per unit area. Indicates the heating area of ​​the branch line. It is obtained by superimposing the natural deviation component on the baseline heating level: ;in, This represents the baseline flow rate per unit area.

[0072] S33. Calculation of the target total flow rate of the heat exchange station. Sum the target flow rates of all branches to obtain the total target flow rate of the heat exchange station: ;in, This indicates the target total flow rate of the heat exchange station.

[0073] S34, Correction of transmission and distribution side resistance and calculation of energy saving potential.

[0074] Based on the pipeline topology and current valve status, the opening degree of the regulating valves in each branch is redistributed according to the target flow rate, and the corresponding circulating pump head is calculated: ; in: Indicates the target lift. Indicates the first Pipeline resistance coefficient Indicates the length of the pipe section. Indicates pipe diameter. Indicates flow rate, It represents the acceleration due to gravity.

[0075] Further calculation of the target pumping power consumption: ;in, Indicates the target pumping power consumption. This represents the proportional coefficient of pipeline resistance.

[0076] The energy-saving potential is: ;in, Indicates potential for energy saving. This indicates the actual power consumption.

[0077] S35. Determination of Energy Efficiency Rating and Balance Rating.

[0078] The heat-saving potential is: ;in, Indicates heat-saving potential, This indicates the recoverable superheat component in the hydraulic deviation.

[0079] The overall energy efficiency index is: ;in, This indicates the overall energy efficiency index.

[0080] The balancing index for the second power grid is: ;in, This indicates the percentage of hydraulic deviation.

[0081] The expected improvement is based on the dispersion of return water temperature in the branch: ;in, This represents the improvement in dispersion. This indicates the standard deviation of the current return water temperature. It represents the standard deviation of the target state.

[0082] S36. Calculation of renovation priority and investment payback period.

[0083] The annualized savings are: ;in, This indicates the annualized cost savings. This indicates the cost per unit of heat. This indicates the cost per unit of electricity.

[0084] The investment payback period is: ;in, Indicates the investment payback period; This indicates the cost of renovation investment.

[0085] Based on the potential for heat saving, energy saving, and investment payback period, the balancing regulation, heat exchange station renovation, and pump unit frequency conversion renovation are ranked to determine the priority of the renovation, and finally an evaluation report is formed.

[0086] The assessment report mainly includes: the integrated assessment results of the overall operation status of the heating system, the determination results of the comprehensive energy efficiency level and the balance level of the secondary network, the quantitative analysis of the heat saving potential and power saving potential, the target flow rate and optimized operation parameter suggestions for each branch and heat exchange station, the target pumping power consumption and power saving space after the transmission and distribution side resistance correction, and the priority ranking and corresponding investment payback period of balance regulation, heat exchange station renovation and pump unit frequency conversion renovation based on the annualized cost savings calculation, thus providing a complete basis for system optimization operation and renovation decisions.

[0087] The integrated evaluation results of the station network include the absolute values ​​and percentages of natural deviation, hydraulic deviation, thermal deviation, and pumping deviation.

[0088] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0089] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system, characterized in that, Includes the following steps: S1. Perform terminal homogeneity discrimination and reference qualification screening on each heating unit in the heating area. Group heating units with similar terminal structures, similar thermal properties and stable operation response into the same evaluation group. Screen out reference evaluation units that are not affected by neighboring over-supply from each of the same evaluation groups and generate the corresponding classification benchmark set. S2. Using the aforementioned classification benchmark set as a reference, perform joint deviation decomposition on the operating status of the heat exchange station and the operating status of each branch, distinguishing multiple categories of deviations, including: Natural deviations caused by differences in building heat demand; Hydraulic deviation caused by imbalance in the distribution of the secondary network; Thermal deviation caused by insufficient or excessive heat exchange; And pumping deviation caused by excessive circulation and distribution; Generate integrated evaluation results for the heating system's station-network integration; S3. Based on the integrated evaluation results of the station network, reconstruct the target flow rate of the branch road and the target total flow rate of the heat exchange station according to the same evaluation group, and output the comprehensive energy efficiency level, the balance level of the secondary network, the heat saving potential, the power saving potential, the renovation priority and the investment payback period in combination with the correction results of the transmission and distribution side resistance, and form an evaluation report.

2. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 1, characterized in that, The process of performing end-point homogeneity identification and reference qualification screening on each heating unit within the heating area includes: Collect the terminal type, comprehensive heat transfer coefficient of the building envelope and design heat load per unit area of ​​each heating unit, construct feature vectors and calculate the weighted Euclidean distance between each pair of units, and classify heating units whose distance is within the preset threshold into the same candidate homogeneous group. Within the candidate homogeneous group, the room temperature or return water temperature sequence of each unit at daily or hourly intervals during the evaluation period is obtained, the standard deviation and autocorrelation coefficient of the sequence are calculated, and unstable units whose standard deviation exceeds the first threshold or whose autocorrelation coefficient deviates from the second threshold range are removed. The remaining units constitute the same evaluation group.

3. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 2, characterized in that, The selection of the reference evaluation units includes obtaining the physical adjacency relationship of each unit. For each unit to be judged, the following judgment is performed: the first partial correlation coefficient between the room temperature sequence of the unit to be judged and its own heating sequence, and the maximum value of the second partial correlation coefficient between the room temperature sequence of the unit to be judged and the heating sequences of each adjacent unit; if the first partial correlation coefficient is greater than the maximum value of the second partial correlation coefficient, and the average heating intensity of all adjacent units during the time period does not exceed a preset multiple of the average heating intensity of the same evaluation group, then the unit to be judged is determined as a reference evaluation unit that is not affected by the over-supply of neighboring units.

4. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 3, characterized in that, The generation of the classification benchmark set includes using the statistical values ​​of the average supply and return water temperature, average supply and return water temperature difference, and average flow rate per unit area of ​​all reference evaluation units within the same evaluation group as the classification benchmark set.

5. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 4, characterized in that, It also includes obtaining the actual total supply water temperature, total return water temperature, total circulation flow, total heating capacity and circulation pump power consumption of the heat exchange station, as well as the actual flow, return water temperature and heating area of ​​each branch. The difference between the actual total heat supply of the heat exchange station and the benchmark total heat supply calculated based on the benchmark operating parameters and total heating area is taken as the total deviation of heat supply. Calculate the flow difference between the actual total circulating flow and the reference total flow, as well as the difference between the actual circulating pump power consumption and the reference power consumption calculated based on the reference total flow and the resistance characteristics of the distribution pipeline.

6. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 5, characterized in that, The total deviation of the heating supply is combined and decomposed to obtain: Natural deviation component: Under the assumption of hydraulic balance between the two networks and that the supply water temperature is equal to the reference supply temperature, the change in heat supply caused by the inherent difference in the heat demand characteristics of each building relative to the reference heat demand level of the same type. Hydraulic deviation component: The change in heat supply caused by the dispersion of return water temperature in each branch due to the deviation of the flow distribution of each branch from the area-weighted balanced flow under the actual supply water temperature and actual total circulation flow of the heat exchange station. Thermal deviation component: Based on the actual total circulation flow rate, the change in heat supply caused only by the deviation of the actual water supply temperature of the heat exchange station from the reference water supply temperature; Pumping deviation component, including the heat supply deviation calculated from the flow rate difference and the power consumption difference; The total heating deviation is calculated by subtracting the heating deviation from the hydraulic deviation component, thermal deviation component, and pumping deviation component, and the remaining value is taken as the natural deviation component.

7. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 5, characterized in that, The integrated evaluation results of the station network include at least the absolute values ​​of four types of deviation components, their percentages relative to the total heating deviation, and the attribution of energy efficiency and balance deficiencies based on the percentage values. The benchmark operating parameters include: the average supply and return water temperature, the average supply and return water temperature difference, and the average flow rate per unit area of ​​the classification benchmark centralized reference evaluation unit.

8. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 7, characterized in that, Based on the integrated evaluation results of the station network, the average flow rate per unit area, the average temperature of the supply and return water, and the temperature difference between the supply and return water of each evaluation group are obtained, as well as the natural deviation component and hydraulic deviation component of each branch. For each branch, under the condition that the branch only has natural deviation and hydraulic distribution is balanced within the same evaluation group, the target flow rate of the branch is reconstructed, so that the target return water temperature of the branch is equal to the average return water temperature of the reference plus the return water temperature deviation caused by natural deviation, and the target supply and return water temperature difference is equal to the reference supply and return water temperature difference. The target flow rate of the branch is then calculated by combining the heating area of ​​the branch. The return water temperature deviation caused by natural deviation is obtained by back-calculation of the natural deviation component and the actual flow rate of the branch. The total target flow of the heat exchange station is obtained by summing the target flow rates of all branches under the jurisdiction of the same heat exchange station.

9. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 8, characterized in that, It also includes performing transmission and distribution side resistance correction: based on the pipeline topology and current valve status, the target opening degree of each branch regulating valve is redistributed according to the target flow of the branch, the required circulating pump head and power consumption to achieve the distribution are calculated, the target pumping power consumption is obtained, and the power consumption difference in the current pumping deviation component is combined with the target pumping power consumption to output the power saving potential after transmission and distribution correction. The system outputs a comprehensive energy efficiency rating and a secondary network balance rating. The comprehensive energy efficiency rating is determined based on the ratio of heat-saving potential to the actual total heat supply of the heat exchange station. The heat-saving potential is determined by the sum of the absolute value of the thermal deviation component and the recoverable superheated component in the hydraulic deviation component. The secondary network balance rating is determined based on the percentage of the hydraulic deviation component to the total heat supply deviation and the expected improvement value of the branch return water temperature dispersion.

10. The method for evaluating the comprehensive energy efficiency and secondary network balance of a heating system according to claim 9, characterized in that, Based on the heat-saving potential and the energy-saving potential after transmission and distribution correction, the annualized cost savings are calculated. Combined with the preset investment quotas for balance regulation, heat exchange station renovation and pump unit frequency conversion renovation, the renovation priority and investment payback period are output to form the evaluation report.

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