Fine calculation method for thermodynamic equilibrium of secondary pipe network

Abstract

The invention provides a refined calculation method for thermal equilibrium of a secondary pipe network. The refined calculation method comprises the following steps: S1, establishing an indoor comprehensive temperature calculation model of a building; s2, an outdoor comprehensive temperature calculation model is established, and time-average calculation optimization is carried out; s3, optimizing an indoor comprehensive temperature calculation model of the building, and eliminating system delay; s4, the theoretical building indoor comprehensive temperature is calculated, whether the building indoor set target temperature is met or not is judged, and pipe network thermodynamic equilibrium adjustment is conducted; and S5, evaluating the thermal equilibrium effect of the pipe network. Data resources of secondary pipe network supply and return water temperature, heating buildings and outdoor meteorological temperature are fully utilized, an indoor and outdoor temperature dynamic calculation model is established through heat balance theory analysis, thermal delay is considered synchronously, a system cooperative adjustment strategy is achieved, and system stability is improved.

Description

Technical Field

[0001] This invention relates to the field of centralized heating technology, and in particular to a refined calculation method for the thermal balance of secondary pipe networks. Background Technology

[0002] Centralized heating networks are an indispensable part of modern urban infrastructure. They centralize heat sources and utilize pipe networks to deliver heat energy to users, meeting the heating and hot water needs of residential, commercial, and industrial users. However, during the long-term operation of centralized heating systems, problems exist in the secondary heating network: 1. Uneven heating and cooling within the network due to a lack of effective and precise adjustment methods. 2. The valve openings of each branch of the network are typically adjusted dynamically based on the consistency of the return temperature target at the building's heat inlet and the supply-return pressure difference. Simply relying on the consistency of the return temperature target at the heat inlet and the supply-return pressure difference to adjust the heat balance cannot accurately regulate and reduce energy consumption. 3. An effective regulatory relationship has not been established between indoor temperature and the return water temperature of the secondary network; furthermore, the maintenance cost of installing temperature monitoring and data acquisition equipment in residential homes is high. 4. With the passage of heating operation time, network aging and building insulation issues cause the original design adjustment calculation methods to become mismatched with actual operational needs. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a refined calculation method for the thermal balance of secondary pipe networks. Without adding real-time indoor temperature acquisition equipment, it can assist in operation and maintain stable heating and hydraulic balance of the secondary pipe network.

[0004] A refined calculation method for the thermal balance of a secondary pipe network, characterized by the following steps: Step S1: Establish a comprehensive indoor temperature calculation model for the building; Step S2: Establish an outdoor comprehensive temperature calculation model and perform time-averaged calculation optimization; Step S3: Optimize the building's indoor temperature calculation model to eliminate system delay; Step S4: Calculate the theoretical building indoor comprehensive temperature, determine whether it meets the building indoor target temperature, and perform pipe network thermal balance adjustment; Step S5: Evaluation of the thermal balance effect of the pipeline network.

[0005] Furthermore, step S1 includes the following steps: Step S11: Establish a dynamic thermal balance model inside the residential building, as shown in equation (1): (1) In the formula ρ air Indoor air density, kg / m³ 3 V represents the room volume, in meters. 3 ;C The total specific heat capacity of indoor air is expressed in J / (kg·K); T in Q represents the building's overall indoor temperature, in °C. in For the heating required by the building, W; Q loss The total heat loss of the building envelope, W; Heat gained from solar radiation, W; For time step; Step S12: Establish a calculation model between the change in return water temperature and the intensity of solar radiation; The contribution of solar radiation intensity is converted into temperature regulation and defined as the radiation regulation coefficient. A calculation model is established between the change in return water temperature and the solar radiation intensity, as shown in equation (2): (2) In the formula The change in return water temperature caused by solar radiation, expressed in °C. The water supply temperature is in °C. The return water temperature is in °C. Heat gained from solar radiation, MJ; MJ; to provide the heat required for the building; For time step; Based on existing local meteorological monitoring data and supply and return water temperature data, the radiation regulation coefficient is calculated according to formula (2). Constant value; Step S13: Establish a building thermal balance model; Based on the basic heat transfer theory, a building heat balance model is established, and equation (3) is obtained from equations (1) and (2): (3) In the formula The overall heat transfer coefficient of the building envelope, W / (m²). 2 ·℃); The total heat exchange area of ​​the building envelope, in m² 2 ; Set a target temperature (°C) for the building's interior. The outdoor temperature is the overall temperature, in °C. The comprehensive heat transfer coefficient of a building heating terminal, W / (m²). 2 ·℃); For the heat exchange area of ​​the building heating terminal, m 2 ; This is the radiation regulation coefficient; Average temperature of supply and return water for the building, °C: (4) The water supply temperature is in °C. The return water temperature is in °C. Step S14: Establish the functional relationship of indoor temperature in the building; Based on the building thermal balance model of formula (3), a functional relationship for the indoor temperature of a building is established: (5) Define the outdoor composite temperature coefficient and indoor comprehensive temperature coefficient The following are expressions respectively: (6) (7) This leads to the integration of a binary linear regression model for calculating indoor comprehensive temperature. (8).

[0006] Furthermore, step S2 includes the following steps: Step S21: Establish an outdoor comprehensive temperature calculation model; By linking heating regulation patterns and outdoor environmental change patterns to an indoor comprehensive temperature calculation model, an outdoor comprehensive temperature calculation model is established: (9) in, Outdoor air temperature, °C; I Solar irradiance, W / m 2 ; v Outdoor wind speed, m / s; coefficient and This indicates the degree of influence of solar irradiance and outdoor wind speed on the overall outdoor temperature, obtained through linear regression using actual heating data and meteorological monitoring data. Step S22: To avoid frequent adjustments due to instantaneous changes in outdoor temperature, an average outdoor temperature calculation is performed over time. (10) in This represents the average outdoor temperature over time; considering the large diurnal temperature range in winter, the time step for calculating the outdoor temperature is... You can select the hour level according to the actual situation.

[0007] Furthermore, step S3 includes the following steps: Step S31: Establish the relationship of the comprehensive thermal characteristic coefficient of the heating building, as shown in equation (11): (11) In the formula The overall heat transfer coefficient of the building envelope, W / (m²). 2 ·℃); The total heat exchange area of ​​the building envelope, in m² 2 ; The comprehensive heat transfer coefficient of a building heating terminal, W / (m²). 2 ·℃); For the heat exchange area of ​​the building heating terminal, m 2 ; Average temperature of supply and return water for the building, °C: Set a target temperature (°C) for the building's interior. The outdoor temperature is the overall temperature, in °C. Step S32: Establish the relationship between the time-averaged comprehensive thermal characteristic coefficients of heated buildings; Based on the determined hourly average outdoor temperature and indoor target temperature The time-weighted average method is used to calculate the comprehensive thermal characteristic coefficient of a heating building. Therefore, the time-averaged comprehensive thermal characteristic coefficient of the heating building is... This can be expressed as: (12) In equation (12) For time period Average internal supply and return water temperatures: (13); Step S33: Determine the discrete time period; The cross-correlation function (CCF) method is used to dynamically identify the pipeline delay time and building thermal delay time at different stages, thereby obtaining the adjustment step size at different stages of the entire heating season, i.e., the hourly average comprehensive thermal characteristic coefficient of the heated building. Selected discrete time period ; Step S34: Optimize the building's overall indoor temperature calculation model; Based on discrete time period The comprehensive temperature coefficient of a certain building can be obtained. and : (14) (15) Furthermore based on and Solving for the theoretical building's overall indoor temperature: (16) in, The instantaneous average temperature of the supply and return water for a certain building is the average instantaneous supply and return water temperature based on the system's acquisition frequency. (17) in, and These are the instantaneous supply water temperature and return water temperature of a certain building, respectively.

[0008] Furthermore, step S4 specifically involves: Step S41: Based on time step Hourly average outdoor temperature ; Step S42: Set target temperature based on building interior and time step Corresponding average temperature of building supply and return water Calculate the temperature coefficient and This allows us to calculate the theoretical comprehensive indoor temperature of a particular building. ; Step S43: Determine the theoretical building's overall indoor temperature Is it related to the target temperature set in the building's interior? Matching, i.e., whether it satisfies (18) This is a threshold value that can be set and adjusted according to actual needs. when If the requirement is met, the flow regulation will not be activated; when If the indoor temperature is not up to standard, the flow rate will be increased. If the supply water temperature remains unchanged, the return water temperature will increase. When the regulating valve opening reaches its maximum value, the supply water temperature needs to be increased. When the supply water temperature exceeds the upper limit, the temperature regulation will end. when If the indoor temperature is considered to be above the standard, the flow rate will be reduced. If the supply water temperature remains unchanged, the return water temperature will decrease. When the opening of the regulating valve reaches the minimum limit, the supply water temperature needs to be reduced. When it is lower than the lower limit of the supply water temperature, the temperature regulation will end. Step S44: After completing flow or temperature regulation, based on the feedback of instantaneous supply and return water temperatures... , Calculate the building's overall indoor temperature again. The process continues with step S43 until the overall indoor temperature matches the target indoor temperature.

[0009] Furthermore, step S5 specifically involves: Using range The standard deviation σ represents the dispersion of the controlled object, evaluates the effectiveness of the control method, and indicates the fluctuation of indoor temperature and return water temperature in each building. The smaller the σ value, the smaller the indoor temperature fluctuation, indicating a better regulation effect. The calculation of σ is expressed as: (19) (20) in This indicates the extreme difference in overall indoor temperature within a building, expressed in °C. The maximum indoor temperature of the building, in °C; The minimum indoor temperature of the building, in °C; This indicates an extreme difference in building return water temperature, expressed in °C. The maximum return water temperature is ℃; The minimum return water temperature is ℃; (twenty one) (twenty two) in The standard deviation of the building's overall indoor temperature, in °C; Set a target temperature (°C) for the building's interior. The average indoor temperature of the building, in °C; The standard deviation of building return water temperature, in °C; Set a target return water temperature for the building, in °C; The average temperature of the building's return water is expressed in °C. For time step.

[0010] The present invention has the following advantages: (1) A new calculation method for precise heating regulation is provided. This method makes full use of the data resources of the heat exchange station secondary network supply and return temperature, heating building and outdoor meteorological temperature of the online monitoring system of heating network. Based on the analysis of heat balance theory, a dynamic calculation model of indoor temperature and a linear error correction method are established. (2) Taking into account the thermal delay of the pipeline network and the building itself, it can realize the differentiated determination of heating regulation of different heat exchange stations and different buildings, make up for the difference in thermal inertia of different buildings, and solve the thermal balance problem caused by the change of pipeline characteristics after long-term operation. (3) This invention uses calculation of indoor temperature instead of direct monitoring and collection of indoor temperature, thus avoiding the problems of large number of indoor monitoring and collection devices, high investment and maintenance costs, and equipment failure and inaccuracy. Therefore, an indoor temperature calculation model is established to replace indoor equipment collection; (4) It can be applied to heat exchange stations and a specific heating building, and feed back to the intelligent regulating valve of the heat exchange station and the intelligent regulating valve of the heating building; (5) It can automatically adjust the return water temperature according to weather changes to ensure that the building obtains the best heating effect at different times. When the temperature is high during the day, the system will reduce the heating supply; while when the temperature is low at night or in the early morning, the system will automatically increase the heating supply to maintain the stability of the indoor temperature; and the heating of the sunny and shady rooms of the building is differentiated and discretely adjusted according to the influence of the comprehensive temperature of the external environment. Attached Figure Description

[0011] Figure 1 This is a flowchart of the thermal balance calculation and adjustment process of the present invention. Detailed Implementation

[0012] To clearly illustrate the technical features of the present invention, the present invention will be described below through specific embodiments.

[0013] This invention establishes a thermal balance analysis theory and a dynamic calculation model for integrated indoor and outdoor temperatures by coupling traditional heating network thermal parameters and thermal environment parameters, thereby realizing a system-wide coordinated regulation strategy. Finally, evaluation indicators are used to verify the effectiveness of the strategy. This invention calculates indoor temperature instead of directly monitoring and collecting indoor temperature data because centralized residential heating buildings have a large number of users, require a large amount of installed equipment, incur high investment and maintenance costs, and are prone to equipment failures and inaccuracies. Furthermore, residents' living habits and objective conditions vary, resulting in different maintained indoor temperatures, making accurate data unreliable. Therefore, an indoor temperature calculation model is established to replace indoor equipment data collection.

[0014] Considering the differences in thermal inertia between different heating seasons and different heating buildings, as well as the long-term operational delay of the pipeline network, it is necessary to analyze based on operational data (such as supply and return water temperatures, indoor temperatures, and outdoor temperatures), establish a dataset of delay time for thermal parameters in different time periods and sections, fit the functional relationship between delay time and indoor and outdoor temperatures of heating buildings, thereby determining the delay time of the pipeline network and buildings, and finally giving the discrete time period or time step required to integrate outdoor temperature and indoor and outdoor temperature coefficients.

[0015] A refined calculation method for the thermal balance of secondary pipe networks, such as... Figure 1 As shown, it includes the following steps: Step S1: Establish a comprehensive indoor temperature calculation model for the building; specifically: Step S11: Establish a dynamic thermal balance model inside the residential building; The indoor thermal environment is affected by various factors, and its heat transfer process is dynamic and complex. Assuming that heat loss from the pipe network is negligible and there are no internal heat sources within the building, a dynamic thermal balance model for the interior of a residential building is established as shown in equation (1): (1) In the formula ρ air Indoor air density, kg / m³ 3 V represents the room volume, in meters. 3 ; C The total specific heat capacity of indoor air is expressed in J / (kg·K); T in Q represents the building's overall indoor temperature, in °C. in For the heating required by the building, W; Q loss The total heat loss of the building envelope, W; Heat gained from solar radiation, W; For time step.

[0016] Step 12: Establish a calculation model between the change in return water temperature and the intensity of solar radiation; Due to the variability and diversity of solar radiation, it is necessary to first establish the impact of solar radiation and establish its relationship with the temperature parameters of the heating system's pipe network. Since indoor solar radiation reception in winter is mainly affected by direct sunlight, and north-facing, shaded rooms receive less direct solar radiation, the incremental load of solar radiation through windows primarily considers the impact of south-facing, sun-facing rooms. This indicates that load regulation of symmetrical north-south rooms with central corridors requires more precise thermal-hydraulic regulation. Furthermore, the larger the window-to-wall ratio, the greater the influence of external factors on solar radiation, and the higher its impact on the heat load. The heat load generated by solar radiation can be considered as heating the indoor environment. Therefore, based on meteorological monitoring and supply and return water temperatures, a calculation model can be established between return water temperature changes and solar radiation intensity, converting the contribution of solar radiation intensity into temperature regulation, defined as the radiation regulation coefficient. Calculate according to formula (2): (2) In the formula The change in return water temperature caused by solar radiation, expressed in °C. The water supply temperature in the pipeline network is expressed in °C. The return water temperature of the pipeline network is in °C. Heat gained from solar radiation, MJ; MJ; to provide the heat required for the building; For time step; Based on existing local meteorological monitoring data and supply and return water temperature data, the radiation regulation coefficient is calculated according to formula (2). Constant value.

[0017] Step S13: Establish a building thermal balance model; Based on the basic heat transfer theory, a building heat balance model is established, and equation (3) is obtained from equations (1) and (2): (3) In the formula The comprehensive heat transfer coefficient of a building envelope, W / (m²). 2 ·℃); The total heat exchange area of ​​the building envelope is given in m. 2 ; Set a target indoor temperature (°C) for a specific building; The outdoor temperature is the overall temperature, in °C. The comprehensive heat transfer coefficient of a heating terminal for a certain building, W / (m²) 2 ·℃); The heat exchange area of ​​a heating terminal for a building is expressed in m. 2 ; This is the radiation regulation coefficient; The average temperature of the supply and return water for a certain building, in °C: (4) The water supply temperature of a building's pipe network, in °C; The return water temperature of a building's pipe network is expressed in °C.

[0018] Step S14: Establish the functional relationship of indoor temperature in the building; Based on the building thermal balance model of formula (3), a functional relationship for the indoor temperature of a building is established: (5) Define the outdoor composite temperature coefficient and indoor comprehensive temperature coefficient The following are expressions respectively: (6) (7) in, It can reflect the degree to which indoor temperature is affected by multiple outdoor factors. The larger the temperature, the greater the influence of the combined outdoor temperature on the indoor temperature, meaning greater heat loss, poorer ability to maintain room temperature, and worse insulation performance of the building envelope; conversely, the smaller the temperature, the greater the impact of the combined outdoor temperature on the indoor temperature. The smaller the size, the greater the thermal inertia of the building, the better the energy-saving effect, and the larger the adjustment time step of the connected heat exchange station and the heating building; This leads to the integration of a binary linear regression model for calculating indoor comprehensive temperature. (8).

[0019] Step S2: Establish an outdoor comprehensive temperature calculation model and perform time-averaged temperature calculation optimization; specifically: Step S21: Establish an outdoor comprehensive temperature calculation model; Based on collected meteorological data, such as wind speed, temperature, and solar radiation, the meteorological type (sunny, cloudy, or rainy / snowy weather) is analyzed and determined. The relationship between indoor temperature and outdoor meteorological data is established, and the heating regulation patterns and outdoor environmental change patterns are linked to the indoor comprehensive temperature calculation model. An outdoor comprehensive temperature calculation model is also established. (9) in, Outdoor air temperature, °C; I Solar irradiance, W / m 2 ; v Outdoor wind speed, m / s; coefficient and This indicates the degree of influence of solar irradiance and outdoor wind speed on the overall outdoor temperature, obtained through linear regression using actual heating data and meteorological monitoring data.

[0020] Step S22: Calculate the average outdoor temperature over time; To avoid frequent adjustments due to instantaneous changes in outdoor temperature, an average outdoor temperature calculation is performed over time. (10) in This represents the average outdoor temperature over time; considering the large diurnal temperature range in winter, the time step for calculating the outdoor temperature is... The time can be selected in hours according to the actual situation. For example, if the building thermal delay time is 6 to 12 hours, you can select 8 hours, 4 hours, or 2 hours, etc.

[0021] Step S3: Optimize the indoor integrated temperature calculation model to eliminate system latency; specifically: Step S31: Establish the formula for the comprehensive thermal characteristic coefficient of the heating building; Indoor comprehensive temperature calculation model coefficients and In the definition, the comprehensive thermal characteristic coefficient of a heating building is defined. : (11).

[0022] Step S32: Establish the relationship between the time-averaged comprehensive thermal characteristic coefficients of heated buildings; To avoid system delays, thermal inertia of heated buildings, and data acquisition errors, the system combines the regulation laws of the thermal system with changes in outdoor temperature. This is based on a determined hourly average outdoor comprehensive temperature. and indoor target temperature The time-weighted average method is used to calculate the comprehensive thermal characteristic coefficient of a heating building. Therefore, the time-averaged comprehensive thermal characteristic coefficient of a certain heating building is... This can be expressed as: (12) In equation (12) For time period Average temperature of internal supply and return water; (13).

[0023] Step S33: Determine the discrete time period; Since the heat transfer characteristics of the pipe network system, the heating building, and data acquisition remain relatively stable over a considerable period, the system delay, the thermal inertia of the heating building, and the error in data acquisition can be considered relatively stable within a certain time frame. Therefore, the cross-correlation function (CCF) method is used to dynamically identify the pipe network delay time and the building thermal delay time at different stages, obtaining the adjustment step size for different stages throughout the heating season, i.e., the hourly average comprehensive thermal characteristic coefficient of the heating building. Selected discrete time period In addition, formula (8) is set. The priority of solving this problem is higher than that of formula (10).

[0024] Step S34: Optimize the building's overall indoor temperature calculation model; Based on discrete time period The comprehensive temperature coefficient of a certain building can be obtained. and : (14) (15) Furthermore based on and Solving for the theoretical building's overall indoor temperature: (16) in, The instantaneous average temperature of the supply and return water for a certain building is the average instantaneous supply and return water temperature based on the system's sampling frequency. (17) in, and These are the instantaneous supply water temperature and return water temperature of a certain building, respectively.

[0025] and It allows for updates, thus avoiding the accumulation of errors caused by long-term system delays, the thermal inertia of heated buildings, and interference from data acquisition, which can lead to poor heating regulation accuracy or even failure. Average outdoor temperature. This system implements feedback mechanisms to the impact of outdoor temperature on indoor temperature, enabling timely adjustments. The average instantaneous supply and return water temperatures are selected. When the indoor temperature does not meet the set target temperature, the system adjusts the flow rate, changes the return water temperature, or increases the supply water temperature, and then promptly feeds this information back into the calculation of the indoor temperature, thus improving the sensitivity of the adjustment.

[0026] Step S4: Calculate the theoretical building indoor comprehensive temperature, determine whether it meets the set target indoor temperature, and perform pipe network thermal balance adjustment; specifically: Step S41: Based on time step Get the average outdoor temperature (Formula 10).

[0027] Step S42: Set target temperature based on building interior and time step Corresponding average temperature of building supply and return water (Formula 13) Calculate the temperature coefficient (Equation 14) and (Formula 15), and thus the theoretical indoor comprehensive temperature of a building can be calculated based on Formula (16). .

[0028] Step S43: Determine the theoretical building's overall indoor temperature Is it related to the target temperature set in the building's interior? Matching, i.e., whether it satisfies (18) This is a threshold value, which can be set and adjusted according to actual needs; for example, 2℃: When the theoretical indoor comprehensive temperature With the target indoor temperature set by the building The deviation between them is within ±2℃, that is... If the requirement is met, the flow regulation will not be activated; When the theoretical indoor comprehensive temperature Lower than the target indoor temperature set by the building And the deviation is less than 2℃, that is If the indoor temperature is not up to standard, the flow rate will be increased. If the supply water temperature is considered unchanged, the return water temperature will be increased. When the theoretical indoor comprehensive temperature Higher than the target indoor temperature set by the building And the deviation is greater than 2℃, that is If the indoor temperature is considered to be above the standard, the flow rate will be reduced. If the supply water temperature is considered to remain unchanged, the return water temperature will be reduced.

[0029] Since there is a possibility that the target indoor temperature cannot be achieved simply by adjusting the flow rate (such as in extremely cold or warm weather), when the flow regulating valve has reached its limit and the indoor temperature requirement cannot be met by adjusting the flow rate, it is necessary to analyze whether it is necessary to achieve the final thermal regulation by means of quality regulation (increasing / decreasing the supply water temperature).

[0030] If the theoretical indoor comprehensive temperature does not meet the requirements If the regulating valve opening reaches its maximum value, the water supply temperature needs to be increased (this can be achieved by increasing the primary side temperature or the heat exchange efficiency of the heat exchanger in the heat exchange station), but at the same time, the upper limit of the actual water supply temperature should be set. If the water supply temperature exceeds the upper limit value This will end the temperature regulation; If the theoretical indoor comprehensive temperature does not meet the requirements If the regulating valve opening reaches the minimum limit, the water supply temperature can be reduced (this can be achieved by reducing the primary side temperature or the heat exchange efficiency of the heat exchanger in the heat exchange station), but at the same time, the lower limit of the actual water supply temperature should be set. If it exceeds the lower limit of the water supply temperature. This will end the temperature regulation.

[0031] Step S44: After completing the above flow rate or temperature adjustment, it is necessary to adjust based on the feedback of the instantaneous supply and return water temperatures. , Calculate the building's overall indoor temperature again. Determine whether the condition is met. And continue to adjust until the overall indoor temperature of the building matches the set target indoor temperature.

[0032] Step S5: Evaluation of the balancing effect; specifically: Using range The standard deviation σ represents the dispersion of the controlled object, evaluates the effectiveness of the control method, and indicates the fluctuation of indoor temperature and return water temperature in each building. The smaller the σ value, the smaller the indoor temperature fluctuation, indicating a better regulation effect. The calculation of σ is expressed as: (19) (20) in This indicates the extreme difference in overall indoor temperature within a building, expressed in °C. The maximum indoor temperature of the building, in °C; The minimum indoor temperature of the building, in °C; This indicates an extreme difference in building return water temperature, expressed in °C. The maximum return water temperature is ℃; The minimum return water temperature is ℃.

[0033] (twenty one) (twenty two) in The standard deviation of the building's overall indoor temperature, in °C; Set a target temperature (°C) for the building's interior. The average indoor temperature of the building, in °C; The standard deviation of building return water temperature, in °C; Set a target return water temperature for the building, in °C; The average temperature of the building's return water is expressed in °C. For time step.

[0034] The technical features of this invention not described can be implemented by or using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this invention, and this invention is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention should also be within the protection scope of this invention.

Claims

1. A refined calculation method for the thermal balance of a secondary pipe network, characterized in that, Includes the following steps: Step S1: Establish a comprehensive indoor temperature calculation model for the building; Step S2: Establish an outdoor comprehensive temperature calculation model and perform time-averaged calculation optimization; Step S3: Optimize the building's indoor temperature calculation model to eliminate system delay; Step S4: Calculate the theoretical building indoor comprehensive temperature, determine whether it meets the set target temperature of the building indoor temperature, and carry out pipe network thermal balance adjustment; Step S5: Evaluation of the thermal balance effect of the pipeline network.

2. The refined calculation method for the thermal balance of a secondary pipe network according to claim 1, characterized in that, Step S1 includes the following steps: Step S11: Establish a dynamic thermal balance model inside the residential building, as shown in equation (1): （1） In the formula ρ air Indoor air density, kg / m³ 3 V represents the room volume, in meters. 3 ; C The total specific heat capacity of indoor air is expressed in J / (kg·K); T in Q represents the building's overall indoor temperature, in °C. in For the heating required by the building, W; Q loss The total heat loss of the building envelope, W; Heat gained from solar radiation, W; For time step; Step S12: Establish a calculation model between the change in return water temperature and the intensity of solar radiation; The contribution of solar radiation intensity is converted into temperature regulation and defined as the radiation regulation coefficient. A calculation model is established between the change in return water temperature and the solar radiation intensity, as shown in equation (2): （2） In the formula The change in return water temperature caused by solar radiation, expressed in °C. The water supply temperature is in °C. The return water temperature is in °C. Heat gained from solar radiation, MJ; MJ; to provide the heat required for the building; For time step; Based on existing local meteorological monitoring data and supply and return water temperature data, the radiation regulation coefficient is calculated according to formula (2). Constant value; Step S13: Establish a building thermal balance model; Based on the basic heat transfer theory, a building heat balance model is established, and equation (3) is obtained from equations (1) and (2): （3） In the formula The overall heat transfer coefficient of the building envelope, W / (m²). 2 ·℃); The total heat exchange area of ​​the building envelope, in m² 2 ; Set a target temperature (°C) for the building's interior. The outdoor temperature is the overall temperature, in °C. The comprehensive heat transfer coefficient of a building heating terminal, W / (m²). 2 ·℃); For the heat exchange area of ​​the building heating terminal, m 2 ; This is the radiation regulation coefficient; Average temperature of supply and return water for the building, °C: （4） The water supply temperature is in °C. The return water temperature is in °C. Step S14: Establish the functional relationship of indoor temperature in the building; Based on the building thermal balance model of formula (3), a functional relationship for the indoor temperature of a building is established: （5） Define the outdoor composite temperature coefficient and indoor comprehensive temperature coefficient The following are expressions respectively: （6） （7） This leads to the integration of a binary linear regression model for calculating indoor comprehensive temperature. （8）。 3. The refined calculation model for the thermal balance of a secondary pipe network according to claim 1, characterized in that, Step S2 includes the following steps: Step S21: Establish an outdoor comprehensive temperature calculation model; By linking heating regulation patterns and outdoor environmental change patterns to an indoor comprehensive temperature calculation model, an outdoor comprehensive temperature calculation model is established: （9） in, Outdoor air temperature, °C; I Solar irradiance, W / m 2 ; v Outdoor wind speed, m / s; coefficient and This indicates the degree of influence of solar irradiance and outdoor wind speed on the overall outdoor temperature, obtained through linear regression using actual heating data and meteorological monitoring data. Step S22: To avoid frequent adjustments due to instantaneous changes in outdoor temperature, an average outdoor temperature calculation is performed over time. （10） in This represents the average outdoor temperature over time; considering the large diurnal temperature range in winter, the time step for calculating the outdoor temperature is... You can select the hour level based on the actual situation.

4. The refined calculation model for the thermal balance of a secondary pipe network according to claim 1, characterized in that, Step S3 includes the following steps: Step S31: Establish the relationship of the comprehensive thermal characteristic coefficient of the heating building, as shown in equation (11): （11） In the formula The overall heat transfer coefficient of the building envelope, W / (m²). 2 ·℃); The total heat exchange area of ​​the building envelope, in m² 2 ; The comprehensive heat transfer coefficient of a building heating terminal, W / (m²). 2 ·℃); For the heat exchange area of ​​the building heating terminal, m 2 ; Average temperature of supply and return water for the building, °C: Set a target temperature (°C) for the building's interior. The outdoor temperature is the overall temperature, in °C. Step S32: Establish the relationship between the time-averaged comprehensive thermal characteristic coefficients of heated buildings; Based on the determined hourly average outdoor temperature and indoor target temperature The time-weighted average method is used to calculate the comprehensive thermal characteristic coefficient of a heating building. Therefore, the time-averaged comprehensive thermal characteristic coefficient of the heating building is... This can be expressed as: （12） In equation (12) For time period Average internal supply and return water temperatures: （13）； Step S33: Determine the discrete time period; The cross-correlation function (CCF) method is used to dynamically identify the pipeline delay time and building thermal delay time at different stages, thereby obtaining the adjustment step size at different stages of the entire heating season, i.e., the hourly average comprehensive thermal characteristic coefficient of the heated building. Selected discrete time period ; Step S34: Optimize the building's overall indoor temperature calculation model; Based on discrete time period The comprehensive temperature coefficient of a certain building can be obtained. and : （14） （15） Furthermore based on and Solving for the theoretical building's overall indoor temperature: （16） in, The instantaneous average temperature of the supply and return water for a certain building is the average instantaneous supply and return water temperature based on the system's acquisition frequency. （17） in, and These are the instantaneous supply water temperature and return water temperature of a certain building, respectively.

5. The refined calculation model for the thermal balance of a secondary pipe network according to claim 1, characterized in that, Step S4 is as follows: Step S41: Based on time step Hourly average outdoor temperature ; Step S42: Set target temperature based on building interior and time step Corresponding average temperature of building supply and return water Calculate the temperature coefficient and This allows us to calculate the theoretical comprehensive indoor temperature of a particular building. ; Step S43: Determine the theoretical building's overall indoor temperature Is it related to the target temperature set in the building's interior? Matching, i.e., whether it satisfies （18） This is a threshold value that can be set and adjusted according to actual needs. when If the requirement is met, the flow regulation will not be activated; when If the indoor temperature is not up to standard, the flow rate will be increased. If the supply water temperature remains unchanged, the return water temperature will increase. When the regulating valve opening reaches its maximum value, the supply water temperature needs to be increased. When the supply water temperature exceeds the upper limit, the temperature regulation will end. when If the indoor temperature is considered to be above the standard, the flow rate will be reduced. If the supply water temperature remains unchanged, the return water temperature will decrease. When the opening of the regulating valve reaches the minimum limit, the supply water temperature needs to be reduced. When it is lower than the lower limit of the supply water temperature, the temperature regulation will end. Step S44: After completing flow or temperature regulation, based on the feedback of instantaneous supply and return water temperatures... , Calculate the building's overall indoor temperature again. The process continues with step S43 until the overall indoor temperature matches the target indoor temperature.

6. The refined calculation model for the thermal balance of a secondary pipe network according to claim 1, characterized in that, Step S5 is as follows: Using range The standard deviation σ represents the dispersion of the controlled object, evaluates the effectiveness of the control method, and indicates the fluctuation of indoor temperature and return water temperature in each building. The smaller the σ value, the smaller the indoor temperature fluctuation, indicating a better regulation effect. The calculation of σ is expressed as: （19） （20） in This indicates the extreme difference in overall indoor temperature within a building, expressed in °C. The maximum indoor temperature of the building, in °C; The minimum indoor temperature of the building, in °C; This indicates an extreme difference in building return water temperature, expressed in °C. The maximum return water temperature is ℃; The minimum return water temperature is ℃; （21） （22） in The standard deviation of the building's overall indoor temperature, in °C; Set a target temperature (°C) for the building's interior. The average indoor temperature of the building, in °C; The standard deviation of building return water temperature, in °C; Set a target return water temperature for the building, in °C; The average temperature of the building's return water is expressed in °C. For time step.

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