A local monitoring and control method suitable for variable air volume air conditioning

Abstract

The present invention discloses a local monitoring and control method for variable air volume (VAV) air conditioners, which relates to the technical field of VAV air conditioners. The method comprises obtaining the adjustment air volume share corresponding to each game node based on the ratio between the adjustment priority value corresponding to each game node and the sum of the adjustment priority values ​​of all game nodes and the total available air volume of the system, adjusting the air volume of each game node, obtaining the operating status data and system topology information of each VAV box in the VAV air conditioner system through comprehensive data collection, constructing a connection structure diagram to intuitively display the system structure, and then quantifying the importance of each node in the system and its impact on the downstream by calculating the connectivity and downstream dependency coefficient. The adjustment priority value is calculated in combination with parameters such as the real-time room temperature deviation value and the turbulence index to determine the adjustment priority value of each node. Finally, the air volume of each VAV box is accurately adjusted based on the adjustment priority value and air volume share, thereby realizing local monitoring and control of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of variable air volume air conditioners, and in particular relates to a local monitoring and control method suitable for variable air volume air conditioners. Background Art

[0002] Variable air volume air conditioning systems are widely used in modern buildings because they can flexibly adjust the air supply volume according to changes in regional load, have significant advantages in energy saving and providing personalized comfort.

[0003] However, variable air volume (VAV) control systems typically operate independently on a per-zone basis. Each VAV box adjusts based solely on the temperature or air volume demand of its own zone, lacking inter-zone communication and coordination mechanisms. This independent control model can easily lead to competition for total air volume when air demand fluctuates simultaneously across multiple zones, causing system instability. Furthermore, when air demand increases across multiple zones simultaneously, the VAV control system attempts to maximize the opening of each damper to maximize air volume. This can quickly deplete the total airflow capacity of the air handling unit (AHU), causing a drop in the main supply duct static pressure. At this point, the system may be unable to meet the needs of all zones, forcing some zones to lack sufficient airflow due to insufficient static pressure, thereby reducing overall comfort. Furthermore, in independent control mode, frequent and disordered adjustments of the VAV boxes can cause significant fluctuations in the main supply duct static pressure, requiring the AHU fan to frequently adjust speed to maintain static pressure. This increases fan energy consumption and noise, while localized airflow turbulence within the duct exacerbates valve cavitation, impacting the air supply efficiency and equipment life of downstream VAV boxes.

[0004] However, the existing system lacks comprehensive analysis and coordinated control of the airflow topology, upstream and downstream dependencies, and real-time operating status of the entire variable air conditioning control system, making it difficult to achieve the optimal balance between energy consumption and comfort at the overall level. This is because when multiple areas have large air supply demands at the same time, the system static pressure often fluctuates due to adjustment competition, causing some areas to be overcooled or under-supplied, affecting user comfort and increasing energy consumption. At the same time, the existing variable air conditioning control system has a weak ability to perceive changes in airflow status. When the air supply demand increases in multiple areas at the same time, the system cannot be dispatched in a unified manner, resulting in a certain area being unable to meet the air supply demand due to insufficient pressure, which restricts the overall efficiency and stability of the system. Based on this, a local monitoring and control method suitable for variable air volume air conditioning is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a local monitoring and control method suitable for variable air volume air conditioning, which solves the technical problem that when multiple areas have large air supply demands at the same time, the existing variable air conditioning control system has a weak perception of changes in airflow states. When the air supply demands in multiple areas increase at the same time, the system cannot be dispatched uniformly, resulting in a certain area being unable to meet the air supply demand due to insufficient pressure, which restricts the overall efficiency and stability of the system.

[0006] A local monitoring and control method applicable to a variable air volume air conditioner comprises the following steps:

[0007] Step 1: Construct a connection structure diagram of the variable air volume air conditioning system based on the pipe connection relationship and airflow direction between each VAV box in the variable air volume air conditioning system;

[0008] Step 2: Analyze and obtain the corresponding connectivity of each node in the variable air volume air conditioning system based on the number of upstream nodes, the number of downstream nodes, and the length of the directed edges with each downstream node;

[0009] Step 3: Establish a two-dimensional coordinate system in the connection structure diagram of the variable air volume air conditioning system. According to the coordinates of each downstream node corresponding to each node, obtain the influence range corresponding to each node, as well as the number of connection edges and downstream nodes corresponding to each node, and obtain the influence propagation path corresponding to each node. According to the influence range and influence propagation path corresponding to each node, obtain the downstream dependence coefficient corresponding to each node.

[0010] Step 4: Mark the nodes whose real-time room temperature deviation value is greater than the preset temperature difference Y2 as game nodes. At the same time, according to the preset interval length T, obtain and analyze the FFT peak frequency offset corresponding to each game node three times in a row, and then obtain the turbulence index corresponding to each game node;

[0011] Step 5: Obtain the real-time room temperature deviation value and air volume demand value corresponding to each game node. Calculate the adjustment priority value corresponding to each game node based on the real-time room temperature deviation value, air volume demand value, connectivity, downstream dependency coefficient, and turbulence index corresponding to each game node.

[0012] Step 6: According to the ratio between the adjustment priority value corresponding to each game node and the sum of the adjustment priority values ​​of all game nodes and the total air volume available in the system, the adjustment air volume share corresponding to each game node is obtained, and the air volume of each game node is adjusted.

[0013] As a further solution of the present invention: a specific method of constructing a connection structure diagram of a variable air volume air conditioning system is as follows:

[0014] Each VAV box is regarded as a node. According to the airflow direction and pipeline connection relationship, the nodes are connected using directed edges, and then the connection structure diagram of the variable air volume air conditioning system is constructed. The direction of the directed edge represents the direction of the airflow, from the source node of the airflow to the node to which the airflow is supplied.

[0015] As a further solution of the present invention, the specific method of analyzing and obtaining the corresponding connectivity of each node in the variable air volume air conditioning system is as follows:

[0016] Identify the number of upstream nodes AAn and the number of downstream nodes ABn corresponding to each node, and obtain the connection length LBn corresponding to each node according to the length of the directed edges between each node and its corresponding downstream nodes. The connectivity J corresponding to each node in the variable air volume air conditioning system is calculated by the formula: Jn=AAn×α+1 / ABn×β+LBn×γ, where 1=α+β+γ and γ>β>α, n refers to the different corresponding nodes in the connection structure diagram of the variable air volume air conditioning system, n=1, 2,…, a, a refers to the total number of nodes in the connection structure diagram of the variable air volume air conditioning system, a is a positive integer, and a satisfies a≥2.

[0017] As a further solution of the present invention, the specific method of obtaining the connection side lengths corresponding to each node is:

[0018] The length of the connecting pipe corresponding to each directed edge is used as the length of the directed edge corresponding to each directed edge, and the total length of the directed edges of each node is used as the connecting edge length LBn corresponding to each node.

[0019] As a further solution of the present invention, the specific method of obtaining the influence range corresponding to each node is:

[0020] A two-dimensional coordinate system is established in the connection structure diagram of the variable air volume air conditioning system, and the node coordinates Dn (DXn, DYn) corresponding to each node are obtained. One node is randomly selected from each node without replacement as the target node, and the coordinates of each downstream node corresponding to the target node are marked as Eq (EXq, EYq), where q refers to the different downstream nodes corresponding to the target node, q = 1, 2, ..., e, e refers to the total number of downstream nodes corresponding to the target node, e is a positive integer, when the value of e is 0 to 2, the influence range F1 corresponding to the target node is set to 0; when the value of e is greater than 2, the coordinates of each downstream ... The nodes are closed and connected to obtain the influence surface corresponding to the target node. According to the coordinates Ee (EXe, EYe) of each downstream node corresponding to the target node, the influence surface area corresponding to the target node is calculated by the formula: F1 = 1 / 2|(EX1×EY2-EY1×EX2)+(EX2×EY3-EY2×EX3)+…+(EXe×EY1-EYe×EX1)|, and it is used as the influence range corresponding to the target node; the same calculation method is used to calculate the coordinates of each downstream node corresponding to each node, and then the influence range Fn corresponding to each node is obtained.

[0021] As a further solution of the present invention, the specific method of obtaining the influencing propagation path corresponding to each node is:

[0022] The ratio between the length of the connection edge corresponding to each node and the number of downstream nodes is used as the influence propagation path Gn corresponding to each node.

[0023] As a further solution of the present invention, the specific method of obtaining the downstream dependency coefficient corresponding to each node is:

[0024] The downstream dependency coefficient YLn corresponding to each node is calculated using the formula: YLn=Fn×θ1+1 / Gn×θ2, where 1=θ1+θ2 and θ1>θ2.

[0025] As a further solution of the present invention, the specific method of obtaining the turbulence index corresponding to each game node is:

[0026] The average of the FFT peak frequency offsets corresponding to three consecutive times at each game node is used as the turbulence index Mr corresponding to each game node, where r refers to different game nodes.

[0027] As a further solution of the present invention, the specific method of calculating and obtaining the adjustment priority value corresponding to each game node is:

[0028] The real-time room temperature deviation value Wr, air volume demand value Qr, connectivity Jr, downstream dependency coefficient YLr and turbulence index Mr corresponding to each game node are calculated by the formula: Xr=Wr×ω1+Qr×ω2+YLr×ω3-Mr×ω4; the adjustment priority value Xr corresponding to each game node is obtained;

[0029] Among them, ω1, ω2, ω3 and ω4 all refer to preset weight coefficients. The specific values ​​are formulated by relevant personnel and satisfy 1=ω1+ω2+ω3+ω4.

[0030] As a further solution of the present invention, the specific method of obtaining the adjusted air volume share corresponding to each game node is:

[0031] The ratio of the adjustment priority value corresponding to each game node to the sum of the adjustment priority values ​​of all game nodes is used as the adjustment priority coefficient corresponding to each game node, and the product of the adjustment priority coefficient corresponding to each game node and the total available air volume of the system is used as the adjustment air volume share corresponding to each game node. All game nodes are sorted in descending order according to the corresponding adjustment priority value Xr, and the air volume of each game node is adjusted accordingly according to the adjustment air volume share corresponding to each game node according to the sorting order.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention calculates the downstream dependency coefficient, evaluates the degree of influence and dependency of a node on downstream nodes, and accurately evaluates the impact of each node on the downstream, thus making up for the deficiency of traditional control in lacking upstream and downstream dependency analysis. When adjusting the system, the present invention can fully consider the chain reaction of node adjustment on the air supply of downstream nodes, thereby improving the accuracy and coordination of system adjustment and ensuring the comfort level of each area.

[0034] (2) The present invention first obtains the operating status data and system topology information of each VAV box in the variable air volume air conditioning system through comprehensive data collection, and constructs a connection structure diagram to intuitively display the system structure. Then, by calculating the connectivity and downstream dependency coefficient, the importance of each node in the system and its impact on the downstream are quantified, and the adjustment priority value is calculated in combination with parameters such as real-time room temperature deviation value and turbulence index to determine the adjustment priority value of each node. Finally, the air volume of each VAV box is accurately adjusted according to the adjustment priority value and air volume share to achieve local monitoring and control of the system. The entire process comprehensively considers the airflow topology structure, upstream and downstream dependency relationship and real-time operating status of the system to form a closed-loop collaborative control system. While changing the disordered regulation in the traditional independent control mode, through comprehensive analysis, when there are changes in air supply demand in multiple areas at the same time, the total air volume competition and excessive fluctuation of the static pressure of the main air supply duct are avoided, the system is maintained in stable operation, and the global collaborative optimization of the VAV system is achieved. When air volume is limited, high-priority areas are prioritized to ensure comfort in core areas, effectively avoiding "competition for air volume" between areas and drastic fluctuations in static pressure, and improving overall operational efficiency and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the framework structure of the method of the present invention;

[0036] Figure 2 This is a flow chart for calculating the influence range of the target node of the present invention. DETAILED DESCRIPTION

[0037] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Example 1: Please refer to Figure 1 and Figure 2 The present application provides a local monitoring and control method applicable to a variable air volume air conditioner, comprising the following steps:

[0039] Step 1: Utilizing sensor networks and communication technologies, temperature and flow measurements are deployed at each VAV box in the VAV air conditioning system, collecting characteristic data corresponding to the temperature and flow at each VAV box in real time. Simultaneously, through VAV air conditioning system design drawings, site surveys, or automated topology discovery algorithms, the VAV boxes in each VAV system, the piping connections between them, and the airflow directions within each VAV box are obtained. The sensor networks and communication technologies used are both existing and mature, so they will not be detailed here.

[0040] By leveraging sensor networks and communication technologies, temperature and flow sensors are deployed at each VAV box in the VAV air conditioning system to collect real-time temperature and flow characteristic data at each VAV box. The system also uses VAV system design drawings, site surveys, or automated topology discovery algorithms to determine the duct connections and airflow directions between VAV boxes. This provides a comprehensive and accurate data foundation for subsequent analysis. This overcomes the lack of global system information in traditional control systems and lays the data foundation for multi-zone coordinated control. Comprehensive data collection enables the system to understand the operating status of each VAV box and the overall system topology, avoiding the chaotic regulation issues caused by information loss in independent control modes and enabling precise analysis and coordinated control.

[0041] Step 2: Based on the pipe connection relationship and airflow direction between each VAV box in the variable air volume air conditioning system, construct the connection structure diagram of the variable air volume air conditioning system. The specific method is as follows:

[0042] Each VAV box is treated as a node. Directed edges are used to connect the nodes according to the airflow direction and pipeline connection relationship. Based on the pipeline connection relationship between each VAV box and the airflow direction, each node is connected by directed edges, thereby constructing a connection structure diagram of the variable air volume air conditioning system. The direction of the directed edge represents the direction of the airflow, pointing from the source node of the airflow to the node to which the airflow is supplied.

[0043] For example, if the airflow flows from VAV1 to VAV2 through a pipe, then add a directed edge from VAV1 to VAV2 in the graph, which clearly defines the upstream and downstream relationship between the nodes. If the airflow flows from VAV2 to VAV3, then add another directed edge from VAV2 to VAV3.

[0044] Based on the acquired pipeline connections and airflow directions, the VAV boxes are used as nodes, and directed edges are used to connect the nodes to construct a connection structure diagram. This clearly presents the system topology and intuitively displays the airflow direction and connection relationships between the VAV boxes. This breaks through the limitations of traditional independent control without inter-regional correlation. Through the visual connection structure diagram, the system can grasp the upstream and downstream relationships between VAV boxes from a holistic perspective. This helps to avoid the problem of total air volume competition caused by a lack of understanding of the mutual relationships when air supply demand changes simultaneously in multiple zones, and provides an intuitive structural model for subsequent analysis of node importance and coordinated regulation.

[0045] Step 3: According to the connection relationship of each node in the variable air volume air conditioning system connection structure diagram, the number of upstream nodes and the number of downstream nodes corresponding to each node are obtained, and the length of the directed edges between each node and the corresponding downstream nodes are obtained. According to the number of upstream nodes, the number of downstream nodes and the length of the directed edges with each downstream node, the corresponding connectivity of each node in the variable air volume air conditioning system is analyzed and obtained. The specific method is:

[0046] The upstream node refers to the source node of the airflow, that is, the starting point of the directed edge, and the downstream node refers to the supplied airflow node, that is, the end point of the directed edge;

[0047] Identify the number of upstream nodes AAn (the number of airflow source nodes) and the number of downstream nodes ABn (the number of airflow supplied nodes) corresponding to each node, where n refers to the corresponding different nodes in the variable air volume air conditioning system connection structure diagram, and is also used as the node number corresponding to the different nodes, n = 1, 2, ..., a, a refers to the total number of nodes in the variable air volume air conditioning system connection structure diagram, a is a positive integer, and a satisfies a ≥ 2;

[0048] The length of the connecting pipe corresponding to each directed edge is used as the length corresponding to each directed edge, and then the length of the directed edge between each node and its corresponding downstream node is obtained. The total length of the directed edge of each node is used as the connecting edge length LBn corresponding to each node;

[0049] It should be noted that the specific method of determining the length of the connecting pipe corresponding to each directed edge is to obtain it through the design drawings of the variable air volume air conditioning system or on-site survey. This is an existing and mature technology, so no further details will be given here.

[0050] Count the number of upstream nodes AAn and downstream nodes ABn of each node, and use the corresponding connection edge length LBn of each node. Use the formula: Jn=AAn×α+1 / ABn×β+LBn×γ to calculate the corresponding connectivity J of each node in the variable air volume air conditioning system. α, β, and γ are preset weight coefficients. The specific values ​​are set by relevant personnel according to actual conditions, satisfying 1=α+β+γ and γ>β>α.

[0051] The number of upstream nodes reflects the richness of the airflow sources, the number of downstream nodes reflects the scope of influence on subsequent nodes, the length of the connection side considers the airflow transmission distance, and the preset weight coefficients highlight the impact of different parameters on connectivity. Quantifying the importance of each node in the system overcomes the defect of traditional control that cannot measure the impact of nodes. When adjusting the system, the degree of connectivity can be used to determine which nodes have a greater impact on the overall system. Prioritize the adjustment of key nodes to avoid system instability caused by blind adjustment. At the same time, when the demand for air supply increases in multiple areas at the same time, the air volume can be reasonably allocated based on the degree of connectivity to prevent the exhaustion of the total air supply capacity and the excessive drop in the static pressure of the main air supply duct.

[0052] Step 4: Establish a two-dimensional coordinate system in the connection structure diagram of the variable air volume air conditioning system, obtain the node coordinates corresponding to each node, and obtain the influence range corresponding to each node based on the coordinates of each downstream node corresponding to each node. At the same time, according to the connection side length LBn and the number of downstream nodes ABn corresponding to each node, obtain the influence propagation path corresponding to each node. According to the influence range and influence propagation path corresponding to each node, obtain the downstream dependence coefficient corresponding to each node. The specific method is as follows:

[0053] A two-dimensional coordinate system is established in the connection structure diagram of the variable air volume air conditioning system to obtain the node coordinates Dn (DXn, DYn) corresponding to each node. One node is randomly selected from each node without replacement as the target node, and the coordinates of each downstream node corresponding to the target node are marked as Eq (EXq, EYq), where q refers to the different downstream nodes corresponding to the target node, q = 1, 2, ..., e, e refers to the total number of downstream nodes corresponding to the target node, and e is a positive integer. When the value of e is 0 to 2, the influence range F1 corresponding to the target node is set to 0;

[0054] When the value of e is greater than 2, each downstream node is closed and connected to obtain the influence surface corresponding to the target node. According to the coordinates Ee (EXe, EYe) of each downstream node corresponding to the target node, the influence surface area corresponding to the target node is calculated and used as the influence range F1 corresponding to the target node;

[0055] The specific calculation method for obtaining the influence range F1 corresponding to the target node is:

[0056] The influence area of ​​the target node, i.e. the influence range F1 of the target node, is calculated using the shoelace formula: F1=1 / 2|(EX1×EY2-EY1×EX2)+(EX2×EY3-EY2×EX3)+…+(EXe×EY1-EYe×EX1)|.

[0057] Using the same calculation method, the coordinates of each downstream node corresponding to each node are calculated, and then the influence range Fn corresponding to each node is obtained;

[0058] The ratio between the length of the connecting edge LBn corresponding to each node and the number of downstream nodes ABn is taken as the influence propagation path Gn corresponding to each node, that is, Gn=LBn / ABn;

[0059] The downstream dependency coefficient YLn corresponding to each node is calculated using the formula: YLn=Fn×θ1+1 / Gn×θ2, where 1=θ1+θ2 and θ1>θ2;

[0060] By calculating the downstream dependency coefficient, the influence and dependency relationships of a node on downstream nodes are assessed. This accurately evaluates the impact of each node on downstream nodes, compensating for the lack of upstream and downstream dependency analysis in traditional control. During system adjustments, the chain reaction of node adjustments on air supply to downstream nodes is fully considered, preventing insufficient air supply or overcooling in some areas due to adjustments to a single node affecting multiple downstream nodes. This improves the accuracy and coordination of system adjustments and ensures comfort in all areas.

[0061] Step 5: Obtain the real-time room temperature deviation value corresponding to each node in real time, mark the node whose real-time room temperature deviation value is greater than the preset temperature difference Y2 as the game node, and obtain and analyze the FFT peak frequency offset corresponding to each game node three times in a row according to the preset interval length T, and then obtain the turbulence index corresponding to each game node. The specific method is as follows:

[0062] The specific value of the preset time length T is 10S;

[0063] The real-time room temperature deviation value refers to the difference between the actual indoor temperature at each node and the set temperature of that area. It is obtained through real-time data collection by temperature sensors deployed at the VAV boxes corresponding to each node. The real-time room temperature deviation value is the most direct indicator for measuring the comfort demand of the control domain corresponding to each VAV box area. The larger the absolute value of the real-time room temperature deviation value, the greater the deviation between the control area temperature of the corresponding VAV box and the set value, and the more urgent the demand for air supply adjustment for this VAV box. Therefore, when calculating the adjustment priority value, the corresponding VAV box usually has a higher weight.

[0064] The average of the FFT peak frequency offsets corresponding to three consecutive times at each game node is used as the turbulence index Mr corresponding to each game node, where r refers to different game nodes;

[0065] By real-time monitoring of the room temperature deviation value of each node, the nodes with a temperature difference greater than the preset temperature difference are marked as game nodes. The FFT peak frequency offset of the game node is obtained three times in a row at an interval of 10S and the average is taken as the turbulence index to reflect the turbulence state in the pipeline. Enhance the system's perception of changes in airflow state and solve the problem of weak perception of traditional systems. By obtaining the turbulence index, the system can promptly detect abnormal changes in airflow in the pipeline, such as valve cavitation and other problems that may be caused by increased turbulence, and take measures in advance to adjust them, so as to avoid airflow problems affecting the air supply efficiency and equipment life of the downstream VAV box. At the same time, when the air supply demand increases in multiple areas at the same time, the air volume distribution can be reasonably adjusted according to the turbulence index to maintain system stability.

[0066] Step 6: Obtain the real-time room temperature deviation value and air volume demand value corresponding to each game node. Based on the real-time room temperature deviation value, air volume demand value, connectivity, downstream dependency coefficient, and turbulence index corresponding to each game node, calculate the adjustment priority value corresponding to each game node. The specific method is as follows:

[0067] The real-time room temperature deviation value Wr, air volume demand value Qr, connectivity Jr, downstream dependency coefficient YLr, and turbulence index Mr corresponding to each game node are calculated using the formula: Xr=Wr×ω1+Qr×ω2+YLr×ω3-Mr×ω4; the adjustment priority value Xr corresponding to each game node is calculated;

[0068] Among them, ω1, ω2, ω3 and ω4 all refer to preset weight coefficients, and the specific values ​​are formulated by relevant personnel to meet the requirement of 1=ω1+ω2+ω3+ω4;

[0069] By comprehensively considering multiple parameters to determine the adjustment priority value for each game node, the adjustment priority is scientifically and rationally determined, changing the chaotic adjustment situation of traditional control. During system adjustment, VAV boxes with greater system impact and significant temperature deviation are prioritized. This avoids frequent and disorderly adjustment of VAV boxes, reduces severe fluctuations in the static pressure of the main air supply duct, and reduces the energy consumption and noise of the AHU fan. At the same time, it improves the system's adjustment accuracy and response speed, better meeting the comfort requirements of various areas.

[0070] Step 7: Calculate the ratio between the adjustment priority value Xr corresponding to each game node and the sum of the adjustment priority values ​​of all game nodes as the adjustment priority coefficient corresponding to each game node. At the same time, obtain the total available air volume of the system. The product of the adjustment priority coefficient corresponding to each game node and the total available air volume of the system is used as the adjustment air volume share corresponding to each game node. The specific method is as follows:

[0071] The ratio of the adjustment priority value Xr corresponding to each game node to the sum of the adjustment priority values ​​of all game nodes is used as the adjustment priority coefficient corresponding to each game node. The adjustment air volume share corresponding to each game node is calculated by: adjustment air volume share = adjustment priority coefficient × total air volume available in the system. All game nodes are sorted in descending order according to the calculated adjustment priority value Xr. The air volume of each game node is adjusted accordingly according to the adjustment air volume share corresponding to each game node according to the sorting order;

[0072] The adjustment priority coefficient is calculated by calculating the ratio of the adjustment priority value of each game node to the sum of the adjustment priority values ​​of all game nodes. The adjustment priority coefficient is multiplied by the total available air volume of the system to obtain the adjustment air volume share. The adjustment priority values ​​are sorted in descending order, and the air volume of each game node is precisely adjusted according to the adjustment air volume share. This achieves reasonable air volume distribution and local optimization control of the system, solving the problem of unreasonable air volume distribution in traditional control when demand changes in multiple regions. When there is simultaneous air supply demand in multiple regions, the air volume is distributed according to the adjustment priority value and air volume share of each node, avoiding competition for the total air volume, meeting the personalized needs of different regions, improving the overall energy efficiency of the system, reducing operating costs, while maintaining system stability and improving overall comfort.

[0073] First, through comprehensive data collection, the operating status data and system topology information of each VAV box in the variable air volume air conditioning system are obtained, and a connection structure diagram is constructed to intuitively display the system structure. Then, the importance of each node in the system and its impact on the downstream are quantified by calculating the connectivity and downstream dependency coefficient. The adjustment priority value is calculated in combination with parameters such as the real-time room temperature deviation value and turbulence index to determine the adjustment priority value of each node. Finally, the air volume of each VAV box is precisely adjusted according to the adjustment priority value and air volume share to achieve local monitoring and control of the system. The entire process comprehensively considers the system's airflow topology, upstream and downstream dependencies, and real-time operating status to form a closed-loop collaborative control system;

[0074] While eliminating the chaotic adjustments inherent in traditional independent control, this system, through comprehensive analysis of system structure and operating status, avoids total air volume competition and excessive fluctuations in main air duct static pressure when air demand fluctuates simultaneously across multiple zones, maintaining stable system operation. It also accurately assesses the impact of each node on downstream nodes, prioritizing VAV units with significant system impact and temperature deviations to prevent overcooling or insufficient air supply in certain zones, effectively improving overall indoor comfort. By enhancing awareness of airflow fluctuations, potential issues can be promptly identified and addressed. It also enables coordinated control across multiple zones, centrally scheduling air volume, improving overall system efficiency and stability, and achieving an optimal balance between energy consumption and comfort overall, achieving global coordinated optimization of the VAV system. When air volume is limited, it prioritizes high-priority zones to ensure comfort in core areas. Dynamic adjustment of the AHU static pressure setpoint significantly reduces fan energy consumption while maintaining system stability. This effectively avoids inter-zone competition for air volume and drastic static pressure fluctuations, improving overall operational efficiency and reliability.

[0075] The above formulas are all dimensionless and numerical calculations. The formulas are obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters and thresholds in the formulas are set by technicians in this field according to actual conditions.

[0076] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A local monitoring and control method for variable air volume air conditioning, characterized in that: The following steps are involved: Step 1: Construct a connection structure diagram of the variable air volume air conditioning system based on the pipe connection relationship and airflow direction between each VAV box in the variable air volume air conditioning system; Step 2: Identify the number of upstream nodes AAn and the number of downstream nodes ABn corresponding to each node, and obtain the connection length LBn corresponding to each node based on the length of the directed edge between each node and its corresponding downstream nodes. Calculate the connectivity J of each node in the variable air volume air conditioning system using the formula: Jn=AAn×α+1 / ABn×β+LBn×γ, where 1=α+β+γ and γ>β>α, n refers to the corresponding different nodes in the connection structure diagram of the variable air volume air conditioning system, n=1, 2, ..., a, a refers to the total number of nodes in the connection structure diagram of the variable air volume air conditioning system, a is a positive integer, and a satisfies a≥2; Step 3: Based on the coordinates of each node's downstream nodes, the number of connected edges and downstream nodes of each node, obtain the influence range and influence propagation path corresponding to each node. Analyze the influence range and influence propagation path of each node to obtain the downstream dependency coefficient corresponding to each node. Step 4: Mark the nodes whose real-time room temperature deviation value is greater than the preset temperature difference Y2 as game nodes. At the same time, analyze the FFT peak frequency offset corresponding to each game node three times in a row according to the preset interval length T to obtain the turbulence index corresponding to each game node; Step 5: Obtain the real-time room temperature deviation value and air volume demand value corresponding to each game node. Calculate the adjustment priority value corresponding to each game node based on the real-time room temperature deviation value, air volume demand value, connectivity, downstream dependency coefficient, and turbulence index corresponding to each game node. Step 6: According to the ratio between the adjustment priority value corresponding to each game node and the sum of the adjustment priority values ​​of all game nodes and the total air volume available in the system, the adjustment air volume share corresponding to each game node is obtained, and the air volume of each game node is adjusted.

2. A local monitoring and control method for a variable air volume air conditioner according to claim 1, characterized in that: The specific method of constructing the connection structure diagram of the variable air volume air conditioning system is as follows: Each VAV box is regarded as a node. According to the airflow direction and pipeline connection relationship, the nodes are connected using directed edges, and then the connection structure diagram of the variable air volume air conditioning system is constructed. The direction of the directed edge represents the direction of the airflow, from the source node of the airflow to the node to which the airflow is supplied.

3. The local monitoring and control method for variable air volume air conditioner according to claim 1, characterized in that: The specific method of obtaining the connection edge length corresponding to each node is: The length of the connecting pipe corresponding to each directed edge is used as the length of the directed edge corresponding to each directed edge, and the total length of the directed edges of each node is used as the connecting edge length LBn corresponding to each node.

4. A local monitoring and control method for a variable air volume air conditioner according to claim 3, characterized in that: The specific method to obtain the influence range corresponding to each node is: A two-dimensional coordinate system is established in the connection structure diagram of the variable air volume air conditioning system to obtain the node coordinates Dn (DXn, DYn) corresponding to each node. One node is randomly selected from each node without replacement as the target node, and the coordinates of each downstream node corresponding to the target node are marked as Eq (EXq, EYq), where q refers to the different downstream nodes corresponding to the target node, q = 1, 2, ..., e, e refers to the total number of downstream nodes corresponding to the target node, e is a positive integer, when the value of e is 0 to 2, the influence range F1 corresponding to the target node is set to 0; when the value of e is greater than 2, the coordinates of each downstream ... The points are closed and connected to obtain the influence surface corresponding to the target node. According to the coordinates Ee (EXe, EYe) of each downstream node corresponding to the target node, the influence surface area corresponding to the target node is calculated by the formula: F1 = 1 / 2|(EX1×EY2-EY1×EX2)+(EX2×EY3-EY2×EX3)+…+(EXe×EY1-EYe×EX1)|, and it is used as the influence range F1 corresponding to the target node. The same calculation method is used to calculate the coordinates of each downstream node corresponding to each node, and then the influence range Fn corresponding to each node is obtained.

5. The local monitoring and control method for variable air volume air conditioner according to claim 4, characterized in that: The specific method of obtaining the impact propagation path corresponding to each node is: The ratio between the length of the connection edge corresponding to each node and the number of downstream nodes is used as the influence propagation path Gn corresponding to each node.

6. A local monitoring and control method for a variable air volume air conditioner according to claim 5, characterized in that: The specific method of obtaining the downstream dependency coefficient corresponding to each node is: The downstream dependency coefficient YLn corresponding to each node is calculated using the formula: YLn=Fn×θ1+1 / Gn×θ2, where 1=θ1+θ2 and θ1>θ2.

7. A local monitoring and control method for a variable air volume air conditioner according to claim 6, characterized in that: The specific method of obtaining the turbulence index corresponding to each game node is: The average of the FFT peak frequency offsets corresponding to three consecutive times at each game node is used as the turbulence index Mr corresponding to each game node, where r refers to different game nodes.

8. The local monitoring and control method for a variable air volume air conditioner according to claim 7, characterized in that: The specific method of obtaining the adjustment priority value corresponding to each game node is: According to the real-time room temperature deviation value Wr, air volume demand value Qr, connectivity Jr, downstream dependency coefficient YLr and turbulence index Mr corresponding to each game node, the adjustment priority value Xr corresponding to each game node is calculated.

9. The local monitoring and control method for a variable air volume air conditioner according to claim 8, characterized in that: The specific method of obtaining the corresponding adjustment air volume share of each game node is as follows: The ratio of the adjustment priority value corresponding to each game node to the sum of the adjustment priority values ​​of all game nodes is used as the adjustment priority coefficient corresponding to each game node, and the product of the adjustment priority coefficient corresponding to each game node and the total available air volume of the system is used as the adjustment air volume share corresponding to each game node. All game nodes are sorted in descending order according to the corresponding adjustment priority value Xr, and the air volume of each game node is adjusted accordingly according to the adjustment air volume share corresponding to each game node according to the sorting order.

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