Local monitoring control method suitable for variable air volume air conditioner

Abstract

The invention discloses a local monitoring control method suitable for a variable air volume air conditioner, and relates to the technical field of variable air volume air conditioners. The method comprises the following steps: acquiring an adjusting air volume share corresponding to each game node, adjusting the air volume of each game node, acquiring operation state data and system topology information of each VAV box of the variable air volume air conditioning system through comprehensive data acquisition, and constructing a connection structure chart to visually display a system structure. Then, the importance degree of each node in the system and the influence relation on the downstream are quantified by calculating the connectivity and the downstream dependency coefficient, adjustment priority values are calculated in combination with parameters such as the real-time room temperature deviation value and the turbulence index, and the adjustment priority values of the nodes are determined; and finally, the air volume of each VAV box is precisely adjusted according to the adjustment priority value and the air volume share, and local monitoring control of the system is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of variable air volume air conditioning, and specifically relates to a local monitoring and control method applicable to variable air volume air conditioning. Background Art

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

[0003] However, variable air volume air conditioning control systems usually control independently in single - zone units, that is, each VAV box adjusts only according to the temperature or air volume demand of its own area, and does not have a communication and coordination mechanism between areas. In this independent control mode, when the supply air demands change simultaneously in multiple zones, it is very easy to cause the total air volume to be scrambled, resulting in system instability. At the same time, when the supply air demands of multiple zones increase simultaneously, the variable air volume air conditioning control system will try to maximize the opening of each air valve to obtain more air volume, which may quickly deplete the total supply air capacity of the air handling unit (AHU), leading to a decrease in the static pressure of the main supply air duct. At this time, the system may not be able to meet the demands of all zones, forcing some zones to be unable to obtain sufficient air volume due to insufficient static pressure, which instead reduces the overall comfort. At the same time, in the independent control mode, the frequent and disorderly adjustment of VAV boxes will cause violent fluctuations in the static pressure of the main supply air duct, making the AHU fan need to frequently adjust the rotation speed to maintain the static pressure, increasing the fan energy consumption and noise. At the same time, the local air flow turbulence in the pipeline intensifies valve cavitation, etc., affecting the air supply efficiency and equipment life of the downstream VAV boxes.

[0004] However, the existing systems lack a comprehensive analysis and coordinated control of the air flow topology, upstream - downstream dependencies, and real - time operating status of the entire variable air conditioning control system, and it is difficult to achieve the best balance between energy consumption and comfort at the overall level. Because when the supply air demands of multiple zones are large simultaneously, it often causes fluctuations in the system static pressure due to adjustment scrambling, resulting in over - cooling or insufficient air supply in some zones, affecting user comfort and increasing energy consumption. At the same time, the existing variable air conditioning control systems also have a weak ability to perceive changes in the air flow state. When the supply air demands of multiple zones increase simultaneously, the system cannot be unifiedly scheduled, resulting in a zone being unable to meet the air supply demand due to insufficient pressure, restricting the overall efficiency and stability of the system. Based on this, a local monitoring and control method applicable to 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 applicable to variable air volume air conditioners, which solves the technical problems that when a large air supply demand occurs in multiple areas simultaneously, the existing variable air volume air conditioner control system has a weak perception ability of the change of air flow state, and when the air supply demand is increased in multiple areas simultaneously, the system cannot be unifiedly scheduled, resulting in insufficient pressure in a certain area to meet the air supply demand, which restricts the overall efficiency and stability of the system.

[0006] A local monitoring and control method applicable to variable air volume air conditioners includes the following steps:

[0007] Step 1: According to the pipeline connection relationship and air flow direction among the VAV boxes in the variable air volume air conditioner system, construct a connection structure diagram of the variable air volume air conditioner system;

[0008] Step 2: Analyze and obtain the connection degrees corresponding to each node in the variable air volume air conditioner system respectively according to the number of upstream nodes, the number of downstream nodes of each node, and the lengths of the directed edges to each downstream node.

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

[0010] Step 4: Mark the nodes with real-time room temperature deviation values greater than the preset temperature difference Y2 among all nodes as game nodes. At the same time, according to the preset time interval T, continuously obtain and analyze the FFT peak frequency offset amounts corresponding to each game node three times in a row, and then obtain the turbulence indexes corresponding to each game node respectively.

[0011] Step 5: Obtain the real-time room temperature deviation values and air volume demand values corresponding to each game node respectively. According to the real-time room temperature deviation values, air volume demand values, connection degrees, downstream dependence coefficients and turbulence indexes corresponding to each game node respectively, calculate and obtain the adjustment priority values corresponding to each game node respectively.

[0012] Step 6: According to the ratios of the adjustment priority values corresponding to each game node respectively to the total sum of the adjustment priority values of all game nodes and the total available air volume of the system, obtain the adjustment air volume shares corresponding to each game node respectively, and adjust the air volume of each game node.

[0013] As a further solution of the present invention: The specific way to construct the connection structure diagram of the variable air volume air conditioner system is:

[0014] Taking each VAV box as a node, according to the air flow direction and the pipe connection relationship, use directed edges to connect the nodes, and then construct the connection structure diagram of the variable air volume air conditioning system, where the direction of the directed edge represents the air flow direction, pointing from the source node of the air flow to the node supplied with the air flow.

[0015] As a further solution of the present invention: The specific way to analyze and obtain the connection degree corresponding to each node in the variable air volume air conditioning system is:

[0016] Identify the number of upstream nodes AAn and the number of downstream nodes ABn corresponding to each node respectively, and obtain the connection side length LBn corresponding to each node according to the lengths of the directed edges between each node and its corresponding downstream nodes. Through the formula: Jn = AAn×α + 1 / ABn×β + LBn×γ, calculate the connection degree J corresponding to each node in the variable air volume air conditioning system, where 1 = α + β + γ and γ > β > α, n represents different nodes corresponding to the connection structure diagram of the variable air volume air conditioning system, n = 1, 2,..., a, a represents 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 way to obtain the connection side length corresponding to each node is:

[0018] Take the connection pipe lengths corresponding to each directed edge as the directed edge lengths corresponding to each directed edge, and take the total side length of the directed edge lengths of each node as the connection side length LBn corresponding to each node.

[0019] As a further solution of the present invention: The specific way to obtain the influence range corresponding to each node is:

[0020] Establish a two-dimensional coordinate system in the connection structure diagram of the variable air volume air conditioning system, obtain the node coordinates Dn (DXn, DYn) corresponding to each node, randomly select one node without replacement from each node as the target node, and mark the coordinates of each downstream node corresponding to the target node as Eq (EXq, EYq), where q refers to 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 e ranges from 0 to 2, the influence range F1 corresponding to the target node is taken as 0; when e is greater than 2, the influence surface corresponding to the target node is obtained by connecting each downstream node in a closed manner. According to the coordinates Ee (EXe, EYe) of each downstream node corresponding to the target node, through the formula: F1 = 1 / 2|(EX1×EY2 - EY1×EX2) + (EX2×EY3 - EY2×EX3) + …… + (EXe×EY1 - EYe×EX1)|, calculate the area of the influence surface corresponding to the target node and take it as the influence range corresponding to the target node; using the same calculation method, calculate the coordinates of each downstream node corresponding to each node respectively, and then obtain the influence range Fn corresponding to each node.

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

[0022] Take the ratio between the connection side length corresponding to each node and the number of downstream nodes as the influence propagation path Gn corresponding to each node.

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

[0024] Calculate the downstream dependence coefficient YLn corresponding to each node through 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 for obtaining the turbulence index corresponding to each game node is:

[0026] Take the mean value of the FFT peak frequency offset corresponding to each game node three times in a row 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 for calculating 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 dependence coefficient YLr, and turbulence index Mr corresponding to each game node are calculated through the formula: Xr = Wr×ω1 + Qr×ω2 + YLr×ω3 - Mr×ω4; the adjustment priority value Xr corresponding to each game node is obtained, where ω1, ω2, ω3, and ω4 are all preset weight coefficients, and 1 = ω1 + ω2 + ω3 + ω4.

[0029] As a further solution of the present invention: the specific way to obtain the adjusted air volume share corresponding to each game node is:

[0030] Taking the ratio of the adjusted priority value corresponding to each game node to the sum of the adjusted priority values of all game nodes as the adjusted priority coefficient corresponding to each game node, multiplying the adjusted priority coefficient corresponding to each game node by the total available air volume of the system as the adjusted air volume share corresponding to each game node, sorting all game nodes in descending order according to the corresponding adjusted priority value Xr, and adjusting the air volume of each game node accordingly according to the sorting order based on the adjusted air volume share corresponding to each game node.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] (1) In the present invention, by calculating the downstream dependence coefficient, the influence degree and dependence relationship of the node on the downstream node are evaluated, the influence of each node on the downstream is accurately evaluated, making up for the deficiency of the traditional control lacking the upstream and downstream dependence analysis. During system adjustment, the chain reaction of node adjustment on the air supply of downstream nodes can be fully considered, improving the accuracy and coordination of system adjustment, and ensuring the comfort of each area;

[0033] (2)In the present invention, first, the operation status data of each VAV box in the variable air volume air conditioning system and the system topology information are obtained through comprehensive data collection, and a connection structure diagram is constructed to visually display the system structure. Then, the importance of each node in the system and its influence relationship on the downstream are quantified by calculating the connection degree and the number of downstream dependencies. Combining parameters such as the real-time room temperature deviation value and the turbulence index, the adjustment priority value is calculated to determine the adjustment priority value of each node. Finally, based on the adjustment priority value and the air volume share, the air volume of each VAV box is accurately adjusted to achieve local monitoring and control of the system. The entire process comprehensively considers the air flow topology structure, upstream and downstream dependency relationships, and real-time operation status of the system, forming a closed-loop collaborative control system. While changing the disorderly adjustment in the traditional independent control mode, through comprehensive analysis, when there are changes in the air supply demand in multiple regions simultaneously, it avoids the competition for the total air volume and excessive fluctuations in the static pressure of the main air supply duct, maintains the stable operation of the system, and realizes the global collaborative optimization of the VAV system. When the air volume is limited, high-priority regions are preferentially satisfied to ensure the comfort of the core regions, effectively avoiding the "competition for air volume" between regions and drastic fluctuations in static pressure, and improving the overall operation efficiency and reliability. Description of the Drawings

[0034] Figure 1 It is a schematic diagram of the method framework structure of the present invention;

[0035] Figure 2 It is a calculation flow chart of the influence range of the target node of the present invention. Detailed Embodiments

[0036] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1: Please refer to Figure 1 and Figure 2 , the present application provides a local monitoring and control method applicable to variable air volume air conditioners, including the following steps:

[0038] Step 1: Using sensor networks and communication technologies, deploy temperature and flow sensors at each VAV box in the variable air volume air conditioning system to collect the characteristic data corresponding to the temperature and flow at each VAV box in real time. At the same time, obtain the pipe connection relationships between each VAV box and the air flow direction between each VAV box in the variable air volume air conditioning system through the design drawings of the variable air volume air conditioning system, on-site surveys, or automatic topology discovery algorithms. The sensor networks and communication technologies used are all existing and mature technologies, so no further elaboration will be made here;

[0039] By using sensor networks and communication technologies, deploy temperature and flow sensors at each VAV box in the variable air volume air conditioning system to collect the temperature and flow characteristic data at each VAV box in real time. Through the design drawings of the variable air volume air conditioning system, on-site surveys, or automatic topology discovery algorithms, obtain the pipe connection relationships and air flow directions between each VAV box. Use the mature sensor networks and communication technologies to deploy temperature and flow sensors at each VAV box in the variable air volume air conditioning system to collect the temperature and flow characteristic data in real time. At the same time, through the design drawings, on-site surveys, or automatic topology discovery algorithms, obtain the pipe connection relationships and air flow directions between the VAV boxes, providing a comprehensive and accurate data basis for subsequent analysis. Change the situation where traditional control lacks system-wide information and lay a data foundation for realizing multi-region collaborative control. Comprehensive data collection enables the system to understand the operating status of each VAV box and the overall topology of the system, avoiding the disorderly regulation problems in the independent control mode caused by information loss and providing the possibility for subsequent precise analysis and collaborative control.

[0040] Step 2: According to the pipe connection relationships and air flow directions 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:

[0041] Take each VAV box as a node, and according to the air flow direction and pipe connection relationships, connect the nodes with directed edges. Connect each node with directed edges according to the pipe connection relationships and air flow directions between each VAV box, and then construct the connection structure diagram of the variable air volume air conditioning system. The direction of the directed edge represents the air flow direction, pointing from the source node of the air flow to the node receiving the supplied air;

[0042] For example, if the air flow passes through a section of pipe from VAV1 to VAV2, then add a directed edge from VAV1 to VAV2 in the diagram, which clearly defines the upstream and downstream relationships between the nodes. If the air flow goes from VAV2 to VAV3, then add another directed edge from VAV2 to VAV3;

[0043] According to the obtained pipeline connection relationship and air flow direction, taking the VAV box as a node, using directed edges to connect the nodes to construct a connection structure diagram, clearly presenting the system topology structure, visually showing the air flow direction and connection relationship between each VAV box, breaking through the limitation of the traditional independent control without the understanding of the association between regions. Through the visual connection structure diagram, the system can grasp the upstream and downstream relationships between each VAV box from the overall level. This helps to avoid the problem of total air volume scrambling caused by the lack of understanding of the mutual relationship when there are changes in the air supply demand in multiple regions simultaneously, and provides an intuitive structural model for subsequent analysis of the importance of nodes and coordinated regulation.

[0044] Step 3: According to the connection relationships respectively corresponding to each node in the variable air volume air conditioning system connection structure diagram, obtain the number of upstream nodes and the number of downstream nodes respectively corresponding to each node, and at the same time obtain the lengths of the directed edges between each node and its corresponding downstream nodes. According to the number of upstream nodes, the number of downstream nodes of each node, and the lengths of the directed edges with each downstream node, analyze and obtain the connection degrees respectively corresponding to each node in the variable air volume air conditioning system. The specific method is as follows:

[0045] Among them, the upstream node refers to the air flow source node, that is, the starting point of the directed edge, and the downstream node refers to the node supplied with air flow, that is, the end point of the directed edge;

[0046] Identify the number of upstream nodes AAn (the number of air flow source nodes) and the number of downstream nodes ABn (the number of nodes supplied with air flow) respectively corresponding to each node, where n refers to the different nodes respectively corresponding in the variable air volume air conditioning system connection structure diagram, and at the same time it is also used as the node number respectively corresponding to 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;

[0047] Take the lengths of the connecting pipelines respectively corresponding to each directed edge as the lengths respectively corresponding to each directed edge, and then obtain the lengths of the directed edges between each node and its corresponding downstream nodes. Take the total length of the directed edge lengths of each node as the connection length LBn respectively corresponding to each node;

[0048] It should be noted that the specific method for obtaining the lengths of the connecting pipelines respectively corresponding to each directed edge is to obtain them through the variable air volume air conditioning system design drawings or on-site surveys, which is an existing and mature technology, so no further elaboration will be made here;

[0049] Statistically count the number of upstream nodes AAn, the number of downstream nodes ABn for each node, and the connection side length LBn corresponding to each node. Through the formula: Jn = AAn×α + 1 / ABn×β + LBn×γ, calculate the connection degree J corresponding to each node in the variable air volume air conditioning system, where α, β, and γ are all preset weight coefficients, and the specific values are set by relevant personnel according to the actual situation, satisfying 1 = α + β + γ and γ > β > α;

[0050] The richness of the air flow source is reflected by the number of upstream nodes, the influence range on subsequent nodes is reflected by the number of downstream nodes, and the air flow transmission distance is considered by the connection side length. The influence of different parameters on the connection degree is highlighted through preset weight coefficients. Quantify the importance of each node in the system and change the defect that traditional control cannot measure the influence of nodes. When adjusting the system, it is possible to judge which node adjustments have a greater impact on the overall system according to the connection degree, and give priority to adjusting key nodes to avoid system instability caused by blind adjustment. At the same time, when increasing the air supply demand in multiple areas simultaneously, the air volume can be reasonably distributed according to the connection degree to prevent the total air supply capacity from being exhausted and the static pressure of the main air supply duct from dropping excessively.

[0051] Step 4: Establish a two-dimensional coordinate system in the connection structure diagram of the variable air volume air conditioning system to obtain the node coordinates corresponding to each node. According to the coordinates of each downstream node corresponding to each node, obtain the influence range 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:

[0052] Establish a two-dimensional coordinate system 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. Randomly select one node from each node without replacement as the target node, and mark the coordinates of each downstream node corresponding to the target node as Eq (EXq, EYq), where q refers to different downstream nodes corresponding to the target node, q = 1, 2,..., e, and e refers to the total number of downstream nodes corresponding to the target node. e is a positive integer. When e takes values from 0 to 2, the influence range F1 corresponding to the target node is taken as 0;

[0053] When e takes values greater than 2, then connect the downstream nodes in a closed manner to obtain the influence surface corresponding to the target node. According to the coordinates of each downstream node Ee (EXe, EYe) corresponding to the target node, calculate the area of the influence surface corresponding to the target node and take it as the influence range F1 corresponding to the target node;

[0054] The specific calculation method for obtaining the influence range F1 corresponding to the target node is as follows:

[0055] Through the shoelace formula: F1 = 1 / 2|(EX1×EY2 - EY1×EX2) + (EX2×EY3 - EY2×EX3) + …… + (EXe×EY1 - EYe×EX1)|, calculate the influence surface area corresponding to the target node, that is, the influence range F1 corresponding to the target node;

[0056] Using the same calculation method, calculate the coordinates of each downstream node corresponding to each node respectively, and then obtain the influence range Fn corresponding to each node;

[0057] Take the ratio between the connection side length LBn corresponding to each node and the number of downstream nodes ABn as the influence propagation path Gn corresponding to each node, that is, Gn = LBn / ABn;

[0058] Through the formula: YLn = Fn×θ1 + 1 / Gn×θ2, calculate the downstream dependence coefficient YLn corresponding to each node, where 1 = θ1 + θ2, and θ1 > θ2;

[0059] By calculating the downstream dependence coefficient, evaluate the influence degree and dependence relationship of the node on the downstream node. Accurately evaluate the influence of each node on the downstream, and make up for the deficiency of the traditional control lacking the upstream and downstream dependence analysis. When the system is adjusted, it can fully consider the chain reaction of the node adjustment on the air supply of the downstream node, avoid the insufficient air supply or overcooling in some areas caused by the adjustment of a single node affecting multiple downstream nodes, improve the accuracy and coordination of the system adjustment, and ensure the comfort of each area.

[0060] Step Five: Obtain the real-time room temperature deviation values corresponding to each node in real time. Mark the nodes with real-time room temperature deviation values greater than the preset temperature difference Y2 as game nodes. According to the preset time interval T, continuously obtain and analyze the FFT peak frequency offset amounts corresponding to each game node three times, and then obtain the turbulence index corresponding to each game node. The specific method is as follows:

[0061] The specific value of the preset time interval T is 10S;

[0062] The real-time room temperature deviation value refers to the difference between the actual indoor temperature at each node and the set temperature of the area. It is obtained by real-time collection through the temperature sensors deployed at the VAV boxes corresponding to each node. The real-time room temperature deviation value is the most direct index to measure 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 of the temperature in the control area of the corresponding VAV box from the set value, and the more urgent the demand for air supply adjustment of the VAV box. Therefore, when calculating the adjustment priority value, the weight corresponding to its VAV box is usually higher;

[0063] Take the mean value of the FFT peak frequency offsets corresponding to three consecutive times at each game node as the turbulence index Mr corresponding to each game node, where r represents different game nodes;

[0064] By real-time monitoring the real-time room temperature deviation values of each node, mark the nodes with a temperature difference greater than the preset temperature difference as game nodes. Continuously obtain the FFT peak frequency offsets of the game nodes three times at intervals of 10S and take the mean value as the turbulence index to reflect the turbulence state in the pipeline. Enhance the system's perception ability of the airflow state change and solve the problem of weak perception ability of the traditional system. By obtaining the turbulence index, the system can timely detect abnormal changes in the airflow in the pipeline, such as valve cavitation problems that may be caused by increased turbulence, and take measures in advance for adjustment to avoid affecting the air supply efficiency and equipment life of the downstream VAV box due to airflow problems. At the same time, when the air supply demand increases simultaneously in multiple regions, the air volume distribution can be reasonably adjusted according to the turbulence index to maintain the stability of the system.

[0065] Step six, obtain the real-time room temperature deviation values and air volume demand values corresponding to each game node respectively. According to the real-time room temperature deviation values, air volume demand values, connection degrees, downstream dependence coefficients and turbulence indices corresponding to each game node respectively, calculate and obtain the adjustment priority values corresponding to each game node. The specific method is as follows;

[0066] For the real-time room temperature deviation value Wr, air volume demand value Qr, connection degree Jr, downstream dependence coefficient YLr and turbulence index Mr corresponding to each game node respectively, calculate the adjustment priority value Xr corresponding to each game node through the formula: Xr = Wr×ω1 + Qr×ω2 + YLr×ω3 - Mr×ω4;

[0067] Where ω1, ω2, ω3 and ω4 all represent preset weight coefficients, and the specific values are determined by relevant personnel, satisfying 1 = ω1 + ω2 + ω3 + ω4;

[0068] By comprehensively considering multiple parameters to determine the adjustment priority values of each game node, scientifically and reasonably determine the adjustment priority level, and change the disordered adjustment situation of traditional control. When the system is adjusted, preferentially adjust the VAV box that has a greater impact on the system and obvious temperature deviation, avoid frequent and disordered adjustment of the VAV box, reduce the drastic fluctuation of the static pressure of the main air supply duct, reduce the energy consumption and noise of the AHU fan, and at the same time improve the adjustment accuracy and response speed of the system to better meet the comfort requirements of each region.

[0069] Step 7: Calculate the ratio of the adjustment priority value Xr corresponding to each game node to the total 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. Multiply the adjustment priority coefficient corresponding to each game node by the total available air volume of the system as the adjustment air volume share corresponding to each game node. The specific method is as follows:

[0070] Take the ratio of the adjustment priority value Xr corresponding to each game node to the total sum of the adjustment priority values of all game nodes as the adjustment priority coefficient corresponding to each game node. Through: adjustment air volume share = adjustment priority coefficient × total available air volume of the system, calculate the adjustment air volume share corresponding to each game node. Sort all game nodes in descending order according to the calculated adjustment priority value Xr, and adjust the air volume of each game node accordingly according to the sorting order based on the adjustment air volume share corresponding to each game node;

[0071] By calculating the ratio of the adjustment priority value of each game node to the total sum of the adjustment priority values of all game nodes, obtain the adjustment priority coefficient; multiply the adjustment priority coefficient by the total available air volume of the system to obtain the adjustment air volume share; sort in descending order according to the adjustment priority value, and accurately adjust the air volume of each game node according to the adjustment air volume share. Realize the reasonable distribution of air volume and the local optimization control of the system, and solve the problem of unreasonable air volume distribution in traditional control when the demand in multiple regions changes. When there is a simultaneous air supply demand in multiple regions, distribute the air volume according to the adjustment priority value and air volume share of each node, avoid the scramble for the total air volume, meet the personalized needs of different regions, improve the overall energy efficiency of the system, reduce the operating cost, maintain the stability of the system at the same time, and improve the overall comfort level.

[0072] First, obtain the operation status data of each VAV box and the system topology information of the variable air volume air conditioning system through comprehensive data collection, and construct a connection structure diagram to intuitively display the system structure. Then, quantify the importance of each node in the system and its influence relationship on the downstream by calculating the connection degree and the number of downstream dependencies, and calculate the adjustment priority value 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, accurately adjust the air volume of each VAV box according to the adjustment priority value and air volume share to achieve the local monitoring and control of the system. The whole process comprehensively considers the air flow topology structure, upstream and downstream dependency relationship and real-time operation status of the system, and forms a closed-loop collaborative control system;

[0073] While changing the disorderly regulation in the traditional independent control mode, by comprehensively analyzing the system structure and operating status, when there are changes in the air supply demand in multiple regions simultaneously, it avoids the competition for the total air volume and excessive fluctuations in the static pressure of the main air supply duct, and maintains the stable operation of the system. It accurately evaluates the impact of each node on the downstream, preferentially adjusts the VAV boxes with a large impact on the system and obvious temperature deviation, avoids overcooling or insufficient air supply in some regions, effectively improves the overall comfort of the indoor environment, strengthens the perception of changes in the air flow state, timely discovers potential problems and makes adjustments, simultaneously realizes the coordinated control of multiple regions, uniformly schedules the air volume, improves the overall efficiency and stability of the system, achieves the best balance between energy consumption and comfort at the overall level, and realizes the global coordinated optimization of the VAV system. When the air volume is limited, it preferentially satisfies the high-priority regions to ensure the comfort of the core regions. Dynamically adjusts the AHU static pressure set point, significantly reduces the fan energy consumption and maintains the system stability. Effectively avoids the "air volume competition" between regions and violent fluctuations in static pressure, and improves the overall operation efficiency and reliability.

[0074] The above formulas are all dimensionless and take their numerical values for calculation. The formulas are obtained by collecting a large amount of data for software simulation to get a formula closest to the actual situation. The preset parameters and threshold selection in the formulas are set by those skilled in the art according to the actual situation.

[0075] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

Claims

1. A local monitoring and control method applicable to variable air volume air conditioners, characterized in that, It includes the following steps: Step 1: Construct a connection structure diagram of the variable air volume air conditioning system according to the pipeline connection relationship and air flow direction among various VAV boxes in the variable air volume air conditioning system; Step 2: Analyze the number of upstream nodes, the number of downstream nodes of each node, and the lengths of the directed edges to each downstream node, and obtain the connection degrees corresponding to each node in the variable air volume air conditioning system; Step 3: According to the coordinates of each downstream node of each node, the connection edges of each node, and the number of downstream nodes, 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 dependence coefficients corresponding to each node; Step 4: Mark the nodes with real-time room temperature deviation values greater than the preset temperature difference Y2 among all nodes as game nodes. At the same time, according to the preset time interval T, analyze the FFT peak frequency offset corresponding to each game node continuously three times to obtain the turbulence index corresponding to each game node; Step 5: Obtain the real-time room temperature deviation values and air volume demand values corresponding to each game node. According to the real-time room temperature deviation values, air volume demand values, connection degrees, downstream dependence coefficients, and turbulence indices corresponding to each game node, calculate and obtain the adjustment priority values corresponding to each game node; Step 6: According to the ratio between the adjustment priority value corresponding to each game node and the total sum of the adjustment priority values of all game nodes, and the total available air volume of the system, obtain the adjusted air volume shares corresponding to each game node, and adjust the air volume of each game node.

2. The local monitoring and control method for a variable air volume air conditioner according to claim 1, characterized in that The specific method for constructing the connection structure diagram of the variable air volume air conditioning system is as follows: Take each VAV box as a node. According to the air flow direction and pipeline connection relationship, use directed edges to connect the nodes, and then construct the connection structure diagram of the variable air volume air conditioning system. The direction of the directed edge represents the air flow direction, pointing from the air source node to the node supplied with air.

3. A local monitoring and control method applicable to variable air volume air conditioners according to claim 1, characterized in that, The specific method for analyzing and obtaining the connection degrees corresponding to each node in the variable air volume air conditioning system is as follows: Identify the number of upstream nodes AAn and the number of downstream nodes ABn corresponding to each node, and obtain the connection edge lengths LBn corresponding to each node according to the lengths of the directed edges between each node and its corresponding downstream nodes. Calculate the connection degree J corresponding to each node in the variable air volume air conditioning system through the formula: Jn = AAn×α + 1 / ABn×β + LBn×γ, where 1 = α + β + γ and γ > β > α. n represents different nodes corresponding to the connection structure diagram of the variable air volume air conditioning system, n = 1, 2,..., a. a represents 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.

4. A local monitoring and control method applicable to variable air volume air conditioners according to claim 3, characterized in that, The specific method for obtaining the connection edge lengths corresponding to each node is as follows: Take the connection pipeline lengths corresponding to each directed edge as the directed edge lengths corresponding to each directed edge, and take the total length of the directed edge lengths of each node as the connection edge length LBn corresponding to each node.

5. The local monitoring and control method for a variable air volume air conditioner according to claim 4, characterized in that, The specific method for obtaining the influence range corresponding to each node is as follows: Establish a two-dimensional coordinate system in the connection structure diagram of the variable air volume air conditioning system, obtain the node coordinates Dn (DXn, DYn) corresponding to each node, randomly select one from each node without replacement as the target node, and mark the coordinates of each downstream node corresponding to the target node as Eq (EXq, EYq), where q refers to 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 e ranges from 0 to 2, the influence range F1 corresponding to the target node is taken as 0; when e is greater than 2, the downstream nodes are connected in a closed manner 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, through the formula: F1 = 1 / 2|(EX1×EY2 - EY1×EX2) + (EX2×EY3 - EY2×EX3) +... + (EXe×EY1 - Eye×EX1)|, calculate the area of the influence surface corresponding to the target node and take it as the influence range F1 corresponding to the target node; using the same calculation method, calculate the coordinates of each downstream node corresponding to each node respectively, and then obtain the influence range Fn corresponding to each node.

6. The local monitoring and control method for a variable air volume air conditioner according to claim 5, wherein, The specific method for obtaining the influence propagation path corresponding to each node is as follows: Take the ratio between the connection side length corresponding to each node and the number of downstream nodes as the influence propagation path Gn corresponding to each node.

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

8. A local monitoring and control method for a variable air volume air conditioner according to claim 7, characterized in that The specific method for obtaining the turbulence index corresponding to each game node is as follows: Take the mean value of the FFT peak frequency offset corresponding to each game node three times in a row as the turbulence index Mr corresponding to each game node, where r refers to different game nodes.

9. The local monitoring and control method for a variable air volume air conditioner according to claim 8, characterized in that, The specific method for obtaining the adjustment priority value corresponding to each game node is as follows: The real-time room temperature deviation value Wr, air volume demand value Qr, connection degree Jr, downstream dependence coefficient YLr, and turbulence index Mr corresponding to each game node, through the formula: Xr = Wr×ω1 + Qr×ω2 + YLr×ω3 - Mr×ω4; calculate the adjustment priority value Xr corresponding to each game node, where ω1, ω2, ω3, and ω4 are all preset weight coefficients, satisfying 1 = ω1 + ω2 + ω3 + ω4.

10. A local monitoring and control method applicable to variable air volume air conditioners according to claim 9, characterized in that, The specific method for obtaining the adjusted air volume share corresponding to each game node is as follows: Take the ratio of the adjustment priority value corresponding to each game node to the sum of the adjustment priority values of all game nodes as the adjustment priority coefficient corresponding to each game node. Multiply the adjustment priority coefficient corresponding to each game node by the total available air volume of the system as the adjustment air volume share corresponding to each game node. Sort all game nodes in descending order according to the corresponding adjustment priority value Xr, and adjust the air volume of each game node according to the adjustment air volume share corresponding to each game node in the sorting order.

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