Energy-saving monitoring system for recycling waste heat of shaft furnace

Abstract

The invention relates to the technical field of waste heat utilization, in particular to an energy-saving monitoring system for waste heat recycling of a shaft furnace, which comprises a waste heat network building module for acquiring waste heat information of the shaft furnace and pipeline information and building a waste heat circulating network; the region segmentation module is used for carrying out region segmentation according to the waste heat circulation network, carrying out thermal distribution analysis on the circulation volume, the heating area and the heating point of each region on the waste heat circulation network, and obtaining thermal distribution characteristics and thermal field change values; the thermal field analysis module is used for carrying out demand analysis on each node of the waste heat circulation network, identifying the thermal disturbance quantity of each node relative to an adjacent heating point by utilizing the thermal distribution characteristics and the thermal field change value, and determining the shortest connection path of the waste heat circulation network under the thermal disturbance quantity; the node feedback module is used for performing node feedback on each node of the waste heat circulation network and determining a node feedback mode of each node; and the waste heat utilization efficiency and safety are improved.

Description

Technical Field

[0001] The invention relates to the technical field of waste heat utilization, and in particular to an energy-saving monitoring system for recycling waste heat from a shaft furnace. Background Art

[0002] As the core equipment in the metallurgical and chemical industries, the vertical furnace will generate a large amount of waste heat resources such as high-temperature exhaust gas and cooling water during its operation. Traditional waste heat recovery systems usually use simple heat exchangers and pipeline networks for heat recovery, but there are the following technical bottlenecks: Network staticization: The waste heat pipeline network is based on a fixed topology design and cannot be dynamically adjusted according to heat source fluctuations and changes in heating demand, resulting in uneven distribution or waste of heat energy. Extensive thermal field analysis: Relying on manual experience or offline models to estimate thermal distribution, it is difficult to capture thermal disturbances between nodes in real time, and local overload or insufficient heating is prone to occur. Feedback control lag: Adjustment relies on a single parameter threshold (such as temperature over-limit alarm), lacks a multi-node collaborative optimization mechanism, has a slow response speed and high energy consumption. Inefficient cascade utilization: Waste heat resources are not graded according to the temperature gradient, and high-temperature waste heat is directly used in low-grade demand scenarios (such as antifreeze), resulting in energy quality waste.

[0003] For example, Chinese patent publication number CN112066742A discloses a method for optimizing the utilization of waste heat and power generation of glass kiln flue gas waste heat power generation, including the following steps: a. calculating the steam production of the waste heat boiler, b. calculating the pressure loss and temperature loss of feed water and steam, c. calculating the power generation of the steam turbine, d. judging whether the power generation power of the steam turbine is the maximum value, if it is the maximum value, outputting the waste heat boiler result parameters, the steam turbine result parameters, and the pipeline result parameters; if it is not the maximum value, adjusting the set steam turbine inlet steam pressure and repeating steps a, b, and c.

[0004] For example, Chinese patent publication No. CN114593612A discloses a high-efficiency recovery system for low-temperature waste heat of a furnace, including a flue gas heat exchanger, a waste heat boiler and a combustion-supporting heat exchanger. The flue gas heat exchanger is a main heat exchanger for producing high-temperature combustion-supporting air; the waste heat boiler is an auxiliary heat exchanger for producing low-pressure steam; the combustion-supporting heat exchanger is used for medium and low temperature waste heat recovery; the flue gas heat exchanger and the waste heat boiler are connected in series in the high-temperature flue in sequence, and the three sets of heat exchangers are each provided with two input ports A1 to A6 and two output ports B1 to B6. The flue gas heat exchanger is provided with a high-temperature flue gas input port and a combustion-supporting air input port. Medium and low temperature dry hot air is input into the combustion-supporting air input port instead of the original natural air, thereby increasing the flue gas temperature and the combustion-supporting air temperature at the heat exchanger outlet, and further increasing the steam output of the waste heat boiler.

[0005] The prior art shows that heating analysis can be performed by comparing expected temperatures, and waste heat heating can be achieved through heat exchangers and combustion-supporting devices. However, in the scenario of waste heat recycling, it is also necessary to describe the distribution and feedback of the overall network so that the waste heat cycle can be controlled one by one in a gradient manner, thereby improving the control of thermal energy distribution. Summary of the invention

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: an energy-saving monitoring system for the recycling of waste heat from a vertical furnace, comprising: a waste heat network building module, which is used to obtain waste heat information and pipeline information of the vertical furnace, identify the node type, waste heat level, node weight and waste heat fluctuation path of each node corresponding to the waste heat information and pipeline information, and build a waste heat circulation network.

[0007] The regional segmentation module is used to perform regional segmentation according to the waste heat circulation network, identify the circulation volume, heating area and heating point of each area on the waste heat circulation network, perform thermal distribution analysis based on the circulation volume, heating area and heating point of each area, and obtain thermal distribution characteristics and thermal field change values.

[0008] The thermal field analysis module is used to perform demand analysis on each node of the waste heat circulation network, identify the thermal disturbance of each node relative to the adjacent heating point by using the thermal distribution characteristics and thermal field change values, and determine the shortest connection path of the waste heat circulation network under the thermal disturbance.

[0009] The node feedback module is used to perform node feedback on each node of the waste heat circulation network according to the shortest connection path of the waste heat circulation network under the thermal disturbance amount, and determine the node feedback mode of each node.

[0010] The beneficial effects of the present invention are as follows: 1. The present invention constructs an adaptively adjustable waste heat circulation network by using dynamic topological modeling of node types, waste heat levels, weights and fluctuation paths; identifies thermal distribution characteristics and changing trends through thermal unit division, circulation volume-heating demand matching and thermal field sequence feature extraction, and adaptively matches the thermal distribution characteristics with the divided waste heat levels to determine the changes in its thermal distribution form when the data represented by the waste heat levels changes, so that the problem of insufficient data acquisition of different nodes during overall waste heat distribution is solved, and real-time optimization of waste heat paths is achieved, thereby improving the efficiency of heat energy transmission.

[0011] 2. The present invention associates the thermal distribution with the fluctuation path, identifies whether the waste heat level at the position adjacent to the fluctuation path will be affected by it, and actively adjusts the waste heat level, which can provide a data basis for dynamic control, solve the problem of incomplete data processing of nodes near the fluctuation path when waste heat heating fluctuates, and respond to the fluctuation of waste heat in a timely manner. After that, by identifying the disturbance amount between each node, using the associated area and the same trend part on the adjacent heating points to quantify the disturbance amount existing in the adjacent heating points when the waste heat circulation network is implemented, it can avoid the spread of local disturbance, reduce the energy loss of the pipe network, and improve the stability of the system.

[0012] 3. The present invention uses the thermal disturbance as the weight of the subsequent path setting to dynamically plan the shortest connection path when there is a disturbance between adjacent heating points, thereby improving the adaptability and tolerance of the overall network to waste heat disturbances; finally, based on the obtained shortest connection path, the nodes on the shortest connection path are screened, and the node control method matching the database is selected to complete the closed-loop control of the waste heat circulation network, thereby realizing the coordinated optimization and common response of multiple nodes in the waste heat circulation network, and improving the safety and efficiency of the waste heat circulation network. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0014] Figure 1 The present invention is a system framework diagram of an energy-saving monitoring system for recycling waste heat from a vertical furnace.

[0015] Figure 2 The present invention is a flow chart of a regional segmentation module of an energy-saving monitoring system for recycling waste heat of a shaft furnace.

[0016] Figure 3 The present invention is a flow chart of a thermal field analysis module of an energy-saving monitoring system for recycling waste heat from a shaft furnace. DETAILED DESCRIPTION

[0017] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in the art or the product specifications are used.

[0018] See also Figure 1 An energy-saving monitoring system for recycling waste heat from a vertical furnace includes: a waste heat network building module, a regional segmentation module, a thermal field analysis module and a node feedback module. The output end of the waste heat network building module is connected to the regional segmentation module, the output end of the regional segmentation module is connected to the thermal field analysis module, and the output end of the thermal field analysis module is connected to the node feedback module.

[0019] The waste heat network building module is used to obtain the waste heat information and pipeline information of the vertical furnace, identify the node type, waste heat level, node weight and waste heat fluctuation path of each node corresponding to the waste heat information and pipeline information, and build a waste heat circulation network.

[0020] The regional segmentation module is used to perform regional segmentation according to the waste heat circulation network, identify the circulation volume, heating area and heating point of each area on the waste heat circulation network, perform thermal distribution analysis based on the circulation volume, heating area and heating point of each area, and obtain thermal distribution characteristics and thermal field change values.

[0021] The thermal field analysis module is used to perform demand analysis on each node of the waste heat circulation network, identify the thermal disturbance of each node relative to the adjacent heating point by using the thermal distribution characteristics and thermal field change values, and determine the shortest connection path of the waste heat circulation network under the thermal disturbance.

[0022] The node feedback module is used to perform node feedback on each node of the waste heat circulation network according to the shortest connection path of the waste heat circulation network under the thermal disturbance amount, and determine the node feedback mode of each node.

[0023] In one embodiment of the present invention, when building a waste heat circulation network, in addition to obtaining waste heat information and pipeline information, it is also necessary to determine the total amount of waste heat available and the waste heat ratio, combine these existing data, and use the data points represented by each data as part of this waste heat circulation network. Then, the entire network is combined to obtain the subsequent effect of judging the current vertical furnace waste heat circulation utilization.

[0024] In the scenario of recycling waste heat from a vertical furnace, the present invention will use pipelines to recycle the saturated steam generated by the vertical furnace during the production process, connect the saturated steam to pipelines of different diameters, and then set heating points and heating areas to recycle the hot air. At this time, the outer diameters of the pipelines set at different heating nodes will also be different. At this time, it is necessary to monitor the flow rate, pressure, temperature, and corresponding heating area to determine the situation and effect of the waste heat recycling.

[0025] Waste heat information includes furnace temperature data, steam flow, steam pressure, and steam temperature; furnace temperature data is a key indicator for monitoring the generation of waste heat from vertical furnaces, and can reflect the heat release during the production process of vertical furnaces; steam flow can help us understand the specific scale and availability of waste heat from vertical furnaces; steam pressure is an important indicator for measuring the energy state of steam, and plays a key role in determining waste heat recovery efficiency and equipment selection; steam temperature reflects the specific temperature level of waste heat from vertical furnaces, and is an important basis for evaluating waste heat quality and determining recovery methods; equipment status includes parameters such as the working status, pressure, and temperature of recovery equipment such as waste heat boilers and heat exchangers, which are used to monitor equipment performance and detect faults in a timely manner.

[0026] Pipeline information includes pipeline flow, pipeline pressure, pipeline temperature and pipeline specifications; Pipeline flow: monitor the flow of saturated steam in the pipeline through flowmeters and other equipment to understand the scale of waste heat transmission. Pipeline pressure: measure the pressure of steam in the pipeline to evaluate the energy state and transmission efficiency of steam. Pipeline temperature: monitor the temperature of steam in the pipeline to reflect the quality of waste heat and heat loss during transmission. Pipeline specifications refer to the outer diameter and length of the pipeline itself to determine the flow and pressure that can pass through the pipeline.

[0027] When these acquired data are subsequently processed, the current system will be controlled and adjusted based on the temperature, pressure, flow rate, and status at different locations contained in these two types of information to choose how to recycle the waste heat energy.

[0028] Compared with the existing technology for heat control, the waste heat circulation network is more inclined to the correlation between the nodes existing on each network and the overall network during the processing process, and considers that when multiple nodes are normal, the setting of the overall network is completed to reduce the large fluctuations in the vertical furnace waste heat heating and the problem of being easily affected by the vertical furnace production.

[0029] Therefore, the implementation method of the waste heat network building module also includes: identifying the connection relationship between each node corresponding to the waste heat information and pipeline information to form an initial connection relationship diagram; deploying the node type, waste heat level, node weight and waste heat fluctuation path of each node to the initial connection relationship diagram to obtain a waste heat circulation network. The implementation method of deploying to the initial connection relationship diagram is to mark the nodes on the initial connection relationship diagram with the data corresponding to the node type, waste heat ladder, node weight and waste heat fluctuation path. For example, when selecting the node type to observe the waste heat circulation network, the distribution of related nodes in the waste heat circulation network can be directly observed; selecting the waste heat ladder to observe the waste heat circulation network will mark the values ​​on different nodes with colors, so that the overall distribution display of different value ranges is presented; the node weight can be used to find out which parts of the nodes in the current waste heat circulation network are relatively important through the set related tables. Finally, the waste heat fluctuation path shows a group of paths with large fluctuations in the current waste heat circulation network. This path will contain multiple nodes, which may be unstable nodes. Later, it is necessary to identify the impact of these nodes on surrounding nodes, or mark the surrounding nodes to reduce the instability of the waste heat circulation network during operation.

[0030] It should be noted that the nodes corresponding to the waste heat information and pipeline information are the same entity as the nodes in the waste heat circulation network. After identification, the nodes corresponding to the waste heat information and pipeline information are marked with multiple labels as nodes used in the subsequent waste heat circulation network.

[0031] The node types of each node corresponding to the waste heat information and pipeline information include: heat source node, heat exchanger node, flow regulation node, temperature and pressure monitoring node and heating point. At the same time, the node type of each node includes the specific attributes of these nodes and also includes the pipeline information existing on these nodes, such as pipeline flow, pipeline pressure, pipeline temperature and pipeline specifications, so as to use the nodes corresponding to the waste heat information and pipeline information to obtain the initial connection relationship diagram.

[0032] Heat source nodes represent locations where waste heat is generated, such as exhaust gas outlets in industrial processes, cooling water discharges in power plants, etc. These nodes are the energetic starting points of the waste heat cycle network.

[0033] Heat exchanger nodes are nodes where high temperature waste heat is converted into a form more suitable for transport, such as steam or hot water. These nodes are key to converting waste heat in its raw form into usable energy.

[0034] Flow regulation nodes include valves and pumping stations, which are used to adjust the flow rate of fluid, usually water or steam, to ensure that heat can be distributed to different heating points according to demand.

[0035] The temperature and pressure monitoring node monitors the temperature and pressure of the medium in real time by installing sensors to ensure that the system operates within a safe range and provide data support for optimizing heat distribution.

[0036] Heating points are where heat is ultimately consumed, such as residential areas, office buildings or other spaces that require heating. Through the work of the above nodes, heat is transported to these locations to meet heating needs.

[0037] In one implementation scenario, the present invention will use a Ф108 diameter pipe as the main pipe, and then set Ф80, Ф50, and Ф40 diameter pipes for connection according to the location of the waste heat circulation network, and then use a Ф133 diameter pipe for the heating point, and a Ф25 diameter pipe can also be used to perform antifreeze, heating, and other treatments on the equipment.

[0038] The waste heat ladder indicates the step of the waste heat cycle processing at which the corresponding node is, that is, the waste heat ladder is divided according to the operating status, waste heat utilization load, waste heat storage balance and the utilization relationship between each node. The level at which the current node is located is divided, and the waste heat is utilized step by step according to the ladder level to ensure that the generated waste heat can be fully utilized.

[0039] The implementation method of identifying the waste heat level of each node corresponding to the waste heat information and pipeline information is: obtaining the temperature, pressure and flow of each node, verifying the temperature, pressure and flow of each node, and marking the operation status label of each node.

[0040] The waste heat utilization load of each node is calculated using the flow and temperature change values ​​of each node and marked as the waste heat utilization load label.

[0041] Record the storage capacity, release capacity and storage efficiency of waste heat utilization at each node under the corresponding temperature, pressure and flow rate, and mark them as the waste heat storage balance label of the corresponding node.

[0042] The corresponding paths of traffic distribution and energy transfer of each node are recorded as the utilization relationship labels between the nodes.

[0043] The operation status label of each node, the waste heat utilization load label, the waste heat storage balance label and the utilization relationship label between each node are used as the output waste heat ladder.

[0044] The operating status refers to the real-time working conditions of each node and device in the waste heat circulation network. In the waste heat cascade utilization system, the operating status of each node directly affects the recovery and utilization efficiency of waste heat resources. For example, when the equipment of a node fails or the efficiency decreases, the waste heat recovery of the node will decrease, which will in turn affect the waste heat utilization effect of the entire system. Therefore, it is necessary to monitor the operating status of each node in real time, discover and solve problems in a timely manner, so as to ensure the stable operation of the system and the efficient use of waste heat resources. The operating status here will be marked according to the temperature, pressure and flow on each node to determine whether it is operating normally and whether the temperature, pressure and flow on the current node are normal values.

[0045] Waste heat utilization load refers to the demand for waste heat resources at each node in the waste heat circulation network. Different nodes have different demands for waste heat resources due to differences in production processes, equipment types, working environments and other factors. Therefore, in the waste heat cascade utilization system, it is necessary to reasonably allocate waste heat resources according to the waste heat utilization load of each node to maximize the utilization of waste heat. At the same time, it is also necessary to consider the changes in load and adjust the waste heat utilization strategy in time to adapt to changes in production demand. The waste heat utilization load will be marked according to the product of the flow rate, specific heat capacity and temperature change value during waste heat utilization to determine the load on the corresponding node at this time, and this value will be marked to facilitate subsequent adjustments to the waste heat circulation network.

[0046] Waste heat storage balance refers to the balance between the storage and utilization of waste heat resources in the waste heat circulation network. Since there is often a time mismatch between the generation and utilization of waste heat resources, it is necessary to set up waste heat storage facilities to balance the supply and demand of waste heat resources. By reasonably adjusting the storage and release strategies of waste heat storage facilities, it can be ensured that waste heat resources are stored in time when they are sufficient, and released in time when demand increases, thereby achieving balanced utilization of waste heat. Waste heat storage balance can be described according to the corresponding storage capacity, release capacity and storage efficiency of waste heat to indicate how the current waste heat is used in the cycle, and the real-time storage capacity, release capacity and storage efficiency are marked as the waste heat storage balance identified at this time.

[0047] The utilization relationship between nodes refers to the mutual correlation and influence of each node in the waste heat circulation network during the waste heat utilization process. In the waste heat cascade utilization system, each node is connected to each other through facilities such as heat exchangers and pipelines to form a complex network structure. The waste heat utilization of each node will have an impact on other nodes. Therefore, it is necessary to comprehensively consider the utilization relationship between each node and formulate a reasonable waste heat utilization strategy. The utilization relationship between nodes here refers to the path corresponding to each node in the flow distribution and energy transfer during the current waste heat distribution, to indicate whether the current node is related to other paths during flow distribution and energy transfer, and mark the relevant nodes to obtain the utilization relationship between the nodes at this time.

[0048] The node weight only considers the weight of each node in the waste heat circulation network in the entire network. The relative importance will be set according to its type first, and then a weight will be set for the position and specific function of each node under this type to represent the weight of this node in the waste heat circulation network. The waste heat fluctuation path queries the nodes in the waste heat circulation network that are prone to large fluctuations in heat supply, and connects these nodes as the waste heat fluctuation path identified at this time; at the same time, the waste heat fluctuation path will record the location of the heat exchange area and flow control device on the waste heat fluctuation path to determine whether this waste heat fluctuation path can be adjusted and utilized.

[0049] For example, the node weights are shown in Table 1.

[0050] Table 1 Node weight priority

[0051]

[0052] In this case, the node weight can also be adjusted by location, function and service scale to illustrate the functions represented by each node in the current waste heat circulation network, as well as the content form required by each node to achieve mutual communication.

[0053] For example, according to the location, the node weight on the trunk pipeline is +0.1, such as the Ф108 / Ф133 main pipeline; the node weight on the branch pipeline is -0.05, such as the Ф50 / Ф40 branch line.

[0054] Or use the function to set the node weight of the pipeline with partial redundancy -0.1, such as parallel pumping stations and dual backup sensors; these parts are used as emergencies or in other forms, and small weights will be set for these parts in judging the overall waste heat circulation network, because this part is unlikely to affect the normal operation of the entire waste heat circulation network.

[0055] The weight of nodes that undertake multi-path allocation functions is +0.15, such as a heat exchanger that is connected to more than three heating points at the same time; these parts that are shared by multiple paths need to have their weight increased to prevent problems with waste heat circulation.

[0056] Finally, it can also be based on the scale of service, for example, the node weight for serving large heating points (>1000 households) is +0.2; the node weight for serving small heating points (<100 households) is -0.1. This is mainly reflected in the setting of node weights when the heating area represented by different heating points is large or small. After completing these node settings, the node weight table in the present invention can also be expressed as the content illustrated in Table 2.

[0057] Table 2 Example node weights

[0058]

[0059] This section will show the weights of each node in the waste heat circulation network after it is formed. The subsequent processing will be carried out in the order of weight to complete the corresponding adjustment of the overall pipeline and equipment.

[0060] The waste heat circulation network set up in the above manner can identify the waste heat circulation network according to the representation of data such as temperature, flow, pressure, etc. of the current node, so as to promptly discover possible problems in normal waste heat circulation use, and make adjustments based on these problems to improve the efficiency and safety of waste heat circulation utilization.

[0061] In one embodiment of the present invention, the regional segmentation module mainly segments the waste heat circulation network based on the heat passing through the nodes at each level. For example, it identifies the circulation volume passed by each node in unit time, the heating area and heating points that can be provided to judge the efficiency of waste heat circulation utilization, and analyzes the thermal distribution in these areas to obtain the average temperature, maximum / minimum temperature, temperature gradient, etc., and then compares the data of different time periods and analyzes the changing trend of the thermal field over time to complete the analysis of the thermal distribution.

[0062] The circulation volume refers to the flow rate of the medium passing through the pipeline or position corresponding to the node per unit time and the temperature difference of the medium per unit time, which indicates the speed of waste heat recycling at a single position or node.

[0063] like Figure 2 As shown, the implementation method of the regional segmentation module includes: evenly dividing the waste heat circulation network into multiple regions in the form of thermal transmission, taking the flow rate and temperature difference of the medium in each region per unit time as the identified circulation volume, and marking the positions corresponding to the heating points and heating areas in each region. The form of thermal transmission represents the path of heat conduction in the waste heat circulation network on a macro scale. These paths are evenly divided so that each divided region can contain heating points and heating areas. These regions are then compared and analyzed to identify the correlation at different positions in each region, such as whether the heat source node, heat exchanger node, flow regulation node, temperature and pressure monitoring node, and heating point will coexist in the divided region, and whether these nodes can affect the thermal distribution in this region. This part of the distribution can be used as the thermal distribution feature for subsequent identification, and the resulting impact value can also be regarded as the thermal field change value, which is convenient for subsequent demand analysis and other processing.

[0064] The circulation volume, heating area and heating point corresponding positions of each area are regarded as thermal units, and the thermal units are matched with the waste heat levels to identify the distribution of thermal units under the corresponding waste heat levels. The distribution of thermal units tends to identify the correspondence between these data and the waste heat levels after matching the waste heat levels, to identify what heating method is suitable for the thermal unit under the current waste heat level. If the temperature of the thermal unit under the waste heat level is high and the waste heat utilization load is relatively stable, this thermal unit is suitable for industrial heating or power generation. If the temperature of the thermal unit is low, then the thermal unit can be used for civil heating or hot water supply. This form of matching indicates what heating demand the current thermal unit can be used for. The form of matching thermal units with waste heat levels is to preliminarily classify the thermal units according to their circulation volume, heating area and heating points, identify the corresponding nodes of the preliminarily classified thermal units in the waste heat circulation network, and use the waste heat levels on the corresponding nodes to mark the thermal units, thereby completing the matching of thermal units with waste heat levels.

[0065] According to the distribution of each thermal unit under the waste heat ladder, the thermal distribution sequence corresponding to each thermal unit is set, and the thermal distribution characteristics and thermal field change values ​​are extracted from the thermal distribution sequence in sequence.

[0066] Thermal distribution characteristics refer to the distribution status and characteristics of temperature (or heat energy) in a specific area. This usually involves temperature gradient, heat transfer direction, temperature distribution and other aspects. In the heating system, thermal distribution characteristics can reflect whether the system is heating evenly, whether there are overheated or overcooled areas, and the specific location and range of these areas. Thermal distribution characteristics will mainly consider temperature changes, such as obtaining data such as temperature gradient, heat transfer direction, temperature distribution, etc. These data can intuitively reflect the temperature distribution at the corresponding position.

[0067] The thermal field change value refers to the value of the temperature or heat energy in a certain area changing with time or other factors. It reflects the dynamic characteristics and stability of the thermal field, that is, the temperature field or the thermal energy field. In the heating system, the thermal field change value can be used to evaluate the stability and reliability of the system's heating effect, and whether there are problems such as excessive temperature fluctuations or unstable heating. The thermal field change value identified at this time will record the values ​​that change with time or other factors in different thermal distribution sequences, and record the factors and trend values ​​that the value may correspond to in the event of fluctuations. The thermal field change value takes into account the changes in temperature, pressure, flow, and temperature difference under the overall situation.

[0068] The method of matching the thermal units with the waste heat levels and identifying the distribution of the thermal units under the corresponding waste heat levels also includes: connecting the node types, node weights and waste heat fluctuation paths related to the waste heat levels of each thermal unit, obtaining the node types and node weights corresponding to the current thermal units, and the distance between each thermal unit and the waste heat fluctuation path. The distance between each thermal unit and the waste heat fluctuation path represents the distance between the location of the thermal unit and the path with larger fluctuations in the current waste heat circulation network, so as to determine whether the thermal unit can affect the fluctuations of the waste heat circulation network. This distance will be calculated using the Euclidean distance between each thermal unit and the waste heat fluctuation path. If the thermal unit represents the position of multiple positions or node combinations, the average Euclidean distance of these positions or nodes and the waste heat fluctuation path is represented as the corresponding distance.

[0069] According to the node type and node weight corresponding to each thermal unit, identify whether there is an intermediate node between the thermal unit and the waste heat level. If there is no intermediate node, the node type corresponding to each thermal unit and the waste heat level corresponding to the node weight are set as the waste heat level of each current thermal unit.

[0070] If there is an intermediate node, the waste heat level corresponding to the shortest distance between each thermal unit and the waste heat fluctuation path is set as the waste heat level of each current thermal unit.

[0071] The description of the intermediate node here means that in the area represented by the current thermal unit, if there is a node in the area represented by the current thermal unit, after its type and weight are identified, the thermal unit has two residual heat gradients under this node type and node weight. This intermediate node will be considered to be the point in the middle of the two gradients when the corresponding node type and node weight exist, that is, the point where the gradients intersect. The identification of the intermediate node indicates that the thermal unit is more inclined to identify the changes in residual heat gradients that occur in the same unit, emphasizing the impact of the overall residual heat gradient on the thermal unit's conduction of temperature to the heating point.

[0072] If there is no intermediate node, it means that the entire thermal unit is in the same residual heat gradient, or there is no obvious intersection point in the residual heat gradient. At this time, it is biased to identify the distance between the thermal unit and the residual heat fluctuation path, identify whether the path with large residual heat conduction fluctuation is likely to affect the heat conduction of the thermal unit, and quantify these situations. This information will be subsequently identified as thermal distribution characteristics, which will serve as a reference for subsequent adjustments to the thermal distribution.

[0073] When setting the thermal distribution sequence corresponding to each thermal unit, the circulation volume, heating point and heating area of ​​each thermal unit under the waste heat level are divided into corresponding data, and then sorted to generate the thermal distribution sequence existing on the corresponding thermal unit, and its flow, pressure, temperature and temperature difference are identified as the thermal distribution sequence used at this time; according to the waste heat level corresponding to the thermal distribution sequence, the thermal distribution characteristics and thermal field change values ​​that may exist under the corresponding waste heat level are extracted to identify its position and the change form of thermal distribution under different conditions when the waste heat is utilized.

[0074] The thermal distribution sequence corresponding to each thermal unit is set, and the thermal distribution characteristics and thermal field change values ​​are extracted from the thermal distribution sequence in sequence as follows: the flow, pressure, temperature and temperature difference on each thermal unit are obtained, and the thermal distribution sequence corresponding to each thermal unit is generated in the form of a time series; the generated thermal distribution sequence will contain the values ​​of flow, pressure, temperature and temperature difference at different time points, and the temperature difference means the difference between the temperature flowing in the pipeline and the temperature at the heating point when the thermal unit conducts heat to the heating point; then the flow, pressure, temperature and temperature difference are used as the ordinate on the coordinate system, and the time is used as the abscissa to obtain the thermal distribution sequence.

[0075] The temperature gradient on each thermal unit is calculated, the overlapping proportion of the temperature gradient on each thermal unit in the thermal distribution sequence is identified, and the data corresponding to the overlapping proportion is output as the thermal distribution feature.

[0076] The temperature gradient is expressed as the temperature difference at two different positions on the thermal unit divided by the relative distance. The overlap ratio indicates whether the positions corresponding to these temperature gradients overlap or have large differences under different time conditions. If the overlap ratio is high, it means that the thermal conduction at this location is stable and no adjustment is required. If the overlap ratio is small, it means that this thermal unit may have insufficient heating, or it may be an area that often needs dynamic adjustment. These areas generally need to be checked. In addition to the overlap ratio, the thermal distribution characteristics will also include the corresponding temperature, pressure, flow, temperature difference and corresponding temperature gradient. These data are combined into thermal distribution characteristics to facilitate subsequent demand analysis for this feature and to discover the form that different thermal units need to process. Since the time series form is used at this time, when the temperature gradient is calculated, the temperature gradient change at the corresponding spatial position will be identified according to the time interval in the time series.

[0077] The slope values ​​of flow rate, pressure, temperature and temperature difference in the thermal distribution sequence in the corresponding time period are obtained in sequence, and the difference of the slope values ​​in adjacent time periods is used as the output thermal field change value.

[0078] The thermal field change values ​​tend to be the change values ​​of temperature, pressure, flow and temperature difference, and these change values ​​are marked in the form of the slope value difference of the trend represented by the time series, so as to find out the change trend of the basic data such as temperature, pressure, flow and temperature difference in the thermal unit under the condition of normal waste heat utilization cycle, so as to identify whether the current thermal unit is normal in utilizing waste heat.

[0079] In one embodiment of the present invention, since the nodes in the waste heat circulation network include heating points, when identifying the thermal disturbance amount of each node relative to the adjacent heating point, the connection relationship between each node and the adjacent heating point will be analyzed. For example, a heating point and the adjacent heating point will be analyzed, and the nodes that are not heating points will be analyzed based on the relationship between the adjacent heating points to determine the form in which the waste heat generated by the current vertical furnace is utilized under the influence of different flow rates, temperatures, pressures and waste heat utilization methods, to determine whether the waste heat from the vertical furnace can reach the expected heat, and when the actual heat is less than the expected heat, the value of the disturbance and the distribution. Finally, these situations are analyzed to find a path with the least thermal disturbance to improve the utilization efficiency of the waste heat.

[0080] When conducting demand analysis on each node of the waste heat circulation network, the main focus is on determining the time, temperature and transmission volume used by each node to complete normal heating of the heating point, that is, identifying the demand flow, demand time and demand temperature of each node when completing the heating of the heating point. The demand flow, demand time and demand temperature can be set by recording the average value of normal heating at the node in the historical data. This demand is then matched and analyzed with the thermal distribution characteristics and thermal field change values ​​to identify the relative relationship therebetween, ultimately finding out the bottlenecks and fault points that may occur in the operation of the waste heat circulation network, and proposing improvement measures.

[0081] like Figure 3 As shown, the implementation method of the thermal field analysis module includes: constructing a task scenario for each node in the waste heat circulation network according to the position of each node in the waste heat circulation network; the task scenario at this time represents the working task of each node in the waste heat circulation network under normal circumstances, and then comparing the parameters required in these task scenarios with the current thermal distribution characteristics and thermal field change values ​​to analyze which parts of the thermal distribution characteristics and thermal field change values ​​are subject to thermal disturbance under normal task execution.

[0082] The task scenarios are set up according to the heat source node, heat exchanger node, flow regulation node, temperature and pressure monitoring node and heating point. For example, the heat source node recovers heat from the flue gas waste heat generated by the combustion of the gas turbine to heat the heating circulating water; the heat exchanger node recovers the waste heat in the flue gas through the intermediate water, and then transfers the heat to the hot network water through the heat pump unit; the flow regulation node can maintain the stability of the indoor temperature by reducing and increasing the circulating water volume; when the temperature in the waste heat circulation network is too high or the pressure is too high, the temperature and pressure monitoring node can automatically start the cooling system or the pressure relief device to ensure the safe operation of the system; the heating point is to adjust the heat dissipation to ensure the stability and comfort of the indoor temperature.

[0083] According to the thermal distribution characteristics and thermal field change values ​​covered in the task scenario, a matching analysis is performed on the thermal energy demands of adjacent heating points, and the associated areas between adjacent heating points and the thermal distribution characteristics and the parts with the same trends between adjacent heating points and the thermal field change values ​​are determined in turn.

[0084] At this point, it is explained that the thermal distribution characteristics and thermal field change values ​​covered in the task scenario are essentially the thermal distribution characteristics and thermal field change values ​​identified from each node, and then the heating points connected to these nodes are identified to find out whether the thermal distribution characteristics and thermal field change values ​​on these nodes change under the action of heat conduction. Will it affect the heating points connected to these nodes, resulting in the final output heat energy failing to meet the thermal energy demand, or being able to complement or weaken the adjacent heating points. If the thermal distribution characteristics and thermal field change values ​​are used to identify the adjacent heating points at this time, and it is found that the trends of the adjacent heating points are consistent, the two heating points can be jointly controlled. If the trends are opposite, the heating points at these positions can be marked and differentiated strategies can be adopted.

[0085] Furthermore, the matching analysis of the heat energy demand of adjacent heating points also includes: using the form of spatial correlation analysis to determine the thermal overlap areas corresponding to adjacent heating points in turn, and using the strongly correlated parts in the thermal overlap areas as the association areas between the adjacent heating points and the thermal distribution characteristics; at this time, by comparing the positions corresponding to the temperature gradients and the overlapping proportions of the temperature gradients in the thermal distribution characteristics, it is identified whether there is overlap in the ranges of the two heating points in the waste heat circulation network. At this time, the range of the heating point in the waste heat circulation network can be understood as the path for the waste heat circulation network to control the heating point, and it is identified whether the nodes on this path and the data contained in the nodes overlap; if there is overlap, it may be said It shows that the two heating points share a heat source or part of the path, and then calculate the similarity between the thermal distribution characteristics of adjacent heating points in the thermal overlap area, and regard the position corresponding to the data with the largest similarity value as the associated area; the similarity calculated in this thermal overlap area uses the Pearson correlation coefficient to calculate the temperature, pressure, flow and temperature difference corresponding to the thermal distribution characteristics, and add the Pearson correlation coefficients calculated for several values ​​to get a comprehensive average value. When the comprehensive average value is greater than 0.6, the corresponding thermal overlap area is regarded as strongly correlated, and the corresponding data is used as the associated area between the adjacent heating points and the thermal distribution characteristics to find the associated area between the adjacent heating points and the thermal distribution characteristics at this time.

[0086] Furthermore, the trend of adjacent heating points and thermal field change values ​​is the same by judging whether the growth trend and decrease trend represented by the slope difference of temperature, pressure, flow and temperature difference of each node on the path passed by the adjacent heating points are the same when changing over time; if there are the same parts of the trends represented by temperature, pressure, flow and temperature difference, then identify the data of that part, for example, the growth trend of temperature and pressure of adjacent heating points is the same, and the growth trend of other data is different, and then obtain the data with the same growth trend of temperature and pressure; the way to judge the same trend here is to compare whether the slope difference corresponding to temperature, pressure, flow and temperature difference is the same as positive or negative, and then compare whether the two slope differences are less than 10% of the corresponding reference value. If it is less than and the signs are the same, it can be considered that the trends are the same, otherwise it is considered that they are not the same trend, and the relevant data is marked. The reference value will indicate the maximum value allowed for the slope difference under the same trend. This value will use the maximum slope value of temperature, pressure, flow and temperature difference under normal conditions in historical data minus the minimum slope value as the reference value at this time.

[0087] According to the associated areas and the same trend parts corresponding to the adjacent heating points, the thermal disturbance amount of each node relative to the adjacent heating points is identified; at this time, the thermal disturbance amount of each node relative to the adjacent heating points is identified by calculating the heat flow at the nodes corresponding to the associated areas and the same trend parts, and then identifying the temperature difference between the inlet and outlet of the pipeline positions corresponding to the associated areas and the same trend parts, and finally calculating the percentage value of this disturbance amount and the heat of the heating point to obtain the thermal disturbance amount of each node relative to the adjacent heating points. These disturbance amounts will explain the amount of loss at each node when transmitted to the heating point.

[0088] For heat flow, the temperature difference between the nodes corresponding to the same part of the associated area and trend is multiplied by the area of ​​the medium in the pipeline and the thermal conductivity of the pipeline, and finally divided by the length of the conduction pipeline to obtain the relative heat flow between the corresponding nodes. After that, this heat flow is multiplied by the specific heat capacity and density of the medium in the pipeline, as well as the temperature difference between the inlet and outlet of the pipeline to obtain the final disturbance. When the disturbance is associated with the percentage of temperature change at the heating point, it is mainly in the form of mutual mapping association in the sense of data, rather than directly processing the data.

[0089] Based on the thermal disturbance of each node, each node is connected to obtain the shortest connection path.

[0090] The way to connect at this time is to use the Dijkstra algorithm, identify the parts of the thermal disturbance, use the thermal disturbance as the weight when connecting the shortest path, connect them one by one according to the value of the thermal disturbance, and generate the shortest connection path from the heat source of the waste heat circulation network to each heating point.

[0091] Finally, based on this path, we can find the key path nodes when the waste heat consumption is minimized, and deal with the abnormal points that exist during the waste heat circulation process to improve the bearing capacity and utilization efficiency of the overall waste heat circulation network.

[0092] In one embodiment of the present invention, the node feedback module performs feedback processing on the nodes on the shortest connection path of the waste heat circulation network, extracts the feedback target and feedback logic classification of each node, and obtains the control strategy corresponding to each node to complete the setting of the node feedback mode of each node.

[0093] The feedback target on each node is explained through the situation on the shortest connection path, and the target nodes in the waste heat circulation network are screened out. These target nodes will represent the abnormal points in the overall processing process, or the parts that need to adjust the parameters. These parts will extract relevant content from these parameters according to the parameters that can be adjusted, and then select the possible control strategy for this parameter, and finally complete the feedback control of the node.

[0094] Therefore, the implementation method of the node feedback module includes: extracting feedback targets for each node on the shortest connection path of the waste heat circulation network, determining the feedback logic classification of each feedback target in turn, and setting the control strategy as the output node feedback method according to the number of nodes corresponding to the feedback logic classification.

[0095] The feedback target can be expressed as follows according to the node type: Heat source node: The feedback target may be to maintain a stable waste heat output to ensure that the heat source does not overheat or overcool; Heat exchanger node: The feedback target may be to ensure efficient heat energy conversion while avoiding equipment damage caused by overheating; Flow regulation node: The feedback target may be to adjust the flow according to system requirements to maintain a stable thermal cycle; Temperature and pressure monitoring node: The feedback target may be to monitor the temperature and pressure in real time to ensure that they are within a safe range; Heating point: The feedback target may be to maintain the indoor temperature within a comfortable range while minimizing energy consumption.

[0096] The feedback logic classification will indicate the node type, feedback parameters, and corresponding control strategy of the node, and then this control strategy will be used as the node feedback method used by subsequent nodes; when the feedback target is obtained, each node will be processed according to the value of the thermal disturbance amount, and the thermal disturbance amount will be used as the basic condition. The thermal disturbance amount of each node will be used to calculate with the thermal disturbance amount in the historical data. When the thermal disturbance amount exceeds the preset threshold and the cosine similarity value with the thermal disturbance amount in the historical data is the largest, the feedback parameters and control strategy of the corresponding thermal disturbance amount will be used as the feedback logic classification of the current feedback target. When the thermal disturbance amount exceeds the preset threshold, For example, when the value of the thermal disturbance is greater than 0.05 or 5%, the corresponding node will be marked and the feedback target will be extracted; as for the thermal disturbance greater than 5%, the point with the abnormality is selected, and after the node type and the thermal disturbance of the abnormal point are identified, the data recorded in the database can be used to know what the main parameters that need to be adjusted in the current solution should be, and then the control strategy required for this parameter will be selected, and then the data will be sent to the external control center, and the relevant staff will view this part of the data, and then choose how to adjust the overall process of waste heat heating in the future to improve the efficiency and safety of waste heat heating.

[0097] Furthermore, the control strategy is set according to the number of nodes corresponding to the feedback logic classification; that is, by selecting the number of nodes existing in the data corresponding to the feedback logic classification, the feedback parameters corresponding to different numbers of nodes are extracted, the longest common subsequence of the feedback parameters is obtained, and the control strategy corresponding to the longest common subsequence is used as the control strategy used by each node under the corresponding number of nodes. By extracting the longest common subsequence, the common characteristics of the feedback parameters under different numbers of nodes can be found, so as to formulate a more general and effective control strategy. This strategy can adapt to the changes in the number of different nodes and improve the flexibility and adaptability of the system. At the same time, by extracting the longest common subsequence, the process of formulating the control strategy can be simplified, the overall operating efficiency of the system can be improved, and deviations can be discovered and corrected in a timely manner, thereby enhancing the stability and reliability of the system.

[0098] For example, the feedback logic classification can be described in the form of Table 3.

[0099] Table 3 Feedback logic classification

[0100]

[0101] The above table shows the parameters that need to be fed back and checked when large thermal disturbances occur at different nodes, as well as the content that the corresponding control strategy actually wants to deal with. This part of the content will be sent to the external control center according to the number and related brief description stored in the database, so that the staff can timely control the process and related issues of the waste heat cycle and improve the efficiency and safety of waste heat recycling.

[0102] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention and they are still covered by the protection scope of the present invention.

Claims

1. An energy-saving monitoring system for recycling waste heat from a shaft furnace, characterized in that: include: A waste heat network building module is used to obtain the waste heat information and pipeline information of the shaft furnace, identify the node type, waste heat level, node weight and waste heat fluctuation path of each node corresponding to the waste heat information and pipeline information, and build a waste heat circulation network; The regional segmentation module is used to perform regional segmentation according to the waste heat circulation network, identify the circulation volume, heating area and heating point of each region on the waste heat circulation network, perform thermal distribution analysis according to the circulation volume, heating area and heating point of each region, and obtain thermal distribution characteristics and thermal field change values; The thermal field analysis module is used to perform demand analysis on each node of the waste heat circulation network, identify the thermal disturbance of each node relative to the adjacent heating point by using the thermal distribution characteristics and thermal field change value, and determine the shortest connection path of the waste heat circulation network under the thermal disturbance; The node feedback module is used to perform node feedback on each node of the waste heat circulation network according to the shortest connection path of the waste heat circulation network under the thermal disturbance amount, and determine the node feedback mode of each node.

2. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 1 is characterized in that: The implementation methods of the waste heat network construction module also include: Identify the connection relationship between the nodes corresponding to the waste heat information and pipeline information to form an initial connection relationship graph; deploy the node type, waste heat level, node weight and waste heat fluctuation path of each node to the initial connection relationship graph to obtain the waste heat circulation network.

3. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 1 is characterized in that: The node types of each node corresponding to the waste heat information and pipeline information include: heat source node, heat exchanger node, flow regulation node, temperature and pressure monitoring node and heating point.

4. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 1 is characterized in that: The implementation method of identifying the waste heat level of each node corresponding to the waste heat information and pipeline information is as follows: Obtain the temperature, pressure and flow of each node, check the temperature, pressure and flow of each node, and mark the operating status label of each node; The waste heat utilization load of each node is calculated using the flow and temperature change values ​​of each node and marked as a waste heat utilization load label; Record the storage capacity, release capacity and storage efficiency of waste heat utilization at each node under the corresponding temperature, pressure and flow rate, and mark them as the waste heat storage balance label of the corresponding node; Record the traffic distribution of each node and the corresponding path of energy transfer as the utilization relationship label between each node; The operation status label of each node, the waste heat utilization load label, the waste heat storage balance label and the utilization relationship label between each node are used as the output waste heat ladder.

5. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 1 is characterized in that: The implementation methods of the region segmentation module include: The waste heat circulation network is evenly divided into multiple areas according to the form of heat transmission, the flow rate and temperature difference of the medium in each area per unit time are used as the identified circulation volume, and the corresponding positions of the heating points and heating areas in each area are marked; The circulation volume, heating area and heating point corresponding positions of each area are regarded as thermal units, and the thermal units are matched with the waste heat levels to identify the distribution of each thermal unit under the corresponding waste heat levels; According to the distribution of each thermal unit under the waste heat ladder, the thermal distribution sequence corresponding to each thermal unit is set, and the thermal distribution characteristics and thermal field change values ​​are extracted from the thermal distribution sequence in sequence.

6. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 5, characterized in that: The implementation method of matching the thermal units with the waste heat levels and identifying the distribution of the thermal units under the corresponding waste heat levels also includes: Connect the node types, node weights and waste heat fluctuation paths related to each thermal unit and the waste heat ladder to obtain the node types and node weights corresponding to each current thermal unit, as well as the distances between each thermal unit and the waste heat fluctuation path; According to the node type and node weight corresponding to each thermal unit, identify whether there is an intermediate node between the thermal unit and the residual heat level. If there is no intermediate node, set the node type and node weight corresponding to each thermal unit as the residual heat level of the current thermal unit; If there is an intermediate node, the waste heat level corresponding to the shortest distance between each thermal unit and the waste heat fluctuation path is set as the waste heat level of each current thermal unit.

7. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 5, characterized in that: The thermal distribution sequence corresponding to each thermal unit is set, and the thermal distribution characteristics and thermal field change values ​​are extracted from the thermal distribution sequence in sequence as follows: Obtain the flow, pressure, temperature and temperature difference on each thermal unit, and generate the thermal distribution sequence corresponding to each thermal unit in the form of time series; Calculate the temperature gradient on each thermal unit, identify the overlap ratio of the temperature gradient on each thermal unit in the thermal distribution sequence, and output the data corresponding to the overlap ratio as the thermal distribution feature; The slope values ​​of flow rate, pressure, temperature and temperature difference in the thermal distribution sequence in the corresponding time period are obtained in sequence, and the difference of the slope values ​​in adjacent time periods is used as the output thermal field change value.

8. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 1 is characterized in that: The implementation methods of thermal field analysis module include: According to the position of each node in the waste heat circulation network, construct the task scenario of each node in the waste heat circulation network; According to the thermal distribution characteristics and thermal field change values ​​covered in the mission scenario, the thermal energy demand of adjacent heating points is matched and analyzed, and the associated areas between adjacent heating points and thermal distribution characteristics, and the parts with the same trend between adjacent heating points and thermal field change values ​​are determined in turn; According to the associated areas and the parts with the same trend corresponding to the adjacent heating points, the thermal disturbance amount of each node relative to the adjacent heating points is identified; Based on the thermal disturbance of each node, each node is connected to obtain the shortest connection path.

9. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 8, characterized in that: The matching analysis of the heat energy demand of adjacent heating points also includes: Using the form of spatial correlation analysis, the thermal overlapping areas corresponding to adjacent heating points are determined in turn, and the strongly correlated parts in the thermal overlapping areas are used as the correlation areas between adjacent heating points and thermal distribution characteristics.

10. The energy-saving monitoring system for recycling waste heat from a shaft furnace according to claim 1, characterized in that: The implementation methods of the node feedback module include: Feedback targets are extracted for each node on the shortest connection path of the waste heat circulation network, the feedback logic classification of each feedback target is determined in turn, and the control strategy is set as the output node feedback method according to the number of nodes corresponding to the feedback logic classification.

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