Measurement point one-dimensional layout method and system for direct air cooling island finned tube bundle anti-freezing monitoring

Abstract

The invention discloses a measuring point one-dimensional layout method and system for anti-freezing monitoring of a finned tube bundle of a direct air cooling island, and relates to the technical field of temperature measurement of direct air cooling units. Comprising the following steps: acquiring temperature monitoring data of the surface of a finned tube bundle, and performing anti-freezing margin calculation processing on the temperature monitoring data to obtain anti-freezing state data; presetting an anti-freezing monitoring model, and inputting the anti-freezing state data into the anti-freezing monitoring model; and performing intelligent monitoring and area positioning on the freezing state of the finned tube bundle according to the output of the anti-freezing monitoring model. By establishing a one-dimensional temperature monitoring layout scheme, the effectiveness of monitoring is ensured, the temperature data acquisition efficiency is improved, freezing positioning is carried out based on working medium flow characteristics, the temperature anomaly of the finned tube bundle is classified into different risk levels, and a corresponding anti-freezing evaluation method is adopted, so that the freezing identification accuracy is improved, and the accuracy of freezing identification is improved. A real-time monitoring evaluation system is established through an anti-freezing margin index, and an anti-freezing monitoring scheme is updated and optimized regularly, so that the monitoring efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of temperature measurement of direct air cooling units, in particular to a one-dimensional arrangement method and system of measuring points for antifreeze monitoring of fin tube bundles in a direct air cooling island. Background Art

[0002] During winter operation, direct air-cooled units are often affected by freezing problems. Direct air-cooled units are subject to factors such as low power generation load, low fan speed, unit start and stop, low ambient temperature, and high ambient wind speed. It is very easy for the working fluid to freeze inside the fin tube bundle, causing deformation and damage to the tube bundle, thus affecting the safe operation and economy of the entire unit. Therefore, antifreeze monitoring of the fin tube bundle is particularly important.

[0003] The direct air-cooled condenser uses a single row of finned tube bundles, connecting the upper distribution pipe with the lower connecting pipe below, maintaining a 60° inclination angle with the ground to ensure that the steam in the distribution pipe can condense into condensate and flow into the lower connecting pipe, so the working fluid in the finned tube bundle flows along the longitudinal direction of the tube bundle.

[0004] When a freezing accident occurs, the temperature of the working fluid in the tube bundle will drop sharply. When the working fluid temperature is lower than the condensation temperature, freezing will occur. Regardless of whether it is a downstream or upstream tube bundle, once freezing occurs, the internal working fluid will continue to condense into ice, resulting in a continuous decrease in the flow of the working fluid and exhaust steam. The most intuitive phenomenon reflected is that the temperature of the frozen tube bundle and the surrounding tube bundles drops significantly. In severe cases, large sections of the tube bundle will freeze.

[0005] At present, the commonly used monitoring device is to use temperature-sensing cables, which usually encapsulate individual sensors in the cables for contact temperature measurement to achieve accurate monitoring of the temperature of the fin tube bundle. The existing layout scheme of temperature-sensing cables usually adopts a multi-cable monitoring method of three or more cables, and performs two-dimensional temperature monitoring on the horizontal and vertical dimensions of the fin tube bundle. Although this method can increase the coverage area of ​​the measuring points, it is not actually very helpful for antifreeze monitoring. The heat dissipation surface of the air-cooled condenser is huge. Common units contain a total of thirty or more air-cooled units, each of which is about 10 meters long and 10 meters high. If multiple cables are arranged on all heat dissipation surfaces, there will be a large number of useless measuring points, which will not only not provide help for freezing monitoring, but will affect the overall heat dissipation effect of the condenser and increase the total cost. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the problem to be solved by the present invention is how to use an economical and efficient monitoring method, utilize the characteristics of the longitudinal flow of the working fluid in the fin tube bundle of the direct air-cooled island, adopt a one-dimensional measuring point layout instead of the traditional two-dimensional layout, while ensuring the freezing accident monitoring and positioning capabilities, reduce the impact on the heat dissipation effect, and reduce the system cost.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] In a first aspect, an embodiment of the present invention provides a one-dimensional arrangement method of measuring points for antifreeze monitoring of a fin tube bundle in a direct air-cooling island, which includes obtaining temperature monitoring data of the surface of the fin tube bundle, and performing antifreeze margin calculation processing on the temperature monitoring data to obtain antifreeze status data;

[0010] Preset an antifreeze monitoring model and input antifreeze status data into the antifreeze monitoring model;

[0011] The freezing status of the fin tube bundle is intelligently monitored and regionally located based on the output of the antifreeze monitoring model.

[0012] As a preferred solution of the one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooling islands of the present invention, the temperature monitoring data includes:

[0013] Temperature data collected by temperature sensing cables laid horizontally on the surface of the fin tube bundle of the direct air cooling island;

[0014] The temperature data is collected through temperature measurement points arranged at preset intervals on the temperature sensing cable.

[0015] As a preferred solution of the one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands of the present invention, the antifreeze margin calculation process includes:

[0016] Calculate the degree of antifreeze from the surface temperature to the freezing point temperature;

[0017] Calculate the maximum antifreeze degree of saturation temperature and freezing temperature;

[0018] Calculate the ratio of the antifreeze margin to the maximum antifreeze degree.

[0019] As a preferred solution of the one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands of the present invention, the antifreeze monitoring model includes:

[0020] Freezing risk classification judgment based on antifreeze margin difference;

[0021] Identification of frozen areas based on temperature changes at adjacent measuring points;

[0022] Evaluation of freezing impact range based on working fluid flow characteristics.

[0023] As a preferred solution of the one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooling islands of the present invention, wherein: the intelligent monitoring of freezing state includes:

[0024] Real-time collection of temperature measurement point data for antifreeze margin calculation;

[0025] Compare the antifreeze margin under normal operating conditions to assess freezing risk;

[0026] The freezing area is located in combination with the flow characteristics of the working fluid.

[0027] As a preferred solution of the one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands of the present invention, the antifreeze margin calculation process adopts:

[0028] Normal working condition antifreeze degree F = T1-T0

[0029] Among them, F is the antifreeze degree under normal working conditions, T1 is the surface temperature of the fin tube bundle under normal working conditions, and T0 is the freezing point temperature;

[0030] Maximum antifreeze degree F under normal working conditions max =T2-T0

[0031] Among them, F max is the maximum antifreeze degree under normal working conditions, T2 is the saturation temperature in the condenser under normal working conditions, and T0 is the freezing point temperature;

[0032] Antifreeze margin:

[0033]

[0034] Among them, θ is the antifreeze margin. The antifreeze margin θ under normal working conditions is calculated, which is the ratio of the antifreeze degree F℃ to the maximum antifreeze degree F under normal working conditions. max Percentage of ℃;

[0035] The criterion for comparing the antifreeze margin difference with the normal working condition is:

[0036] If the difference is less than 0.5, it is judged that there is no freezing danger;

[0037] 0.5≤Difference<0.8 determines that there is a risk of freezing of the surrounding pipe bundles;

[0038] 0.8≤Difference<1 determines that there is a risk of freezing around the pipe bundle at the measuring point;

[0039] If the difference is ≥ 1, it is determined that the measuring point is frozen.

[0040] As a preferred solution of the one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands of the present invention, the specific implementation of freezing area identification includes:

[0041] The layout structure has an angle of 60 degrees between the heat dissipation surface and the ground;

[0042] The temperature measurement points are arranged at intervals of 0.55 meters;

[0043] Density distribution with one measuring point arranged for every 5 fin tube bundles;

[0044] A layout method in which a temperature sensing cable is arranged on each side of the heat dissipation surface;

[0045] The layout method is adapted to the longitudinal flow characteristics of the working medium in a single-row tube bundle, and freezing monitoring of the entire heat dissipation surface is achieved through one-dimensional measurement point layout.

[0046] In a second aspect, an embodiment of the present invention provides a one-dimensional arrangement system of measuring points for antifreeze monitoring of finned tube bundles in a direct air-cooled island, which includes a data acquisition module, an antifreeze evaluation module, and a freezing identification module;

[0047] The data acquisition module is used to collect temperature data of the temperature sensing cable measuring point, working fluid flow data, ambient temperature data, and tube bundle position data to establish a fin tube bundle temperature monitoring model;

[0048] The antifreeze assessment module is used to calculate the antifreeze margin based on the collected temperature data and conduct freezing risk assessment;

[0049] The freezing identification module is used to track the antifreeze monitoring process in real time, establish a freezing area identification system through antifreeze margin indicators, and regularly optimize and update the antifreeze monitoring plan.

[0050] In a third aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, the steps of the one-dimensional layout method of measurement points for antifreeze monitoring of the direct air-cooled island fin tube bundle are implemented as in the first aspect of the present invention.

[0051] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the one-dimensional layout method of measurement points for antifreeze monitoring of a fin tube bundle in a direct air-cooled island as in the first aspect of the present invention are implemented.

[0052] The beneficial effects of the present invention are as follows: the one-dimensional layout method of measuring points for antifreeze monitoring of the fin tube bundle of the direct air-cooled island provided by the present invention ensures the effectiveness of monitoring and the economy of the system by establishing a one-dimensional temperature monitoring layout scheme, improves the efficiency of temperature data collection, reduces layout redundancy, and improves the accuracy and reliability of antifreeze monitoring; by performing freezing positioning based on the flow characteristics of the working fluid, the temperature anomalies of the fin tube bundle are classified into different risk levels, and a corresponding antifreeze evaluation method is adopted, which improves the accuracy of freezing identification, reduces the monitoring cost and the impact on heat dissipation, and ensures the economy and practicality of antifreeze monitoring; a real-time monitoring and evaluation system is established through antifreeze margin indicators, and the antifreeze monitoring scheme is regularly updated and optimized, which improves the monitoring efficiency, reduces the occurrence of freezing accidents, and ensures the advancement and efficiency of the monitoring scheme. The present invention achieves better results in terms of monitoring efficiency, system cost and antifreeze warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 It is a flow chart of the one-dimensional layout method of measuring points for antifreeze monitoring of fin tube bundles in direct air-cooling islands;

[0055] Figure 2 This is a simulation diagram for verifying the one-dimensional layout method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooling islands; DETAILED DESCRIPTION

[0056] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0057] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0058] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0059] Example 1

[0060] Reference Figure 1-2 , which is the first embodiment of the present invention, provides a one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in a direct air-cooling island, including:

[0061] S1, obtaining temperature monitoring data of the surface of the fin tube bundle, and performing antifreeze margin calculation processing on the temperature monitoring data to obtain antifreeze status data;

[0062] In the embodiment of the present application, the temperature monitoring data includes:

[0063] Temperature data collected by temperature sensing cables laid horizontally on the surface of the finned tube bundle of the direct air cooling island;

[0064] The temperature data is collected through temperature measurement points arranged at preset intervals on the temperature sensing cable.

[0065] In the embodiment of the present application, the antifreeze margin calculation process includes:

[0066] Calculate the degree of antifreeze from the surface temperature to the freezing point temperature;

[0067] Calculate the maximum antifreeze degree of saturation temperature and freezing temperature;

[0068] Calculate the ratio of the antifreeze margin to the maximum antifreeze degree.

[0069] Furthermore, the temperature monitoring data includes temperature data of temperature sensing cable measuring points, working fluid flow data, ambient temperature data, and tube bundle position data; temperature data of temperature sensing cable measuring points includes real-time surface temperature and historical surface temperature; working fluid flow data includes working fluid flow rate and flow direction; ambient temperature data includes ambient temperature and wind speed; and tube bundle position data includes relative position information of measuring points.

[0070] It should be noted that for the 660MW direct air-cooled unit, the air-cooling island of the unit contains 8 rows of radiators, each row of radiators has 7 air-cooling units, each fan corresponds to an air-cooling unit, and each air-cooling unit contains 220 finned tube bundles with a total length of 11 meters. A temperature sensing cable is arranged horizontally on the heat dissipation surface on both sides of a row of radiators, and a measuring point is arranged inside the cable at intervals of about 0.55 meters and about every 5 finned tube bundles. In this way, the row of radiators can be monitored, and this step is repeated for the arrangement of other rows of radiators, so as to realize the monitoring of the air-cooling island as a whole.

[0071] It should also be noted that the temperature of the temperature sensing cable measuring point reflects the real-time temperature status of the fin tube bundle surface, and the historical data is used to establish the normal working condition benchmark. The flow rate and flow direction of the working fluid directly affect the heat transfer effect inside the tube bundle, while the ambient temperature and wind speed have a significant impact on the heat dissipation performance. The coordinated analysis of these data helps to accurately assess the freezing risk. The measuring point location information is used to determine the specific area of ​​temperature anomaly, providing a spatial positioning basis for subsequent freezing warnings.

[0072] The patent of this invention sets the surface temperature of the finned tube bundle under normal working conditions to be T1°C and the freezing point temperature to be T0°C. The calculation formula for the antifreeze degree F°C under normal working conditions is as follows:

[0073] F=T1-T0

[0074] S2, presetting an antifreeze monitoring model and inputting antifreeze status data into the antifreeze monitoring model;

[0075] In an embodiment of the present application, the antifreeze monitoring model includes:

[0076] Freezing risk classification judgment based on antifreeze margin difference;

[0077] Identification of frozen areas based on temperature changes at adjacent measuring points;

[0078] Evaluation of freezing impact range based on working fluid flow characteristics.

[0079] Preferably, the present invention sets the surface temperature of the fin tube bundle under normal working conditions to be T1°C and the freezing point temperature to be T0°C. At this time, the calculation formula for the antifreeze degree F°C under normal working conditions is as follows:

[0080] F=T1-T0

[0081] The invention sets the saturation temperature in the condenser under normal working conditions to be T2°C. At this time, the maximum antifreeze degree under normal working conditions is F max The calculation formula of ℃ is as follows:

[0082] F max =T2-T0

[0083] The antifreeze margin defined in the present invention is θ. The antifreeze margin θ under normal working conditions is calculated as the ratio of the antifreeze degree F°C to the maximum antifreeze degree F under normal working conditions. max The percentage of ℃ is as follows:

[0084]

[0085] It should be noted that the verification experiment of freezing monitoring was carried out when the ambient temperature was -5℃, the condenser back pressure was 5kpa, the freezing point temperature was 0℃, and the fin tube bundle surface temperature was 41℃. At this time, the condenser saturation temperature was 32.1℃. Compare the antifreeze margin difference with the normal operating conditions. If the difference is less than 0.5, it means that the tube bundle monitored by the measuring point is not dangerous; if the difference is between 0.5-0.8, it means that the surrounding tube bundles will be in danger of freezing; if the difference is between 0.8-1, it means that the tube bundle around the measuring point will be in danger of freezing; if the difference is greater than 1, it means that the measuring point has already frozen.

[0086] It should also be noted that during the calculation of the antifreeze margin, the change trend of the surface temperature is monitored in real time, and combined with the fluctuation range of the working fluid saturation temperature, potential freezing risks can be discovered in time. By establishing a temperature gradient distribution map and analyzing the temperature change law between adjacent measuring points, it is helpful to determine the development trend and impact range of freezing.

[0087] S3, intelligent monitoring of the freezing state of the fin tube bundle and regional positioning according to the output of the antifreeze monitoring model;

[0088] In the embodiment of the present application, the freezing state intelligent monitoring includes:

[0089] Real-time collection of temperature measurement point data for antifreeze margin calculation;

[0090] Compare the antifreeze margin under normal operating conditions to assess freezing risk;

[0091] The freezing area is located in combination with the flow characteristics of the working fluid.

[0092] Furthermore, freezing state monitoring includes real-time evaluation of the antifreeze margin and positioning of the freezing area based on the longitudinal flow characteristics of the working fluid in the tube bundle. According to the single-row tube principle adopted by the direct air-cooled condenser, the working fluid in the tube can only flow along the longitudinal direction of the tube bundle. When a single tube bundle freezes, it will cause blockage inside the tube bundle, and the temperature and flow of the working fluid in the longitudinal direction of the tube bundle will decrease accordingly.

[0093] It should be noted that when a freezing accident occurs, the temperature of the working fluid in the tube bundle will drop sharply. When the working fluid temperature is lower than the condensation temperature, freezing will occur. Regardless of whether it is a downstream or upstream tube bundle, once freezing occurs, the internal working fluid will continue to condense into ice, resulting in a continuous decrease in the flow rate of the working fluid and exhaust steam. This change will radiate to several surrounding tube bundles.

[0094] It should also be noted that the intelligent monitoring system can accurately identify the initial location and expansion trend of freezing through real-time data analysis. The system will automatically adjust the monitoring frequency according to the freezing risk level and focus on high-risk areas. At the same time, through the accumulation and analysis of historical data, the monitoring parameters and judgment criteria are continuously optimized to improve the accuracy and reliability of the system's early warning.

[0095] Furthermore, this embodiment also provides a one-dimensional arrangement system of measuring points for antifreeze monitoring of finned tube bundles in a direct air-cooling island, including:

[0096] Data acquisition module, antifreeze assessment module, freeze identification module;

[0097] The data acquisition module is used to collect temperature data of the temperature sensing cable measuring point, working fluid flow data, ambient temperature data, and tube bundle position data to establish a fin tube bundle temperature monitoring model;

[0098] The antifreeze assessment module is used to calculate the antifreeze margin based on the collected temperature data and perform freezing risk assessment;

[0099] The freezing identification module is used to track the antifreeze monitoring process in real time, establish a freezing area identification system through antifreeze margin indicators, and regularly optimize and update the antifreeze monitoring plan.

[0100] This embodiment also provides a computer device, which is suitable for the one-dimensional layout method of measuring points for antifreeze monitoring of fin tube bundles in a direct air-cooling island, and includes a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the one-dimensional layout method of measuring points for antifreeze monitoring of fin tube bundles in a direct air-cooling island as proposed in the above embodiment.

[0101] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0102] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the one-dimensional arrangement method of measuring points for antifreeze monitoring of fin tube bundles in a direct air-cooling island as proposed in the above embodiment is implemented.

[0103] In summary, the one-dimensional layout method of measuring points for antifreeze monitoring of the fin tube bundle of the direct air-cooled island provided by the present invention ensures the effectiveness of monitoring and the economy of the system by establishing a one-dimensional temperature monitoring layout scheme, improves the efficiency of temperature data collection, reduces layout redundancy, and improves the accuracy and reliability of antifreeze monitoring; by performing freezing positioning based on the flow characteristics of the working fluid, the temperature anomalies of the fin tube bundle are classified into different risk levels, and a corresponding antifreeze evaluation method is adopted, which improves the accuracy of freezing identification, reduces the monitoring cost and the impact on heat dissipation, and ensures the economy and practicality of antifreeze monitoring; a real-time monitoring and evaluation system is established through antifreeze margin indicators, and the antifreeze monitoring scheme is regularly updated and optimized, which improves the monitoring efficiency, reduces the occurrence of freezing accidents, and ensures the advancement and efficiency of the monitoring scheme. The present invention achieves better results in monitoring efficiency, system cost and antifreeze warning.

[0104] Example 2

[0105] Reference Figure 1-Figure 2 , which is the second embodiment of the present invention, and provides a one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in a direct air-cooling island, comprising:

[0106] S1: Obtain temperature monitoring data on the surface of the fin tube bundle.

[0107] Furthermore, the temperature monitoring data includes temperature data of the temperature sensing cable measuring point, pressure difference data, ambient temperature data, and tube bundle status data; the temperature data of the temperature sensing cable measuring point includes instantaneous temperature and temperature change rate; the pressure difference data includes the pressure difference and flow resistance at both ends of the tube bundle; the ambient temperature data includes ambient temperature and wind speed; the tube bundle status data includes information on the degree of blockage of the tube bundle.

[0108] It should be noted that for the 350MW direct air-cooled unit, in the 6 rows of radiators in the air-cooling island, 5 air-cooling units are arranged in each row, each unit contains 180 finned tube bundles, and the temperature sensing cables are arranged between adjacent heat dissipation surfaces. A temperature measuring point is arranged every 0.5 meters so that adjacent measuring points can monitor the temperature changes of 4-5 tube bundles.

[0109] It should also be noted that by monitoring the pressure difference and flow resistance at both ends of the tube bundle, combined with temperature change data, flow anomalies inside the tube bundle can be detected early. Real-time monitoring of ambient temperature and wind speed helps to evaluate the impact of external conditions on heat dissipation, and monitoring of the degree of tube bundle blockage provides a basis for preventive maintenance.

[0110] S2: Calculate and process the antifreeze margin for the temperature monitoring data.

[0111] Furthermore, the antifreeze margin calculation takes into account temperature data, pressure difference data and tube bundle status data. When the pressure difference at both ends of the tube bundle increases abnormally, the monitoring frequency of this area will be increased; when a tube bundle blockage trend is detected, the antifreeze warning threshold will be adjusted accordingly.

[0112] It should be noted that in actual operation, potential freezing risks can be identified by analyzing the temperature change rate and pressure difference change trend. The system will dynamically adjust the calculation parameters of the antifreeze margin according to the changes in the monitoring data to adapt to different operating conditions.

[0113] S3: Perform intelligent monitoring of the freezing status and regional positioning.

[0114] Furthermore, freezing state monitoring adopts a zone monitoring strategy. The heat dissipation surface is divided into multiple monitoring areas, and several key monitoring points are set in each area. By analyzing the temperature distribution characteristics and pressure difference change rules of the measuring points in the area, accurate freezing state judgment and regional positioning can be achieved.

[0115] It should be noted that the system establishes a library of temperature distribution patterns under different working conditions based on historical operating data. When an abnormality is detected, the specific location and impact range of the freeze are determined through comparative analysis. At the same time, combined with the monitoring data of the degree of tube bundle blockage, the potential risk of freezing development is evaluated.

[0116] It should be noted that the one-dimensional layout method of measuring points for antifreeze monitoring of the fin tube bundle of the direct air-cooled island of the present invention is mainly based on the following principle: the fin tube bundle of the condenser adopts a single row of tubes, and the internal working fluid flows in the longitudinal direction of the tube bundle. If a single fin tube bundle is frozen, it will cause blockage inside the tube bundle, and the working fluid temperature and flow rate in the longitudinal direction of the tube bundle will decrease accordingly, which will be reflected on the outside of the fin tube bundle, that is, the temperature of the frozen tube bundle will drop sharply, and this change will radiate to several surrounding tube bundles, and the temperature measured by the temperature sensing cable measuring point in the freezing area will also change to a certain extent. Therefore, the temperature change is described as the difference between the antifreeze margin under normal working conditions and the antifreeze margin under actual conditions. The smaller the difference is, the closer the current temperature is to the normal temperature, and the less likely freezing will occur. When the difference is larger, the more the current temperature deviates from the normal temperature. Therefore, the antifreeze monitoring process can be shortened to several fin tube bundles, where only one measuring point needs to be arranged in the middle of the middle fin tube bundle. Therefore, in this process, the measuring points only need to be arranged with a temperature measuring point every few tube bundles in the horizontal dimension of the fin tube bundle, and finally a horizontal one-dimensional measuring point layout method is formed. After that, the freezing position is roughly located based on the temperature data measured in real time at the measuring points.

[0117] Example 3

[0118] Reference Figure 1-Figure 2, which is the second embodiment of the present invention, and this embodiment provides a one-dimensional layout method of measuring points for antifreeze monitoring of fin tube bundles in a direct air-cooling island. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0119] Take the 660MW direct air-cooled unit as an example. The air-cooling island of the unit contains 8 rows of radiators, each row of radiators has 7 air-cooling units (each fan corresponds to an air-cooling unit), and each air-cooling unit contains 220 finned tube bundles with a total length of 11 meters. A temperature sensing cable is arranged horizontally on the heat dissipation surface on both sides of a row of radiators, and a measuring point is arranged inside the cable at intervals of about 0.55 meters (about one measuring point is arranged every 5 finned tube bundles). In this way, the row of radiators can be monitored. Repeat this step for the arrangement of other rows of radiators, so as to realize the monitoring of the entire air-cooling island.

[0120] According to the monitoring method in the example, the surface temperature data of the finned tube bundle monitored by the temperature sensing cable is substituted into the antifreeze margin calculation formula to obtain the antifreeze margin at the moment, recorded as, and then compared with the antifreeze margin under normal working conditions. If the difference between the two is less than 0.5, it means that the tube bundle monitored by the measuring point is not dangerous; if the difference between the two is between 0.5-0.8, it means that the surrounding tube bundles will be in danger of freezing; if the difference between the two is between 0.8-1, it means that the tube bundle around the measuring point will be in danger of freezing; if the difference between the two is greater than 1, it means that the measuring point has been frozen.

[0121]

[0122] The Simulink platform in Matlab is used to simulate the heat transfer process of an air-cooling unit of a 660MW direct air-cooling unit to verify the feasibility of the antifreeze warning method for the fin tube bundle of the direct air-cooling island. The freezing monitoring verification experiment was carried out when the ambient temperature was -5℃, the condenser back pressure was 5kpa, the freezing point temperature was 0℃, and the fin tube bundle surface temperature was 41℃. From the pressure and saturation temperature comparison table, it can be seen that the condenser saturation temperature at this time is the antifreeze margin under this condition. The effectiveness of the antifreeze margin difference was verified when the fin tube bundle surface temperature was 5℃-45℃. The verification effect is as follows: Figure 2 As shown. According to the empirical parameters of actual operation, when the surface temperature of the finned tube bundle is above 25℃, there is no danger of freezing; when it is between 10℃-25℃, freezing may occur around the measuring point; when it is between 5℃-10℃, the tube bundle at the measuring point is generally frozen; and when it is below 5℃, a freezing accident has generally occurred. The data in the table is basically consistent with the empirical parameters of actual operation, thus verifying the effectiveness of this method.

[0123] In summary, compared with the prior art, the present invention has the following advantages: by adopting a one-dimensional cable layout scheme, the occurrence and location of freezing accidents can be monitored and judged, which will not only reduce the impact on the heat dissipation effect, but also be more conducive to economy. The present invention provides an anti-freeze warning method for the fin tube bundle of a direct air-cooled island with respect to the layout method, and uses this method to help the one-dimensional layout method of the temperature sensing cable to achieve the purpose of anti-freeze monitoring. The present invention proposes that the layout method of the present invention is different from the two-dimensional monitoring scheme, but adopts a one-dimensional layout method, which can improve the ability to analyze the status of air-cooled radiators in severely cold areas in winter, the level of temperature warning and logic control, accumulate winter operation experience, and reduce the labor intensity of personnel.

[0124] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A one-dimensional layout method of measuring points for antifreeze monitoring of finned tube bundles in a direct air-cooling island, characterized in that: include, Acquiring temperature monitoring data of the surface of the fin tube bundle, and performing antifreeze margin calculation processing on the temperature monitoring data to obtain antifreeze status data; Presetting an antifreeze monitoring model, and inputting the antifreeze status data into the antifreeze monitoring model; The freezing state of the fin tube bundle is intelligently monitored and the regional positioning is performed according to the output of the antifreeze monitoring model.

2. The one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands according to claim 1 is characterized in that: The temperature monitoring data includes: Temperature data collected by temperature sensing cables laid horizontally on the surface of the finned tube bundle of the direct air cooling island; The temperature data is obtained by collecting temperature measurement points arranged at preset intervals on the temperature sensing cable.

3. The one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands according to claim 2 is characterized in that: The antifreeze margin calculation process includes: Calculate the degree of antifreeze from the surface temperature to the freezing point temperature; Calculate the maximum antifreeze degree of saturation temperature and freezing temperature; The antifreeze margin ratio of the antifreeze degree to the maximum antifreeze degree is calculated.

4. The one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands according to claim 3 is characterized in that: The antifreeze monitoring model includes: Freezing risk classification judgment based on antifreeze margin difference; Identification of frozen areas based on temperature changes at adjacent measuring points; Evaluation of freezing impact range based on working fluid flow characteristics.

5. The one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooled islands according to claim 4 is characterized in that: The freezing state intelligent monitoring includes: Real-time collection of temperature measurement point data for antifreeze margin calculation; Compare the antifreeze margin under normal operating conditions to assess freezing risk; The freezing area is located in combination with the flow characteristics of the working fluid.

6. The one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooling islands according to claim 5 is characterized in that: The antifreeze margin calculation process adopts: Normal working condition antifreeze degree F = T1-T0 Among them, F is the antifreeze degree under normal working conditions, T1 is the surface temperature of the fin tube bundle under normal working conditions, and T0 is the freezing point temperature; Maximum antifreeze degree F under normal working conditions max =T2-T0 Among them, F max is the maximum antifreeze degree under normal working conditions, T2 is the saturation temperature in the condenser under normal working conditions, and T0 is the freezing point temperature; Antifreeze margin: Among them, θ is the antifreeze margin. The antifreeze margin θ under normal working conditions is calculated as the antifreeze degree F (℃) divided by the maximum antifreeze degree F under normal working conditions. max (℃) percentage; The criterion for comparing the antifreeze margin difference with the normal working condition is: If the difference is less than 0.5, it is judged that there is no freezing danger; 0.5≤Difference<0.8 determines that there is a risk of freezing of the surrounding pipe bundles; 0.8≤Difference<1 determines that there is a risk of freezing around the pipe bundle at the measuring point; If the difference is ≥ 1, it is determined that the measuring point is frozen.

7. The one-dimensional arrangement method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooling islands according to claim 6 is characterized in that: The specific implementation of the frozen area identification includes: The layout structure has an angle of 60 degrees between the heat dissipation surface and the ground; The temperature measurement points are arranged at intervals of 0.55 meters; Density distribution with one measuring point arranged for every 5 fin tube bundles; A layout method in which a temperature sensing cable is arranged on each side of the heat dissipation surface; The arrangement method is adapted to the longitudinal flow characteristics of the working medium in the single-row tube bundle, and freezing monitoring of the entire heat dissipation surface is achieved through one-dimensional measurement point arrangement.

8. A one-dimensional layout system of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooling islands, based on the one-dimensional layout method of measuring points for antifreeze monitoring of finned tube bundles in direct air-cooling islands according to any one of claims 1 to 7, characterized in that: It also includes a data acquisition module, an antifreeze assessment module, and a freeze identification module; The data acquisition module is used to collect temperature data of the temperature sensing cable measuring point, working fluid flow data, ambient temperature data, and tube bundle position data to establish a fin tube bundle temperature monitoring model; The antifreeze assessment module is used to calculate the antifreeze margin based on the collected temperature data and perform freezing risk assessment; The freezing identification module is used to track the antifreeze monitoring process in real time, establish a freezing area identification system through antifreeze margin indicators, and regularly optimize and update the antifreeze monitoring plan.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the one-dimensional layout method of measuring points for antifreeze monitoring of the fin tube bundle of the direct air-cooling island described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the one-dimensional arrangement method of measuring points for antifreeze monitoring of fin tube bundles in a direct air-cooled island as described in any one of claims 1 to 7 are implemented.

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