Heat exchanger leakage monitoring system and method

Abstract

The embodiment of the invention discloses a heat exchanger leakage monitoring system and method. The system comprises a primary and secondary air supply module, a primary and secondary air heating module and a leakage detection module, an air duct of the primary and secondary air supply module is provided with a water accumulation area, and the primary and secondary air heating module comprises an air heater body and an obliquely arranged air heater heat exchange tube bundle. The leakage detection module comprises a bottom low-point liquid level sensor arranged at the bottom of the air duct water accumulation area, a partition rapid leakage detection device arranged at the inclined low-point end of the heat exchange tube bundle and a DCS in communication connection with the components. According to the method, a DCS collects a liquid level signal of a bottom low-point liquid level sensor and monitoring information of a partition rapid leakage detection device, receives a leakage signal containing a corresponding leakage position when a heat exchange tube bundle leaks, judges whether the liquid level of a water accumulation area reaches a preset drainage liquid level or not according to the liquid level signal, indicates a leakage partition according to the leakage signal, and sends the leakage partition to the heat exchange tube bundle. And real-time monitoring and zoning positioning of leakage of the heating system are realized.

Description

Technical Field

[0001] This application relates to the field of safety monitoring technology for power plant thermal equipment, and in particular to a heat exchanger leakage monitoring system and method. Background Technology

[0002] In thermal power generating units, the boiler's primary and secondary air heaters heat the primary and secondary air through heat exchanger tube bundles, serving as crucial equipment for ensuring stable combustion and improving unit efficiency. If a leak occurs in the heat exchanger tube bundles, the leaking medium, water, will enter the primary and secondary air ducts. This water can accumulate in the ducts or be carried into downstream equipment, potentially causing adverse effects on critical components such as the blower and air preheater. Therefore, effective monitoring and timely handling of leaks in the heating system are essential.

[0003] In existing technologies, monitoring of air heater leaks mainly relies on changes in operating parameters such as air preheater differential pressure, flue gas temperature, and unit efficiency, or on operators observing water accumulation in the ducts during on-site inspections. These methods often only reveal obvious anomalies after the leak has persisted for some time and the air preheater's heat storage elements have shown signs of scaling and blockage. This results in detection lag and an inability to accurately reflect the leak status in real time. Furthermore, it cannot quickly pinpoint the specific leaking tube bundle or section, leading to extensive and time-consuming repairs. During this period, the leak continues, increasing the operational risks of the fan being submerged in water and the air preheater becoming clogged.

[0004] It is evident that existing methods for detecting leaks in air heaters are insufficient to identify leaks in the heat exchanger tube bundles of air heaters in a timely and accurate manner and to pinpoint the leak location precisely. There is an urgent need for a technical solution that can provide early warning, real-time monitoring, and rapid location of leaks in air heater systems to improve the operational safety and maintainability of boiler primary and secondary air systems. Summary of the Invention

[0005] The embodiments of this application provide a heat exchanger leak monitoring system and method to solve the problems of delayed leak detection, inability to reflect the leak status in real time, and inability to accurately reflect the leak location.

[0006] To address the aforementioned technical problems, embodiments of this application disclose the following technical solutions: In a first aspect, a heat exchanger leakage monitoring system is provided, comprising a primary and secondary air supply module, a primary and secondary air heating module, and a leakage detection module; the primary and secondary air supply module includes at least one air duct, the air duct having at least one water accumulation area; the primary and secondary air heating module includes a primary and secondary air heater body and a heater heat exchange tube bundle, the heater heat exchange tube bundle being inclinedly arranged within the primary and secondary air heater body; the leakage detection module includes a zoned rapid leakage detection device, a bottom low-point liquid level sensor, and a DCS; the zoned rapid leakage detection device is disposed at the inclined low end of the heater heat exchange tube bundle; the bottom low-point liquid level sensor is disposed at the water accumulation area of ​​the air duct; the DCS is communicatively connected to the zoned rapid leakage detection device and the bottom low-point liquid level sensor.

[0007] Furthermore, the leakage detection module also includes a vibration detection component; the vibration detection component is located at the position of the heat exchange medium pipeline connected to the inlet valve of the primary and secondary air heater body, and is used to collect vibration signals of the working state of the primary and secondary air heater module; the DCS communication is connected to the vibration detection component and is configured to determine the vibration condition of the heater heat exchange tube bundle based on the vibration signal, so as to output vibration warning information when the vibration signal exceeds a preset value.

[0008] Furthermore, the zoned rapid leak detection device includes multiple sets of tube bundle zoned liquid storage boxes, electrode level relays, and duct sealing plates; each set of tube bundle zoned liquid storage boxes, electrode level relays, and duct sealing plates is correspondingly arranged below the inclined low end of the heat exchanger tube bundle of the heater in each zone; wherein, the tube bundle zoned liquid storage box is used to collect the leaked medium water from the heat exchanger tube bundle of the heater, the electrode level relay is installed on the tube bundle zoned liquid storage box with its electrode extending into the interior of the tube bundle zoned liquid storage box, and the duct sealing plate covers the opening of the tube bundle zoned liquid storage box facing the duct to isolate the tube bundle zoned liquid storage box from the interior space of the duct; the electrode level relay is configured to send a leak signal containing the location of the corresponding leaking heat exchanger tube bundle to the DCS when the water level in the tube bundle zoned liquid storage box reaches the electrode installation position.

[0009] Furthermore, the partitioned rapid leakage detection device also includes a liquid accumulation drain plug and a visual level gauge; the liquid accumulation drain plug is located at the bottom of the tube bundle partitioned liquid storage box and is used to drain the liquid accumulated in the tube bundle partitioned liquid storage box after isolating the primary and secondary air heating modules; the visual level gauge is installed on the air duct sealing plate and is connected to the tube bundle partitioned liquid storage box through a quick plug, and the visual level gauge adopts a transparent tube structure.

[0010] Furthermore, the leakage detection module also includes a bottom air duct electric drain valve; the bottom low-point liquid level sensor is located at the bottom of the water accumulation area of ​​the air duct; the bottom air duct electric drain valve is located on the drainage pipe of the air duct and is communicatively connected to the DCS; the DCS is also configured to receive the liquid level signal sent by the bottom low-point liquid level sensor, and when it determines that the liquid level in the water accumulation area has reached the preset drain level based on the liquid level signal, it outputs leakage alarm information and controls the bottom air duct electric drain valve to open.

[0011] Furthermore, the inclination rate of the heat exchange tube bundle of the heater is greater than or equal to 3‰.

[0012] Furthermore, the partitioned rapid leakage detection device and / or the bottom low point liquid level sensor use an electrode liquid level relay as the liquid level detection element, and the electrode of the electrode liquid level relay is made of a round steel column with a diameter greater than or equal to 10 mm.

[0013] Secondly, a method for monitoring leaks in a heater is provided, comprising the following steps: S1, collecting liquid level signals in the water accumulation zone of the air duct in the primary and secondary air supply module; S2, collecting monitoring information from a zoned rapid leak detection device installed at the low end of the tilted heat exchange tube bundle in the primary and secondary air heating module, and receiving a leak signal containing the location of the leaking heat exchange tube bundle when a leak occurs in the heat exchange tube bundle of the heater; S3, determining whether the water level in the water accumulation zone has reached a preset drain level based on the liquid level signals, and indicating the location of the leaking heat exchange tube bundle based on the leaking signals.

[0014] Furthermore, the detection method also includes: acquiring the vibration signal output by the vibration detection component; and outputting vibration warning information when the amplitude of the vibration signal exceeds a preset value.

[0015] Furthermore, step S3 also includes: when the water level reaches the preset drain level, outputting a heater leak alarm message and performing emergency draining of the water at the bottom of the duct.

[0016] The above-mentioned technical solutions have at least the following beneficial effects: Without changing the basic structure of the original boiler and air preheating system, the present invention achieves early detection, real-time monitoring and rapid location of leaks in the heating system through the coordinated design of multi-point liquid level monitoring and zoned rapid leak detection, which significantly improves the operational safety and maintainability of the power plant heating system.

[0017] The above-mentioned technical solutions also have the following beneficial effects: By setting a bottom low-point liquid level sensor in the water accumulation area of ​​the air duct and setting a zoned rapid leak detection device at the tilted low point of the heater tube bundle, the DCS can collect the bottom liquid level signal and the zoned leak signal respectively, and can simultaneously grasp the overall water accumulation situation and the leakage situation of each zone. This allows for rapid indication of the location of the corresponding leaking heat exchange tube bundle when a leak occurs, improving the timeliness and positioning accuracy of leak monitoring. The heater tube bundle is arranged with an inclination rate not less than a preset inclination rate, and multiple sets of tube bundle zoned liquid storage boxes are set at the tilted low point. This allows the leaking medium water to concentrate and collect in the corresponding zone under gravity, which is beneficial for reliable detection of liquid level changes by electrode liquid level relays under small leakage conditions, improving the ability to identify early leaks. Both the liquid level sensor and the electric drain valve in the bottom air duct are connected to the DCS. When the liquid level in the water accumulation area reaches the preset drain level, the DCS outputs a leakage alarm and controls the electric drain valve in the bottom air duct to open, allowing for timely drainage of the water accumulated at the bottom of the air duct. This helps reduce the adverse effects of water accumulation in the air duct on subsequent equipment in the heating system. The zoned rapid leakage detection device and / or the bottom low-point liquid level sensor use an electrode liquid level relay as the liquid level detection element, and select round steel electrodes with a diameter of not less than 10mm, which can maintain good mechanical strength and wear resistance under the condition of air supply scouring. A drain plug and a visual liquid level gauge are installed on the liquid storage box in the tube bundle zone, which facilitates the drainage of the accumulated liquid after isolating the corresponding primary and secondary air heating modules and allows for intuitive observation of liquid level changes, facilitating on-site verification and maintenance. Attached Figure Description

[0018] The technical solution and its beneficial effects will become apparent from the following detailed description of specific embodiments of this application, in conjunction with the accompanying drawings.

[0019] Figure 1 This application provides a schematic diagram of a heat exchanger leakage monitoring system. Figure 2 A schematic diagram of the installation of the primary and secondary air heating module 200 and the zoned rapid leak detection system provided in this application; Figure 3 Provided for this application Figure 2 Side perspective view; Figure 4 A flowchart illustrating an exemplary heat exchanger leak monitoring method provided in this application; Figure 5 A flowchart of the three-layer monitoring method provided in this application.

[0020] Explanation of reference numerals in the attached figures: 100. Primary and secondary air supply module; 200. Primary and secondary air heating module; 300. Leak detection module; 400. DCS; 101. Primary air fan and supply fan; 102. Air duct; 201. Primary and secondary air heater body; 202. Heat exchanger tube bundle of heater; 203. Heat exchange medium pipeline; 204. Return water pipeline; 205. Module inlet valve; 206. Module outlet valve; 301. Zoned rapid leak detection device; 302. Bottom low point liquid level sensor; 303. Vibration detection component; 304. Bottom air duct electric drain valve; 3011. Tube bundle zoned liquid storage box; 3012. Electrode liquid level relay; 3013. Air duct sealing plate; 3014. Electrode; 3015. Liquid accumulation drain plug; 3016. Visual liquid level gauge; 500. Air preheater. Detailed Implementation

[0021] To make the objectives, technical solutions, and beneficial effects of this application clearer, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, further clarifies this application. It should be understood that the specific embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "coupling," "docking," and "communication connection" should be interpreted broadly, referring to fixed connections, detachable connections, or integral moldings, as well as mechanical, electrical, or data connections, or combinations thereof; they can refer to direct connections or indirect connections through an intermediate medium. Terms such as "set at," "located in," "upper / lower / inner / outer / front / rear" are used only to describe relative positions and orders, and do not constitute a limitation on absolute spatial orientation. Terms such as "first," "second," and "third" are used only to distinguish objects and do not limit their quantity, order, or importance. Terms such as "including / contains / has" are open-ended terms, indicating the existence of, but not limited to, the listed elements; the terms "at least one," "at least one," and "several" should be understood as one or more, or one or more. The term "and / or" indicates any or all combinations in a parallel relationship. Unless otherwise specified, numerical ranges include endpoints. The term "based on" should be understood as "at least partially based on." Without causing confusion, the same element or structure may be described using different names in this specification. These names may correspond to each other and do not constitute a limitation on the form of the element or structure.

[0023] In this application, terms such as "module / unit / device / system / server / processor / storage medium / computer program" can be implemented through software, hardware, or a combination of both. Terms such as "acquire / collect / read / receive / calculate / determine / output / generate" are used interchangeably when there is no ambiguity, referring to routine data processing operations performed by the module / system / device / program.

[0024] After reading this specification, those skilled in the art can make various modifications or substitutions to the specific embodiments without departing from the spirit and essence of the present invention, and all such modifications or substitutions fall within the protection scope of the present invention.

[0025] In the primary and secondary air heating systems of power heating equipment, the heat exchange tube bundles of the air heaters are prone to leakage during long-term operation. Existing technologies mainly rely on air preheater differential pressure changes, operating parameter fluctuations, and manual inspections for monitoring. This not only results in delayed leak identification and a lack of effective control over water accumulation in the air ducts and its impact on downstream equipment, but also makes it difficult to locate the specific leaking tube bundle or leaking zone in a timely and accurate manner, which has an adverse impact on operational safety and maintenance.

[0026] To this end, this application proposes a heat exchanger leakage monitoring system and method. By arranging corresponding detection devices in the air duct and the heat exchange tube bundle of the heater, and cooperating with a distributed control system (DCS) for comprehensive judgment, the system can realize early detection, real-time monitoring and rapid location of leakage in the heating system. The technical solution of this application will be further described below with reference to specific embodiments.

[0027] Figure 1 This is a schematic diagram of a heat exchanger leakage monitoring system provided in this application. Figure 2 This is a schematic diagram of the installation of the primary and secondary air heating module 200 and the zoned rapid leak detection system provided in this application. Figure 3 Provided for this application Figure 2 A side perspective view. See below for reference. Figures 1 to 3 This application provides a detailed description of the exemplary heater leak monitoring system provided in this application.

[0028] like Figure 1 As shown, the heat exchanger leakage monitoring system provided in this application includes a primary and secondary air supply module 100, a primary and secondary air heating module 200, a leakage detection module 300, and a DCS (distributed control system) 400.

[0029] Combination Figure 1 and Figure 2In this embodiment, the primary and secondary air supply module 100 includes a primary air fan and a supply air fan 101, as well as an air duct 102 connected to them. The air duct 102 is connected sequentially to the primary and secondary air heating module 200 and the air preheater 500 along the airflow direction. At least one water accumulation area is formed at the bottom of the air duct 102 according to its arrangement height and slope, used to collect leaked water flowing from the primary and secondary air heating module 200 when the heater leaks. The primary and secondary air heating module 200 includes a primary and secondary air heater body 201 and a heater heat exchange tube bundle 202 disposed inside the primary and secondary air heater body 201. The heater heat exchange tube bundle 202 is composed of multiple heat exchange tubes, arranged at an angle within the primary and secondary air heater body 201, with a low-angle end formed on its lower side. This allows the leaking medium water to tend to flow towards the low-angle end under gravity when a heat exchange tube leaks, facilitating subsequent concentrated detection of leaked water in a localized area and improving the detectability of the leak signal. One end of the heat exchanger tube bundle 202 of the heater is connected to the external heat exchanger system through the heat exchanger medium pipeline 203, and the other end is returned through the return water pipeline 204. A module inlet valve 205 is installed on the heat exchanger medium pipeline 203, and a module outlet valve 206 is installed on the return water pipeline 204, which are used to control the activation or isolation of the primary and secondary air heating modules 200.

[0030] Combined with reference Figure 1 , Figure 2 and Figure 3 In this embodiment, the leak detection module 300 includes at least a zoned rapid leak detection device 301 and a bottom low-point liquid level sensor 302. For example... Figures 1 to 3 As shown, the zoned rapid leak detection device 301 is installed at the inclined low end of the heat exchange tube bundle 202 of the heater, and is used to monitor leaks in different tube bundle zones; the bottom low point liquid level sensor 302 is installed at the bottom of the water accumulation area of ​​the air duct 102, and is used to detect changes in liquid level at the low point of the air duct; the DCS400 is communicatively connected to the zoned rapid leak detection device 301 and the bottom low point liquid level sensor 302, respectively, and is used to collect and process the signals output by each detection device, and to provide alarm and location information when leak-related abnormalities are detected.

[0031] With the above module arrangement, the overall water accumulation status and local leakage location of the heating system can be jointly monitored without changing the original process flow of the air duct 102 and the primary and secondary air heating module 200.

[0032] In a preferred embodiment, reference Figure 2 and Figure 3The illustrated zoned rapid leak detection device 301 specifically includes multiple sets of tube bundle zone liquid storage boxes 3011, electrode level relays 3012, and air duct sealing plates 3013. The multiple sets of tube bundle zone liquid storage boxes 3011 are arranged at intervals along the tube bundle arrangement direction of the heater heat exchange tube bundle 202. Each set of tube bundle zone liquid storage boxes 3011 is correspondingly arranged below the inclined low point end of each zone of the heater heat exchange tube bundle 202, used to collect the leaked medium water from each zone. The electrode level relay 3012 is installed on the corresponding tube bundle zone liquid storage box 3011, with its electrode 3014 extending into the tube bundle zone liquid storage box 3011. When the liquid level in the box rises to the height of the electrode 3014, the electrode level relay 3012 sends a leak signal containing the location of the corresponding leaking heat exchange tube bundle zone to the DCS400. The air duct sealing plate 3013 covers the opening on the side of the tube bundle partition liquid storage box 3011 facing the air duct 102, which is used to isolate the liquid storage space of each partition from the air flow space inside the air duct 102. This ensures that the leaked water is concentrated in the box and avoids the airflow from directly washing the liquid surface, which is conducive to the stable detection of liquid level and the rapid judgment of the leak partition.

[0033] Furthermore, such as Figure 3 As shown, the zoned rapid leak detection device 301 may further include a liquid drain plug 3015 and a visual level gauge 3016. The liquid drain plug 3015 is located at the bottom of the tube bundle zoned liquid storage box 3011. When maintenance or leak confirmation is required, the liquid in the storage box can be emptied by unscrewing the liquid drain plug 3015 after isolating the corresponding primary and secondary air heating modules 200, allowing for cleaning and restoration to the initial state. The visual level gauge 3016 is installed on the air duct sealing plate 3013 and connected to the tube bundle zoned liquid storage box 3011 via a quick-connect plug. The visual level gauge 3016 adopts a transparent tube structure, allowing operation and maintenance personnel to visually observe changes in the liquid level within the corresponding zoned liquid storage box on-site. When the electrode level relay 3012 issues a leak signal, the liquid level can be verified through the transparent tube, thereby improving the reliability of leak detection and facilitating daily maintenance.

[0034] In another preferred embodiment, reference Figure 1The leakage detection module 300 shown also includes a bottom duct electric drain valve 304. A bottom low-point level sensor 302 is located at the bottom of the water accumulation area in the duct 102, and the bottom duct electric drain valve 304 is installed on the drainage pipe of the duct 102 and is communicatively connected to the DCS400. When the DCS400 receives a level signal from the bottom low-point level sensor 302 indicating that the water level in the accumulation area has reached the preset drain level, the DCS400 outputs a heater leakage alarm and controls the bottom duct electric drain valve 304 to open, draining the water accumulated at the bottom of the duct. Through this coordinated control, water can be drained promptly when an abnormal increase in water accumulation is detected in the duct 102, reducing the impact of water accumulation on downstream equipment.

[0035] Preferably, in the above embodiments, the inclination rate of the heat exchange tube bundle 202 of the heater is set to be greater than or equal to 3‰. By setting a certain inclination rate, the leaking medium water can reliably flow along the direction of the tube bundle towards the lower end of the inclination while ensuring heat exchange performance, thereby ensuring that the liquid storage boxes 3011 of each zone can fully collect the potential leaking water and improve the response effect of the zone rapid leak detection device 301 to leaks.

[0036] In the embodiments provided in this application, the partitioned rapid leakage detection device 301 and / or the bottom low point liquid level sensor 302 use an electrode liquid level relay as the liquid level detection element. The electrode 3014 of the electrode liquid level relay is selected as a round steel column structure with a diameter of not less than 10mm to improve the mechanical strength and wear resistance under dusty airflow scouring and long-term operating conditions, reduce detection failure caused by electrode bending or wear, and thus improve the long-term stability of liquid level detection.

[0037] Furthermore, in an alternative implementation, reference Figure 1 The leakage detection module 300 shown also includes a vibration detection component 303. The vibration detection component 303 is located at the position of the heat exchange medium pipeline 203 connected to the module inlet valve 205 of the primary and secondary air heater body 201. It is used to collect vibration signals reflecting the operating status of the primary and secondary air heater module 200. The DCS400 is communicatively connected to the vibration detection component 303. The DCS400 can determine the vibration condition of the heater's heat exchange tube bundle 202 based on the vibration signals output by the vibration detection component 303. When the vibration amplitude exceeds a preset value, it outputs a vibration warning message to prompt operators to pay attention to the heater's operating status, thereby intervening in abnormal vibration conditions that may lead to leakage before a leak occurs.

[0038] As can be seen from the above embodiments, the heat exchanger leakage monitoring system of this application is based on the primary and secondary air supply module 100, the primary and secondary air heating module 200 and the leakage detection module 300 to form a minimum technical solution. On this basis, through the coordinated cooperation of components such as the zoned rapid leakage detection device 301, the bottom low point liquid level sensor 302, the bottom air duct electric drain valve 304 and the vibration detection component 303 with the DCS400, the system achieves layered monitoring and zoned rapid location of leakage status of the heating system, taking into account both the timeliness of online monitoring and the accuracy of maintenance location.

[0039] This application also provides an exemplary heat exchanger leakage monitoring method for application to the above-described exemplary heat exchanger leakage monitoring system. Figure 4 A flowchart illustrating an exemplary heat exchanger leak monitoring method provided in this application. Figure 4 As shown, the method includes the following steps: S1, the DCS400 collects the liquid level signal from the liquid level sensor at the bottom low point of the water accumulation area in the air duct of the primary and secondary air supply module; S2, the DCS400 collects the monitoring information from the partitioned rapid leakage detection device at the tilted low end of the heat exchange tube bundle of the heater in the primary and secondary air heating module, and receives the leakage signal containing the location of the corresponding leaking heat exchange tube bundle when a leak occurs in the heat exchange tube bundle of the heater; S3, the DCS400 determines whether the water level in the water accumulation area of ​​the air duct has reached the preset drain level based on the liquid level signal, and indicates the location of the leaking heat exchange tube bundle based on the leakage signal.

[0040] Figure 5 The flowchart of the three-layer monitoring method provided in this application is shown below. Figure 5 As shown, based on the above exemplary heat exchanger leakage monitoring system, the heater leakage monitoring system equipped with vibration detection component 303 can apply the following three-layer monitoring method process of "liquid level monitoring - zone positioning - vibration early warning".

[0041] In the bottom liquid level monitoring, after executing step S1 above, the DCS400 executes step S3.1 based on the liquid level signal from the bottom low-point liquid level sensor 302 to determine whether the water level in the water accumulation area of ​​the air duct 102 has reached the preset drain level. If yes, step S3.4 is executed, outputting a heater leak alarm message and controlling the bottom air duct electric drain valve 304 to open, thus draining the water accumulated at the bottom of the air duct 102 in an emergency. If no, the liquid level signal from the bottom low-point liquid level sensor 302 continues to be periodically collected to continuously monitor the water accumulation in the air duct. Through this monitoring, the drain action can be triggered in a timely manner when an abnormal water accumulation trend occurs in the air duct 102, preventing the water level from continuing to rise.

[0042] In the zoned rapid leak detection, after executing step S2 above, the DCS400 executes step S3.2 based on the monitoring information from the zoned rapid leak detection device 301 to determine whether there is a leak signal from a certain zone. If yes, step S3.5 is executed, indicating the location of the corresponding leaking heat exchanger tube bundle zone according to the zone identifier carried in the leak signal, and displaying or alarming on the DCS400 operation screen. If no, the monitoring information from the zoned rapid leak detection device 301 continues to be collected to continuously monitor the leak status of each zone. Through this monitoring, the leaking zone can be quickly located when a local leak occurs in the heater heat exchanger tube bundle 202, providing a clear location basis for subsequent maintenance.

[0043] In vibration monitoring, the DCS400 executes step S4 to collect the vibration signal output by the vibration detection component 303, and in step S3.3, it determines whether the amplitude of the vibration signal exceeds a preset value. If so, it executes step S3.6 to output vibration warning information to remind maintenance personnel to pay attention to the operating status of the primary and secondary air heating modules 200. If not, it continues to collect the vibration signal of the vibration detection component 303 to achieve continuous monitoring of the vibration condition of the heater heat exchange tube bundle 202. Through this monitoring, abnormal vibration conditions that may induce leakage can be warned in advance, which helps maintenance personnel to take measures such as adjusting the load and optimizing the operating conditions before leakage occurs.

[0044] Based on the aforementioned three-layer monitoring process, when the DCS400 outputs a heater leak alarm and indicates the specific leak zone, operators can isolate the corresponding primary and secondary air heater modules 200 according to the alarm information. For example, they can close the module inlet valve 205 and the module outlet valve 206 to stop the heat exchange medium supply to the leaking zone. Subsequently, after shutdown and cooling, maintenance personnel can drain the liquid in the corresponding tube bundle zone's liquid storage box 3011 by opening the drain plug 3015 and, in conjunction with the change in the liquid level in the transparent tube of the visual level gauge 3016, verify the leak on-site. At the same time, they can clean the accumulated water and dust in the liquid storage box and, if necessary, further inspect and treat the leaking heat exchange tube bundle 202. For vibration warning information, maintenance personnel can arrange on-site inspections based on the warning records provided by DCS400, check the operating status of heat exchange medium pipeline 203, support structure and primary and secondary air heater body 201, and adjust the operation mode or arrange maintenance plan according to the actual situation, thereby comprehensively reducing the risk of leakage and related failures in the heating system.

[0045] In summary, this application constructs a rapid leak detection device 301 for the inclined low end of the heat exchange tube bundle 202 of the heater, a bottom low-point liquid level sensor 302 for the water accumulation area of ​​the air duct 102, and a matching electric drain valve 304 and vibration detection component 303 for the bottom air duct in the primary and secondary air supply module 100 and the primary and secondary air heating module 200 of the boiler's primary and secondary air system. All the above detection signals are then uniformly connected to the DCS400, thus constructing a heater leak monitoring system that combines "vibration early warning - bottom water accumulation monitoring - rapid leak detection in zones". By employing the inclined arrangement of the heater heat exchanger tube bundle 202 and the coordination of multiple tube bundle partitioned liquid storage boxes 3011, electrode level relays 3012, electrodes 3014, duct sealing plates 3013, liquid drain plugs 3015, and visual level gauges 3016, this application can automatically release water when abnormal water accumulation occurs in the duct 102. It can also quickly indicate the location of the leaking heat exchanger tube bundle when leakage occurs in a single or localized area. Leak confirmation and maintenance are achieved through intuitive liquid level observation and manual water release. Furthermore, combined with the vibration detection component 303 for early warning monitoring of operating conditions, leaks in the heating system can be detected early, accurately located, and dealt with promptly. This effectively reduces the impact of duct water accumulation and heater leaks on downstream equipment such as fans and air preheaters, improving the safety and maintainability of the unit operation.

[0046] The above embodiments are provided only to help understand the methods, structures, and core ideas of this application. Those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A heat exchanger leakage monitoring system, characterized in that, Includes primary and secondary air supply modules, primary and secondary air heating modules, and leakage detection modules; The primary and secondary air supply modules include at least one air duct, and the air duct has at least one water accumulation area. The primary and secondary air heating module includes a primary and secondary air heater body and a heater heat exchange tube bundle, wherein the heater heat exchange tube bundle is inclinedly arranged in the primary and secondary air heater body. The leak detection module includes a zoned rapid leak detection device, a bottom low-point liquid level sensor, and a DCS; the zoned rapid leak detection device is located at the inclined low end of the heat exchange tube bundle of the heater; the bottom low-point liquid level sensor is located at the water accumulation area of ​​the air duct; the DCS is communicatively connected to the zoned rapid leak detection device and the bottom low-point liquid level sensor.

2. The heat exchanger leakage monitoring system as described in claim 1, characterized in that, The leakage detection module also includes a vibration detection component; The vibration detection component is located at the position of the heat exchange medium pipeline connected to the inlet valve of the primary and secondary air heater body, and is used to collect vibration signals of the working state of the primary and secondary air heater module. The DCS communication is connected to the vibration detection component and is configured to determine the vibration condition of the heater heat exchange tube bundle based on the vibration signal, so as to output vibration warning information when the vibration signal exceeds a preset value.

3. The heat exchanger leakage monitoring system as described in claim 1, characterized in that, The partitioned rapid leakage detection device includes multiple sets of tube bundle partitioned liquid storage boxes, electrode liquid level relays, and air duct sealing plates; Each of the tube bundle partition liquid storage boxes, electrode liquid level relays and air duct sealing plates is respectively set below the inclined low end of the heat exchange tube bundle of the heater in each partition. The tube bundle partition liquid storage box is used to collect the medium water leaked from the heat exchange tube bundle of the heater. The electrode liquid level relay is installed on the tube bundle partition liquid storage box, and its electrode extends into the interior of the tube bundle partition liquid storage box. The air duct sealing plate covers the opening of the tube bundle partition liquid storage box facing the air duct to isolate the tube bundle partition liquid storage box from the interior space of the air duct. The electrode level relay is configured to send a leakage signal to the DCS, which includes the location of the corresponding leak in the heat exchange tube bundle, when the water level in the tube bundle partition storage box reaches the electrode installation position.

4. The heat exchanger leakage monitoring system as described in claim 3, characterized in that, The zoned rapid leak detection device also includes a liquid accumulation drain plug and a visual level gauge; The liquid drain plug is located at the bottom of the tube bundle partitioned liquid storage box and is used to drain the liquid accumulated in the tube bundle partitioned liquid storage box after isolating the primary and secondary air heating modules. The visual level gauge is installed on the air duct sealing plate and is connected to the tube bundle partitioned liquid storage box through a quick plug. The visual level gauge adopts a transparent tube structure.

5. The heat exchanger leakage monitoring system as described in any one of claims 1 to 4, characterized in that, The leak detection module also includes an electrically operated drain valve in the bottom air duct; The bottom low-point liquid level sensor is located at the bottom of the water accumulation area in the air duct; The bottom air duct electric drain valve is installed on the drain pipe of the air duct and is communicatively connected to the DCS. The DCS is also configured to receive the liquid level signal sent by the bottom low-point liquid level sensor, and when it determines that the liquid level in the water accumulation area has reached the preset drain level based on the liquid level signal, it outputs a leakage alarm message and controls the bottom air duct electric drain valve to open.

6. The heat exchanger leakage monitoring system as described in any one of claims 1 to 4, characterized in that, The inclination rate of the heat exchange tube bundle of the heater is greater than or equal to 3‰.

7. The heat exchanger leakage monitoring system as described in any one of claims 1 to 4, characterized in that, The partitioned rapid leakage detection device and / or the bottom low point liquid level sensor use an electrode liquid level relay as the liquid level detection element, and the electrode of the electrode liquid level relay is made of a round steel column with a diameter greater than or equal to 10 mm.

8. A method for monitoring leaks in a heat exchanger, characterized in that, Includes the following steps: S1, collects the liquid level signal in the water accumulation area of ​​the air duct in the primary and secondary air supply modules; S2, collects monitoring information from the partitioned rapid leakage detection device set at the low end of the tilted heat exchange tube bundle of the heater in the primary and secondary air heating modules, and receives a leakage signal containing the location of the corresponding leaking heat exchange tube bundle when a leak occurs in the heat exchange tube bundle of the heater. S3, determine whether the water level in the water accumulation area has reached the preset drain level based on the liquid level signal, and indicate the location of the leaking heat exchange tube bundle based on the leakage signal.

9. The heat exchanger leakage monitoring method as described in claim 8, characterized in that, Also includes: Collect and set the vibration signal output by the vibration detection component; When the amplitude of the vibration signal exceeds a preset value, a vibration warning message is output.

10. The heat exchanger leakage monitoring method as described in claim 8, characterized in that, Step S3 further includes: When the accumulated water level reaches the preset drain level, a heater leakage alarm message is output, and emergency water is drained from the bottom of the air duct.

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