Sensor-based test method and system for performance of a spiral wound heat exchanger

Abstract

The embodiment of the application provides a kind of based on sensor's winding tube heat exchanger performance test method and system, it is related to winding tube heat exchanger performance test technical field, method includes by sensor obtains the surface temperature distribution data of winding tube heat exchanger outer wall to determine heat exchange condition, based on external heat exchange condition, preset winding tube heat exchanger's structure parameter and the thermal physical property of winding tube material, obtain the heat transfer state in each local area in winding tube heat exchanger interior and calculate the local heat transfer coefficient of each local area in winding tube heat exchanger interior;According to the local heat transfer coefficient of each local area and the preset reference coefficient value, obtain the distribution state of winding tube heat exchanger interior scale formation and calculate the thermal stress of winding tube heat exchanger interior structure to judge the potential damage risk of winding tube heat exchanger interior structure.The application can improve the safety, reliability and energy efficiency evaluation accuracy of winding tube heat exchanger operation.

Description

Technical Field

[0001] This application relates to the field of heat exchanger performance testing technology, and more specifically, to a sensor-based method and system for testing the performance of wound tube heat exchangers. Background Technology

[0002] In the performance verification of industrial heat exchange systems, especially wound tube heat exchangers, traditional testing methods mainly rely on manually operated temperature and pressure gauges and offline data analysis. This approach not only results in poor real-time performance and limited data dimensions, but also leads to delayed responses to abnormal operating conditions. Especially when wound tube heat exchangers operate under high temperature and high pressure environments, even minor deformations or uneven fluid distribution are difficult for conventional testing methods to capture, potentially leading to biased energy efficiency assessments and even creating potential safety hazards. When conducting long-term performance testing on wound tube heat exchangers used in the synthesis of new chemical materials, existing systems primarily assess overall thermal performance by monitoring the overall fluid parameters at the equipment inlet and outlet. However, in actual industrial fluid environments, particularly when the hot fluid side uses circulating process fluids containing trace amounts of catalyst residues and unreacted monomers, severe localized scaling may occur inside the wound tube heat exchanger due to uneven flow fields. This uneven scaling not only reduces overall heat exchange efficiency but also causes uneven temperature distribution within the tube bundle. Under high temperature and high pressure environments, this uneven temperature distribution leads to inconsistent thermal expansion in different areas of the tubes, resulting in localized thermal stress concentration. This thermal stress concentration can cause contact and compression between adjacent pipes that were originally designed with minute gaps, or between pipes and supporting baffles, due to differences in deformation. This can even induce high-frequency micro-vibrations and friction. These mechanical problems caused by localized overheating and uneven thermal stress are completely imperceptible to traditional testing systems that only focus on inlet and outlet fluid parameters. The decrease in the overall heat transfer coefficient monitored by the system is merely a comprehensive external manifestation of this complex internal problem; it masks the more dangerous localized structural stress concentration and material fatigue accumulation occurring internally. Ultimately, before the overall thermal performance deteriorates to the point of requiring cleaning, a localized area of ​​the pipe may wear down due to long-term vibration and friction, even developing fatigue cracks, causing high-pressure fluid leakage and triggering serious safety accidents. Existing testing methods cannot penetrate the equipment casing to effectively monitor and diagnose the distribution of this internal scaling and the resulting localized thermo-mechanical coupling effects. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a sensor-based performance testing method and system for wound tube heat exchangers, aiming to improve the safety, reliability, and accuracy of energy efficiency assessment of wound tube heat exchanger operation.

[0004] In a first aspect, embodiments of this application provide a sensor-based performance testing method for wound tube heat exchangers, applied to wound tube heat exchangers, comprising: Data on the surface temperature distribution of the outer wall of the wound tube heat exchanger is obtained using sensors. Based on the surface temperature distribution data, the heat exchange conditions outside the wound tube heat exchanger are determined, wherein the heat exchange conditions outside the wound tube heat exchanger characterize the boundary conditions when heat transfer occurs between the outer wall of the wound tube heat exchanger and the external heat exchange medium. Based on the external heat exchange conditions, the preset structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material, the heat transfer state of each local area inside the wound tube heat exchanger is obtained. Based on the heat transfer state of each local area, calculate the local heat transfer coefficient of each local area inside the wound tube heat exchanger. Based on the local heat transfer coefficient of each local area and the preset reference coefficient value, the distribution state of the fouling inside the wound tube heat exchanger is obtained. Based on the distribution of the scale, the thermal stress of the internal structure of the wound tube heat exchanger is calculated. Based on the thermal stress, the potential damage risk to the internal structure of the wound tube heat exchanger is determined.

[0005] According to some embodiments of this application, obtaining the heat transfer state of each local region inside the wound tube heat exchanger based on the external heat exchange conditions, the preset structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material includes: Based on the external heat exchange conditions, the pre-set structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material, the local heat flux density and temperature distribution of each local area inside the wound tube heat exchanger are derived in reverse using the finite element method. Based on the local heat flux density and the temperature distribution, the heat transfer state of each local area inside the wound tube heat exchanger is obtained.

[0006] According to some embodiments of this application, calculating the local heat transfer coefficient of each local region inside the wound tube heat exchanger based on the heat transfer state of each local region includes: Obtain the fluid inlet temperature of the wound tube heat exchanger; Based on the heat transfer status of each local area and the fluid inlet temperature, the local heat transfer coefficient of each local area inside the wound tube heat exchanger is calculated.

[0007] According to some embodiments of this application, obtaining the distribution state of fouling inside the wound tube heat exchanger based on the local heat transfer coefficient of each local region and a preset reference coefficient value includes: The local heat transfer coefficient of each local area is compared with a preset reference coefficient value to determine the distribution location of the scale inside the wound tube heat exchanger. The thickness of the scale in each local area inside the wound tube heat exchanger is obtained by calculating the local heat transfer coefficient of each local area and the preset reference coefficient value. Based on the distribution location and the thickness, the distribution state of the scale inside the wound tube heat exchanger is obtained.

[0008] According to some embodiments of this application, the local heat transfer coefficient of each local region is compared with a preset reference coefficient value to determine the distribution location of fouling inside the wound tube heat exchanger, including: The local heat transfer coefficient of each local region is compared with a preset reference coefficient value to obtain the comparison result; When the comparison result indicates that the local heat transfer coefficient is less than the preset reference coefficient value, it is determined that there is scaling at the corresponding local location inside the wound tube heat exchanger; When the comparison result indicates that the local heat transfer coefficient is greater than or equal to the preset reference coefficient value, it is determined that there is no scaling at the corresponding local location inside the wound tube heat exchanger.

[0009] According to some embodiments of this application, the step of calculating the thickness of scale in each local area inside the wound tube heat exchanger by comparing the local heat transfer coefficient of each local area with a preset reference coefficient value includes: The scaling thermal resistance of the scale in each local area inside the wound tube heat exchanger is obtained by calculating the local heat transfer coefficient of each local area and the preset reference coefficient value. Obtain the thermal conductivity of the scale inside the wound tube heat exchanger; The thickness of the scale in each local area inside the wound tube heat exchanger is obtained based on the scaling thermal resistance and the thermal conductivity.

[0010] According to some embodiments of this application, calculating the thermal stress of the internal structure of the wound tube heat exchanger based on the distribution state of the scale includes: Based on the distribution of the scale, the actual temperature gradient of each local area inside the wound tube heat exchanger is determined. Obtain the coefficient of thermal expansion and elastic modulus of the wound tube heat exchanger; The thermal stress of the internal structure of the wound tube heat exchanger is calculated based on the actual temperature gradient, the coefficient of thermal expansion, and the elastic modulus.

[0011] According to some embodiments of this application, determining the potential damage risk to the internal structure of the wound tube heat exchanger based on the thermal stress includes: The thermal stress is compared with the preset thermal stress to obtain the comparison result, wherein the preset thermal stress is the allowable stress limit of the material of the wound tube heat exchanger under high temperature and high pressure. The potential damage risk to the internal structure of the wound tube heat exchanger is determined based on the comparison results.

[0012] According to some embodiments of this application, determining the potential damage risk to the internal structure of the wound tube heat exchanger based on the comparison result includes: When the comparison result indicates that the thermal stress is greater than the preset thermal stress, the potential damage risk of the internal structure of the wound tube heat exchanger is determined, wherein the damage risk includes inter-tube contact extrusion, aggravation of high-frequency micro-vibration, and material fatigue accumulation.

[0013] Secondly, this application also discloses a sensor-based performance testing system for wound tube heat exchangers, applied to wound tube heat exchangers, comprising: The acquisition module is used to acquire surface temperature distribution data of the outer wall of the wound tube heat exchanger through sensors; The determination module is used to determine the heat exchange conditions outside the wound tube heat exchanger based on the surface temperature distribution data, wherein the heat exchange conditions outside the wound tube heat exchanger characterize the boundary conditions when heat transfer occurs between the outer wall of the wound tube heat exchanger and the external heat exchange medium. The state determination module is used to determine the heat transfer state of each local area inside the wound tube heat exchanger based on the external heat exchange conditions, the preset structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material. The coefficient calculation module is used to calculate the local heat transfer coefficient of each local area inside the wound tube heat exchanger based on the heat transfer state of each local area. The comparison module is used to obtain the distribution state of fouling inside the wound tube heat exchanger based on the local heat transfer coefficient of each local area and the preset reference coefficient value. A thermal stress calculation module is used to calculate the thermal stress of the internal structure of the wound tube heat exchanger based on the distribution state of the scale. The judgment module is used to determine the potential damage risk to the internal structure of the wound tube heat exchanger based on the thermal stress.

[0014] The technical solution according to the embodiments of this application has at least the following beneficial effects: This application provides a sensor-based performance testing method for wound tube heat exchangers. By deploying sensors on the outer wall of the wound tube heat exchanger to acquire surface temperature distribution data, and based on this, combined with finite element inversion technology, the heat transfer state, local heat transfer coefficient, and the distribution state and thickness of scale in various local areas inside the wound tube heat exchanger can be accurately derived. This method further calculates the thermal stress of the internal structure based on the scale distribution state and compares it with the allowable stress limit, thereby determining the potential damage risk to the internal structure of the wound tube heat exchanger, including inter-tube contact compression, aggravated high-frequency micro-vibrations, and material fatigue accumulation. Compared with traditional methods relying on manual operation and offline analysis, the technical solution of this application overcomes the shortcomings of poor real-time performance, single data dimension, and inability to capture local abnormal operating conditions. By non-invasive, real-time monitoring and diagnosis of the internal scale distribution and the resulting local thermal stress in the wound tube heat exchanger, this application can effectively solve the problems of uneven temperature distribution and thermal stress concentration caused by local scale in the prior art. It avoids the safety hazards that may be caused by the inability of traditional methods to detect internal lesions, and significantly improves the safety, reliability and accuracy of energy efficiency assessment of the wound tube heat exchanger.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0017] Figure 1 A schematic flowchart of a sensor-based performance testing method for a wound tube heat exchanger provided in one embodiment of this application; Figure 2 This is a schematic diagram of a sensor-based performance testing system for a wound tube heat exchanger, provided as an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical methods, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] It should be noted that the meaning of "multiple" (or "more than") in the description of the embodiments of this application refers to two or more, and "greater than," "less than," "exceeding," etc. are understood to exclude the number itself, while "above," "below," "within," etc. are understood to include the number itself. If "first," "second," etc. are used in the description, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0020] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: the existence of a alone, the existence of b alone, the existence of c alone, the simultaneous existence of a and b, the simultaneous existence of a and c, the simultaneous existence of b and c, or the simultaneous existence of a, b, and c, where a, b, and c can be single or multiple.

[0021] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0022] Based on the above, this application proposes a sensor-based performance testing method and system for wound tube heat exchangers, aiming to improve the safety, reliability, and accuracy of energy efficiency assessment of wound tube heat exchangers.

[0023] The sensor-based performance testing method for wound tube heat exchangers provided in this application can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, etc.; the server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDN), and big data and artificial intelligence platforms; the software can be an application that implements the sensor-based performance testing method for wound tube heat exchangers, etc., but is not limited to the above forms.

[0024] This application can be applied to numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via communication networks. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices. It should be noted that in various specific embodiments of this invention, when processing is required based on data related to the characteristics of an object (e.g., user attributes or sets of attribute information), permission or consent from the corresponding object is obtained first, and the collection, use, and processing of this data comply with relevant laws and standards. Furthermore, when the embodiments of the present invention need to obtain the attribute information of an object, they will obtain the separate permission or separate consent of the corresponding object through pop-up windows or redirection to a confirmation page. After obtaining the separate permission or separate consent of the corresponding object, they will then obtain the relevant data of the object necessary for the embodiments of the present invention to operate normally.

[0025] See Figure 1 , Figure 1 This is a schematic flowchart illustrating a sensor-based performance testing method for wound tube heat exchangers according to an embodiment of this application. The sensor-based performance testing method for wound tube heat exchangers provided in this embodiment includes, but is not limited to, steps S110 to S170, which are described in detail below.

[0026] Step S110: Obtain surface temperature distribution data of the outer wall of the wound tube heat exchanger using a sensor; Step S120: Determine the heat exchange conditions outside the wound tube heat exchanger based on the surface temperature distribution data. The heat exchange conditions outside the wound tube heat exchanger characterize the boundary conditions when heat transfer occurs between the outer wall of the wound tube heat exchanger and the external heat exchange medium. Step S130: Based on external heat exchange conditions, preset structural parameters of the wound tube heat exchanger, and thermophysical properties of the wound tube material, obtain the heat transfer state of each local area inside the wound tube heat exchanger. Step S140: Calculate the local heat transfer coefficient of each local area inside the wound tube heat exchanger based on the heat transfer state of each local area. Step S150: Based on the local heat transfer coefficient of each local area and the preset reference coefficient value, the distribution state of fouling inside the wound tube heat exchanger is obtained. Step S160: Calculate the thermal stress of the internal structure of the spiral tube heat exchanger based on the distribution of scale. Step S170: Based on thermal stress, determine the potential damage risk to the internal structure of the wound tube heat exchanger.

[0027] It should be noted that a "wound tube heat exchanger" is a highly efficient and compact heat exchange device, composed of multiple spirally wound heat exchange tube bundles, and is widely used in liquefied natural gas, petrochemical, and other fields. "Sensor" here refers to a device capable of measuring temperature and outputting an electrical signal, such as a thermocouple, resistance temperature detector (RTD), or infrared thermal imager, used to acquire surface temperature distribution data of the outer wall of the wound tube heat exchanger. "Surface temperature distribution data" refers to the set of temperature measurements at different locations on the outer wall of the wound tube heat exchanger; these data reflect the heat exchange between the heat exchanger's exterior and the environment or external heat exchange medium. "External heat exchange conditions" refer to the boundary conditions during heat transfer between the outer wall of the wound tube heat exchanger and the external heat exchange medium, such as the convective heat transfer coefficient and ambient temperature; it characterizes the intensity of external heat loss or absorption. "Structural parameters of the wound tube heat exchanger" include geometric information such as the diameter, wall thickness, winding pitch, tube bundle arrangement, and shell dimensions of the wound tubes. "Thermophysical properties of the wound tube material" refers to the physical properties of the wound tube material related to heat transfer and mechanical deformation, such as thermal conductivity, specific heat capacity, density, coefficient of thermal expansion, and modulus of elasticity. "Local heat transfer state" refers to the heat flux density and temperature distribution in various small regions inside the wound tube heat exchanger. "Local heat transfer coefficient" refers to the heat transfer intensity index between the fluid and the tube wall in various local regions inside the wound tube heat exchanger. "Reference coefficient value" is a preset baseline heat transfer coefficient value used to assess the fouling condition inside the wound tube heat exchanger, typically corresponding to normal operation with no or slight fouling. "Fouling distribution state" refers to information such as the location, thickness, and coverage of fouling inside the wound tube heat exchanger. "Thermal stress" refers to the internal stress of an object caused by temperature changes or uneven temperature distribution. "Damage risk" refers to the failure modes that may occur in the internal structure of the wound tube heat exchanger due to excessive thermal stress, such as inter-tube contact compression, increased high-frequency micro-vibrations, and material fatigue accumulation.

[0028] First, surface temperature distribution data of the outer wall of the wound tube heat exchanger is acquired using sensors. Multiple temperature sensors, such as thermocouple arrays, can be placed at different locations on the outer wall of the wound tube heat exchanger to monitor and record the temperature values ​​at each point in real time. Alternatively, an infrared thermal imager can be used to scan the outer wall of the wound tube heat exchanger to obtain temperature distribution image data of the entire outer wall surface. This data forms the basis for subsequent analysis, reflecting the heat exchange between the wound tube heat exchanger and the external environment. Second, based on the surface temperature distribution data, the external heat exchange conditions of the wound tube heat exchanger are determined. Based on the measured surface temperature distribution data, combined with information such as ambient temperature and air velocity, the convective heat transfer coefficient between the outer wall of the wound tube heat exchanger and the external heat exchange medium can be calculated using empirical formulas or numerical simulation methods. In addition, the influence of radiative heat transfer can be considered to more comprehensively characterize the external heat exchange conditions. These external heat exchange conditions are the boundary conditions for reverse thermal analysis. Next, based on the external heat exchange conditions, the preset structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material, the heat transfer state of each local region inside the wound tube heat exchanger is obtained. Finite element analysis software can be used to input the geometric model, material properties, and external heat exchange conditions of the wound tube heat exchanger into a simulation model. By solving the steady-state or transient heat conduction equations, the temperature distribution and heat flux density of each local region inside the wound tube heat exchanger can be derived in reverse, thus obtaining its heat transfer state. Then, based on the heat transfer state of each local region, the local heat transfer coefficient of each local region inside the wound tube heat exchanger can be calculated. Based on the obtained local heat flux density and local temperature distribution, combined with the inlet temperature of the fluid inside the wound tube heat exchanger, the convective heat transfer coefficient of each local region, i.e., the local heat transfer coefficient, can be calculated using basic heat transfer formulas. Subsequently, based on the local heat transfer coefficient of each local region and a preset reference coefficient value, the distribution state of fouling inside the wound tube heat exchanger can be obtained. The calculated local heat transfer coefficient can be compared with the preset reference coefficient value for no fouling or slight fouling. If the local heat transfer coefficient of a certain local region is significantly lower than the reference coefficient value, it indicates that fouling may exist in that region. Through this comparison, the location of fouling distribution can be determined. Furthermore, the thickness of the scale can be estimated based on the degree of decrease in the local heat transfer coefficient and the thermal conductivity of the scale, thus obtaining the scale distribution. Next, based on the scale distribution, the thermal stress of the internal structure of the wound tube heat exchanger can be calculated. For example, based on the location and thickness of the scale, the actual temperature gradient of each local area inside the wound tube heat exchanger can be determined. Combining the thermal expansion coefficient and elastic modulus of the wound tube material, the thermal stress generated by the uneven temperature distribution within the internal structure of the wound tube heat exchanger can be calculated using a thermal stress calculation model. Finally, based on the thermal stress, the potential damage risk to the internal structure of the wound tube heat exchanger can be assessed.The calculated thermal stress can be compared with the allowable stress limit of the wound tube material under high temperature and high pressure. If the thermal stress exceeds the allowable stress limit, it indicates that there is a potential risk of damage to the internal structure of the wound tube heat exchanger, such as inter-tube contact compression, increased high-frequency micro-vibration, and material fatigue accumulation.

[0029] This application embodiment achieves comprehensive, real-time monitoring of the internal operating status of a wound tube heat exchanger by combining external non-destructive measurement with internal state inference. First, the application acquires surface temperature distribution data of the outer wall of the wound tube heat exchanger using sensors. This data directly reflects the internal heat transfer state of the heat exchanger. Next, based on this surface temperature distribution data and the characteristics of the external heat exchange medium, the external heat exchange conditions of the wound tube heat exchanger are determined, providing accurate boundary conditions for subsequent reverse thermal analysis. Based on this, using the structural parameters and material thermophysical properties of the wound tube heat exchanger, advanced numerical simulation methods (such as the finite element method) are used to reverse-engineer the heat transfer state of each local region inside the wound tube heat exchanger, including local heat flux density and temperature distribution. Subsequently, based on the obtained local heat transfer state, the local heat transfer coefficient of each local region is calculated. These local heat transfer coefficients directly reflect the heat exchange efficiency of that region. By comparing these local heat transfer coefficients with preset reference coefficient values, the distribution location and thickness of fouling inside the wound tube heat exchanger can be accurately identified, thus obtaining the fouling distribution state. Scaling is one of the main causes of decreased heat exchange efficiency and localized overheating. Furthermore, based on the distribution of scale, the actual temperature gradient in various local areas inside the wound tube heat exchanger can be determined. Combined with the material's coefficient of thermal expansion and elastic modulus, the thermal stress of the internal structure of the wound tube heat exchanger can be calculated. Thermal stress is a direct cause of structural deformation, fatigue, and even failure. Finally, by comparing the calculated thermal stress with the material's allowable stress limit, it is possible to determine whether there are potential damage risks to the internal structure of the wound tube heat exchanger and identify specific damage modes, such as inter-tube contact compression, intensified high-frequency micro-vibrations, and material fatigue accumulation.

[0030] It is worth noting that this application can reveal the scaling condition, heat transfer characteristics, and resulting mechanical response inside the wound tube heat exchanger layer by layer from external non-destructive measurement data, ultimately achieving early warning and diagnosis of potential damage risks. This method not only solves the problems of poor real-time performance, single data dimension, and inability to detect internal local lesions in traditional testing methods, but also provides a scientific and accurate basis for the safe operation and maintenance of wound tube heat exchangers, significantly improving the operational reliability and economy of the equipment. This application's embodiments introduce sensors to acquire surface temperature distribution data of the outer wall of the wound tube heat exchanger and combine it with reverse thermal analysis technology to achieve a "penetration" of the internal state of the wound tube heat exchanger. Specifically, through precise measurement of the external surface temperature distribution data, this application can reversely deduce the heat transfer state of various local areas inside the wound tube heat exchanger, including local heat flux density and temperature distribution. This is something that existing technologies cannot directly achieve. Based on these internal heat transfer states, this application further calculates the local heat transfer coefficient of each local area and compares it with a reference coefficient value, thereby accurately obtaining the distribution state of scaling inside the wound tube heat exchanger, including the location and thickness of the scaling. This capability allows maintenance personnel to accurately locate areas of scale buildup and perform targeted cleaning, avoiding problems such as blind cleaning or incomplete cleaning.

[0031] In some embodiments described above, this application proposes obtaining the heat transfer state of various local regions within the spiral wound tube heat exchanger based on external heat exchange conditions, preset structural parameters of the spiral wound tube heat exchanger, and the thermophysical properties of the spiral wound tube material. However, in practical applications, the structure of the spiral wound tube heat exchanger is complex, and the internal heat transfer process is affected by various factors. If derivation is performed solely using simple physical models or empirical formulas, it may be difficult to accurately capture the fine heat transfer state of each local region, thus affecting the accuracy of subsequent fouling distribution and damage risk assessment. Therefore, this application further proposes the following steps for obtaining the heat transfer state of each local region within the spiral wound tube heat exchanger: Based on external heat exchange conditions, pre-set structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material, the local heat flux density and temperature distribution of each local region inside the wound tube heat exchanger are derived in reverse using the finite element method. Based on the local heat flux density and temperature distribution, the heat transfer state of each local area inside the wound tube heat exchanger is obtained.

[0032] Specifically, the finite element method (FEM) is a numerical calculation method that discretizes a complex continuum into a finite number of simple elements, solves each element, and finally integrates them to obtain an approximate solution for the entire system. In the performance testing of wound tube heat exchangers, the FEM can accurately simulate the complex geometry and material properties of the heat exchanger, thus providing a high-precision computational basis for analyzing the internal heat transfer state. Inverse derivation refers to the process of using known external boundary conditions (such as external heat exchange conditions) and internal structural parameters and material thermophysical properties to infer internal physical quantities (such as local heat flux density and temperature distribution) that are difficult to measure directly through numerical simulation or optimization algorithms. Its purpose is to accurately inversely deduce the internal thermal parameters of the wound tube heat exchanger using externally measurable data when detailed internal data cannot be directly obtained. Local heat flux density and temperature distribution are key parameters characterizing the internal heat transfer state of a wound tube heat exchanger. Local heat flux density reflects the rate and direction of heat transfer per unit area, while temperature distribution directly reflects the temperature field characteristics of each local region.

[0033] This application's solution addresses the insufficient accuracy of traditional methods in acquiring the internal heat transfer state of complex wound tube heat exchangers by introducing the finite element method (FEM) and reverse derivation techniques. The FEM can accurately model the complex geometry and non-uniform material distribution of wound tube heat exchangers, providing a solid foundation for simulating the heat transfer process. Based on this, through reverse derivation, using surface temperature distribution data acquired from external sensors as boundary conditions, combined with preset structural parameters and material thermophysical properties, the local heat flux density and temperature distribution of various local regions inside the wound tube heat exchanger can be calculated with high precision. This method avoids the difficulty of directly measuring the internal state while ensuring the accuracy and reliability of the obtained heat transfer state data. The heat transfer state of various local regions inside the wound tube heat exchanger can be determined more accurately, providing more reliable input data for subsequent calculations of local heat transfer coefficients, assessment of fouling distribution, and thermal stress analysis. This significantly improves the overall accuracy and diagnostic capability of wound tube heat exchanger performance testing, helping to identify potential problems earlier, optimize operating strategies, and extend equipment lifespan.

[0034] In some preferred embodiments, when performing performance testing on a running wound tube heat exchanger, firstly, surface temperature distribution data is acquired in real time using multiple sensors arranged on the outer wall of the heat exchanger. Simultaneously, the detailed structural parameters of the heat exchanger (e.g., diameter, spacing, number of layers, shell dimensions, etc. of the wound tubes) and the thermophysical properties of the wound tube and shell materials (e.g., thermal conductivity, specific heat capacity, density, etc.) are known. This data is input into a pre-established simulation model based on the finite element method. The simulation model discretizes the wound tube heat exchanger into millions of tiny elements and considers the material properties and interactions of each element. By applying a back-derivative algorithm, the model uses the external surface temperature distribution data as known boundary conditions to iteratively calculate and converge to obtain the precise temperature and heat flux density distributions of various local regions inside the wound tube heat exchanger (including the wound tube wall, the fluid inside the tubes, and the fluid between the tubes). In a certain local region, if the external surface temperature shows an anomaly, the temperature gradient and heat flux direction within that region can be accurately determined through back-derivative, thus obtaining the detailed heat transfer state of that local region.

[0035] Specifically, in some embodiments of the above method, in order to more accurately calculate the local heat transfer coefficient of each local region inside the wound tube heat exchanger, this application further proposes specific calculation steps. The calculation of the local heat transfer coefficient of each local region inside the wound tube heat exchanger based on the heat transfer state of each local region includes: Obtain the fluid inlet temperature of the wound tube heat exchanger; Calculate the local heat transfer coefficient of each local area inside the wound tube heat exchanger by considering the heat transfer status and fluid inlet temperature of each local area.

[0036] The acquisition of the fluid inlet temperature in a wound tube heat exchanger involves measuring the initial temperature of the fluid entering the heat exchanger in real time or periodically using a temperature sensor installed at the fluid inlet. This fluid inlet temperature is a key parameter for calculating the local heat transfer coefficient within the heat exchanger, as it directly affects the temperature distribution and heat transfer process of the fluid inside the heat exchanger. The calculation of the local heat transfer coefficient for each local region within the wound tube heat exchanger is accomplished by combining the obtained heat transfer state of each local region with the acquired fluid inlet temperature. The heat transfer state typically includes information such as local heat flux density and temperature distribution, while the fluid inlet temperature provides the initial thermal boundary conditions on the fluid side. By substituting this information into the corresponding heat transfer calculation model or empirical formula, the heat transfer coefficient for each local region can be accurately derived. A variant of Newton's law of cooling can be used, where the local heat flux density is related to the local temperature difference (the difference between the local fluid temperature and the local wall temperature) and the local heat transfer coefficient. The fluid inlet temperature helps establish the overall temperature field of the fluid inside the heat exchanger, thereby more accurately determining the local temperature difference.

[0037] It should be noted that the proposed solution incorporates the fluid inlet temperature of the wound tube heat exchanger, enabling the calculation of the local heat transfer coefficient to fully consider the actual thermal parameters on the fluid side. During heat exchanger operation, the fluid inlet temperature is a crucial factor affecting internal heat transfer efficiency and temperature distribution. Calculating the local heat transfer coefficient solely based on the heat transfer states (such as local heat flux density and temperature distribution) of various local areas within the wound tube heat exchanger may not fully reflect the actual heat transfer situation on the fluid side. Obtaining the fluid inlet temperature provides an accurate benchmark for subsequent heat transfer calculations, allowing for a more precise establishment of the temperature difference relationship between the fluid and the wall, thereby improving the accuracy of the local heat transfer coefficient calculation. When calculating the local heat transfer coefficient of various local areas within the wound tube heat exchanger, the actual thermal conditions at the fluid inlet are fully considered, making the calculation results closer to actual operating conditions. This not only improves the accuracy and reliability of the local heat transfer coefficient calculation but also provides a more solid data foundation for subsequent fouling distribution analysis, thermal stress calculation, and damage risk assessment, thus enhancing the accuracy and practicality of the entire performance testing method.

[0038] In some embodiments described above in this application, the distribution of fouling inside a wound tube heat exchanger is obtained based on the local heat transfer coefficient of each local region and a preset reference coefficient value. Specifically, to obtain more accurate detailed information on the fouling inside the wound tube heat exchanger, the steps for obtaining the distribution of fouling inside the wound tube heat exchanger can be further refined. The steps for obtaining the distribution of fouling inside the wound tube heat exchanger based on the local heat transfer coefficient of each local region and a preset reference coefficient value include: The local heat transfer coefficient of each local area is compared with the preset reference coefficient value to determine the distribution location of scale inside the wound tube heat exchanger. The thickness of the scale in each local area inside the wound tube heat exchanger is obtained by calculating the local heat transfer coefficient of each local area and the preset reference coefficient value. Based on the location and thickness of the scale, the distribution pattern of the scale inside the wound tube heat exchanger is obtained.

[0039] The process involves comparing the local heat transfer coefficients of various regions with preset reference coefficient values ​​to identify potential fouling areas within the wound tube heat exchanger. The preset reference coefficient values ​​typically represent the local heat transfer coefficients under non-fouling or normal operating conditions. When the actual measured local heat transfer coefficient deviates from this reference value, fouling in that region can be preliminarily identified. Further, calculations based on the local heat transfer coefficients and preset reference coefficient values ​​quantify the degree of fouling, yielding the fouling thickness in each local region. Scale thickness is a key parameter for assessing the severity of fouling; its calculation is usually based on the principle of thermal resistance, where fouling leads to additional thermal resistance, thus affecting the local heat transfer coefficient. Finally, by combining the location of the fouling distribution and the thickness of the fouling in each local region, a comprehensive understanding of the fouling distribution within the wound tube heat exchanger can be obtained. This distribution not only indicates the location of fouling but also provides quantitative information on fouling, offering detailed data support for subsequent maintenance and performance evaluation.

[0040] This application's solution compares and calculates the local heat transfer coefficients of various regions inside a wound tube heat exchanger with preset reference coefficient values, enabling precise characterization of fouling distribution from two dimensions—location and thickness. The local heat transfer coefficient is a key indicator of heat exchange efficiency. When fouling occurs inside the heat exchanger, the fouling layer increases thermal resistance, leading to a decrease in the local heat transfer coefficient. By comparing the actually measured local heat transfer coefficients with the reference coefficient values ​​in a non-fouling state, the presence and location of fouling can be intuitively determined. Furthermore, by quantifying these coefficients, the thermal resistance of the fouling layer can be derived, and then, combined with the thermal conductivity of the fouling material, the fouling thickness in each local region can be accurately calculated. This method utilizes the direct impact of fouling on heat transfer characteristics, achieving a non-invasive, localized assessment of the fouling state. Through the above technical solution, a refined and quantitative assessment of the fouling distribution inside a wound tube heat exchanger can be achieved. Compared to simply determining the presence of fouling, this solution not only clarifies the specific location of the fouling but also provides information on the thickness of the fouling in each region. This detailed data on scale distribution provides a more accurate and comprehensive basis for the operation, maintenance, fault diagnosis, and cleaning strategy formulation of wound tube heat exchangers. It helps to detect and deal with scale problems in a timely manner, thereby effectively avoiding the risk of decreased heat exchange efficiency, increased pressure drop, and potential structural damage caused by scale, and significantly improving the operational reliability and economy of wound tube heat exchangers.

[0041] Specifically, in determining the distribution location of scale inside the wound tube heat exchanger, the following method can be used: The local heat transfer coefficient of each local area is compared with a preset reference coefficient value to determine the distribution location of scale inside the wound tube heat exchanger, including: The local heat transfer coefficient of each local area is compared with the preset reference coefficient value to obtain the comparison results; When the comparison results indicate that the local heat transfer coefficient is less than the preset reference coefficient value, it is determined that there is scaling at the corresponding local location inside the wound tube heat exchanger. When the comparison result indicates that the local heat transfer coefficient is greater than or equal to the preset reference coefficient value, it is determined that there is no scaling at the corresponding local location inside the wound tube heat exchanger.

[0042] The local heat transfer coefficient refers to the heat transfer efficiency of various local areas within a wound tube heat exchanger under actual operating conditions. The preset reference coefficient value typically refers to the baseline value of the local heat transfer coefficient of the wound tube heat exchanger under clean, scale-free conditions, or with an acceptable level of slight scaling. This reference coefficient value can be obtained through theoretical calculations, experimental tests, or historical operating data analysis, and is calibrated according to the heat exchanger's design parameters, fluid properties, and operating conditions. Specifically, comparing the actually measured local heat transfer coefficients of each local area with this reference coefficient value yields a comparison result. This comparison result is used to determine whether the heat transfer performance of the local area has deteriorated.

[0043] It should be noted that the solution in this application utilizes the direct impact of scaling on the heat transfer performance of the heat exchanger by comparing the actual local heat transfer coefficient of each local area inside the wound tube heat exchanger with a preset reference coefficient value. The formation of a scaling layer significantly increases the resistance to heat transfer, leading to a decrease in the local heat transfer coefficient. Therefore, when the comparison result shows that the local heat transfer coefficient is less than the preset reference coefficient value, it means that the heat transfer efficiency of that local area is lower than the normal or benchmark level. This is usually due to the formation of a scaling layer on the heat exchange surface, which increases the thermal resistance. Thus, it can be determined that scaling exists at that local location. Conversely, when the local heat transfer coefficient is greater than or equal to the preset reference coefficient value, the heat transfer performance of that local area is considered to be within the normal or acceptable range, thus determining that there is no scaling at that local location. This judgment mechanism based on the change of heat transfer coefficient can directly reflect the actual operating status inside the heat exchanger, providing data support for subsequent scaling management and maintenance. It can achieve accurate and quantitative judgment of the scaling distribution location inside the wound tube heat exchanger. This method avoids the limitations of traditional visual inspection or disassembly inspection, improving the efficiency and accuracy of scaling detection. By establishing clear comparison standards, the scaling status of each local area can be objectively assessed, providing a reliable basis for targeted cleaning, maintenance, and operational optimization. This effectively extends the service life of the heat exchanger, reduces operating costs, and ensures that the heat exchanger operates at its optimal performance.

[0044] In some embodiments of this application, the above calculation based on the local heat transfer coefficient of each local area and a preset reference coefficient value to obtain the thickness of the scale in each local area inside the wound tube heat exchanger may specifically include the following steps: The scaling thermal resistance of each local area inside the wound tube heat exchanger is obtained by calculating the local heat transfer coefficient of each local area and the preset reference coefficient value. To obtain the thermal conductivity of the scale inside the wound tube heat exchanger; The thickness of the scale in each local area inside the wound tube heat exchanger is obtained based on the scaling thermal resistance and thermal conductivity.

[0045] Specifically, when calculating the thickness of scale in various local areas inside a wound tube heat exchanger, it is first necessary to calculate the scaling thermal resistance of the scale in each local area based on the local heat transfer coefficient of each area and a preset reference coefficient value. The scaling thermal resistance is the additional thermal resistance due to the presence of the scale layer, and its value is usually obtained by comparing the actually measured local heat transfer coefficient with the reference coefficient value in the non-scaling state (i.e., the local heat transfer coefficient in the clean state). The scaling thermal resistance can be calculated by subtracting the reciprocal of the actual local heat transfer coefficient from the reciprocal of the heat transfer coefficient in the clean state. The purpose is to quantify the impact of scaling on heat transfer efficiency. Further, it is necessary to obtain the thermal conductivity of the scale inside the wound tube heat exchanger. Thermal conductivity refers to the ability of the scaling material itself to conduct heat, and its value is usually related to factors such as the composition, density, and porosity of the scale. In practical applications, this thermal conductivity can be obtained through experimental measurement, consulting material handbooks, or estimation based on the type of scale. Finally, based on the scaling thermal resistance and thermal conductivity, the thickness of the scale in each local area inside the wound tube heat exchanger can be obtained. This step is based on the fundamental principle of heat conduction, namely, thermal resistance equals thickness divided by thermal conductivity. Using the known scaling thermal resistance and thermal conductivity, the actual physical thickness of the scale layer can be calculated in reverse. The scheme in this application refines the calculation process of scale thickness into determining the scaling thermal resistance, obtaining the scaling thermal conductivity, and calculating the thickness based on both, forming a logically rigorous quantitative evaluation system. First, by comparing the actual local heat transfer coefficient with the reference coefficient value, the degree to which scaling hinders heat exchange performance, i.e., scaling thermal resistance, can be accurately quantified. This method avoids the difficulty of directly measuring scale thickness, instead starting from changes in thermodynamic properties. Second, by introducing the scaling thermal conductivity as an inherent material property, the conversion from thermal resistance to physical thickness becomes possible. It is precisely because of the combination of fouling thermal resistance and fouling thermal conductivity that the fouling thickness in various local areas inside a wound tube heat exchanger can be accurately calculated, thus providing a reliable physical basis for subsequent thermal stress analysis and damage risk assessment. The embodiments of this application provide a more accurate and reliable method for quantifying the fouling thickness inside a wound tube heat exchanger. This method not only identifies the presence of fouling but also calculates the actual physical thickness of the fouling, providing crucial data for assessing the specific impact of fouling on heat exchanger performance. This precise thickness information is significant for predicting heat exchanger performance degradation, optimizing cleaning cycles, and conducting structural integrity assessments (such as thermal stress analysis), significantly improving the precision and practical value of wound tube heat exchanger performance testing.

[0046] Specifically, the calculation of thermal stress in the internal structure of the wound tube heat exchanger based on the distribution of scale includes the following steps: Based on the distribution of scale, the actual temperature gradient of each local area inside the wound tube heat exchanger is determined. To obtain the coefficient of thermal expansion and elastic modulus of the wound tube heat exchanger; The thermal stress of the internal structure of the wound tube heat exchanger is calculated based on the actual temperature gradient, coefficient of thermal expansion, and modulus of elasticity.

[0047] Determining the actual temperature gradient in various local areas within the wound tube heat exchanger involves analyzing the impact of scale distribution on heat transfer, thereby accurately deriving the temperature differences at different locations on the heat exchanger wall and within the internal fluid. The presence of scale alters the heat exchanger's heat transfer efficiency, leading to changes in local temperature distribution and thus forming specific temperature gradients. Furthermore, obtaining the coefficient of thermal expansion and the modulus of elasticity of the wound tube heat exchanger involves acquiring the inherent physical properties of the materials used in the heat exchanger. The coefficient of thermal expansion characterizes the degree of volume or length change of a material with temperature variations, while the modulus of elasticity reflects the material's resistance to elastic deformation. These parameters are crucial inputs for calculating thermal stress. Therefore, calculating the thermal stress within the wound tube heat exchanger's internal structure based on the actual temperature gradient, coefficient of thermal expansion, and modulus of elasticity involves substituting the aforementioned physical quantities into the thermal stress calculation formula to quantify the internal stress caused by uneven temperature distribution and the material's thermal expansion and contraction characteristics. Numerical simulation methods such as finite element analysis can be used to divide the wound tube heat exchanger into multiple elements, calculate the temperature gradient and material properties of each element, and thus obtain the stress distribution of the entire structure. The scheme in this application, by first determining the actual temperature gradient under the fouling distribution state, can accurately reflect the impact of fouling on the internal temperature field of the heat exchanger. The presence of a fouling layer increases thermal resistance, causing the heat exchanger wall temperature to rise or fall, thus forming a non-uniform temperature distribution in different regions. By obtaining these actual temperature gradients and combining them with the inherent thermal expansion coefficient and elastic modulus of the wound tube heat exchanger material, the internal stress generated by the material expansion or contraction due to temperature changes can be accurately calculated. This stress, i.e., thermal stress, is an important factor leading to structural deformation, fatigue, and even failure. Therefore, this scheme provides a method for quantifying thermal stress by combining the temperature change caused by fouling with the material's mechanical properties.

[0048] The above technical solution enables a more accurate assessment of the thermal stress state of the internal structure of a wound tube heat exchanger under fouling conditions. Compared to thermal stress assessments based solely on ideal conditions or simplified models, this solution considers the actual impact of fouling on local temperature gradients, making the thermal stress calculation results closer to actual operating conditions. This helps to more accurately predict potential damage risks to the internal structure of the wound tube heat exchanger, such as inter-tube contact compression, increased high-frequency micro-vibrations, and material fatigue accumulation. Therefore, it provides a more reliable basis for the operation, maintenance, and safety management of the heat exchanger, effectively extending the equipment's service life and improving operational safety.

[0049] The steps described above for assessing the potential damage risk to the internal structure of a wound tube heat exchanger based on thermal stress specifically include: The thermal stress is compared with the preset thermal stress to obtain the comparison result. The preset thermal stress is the allowable stress limit of the material of the wound tube heat exchanger under high temperature and high pressure. The comparison results are used to determine the potential damage risk to the internal structure of the wound tube heat exchanger.

[0050] Specifically, after calculating the thermal stress of the internal structure of the wound tube heat exchanger, this thermal stress is compared with a preset thermal stress. This preset thermal stress is not arbitrarily set, but specifically refers to the allowable stress limit of the material used in the wound tube heat exchanger under specific high-temperature and high-pressure operating conditions. This allowable stress limit is determined comprehensively based on factors such as the material's mechanical properties, fatigue characteristics, and safety margin, representing the maximum safe stress the material can withstand during long-term operation. By comparing the actually calculated thermal stress with this inherent safety threshold of the material, a clear comparison result can be obtained. Based on this comparison result, it is possible to determine whether there is a potential risk of damage to the internal structure of the wound tube heat exchanger. When the calculated thermal stress exceeds the allowable stress limit, it indicates a high risk of damage in that area; conversely, if the thermal stress is lower than or equal to the allowable stress limit, the area is considered safe. This application's solution, by introducing the allowable stress limit of the material under high temperature and high pressure as a judgment benchmark, transforms the abstract thermal stress value into a risk assessment indicator with practical engineering significance. When the thermal stress generated within the internal structure of a wound tube heat exchanger exceeds the allowable stress limit of its material during operation, it indicates that the material in that area may have entered the plastic deformation zone, or its fatigue life is being rapidly depleted, significantly increasing the probability of structural damage. This quantitative comparison based on the inherent safety performance of the material effectively avoids judgment biases that may arise from relying solely on experience or qualitative analysis, making the assessment of damage risk more objective and accurate. Therefore, it provides a more solid scientific basis for the operation, management, and maintenance of heat exchangers.

[0051] In one embodiment, this application enables precise quantitative assessment of the risk of internal structural damage in wound tube heat exchangers. Compared to fuzzy assessments based solely on thermal stress, introducing allowable stress limits as a benchmark provides a clear engineering standard for risk assessment, significantly improving the accuracy and reliability of the judgment. This helps to promptly detect and warn of potential structural damage, such as inter-tube contact compression, increased high-frequency micro-vibrations, and material fatigue accumulation, thereby effectively guiding the development of preventative maintenance measures, avoiding equipment failures or even safety accidents caused by structural damage, extending the service life of wound tube heat exchangers, and ensuring their safe and stable operation.

[0052] In some preferred embodiments, it is assumed that the thermal stress in a certain local area of ​​the wound tube heat exchanger is calculated to be 180 MPa using the above method. Simultaneously, the allowable stress limit for the material used in the wound tube heat exchanger (e.g., a specific grade of stainless steel) at the current operating temperature (e.g., 500°C) and pressure (e.g., 10 MPa) is determined to be 150 MPa. The calculated thermal stress of 180 MPa is then compared with the preset allowable stress limit of 150 MPa. Since 180 MPa is greater than 150 MPa, the comparison result indicates that the thermal stress in this local area has exceeded the material's safe tolerance range. Therefore, it can be clearly determined that this local area has a potential risk of damage and may face problems such as inter-tube contact compression, increased high-frequency micro-vibrations, or material fatigue accumulation.

[0053] In this regard, this application further proposes to assess the potential damage risk to the internal structure of the wound tube heat exchanger based on the comparison results, including: When the comparison results indicate that the thermal stress is greater than the preset thermal stress, the potential damage risk of the internal structure of the wound tube heat exchanger is judged. Among them, the damage risk includes inter-tube contact extrusion, aggravation of high-frequency micro-vibration, and material fatigue accumulation.

[0054] Specifically, when the above comparison results indicate that the thermal stress is greater than the preset thermal stress, the potential damage risk to the internal structure of the wound tube heat exchanger can be further refined into several specific damage types. Among them, "inter-tube contact compression" refers to the possibility of local deformation of the wound tube under excessive thermal stress, leading to physical contact and mutual compression between adjacent tube bundles, resulting in tube wall wear, localized stress concentration, or even tube wall rupture. "Intensified high-frequency micro-vibration" refers to the possibility that the natural frequency of the wound tube may change under thermal stress, or that the excitation frequency of the external fluid may be close to the natural frequency of the tube bundle, leading to an increase in the vibration amplitude of the tube bundle, thereby accelerating fatigue damage or triggering other mechanical damage. "Material fatigue accumulation" refers to the accumulation of damage to the internal microstructure of the wound tube material under long-term alternating thermal stress or high stress conditions, ultimately leading to the initiation and propagation of macroscopic cracks until failure.

[0055] This application's solution clarifies the specific types of damage that may occur when thermal stress exceeds the allowable stress limit, making the assessment of potential damage risks to the internal structure of wound tube heat exchangers more specific and instructive. When thermal stress is excessive, the wound tube structure will bear loads exceeding its design tolerance, triggering a series of physical and material-level failure mechanisms. For example, excessive thermal stress may cause local deformation of the tube bundle, leading to inter-tube contact compression, causing tube wall wear or localized stress concentration. Simultaneously, structural deformation caused by thermal stress may also alter the dynamic characteristics of the tube bundle, making its response to fluid excitation more severe, thereby exacerbating high-frequency micro-vibrations and accelerating fatigue damage. Furthermore, long-term or repeated exposure to thermal stress exceeding the allowable limit will directly lead to the accumulation of fatigue damage within the wound tube material, potentially causing crack propagation or even structural failure. Through the above technical solution, a more detailed and specific assessment of the potential damage risks to the internal structure of wound tube heat exchangers can be achieved. Once the risk of tube contact compression is identified, the tube bundle clearance can be specifically checked or additional support can be considered. If it is determined to be due to increased high-frequency micro-vibrations, the hydrodynamic characteristics can be assessed or damping measures can be considered. The risk of material fatigue accumulation indicates the need to pay attention to the material life and cyclic characteristics of operating conditions. Therefore, this application can effectively avoid maintenance blind spots or over-maintenance caused by general risk assessments, thereby improving the reliability and safety of wound tube heat exchangers and extending their service life.

[0056] See Figure 2 , Figure 2 This is a schematic diagram of a sensor-based performance testing system for wound tube heat exchangers according to an embodiment of this application. The sensor-based performance testing system 200 for wound tube heat exchangers includes: The acquisition module 210 is used to acquire surface temperature distribution data of the outer wall of the wound tube heat exchanger through a sensor; The determination module 220 is used to determine the heat exchange conditions outside the wound tube heat exchanger based on the surface temperature distribution data. The heat exchange conditions outside the wound tube heat exchanger characterize the boundary conditions when heat transfer occurs between the outer wall of the wound tube heat exchanger and the external heat exchange medium. The state determination module 230 is used to obtain the heat transfer state of each local area inside the wound tube heat exchanger based on external heat exchange conditions, preset structural parameters of the wound tube heat exchanger and thermophysical properties of the wound tube material. The coefficient calculation module 240 is used to calculate the local heat transfer coefficient of each local area inside the wound tube heat exchanger based on the heat transfer status of each local area. The comparison module 250 is used to obtain the distribution of fouling inside the wound tube heat exchanger based on the local heat transfer coefficient of each local area and the preset reference coefficient value. The thermal stress calculation module 260 is used to calculate the thermal stress of the internal structure of the wound tube heat exchanger based on the distribution of scale. The judgment module 270 is used to judge the potential damage risk to the internal structure of the wound tube heat exchanger based on thermal stress.

[0057] It should be noted that the information interaction and execution process between the above modules are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0058] Those skilled in the art will understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or temporary media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory, or other memory technologies. Digital multifunction discs (DVDs) or other optical disc storage, cartridges, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically include computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0059] The foregoing has provided a detailed description of the preferred embodiments of this application. However, this application is not limited to the above-described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined in this application.

Claims

1. A sensor-based performance testing method for wound tube heat exchangers, characterized in that, Applications in wound tube heat exchangers include: Data on the surface temperature distribution of the outer wall of the wound tube heat exchanger is obtained using sensors. Based on the surface temperature distribution data, the heat exchange conditions outside the wound tube heat exchanger are determined, wherein the heat exchange conditions outside the wound tube heat exchanger characterize the boundary conditions when heat transfer occurs between the outer wall of the wound tube heat exchanger and the external heat exchange medium. Based on the external heat exchange conditions, the preset structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material, the heat transfer state of each local area inside the wound tube heat exchanger is obtained. Based on the heat transfer state of each local area, calculate the local heat transfer coefficient of each local area inside the wound tube heat exchanger. Based on the local heat transfer coefficient of each local area and the preset reference coefficient value, the distribution state of the fouling inside the wound tube heat exchanger is obtained. Based on the distribution of the scale, the thermal stress of the internal structure of the wound tube heat exchanger is calculated. Based on the thermal stress, the potential damage risk to the internal structure of the wound tube heat exchanger is determined.

2. The method according to claim 1, characterized in that, The heat transfer state of each local region inside the wound tube heat exchanger is obtained based on the external heat exchange conditions, the preset structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material, including: Based on the external heat exchange conditions, the pre-set structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material, the local heat flux density and temperature distribution of each local area inside the wound tube heat exchanger are derived in reverse using the finite element method. Based on the local heat flux density and the temperature distribution, the heat transfer state of each local area inside the wound tube heat exchanger is obtained.

3. The method according to claim 1, characterized in that, The step of calculating the local heat transfer coefficient of each local region inside the wound tube heat exchanger based on the heat transfer state of each local region includes: Obtain the fluid inlet temperature of the wound tube heat exchanger; Based on the heat transfer status of each local area and the fluid inlet temperature, the local heat transfer coefficient of each local area inside the wound tube heat exchanger is calculated.

4. The method according to claim 1, characterized in that, The step of obtaining the scale distribution state inside the wound tube heat exchanger based on the local heat transfer coefficient of each local region and a preset reference coefficient value includes: The local heat transfer coefficient of each local area is compared with a preset reference coefficient value to determine the distribution location of the scale inside the wound tube heat exchanger. The thickness of the scale in each local area inside the wound tube heat exchanger is obtained by calculating the local heat transfer coefficient of each local area and the preset reference coefficient value. Based on the distribution location and the thickness, the distribution state of the scale inside the wound tube heat exchanger is obtained.

5. The method according to claim 4, characterized in that, The local heat transfer coefficient of each local region is compared with a preset reference coefficient value to determine the distribution location of fouling inside the wound tube heat exchanger, including: The local heat transfer coefficient of each local region is compared with a preset reference coefficient value to obtain the comparison result; When the comparison result indicates that the local heat transfer coefficient is less than the preset reference coefficient value, it is determined that there is scaling at the corresponding local location inside the wound tube heat exchanger; When the comparison result indicates that the local heat transfer coefficient is greater than or equal to the preset reference coefficient value, it is determined that there is no scaling at the corresponding local location inside the wound tube heat exchanger.

6. The method according to claim 4, characterized in that, The step of calculating the thickness of scale in each local area inside the wound tube heat exchanger by comparing the local heat transfer coefficient of each local area with a preset reference coefficient value includes: The scaling thermal resistance of the scale in each local area inside the wound tube heat exchanger is obtained by calculating the local heat transfer coefficient of each local area and the preset reference coefficient value. Obtain the thermal conductivity of the scale inside the wound tube heat exchanger; The thickness of the scale in each local area inside the wound tube heat exchanger is obtained based on the scaling thermal resistance and the thermal conductivity.

7. The method according to claim 1, characterized in that, The calculation of the thermal stress of the internal structure of the wound tube heat exchanger based on the distribution of the scale includes: Based on the distribution of the scale, the actual temperature gradient of each local area inside the wound tube heat exchanger is determined. Obtain the coefficient of thermal expansion and elastic modulus of the wound tube heat exchanger; The thermal stress of the internal structure of the wound tube heat exchanger is calculated based on the actual temperature gradient, the coefficient of thermal expansion, and the elastic modulus.

8. The method according to claim 1, characterized in that, The step of determining the potential damage risk to the internal structure of the wound tube heat exchanger based on the thermal stress includes: The thermal stress is compared with the preset thermal stress to obtain the comparison result, wherein the preset thermal stress is the allowable stress limit of the material of the wound tube heat exchanger under high temperature and high pressure. The potential damage risk to the internal structure of the wound tube heat exchanger is determined based on the comparison results.

9. The method according to claim 8, characterized in that, The determination of potential damage risk to the internal structure of the wound tube heat exchanger based on the comparison results includes: When the comparison result indicates that the thermal stress is greater than the preset thermal stress, the potential damage risk of the internal structure of the wound tube heat exchanger is determined, wherein the damage risk includes inter-tube contact extrusion, aggravation of high-frequency micro-vibration, and material fatigue accumulation.

10. A sensor-based performance testing system for wound tube heat exchangers, characterized in that, Applications in wound tube heat exchangers include: The acquisition module is used to acquire surface temperature distribution data of the outer wall of the wound tube heat exchanger through sensors; The determination module is used to determine the heat exchange conditions outside the wound tube heat exchanger based on the surface temperature distribution data, wherein the heat exchange conditions outside the wound tube heat exchanger characterize the boundary conditions when heat transfer occurs between the outer wall of the wound tube heat exchanger and the external heat exchange medium. The state determination module is used to determine the heat transfer state of each local area inside the wound tube heat exchanger based on the external heat exchange conditions, the preset structural parameters of the wound tube heat exchanger, and the thermophysical properties of the wound tube material. The coefficient calculation module is used to calculate the local heat transfer coefficient of each local area inside the wound tube heat exchanger based on the heat transfer state of each local area. The comparison module is used to obtain the distribution state of fouling inside the wound tube heat exchanger based on the local heat transfer coefficient of each local area and the preset reference coefficient value. A thermal stress calculation module is used to calculate the thermal stress of the internal structure of the wound tube heat exchanger based on the distribution state of the scale. The judgment module is used to determine the potential damage risk to the internal structure of the wound tube heat exchanger based on the thermal stress.

Images