Cooperative anti-blocking and anti-corrosion waste heat utilization method for low-temperature economizer

Abstract

The invention belongs to the technical field of waste heat recovery, and discloses a waste heat utilization method for synergistically preventing blockage and corrosion through a low-temperature economizer. Comprising the steps that multi-source sensing data, including a flue gas temperature distribution set, a flow velocity distribution set and a component parameter set, in a flue gas channel in the operation process of the low-temperature economizer are obtained; acquiring a temperature margin according to the flue gas temperature distribution set, and performing risk analysis in combination with the flow velocity distribution set and the component parameter set to obtain a blockage risk factor and a corrosion risk factor; a comprehensive risk distribution diagram is constructed based on the heat exchange area, area division is conducted on the heat exchange surface, and a heat exchange area division mode is obtained and dynamically adjusted; the heat exchange efficiency and the waste heat utilization efficiency are obtained, and secondary dynamic adjustment is conducted on the heat exchange partition mode till a preset adjustment rule is met; according to the method, accurate risk assessment is achieved through multi-parameter monitoring and fusion analysis, dynamic partition optimization is adopted, the limitation of traditional protection measures is solved, and the reliability and economical efficiency of system operation are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology, and more specifically, to a method for utilizing waste heat in conjunction with a low-temperature economizer to prevent clogging and corrosion. Background Technology

[0002] With increasingly stringent environmental protection requirements, various anti-clogging and anti-corrosion technologies have emerged, such as material optimization, surface coatings, and heating devices. However, these methods generally suffer from high energy consumption, short-lived effects, and complex maintenance. Existing technologies struggle to balance the conflict between waste heat recovery efficiency and equipment safety. Overemphasizing waste heat recovery increases the risk of clogging and corrosion, while conservative operation results in a significant waste of recoverable heat energy.

[0003] The variability of flue gas parameters further complicates the problem. Changes in fuel characteristics, load fluctuations, and differences in environmental conditions lead to dynamic changes in flue gas temperature distribution, velocity distribution, and composition characteristics, while existing technologies lack the ability to comprehensively analyze these multi-source parameters. Traditional single-parameter monitoring systems struggle to capture early signs of blockage and corrosion risks, especially microscopic changes such as non-uniform flue gas flow fields, particulate deposition, and localized enrichment of acidic gases.

[0004] Current technologies lack intelligent strategies for differentiated protection of different regions in cryogenic economizers. Globally uniform protection measures often lead to overprotection in some areas, resulting in resource waste, while underprotection in others increases risk. The lack of a dynamic optimization mechanism that integrates heat exchange efficiency and risk control makes it difficult for cryogenic economizers to maintain stable and reliable operation under varying conditions, thus failing to maximize waste heat utilization benefits.

[0005] In view of this, the present invention proposes a waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion to solve the above problems. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art and to achieve the above objectives, the present invention provides the following technical solution:

[0007] A waste heat utilization method for low-temperature economizer with synergistic anti-clogging and anti-corrosion features, comprising:

[0008] Step S1: Acquire multi-source sensing data in the flue gas channel during the operation of the low-temperature economizer. The multi-source sensing data includes a flue gas temperature distribution set, a flue gas velocity distribution set, and a flue gas composition parameter set.

[0009] Step S2: Obtain the temperature margin at each location in the flue gas channel based on the flue gas temperature distribution set, and conduct risk analysis on the corresponding flue gas channel in combination with the flue gas velocity distribution set and the flue gas composition parameter set to obtain the blockage risk factor and corrosion risk factor.

[0010] Step S3: Based on corrosion risk factors and blockage risk factors, construct a comprehensive risk distribution map, and divide the heat exchange surface of the low-temperature economizer into regions based on it to obtain a heat exchange zoning mode, and dynamically adjust the heat exchange surface based on it.

[0011] Step S4: After the adjustment is completed, obtain the heat exchange efficiency in the flue gas channel, and obtain the waste heat utilization efficiency of the low temperature economizer in combination with the comprehensive risk distribution map. Based on this, perform secondary dynamic adjustment on the marked heat exchange zone mode until it meets the preset adjustment rules.

[0012] Furthermore, the process of obtaining blockage risk factors includes:

[0013] Temperature data at various locations within the flue gas channel are obtained based on the flue gas temperature distribution set. The difference between the data and the preset acid dew point temperature threshold is then obtained and normalized to obtain the temperature margin.

[0014] The Reynolds number at each location within the flue gas channel data is obtained based on the flue gas velocity distribution set, and the corresponding flow disturbance factor at that location is obtained accordingly.

[0015] The particulate matter concentration at each location is obtained based on the flue gas composition parameters, and a deposition probability mapping is performed based on this information to obtain the particulate deposition probability.

[0016] The blockage risk factor at each location within the flue gas passage is obtained by weighting and summing the temperature margin, flow disturbance factor, and particle deposition probability.

[0017] Furthermore, the process of obtaining the particle deposition probability includes:

[0018] Based on the particulate matter concentration at each location within the flue gas channel, obtain the particle size distribution at the corresponding location; calculate the particle size-weighted average of the particulate matter concentration based on the particle size distribution;

[0019] Based on the flue gas velocity distribution at each location within the flue gas channel, the critical velocity for particle deposition at the corresponding location is obtained.

[0020] The particle deposition probability is obtained by substituting the difference between the flue gas velocity distribution and the critical velocity for particle deposition into a pre-constructed exponential mapping function.

[0021] Furthermore, the process of obtaining corrosion risk factors includes:

[0022] Based on the acid gas concentration data in the flue gas composition parameter set, the acid deposition rate at each location in the flue gas channel is obtained, and the scouring intensity at the corresponding location is obtained based on the flue gas velocity distribution set.

[0023] The material parameters of the heat exchange surface at various locations within the flue gas passage are obtained, and the corrosion resistance factor of the material at the corresponding location is obtained. Based on the acid deposition rate and scouring intensity, a negative correlation mapping is performed on the corresponding material corrosion resistance factor to obtain the corrosion risk factor at the corresponding location.

[0024] Furthermore, the process of dynamically adjusting the corresponding heat exchange surface includes:

[0025] The corrosion risk factors and blockage risk factors in the flue gas passage are weighted and summed to obtain the comprehensive risk value, and its spatial distribution in the flue gas passage is obtained to obtain the comprehensive risk distribution map.

[0026] Based on the comprehensive risk distribution map, the heat exchange surface in the flue gas channel is divided into multiple candidate zones; and the average risk value of the comprehensive risk value in each candidate zone is calculated to obtain the average risk value of the corresponding candidate zone.

[0027] Based on the flue gas temperature distribution at various locations within the flue gas passage and the heat exchange requirements of the low-temperature economizer, the heat exchange potential of each candidate zone is obtained.

[0028] All candidate zones are sorted according to average risk value and heat exchange potential, and heat exchange zone patterns are marked for the corresponding candidate zones based on the sorting results; the heat exchange zone patterns include high heat exchange efficiency zones and risk mitigation zones; and the heat exchange surface of the corresponding low temperature economizer is dynamically adjusted according to the heat exchange zone patterns. The dynamic adjustment process includes arranging turbulence enhancement structures in high heat exchange efficiency zones and arranging adaptive drainage structures in risk mitigation zones.

[0029] Furthermore, the arrangement process of the turbulence-enhancing structure includes:

[0030] The turbulence demand factor corresponding to each location in the high heat transfer efficiency zone is obtained based on the flue gas velocity distribution set; and the geometric parameters of the turbulence enhancement structure are updated based on it.

[0031] The heat flux density at each location within the high heat transfer efficiency zone is obtained based on the flue gas temperature distribution set, and the arrangement spacing of the turbulence enhancement structure is dynamically adjusted based on the product of the heat flux density and the turbulence demand factor.

[0032] Furthermore, the arrangement process of the adaptive drainage structure includes:

[0033] Within the risk mitigation zone, the particle diversion requirements at each location are obtained based on the comprehensive risk distribution map; and the depth and width of the diversion channel for the adaptive diversion structure are designed according to the particle diversion requirements.

[0034] Within the risk mitigation zone, the flow field smoothing factor at each location is obtained based on the flue gas velocity distribution; and the arrangement angle of the adaptive guidance structure is dynamically adjusted based on the flow field smoothing factor and particle guidance requirements.

[0035] Furthermore, the process of obtaining waste heat utilization efficiency includes:

[0036] The actual heat exchange of the corresponding low-temperature economizer is calculated based on the flue gas temperature distribution set and the heat exchange medium temperature distribution; the overall heat exchange efficiency of the low-temperature economizer is obtained by combining the flue gas velocity distribution and the heat exchange zoning mode; and the waste heat utilization efficiency of the low-temperature economizer is obtained by combining the comprehensive risk distribution map.

[0037] Furthermore, the process of making secondary dynamic adjustments to the marked heat exchange zone pattern includes:

[0038] Based on the updated comprehensive risk distribution map, the boundaries between the high heat exchange efficiency zone and the risk mitigation zone are redefined; the arrangement positions of the turbulence enhancement structure and the adaptive drainage structure are adjusted and updated based on the direction of boundary movement; and the arrangement density of the turbulence enhancement structure and the adaptive drainage structure is adjusted according to the magnitude of boundary movement; the adjustment process is repeated until the preset adjustment rules are met.

[0039] Furthermore, the preset adjustment rule refers to the waste heat utilization efficiency reaching its maximum and the comprehensive risk value at all locations in the comprehensive risk distribution map being less than the preset risk threshold.

[0040] The technical effects and advantages of the waste heat utilization method of the low-temperature economizer with synergistic anti-clogging and anti-corrosion properties in this invention are as follows:

[0041] 1. This invention achieves accurate capture and analysis of the comprehensive characteristics of multi-source parameters in the flue gas channel of a low-temperature economizer; this invention transforms the previously unpredictable risk of blockage and corrosion into a quantifiable basis for prevention and control; it changes the protection mode of waste heat recovery equipment, advances the risk prevention and control point to the early stage of problem formation, and significantly reduces equipment damage and maintenance downtime.

[0042] 2. This invention can accurately allocate resources based on a comprehensive risk distribution map, thereby improving the operational reliability and efficiency of the waste heat recovery system;

[0043] 3. The dynamic adjustment mechanism of this invention can adapt to changes in operating conditions, achieve the optimal balance between heat exchange efficiency and equipment safety, extend the service life of the equipment, reduce operating and maintenance costs, and maximize the utilization of waste heat, thus having significant economic and environmental value. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of a waste heat utilization method for a low-temperature economizer with synergistic anti-clogging and anti-corrosion features according to the present invention. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1

[0047] Please see Figure 1 As shown in this embodiment, a waste heat utilization method for synergistic anti-clogging and anti-corrosion of a low-temperature economizer includes:

[0048] Step S1: Acquire multi-source sensing data in the flue gas channel during the operation of the low-temperature economizer. The multi-source sensing data includes the flue gas temperature distribution set, the flue gas velocity distribution set, and the flue gas composition parameter set.

[0049] Step S2: Obtain the temperature margin at each location in the flue gas channel based on the flue gas temperature distribution set, and conduct risk analysis on the corresponding flue gas channel in combination with the flue gas velocity distribution set and the flue gas composition parameter set to obtain the blockage risk factor and corrosion risk factor.

[0050] Step S3: Based on corrosion risk factors and blockage risk factors, construct a comprehensive risk distribution map, and divide the heat exchange surface of the low-temperature economizer into regions based on it to obtain a heat exchange zoning mode, and dynamically adjust the heat exchange surface based on it.

[0051] Step S4: After the adjustment is completed, obtain the heat exchange efficiency in the flue gas channel, and obtain the waste heat utilization efficiency of the low temperature economizer in combination with the comprehensive risk distribution map. Based on this, perform secondary dynamic adjustment on the marked heat exchange zone mode until it meets the preset adjustment rules.

[0052] In this embodiment, accurate risk assessment of the low-temperature economizer is achieved through multi-parameter monitoring and fusion analysis. A correlation analysis framework between flue gas temperature distribution and flue gas composition parameters is constructed to provide a data foundation for comprehensive risk assessment. Blockage risk calculation based on temperature margin and flue gas velocity distribution enables real-time adaptability of monitoring. Dynamic division of heat exchange zones can adapt to changes in flue gas parameters under different operating environments. Cross-factor feature extraction combined with temperature, velocity, and composition parameters improves the comprehensiveness of risk assessment. Comprehensive risk distribution map analysis considers the impact of environmental factors on heat exchange efficiency to ensure the accuracy of assessment. The synergistic optimization of turbulence enhancement structure and adaptive venting structure solves the limitations of traditional single protection measures. Dynamic optimization of waste heat utilization efficiency enhances the reliability and economy of system operation. Dynamic adjustment mechanism based on risk threshold improves system response efficiency and pertinence.

[0053] It should be further explained that, in the specific implementation process, the acquisition of multi-source sensing data includes the following steps:

[0054] Flue gas temperature data is obtained from a temperature sensor array distributed in the flue gas channel of the low-temperature economizer to obtain a flue gas temperature distribution set.

[0055] Flue gas velocity data are obtained from velocity measurement devices distributed in the flue gas passage of the low-temperature economizer to obtain the flue gas velocity distribution set;

[0056] Flue gas composition data are obtained from the component analyzers distributed in the flue gas channels of the low-temperature economizer, and a set of flue gas composition parameters is obtained.

[0057] Spatiotemporal registration is performed on the flue gas temperature distribution set, flue gas velocity distribution set, and flue gas composition parameter set to obtain a spatiotemporally aligned multi-parameter dataset. The spatiotemporally aligned multi-parameter dataset is then organized temporally according to the acquisition time to obtain multi-source sensing data.

[0058] In this embodiment, multiple temperature sensors are first deployed in the flue gas passage of the low-temperature economizer (such as the economizer inlet section, middle region, outlet section, etc.), and the temperature distribution information in the flue gas passage is captured to form a temperature distribution set containing location and temperature value.

[0059] Meanwhile, velocity measurement devices (such as Pitot tubes, hot-wire anemometers, ultrasonic flow meters, etc.) are deployed in the flue gas channel to obtain flue gas velocity distribution information and generate a flue gas velocity distribution set containing location and velocity vectors.

[0060] Install flue gas composition analyzers (such as gas analyzers, dust concentration meters, etc.) in the flue gas passage to detect the flue gas density, acid gas concentration and particulate matter concentration in the flue gas, and form a set of flue gas composition parameters;

[0061] Then, a multi-parameter data registration method was used to establish the spatial correspondence between temperature distribution, flow velocity distribution, and composition parameters. Time synchronization was applied to handle the sampling rate differences of different sensors to ensure that the three parameters were synchronized in time, forming a spatiotemporally aligned multi-parameter dataset. Finally, the spatiotemporally aligned multi-parameter dataset was sorted according to timestamps to form multi-source sensing data. Each moment in the multi-source sensing data contains a set of corresponding flue gas temperature distribution, flue gas flow velocity distribution, and flue gas composition parameters. These multi-parameter data together constitute the basic data source for the analysis of the operating status of the low-temperature economizer, providing comprehensive monitoring information for subsequent risk assessment and zoning optimization.

[0062] It should be further explained that, in the specific implementation process, the acquisition of blocking risk factors includes the following steps:

[0063] Temperature data at various locations within the flue gas channel are obtained based on the flue gas temperature distribution set. The difference between the data and the preset acid dew point temperature threshold is then obtained and normalized to obtain the temperature margin.

[0064] The Reynolds number at each location within the flue gas channel data is obtained based on the flue gas velocity distribution set, and the corresponding flow disturbance factor at that location is obtained accordingly.

[0065] The particulate matter concentration at each location is obtained based on the flue gas composition parameters, and a deposition probability mapping is performed based on this information to obtain the particulate deposition probability.

[0066] The blockage risk factor at each location within the flue gas passage is obtained by weighting and summing the temperature margin, flow disturbance factor, and particle deposition probability.

[0067] In this embodiment, firstly, temperature data corresponding to each location in the corresponding flue gas channel is obtained based on the flue gas temperature distribution set; simultaneously, a preset acid dew point temperature threshold (such as sulfuric acid dew point, nitric acid dew point, etc.) is determined according to the current fuel characteristics and flue gas composition; the difference between the temperature data at each location and the corresponding acid dew point temperature threshold is obtained and normalized, and mapped to the range [0,1] to obtain the temperature margin. The temperature margin can be used to reflect the degree to which the flue gas temperature at different locations is higher than the acid dew point, and the smaller the temperature margin, the closer it is to the acid dew point, and the higher the risk of blockage.

[0068] Then, the characteristic dimensions of the current flue gas channel (such as the diameter of the flue gas channel) are obtained, and the Reynolds number at each location is obtained by combining the flue gas velocity distribution set. In the formula, ρ1 represents the flue gas density; v represents the flue gas velocity; D represents the characteristic dimension; μ represents the dynamic viscosity, which is a physical quantity used to describe the intermolecular friction force inside the flue gas and represents the flue gas's ability to resist flow deformation. The corresponding value can be found in existing thermal engineering handbooks.

[0069] Set a turbulence threshold, where the turbulence threshold refers to the critical Reynolds value for the fluid to change from a laminar state to a turbulent state. It is set by those skilled in the art based on experience and is usually 2300.

[0070] The Reynolds number at each location within the flue gas channel is obtained and compared with a set turbulence threshold. If the Reynolds number is less than the turbulence threshold, it indicates that the flow at the corresponding location is laminar or transitional, and particles are prone to deposition. In this case, the flow disturbance factor at the corresponding location takes a negative value between -1 and 0. If the Reynolds number is not less than the turbulence threshold, it indicates that the flow at the corresponding location is turbulent, and particles are not prone to deposition. In this case, the flow disturbance factor at the corresponding location takes a positive value between 0 and 1. The specific value of the flow disturbance factor can be determined through function mapping (either linear mapping or S-shaped function mapping can be selected based on the actual application scenario).

[0071] Furthermore, based on the particulate matter concentration at each location within the flue gas channel, the particle deposition probability at the corresponding location is obtained; the particle deposition probability reflects the likelihood of particulate matter adhering to the heat exchange surface under specific conditions and is a direct indicator of blockage risk.

[0072] The blockage risk factor is obtained by weighted summation based on the obtained temperature margin, flow disturbance factor, and particulate matter deposition probability.

[0073] Furthermore, based on the corresponding calculation process, the blockage risk factors at each location within the corresponding flue gas channel are obtained. These blockage risk factors can be used to comprehensively reflect the blockage risk at each location due to factors such as temperature approaching the acid dew point, flow characteristics, and particle deposition, providing an important basis for subsequent comprehensive risk analysis and zoning optimization.

[0074] It should be further explained that, in the specific implementation process, the process of obtaining the particle deposition probability includes:

[0075] Based on the particulate matter concentration at each location within the flue gas channel, obtain the particle size distribution at the corresponding location; calculate the particle size-weighted average of the particulate matter concentration based on the particle size distribution;

[0076] Based on the flue gas velocity distribution at each location within the flue gas channel, the critical velocity for particle deposition at the corresponding location is obtained.

[0077] The particle deposition probability is obtained by substituting the difference between the flue gas velocity distribution and the critical velocity for particle deposition into a pre-constructed exponential mapping function.

[0078] First, analyze the particulate matter data in the flue gas composition parameters. In addition to the total concentration, it is also necessary to obtain particle size distribution information, which can be obtained through a particle size analyzer or sampling analysis. Divide the particles into multiple intervals according to their size range (e.g., <2.5μm, 2.5-10μm, 10-50μm, >50μm, etc.), and calculate the proportion of particulate matter concentration (ND) in each interval. h Assign a representative particle size LJ to each interval h (e.g., interval median or weighted average), calculate the particle size weighted average d. avg =∑(ND) h ×LJ h In the formula, h represents the interval index; this value reflects the overall particle size characteristics of the particles. The larger the particle size weighted average, the higher the proportion of large particles and the stronger the deposition trend. Then, according to the fluid dynamics theory, the critical flow velocity for particle deposition is calculated for each location.

[0079] Based on particle size weighted average d avg The critical deposition velocity is calculated based on the corresponding flue gas velocity distribution set; wherein, the critical deposition velocity of the particles is obtained by logarithmically mapping the ratio of the flue gas velocity distribution to the particle size weighted average.

[0080] Next, the difference between the actual flow velocity and the critical deposition velocity is calculated as Δv = v - vcr; where v and vcr represent the actual flow velocity and the critical deposition velocity, respectively.

[0081] Substituting this into a pre-constructed exponential mapping function yields the particulate deposition probability; where the exponential mapping function is... Where c is a positive parameter used to control the steepness of the function; P represents the particle deposition probability.

[0082] It should be further explained that, in the specific implementation process, the acquisition of corrosion risk factors includes the following steps:

[0083] Based on the acid gas concentration data in the flue gas composition parameter set, the acid deposition rate at each location in the flue gas channel is obtained, and the scouring intensity at the corresponding location is obtained based on the flue gas velocity distribution set.

[0084] The material parameters of the heat exchange surface at various locations within the flue gas passage are obtained, and the corrosion resistance factor of the material at the corresponding location is obtained. Based on the acid deposition rate and scouring intensity, a negative correlation mapping is performed on the corresponding material corrosion resistance factor to obtain the corrosion risk factor at the corresponding location.

[0085] In this embodiment, acid gas concentration data, including the concentrations of acid gas components such as SO2, SO3, NOx, and HCl, are extracted from the flue gas component parameter set. The product of the corresponding acid gas component concentration and the temperature margin at the corresponding location is obtained. This product reflects the intensity of the acidic environment under the combined influence of temperature and composition, and is mapped to the acid deposition rate. The mapping formula for the acid deposition rate is: ASR=K1×∑[(c_i×W_i)×(1-WY)]; where c_i and W_i represent the concentration and weight of the i-th acid gas component, respectively; i is a natural number; K1 represents the proportionality coefficient, which can be adjusted according to the engineering scenario (e.g., 0.4-0.5 for high-sulfur coal scenarios and 0.1-0.2 for low-sulfur coal scenarios); WY represents the temperature margin.

[0086] scouring intensity at each location is calculated based on the flue gas velocity distribution set. In the formula, ρ1 represents the flue gas density, v represents the flue gas velocity, and n represents the velocity index, which is used to represent the degree of amplification of the scouring intensity by the velocity. The larger n is, the more significant the effect of a small change in velocity on the scouring intensity; it is usually taken as 1.5-2.

[0087] Furthermore, the material parameters of the heat exchange surfaces at various locations within the flue gas passage are obtained, including material type (such as ordinary carbon steel, low alloy steel, stainless steel, etc.), surface treatment method (such as coating, spraying, etc.), and service life. Based on the material parameters, the corresponding material corrosion resistance factor MRC = MRC0 × (1 + δ)exp(-λ1 × t) is obtained at the corresponding location. In the formula, MRC0 represents the corrosion resistance benchmark value corresponding to the heat exchange surface material at the corresponding location (different materials have different benchmark values), λ1 represents the aging coefficient, which can be used to reflect the rate of decay of the material's corrosion resistance in the flue gas environment over time, and is obtained in advance through accelerated aging tests in the laboratory; t represents the service time; δ represents the surface protection gain coefficient, which is used to reflect the effect of surface treatment measures on the material's corrosion resistance (i.e., the degree to which the surface treatment measures of the heated surface material delay the corrosion efficiency of the material).

[0088] Next, taking a specific location within the acid gas channel as an example, the product of the acid deposition rate and the erosion intensity at that location is obtained. This product characterizes the synergistic effect of chemical corrosion and mechanical erosion. Furthermore, the product is negatively correlated with the material's corrosion resistance factor to obtain the corrosion risk factor. Where M is the material corrosion resistance factor and λ0 is the adjustment coefficient, which is determined by collecting corrosion data of different locations and different material components of the actual operating low-temperature economizer and performing statistical regression analysis. The corresponding negative correlation mapping ensures that the better the material corrosion resistance, the lower the corrosion risk factor. Finally, according to the above formula, the corrosion risk factor of each location in the flue gas channel is calculated. This factor comprehensively considers the influence of acidic environment, flow erosion and material characteristics on the corrosion process, and provides key input for the construction of comprehensive risk distribution map.

[0089] It should be further explained that, in the specific implementation process, the dynamic adjustment of the corresponding heat exchange surface includes:

[0090] The corrosion risk factors and blockage risk factors in the flue gas passage are weighted and summed to obtain the comprehensive risk value, and its spatial distribution in the flue gas passage is obtained to obtain the comprehensive risk distribution map.

[0091] Based on the comprehensive risk distribution map, the heat exchange surface in the flue gas channel is divided into multiple candidate zones; and the average risk value of the comprehensive risk value in each candidate zone is calculated to obtain the average risk value of the corresponding candidate zone.

[0092] Based on the flue gas temperature distribution at various locations within the flue gas passage and the heat exchange requirements of the low-temperature economizer, the heat exchange potential of each candidate zone is obtained.

[0093] All candidate zones are sorted according to average risk value and heat exchange potential, and heat exchange zone pattern is marked for the corresponding candidate zones based on the sorting results; the heat exchange zone pattern includes high heat exchange efficiency zone and risk mitigation zone; and the heat exchange surface of the corresponding low temperature economizer is dynamically adjusted according to the heat exchange zone pattern. The dynamic adjustment process includes arranging turbulence enhancement structure in the high heat exchange efficiency zone and arranging adaptive drainage structure in the risk mitigation zone.

[0094] In this embodiment, firstly, a three-dimensional twin model of the corresponding low-temperature economizer is constructed based on digital twin technology; simultaneously, corrosion risk factors and blockage risk factors at various locations within the flue gas channel are obtained, and they are weighted and summed to obtain the comprehensive risk value corresponding to the location; the obtained comprehensive risk values ​​are organized according to spatial coordinates to form a three-dimensional risk distribution matrix, and the corresponding three-dimensional risk distribution matrix is ​​colored based on pseudo-color mapping technology to obtain a comprehensive risk distribution map;

[0095] Furthermore, based on the comprehensive risk distribution map, and by applying spatial segmentation algorithms (such as region growing, watershed algorithm, or superpixel segmentation algorithm), the heat exchange surface in the flue gas channel is divided into multiple relatively independent candidate partitions; and the average risk value of the comprehensive risk value in each candidate partition is obtained.

[0096] Furthermore, the temperature distribution of the heat exchange medium (such as the feedwater temperature distribution) at various locations within the flue gas channel of the low-temperature economizer is obtained, and the difference between the flue gas temperature and the heat exchange medium temperature is obtained based on it, and marked as the temperature driving force. By considering the partition area and flow distribution, the temperature driving force in each candidate partition is spatially integrated to obtain the heat exchange potential of the partition. The heat exchange potential represents the heat exchange capacity of the corresponding candidate partition under ideal conditions.

[0097] The ratio of the average risk value to the heat transfer potential of each candidate partition is calculated and compared with a preset potential threshold. Candidate partitions with a ratio greater than the preset potential threshold are marked as high heat transfer efficiency partitions, which have high heat transfer potential and relatively controllable risks. Candidate partitions with a ratio less than or equal to the preset potential threshold are marked as risk mitigation partitions, which have higher risks or lower heat transfer potential. Finally, based on the partition marking results, a structural layout strategy is designed. In high heat transfer efficiency partitions, turbulence enhancement structures (such as turbulence deflectors, vortex generators, etc.) are prioritized to enhance the heat transfer effect. The layout density of turbulence enhancement structures increases with the increase of the partition's heat transfer potential to maximize heat transfer efficiency. In risk mitigation partitions, adaptive drainage structures (such as flow channels, dust removal devices, etc.) are prioritized to reduce the risk of blockage and corrosion. The layout density of adaptive drainage structures increases with the increase of the partition's average risk value to minimize risk. Through this risk-benefit assessment-based dynamic partition adjustment method, the system can effectively control the risk of blockage and corrosion while ensuring heat transfer efficiency, achieving synergistic optimization.

[0098] It should be further explained that, in the specific implementation process, the arrangement of the turbulence-enhancing structure includes:

[0099] The turbulence demand factor corresponding to each location in the high heat transfer efficiency zone is obtained based on the flue gas velocity distribution set; and the geometric parameters of the turbulence enhancement structure are updated based on it.

[0100] The heat flux density at each location within the high heat transfer efficiency zone is obtained based on the flue gas temperature distribution set, and the arrangement spacing of the turbulence enhancement structure is dynamically adjusted based on the product of the heat flux density and the turbulence demand factor.

[0101] In this embodiment, the flue gas velocity distribution is first analyzed in the high heat transfer efficiency zone, and the spatial gradient of the velocity field is calculated. The magnitude of the gradient reflects the non-uniformity of the flow field. The larger the velocity gradient, the more non-uniform the flow field and the higher the demand for turbulence enhancement. The calculated velocity gradient is normalized, such as by linear normalization or nonlinear normalization based on the distribution characteristics, to obtain the turbulence demand factor. The value of this factor is usually in the range of 0-1. The higher the value, the greater the demand for turbulence enhancement.

[0102] Then, based on the turbulence demand factor at each location, the geometric parameters of the turbulence enhancement structure are determined. The tilt angle of the turbulence vane is designed as angle = JDmin + (JDmax - JDmin) × turbulence demand factor, where JDmin and JDmax are the minimum and maximum allowable angles (e.g., 15° and 45°). The higher the turbulence demand factor, the larger the tilt angle, and the stronger the disturbance effect. The aperture of the turbulence orifice is designed as aperture = KJmax - (KJmax - KJmin) × turbulence demand factor, where KJmin and KJmax are the minimum and maximum allowable apertures (e.g., 5mm and 20mm). The higher the turbulence demand factor, the smaller the aperture, the higher the jet velocity, and the better the turbulence enhancement effect.

[0103] Next, based on the flue gas temperature distribution and the heat exchange medium temperature distribution, the temperature driving force at each location is calculated, and the heat flux density at each location is estimated in combination with the heat exchange potential. The heat flux density can be used to reflect the heat exchange intensity per unit area.

[0104] Obtain the product S1 of heat flux density and turbulence demand factor, and set the layout spacing based on it; wherein, the formula for calculating the design layout spacing is: Spacing = Maximum spacing - (Maximum spacing - Minimum spacing) × S1 / S1 max S1 max The maximum value of the product between the obtained heat flux density and the turbulence demand factor is taken as the maximum value. The larger the product, the smaller the arrangement spacing, and the more significant the turbulence enhancement effect. Finally, based on the calculation results, the turbulence enhancement structure arrangement is implemented in the high heat transfer efficiency zone, including determining the position, angle, shape and density of the turbulence fins, or determining the position, aperture, distribution and density of the turbulence holes. Through this refined design based on the local flow field and heat transfer demand, the system resistance and material consumption can be reduced while ensuring heat transfer efficiency, and the pertinence enhancement can be improved in terms of its targeting and efficiency.

[0105] It should be further explained that, in the specific implementation process, the arrangement of the adaptive diversion structure includes:

[0106] Within the risk mitigation zone, the particle diversion requirements at each location are obtained based on the comprehensive risk distribution map; and the depth and width of the diversion channel for the adaptive diversion structure are designed according to the particle diversion requirements.

[0107] Within the risk mitigation zone, the flow field smoothing factor at each location is obtained based on the flue gas velocity distribution; and the arrangement angle of the adaptive guidance structure is dynamically adjusted based on the flow field smoothing factor and particle guidance requirements.

[0108] In this embodiment, firstly, the blockage risk factor in the comprehensive risk distribution map is analyzed within the risk mitigation zone. Combined with the particulate matter concentration data in the flue gas composition parameters, the product of the blockage risk factor and the particulate matter concentration is calculated, and the product is normalized to obtain the particulate matter evacuation requirements. Then, based on the particulate matter evacuation requirements corresponding to each location, the key parameters of the adaptive evacuation structure are obtained. The key parameters include the evacuation channel depth and the evacuation channel width.

[0109] Wherein, the depth of the drainage channel = SDmin + (SDmax - SDmin) × particle drainage requirements, where SDmin and SDmax are the minimum and maximum allowable depths (e.g., 5mm and 30mm, respectively);

[0110] The width of the drainage channel = KDmax - (KDmax - KDmin) × particle drainage requirements; where KDmin and KDmax are the minimum and maximum allowable widths (e.g., 10mm and 40mm, respectively);

[0111] Next, the second-order spatial derivative of the corresponding flue gas velocity distribution set is performed, and the absolute value of the derivative result is normalized to obtain the flow field smoothing factor, which can be used to reflect the curvature or acceleration variation characteristics of the flow field.

[0112] Furthermore, the product S2 of the flow field smoothing factor and particle conduction requirement is obtained, and the arrangement angle is calculated based on it. The formula for calculating the arrangement angle is: Arrangement angle = JDmax - (JDmax - JDmin) × S2 / S2 max Where JDmin and JDmax are the minimum and maximum allowed angles (e.g., 15° and 75°), respectively, S2 max This represents the maximum value of the product;

[0113] Finally, based on the above calculation results, an adaptive diversion structure layout is implemented within the risk mitigation zone. This includes determining the location, depth, width, and angle of the diversion channel, or determining the geometric parameters and distribution of other diversion structures (such as guide vanes, flow-blocking rings, etc.). Through this refined design based on risk analysis and flow field characteristics, particulate matter can be effectively diverted, reducing deposition and accumulation, lowering the risk of blockage and corrosion, while minimizing interference with the main flow field and maintaining the system's heat exchange efficiency.

[0114] It should be further explained that, in the specific implementation process, the process of obtaining waste heat utilization efficiency includes the following steps:

[0115] The actual heat exchange of the corresponding low-temperature economizer is calculated based on the flue gas temperature distribution set and the heat exchange medium temperature distribution; the overall heat exchange efficiency of the low-temperature economizer is obtained by combining the flue gas velocity distribution and the heat exchange zoning mode; and the waste heat utilization efficiency of the low-temperature economizer is obtained by combining the comprehensive risk distribution map.

[0116] In this embodiment, corresponding flue gas temperature parameters and medium temperature parameters are obtained based on the obtained flue gas temperature distribution set and heat exchange medium temperature distribution, respectively. The flue gas temperature parameters include the flue gas temperature at the inlet and outlet of the flue gas channel; the medium temperature parameters include the medium temperature at the inlet and outlet of the heat exchange medium and the flow rate of the heat exchange medium at the inlet. Based on the obtained flue gas temperature parameters and medium temperature parameters, the actual heat exchange of the flue gas channel is estimated, and the corresponding formula for obtaining the actual heat exchange is: Q actual =G w ×c p,w ×(T w,out -T w,in In the formula, Q actual G represents the actual heat exchange; w Indicates the flow rate of the heat exchange medium at the inlet; c p,w T represents the specific heat capacity of the heat exchange medium. w,out and T w,in These represent the medium temperatures at the inlet and outlet of the heat exchange medium, respectively.

[0117] Then, the cross-section of the flue gas passage is obtained, and the flue gas flow rate G at the corresponding inlet position is obtained by combining the flue gas velocity distribution set. g =∫∫v(x,y)dA(x,y); where v(x,y) represents the velocity distribution at (x,y) within the channel cross-section, and dA(x,y) represents a micro-element of the channel cross-section; and based on the obtained flue gas flow rate, the maximum theoretical heat transfer Q corresponding to the flue gas channel is obtained. max =G g ×c p,g ×(T g,in -T w,in In the formula, T g,in Indicates the flue gas temperature at the inlet; c p,g This represents the specific heat capacity of the flue gas; by comparing the actual heat exchange obtained with the corresponding maximum theoretical heat exchange, the overall heat exchange efficiency is obtained.

[0118] The multi-source sensing data corresponding to the adjusted low-temperature economizer is obtained, and the original comprehensive risk distribution map is updated based on it. The ratio between the overall average value of the comprehensive risk value corresponding to each position before and after the adjustment is obtained (i.e., the comprehensive risk value is first averaged and then the ratio is calculated). The ratio is then weighted and summed with the corresponding overall heat exchange efficiency to obtain the waste heat utilization efficiency of the corresponding low-temperature economizer.

[0119] It should be further explained that, in the specific implementation process, the process of making secondary dynamic adjustments to the marked heat exchange zone pattern includes:

[0120] Based on the updated comprehensive risk distribution map, the boundaries between the high heat exchange efficiency zone and the risk mitigation zone are redefined; the arrangement positions of the turbulence enhancement structure and the adaptive drainage structure are adjusted and updated based on the direction of boundary movement; and the arrangement density of the turbulence enhancement structure and the adaptive drainage structure is adjusted according to the magnitude of boundary movement; the adjustment process is repeated until the preset adjustment rules are met.

[0121] In this embodiment, the comprehensive risk distribution maps before and after the update are compared to identify areas where the risk level has changed significantly. The boundaries between high heat transfer efficiency zones and risk mitigation zones are redefined using boundary tracking methods (such as activity profiles and level set methods). The direction and magnitude of boundary movement are analyzed; the direction of movement indicates the expansion or contraction of the zone, and the magnitude reflects the degree of change. Based on the new zone boundaries, the structural layout strategy is adjusted. For turbulence-enhancing structures, when a high heat transfer efficiency zone expands, the structure is extended towards the new boundary area; when a high heat transfer efficiency zone shrinks, structures outside the boundary are removed or their workload is reduced. The turbulence-enhancing structure is always positioned within the high heat transfer efficiency zone and tilted towards the boundary area to maximize heat transfer potential. Similarly, for adaptive drainage structures, when a risk mitigation zone expands, the structure is extended towards the new boundary area; when a risk mitigation zone shrinks, the structural layout of the boundary area is optimized. The adaptive drainage structure is always positioned within the risk mitigation zone and tilted towards the boundary area to enhance the high-risk zone. The protection of the area is then implemented, followed by adjusting the structural layout density based on the magnitude of boundary movement. A density adjustment function is designed, such as density change rate = k2·boundary movement magnitude, where k2 is a proportional parameter. The larger the boundary movement magnitude, the more significant the density change. When the boundary moves rapidly, it indicates a significant change in the system state, requiring a more aggressive adjustment strategy. When the boundary moves slowly, it indicates a relatively stable system, allowing for gradual adjustment. Finally, based on the adjustment results, the operating parameters of the cryogenic economizer are optimized in real time, such as adjusting flue gas flow distribution, heat exchange medium flow rate, or temperature, and the corresponding adjustment process is repeated until the preset adjustment rules are met. The preset adjustment rules refer to maximizing waste heat utilization efficiency and ensuring that the comprehensive risk value at all locations in the comprehensive risk distribution map is less than the preset risk threshold. This ensures that the system maintains optimal waste heat utilization efficiency under dynamically changing conditions. Through this closed-loop feedback dynamic adjustment mechanism, the system can adapt to fluctuations in fuel characteristics, load changes, environmental conditions, and other factors, maintaining a highly efficient and safe operating state, and improving the reliability and economy of the cryogenic economizer.

[0122] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0123] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0124] In the description of this invention, it should be understood that the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0125] In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0126] In the description of this invention, "several" means one or more, and "a large number" means two or more.

[0127] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0128] All formulas in this manual are dimensionless and calculated numerically. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters and thresholds in the formulas are set by those skilled in the art according to the actual situation.

[0129] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for utilizing waste heat in conjunction with a low-temperature economizer to prevent clogging and corrosion, characterized in that, include: Step S1: Acquire multi-source sensing data in the flue gas channel during the operation of the low-temperature economizer. The multi-source sensing data includes a flue gas temperature distribution set, a flue gas velocity distribution set, and a flue gas composition parameter set. Step S2: Obtain the temperature margin at each location in the flue gas channel based on the flue gas temperature distribution set, and conduct risk analysis on the corresponding flue gas channel in combination with the flue gas velocity distribution set and the flue gas composition parameter set to obtain the blockage risk factor and corrosion risk factor. Step S3: Based on corrosion risk factors and blockage risk factors, construct a comprehensive risk distribution map, and divide the heat exchange surface of the low-temperature economizer into regions based on it to obtain a heat exchange zoning mode, and dynamically adjust the heat exchange surface based on it. Step S4: After the adjustment is completed, obtain the heat exchange efficiency in the flue gas channel, and obtain the waste heat utilization efficiency of the low temperature economizer in combination with the comprehensive risk distribution map. Based on this, perform secondary dynamic adjustment on the marked heat exchange zone mode until it meets the preset adjustment rules.

2. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 1, characterized in that, The process of obtaining congestion risk factors includes: Temperature data at various locations within the flue gas channel are obtained based on the flue gas temperature distribution set. The difference between the data and the preset acid dew point temperature threshold is then obtained and normalized to obtain the temperature margin. The Reynolds number at each location within the flue gas channel data is obtained based on the flue gas velocity distribution set, and the corresponding flow disturbance factor at that location is obtained accordingly. The particulate matter concentration at each location is obtained based on the flue gas composition parameters, and a deposition probability mapping is performed based on this information to obtain the particulate deposition probability. The blockage risk factor at each location within the flue gas passage is obtained by weighting and summing the temperature margin, flow disturbance factor, and particle deposition probability.

3. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 2, characterized in that, The process of obtaining the particle deposition probability includes: Based on the particulate matter concentration at each location within the flue gas channel, obtain the particle size distribution at the corresponding location; calculate the particle size-weighted average of the particulate matter concentration based on the particle size distribution; Based on the flue gas velocity distribution at each location within the flue gas channel, the critical velocity for particle deposition at the corresponding location is obtained. The particle deposition probability is obtained by substituting the difference between the flue gas velocity distribution and the critical velocity for particle deposition into a pre-constructed exponential mapping function.

4. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 1, characterized in that, The process of obtaining corrosion risk factors includes: Based on the acid gas concentration data in the flue gas composition parameter set, the acid deposition rate at each location in the flue gas channel is obtained, and the scouring intensity at the corresponding location is obtained based on the flue gas velocity distribution set. The material parameters of the heat exchange surface at various locations within the flue gas passage are obtained, and the corrosion resistance factor of the material at the corresponding location is obtained. Based on the acid deposition rate and scouring intensity, a negative correlation mapping is performed on the corresponding material corrosion resistance factor to obtain the corrosion risk factor at the corresponding location.

5. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 1, characterized in that, The process of dynamically adjusting the corresponding heat exchange surface includes: The corrosion risk factors and blockage risk factors in the flue gas passage are weighted and summed to obtain the comprehensive risk value, and its spatial distribution in the flue gas passage is obtained to obtain the comprehensive risk distribution map. Based on the comprehensive risk distribution map, the heat exchange surface in the flue gas passage is divided into multiple candidate zones; and the average risk value of the comprehensive risk value in each candidate zone is calculated to obtain the average risk value of the corresponding candidate zone. Based on the flue gas temperature distribution at various locations within the flue gas passage and the heat exchange requirements of the low-temperature economizer, the heat exchange potential of each candidate zone is obtained. All candidate zones are sorted according to average risk value and heat exchange potential, and heat exchange zone patterns are marked for the corresponding candidate zones based on the sorting results; the heat exchange zone patterns include high heat exchange efficiency zones and risk mitigation zones; and the heat exchange surface of the corresponding low temperature economizer is dynamically adjusted according to the heat exchange zone patterns. The dynamic adjustment process includes arranging turbulence enhancement structures in high heat exchange efficiency zones and arranging adaptive drainage structures in risk mitigation zones.

6. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 5, characterized in that, The arrangement process of the turbulence-enhancing structure includes: The turbulence demand factor corresponding to each location in the high heat transfer efficiency zone is obtained based on the flue gas velocity distribution set; and the geometric parameters of the turbulence enhancement structure are updated based on it. The heat flux density at each location within the high heat transfer efficiency zone is obtained based on the flue gas temperature distribution set, and the arrangement spacing of the turbulence enhancement structure is dynamically adjusted based on the product of the heat flux density and the turbulence demand factor.

7. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 5, characterized in that, The process of arranging the adaptive drainage structure includes: Within the risk mitigation zone, the particle diversion requirements at each location are obtained based on the comprehensive risk distribution map; and the depth and width of the diversion channel for the adaptive diversion structure are designed according to the particle diversion requirements. Within the risk mitigation zone, the flow field smoothing factor at each location is obtained based on the flue gas velocity distribution; and the arrangement angle of the adaptive guidance structure is dynamically adjusted based on the flow field smoothing factor and particle guidance requirements.

8. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 1, characterized in that, The process of obtaining waste heat utilization efficiency includes: The actual heat exchange of the corresponding low-temperature economizer is calculated based on the flue gas temperature distribution set and the heat exchange medium temperature distribution; the overall heat exchange efficiency of the low-temperature economizer is obtained by combining the flue gas velocity distribution and the heat exchange zoning mode; and the waste heat utilization efficiency of the low-temperature economizer is obtained by combining the comprehensive risk distribution map.

9. The waste heat utilization method for low-temperature economizer synergistic anti-clogging and anti-corrosion as described in claim 1, characterized in that, The process of making secondary dynamic adjustments to the marked heat exchange zone pattern includes: Based on the updated comprehensive risk distribution map, the boundaries between the high heat exchange efficiency zone and the risk mitigation zone are redefined; the arrangement positions of the turbulence enhancement structure and the adaptive drainage structure are adjusted and updated based on the direction of boundary movement; and the arrangement density of the turbulence enhancement structure and the adaptive drainage structure is adjusted according to the magnitude of boundary movement; the adjustment process is repeated until the preset adjustment rules are met.

10. The waste heat utilization method for synergistic anti-clogging and anti-corrosion of low-temperature economizer according to claim 9, characterized in that, The preset adjustment rule refers to the waste heat utilization efficiency reaching its maximum and the comprehensive risk value at all locations in the comprehensive risk distribution map being less than the preset risk threshold.

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