A wide coal reformed gas heat exchanger exchange processing system

Abstract

The present application relates to dust-containing gas heat exchange technical field, disclose a kind of wide coal transformation gas heat exchanger exchange processing system, comprising: one with a large number of independent inert particles constitutes fluidized state suspended bed as dynamic heat exchange medium vertical heat exchange tower, and integrated a fluidized bed early warning and self-healing unit of instability;The unit is by analyzing the frequency spectrum characteristics of aerodynamic parameters, before instability process occurs, high pressure air flow pulse is applied to intervene, the present application is by decoupling heat exchange and dust removal in physical mechanism, so that system in processing high dust-containing gas, avoid the process interruption and heat loss caused by periodic dust removal in traditional way, and combine its early warning and self-healing ability of instability precursor to operating state, improve the reliability and operation continuity of system in complex industrial environment.

Description

Technical Field

[0001] This invention relates to a heat exchanger system for coal-fired gas conversion, belonging to the field of dust-laden gas heat exchange technology. Background Technology

[0002] In the heat exchange process of gases with complex coal quality and high dust content, there is a common operational contradiction in the industry: it is difficult to balance the maintenance of heat exchange efficiency with the continuity of the process. To ensure heat exchange efficiency, frequent ash removal operations are often required, but this will interrupt or affect the continuous stability of the process. Conversely, if the ash removal frequency is reduced to ensure continuous operation, the efficiency of the heat exchange surface will drop sharply due to severe ash accumulation. The reason for the above operational contradiction is that the existing technology usually uses heat exchangers with fixed heat exchange surfaces and relies on periodic external forced means, such as mechanical scraping or high-pressure gas purging, to remove the dust attached to them.

[0003] Existing technologies attempt to alleviate this contradiction by adjusting the frequency and intensity of dust removal. However, this forces the entire system to choose between energy consumption, heat exchange efficiency loss, and operational continuity, failing to address its core flaw. This technology, based on a fixed surface and periodic forced dust removal, has limitations specifically: the heat exchange and dust removal processes are physically bound to the same fixed surface, causing them to mutually constrain each other in their operational mechanisms; optimization of one comes at the expense of the other. Furthermore, the static structural design of the heat exchanger is ill-suited to adapting to dynamically changing gas source conditions with varying dust content, particle size, and viscosity, resulting in a lack of ability to cope with the uncertainties of real industrial environments. Therefore, designing a heat exchange system that physically separates the heat exchange and dust removal processes, maintains heat exchange efficiency during continuous operation, and simultaneously possesses the stability to cope with complex industrial operating conditions is a technical problem that those skilled in the art are currently working to solve. Summary of the Invention

[0004] This invention provides a heat exchanger system for coal gas conversion, the main purpose of which is to solve the problem of how to fundamentally decouple the heat exchange and dust removal processes to achieve continuous and efficient operation when processing high dust-containing gases, while ensuring the system's operational stability and long-term reliability under complex operating conditions.

[0005] To achieve the above objectives, the present invention provides a gas heat exchanger system for coalfield gas conversion, the system comprising:

[0006] A vertical heat exchange tower;

[0007] An air distribution device located at the bottom of a vertical heat exchange tower; a large number of independent inert particle heat exchange media filled inside the vertical heat exchange tower and blown upward by the air distribution device to form a fluidized suspended bed.

[0008] A gas inlet for introducing dust-laden high-temperature gas into the lower part of the fluidized bed, a purified gas outlet located at the top of the vertical heat exchange tower, and a dust outlet located at the bottom of the vertical heat exchange tower.

[0009] An aerodynamic feature acquisition unit is configured to acquire raw signals of aerodynamic parameters generated by the upward blowing of the air distribution device;

[0010] A fluidized bed instability precursor warning and self-healing unit is configured to: perform frequency domain analysis on the original signal to obtain the spectral characteristics of aerodynamic parameters; when an energy peak in the frequency range of 0.5 Hz to 2 Hz is detected in the spectral characteristics, generate an instantaneous intervention command; and based on the instantaneous intervention command, apply a short high-pressure airflow pulse to the bottom of the fluidized bed, the energy and duration of which are sufficient to disrupt the nascent cooperative oscillation structure within the fluidized bed.

[0011] Preferably, it also includes a partitioned heat exchange coil immersed in a fluidized bed, the partitioned heat exchange coil being used to transfer heat from the inert particulate heat exchange medium to the second gas to be heated; and the inert particulate heat exchange medium is alumina ceramic spheres with a diameter of 2 mm to 3 mm.

[0012] Preferably, the fluidized bed precursor instability early warning and self-healing unit is further configured to: obtain spectral characteristics by performing a fast Fourier transform on the original signal of aerodynamic parameters; and the duration of the short high-pressure airflow pulse is 0.2 to 0.5 seconds, and its pressure is 2 to 3 times that of the main blower pressure.

[0013] Preferably, the system further includes: a non-destructive diagnostic unit for the heat transfer activity of the fluidized bed, configured to: periodically apply a controlled, brief transient disturbance to a thermodynamic input parameter of the dust-laden, high-temperature gas entering the fluidized bed as a thermal pulse excitation; acquire the temperature response at the outlet of the purified gas; and measure the time delay from the application of the thermal pulse excitation to the temperature response reaching its peak or trough. The heat transfer activity health index of inert particulate heat exchange media is calculated according to the following formula. , ,in, The reference time delay is the time delay measured by the same thermal pulse excitation on an inert particulate heat transfer medium under initial healthy conditions; and when the heat transfer activity health index When the health threshold is below a certain level, a predictive maintenance alert is output.

[0014] Preferably, the air distribution device has an adjustable airflow rate to adjust the fluidization degree and heat transfer intensity of the fluidized bed.

[0015] Preferably, the system further includes: a critical phase change early warning and targeted removal unit, which is configured to: receive a coal ash melting temperature corresponding to the coal type currently used; monitor the absolute temperature of multiple regions in the fluidized bed in real time; and when the absolute temperature of any region reaches the coal ash melting temperature, apply a high-pressure pulse to that region to forcibly strip and cool the coal dust in the critical phase change state, thereby interrupting its physicochemical process of transformation into sintered body.

[0016] Preferably, the critical phase change early warning and targeted removal unit also uses the coal ash melting temperature minus a safety margin value as the early warning temperature, and when the absolute temperature of any region reaches the early warning temperature, it determines and applies the corresponding level of pressure and duration in a mapping relationship based on the excess value of the absolute temperature relative to the early warning temperature.

[0017] Preferably, the system further includes: an adaptive diagnostic unit for the health of the heat storage layer structure, which is connected to a vibration sensor installed outside the vertical heat exchange tower. The adaptive diagnostic unit for the health of the heat storage layer structure is configured to: capture the transient acoustic vibration signal generated by the event collected by the vibration sensor when the system performs a pulse cleaning event; extract the time required for the transient acoustic vibration signal to decay from its peak to the background noise level as the acoustic decay time; compare the acoustic decay time with a reference decay time characterizing the fluidized bed in a fluffy state; and if the acoustic decay time is longer than the reference decay time, determine that the fluidized bed has a tendency to caking, and adjust the execution parameters of at least one subsequent pulse cleaning, including the cleaning interval time and the cleaning pressure.

[0018] Preferably, the adaptive diagnostic unit for the health of the heat storage layer structure is further configured to: if the acoustic decay time is shorter than the reference decay time, determine that the fluidized bed is healthy and fluffy, and select a longer interval time as the subsequent dust removal interval time according to a predetermined rule that includes multiple interval time levels.

[0019] Preferably, the gas inlet is located on the lower middle side wall of the vertical heat exchange tower, so that the introduced dust-laden high-temperature gas forms a tangential flow in the fluidized bed, thereby enhancing the contact between the gas and the inert particle heat exchange medium and prolonging the residence time.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. By constructing a fluidized bed composed of a large number of independent inert particles as a dynamic heat exchange medium, the heat exchange mode of high dust-content gas is changed. In this mode, the two actions of heat exchange and dust removal are decoupled in terms of physical mechanism. The heat transfer and dust removal rely on the violent turbulence and gravity settling of the particle medium itself to proceed synchronously and continuously. This avoids the process interruption and heat loss caused by the periodic forced dust removal of traditional fixed heat exchange surfaces. This allows the system to maintain continuous and stable operation of the heat exchange process when dealing with a wide range of coal gas sources with drastic fluctuations in dust content and composition.

[0022] 2. By combining the aerodynamic characteristic acquisition unit of the fluidized bed with the early warning and self-healing unit for instability precursors, a system operation maintenance mechanism was constructed. This system no longer passively responds to macroscopic instability phenomena that have already occurred. Instead, by analyzing the spectrum of aerodynamic parameters, it can identify the energy peak characteristics at the nascent stage of unstable flow states such as slugging or channeling, and instantaneously apply high-pressure airflow pulses to disrupt them. This shift from post-failure recovery to pre-failure intervention enables the fluidized bed heat exchange mechanism, as the core of the system, to have the ability to self-correct and maintain stability when facing extreme operating conditions such as upstream process anomalies or dust surges, thereby improving the reliability and service life of the entire heat exchange system in complex industrial environments.

[0023] 3. Through the synergistic effect of the critical phase change early warning and targeted removal unit and the suspended bed heat transfer active non-destructive diagnostic unit, the system's self-awareness and predictive maintenance capabilities across multiple time scales are enhanced. On the one hand, by monitoring the correlation between local bed temperature and coal ash melting temperature in real time, the system can anticipate and intervene in irreversible sintering risks caused by chemical phase changes, thus avoiding permanent damage to core components. On the other hand, by periodically applying controlled heat pulses and analyzing their time-domain response characteristics, the system can non-destructively quantify and assess the trend of microscopic performance degradation of the heat exchange medium due to long-term operation. The combination of these two mechanisms enables the system to go beyond managing current operating parameters, possess risk identification capabilities, and transform the maintenance mode from passive fault-driven to proactive state-driven, reducing the risk of unplanned downtime and the overall life-cycle maintenance costs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall architecture of a coal-to-gas heat exchanger system according to the present invention.

[0025] Figure 2 This is a flowchart illustrating the workflow for diagnosing the structural health of the heat storage layer and the heat transfer activity of the suspended bed in this invention.

[0026] Figure 3 This is a diagram showing the data flow and decision logic relationship for the comprehensive diagnosis and early warning system of this invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of this invention, but not all embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] This invention discloses a heat exchanger system for wide-source coal gas conversion. Its architecture mainly consists of a vertical heat exchange tower serving as the reaction vessel, a fluidized bed forming the dynamic heat exchange medium, and a series of diagnostic and control units for process sensing and regulation. Specifically, the diagnostic and control units include a fluidized bed precursor instability early warning and self-healing unit, a fluidized bed heat transfer activity non-destructive diagnostic unit, a critical phase change early warning and targeted removal unit, and a heat storage layer structure health adaptive diagnostic unit. These units work synergistically to address the challenges posed by high-temperature coal gas sources. The technical challenge of simultaneously maintaining heat exchange efficiency and process continuity in continuous heat exchange processes for dust-laden gases with drastically fluctuating composition presents a significant challenge. In a retrofit application scenario for coke oven gas waste heat recovery in the coal chemical industry, equipment with a fixed heat exchange surface faces interdependent heat exchange and dust removal processes. To address this challenge, the present invention's structure and operating mechanism are designed to physically separate the heat exchange and dust removal processes. During system operation, an air distribution device located at the bottom of the vertical heat exchange tower continuously blows upwards, causing the large number of independent inert particles filling the tower to exchange heat. The medium is lifted and turbulent by the gas, forming a fluidized bed. This fluidized bed itself constitutes a heat exchange medium with a large total surface area and dynamic renewal on a macroscopic scale. The dust-laden, high-temperature gas to be treated is tangentially introduced through a gas inlet located in the lower part of the vertical heat exchange tower. During the collision and contact between the gas and the fluidized inert particulate heat exchange medium, the gas transfers heat to the particulate medium. At the same time, the dust particles entrained in the gas also collide with the particulate medium. However, due to the smooth surface of the inert particulate heat exchange medium and its constant high-frequency mutual friction and tumbling, the dust particles attempt to adhere to it. The dust is mechanically stripped off upon contact and settles to the bottom of the tower under gravity, exiting through the dust outlet. The purified gas, having completed heat exchange, exits through the purified gas outlet located at the top of the vertical heat exchange tower. The partitioned heat exchange coils immersed in the fluidized bed acquire heat from the heated inert particle heat exchange medium and transfer it to the second gas flowing inside the coils. Thus, heat transfer and dust stripping occur simultaneously and continuously, enabling the system to maintain continuous operation of the heat exchange process when dealing with gas sources with fluctuating dust content and composition.

[0029] Furthermore, to address the potential for instantaneous dust surges caused by upstream process anomalies, which could induce instability phenomena such as channeling or throttling in the fluidized bed, and considering the lag in conventional monitoring methods, the system integrates a fluidized bed instability early warning and self-healing unit. This unit analyzes fluctuations in aerodynamic parameters, traditionally considered noise, to extract characteristic signals that characterize the system's operating state. It is configured to continuously acquire raw aerodynamic parameter signals generated by the air distribution device's blower via an aerodynamic feature acquisition unit, and perform a Fast Fourier Transform (FFT) on these raw signals to obtain their spectral characteristics. Given that the pressure fluctuation spectrum of a stable fluidized bed exhibits a broad spectrum without a clear main peak, and that weak coordinated oscillations occur within the bed when instability is imminent but has not yet macroscopically formed, the unit's logic is set to continuously monitor an energy peak in the 0.5 Hz to 2 Hz frequency range within the spectral characteristics. The appearance of this energy peak serves as a precursor signal for instability. Once this energy peak is detected and its intensity exceeds a calibrated threshold, the unit generates an instantaneous intervention. The system receives a command and, based on this command, applies a short, high-pressure airflow pulse to the bottom of the fluidized bed, lasting 0.2 to 0.5 seconds and with a pressure 2 to 3 times that of the main blower. The energy and duration of this pulse can disrupt the nascent oscillatory structure within the fluidized bed without interrupting the main process, thus preventing operational interruptions due to instability. Simultaneously, to detect potential microscopic performance degradation of the inert particles used as the heat exchange medium due to long-term operation, such as decreased heat transfer activity caused by surface vitrification of trace impurities at high temperatures, the system also includes a non-destructive diagnostic unit for the fluidized bed's heat transfer activity. To achieve online diagnostics without shutting down the system, this unit is configured to execute a periodic detection procedure. This procedure applies a controlled and brief transient disturbance to a thermodynamic input parameter of the dust-laden, high-temperature gas entering the fluidized bed, such as flow rate or temperature, as a thermal pulse excitation. Subsequently, the unit accurately acquires the temperature response at the purified gas outlet and measures the time delay from the start of the thermal pulse excitation to the temperature response reaching its peak or trough. This time delay The heat transfer activity health index of the inert particulate heat exchange medium directly reflects the average thermal inertia and heat transfer rate of the entire bed. It is calculated using the following formula. , ,in, This reference time delay is the time delay measured for an inert particulate heat transfer medium under the same thermal pulse excitation in its initial state. The calculated heat transfer activity health index can be obtained and stored by executing a calibration program once during the initial system debugging run. When the health threshold is lower than a preset threshold, the system outputs a predictive maintenance alert, providing operators with a basis for maintenance and enabling them to schedule repairs before a significant performance degradation occurs.

[0030] Predictive maintenance alarm health threshold for heat transfer activity health index H Its value is determined by a calibration procedure that correlates heat transfer activity with the overall system heat transfer coefficient K. This procedure is performed during the system commissioning phase by introducing deactivated inert particles into the fluidized bed in batches to simulate the gradual degradation of performance. At each degradation point, the heat transfer activity health index H and the overall heat transfer coefficient K calculated from data from various temperature and flow sensors are measured and recorded simultaneously. This yields a set of discrete data pairs of H, and the overall heat transfer coefficient K is then used to determine when it first drops below its initial health state value. 5% of The H value corresponding to the time is set to ) To address potential drift or failure of sensors during long-term operation, as well as irreversible physical wear of the inert medium, the system integrates a lifecycle self-calibration and diagnostic protocol. This protocol is set to automatically activate every 2000 hours of cumulative operation or after each replacement of a new batch of inert particles. Upon activation, the protocol first performs a sensor consistency check, comparing the readings of multiple physically adjacent temperature sensors. If the deviation between any two sensors consistently exceeds three times their nominal error, the sensor with the larger deviation is marked as abnormal, and its data is temporarily isolated. Subsequently, the protocol will call upon and re-execute the reference time delay. The calibration procedure for the reference acoustic decay time overwrites the old value with the newly measured reference value, thereby ensuring that the evaluation baseline of all diagnostic units remains synchronized with the current actual physical state of the system. Furthermore, considering the complex composition of coal dust in a wide coal gas source, and the possibility that some low-melting-point impurities may undergo chemical phase transformation at local overheating points to form irreversible sintered bodies, the system is further equipped with a critical phase transformation early warning and targeted removal unit. The operation of this unit first requires inputting a coal ash melting temperature corresponding to the currently used coal type as a reference parameter into the system. Simultaneously, the unit subtracts a certain value from the coal ash melting temperature. A safety margin value is used as the warning temperature. During system operation, the unit monitors the absolute temperature of multiple regions in the fluidized bed in real time. When the absolute temperature of any region reaches the warning temperature, the unit will determine and apply a high-pressure pulse of the corresponding level and duration based on the difference between the absolute temperature and the warning temperature in a preset mapping relationship. The high-pressure pulse is applied to the overheated region to forcibly strip and cool the coal dust that is in the critical phase change state, thereby interrupting its physicochemical process of transformation into sintered body, so as to avoid permanent blockage of the heat exchange unit.

[0031] The setting of the critical phase transition warning temperature is based on a safety margin value. The system outputs deterministically a procedure that includes statistical analysis and error superposition. This procedure first collects multi-point temperature data within the bed over at least 100 working cycles under stable operating conditions and calculates its 99th percentile fluctuation. This statistic defines the extreme normal fluctuations of the operating condition itself, and then the maximum measurement error within the target temperature range is obtained from the sensor's technical specifications. Ultimately, the safety margin value was calculated as follows: Simultaneously, the mapping relationship between the overtemperature difference and the pulse parameters is solidified into a multi-level discrete lookup table stored in the controller. The generation of this table is based on an offline simulation. This simulation first establishes a model of the interfacial adhesion force generated by coal ash melting on the surface of inert particles under different overtemperature conditions. Then, for each adhesion force level, the minimum pulse pressure-duration combination required to generate a mechanical peeling effect sufficient to overcome the adhesion force is solved through fluid dynamics calculations. This allows the physical model results to be directly converted into an unambiguous and hierarchical set of control instructions. To optimize the energy efficiency of the cleaning operation and to track the physical structural state of the heat storage layer over a long period, the system also includes an adaptive diagnostic unit for the structural health of the heat storage layer. This unit can be implemented by installing a vibration sensor on the outside of the vertical heat exchange tower. Its operating logic is that when the system executes a pulse cleaning event, it uses it as an acoustic probe of the internal structure of the bed. When the system executes a pulse cleaning event, the unit captures the transient acoustic vibration signal generated by the event, which is collected by the vibration sensor, and extracts the time required for the signal to decay from its peak to the background noise level, defining it as the acoustic decay time. Given that a loosely structured bed can cause acoustic... The vibration can be dissipated quickly, while a bed with a tendency to harden will cause the vibration to last longer. The unit compares the measured acoustic decay time with a reference decay time that characterizes a healthy and fluffy fluidized bed. If the acoustic decay time is longer than the reference decay time, it is determined that the fluidized bed has a tendency to harden, and the execution parameters of at least one subsequent pulse cleaning are automatically adjusted, such as shortening the cleaning interval and increasing the cleaning pressure. Conversely, if the acoustic decay time is shorter than the reference decay time, it is determined that the bed is healthy and fluffy, and a longer interval can be selected from a predetermined rule that includes multiple interval time levels as the subsequent cleaning interval, thereby establishing a closed-loop adjustment mechanism that adjusts the cleaning parameters in real time according to the actual physical state of the bed.

[0032] Example 1: In a coal chemical production facility that has undergone energy-saving renovation, its gas heat exchanger faces the following problems when processing coke oven gas originating from wide coal gasification and with fluctuating dust content and coal dust viscosity: the high-frequency external forced ash removal operation performed to maintain heat exchange efficiency consumes energy that is close to the energy-saving benefits of heat recovery under some operating conditions. However, once the ash removal frequency is reduced to ensure continuous operation, the heat exchange surface becomes hotter due to ash accumulation, causing fluctuations in the gas inlet temperature of downstream process units. The entire system is caught in a state where efficiency and continuity are difficult to balance. The facility was subsequently replaced with a wide coal gas gas heat exchanger exchange treatment system using the aforementioned technical solution. After the system was put into operation, its interior consists of a fluidized bed of heat exchange media composed of a large number of independent inert particles. Through the tumbling and gravity settling of the particles themselves, heat transfer and dust removal are carried out simultaneously and continuously, thereby physically changing the interaction between heat exchange and ash removal. The aforementioned operational contradiction between efficiency and continuity is alleviated under the architecture of this system.

[0033] During a period of continuous operation, the operating conditions of the upstream gasifier changed, causing a dust surge far exceeding normal levels to impact the heat exchange system. Under this condition, a coordinated oscillating structure began to appear within the bed, showing a tendency to develop into an overall instability state. At this time, the system's fluidized bed precursor instability early warning and self-healing unit, through analysis of the spectrum of aerodynamic parameters, captured the... Hertz An abnormal energy peak appeared within the Hertz frequency range, followed by a short, high-pressure gas pulse applied to the bottom of the fluidized bed. This pulse disrupted the nascent synergistic oscillation structure within the bed before macroscopic instability occurred, restoring the fluidized bed to a uniform and stable operating state. The continuous self-cleaning mechanism of the fluidized bed provides the system with the ability to operate with conventional dust-laden gases, while the fluidized bed early warning and self-healing unit provides protection against operational shocks. The synergistic effect of these two components enables the entire system to adapt to a wider range of uncertain gas source conditions. Ultimately, without human intervention, the heat exchange system maintained a stable inlet gas temperature for the downstream process unit for an extended period, while the heat exchange efficiency did not decrease due to fluctuations in the dust content of the upstream coal gas.

[0034] Example 2: To objectively verify the stability and operational continuity of the heat exchange performance of the technical solution of the present invention when handling dynamically changing high-dust-laden gas, a parallel comparative test platform was built, including the sample group and the control group of the present invention. This test platform was constructed to simulate the periodic fluctuations in dust-laden gas concentration in an industrial environment, and to quantitatively evaluate the performance indicators of the two technical solutions. The test platform consists of a hot air generation and dust mixing system that can control the outlet temperature, flow rate, and dust concentration, and two parallel heat exchange test branches receiving the same inlet gas source. The control group branch is equipped with a traditional tubular heat exchanger using a periodic high-pressure gas pulse cleaning method. The sample branch of this invention is equipped with a wide coal-to-gas heat exchanger system with dimensions and rated heat exchange capacity comparable to the control group, using the aforementioned technical solution. Temperature and pressure sensors are installed at key locations on both branches, and all data are recorded by a unified data acquisition system with a sampling period of 1 second. This sampling period is designed to capture short-term events such as transient responses and dust removal pulses during the heat exchange process, while also taking into account the load on the data processing system. The entire test is conducted over a continuous 24-hour period. This duration is designed to ensure that the system can undergo multiple complete cycles of high and low dust concentrations to observe whether there is a cumulative performance degradation.

[0035] During the experiment, the dust concentration of the high-temperature dust-laden gas received by the two test branches was set to fluctuate in a square wave pattern with a 4-hour cycle. Specifically, the concentration was maintained at a low level of 5.0 g / m³ for 2 hours, followed by a high concentration of 25.0 g / m³ for another 2 hours, and this cycle repeated. The different mechanisms of the two technical solutions in addressing dust accumulation resulted in differences during the high-concentration operation phase. For example, by the 3.8-hour mark, in the latter half of the first high-concentration operation cycle, the outlet temperature of the control group had decreased from its initial stable value to 431.3°C, while its inlet and outlet pressure drop had increased to 1450 Pa. In contrast, the outlet temperature of the sample group of this invention remained at 449.8°C, and the pressure drop was... 1225 Pa; This trend was reproduced in each subsequent cycle. By the 23.8-hour mark at the end of the experiment, the outlet temperature of the control group was 431.8°C, while the outlet temperature of the sample group of the present invention was 450.2°C. The performance fluctuation of the control group was due to the cycle between the formation of ash layer on its fixed heat exchange surface and the periodic forced removal. Ash accumulation leads to an increase in thermal resistance and flow resistance, and the ash removal operation itself also introduces process disturbance. The reason why the performance of the sample group of the present invention can remain stable is that the physical structure of its fluidized bed makes heat exchange and ash removal two sides of the same process and occur continuously. Any attached dust is stripped off by the continuous movement of the particulate medium and discharged by gravity settling, thereby avoiding the phenomenon of thermal resistance accumulating over time.

[0036] Example 3: This example combines Figures 1 to 3 This paper describes the implementation of a gas heat exchanger system for coal-to-gas conversion. Figure 1 As shown in the diagram, this figure illustrates the physical execution layer, the process perception and execution layer, and the intelligent diagnosis and decision-making layer. The physical execution layer, centered on a vertical heat exchange tower, receives dust-laden high-temperature gas and ultimately outputs purified gas and dust. The process perception and execution layer comprises a series of sensors and actuators. Among them, the aerodynamic feature acquisition unit collects raw signals, the multi-zone temperature sensor and thermal pulse exciter collect local temperature data and apply thermal pulse excitation, the vibration sensor collects acoustic vibration signals, and the high-pressure pulse application device applies action to the vertical heat exchange tower according to instructions. The intelligent diagnosis and decision-making layer consists of four collaboratively working units: the fluidized bed precursor instability early warning and self-healing unit receives raw signals and outputs self-healing intervention instructions; the suspended bed heat transfer activity non-destructive diagnosis unit receives temperature and response signals and outputs diagnostic excitation instructions; the critical phase change early warning and targeted removal unit receives local temperature data and outputs targeted removal instructions; and the heat storage layer structural health adaptive diagnosis unit receives acoustic vibration signals and outputs dust removal parameter adjustment instructions.

[0037] like Figure 2 As shown in the figure, this diagram illustrates the specific workflow of two core diagnostic units in the intelligent diagnostic and decision-making layer. Both units utilize the fluidized bed, which serves as the core heat exchange medium and the object of diagnosis, for closed-loop regulation or state assessment. The closed-loop feedback loop on the left demonstrates the diagnostic and adaptive adjustment process for the health of the heat storage layer structure. This process uses pulse cleaning as the acoustic excitation source, captures transient acoustic vibration signals through external vibration sensors, analyzes the time it takes for the signal to decay from its peak to background noise (the acoustic decay time), and compares it with a reference time to determine if there is a tendency for bed caking. Finally, based on the determination result, it adaptively adjusts subsequent cleaning intervals and pressure parameters. The state output process on the right demonstrates the non-destructive diagnostic process for the heat transfer activity of the fluidized bed. This process first applies a controlled thermal pulse excitation to the inlet gas parameters, then collects the outlet temperature response and measures the peak or trough time difference between the excitation and the response, i.e., the time delay. Then based on that time delay Compared with the initial reference delay Comparison to assess the health index of heat transfer activity It will also output a predictive maintenance alert when the health index falls below a threshold.

[0038] like Figure 3 As shown in the figure, the process begins with two parallel initial data processing steps: 1.0, acquiring and processing the acoustic signal, whose output is the processed acoustic decay time; and 2.0, acquiring and processing the thermal pulse response, whose output is the time delay. The processed acoustic decay time is sent to the 3.0 structural health assessment module, which compares it with the D1 baseline decay time and outputs the structural health assessment result and the determination of the compaction trend, with a time delay. It is then sent to the 4.0 heat transfer activity evaluation module, which is based on the D2 reference time delay. Compare and output the heat transfer activity health index Ultimately, the determination of slagging trend and the health index of heat transfer activity were analyzed. The two assessment results are combined into the 5.0 integrated diagnosis and early warning module. On the one hand, this module feeds back the caking trend judgment to the core heat exchange system to achieve adaptive adjustment of the cleaning parameters. On the other hand, it generates predictive maintenance alarms when needed and sends the information to the operation and maintenance personnel.

[0039] Example 4: In a newly installed gas heat exchanger system for coal conversion using the aforementioned technical solution, before being put into actual industrial production, a set of start-up and parameter calibration procedures are implemented to ensure that the internal operating parameters of its various diagnostic and self-healing units are adapted to the physicochemical properties of the specific coal type and the on-site working conditions. The initial conditions of this procedure are that the vertical heat exchange tower is filled with brand-new inert alumina ceramic balls with a diameter of 2 to 3 mm, and the system is connected to a hot air source that can provide stable temperature and flow rate for collecting reference parameters in a clean environment free from dust interference.

[0040] After the procedure is initiated, the trigger threshold of the fluidized bed precursor instability early warning and self-healing unit is first calibrated. The system operates stably at a moderate blower rate for 60 minutes. The aerodynamic parameter signals during this period are recorded by the aerodynamic feature acquisition unit and processed by Fast Fourier Transform to obtain a reference spectrum characteristic under stable operating conditions. This characteristic has no obvious energy peak in the frequency range of 0.5 Hz to 2 Hz. Subsequently, the control system applies a series of weak sinusoidal perturbations with a period of 1 second and an amplitude that gradually increases to the blower rate of the blower. At the same time, the motion state of the particles in the bed is monitored through an optical observation window set on the tower wall. The system records the peak value A of the first stable energy peak appearing in the frequency range of 0.5 Hz to 2 Hz, based on the moment when initial localized particle coordinated oscillation occurs. The warning trigger threshold for this unit is set to 150% of the value of A, and this calibration value is stored in the system's control logic. Simultaneously, the system performs a reference time delay calibration for the suspended bed heat transfer activity non-destructive diagnostic unit. Under stable hot airflow, the system continuously executes five controlled thermal pulse excitations and measures the time delay from excitation application to the outlet temperature response valley. After removing the maximum and minimum values, the arithmetic mean of the remaining three measurements is used as the reference time delay under the initial healthy state. The data is stored. In addition, while performing each thermal pulse excitation, the adaptive diagnostic unit for the health of the heat storage layer structure also records the acoustic vibration signal captured by the vibration sensor and calculates its acoustic decay time. Similarly, the average value of 5 measurements is taken as the reference decay time characterizing the bed layer as being in a healthy and fluffy state and stored in the system.

[0041] For the critical phase change early warning and targeted removal unit, the operators input the coal ash melting temperature value given in the coal quality analysis report of the coal type to be treated into the system control unit. The system then generates a pressure and duration mapping table of the targeted removal pulse corresponding to different degrees of overheating under the melting temperature constraint, based on a built-in heat transfer and hydrodynamic model for alumina ceramic spheres. At this point, all diagnostic and self-healing units of the system have completed parameter calibration based on the field conditions.

[0042] Example 5: The adaptive diagnostic unit for the health of the heat storage layer structure is configured to periodically execute a self-optimizing procedure for a cleaning strategy, so that its diagnostic benchmark can dynamically adapt to changes in the physical properties of the inert particulate heat exchange medium due to long-term operation. In a continuously operating system, when the accumulated operating time reaches a set value, the unit will extend the interval of the next cleaning by a fixed time step based on the current cleaning interval, and remeasure the acoustic decay time during the cleaning event of this extended interval. If the measured acoustic decay time does not increase compared to the previous measurement, the system determines that there is still room for optimization in the current cleaning interval and continues to try to extend it in the next cycle. If the acoustic decay time increases after the interval is extended, the system restores the cleaning interval to the set value before the extension. In this way, the system can dynamically track and set a cleaning interval that can maintain the bed fluffiness and save energy under the current bed condition, so that its diagnostic benchmark and execution strategy are in an adaptive adjustment state.

[0043] The non-destructive diagnostic unit for heat transfer activity in the fluidized bed employs a differential measurement method to eliminate interference from fluctuations in the thermophysical properties of the high-temperature gas entering the system. When this unit applies a controlled, brief transient disturbance to the dust-laden high-temperature gas entering the fluidized bed, it not only collects the temperature response at the purified gas outlet but also measures its time delay. In addition, the system uses an independent temperature sensor with fast response characteristics installed at the gas inlet pipe to synchronously measure the original time waveform of the transient disturbance before it is acted upon by the bed, and calculates an inlet reference response time; the system control logic compares the outlet temperature response time delay. The correlation with changes in the inlet reference response time is used to determine changes in heat transfer activity; only when the outlet temperature response time is delayed... Only when the trend of change is inconsistent with the trend of change of inlet reference response time will the system attribute it to the change in heat transfer activity of the inert particulate heat transfer medium, and update the heat transfer activity health index accordingly. The diagnostic results obtained through this differential measurement reflect the change in the heat transfer activity of the inert particulate heat exchange medium after eliminating the influence of fluctuations in the gas source itself.

[0044] Example 6: In a scenario where a heat exchange system is to be used to process a new wide range of coal gas sources with uncertain physical properties, in order to find a blower rate that maximizes the overall energy efficiency of the system and to establish an online monitoring and response mechanism for potential operational risks caused by changes in coal ash melting characteristics, a set of operating parameter setting procedures combining offline optimization and online monitoring needs to be implemented. The goal of this procedure is to determine, through systematic testing, an optimal blower rate that maximizes the ratio of the total heat transfer coefficient to the blower input power, while ensuring the safety of the system operating at this rate. In this process, inert particulate heat exchange medium is selected from alumina ceramic spheres with a diameter of 2 mm to 3 mm, which provides a good physical basis for the subsequent fluidization and optimization process.

[0045] After the procedure is initiated, the system processes the new gas flow with an initial blower rate. Starting from this point, the blower rate is increased stepwise with a fixed increment. At each rate step, the system operates stably for 30 minutes, and the data acquisition system records the blower input power and the total heat transfer coefficient calculated from various temperature sensors at that rate platform, thus obtaining the comprehensive energy efficiency index at that rate. By traversing multiple rate steps, a set of discrete data points showing the comprehensive energy efficiency index changing with the blower rate is obtained. The blower rate corresponding to the peak comprehensive energy efficiency index in this set of data points is determined as the optimal blower rate for this specific gas source and used as the benchmark setpoint for subsequent routine operation. Based on this benchmark, the system activates an online abnormal state monitoring logic based on multi-physical quantity correlation analysis. This logic continuously monitors and analyzes bed pressure. In the normal evolution of the bed's physical state, the changes in pressure drop and acoustic decay time should show a synchronous and gradual correlation. If the system detects an independent and rapid increase in bed pressure drop that is unrelated to the trend of acoustic decay time, the event is determined to be caused by the local melting of low-melting-point coal ash and the formation of initial sintered bodies. Once this independent and rapid pressure drop increase event is identified, the system control logic triggers a global high-pressure purging covering the entire air distribution plate area with an intensity higher than that of a conventional ash cleaning pulse to destroy and remove the newly formed sintered agglomerates. At the same time, an alarm is sent to the central control room, prompting the operators to verify the physicochemical properties of the current coal type. This procedure enables the system to operate with optimized parameters while also having the ability to identify and intervene in online risks related to raw material uncertainties.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A wide coal reformed gas heat exchanger exchange treatment system, characterized by, The system comprises: a vertical heat exchange tower; an air distribution device arranged at the bottom of the vertical heat exchange tower; a large number of independent inert particle heat exchange media filled in the vertical heat exchange tower and blown upward by the air distribution device to form a fluidized suspension bed; a gas inlet for introducing a high-temperature gas containing dust into the lower part of the fluidized suspension bed, a purified gas outlet arranged at the upper part of the vertical heat exchange tower, and a dust outlet arranged at the bottom of the vertical heat exchange tower; an aerodynamic characteristic acquisition unit configured to acquire original signals of aerodynamic parameters generated by the upward blowing of the air distribution device; a fluidized bed pre-instability early warning and self-healing unit configured to: perform frequency domain analysis on the original signals to obtain spectral characteristics of the aerodynamic parameters; generate an instantaneous intervention instruction when an energy peak in the frequency range of 0.5 Hz to 2 Hz is monitored in the spectral characteristics; and based on the instantaneous intervention instruction, apply a short high-pressure air flow pulse to the bottom of the fluidized suspension bed, the energy and action time of the high-pressure air flow pulse being sufficient to destroy the nascent cooperative oscillation structure in the fluidized suspension bed; The system further comprises a floating bed heat transfer activity non-destructive diagnosis unit configured to periodically apply a controlled short transient disturbance to a thermodynamic input parameter of the dust-laden high-temperature gas entering the fluidized floating bed as a thermal pulse excitation, collect the temperature response at the outlet of the purified gas, and measure the time delay from the thermal pulse excitation to the peak or valley of the temperature response ; calculate the heat transfer activity health index of the inert particle heat exchange medium according to the following formula , , wherein is a reference time delay of the inert particle heat exchange medium in the initial healthy state measured by the same thermal pulse excitation; and output a predictive maintenance alarm when the heat transfer activity health index is lower than a health threshold.

2. A wide coal reformed gas heat exchanger exchange processing system according to claim 1, wherein, further comprising a partition wall type heat exchange coil immersed in the fluidized suspension bed, the partition wall type heat exchange coil being used to transfer heat from the inert particle heat exchange media to a second gas to be heated; and the inert particle heat exchange media being 2 mm to 3 mm in diameter.

3. A wide coal reformed gas heat exchanger exchange processing system according to claim 1, wherein, The fluidized bed pre-instability early warning and self-healing unit is further configured to: obtain the spectral characteristics by performing a fast Fourier transform on the original signals of the aerodynamic parameters; and the duration of the short high-pressure air flow pulse is 0.2 s to 0.5 s, and the pressure thereof is 2 times to 3 times the main blowing pressure.

4. A wide coal reformed gas heat exchanger exchange processing system according to claim 1, wherein, The blowing rate of the air distribution device is adjustable for adjusting the fluidization degree and heat exchange intensity of the fluidized suspension bed.

5. A wide coal reformed gas heat exchanger exchange processing system according to claim 1, wherein, The system further comprises a critical phase transition early warning and targeted removal unit configured to: receive an ash fusion temperature corresponding to the currently used coal type; monitor the absolute temperatures of multiple regions in the fluidized suspension bed in real time; and when the absolute temperature of any region reaches the ash fusion temperature, apply a high-pressure pulse to the region to forcibly strip and cool the coal dust in the critical phase transition state, thereby interrupting the physical and chemical process of its transformation into sintered bodies.

6. A wide coal reformed gas heat exchanger exchange processing system according to claim 5, wherein, The critical phase transition early warning and targeted removal unit further subtracts a safety margin value from the ash fusion temperature as a warning temperature, and when the absolute temperature of any region reaches the warning temperature, determines and applies a corresponding level of pressure and duration in a mapping relationship according to the excess value of the absolute temperature relative to the warning temperature.

7. A wide coal reformed gas heat exchanger exchange system according to claim 1, wherein, The system further comprises a regenerator structure health adaptive diagnosis unit connected with a vibration sensor installed outside the vertical heat exchange tower, the regenerator structure health adaptive diagnosis unit is configured to: capture the transient acoustic vibration signal generated by the vibration sensor during a pulse cleaning event; extract the time required for the transient acoustic vibration signal to decay from the peak value to the background noise level as the acoustic decay time; compare the acoustic decay time with a reference decay time representing the loose state of the fluidized suspended bed; and if the acoustic decay time is longer than the reference decay time, determine that the fluidized suspended bed has a tendency to be caked, and adjust the execution parameters of at least one subsequent pulse cleaning, the execution parameters including the cleaning interval time and the cleaning pressure.

8. A wide coal reformed gas heat exchanger exchange processing system according to claim 7, wherein, The regenerator structure health adaptive diagnosis unit is further configured to: if the acoustic decay time is shorter than the reference decay time, determine that the fluidized suspended bed is healthy and loose.

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