Exchange treatment system of wide coal modified gas-gas heat exchanger

Abstract

The invention relates to the technical field of dust-containing gas heat exchange, and discloses a wide coal transformation gas-gas heat exchanger exchange treatment system which comprises a vertical heat exchange tower with a fluidized suspended bed composed of a large number of independent inert particles as a dynamic heat exchange medium, and a fluidized bed threatened instability early warning and self-healing unit is integrated; the unit applies high-pressure airflow pulse for intervention before the instability process by analyzing frequency spectrum characteristics of aerodynamic parameters, heat exchange and ash removal are decoupled on a physical mechanism, so that when the system treats high-dust-content gas, process interruption and heat energy loss caused by periodic ash removal in a traditional mode are avoided, and the stability of the system is improved. And the reliability and the operation continuity of the system in a complex industrial environment are improved in combination with the threatened instability early warning and self-healing capability of the system on the operation state.

Description

Technical Field

[0001] The invention relates to a wide coal reforming gas-to-gas heat exchanger exchange processing system, belonging to the technical field of dust-containing gas heat exchange. Background Art

[0002] In the heat exchange process of processing gases with complex coal quality and high dust content, there is a common operational contradiction in the industry, that is, it is difficult to balance the maintenance of heat exchange efficiency and the continuity of the process flow. In order to ensure heat exchange efficiency, frequent cleaning operations are often required, but this will interrupt or affect the continuity and stability of the process; on the contrary, reducing the cleaning frequency to ensure continuous operation will cause the heat exchange surface to accumulate dust and the efficiency to drop sharply. The reason for the above operational contradiction is that the existing technology usually uses a heat exchanger with a fixed heat exchange surface and relies on periodic external forced means, such as mechanical scraping or high-pressure gas blowing to remove the dust attached thereto.

[0003] Existing technologies attempt to alleviate this contradiction by adjusting the frequency and intensity of dust cleaning, but this forces the entire system to choose between energy consumption, loss of heat exchange efficiency, and operational continuity, and does not resolve its core flaw. This technology, based on a fixed surface and periodic forced dust cleaning, has the following limitations: the heat exchange and dust cleaning processes are physically bound to the same fixed surface, resulting in mutual constraints between the two in terms of operating mechanism, and the optimization of either comes at the expense of the other; the static structural design of the heat exchanger makes it difficult to effectively adapt to the gas source conditions where parameters such as dust content, particle size, and viscosity are dynamically changing, making the system lack the ability to cope with the uncertainty of real industrial environments. Therefore, how to design a heat exchange system that can physically separate the heat exchange and dust cleaning processes, maintain heat exchange efficiency during continuous operation, and at the same time have the stable ability to cope with changes in complex industrial conditions is a technical problem that technicians in this field are currently working to solve. Summary of the Invention

[0004] The present invention provides a wide coal reforming gas-to-gas heat exchanger exchange and processing system, the main purpose of which is to solve the problem of how to fundamentally decouple the heat exchange and dust cleaning processes when treating high-dust gases to achieve continuous and efficient operation, while ensuring the operating stability and long-term reliability of the system under complex working conditions.

[0005] To achieve the above objectives, the present invention provides a wide coal reforming gas-to-gas heat exchanger processing system, the system comprising:

[0006] a vertical heat exchange tower;

[0007] An air distribution device is provided at the bottom of the vertical heat exchange tower; a large number of independent inert granular heat exchange media are filled in the vertical heat exchange tower and blown upward by the air distribution device to form a fluidized suspension bed;

[0008] A gas inlet for introducing dust-laden high-temperature gas into the lower middle portion of the fluidized suspension bed, a purified gas outlet located at the upper portion of the vertical heat exchange tower, and a dust outlet located at the bottom of the vertical heat exchange tower;

[0009] an aerodynamic characteristic acquisition unit, the aerodynamic characteristic acquisition unit being configured to acquire original signals of aerodynamic parameters generated by the upward blowing of the air distribution device;

[0010] A fluidized bed precursory instability warning and self-healing unit is configured to: perform frequency domain analysis on the original signal to obtain the 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 detected in the spectral characteristics; and based on the instantaneous intervention instruction, apply a short high-pressure airflow pulse to the bottom of the fluidized suspension bed, the energy and action time of the high-pressure airflow pulse being sufficient to destroy the nascent cooperative oscillation structure in the fluidized suspension bed.

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

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

[0013] Preferably, the system further comprises: a suspension bed heat transfer activity non-destructive diagnostic unit, the suspension bed heat transfer activity non-destructive diagnostic unit being configured to: periodically apply a controlled short transient disturbance to a thermodynamic input parameter of the dust-laden high-temperature gas entering the fluidized suspension bed as a thermal pulse excitation; collect 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 a peak or valley value ; Calculate the heat transfer activity health index of the inert granular heat exchange medium according to the following formula , ,in, is the benchmark time delay measured by the same heat pulse excitation when the inert granular heat transfer medium is in the initial healthy state; and when the heat transfer activity health index When a health threshold is lowered, a predictive maintenance alert is output.

[0014] Preferably, the blowing rate of the air distribution device is adjustable to adjust the fluidization degree and heat exchange intensity of the fluidized suspension bed.

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

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

[0017] Preferably, the system further comprises: a heat storage layer structure health adaptive diagnosis unit, the heat storage layer structure health adaptive diagnosis unit is connected to a vibration sensor installed on the outside of the vertical heat exchange tower, and the heat storage layer structure health adaptive diagnosis unit is configured to: when the system executes a pulse cleaning event, capture the transient acoustic vibration signal generated by the event collected by the vibration sensor; extract the time required for the transient acoustic vibration signal to decay from the peak to the background noise level as the acoustic decay time; compare the acoustic decay time with a benchmark decay time that characterizes the fluidized suspended bed in a fluffy state; and if the acoustic decay time continues to be longer than the benchmark decay time, it is determined that the fluidized suspended bed has a tendency to compact, and adjust the execution parameters of at least one subsequent pulse cleaning, and the execution parameters include the cleaning interval time and the cleaning pressure.

[0018] Preferably, the heat storage layer structure health adaptive diagnosis unit is further configured as follows: if the acoustic attenuation time is shorter than the benchmark attenuation time, the fluidized suspension bed is judged to be healthy and fluffy, and a longer interval time is selected as the subsequent cleaning interval time based on a predetermined rule including multiple interval time levels.

[0019] Preferably, the gas inlet is arranged 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 suspension bed, thereby strengthening the contact between the gas and the inert particle heat exchange medium and prolonging the residence time.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. By constructing a fluidized suspension bed composed of a large number of independent inert particles as a dynamic heat exchange medium, the heat exchange mode of highly dusty gas is changed. In this way, the heat exchange and dust cleaning actions are physically decoupled. The heat transfer and dust removal are carried out synchronously and continuously by the violent tumbling and gravitational settling of the particle medium itself. This avoids the process interruption and heat energy loss caused by periodic forced cleaning of traditional fixed heat exchange surfaces. The system can maintain continuous and stable operation of the heat exchange process when processing a wide range of gas sources with violent fluctuations in dust content and composition.

[0022] 2. By combining the fluidized bed's aerodynamic feature acquisition unit with a precursory instability warning and self-healing unit, a system operating status maintenance mechanism has been constructed. The system no longer passively responds to macroscopic instability phenomena that have already occurred. Instead, through analysis of the aerodynamic parameter spectrum, it can identify the energy peak characteristics of unstable flow states such as slugging or channeling at the embryonic stage of formation and instantly apply high-pressure airflow pulses to destroy them. This transition 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 faced with extreme operating conditions such as upstream process anomalies or dust surges, thereby improving the reliability and operating life of the entire heat exchange system in complex industrial environments.

[0023] 3. Through the synergistic effect of the critical phase change warning and targeted removal unit, and the suspended bed heat transfer activity non-destructive diagnosis unit, the system's multi-time scale self-perception and predictive maintenance capabilities are improved. On the one hand, the system can foresee and intervene in the irreversible sintering risk caused by chemical phase change by real-time monitoring of the relationship between the local temperature in the bed and the ash melting temperature, thereby avoiding permanent damage to core components; on the other hand, the system can non-destructively quantify and evaluate the micro-performance degradation trend of the heat exchange medium due to long-term operation by periodically applying controlled thermal pulses and analyzing their time domain response characteristics; the combination of these two mechanisms enables the system to go beyond the management of current operating parameters and possess risk identification capabilities, transforming the maintenance mode from passive fault-driven to active state-driven, reducing the risk of unplanned downtime and the operation and maintenance costs of the entire life cycle. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 2 This is a workflow diagram for diagnosing the health of the thermal storage layer structure and the heat transfer activity of the suspended bed according to the present invention;

[0026] Figure 3 This is a diagram of the data flow and decision logic relationship of the comprehensive diagnosis and early warning of the present invention. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; it should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] The present invention discloses a wide coal reforming gas-to-gas heat exchanger exchange processing system, whose architecture is mainly composed of a vertical heat exchange tower as a reaction vessel, a fluidized suspended bed for forming a dynamic heat exchange medium, and a series of diagnosis and control units for realizing process perception and regulation; the diagnosis and control unit specifically includes a fluidized bed precursor instability warning and self-healing unit, a suspended bed heat transfer activity non-destructive diagnosis unit, a critical phase change warning and targeted removal unit, and a heat storage layer structure health adaptive diagnosis unit, each unit works together to solve the problem of wide coal gas source such as high The technical problem of maintaining heat exchange efficiency and process continuity during the continuous heat exchange of dust-laden gases with drastic composition fluctuations is that it is difficult to balance this. In a modification and application scenario for waste heat recovery of coke oven gas in the coal chemical industry, equipment with fixed heat exchange surfaces is used, and the heat exchange and dust cleaning processes are mutually constrained in the operating mechanism. To meet this technical challenge, the structure and operating mechanism of the present invention are set to separate the heat exchange and dust cleaning processes at the physical level. When the system is running, the air distribution device at the bottom of the vertical heat exchange tower continuously blows air upward, so that a large number of independent inert particles filled in the tower are heat exchanged. The medium is lifted and tumbled by the gas to form a fluidized suspension bed, which itself constitutes a heat exchange medium with a large total surface area and is dynamically updated on a macro scale. The dust-laden high-temperature gas to be treated is introduced tangentially from the gas inlet located in the middle and lower part of the vertical heat exchange tower. During the collision and contact between the gas and the fluidized inert granular heat exchange medium, the gas transfers heat to the granular medium. At the same time, the dust particles entrained in the gas will also collide with the granular medium. However, since the surface of the inert granular heat exchange medium is smooth and is always in a high-frequency mutual friction and tumbling state, the dust particles try to adhere to it. The dust will be mechanically stripped off at the moment of contact and settle to the bottom of the tower under the action of gravity and discharged from the dust outlet, while the gas that has completed heat exchange and is purified will be discharged from the purified gas outlet located at the upper part of the vertical heat exchange tower; the partition wall heat exchange coil immersed in the fluidized suspension bed obtains heat from the heated inert particle heat exchange medium and transfers it to the second gas to be heated flowing in the coil; in this way, the heat transfer and dust stripping are carried out synchronously and continuously, so that the system can maintain the continuous operation of the heat exchange process when processing gas sources with fluctuating dust content and components.

[0029] Furthermore, to address transient dust surges that may be caused by upstream process anomalies, which can induce instabilities such as channeling or slugging in the fluidized bed, and conventional monitoring methods have lags, the system integrates a fluidized bed precursor instability warning and self-healing unit. This unit analyzes fluctuations in aerodynamic parameters, traditionally considered noise, during operation to extract characteristic signals that can represent the system's operating status. It is configured to continuously collect the raw signals of aerodynamic parameters generated by the air distribution device through an aerodynamic characteristic acquisition unit and perform a fast Fourier transform (FFT) on this raw signal to obtain its spectral characteristics. Given that the pressure fluctuation spectrum of a stable fluidized bed is broad and has no obvious main peak, when instability is about to occur but has not yet formed macroscopically, weak cooperative oscillations will occur within the bed. The logic of this unit is set to continuously monitor the spectral characteristics for an energy peak in the frequency range of 0.5 Hz to 2 Hz. The appearance of this energy peak is regarded as a precursor to instability. Once this energy peak is detected and its intensity exceeds a calibrated threshold, the unit generates an instantaneous intervention. Based on this instruction, a short high-pressure airflow pulse of 0.2 to 0.5 seconds and 2 to 3 times the main blast pressure is applied to the bottom of the fluidized suspension bed. The energy and duration of this pulse can destroy the nascent cooperative oscillation structure in the fluidized suspension bed without interrupting the main process, thereby avoiding possible operational interruption due to instability. At the same time, to detect the microscopic performance degradation of the inert particles used as the heat exchange medium that may occur due to long-term operation, such as the decrease in heat transfer activity due to surface vitrification formed by trace impurities at high temperatures, the system also has a non-destructive diagnosis unit for the heat transfer activity of the suspension bed. To achieve non-stop online diagnosis, this unit is configured to execute a periodic detection procedure. This procedure applies a controlled and short transient disturbance to a thermodynamic input parameter of the dust-laden high-temperature gas entering the fluidized suspension bed, such as flow rate or temperature, as a thermal pulse excitation. Subsequently, the unit accurately collects the temperature response at the outlet of the purified gas and measures the time delay from the start of the thermal pulse excitation to the temperature response reaching a peak or valley value. ; This time delay It directly reflects the average thermal inertia and heat transfer rate of the entire bed. The heat transfer activity health index of the inert particle heat exchange medium is calculated according to the following formula: , ,in, The reference time delay is the time delay measured when the inert granular heat exchange medium is excited by the same heat pulse in the initial state. It can be obtained and stored by executing a calibration procedure during the first commissioning of the system; when the calculated heat transfer activity health index When the health threshold falls below a preset threshold, the system outputs a predictive maintenance alert, providing operators with a basis for maintenance so that they can arrange maintenance before performance deteriorates significantly.

[0030] Predictive maintenance alert health threshold for heat transfer activity health index H Its value is determined by a calibration procedure that relates heat transfer activity to the system's total heat transfer coefficient K. This procedure is performed during the system commissioning phase. Deactivated inert particles are quantitatively added to the fluidized bed in batches to simulate the gradual decline in performance. At each decline point, the heat transfer activity health index H and the total heat transfer coefficient K calculated from the temperature and flow sensor data are simultaneously measured and recorded. A set of discrete data pairs of HK are obtained, and the total heat transfer coefficient K is calculated as the first time it drops beyond its initial healthy state value. 5% of ) is set to the corresponding H value To cope with possible drift or failure of sensors during long-term operation and irreversible physical wear of inert media, the system also integrates a lifecycle self-calibration and diagnostic protocol. The protocol is set to automatically activate every 2,000 cumulative hours of operation or after each replacement of a new batch of inert particles. After activation, the protocol will first perform a sensor consistency check, that is, comparing the readings of multiple temperature sensors that are physically adjacent. If the deviation between any two of them continues to exceed 3 times their nominal error, the sensor with the larger deviation will be marked as abnormal and its data will be temporarily isolated. The protocol will then call and re-execute the baseline time delay The calibration procedure with the benchmark acoustic attenuation time overwrites the old value with the newly measured benchmark value to ensure that the evaluation baseline of all diagnostic units is always synchronized with the current real physical state of the system; in addition, considering the complex composition of coal dust in the wide coal gas source, some low-melting-point impurities may undergo chemical phase change at local over-temperature points to form irreversible sintered bodies, the system is further configured with a critical phase change early warning and targeted removal unit; the operation of this unit first requires a coal ash melting temperature corresponding to the currently used coal type to be input into the system as a benchmark parameter, and at the same time, the unit also subtracts a coal ash melting temperature from the coal ash melting temperature. A safety margin value is used as the warning temperature; during the operation of the system, the unit monitors the absolute temperature of multiple areas in the fluidized suspension bed in real time. When the absolute temperature of any area reaches the warning temperature, the unit will determine and apply a high-voltage pulse of corresponding pressure and duration in a preset mapping relationship based on the difference between the absolute temperature and the warning temperature. The high-voltage pulse is applied to the over-temperature area to forcibly strip off and cool the coal dust in the critical phase change state, thereby interrupting the physical and chemical process of its transformation into a sintered body, thereby avoiding permanent blockage of the heat exchange unit.

[0031] The setting of critical phase change warning temperature is based on the safety margin value The output is determined by a procedure that includes statistical analysis and error superposition. The procedure first collects temperature data at multiple points in the bed for at least 100 working cycles under stable conditions and calculates the 99th percentile fluctuation range. This statistic defines the extreme normal fluctuations of the working condition itself, and then the maximum measurement error in the target temperature range is obtained from the sensor technical specification. , and finally the safety margin value is calculated as At the same time, the mapping relationship between the over-temperature 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. The simulation first establishes a model of the interfacial adhesion force generated by the melting of coal ash on the surface of inert particles under different over-temperature conditions. Then, for each adhesion level, the minimum pulse pressure-duration combination required to produce a mechanical peeling effect sufficient to overcome the adhesion force is solved through fluid dynamics calculation. , thereby directly converting the results of the physical model into an unambiguous and hierarchical set of control instructions; in order to optimize the energy efficiency of the cleaning operation and track the physical structural state of the heat storage layer for a long time, the system also includes a heat storage layer structural health adaptive diagnosis unit. The implementation of this unit can be achieved 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 is used as an acoustic detection 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 collected by the vibration sensor, and extracts the time required for the signal to decay from the peak to the background noise level, which is defined as the acoustic decay time; given that the fluffy bed structure will cause the sound The vibration can be dissipated quickly, while a bed with a structure that tends to be compacted will cause the vibration to last longer. The unit compares the measured acoustic attenuation time with a benchmark attenuation time that characterizes the fluidized suspended bed in a healthy and fluffy state; if the acoustic attenuation time is continuously longer than the benchmark attenuation time, it is determined that the fluidized suspended bed has a tendency to compact, 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 attenuation time is shorter than the benchmark attenuation time, it is determined that the bed is healthy and fluffy, and a longer interval can be selected as the subsequent cleaning interval in a predetermined rule containing multiple interval time levels, thereby establishing a closed-loop regulation 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 completed energy-saving transformation, its gas heat exchanger faces the following operational problems when processing coke oven gas derived from wide coal gasification and with fluctuating dust content and coal dust viscosity: the high-frequency external forced dust cleaning operation performed to maintain heat exchange efficiency has its own energy consumption close to the energy saving benefits brought by heat recovery under some operating conditions. However, once the dust cleaning frequency is reduced to ensure continuous operation, the heat exchange surface will increase its thermal resistance due to dust accumulation, causing the gas inlet temperature of the downstream process unit to fluctuate, and the entire system will fall into a state where it is difficult to balance efficiency and continuity. The facility subsequently switched to a wide coal transformation gas-to-gas heat exchanger exchange treatment system adopting the aforementioned technical solution. After the system was put into operation, its internal fluidized suspension bed composed of a large number of independent inert granular heat exchange media allowed heat transfer and dust stripping to proceed simultaneously and continuously through the tumbling and gravitational settling of the granular media themselves, thereby physically changing the interactive relationship between heat exchange and dust cleaning. The aforementioned operational contradiction between efficiency and continuity was alleviated under the architecture of this system.

[0033] During one continuous operation, the operating conditions of the upstream gasifier changed, causing a dust surge far exceeding the normal value to impact the heat exchange system. Under this operating condition, a coordinated oscillation structure began to appear inside the bed, and there was a trend towards an overall surge instability. At this time, the system's fluidized bed precursor instability warning and self-healing unit, through analysis of the spectrum of aerodynamic parameters, captured the Hertz to An abnormal energy peak appeared in the Hertz frequency range, and then a short high-pressure airflow pulse was applied to the bottom of the fluidized suspension bed. This pulse destroyed the nascent cooperative oscillation structure in the bed before the macroscopic instability phenomenon occurred, and the fluidized suspension bed was restored to a uniform and stable operating state; the continuous self-cleaning mechanism of the fluidized suspension bed provided the system with the ability to cope with conventional dust-laden gases, while the fluidized bed precursor instability warning and self-healing unit provided a guarantee for this operating capability to cope with the impact of operating conditions. The synergistic effect of the two enabled the entire system to adapt to a wider range of and uncertain gas source conditions; finally, the heat exchange system maintained the stability of the inlet gas temperature of the downstream process unit for a long time without human intervention, and the heat exchange efficiency did not decline due to fluctuations in the dust content of the upstream coal gas.

[0034] Example 2: In order to objectively verify the stability of the heat exchange performance and the continuity of operation of the technical solution of the present invention when dealing with dynamically changing high-dust gases, a parallel comparative test platform including the sample group of the present invention and the control group was built. The construction of the test platform is used to simulate the working conditions of periodic fluctuations in the dust-laden gas concentration in the 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 that receive the same inlet air source. Among them, the control group branch is equipped with a set of traditional tubular heat exchangers that adopt periodic high-pressure gas pulse cleaning method. The sample group branch of the present invention is equipped with a wide coal-to-gas heat exchanger exchange processing system with the same size and rated heat exchange capacity as the control group, which adopts the above-mentioned technical solution; temperature and pressure sensors are arranged at key positions of the two branches, and all data are recorded by a unified data acquisition system with a sampling period of 1 second. The setting of this sampling period is based on the consideration of capturing short-term events such as transient response of the heat exchange process and cleaning pulses, while taking into account the load of the data processing system; the entire test is carried out within a period of 24 hours. The setting of this duration is to ensure that the system can undergo multiple complete high and low dust concentration cycles to observe whether there is cumulative performance degradation.

[0035] During the test, the dust concentration of the inlet dust-laden high-temperature gas received by the two test branches was set to fluctuate in a square wave form with a period of 4 hours, that is, it was maintained at a low concentration level of 5.0 g / m3 for 2 hours, and then switched to a high concentration level of 25.0 g / m3 for 2 hours, and so on. The results caused by the different mechanisms of the two technical solutions in dealing with the dust accumulation problem showed differences in the high-concentration operation stage. For example, when the test was carried out to the 3.8th hour, that is, in the second half of the first high-concentration operation cycle, the outlet temperature of the control group had dropped from the initial stable value to 431.3°C, and its inlet and outlet pressure drop rose to 1450Pa, while the outlet temperature of the sample group of the present invention was still maintained at 449.8°C, and the pressure drop was 1225Pa; this trend is reproduced in each subsequent cycle. At the 23.8th hour at the end of the test, the outlet temperature of the control group is 431.8°C, while the outlet temperature of the sample group of the present invention is 450.2°C. The performance fluctuation of the control group is due to the cycle between the formation of the dust layer on its fixed heat exchange surface and the periodic forced removal. The dust accumulation leads to increased thermal resistance and flow resistance, and the dust cleaning operation itself also introduces process disturbances. The performance of the sample group of the present invention can remain stable because the physical structure of the fluidized suspension bed makes heat exchange and dust cleaning a two-sided and continuous process. Any attached dust is peeled off by the continuous movement of the granular medium and discharged by gravity sedimentation, thereby avoiding the phenomenon of thermal resistance accumulating over time.

[0036] Example 3: This example combines Figures 1 to 3 , a wide coal reforming gas-to-gas heat exchanger exchange processing system is described. Figure 1 As shown in the figure, the physical execution layer, process perception and execution layer, and intelligent diagnosis and decision-making layer are shown. The physical execution layer, with the vertical heat exchange tower as its core, receives dust-laden high-temperature gas and ultimately outputs purified gas and dust. The process perception and execution layer includes a series of sensors and actuators. Among them, the aerodynamic characteristic acquisition unit collects raw signals, the multi-region 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-voltage pulse application device applies the vertical heat exchange tower according to the instructions. The intelligent diagnosis and decision-making layer consists of four collaborative units: the fluidized bed precursor instability 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 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 cleaning parameter adjustment instructions.

[0037] like Figure 2 As shown in the figure, the specific work flow of the two core diagnostic units in the intelligent diagnosis and decision-making layer is shown. Both of them perform closed-loop adjustment or state evaluation with the fluidized suspension bed as the core heat exchange medium and diagnostic object as the center. The closed-loop feedback loop on the left shows the diagnosis and adaptive adjustment process of the health of the heat storage layer structure. The process uses pulse cleaning as the acoustic excitation source, captures the transient acoustic vibration signal through the vibration sensor outside the tower, and then analyzes the time for the signal to decay from the peak to the background noise, that is, the acoustic decay time, and compares it with the reference time to determine whether the bed has a tendency to compact. Finally, the subsequent cleaning interval and pressure and other parameters are adaptively adjusted according to the judgment result; the state output process on the right shows the non-destructive diagnosis process of the heat transfer activity of the suspension bed. The process first applies a controlled thermal pulse excitation to the inlet gas parameters, and then collects the outlet temperature response and measures the peak or valley time difference between the excitation and the response, that is, the time delay , and then based on this time delay Delay from initial baseline Comparison to evaluate heat transfer activity health index , and outputs a predictive maintenance alert when the health index falls below a threshold.

[0038] like Figure 3 As shown, the figure begins with two parallel initial data processing steps, namely 1.0 acquisition and processing of acoustic signals, whose output is the processed acoustic decay time, and 2.0 acquisition and processing of thermal impulse responses, 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 benchmark decay time and outputs the structural health assessment results and the determination of the hardening trend. It is sent to the 4.0 heat transfer activity evaluation module, which uses the D2 benchmark time delay Compare and output the heat transfer activity health index Finally, the determination of the hardening trend and the heat transfer activity health index The two evaluation results are combined into 5.0 to generate a comprehensive diagnosis and early warning module. On the one hand, this module feeds back the compaction trend judgment to the core heat exchange system to achieve adaptive adjustment of cleaning parameters. On the other hand, it generates predictive maintenance alerts when necessary and sends the information to operation and maintenance personnel.

[0039] Example 4: In a recently installed wide coal conversion gas-to-gas heat exchanger exchange processing system that adopts the above-mentioned technical solution, before it is put into actual industrial production, a set of startup debugging and parameter calibration procedures are implemented to enable the internal operating parameters of its various diagnostic and self-healing units to adapt to the physical and chemical properties of the specific coal type and the on-site working conditions; the initial conditions of the procedure are that the vertical heat exchange tower has been filled with new inert alumina ceramic balls with a diameter of 2 mm to 3 mm, and the system has been connected to a hot air source that can provide stable temperature and flow, so as to collect baseline parameters in a clean environment without dust interference.

[0040] After the procedure is started, the trigger threshold of the fluidized bed precursor instability warning and self-healing unit is calibrated first. The system runs stably at a medium-intensity blowing rate for 60 minutes. The aerodynamic parameter signal of this stage is recorded by the aerodynamic characteristic acquisition unit and processed by fast Fourier transform to obtain a baseline spectrum feature under a stable operating state. This feature 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 disturbances with a period of 1 second and a gradual amplitude from small to large to the blowing rate of the blowing device. At the same time, the movement state of the particles in the bed is monitored through the optical observation window set on the tower wall to The moment when the initial localized particle cooperative oscillation occurs is taken as the time point, and the peak value A of the stable energy peak corresponding to this moment and appearing for the first time in the frequency range of 0.5 Hz to 2 Hz is recorded, and the warning trigger threshold of the unit is set to 150% of the A value. The calibration value is stored in the control logic of the system; at the same time, the system executes the benchmark time delay calibration of the suspended bed heat transfer activity non-destructive diagnosis unit. Under stable hot air flow, the system continuously executes 5 controlled thermal pulse excitations, and measures the time delay from the application of the excitation to the valley value of the outlet temperature response. After eliminating the maximum and minimum values, the arithmetic average of the remaining 3 measurement values ​​is used as the benchmark time delay under the initial healthy state. In addition, while executing each thermal pulse excitation, the heat storage layer structure health adaptive diagnosis unit also synchronously 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 benchmark decay time characterizing that the bed is in a healthy and fluffy state and stored in the system.

[0041] For the critical phase change warning and targeted removal unit, the operating personnel input the ash melting temperature value given in the coal quality analysis report of the coal to be processed into the system control unit. The system is based on a built-in heat transfer and fluid mechanics model for alumina ceramic balls to generate a mapping relationship table of the pressure and duration of the targeted removal pulse corresponding to different degrees of overheating under the melting temperature constraint. At this point, all diagnostic and self-healing units of the system have completed parameter calibration based on 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-optimization procedure for a cleaning strategy so that its diagnostic benchmark can dynamically adapt to the changes in the physical properties of the inert granular heat exchange medium caused by long-term operation; in a continuously operating system, when the cumulative operating time reaches a set value, the unit will extend the next cleaning interval by a fixed time step based on the current cleaning interval, and re-measure its acoustic attenuation time during the cleaning event of this extended interval; if the measured acoustic attenuation time has not increased compared with the previous measurement value, the system determines that the current cleaning interval still has room for optimization and continues to try to extend it in the next cycle; if the acoustic attenuation time increases after the extended interval, the system will restore 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 fluffy and save energy under the current bed state, so that its diagnostic benchmark and execution strategy are in an adaptive adjustment state.

[0043] The non-destructive diagnostic unit for the heat transfer activity of the suspended bed uses a differential measurement method to eliminate the interference of the fluctuation of the thermophysical properties of the high-temperature gas entering the system on the measurement results; when the unit applies a controlled short transient disturbance to the dust-laden high-temperature gas entering the fluidized suspended bed, in addition to collecting the temperature response at the outlet of the purified gas and measuring its time delay In addition, the system also uses an independent temperature sensor with fast response characteristics installed at the gas inlet pipeline to synchronously measure the original time waveform of the transient disturbance before the bed layer acts, and calculates an inlet reference response time; the system control logic compares the outlet temperature response time delay The correlation with the change of the inlet benchmark response time is used to judge the change of heat transfer activity. When the changing trend of the inlet benchmark response time is inconsistent with the changing trend of the inlet benchmark response time, the system attributes it to the change of the heat transfer activity of the inert particle heat exchange medium and updates the heat transfer activity health index accordingly. Through this differential measurement, the diagnostic results reflect the changes in the heat transfer activity of the inert particle heat exchange medium after eliminating the influence of the gas source's own fluctuations.

[0044] Example 6: In a scenario where a heat exchange system is to be used to process a new wide coal gas source with uncertain physical properties, in order to find a blast rate that can achieve the peak comprehensive energy efficiency of the system and establish an online monitoring and response mechanism for potential operational risks caused by changes in the ash melting characteristics, it is necessary to implement a set of operating parameter setting procedures that combine offline optimization and online monitoring. The goal of this procedure is to determine, through systematic testing, an optimal blast rate that maximizes the ratio of the total heat transfer coefficient to the blower input power, while ensuring the safety of the system operation at this rate. Among them, the inert granular heat exchange medium uses alumina ceramic balls with a diameter of 2 mm to 3 mm. This particle size range provides a good physical basis for the subsequent fluidization and optimization process.

[0045] After the program is started, the system processes the new gas flow at an initial blast rate, and uses this as a starting point to increase the blast rate in a step-by-step manner with a fixed incremental step size. At each rate step, the system runs stably for 30 minutes, and the data acquisition system records the blower input power under the rate platform and the total heat transfer coefficient calculated by each temperature sensor, thereby obtaining the comprehensive energy efficiency index under the rate; by traversing multiple rate steps, a set of discrete data points of comprehensive energy efficiency index changing with blast rate can be obtained, and the blast rate corresponding to the peak value of the comprehensive energy efficiency index in this set of data points is determined as the optimal blast rate for this specific gas source, and it is used as the benchmark setting value for subsequent routine operation; on this benchmark, the system activates an online abnormal state monitoring logic based on multi-physical quantity correlation analysis, which continuously monitors and analyzes the bed pressure The changing trends of the two physical quantities of pressure drop and acoustic decay time. In the normal evolution of the bed physical state, the increase in pressure drop and the extension of acoustic decay time should show a synchronous and gradual correlation. If the system monitors that the bed pressure drop has an independent rapid increase in a short period of time that is unrelated to the changing trend of the 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 the independent rapid pressure drop increase event is identified, the system control logic triggers a global high-pressure purge covering the entire air distribution plate area and with an intensity higher than the conventional cleaning pulse to destroy and remove the nascent sintered agglomerates, and at the same time sends an alarm to the central control room to prompt the operating personnel to verify the physical and chemical 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 to deal with 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 limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A wide coal reforming gas-to-gas heat exchanger exchange processing system, characterized in that: The system includes: a vertical heat exchange tower; An air distribution device provided at the bottom of the vertical heat exchange tower; A large number of independent inert granular heat exchange media are 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 dust-laden high-temperature gas into the lower middle portion of the fluidized suspension bed, a purified gas outlet located at the upper portion of the vertical heat exchange tower, and a dust outlet located at the bottom of the vertical heat exchange tower; an aerodynamic characteristic acquisition unit, the aerodynamic characteristic acquisition unit being configured to acquire original signals of aerodynamic parameters generated by the upward blowing of the air distribution device; A fluidized bed precursory instability warning and self-healing unit is configured to: perform frequency domain analysis on the original signal to obtain the 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 detected in the spectral characteristics; and based on the instantaneous intervention instruction, apply a short high-pressure airflow pulse to the bottom of the fluidized suspension bed, the energy and action time of the high-pressure airflow pulse being sufficient to destroy the nascent cooperative oscillation structure in the fluidized suspension bed.

2. A wide coal reforming gas-to-gas heat exchanger processing system according to claim 1, characterized in that: It also includes a partition wall heat exchange coil immersed in the fluidized suspension bed, which is used to transfer heat from the inert particle heat exchange medium to the second gas to be heated; and the inert particle heat exchange medium is alumina ceramic balls with a diameter of 2 mm to 3 mm.

3. The wide coal reforming gas-to-gas heat exchanger processing system according to claim 1, characterized in that: The fluidized bed precursory instability warning and self-healing unit is further configured to obtain spectral characteristics by performing fast Fourier transform on the original signal of the aerodynamic parameters; and the duration of the short high-pressure airflow pulse is 0.2 seconds to 0.5 seconds, and its pressure is 2 to 3 times the main blast pressure.

4. The wide coal reforming gas-to-gas heat exchanger processing system according to claim 1 is characterized in that: The system also includes: a suspension bed heat transfer activity non-destructive diagnostic unit, which is configured to: periodically apply a controlled short transient disturbance to a thermodynamic input parameter of the dust-laden high-temperature gas entering the fluidized suspension bed as a thermal pulse excitation; collect 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 a peak or valley value ; Calculate the heat transfer activity health index of the inert granular heat exchange medium according to the following formula , ,in, is the benchmark time delay measured by the same heat pulse excitation when the inert granular heat transfer medium is in the initial healthy state; and when the heat transfer activity health index When a health threshold is lowered, a predictive maintenance alert is output.

5. The wide coal reforming gas-to-gas heat exchanger processing system according to claim 1 is characterized in that: The blowing rate of the air distribution device is adjustable to adjust the fluidization degree and heat exchange intensity of the fluidized suspension bed.

6. The wide coal reforming gas-to-gas heat exchanger processing system according to claim 1 is characterized in that: The system also includes: a critical phase change early warning and targeted removal unit, which is configured to: receive a coal ash melting temperature corresponding to the type of coal currently used; monitor the absolute temperatures of multiple areas in the fluidized suspension bed in real time; and when the absolute temperature of any area reaches the coal ash melting temperature, apply a high-voltage pulse to the area to forcibly strip and cool the coal dust in the critical phase change state, thereby interrupting its physical and chemical process of transformation into a sintered body.

7. A wide coal reforming gas-to-gas heat exchanger processing system according to claim 6, characterized in that: The critical phase change warning and targeted removal unit also uses the coal ash melting temperature minus a safety margin value as the warning temperature, and when the absolute temperature in any area reaches the 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 warning temperature.

8. The wide coal reforming gas-to-gas heat exchanger processing system according to claim 1 is characterized in that: The system also includes: a heat storage layer structure health adaptive diagnosis unit, which is connected to a vibration sensor installed on the outside of the vertical heat exchange tower. The heat storage layer structure health adaptive diagnosis unit is configured to: when the system executes a pulse cleaning event, capture the transient acoustic vibration signal generated by the event collected by the vibration sensor; extract the time required for the transient acoustic vibration signal to decay from a peak value to the background noise level as the acoustic decay time; compare the acoustic decay time with a benchmark decay time that characterizes the fluidized suspended bed in a fluffy state; and if the acoustic decay time continues to be longer than the benchmark decay time, it is determined that the fluidized suspended bed has a tendency to compact, and adjust the execution parameters of at least one subsequent pulse cleaning, and the execution parameters include the cleaning interval time and the cleaning pressure.

9. A wide coal reforming gas-to-gas heat exchanger processing system according to claim 8, characterized in that: The heat storage layer structure health self-adaptive diagnosis unit is further configured to: if the acoustic decay time is shorter than the reference decay time, it is determined that the fluidized suspension bed is healthy and fluffy.

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