An electric-gas dual heat source coupled catalytic oxidation control system and control method

Abstract

The present application relates to the technical field of atmospheric pollution control, and discloses a catalytic oxidation control device and system coupled with electric and gas dual heat sources, comprising a CO reactor, a gas-gas heat exchanger, a gas heater, an electric heater and an intelligent control unit. The intelligent control unit builds and maintains a composite thermal balance parameter during operation and switching process, which is composed of an external heat supplement total power, a heat source response lag correction and a system heat storage drift correction. The heat source response lag correction is used to suppress the reverse response caused by solid phase thermal inertia, and the system heat storage drift correction is used to compensate for the energy storage fluctuation in the heat network. The intelligent control unit inversely calculates the external heat supplement total power according to the requirement of maintaining the parameter constant, and distributes it to the dual heat sources. The present application can effectively suppress thermal oscillation under tight heat integration conditions, realize seamless switching under dual heat source fault conditions, and ensure equipment safety.

Description

Technical Field

[0001] This invention relates to the field of air pollution control technology, and more specifically, to a catalytic oxidation control system and control method that couples electric and gas dual heat sources. Background Technology

[0002] Air pollution control and treatment are key areas for green industrial development. Deep purification of volatile organic compounds (VOCs) is a core component in improving air quality and achieving air pollution control goals. Catalytic oxidation technology, due to its high purification efficiency and lack of secondary pollution, has become the mainstream technology in this field. To reduce the operating energy consumption of such specialized air pollution control equipment, modern industrial designs typically employ a tightly integrated thermal structure, utilizing a gas-to-gas heat exchanger (FEHE) to transfer heat from the high-temperature exhaust gas at the reactor outlet to the inlet exhaust gas, thereby reducing external energy consumption. Furthermore, since air pollution control and treatment usually have stringent continuous compliance requirements for emission standards, to ensure system continuity and safety, the equipment is typically equipped with both electric heaters and gas furnaces as backup dual heat sources. When the primary heat source fails or requires maintenance, the control system switches the heating task to the backup heat source to maintain the reactor inlet temperature within the catalyst's activity window. However, in the aforementioned tightly integrated thermal systems used for air pollution control and treatment, the gas-to-gas heat exchanger introduces a strong energy feedback mechanism. As heat recovery efficiency increases, fluctuations in outlet temperature are amplified and fed back to the inlet, significantly reducing the system's thermal stability margin. Simultaneously, the ceramic support of the catalytic reactor, the metal walls of the heat exchanger, and the connecting pipes all possess significant thermal inertia, creating a substantial time-scale difference compared to the rapid transport of the gaseous fluid. This thermal inertia causes the system to exhibit significant hysteresis or even short-term reverse responses (i.e., non-minimum phase behavior) when adjusting external supplemental heating power. During the switching between dual heat sources, existing control strategies typically focus only on a simple, smooth transition of power values ​​or hard switching based on logical judgment. Ignoring the complex dynamic effects of the aforementioned energy feedback mechanism and solid-phase thermal inertia, conventional switching operations easily induce slowly changing energy accumulation fluctuations within the system. Under critical heat recovery conditions, these minute switching disturbances are amplified by the energy feedback loop, inducing sustained and significant temperature oscillations. Such thermal oscillations not only lead to key emission indicators failing to meet standards in the process of air control and pollution treatment, but also subject brittle ceramic catalyst supports and heat exchanger structures to repeated thermal shock stress, causing catalyst sintering, reduced activity, and even equipment cracking, which seriously restricts the long-term reliability of air control and pollution treatment systems. Summary of the Invention

[0003] This invention provides a catalytic oxidation control system and method with coupled electric and gas dual heat sources, solving the technical problems mentioned in the background art.

[0004] In a first aspect, a catalytic oxidation control device coupled with both electric and gas heat sources includes: Exhaust gas pretreatment unit: includes a gas-liquid separator, the gas-liquid separator’s inlet is connected to an exhaust gas pipeline, the bottom is provided with a drain outlet connected to a sewage pipeline, and the top is provided with a gas outlet; in addition, it is also provided with an oxygen supplementation and start-up fan, the outlet of which is connected to the exhaust gas pipeline upstream of the gas-liquid separator; Heat recovery unit: includes a gas-to-gas heat exchanger, which is provided with a cold flow channel and a hot flow channel, and the top gas outlet of the gas-liquid separator is connected to the inlet of the cold flow channel; Dual heat source series heating unit: includes an electric heater and a gas heater connected in series along the airflow direction; the inlet of the electric heater is connected to the outlet of the cold flow channel of the gas-to-gas heat exchanger, and the outlet of the electric heater is connected to the inlet of the gas heater; Catalytic reaction unit: includes a CO reactor, the inlet of which is connected to the outlet of the gas heater; the outlet of the CO reactor is connected to the inlet of the heat flow channel of the gas-to-gas heat exchanger, and the outlet of the heat flow channel is connected to the vent pipe; Gas supply and ignition system: connected to the gas heater, including a combustible material main pipe, which collects at least one of combustible material A and combustible material B, and the main pipe is divided into a main fire branch and an ignition branch in parallel; the main fire branch is provided with a main fire valve 1, a main fire valve 2 and a gas regulating valve in sequence along the airflow direction; the ignition branch is provided with an ignition solenoid valve 1 and an ignition solenoid valve 2 in sequence along the airflow direction; Combustion air supply system: including combustion air blower and combustion air regulating valve located downstream of it, wherein the outlet pipe of the combustion air regulating valve is connected to the burner part of the gas heater; The process is as follows: the waste gas to be treated is mixed with the oxygen supplement and the air supplied by the start-up fan, and then enters the gas-liquid separator to separate condensate and impurities; the separated gas enters the cold flow channel of the gas-gas heat exchanger for preliminary preheating, and then passes through the electric heater and the gas heater in sequence, and is heated to the catalytic ignition temperature in stages by the dual heat sources; the heated gas enters the CO reactor to undergo catalytic oxidation reaction, and the high-temperature purified gas produced by the reaction flows back to the hot flow channel of the gas-gas heat exchanger, transfers the heat to the front-end cold waste gas, and is finally discharged through the exhaust pipe.

[0005] Secondly, a catalytic oxidation control system with coupled electric and gas heat sources is applied to a CO reactor, a gas-to-gas heat exchanger, a gas heater, and an electric heater, and also includes an intelligent control unit: The intelligent control unit is configured to build and maintain composite thermal balance parameters during operation and switching. The composite thermal balance parameters are composed of the total external heating power, the heat source response lag correction amount, and the system heat storage drift correction amount. The heat source response hysteresis correction is calculated based on the rate of change of the total external heating power and the solid phase thermal conduction time constant, and is used to suppress the reverse response of the outlet temperature caused by the solid phase thermal inertia of the reactor; the system heat storage drift correction is calculated based on the rate of change of the total heat storage enthalpy of the thermal integrated network and the heat storage coupling gain coefficient, and is used to compensate for the energy accumulation fluctuations in the thermal network composed of the gas-to-gas heat exchanger and connecting pipelines. The intelligent control unit calculates the total external heating power in reverse according to the requirement of maintaining the constant composite thermal balance parameters, and distributes the total external heating power to the gas heater and the electric heater.

[0006] The beneficial effects of this invention are as follows: By constructing a composite thermal equilibrium parameter that includes a heat source response hysteresis correction and a system heat storage drift correction, the non-minimum phase response and thermal oscillation problems caused by the energy feedback mechanism and solid-phase thermal inertia under tight thermal integration conditions are effectively solved. This invention utilizes heat source hysteresis correction to suppress reverse fluctuations in outlet temperature and compensates for energy accumulation deviations during switching through heat storage drift correction, thereby maintaining thermal stability during the switching and steady-state operation of dual electric and gas heat sources. Furthermore, the continuous weight allocation strategy based on health status achieves a seamless and smooth transition between the two heat sources, eliminating the impact of logical switching, significantly reducing the risk of thermal stress damage to the catalyst carrier and heat exchange equipment, and improving the system's operational safety and energy efficiency. Simultaneously, it provides support for air pollution control. Attached Figure Description

[0007] Figure 1 This is a structural diagram of the catalytic oxidation control system of the present invention, which is a coupling of electric and gas dual heat sources. Detailed Implementation

[0008] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0009] Example 1: As Figure 1 As shown, a catalytic oxidation control device with coupled electric and gas dual heat sources includes: Exhaust gas pretreatment unit: includes a gas-liquid separator, the gas-liquid separator’s inlet is connected to an exhaust gas pipeline, the bottom is provided with a drain outlet connected to a sewage pipeline, and the top is provided with a gas outlet; in addition, it is also provided with an oxygen supplementation and start-up fan, the outlet of which is connected to the exhaust gas pipeline upstream of the gas-liquid separator; Heat recovery unit: includes a gas-to-gas heat exchanger, which is provided with a cold flow channel and a hot flow channel, and the top gas outlet of the gas-liquid separator is connected to the inlet of the cold flow channel; Dual heat source series heating unit: includes an electric heater and a gas heater connected in series along the airflow direction; the inlet of the electric heater is connected to the outlet of the cold flow channel of the gas-to-gas heat exchanger, and the outlet of the electric heater is connected to the inlet of the gas heater; Catalytic reaction unit: includes a CO reactor, the inlet of which is connected to the outlet of the gas heater; the outlet of the CO reactor is connected to the inlet of the heat flow channel of the gas-to-gas heat exchanger, and the outlet of the heat flow channel is connected to the vent pipe; Gas supply and ignition system: connected to the gas heater, including a combustible material main pipe, which collects at least one of combustible material A and combustible material B, and the main pipe is divided into a main fire branch and an ignition branch in parallel; the main fire branch is provided with a main fire valve 1, a main fire valve 2 and a gas regulating valve in sequence along the airflow direction; the ignition branch is provided with an ignition solenoid valve 1 and an ignition solenoid valve 2 in sequence along the airflow direction; Combustion air supply system: including combustion air blower and combustion air regulating valve located downstream of it, wherein the outlet pipe of the combustion air regulating valve is connected to the burner part of the gas heater; The process is as follows: the waste gas to be treated is mixed with the oxygen supplement and the air supplied by the start-up fan, and then enters the gas-liquid separator to separate condensate and impurities; the separated gas enters the cold flow channel of the gas-gas heat exchanger for preliminary preheating, and then passes through the electric heater and the gas heater in sequence, and is heated to the catalytic ignition temperature in stages by the dual heat sources; the heated gas enters the CO reactor to undergo catalytic oxidation reaction, and the high-temperature purified gas produced by the reaction flows back to the hot flow channel of the gas-gas heat exchanger, transfers the heat to the front-end cold waste gas, and is finally discharged through the exhaust pipe.

[0010] Example 2: A catalytic oxidation control system with coupled electric and gas heat sources, comprising a CO reactor, a gas-to-gas heat exchanger, a gas heater, an electric heater, and an intelligent control unit; The intelligent control unit is configured to build and maintain composite thermal balance parameters during operation and switching. The composite thermal balance parameters are composed of the total external heating power, the heat source response lag correction amount, and the system heat storage drift correction amount. The heat source response hysteresis correction is calculated based on the rate of change of the total external heating power and the solid phase thermal conduction time constant, and is used to suppress the reverse response of the outlet temperature caused by the solid phase thermal inertia of the reactor; the system heat storage drift correction is calculated based on the rate of change of the total heat storage enthalpy of the thermal integrated network and the heat storage coupling gain coefficient, and is used to compensate for the energy accumulation fluctuations in the thermal network composed of the gas-to-gas heat exchanger and connecting pipelines. The intelligent control unit calculates the total external heating power in reverse according to the requirement of maintaining the constant composite thermal balance parameters, and distributes the total external heating power to the gas heater and the electric heater.

[0011] Preferably, the heat source response hysteresis correction includes: The heat source response hysteresis correction amount Calculate using the following formula: in, The total external heating power at the current moment is [value]. The total external heating power at the previous moment. The sampling period is The solid-state thermal conductivity time constant at the current moment; The solid-phase thermal conductivity time constant The following formula was used to calculate the result: in, This is the preset minimum physical limit; It is a smooth positive function; and These are the input coefficients and derivative coefficients of the discrete-time transfer model, which is: in, For inlet temperature deviation, This is the actual applied power superimposed with a tiny sinusoidal detection signal; The safety value of the derivative term coefficient Calculate using the following formula to avoid division by zero: in, For a preset small value safety threshold, It is the hyperbolic tangent function.

[0012] The total external supplementary heating power at the current moment is the total supplementary heating power output by the electric and gas dual heat sources within the current sampling period. It can be obtained by detecting the active power of the electric heater with an electric power meter and combining it with the fuel flow rate, low calorific value, combustion efficiency, and heat transfer efficiency of the gas heater.

[0013] The total external heating power at the previous moment is the total heating power output by the electric and gas dual heat sources in the previous sampling period, which can be obtained by storing the detection data of the previous sampling period.

[0014] The sampling period is the time interval between discrete data acquisition and calculation by the system, preferably 0.5 to 2 seconds. This range takes into account both the dynamic response speed of the thermal system and differential noise control, and meets the conventional sampling requirements of industrial distributed control systems or programmable logic intelligent control units.

[0015] The solid-phase thermal conductivity time constant at the current moment is a real-time estimated parameter characterizing the hysteresis of heat transfer caused by the solid-phase thermal inertia of the reactor.

[0016] The minimum physical limit of the solid phase thermal conductivity time constant is the lower limit value to ensure that the solid phase thermal conductivity time constant has physical rationality. It is preferably the reciprocal of 0.01 to 0.1 seconds. This range avoids numerical rigidity problems in the control algorithm due to excessively small values ​​and matches the physical characteristics of the solid phase thermal inertia of the reactor.

[0017] The input coefficients of the discrete-time transfer model are updated using a recursive least squares algorithm and are model parameters that characterize the degree of influence of external heating power on the inlet temperature deviation.

[0018] The coefficients of the derivative term in the discrete-time transfer model are updated using a recursive least squares algorithm. These are model parameters that characterize the influence of the rate of change of external heating power on the inlet temperature deviation.

[0019] The safe value of the derivative term coefficients is a correction parameter that is applied to the coefficients of the derivative term in the discrete-time transfer model to avoid division by zero during the calculation process.

[0020] The small value safety threshold is a smoothing threshold used when constructing the safety value of the derivative term coefficients. It is preferably between 10 to the power of -6 and 10 to the power of -4. This range can effectively avoid the risk of division by zero and will not significantly interfere with the original characteristics of the derivative term coefficients.

[0021] The inlet temperature deviation is the difference between the target set temperature of the CO reactor and the actual inlet temperature after filtering.

[0022] The actual applied power of the superimposed small sinusoidal detection signal is the actual heating power applied to the system after the small sinusoidal signal is superimposed on the total external heating power.

[0023] The amplitude of the small sinusoidal probe signal is the power amplitude of the sinusoidal probe signal superimposed on the total external heating power. It is preferably 0.5% to 2% of the rated heating power. An amplitude within this range can provide continuous excitation for parameter identification without causing significant disturbance to the stable operation of the system temperature.

[0024] The frequency of the small sinusoidal detection signal is the oscillation frequency of the sinusoidal detection signal superimposed on the total external heating power, preferably 0.01 to 0.05 Hz. This frequency range is used to match the slow dynamic characteristics of the thermal system, ensuring that the inlet temperature can produce an observable response and meet the identification requirements.

[0025] Superimposing a small sinusoidal detection signal is beneficial because the small variation in supplementary heating power during stable operation of the thermal system can easily lead to parameter degradation. By superimposing this signal onto the supplementary heating power, a small, observable response in the inlet temperature can be generated, ensuring that the recursive least squares algorithm continuously updates the model parameters. For example, with a rated supplementary heating power of 100 kW, superimposing a sinusoidal signal of 0.5 to 2 kW at a frequency of 0.02 Hz does not affect the achievement of the target reaction temperature while obtaining effective identification data.

[0026] Discrete-time transfer models with derivative terms include: the solid-phase thermal inertia of the reactor induces an inverse response, and considering only the static influence of the supplementary heating power cannot accurately describe the dynamic characteristics. Introducing derivative terms into the model can capture the effect of the rate of change of supplementary heating power on temperature deviation. For example, when the supplementary heating power suddenly increases, the solid-phase thermal inertia will cause the inlet temperature to initially decrease slightly and then increase; the derivative term coefficient can accurately characterize this dynamic law related to the rate of change.

[0027] Smooth positive value function mapping includes a smooth positive value function combining the natural logarithm and exponential function, avoiding parameter discontinuities caused by traditional hard limiting. This function maps the derivative term coefficients to a solid-state thermal conductivity time constant that is always positive, while maintaining the differentiability of the mapping relationship, ensuring numerical stability of the control algorithm. For example, when the derivative term coefficient is 0.001, it can still remain above the minimum physical limit after mapping, avoiding abrupt changes in control output.

[0028] The construction of safe values ​​for derivative term coefficients includes: using the hyperbolic tangent function to construct safe values, which is a branchless division-to-zero protection method. The hyperbolic tangent function has smooth saturation properties; when the derivative term coefficients approach zero, the safe value transitions smoothly without abrupt numerical changes. For example, when the derivative term coefficient is 0, the safe value is a small numerical safety threshold multiplied by the hyperbolic tangent function value, ensuring that the denominator is never zero.

[0029] The parameters of the recursive least squares algorithm include: the forgetting factor is preferably set to 0.98 to 0.995 to balance the parameter identification and tracking speed and stability and avoid short-term noise interference; the initial covariance matrix is ​​preferably set to an identity matrix of 1,000 to 1,000,000 to ensure that the algorithm has sufficient identification sensitivity in the initial stage and gradually converges to the true parameters.

[0030] The numerical precision of smooth positive functions includes: retaining 6 to 8 decimal places during calculation, adopting the standard floating-point calculation of industrial control, ensuring accurate mapping results, and avoiding parameter jitter caused by insufficient precision.

[0031] The method of applying the small sinusoidal detection signal includes: calculating the actual applied power for each sampling period using the formula = total external heating power + amplitude × sine (2 × pi × frequency × sampling period × current time), ensuring that the signal is applied continuously and updated synchronously with the heating power.

[0032] Preferably, the system heat storage drift correction amount includes: The system's thermal storage drift correction amount Calculate using the following formula: in, The heat storage coupling gain coefficient is... The total heat storage enthalpy value at the current moment. The total heat storage enthalpy value mentioned at the previous moment. The sampling period; The total heat storage enthalpy Calculate using the following formula: in, For the system's equivalent heat capacity, The equivalent weighted temperature at the current moment; The equivalent weighted temperature Calculate using the following formula: in, This represents the outlet temperature of the CO reactor after filtering. This is the cold end outlet temperature of the filtered gas-to-gas heat exchanger. The hot-end weighting coefficient is determined by the following formula: in, This represents the total heat capacity of the solid components near the hot end. The sum of the heat capacities of the solid components near the cold end is equal to the equivalent heat capacity of the system. .

[0033] The heat storage coupling gain coefficient is a dimensionless coefficient of the change rate of the total heat storage enthalpy of the associated heat integrated network and the equivalent heat input compensation amount. It is preferably 0.1 to 5, so as to match the energy accumulation fluctuation compensation requirements of the gas-to-gas heat exchanger and the connecting pipeline through small disturbance experiments.

[0034] The total heat storage enthalpy at the current moment is a physical quantity characterizing the solid-phase energy storage state of the thermal integrated network, which is obtained by multiplying the system's equivalent heat capacity and equivalent weighted temperature.

[0035] The total heat storage enthalpy is a physical quantity representing the solid-phase energy storage state of the thermal integrated network in the previous sampling period, obtained by storing the calculation results of the previous period.

[0036] The equivalent heat capacity of the system is the weighted sum of the products of the mass and specific heat capacity of the metal and ceramic components in the gas-to-gas heat exchanger, CO reactor and connecting pipelines, reflecting the overall level of solid-phase thermal inertia of the system.

[0037] The equivalent weighted temperature at the current moment is the weighted average of the CO reactor outlet temperature and the cold end outlet temperature of the gas-to-gas heat exchanger, used to comprehensively characterize the solid phase temperature state of the system.

[0038] The hot-end weighting coefficient is the proportion of the heat capacity of the hot-end component in the equivalent heat capacity of the system, and is used to determine the weight of each temperature component in the equivalent weighted temperature.

[0039] The total heat capacity of solid components on the hot end side is the sum of the product of the mass and specific heat capacity of each solid component near the hot end, including components near the outlet side of the reactor shell, such as the hot end wall of the gas-to-gas heat exchanger.

[0040] The total heat capacity of solid components on the cold end side is the sum of the product of the mass and specific heat capacity of each solid component near the cold end, including the cold end wall of the gas-to-gas heat exchanger, connecting pipes, and cold end metal components.

[0041] The filtered CO reactor outlet temperature is the reactor outlet temperature processed by a first-order discrete filter. It can be obtained by collecting raw data from a temperature sensor installed at the reactor outlet and then processing it through a filtering algorithm.

[0042] The filtered gas-to-gas heat exchanger cold end outlet temperature is obtained by processing the raw data from the temperature sensor installed at the cold end outlet of the gas-to-gas heat exchanger using a first-order discrete filter and then processing it with a filtering algorithm.

[0043] The definition of total heat storage enthalpy (THU) includes the fact that energy storage fluctuations in a thermally integrated network originate from the thermal inertia of solid-phase components, a state not explicitly characterized by traditional control methods. Defining THU as the product of the system's equivalent heat capacity and equivalent weighted temperature allows for precise quantification of solid-phase energy storage, including the gas-to-gas heat exchanger walls, reactor shell, and connecting pipelines, providing a clear physical object for fluctuation compensation. For example, if the system's equivalent heat capacity is 980 kJ per Kelvin and the equivalent weighted temperature is 320 degrees Celsius, the THU is 980 multiplied by 320, equaling 313,600 kJ, directly reflecting the total solid-phase energy storage.

[0044] The calculation of the system's equivalent heat capacity includes explicitly including metal and ceramic components in the calculation, covering the gas-to-gas heat exchanger, CO reactor, and connecting pipelines, and comprehensively reflecting the system's thermal inertia distribution. For example, if the mass of the gas-to-gas heat exchanger's metal wall is 800 kg with a specific heat capacity of 0.5 kJ / kg Kelvin, the reactor shell mass is 500 kg with a specific heat capacity of 0.5 kJ / kg Kelvin, the catalyst support mass is 200 kg with a specific heat capacity of 0.9 kJ / kg Kelvin, and the connecting pipeline mass is 300 kg with a specific heat capacity of 0.5 kJ / kg Kelvin, then the system's equivalent heat capacity is 800 × 0.5 + 500 × 0.5 + 200 × 0.9 + 300 × 0.5 = 980 kJ / Kelvin.

[0045] The weighting of the equivalent weighted temperature includes: the weights are determined by the heat capacity ratio of the hot-end components, matching the thermal inertia distribution characteristics. The higher the heat capacity ratio of the hot-end components, the greater the influence of the outlet temperature on the equivalent weighted temperature, ensuring that the temperature characterization is consistent with the solid-state energy storage distribution. For example, if the heat capacity of the hot-end components is 600 kJ / Kelvin and that of the cold-end is 380 kJ / Kelvin, the hot-end weighting coefficient is 600 divided by 980, which equals 0.612. The equivalent weighted temperature is then 0.612 × outlet temperature + 0.388 × cold-end outlet temperature.

[0046] The calculation of the system's thermal storage drift correction includes: directly converting solid-state energy storage fluctuations into equivalent heat input compensation by multiplying the thermal storage coupling gain coefficient by the rate of change of the total thermal storage enthalpy, thus accurately offsetting energy accumulation fluctuations. For example, if the thermal storage coupling gain coefficient is 2, the total thermal storage enthalpy is 313,600 kJ at the current moment and 312,600 kJ at the previous moment, and the sampling period is 1 second, the correction amount is 2 × (313,600 - 312,600) ÷ 1 = 200 kW, directly compensating for the energy drift within that period.

[0047] The calibration of the thermal storage coupling gain coefficient includes: applying an external heat supply power disturbance of known amplitude under stable system operating conditions, and recording the rate of change of the total thermal storage enthalpy and the fluctuation amplitude of the inlet temperature before and after the disturbance. Based on the compensation requirements when the temperature fluctuation amplitude reaches the allowable range, the thermal storage coupling gain coefficient is calculated. For example, if a 50 kW power disturbance is applied, and the measured rate of change of the total thermal storage enthalpy is 25 kW with an inlet temperature fluctuation of 0.8 degrees Celsius, and the allowable fluctuation is 0.4 degrees Celsius, then the thermal storage coupling gain coefficient can be taken as 2.

[0048] The criteria for distinguishing between hot-end and cold-end solid components include: based on the direction of system heat flow, the hot end of the gas-to-gas heat exchanger located at the reactor outlet and the piping connecting them are defined as the hot-end side; the piping located from the cold-end outlet of the gas-to-gas heat exchanger to the reactor inlet is defined as the cold-end side. The temperature design range in the equipment drawings can be referenced during the distinction to ensure that the long-term operating temperature of the hot-end side components is higher than that of the cold-end side.

[0049] The determination of component mass and specific heat capacity includes: component mass is calculated from the material specifications in the equipment drawings. For example, the mass of steel pipe can be calculated based on pipe diameter, wall thickness, length and density; specific heat capacity is determined by consulting the material manual based on the component material. For metal materials, it can be 0.45 to 0.6 kJ / kg Kelvin, and for ceramic honeycomb carrier, it can be 0.7 to 1.0 kJ / kg Kelvin.

[0050] The filtering parameters for the equivalent weighted temperature include: the filtering time constant is preferably 3 to 10 times the sampling period, and the sampling period is preferably 0.5 to 2 seconds, to ensure that the filtered temperature signal can both suppress noise and track the slow dynamic changes in solid phase temperature. For example, if the sampling period is 1 second and the filtering time constant is 5 seconds, the filtering coefficient is approximately 0.819, which is the natural exponent divided by 1 to the power of 5.

[0051] Preferably, the composite thermal equilibrium parameters include: The composite thermal equilibrium parameters Calculate using the following formula: in, This represents the total external heating power after filtering at the current moment. This represents the total external heating power after filtering at the previous moment; The solid-phase thermal conductivity time constant is obtained through online identification at the current moment; The heat storage coupling gain coefficient is a dimensionless constant obtained through small perturbation experiments. The total heat storage enthalpy value at the current moment. This is the total heat storage enthalpy value mentioned at the previous moment; The sampling period; The second term in the formula Corresponding to the heat source response hysteresis correction amount; The third term in the formula The corresponding system heat storage drift correction amount.

[0052] The current external heating total power after unified phase filtering is the value of the current sampling period after performing a first-order discrete filter on the original external heating total power. It can be obtained by summing the feedback power of the electric heater and the gas heater and then processing it through a unified filtering algorithm.

[0053] The total external heating power after unified phase filtering is the value of the previous sampling period after the original total external heating power is filtered by first-order discrete filtering. It can be obtained by storing the filtering result of the previous period.

[0054] The unified phase filter coefficient is a coefficient used to adjust the smoothness of the unified phase filter. It is preferably the result of dividing the negative sampling period of the natural exponent by the filter time constant. The filter time constant is preferably 3 to 10 times the sampling period. Within this range, the phase of each signal can be unified, measurement noise can be suppressed, and the dynamic response of the system can be maintained.

[0055] The construction of composite thermal balance parameters involves addressing the limitations of traditional control methods that focus solely on either supplementary heating power or temperature, failing to simultaneously address inverse response and energy accumulation fluctuations. By superimposing supplementary heating power, heat source response lag correction, and system heat storage drift correction, composite thermal balance parameters are constructed, simultaneously covering the three core dimensions of power input, dynamic lag compensation, and energy fluctuation compensation. For example, with a supplementary heating power of 500 kW, a heat source response lag correction of -20 kW, and a system heat storage drift correction of 15 kW, the composite thermal balance parameter would be 500 - 20 + 15 = 495 kW, achieving multi-factor coordinated control.

[0056] The application of unified phase filtering includes: phase differences in the measurement chains of different sensors can lead to time synchronization deviations between the heating power and temperature signals, thus interfering with the calculation of correction values. Unified phase filtering of the heating power ensures that all signals involved in the calculation are in phase. For example, if the temperature signal is filtered for 3 seconds, the heating power signal should also use the same filtering parameters, avoiding calculation deviations in correction values ​​caused by phase differences.

[0057] The calculation of the heat source response hysteresis correction includes: combining the differential ratio of the supplementary heating power with the solid-state thermal conductivity time constant, rather than directly using the power change rate, to match the hysteresis characteristics of solid-state thermal inertia. For example, if the supplementary heating power is currently 500 kW and was 480 kW at the previous moment, with a sampling period of 1 second and a solid-state thermal conductivity time constant of 5 seconds, the correction is -(500-480)÷1÷5=-4 kW, accurately offsetting the hysteresis effect.

[0058] The calculation of the system's thermal storage drift correction includes multiplying the difference ratio of the total thermal storage enthalpy with the thermal storage coupling gain coefficient, which can convert the solid-phase energy storage change into equivalent heat compensation. For example, if the current total thermal storage enthalpy is 313,600 kJ and the previous value was 312,600 kJ, with a sampling period of 1 second and a thermal storage coupling gain coefficient of 2, the correction amount is 2 × (313,600 - 312,600) ÷ 1 = 200 kW, directly compensating for energy drift.

[0059] The specific implementation of unified phase filtering includes the following: The filtering formula is: Current filter value = Filter coefficient × Previous filter value + (1 - Filter coefficient) × Current original value. For example, with a sampling period of 1 second and a filtering time constant of 5 seconds, the filter coefficient = natural exponent -1 ÷ 5 ≈ 0.819. If the current original heating power is 500 kW and the previous filter value was 490 kW, the current filter value = 0.819 × 490 + (1 - 0.819) × 500 ≈ 491.81 kW.

[0060] The calculation of the filtering coefficients includes: retaining 6 to 8 decimal places, using the standard floating-point arithmetic of industrial control, to ensure the consistency of the filtering effect and avoid signal jitter caused by insufficient precision.

[0061] Noise suppression for the differential ratio includes: performing unified phase filtering on the raw data of the supplementary heating power and total heat storage enthalpy before calculating the differential, and then calculating the difference between the current value and the previous value to reduce noise interference to the differential ratio.

[0062] Preferably, the composite thermal equilibrium parameters are established and maintained during operation and switching, including: The intelligent control unit calculates the target thermal balance value. And let the composite thermal equilibrium parameters Equal to the target thermal equilibrium value ; The target thermal balance value Calculate using the following formula: in, This is the proportional adjustment coefficient. This is the integral adjustment coefficient; The first term in the formula Corresponding to the temperature deviation ratio term, where Temperature deviation is calculated using the following formula: in, Set the temperature for the target. This represents the inlet temperature of the filtered CO reactor. The second term in the formula Corresponding to the temperature deviation integral term, where For the integral state variable, update it using the following formula with an exponential decay factor: in, To prevent exponential decay factors for long-term drift, This is the integral state quantity from the previous time step. The sampling period; The third term in the formula The corresponding sensible heat feedforward compensation term is calculated using the following formula: in, The process gas mass flow rate at the current moment. The isobaric specific heat of the process gas at the current moment. This represents the cold inlet temperature of the filtered gas-to-gas heat exchanger.

[0063] The target thermal equilibrium value is a constant target value that the composite thermal equilibrium parameters need to be locked in. It is obtained by superimposing the temperature deviation proportional term, the temperature deviation integral term, and the sensible heat feedforward compensation term.

[0064] The proportional control coefficient is used to adjust the response intensity of the proportional term of temperature deviation. It is preferably the static gain divided by the target closed-loop time constant. The static gain is preferably calculated as the process gas mass flow rate multiplied by the specific heat at constant pressure divided by (1 minus the FEHE recovery intensity). The target closed-loop time constant is preferably 60 to 180 seconds to match the system's thermal dynamic response speed and achieve rapid deviation correction. The FEHE recovery intensity is a quantitative indicator of the gas-to-gas heat exchanger's ability to transfer heat from the reactor's high-temperature exhaust gas to the cold feed to be treated, reflecting the adequacy of heat recovery. The FEHE recovery intensity ranges from 0 to 1; the closer the value is to 1, the better the FEHE heat recovery effect, and the more usable heat in the exhaust gas can be transferred to the cold feed. For example, a recovery intensity of 0.9 means that 90% of the usable heat in the exhaust gas is recovered for preheating the feed, significantly reducing the need for external heat replenishment and meeting the system's energy-saving design goals. The FEHE recovery intensity is obtained through pre-calibration using historical data.

[0065] The integral adjustment coefficient is used to adjust the ability of the integral term of temperature deviation to eliminate steady-state error. It is preferably the proportional adjustment coefficient divided by the target closed-loop time constant to match the proportional adjustment coefficient and avoid system fluctuations caused by excessive integration.

[0066] Temperature deviation is the real-time difference between the target set temperature and the filtered CO reactor inlet temperature.

[0067] The integral state quantity is the historical cumulative amount of temperature deviation, which is used to gradually eliminate the steady-state error of the system.

[0068] The sensible heat feedforward compensation term is the reference power required to heat the process gas from the cold end inlet temperature to the target set temperature, and is used to compensate for the sensible heat demand in advance.

[0069] The target set temperature is the target reaction temperature at the inlet of the CO reactor, preferably the catalyst activity window temperature, such as 300 to 400 degrees Celsius, to match the catalyst reaction activity requirements and ensure the effective oxidation of VOCs.

[0070] The filtered CO reactor inlet temperature is the reactor inlet temperature after being processed by a first-order discrete filter. It can be obtained by collecting raw data from a temperature sensor installed at the reactor inlet and then processing it through a filtering algorithm.

[0071] Process gas mass flow rate is the mass of process gas passing through the system per unit time. It can be directly collected by a mass flow sensor. If only volumetric flow rate is available, it can be calculated based on standard density.

[0072] The specific heat of a process gas at constant pressure is the amount of heat required for a unit mass of the process gas to increase its temperature by a unit under constant pressure. It is preferably 1.0 kJ / kg Kelvin, and air is approximately suitable for working conditions with low VOC content.

[0073] The filtered gas-to-gas heat exchanger cold end inlet temperature is the FEHE cold end inlet temperature after being processed by a first-order discrete filter. It can be obtained by collecting raw data from a temperature sensor installed at the FEHE cold end inlet and then processing it through a filtering algorithm.

[0074] The integral exponent decay factor is a decay coefficient that prevents long-term drift of the integral state quantity. It is preferably the negative sampling period of the natural exponent divided by the decay time constant. The decay time constant is preferably 30 to 300 minutes to achieve slow discharge of the integral term without affecting the normal steady-state error elimination.

[0075] The three-component construction of the target thermal balance value includes: Traditional control often uses a proportional-integral-derivative (PID) structure without feedforward compensation. This scheme combines the proportional term for rapid response to deviation, the integral term for eliminating static error, and the feedforward term for compensating for sensible heat demand, enabling simultaneous response to dynamic deviations and static load changes. For example, when the process gas flow rate increases, the sensible heat feedforward compensation term first increases the power reference, and then the proportional-integral term fine-tunes the deviation to avoid temperature lag.

[0076] The update of integral state variables with exponential decay includes: the integral term is prone to drift due to long-term operation, and by introducing an exponential decay factor, the integral state variable is slowly discharged. For example, the decay time constant is set to 120 minutes, the sampling period is 1 second, and the decay factor is about 0.9998, which does not affect the elimination of steady-state error in a short period of time, and avoids control saturation caused by long-term accumulation.

[0077] The calculation of the sensible heat feedforward compensation term includes: based on the principle of energy conservation, directly linking flow rate, specific heat, and temperature difference, to accurately quantify the intake gas heating demand. For example, if the process gas flow rate is 0.5 kg / s, the constant pressure specific heat is 1.0 kJ / kg Kelvin, the target set temperature is 350 degrees Celsius, and the cold end inlet temperature is 25 degrees Celsius, the sensible heat feedforward compensation term is 0.5 × 1.0 × (350 - 25) = 162.5 kW, compensating for the core heat demand in advance.

[0078] The tuning of the proportional and integral control coefficients includes: first, experimentally determining the system's static gain, for example, by adding 10 kW of supplementary heating power under stable operating conditions, recording the inlet temperature change, and calculating the static gain. Then, setting the target closed-loop time constant, and calculating the initial values ​​using the formulas: proportional control coefficient = static gain / closed-loop time constant, and integral control coefficient = proportional control coefficient / closed-loop time constant. Fine-tuning is then performed on-site until the temperature response is stable.

[0079] The calculation of the isobaric specific heat of the process gas includes: if the VOCs content is high or the gas composition is clear, multiply the mole fraction of each component by the corresponding isobaric specific heat and sum them. For example, if the gas contains 78% nitrogen, 21% oxygen, and 1% water vapor, the corresponding isobaric specific heats are 1.039, 0.918, and 1.863 kJ / kg Kelvin, respectively. After weighting, the isobaric specific heat = 0.78 × 1.039 + 0.21 × 0.918 + 0.01 × 1.863 ≈ 1.01 kJ / kg Kelvin.

[0080] Matching the filtering parameters includes ensuring that the filtering time constant of the temperature signal is consistent with the sampling period, preferably 3 to 10 times the sampling period. For example, if the sampling period is 1 second, the filtering time constant is 5 seconds to ensure that the filtered signal can suppress noise and track slow dynamic changes in temperature.

[0081] The determination of the target set temperature includes: determining it based on the activity window provided by the catalyst manufacturer. For example, the activity window of a precious metal catalyst is 300 to 380 degrees Celsius, and the target set temperature can be selected as 350 degrees Celsius, taking into account both oxidation efficiency and energy consumption.

[0082] Preferably, based on the requirement to maintain the constant composite thermal balance parameters, the total external heating power is calculated in reverse, including: The intelligent control unit calculates the total external heating power at the current moment using a discrete difference equation with a numerical rigidity suppression factor. The formula is as follows: in, The feedback closed-loop equivalent power of the previous moment; The numerical rigidity suppression factor is calculated using the following formula to ensure computational stability: The sampling period is The solid-state thermal conductivity time constant at the current moment; This is the system heat storage drift correction amount at the current moment; The target thermal equilibrium value at the current moment; The equivalent power of the feedback closed loop Update according to the following formula to incorporate the actual execution status: in, For power filtering coefficients, and These are the actual feedback power of the gas heater and the electric heater, respectively.

[0083] The feedback closed-loop equivalent power at the current moment is the sum of the actual detected feedback power of the two heat sources after a first-order low-pass filter, which is used to introduce the actual response state of the actuator in the reverse calculation.

[0084] The equivalent power of the feedback closed loop at the previous moment is the sum of the feedback power of the two heat sources in the previous sampling period after being filtered by a first-order low-pass filter. It is obtained by storing the calculation results of the previous period.

[0085] The numerical rigidity suppression factor is a coefficient used to suppress numerical instability in discrete computation. It is calculated using a specific formula and matches the dynamic characteristics of the system.

[0086] The incremental correction value is the updated increment of the total external heating power, used to gradually adjust the total power value and avoid sudden changes.

[0087] The model-driven error is the difference between the sum of the equivalent power of the feedback closed loop at the previous moment and the current system heat storage drift correction, and the current target thermal balance value, providing a driving basis for power adjustment.

[0088] The power filtering coefficient is a custom parameter used to adjust the smoothness of the equivalent power filtering in the feedback closed loop. It is preferably between 0.95 and 0.99 to balance the smoothness of the filtered signal and the dynamic response speed, and to avoid hysteresis caused by over-filtering.

[0089] The actual feedback power of a gas heater is the net heat power output by the gas heater in real time, which can be obtained by converting the gas heater's fuel flow rate, lower heating value, combustion efficiency, and heat transfer efficiency.

[0090] The actual feedback power of the electric heater is the net heat power output by the electric heater in real time, which can be obtained by directly collecting the active power through an electric power meter.

[0091] Feedback closed-loop equivalent power includes: Traditional power inverse kinematics relies solely on model calculations, which are prone to divergence due to actuator response deviations. Filtering the actual feedback power from both heat sources and using it as the closed-loop equivalent power allows the true response state of the actuator to be incorporated into the inverse kinematics process. For example, when the actual power of the gas heater is lower than the commanded value due to fuel supply fluctuations, the feedback closed-loop equivalent power will reflect this deviation in real time, preventing the model calculation from deviating from reality.

[0092] The construction of the numerical stiffness suppression factor includes: When discretizing differential equations, numerical stiffness problems can easily occur if the solid-state thermal conductivity time constant is small. This factor can be constructed in the form of "1 divided by (1 plus the product of the sampling period and the solid-state thermal conductivity time constant)" to effectively suppress instability. For example, with a sampling period of 1 second and a solid-state thermal conductivity time constant of 0.5 seconds, the suppression factor = 1 ÷ (1 + 1 × 0.5) ≈ 0.667, making the incremental correction value change smoothly.

[0093] The calculation of model-driven error includes: correlating the previous closed-loop equivalent power, the current thermal storage drift correction, and the target thermal balance value to accurately quantify the deviation between the model and the target. For example, if the previous closed-loop equivalent power was 500 kW, the current thermal storage drift correction was 15 kW, and the target thermal balance value was 495 kW, the model-driven error would be 500 + 15 - 495 = 20 kW, providing a clear direction for power adjustment.

[0094] The combination of incremental correction values ​​includes: constructing the increment by multiplying the suppression factor, sampling period, solid-state thermal conductivity time constant, and model driving error, so that the power adjustment simultaneously matches the system's dynamic characteristics and numerical stability requirements. For example, with a suppression factor of 0.667, a sampling period of 1 second, a solid-state thermal conductivity time constant of 0.5 seconds, and a model driving error of 20 kW, the incremental correction value = 0.667 × 1 × 0.5 × 20 ≈ 6.67 kW, achieving smooth adjustment.

[0095] Matching the power filter coefficients includes: matching the filter coefficients with the sampling period, with the filter time constant preferably between 5 and 20 seconds. The filter coefficient is calculated as the negative sampling period divided by the filter time constant. For example, with a sampling period of 1 second and a filter time constant of 10 seconds, the filter coefficient is approximately 1 / 10 ≈ 0.905, ensuring that the filtered power signal can track actual changes.

[0096] The convergence of the numerical rigidity suppression factor includes: when the suppression factor is between 0.1 and 0.9, the numerical calculation exhibits good convergence. If the calculation result exceeds this range, it is constrained to within 0.1 to 0.9 using a smoothing saturation function to avoid numerical divergence.

[0097] The limit setting for incremental correction values ​​includes: an upper limit of 5% of the sum of the maximum heating capacities of the two heat sources and a lower limit of -5%, to prevent excessive power adjustment from causing temperature fluctuations. For example, if the sum of the maximum heating capacities is 1000 kW, the upper limit of the incremental correction value is 50 kW and the lower limit is -50 kW.

[0098] Small error handling for model-driven errors includes: when the absolute value of the model-driven error is less than 1 kW, it is considered a small error, multiplied by an attenuation coefficient of 0.1 before being included in incremental calculation, to avoid frequent power fluctuations caused by small errors.

[0099] Preferably, distributing the total external heating power to the gas heater and the electric heater includes: The intelligent control unit calculates the power command value of the gas heater. With respect to the power command value of the electric heater The formula is as follows: in, and These are the maximum heating capacities of the gas heater and the electric heater, respectively. This represents the current value of the total external heating power. It is a hyperbolic tangent function, used to achieve smooth and differentiable amplitude saturation; and The weights assigned to the gas heater and the electric heater are calculated using the following normalized exponential function formula: in, This is the weighted sharpness factor; and The health status of the gas heater and the electric heater are calculated using the following Gaussian function form: in, and The power tracking residuals of the gas heater and the electric heater are defined as follows: and This is the actual feedback power. and This is the power command value from the previous moment; and The residual scale is used for online estimation.

[0100] The power command value of the gas heater at the current moment is the power control command allocated to the gas heater within the current sampling period, which is calculated from the total external supplementary heating power and the maximum heating capacity of the gas heater.

[0101] The current power command value of the electric heater is the power control command allocated to the electric heater within the current sampling period, which is calculated from the total external supplementary heating power and the maximum heating capacity of the electric heater.

[0102] The maximum heating capacity of a gas heater is the maximum net heat power that the gas heater can output. It is preferably the maximum fuel flow rate of the gas heater multiplied by the lower heating value combustion efficiency and heat transfer efficiency, and then divided by 1000, in order to match the physical combustion limit and heat transfer capacity of the gas heater.

[0103] The maximum heating capacity of the electric heater is the maximum net heat power that the electric heater can output, preferably 0.95 times the rated power of the electric heater, in order to avoid overloading the electric heating element and ensure the safe operation of the equipment.

[0104] The allocation weight of the gas heater is the proportion of the gas heater in the total supplementary heating power during the current sampling period, which is calculated by the health status of the gas heater and the health status of the electric heater through a normalized exponential function.

[0105] The electric heater allocation weight is the proportion of the electric heater in the total supplementary heating power during the current sampling period, which is numerically equal to 1 minus the gas heater allocation weight.

[0106] The health status of a gas heater is a quantitative assessment of its operating condition, obtained by mapping the power tracking residual and the residual scale using a Gaussian function.

[0107] The health status of an electric heater is a quantitative assessment of its operating condition, obtained by mapping the power tracking residual and the residual scale through a Gaussian function.

[0108] The power tracking residual of a gas heater is the difference between the actual feedback power of the gas heater at the current moment and the power command value at the previous moment, which is used to reflect the power tracking performance of the gas heater.

[0109] The power tracking residual of an electric heater is the difference between the actual feedback power of the electric heater at the current moment and the power command value at the previous moment, which is used to reflect the power tracking performance of the electric heater.

[0110] The gas heater residual scale is an online estimation reference scale for the power tracking residual of the gas heater, used to normalize the residual to calculate the health status.

[0111] The electric heater residual scale is an online estimation reference scale for the electric heater power tracking residual, used to normalize the residual to calculate health.

[0112] The weight sharpness factor is a parameter that adjusts the steepness of the weight switching. It is preferably between 2 and 8. Within this range, a balance can be achieved between switching speed and smoothness. The larger the value, the steeper the switching but still maintains continuity.

[0113] The power command value of the gas heater at the previous moment is the power control command assigned to the gas heater in the previous sampling period, which is obtained by storing the calculation results of the previous period.

[0114] The power command value of the electric heater at the previous moment is the power control command assigned to the electric heater in the previous sampling period, which is obtained by storing the calculation results of the previous period.

[0115] Power tracking residuals include: Traditional heat source status assessments often rely on hardware fault signals. This solution defines the residual by the difference between the current feedback power and the previous command value, which can quantify the dynamic tracking capability of the heat source in real time. For example, if the previous command value for a gas heater was 300 kW and the current feedback power is 295 kW, the residual is 5 kW, which directly reflects the tracking deviation.

[0116] The Gaussian function mapping for health status includes the following: The Gaussian function has the characteristic of being high in the middle and low at both ends, which can normalize the residuals and map them to a health status between 0 and 1. The smaller the residual, the closer the health status is to 1; the larger the residual, the closer the health status is to 0, achieving a continuous and smooth assessment of the heat source status. For example, for a gas heater with a residual of 5 kW and a residual scale of 10 kW, the health status = exponent (- (5 / 10)). 2 The value is approximately 0.779, indicating that the system is operating well.

[0117] The calculation of the normalized exponential function for weight allocation includes: calculating the weights using a normalized exponential function (softmax), which enables dynamic allocation of weights for dual heat sources without branching logic. The steepness is adjusted by a weight sharpness factor, achieving both a smooth transition and an effect close to traditional switching. For example, with a gas heater health level of 0.779, an electric heater health level of 0.95, a sharpness factor of 4, and a gas heater weight of 0.779. 4 ÷ (0.779) 4 +0.95 4 The weight of the electric heater is approximately 0.38, and the weight of the electric heater is approximately 0.62, thus achieving a reasonable allocation.

[0118] The smooth saturation of the hyperbolic tangent function addresses the issue that traditional power saturation uses hard limiting, which can easily lead to abrupt changes in the command. The hyperbolic tangent function, however, achieves smooth and differentiable amplitude limiting. When the allocated power exceeds the maximum heating capacity, the command smoothly approaches the maximum value. For example, for a gas heater with a maximum heating capacity of 400 kW and an allocated power of 450 kW, the command value = 400 × hyperbolic tangent (450 / 400) ≈ 392 kW, avoiding the abrupt interference of hard limiting.

[0119] Online estimation of residual scales includes: calculating the variance of the residuals using an exponentially weighted moving average (EWMA), with the residual scale being the square root of the variance plus a small positive value. For example, in calculating the variance of the exponentially weighted moving average of the residuals of a gas heater, the attenuation factor is preferably set to 0.95 to 0.99, the initial variance is set to 100, and the residual scale is calculated as the square root of (variance + 0.25), ensuring that the scale is always positive and stable.

[0120] The calculation of the maximum heating capacity of a gas heater includes: the maximum fuel flow rate is taken from the range of the fuel flow meter or the flow rate when the valve is fully open; the lower heating value is determined by the fuel type (e.g., natural gas, approximately 35,588 kJ per kilogram); the combustion efficiency is preferably taken as 0.9 to 0.95; and the heat transfer efficiency is preferably taken as 0.85 to 0.9. The maximum heating capacity is calculated using the formula: Maximum heating capacity = (Maximum fuel flow rate × Lower heating value × Combustion efficiency × Heat transfer efficiency) ÷ 1000.

[0121] Fine-tuning of the weighted sharpness factor includes: an initial value of 4; if temperature fluctuations are large during the switching process, reduce it to 2 to 3; if the switching response is too slow, increase it to 5 to 8. During fine-tuning, adjust by 1 each time, observing for 2 to 3 sampling periods until the switching is smooth and the response is timely.

[0122] The numerical precision requirements for the hyperbolic tangent function include: retaining 4 to 6 decimal places during calculation, adopting the standard floating-point arithmetic used in industrial control, ensuring the consistency of saturation characteristics, and avoiding instruction jitter caused by insufficient precision.

[0123] It should be noted that the interval and threshold sizes are set for ease of comparison. The size of the threshold depends on the amount of sample data and the base number set by those skilled in the art for each set of sample data, as long as it does not affect the proportional relationship between the parameter and the quantized value. Furthermore, the above formulas are all dimensionless calculations, and the formulas are derived from software simulations using a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0124] Example 2: A catalytic oxidation control method with coupled electric and gas heat sources, used to realize a catalytic oxidation control system with coupled electric and gas heat sources as described in any one of the claims, which is applied to a system including a CO reactor, a gas-gas heat exchanger, a gas heater, an electric heater and an intelligent control unit; During operation and switching, the intelligent control unit constructs and maintains composite thermal balance parameters, which are composed of the total external heating power, the heat source response lag correction amount, and the system heat storage drift correction amount. The heat source response hysteresis correction is calculated based on the rate of change of the total external heating power and the solid phase thermal conduction time constant, and is used to suppress the reverse response of the outlet temperature caused by the solid phase thermal inertia of the reactor; the system heat storage drift correction is calculated based on the rate of change of the total heat storage enthalpy of the thermal integrated network and the heat storage coupling gain coefficient, and is used to compensate for the energy accumulation fluctuations in the thermal network composed of the gas-to-gas heat exchanger and connecting pipelines. Based on the requirement to maintain the constant composite thermal balance parameters, the intelligent control unit calculates the total external heating power in reverse and distributes the total external heating power to the gas heater and the electric heater.

[0125] The embodiments of this example have been described above. However, this example is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of this example, and all of them are within the protection scope of this example.

Claims

1. An electric gas dual heat source coupled catalytic oxidation control device, characterized in that, include: Exhaust gas pretreatment unit: includes a gas-liquid separator, the gas-liquid separator’s inlet is connected to an exhaust gas pipeline, the bottom is provided with a drain outlet connected to a sewage pipeline, and the top is provided with a gas outlet; in addition, it is also provided with an oxygen supplementation and start-up fan, the outlet of which is connected to the exhaust gas pipeline upstream of the gas-liquid separator; Heat recovery unit: includes a gas-to-gas heat exchanger, which is provided with a cold flow channel and a hot flow channel, and the top gas outlet of the gas-liquid separator is connected to the inlet of the cold flow channel; Dual heat source series heating unit: includes an electric heater and a gas heater connected in series along the airflow direction; the inlet of the electric heater is connected to the outlet of the cold flow channel of the gas-to-gas heat exchanger, and the outlet of the electric heater is connected to the inlet of the gas heater; Catalytic reaction unit: includes a CO reactor, the inlet of which is connected to the outlet of the gas heater; the outlet of the CO reactor is connected to the inlet of the heat flow channel of the gas-to-gas heat exchanger, and the outlet of the heat flow channel is connected to the vent pipe; Gas supply and ignition system: connected to the gas heater, including a combustible material main pipe, which collects at least one of combustible material A and combustible material B, and the main pipe is divided into a main fire branch and an ignition branch in parallel; the main fire branch is provided with a main fire valve 1, a main fire valve 2 and a gas regulating valve in sequence along the airflow direction; the ignition branch is provided with an ignition solenoid valve 1 and an ignition solenoid valve 2 in sequence along the airflow direction; Combustion-supporting air supply system: including a combustion-supporting blower and a combustion-supporting air regulating valve located downstream of it, wherein the outlet pipe of the combustion-supporting air regulating valve is connected to the burner section of the gas heater; The process is as follows: the waste gas to be treated is mixed with the oxygen supplement and the air supplied by the start-up fan, and then enters the gas-liquid separator to separate condensate and impurities; the separated gas enters the cold flow channel of the gas-gas heat exchanger for preliminary preheating, and then passes through the electric heater and the gas heater in sequence, and is heated to the catalytic ignition temperature in stages by the dual heat sources; the heated gas enters the CO reactor to undergo catalytic oxidation reaction, and the high-temperature purified gas produced by the reaction flows back to the hot flow channel of the gas-gas heat exchanger, transfers the heat to the front-end cold waste gas, and is finally discharged through the exhaust pipe.

2. A catalytic oxidation control system of electric and gas dual heat source coupling, applied to a CO reactor, a gas-gas heat exchanger, a gas heater and an electric heater, characterized in that, It also includes an intelligent control unit: The intelligent control unit is configured to build and maintain composite thermal balance parameters during operation and switching. The composite thermal balance parameters are composed of the total external heating power, the heat source response lag correction amount, and the system heat storage drift correction amount. The heat source response hysteresis correction is calculated based on the rate of change of the total external heating power and the solid phase thermal conduction time constant, and is used to suppress the reverse response of the outlet temperature caused by the solid phase thermal inertia of the reactor; the system heat storage drift correction is calculated based on the rate of change of the total heat storage enthalpy of the thermal integrated network and the heat storage coupling gain coefficient, and is used to compensate for the energy accumulation fluctuations in the thermal network composed of the gas-to-gas heat exchanger and connecting pipelines. The intelligent control unit calculates the total external heating power in reverse according to the requirement of maintaining the constant composite thermal balance parameters, and distributes the total external heating power to the gas heater and the electric heater.

3. The catalytic oxidation control system with coupled electric and gas dual heat sources according to claim 2, characterized in that, The heat source response hysteresis correction includes: The value of the heat source response hysteresis correction is equal to the negative value of the quotient obtained by dividing the differential of the total external heating power with respect to time by the solid-phase thermal conductivity time constant; wherein, the solid-phase thermal conductivity time constant is a real-time estimated value obtained through online recursive identification, and the acquisition process of the solid-phase thermal conductivity time constant is configured as follows: superimposing a small sinusoidal detection signal on the total external heating power, collecting the inlet temperature response data of the CO reactor, updating the discrete-time transfer model containing the identification coefficients of the derivative term using the recursive least squares algorithm, and mapping the identification coefficients of the derivative term to the solid-phase thermal conductivity time constant through a smooth positive value function, wherein the smooth positive value function is used to ensure that the solid-phase thermal conductivity time constant is always positive and greater than the minimum physical limit.

4. The catalytic oxidation control system with coupled electric and gas dual heat sources according to claim 3, characterized in that, System heat storage drift correction includes: The numerical value of the system heat storage drift correction is equal to the product of the heat storage coupling gain coefficient and the differential value of the total heat storage enthalpy with respect to time; wherein, the total heat storage enthalpy is the product of the system's equivalent heat capacity and the equivalent weighted temperature, used to characterize the solid-phase energy storage state including the gas-to-gas heat exchanger wall, reactor shell, and connecting pipelines; the system's equivalent heat capacity is the weighted sum of the products of the mass and specific heat capacity of the metal and ceramic components of the gas-to-gas heat exchanger, CO reactor, and connecting pipelines; the equivalent weighted temperature is the weighted average of the outlet temperature of the CO reactor and the cold-end outlet temperature of the gas-to-gas heat exchanger, and its weight is determined by the hot-end weight coefficient determined by the proportion of the hot-end component's heat capacity in the system's equivalent heat capacity.

5. A catalytic oxidation control system with coupled electric and gas dual heat sources according to claim 4, characterized in that, Composite thermal equilibrium parameters include: The values ​​of the composite thermal balance parameters are the real-time algebraic sum of the total external heating power, the heat source response hysteresis correction, and the system heat storage drift correction; wherein, the total external heating power is the current value after unified phase filtering; the heat source response hysteresis correction is determined by the difference ratio between the current value and the previous value of the total external heating power and the solid-phase thermal conductivity time constant; the system heat storage drift correction is determined by the difference ratio between the current value and the previous value of the total heat storage enthalpy and the heat storage coupling gain coefficient.

6. The catalytic oxidation control system with coupled electric and gas dual heat sources according to claim 5, characterized in that, Establishing and maintaining composite thermal equilibrium parameters during operation and switchover, including: Calculate the target thermal balance value and lock the value of the composite thermal balance parameter as the target thermal balance value. The target thermal balance value is composed of the superposition of a temperature deviation proportional term, a temperature deviation integral term, and a sensible heat feedforward compensation term. The temperature deviation proportional term is determined by multiplying the real-time difference between the target set temperature and the inlet temperature of the CO reactor by a proportional adjustment coefficient. The temperature deviation integral term is determined by multiplying the historical cumulative amount of the real-time difference by an integral adjustment coefficient. The sensible heat feedforward compensation term is determined by the product of the process gas mass flow rate, the process gas specific heat at constant pressure, and the difference between the target set temperature and the cold end inlet temperature of the gas-to-gas heat exchanger, and is used to characterize the sensible heat power reference required to heat the inlet gas to the reaction temperature.

7. A catalytic oxidation control system with coupled electric and gas dual heat sources according to claim 6, characterized in that, Based on the requirement to maintain the constant composite thermal balance parameters, the total external heating power is calculated in reverse, including: Based on the feedback closed-loop equivalent power, numerical rigidity suppression factor, and model driving error from the previous moment, the total external heat compensation power at the current moment is calculated. The current value of the total external heat compensation power is calculated as the sum of the feedback closed-loop equivalent power from the previous moment and the incremental correction value. The incremental correction value is equal to the product of the numerical rigidity suppression factor, the sampling period, the solid-phase thermal conductivity time constant, and the model driving error. The model driving error is equal to the sum of the feedback closed-loop equivalent power from the previous moment and the system heat storage drift correction at the current moment, minus the target thermal equilibrium value at the current moment. The numerical rigidity suppression factor is used to suppress numerical instability in discrete calculations, and its value is equal to one divided by the sum of the products of the sampling period and the solid-phase thermal conductivity time constant. The feedback closed-loop equivalent power is the sum of the actual detected dual-heat-source feedback power after a first-order low-pass filter, used to introduce the actual response state of the actuator during the reverse calculation process to prevent calculation divergence.

8. A catalytic oxidation control system with coupled electric and gas dual heat sources according to claim 7, characterized in that, Distributing the total external heating power to the gas heater and the electric heater includes: The power tracking residuals of the gas heater and the electric heater are calculated separately. The value of the power tracking residual is equal to the feedback power at the current moment minus the power command value at the previous moment. Based on the power tracking residual and the residual scale estimated online, the health of the gas heater and the electric heater is calculated separately using a Gaussian function mapping relationship. Based on the health of the gas heater and the electric heater, the allocation weights of the gas heater and the electric heater are calculated separately using a normalized exponential function relationship. The calculation of the allocation weights includes a weight sharpness factor for adjusting the switching steepness. The power command values ​​of the gas heater and the electric heater are calculated separately. The value of the power command value is equal to the maximum heating capacity of the heat source multiplied by the hyperbolic tangent function value. The independent variable of the hyperbolic tangent function is the quotient obtained by dividing the product of the allocation weight and the total external heating power by the maximum heating capacity of the heat source. The hyperbolic tangent function is used to provide smooth and differentiable amplitude saturation characteristics to ensure the continuity of control commands when the total external heating power exceeds the physical limit.

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