Automatic feeding method and system for biomass gasifier

Abstract

The invention discloses an automatic feeding method and system for a biomass gasifier, and relates to the technical field of automatic feeding of gasifiers, and the automatic feeding method comprises the following steps: detecting and screening raw materials by using multiple sensors to detect humidity, metal impurities and sizes, monitoring a temporary storage bin by a material level, and calculating the feeding amount according to parameters of the gasifier; a neural network and a fuzzy algorithm control a motor or frequency to achieve accurate feeding, feeding uniformity is assisted by a special feeder and airflow, crushing and drying are conducted according to experimental proportion adjustment and raw material pretreatment, parameters and hot air flow are controlled, a heat exchanger is recycled through energy, gas is preheated, power is generated, parameters are calculated according to a formula to control emission, and emissions are monitored, regulated and controlled. Adjusting operating parameters according to coefficients when the parameters exceed the standard, performing fault detection and early warning, monitoring component states, and performing early warning, self-diagnosis and notification when the components are abnormal. The feeding precision and stability are improved, the raw material quality and equipment safety are guaranteed, the feeding uniformity is optimized, energy recovery, environmental protection and emission reduction are achieved, the energy conversion efficiency is improved, and the equipment maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of automatic feeding of a biomass gasifier, and in particular to an automatic feeding method and system for a biomass gasifier. Background Art

[0002] With the growing global demand for clean energy and concerns about the environmental impact of traditional fossil energy, biomass energy is gaining increasing attention as a renewable, low-carbon energy source. Biomass gasification technology is one of the important ways to utilize biomass energy. It can convert biomass raw materials into combustible gas, which can be used in power generation, heating, gas supply and other fields.

[0003] However, in the operation of the biomass gasifier, there are many technical difficulties in the automatic feeding process. Traditional feeding methods often rely on manual operation or simple mechanical feeding devices, which make it difficult to accurately control the feeding amount. This leads to unstable reactions in the gasifier. When the feeding amount is too much, it will cause incomplete gasification, produce a large amount of tar and unburned solid residue, reduce energy conversion efficiency, and increase the difficulty and cost of subsequent processing; and when the feeding amount is too little, it cannot meet the normal operation requirements of the gasifier, affecting the gas production rate and equipment capacity.

[0004] In addition, the quality of biomass raw materials varies, and factors such as humidity, size, and possible metal impurities can have a significant impact on the gasification process. High-humidity raw materials will absorb a lot of heat for water evaporation, lowering the gasification reaction temperature and making it difficult for the reaction to proceed continuously and efficiently; raw materials that are too large or too small may lead to uneven feeding and cause local reaction abnormalities; metal impurities entering the gasifier may damage the equipment in the furnace, affecting the service life and operation safety of the equipment.

[0005] Furthermore, the existing feeding system lacks effective safeguards for feeding uniformity. Uneven feeding will cause uneven distribution of materials in the gasifier, forming local high or low temperature areas, which will not only affect the stability and efficiency of the gasification reaction, but may also cause slagging and blockage in the furnace, increasing equipment maintenance costs and downtime.

[0006] In terms of energy utilization and environmental protection, the traditional biomass gasifier feeding system lacks an effective energy recovery mechanism, a large amount of waste heat is wasted, and the monitoring and control capabilities of emissions are insufficient, which easily causes environmental pollution and cannot meet the increasingly stringent environmental protection requirements. Therefore, the development of an efficient, intelligent, and environmentally friendly biomass gasifier automatic feeding method and system has extremely important practical significance, which can effectively solve the above problems and promote the further development and widespread application of biomass gasification technology. Summary of the invention

[0007] The present invention provides a biomass gasifier automatic feeding method and system to solve the problems mentioned in the prior art.

[0008] In order to achieve the above object, the present invention adopts the following technical solution: a biomass gasification furnace automatic feeding method, comprising the following steps:

[0009] S1. Raw material detection and screening step: using a variety of sensors to detect the biomass raw materials, including a humidity sensor to detect the humidity of the raw materials, a capacitive humidity sensor, a metal detector to detect metal impurities in the raw materials, an electromagnetic induction metal detector, and a size screening device to screen out raw materials that meet the size requirements of the gasifier feed port;

[0010] The temporary storage silo has a material level monitoring function, using an ultrasonic level meter or a radar level meter. When the material level is lower than the set lower limit, a raw material replenishment signal is triggered;

[0011] S2, feeding amount calculation and control steps: according to the real-time operating parameters of the gasifier, the required biomass feeding amount is calculated by the built-in intelligent algorithm. The algorithm is based on the gasifier operation model established by big data analysis. The intelligent algorithm adopts a combination of neural network algorithm and fuzzy control algorithm. The learning rate of the neural network algorithm is set to η, and the initial value is 0.01. During the training process, it is adjusted according to the change of the loss function L. When the decrease of L after k consecutive iterations is less than δ, k=5, δ=0.01, η=η×0.5, and the control rules of the fuzzy control algorithm are determined based on expert experience and experimental data;

[0012] Control the motor speed or conveying frequency of the feeding device to accurately adjust the feeding amount, so as to achieve an accurate match between the feeding amount and the operating requirements of the gasifier;

[0013] S3. Feeding uniformity guarantee step: adopt a screw feeder or a vibrating feeder for feeding operation, and the internal structure of the feeder is designed, specifically: the pitch gradient of the spiral blade or the amplitude adjustment function of the vibrating plate, so that the biomass raw materials are evenly distributed in the reaction area of ​​the gasifier;

[0014] During the feeding process, an appropriate amount of inert gas or air is injected into the feeding channel through the airflow auxiliary device. The proportional relationship between the airflow flow rate Q of the airflow auxiliary device and the feeding amount M is determined by experiments, and the adjustment range of the proportional coefficient is between 0.1 and 1;

[0015] S4, raw material pretreatment optimization step: the screened biomass raw materials are crushed, and the particle size of the crushed raw materials meets the reaction requirements of the gasifier. A jaw crusher or a hammer crusher is used, and the crushing ratio of the crusher can be adjusted between 5-20;

[0016] The crushed raw materials are dried through a hot air circulation system. The hot air flow rate is calculated based on the volume and humidity of the raw materials. The calculation formula is: Where V is the hot air flow rate, m is the raw material mass, H1 is the initial humidity of the raw material, H2 is the target humidity, C is the specific heat capacity of air, T1 is the initial temperature of the hot air, and T2 is the exhaust temperature of the hot air;

[0017] S5. Energy recovery and utilization steps: During the operation of the gasifier, the heat in the high-temperature flue gas is recovered through the heat exchanger. Part of the recovered heat is used to preheat the air or inert gas entering the gasifier. The preheating temperature can be increased to 100℃-300℃. The calculation formula is: Where T p is the gas temperature after preheating, T i is the initial gas temperature, Q r To recover heat, m a is the gas mass flow rate, C a The specific heat capacity of the gas, and the other part is used to drive the power generation device to generate electricity, with a power generation efficiency between 10% and 30%. The generated electricity can be supplied to the motor and other equipment in the feeding system;

[0018] S6. Emission monitoring and control steps: Real-time monitoring of gasifier emissions, including carbon monoxide, carbon dioxide, and particulate matter, using high-precision gas sensors and particulate matter sensors. When the emission concentration exceeds the environmental protection standard, the gasifier operating parameters are adjusted. The carbon monoxide concentration adjustment coefficient is set to β, the carbon dioxide concentration adjustment coefficient is set to γ, and the particulate matter concentration adjustment coefficient is set to ε. The adjustment coefficient is determined according to the emission concentration exceeding the standard. The adjustment range is calculated by changing the feed amount. Among them, △M is the adjustment range of feeding amount, M0 is the initial feeding amount, C CO is the excess concentration of carbon monoxide, C CO2 is the excess concentration of carbon dioxide, C PM is the concentration of particulate matter exceeding the standard;

[0019] S7, Fault detection and early warning step: real-time monitoring of key components of the feeding system, monitoring of motor working current through current sensors, and monitoring of key parts temperature through temperature sensors. When abnormal conditions are detected, fault early warning signals are immediately issued;

[0020] The fault warning signal is sent to the operator through various means such as sound and light alarms, SMS notifications or system pop-ups. It also has a fault self-diagnosis function. When a fault warning signal is issued, if the working current I deviates from the normal current I0 by more than β, β=0.2I0, or the temperature T deviates from the normal working temperature T0 by more than γ, γ=5°C, the system automatically makes a preliminary diagnosis of the cause of the fault and provides corresponding maintenance suggestions.

[0021] Furthermore, in the raw material detection and screening step, the humidity sensor adopts a capacitive humidity sensor, and the relationship between the capacitance change and humidity is determined by a calibration curve, and the fitting degree of the calibration curve is not less than 98%.

[0022] Furthermore, in the step of calculating and controlling the feeding amount, the intelligent algorithm adopts a combination of a neural network algorithm and a fuzzy control algorithm. The neural network algorithm learns and predicts the gasifier operation data, and the fuzzy control algorithm accurately controls the feeding amount according to the prediction results.

[0023] Furthermore, in the step of ensuring uniformity of feeding, the proportional relationship between the airflow flow rate of the airflow assisting device and the feeding amount is determined through experiments, and the adjustment range of the proportional coefficient is between 0.1 and 1, which can be flexibly adjusted according to the characteristics of different biomass raw materials.

[0024] Furthermore, in the energy recovery and utilization step, the heat exchanger adopts a high-efficiency fin-type heat exchanger, and its fin structure is optimized to increase the heat exchange area. The calculation formula is S=n×l×w×cosθ, where S is the heat exchange area, n is the number of fins, l is the fin length, w is the fin width, and cosθ is the angle between the fin and the airflow direction. The material of the heat exchanger is a high-temperature resistant and corrosion-resistant alloy material.

[0025] Furthermore, a system for realizing the automatic feeding of the biomass gasifier includes:

[0026] The raw material detection and screening device includes a humidity sensor, a metal detector, a size screening device and a temporary storage silo, which is used to detect, screen and temporarily store biomass raw materials, and each component works in coordination;

[0027] The feed amount calculation control unit is composed of a data acquisition module, an intelligent algorithm module and a control execution module. The data acquisition module collects the gasifier operation parameters, the intelligent algorithm module calculates the feed amount according to the operation parameters, and the control execution module controls the operation of the feed device;

[0028] The feeding uniformity guarantee mechanism is equipped with a spiral feeder or a vibrating feeder and an airflow auxiliary device. The feeder and the airflow auxiliary device ensure the uniform distribution of the biomass raw materials in the gasifier;

[0029] Raw material pretreatment optimization module, including jaw crusher or hammer crusher and hot air circulation drying system, used to crush and dry biomass raw materials so that the particle size and humidity of raw materials meet the reaction requirements of gasifier;

[0030] The energy recovery module is composed of a heat exchanger, a preheating pipe and a power generation device. The heat exchanger recovers the heat of the high-temperature flue gas of the gasifier, the preheating pipe transfers the heat to the air or inert gas entering the gasifier, and the power generation device uses the recovered heat to generate electricity and supply it to the system equipment;

[0031] The emission monitoring and control module is equipped with high-precision gas sensors and particulate matter sensors to monitor the emission concentration of the gasifier. When it exceeds the standard, it will be regulated by adjusting the gasifier operating parameters to ensure that the emission meets environmental protection requirements;

[0032] The fault detection and early warning module is connected to the key components of the feeding system to monitor its working status in real time. When a fault occurs, it will promptly issue an early warning signal and perform preliminary fault diagnosis.

[0033] Furthermore, the metal detector in the raw material detection and screening device adopts an electromagnetic induction metal detector, whose operating frequency is adjusted between 5 kHz and 100 kHz to detect different types of metal impurities, and the detection depth of iron, copper and aluminum is not less than 5 cm.

[0034] Furthermore, the data acquisition module in the feed quantity calculation control unit adopts a high-precision sensor, and the data acquisition frequency of the sensor is adjusted between 1 Hz and 10 Hz to obtain the gasifier operation parameters in real time and accurately.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] Through precise raw material detection and screening as well as intelligent feed amount calculation and control, the feed amount can be accurately adjusted according to the real-time operating parameters of the gasifier, and the error is controlled within a small range, ensuring that the gasification reaction is stable and efficient, effectively improving the energy conversion efficiency. Compared with traditional feeding methods, the energy conversion efficiency can be increased by 20%-30%.

[0037] Strict detection and screening of raw material moisture, metal impurities and size can avoid abnormal gasification reaction and equipment damage caused by raw material problems, extend equipment service life, reduce equipment maintenance costs, and reduce equipment maintenance frequency by 30%-50%.

[0038] The specially designed feeder structure and airflow auxiliary device make the raw materials evenly distributed in the gasifier, reduce local reaction abnormalities and slagging blockage, improve the continuity and reliability of the gasifier operation, and improve the equipment operation stability by 40%-60%.

[0039] The energy recovery and utilization module effectively recovers waste heat, reduces system energy consumption, and partially achieves self-sufficiency; the emission monitoring and control module can monitor and control emission concentrations in real time to make it meet environmental protection standards and reduce pollution to the environment. The environmental protection indicator compliance rate can reach more than 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic block diagram of an automatic feeding method for a biomass gasifier proposed by the present invention;

[0041] Figure 2 This is a schematic block diagram of an automatic feeding system for a biomass gasifier proposed by the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, and it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0045] Reference Figure 1-2 : A biomass gasifier automatic feeding method, comprising the following steps:

[0046] S1. Raw material detection and screening steps: Use a variety of sensors to detect biomass raw materials, including humidity sensors to detect raw material humidity with an accuracy within ±3%. Use a capacitive humidity sensor, and the relationship between its capacitance change and humidity is determined by a specific calibration curve. The calibration curve fit is not less than 98%. Use a metal detector to detect metal impurities in the raw materials with a detection sensitivity of not less than 0.5 grams. Use an electromagnetic induction metal detector with an adjustable operating frequency between 5 kHz and 100 kHz. The detection depth of common metals such as iron, copper, and aluminum is not less than 5 cm. Use a size screening device to screen out raw materials that meet the size requirements of the gasifier feed port. The screening accuracy is not less than 95%, and the qualified raw materials are transported to the temporary storage silo.

[0047] The temporary storage silo has a material level monitoring function, using an ultrasonic level meter or a radar level meter with a monitoring accuracy within the range of ±5 cm. When the material level is lower than the set lower limit, the raw material replenishment signal is triggered to ensure the continuity of the feeding process.

[0048] S2, feed amount calculation and control steps: According to the real-time operating parameters of the gasifier, such as power, temperature, pressure, etc., the required biomass feed amount is calculated through the built-in intelligent algorithm. The algorithm is based on the gasifier operation model established by big data analysis. The model training data volume is not less than 500 groups, covering the operation data under different working conditions, and the calculated feed amount error does not exceed ±10%. The intelligent algorithm adopts a combination of neural network algorithm and fuzzy control algorithm. The learning rate of the neural network algorithm is set to η, and the initial value is 0.01. During the training process, it is adjusted according to the change of the loss function L. When the decrease of L after k consecutive iterations is less than δ (k=5, δ=0.01), η=η×0.5. The control rules of the fuzzy control algorithm are determined based on expert experience and experimental data, making the control effect more stable and accurate, and the system response time is shortened by not less than 20%.

[0049] The feeding amount can be precisely adjusted by controlling the motor speed or conveying frequency of the feeding device. The motor speed adjustment accuracy is ±5 rpm, and the conveying frequency adjustment accuracy is ±0.1 Hz, so as to achieve an accurate match between the feeding amount and the operating requirements of the gasifier.

[0050] S3. Feeding uniformity guarantee steps: Use a screw feeder or a vibrating feeder for feeding operations. The internal structure of the feeder is specially designed, such as the pitch gradient of the spiral blade or the amplitude adjustment function of the vibration plate, so that the biomass raw materials can be evenly distributed in the reaction area of ​​the gasifier, and the raw material distribution uniformity deviation does not exceed ±15%.

[0051] During the feeding process, an appropriate amount of inert gas or air is injected into the feeding channel through the airflow auxiliary device. The airflow velocity can be adjusted between 1 m / s and 10 m / s. The proportional relationship between the airflow flow Q of the airflow auxiliary device and the feeding amount M is determined by experiments. The adjustment range of the proportional coefficient is between 0.1 and 1. It can be flexibly adjusted according to the different characteristics of biomass raw materials to achieve the best feeding uniformity effect, further promote the dispersion and uniform distribution of raw materials, and improve the gasification reaction efficiency.

[0052] S4. Raw material pretreatment optimization step: The screened biomass raw materials are crushed, and the particle size of the crushed raw materials meets the reaction requirements of the gasifier. A jaw crusher or a hammer crusher is used, and the crushing ratio of the crusher is adjustable between 5-20. The appropriate crushing ratio is selected according to the characteristics of different raw materials. The uniformity of the particle size of the crushed raw materials is not less than 80%.

[0053] The crushed raw materials are dried. The drying temperature can be adjusted between 50℃-150℃. The drying time is determined according to the raw material humidity and feed amount. The raw materials are dried through a hot air circulation system. The hot air flow is calculated according to the raw material volume and humidity. The calculation formula is: Where V is the hot air flow rate, m is the raw material mass, H1 is the initial humidity of the raw material, H2 is the target humidity, C is the specific heat of air, T1 is the initial temperature of the hot air, and T2 is the hot air exhaust temperature. The raw material humidity is reduced to the optimal reaction humidity range of the gasifier to improve the gasification efficiency.

[0054] S5. Energy recovery and utilization steps: During the operation of the gasifier, the heat in the high-temperature flue gas is recovered through the heat exchanger, and the heat exchange efficiency is not less than 70%. Part of the recovered heat is used to preheat the air or inert gas entering the gasifier. The preheating temperature can be raised to 100℃-300℃. The calculation formula is Where T p is the gas temperature after preheating, T i is the initial gas temperature, Q r To recover heat, m a is the gas mass flow rate, C a The other part is used to drive the power generation device to generate electricity with a power generation efficiency between 10% and 30%. The generated electricity can be supplied to the motors and other equipment in the feeding system to reduce the overall energy consumption of the system.

[0055] S6. Emission monitoring and control steps: Real-time monitoring of gasifier emissions, including carbon monoxide, carbon dioxide, particulate matter, etc., using high-precision gas sensors and particulate matter sensors, with carbon monoxide detection accuracy of ±5ppm, carbon dioxide detection accuracy of ±20ppm, and particulate matter detection accuracy of ±1mg / m 3When the emission concentration exceeds the environmental protection standard, the gasifier operating parameters such as temperature, feed rate, and air supply are adjusted to control the emission. Assume that the carbon monoxide concentration adjustment coefficient is β, the carbon dioxide concentration adjustment coefficient is γ, and the particulate matter concentration adjustment coefficient is ε. The adjustment coefficient is determined according to the emission concentration exceeding the standard. The adjustment range of the feed rate is calculated by the following formula: Among them, △M is the adjustment range of feeding amount, M0 is the initial feeding amount, C CO is the excess concentration of carbon monoxide, C CO2 is the excess concentration of carbon dioxide, C PM The concentration of particulate matter exceeds the standard to ensure that emissions meet environmental protection requirements.

[0056] S7. Fault detection and early warning steps: Real-time monitoring of the working status of key components of the feeding system, such as sensors, motors, feeders, etc. The working current of the motor is monitored by the current sensor with a monitoring accuracy of ±0.1 ampere. The temperature sensor monitors the temperature of key parts with an accuracy of ±2°C. When an abnormal situation is detected, such as excessive current, excessive temperature, abnormal sensor signal, etc., a fault early warning signal is immediately issued.

[0057] The fault warning signal is sent to the operator through various means such as sound and light alarm, SMS notification or system pop-up window, and the sending time does not exceed 1 minute, so that maintenance measures can be taken in time to ensure the stable operation of the system. It also has a fault self-diagnosis function. When the fault warning signal is issued, when the working current I deviates from the normal current I0 by more than β, β = 0.2I0, and the temperature T deviates from the normal working temperature T0 by more than γ, γ = 5℃, the system automatically makes a preliminary diagnosis of the cause of the fault, with a diagnostic accuracy of not less than 80%, and provides corresponding maintenance suggestions, with an efficiency of not less than 70%.

[0058] In the present invention, in the raw material detection and screening steps, the humidity sensor adopts a capacitive humidity sensor, and the relationship between its capacitance change and humidity is determined by a specific calibration curve, and the fitting degree of the calibration curve is not less than 98%, so as to improve the accuracy of humidity detection.

[0059] In the present invention, in the step of calculating and controlling the feed amount, the intelligent algorithm adopts a combination of a neural network algorithm and a fuzzy control algorithm. The neural network algorithm learns and predicts the gasifier operation data, and the fuzzy control algorithm accurately controls the feed amount according to the prediction results, so that the control effect is more stable and accurate, and the system response time is shortened by no less than 20%.

[0060] In the present invention, in the step of ensuring feeding uniformity, the proportional relationship between the airflow flow rate of the airflow assisting device and the feeding amount is determined by experiments, and the adjustment range of the proportional coefficient is between 0.1 and 1, which is flexibly adjusted according to different biomass raw material characteristics to achieve the best feeding uniformity effect.

[0061] In the present invention, in the energy recovery and utilization step, the heat exchanger adopts a high-efficiency fin-type heat exchanger, and its fin structure is optimized and designed to increase the heat exchange area. The calculation formula is S=n×l×w×cosθ, where S is the heat exchange area, n is the number of fins, l is the fin length, w is the fin width, and cosθ is the angle between the fin and the airflow direction, thereby improving the heat exchange efficiency. The material of the heat exchanger is a high-temperature resistant and corrosion-resistant alloy material to extend the service life.

[0062] The present invention also discloses an automatic feeding system for a biomass gasifier, comprising:

[0063] The raw material detection and screening device includes a humidity sensor, a metal detector, a size screening device and a temporary storage silo, which is used to detect, screen and temporarily store biomass raw materials. The various components work together to ensure that the raw materials entering the feeding system are of qualified quality and have a stable supply.

[0064] The feed amount calculation control unit is composed of a data acquisition module, an intelligent algorithm module and a control execution module. The data acquisition module collects the operating parameters of the gasifier, the intelligent algorithm module calculates the feed amount according to the operating parameters, and the control execution module controls the operation of the feeding device to achieve precise control of the feed amount.

[0065] The feeding uniformity guarantee mechanism is equipped with a spiral feeder or a vibrating feeder and an airflow assisting device. Through the specially designed feeder structure and airflow assisting device, the uniform distribution of the biomass raw materials in the gasifier is guaranteed.

[0066] The raw material pretreatment optimization module includes a jaw crusher or a hammer crusher and a hot air circulation drying system, which is used to crush and dry the biomass raw materials so that the particle size and humidity of the raw materials meet the reaction requirements of the gasifier.

[0067] The energy recovery and utilization module consists of a heat exchanger, a preheating pipe and a power generation device. The heat exchanger recovers the heat of the high-temperature flue gas in the gasifier, the preheating pipe transfers the heat to the air or inert gas entering the gasifier, and the power generation device uses the recovered heat to generate electricity and supply it to the system equipment.

[0068] The emission monitoring and control module is equipped with high-precision gas sensors and particulate matter sensors to monitor the emission concentration of the gasifier. When it exceeds the standard, it will adjust the gasifier operating parameters to ensure that the emissions meet environmental protection requirements.

[0069] The fault detection and early warning module connects the key components of the feeding system and monitors its working status in real time. When a fault occurs, it will promptly issue an early warning signal and perform preliminary fault diagnosis to maintain the normal operation of the system.

[0070] In the present invention, the metal detector in the raw material detection and screening device adopts an electromagnetic induction metal detector, whose operating frequency is adjustable between 5 kHz and 100 kHz, and can effectively detect different types of metal impurities. The detection depth of common metals such as iron, copper, and aluminum is not less than 5 cm.

[0071] In the present invention, the data acquisition module in the feed amount calculation control unit adopts a high-precision sensor, and the data acquisition frequency of the sensor is adjustable between 1 Hz and 10 Hz, which can accurately obtain the gasifier operating parameters in real time and provide a reliable basis for feed amount calculation.

[0072] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A biomass gasifier automatic feeding method, characterized in that: The following steps are involved: S1. Raw material detection and screening step: using a variety of sensors to detect the biomass raw materials, including a humidity sensor to detect the humidity of the raw materials, a capacitive humidity sensor, a metal detector to detect metal impurities in the raw materials, an electromagnetic induction metal detector, and a size screening device to screen out raw materials that meet the size requirements of the gasifier feed port; The temporary storage silo has a material level monitoring function, using an ultrasonic level meter or a radar level meter. When the material level is lower than the set lower limit, a raw material replenishment signal is triggered; S2, feeding amount calculation and control steps: according to the real-time operating parameters of the gasifier, the required biomass feeding amount is calculated by the built-in intelligent algorithm. The algorithm is based on the gasifier operation model established by big data analysis. The intelligent algorithm adopts a combination of neural network algorithm and fuzzy control algorithm. The learning rate of the neural network algorithm is set to η, and the initial value is 0.

01. During the training process, it is adjusted according to the change of the loss function L. When the decrease of L after k consecutive iterations is less than δ, k=5, δ=0.01, η=η×0.5, and the control rules of the fuzzy control algorithm are determined based on expert experience and experimental data; Control the motor speed or conveying frequency of the feeding device to accurately adjust the feeding amount, so as to achieve an accurate match between the feeding amount and the operating requirements of the gasifier; S3. Feeding uniformity guarantee step: adopt a screw feeder or a vibrating feeder for feeding operation, and the internal structure of the feeder is designed, specifically: the pitch gradient of the spiral blade or the amplitude adjustment function of the vibrating plate, so that the biomass raw materials are evenly distributed in the reaction area of ​​the gasifier; During the feeding process, an appropriate amount of inert gas or air is injected into the feeding channel through the airflow auxiliary device. The proportional relationship between the airflow flow rate Q of the airflow auxiliary device and the feeding amount M is determined by experiments, and the adjustment range of the proportional coefficient is between 0.1 and 1; S4, raw material pretreatment optimization step: the screened biomass raw materials are crushed, and the particle size of the crushed raw materials meets the reaction requirements of the gasifier. A jaw crusher or a hammer crusher is used, and the crushing ratio of the crusher can be adjusted between 5-20; The crushed raw materials are dried through a hot air circulation system. The hot air flow rate is calculated based on the volume and humidity of the raw materials. The calculation formula is: Where V is the hot air flow rate, m is the raw material mass, H1 is the initial humidity of the raw material, H2 is the target humidity, C is the specific heat capacity of air, T1 is the initial temperature of the hot air, and T2 is the exhaust temperature of the hot air; S5. Energy recovery and utilization steps: During the operation of the gasifier, the heat in the high-temperature flue gas is recovered through the heat exchanger. Part of the recovered heat is used to preheat the air or inert gas entering the gasifier. The preheating temperature can be increased to 100℃-300℃. The calculation formula is: Where T p is the gas temperature after preheating, T i is the initial gas temperature, Q r To recover heat, m a is the gas mass flow rate, C a The specific heat capacity of the gas, and the other part is used to drive the power generation device to generate electricity, with a power generation efficiency between 10% and 30%. The generated electricity can be supplied to the motor and other equipment in the feeding system; S6. Emission monitoring and control steps: Real-time monitoring of gasifier emissions, including carbon monoxide, carbon dioxide, and particulate matter, using high-precision gas sensors and particulate matter sensors. When the emission concentration exceeds the environmental protection standard, the gasifier operating parameters are adjusted. The carbon monoxide concentration adjustment coefficient is set to β, the carbon dioxide concentration adjustment coefficient is set to γ, and the particulate matter concentration adjustment coefficient is set to ε. The adjustment coefficient is determined according to the emission concentration exceeding the standard. The adjustment range is calculated by changing the feed amount. Among them, △M is the adjustment range of feeding amount, M0 is the initial feeding amount, C CO is the excess concentration of carbon monoxide, C CO2 is the excess concentration of carbon dioxide, C PM is the concentration of particulate matter exceeding the standard; S7, Fault detection and early warning step: real-time monitoring of key components of the feeding system, monitoring of motor working current through current sensors, and monitoring of key parts temperature through temperature sensors. When abnormal conditions are detected, fault early warning signals are immediately issued; The fault warning signal is sent to the operator through various means such as sound and light alarms, SMS notifications or system pop-ups. It also has a fault self-diagnosis function. When a fault warning signal is issued, if the working current I deviates from the normal current I0 by more than β, β=0.2I0, or the temperature T deviates from the normal working temperature T0 by more than γ, γ=5°C, the system automatically makes a preliminary diagnosis of the cause of the fault and provides corresponding maintenance suggestions.

2. The automatic feeding method for a biomass gasifier according to claim 1, characterized in that: In the raw material detection and screening step, the humidity sensor adopts a capacitive humidity sensor, the relationship between the capacitance change and the humidity is determined by a calibration curve, and the fitting degree of the calibration curve is not less than 98%.

3. The automatic feeding method for a biomass gasifier according to claim 1, characterized in that: In the step of calculating and controlling the feeding amount, the intelligent algorithm adopts the combination of neural network algorithm and fuzzy control algorithm. The neural network algorithm learns and predicts the gasifier operation data, and the fuzzy control algorithm accurately controls the feeding amount according to the prediction results.

4. The automatic feeding method for a biomass gasifier according to claim 1, characterized in that: In the step of ensuring uniformity of feeding, the proportional relationship between the airflow flow rate of the airflow assisting device and the feeding amount is determined through experiments, and the adjustment range of the proportional coefficient is between 0.1 and 1, which can be flexibly adjusted according to the characteristics of different biomass raw materials.

5. The automatic feeding method for a biomass gasifier according to claim 1, characterized in that: In the energy recovery and utilization step, the heat exchanger adopts a high-efficiency fin heat exchanger, and its fin structure is optimized to increase the heat exchange area. The calculation formula is S=n×l×w×cosθ, where S is the heat exchange area, n is the number of fins, l is the fin length, w is the fin width, and cosθ is the angle between the fin and the airflow direction. The material of the heat exchanger is a high-temperature resistant and corrosion-resistant alloy material.

6. An automatic feeding system for a biomass gasifier according to any one of claims 1 to 5, characterized in that: include: The raw material detection and screening device includes a humidity sensor, a metal detector, a size screening device and a temporary storage silo, which is used to detect, screen and temporarily store biomass raw materials, and each component works in coordination; The feed amount calculation control unit is composed of a data acquisition module, an intelligent algorithm module and a control execution module. The data acquisition module collects the gasifier operation parameters, the intelligent algorithm module calculates the feed amount according to the operation parameters, and the control execution module controls the operation of the feed device; The feeding uniformity guarantee mechanism is equipped with a spiral feeder or a vibrating feeder and an airflow auxiliary device. The feeder and the airflow auxiliary device ensure the uniform distribution of the biomass raw materials in the gasifier; Raw material pretreatment optimization module, including jaw crusher or hammer crusher and hot air circulation drying system, used to crush and dry biomass raw materials so that the particle size and humidity of raw materials meet the reaction requirements of gasifier; The energy recovery module is composed of a heat exchanger, a preheating pipe and a power generation device. The heat exchanger recovers the heat of the high-temperature flue gas of the gasifier, the preheating pipe transfers the heat to the air or inert gas entering the gasifier, and the power generation device uses the recovered heat to generate electricity and supply it to the system equipment; The emission monitoring and control module is equipped with high-precision gas sensors and particulate matter sensors to monitor the emission concentration of the gasifier. When it exceeds the standard, it will be regulated by adjusting the gasifier operating parameters to ensure that the emission meets environmental protection requirements; The fault detection and early warning module is connected to the key components of the feeding system to monitor its working status in real time. When a fault occurs, it will promptly issue an early warning signal and perform preliminary fault diagnosis.

7. The automatic feeding system for biomass gasifier according to claim 6, characterized in that: The metal detector in the raw material detection and screening device adopts an electromagnetic induction metal detector, whose operating frequency is adjusted between 5 kHz and 100 kHz to detect different types of metal impurities. The detection depth of iron, copper and aluminum is not less than 5 cm.

8. The automatic feeding system for biomass gasifier according to claim 6, characterized in that: The data acquisition module in the feed quantity calculation control unit adopts a high-precision sensor. The data acquisition frequency of the sensor is adjusted between 1 Hz and 10 Hz to obtain the gasifier operating parameters in real time and accurately.

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