Electrical control system and control method of gas-fired boiler

Abstract

The invention provides an electrical control system and method for a gas-fired boiler. The electrical control system comprises an upper computer, a burner system, a data processing module, a feedback system and a man-machine interaction interface. The upper computer, the burner system, the feedback system, the man-machine interaction interface and the data processing module are connected. The control strategy can be accurately adjusted in real time according to the operation state and the target parameters of the gas-fired boiler, the control precision of parameters such as temperature and pressure is improved, energy waste is effectively reduced, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical control of gas boilers, and particularly relates to an electrical control system and control method for gas boilers. Background Art

[0002] With the continuous improvement of energy utilization efficiency and environmental protection requirements, gas boilers have been widely used in industrial production and civil heating fields. However, there are some problems in the existing electrical control systems of gas boilers. On the one hand, traditional control methods are not precise enough in monitoring and adjusting boiler operation parameters, resulting in energy waste and poor equipment operation stability. For example, in terms of temperature control, it cannot quickly and accurately adjust the combustion intensity according to the actual heat load demand, and it is easy to cause excessive temperature fluctuations. On the other hand, the safety protection mechanism is not perfect enough, and it cannot give early warnings and handle some potential faults and dangerous situations in a timely and effective manner, there are certain safety hazards. In addition, the degree of system intelligence is relatively low, lacking effective analysis and utilization of operation data, and it is impossible to achieve optimized operation and predictive maintenance of gas boilers. Traditional control methods mostly rely on mechanical or simple electrical control, with problems such as slow response, low precision, and high energy consumption. Therefore, it is of great significance to develop an efficient and precise electrical control method. Summary of the Invention

[0003] The present invention aims to solve the problems that traditional control methods mostly rely on mechanical or simple electrical control, with slow response, low precision, and high energy consumption, so as to provide an electrical control system and control method for gas boilers, improve equipment stability, and ensure the safety and reliability of gas boilers.

[0004] To achieve the above invention purpose, the present invention provides an electrical control system for gas boilers, including a host computer, a burner system, a data processing module, a feedback system, and a man-machine interface; the host computer, the burner system, the feedback system, the man-machine interface, and the data processing module are connected;

[0005] The host computer is used to store the collected operation data, fault information, and control parameters;

[0006] The burner system is used to collect the operation parameters of the burner in real time, send them to the data processing module, and control the burner system according to the control instructions of the data processing module;

[0007] The feedback system is used to collect the operation parameters of the boiler in real time by using a variety of sensors, send them to the data processing module, and after calculation and analysis by the data processing module, send them to the host computer;

[0008] The data processing module is used to receive digital signals and analog signals, analyze, process and store them, and based on the algorithm of model predictive control, combine the mathematical model of the gas boiler and the current operating state to predict the parameter change trend in the future period of time. According to the set target parameters, calculate the optimal control strategy and send control instructions to the burner system;

[0009] The human-machine interaction interface includes a touch screen and an operation panel, which are used to display the operating state of the boiler, set operating parameters, query historical records and fault information.

[0010] Further, the burner system includes a burner module, an actuator, a gas pressure switch, a gas leak detector, and a flame detector; the burner module is connected to the actuator, the gas pressure switch, the gas leak detector, and the flame detector; the actuator is connected to a gas regulating valve, a blower frequency converter, and a burner controller; the burner module sends the information collected by the gas pressure switch, the gas leak detector, and the flame detector to the data processing module, and the data processing module sends control instructions to the burner module according to the received information, and the burner module sends the control instructions to the actuator; the actuator is used to send control instructions to the gas regulating valve, the blower frequency converter, and the burner controller, and when an abnormal situation is detected, trigger protection measures, cut off the gas supply, stop the burner operation, and start the alarm device; the gas regulating valve is used to adjust the gas flow according to the control instructions output by the actuator; the blower frequency converter is used to control the rotation speed of the air blower and adjust the air flow; the burner controller is used to control the ignition, combustion intensity, and power adjustment of the burner.

[0011] Further, the feedback system includes a feedback sensor and a sensor module, and the feedback sensor is connected to the sensor module; the feedback sensor includes a furnace temperature sensor, a steam flow sensor, a furnace differential pressure sensor, a boiler water level sensor, a gas pipeline pressure sensor, an air preheater inlet and outlet differential pressure sensor, a blower frequency feedback sensor, and an electric regulating water valve opening feedback sensor;

[0012] The feedback sensor is used to send the collected signal to the sensor module, and the sensor module is used to convert the physical quantity collected by the feedback sensor into an electrical signal and transmit the signal to the data processing module through a signal transmission line. After being calculated and analyzed by the data processing module, it is sent to the upper computer, and the upper computer is used to display various operating parameters and warning information of the boiler.

[0013] The present invention also provides a control method for an electrical control system of the above gas boiler, including the following steps:

[0014] Data acquisition: The burner system uses gas pressure switches, gas leak detectors, and flame detectors to transmit the collected analog signals through a transmitter to the data processing module; the sensor module is used to convert the physical quantities collected by the feedback sensors into electrical signals and transmit the signals to the data processing module through signal transmission lines;

[0015] Intelligent control decision-making: The data processing module analyzes and processes the operating parameters collected by the gas pressure switch, gas leak detector, and flame detector; adopts an algorithm based on model predictive control, combines the current operating state of the gas boiler, and predicts the parameter change trend in the next period of time; calculates the optimal control strategy according to the set target parameters and sends control instructions to the burner system;

[0016] Combustion control: The burner system dynamically sets the air-fuel ratio according to the control instructions output by the data processing module and precisely controls the combustion process of the gas boiler through the actuator; the actuator is used to send control instructions to the gas regulating valve, blower frequency converter, and burner controller; the gas regulating valve adjusts the gas flow according to the control instructions output by the actuator; the blower frequency converter controls the speed of the air blower and adjusts the air flow; the burner controller controls the ignition, combustion intensity, and power adjustment of the burner;

[0017] Safety protection: When the gas pressure switch, gas leak detector, and flame detector detect abnormal conditions, they trigger protection measures, cut off the gas supply, stop the burner from running, and start the alarm device to send out audible and visual alarm signals to the operator; at the same time, record the fault information in the fault database and upload it to the upper computer for timely fault troubleshooting and handling;

[0018] Data analysis and optimization: The data processing module stores and analyzes a large amount of operating data collected by the feedback sensors, analyzes the relationships and laws between the operating data, and discovers potential energy-saving spaces and equipment fault hazards; according to the analysis results, optimizes and adjusts the operating parameters and control strategies of the gas boiler to achieve energy-saving operation and predictive maintenance of the equipment;

[0019] Remote monitoring and interaction: The operating data of the gas boiler is uploaded to the upper computer in real time through the data processing module; the operator can remotely monitor the operating status of the boiler through a computer terminal device, view real-time data, historical records, and fault information; at the same time, the operator can set and adjust the operating parameters of the boiler through the upper computer and send control instructions to achieve remote control.

[0020] Furthermore, the algorithm of model predictive control in the intelligent control decision-making is specifically as follows: The data processing module analyzes the gas pipeline pressure collected by the feedback system:

[0021] The gas flow rate Qn = (Zn / Zg) × (Pg + Pa) / Pn × (Tn / Tg) × Qg,

[0022] In the formula:

[0023] Qn is the volume flow rate under standard conditions;

[0024] Zn is the compression factor under standard conditions;

[0025] Zg is the compression factor under operating conditions;

[0026] Pg is the gauge pressure; Pa is the local atmospheric pressure;

[0027] Pg + Pa is the absolute pressure under working conditions;

[0028] Pn is the standard atmospheric pressure;

[0029] Tn is the absolute temperature under standard conditions;

[0030] Tg is the absolute temperature of the medium;

[0031] Qg is the uncorrected volume flow rate.

[0032] In the Bernoulli equation, P + 1 / 2ρv 2 + ρgh = constant;

[0033] P: The static pressure of the fluid (unit: Pa);

[0034] ρ: The density of the fluid (unit: kg / m 3 );

[0035] v: The flow velocity (unit: m / s);

[0036] g: The acceleration due to gravity (9.8 m / s 2 );

[0037] h: The height of the fluid relative to the reference point (unit: m);

[0038] According to the Bernoulli effect, when the gas pressure changes, the flow velocity changes, that is, when the gas pressure decreases, the gas flow rate Qn increases. The pressure data processing module analyzes and predicts the parameter change trend in the future for a period of time, preventing the gas pressure from being too low or too high. Combining with the operating conditions, a gas flow rate Qn function is formed according to the flow rate calculation formula, and the extreme point is obtained. The data processing module precisely controls the gas pressure switch.

[0039] Furthermore, the data processing module in the combustion control issues control instructions to the burner system, and scientifically and dynamically sets the air-fuel ratio in combination with the actual operating conditions. Its algorithm logic route: input the parameters of outer loop air volume, central air volume, damper opening, and fan frequency → simulate and calculate the gas consumption → correct the excess coefficient curve to generate the air ratio → calculate the oxygen content in the boiler flue gas based on the excess coefficient → calculate the online oxygen content in the flue gas at the emission port in combination with factors such as temperature, load, and furnace pressure → output reasonable converted values of nitrogen oxides and particulate matter and the carbon dioxide emission value according to the calculation formulas of nitrogen oxides and particulate matter → dynamically set the air-fuel ratio.

[0040] Advantages of the present invention:

[0041] (1) The present invention adopts an advanced model predictive control algorithm, which can adjust the control strategy in real time and accurately according to the operating state and target parameters of the gas boiler, improves the control accuracy of parameters such as temperature and pressure, effectively reduces energy waste, and improves energy utilization efficiency.

[0042] (2) The multi-level safety protection mechanism and perfect fault warning system can timely detect and handle various potential safety hazards and equipment failures, ensure the safe and stable operation of the gas boiler, and reduce the risk of accidents.

[0043] (3) The intelligent data analysis and optimization function realizes the optimized adjustment of the operating parameters of the gas boiler and the predictive maintenance of the equipment through the mining and analysis of a large amount of operating data, prolongs the service life of the equipment, and reduces the maintenance cost.

[0044] (4) The remote monitoring and human-computer interaction functions facilitate the operators to monitor the operating state of the boiler at any time and place, perform remote control and parameter setting, and improve the convenience and efficiency of management and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is the structural diagram of the electrical control system of this gas boiler;

[0046] Figure 2 is the internal structural diagram of the burner system 200;

[0047] Figure 3 is the internal structural diagram of the feedback system 400;

[0048] Wherein: 100, upper computer; 200, burner system; 300, data processing module; 400, feedback system; 500, human-computer interaction interface; 201, burner module; 202, actuator; 401, sensor module. DETAILED DESCRIPTION OF THE INVENTION

[0049] To better understand the purpose, structure, and function of the present invention, the following further describes in detail an electrical control system and a control method for a gas boiler of the present invention with reference to the accompanying drawings.

[0050] Referring to Figure 1 , the electrical control system of the gas boiler of the present invention includes a host computer 100, a burner system 200, a data processing module 300, a feedback system 400, and a human-machine interface 500. The host computer 100, the burner system 200, the feedback system 400, the human-machine interface 500, and the data processing module 300 are connected.

[0051] The burner system 200 collects the operating parameters of the burner in real time, sends them to the data processing module 300, and controls the burner system 200 according to the control instructions of the data processing module 300. The burner system 200 includes a burner module 201, an actuator 202, a gas pressure switch, a gas leak detector, and a flame detector.

[0052] The feedback system 400 uses a variety of sensors to collect the operating parameters of the boiler in real time, sends them to the data processing module 300, and after being calculated and analyzed by the data processing module 300, sends them to the host computer 100. The feedback system 400 includes a feedback sensor and a sensor module 401, and the feedback sensor is connected to the sensor module 401. System communication can use industrial Ethernet communication, and the wiring uses cable connection.

[0053] Host computer 100: Used to store the collected operating data, fault information, control parameters, etc. The storage module uses a large-capacity hard disk or solid-state drive to ensure long-term data storage and fast access.

[0054] Data processing module 300: The core of the entire system, using a high-performance microprocessor or PLC. It receives digital signals and analog signals for analysis, processing, and storage. At the same time, it runs an algorithm based on model predictive control, generates control instructions according to the operating parameters and set targets, and sends the control instructions to the actuator 202 of the burner system 200.

[0055] Human-machine interface 500: Includes a touch screen, an operation panel, etc., providing an intuitive operation interface for operators. Operators can view the operating status of the boiler, set operating parameters, query historical records and fault information, etc. through the human-machine interface.

[0056] The burner module 201 is connected to the actuator 202, gas pressure switch, gas leakage detector, and flame detector. The burner module 201 sends the information collected by the gas pressure switch, gas leakage detector, and flame detector to the data processing module 300. The data processing module 300 sends control instructions to the burner module 201 based on the received information, and the burner module 201 sends the control instructions to the actuator 202.

[0057] The actuator 202 is connected to the gas regulating valve, blower frequency converter, and burner controller. The actuator 202 issues control instructions to the gas regulating valve, blower frequency converter, and burner controller. When an abnormal situation is detected, it triggers protective measures, cuts off the gas supply, stops the burner from running, and activates the alarm device. The gas regulating valve adjusts the gas flow according to the control instructions output by the data processing module 300; the blower frequency converter controls the speed of the air blower and adjusts the air flow; the burner controller controls the ignition, combustion intensity, and power regulation of the burner, and the flame detector is responsible for detecting whether the gas combustion in the boiler furnace is normal.

[0058] The feedback sensors include a furnace temperature sensor, steam flow sensor, furnace differential pressure sensor, boiler water level sensor, gas pipeline pressure sensor, air preheater inlet and outlet air differential pressure sensor, blower frequency feedback sensor, and electric regulating water valve opening feedback sensor. The feedback sensors are used to collect various operating parameters of the gas boiler. The feedback sensors are used to send the collected signals to the sensor module 401. The sensor module 401 is used to convert the physical quantities collected by the feedback sensors into electrical signals and transmit the signals to the data processing module 300 through signal transmission lines. After being calculated and analyzed by the data processing module 300, the signals are sent to the upper computer 100, and the upper computer is used to display various operating parameters and warning information of the boiler.

[0059] Figure 1 It is a system structure diagram. The gas boiler electrical control network connection uses industrial Ethernet communication. Industrial Ethernet technology has the advantages of low price, stable and reliable, high communication rate, rich software and hardware products, wide application, and mature support technology. The data processing module 300 and the upper computer 100 can be connected and communicated through line 11 to store operating data, fault information, control parameters, etc. The data processing module 300 and the burner system 200 can be connected and communicated through line 21. Detect the safety status of the gas and control the working status of actuators such as the fan. The data processing module 300 and the human-machine interface 500 can be connected and communicated through line 51 to display the device current, voltage, and the operating status of the boiler. The data processing module 300 and the feedback system 400 can be connected through cable 41, and the feedback system 400 transmits parameters such as furnace temperature, differential pressure, and steam flow to the data processing module 300.

[0060] Figure 2It is the internal structure diagram of the burner system 200, which mainly consists of a burner module 201, an actuator 202, various sensors, and actuating elements. The gas leakage detector, flame detector, and gas pressure switch transmit electrical signals to the burner module 201 through a transmitter. The burner module 201 communicates with the data processing module 300 through line 21. The burner module 201 transmits signals to the actuator 22 through line 22. The actuator 202 controls the blower frequency converter, burner controller, and gas regulating valve through cables.

[0061] Figure 3 It is the internal structure diagram of the feedback system 400. It mainly includes a furnace temperature sensor, steam flow sensor, furnace differential pressure sensor, boiler water level sensor, gas pipeline pressure sensor, air preheater inlet and outlet air differential pressure sensor, blower frequency feedback sensor, and electric regulating water valve opening feedback sensor. These sensors transmit electrical signals to the sensor module 401 through a transmitter, and the sensor module 401 sends signals to the data processing module 300 through line 41.

[0062] The control method of the electrical control system of the present invention includes the following steps:

[0063] (1) Data acquisition: The burner system 200 uses the gas pressure switch, gas leakage detector, and flame detector to transmit the collected analog signals through a transmitter to the data processing module 300; the sensor module 401 is used to convert the physical quantities collected by the feedback sensors into electrical signals and transmit the signals to the data processing module 300 through signal transmission lines;

[0064] Among them, the furnace temperature sensor uses a high-temperature-resistant thermocouple and is installed at key positions inside the furnace; the steam temperature and pressure sensors are respectively installed on the steam pipeline; the boiler water level sensor uses an electric contact and a double-chamber balancer combined with a pressure sensor to monitor the boiler water level in real time; the gas pipeline pressure sensor and the air preheater inlet and outlet air differential pressure sensors are respectively installed on the gas pipeline and the air pipeline. The collected analog signals are transmitted through a transmitter to the data processing module 300.

[0065] (2) Intelligent control decision-making: The data processing module 300 analyzes and processes the operating parameters collected by the gas pressure switch, gas leakage detector, and flame detector. An algorithm based on model predictive control is adopted, combined with the current operating state of the gas boiler, to predict the parameter change trend in the next period of time. According to the set target parameters (such as steam temperature, pressure, etc.), the optimal control strategy is calculated and control instructions are sent to the burner system 200, including the opening of the gas regulating valve, the speed of the blower, and the power adjustment of the burner. At the same time, considering the dynamic characteristics and interference factors of the system, the control strategy is adjusted and optimized in real time.

[0066] The algorithm of model predictive control is as follows: The data processing module 300 analyzes the gas pipeline pressure collected by the feedback system 400:

[0067] The gas flow rate Qn = (Zn / Zg) × (Pg + Pa) / Pn × (Tn / Tg) × Qg,

[0068] In the formula:

[0069] Qn is the volume flow rate under standard conditions;

[0070] Zn is the compression coefficient under standard conditions;

[0071] Zg is the compression coefficient under working conditions;

[0072] Pg is the gauge pressure; Pa is the local atmospheric pressure;

[0073] Pg + Pa is the absolute pressure under working conditions;

[0074] Pn is the standard atmospheric pressure;

[0075] Tn is the absolute temperature under standard conditions;

[0076] Tg is the absolute temperature of the medium;

[0077] Qg is the uncorrected volume flow rate.

[0078] In the Bernoulli equation, P + 1 / 2ρv 2 + ρgh = constant;

[0079] P: The static pressure of the fluid (unit: Pa);

[0080] ρ: The fluid density (unit: kg / m 3 );

[0081] v: The flow velocity (unit: m / s);

[0082] g: The acceleration due to gravity (9.8 m / s 2 );

[0083] h: The height of the fluid relative to the reference point (unit: m).

[0084] According to the Bernoulli effect, when the gas pressure changes, the flow rate changes. That is, when the gas pressure decreases, the gas flow rate Qn increases. The pressure data processing module 300 analyzes and predicts the parameter change trend in the future period of time, preventing the gas pressure from being too low or too high. Combining with the operating conditions, according to the flow rate calculation formula, a gas flow rate Qn function is formed, and the extreme point is obtained. The data processing module 300 precisely controls the gas pressure switch to match the optimal gas pressure. In the scenario of the medium-pressure gas transmission and distribution pipeline pressure of 50 - 60 Kpa, it is calculated and adjusted to 52 - 55 Kpa to achieve the lowest gas flow rate Qn operation mode.

[0085] (3) Combustion control: The burner system 200 precisely controls the combustion process of the gas boiler according to the control instructions output by the data processing module 300 through the actuator 202. The actuator 202 is used to send control instructions to the gas regulating valve, the blower frequency converter, and the burner controller. The gas regulating valve adjusts the gas flow rate according to the control instructions, and the blower adjusts the rotation speed through the frequency converter to control the air flow rate, thereby achieving the best ratio of gas to air and improving the combustion efficiency. The burner controller controls the ignition, combustion intensity, and power adjustment of the burner to ensure that the boiler can operate stably and efficiently under different loads.

[0086] The data processing module 300 sends control instructions to the burner system 200 and scientifically and dynamically sets the air-fuel ratio in combination with the actual operating conditions. Algorithm logic route: Input the outer ring air volume, central air volume, damper opening, and fan frequency parameters → Simulate and calculate the gas consumption → Modify the excess coefficient curve to generate the air ratio → Calculate the oxygen content in the boiler flue gas based on the excess coefficient → Calculate the on-line oxygen content in the flue gas at the emission port in combination with factors such as temperature, load, and furnace pressure → Output the reasonable conversion values of nitrogen oxides and particulate matter and the carbon dioxide emission value according to the nitrogen oxide and particulate matter calculation formulas → Dynamically set the air-fuel ratio.

[0087] Establish a nitrogen oxide and flue gas oxygen content model curve: Y = A - BX, where Y is nitrogen oxide and X is the flue gas oxygen content. The value range of coefficient A is (110 - 180), and the value range of coefficient B is (9 - 11). Combine the actual operating conditions such as the efficiency of a single furnace to debug and generate the boiler nitrogen oxide curve.

[0088] Nitrogen oxide conversion = 17.5×(115 - 11×flue gas oxygen content) / (21 / excess coefficient);

[0089] Particulate matter conversion value = flue gas oxygen content × 17.5 × 1.07 × 4 × 1.02 / 3.5×(21 - flue gas oxygen content);

[0090] Air consumption = (damper opening / 70)×0.12×1.732×380×0.88×0.73×0.95×360 / (6.8×fan frequency×fan frequency / 2500);

[0091] Fan power = (damper opening / 70) × 0.12 × 1.732 × 380 × 0.88;

[0092] According to the nitrogen oxide conversion value being less than 80 mg / m 3 , and the particulate matter conversion value being less than 5 mg / m 3 , reasonably match the air flow. When working conditions change such as the furnace pressure drops, the furnace temperature rises, and the residence time increases, the calculated value ratio of nitrogen oxides increases. If the parameters are unreasonable, with low pressure and high temperature, it can reach Y = 180 - 9X (there is a risk of nitrogen oxide exceeding the standard). The actuator 202 sends control commands to the gas regulating valve and the blower, and the gas regulating valve adjusts the gas flow according to the control commands. Through simulation debugging of the outer loop air volume, central air volume, damper opening, and fan frequency parameters, minimize the opening degrees of the outer loop air volume and central air volume switching valves at each load level to achieve the optimal solution for the ecological and precise operation of the gas boiler.

[0093] (4) Safety protection: When the gas pressure switch, gas leak detector, and flame detector detect abnormal conditions, corresponding protection measures are immediately triggered. First, cut off the gas supply, close the gas regulating valve, stop the operation of the blower, stop the operation of the burner, and start the alarm device to send an audible and visual alarm signal to the operator. At the same time, record the fault information in the fault database and upload it to the upper computer 100 for timely fault troubleshooting and handling. When the gas pressure decreases and the gas flow Qn increases, the pressure data processing module 300 analyzes and predicts the parameter change trend in the next period of time. When the gas pressure is too low or too high, trigger the alarm setting value of the gas pressure switch valve and start the safety interlock protection according to the threshold.

[0094] (5) Data analysis and optimization: The data processing module 300 stores and analyzes a large amount of operation data collected by the feedback sensors, analyzes the relationships and rules among the operation data, and mines potential energy-saving spaces and equipment fault hidden dangers; according to the analysis results, optimizes and adjusts the operation parameters and control strategies of the gas boiler to achieve energy-saving operation and predictive maintenance of the equipment. For example, by analyzing the relationship between the gas flow and the steam output, optimize the control parameters of the gas regulating valve to improve the energy utilization efficiency; by monitoring and analyzing the equipment operation state parameters, predict equipment failures in advance, arrange maintenance plans, and reduce equipment downtime and maintenance costs. The data processing module 300 performs big data analysis on a large amount of operation data collected by the feedback sensors, sends control commands, and the actuator 202 precisely fits the air-fuel ratio curve of the gas boiler and sets the flue gas oxygen content in stages. When the boiler load is ≥ 31 t / h, the flue gas oxygen content is 4%; when 24 t / h ≤ boiler load < 31 t / h, the flue gas oxygen content is 3.5%; when the boiler load < 24 t / h, the flue gas oxygen content is 3% to achieve the optimized operation of the boiler equipment.

[0095] By analyzing the relationship between gas flow and steam output, optimize the control parameters of the gas regulating valve to improve energy utilization efficiency. Construct a relationship model between outdoor temperature and the pressure of the steam distribution cylinder, and draw a curve showing the impact of temperature changes on the calculated steam pressure delivered by the boiler. The steam output and the pressure delivered by the steam distribution cylinder take into account factors such as steam density changes, heat loss factors, steam demand changes, and boiler operation parameter adjustment factors. Temperature changes will affect the calculation of the steam pressure delivered by the boiler. In a low-temperature environment, increase the boiler outlet pressure to compensate for greater resistance losses and heat dissipation; in a high-temperature environment, appropriately reduce the boiler outlet pressure to save energy consumption.

[0096] In this invention, the data processing module 300 takes into account factors such as thermal parameters, outdoor temperature, the pressure of the steam distribution cylinder, steam enthalpy value, production process changes, sunny or cloudy days during the day, etc. According to the minimum pressure requirement at the user end, plus pipeline pressure loss, plus factors such as dynamic ambient temperature, calculate the minimum pressure of the steam distribution cylinder for delivery. The data processing module 300 combines and analyzes the operation data pattern, outputs a control instruction to the burner system 200, and the actuator 202 outputs the minimum gas volume to the gas regulating valve.

[0097] The outdoor ambient temperature is (-4°C to -6°C), and the pressure of the steam distribution cylinder is 0.18 MPa;

[0098] The outdoor ambient temperature is (-6°C to -9°C), and the pressure of the steam distribution cylinder is 0.22 MPa;

[0099] The outdoor ambient temperature is (-9°C to -11°C), and the pressure of the steam distribution cylinder is 0.23 MPa;

[0100] The outdoor ambient temperature is (-11°C to -14°C), and the pressure of the steam distribution cylinder is 0.25 MPa;

[0101] The outdoor ambient temperature is (-14°C to -16°C), and the pressure of the steam distribution cylinder is 0.28 MPa;

[0102] The outdoor ambient temperature is (-16°C to -19°C), and the pressure of the steam distribution cylinder is 0.33 MPa;

[0103] The outdoor ambient temperature is (-19°C to -21°C), and the pressure of the steam distribution cylinder is 0.38 MPa;

[0104] The outdoor ambient temperature is (-21°C to -24°C), and the pressure of the steam distribution cylinder is 0.4 MPa;

[0105] The outdoor ambient temperature is (-24°C to -26°C), and the pressure of the steam distribution cylinder is 0.45 MPa;

[0106] The outdoor ambient temperature is (-26°C to -29°C), and the pressure of the steam distribution cylinder is 0.49 MPa;

[0107] The outdoor ambient temperature is (-29°C to -31°C), and the pressure of the manifold is 0.54 MPa;

[0108] Combined with the actual pipeline network operating conditions and temperature changes, the burner system 200 precisely controls the combustion process of the gas boiler according to the control instructions output by the data processing module 300. The gas regulating valve of the actuator 202 in the combustion control system 200 is adjusted smaller, the manual value of the load regulation is lowered, and the natural gas consumption is reduced.

[0109] Optimize and adjust the operating parameters and control strategies of the gas boiler to achieve predictive maintenance of the equipment. Flue gas oxygen content modeling analysis: Taking 1 Nm 3 of CH4 fuel as the calculation basis, the air volume is 15.5 m 3 , the air leakage of the air preheater is about 0.5 m 3 (3% air leakage rate), and the air volume entering the furnace for combustion is 15 m 3 , among which the oxygen content is 3 m 3 , and the remaining flue gas oxygen after complete combustion is 1 m 3 , and the oxygen content of the flue gas before entering the condenser of the air preheater at the tail of the flue gas is 1 + 0.5×20% = 1.1 m 3 ; The online monitored proportion of flue gas oxygen content is 1.1 / 16.5 = 6.7%; The proportion of flue gas oxygen content before entering the economizer is 1 / 16 = 6.2%. Select a certain scenario during operation, that is, the gas volume is 2000 Nm 3 / h, and the air is 30000 m 3 / h. The theoretically calculated air leakage per second is about 32000 / 60 / 60×3% = 0.25 m 3 ; The actual flue gas flow rate per second in the tail flue is 3.14×0.6 m×0.6 m×7.5 m / s×3%×1 s = 0.25 m 3 . The oxygen content of the tail flue gas increases, and the flue gas temperature before the air preheater enters the condenser decreases by about 5 degrees Celsius. The actual air leakage rate is 3%. Therefore, the data processing module 300 guides the scientific maintenance of the air preheater through data analysis, reduces the heat loss of the flue gas before the air preheater enters the condenser, and improves the efficiency.

[0110] (6) Remote monitoring and interaction: The operation data of the gas boiler is uploaded to the host computer 100 in real time through the data processing module 300. Operators can remotely monitor the operation status of the boiler through computer terminal devices, view real-time data, historical records, and fault information. At the same time, operators can set and adjust the operation parameters of the boiler through the host computer 100, send control commands, and achieve remote control. In addition, the system also has a human-computer interaction interface, and operators can operate and set the boiler locally through the touch screen, which is convenient for on-site management and maintenance. The data processing module 300 uploads data such as the water consumption per ton of steam of the gas boiler to the host computer 100 in real time. Through dynamic monitoring, combined with the chloride ion value, conductivity, etc., control commands are sent to reduce heat energy loss. In the water treatment link, the backwashing time is increased (10 - 15 minutes), the regeneration time is reduced (45 - 65 minutes), and the normal flushing time is reduced (10 - 20 minutes); the operation status of the boiler is remotely monitored through computer terminal devices, and control commands are sent according to the fluctuation of the boiler water level to optimize the PID setting of the boiler water level, P (gain 0.5 - 2), I (integration time 40 - 100 seconds), D (differential time 0 - 2 seconds).

Claims

1. An electrical control system for a gas boiler, characterized in that: It includes a host computer (100), a burner system (200), a data processing module (300), a feedback system (400), and a human-machine interface (500); the host computer (100), the burner system (200), the feedback system (400), the human-machine interface (500), and the data processing module (300) are connected; The host computer (100) is used to store the collected operation data, fault information, and control parameters; The burner system (200) is used to collect the operation parameters of the burner in real time, send them to the data processing module (300), and control the burner system (200) according to the control instructions of the data processing module (300); The feedback system (400) is used to collect the operation parameters of the boiler in real time by using a variety of sensors, send them to the data processing module (300), and after being calculated and analyzed by the data processing module (300), send them to the host computer (100); The data processing module (300) is used to receive digital signals and analog signals for analysis, processing, and storage, and based on the algorithm of model predictive control, combined with the current operation state of the gas boiler, predict the parameter change trend in the next period of time, calculate the optimal control strategy according to the set target parameters, and send control instructions to the burner system (200); The human-machine interface (500) includes a touch screen and an operation panel, and is used to display the operation state of the boiler, set operation parameters, query historical records, and fault information.

2. An electric control system for a gas boiler according to claim 1, characterized in that: The burner system (200) includes a burner module (201), an actuator (202), a gas pressure switch, a gas leakage detector, and a flame detector; the burner module (201) is connected to the actuator (202), the gas pressure switch, the gas leakage detector, and the flame detector; the actuator (202) is connected to a gas regulating valve, a blower frequency converter, and a burner controller; the burner module (201) sends the information collected by the gas pressure switch, the gas leakage detector, and the flame detector to the data processing module (300), and the data processing module (300) sends control instructions to the burner module (201) according to the received information, and the burner module (201) sends the control instructions to the actuator (202); the actuator (202) is used to send control instructions to the gas regulating valve, the blower frequency converter, and the burner controller, and when an abnormal situation is detected, trigger a protection measure, cut off the gas supply, stop the burner operation, and start an alarm device; the gas regulating valve is used to adjust the gas flow according to the control instructions output by the actuator (202); the blower frequency converter is used to control the rotation speed of the air blower and adjust the air flow; the burner controller is used to control the ignition, combustion intensity, and power adjustment of the burner.

3. The electrical control system of a gas boiler according to claim 2, characterized in that: The feedback system (400) includes a feedback sensor and a sensor module (401), and the feedback sensor is connected to the sensor module (401); the feedback sensors include a furnace temperature sensor, a steam flow sensor, a furnace differential pressure sensor, a boiler water level sensor, a gas pipeline pressure sensor, an air preheater inlet and outlet differential pressure sensor, a blower frequency feedback sensor, and an electric regulating water valve opening feedback sensor; The feedback sensor is used to send the collected signals to the sensor module (401). The sensor module (401) is used to convert the physical quantities collected by the feedback sensor into electrical signals and transmit the signals to the data processing module (300) through signal transmission lines. After being calculated and analyzed by the data processing module (300), the signals are sent to the host computer (100), and the host computer is used to display various operation parameters and warning information of the boiler.

4. A control method for an electrical control system of a gas boiler according to claim 3, characterized in that, It includes the following steps: Data acquisition: The burner system (200) transmits the collected analog signals through a transmitter by using a gas pressure switch, a gas leak detector, and a flame detector, and transmits them to the data processing module (300); the sensor module (401) is used to convert the physical quantities collected by the feedback sensor into electrical signals and transmit the signals to the data processing module (300) through signal transmission lines; Intelligent control decision-making: The data processing module (300) analyzes and processes the operation parameters collected by the gas pressure switch, the gas leak detector, and the flame detector; adopts an algorithm based on model predictive control, combines the current operation state of the gas boiler, and predicts the parameter change trend in a future period of time; calculates the optimal control strategy according to the set target parameters and issues control instructions to the burner system (200); Combustion control: The burner system (200) dynamically sets the air-fuel ratio according to the control instructions output by the data processing module (300), and precisely controls the combustion process of the gas boiler through the actuator (202); the actuator (202) is used to issue control instructions to the gas regulating valve, the blower frequency converter, and the burner controller; the gas regulating valve adjusts the gas flow according to the control instructions output by the actuator (202); the blower frequency converter controls the rotation speed of the air blower and adjusts the air flow; the burner controller controls the ignition, combustion intensity, and power adjustment of the burner; Safety protection: When the gas pressure switch, the gas leak detector, and the flame detector detect abnormal conditions, they trigger protection measures, cut off the gas supply, stop the operation of the burner, and start the alarm device to send an audible and visual alarm signal to the operator; at the same time, record the fault information in the fault database and upload it to the host computer (100) for timely fault troubleshooting and handling; Data analysis and optimization: The data processing module (300) stores and analyzes a large amount of operation data collected by the feedback sensor, analyzes the relationships and laws between the operation data, and mines potential energy-saving spaces and equipment fault hidden dangers; according to the analysis results, optimally adjusts the operation parameters and control strategies of the gas boiler to achieve energy-saving operation and predictive maintenance of the equipment; Remote monitoring and interaction: The operation data of the gas boiler are real-time uploaded to the host computer (100) through the data processing module (300); the operator can remotely monitor the operation state of the boiler through a computer terminal device, view real-time data, historical records, and fault information; at the same time, the operator can set and adjust the operation parameters of the boiler through the host computer (100) and send control instructions to achieve remote control.

5. The electrical control method of a gas boiler according to claim 4, characterized in that: The algorithm of model predictive control in the intelligent control decision-making is as follows: The data processing module (300) analyzes the gas pipeline pressure collected by the feedback system (400): Gas flow rate Qn = (Zn / Zg) × (Pg + Pa) / Pn × (Tn / Tg) × Qg, In the formula: Qn is the volume flow rate under standard conditions; Zn is the compression factor under standard conditions; Zg is the compression factor under operating conditions; Pg is the gauge pressure; Pa is the local atmospheric pressure; Pg + Pa is the absolute pressure under operating conditions; Pn is the standard atmospheric pressure; Tn is the absolute temperature under standard conditions; Tg is the absolute temperature of the medium; Qg is the uncorrected volume flow rate. In the Bernoulli equation, P + 1 / 2ρv 2 + ρgh = constant; P: The static pressure of the fluid (unit: Pa); ρ: fluid density (unit: kg / m 3 ); v: Flow velocity (unit: m / s); g: acceleration due to gravity (9.8 m / s 2 ); h: The height of the fluid relative to the reference point (unit: m); According to the Bernoulli effect, when the gas pressure changes, the flow velocity changes, that is, when the gas pressure decreases, the gas flow rate Qn increases. The pressure data processing module (300) analyzes and predicts the parameter change trend in the next period of time, preventing the gas pressure from being too low or too high. Combining the operating conditions, a gas flow rate Qn function is formed according to the flow rate calculation formula, and the extreme point is obtained. The data processing module (300) precisely controls the gas pressure switch to match the optimal gas pressure. In the scenario of the medium-pressure gas transmission and distribution pipeline pressure of 50 - 60 Kpa, it is calculated and adjusted to 52 - 55 Kpa to achieve the lowest gas flow rate Qn operation mode.

6. The electrical control method of a gas boiler according to claim 4, characterized in that: In the combustion control, the data processing module (300) issues control instructions to the burner system (200), and scientifically and dynamically sets the air-fuel ratio in combination with the actual operating conditions. Its algorithm logic route: Input the outer ring air volume, central air volume, damper opening, and fan frequency parameters → Simulate and calculate the gas consumption → Modify the excess coefficient curve to generate the air ratio → Calculate the oxygen content in the boiler flue gas according to the excess coefficient → Calculate the online oxygen content in the flue gas at the emission port in combination with factors such as temperature, load, and furnace pressure → Output reasonable nitrogen oxide and particulate matter conversion values and carbon dioxide emission values according to the nitrogen oxide and particulate matter calculation formulas → Dynamically set the air-fuel ratio.

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