Combustion proportion control system

Abstract

The utility model discloses a combustion proportion control system which comprises a combustor, a gas pipe and a combustion-supporting air pipe, the gas pipe and the combustion-supporting air pipe are respectively connected with the combustor, and a first temperature sensor, a first flow meter and a first executing mechanism are arranged in the gas pipe. A second temperature sensor, a second flow meter and a second executing mechanism are arranged in the combustion-supporting air pipe; the controller sends a first signal for adjusting the amount of fuel gas entering the combustor to the first executing mechanism according to the readings of the first temperature sensor and the first flow meter; and the controller sends a second signal for adjusting the amount of air entering the combustor to the second executing mechanism according to the readings of the second temperature sensor and the second flow meter. By arranging the gas pipe and the combustion-supporting air pipe, the first temperature sensor and the second temperature sensor can obtain the temperature of gas and the temperature of air entering the combustor in real time, and the opening degree of the gas pipe and the opening degree of the combustion-supporting air pipe are accurately controlled through the first executing mechanism and the second executing mechanism; and the response speed and the control precision of the combustion proportion control system are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of combustion control, in particular to a combustion ratio control system. Background Art

[0002] The combustion system is connected to the gas and combustion-supporting air monitoring systems through signals, and can collect the flow data of the gas path and the air path in real time, regulate the air volume and gas volume entering the burner, and ensure that the air-fuel ratio is always in the best state. However, in fluid measurement, the volume of the fluid will change with the change of temperature and pressure, thus affecting the reading of the flowmeter. Therefore, in practical applications, the amounts of air and gas input into the burner need to be adjusted in real time according to the changes of temperature and pressure. In order to monitor the changes of temperature and pressure in real time, a temperature sensor needs to be used in cooperation with a volume flowmeter. That is, according to the relationship between the physical properties of the fluid and the temperature, the influence of the temperature change on the fluid volume is calculated, and then the corrected volume flow data is output. The existing combustion ratio control system only adjusts the air volume and gas volume by detecting the temperature and oxygen content of the burner, and cannot ensure that the air-fuel ratio is always in the best state, which affects the response speed and control accuracy of the combustion system. Summary of the Invention

[0003] In order to solve the above problems, the purpose of the utility model is to provide a combustion ratio control system, which can accurately control the air volume and gas volume entering the burner according to the gas temperature and air temperature, and ensure the response speed and control accuracy of the combustion ratio control system.

[0004] The technical solution adopted by the utility model to solve its problems is as follows:

[0005] A combustion ratio control system includes a burner, a gas pipe and a combustion-supporting air pipe which are respectively connected thereto. A first temperature sensor for obtaining the gas temperature in the gas pipe, a first flowmeter for recording the gas flow in the gas pipe, and a first actuator for controlling the opening degree of the gas pipe are arranged in the gas pipe; a second temperature sensor for obtaining the air temperature in the combustion-supporting air pipe, a second flowmeter for recording the air flow in the combustion-supporting air pipe, and a second actuator for controlling the opening degree of the combustion-supporting air pipe are arranged in the combustion-supporting air pipe; the first temperature sensor, the first flowmeter, the first actuator, the second temperature sensor, the second flowmeter and the second temperature sensor are all connected to a controller; the controller sends a first signal for adjusting the gas volume entering the burner to the first actuator according to the readings of the first temperature sensor and the first flowmeter; the controller sends a second signal for adjusting the air volume entering the burner to the second actuator according to the readings of the second temperature sensor and the second flowmeter.

[0006] The above combustion ratio control system has at least the following beneficial effects: By setting the gas pipe and the combustion air pipe, the first temperature sensor and the second temperature sensor can obtain the gas temperature and the air temperature entering the burner in real time, and accurately control the opening degrees of the gas pipe and the combustion air pipe through the first actuator and the second actuator, ensuring that the air-fuel ratio is always in the best state, improving the response speed and control accuracy of the combustion ratio control system; By setting the first flow meter and the second flow meter, it is convenient to accurately count the gas volume and air volume entering the gas pipe and the combustion air pipe, so as to accurately control the ratio of gas and air and improve the control accuracy of the combustion ratio control system.

[0007] Further, there is a first pressure transmitter in the gas pipe for obtaining the magnitude of the gas pressure in the gas pipe, and the first pressure transmitter is connected to the first actuator; A second pressure transmitter for obtaining the magnitude of the air pressure in the combustion air pipe is provided in the combustion air pipe, and the second pressure transmitter is connected to the second actuator. By setting the first pressure transmitter and the second pressure transmitter, the gas pressure and the air pressure entering the burner can be obtained in real time, which is convenient for the first actuator and the second actuator to perform accurate control and improve the control accuracy of the combustion ratio control system.

[0008] Further, a safety cut-off assembly is also provided between the first pressure transmitter and the first actuator, and a safety cut-off valve is provided in the safety cut-off assembly. By setting the safety cut-off assembly, it is convenient for the safety cut-off valve to cut off the gas flow in the gas pipe, improve the protection performance of the gas pipe, and avoid the excessive or too low pressure in the gas pipe from affecting the stability of the gas entering the burner.

[0009] Further, the safety cut-off assembly includes a first pressure gauge for displaying the pressure inside the gas pipe and a low-pressure switch for detecting the pressure inside the gas pipe, and the low-pressure switch is electrically connected to the controller; When the reading of the low-pressure switch is less than a preset low-pressure threshold, the low-pressure switch sends a low-pressure signal to the controller, and the controller sends a closing instruction to the safety cut-off valve according to the low-pressure signal. By setting the first pressure gauge and the low-pressure switch, the first pressure gauge can accurately display the pressure inside the gas pipe; The low-pressure switch can close the gas pipe when the pressure in the gas pipe is too low, avoiding damage to the gas pipe caused by too low pressure and improving the service life of the combustion ratio control system.

[0010] Further, the safety cut-off assembly further includes a high-pressure switch for detecting the pressure inside the gas pipe, and the high-pressure switch is electrically connected to the controller; when the reading of the high-pressure switch is greater than a preset high-pressure threshold, the high-pressure switch sends a high-pressure signal to the controller, and the controller sends a closing instruction to the safety cut-off valve according to the high-pressure signal. By setting the high-pressure switch, the gas pipe is closed when the pressure inside the gas pipe is too high, avoiding damage to the gas pipe caused by excessive pressure and improving the service life of the combustion ratio control system.

[0011] Further, a leak detection switch for detecting the pressure change value inside the gas pipe is also provided in the safety cut-off assembly, and the leak detection switch is electrically connected to the controller; when the reading of the leak detection switch is greater than a preset pressure change threshold, the leak detection switch sends a leak signal to the controller, and the controller sends a closing instruction to the safety cut-off valve according to the leak signal. By setting the leak detection switch, the gas pipe is closed when the gas pressure change inside the gas pipe is too large, avoiding production accidents caused by gas leakage and ensuring the safety of the combustion ratio control system.

[0012] Further, the number of the safety cut-off valves is two, and the two safety cut-off valves are respectively arranged on both sides of the leak detection switch. By setting two safety cut-off valves, it is convenient to quickly close the gas pipe in case of gas leakage, avoiding excessive gas leakage into the environment and affecting the safety of the combustion ratio control system.

[0013] Further, a pressure regulating valve and a second pressure gauge are also provided between the first pressure transmitter and the safety cut-off assembly, and the pressure regulating valve is used to adjust the pressure of the gas inside the gas pipe. By setting the second pressure gauge and the pressure regulating valve, the second pressure gauge is used to display the pressure between the first pressure transmitter and the safety cut-off assembly, and the pressure regulating valve automatically adjusts the gas pressure inside the gas pipe to ensure the stability and safety of the gas pipe.

[0014] Further, a third pressure gauge is also provided between the first actuator and the burner. By setting the third pressure gauge, the gas pressure entering the burner can be obtained in real time, which is convenient for the first actuator to perform precise control and improves the control accuracy of the combustion ratio control system.

[0015] Further, a manual regulating valve is also provided between the first actuator and the third pressure gauge. By setting the manual regulating valve, it is convenient to adjust the pressure inside the gas pipe manually, improving the usability and control accuracy of the combustion ratio control system. At the same time, the manual regulating valve can also adjust the pressure inside the gas pipe when all the electric regulating valves such as the first actuator fail, ensuring the safety of the combustion ratio control system.

[0016] The beneficial effects of the above combustion ratio control system are as follows: By setting the gas pipe and the combustion-supporting air pipe, the first temperature sensor and the second temperature sensor can obtain the gas temperature and the air temperature entering the burner in real time, and accurately control the opening degrees of the gas pipe and the combustion-supporting air pipe through the first actuator and the second actuator, ensuring that the air-fuel ratio is always in the optimal state, improving the response speed and control accuracy of the combustion ratio control system; By setting the first flowmeter and the second flowmeter, it is convenient to accurately count the gas volume and air volume entering the gas pipe and the combustion-supporting air pipe, so as to accurately control the ratio of gas and air, and improve the control accuracy of the combustion ratio control system; By setting the second pressure gauge and the pressure regulating valve, the second pressure gauge is used to display the pressure between the first pressure transmitter and the safety cut-off component, and the pressure regulating valve automatically adjusts the gas pressure in the gas pipe to ensure the stability of the gas pipe; By setting the safety cut-off component, the protection performance of the gas pipe is improved, avoiding excessive or too low pressure in the gas pipe, which affects the stability and safety of the gas entering the burner; By setting the manual regulating valve, it is convenient to adjust the pressure in the gas pipe manually, improving the usability and control accuracy of the combustion ratio control system.

[0017] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and additional aspects and advantages of the present utility model will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0019] Figure 1 is a schematic structural diagram of a combustion ratio control system according to an embodiment of the present utility model;

[0020] Figure 2 is a schematic diagram of the principle of a combustion ratio control system according to an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary only for explaining the present utility model and should not be construed as limiting the present utility model.

[0022] Refer to Figure 1 and Figure 2, an embodiment of the present utility model provides a combustion ratio control system, including a burner 100, a gas pipeline 200 and a combustion air pipeline 300 respectively connected thereto. A first temperature sensor 210 for obtaining the gas temperature in the gas pipeline 200, a first flowmeter 220 for recording the gas flow in the gas pipeline 200, and a first actuator 230 for controlling the opening degree of the gas pipeline 200 are provided in the gas pipeline 200; a second temperature sensor 310 for obtaining the air temperature in the combustion air pipeline 300, a second flowmeter 320 for recording the air flow in the combustion air pipeline 300, and a second actuator 330 for controlling the opening degree of the combustion air pipeline 300 are provided in the combustion air pipeline 300; the first temperature sensor 210, the first flowmeter 220, the first actuator 230, the second temperature sensor 310, the second flowmeter 320 and the second temperature sensor 310 are all connected to a controller 400; the controller 400 sends a first signal for adjusting the gas volume entering the burner 100 to the first actuator 230 according to the readings of the first temperature sensor 210 and the first flowmeter 220; the controller 400 sends a second signal for adjusting the air volume entering the burner 100 to the second actuator 330 according to the readings of the second temperature sensor 310 and the second flowmeter 320.

[0023] By providing the gas pipeline 200 and the combustion air pipeline 300, the first temperature sensor 210 and the second temperature sensor 310 can obtain the gas temperature and the air temperature entering the burner 100 in real time, and accurately control the opening degrees of the gas pipeline 200 and the combustion air pipeline 300 through the first actuator 230 and the second actuator 330, ensuring that the air-fuel ratio is always in the best state, and improving the response speed and control accuracy of the combustion ratio control system; by providing the first flowmeter 220 and the second flowmeter 320, it is convenient to accurately count the gas volume and the air volume entering the gas pipeline 200 and the combustion air pipeline 300, so as to accurately control the ratio of gas and air, and improve the control accuracy of the combustion ratio control system.

[0024] In some embodiments, the controller 400 adopts a Programmable Logic Controller (PLC). In practical applications, a PLC is a digital operation electronic system specifically designed for use in industrial environments. A PLC uses a programmable memory to store instructions for performing operations such as logical operations, sequential control, timing, counting, and arithmetic operations inside it, and controls various types of mechanical equipment or production processes through digital or analog inputs and outputs.

[0025] In another embodiment, there is also a first pressure transmitter 240 in the gas pipeline 200 for obtaining the magnitude of the gas pressure in the gas pipeline 200. The first pressure transmitter 240 is connected to the first actuator 230. A second pressure transmitter 340 for obtaining the magnitude of the air pressure in the combustion air duct 300 is provided in the combustion air duct 300, and the second pressure transmitter 340 is connected to the second actuator 330. By providing the first pressure transmitter 240 and the second pressure transmitter 340, the gas pressure and the air pressure entering the burner can be obtained in real time, facilitating the precise control of the first actuator 230 and the second actuator 330 and improving the control accuracy of the combustion ratio control system.

[0026] In another embodiment, a safety cut-off assembly 260 is further provided between the first pressure transmitter 240 and the first actuator 230; a safety cut-off valve 265 is provided in the safety cut-off assembly 260. By providing the safety cut-off assembly 260, it is convenient for the safety cut-off valve 265 to cut off the gas flow in the gas pipeline 200, improving the protection performance of the gas pipeline 200 and preventing the pressure in the gas pipeline 200 from being too high or too low, which may affect the stability of the gas entering the burner 100.

[0027] In another embodiment, the safety cut-off assembly 260 includes a first pressure gauge 261 for displaying the pressure inside the gas pipeline 200 and a low-pressure switch 262 for detecting the pressure inside the gas pipeline 200. The low-pressure switch 262 is electrically connected to the controller 400; when the reading of the low-pressure switch 262 is less than a preset low-pressure threshold, the low-pressure switch 262 sends a low-pressure signal to the controller 400, and the controller 400 sends a closing instruction to the safety cut-off valve 265 according to the low-pressure signal. By providing the first pressure gauge 261 and the low-pressure switch 262, the first pressure gauge 261 can accurately display the pressure inside the gas pipeline 200; the low-pressure switch 262 can close the gas pipeline 200 when the pressure in the gas pipeline 200 is too low, avoiding damage to the gas pipeline 200 caused by too low pressure and improving the service life of the combustion ratio control system.

[0028] In another embodiment, the safety cut-off assembly 260 further includes a high-pressure switch 263 for detecting the pressure inside the gas pipeline 200. The high-pressure switch 263 is electrically connected to the controller 400; when the reading of the high-pressure switch 263 is greater than a preset high-pressure threshold, the high-pressure switch 263 sends a high-pressure signal to the controller 400, and the controller 400 sends a closing instruction to the safety cut-off valve 265 according to the high-pressure signal. By providing the high-pressure switch 263, the gas pipeline 200 can be closed when the pressure in the gas pipeline 200 is too high, avoiding damage to the gas pipeline 200 caused by too high pressure and improving the service life of the combustion ratio control system.

[0029] In another embodiment, a leak detection switch 264 for detecting the pressure change value inside the gas pipe 200 is further provided in the safety cut-off assembly 260. The leak detection switch 264 is electrically connected to the controller 400. When the reading of the leak detection switch 264 is greater than a preset pressure change threshold, the leak detection switch 264 sends a leakage signal to the controller 400, and the controller 400 sends a closing instruction to the safety cut-off valve 265 according to the leakage signal. By providing the leak detection switch 264, the gas pipe 200 is closed when the gas pressure change in the gas pipe 200 is too large, avoiding production accidents caused by gas leakage and ensuring the safety of the combustion ratio control system.

[0030] In another embodiment, the number of safety cut-off valves 265 is two, and the two safety cut-off valves 265 are respectively arranged on both sides of the leak detection switch 264. By providing two safety cut-off valves 265, it is convenient to quickly close the gas pipe 200 in case of gas leakage in the gas pipe 200, avoiding excessive gas leakage into the environment and affecting the safety of the combustion ratio control system.

[0031] In another embodiment, a pressure regulating valve 250 and a second pressure gauge 270 are further provided between the first pressure transmitter 240 and the safety cut-off assembly 260. The pressure regulating valve 250 is used to adjust the gas pressure in the gas pipe 200. By providing the second pressure gauge 270 and the pressure regulating valve 250, the second pressure gauge 270 is used to display the pressure between the first pressure transmitter 240 and the safety cut-off assembly 260, and the pressure regulating valve 250 automatically adjusts the gas pressure in the gas pipe 200 to ensure the stability and safety of the gas pipe. In practical applications, the pressure regulating valve 250 is a self-acting pressure regulating valve, which is an energy-saving control device that does not require external energy but only relies on the pressure change of the medium itself to automatically adjust the pressure. The pressure regulating valve 250 has comprehensive functions of measurement, execution, and control, and is widely applicable to industrial sectors such as petroleum, chemical industry, metallurgy, and light industry, as well as urban heating and heating systems. Since the pressure regulating valve 250 does not require other external energy sources such as power supply and gas source, and only relies on the energy of the medium itself to drive, it is both energy-saving and environmentally friendly, easy to use, and can be put into automatic operation according to the preset adjustment threshold after installation. Specifically, the pressure regulating valve 250 automatically adjusts the opening degree of the pressure regulating valve 250 according to the preset adjustment threshold to adjust the gas pressure in the gas pipe 200.

[0032] In another embodiment, a third pressure gauge 280 is further provided between the first actuator 230 and the burner 100. By providing the third pressure gauge 280, the gas pressure entering the burner 100 can be obtained in real time, which is convenient for the first actuator 230 to perform precise control and improve the control accuracy of the combustion ratio control system.

[0033] In another embodiment, a manual regulating valve 290 is further provided between the first actuator 230 and the third pressure gauge 280. By providing the manual regulating valve 290, it is convenient to adjust the pressure in the gas pipe 200 manually, improving the convenience and control accuracy of the combustion ratio control system. At the same time, the manual regulating valve 290 can also adjust the pressure in the gas pipe 200 when all the electric regulating valves such as the first actuator 230, the safety cut-off valve 265, and the pressure regulating valve 250 fail, ensuring the safety of the combustion ratio control system.

[0034] In some embodiments, the gas pipe 200 and the combustion air pipe 300 are also provided with an operation interface. By providing an intuitive operation interface, the operator can easily monitor the combustion state of the burner 100, adjust the control parameters of the first actuator 230 and the second actuator 330, and receive the operation parameters and alarm information of each component of the combustion ratio control system. The first actuator 230 and the second actuator 330 are also connected to the Internet of Things through a remote control module, facilitating remote control by the operator and enabling timely diagnosis and maintenance.

[0035] The working principle of the present utility model will be further described below.

[0036] During use, the combustion ratio control system will, based on the air and gas temperature data real-time monitored by the first temperature sensor 210 and the second temperature sensor 310, and in combination with the air flow rate and gas flow rate data monitored by the first flowmeter 220 and the second flowmeter 320, adjust the opening degrees of the first actuator 230 and the second actuator 330 through the controller 400 to precisely control the mixing ratio of the gas and air output by the gas pipe 200 and the combustion air pipe 300, so as to achieve the optimal air-fuel ratio inside the burner 100. Specifically, the first temperature sensor 210 and the second temperature sensor 310 ensure the measurement accuracy of the first flowmeter 220 and the second flowmeter 320. Since in fluid measurement, the volume of the fluid will change with the temperature and pressure, thus affecting the reading of the flowmeter. To compensate for this change, the temperature sensor is used in conjunction with the volumetric flowmeter. The combustion ratio control system calculates the influence of the temperature change on the volumes of the gas and air according to the relationship between the physical properties of the gas and air and the temperature, and then outputs the corrected volumetric flow rate data. When the combustion ratio control system detects a change in the readings of the first temperature sensor 210 and the second temperature sensor 310, the controller 400 will automatically adjust the gas and air intake through the first actuator 230 and the second actuator 330 to maintain the optimal combustion efficiency and temperature control. By setting the second pressure gauge 270 and the pressure regulating valve 250, the second pressure gauge 270 is used to display the pressure between the first pressure transmitter 240 and the safety cut-off assembly 260, and the pressure regulating valve 250 automatically adjusts the gas pressure inside the gas pipe 200 to ensure the stability and safety of the gas pipe 200. At the same time, in order to prevent the pressure inside the gas pipe 200 from being too high or too low, which affects the stability of the gas entering the burner 100, a safety cut-off assembly 260 is set between the pressure regulating valve 250 and the first actuator 230. By setting the first pressure gauge 261 and the low-pressure switch 262, the gas pipe 200 is closed when the pressure inside the gas pipe 200 is too low, to avoid damage to the gas pipe 200 caused by too low pressure and improve the service life of the combustion ratio control system; by setting the leak detection switch 264, the gas pipe 200 is closed when the gas pressure change inside the gas pipe 200 is too large, to avoid production accidents caused by gas leakage and ensure the safety of the combustion ratio control system.

[0037] As can be seen from the above description, in the combustion ratio control system of the present utility model, by providing the gas pipe 200 and the combustion air pipe 300, the first temperature sensor 210 and the second temperature sensor 310 can obtain the gas temperature and the air temperature entering the burner 100 in real time, and accurately control the opening degrees of the gas pipe 200 and the combustion air pipe 300 through the first actuator 230 and the second actuator 330, ensuring that the air-fuel ratio is always in the optimal state, and improving the response speed and control accuracy of the combustion ratio control system; by providing the first flowmeter 220 and the second flowmeter 320, it is convenient to accurately count the gas volume and the air volume entering the gas pipe 200 and the combustion air pipe 300, so as to accurately control the ratio of gas and air and improve the control accuracy of the combustion ratio control system; by providing the second pressure gauge 270 and the pressure regulating valve 250, the second pressure gauge 270 is used to display the pressure between the first pressure transmitter 240 and the safety cut-off assembly 260, and the pressure regulating valve 250 automatically adjusts the gas pressure in the gas pipe 200 to ensure the stability and safety of the gas pipe 200; by providing the safety cut-off assembly 260, the protection performance of the gas pipe 200 is improved, and the influence on the stability of the gas entering the burner 100 caused by too high or too low pressure in the gas pipe 200 is avoided; by providing the manual regulating valve 290, it is convenient to adjust the pressure in the gas pipe 200 manually, improving the usability and control accuracy of the combustion ratio control system.

[0038] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present utility model within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A combustion ratio control system, characterized in that: It includes a burner and a gas pipe and a combustion-supporting air duct respectively connected thereto, wherein the gas pipe is provided with a first temperature sensor for obtaining the gas temperature in the gas pipe, a first flowmeter for recording the gas flow in the gas pipe and a first actuator for controlling the opening of the gas pipe; the combustion-supporting air duct is provided with a second temperature sensor for obtaining the air temperature in the combustion-supporting air duct, a second flowmeter for recording the air flow in the combustion-supporting air duct and a second actuator for controlling the opening of the combustion-supporting air duct; the first temperature sensor, the first flowmeter, the first actuator, the second temperature sensor, the second flowmeter and the second temperature sensor are all connected to a controller; the controller sends a first signal to the first actuator for adjusting the amount of gas entering the burner according to the readings of the first temperature sensor and the first flowmeter; the controller sends a second signal to the second actuator for adjusting the amount of air entering the burner according to the readings of the second temperature sensor and the second flowmeter.

2. A combustion ratio control system according to claim 1, characterized in that: The gas pipe also has a first pressure transmitter for obtaining the magnitude of the gas pressure in the gas pipe, and the first pressure transmitter is connected to the first actuator; the combustion-supporting air duct is provided with a second pressure transmitter for obtaining the magnitude of the air pressure in the combustion-supporting air duct, and the second pressure transmitter is connected to the second actuator.

3. A combustion ratio control system according to claim 2, characterized in that: A safety cut-off assembly is further provided between the first pressure transmitter and the first actuator, and a safety cut-off valve is provided in the safety cut-off assembly.

4. A combustion ratio control system according to claim 3, characterized in that: The safety cut-off assembly includes a first pressure gauge for displaying the pressure inside the gas pipe and a low-pressure switch for detecting the pressure inside the gas pipe, and the low-pressure switch is electrically connected to the controller; when the reading of the low-pressure switch is less than a preset low-pressure threshold, the low-pressure switch sends a low-pressure signal to the controller, and the controller sends a closing instruction to the safety cut-off valve according to the low-pressure signal.

5. A combustion ratio control system according to claim 4, characterized in that: The safety cut-off assembly also includes a high-pressure switch for detecting the pressure inside the gas pipe, and the high-pressure switch is electrically connected to the controller; when the reading of the high-pressure switch is greater than a preset high-pressure threshold, the high-pressure switch sends a high-pressure signal to the controller, and the controller sends a closing instruction to the safety cut-off valve according to the high-pressure signal.

6. A combustion ratio control system according to claim 4, characterized in that: The safety cut-off assembly is also provided with a leak detection switch for detecting the pressure change value inside the gas pipe, and the leak detection switch is electrically connected to the controller; when the reading of the leak detection switch is greater than a preset pressure change threshold, the leak detection switch sends a leakage signal to the controller, and the controller sends a closing instruction to the safety cut-off valve according to the leakage signal.

7. A combustion ratio control system according to claim 6, characterized in that: The number of the safety cut-off valves is two, and the two safety cut-off valves are respectively arranged on both sides of the leakage detection switch.

8. A combustion ratio control system according to claim 3, characterized in that: A pressure regulating valve and a second pressure gauge are also provided between the first pressure transmitter and the safety cut-off assembly, and the pressure regulating valve is used to adjust the pressure of the gas in the gas pipe.

9. A combustion ratio control system according to claim 1, characterized in that: A third pressure gauge is also provided between the first actuator and the burner.

10. A combustion ratio control system according to claim 9, characterized in that: A manual regulating valve is also provided between the first actuator and the third pressure gauge.

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