An air-fuel ratio adjusting method, device, gas equipment and medium

Abstract

This application discloses an air-fuel ratio adjustment method, device, gas equipment, and medium, belonging to the field of gas stove technology. The method includes: acquiring relevant parameters of the target gas equipment; the relevant parameters include first correlation information and the actual air resistance of the blower duct of the target gas equipment; the first correlation information is used to indicate the correspondence between speed control commands and air volume under multiple air resistance conditions; calculating the required air volume based on the current gas flow rate of the target gas equipment; and determining the speed control command of the centrifugal fan in the target gas equipment based on the required air volume, the actual air resistance of the blower duct, and the first correlation information, so as to adjust the air-fuel ratio of the target gas equipment. This solution enables the controller to determine the corresponding speed control command based on actual operating conditions, thereby ensuring that the centrifugal fan outputs an air flow rate that matches the required air volume, improving the air-fuel ratio adjustment effect and combustion stability.

Description

Technical Field

[0001] This application relates to the field of gas stove technology, and in particular to a method, device, gas equipment and medium for adjusting the air-fuel ratio. Background Technology

[0002] With the widespread application of premixed combustion technology in commercial gas appliances, air-fuel ratio control has a significant impact on combustion efficiency, combustion stability, and pollutant emission levels. Therefore, during the operation of gas appliances, it is usually necessary to adjust the air supply according to changes in gas flow to maintain a suitable air-fuel ratio.

[0003] Currently, in the design of premixed burners for commercial gas stoves, designers often use an airflow regulation method of "AC constant-speed fan + air valve throttling." The determination of the gas nozzle orifice diameter usually relies on empirical values, and the air-fuel ratio is adjusted through mechanical linkage between the gas valve and the air valve. While this solution can meet basic combustion requirements, its air supply mainly relies on manual or mechanical adjustment, resulting in limited adjustment precision.

[0004] Therefore, there is an urgent need for an air-fuel ratio adjustment method to improve the air-fuel ratio adjustment accuracy during the operation of gas equipment. Summary of the Invention

[0005] Based on this, this application provides an air-fuel ratio adjustment method, device, gas equipment, and medium, which can improve the air-fuel ratio adjustment accuracy during the operation of gas equipment.

[0006] On one hand, this application provides an air-fuel ratio adjustment method, which is applied to a target gas-fired equipment; the impeller aerodynamic load of the centrifugal fan in the target gas-fired equipment is positively correlated with the operating air volume; and the steady-state speed of the speed-regulating motor corresponding to the centrifugal fan is negatively correlated with the fan load; the method includes: Obtain relevant parameters of the target gas equipment; the relevant parameters include first association information and the actual air resistance of the blower duct of the target gas equipment; the first association information is used to indicate the correspondence between speed control command and air volume under multiple air resistance conditions; Calculate the required air volume based on the current gas flow rate of the target gas equipment; Based on the required air volume, the actual air resistance of the blower duct, and the first associated information, the speed control command of the centrifugal fan in the target gas equipment is determined to adjust the air-fuel ratio of the target gas equipment.

[0007] In another aspect, an air-fuel ratio regulating device is provided; the device includes: The parameter acquisition module is used to acquire relevant parameters of the target gas equipment; the relevant parameters include first association information and the actual air resistance of the blower pipe of the target gas equipment; the first association information is used to indicate the correspondence between speed control command and air volume under multiple air resistance conditions. The demand calculation module is used to calculate the required air volume based on the current gas flow rate of the target gas equipment. The speed control module is used to determine the speed control command of the centrifugal fan in the target gas equipment based on the required air volume, the actual air resistance of the blower duct, and the first associated information, so as to adjust the air-fuel ratio of the target gas equipment.

[0008] On another front, a gas device is provided, which further includes a memory and a processor. The memory and the processor are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the aforementioned air-fuel ratio adjustment method.

[0009] In another aspect, a computer-readable storage medium is provided, on which computer instructions are stored, the computer instructions being used to cause a computer to perform the above-described air-fuel ratio adjustment method.

[0010] Compared with the prior art, the technical solution provided in this application has the following advantages: After obtaining the current gas flow rate of the target gas equipment, the corresponding air demand is first calculated based on the current gas flow rate. Then, combining the actual air resistance of the target gas equipment's blower duct and the pre-established first correlation information, the corresponding speed control command is determined, and the centrifugal fan is controlled to operate according to the speed control command, thereby adjusting the air supply of the target gas equipment and achieving air-fuel ratio regulation. In the above scheme, by establishing the correlation between air volume, speed control command, and air resistance, the speed control command of the centrifugal fan is not only related to the air demand corresponding to the gas flow rate, but can also be determined in combination with the actual air resistance of the blower duct. Therefore, the controller can determine the corresponding speed control command according to the actual operating conditions, thereby enabling the centrifugal fan to output an air flow rate that matches the air demand, improving the air-fuel ratio regulation effect and combustion stability. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a commercial gas stove functional system according to an embodiment of this application; Figure 2 A flowchart of an air-fuel ratio adjustment method according to an embodiment of this application is shown; Figure 3 This application provides an overall flowchart illustrating the design of a target gas-fired device and an air-fuel ratio adjustment method according to an embodiment of the present application. Figure 4 A structural block diagram of an air-fuel ratio regulating device according to an embodiment of this application is shown; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an optional embodiment of this application. Detailed Implementation

[0012] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0013] Currently, in the design of premixed burners for commercial gas stoves, designers mostly use an air volume adjustment method of "AC constant speed fan + air valve throttling". The determination of the gas nozzle orifice diameter relies heavily on experience values, and the adjustment of the air-fuel ratio is achieved through the mechanical linkage between the gas manual valve and the manual air valve, which can only achieve a rough matching and adjustment of the air-fuel ratio.

[0014] For ease of description, this application uses a commercial gas stove as the target gas device involved in this application. The target gas device can also be a related gas device with similar functions to the commercial gas stove. This application does not specifically limit the type of target gas device.

[0015] First, before introducing the technical solutions involved in this application, it is necessary to briefly explain the structure of the gas equipment involved in this application (taking a commercial gas stove system as an example). Figure 1 This is a schematic diagram of a commercial gas stove functional system according to an embodiment of this application.

[0016] like Figure 1 As shown, this commercial gas stove system mainly includes an air supply system and a gas supply system. The air supply system includes a forward centrifugal fan, a soft-characteristic speed-regulating fan motor connected to the forward (impeller) centrifugal fan, and sequentially connected components such as a pilot flame fan (optional), a pilot flame blower duct, a main flame blower duct, a premixing chamber, a furnace chamber, and a furnace ring. The gas supply system includes a main gas pipe, a shut-off valve and a pressure regulating valve installed on the main gas pipe, and gas branch lines. Each gas branch line includes a pilot flame burner duct, a regulating valve, an electronic controller, a main flame burner duct, a gas nozzle, and a premixing chamber.

[0017] In other words, in the embodiments of this application, the centrifugal fan in the gas equipment can be a forward impeller centrifugal fan, in which case the impeller aerodynamic load of the centrifugal fan is positively correlated with the operating air volume; and the speed-regulating motor corresponding to the centrifugal fan can be a soft-characteristic speed-regulating fan motor, in which case the steady-state speed of the speed-regulating motor is negatively correlated with the fan load.

[0018] During air supply, a forward centrifugal fan, driven by a variable-speed fan motor, generates the air required for combustion. This air is then delivered to the premixing chamber via the pilot flame duct or the main flame duct. During gas supply, the gas is transported through the main gas pipe and sequentially passes through a shut-off valve and a pressure regulating valve before entering the gas branch circuit. The gas can be supplied to the pilot flame burner via the pilot flame combustion pipe, or its flow rate can be regulated by a regulating valve before entering the premixing chamber via the main flame combustion pipe and the gas nozzle.

[0019] Within the premixing chamber, air from the air supply system is mixed with fuel gas from the gas supply system to form a premixed gas. This premixed gas then enters the furnace and is burned at the burner ring to provide heat to external cooking appliances. An electronic controller is used to regulate the regulating valves and fan motor, thereby adjusting the gas and air flow rates.

[0020] It should be noted that, Figure 1 The commercial gas stove system shown is only an exemplary structure of this application embodiment. The air-fuel ratio adjustment method in this application embodiment is also applicable to other gas equipment that adopts a similar premixed combustion structure, such as commercial gas furnaces, gas water heaters and gas boilers, etc., and this application does not limit it.

[0021] To address the aforementioned problems, this application provides an air-fuel ratio adjustment method applicable to target gas-fired equipment. The aerodynamic load of the centrifugal fan impeller in the target gas-fired equipment is positively correlated with the operating air volume; and the steady-state speed of the speed-regulating motor corresponding to the centrifugal fan is negatively correlated with the fan load, for example... Figure 1 The commercial gas stove system shown.

[0022] Figure 2 A flowchart of an air-fuel ratio adjustment method according to an embodiment of this application is shown, as follows: Figure 2 As shown, the air-fuel ratio adjustment method provided in this application includes the following steps: Step 201: Obtain relevant parameters of the target gas equipment; the relevant parameters include first association information and the actual air resistance of the blower pipe of the target gas equipment; the first association information is used to indicate the correspondence between speed control command and air volume under multiple air resistance conditions.

[0023] In the embodiments of this application, the target gas appliance can be a commercial gas stove, gas furnace, gas water heater, gas boiler, or other gas appliances that employ premixed combustion. This application does not specifically limit this.

[0024] The first correlation information can be obtained through pre-calibration and is used to characterize the operating characteristics of the centrifugal fan under different air resistance conditions. For example, the speed control command of the centrifugal fan is adjusted under multiple air resistance conditions, and the corresponding output air volume is recorded, thereby establishing the correspondence between the speed control command, air resistance, and air volume.

[0025] The first association information can be stored using a lookup table, mapping relationship, fitting function, fitting curve, parametric model, or other data structure that can represent the above correspondence. In this embodiment, the first association information will be illustrated by way of a fitting curve.

[0026] Furthermore, the actual air resistance of the blower duct is used to characterize the resistance encountered by air during its flow within the target gasification equipment. This actual air resistance can be obtained through pre-measurement or determined based on the equipment's operating conditions.

[0027] In one alternative implementation, before the target gas equipment is installed, differential pressure sensors can be installed at both ends of the blower duct of the target gas equipment; based on the differential pressure ΔP at both ends of the blower duct and the blower volume Q, the actual air resistance R of the blower duct is calculated according to R=ΔP / Q².

[0028] Step 202: Calculate the required air volume based on the current gas flow rate of the target gas equipment.

[0029] In this embodiment, during the operation of the target gas equipment, the gas flow rate may change due to user-set heat output, load variations, or adjustments to the control strategy. Since the gas-air mixing ratio affects the combustion state, it is necessary to determine the corresponding air demand based on the current gas flow rate.

[0030] Specifically, the required air volume can be calculated based on a preset air-fuel ratio and the current gas flow rate. This preset air-fuel ratio can be pre-set based on the combustion characteristics of the target gas equipment, the type of gas, and its operating conditions. By correlating the current gas flow rate with the preset air-fuel ratio, the required air volume matching the current gas flow rate can be obtained.

[0031] Step 203: Based on the required air volume, the actual air resistance of the blower duct, and the first associated information, determine the speed control command of the centrifugal fan in the target gas equipment to adjust the air-fuel ratio of the target gas equipment.

[0032] In this embodiment of the application, since the actual output air volume of the centrifugal fan is not only related to the speed control command, but also affected by the air resistance of the blower duct, determining the speed control command based solely on the required air volume may result in a deviation between the actual output air volume and the required air volume.

[0033] Therefore, in this embodiment, the required air volume and the actual air resistance of the blower duct are used as input parameters, and the corresponding speed control command is determined in conjunction with the first associated information. Specifically, the speed control command corresponding to the required air volume and the actual air resistance can be found in the first associated information.

[0034] After receiving the speed control command, it can be sent to the corresponding speed-regulating motor of the centrifugal fan to control the operation of the centrifugal fan. Since the determined speed control command takes into account both the required air volume and the actual air resistance of the blower duct, the centrifugal fan can output an airflow that matches the required air volume, thereby maintaining the expected matching relationship between the air supply and the gas supply and achieving the adjustment of the air-fuel ratio of the target gas equipment.

[0035] In summary, after obtaining the current gas flow rate of the target gas equipment, the corresponding air demand is first calculated based on the current gas flow rate. Then, combining the actual air resistance of the target gas equipment's blower duct and the pre-established first correlation information, the corresponding speed control command is determined, and the centrifugal fan is controlled to operate according to this speed control command, thereby adjusting the air supply of the target gas equipment and achieving air-fuel ratio regulation. In the above scheme, by establishing the correlation between air volume, speed control command, and air resistance, the speed control command of the centrifugal fan is not only related to the air demand corresponding to the gas flow rate but can also be determined in conjunction with the actual air resistance of the blower duct. Therefore, the controller can determine the corresponding speed control command according to the actual operating conditions, thereby enabling the centrifugal fan to output an air flow rate that matches the air demand, improving the air-fuel ratio regulation effect and combustion stability.

[0036] Figure 3 This diagram illustrates the overall flowchart of the design of a target gas-fired device and the air-fuel ratio adjustment method according to an embodiment of this application. Figure 2 The illustrated embodiment primarily addresses the different air-fuel ratio adjustments during the operation of gas equipment. This embodiment further links the initial design process of the target gas equipment with the air-fuel ratio adjustment process during operation, ensuring that equipment selection, nozzle matching, and operational control are all based on unified fan characteristics, thereby improving the overall matching effect and air-fuel ratio adjustment effect of the target gas equipment. Figure 3 As shown, the method is as follows: Step 301: Obtain multiple candidate wind turbines. These candidate wind turbines have different performance parameters.

[0037] In this embodiment, the candidate fans can be multiple centrifugal fans of different models, and these candidate fans can have different performance parameters such as impeller structure, motor power, rated speed, and rated air volume. In other words, during the design process of the target combustion equipment, multiple candidate fans can be obtained in advance, providing a basis for subsequent fan selection.

[0038] Step 302: Connect each candidate fan to the wind resistance calibration device and set the candidate fan to the maximum speed control command. Obtain the second correlation information corresponding to each candidate fan by measuring the air volume and the rotation speed of the candidate fan.

[0039] In this embodiment, the wind resistance calibration device is used to simulate different pipeline resistance environments. For each candidate fan, the candidate fan can be operated at maximum speed under multiple wind resistance conditions, and the corresponding output air volume and motor speed can be measured.

[0040] In this embodiment, the aerodynamic load on the centrifugal fan impeller corresponds to the operating air volume (the larger the operating air volume, the larger the aerodynamic load on the impeller; in scenarios such as air congestion or high pipeline resistance, the smaller the air volume, the smaller the aerodynamic load on the impeller). The steady-state speed of the speed-regulating motor also corresponds to the fan load (when the load decreases, the steady-state speed automatically decreases). Therefore, by setting the candidate fan to the maximum speed regulation command, that is, the motor's rated maximum speed, and gradually changing the pipeline resistance and correspondingly collecting the motor's steady-state speed, the resistance level-air volume-speed characteristic curve can be calibrated and plotted to form the second correlation information.

[0041] Step 303: Based on the second association information of each candidate fan, determine the maximum air volume of each candidate fan under the actual air resistance of the blower duct of the target gas equipment.

[0042] When a candidate fan is connected to the actual blower duct, i.e., the wind resistance setting is determined, the controller collects the real-time speed of the speed-regulating motor under the rated maximum speed condition, i.e., when the speed regulation command is at its maximum value, and retrieves the preset air volume-speed characteristic curve (i.e., the second correlation information) to determine the maximum air volume of the fan under the actual wind resistance of the duct.

[0043] Step 304: Determine the centrifugal fan from the candidate fans based on the maximum air volume of each candidate fan under the actual air resistance of the blower duct of the target gas equipment and the air volume required under the rated heat load of the target gas equipment.

[0044] In this embodiment of the application, the maximum air volume can be compared with the blower volume required under the rated heat load, which can be used as the basis for selecting the centrifugal fan model.

[0045] For example, the measured maximum air volume of the centrifugal fan should be slightly higher than the air volume required by the rated heat load, such as 10-15% higher (too low may not meet the heat load requirements, while too high may lead to excessive margin and low working efficiency of the centrifugal fan); and the maximum air pressure of the centrifugal fan (which can be measured by the pressure sensor at the fan outlet or in the premixing chamber) should be higher than the actual required air pressure, such as 20-30% higher.

[0046] Specifically, in this embodiment of the application, after the centrifugal fan selection is completed, the gas nozzle orifice diameter that matches the selected centrifugal fan can be further determined.

[0047] First, install the centrifugal fan into the blower duct corresponding to the target gas equipment, and set the speed control command of the centrifugal fan to maximum, so that the centrifugal fan operates in the maximum blower state. Since the centrifugal fan can generate the maximum airflow at this time, it can simulate the premixing chamber working state of the burner under rated heat load conditions.

[0048] Subsequently, the actual pressure within the burner premixing chamber is collected and used as the working pressure at the gas nozzle outlet, i.e., the working back pressure of the gas nozzle. Since the air pressure in the premixing chamber affects the gas nozzle injection process, this working back pressure reflects the outlet pressure conditions that the gas nozzle actually withstands during operation.

[0049] After determining the nozzle outlet pressure, further hydraulic calculations can be performed on the gas pipeline. Specifically, the required gas flow rate under rated operating conditions is determined based on the rated heat load of the target gas equipment and the calorific value of the gas. Then, by combining the inlet pressure of the main natural gas pipe, the pressure drop of the shut-off valve, the pressure drop of the pressure regulating valve, the pressure drop of the proportional valve or manual valve, and the friction loss and local resistance loss of the gas pipeline, the pressure change of the gas during the transportation process is calculated step by step, thereby determining the inlet pressure of the gas nozzle.

[0050] Furthermore, based on the inlet pressure of the gas nozzle and the corresponding back pressure of the premixing chamber at the outlet of the gas nozzle, the effective pressure difference across the gas nozzle is determined. This effective pressure difference can be expressed as: ΔP=P1 P2 Where P1 represents the gas nozzle inlet pressure and P2 represents the premixing chamber back pressure.

[0051] After obtaining the gas flow rate and the pressure difference across the nozzle, the gas nozzle orifice diameter can be determined based on a preset nozzle flow rate model. For example, for a single-nozzle structure, the nozzle orifice diameter can be determined based on the correspondence between the gas flow rate and the nozzle pressure difference; for a multi-nozzle structure, the orifice diameter of each nozzle can be determined based on the gas flow rate and corresponding pressure difference handled by each individual nozzle.

[0052] In one optional implementation, the gas flow rate Vg under rated operating conditions is first calculated based on the rated heat load Q of the target gas equipment. Then, the gas nozzle orifice diameter d is determined by combining the pressure difference ΔP across the nozzle. There is a corresponding relationship between the gas flow rate Vg and the rated heat load Q, and a corresponding relationship between the nozzle orifice diameter d, the gas flow rate Vg, and the pressure difference ΔP across the nozzle.

[0053] Specifically, in the embodiments of this application, the nozzle flow rate Vg and the heat load follow the following formula: Vg=Q* 3600 / H Where Q is the heat load of a single nozzle, in kW; H represents the lower calorific value of natural gas, approximately 35,900 kJ / Nm³.

[0054] Step 305: Obtain relevant parameters of the target gas equipment; the relevant parameters include first association information and the actual air resistance of the blower pipe of the target gas equipment; the first association information is used to indicate the correspondence between speed control command and air volume under multiple air resistance conditions.

[0055] Optionally, in this embodiment of the application, the first association information can be obtained through the following steps: Connect the centrifugal fan to the air resistance calibration device; Adjust the air resistance of the air resistance calibration device so that the centrifugal fan is in different air resistance states in sequence; For each wind resistance, the air volume output when the centrifugal fan is set with each speed control command is obtained to generate the first associated information.

[0056] In the process of generating the aforementioned first correlation information, it is generally difficult to directly measure airflow under engineering conditions; that is, the air volume output by the centrifugal fan when set to various speed control commands cannot be directly measured. In this case, the second correlation information obtained during the design process of the target gas equipment can be used to assist in generating the first correlation information.

[0057] In other words, the relevant parameters of the target gas equipment obtained may also include second related information; Furthermore, the second correlation information is used to indicate the correlation between the centrifugal fan's rotational speed, air volume, and air resistance.

[0058] At this point, the rotational speed of the centrifugal fan when each speed control command is set can be obtained. Since the second correlation information can determine the conversion relationship between the rotational speed and air volume of the centrifugal fan under each wind resistance, it is obvious that the output air volume of the centrifugal fan when each speed control command is set can be determined based on the rotational speed, wind resistance and the second correlation information.

[0059] It should be noted that, in the embodiments of this application, the second related information is obtained by measuring the air volume and the rotational speed of the centrifugal fan when the centrifugal fan is connected to different wind resistance environments and the centrifugal fan is set to the maximum speed regulation command.

[0060] During the generation of the first correlation information, the speed regulation command is not necessarily the maximum speed regulation command. However, because there is a correspondence between the aerodynamic load on the centrifugal fan impeller and the operating air volume in the target gas equipment, and a correspondence between the steady-state speed of the speed-regulating motor and the fan load, the actual operating state of the centrifugal fan is not directly affected by the speed regulation command, and the speed regulation command does not form a fixed correspondence with the air volume. For the same speed regulation command, the steady-state speed and output air volume of the centrifugal fan may differ under different air resistance conditions. The speed regulation command is used to limit the upper limit of the target speed that the speed-regulating motor can reach, while the actual steady-state speed of the centrifugal fan is also affected by the aerodynamic load of the fan. Therefore, under known air resistance conditions, it is necessary to determine the corresponding air volume by combining the actual speed with the second correlation information.

[0061] Therefore, when operating under the maximum speed control command, the centrifugal fan can cover all working states within the target wind resistance range, thereby constructing the correspondence between fan speed, air volume, and wind resistance through the collected data. Since the steady-state speed of the centrifugal fan corresponds to the aerodynamic load, and the aerodynamic load corresponds to the air volume, the established speed-air volume-wind resistance relationship can be used as a characterization parameter of the fan's operating characteristics for subsequent air volume estimation under different speed control conditions.

[0062] Step 306: Determine the preset air-fuel ratio of the target gas equipment.

[0063] In this embodiment, the preset air-fuel ratio can be pre-set according to the type of gas, burner structure, and combustion performance requirements. For example, the preset air-fuel ratio can be determined according to the optimal combustion conditions of the target gas equipment.

[0064] Step 307: Determine the required air volume based on the preset air-fuel ratio and the current gas flow rate.

[0065] In this embodiment, the controller can obtain the current gas flow rate of the target gas device in real time, and calculate the required air volume that matches the current gas flow rate by combining the preset air-fuel ratio, thereby providing a basis for subsequent air flow rate adjustment.

[0066] Specifically, it follows the formula as follows: Air volume ÷ fuel volume = AFR (Air-fuel ratio) The air-fuel ratio (AFR) range for commercial fully premixed fuels can be set to 10.0–11.5.

[0067] In this embodiment of the application, the current gas flow rate can be obtained in the following ways: First, turn on the main combustion gas supply to the target gas equipment and adjust the gas flow rate by regulating the gas valve. The gas valve includes, but is not limited to, one or more combinations of manual valves, segmented solenoid valves, or solenoid proportional valves.

[0068] In one optional implementation, a differential pressure sensor is used to actually measure the pressure difference before and after the gas nozzle, and the current gas flow rate is calculated based on the nozzle's geometric parameters (such as orifice diameter, flow coefficient, etc.). Specifically, the controller reads the pressure before and after the nozzle (i.e., the premixing chamber back pressure) collected by the differential pressure sensor, calculates the difference between the two, and then, in conjunction with a pre-stored nozzle parameter table, calculates the real-time gas flow rate using the nozzle flow rate formula.

[0069] As an alternative approach, when a differential pressure sensor is not installed or cost reduction is required, the working pressure before the nozzle can be calculated based on the gas pipeline calibration value, and then the gas flow rate can be estimated.

[0070] The specific steps include: calculating the pressure in the premixing chamber (i.e., the pressure after the nozzle) based on the current blower volume; calculating the pressure before the nozzle based on the gas pipeline calibration values ​​(including the outlet pressure of the pressure regulator, the friction loss along the pipeline, and local resistance loss, etc.); subtracting the pressure after the nozzle from the pressure before the nozzle to obtain the pressure difference before and after the nozzle; and finally, looking up the nozzle parameter table to calculate the current gas flow rate.

[0071] Step 308: Based on the required air volume, the actual air resistance of the blower duct, and the first associated information, determine the speed control command of the centrifugal fan in the target gas equipment to adjust the air-fuel ratio of the target gas equipment.

[0072] In this embodiment, the controller searches for or calculates the corresponding speed control command in the first associated information based on the current required air volume and the actual air resistance of the blower duct, and sends the speed control command to the speed-regulating motor corresponding to the centrifugal fan. After the centrifugal fan operates according to the speed control command, it can output an airflow that matches the required air volume, thereby achieving the adjustment of the air-fuel ratio of the target gas equipment.

[0073] Furthermore, during the operation of the target gas equipment, the gas flow rate may change due to user adjustments to heating power, load variations, or changes in control strategies. Therefore, in this embodiment, the gas flow rate of the target gas equipment can also be detected in real time.

[0074] Specifically, the controller can periodically acquire gas flow data output by the gas flow detection device, or calculate the current gas flow based on the proportional valve opening, gas supply pressure, and a preset flow model. When a change in gas flow is detected, the controller recalculates the corresponding required air volume based on the updated gas flow and the preset air-fuel ratio, and further determines the corresponding speed control command by combining the actual air resistance of the blower duct and the first correlation information.

[0075] Subsequently, the controller sends the updated speed control command to the corresponding speed-regulating motor of the centrifugal fan to adjust the output air volume of the centrifugal fan, ensuring that the air supply matches the current gas flow rate. In this way, the air supply can be adjusted in real time according to changes in gas flow rate, thereby achieving dynamic adjustment of the air-fuel ratio.

[0076] Furthermore, in some implementations, the air-fuel ratio can be corrected in a closed loop by detecting the exhaust parameters after combustion.

[0077] Specifically, the controller can acquire the exhaust gas detection results of the target gas-fired equipment. These results may include CO concentration, CO2 concentration, O2 concentration, or other parameters reflecting the combustion state. In this embodiment, the CO value is used as an example for illustration.

[0078] Since CO concentration reflects the completeness of combustion, the controller can compare the detected CO value with a preset CO value. When the actual CO value deviates from the preset CO value, it indicates a discrepancy between the current air-fuel ratio and the target air-fuel ratio. At this point, the controller readjusts the required air volume based on this discrepancy and further combines the first correlation information and the actual wind resistance to determine a new speed control command.

[0079] For example, when the actual CO value is higher than the preset CO value, the required air volume can be appropriately increased to increase the air supply; when the actual CO value is lower than the preset CO value and there is excess air, the required air volume can be appropriately reduced. Through this method, the exhaust results after combustion can be used to correct the air-fuel ratio, thereby further improving combustion efficiency and combustion stability.

[0080] Furthermore, in this embodiment of the application, the operating status of the centrifugal fan can also be monitored using the second associated information.

[0081] Specifically, when the speed control command corresponding to the centrifugal fan reaches its maximum, the current motor speed of the centrifugal fan is obtained. Subsequently, based on the motor speed and the pre-established second correlation information, the actual maximum air volume corresponding to the current centrifugal fan is determined.

[0082] The second correlation information is used to characterize the relationship between centrifugal fan speed, air volume, and air resistance, thus enabling the calculation of the centrifugal fan's blowing capacity in the actual operating environment based on the current speed. When dust accumulates on the centrifugal fan impeller, the pipes become blocked, the motor performance deteriorates, or other abnormal conditions occur, the actual maximum blowing volume of the centrifugal fan may change.

[0083] Therefore, in this embodiment, the actual maximum air volume can be compared with the deviation range of the preset maximum air volume of the target gas equipment. When the actual maximum air volume exceeds the deviation range, the controller issues an alarm signal.

[0084] The alarm signal can be an audible and visual alarm, a displayed alarm message, a remote maintenance alarm, or other forms of alarm information. This application does not limit this. Maintenance personnel can check the operating status of the centrifugal fan, motor, and blower duct based on the alarm results, thereby promptly detecting problems such as fan performance degradation, duct blockage, or component failure, ensuring the long-term stable operation of the target gas equipment.

[0085] In summary, after obtaining the current gas flow rate of the target gas equipment, the corresponding air demand is first calculated based on the current gas flow rate. Then, combining the actual air resistance of the target gas equipment's blower duct and the pre-established first correlation information, the corresponding speed control command is determined, and the centrifugal fan is controlled to operate according to the speed control command, thereby adjusting the air supply of the target gas equipment and achieving air-fuel ratio regulation. In the above scheme, by establishing the correlation between air volume, speed control command, and air resistance, the speed control command of the centrifugal fan is not only related to the air demand corresponding to the gas flow rate but can also be determined in conjunction with the actual air resistance of the blower duct. Therefore, the controller can determine the corresponding speed control command according to the actual operating conditions, thereby enabling the centrifugal fan to output an air flow rate that matches the air demand, improving the air-fuel ratio regulation effect and combustion stability.

[0086] Figure 4 A structural block diagram of an air-fuel ratio regulating device according to an embodiment of this application is shown. Figure 4 As shown, the device includes: The parameter acquisition module 401 is used to acquire relevant parameters of the target gas equipment; the relevant parameters include first association information and the actual air resistance of the blower pipe of the target gas equipment; the first association information is used to indicate the correspondence between speed adjustment command and air volume under multiple air resistance conditions. The demand calculation module 402 is used to calculate the required air volume based on the current gas flow rate of the target gas equipment; The speed control module 403 is used to determine the speed control command of the centrifugal fan in the target gas equipment based on the required air volume, the actual air resistance of the blower duct and the first associated information, so as to adjust the air-fuel ratio of the target gas equipment.

[0087] In summary, after obtaining the current gas flow rate of the target gas equipment, the corresponding air demand is first calculated based on the current gas flow rate. Then, combining the actual air resistance of the target gas equipment's blower duct and the pre-established first correlation information, the corresponding speed control command is determined, and the centrifugal fan is controlled to operate according to the speed control command, thereby adjusting the air supply of the target gas equipment and achieving air-fuel ratio regulation. In the above scheme, by establishing the correlation between air volume, speed control command, and air resistance, the speed control command of the centrifugal fan is not only related to the air demand corresponding to the gas flow rate but can also be determined in conjunction with the actual air resistance of the blower duct. Therefore, the controller can determine the corresponding speed control command according to the actual operating conditions, thereby enabling the centrifugal fan to output an air flow rate that matches the air demand, improving the air-fuel ratio regulation effect and combustion stability.

[0088] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0089] The system in this embodiment is presented in the form of functional units. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0090] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an optional embodiment of this application. This electronic device can be implemented as a controller in a target gas appliance, used to achieve, for example... Figure 4 The device shown includes one or more processors 10, a memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processor can process instructions executed within the electronic device, including instructions stored in or on memory to display graphical information of a GUI on an external input / output device (such as a display device coupled to the interface).

[0091] The processor 10 may further include a hardware chip. This hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0092] The memory 20 stores instructions executable by at least one processor 10 to cause the at least one processor 10 to perform the method shown in the above embodiments.

[0093] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the use of the electronic device based on the display of a mini-program landing page. Furthermore, the memory 20 may include high-speed random access memory (RAM), and may also include non-transient memory, such as at least one disk storage device, flash memory device, or other non-transient solid-state storage device. The memory 20 may include volatile memory, such as RAM; the memory may also include non-volatile memory, such as flash memory, hard disk, or solid-state drive; the memory 20 may also include combinations of the above types of memory.

[0094] The electronic device also includes a communication interface 30 for communicating with other devices or communication networks.

[0095] This application also provides a computer-readable storage medium. The methods described in this application can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code downloaded over a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the methods shown in the above embodiments are implemented.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for adjusting the air-fuel ratio, characterized in that, The method includes: Obtain relevant parameters of the target gas equipment; the relevant parameters include first association information and the actual air resistance of the blower duct of the target gas equipment; the first association information is used to indicate the correspondence between speed control command and air volume under multiple air resistance conditions; Calculate the required air volume based on the current gas flow rate of the target gas equipment; Based on the required air volume, the actual air resistance of the blower duct, and the first associated information, the speed control command of the centrifugal fan in the target gas equipment is determined to adjust the air-fuel ratio of the target gas equipment.

2. The method according to claim 1, characterized in that, The step of calculating the required air volume based on the current gas flow rate of the target gas equipment includes: Determine the preset air-fuel ratio of the target gas equipment; The required air volume is determined based on the preset air-fuel ratio and the current gas flow rate.

3. The method according to claim 2, characterized in that, Obtaining the first associated information includes: Connect the centrifugal fan to the wind resistance calibration device; Adjust the wind resistance of the wind resistance calibration device so that the centrifugal fan is in different wind resistance states in sequence; For each wind resistance, the air volume output when the centrifugal fan is set with each speed regulation command is obtained to generate the first association information.

4. The method according to claim 3, characterized in that, The impeller aerodynamic load of the centrifugal fan in the target gas equipment is positively correlated with the operating air volume; and the steady-state speed of the speed-regulating motor corresponding to the centrifugal fan is negatively correlated with the fan load; the relevant parameters of the target gas equipment also include second correlation information; the second correlation information is used to indicate the correlation between the speed, air volume and air resistance of the centrifugal fan; The process of obtaining the air volume output when setting various speed control commands for the centrifugal fan includes: Obtain the rotational speed of the centrifugal fan when setting various speed control commands; Based on the rotational speed, wind resistance, and the second related information, the output air volume of the centrifugal fan when setting various speed control commands is determined.

5. The method according to claim 4, characterized in that, The second related information is obtained by measuring the air volume and the rotational speed of the centrifugal fan when the centrifugal fan is connected to different wind resistance environments and the centrifugal fan is set to the maximum speed control command.

6. The method according to claim 5, characterized in that, Before obtaining the relevant parameters of the target gas equipment, the process also includes: Multiple candidate wind turbines are obtained; the multiple candidate wind turbines have different performance parameters; Each candidate fan is connected to a wind resistance calibration device and the candidate fan is set to the maximum speed control command. The second association information corresponding to each candidate fan is obtained by measuring the air volume and the rotation speed of the candidate fan. Based on the second association information of each candidate fan, determine the maximum air volume of each candidate fan under the actual air resistance of the blower duct of the target gas equipment; The centrifugal fan is determined from the candidate fans based on the maximum air volume of each candidate fan under the actual air resistance of the blower duct of the target gas equipment, and the blower volume required under the rated heat load of the target gas equipment.

7. The method according to claim 6, characterized in that, The method further includes: When the centrifugal fan is connected to the blower pipe of the target gas equipment, the speed control command of the centrifugal fan is set to the maximum to collect the actual pressure in the burner premixing chamber of the target gas equipment. The working back pressure of the gas nozzle is determined based on the actual pressure. The matching orifice diameter of the gas nozzle is determined based on the gas flow rate under the rated heat load of the target gas equipment and the pressure difference before and after the nozzle.

8. The method according to claim 6, characterized in that, The centrifugal fan is a forward impeller centrifugal fan.

9. The method according to any one of claims 1 to 8, characterized in that, After determining the speed control command for the centrifugal fan in the target gas equipment, the method further includes: Real-time detection of gas flow rate of the target gas equipment; The required air volume is recalculated based on the updated gas flow rate to iteratively adjust the air-fuel ratio of the target gas equipment.

10. The method according to any one of claims 1 to 8, characterized in that, After determining the speed control command for the centrifugal fan in the target gas equipment, the method further includes: Obtain the exhaust gas detection results of the target gas equipment; The required air volume is recalculated based on the CO value in the exhaust gas test results and the preset CO value, so as to iteratively adjust the air-fuel ratio of the target gas equipment.

11. The method according to any one of claims 4 to 8, characterized in that, The method further includes: When the speed control command of the centrifugal fan is at its maximum, the motor speed is measured; The actual maximum air volume of the centrifugal fan is determined based on the motor speed and the second correlation information of the centrifugal fan. If the actual maximum blower volume deviates from the preset maximum blower value deviation range of the target gas equipment, an alarm signal will be issued.

12. An air-fuel ratio regulating device, characterized in that, The device includes: The parameter acquisition module is used to acquire relevant parameters of the target gas equipment; the relevant parameters include first association information and the actual air resistance of the blower pipe of the target gas equipment; the first association information is used to indicate the correspondence between speed control command and air volume under multiple air resistance conditions. The demand calculation module is used to calculate the required air volume based on the current gas flow rate of the target gas equipment. The speed control module is used to determine the speed control command of the centrifugal fan in the target gas equipment based on the required air volume, the actual air resistance of the blower duct, and the first associated information, so as to adjust the air-fuel ratio of the target gas equipment.

13. A gas-fired device, characterized in that, The gas equipment also includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the air-fuel ratio adjustment method according to any one of claims 1 to 11.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the air-fuel ratio adjustment method according to any one of claims 1 to 11.

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