Energy-saving mute gas burner and smoke exhaust system

Abstract

The invention relates to an energy-saving silent gas burner and a smoke exhaust system, and relates to the technical field of gas burning equipment.The energy-saving silent gas burner comprises a burner part which is of a multi-stage mixing structure formed by combining a gradually-shrunk and gradually-expanded gas nozzle and a spiral flow deflector and is combined with the stratified burning technology and a porous ceramic plate to stabilize flames, efficient premixing of gas and air is achieved, and the gas burner part is provided with an air inlet and an air outlet; the deflagration noise is reduced; a shell of the combustor is covered with a high-temperature-resistant heat reflection coating (such as an Al2O3-SiO2 composite coating, the reflectivity is larger than or equal to 90%), and heat loss is reduced. The inner layer of a dual-channel smoke exhaust pipe is a smoke channel, and the outer layer of the dual-channel smoke exhaust pipe is communicated with a combustion-supporting air inlet to preheat air; a variable-frequency fan and a flexible connection damping structure are arranged, and smoke latent heat is recovered in cooperation with a condensation heat exchanger. The heat efficiency of the gas burner can be improved by more than or equal to 20%, the operation noise is less than or equal to 50dB (A), the smoke exhaust temperature is less than or equal to 60 DEG C, and the CO emission is less than 100ppm.

Description

Technical Field

[0001] This invention relates to the field of gas combustion equipment technology, specifically to an energy-saving and quiet gas burner and exhaust system. Background Technology

[0002] As a core component for heat energy conversion, the gas burner has undergone three key stages of technological iteration:

[0003] First-generation diffusion burners (1980s-2000s): rely on natural diffusion of gas pressure to mix air, with low air-fuel ratio adjustment accuracy (±15%), thermal efficiency generally below 80%, and CO emissions >200ppm;

[0004] The second-generation premixed burner (2010s-2018) adopts venturi tube forced premixing (such as CN201510123456.7), and the thermal efficiency is increased to 85%, but it has defects such as insufficient mixing uniformity (≤85%) and prominent detonation noise (>60dB(A)).

[0005] Third-generation catalytic burners (2019-present): Introducing precious metal catalytic coatings (refer to JP201789654A), reducing NOx emissions to 50 mg / m³. 3 However, it faces technical bottlenecks such as catalyst sintering (deactivation at >600℃) and low waste heat recovery rate (≤80%).

[0006] Existing gas burners have the following technical defects:

[0007] Low combustion efficiency: Traditional diffusion burners do not mix gas and air sufficiently, with measured thermal efficiency of only 80%-85%, and exhaust gas temperature is generally higher than 120℃, resulting in energy waste.

[0008] Severe noise pollution:

[0009] Uneven mixing of fuel gas and air can lead to deflagration, generating high-frequency noise of 1000-4000Hz (typical value 65dB(A));

[0010] Noise from fan blade vibration and motor drive (typical value 55-60 dB(A)).

[0011] Insufficient waste heat recovery: Conventional flue gas systems only recover sensible heat through a single-stage heat exchanger, and the latent heat of water vapor in the flue gas is not utilized, resulting in a heat loss rate of ≥15%. Summary of the Invention

[0012] Purpose of the invention: To provide an energy-saving and quiet gas burner and exhaust system to solve the above-mentioned problems existing in the prior art.

[0013] Technical solution: An energy-saving and quiet gas burner, comprising a multi-stage mixing device, a layered combustion structure, and a heat-reflective coating.

[0014] The multi-stage mixing device consists of a gradually converging and expanding gas nozzle and a spiral guide vane, and the gas-air volume mixing ratio is 1:10 to 1:15.

[0015] The layered combustion structure is divided into a lean combustion zone and a rich combustion zone, and the combustion surface is covered with a porous ceramic plate.

[0016] The heat-reflective coating burner shell is coated with an Al2O3-SiO2 composite coating with a thickness of 0.1-0.3 mm and a heat reflectivity of ≥90%.

[0017] In a further embodiment, the porous ceramic plate supports an Fe2O3-MnO2 catalyst with a catalytic activity temperature of 300-500℃, which is used to reduce CO emissions.

[0018] In a further embodiment, the converging angle of the gas nozzle is 15°-30°, and the throat diameter is 2-5mm; the guiding angle of the spiral guide vane is 45°-60°, and the pitch is 10-20mm.

[0019] In a further embodiment, the excess air coefficient of the lean combustion zone is 1.2-1.5, the excess air coefficient of the rich combustion zone is 0.8-1.0, and the porous ceramic plate covering the combustion surface has a pore size of 0.5-2 mm and a porosity of 40%-60%.

[0020] An energy-saving and quiet smoke exhaust system is applied to the aforementioned energy-saving and quiet gas burner.

[0021] In a further embodiment, the energy-saving and silent smoke exhaust system also includes three components: a dual-channel smoke exhaust pipe, a variable frequency silent fan, and a condensing heat exchanger. The inner flue gas channel and the outer air preheating channel of the dual-channel smoke exhaust pipe are coaxially nested, with the outer channel inlet connected to the burner's combustion air supply pipeline. The variable frequency silent fan uses a brushless DC motor with a power of 50-500W, and its speed is adjusted according to the flue gas temperature signal by a PID controller. The condensing heat exchanger is constructed of 316L stainless steel corrugated tubing, with a heat exchange area of ​​2-20m². 2 The flue gas outlet temperature is ≤60℃.

[0022] In a further embodiment, the fan and the exhaust pipe are connected by a silicone rubber flexible connector and a spring shock absorber, wherein the silicone rubber flexible connector has a Shore hardness of 40-60HA and the spring shock absorber has a stiffness coefficient of 10-30N / mm.

[0023] In a further embodiment, the diameter of the inner flue gas channel is 80-200 mm, and the annular gap width of the outer air preheating channel is 10-30 mm. The stainless steel corrugated tube of the condenser heat exchanger has a diameter of 8-15 mm and a wall thickness of 0.5 mm.

[0024] In a further embodiment, the diameter of the inner flue gas channel is 80-200 mm, and the annular gap width of the outer air preheating channel is 10-30 mm.

[0025] The stainless steel corrugated tubes of the condenser heat exchanger have a diameter of 8-15 mm and a wall thickness of 0.5 mm.

[0026] In a further embodiment, the control method of the energy-saving and silent smoke exhaust system is as follows:

[0027] S1. Real-time monitoring of gas supply using a flow sensor to calculate theoretical air demand;

[0028] S2. Adjust the opening of the spiral guide vane to match the air flow and maintain the air-fuel ratio error ≤ ±3%.

[0029] S3. Dynamically adjust the fan speed according to the exhaust gas temperature to maintain the system resistance at 200-500Pa.

[0030] In a further embodiment, in step S3, the control system dynamically adjusts the fan speed based on the real-time monitored flue gas temperature and the set threshold to maintain the system resistance within the range of 200-500 Pa. The specific adjustment process is as follows:

[0031] When the exhaust gas temperature exceeds the set threshold of 60℃, it indicates that the combustion system may have incomplete combustion or poor heat dissipation, requiring an increase in airflow to improve combustion efficiency. At this time, the control system will increase the fan speed and increase the air supply, which will also increase the system resistance. During the adjustment process, the control system will monitor the system resistance in real time. When the system resistance exceeds 500Pa, it will appropriately reduce the fan speed to maintain the system resistance within a reasonable range.

[0032] When the exhaust gas temperature is lower than the set threshold of 60℃, it indicates that the combustion system may be supplying too much air, resulting in a decrease in combustion temperature. At this time, the control system will reduce the fan speed and reduce the air supply, and the system resistance will also decrease accordingly. When the system resistance is lower than 200Pa, the fan speed will be appropriately increased to maintain the system resistance within the range of 200-500Pa.

[0033] Beneficial effects: This invention relates to an energy-saving and quiet gas burner and exhaust system, and relates to the technical field of gas combustion equipment, including:

[0034] Burner section: It adopts a multi-stage mixing structure combining a converging-expanding gas nozzle and a spiral guide vane, combined with stratified combustion technology (lean and rich combustion zones) and porous ceramic plates to stabilize the flame, so as to achieve efficient premixing of gas and air and reduce detonation noise; the burner shell is covered with a high-temperature heat-reflective coating (such as an Al2O3-SiO2 composite coating with a reflectivity of ≥90%) to reduce heat loss.

[0035] Smoke exhaust system: The inner layer of the dual-channel smoke exhaust pipe is a flue gas passage, and the outer layer is connected to the combustion air inlet to preheat the air; it is equipped with a variable frequency fan (speed range 500-3000rpm) and a flexible connection shock absorption structure (damping coefficient 0.2-0.4), and is matched with a condensing heat exchanger to recover the latent heat of the flue gas.

[0036] Technical benefits: Thermal efficiency improved by ≥20%, operating noise ≤50dB(A), exhaust gas temperature ≤60℃, CO emissions <100ppm, in compliance with GB17820-2018 standards.

[0037] This invention improves thermal efficiency through multi-stage mixing and stratified combustion, and achieves deep waste heat recovery through dual-channel flue gas exhaust and condensation heat exchange. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the energy-saving and silent gas burner described in this invention.

[0039] Figure 2 This is a cross-sectional schematic diagram of the energy-saving and silent gas burner described in this invention.

[0040] Figure 3 This is a cross-sectional schematic diagram of some components of the energy-saving and silent gas burner described in this invention.

[0041] Figure 4 This is a schematic diagram of the composition of the energy-saving and silent smoke exhaust system described in this invention.

[0042] Figure 5 This is a schematic diagram of the control process of the energy-saving and silent smoke exhaust system of the present invention.

[0043] Figure reference numerals: 1. Gradual converging and expanding gas nozzle; 2. Spiral guide vane; 3. Porous ceramic plate; 4. Housing. Detailed Implementation

[0044] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0045] The energy-saving and silent gas burner involved in this invention mainly includes a multi-stage mixing device, a layered combustion structure, and a heat-reflective coating. The multi-stage mixing device consists of a gradually converging and expanding gas nozzle 1 and a spiral guide vane 2, with a gas-to-air volume mixing ratio of 1:10 to 1:15. The layered combustion structure divides the combustion zone into a lean combustion zone and a rich combustion zone, and the combustion surface is covered with a porous ceramic plate 3. The heat-reflective coating on the burner shell is an Al2O3-SiO2 composite coating with a thickness of 0.1-0.3 mm and a heat reflectivity ≥90%.

[0046] The porous ceramic plate 3 supports the Fe2O3-MnO2 catalyst, with a catalytic activity temperature of 300-500℃, and is used to reduce CO emissions.

[0047] The converging angle of the gas nozzle 1 is 15°-30°, and the throat diameter is 2-5mm; the guide angle of the spiral guide vane 2 is 45°-60°, and the pitch is 10-20mm.

[0048] The excess air coefficient in the lean combustion zone is 1.2-1.5, the excess air coefficient in the rich combustion zone is 0.8-1.0, and the porous ceramic plate 3 covering the combustion surface has a pore size of 0.5-2 mm and a porosity of 40%-60%.

[0049] In a further preferred embodiment, the multi-stage mixing device, the layered combustion structure, and the heat-reflective coating are all housed and supported by the corresponding support housing 4.

[0050] An energy-saving and quiet smoke exhaust system is applied to the aforementioned energy-saving and quiet gas burner.

[0051] The energy-saving and silent flue gas exhaust system includes three components: a dual-channel exhaust pipe, a variable frequency silent fan, and a condensing heat exchanger. The inner flue gas channel and the outer air preheating channel of the dual-channel exhaust pipe are coaxially nested, with the outer channel inlet connected to the burner's combustion air supply pipeline. The variable frequency silent fan uses a brushless DC motor with a power of 50-500W, and its speed is adjusted according to the flue gas temperature signal by a PID controller. The condensing heat exchanger is constructed of 316L stainless steel corrugated tubes, with a heat exchange area of ​​2-20m². 2 The flue gas outlet temperature is ≤60℃.

[0052] The fan and the exhaust pipe are connected by a silicone rubber flexible connector and a spring shock absorber. The silicone rubber flexible connector has a Shore hardness of 40-60HA, and the spring shock absorber has a stiffness coefficient of 10-30N / mm.

[0053] The inner flue gas passage has a diameter of 80-200mm, and the outer air preheating passage has an annular gap width of 10-30mm. The stainless steel corrugated tube of the condenser heat exchanger has a diameter of 8-15mm and a wall thickness of 0.5mm.

[0054] The diameter of the inner flue gas channel is 80-200mm, and the annular gap width of the outer air preheating channel is 10-30mm.

[0055] The stainless steel corrugated tubes of the condenser heat exchanger have a diameter of 8-15 mm and a wall thickness of 0.5 mm.

[0056] The control method for the energy-saving and silent smoke exhaust system is as follows:

[0057] Step 1: Monitor the gas supply in real time using a flow sensor and calculate the theoretical air demand;

[0058] Step 2: Adjust the opening of the spiral guide vane 2 to match the air flow and maintain the air-fuel ratio error ≤ ±3%.

[0059] Step 3: Dynamically adjust the fan speed according to the exhaust gas temperature to maintain the system resistance at 200-500Pa.

[0060] In step S3, the control system dynamically adjusts the fan speed based on the real-time monitored flue gas temperature and the set threshold to maintain the system resistance within the range of 200-500 Pa. The specific adjustment process is as follows:

[0061] When the exhaust gas temperature exceeds the set threshold of 60℃, it indicates that the combustion system may have incomplete combustion or poor heat dissipation, requiring an increase in airflow to improve combustion efficiency. At this time, the control system will increase the fan speed and increase the air supply, which will also increase the system resistance. During the adjustment process, the control system will monitor the system resistance in real time. When the system resistance exceeds 500Pa, it will appropriately reduce the fan speed to maintain the system resistance within a reasonable range.

[0062] When the exhaust gas temperature is lower than the set threshold of 60℃, it indicates that the combustion system may be supplying too much air, resulting in a decrease in combustion temperature. At this time, the control system will reduce the fan speed and reduce the air supply, and the system resistance will also decrease accordingly. When the system resistance is lower than 200Pa, the fan speed will be appropriately increased to maintain the system resistance within the range of 200-500Pa.

[0063] To further clarify, the specific formula for calculating thermal efficiency is as follows:

[0064]

[0065] This invention reduces the amount of flue gas Q_ to less than 15% of the input heat and η≥95% through waste heat recovery.

[0066] The noise control principle is as follows:

[0067] Combustion noise spectrum analysis shows that the main noise source is the 1000-4000Hz high frequency band, which is attenuated by ≥20dB through the porous ceramic plate 3 and the sound-absorbing structure.

[0068] In a further preferred embodiment, specific examples are listed below:

[0069] Example 1 (Household Water Heater):

[0070] The burner has a power of 24kW, a nozzle throat diameter of 3mm, and two spiral guide vanes with a guide angle of 55°.

[0071] The outer channel of the exhaust pipe preheats the air to 75°C, and the condensation heat exchange area is 5m². 2 ;

[0072] Actual measured data: thermal efficiency 98%, noise level 43 dB(A), NOx emission 28 mg / m³ 3 .

[0073] Example 2 (Industrial Boiler):

[0074] Multiple burners are connected in parallel, with a single unit power of 150kW and a total load of 1.2MW;

[0075] The flue gas exhaust system is equipped with a multi-stage condensing heat exchanger (total area 200m²). 2 The waste heat from the flue gas is used to preheat the boiler feedwater; measured data shows that the overall energy saving rate is 27%, and the power consumption of the fan is reduced by 40%.

[0076] The experimental data table is as follows:

[0077] Table 1: Data Analysis Table for Example Implementation

[0078] index Traditional equipment This invention Test Standards Thermal efficiency 80％ 98％ GB / T10180-2017 Operating noise 65dB(A) 43dB(A) GB / T4214-2008 Smoke temperature 120℃ 55℃ GB / T16157-2012

[0079] In a further preferred embodiment, specific examples are analyzed and compared as follows:

[0080] Example 3: Household wall-mounted boiler (28kW)

[0081] Burner parameters:

[0082] Nozzle throat diameter 3mm, guide vane 2 pitch 15mm;

[0083] The ceramic slab in the low-combustion zone has a pore size of 1mm and an area of ​​0.15m². 2 ;

[0084] The heat-reflective coating thickness is 0.2 mm.

[0085] Smoke extraction system parameters:

[0086] The total length of the flue is 2m, and the condensing heat exchange area is 4.5m². 2 ;

[0087] The fan power is 150W, and the flexible connection length is 100mm.

[0088] Performance testing (based on GB25034-2020):

[0089] Thermal efficiency: 98.5%;

[0090] Operating noise: 43dB(A) (combustion chamber), 48dB(A) (fan);

[0091] Emission targets: CO = 28 ppm, NOx = 35 mg / m³ 3 .

[0092] Example 4: Industrial boiler (1.2MW power)

[0093] Modular design: 8 burner units connected in parallel, with a single unit power of 150kW;

[0094] Smoke exhaust system:

[0095] Dual-channel exhaust pipe with a diameter of 500mm and a condensing heat exchange area of ​​200m² 2 ;

[0096] Waste heat is used to preheat boiler feedwater (raising the water temperature from 20℃ to 70℃).

[0097] Economic analysis:

[0098] Annual gas savings: 186,000 m³ 3 (Based on 8,000 hours of operation per year);

[0099] Investment payback period: 2.3 years (compared to traditional equipment).

[0100] Experimental data and comparative analysis:

[0101] Table 2: Comparison of Combustion Performance

[0102] parameter conventional burners This invention Test Standards Thermal efficiency (%) 82 98.5 GB / T10180-2017 CO emissions (ppm) 150 28 GB13271-2014 Smoke exhaust temperature (°C) 120 55 GB / T16157-2012

[0103] Table 3: Noise Test Results

[0104] noise source Traditional equipment (dB(A)) This invention (dB(A)) Noise reduction range Combustion noise (at 1m) 65 43 22 Fan noise (at 1m) 58 48 10

[0105] Based on the above embodiments, the following summary can be made:

[0106] 1. Breakthrough in energy efficiency

[0107] Thermal efficiency is increased to 98.5% (compared to 82% for conventional equipment), achieving near-complete combustion;

[0108] The flue gas temperature dropped from 120℃ to 55℃, resulting in a significant waste heat recovery rate.

[0109] 2. Environmental advantages

[0110] CO emissions were reduced by 81.3% (28 ppm vs 150 ppm);

[0111] NOx emissions 35mg / m³ 3 (Industrial boilers) meet stringent environmental protection standards.

[0112] 3. Silent design

[0113] Combustion noise is reduced by 22 dB(A), and fan noise is reduced by 10 dB(A), meeting the needs of civilian applications.

[0114] 4. Economic benefits

[0115] Industrial boilers save 186,000 cubic meters of gas annually, with an investment payback period of only 2.3 years.

[0116] In a further preferred embodiment, the control method of the energy-saving and silent smoke exhaust system is described in detail in conjunction with the control principle of the gas combustion system:

[0117] S1: Real-time monitoring of gas supply using a flow sensor to calculate theoretical air demand.

[0118] Background principle:

[0119] As a fuel, natural gas requires a certain amount of air (mainly oxygen) to burn, and the amount of air supplied directly affects combustion efficiency and emission standards. For a system to achieve efficient and clean combustion, it is essential to accurately determine the amount of natural gas supplied.

[0120] Detailed process description:

[0121] (1) Use a flow sensor: Install a high-precision gas flow sensor to measure the instantaneous flow rate of gas through the pipeline in real time (usually in Nm³). 3 / h or m 3 / h (calculated).

[0122] (2) Data acquisition and processing: The sensor transmits the measured flow data to the control system (such as PLC or DCS) to achieve real-time monitoring.

[0123] (3) Calculate the theoretical air requirement: Based on the chemical composition of the fuel gas (such as natural gas, which is mainly methane CH4), calculate the theoretical air requirement for combustion using stoichiometry.

[0124] Theoretical air volume = fuel gas volume × theoretical air-fuel ratio (generally, the theoretical air-fuel ratio for methane is approximately 9.5:1, by volume). Example formula:

[0125] Q air,theo =Q gas ×AFR theo

[0126] Among them, Q gas For gas flow rate, AFR theo This is the theoretical air coefficient.

[0127] significance:

[0128] Accurately obtaining gas flow rate and calculating ideal air demand are fundamental to controlling air supply, ensuring combustion efficiency, and reducing emissions.

[0129] S2: Adjust the opening of the spiral guide vane 2 (0°-90°) to match the airflow and maintain the air-fuel ratio error ≤ ±3%.

[0130] Background principle:

[0131] During combustion, the gas supply and air supply must maintain a reasonable ratio, that is, the air-fuel ratio (the volume ratio of air to fuel gas) must be kept within a set range to avoid excessive air leading to energy waste or insufficient air leading to incomplete combustion.

[0132] Detailed process description:

[0133] (1) Structure and function of spiral guide vane 2

[0134] The spiral guide vane 2 is installed at the air channel or fan outlet. By rotating it, the opening degree is adjusted, thereby changing the air flow cross-sectional area and flow velocity to achieve the purpose of regulating air flow.

[0135] (2) Closed-loop control strategy

[0136] Based on the theoretical air demand calculated by S1, the control system adjusts the airflow in real time by adjusting the angle of the spiral guide vane 2.

[0137] The spiral guide vane 2 has an angle range of 0° to 90°, with 0° being the closed state and 90° being the fully open state. The angle can be adjusted to the appropriate angle as needed.

[0138] (3) Air-fuel ratio error control

[0139] The actual airflow is measured in real time using sensors (or the air volume is indirectly estimated through wind speed sensors and pressure sensors).

[0140] The control system compares the actual air-fuel ratio with the set air-fuel ratio and adjusts the angle of the guide vane 2 to keep the air-fuel ratio error not exceeding ±3%.

[0141] Error limits ensure a stable and efficient combustion process, avoiding incomplete combustion or excessive dilution.

[0142] significance:

[0143] By combining mechanical structure with automatic control, the air flow is precisely matched with the gas flow to achieve the best combustion state.

[0144] S3: Dynamically adjust the fan speed according to the exhaust temperature (set threshold 60℃) to maintain the system resistance at 200-500Pa.

[0145] Background principle:

[0146] Flue gas temperature is an important parameter for determining combustion status and waste heat recovery conditions. Fan speed affects system airflow and pressure, which in turn affects air supply and overall system resistance.

[0147] Detailed process description:

[0148] (1) Set the smoke exhaust temperature threshold

[0149] The exhaust temperature threshold is set at 60℃ as the basis for adjustment.

[0150] (2) Smoke temperature measurement

[0151] Install a temperature sensor to monitor the exhaust gas temperature in real time after combustion.

[0152] (3) Fan speed regulation mechanism

[0153] When the exhaust gas temperature exceeds the set threshold, it may indicate that there is too much air supply or excessive combustion. The control system should appropriately reduce the fan speed and reduce the airflow.

[0154] Conversely, if the exhaust temperature is below the threshold, it indicates that combustion may be incomplete, and the system will increase the fan speed and increase the airflow.

[0155] (4) System resistance control

[0156] Maintaining system resistance (pressure drop) within the range of 200-500 Pa is crucial for ensuring stable airflow in the combustion system and safe operation of the equipment.

[0157] Changes in fan speed affect airflow resistance. By adjusting the speed, the resistance can be kept within a reasonable range to prevent unstable airflow or fan overload.

[0158] (5) Closed-loop regulation

[0159] The control system collects data on exhaust temperature and system pressure, and adjusts the speed of the fan frequency converter according to preset control rules to achieve dynamic balance.

[0160] significance:

[0161] By controlling the fan speed through flue gas temperature feedback, the combustion temperature is kept safe and stable, the system's aerodynamic performance is optimized, and the overall combustion efficiency is improved.

[0162] Summarize:

[0163] These three steps are interconnected and constitute a complete gas combustion air supply control strategy, in which:

[0164] S1 ensures accurate control of gas supply and corresponding air demand.

[0165] The S2 uses a mechanical device to precisely adjust the airflow, ensuring a stable air-fuel ratio.

[0166] S3 uses temperature feedback to adjust fan speed and system resistance, enabling dynamic maintenance of combustion efficiency and equipment safety.

[0167] In a further preferred embodiment, the control method of another implementation of the control method for the energy-saving and silent smoke exhaust system is described in detail below:

[0168] S1: Real-time monitoring of gas supply using a flow sensor to calculate theoretical air demand.

[0169] 1. Selection and installation of flow sensors

[0170] Sensor Selection: To monitor the gas supply accurately and in real time, a suitable flow sensor needs to be selected. Common gas flow sensors include vortex flow meters and thermal mass flow meters. Vortex flow meters are suitable for measuring the volumetric flow rate of various gases and have advantages such as high accuracy and high reliability; thermal mass flow meters can directly measure the mass flow rate of gases, are not affected by changes in temperature and pressure, and are more suitable for accurate measurement of gas flow.

[0171] Installation Location: The flow sensor should be installed on the gas pipeline. The installation location should ensure stable gas flow and avoid installation near pipe bends, valves, etc., to reduce measurement errors. Generally, it is selected on a straight pipe section, and the length of the upstream and downstream straight pipe sections should meet the sensor's installation requirements.

[0172] 2. Real-time monitoring of gas supply

[0173] The flow sensor converts the real-time measured gas flow signal into an electrical signal and transmits it to the control system. The control system processes and analyzes these signals to determine the current gas supply.

[0174] To ensure measurement accuracy, flow sensors need to be calibrated and maintained regularly to ensure that their measurement accuracy is within the specified range.

[0175] 3. Calculation of theoretical air demand

[0176] Different types of fuel gases have different chemical compositions and combustion characteristics, and therefore require different theoretical air volumes for complete combustion. Taking common natural gas (primarily methane CH4) as an example, its complete combustion chemical reaction equation is:

[0177] CH4 + 2O2 → CO2 + 2H2O

[0178] The equation shows that the complete combustion of 1 mole of methane requires 2 moles of oxygen. Since the volume fraction of oxygen in air is approximately 21%, the theoretical amount of air required for the complete combustion of 1 mole of methane is approximately...

[0179] The control system calculates the theoretical air demand based on real-time monitoring of the gas supply and its composition, using chemical reaction equations. The calculation formula is generally as follows:

[0180]

[0181] Among them, V air V is the theoretical air demand. gas For gas supply, This is the amount of oxygen required for the complete combustion of a gas.

[0182] S2: Adjust the opening of the spiral guide vane 2 (0°-90°) to match the air flow and maintain the air-fuel ratio error ≤±3%.

[0183] 1. Working principle of spiral guide vane 2

[0184] The spiral guide vane 2 is installed in the air duct. By changing its opening, the cross-sectional area of ​​airflow can be adjusted, thereby controlling the airflow rate. When the opening of the spiral guide vane 2 increases, the cross-sectional area of ​​airflow increases, and the airflow rate increases; conversely, when the opening decreases, the airflow rate decreases.

[0185] 2. The concept and importance of air-fuel ratio

[0186] The air-fuel ratio refers to the mass or volume ratio of air to fuel during combustion. A suitable air-fuel ratio is crucial for the complete combustion and combustion efficiency of fuel gas. If the air-fuel ratio is too low, the fuel cannot burn completely, producing harmful gases such as carbon monoxide and reducing combustion efficiency; if the air-fuel ratio is too high, it will lead to a decrease in combustion temperature, which also affects combustion efficiency.

[0187] 3. Adjustment of the opening degree of the spiral guide vane 2

[0188] The control system matches the airflow by adjusting the opening of the spiral guide vane 2 based on the calculated theoretical air demand and the real-time monitored airflow. The specific adjustment process is as follows:

[0189] First, the control system compares the real-time monitored airflow with the theoretical air demand and calculates the air-fuel ratio error.

[0190] If the air-fuel ratio error exceeds ±3%, the control system will issue an adjustment command based on the magnitude and direction of the error, driving the actuator (such as an electric actuator) to adjust the opening of the spiral guide vane 2. For example, if the air-fuel ratio is too low, indicating insufficient airflow, the control system will increase the opening of the spiral guide vane 2 to increase airflow; conversely, if the air-fuel ratio is too high, indicating excessive airflow, the control system will decrease the opening of the spiral guide vane 2 to reduce airflow.

[0191] During the adjustment process, the control system continuously monitors the airflow and air-fuel ratio error until the air-fuel ratio error is maintained within ±3%.

[0192] S3: Dynamically adjust the fan speed according to the exhaust gas temperature (set threshold 60℃) to maintain the system resistance at 200-500Pa.

[0193] 1. Monitoring of flue gas temperature

[0194] Temperature sensors should be installed on the exhaust ducts to monitor the exhaust temperature in real time. High-precision, fast-response temperature sensors should be selected to ensure timely and accurate reflection of changes in exhaust temperature.

[0195] 2. Relationship between fan speed and system resistance

[0196] The main function of a blower is to provide the necessary air to the combustion system and to exhaust the flue gas produced by combustion. The blower's rotational speed directly affects the airflow and system resistance. When the blower speed increases, the airflow increases, and the system resistance also increases accordingly; conversely, when the blower speed decreases, the airflow decreases, and the system resistance decreases.

[0197] 3. Dynamic adjustment of fan speed

[0198] The control system dynamically adjusts the fan speed based on the real-time monitored flue gas temperature and the set threshold (60℃) to maintain the system resistance within the range of 200-500Pa. The specific adjustment process is as follows:

[0199] When the exhaust gas temperature exceeds the set threshold of 60℃, it indicates that the combustion system may have problems such as incomplete combustion or poor heat dissipation, requiring an increase in airflow to improve combustion efficiency. At this time, the control system will increase the fan speed to increase the air supply, which will also increase the system resistance. During the adjustment process, the control system will monitor the system resistance in real time. When the system resistance exceeds 500Pa, it will appropriately reduce the fan speed to maintain the system resistance within a reasonable range.

[0200] When the exhaust gas temperature is below the set threshold of 60℃, it indicates that the combustion system may be supplying too much air, leading to a decrease in combustion temperature. In this case, the control system will reduce the fan speed to decrease the air supply, and the system resistance will also decrease accordingly. When the system resistance is below 200Pa, the fan speed will be appropriately increased to maintain the system resistance within the range of 200-500Pa.

[0201] Through the synergistic effect of the above three steps, precise control of the gas combustion system can be achieved, combustion efficiency can be improved, harmful gas emissions can be reduced, and the safe and stable operation of the system can be guaranteed.

[0202] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An energy-saving and silent gas burner, characterized in that: include: The multi-stage mixing equipment consists of a gradually converging and expanding gas nozzle and a spiral guide vane, with a gas-air volume mixing ratio of 1:10 to 1:

15. The combustion structure is layered, with the combustion zone divided into a lean combustion zone and a rich combustion zone, and the combustion surface is covered with a porous ceramic plate. Heat-reflective coating: The burner shell is coated with an Al2O3-SiO2 composite coating with a thickness of 0.1-0.3 mm and a heat reflectivity of ≥90%.

2. The energy-saving and silent gas burner according to claim 1, characterized in that: The porous ceramic plate supports the Fe2O3-MnO2 catalyst, with a catalytic activity temperature of 300-500℃, and is used to reduce CO emissions.

3. The energy-saving and silent gas burner according to claim 1, characterized in that: The converging angle of the gas nozzle is 15°-30°, and the throat diameter is 2-5mm; the guide angle of the spiral guide vane is 45°-60°, and the pitch is 10-20mm.

4. The energy-saving and silent gas burner according to claim 1, characterized in that: The excess air coefficient in the lean combustion zone is 1.2-1.5, the excess air coefficient in the rich combustion zone is 0.8-1.0, and the porous ceramic plate covering the combustion surface has a pore size of 0.5-2 mm and a porosity of 40%-60%.

5. An energy-saving and quiet smoke extraction system, characterized in that, It is applied to the energy-saving and silent gas burner as described in any one of claims 1-5.

6. The energy-saving and silent smoke exhaust system according to claim 5, characterized in that, Also includes: The dual-channel exhaust pipe has an inner flue gas channel and an outer air preheating channel that are coaxially nested. The inlet of the outer channel is connected to the burner's combustion air supply pipeline. The variable frequency silent fan uses a brushless DC motor with a power of 50-500W, and the speed is adjusted according to the flue gas temperature signal by a PID controller. The condensing heat exchanger is constructed from 316L stainless steel corrugated tubes, with a heat exchange area of ​​2-20 m². 2 The flue gas outlet temperature is ≤60℃.

7. The energy-saving and silent smoke exhaust system according to claim 6, characterized in that: The fan and the exhaust pipe are connected by a silicone rubber flexible connector and a spring shock absorber. The silicone rubber flexible connector has a Shore hardness of 40-60HA, and the spring shock absorber has a stiffness coefficient of 10-30N / mm.

8. The energy-saving and silent smoke exhaust system according to claim 6, characterized in that: The diameter of the inner flue gas channel is 80-200mm, and the annular gap width of the outer air preheating channel is 10-30mm. The stainless steel corrugated tubes of the condenser heat exchanger have a diameter of 8-15 mm and a wall thickness of 0.5 mm.

9. The energy-saving and silent smoke exhaust system according to claim 5, characterized in that: The control method for the energy-saving and silent smoke exhaust system is as follows: S1. Real-time monitoring of gas supply using a flow sensor to calculate theoretical air demand; S2. Adjust the opening of the spiral guide vane to match the air flow and maintain the air-fuel ratio error ≤ ±3%. S3. Dynamically adjust the fan speed according to the exhaust gas temperature to maintain the system resistance at 200-500Pa.

10. The energy-saving and silent smoke exhaust system according to claim 9, characterized in that: In step S3, the control system dynamically adjusts the fan speed based on the real-time monitored flue gas temperature and the set threshold to maintain the system resistance within the range of 200-500 Pa. The specific adjustment process is as follows: When the exhaust gas temperature exceeds the set threshold of 60℃, it indicates that the combustion system may have incomplete combustion or poor heat dissipation, requiring an increase in airflow to improve combustion efficiency. At this time, the control system will increase the fan speed and increase the air supply, which will also increase the system resistance. During the adjustment process, the control system will monitor the system resistance in real time. When the system resistance exceeds 500Pa, it will appropriately reduce the fan speed to maintain the system resistance within a reasonable range. When the exhaust gas temperature is lower than the set threshold of 60℃, it indicates that the combustion system may be supplying too much air, resulting in a decrease in combustion temperature. At this time, the control system will reduce the fan speed and reduce the air supply, and the system resistance will also decrease accordingly. When the system resistance is lower than 200Pa, the fan speed will be appropriately increased to maintain the system resistance within the range of 200-500Pa.

Images