Plasma generator and lean fuel combustion device

Abstract

The application discloses a kind of plasma generator and rare fuel combustion device, belong to plasma combustion-supporting technical field.The plasma generator uses innovative four-stage electrode cascade discharge structure, including shell, first electrode, second electrode, third electrode, fourth electrode and flow guide helix.First, second electrode generates low-temperature plasma to carry out preliminary activation cracking to gas-air mixture;Third, fourth electrode generates high-temperature plasma to carry out depth catalysis and directly ignites, forms the cascade process of "first activation, then ignition", significantly improves gas molecule activation efficiency.The taper flow channel of device shell and trapezoidal combustion chamber structure optimize the air flow and anchor flame, enhance stability.The rare fuel combustion device containing the generator integrates precise gas supply system and intelligent ignition control system, can automatically adjust gas-electricity parameters according to combustion state, realizes the efficient, clean, stable combustion of gas.

Description

Technical Field

[0001] This invention relates to the field of plasma combustion technology, specifically to a plasma generator and a lean fuel combustion device. Background Technology

[0002] As a commonly used heating device, the core performance of gas stoves depends on the combustion efficiency and environmental friendliness of the gas. However, traditional gas stoves generally adopt atmospheric combustion, which has problems such as low combustion efficiency, high emissions of harmful gases, poor stability, and difficulty in starting at low temperatures. Specifically, gas molecules are difficult to fully activate, resulting in low energy utilization. During the combustion process, pollutants such as nitrogen oxides and carbon monoxide are easily produced due to local high temperature and uneven mixing. Furthermore, under fluctuating gas pressure or low temperature conditions, unstable flames, flameout, and difficulty in ignition are prone to occur, which seriously restricts the improvement of energy efficiency and safe use.

[0003] Plasma-assisted combustion technology, as a cutting-edge method that can effectively improve gas combustion efficiency and reduce pollutant emissions, has been gradually applied in the field of combustion devices. Existing plasma combustion devices generate plasma by applying an electric field near the burner, utilizing its highly reactive particles to promote fuel combustion, achieving certain results. However, inherent defects in the structural design of plasma generators limit further performance improvements and widespread application.

[0004] Existing plasma combustion devices suffer from insufficient plasma generation efficiency and activation effect. Most existing devices employ a simple dual-electrode structure to generate plasma in the gas flow path. This structure produces a limited plasma region, and the mixing with the combustion gas is incomplete. The short interaction time between the gas flow and the plasma results in insufficient activation and breakdown of combustion gas molecules, ineffective disruption of their chemical bonds, and a limited reduction in the activation energy of the combustion reaction. Therefore, the improvement in combustion efficiency encounters a bottleneck, making it difficult to achieve deep and clean combustion of combustion gas molecules. Thus, there is an urgent need for a novel, integrated plasma generator design that can simultaneously address the issues of efficient activation, reliable ignition, and stable combustion. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a plasma generator and a lean fuel combustion device. The activation effect of ultra-low temperature plasma on the gas-air mixture solves the problems of low efficiency, high harmful gas emissions, poor combustion stability, and difficulty in low-temperature start-up of traditional gas stoves, achieving efficient, clean, and stable combustion of gas.

[0006] This invention is achieved through the following technical solution:

[0007] A plasma generator includes a housing, a first electrode, a second electrode, a third electrode, a fourth electrode, and a flow-guiding spiral.

[0008] The outer shell includes an upper shell and a lower shell. The lower shell has a hollow slotted structure inside, which includes a wide end and a narrow end. An air inlet is provided at the bottom of the lower shell. The air inlet is connected to the hollow slotted structure inside to form an air outlet gap. A flow guide spiral is placed inside the air inlet.

[0009] The first electrode and the second electrode are placed in the slot at the wide end of the upper part. The first electrode and the second electrode are respectively attached to the inner side of the slot in the lower housing. The distance between the first electrode and the second electrode is the same as the distance at the narrow end of the lower part.

[0010] The upper housing has a trapezoidal slotted structure inside, and a third electrode and a fourth electrode are attached to the inclined side of the trapezoidal slotted structure. The tops of the first electrode and the second electrode extend into the trapezoidal slotted structure inside the upper housing.

[0011] Furthermore, the first electrode and the second electrode are made of conductive material with a thickness of 1-2 mm. The opposing surfaces of the first electrode and the second electrode are covered with a high-temperature resistant insulating layer with a thickness of 1-2 mm, and are respectively fixedly attached to the outer shell of the plasma generator, forming a discharge gap of 0.5-2 mm between them.

[0012] Furthermore, the third and fourth electrodes are made of conductive material with a thickness of 1-3 mm.

[0013] A lean fuel combustion device including the plasma generator comprises an outer shell, a plasma power supply, a gas supply system, and a combustion section. The outer shell is hollow, and a mounting groove is formed on the top plate of the outer shell. The combustion section is fixed within the mounting groove, and the combustion section includes a cylindrical barrel. The bottom of the cylindrical barrel is fixed inside the outer shell, and the top of the cylindrical barrel extends out of the mounting groove on the top plate. An insulating heat-insulating plate is fixed inside the cylindrical barrel, and several slots are provided on the circumference of the insulating heat-insulating plate. The plasma generator is fixed within each slot, and the plasma power supply provides power to the plasma generator. A pot rack is placed on the outer periphery of the cylindrical barrel on the top plate.

[0014] The gas supply system consists of a small air pump, a gas storage tank, a gas filter, an air filter, a mixer, a gas flow controller, an air flow controller, and a mixed gas flow controller.

[0015] The small air pump is fixed inside the housing to provide a continuous air source for the air supply system; the air outlet of the small air pump is connected to the air inlet of the air filter through a pressure-resistant hose; the air outlet of the air filter is connected to the air inlet of the air flow controller through a pipeline; and the air outlet of the air flow controller is connected to the air interface of the mixer through a pipeline.

[0016] The gas outlet valve of the gas storage tank is connected to the gas inlet of the gas filter via a gas pipeline; the gas outlet of the gas filter is connected to the gas inlet of the gas flow controller via a pipeline; and the gas outlet of the gas flow controller is connected to the gas interface of the mixer via a pipeline.

[0017] The outlets of the air flow controller and the gas flow controller are connected to the two independent air inlets of the mixer through pipelines with one-way valves; the mixed gas processed by the mixer is connected to the air inlet of the mixed gas flow controller through a pipeline; the outlet of the mixed gas flow controller is connected to the air inlet of the plasma generator through a pipeline.

[0018] Furthermore, the gas storage tank is equipped with a pressure safety valve outside the overall structure to store gas and ensure a stable gas supply.

[0019] Furthermore, the mixer has a gas inlet on one side and an air inlet on the other side. A first guide plate and a second guide plate are fixed inside the mixer. Each guide plate has several air guide holes, with the diameter of the holes on the first guide plate being smaller than the diameter of the holes on the second guide plate. The top plate of the mixer has several air outlets. The function of the mixer is to ensure thorough mixing of air and gas upon entry, preventing excessively high or low local gas concentrations.

[0020] Furthermore, the gas filter or air filter is equipped with a stainless steel filter screen and an activated carbon adsorption layer to filter impurities and moisture in the gas source, preventing impurities from clogging the discharge gap of the plasma generator or moisture from affecting the discharge and combustion effects, and extending the service life of the plasma generator.

[0021] Furthermore, the gas supply system consists of a mixture of air and a trace amount of fuel gas, wherein the fuel gas is selected as methane or butane, and the air-to-fuel gas volume ratio is (50-100):1. This ratio ensures that the gas source is fully ionized during the discharge process to generate high-concentration plasma, while the fuel gas is controlled below the explosion limit to avoid safety risks caused by excessive fuel gas, thus balancing plasma activity and equipment safety.

[0022] Furthermore, the flow controller adopts an electromagnetic flow control valve, which can adjust the delivery flow rate of the mixed gas in real time, and achieve the matching of gas source flow rate and plasma power through linkage control with the plasma power supply, so as to ensure plasma stability under different processing conditions. The flow controller can adopt commonly used sensors such as mass flow controllers available on the market.

[0023] Furthermore, it also includes a temperature sensor for detecting combustion temperature.

[0024] Furthermore, the lean fuel combustion device also includes an ignition control system. This system uses a PCB circuit board as its core, integrating a gas flow controller, an air flow controller, a temperature sensor, and a device start / stop switch. The control system is precisely programmed and can collect real-time data on gas flow, air flow, and combustion temperature, maintaining the gas-air mixture ratio within the optimal range. Simultaneously, it controls the operating mode of the plasma power supply and gas supply system according to the combustion state: during the ignition phase, the plasma generator operates at high power or the gas-air mixture ratio in the gas supply system is increased to improve the ignition success rate; during the stable combustion phase, the gas-air mixture ratio is slowly reduced, and the plasma output intensity is automatically adjusted based on the gas flow and temperature to balance combustion efficiency and harmful gas emissions; in abnormal conditions (such as excessively low gas pressure), the plasma intensity is increased to prevent flame extinguishing.

[0025] Beneficial technical effects of the present invention:

[0026] (1) This invention employs a two-stage discharge structure consisting of a first and a second electrode and a third and a fourth electrode. The first and second electrodes are responsible for the initial discharge, generating low-temperature plasma to preliminarily activate and crack the combustion gas; the third and fourth electrodes generate high-temperature plasma for deep catalysis and direct ignition. This cascade structure of "activation first, then ignition" greatly prolongs the residence and reaction time of combustion gas molecules in the plasma environment, allowing the CH bonds of the combustion gas to be more fully destroyed, fundamentally reducing the activation energy of the combustion reaction physically, significantly improving combustion efficiency, and greatly reducing harmful gas emissions.

[0027] (2) The guide spiral of the air inlet at the bottom of the lower shell of this invention causes the gas to rotate, resulting in more uniform mixing; combined with the gradually narrowing flow channel of the lower shell, it accelerates the gas and guides it smoothly to the discharge gap. The trapezoidal slotted structure of the upper shell and the precise fit between the third and fourth electrodes and the first and second electrodes form a natural flame combustion chamber. This structure firmly confines the high-temperature plasma zone and the initial flame within the narrow space between the third and fourth electrodes, producing a strong "anchoring" effect. This makes it extremely difficult for the flame to be blown away or extinguished by the airflow, fundamentally solving the problem of poor flame stability in traditional stoves, and maintaining stability even when the gas pressure fluctuates.

[0028] (3) The first and second electrodes are made of conductive material with a thickness of 1-2 mm and covered with a high-temperature resistant insulating layer of the same thickness. The insulating layer acts as a barrier to prevent the discharge from directly contacting the metal electrode and to limit the current growth, so that the discharge remains stable.

[0029] (4) The gas supply system (flow controller, mixer) and plasma power supply of this application are structurally linked through the ignition control system (PCB), rather than operating independently. This structure allows the system to automatically adjust the gas path (gas / air ratio, total flow rate) and circuit (plasma power) according to different states such as ignition, stable combustion, and abnormality, to achieve optimal matching of gas and electrical parameters. Through structural closed-loop control, the gas concentration is always kept within a safe range, and structural intervention (such as cutting off the gas path) can be performed immediately in case of abnormality, thus fundamentally improving safety. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a plasma generator.

[0031] Figure 2 This is a cross-sectional view of the plasma generator;

[0032] Figure 3 This is another cross-sectional view of the plasma generator;

[0033] Figure 4 This is a schematic diagram of the lower housing of a plasma generator;

[0034] Figure 5 This is a cross-sectional schematic diagram of the lower housing of the plasma generator;

[0035] Figure 6 This is a schematic diagram of the combustion section;

[0036] Figure 7 This is a partial structural diagram of the combustion section;

[0037] Figure 8 A schematic diagram of the overall structure of a lean fuel combustion device;

[0038] Figure 9 A schematic diagram of the internal structure of a lean fuel combustion device;

[0039] In the diagram: 1-Outer shell, 2-Upper shell, 3-Lower shell, 4-First electrode, 5-Second electrode, 6-Third electrode, 7-Fourth electrode, 8-Guiding spiral, 9-Wide end, 10-Narrow end, 11-Air inlet, 12-Outer shell, 13-Combustion section, 14-Cylinder, 15-Insulating heat shield, 16-Plasma generator, 17-Boiler frame, 18-Ignition control system, 19-Plasma power supply, 20-Small air pump, 21-Mixer. Detailed Implementation

[0040] Example 1: A plasma generator

[0041] See Figure 1-5The plasma generator 16 is the core activation and ignition component, and its specific components include a housing 1, an electrode system, and a flow guiding spiral 8.

[0042] The outer shell 1 is divided into an upper shell 2 and a lower shell 3, which are made of high-temperature resistant insulating materials such as alumina ceramic.

[0043] The lower shell 3 has a hollow, tapering flow channel structure, including a wide upper end 9 and a narrow lower end 10. An air inlet 11 is located at the bottom, communicating with the internal flow channel to form an exhaust gap. The upper shell 2 has a trapezoidal slotted structure inside, which naturally forms a combustion chamber.

[0044] The electrode system adopts a four-stage electrode design to achieve cascaded discharge.

[0045] The first electrode 4 and the second electrode 5 are made of conductive materials such as brass or stainless steel with a thickness of 1-2 mm. Their outer surfaces are covered with a high-temperature resistant insulating layer such as alumina ceramic with a thickness of 1-2 mm. The two electrodes are fixed in parallel to the inside of the wide end 9 of the lower housing 3, forming a discharge gap of 0.5-2 mm between them. Their function is to perform initial discharge, generate low-temperature plasma, and perform preliminary activation and cracking of the fuel gas-air mixture.

[0046] The third electrode 6 and the fourth electrode 7 are made of conductive materials such as brass and stainless steel with a thickness of 1-3 mm. They are respectively attached and fixed to the two inclined sides of the trapezoidal slot of the upper shell 2, and their bottoms are perfectly attached to the tops of the first and second electrodes 5. Their function is to generate high-temperature plasma up to 2000K or higher, to deeply catalyze and crack the pre-activated gas, and to directly ignite the mixture.

[0047] The flow-guiding spiral 8 is installed inside the air inlet duct 11 at the bottom of the lower housing 3. Its function is to cause the incoming mixed gas to rotate, making the mixing more uniform and increasing the initial flow rate of the gas.

[0048] The plasma generator 16 operates as follows: The mixed gas enters through the bottom inlet 11, is guided by the flow-guiding spiral 8, and then accelerates upward along the narrowing flow channel. First, it passes through the discharge gap between the first and second electrodes 5, where it is ionized to generate low-temperature plasma, initially activating the gas molecules. Subsequently, the activated gas enters the trapezoidal combustion chamber of the upper shell 2, where it is further acted upon by the high-temperature plasma between the third and fourth electrodes 7, ultimately being ignited. The trapezoidal structure "anchors" the flame between the third and fourth electrodes 7, greatly enhancing flame stability.

[0049] Example 2 Lean Fuel Combustion Device

[0050] See Figure 6-9The lean fuel combustion device is a complete system built around the plasma generator 16, including an outer shell 12 and a combustion section 13. The outer shell 12 serves as the main support for the device, is hollow inside, and has a cooling fan and a heat insulation layer to control the internal temperature. The top plate has an installation slot.

[0051] The core of the combustion section 13 is a cylindrical barrel 14 fixed inside the casing, with its top extending out of a mounting slot on a top plate. An insulating heat insulation plate 15 is fixed inside the cylindrical barrel 14, and multiple slots are evenly cut on the circumference of the heat insulation plate, with one of the aforementioned plasma generators 16 fixed in each slot. The plasma power supply 19 supplies power to the plasma generators 16, and a pot rack 17 is placed on the outer periphery of the cylindrical barrel 14.

[0052] The gas supply system of the lean fuel combustion device provides a precisely proportioned and flow-controlled mixture. The gas source includes a small air pump 20 supplying air and an external gas storage tank storing methane or butane. The gas storage tank is equipped with a pressure relief valve. Air and gas pass through air filters and gas filters, respectively, which contain stainless steel mesh and activated carbon adsorption layers to filter impurities. The mixture then passes through independent air flow controllers and gas flow controllers, such as electromagnetic mass flow controllers, to precisely control the flow rate before entering the mixer 21.

[0053] The mixer 21 is internally equipped with a first guide plate and a second guide plate, both with air guide holes of different diameters to ensure thorough static mixing of air and fuel gas, preventing uneven concentration. The volume ratio of the mixed gas is controlled at air:fuel gas = (50-100):1, ensuring it is within the explosion limits and conducive to ionization. The uniformly mixed gas then passes through a mixed gas flow controller and is finally delivered through pipelines to the air inlet ducts 11 of each plasma generator 16.

[0054] The lean fuel combustion device also includes an ignition and control system. The system, centered on a PCB circuit board, integrates a gas / air flow controller, a temperature sensor to detect combustion temperature, and a device start / stop switch. The system collects real-time data on gas flow, air flow, and combustion temperature, and controls the combustion precisely through a program.

[0055] During the ignition phase, the ignition success rate can be improved by controlling the high power output of the plasma power supply 19 or by appropriately increasing the proportion of gas in the mixture.

[0056] During the stable combustion phase, the proportion of fuel gas is gradually reduced, and the plasma output power is automatically adjusted according to the real-time fuel gas flow and temperature to balance combustion efficiency and pollutant emissions.

[0057] In abnormal situations, such as detecting abnormalities like low gas pressure, the system will automatically increase plasma intensity to stabilize the flame or cut off the gas supply to ensure safety.

[0058] The lean fuel combustion device also includes a safety protection system to provide flameout and fault protection. It employs a sensor that, upon detecting accidental flameout, immediately commands the gas flow controller to shut down, cutting off the gas supply. When critical components such as the plasma generator 16 and the small gas pump 20 malfunction, the system will issue an alarm and stop the gas supply.

[0059] In summary, this invention, through its innovative four-stage electrode plasma generator 16 structure, combined with a precise gas supply system and intelligent ignition control, achieves efficient activation, stable ignition, and clean combustion of gas, effectively solving the problems of low combustion efficiency, high emissions, and poor stability of traditional gas stoves.

Claims

1. A plasma generator characterized by: The shell (1) includes an upper shell (2) and a lower shell (3), the inside of the lower shell (3) is a hollow slot structure, the hollow slot structure includes a wide end (9) and a narrow end (10), the bottom of the lower shell (3) is provided with an air inlet channel (11), the air inlet channel (11) is communicated with the hollow slot structure inside, forming an air outlet gap, the air inlet channel (11) is placed with a flow guide spiral (8); The wide end (9) of the upper slot is placed with a first electrode (4) and a second electrode (5), the first electrode (4) and the second electrode (5) are respectively attached to the inner side of the lower shell (3) slot, the distance between the first electrode (4) and the second electrode (5) is the same as the distance of the narrow end (10) below; The inside of the upper shell (2) is provided with a trapezoidal slot structure, the third electrode (6) and the fourth electrode (7) are attached to the inclined side of the trapezoidal slot structure, the top of the first electrode (4) and the second electrode (5) extends into the trapezoidal slot structure inside the upper shell (2). The first electrode (4) and the second electrode (5) are made of conductive material with a thickness of 1-2mm, the opposite faces of the first electrode (4) and the second electrode (5) are covered with a high-temperature-resistant insulating layer with a thickness of 1-2mm, and are respectively fixedly attached to the shell (1) of the plasma generator (16), and a discharge gap of 0.5-2mm is formed between them.

2. The plasma generator of claim 1, wherein: The third electrode (6) and the fourth electrode (7) are made of conductive material with a thickness of 1-3mm; the shell (1) is made of high-temperature-resistant insulating material.

3. The plasma generator of claim 1, wherein: The external shell (12) is hollow, the top plate of the external shell (12) is provided with a mounting groove, and the mounting groove is fixedly provided with a combustion part (13); 4. A lean fuel combustion device comprising the plasma generator of any one of claims 1-3, characterized by: The combustion part (13) includes a barrel (14), the bottom of the barrel (14) is fixed in the inside of the external shell (12), the top of the barrel (14) extends out of the mounting groove of the top plate, the barrel (14) is fixedly provided with an insulating heat insulation plate (15), a plurality of grooves are arranged on the circumference of the insulating heat insulation plate (15), and a plasma generator (16) is fixedly arranged in the groove, the plasma power supply (19) supplies power to the plasma generator (16), and a pot rack (17) is arranged on the top plate and the outer circumference of the barrel (14). The lean fuel combustion device further comprises a gas supply system, and the gas supply system is composed of a small air pump (20), a gas storage tank, a gas filter, an air filter, a mixer (21), a gas flow controller, an air flow controller and a mixed gas flow controller; 5. The lean fuel burning device of claim 4, wherein: ​ The small air pump (20) is fixed in the shell and provides a continuous air source for the air supply system; the air outlet of the small air pump (20) is connected to the air inlet of the air filter through a pressure-resistant hose; the air outlet of the air filter is connected to the air inlet of the air flow controller through a pipeline, and the air outlet of the air flow controller is connected to the air inlet of the mixer (21) through a pipeline; The gas outlet valve of the gas storage tank is connected to the air inlet of the gas filter through a gas pipeline; the air outlet of the gas filter is connected to the air inlet of the gas flow controller through a pipeline, and the air outlet of the gas flow controller is connected to the gas inlet of the mixer (21) through a pipeline; The air outlets of the air flow controller and the gas flow controller are respectively connected to the two independent air inlets of the mixer (21) through pipelines with one-way valves; the mixed gas treated by the mixer (21) is connected to the air inlet of the mixed gas flow controller through a pipeline; the air outlet of the mixed gas flow controller is connected to the air inlet of the plasma generator (16) through a pipeline.

6. The lean fuel burning device of claim 5, wherein: One side of the mixer (21) is provided with a gas inlet, and the other side is provided with an air inlet; the inside of the mixer (21) is fixed with a first guide plate and a second guide plate, the first guide plate and the second guide plate are provided with a plurality of air guide holes, the diameter of the air guide holes on the first guide plate is smaller than that of the air guide holes on the second guide plate, and the top plate of the mixer (21) is provided with a plurality of air outlets; the mixer (21) can fully mix the air and the gas after entering the mixer (21), so as to avoid local high or low gas concentration.

7. The lean fuel burning device of claim 5, wherein: The lean fuel combustion device further comprises an ignition control system (18), which takes a PCB circuit board as a control core and is combined with a gas flow controller, an air flow controller, a temperature sensor and a device start-stop switch; the control system is controlled by a program and can collect gas flow, air flow and combustion temperature data in real time, so as to maintain the mixing ratio of gas and air in an optimal range.

8. The lean fuel burning device of claim 7, wherein: According to the working modes of the plasma power supply (19) and the air supply system controlled by the combustion state: in the ignition stage, the plasma generator (16) power supply is operated at high power or the proportion of mixed gas in the air supply system is increased to improve the ignition success rate; in the stable combustion stage, the proportion of gas in the mixed gas is reduced, the plasma output intensity is automatically adjusted according to the gas flow and temperature, and the combustion efficiency and harmful gas emission are balanced; when the gas pressure is too low, the plasma intensity is increased to prevent the flame from being extinguished.

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