Natural gas heating furnace with flue gas purification effect

Abstract

The invention belongs to the technical field of natural gas heating equipment, and particularly relates to a natural gas heating furnace with a flue gas purification effect, which comprises a combustion device for natural gas combustion and heat release, a flue gas purification net is arranged above the combustion device, and when the combustion device works, the flue gas purification net is arranged above the combustion device. And the flue gas purification net can be heated to a carbon monoxide ignition point by heat released by natural gas combustion. Compared with the prior art, by arranging the smoke purification net, the technical problems that in the prior art, carbon monoxide is generated due to insufficient combustion in the natural gas combustion process, carbon monoxide is rapidly accumulated indoors, and the body health of a user is harmed are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural gas heating equipment, and particularly relates to a natural gas stove with a flue gas purification effect. Background Art

[0002] Sitting around a stove to keep warm is one of the traditional heating methods in China. Especially in the southwestern regions with cold, humid climates, stoves were once very popular. However, traditional heating methods using firewood or coal directly produce a large amount of harmful gases such as carbon monoxide and sulfur dioxide, and the ashes generated after combustion also cause relatively large pollution to the environment. Therefore, this direct combustion of solid fuels for heating has been gradually phased out, replaced by more environmentally friendly and efficient heating methods such as electric heating and natural gas heating.

[0003] For relatively small indoor environments, electric heaters have become the first choice. Electric heaters convert electrical energy into heat energy, do not produce harmful gases and ashes, and are safe and convenient to use. However, in the face of larger indoor environments, the heat radiation range of electric heaters is relatively small. To achieve an ideal indoor heating effect, it often involves relatively large power consumption. Therefore, natural gas heating solutions have become a better choice for indoor heating.

[0004] Existing natural gas heating equipment mostly uses natural gas as fuel and does not produce solid waste during the combustion process. Compared with electric heating solutions, natural gas heating is more energy-efficient and has lower usage costs. At the same time, natural gas has a high combustion efficiency and a large heat output, making it suitable for indoor heating environments with a relatively large area.

[0005] Existing natural gas heating equipment includes a table body, and a heating device is arranged under the tabletop of the table body. The heating device includes a natural gas furnace, and the natural gas furnace is connected to a natural gas pipeline. The natural gas pipeline supplies natural gas into the furnace and mixes with air, and then is ignited by an ignition device in the heating device to generate heat for heating the environment. When it is necessary to adjust the firepower of the natural gas furnace, the adjustment method is mostly as described in the patent "A Flow Control System and Method for a Natural Gas Intelligent Heater" (application number CN202411230725.X, publication date 20241029): A flow control method for a natural gas intelligent heater,... By controlling the valve core opening of the proportional solenoid valve or controlling the stepping motor to adjust the valve core opening of the control valve, the natural gas flow can be accurately regulated, and by adjusting the natural gas flow in the pipeline through the proportional solenoid valve or the stepping motor, the firepower output of the heater can be indirectly controlled...; Another example is as described in the patent "An Environment-Adaptive Fully Premixed Condensing Natural Gas Dual-Purpose Boiler" (application number CN202120384831.9, publication date 20211119): If the temperature value feedback by the second temperature sensor is lower than the calibration value, the controller sends an instruction to the natural gas regulating valve to increase the natural gas supply flow. If the temperature value feedback by the second temperature sensor is higher than the calibration value, the controller sends an instruction to the natural gas regulating valve to decrease the natural gas supply flow. The controller adjusts the natural gas proportional valve according to the feedback signal to control the air-natural gas ratio to make it reach the optimal ratio.

[0006] In the above prior art, the method of adjusting the firepower is mostly to adjust the natural gas flow by controlling the opening of the valve body, and then adjust the firepower. The advantage of this stepless adjustment method is that the firepower can be freely adjusted according to the user's usage habits. However, this adjustment method also has the following defects: During the firepower adjustment process, since the natural gas flow will change, in order to ensure a certain combustion efficiency, a certain amount of air will also be introduced into the equipment to ensure that the air-fuel ratio is within a certain range so that the natural gas combustion efficiency is close to the maximum combustion efficiency. However, during the adjustment process, these heating equipment cannot maintain the air-natural gas ratio at the ideal air-fuel ratio constantly, resulting in a decrease in the natural gas combustion efficiency in some temperature ranges; In the case of reduced combustion efficiency, due to the incomplete combustion of natural gas, carbon monoxide is generated during the combustion process. When the amount of carbon monoxide generated is large, it will endanger the health of users in the case of long-term use. Moreover, natural gas heating equipment is mostly used in cold weather, and users usually close the doors and windows for insulation. In this case, carbon monoxide accumulates rapidly, and in severe cases, it will cause carbon monoxide poisoning of users. Summary of the Invention

[0007] The present invention aims to provide a natural gas heater with a flue gas purification effect, mainly to solve the technical problem existing in the prior art that carbon monoxide is generated due to incomplete combustion during the combustion of natural gas, and the carbon monoxide rapidly accumulates indoors, endangering the health of users.

[0008] To solve the above technical problems, the present invention provides the following technical solutions:

[0009] A natural gas heater with a flue gas purification effect, including a combustion device for burning natural gas to release heat, a flue gas purification net is arranged above the combustion device, and when the combustion device works, the flue gas purification net can be heated to the ignition point of carbon monoxide by the heat released from the combustion of natural gas.

[0010] The beneficial effects of the present invention are as follows:

[0011] When natural gas burns at the combustion device, the released heat also heats the flue gas purification net to the ignition point of carbon monoxide. During the combustion process of natural gas, the carbon monoxide generated due to an imperfect combustion ratio contacts the flue gas purification net and is re-burned into harmless carbon dioxide. Compared with the prior art, this solution reduces the release amount of carbon monoxide during the use of the natural gas heater by adding a flue gas purification net to re-burn the waste gas generated during the combustion process, and solves the technical problem existing in the prior art that carbon monoxide is generated due to incomplete combustion during the combustion of natural gas, and the carbon monoxide rapidly accumulates indoors, endangering the health of users.

[0012] Preferably, the combustion device includes a plurality of combustion units, each combustion unit includes a combustion chamber and a combustion plate arranged on the combustion chamber, the combustion plate includes a carrier provided with a plurality of honeycomb holes, and a solid catalyst for catalytic combustion is attached to the surface of the carrier;

[0013] The combustion chamber is communicated with a gas supply device, and the gas supply device is used to send the mixed gas formed by mixing natural gas and air according to the ideal air-fuel ratio into the interior of the combustion chamber and spray it out from the honeycomb holes of the combustion plate; the combustion device also includes an ignition device for igniting the mixed gas sprayed out at the combustion plate; the gas supply devices corresponding to the plurality of combustion units can be individually controlled to open and close, and the gas supply volume of the gas supply device is a constant value when it is opened and 0 when it is closed.

[0014] In this solution, if the heating power needs to be adjusted, the air supply device can be controlled to select the corresponding number of combustion units to be turned on. The more combustion units are turned on, the more heat is generated, so as to adjust the heating temperature to the required temperature. At the same time, since this solution adjusts the heating temperature by adjusting the number of combustion units, and the way of adjusting the temperature does not involve the change of the natural gas delivery volume, the designed actual air-fuel ratio will not change due to the adjustment of the heating temperature, thus avoiding the problem of air-fuel ratio change caused by stepless adjustment in the prior art, which leads to incomplete combustion of natural gas.

[0015] In addition, in this solution, a solid catalyst is used to catalytically combust natural gas, which can reduce the activation energy required for the combustion of natural gas and carbon monoxide, enabling natural gas and carbon monoxide to burn at a lower temperature, thereby improving the combustion efficiency of natural gas and reducing the concentration of carbon monoxide in the exhaust gas generated after combustion.

[0016] Preferably, the heat capacity of the flue gas purification net is smaller than that of the combustion plate, so that the flue gas purification net can reach the ignition point of carbon monoxide faster than the combustion plate.

[0017] In this solution, even during the normal use of the natural gas stove, it is impossible for natural gas to burn completely on the combustion plate 100%. Some unburned gas will be directly discharged into the air, resulting in a decrease in indoor air quality and a risk of carbon monoxide poisoning. At the same time, since the combustion device takes time to heat up, at the moment when the natural gas stove is turned on, the flame that ignites the natural gas cannot burn the natural gas fully, thus generating a large amount of carbon monoxide. The concentration of carbon monoxide in the exhaust gas generated in the early stage of the combustion device is the highest, and the concentration of carbon monoxide gradually decreases to below the safety standard as the combustion time progresses. On this basis, in this solution, a flue gas purification net is provided on the original combustion unit, forming a relatively enclosed combustion space with the combustion plate surface. The area within the combustion space is less affected by external factors such as wind. The unburned gas undergoes secondary combustion in this combustion space, greatly improving the combustion efficiency. And because the combustion plate is closer to the natural gas combustion source than the flue gas purification net, the heat absorbed by the flue gas purification net per unit time is less than that absorbed by the combustion plate. To solve the defect of a large amount of carbon monoxide generated in the early stage of natural gas ignition, it is designed that the heat capacity of the flue gas purification net is smaller than that of the combustion plate (the heat capacity is the product of specific heat capacity and mass cm). On the premise of absorbing less heat, it can heat up to the ignition point of carbon monoxide faster than the combustion plate, ignite and remove the carbon monoxide in the exhaust gas, and greatly reduce the accumulation of indoor carbon monoxide during a single use.

[0018] Preferably, the material for making the flue gas purification net includes one or more of metal materials, ceramic materials, and carbon-based materials.

[0019] Preferably, the material for making the flue gas purification net includes one or several of ferritic stainless steel, nickel-chromium alloy, stainless steel, silver, copper, aluminum, iron, gold, copper-sodium alloy, copper-iron alloy, copper-nickel alloy, aluminum alloy, graphene, graphite, and carbon fiber.

[0020] In this solution, the flue gas purification net uses materials with extremely high thermal conductivity. By controlling the material selection and material quality, a better structure of the flue gas purification net can be optimized, enabling the flue gas purification net to be quickly heated to 600-1000°C by the combustion plate, which is much higher than the ignition point of natural gas. Unburned carbon monoxide will be ignited immediately when it encounters the net and burn again, enabling the full combustion of natural gas and its by-products. The comprehensive combustion efficiency of natural gas can exceed 99.3%, almost completely burning, and the combustion products are only carbon dioxide and water, achieving the purpose of flue gas purification for natural gas stoves.

[0021] At the same time, the listed materials have a relatively high specific heat capacity. The flue gas purification net can be made of only one substance, or multiple materials can be compounded to make the flue gas purification net. At the same time, by reducing the mass per unit area of the flue gas purification net, the heat capacity value of the flue gas purification net can be adjusted to meet the preset requirements.

[0022] Preferably, the distance between the top surface of the flue gas purification net and the combustion plate is 5-20 cm, and the distance between the side surface of the flue gas purification net and the side surface of the combustion plate is 3-20 cm; the mesh number of the flue gas purification net is 6-60 meshes; the flue gas purification net includes several intersecting mesh strips, and the cross-sectional diameter of the mesh strips is 0.1-1 mm.

[0023] In this solution, the difference between the flue gas purification net and the ordinary net cover covering the natural gas heat source is that the flue gas purification net in this solution needs to form a certain combustion space above the combustion unit, with smaller mesh holes, thinner mesh strips, lighter mass per unit volume, smaller heat capacity, and is easier to be heated to the required temperature in a short time.

[0024] Preferably, it further includes a table body. The table body includes a table bottom plate, on which liftable table legs are installed, and a table top is installed on the liftable table legs. The combustion device is installed on the table bottom plate, and the lower edge of the flue gas purification net is detachably connected to the upper surface of the table bottom plate; the combustion device further includes one or two of a thermal power balance chamber and a heat insulation cover that cover several combustion units from the inside out to allow the heat supply gas to dissipate; the flue gas purification net covers several combustion units above, and the flue gas purification net is set as any one of a cover-shaped structure, a support composite structure, a layered structure, and a semi-reel structure located inside the thermal power balance chamber or the heat insulation cover.

[0025] In this solution, on the one hand, the thermo-dynamic balance chamber can prevent the influence of external wind and other factors, making the combustion condition stable. On the other hand, it can slow down the speed of natural gas emission during the combustion process, reflect the generated tail gas to the combustion plate for secondary combustion, improve the combustion efficiency, and reduce the concentration of carbon monoxide in the tail gas. The anti-scald net cover is arranged on the outermost layer to prevent users from being scalded by approaching the combustion source too closely. Or when the flue gas purification net is connected to the thermo-dynamic balance chamber, the thermo-dynamic balance chamber can support the flue gas purification net to prevent it from deforming after long-term use. At the same time, in this solution, natural gas first burns in the honeycomb holes of the combustion plate, and then undergoes two combustion processes after being processed by the thermo-dynamic balance chamber and the flue gas purification net. That is, after the natural gas undergoes three rounds of combustion in total, the generated tail gas will enter the indoor environment, greatly reducing the content of carbon monoxide in the tail gas, and further solving the problem of carbon monoxide accumulation during the use of traditional natural gas heating stoves, which endangers the health of users.

[0026] Preferably, the flue gas purification net is arranged above a plurality of the combustion units, and the flue gas purification net is arranged in a hood-like structure or a support composite structure.

[0027] In this solution, the flue gas purification net uniformly surrounds the space above a plurality of the combustion units, and the tail gas generated by the combustion units must pass through the flue gas purification net to be purified before entering the indoor environment when it spreads around.

[0028] Preferably, the gas supply device includes a mixing pipe connected to the combustion chamber, one end of the mixing pipe away from the combustion chamber is connected to a gas supply pipe for transporting natural gas, a sectional valve is installed at the end of the gas supply pipe away from the mixing pipe, and one end of the sectional valve away from the gas supply pipe is connected to the natural gas supply system. When the sectional valve is opened, natural gas always enters the gas supply pipe at a constant flow rate; through holes are formed on the circumferential surface of the mixing pipe.

[0029] In this solution, when the sectional valve is opened, the natural gas in the natural gas supply system enters the gas supply pipe and passes through the mixing pipe at a constant flow rate. During the flow of natural gas, a negative pressure is formed in the mixing pipe, sucking the air around the mixing pipe into the mixing pipe through the through holes to mix with the natural gas, and then entering the combustion chamber together. By adjusting the flow rate of natural gas in this solution, the mixing ratio of natural gas and air can be adjusted. Compared with the proportional valve in the prior art, the structure used in this solution is simpler and has a lower maintenance rate.

[0030] Preferably, the natural gas supply system includes a gas source for providing natural gas and an electric control cut-off valve installed on the gas source for cutting off the natural gas supply system. The electric control cut-off valve is connected to the sectional valve; a gas sensor for detecting the carbon monoxide concentration is arranged outside the flue gas purification net. The gas sensor is electrically connected to a controller, and the controller is electrically connected to the electric control cut-off valve.

[0031] In this solution, when the gas sensor detects that the carbon monoxide concentration in the airflow passing through the flue gas purification net exceeds the standard, it sends an electrical signal to the controller. After determining that the carbon monoxide concentration exceeds the standard through the built-in program, the controller controls the electric control cut-off valve to operate to cut off the natural gas supply system and stop supplying gas to the combustion chamber.

[0032] Preferably, it further includes a fresh air system for exchanging indoor air and outdoor air. The fresh air system is electrically connected to the controller, and the gas source is electrically connected to the controller. When the gas source starts to supply gas, the controller controls the fresh air system to start working.

[0033] In this solution, in order to improve the safety of product use, when the gas source starts to supply gas and the combustion device starts to burn, the fresh air system is started to ventilate the room to avoid lack of oxygen, accumulation of carbon monoxide or carbon dioxide indoors. Brief Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to actual scale.

[0035] Figure 1 It is a three-dimensional structure diagram of Embodiment 1 of a natural gas roasting stove with a flue gas purification effect of the present invention patent;

[0036] Figure 2 It is an exploded three-dimensional structure diagram of Embodiment 1 of a natural gas roasting stove with a flue gas purification effect of the present invention patent;

[0037] Figure 3 It is a three-dimensional structure diagram of Embodiment 5 of a natural gas roasting stove with a flue gas purification effect of the present invention patent;

[0038] Figure 4 It is an exploded three-dimensional structure diagram of Embodiment 5 of a natural gas roasting stove with a flue gas purification effect of the present invention patent;

[0039] Figure 5 It is a three-dimensional structure diagram of the thermal power balance chamber and the flue gas purification net of Embodiment 6 of a natural gas roasting stove with a flue gas purification effect of the present invention patent;

[0040] Figure 6 It is a three-dimensional structure diagram of Embodiment 7 of a natural gas roasting stove with a flue gas purification effect of the present invention patent;

[0041] Figure 7 It is an exploded three-dimensional structure diagram of Embodiment 7 of a natural gas roasting stove with a flue gas purification effect of the present invention patent;

[0042] Figure 8 Exploded perspective view of Embodiment 8 of a natural gas roasting stove with flue gas purification effect of this invention patent;

[0043] Figure 9 Working flowchart of the protection system of Embodiment 1 of a natural gas roasting stove with flue gas purification effect of this invention patent;

[0044] Figure 10 Exploded perspective view of Embodiment 10 of a natural gas roasting stove with flue gas purification effect of this invention patent;

[0045] Figure 11 For a natural gas roasting stove with flue gas purification effect of this invention patent Figure 11 Enlarged view at position A.

[0046] Reference numerals in the accompanying drawings of the specification include: 1, table body; 11, table bottom plate; 21, combustion plate; 3, flue gas purification net; 31, support frame; 32, mesh surface; 33, protection plate; 34, clamping plate; 4, thermodynamic balance chamber; 5, anti-scald cover; 6, ignition device. Detailed implementation manners

[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0048] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "top part", "bottom part", "top surface", "bottom surface", "inner", "outer", "inner side", "outer side", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0049] In the description of the present invention, the meaning of "a number of" is one or more, the meaning of "a plurality of" is more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the corresponding number, while understandings such as "above", "below", "within", etc. include the corresponding number. If there are descriptions of the terms "first", "second", "third", etc., they are only for descriptive purposes and for distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0050] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. The following will describe the embodiments according to the overall structure of the present invention.

[0051] Embodiment 1:

[0052] As Figure 1-2 shown, a natural gas roasting stove with a flue gas purification effect includes a table body 1. The table body 1 includes a table bottom plate 11, and liftable table legs are installed on the table bottom plate 11, and a tabletop is installed on the liftable table legs; a warming plate for temporarily placing food is arranged below the tabletop.

[0053] A combustion device is installed on the table bottom plate 11. The combustion device includes three combustion units. Each combustion unit includes a combustion chamber and a combustion plate 21 arranged on the combustion chamber. The combustion plate 21 includes a carrier provided with a number of honeycomb holes, and a solid catalyst for catalytic combustion is attached to the surface of the carrier.

[0054] The combustion chamber is communicated with a gas supply device. The gas supply device is used to send the mixed gas formed by mixing natural gas and air according to the ideal air-fuel ratio into the interior of the combustion chamber and spray it out from the honeycomb holes of the combustion plate 21; the combustion device further includes an ignition device 6, and the ignition device 6 is a pulse igniter, which can ignite the mixed gas sprayed out at the combustion plate 21 after being started.

[0055] The air supply devices corresponding to the three combustion units can be controlled to open and close individually, and the air supply volume of the air supply device is a constant value when it is turned on and is 0 when it is closed; when the firepower needs to be adjusted, the air supply device can be controlled to choose to open the corresponding number of combustion units. The more combustion units are turned on, the more heat is generated, thereby adjusting the heating temperature to the required temperature; at the same time, because the present scheme adjusts the heating temperature by opening and closing the number of combustion units, the method of adjusting the temperature does not involve changes in the natural gas delivery volume, so the designed actual air-fuel ratio will not change due to the adjustment of the heating temperature, thereby avoiding the problem of insufficient combustion of natural gas caused by the change of air-fuel ratio due to stepless adjustment in the prior art.

[0056] In addition, the solid catalyst in this scheme is used to catalyze the combustion of natural gas, which can reduce the reaction activation energy required during the combustion of natural gas and carbon monoxide, so that natural gas and carbon monoxide can also burn at a lower temperature (lower than the original ignition point of natural gas and carbon monoxide), thereby improving the combustion efficiency of natural gas and reducing the concentration of carbon monoxide in the exhaust gas generated after combustion.

[0057] The air supply device includes an air mixing pipe connected to the combustion chamber, wherein one end of the air mixing pipe away from the combustion chamber is connected to an air supply pipe for conveying natural gas, and one end of the air supply pipe away from the mixing pipe is installed with a sectional valve, and the end of the sectional valve away from the air supply pipe is connected to the natural gas supply system. When the sectional valve is opened, the natural gas always enters the air supply pipe at a constant flow rate; a through hole is opened on the circumference of the mixing pipe, and when the sectional valve is opened, the natural gas in the natural gas supply system enters the air supply pipe and passes through the mixing pipe at a constant flow rate. During the flow of the natural gas, a negative pressure is formed in the mixing pipe, and the air around the mixing pipe is sucked into the mixing pipe from the through hole and mixed with the natural gas, and then enters the combustion chamber together; in summary, the mixing ratio of the natural gas and the air can be adjusted by adjusting the flow rate of the natural gas. Compared with the proportional valve in the prior art, the structure used in this scheme is simpler and has a lower maintenance rate. As long as the air flow rate of the natural gas is constant, the air-fuel ratio entering the combustion unit can be kept constant.

[0058] The carrier of the combustion plate 21 used in this embodiment is a cordierite honeycomb ceramic plate, the composition and structure of which are determined after multiple tests and continuous improvements. It can ensure stable combustion, high combustion efficiency, long service life and small waste emissions during use. Therefore, the combustion plate 21 has become one of the conventional choices in this industry.

[0059] A flue gas purification net 33 is arranged above the combustion device. The flue gas purification net 3 is a hood-like structure with only the bottom surface open. The lower edge of the flue gas purification net 3 is folded and detachably connected to the upper surface of the table bottom plate 11 by screws. When the combustion device is working, the flue gas purification net 3 can be heated to the ignition point of carbon monoxide by the heat released by the combustion of natural gas.

[0060] The distance between the top surface of the flue gas purification combustion net and the combustion plate 21 is 15 cm, and the distance between the side surface of the flue gas purification net 3 and the side surface of the combustion plate 21 is 4 cm; the mesh number of the flue gas purification net 3 is 6 meshes; the flue gas purification net 3 includes a number of intersecting wire rods, the cross-sectional diameter of the wire rods is 0.38 mm, and the flue gas purification net 3 is made of FeCrAl. In some embodiments, different materials can also be selected to make the flue gas purification net 3 according to actual situations, such as one or several of metal materials, ceramic materials, and carbon-based materials. It is also possible to preferably use the following materials for production, such as one or several of FeCrAl, nickel-chromium alloy, stainless steel, silver, copper, aluminum, iron, gold, copper-sodium alloy, copper-iron alloy, copper-nickel alloy, aluminum alloy, graphene, graphite, and carbon fiber.

[0061] In addition, the combustion device further includes a heat insulation cover 5 that covers the outside of the flue gas purification net 3 from the inside to the outside to prevent users from being scalded by getting too close to the combustion source.

[0062] The material properties of the flue gas purification net 3 and the material properties of the combustion plate 21 satisfy the following relational formula:

[0063] Q1 = c1m1ΔT1

[0064] Q2 = c2m2ΔT2

[0065] ΔT1 = ΔT2

[0066] Q1 > Q2

[0067] c1m1 > c2m2

[0068] In the formula, Q1 is the heat absorbed by the combustion plate 21, c1 is the specific heat capacity of the combustion plate 21, m1 is the mass of the combustion plate 21, and ΔT1 is the temperature difference per unit time of the combustion plate 21; Q2 is the heat absorbed by the flue gas purification net 3, c2 is the specific heat capacity of the flue gas purification net 3, m2 is the mass of the flue gas purification net 3, and ΔT2 is the temperature difference per unit time of the combustion plate 21. That is, the heat capacity of the flue gas purification net 3 is less than the heat capacity of the combustion plate 21 (the heat capacity is the product of the specific heat capacity and the mass cm). When the heat absorbed by the flue gas purification net 3 is less than that of the combustion plate 21, the temperature of the flue gas purification net 3 can also be higher than the temperature of the combustion plate 21.

[0069] The setting of the flue gas purification net 3 solves several key problems in the use process of the natural gas roasting stove:

[0070] 1. During the use process, although the combustion plate 21 can ensure the efficient and stable combustion of natural gas in the middle stage of combustion, it is certain that natural gas cannot be 100% fully burned on the combustion plate 21 and completely converted into carbon dioxide and water. During the combustion process, some carbon monoxide will still be produced as a by-product. After the flue gas purification net 3 is added, when natural gas burns at the combustion device, the released heat also heats the flue gas purification net 3 to the ignition point of carbon monoxide. During the combustion process of natural gas, the carbon monoxide generated due to the imperfect combustion ratio contacts the flue gas purification net 3 and is burned again to be converted into harmless carbon dioxide, achieving the function of filtering carbon monoxide, reducing the release amount of carbon monoxide during the use of the natural gas heating furnace, and solving the technical problem in the prior art that carbon monoxide is produced due to incomplete combustion during the combustion of natural gas, and carbon monoxide rapidly accumulates indoors, endangering the health of users.

[0071] 2. Since the combustion device needs time to heat up, at the moment when the natural gas heater is turned on, the flame that ignites the natural gas cannot fully burn the natural gas, resulting in a large amount of carbon monoxide being produced. The concentration of carbon monoxide in the exhaust gas generated in the early stage of the combustion of the combustion device is the highest, and the concentration of carbon monoxide gradually decreases to below the safety standard as the combustion time progresses. On this basis, in this solution, a flue gas purification net 3 is provided on the original combustion unit. The flue gas purification net 3 and the surface of the combustion plate 21 form a relatively closed combustion space. The area inside the combustion space is less affected by external factors such as wind, and the combustion conditions inside the chamber are relatively stable. During the whole process, the flue gas purification net 3 prolongs the residence time of the hot gas near the combustion plate 21, so that the exhaust gas will not escape too quickly, and the unburned natural gas and carbon monoxide gas are burned again in this combustion space, greatly improving the combustion efficiency;

[0072] And because the combustion plate 21 is closer to the natural gas combustion source than the flue gas purification net 3, the heat absorbed by the flue gas purification net 3 per unit time is less than the heat absorbed by the combustion plate 21. To solve the defect of a large amount of carbon monoxide generated in the early stage of natural gas ignition, it is designed that the heat capacity of the flue gas purification net 3 is less than the heat capacity of the combustion plate 21 (the heat capacity is the product of the specific heat capacity and the mass cm). Even on the premise of absorbing less heat, it can still heat up to the ignition point of carbon monoxide faster than the combustion plate 21, and preferentially ignite and remove the carbon monoxide in the exhaust gas, thus greatly reducing the accumulation amount of carbon monoxide indoors during a single use;

[0073] After testing, the flue gas purification net 3 can heat up to the ignition point of carbon monoxide within 10 seconds, while the combustion plate 21 of the natural gas stove in this embodiment needs 60 seconds to stably heat up to the ignition point of carbon monoxide. The flue gas purification net 3 can heat up to the ignition point of carbon monoxide faster than the combustion plate 21. Without replacing the combustion plate 21 or changing the combustion mode of the stove, the residual carbon monoxide in the tail gas can be ignited and removed, greatly reducing the carbon monoxide production of the natural gas stove during the ignition stage.

[0074] 3. During the actual use process, according to the feedback from multiple customers, the smell of the natural gas stove is relatively strong at the moment of ignition (odorants are added to household natural gas). After analysis, it can be known that due to the limitations of the structure and combustion mode of the natural gas stove itself, it is very difficult for the combustion plate 21 to quickly heat up to the effective combustion temperature at the moment of ignition. Therefore, within about 1 minute during the ignition stage, the combustion efficiency of natural gas is lower than the preset value. During this stage, a large amount of natural gas is wasted (so customers can smell the odor of natural gas), and a large amount of carbon monoxide waste gas is generated during combustion, affecting the customer experience. In the long term, if customers do not use it in accordance with the specified usage method, it may also lead to excessive indoor accumulation of carbon monoxide, endangering the health of users. After installing the flue gas purification net 3, it can effectively filter natural gas, slow down the overflow of the natural gas odor at the moment of ignition, and improve the product experience.

[0075] 4. The structure of the flue gas purification net 3 bin is simple and the cost is low. Without the need for high-cost upgrades to the combustion plate 21 or the combustion mode of the stove, it can further purify the carbon monoxide content in the tail gas, reduce the carbon monoxide production during the use of the natural gas stove, and achieve the effect of cost reduction and efficiency improvement.

[0076] To further improve the safety of using the natural gas stove, the natural gas stove is also equipped with a protection system to prevent indoor oxygen deficiency. The working mode of the protection system is as follows: As Figure 9 shown, the natural gas supply system includes a gas source for supplying natural gas and an electric control cut-off valve installed on the gas source for cutting off the natural gas supply. The electric control cut-off valve is connected to the sectional valve; a gas sensor for detecting the oxygen concentration is arranged outside the flue gas purification net 3. The gas sensor is electrically connected to a controller, and the controller is electrically connected to the electric control cut-off valve; when the flue gas analyzer detects that the oxygen content in the heating room ≤ 18.2%, there may be incomplete combustion due to oxygen deficiency, resulting in an excessive carbon monoxide concentration. At this time, the gas sensor sends an electrical signal to the controller to control the electric control cut-off valve to work and cut off the natural gas supply system, immediately stop supplying gas to the combustion device, close the valve, and turn off the fire source.

[0077] Embodiments 2 - 4:

[0078] Different from Example 1, the structure of the flue gas purification net 3, the distance from the combustion plate 21, and the materials used are as shown in the following table (the data of Example 1 are also listed for easy comparison):

[0079]

[0080] Example 5:

[0081] Different from Example 1, as Figure 3 、 Figure 4 , the combustion device further includes a thermal power balance chamber 4 for the heat supply gas to dissipate outwardly, which is sheathed on the three combustion units from the inside to the outside. The thermal power balance chamber 4 is arranged between the flue gas purification net 3 and the anti-scald cover 5, and the bottom of the thermal power balance chamber 4 can be detachably fixed on the table bottom plate 11 by bolts. The thermal power balance chamber 4 includes a chamber body, the chamber body has an opening downward and is sheathed on the flue gas purification net 3, and a plurality of air permeable holes are opened on the side wall of the chamber body. The hot gas generated by the combustion unit first accumulates in the chamber body, and then passes through the air permeable holes in the chamber body and penetrates out to supply heat to the external environment; in some embodiments, the flue gas purification net 3 can also be arranged outside the thermal power balance chamber 4 according to the actual size and use requirements of the thermal power balance chamber 4.

[0082] During use, natural gas first burns in the honeycomb holes of the combustion plate 21. The thermal power balance chamber 4 and the flue gas purification net 3 can slow down the speed of the natural gas diffusing outward during the combustion process, reflect the generated tail gas to the combustion plate 21 for secondary combustion, and remove the residual carbon monoxide. Natural gas is reflected by the combustion plate 21, the flue gas purification net 3, and the thermal power balance chamber 4 in sequence to complete the third round of combustion. Only after three rounds of combustion will the generated tail gas enter the indoor environment, greatly reducing the content of carbon monoxide in the tail gas, and further solving the problem of carbon monoxide accumulation during the use of traditional natural gas heating stoves, which is harmful to the health of users.

[0083] Example 6:

[0084] Different from Example 5, as shown in Figure 5, the flue gas purification net 3 is a layered structure. The flue gas purification net 3 is arranged parallel to the surface of the thermal power balance chamber 4 and is kept at a distance of 15 cm from the thermal power balance chamber 4, and the four sides of the flue gas purification net 3 are fixed to the inner wall of the thermal power balance chamber 4. In this embodiment, the flue gas purification net 3 and the side wall of the thermal power balance chamber 4 together enclose a combustion space, and the tail gas floats upward as a whole and can pass through the flue gas purification net 3 arranged above the combustion plate 21 to be purified. At the same time, the structure of the flue gas purification net 3 in this embodiment is simple, easy to replace, has low maintenance cost, and has a certain degree of adjustability. This installation scheme is more suitable for adapting to different sizes of combustion units and the thermal power balance chamber 4.

[0085] Example 7:

[0086] Different from Embodiment 1, as Figure 6 , Figure 7 shown, the flue gas purification net 3 is a support composite structure, including a support frame 31. The six faces of the support frame 31, namely the top, bottom, left, right, front, and back, are all hollowed out, and the net surface 32 is covered on the front, back, left, right, and top faces of the support frame 31. The net surface 32 is composed of the net strips in Embodiment 1, and the arrangement relationship between the net strips is the same as that in Embodiment 1; the bottom surface of the support frame 31 is detachably connected to the bottom plate 11 by bolts. In this embodiment, after adding the support frame 31, it can provide support for the net surface 32 and extend the service life of the flue gas purification net 3.

[0087] Embodiment 8:

[0088] The support frame 31 is also a support composite structure. Different from Embodiment 7, as Figure 8 shown, the net surface 32 is not provided on the top surface of the support frame 31, and a protective plate 33 made of stainless steel is detachably fixed on the top surface of the support frame 31. If the net surface 32 is provided on the top surface of the support frame 31 and is in a high-temperature environment for a long time, rust slag may be generated on the net surface 32 and fall onto the combustion plate to block the honeycomb holes. After replacing it with a stainless steel protective plate 33, this situation can be avoided.

[0089] Embodiment 9:

[0090] On the basis of Embodiment 1, the combustion device is also equipped with a fresh air system for exchanging indoor air and outdoor air. The fresh air system includes an air extraction pump, the air extraction pump is electrically connected to the controller, and the gas source is electrically connected to the controller. When the gas source starts to supply gas and the combustion device starts to work, the controller detects that the gas source starts to supply gas and then controls the air extraction pump to start working for indoor ventilation to avoid indoor oxygen deficiency and the accumulation of carbon monoxide or carbon dioxide.

[0091] In this embodiment, the tail gas is purified through catalytic combustion and the flue gas purification net 3, and the protection system monitors the indoor oxygen content in real time to open and close the natural gas supply system and the fresh air system for ventilation, providing multi-faceted safety protection for the use of the natural gas heater, comprehensively solving the drawbacks of the use of the natural gas heater, that is, the defect of carbon monoxide accumulation, and improving the comfort and safety of the use of the natural gas heater.

[0092] Embodiment 10:

[0093] Different from Embodiment 5, as Figure 10 and Figure 11As shown, the flue gas purification net 3 is a semi-reel structure formed by rolling a one-piece structure. Clamping plates 34 are respectively fixed at both ends of the flue gas purification net 3. The flue gas purification net is arranged inside the thermo-dynamic balance chamber 4, and the clamping plates 34 can be clamped between the thermo-dynamic balance chamber 4 and the table bottom plate 11. In the case of removing the thermo-dynamic balance chamber 4, the flue gas purification net 3 can also be arranged inside the heat insulation cover 5, and the clamping plates 34 are clamped between the heat insulation cover 5 and the table bottom plate 11.

[0094] In this embodiment, the flue gas purification net 3 is rolled inside the thermo-dynamic balance chamber 4 or the heat insulation cover 5, and the clamping plates 34 at both ends are clamped under the thermo-dynamic balance chamber 4 or the heat insulation cover 5. The flue gas purification net 3 fits the inner wall of the thermo-dynamic balance chamber 4 or the heat insulation cover 5 and forms an arch at the top. This structure has the following advantages:

[0095] 1. For customers who have already purchased traditional natural gas grills and need to upgrade to use the flue gas purification net, the original furnace body needs to be structurally modified to assemble the flue gas purification net 3. However, by setting the structure of the flue gas purification net 3 as a semi-reel structure that can freely change its shape, only the flue gas purification net 3 of this structure needs to be purchased and used in combination with the original thermo-dynamic balance chamber 4 or the heat insulation cover 5.

[0096] 2. The top of the flue gas purification net 3 of this structure naturally forms an arch, which can keep the flue gas purification net 3 at a relatively long distance from the hottest part of the combustion unit, avoiding damage to the flue gas purification net caused by overheating.

[0097] 3. The structure of this flue gas purification net is simple, easy to replace, with low manufacturing and usage costs, and the effect is not much different from that of Embodiment 5 or Embodiment 6.

[0098] Comparative Example 1:

[0099] Different from Embodiment 1, the flue gas purification net 3 is not provided.

[0100] During the use of the natural gas grills in Embodiments 1-9 and Comparative Example 1, various indicators were tested:

[0101] Filtration effect test: The flue gas analyzer was fixed on the table bottom plate 11 at a horizontal distance of 2 m from the combustion plate 21, and all three combustion units of the natural gas grill were turned on; the readings of various test items on the flue gas analyzer at 1 h after firing were recorded for each embodiment, and the test results are recorded in the following table:

[0102]

[0103] Analysis based on the test results:

[0104] 1. According to the data of Examples 1-10 and Comparative Example 1, when a flue gas purification net is added to a traditional natural gas roasting stove, the indoor CO content is significantly reduced, and the ambient temperature and flue gas temperature are significantly increased. This proves that after adding the flue gas purification net, there is an obvious filtering effect on carbon monoxide in the combustion exhaust gas, and it makes the natural gas combustion more complete, releasing more heat, resulting in a significant increase in both the ambient temperature and the flue gas temperature.

[0105] 2. Comparing the data of Example 9 with that of Example 1 and Comparative Example 1, when a fresh air system is added, the ventilation efficiency indoors is enhanced, and the accumulation of carbon monoxide indoors is further alleviated.

[0106] Odor test: The main test method is to smell by nose. From Example 1 to Example 10, no natural gas odor can be smelled at all 30 seconds after starting combustion; in Comparative Example 1, a slight odor of incompletely burned natural gas can still be smelled 30 seconds after starting combustion.

[0107] According to the analysis of the test results, setting the flue gas purification net 3 can effectively improve the combustion efficiency of burning natural gas. It not only reduces the residual amount of carbon monoxide, but also can filter out a large amount of odorous natural gas in the initial stage of combustion, improving the product use experience.

[0108] Gas content detection at the moment of firing:

[0109] Fix the flue gas analyzer on the table bottom plate 11 at a horizontal distance of 2 m from the combustion plate 21, and turn on all three combustion units of the natural gas roasting stove; record the readings of the carbon monoxide content on the flue gas analyzer 30 seconds after firing in Example 1 and Comparative Example 1. Test results: The test data of Example 1 is 22 ppm, and the test data of Comparative Example 1 is 29 ppm. From this, it can be proved that in the initial stage of firing, the flue gas purification net can indeed effectively purify the carbon monoxide exhaust gas generated in the initial stage of combustion.

[0110] The foregoing description of the specific exemplary embodiments of the present invention is for the purposes of illustration and exemplification. These descriptions are not intended to limit the present invention to the precise forms disclosed, and obviously, many changes and variations are possible in light of the above teachings. Although the embodiments of the present invention have been shown and described, the specific embodiments are merely interpretations of the present invention and not limitations thereof. The specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical applications, so that those skilled in the art can, after reading this specification, make modifications, substitutions, variations, and various different selections and changes that do not make creative contributions to the embodiments without departing from the principles and purposes of the present invention, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A natural gas stove with flue gas purification effect, comprising a combustion device for burning natural gas to release heat, characterized in that: A flue gas purification net is arranged above the combustion device. When the combustion device is working, the flue gas purification net can be heated to the ignition point of carbon monoxide by the heat released by the combustion of natural gas.

2. A natural gas stove with flue gas purification effect according to claim 1, characterized in that: The combustion device comprises a plurality of combustion units, wherein the combustion units comprise a combustion chamber and a combustion plate arranged on the combustion chamber, wherein the combustion plate comprises a carrier provided with a plurality of honeycomb holes, and a solid catalyst for catalytic combustion is attached to the surface of the carrier; The combustion chamber is connected to an air supply device, which is used to supply a mixed gas formed by mixing natural gas and air at an ideal air-fuel ratio into the combustion chamber and spray it out from the honeycomb holes of the combustion plate; the combustion device also includes an ignition device for igniting the mixed gas sprayed from the combustion plate; the air supply devices corresponding to several of the combustion units can be controlled to open and close individually, and the air supply volume of the air supply device is a constant value when it is turned on, and is 0 when it is closed.

3. The natural gas stove with flue gas purification effect according to claim 1, characterized in that: The heat capacity of the flue gas purification net is smaller than the heat capacity of the combustion plate, so that the flue gas purification net can reach the ignition point of carbon monoxide faster than the combustion plate.

4. The natural gas stove with flue gas purification effect according to claim 1, characterized in that: The material used to make the flue gas purification net includes one or more of metal materials, ceramic materials, and carbon-based materials.

5. The natural gas stove with flue gas purification effect according to claim 1, characterized in that: The material of the flue gas purification net includes one or more of iron-chromium-aluminum, nickel-chromium alloy, stainless steel, silver, copper, aluminum, iron, gold, copper-sodium alloy, copper-iron alloy, copper-nickel alloy, aluminum alloy, graphene, graphite, and carbon fiber.

6. The natural gas stove with flue gas purification effect according to claim 1, characterized in that: The distance between the top surface of the flue gas purification net and the combustion plate is 5 to 20 cm, and the distance between the side surface of the flue gas purification net and the side surface of the combustion plate is 3 to 20 cm; the mesh number of the flue gas purification net is 6 to 60 meshes; the flue gas purification net includes a plurality of staggered mesh strips, and the cross-sectional diameter of the mesh strips is 0.1 to 1 mm.

7. The natural gas stove with flue gas purification effect according to claim 1, characterized in that: It also includes a table body, which includes a table bottom plate, on which are mounted liftable table legs, on which are mounted a table top, the combustion device is mounted on the table bottom plate, and the lower edge of the flue gas purification net is detachably connected to the upper surface of the table bottom plate; the combustion device also includes one or two of a thermodynamic balance chamber and an anti-scalding cover for radiating heat from the inside to the outside, which are arranged on a number of combustion units; the flue gas purification net cover is arranged above a number of the combustion units, and the flue gas purification net is arranged to be any one of a cover-like structure, a supporting composite structure, a layered structure, and a semi-rolled structure located inside the thermodynamic balance chamber or the anti-scalding cover.

8. A natural gas stove with flue gas purification effect according to claim 2, characterized in that: The flue gas purification net cover is arranged above a plurality of the combustion units, and the flue gas purification net is arranged as a cover-shaped structure or a supporting composite structure.

9. The natural gas stove with flue gas purification effect according to claim 2, characterized in that: The air supply device includes a mixing pipe connected to the combustion chamber, the end of the mixing pipe away from the combustion chamber is connected to an air supply pipe for conveying natural gas, the end of the air supply pipe away from the mixing pipe is installed with a section valve, the end of the section valve away from the air supply pipe is connected to the natural gas supply system, when the section valve is opened, the natural gas always enters the air supply pipe at a constant flow rate; the circumferential surface of the mixing pipe is provided with through holes.

10. A natural gas stove with flue gas purification effect according to claim 9, characterized in that: The natural gas supply system includes a gas source for providing natural gas and an electrically controlled shut-off valve installed on the gas source for cutting off the natural gas supply system, wherein the electrically controlled shut-off valve is connected to a sectional valve; a gas sensor for detecting carbon monoxide concentration is arranged outside the flue gas purification network, wherein the gas sensor is electrically connected to a controller, and the controller is electrically connected to the electrically controlled shut-off valve.

Images