Pure hydrogen gas stove with precisely controlled hydrogen-air premix ratio

Abstract

This invention relates to a pure hydrogen gas stove with precise control of the hydrogen-air premixing ratio. It includes an electronically controlled pressure regulating valve, a fan, an expansion bladder, a pressure chamber, a constant pressure valve, an electromagnetic flow valve, a check valve, a gas turbulence device, a gas mixer, a gas mixing layer, a flow stabilizing chamber, a backfire prevention support layer, a gas preheating layer, a pre-combustion layer, an ignition surface, and a combustion radiation layer. Through the combined action of the electronically controlled pressure regulating valve, the expansion bladder, and the constant pressure valve under controller monitoring, the gas is kept at a constant pressure and introduced into the pipeline in a predetermined ratio, thus precisely controlling the hydrogen-air mixing ratio. Air then enters the mixer via the gas turbulence device and undergoes preliminary mixing with hydrogen before entering the stove body in a turbulent flow. The gas mixture layer, with its gradual design, fully mixes the gas before reaching the combustion layer. A fuzzy control algorithm is used to achieve real-time and precise control of the adjustment range of the electronically controlled valve and the fan, avoiding imbalances in the gas premixing ratio caused by valve and fan speed adjustments.

Description

Technical Field

[0001] This invention relates to gas stoves, and more particularly to a pure hydrogen gas stove that precisely controls the hydrogen-air premixing ratio. Background Technology

[0002] Hydrogen has the highest calorific value among all fossil fuels, chemical fuels, and biofuels. It also has advantages such as fast combustion rate, high ignition point, and pollution-free combustion products, making it a highly promising direction for future energy development.

[0003] Currently, pure hydrogen gas appliances are extremely rare in daily life, but replacing natural gas and coal gas stoves with hydrogen gas stoves is an effective solution for clean energy to replace fossil fuels. The common practice is to premix hydrogen and oxygen to ensure complete combustion; however, existing gas stove premixing methods have low mixing accuracy and are prone to ratio fluctuations during fuel quantity adjustments. This makes it difficult to guarantee the uniformity of the gas at the ignition point after transmission, leading to an imbalance in the mixing ratio within the stove body and potentially causing an explosion. Therefore, it is necessary to design the internal structure of the gas stove to ensure the uniformity of the gas during premixing and transmission, while simultaneously using a controller to adjust the gas intake and ratio during the adjustment process to control the precise gas ratio and the real-time ratio during adjustment. Summary of the Invention

[0004] This invention proposes a pure hydrogen gas stove that precisely controls the hydrogen-air premixing ratio, solving the problems of uneven mixing during gas delivery and difficulty in controlling the real-time ratio during gas stove adjustment in current hydrogen gas stoves.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a pure hydrogen gas stove with precise control of hydrogen-air premixing ratio, comprising an electronically controlled pressure regulating valve, a fan, an expansion bladder, a pressure chamber, a constant pressure valve, an electromagnetic flow valve, a one-way valve, a gas turbulence device, a gas mixer, a gas mixing layer, a flow stabilizing chamber, a backfire prevention support layer, a gas preheating layer, a pre-combustion layer, an ignition surface, and a combustion radiation layer.

[0007] Two gases to be premixed pass sequentially through the corresponding pipelines, including an electrically controlled pressure regulating valve, a fan, an expansion bladder, a constant pressure valve, and an electromagnetic flow valve. The air pipeline is equipped with a one-way valve and a gas turbulence device after the electromagnetic flow valve. The two gases are premixed with hydrogen in a gas mixer and then pass sequentially through a gas mixing layer and a flow stabilizing chamber to ensure thorough mixing. After passing through the backfire prevention support layer, the mixed gas passes sequentially through a gas preheating layer and a pre-combustion layer before reaching the ignition surface for ignition and combustion. The combustion flame is mainly concentrated inside the combustion radiation layer.

[0008] Furthermore, the fan speed will be controlled by the controller according to the valve opening of the electromagnetic flow valve to ensure the real-time proportion of gas and ensure that the gas proportion is within the preset control range during the adjustment process, with the accuracy controlled within 1% during the adjustment process;

[0009] Furthermore, the expansion bladder is surrounded by a pressure chamber and is divided into two parts, front and rear, connected by a constant pressure valve;

[0010] Furthermore, the air pressure chamber is pre-filled with pressure, the pressure value of which is 500~1000Pa lower than the air pressure used;

[0011] Furthermore, the electromagnetic flow valve for the hydrogen pipeline and the electromagnetic flow valve for the air pipeline can control the gas input according to user needs, and simultaneously control the air mixing range to 10~20% with an accuracy of 0.5% according to preset values;

[0012] Furthermore, the front end of the multi-hole ejector is conical, with uniformly arranged circular through holes in the front end portion, and the conical wall is arranged at 15~45° with the wall of the hydrogen pipeline.

[0013] Furthermore, the gas mixer has a nickel / copper foam front end with a porosity between 0.9 and 0.95. A cavity is present between the outlet end and the wall surface, and the outlet wall surface has uniformly distributed through holes.

[0014] The gas mixing layer is arranged with porous metal guide plates. The metal guide plates gradually become shorter from the edge to the center. The gradual arrangement creates a pressure gradient between the decreasing porous metal plates and the gaps between the metal plates, which allows the gas to continuously convect between the metal plates to achieve thorough mixing.

[0015] The anti-backfire support layer, gas preheating layer, pre-combustion layer, and combustion radiation layer together form the combustion radiation section from bottom to top. Al2O3 foam with a porosity of 0.8~0.9 is used as the anti-backfire support layer, alumina microspheres are used as the preheating layer, and zirconium oxide foam ceramic is used as the combustion radiation layer.

[0016] The combustion radiation section uses foam ceramic with a larger pore size upstream than downstream to increase the flame propagation speed, while the porous medium with a smaller pore size downstream has a larger gas contact area, which improves the heat return.

[0017] After detecting the knob start, the fuzzy controller takes the detected gear deviation S(c) and the knob deviation change Se(i) as input quantities. After calculation by the fuzzy controller, the output quantity valve adjustment degree u is obtained. Based on u, the opening of the electromagnetic flow valve is controlled. At the same time, the electric pressure regulating valve in the hydrogen pipeline and the fan in the air pipeline are started to supply gas with the corresponding pressure to the pipeline. The gas in the pipeline is first depressurized by the electric pressure regulating valve and then enters the front expansion bladder. Then it passes through the constant pressure valve to reach the rear expansion bladder. The predetermined pressure in the expansion bladder is consistent with the working pressure in the gas stove. The air mixes with hydrogen in the pipeline after passing through the baffle.

[0018] The internal logic of the fuzzy controller is as follows:

[0019] S1: First, define the knob position deviation as -50≤S(c)≤50, the knob deviation change as -25≤Se(i)=S(c)-S(c-1)≤25; the basic universe of discourse for S(c) is [-50, 50], the basic universe of discourse for Se(i) is [-25, 25], and the basic universe of discourse for valve adjustment u is [-30, 30].

[0020] S2: Discretize the three variables accordingly:

[0021]

[0022] Where x∈[a,b], n is the degree of dispersion, and all three variables take a degree of dispersion of n=3. The domain of discourse for the discretized linguistic values ​​is {-3,-2,-1,0,1,2,3}, which corresponds to the states of the input and output variables of the fuzzy controller. In addition to the two directions (positive and negative) and the zero state, there are a total of 7 terms: {negative large, negative medium, negative small, zero, positive small, positive medium, positive large}. These terms are generally abbreviated using the initials of their English names as: {NB,NM,NS,O,PS,PM,PB}.

[0023] S3: A smooth Gaussian function is used as the membership function, and a bell-shaped membership function is used for the boundary. The specific formula is as follows:

[0024]

[0025] S4: Set the corresponding fuzzy rule base as shown in the table below:

[0026]

[0027] S5: The fuzzy relationship between input and output can be obtained from the fuzzy rule table. Fuzzy inference is performed according to different rules. The analog output is obtained by taking the union of each fuzzy relation sub-matrix. The centroid method is used to defuzzify the fuzzy quantity. The corresponding formula is as follows:

[0028]

[0029] This allows us to obtain the precise value of the valve adjustment, u.

[0030] S6: The controller adjusts the valve opening and fan speed according to u to ensure that the gas stove receives the required flow of gas at a preset ratio.

[0031] This invention discloses a pure hydrogen gas stove with precise control of the hydrogen-air premixing ratio. Its beneficial effects are as follows: The controller adjusts the pressure of the gas entering the expansion bladder by controlling the opening of the electronically controlled pressure regulating valve and the fan speed. The expansion bladder, consisting of two sections and a buffer valve in the middle, maintains a constant and stable pressure within the bladder. The controller controls the opening of the electromagnetic flow valve, allowing hydrogen and air to enter the pipeline at a predetermined mixing ratio. After initial premixing through gas turbulence, the gas enters the stove body in a turbulent flow. A pressure gradient exists between the decreasing porous metal plates in the gas mixing layer, causing continuous convection between the metal plates for thorough mixing. Finally, the gas undergoes complete combustion in the combustion radiation section. The combustion radiation layer uses foam ceramic with a larger pore size than the pre-combustion layer, which improves heat return in the porous medium, effectively increasing flame propagation speed and improving the gas stove's thermal efficiency. The use of a fuzzy control algorithm allows for timely and precise control of the adjustment range of the electric regulating valve and the electromagnetic flow valve, avoiding gas premixing imbalance caused by timing deviations in the hydrogen-air pipeline valve adjustment during valve adjustment. Attached Figure Description

[0032] Figure 1 A pure hydrogen gas stove that precisely controls the hydrogen-air premixing ratio;

[0033] Figure 2 Wiring diagram for the monitoring system;

[0034] Figure 3 For the control process flowchart;

[0035] Figure 4 This is a flowchart of the premixing process. Detailed Implementation

[0036] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0038] The specific working process and implementation of this invention are as follows:

[0039] like Figure 1 The quantitative premixed porous medium hydrogen gas stove shown includes an electronically controlled pressure regulating valve 1, a fan 2, an expansion bladder 3, a pressure chamber 4, a constant pressure valve 5, an electromagnetic flow valve 6, a one-way valve 7, a gas turbulence device 8, a gas mixer 9, a gas mixing layer 10, a flow stabilizing chamber 11, a backfire prevention support layer 12, a gas preheating layer 13, a pre-combustion layer 14, an ignition surface 15, and a combustion radiation layer 16.

[0040] Two gases to be premixed pass sequentially through the corresponding pipelines via an electrically controlled pressure regulating valve 1, a fan 2, an expansion bladder 3, a constant pressure valve 5, and an electromagnetic flow valve 6. After the electromagnetic flow valve 6, the air pipeline is equipped with a one-way valve 7 and a gas turbulence device 8. The two gases are premixed with hydrogen in a gas mixer 9 and then sequentially pass through a gas mixing layer 10 and a flow stabilizing chamber 11 to ensure thorough mixing. The mixed gas passes through a backfire prevention support layer 12 and then sequentially passes through a gas preheating layer 13 and a pre-combustion layer 14 before reaching the ignition surface 15 for ignition and combustion. The combustion flame is mainly concentrated inside the combustion radiation layer 16.

[0041] The fan speed will be controlled by the controller according to the valve opening of the electromagnetic flow valve to ensure the real-time gas ratio and ensure that the gas ratio is within the preset control range during the adjustment process, with an accuracy control of 1% during the adjustment process;

[0042] The expansion chamber is surrounded by a pressure chamber and is divided into two parts, front and rear, connected by a constant pressure valve; the pressure chamber is pre-filled with pressure, with a pressure value of 2.5 kPa;

[0043] The outlet pressure of the electromagnetic flow valve in the hydrogen pipeline is 4 kPa. The controller adjusts the electromagnetic flow valve and the fan according to user needs to make the air mixing ratio 15% ± 0.5%. The outlet pressure of the check valve is 5 kPa to prevent gas backflow and thus prevent mixing.

[0044] The gas turbulence device shown has a conical front end with uniformly arranged circular through holes, and the conical wall is arranged at a 30° angle to the wall of the hydrogen pipeline.

[0045] The gas mixer has nickel foam with a porosity of 0.9 at its front end. There is a cavity between the outlet end and the wall surface, and the outlet wall surface has uniformly distributed through holes.

[0046] A porous metal guide plate is arranged in the gas mixing layer. The metal guide plate gradually becomes shorter from the edge to the center. The gradual arrangement creates a pressure gradient between the decreasing porous metal plate and the gap between the metal plate, which allows the gas to continuously convect between the metal plates to achieve thorough mixing.

[0047] The combustion radiation section is composed of a tempering support layer, a gas preheating layer, a pre-combustion layer, and a combustion radiation layer from bottom to top. The tempering support layer is made of Al2O3 foam with a pore density of 60ppi and a porosity of 0.8 with a thickness of 30mm. The preheating layer is made of alumina microspheres with a porosity of 0.4 and a thickness of 6mm with a thickness of 6mm. The combustion radiation layer is made of zirconia foam ceramic with a pore density of 10ppi and a porosity of 0.82 with a thickness of 40mm.

[0048] The combustion radiation section uses 10ppi foam ceramic with a larger pore size than the pre-combustion layer in the upstream to improve the flame propagation speed, while the downstream porous medium with a small pore size has a larger gas contact area to improve heat return.

[0049] After detecting the knob start, the fuzzy controller takes the detected gear deviation S(c) and the knob deviation change Se(i) as input quantities. After calculation by the fuzzy controller, the output quantity valve adjustment degree u is obtained. Based on u, the opening of the electromagnetic flow valve is controlled. At the same time, the electric pressure regulating valve in the hydrogen pipeline and the fan in the air pipeline are started to supply gas with the corresponding pressure into the pipeline. The gas in the pipeline is first depressurized by the electric pressure regulating valve and then enters the front expansion bladder. Then it passes through the constant pressure valve to reach the rear expansion bladder. The predetermined pressure in the expansion bladder is consistent with the working pressure in the gas stove. The air mixes with hydrogen in the pipeline after passing through the baffle.

[0050] The internal logic of the fuzzy controller is as follows:

[0051] S1: First, define the knob position deviation as -50≤S(c)≤50, the knob deviation change as -25≤Se(i)=S(c)-S(c-1)≤25; the basic universe of discourse for S(c) is [-50, 50], the basic universe of discourse for Se(i) is [-25, 25], and the basic universe of discourse for valve adjustment u is [-30, 30].

[0052] S2: Discretize the three variables accordingly:

[0053]

[0054] Where x∈[a,b], n is the degree of dispersion, and all three variables take a degree of dispersion of n=3. The domain of discourse for the discretized linguistic values ​​is {-3,-2,-1,0,1,2,3}, which corresponds to the states of the input and output variables of the fuzzy controller. In addition to the two directions (positive and negative) and the zero state, there are a total of 7 terms: {negative large, negative medium, negative small, zero, positive small, positive medium, positive large}. These terms are generally abbreviated using the initials of their English names as: {NB,NM,NS,O,PS,PM,PB}.

[0055] S3: A smooth Gaussian function is used as the membership function, and a bell-shaped membership function is used for the boundary. The specific formula is as follows:

[0056]

[0057] S4: Set the corresponding fuzzy rule base as shown in the table below:

[0058]

[0059] S5: The fuzzy relationship between input and output can be obtained from the fuzzy rule table. Fuzzy inference is performed according to different rules. The analog output is obtained by taking the union of each fuzzy relation sub-matrix. The centroid method is used to defuzzify the fuzzy quantity. The corresponding formula is as follows:

[0060]

[0061] This allows us to obtain the precise value of the valve adjustment, u.

[0062] S6: The controller adjusts the valve opening and fan speed according to u to ensure that the gas stove receives the required flow of gas at a preset ratio.

[0063] By employing fuzzy control algorithms, the adjustment range of electric control valves and electromagnetic flow valves can be controlled in real time and accurately, avoiding gas premixing imbalance caused by adjustment time deviation during valve and fan speed adjustment.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A control method for a pure hydrogen gas stove that precisely controls the hydrogen-air premixing ratio, characterized in that, A fuzzy controller was used to precisely control the premixing ratio. The specific process is as follows: After the knob is activated, the detected gear deviation S(c) and the knob deviation change Se(i) are used as inputs. The output valve adjustment degree u is obtained after calculation by the fuzzy controller. The opening of the electromagnetic flow valve is controlled according to u. At the same time, the electric pressure regulating valve in the hydrogen pipeline and the fan in the air pipeline are started to supply gas with the corresponding pressure to the pipeline. The gas in the pipeline is first depressurized by the electric pressure regulating valve and then enters the front expansion bladder. Then it passes through the constant pressure valve to reach the rear expansion bladder. The predetermined pressure in the expansion bladder is consistent with the working pressure in the gas stove. The air mixes with hydrogen in the pipeline after passing through the baffle. The internal logic of the fuzzy controller is as follows: S1: First, define the knob position deviation as -50≤S(c)≤50, the knob deviation change as -25≤Se(i)=S(c)-S(c-1)≤25; the basic universe of discourse for S(c) is [-50, 50], the basic universe of discourse for Se(i) is [-25, 25], and the basic universe of discourse for valve adjustment u is [-30, 30]. S2: Discretize the three variables accordingly: Where x∈[a,b], n is the degree of dispersion, and all three variables take a degree of dispersion n=3; the discretized linguistic value domain is {-3,-2,-1,0,1,2,3}, which corresponds to the states of the input and output variables of the fuzzy controller. Adding the positive and negative directions and the zero state, there are a total of 7 terms: {negative large, negative medium, negative small, zero, positive small, positive medium, positive large}. These terms are abbreviated using their initials: {NB,NM,NS,O,PS,PM,PB} S3: A smooth Gaussian function is used as the membership function, and a bell-shaped membership function is used for the boundary. The specific formula is as follows: S4: Set the corresponding fuzzy rule base as shown in the table below: S5: The fuzzy relationship between input and output can be obtained from the fuzzy rule table. Fuzzy inference is performed according to different rules. The analog output is obtained by taking the union of each fuzzy relation sub-matrix. The centroid method is used to defuzzify the fuzzy quantity. The corresponding formula is as follows: This yields the precise value of the valve adjustment, u; S6: The controller adjusts the valve opening and fan speed according to u to ensure that the gas stove receives the required flow of gas at a preset ratio.

2. The method according to claim 1, characterized in that: The pure hydrogen gas stove includes an electronically controlled pressure regulating valve, a fan, an expansion bladder, a pressure chamber, a constant pressure valve, an electromagnetic flow valve, a one-way valve, a gas turbulence device, a gas mixer, a gas mixing layer, a flow stabilizing chamber, a backfire prevention support layer, a gas preheating layer, a pre-combustion layer, an ignition surface, and a combustion radiation layer. Two gases to be premixed pass sequentially through the corresponding pipelines, including the electrically controlled pressure regulating valve, fan, expansion bladder, constant pressure valve, and electromagnetic flow valve. The air pipeline is equipped with a one-way valve and a gas turbulence device after the electromagnetic flow valve. The two gases are premixed with hydrogen in the gas mixer and then pass sequentially through the gas mixing layer and the flow stabilizing chamber to ensure that the gases are fully mixed. After passing through the backfire prevention support layer, the mixed gas passes sequentially through the gas preheating layer and the pre-combustion layer to reach the ignition surface for ignition and combustion. The combustion flame is mainly concentrated inside the combustion radiation layer. The fan speed will be controlled by the controller according to the valve opening of the electromagnetic flow valve to ensure the real-time gas ratio and ensure that the gas ratio is within the preset control range during the adjustment process, with the accuracy controlled within 1% during the adjustment process; The expansion bladder is surrounded by a pressure chamber and is divided into two parts, front and rear, connected by a constant pressure valve. The air pressure chamber is pre-charged with pressure, and the pre-charge pressure is 500~1000Pa; The electromagnetic flow valve can control the gas input according to user needs, controlling the air mixing range in the mixed gas to be 10~20%, with an accuracy of 0.5%. The front end of the gas turbulence device is conical, with uniformly arranged circular through holes in the front part, and the conical wall is arranged at 15~45° with the wall of the hydrogen pipeline.

3. The method according to claim 2, characterized in that: The gas mixer has a foamed nickel / copper structure at the front end with a porosity between 0.9 and 0.95; there is a cavity between the outlet end and the wall, and there are uniform through holes on the outlet wall.

4. The method according to claim 2, characterized in that: Porous metal guide plates are arranged in the gas mixing layer, and the metal guide plates gradually become shorter from the edge to the center.

5. The method according to claim 2, characterized in that: The backfire prevention support layer, gas preheating layer, pre-combustion layer, and combustion radiation layer together form the combustion radiation section from bottom to top, using Al2O3 with a porosity of 0.8~0.

9. 3 Foam is used as the backfire prevention support layer, alumina microspheres are used as the preheating layer, and zirconium oxide foam ceramic is used as the combustion radiation layer. The combustion radiation section uses foam ceramic with a larger pore size upstream than downstream to increase the flame propagation speed, while the porous medium with a smaller pore size downstream has a larger gas contact area, which improves the heat return.

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