Natural gas and hydrogen mixing device and method for efficient large-flow gas power plant

Abstract

The invention discloses a natural gas and hydrogen mixing device and method for an efficient large-flow gas power plant, and relates to the technical field of gas power generation. Comprising a natural gas pipeline, a hydrogen pipeline, a gas mixing pipeline and a PLC control unit. The natural gas pipeline is provided with a first flowmeter and a first scaling pipeline, the hydrogen pipeline is provided with a second flowmeter, a flow regulating valve and a second scaling pipeline, and the gas mixing pipeline is sequentially provided with a static mixer, a cyclone and a mixing concentration meter in the gas flowing direction. The PLC control unit calculates the target hydrogen flow according to the natural gas flow change measured by the first flow meter and the preset mixing concentration and controls the opening degree of the flow adjusting valve, and meanwhile dynamic correction is conducted according to a real-time feedback signal of the mixing concentration meter, and a double-closed-loop control strategy is formed. The problems that in the prior art, the gas power plant load fluctuation is difficult to adapt, the hydrogen doping proportion control precision is low, and mixing is uneven are solved, and high-precision dynamic mixing and sufficient and even mixing under the large-flow working condition are achieved.

Description

A high-efficiency, high-flow-rate natural gas and hydrogen blending device and method for gas-fired power plants Technical Field

[0001] This invention relates to the field of gas-fired power generation technology, specifically to a high-efficiency, high-flow-rate gas-fired power plant natural gas and hydrogen blending device and method. Background Technology

[0002] Gas turbine power generation is characterized by its flexible start-up and shutdown and rapid load adjustment, making it a crucial regulating power source for my country's new power system and supporting large-scale grid integration of renewable energy. With the rapid development of my country's gas-fired power generation industry, the demand for natural gas, as a conventional fuel for gas turbine power generation, is increasing daily. However, due to the uneven distribution of natural gas resources and limitations in pipeline transportation capacity, gas-fired power plants generally face the reality of tight natural gas supply. Many gas-fired power plants struggle to operate at full capacity due to insufficient gas supply, even experiencing a passive "on-off" situation, severely restricting the peak-shaving capacity of gas-fired power generation.

[0003] Meanwhile, hydrogen, as a clean energy source, can effectively reduce carbon dioxide emissions when blended with natural gas, contributing to the achievement of the "dual carbon" goal. Natural gas blending with hydrogen is considered an ideal method for low-cost, long-distance hydrogen transportation. Utilizing existing natural gas pipeline networks for blended hydrogen transportation can significantly reduce hydrogen storage and transportation costs. Currently, several natural gas blending demonstration projects have been carried out in China, with the blending ratio gradually increasing from 5% to over 20%, verifying the feasibility of the technology.

[0004] However, existing natural gas hydrogen blending technology still faces many challenges in practical applications. On the one hand, as peak-shaving units, gas-fired power plants experience real-time fluctuations in natural gas flow with the grid load, characterized by large flow variations and rapid adjustment. This necessitates that the hydrogen blending device possess excellent dynamic response capabilities and a wide flow adaptation range. On the other hand, hydrogen and natural gas have significantly different physical properties, and the uniformity of their mixing directly affects the combustion stability and emission performance of the gas turbine. Existing blending devices often struggle to achieve high precision and uniformity under high flow rates and wide load conditions. Furthermore, hydrogen's flammability, explosiveness, and leakage characteristics place higher demands on the safety of the blending device.

[0005] Therefore, how to develop a blending device and method that can adapt to the load fluctuation characteristics of gas-fired power plants, achieve high-precision and uniform blending of natural gas and hydrogen, and have complete safety protection functions has become a technical problem that the gas-fired power generation industry urgently needs to solve. Summary of the Invention

[0006] (I) Technical problems to be solved In view of the shortcomings of the prior art, the present invention provides a high-efficiency, high-flow-rate natural gas and hydrogen blending device and method for gas-fired power plants. It has the advantages of high-precision dynamic blending control, good mixing uniformity, and safety protection. It solves the problems of the prior art being unable to adapt to the load fluctuation conditions of gas-fired power plants, low accuracy of hydrogen blending ratio control, uneven mixing, and the safety hazard of hydrogen leakage.

[0007] (II) Technical Solution To achieve the aforementioned objectives of high-precision dynamic blending control, good mixing uniformity, and safety protection, this invention provides the following technical solution: The first aspect of this invention provides a high-efficiency, high-flow-rate gas-fired power plant natural gas and hydrogen blending device, comprising: a natural gas pipeline with a first flow meter and a first expansion / contraction pipe installed thereon; a hydrogen pipeline with a second flow meter, a flow regulating valve, and a second expansion / contraction pipe installed thereon; a mixing pipeline with a static mixer, a cyclone separator, and a blending concentration meter sequentially installed along the gas flow direction; and a PLC control unit electrically connected to the first flow meter, the second flow meter, the flow regulating valve, and the blending concentration meter, respectively; wherein the natural gas pipeline and the hydrogen pipeline are respectively connected to the inlet of the static mixer; the PLC control unit calculates the target hydrogen flow rate based on the natural gas flow rate change measured by the first flow meter and the preset blending concentration, and controls the opening of the flow regulating valve; the PLC control unit also corrects the opening of the flow regulating valve in real time based on the mixed gas concentration signal measured by the blending concentration meter.

[0008] Furthermore, both the first and second scaling pipes are Venturi tube structures.

[0009] Furthermore, the static mixer has a cylindrical structure with a natural gas interface and a hydrogen interface at the front and a mixed gas interface at the rear. Inside, there is a connecting rod and multiple perforated plates connected to the connecting rod.

[0010] Furthermore, the cyclone separator has a circular chamber structure with a spiral guide structure inside. The gas, which has been initially mixed by the static mixer, enters the circular chamber and generates a swirling flow under the action of the spiral guide structure, so that the mixed gas is further mixed evenly.

[0011] Furthermore, the control logic of the PLC control unit includes: calculating the required blended hydrogen flow rate based on the natural gas flow rate measured by the first flow meter and the preset hydrogen blending concentration; determining the target opening degree of the flow regulating valve and driving its operation based on the calculated blended hydrogen flow rate; and dynamically correcting the opening degree of the flow regulating valve based on the real-time feedback signal from the blending concentration meter until the mixed gas concentration meets the set requirements.

[0012] Furthermore, it also includes an alarm device connected to a PLC control unit. When the hydrogen concentration detected by the mixing concentration meter exceeds a preset safety threshold, the PLC control unit triggers the alarm device and simultaneously controls the flow regulating valve to close.

[0013] The second aspect of this invention provides a method for blending natural gas and hydrogen in a high-efficiency, high-flow-rate gas-fired power plant using the above-mentioned device, comprising the following steps: S1: The real-time flow rate of natural gas is measured by a first flow meter, and the PLC control unit calculates the target hydrogen flow rate to be blended according to a preset blending concentration, and adjusts the flow regulating valve on the hydrogen pipeline to the corresponding opening degree; S2: After the natural gas diffuses through a first expansion pipe, it is initially mixed with the hydrogen diffused through a second expansion pipe in a static mixer; S3: The initially mixed gas enters a cyclone separator for further homogenization to form a mixed gas that meets the blending requirements; S4: The concentration of the mixed gas is detected in real time by a blending concentration meter and fed back to the PLC control unit. The PLC control unit dynamically corrects the opening degree of the flow regulating valve according to the deviation between the feedback signal and the preset blending concentration until the concentration of the mixed gas meets the set requirements.

[0014] (III) Beneficial Effects Compared with the prior art, the present invention provides a high-efficiency, high-flow-rate gas-fired power plant natural gas and hydrogen blending device and method, which has the following beneficial effects: 1. The present invention calculates the target hydrogen flow rate based on the real-time natural gas flow rate change measured by the first flow meter through the PLC control unit and controls the opening of the flow regulating valve. At the same time, it performs dynamic correction based on the real-time feedback signal of the blending concentration meter, forming a dual closed-loop control strategy of "feedforward calculation + feedback correction", which realizes the precise control of the hydrogen blending ratio under high flow rate fluctuation conditions.

[0015] 2. In this invention, natural gas and hydrogen are diffused through the first and second expansion pipes respectively and then enter the static mixer. They are initially mixed under the cutting and polymerization action of the porous plate, and then enter the hydrocyclone where the spiral guide structure generates swirling flow for further uniform mixing. The three-stage structure works together to achieve a thorough and uniform mixing of two gases with significantly different physical properties.

[0016] 3. This invention, by setting up an alarm device connected to the PLC control unit, when the hydrogen concentration detected by the mixing concentration meter exceeds a preset safety threshold, triggers the alarm device to sound an alarm and simultaneously controls the flow regulating valve to close, thus achieving automatic shut-off safety protection against hydrogen exceeding the limit. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the structure of the device of the present invention; Figure 2 is a block diagram of the control principle of the present invention; Figure 3 is a flowchart of the method of the present invention.

[0018] In the diagram: 1. Natural gas pipeline; 2. Hydrogen pipeline; 3. Mixing pipeline; 4. PLC control unit; 5. First flow meter; 6. Second flow meter; 7. Flow regulating valve; 8. Static mixer; 9. Hydrocyclone; 10. Mixing concentration meter; 11. Alarm device; 101. First expansion pipe; 201. Second expansion pipe; 801. Connecting rod; 802. Perforated plate. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 (Referring to Figures 1-2): The first aspect of this invention provides a high-efficiency, high-flow-rate natural gas and hydrogen blending device for gas-fired power plants, comprising: a natural gas pipeline 1, on which a first flow meter 5 and a first expansion pipe 101 are installed; the first flow meter 5 is used to monitor the instantaneous flow rate of natural gas in real time, providing accurate flow data as a control reference for the PLC control unit 4. Because the load of gas-fired power plants fluctuates frequently, and the natural gas flow rate changes significantly and rapidly, the first flow meter 5 must possess good dynamic response characteristics and a wide range ratio to ensure accurate reflection of the actual flow rate under various operating conditions.

[0021] Hydrogen pipeline 2 is equipped with a second flow meter 6, a flow regulating valve 7, and a second expansion / contraction pipe 201. The second flow meter 6 monitors the actual hydrogen blending flow rate, providing feedback data to the PLC control unit 4 to verify the adjustment effect. The flow regulating valve 7 is a key component for performing blending control and is located upstream of the second flow meter 6. It receives a 4-20mA control signal output from the PLC control unit 4 and precisely adjusts the hydrogen flow rate by changing the valve opening, thereby achieving rapid adjustment of different blending ratios.

[0022] Furthermore, the blending concentration meter 10 can be selected from various models according to different measurement principles and operating conditions. Preferably, the ADEV 8866 explosion-proof thermal conductivity gas analyzer can be used. This analyzer adopts the thermal conductivity principle, utilizing the significant difference in thermal conductivity between hydrogen and natural gas for concentration measurement. The measurement range can cover various hydrogen blending concentration requirements such as 0-20%, 0-30%, and 0-40%, with an accuracy of ±1%FS, repeatability ≤0.3%, response time T90 of 24 seconds, and output signal as a standard 4-20mA analog signal, which can be directly interfaced with the PLC control unit 4.

[0023] The gas mixing pipeline 3 is equipped with a static mixer 8, a cyclone separator 9, and a mixing concentration meter 10 arranged sequentially along the gas flow direction. The mixing concentration meter 10 is used to detect the hydrogen concentration in the mixed gas online in real time and feeds back the detection signal to the PLC control unit 4 to form a closed-loop control. Its installation position is after the cyclone separator 9 to ensure that the detected gas has been fully mixed and the concentration value is representative.

[0024] The PLC control unit 4 is electrically connected to the first flow meter 5, the second flow meter 6, the flow regulating valve 7, and the blending concentration meter 10. The PLC control unit 4 is the core control unit of the entire blending device, responsible for receiving detection signals from each instrument, executing control algorithms, and outputting adjustment commands. Its built-in control program implements a dual closed-loop control strategy of "feedforward calculation + feedback correction," enabling it to quickly calculate the required hydrogen quantity based on real-time changes in natural gas flow and make precise corrections based on feedback signals from the concentration meter.

[0025] Furthermore, the PLC control unit 4 is a programmable logic controller (PLC), and can be a commercially available general-purpose PLC, such as the Siemens S7 series, Mitsubishi FX series, Omron CJ series, etc. The specific model selection is determined based on conventional engineering requirements such as the number of input / output points and communication interface requirements. The electrical or communication connection between the PLC control unit 4 and each instrument adopts a standard 4-20mA analog signal or digital communication protocol. The above signal transmission methods and PLC programming technology are conventional techniques well known to those skilled in the art.

[0026] In this system, the natural gas pipeline 1 and the hydrogen pipeline 2 are respectively connected to the inlet of the static mixer 8. The PLC control unit 4 calculates the target hydrogen flow rate based on the natural gas flow rate change measured by the first flow meter 5 and the preset blending concentration, and controls the opening of the flow regulating valve 7. The PLC control unit 4 also corrects the opening of the flow regulating valve 7 in real time based on the mixed gas concentration signal measured by the blending concentration meter 10. This control method uses the natural gas flow rate as the primary variable and the hydrogen flow rate as the secondary variable, which perfectly matches the operating characteristic of gas-fired power plants where "natural gas flow rate is determined by grid load". Regardless of the fluctuation of the natural gas flow rate, the PLC can calculate the corresponding target hydrogen flow rate in real time and adjust it quickly, realizing dynamic and precise blending within a large flow rate variation range.

[0027] In this embodiment, both the first and second scaling conduits 101 and 201 are Venturi tube structures. This structure features a variable cross-section that contracts before expanding. When gas flows through the scaling conduit, the velocity increases and the pressure decreases in the contraction section, allowing gas molecules to gain greater kinetic energy. The highest velocity is reached at the throat, creating strong turbulent disturbances. In the expansion section, the velocity decreases and the pressure recovers, allowing the gas to diffuse fully. This conversion of pressure energy into kinetic energy promotes the diffusion of gas molecules, which is beneficial for subsequent mixing. It also ensures that the gas is in a good turbulent state before entering the static mixer 8, creating favorable conditions for subsequent uniform mixing.

[0028] In this embodiment, the static mixer 8 is a cylindrical structure with a natural gas interface and a hydrogen interface at the front, and a mixed gas interface at the rear. Inside, there is a connecting rod 801 and multiple perforated plates 802 connected to the connecting rod 801. The static mixer 8 is the first-stage mixing unit of this invention, and its core working principle is the "segmentation-polymerization" effect: after natural gas and hydrogen enter the static mixer 8, they flow through multiple perforated plates 802. Each time they pass through a perforated plate 802, the gas flow is divided into multiple fine streams, which then re-converge in the space behind the plate. After multiple such segmentation and polymerization processes, the two gases achieve preliminary uniform mixing on a macroscopic scale. The arrangement of the perforated plates 802 continuously changes the gas flow path, generating local turbulence and enhancing the mixing effect. This static mixer 8 has no moving parts and relies entirely on the kinetic energy of the fluid itself to achieve mixing, requiring no external energy source, making it reliable in operation and easy to maintain.

[0029] In this embodiment, the cyclone separator 9 is a circular chamber structure with a spiral guide structure inside. Gases initially mixed by the static mixer 8 enter this circular chamber, where they swirl under the influence of the spiral guide structure, further homogenizing the mixture. The cyclone separator 9 is the second-stage mixing unit of this invention, and its function is to solve the problem of microscale uniformity that is difficult to achieve with the static mixer 8. The initially mixed gas enters the cyclone separator 9 chamber tangentially, generating high-speed rotating flow under the guidance of the spiral guide structure, ultimately achieving uniform mixing. This swirling mixing method is particularly suitable for gas systems with large density differences, effectively overcoming the gravity separation effect and ensuring the concentration uniformity of the mixed gas before entering the gas turbine.

[0030] In this embodiment, the control logic of the PLC control unit 4 includes: calculating the required blended hydrogen flow rate based on the natural gas flow rate measured by the first flow meter 5 and the preset hydrogen blending concentration; this is the feedforward control part, which is based on the material balance principle: under stable operating conditions, the hydrogen integral in the mixed gas is equal to the hydrogen flow rate divided by the total flow rate. The PLC quickly calculates the target hydrogen flow rate based on the real-time natural gas flow rate in each control cycle, enabling the control system to respond quickly to changes in the natural gas flow rate and overcoming the slow response of pure feedback control.

[0031] Based on the calculated hydrogen flow rate, the target opening degree of the flow regulating valve 7 is determined and its operation is initiated. The PLC matches the calculated target hydrogen flow rate with the valve's flow characteristic curve to determine the corresponding valve opening degree and outputs a control signal. The valve characteristic curve can be obtained through on-site calibration or theoretical calculation to ensure an accurate and reliable correspondence between opening degree and flow rate.

[0032] Based on the real-time feedback signal from the mixing concentration meter 10, the opening of the flow regulating valve 7 is dynamically corrected until the mixed gas concentration meets the set requirements. This is the feedback control section, used to eliminate possible errors in the feedforward control, such as flow meter measurement errors, valve characteristic deviations, and gas composition fluctuations. The PLC compares the measured value from the concentration meter with the set value, calculates the correction amount using a PID algorithm, and adds it to the opening value of the feedforward control to form the final control command. This dual closed-loop control strategy of "fast feedforward response + precise feedback correction" ensures both the dynamic response speed of the system and the steady-state accuracy, keeping the mixing ratio consistently stable near the set value.

[0033] Furthermore, the system also includes an alarm device 11, which is connected to the PLC control unit 4. When the hydrogen concentration detected by the blending concentration meter 10 exceeds a preset safety threshold, the PLC control unit 4 triggers the alarm device 11 and simultaneously controls the flow regulating valve 7 to close. Because hydrogen is flammable and explosive, excessively high blending ratios can pose safety hazards. This invention incorporates a concentration over-limit protection function: once the blending concentration meter 10 detects that the hydrogen concentration exceeds a preset safety threshold (such as 120% of the set value or the upper limit of the absolute concentration), the PLC immediately triggers an audible and visual alarm and simultaneously shuts off the flow regulating valve 7 on the hydrogen pipeline to prevent further hydrogen entry. In addition, the entire device is made of hydrogen-resistant alloy steel, and the pipeline connections employ a reliable sealing structure. A hydrogen leak detection probe can be further installed, forming multiple safety safeguards to ensure the safe operation of the hydrogen blending system.

[0034] Example 2 (Referring to Figure 3) The second aspect of this invention provides a method for blending natural gas and hydrogen in a high-efficiency, high-flow-rate gas-fired power plant using the aforementioned device, comprising the following steps: S1: The real-time flow rate of natural gas is measured by a first flow meter 5. The PLC control unit 4 calculates the target hydrogen flow rate to be blended according to a preset blending concentration and adjusts the flow regulating valve 7 on the hydrogen pipeline 2 to the corresponding opening degree. It should be noted that since the natural gas flow rate of the gas-fired power plant is determined by the grid load and is an uncontrollable input variable, the hydrogen flow rate must actively follow the changes in the natural gas flow rate. The PLC control unit 4 reads the real-time data from the first flow meter 5 in each control cycle and substitutes it into the calculation formula Q(H2). target =Q(NG)×(r set / (1-r set This allows for rapid determination of the target hydrogen flow rate and immediate output of a control signal to adjust the valve opening, achieving rapid feedforward control; where Q(H2) is the target hydrogen flow rate. target Let Q(NG) be the target hydrogen flow rate, and r be the measured natural gas flow rate. set This is the preset mixing concentration of hydrogen.

[0035] S2: After natural gas diffuses through the first expansion and contraction pipe 101, it is initially mixed with hydrogen gas, which diffuses through the second expansion and contraction pipe 201, in the static mixer 8. It should be noted that this step completes the pre-mixing preparation and initial mixing of the gases. When natural gas and hydrogen flow through the expansion and contraction pipes respectively, they obtain sufficient turbulent disturbance and molecular diffusion through the variable cross-section structure of first contracting and then expanding, creating favorable conditions for subsequent mixing. After the two gases enter the static mixer 8, under the multiple "segmentation-polymerization" actions of the porous plate 802, preliminary uniform mixing on a macroscopic scale is achieved, eliminating large-scale concentration inhomogeneities.

[0036] S3: The initially mixed gas enters the hydrocyclone 9 for further homogenization, forming a mixed gas that meets the blending requirements. It should be noted that the initially mixed gas enters the hydrocyclone 9 chamber tangentially, generating a high-speed swirling flow under the guidance of the spiral flow guide structure. Under centrifugal force, hydrogen and natural gas molecules of different densities undergo intense radial exchange, ultimately achieving a molecular-level homogeneous mixture. Thus, through pre-diffusion via the scaling pipe, macroscopic mixing in the static mixer 8, and microscopic mixing in the hydrocyclone 9, the three-stage structure collaboratively completes the entire mixing process from two independent gases to a homogeneous mixture.

[0037] S4: The concentration of the mixed gas is detected in real time by the mixing concentration meter 10 and fed back to the PLC control unit 4. The PLC control unit 4 dynamically corrects the opening of the flow regulating valve 7 according to the deviation between the feedback signal and the preset mixing concentration until the concentration of the mixed gas meets the set requirements.

[0038] It should be noted that the blending concentration meter 10 continuously monitors the hydrogen concentration in the mixed gas online and feeds back the measured value to the PLC control unit 4. The PLC control unit 4 compares the measured value with the set value, calculates the deviation, and generates a correction amount through a PID algorithm to dynamically fine-tune the opening of the flow regulating valve 7. This feedback correction process continues until the deviation is eliminated, ensuring that the actual blending concentration remains stable near the set value. Through the fast feedforward response of S1 and the precise feedback correction of S4, this invention achieves high-precision dynamic blending control of hydrogen under conditions of large flow fluctuations in natural gas.

[0039] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A high-efficiency, high-flow-rate natural gas and hydrogen blending device for gas-fired power plants, characterized in that, include: A natural gas pipeline is equipped with a first flow meter and a first expansion / contraction pipe; a hydrogen pipeline is equipped with a second flow meter, a flow regulating valve, and a second expansion / contraction pipe; a gas mixing pipeline is equipped with a static mixer, a cyclone separator, and a mixing concentration meter sequentially arranged along the gas flow direction; a PLC control unit is electrically connected to the first flow meter, the second flow meter, the flow regulating valve, and the mixing concentration meter; wherein, the natural gas pipeline and the hydrogen pipeline are respectively connected to the inlet of the static mixer; the PLC control unit calculates the target hydrogen flow rate based on the change in natural gas flow rate measured by the first flow meter and the preset mixing concentration, and controls the opening of the flow regulating valve; the PLC control unit also corrects the opening of the flow regulating valve in real time based on the mixed gas concentration signal measured by the mixing concentration meter.

2. The high-efficiency, high-flow-rate natural gas and hydrogen blending device for gas-fired power plants according to claim 1, characterized in that: Both the first and second scaling pipes are Venturi tube structures.

3. The high-efficiency, high-flow-rate natural gas and hydrogen blending device for gas-fired power plants according to claim 1, characterized in that: The static mixer has a cylindrical structure with a natural gas interface and a hydrogen interface at the front and a mixed gas interface at the rear. Inside, there is a connecting rod and multiple perforated plates connected to the connecting rod.

4. The high-efficiency, high-flow-rate natural gas and hydrogen blending device for gas-fired power plants according to claim 1, characterized in that: The cyclone separator has a circular chamber structure with a spiral guide structure inside. The gas, which has been initially mixed by the static mixer, enters the circular chamber and is swirled under the action of the spiral guide structure, so that the mixed gas is further mixed evenly.

5. The high-efficiency, high-flow-rate natural gas and hydrogen blending device for gas-fired power plants according to claim 1, characterized in that: The control logic of the PLC control unit includes: calculating the required blended hydrogen flow rate based on the natural gas flow rate measured by the first flow meter and the preset hydrogen blending concentration; determining the target opening degree of the flow regulating valve and driving its operation based on the calculated blended hydrogen flow rate; and dynamically correcting the opening degree of the flow regulating valve based on the real-time feedback signal from the blending concentration meter until the mixed gas concentration meets the set requirements.

6. The high-efficiency, high-flow-rate natural gas and hydrogen blending device for gas-fired power plants according to claim 1, characterized in that: It also includes an alarm device, which is connected to the PLC control unit. When the hydrogen concentration detected by the mixing concentration meter exceeds a preset safety threshold, the PLC control unit triggers the alarm device and simultaneously controls the flow regulating valve to close.

7. A method for blending natural gas and hydrogen for high-efficiency, high-flow-rate gas-fired power plants based on the apparatus described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1: The real-time flow rate of natural gas is measured by the first flow meter. The PLC control unit calculates the target flow rate of hydrogen to be mixed according to the preset mixing concentration and adjusts the flow regulating valve on the hydrogen pipeline to the corresponding opening degree. S2: After natural gas diffuses through the first expansion pipe, it is initially mixed with hydrogen gas diffused through the second expansion pipe in a static mixer; S3: The initially mixed gas enters a cyclone separator for further homogenization, forming a mixed gas that meets the mixing requirements; S4: The concentration of the mixed gas is detected in real time by a mixing concentration meter and fed back to the PLC control unit. The PLC control unit dynamically corrects the opening of the flow regulating valve according to the deviation between the feedback signal and the preset mixing concentration until the mixed gas concentration meets the set requirements.

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