CN-122015087-A - Natural gas-hydrogen dual-fuel low-nitrogen combustion self-adaptive regulation and control system

CN122015087ACN 122015087 ACN122015087 ACN 122015087ACN-122015087-A

Abstract

The invention discloses a natural gas-hydrogen dual-fuel low-nitrogen combustion self-adaptive regulation and control system, and relates to the technical field of proportional mixing combustion systems. The system comprises a control unit, a combustion characteristic detection unit, a self-adaptive regulation and control unit, a fuel supply unit, a three-stage cyclone burner unit and a carbon capture and resource utilization unit. The combustion characteristic detection unit collects the flame speed in real time, The concentration and boiler load data, the self-adaptive regulation and control unit is coupled with the data to calculate the optimal hydrogen mixing proportion, the fuel supply unit is used for accurately mixing fuel according to instructions, the three-stage cyclone burner unit is used for realizing low-nitrogen stable combustion, and the carbon capture and resource utilization unit is used for supplying low-carbon hydrogen and supplying the low-carbon hydrogen And (5) recycling to prepare methanol. The system can adapt to fuel mixing and load fluctuation, and solve unstable combustion, The problems of exceeding standard, high catalyst cost, incomplete carbon emission reduction and the like are solved, and the low-carbon and low-nitrogen operation of the industrial boiler is realized.

Inventors

LU YUANGANG
ZHOU LIYA
HUANG FUCHUAN
LU YUNFAN
LI KANGCHUN
YU ZHOU
LI ZHENPENG

Assignees

广西大学

Dates

Publication Date: 20260512
Application Date: 20260326

Claims (10)

1. Natural gas-hydrogen dual fuel low nitrogen burning self-adaptation regulation and control system, characterized by comprising: a control unit; the combustion characteristic detection unit is used for measuring flame speed, nitrogen oxide concentration and boiler load in real time and transmitting data to the control unit; the self-adaptive regulation and control unit is used for acquiring the optimal hydrogen blending proportion according to the detection data; The fuel supply unit is used for acquiring the instruction of the self-adaptive regulation and control unit, accurately mixing the natural gas and the low-carbon hydrogen from the hydrogen production unit according to the instruction, and sending the low-carbon hydrogen to the combustor; The three-stage cyclone burner unit is used for burning the mixed fuel, the generated waste heat is transmitted to the carbon capture unit, and the flue gas is transmitted to the detection unit; and the carbon capturing and recycling unit is used for supplying low-carbon hydrogen to the fuel supply unit and recycling the captured carbon dioxide to prepare methanol.
2. The natural gas-hydrogen dual-fuel low-nitrogen combustion self-adaptive regulation and control system according to claim 1, wherein the combustion characteristic detection unit comprises a flame speed detection module for acquiring flame speed, a nitrogen oxide concentration detection module for acquiring nitrogen oxide concentration and a boiler load detection module for acquiring boiler load, the flame speed detection module, the nitrogen oxide concentration detection module and the boiler load detection module are connected with the control unit, and acquired data are transmitted to the control unit in real time after being subjected to signal processing.
3. The self-adaptive regulation and control system for natural gas-hydrogen dual-fuel low-nitrogen combustion according to claim 1, wherein a fuel combustion characteristic database is built in the self-adaptive regulation and control unit, and the self-adaptive regulation and control system is used for carrying out operation on coupling detection data and carrying out dynamic self-adaptive regulation on hydrogen blending proportion so as to adapt to load fluctuation working conditions of a boiler.
4. The self-adaptive regulation and control system for natural gas-hydrogen dual-fuel low-nitrogen combustion according to claim 1, wherein the fuel supply unit comprises a mixing module and a flow regulation module, the flow regulation module regulates the delivery flow of natural gas and low-carbon hydrogen according to the instruction of the self-adaptive regulation and control unit to ensure that the mixing proportion meets the regulation and control requirement, and the mixing module is used for realizing uniform mixing of two fuels.
5. The self-adaptive regulation and control system for natural gas-hydrogen dual-fuel low-nitrogen combustion according to claim 1, wherein the three-stage cyclone burner unit adopts a hierarchical partition structure, and comprises a central hydrogen enrichment area and a peripheral natural gas area, so that the synergistic stable combustion of natural gas and low-carbon hydrogen is realized, and meanwhile, the generation of nitrogen oxides is inhibited by shortening the flame length; The three-stage cyclone burner unit is internally provided with a metal-free catalytic layer, the metal-free catalytic layer is loaded with a nitrogen-doped nano-carbon metal-free catalyst and is used for assisting the mixed fuel to fully burn, reducing the ignition temperature and further inhibiting the generation of nitrogen oxides, and the nitrogen-doped nano-carbon metal-free catalyst adopts graphene or carbon nano tubes as a base material and is subjected to multielement co-doping modification and/or defect engineering modification treatment.
6. The self-adaptive regulation and control system for natural gas-hydrogen dual-fuel low-nitrogen combustion according to claim 5, wherein the multi-element co-doping modification is to introduce one or more nonmetallic elements of boron, sulfur and fluorine to form a co-doping structure on the basis of nitrogen doping and phosphorus doping, wherein the molar ratio of nitrogen to phosphorus is controlled in (3:1) - (5:1), and the co-doping elements increase active sites by regulating and controlling the nano carbon electronic structure.
7. The self-adaptive regulation and control system for natural gas-hydrogen dual-fuel low-nitrogen combustion according to claim 5, wherein the defect engineering modification adopts one or more of plasma etching, ball milling, strong acid oxidation or high-temperature annealing to manufacture edge defects or vacancy defects on the surface of the nitrogen-doped nano carbon material, increase the number of edge active sites and inhibit carbon deposition on the surface of the catalyst.
8. The self-adaptive regulation and control system for natural gas-hydrogen dual-fuel low-nitrogen combustion of claim 5, wherein the metal-free catalytic layer is arranged on the inner wall of a combustion chamber of a three-stage cyclone burner unit and the surface of a micro-scale structure, and the nitrogen-doped nano-carbon metal-free catalyst can be prepared by using byproducts of a carbon trapping unit.
9. The natural gas-hydrogen dual-fuel low-nitrogen combustion self-adaptive regulation and control system according to claim 1, wherein the carbon capture and recycling unit comprises a hydrogen production module, a carbon capture module and a recycling module, wherein the hydrogen production module is used for preparing low-carbon hydrogen, the carbon capture module is used for capturing carbon dioxide, and the recycling module is used for coupling the captured carbon dioxide with green hydrogen to synthesize methanol.
10. The self-adaptive regulation and control system for natural gas-hydrogen dual-fuel low-nitrogen combustion according to claim 1, wherein the control unit has the functions of data receiving, instruction issuing, linkage coordination and fault early warning.

Description

Natural gas-hydrogen dual-fuel low-nitrogen combustion self-adaptive regulation and control system Technical Field The invention relates to the technical field of proportional mixing combustion systems, in particular to a natural gas-hydrogen dual-fuel low-nitrogen combustion self-adaptive regulation and control system. Background Along with the global energy structure advancing to green low-carbon transformation, the industrial boiler is used as high-energy-consumption and high-emission equipment, and carbon and nitrogen reduction transformation of the industrial boiler is a key development direction. The natural gas is used as clean fossil fuel and is widely applied to industrial boiler combustion, but the problems of higher emission of nitrogen oxides and limited carbon emission reduction potential still exist in single natural gas combustion, and the hydrogen is used as zero-carbon fuel, only water is generated in the combustion process, no carbon emission exists, and the natural gas is mixed with the natural gas for combustion, so that the carbon emission of a combustion system can be effectively reduced, and the combustion characteristic is improved, and therefore, the natural gas-hydrogen dual-fuel combustion technology becomes a preferred path for low-carbon reformation of the industrial boiler. At present, the natural gas-hydrogen dual-fuel combustion technology still faces a plurality of key technical bottlenecks in industrial application, and restricts the large-scale popularization of the technology. Firstly, the combustion characteristics of hydrogen and natural gas are obviously different, the ignition point of hydrogen is low, the flame propagation speed is high, the combustion strength is high, and the combustion stability of natural gas is good butThe production amount is high, and when the mixing proportion of hydrogen fluctuates within the range of 0-30% by volume and the industrial boiler load fluctuates by +/-20%, unstable combustion, tempering, and the like are easy to occur,Emissions exceeding and the like, the existing combustion system lacks accurate self-adaptive regulation and control capability, and cannot dynamically match fuel blending proportion and load change. Secondly, most of the existing dual-fuel combustors are reformed from traditional single-fuel combustors, no targeted hierarchical partition structural design is adopted, cooperative stable combustion of hydrogen and natural gas cannot be realized, and suppression by optimizing combustion space distribution is difficultMeanwhile, in order to improve the combustion efficiency and reduce the ignition temperature, noble metal catalysts such as platinum, rhodium and the like or metal oxide catalysts such as iron, cerium and the like are mostly adopted in the prior art, so that the metal catalysts are high in mining energy consumption and high in cost, are easy to be polluted by carbon deposition and attenuated in activity under the high-temperature combustion working condition for a long time, are required to be replaced frequently, increase the operation and maintenance cost of the system, and are contrary to the industrial transformation requirements of low carbon and low cost. Moreover, the hydrogen supply of the natural gas-hydrogen dual-fuel combustion system depends on the traditional hydrogen production process, a large amount of carbon dioxide tail gas is generated in the traditional hydrogen production process, if the tail gas is directly discharged, the carbon reduction effect caused by hydrogen blending combustion is offset, the closed loop of hydrogen production, combustion and carbon emission reduction cannot be realized, the existing carbon trapping technology is mostly deployed independently, the synergy with the combustion system and the hydrogen production system is poor, the trapping energy consumption is high, the trapped carbon dioxide lacks an effective recycling path, and a complete low-carbon closed loop system is difficult to form. In addition, most units of the existing natural gas-hydrogen dual-fuel combustion system independently operate, and lack of a unified control unit for linkage coordination, so that a real-time closed loop for detection, regulation and control, feeding, combustion and re-detection cannot be formed, and the system has low operating efficiency and lag in regulation and control, so that combustion stability and low combustion stability are difficult to considerEmissions and low carbon targets. Aiming at the defects existing in the prior art, a system which can realize the self-adaptive regulation and control of the wide-proportion mixing of natural gas and hydrogen, low-nitrogen stable combustion and realize closed loop of carbon capture and resource utilization is urgently needed to be developed, and the problems of unstable combustion in the prior art are solved,The problems of exceeding emission, high catalyst cost, incomplete carbon emission reduction, poor system coopera