| With the increasingly serious greenhouse effect,reducing carbon dioxide emissions has become a common challenge faced by all countries in the world.As the largest developing country,China consumes a lot of energy products every year and emits a lot of carbon dioxide gas.In September 2020,President Xi Jinping made a commitment to the international community to "peak carbon and be carbon neutral" at the United Nations General Assembly.China is facing tremendous pressure to reduce carbon emissions and it is imperative to capture carbon dioxide.With the continuous development of China's social economy,China's energy structure is gradually changing,and the scale of natural gas consumption continues to expand.Winter is the heating season.A large number of gas boilers are started for heating and consume a lot of natural gas.After natural gas is burned,a large amount of carbon dioxide gas is produced.The capture of carbon dioxide in gas boiler flue gas has important ecological and economic value.The main components of natural gas are methane and other hydrocarbon gases,which contain a small amount of non-hydrocarbon gases and generally do not contain moisture.The combustion of natural gas mainly produces carbon dioxide and water,and releases a large amount of heat energy.The combustion products basically do not contain harmful pollutants SOX,and NOX emissions are relatively small.Compared with the traditional coal-fired boiler,the composition of the flue gas is much simpler.Therefore,the carbon dioxide capture device in the flue gas of the gas-fired boiler can reduce multiple pollution reduction treatment links to a certain extent and improve the collection efficiency.After a comprehensive analysis of the development status of carbon dioxide capture technology,the mainstream solution absorption method has problems such as absorbent degradation and secondary pollution.The adsorption method is difficult to apply to large-scale carbon dioxide because the current mainstream adsorbent has a small adsorption capacity.Concentration,membrane separation technology is mainly due to high cost,easy to damage and other problems,resulting in higher maintenance costs in the later stage.Compared with the above processes,the low temperature separation method consumes relatively large energy,but the captured carbon dioxide is liquid,which is convenient for carbon dioxide.Transportation and storage.Combined with the large number of start-ups of gas boilers in winter,the ambient cold energy in the winter air can be used to directly cool the flue gas,which reduces the energy consumption in the low-temperature separation process to the greatest extent.According to the process requirements of the gas boiler carbon dioxide capture device,the preliminary design of the process flow and the measurement and control system was completed,and the simulation experiment of the flue gas cooling control system was carried out based on the MATLAB/Simulink platform.Based on the conventional PID control algorithm,the flue gas cooling control system and the carbon dioxide compressor system are simulated.Aiming at the shortcomings of the conventional PID algorithm in the flue gas cooling control system,the fuzzy adaptive PID control algorithm is used to re-control the flue gas cooling.The system controller is designed,and the simulation results obtained are compared and analyzed with the conventional PID simulation results.The measurement and control system of the carbon dioxide capture device is built on the UW500 DCS system.According to the requirements of system measurement an d control,the system hardware is selected and designed,and the system software and hardware are configured through UWin Tech,and the program flowcharts of each control subsystem are designed.Finally,the intelligent control of the measurement and control system of the carbon dioxide recovery device is realized,and the purpose of highefficiency and energy-saving recovery of carbon dioxide in the flue gas of the gas boiler is achieved. |
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