Study On Energy-saving And Optimization Technology Of Carbon Dioxide Captured System Of Flue Gas In Coal-fired Power Plant

The higher temperature of the world appeare because of overmeasure greenhouse gas. The control and recycle of CO2 was very important. The energy consumption,the interaction of nodes and the weakness of the whole system couldn't be holded. In this paper, the process was improved, the influence factors of removal rate were analyzed, the energy consumption analysis and themal economic analysis were done.The flue gas in coal-fired power plant is the object in the paper, MEA chemical absorption method was selected to capture, the mechanism of MEA chemical absorption method was analyzed, the advantages and disadvantages of MEA chemical absorption method were analyzed.The process analyzed model of MEA chemical absorption method was built based on AMSIM module of PRO/II sofeware, the effect of carbon dioxide removal rate, themal load and regeneration rate with absorption temperature, absorbent flow, absorbent concentration and regeneration temperature were analyzed. the analysis results showed the higher absorption temperature was, the higher removal rate was, the better absorption temperature was 30～40℃; the higher absorbent flow was, the higher removal rate was, the better absorbent flow was round 80~120m3/h; the higher absorbent concentration was, the higher removal rate was, the better absorbent concentration was round 15%~20%; the higher regeneration temperature was, the higher regeneration rate was, the better regeneration temperature was 100℃~120℃.The themal analyzed method was analyzed based on themal first law and second law, the energy analyzed method for carbon dioxide captured system was decided, the energy analyzed model for carbon dioxide captured system was built, the heat load calculation, energy balance calculation, theory power consumption and energy analysis ?for carbon dioxide captured system was done with black-box model, the analysis results showed that the separation rate was 12.8%. The exergy analyzed model for carbon dioxide captured system was built according to exergy analyzed method, the exergy analysis and exergy consumption analysis were done to system and subsystems with black-box model, the analysis results showed that the exergy efficiency of reboiler was lowest, the exergy consumption of absorption was very high. the regeneration exergy consumption was analyzed, the results showed the higher absorbent concentration could decrease regeneration exergy consumption, but absorbent concentration had a highest valueφmax; the higher the regeneration degreeξwas, the lower the regeneration exergy consumption qs tr, butξhad a limit value; the high property poor and rich exchanger could decrease regeneration exergy consumption.The themal economic analysis method for captured system was built based on themal economy, the themal economic analysis model and energy cost equation were built, the optimizing objective function was determined, and the themal economic analysis was done, the result showed that the cost of recycle CO2 was 582 per tun.The solution of energy-saving and consumption reducing was discussed. The theory basis and economic basis were established for energy-saving and optimization thenology of carbon dioxide captured system with chemical absorption method according to the study in this paper.