화학반응을 고려한 스토커식 소각로의 3차원 모사연구

권순우; 이종협

HWAHAK KONGHAK, Vol.36, No.3, 353-363, June, 1998

Export Citation

화학반응을 고려한 스토커식 소각로의 3차원 모사연구

Three-Dimensional Simulation of the Stoker-type Incinerator Considering Chemical Reactions

권순우, 이종협

초록

본 연구에서는 도시 폐기물의 소각을 위하여 사용되고 있는 스토커식 소각로에 대한 삼차원 모델링 연구가 수행되었다. 특히, 소각로내에서의 난류 유동 현상과 혼합 반응을 동시에 고려하여 조업 조건의 변화에 따른 소각로내에서의 유동 현상의 변화와 동시에 CO, NO와 같은 대기오염물질의 배출량을 정량적으로 예측하고, 고체 입자의 궤적 추적을 통하여 체류시간을 예측하였다. 스토커 소각로의 1차 과잉공기를 100%로 일정하게 하고 2차 과잉공기를 0%, 20%, 50%, 100%, 150%로 변화시키면서 연구결과에 대한 해석을 수행하였다. 해석결과 2차 과잉공기가 100%, 150%로 공급될 때 가장 낮은 농도의 CO와 NO를 방출하지만 이 경우 1,123K(850℃)이상에서의 체류시간이 2초에 미치지 못하여 독성 유기물질인 다이옥신류의 분해가 제대로 일어나지 못할 것으로 예상되었다 본 연구결과 화학반응과 체류시간의 예측을 통하여 1차 과잉공기의 양이 100%, 2차 과잉공기의 양이 50%일 경우가 대기 오염물질의 최소 배출을 위한 최적조업조건으로 예상되었다. 또한 화학반응 특성 시간과 난류 혼합특성시간을 비교할 때, 유동에 의한 혼합률이 지배적이지만 전체 과잉공기의 양이 200% 이상이 될 때는 화학반응의 특성시간이 길어져 화학반응을 완전히 무시할 수 없는 것으로 나타났다. 본 연구에서 제시하는 방법론은 새로운 소각시스템을 설계하거나, 기존의 소각로의 최적 운전조건 탐색에도 유효하게 적용될 수 있을 것이다.

A three-dimensional simulation study is performed to provide a design basis for maximum performance operation of the stoker-type incinerator. The model equations consider turbulent flows and gaseous chemical reactions to investigate the flow field, the amount of CO and NO emissions and the residence time in the furnace and boiler parts among the incinerator systems. Results show that the concentrations of CO and NO emitted decrease with the increase of the secondary excess air under given conditions. However, the residence times in the temperature cone above 1,123K(850℃) are less than 2 seconds, when the primary excess air of 100% is supplied with the secondary excess air of 100% and 150%. Based on the simulation results, the emission of air pollutants would be minimized for the primary excess air of 100% and the secondary air of 50% when considering chemical reactions and residence time in the incinerator. Comparison of characteristic times of the chemical reactions and the turbulent mixing of gases shows that the mixing effect is dominant. However, in the cases of the total excess air of 200% and 250%, the effect of chemical reactions on the incineration efficiency could not be neglected because of the relatively long characteristic time of the combustion reactions. The methodology suggested in the study would be applied to obtain the design parameters of new incinerators and determine the operating ranges of incinerators for the maximum performance.

Keywords:Stoker;Incineration;Turbulent Flow;Reaction

[References]

Hester RE, Harrison RM, "Waste Incineration and the Environment," Royal Society of Chemistry, UK (1994)
Robinson GF, J. Inst. Energy, Sep., 116 (1985)
Ravichandran M, Gouldin FC, Sci. Tech., 85, 165 (1992)
Nasserzadeh V, Swithenbank J, Scott D, Jones B, Waste Management, 11, 249 (1991)
Nasserzadeh V, Swithenbank J, Schofield C, Scott DW, Loader A, Environ. Prog., 13, 124 (1994)
Schindler PJ, Nelson LP, "Numicipal Waste Combustion Assessment-Technical Basis for Good Combustion Practice," EPA-600/8-89-063 (1989)
Kim SK, J. Environ. Hi-Technol., Jan. (1994)
Santos AM, "Study of MSW Incinerator-Overall Operation and On-Site Measurements Over the Grate," STEV-FBT-91-14 (1991)
Shahani GH, Bucci D, Vincentis D, Goff S, Mucher MB, Chem. Eng., Feb. (1994)
Fluent User's Guide V4.2, Fluent. Inc., Lebanon, NH (1993)
Seinfeld JH, "Atmospheric Chemistry and Physical of Air Pollution," A Wiley-Interscience publication, U.S.A. (1986)
Flagan RC, Seinfeld JH, "Fundamentals of Air Pollution Engineering," Prentice Hall, Englewood Cliffs, New Jersey (1988)
Bowman CT, Prog. Energy Combust. Sci., 1, 33 (1975)
Calvert JG, The Chemistry of the Atmosphere; Its Impact on Global Change, IUPAC, Blackwell Scientific Publication, UK (1994)
Kim SK, Shin DH, Ryu CK, Choi SM, J. Korean Solid Wastes Eng. Soc., 11, 545 (1994)
chomiak J, "Combustion(A Study in Theory, Fact and Application)," Abacus Press, Gordon and Breach Science Publishers, Switzerland (1990)
Choi SM, "Private Communication and Document for Continuing Education Program," KAIST (1994)
Kim SJ, Kim SK, Yoo YD, Choi SM, J. Korean Solid Wastes Eng. Soc., 11, 619 (1994)
Dellinger B, Taylor PH, Tirey DA, "Minimization and Control of Hazardous Combustion Byproduct," EPA/600/S2-90/039 (1990)
Um TI, Chang TS, Chae JW, Energetika, 2, 54 (1993)

[Referenced By]

[1] Hester RE, Harrison RM, "Waste Incineration and the Environment," Royal Society of Chemistry, UK (1994)

[2] Robinson GF, J. Inst. Energy, Sep., 116 (1985)

[3] Ravichandran M, Gouldin FC, Sci. Tech., 85, 165 (1992)

[4] Nasserzadeh V, Swithenbank J, Scott D, Jones B, Waste Management, 11, 249 (1991)

[5] Nasserzadeh V, Swithenbank J, Schofield C, Scott DW, Loader A, Environ. Prog., 13, 124 (1994)

[6] Schindler PJ, Nelson LP, "Numicipal Waste Combustion Assessment-Technical Basis for Good Combustion Practice," EPA-600/8-89-063 (1989)

[7] Kim SK, J. Environ. Hi-Technol., Jan. (1994)

[8] Santos AM, "Study of MSW Incinerator-Overall Operation and On-Site Measurements Over the Grate," STEV-FBT-91-14 (1991)

[9] Shahani GH, Bucci D, Vincentis D, Goff S, Mucher MB, Chem. Eng., Feb. (1994)

[10] Fluent User's Guide V4.2, Fluent. Inc., Lebanon, NH (1993)

[11] Seinfeld JH, "Atmospheric Chemistry and Physical of Air Pollution," A Wiley-Interscience publication, U.S.A. (1986)

[12] Flagan RC, Seinfeld JH, "Fundamentals of Air Pollution Engineering," Prentice Hall, Englewood Cliffs, New Jersey (1988)

[13] Bowman CT, Prog. Energy Combust. Sci., 1, 33 (1975)

[14] Calvert JG, The Chemistry of the Atmosphere; Its Impact on Global Change, IUPAC, Blackwell Scientific Publication, UK (1994)

[15] Kim SK, Shin DH, Ryu CK, Choi SM, J. Korean Solid Wastes Eng. Soc., 11, 545 (1994)

[16] chomiak J, "Combustion(A Study in Theory, Fact and Application)," Abacus Press, Gordon and Breach Science Publishers, Switzerland (1990)

[17] Choi SM, "Private Communication and Document for Continuing Education Program," KAIST (1994)

[18] Kim SJ, Kim SK, Yoo YD, Choi SM, J. Korean Solid Wastes Eng. Soc., 11, 619 (1994)

[19] Dellinger B, Taylor PH, Tirey DA, "Minimization and Control of Hazardous Combustion Byproduct," EPA/600/S2-90/039 (1990)

[20] Um TI, Chang TS, Chae JW, Energetika, 2, 54 (1993)