Modelling and Prediction of NOx emissions from coal fired boilers: Case study

Transcription

1 Interntionl Reserh Journl of Engineering nd Tehnology (IRJET) e-issn: 9 - Volume: Issue: June- p-issn: 9-7 Modelling nd redition of NO emissions from ol fired boilers: se study Vineeth Morris J, Anumod D M G Student, Eletril nd Eletronis Dept, Aml Jyothi ollege of Engineering, Kottym, Kerl, Indi Assistnt rofessor, Eletril nd Eletronis Dept, Aml Jyothi ollege of Engineering, Kottym, Kerl, Indi *** Abstrt As Indi modernizes nd s the popultion produed in Indi omes from ol. The ombustion of ol shifts to urbn res, the ountry hs lso shifted from produes vrious pollutnts, suh s oides of rbon (O), oides of sulphur (SO), oides of nitrogen (NO) using trditionl biomss nd wste to relying on other nd prtiultes.these pollutnts degrdes the energy soures, inluding fossil fuels. Indi is strongly environmentl qulity by using id rin,ozone hole fossil fuel dependent nd ol is the mjor fossil fuel in depletion nd limte hnge. limte hnge ffets Indi. The ountry ws rnked s the third-lrgest globl ol produer, onsumer, nd importer of ol in griulture, eosystem, humn helth nd hbitt of the entire living beings. Hene it is the responsibility of these, nd ol plys pioneer role in the power setor. industries to hek these emissions nd keep them to miniml level. Fly-sh prtiultes n be removed by Due to growing energy demnd dependene on ol is fitting eletrostti preipittors nd SO by instlling inresing dy by dy. Despite hving signifint ol flue gs desulphuriztion plnt. The best wy to redue reserves, Indi hs eperiened inresing supply O emissions is to improve power genertion effiieny. shortges s result of lk of ompetition mong However, no prtil methods eist for reduing NO, produers, insuffiient investment, nd systemi leding to inresed reserh into this re. During the problems with our mining industry ombustion of ol ombustion proess in ol-fired power plnt, nitrogen produes emissions of Nitrogen (NO&NO ) ommonly from the ol nd ir is onverted into nitri oide (NO) nd nitrogen dioide (NO referred to s NO whih uses hrmful environmentl ); together these oides of nitrogen re ommonly referred to s NO. problems suh s id rin nd smog. In this rtile mthemtil model bsed on dimensionl nlysis is developed to estblish the reltionship between boiler opertionl prmeters nd Nitrogen oides (NO) formtion. Dimensionl nlysis works on the proper. DIMENSIONAL ANALYSIS Dimensionl nlysis is mens of simplifying physil problem by ppeling to dimensionl homogeneity to redue the number of relevnt vribles []. It is bsed on seletion of prmeters ffeting the proess (NO the ukinghm i-theorem. Dimensionl nlysis works on the proper seletion of prmeters ffeting the formtion).it opertes on the dimensions of the seleted proess (NO formtion).it opertes on the dimensions of prmeters rther thn their vlues. In dimensionl the seleted prmeters rther thn their vlues. In nlysis, it is not neessry to identify detils of the dimensionl nlysis, it is not neessry to identify detils tul ombustion equipment e.g. its design, of the tul ombustion equipment e.g. its design, ombustion ir distribution system, positions of ombustion ir distribution system, positions of burners, burners, et. nd wht will be the effet on ombustion et. nd wht will be the effet on ombustion of fuel if of fuel if prmeters like humidity hnges; All these prmeters like humidity hnges; All these effets re refleted in the model through mesured vlues of effets re refleted in the model through mesured quntities tht re used to build up the model. vlues of quntities tht re used to build up the model. The eperiment is bsed on on-line mesurements of seleted opertionl prmeters for the given boiler. Key Words: dimensionl nlysis, nitrogen oides. INTRODUTION ol is the mjor fossil fuel in Indi nd plys key role in the energy setor []. ol meets bout % of the ommeril energy needs nd bout 7% of the eletriity.mathematial MODELLING Y DIMENSIONAL ANALYSIS Aording to ukinghm pi theorem if problem involves n relevnt vribles & m independent dimensions then it n be redued to reltionship between n m non-.. dimensionl prmeters, IRJET.NET- All Rights Reserved ge 87 n m Aordingly the prmeters seleted s input vribles re s follows:

2 Interntionl Reserh Journl of Engineering nd Tehnology (IRJET) e-issn: 9 - Volume: Issue: June- p-issn: 9-7 Volume of ombustion ir,(m /s) Mss flow rte of ol, ṁ (kg/s) Temperture of ombustion ir,t(k) Volume of Nitrogen oides,no(kg/m ) oiler performne, (kgm /s ) lorifi vlue of fuel, (m /s ) Here the number of seleted prmeters = Number of bsi dimensions = Number of dimensionless rguments = - = the dimensionless rguments re nd It is possible in dimensionl nlysis to epress the seleted prmeters inluding NO formed in funtionl form s follows: For the mtries with A nd D dimensions nd vetor mtries of unknown prmeters nd E the following eqution n be pplied: A ( )D E y epnding A,, D, E the following set of liner equtions is obtined: ( ) f(,m,t,no,, ) () The prmeters epressed in the funtionl form hve fudmentl dimensions of length, mss nd time.the bove prmeters n be epressed s follows: m T NO () The reltion for dimensionl rguments nd will be obtined from dimensionl mtri A s presribed below: Tble-: rmeters nd Dimensions ṁ T NO M - S Kg K Dimensionl mtri A will be formulted from tble suh tht determinnt of A. Mtri A will be formulted by hoosing vribles,,, nd A A Vlues for nd will be ssumed suh tht its determinnt lso should not be zero: () y substituting the vlues of nd in the liner equtions we obtin the vlues of nd s tbulted in tble : Tble-: Dimensionless rguments nd their vlues - - * () * (), IRJET.NET- All Rights Reserved ge 87

3 Interntionl Reserh Journl of Engineering nd Tehnology (IRJET) e-issn: 9 - Volume: Issue: June- p-issn: 9-7 i.e. * NO m m * (7) The term ontins NO term nd hene it n be epressed s funtion of i.e. ( ) (8) Also nd is epressed in the power funtion form to get reltion between dimensionless rguments in Xel s follows: A (9). EXERIMENTAL ANALYSIS Tble:- rmeters nd their vlues obtined from online mesurements Slno (m/s) ṁ (kg/s) T (k) (kgm/s) (m/s) NO (kg/m) RESULTS OTAINED Dimensionless rguments nd is omputed by substituting vlues from tble onto equtions in 7 Tble:- Dimensionless rguments nd their vlues Sl.no , IRJET.NET- All Rights Reserved ge 877

4 Interntionl Reserh Journl of Engineering nd Tehnology (IRJET) e-issn: 9 - Volume: Issue: June- p-issn: 9-7 Tble :- Mesured NO vs. redited NO vlues nd their errors Sl.no NO mesured (kg/m ) NO predited (kg/m ) Error (%) Fig -: plot of vs. From fig we obtin the vlues of A nd of eqution9 s A=. = -. Substituting A nd in eqn 9 we get the formul for NO (kg/m ) s below: (.. () * NO m NO(kg m * ).( m ).* ). m (). () *( u ) hrt -: Mesured NO vs. redited NO. ONLUSION Modelling of NO emissions from MW power plnt, bsed on dimensionl nlysis hs been done. The predited vlue goes well in ord with the mesured vlues nd it hs been tbulted in tble long with the errors. In four ses error hs risen by more thn ±% nd it n be ttributed to the error inurred while tking the online observtions. During the eqution formultion bsed on dimensionl nlysis one n observe tht the vrible ombustion temperture gets eluded. As lredy stted bove even if the prmeter gets eluded it s effeted will be refleted through the other prmeters whih mkes the model., IRJET.NET- All Rights Reserved ge 878

5 Interntionl Reserh Journl of Engineering nd Tehnology (IRJET) e-issn: 9 - Volume: Issue: June- p-issn: 9-7 AKNOWLEDGMENT First of ll, uthors would like to thnk God lmighty, for best owing his blessings in this endevour. The uthors lso knowledge the tehnil support from ll those who guided nd helped during the preprtion of this report. REFERENES [] Mri mogursk, Modelling of nitrogen oides formtion pplying dimensionl nlysis, hemil nd roess Engineering. Vol. () pp.7-8,. [] M.A.Hbib nd M.Elshfei. Influene of ombustion prmeters on NO prodution in n industril boiler." Siene Diret, omputers nd fluids7, pp, 8., IRJET.NET- All Rights Reserved ge 879