ENERGY CHARACTERISTICS OF Pp-330/140-P55 STEAM BOILER

Transcription

1 Aals of the Uversty of Petroşa, Mechacal Egeerg, 5 (03), ENERGY CHARACTERISTICS OF Pp-330/0-P55 STEAM OILER ION OŞA, AN CORUŢ PETRILEAN Abstract: Eergy characterstc of a boler represets the fuel cosumpto depedg o boler load. After a log-tme operato eergy characterstc ca chage as a result of wear ad mateace. I ths paper eergy characterstc of Pp-330/0-P55 steam boler s establshed by measuremets carred out at dfferet loads. ey words: steam boler, eergy characterstc, fuel cosumpto.. INTROUCTION Large combusto bolers are used to geerate steam for power geerato. Eergy effcecy s a mportat aspect of moder ecoomy, therefore predctg eergy cosumpto depedg o load ca be useful for determg fuel requremets order to keep stocks low. eepg coal stocks low s mportat ot oly from ecoomc pot of vew, but also large stockples of coal ca self-gte, producg dsrupto ormal power plat operato. Savg 0% of EU s prmary eergy cosumpto by 00 as stated rectve 0/7/EU o eergy effcecy [], ca be acheved oly by creasg eergy effcecy. y creasg effcecy, less fuel s requred to geerate same amout of steam, ad more fuel supply wll be avalable. Eergy characterstc for a steam boler ca be useful may ways: the approprate fuctog of the boler ca be motored, ad at the same tme fuel supples ca be kept at optmal levels. Ay chage tme of the eergy characterstc of steam boler ca be a sg that mateace must be carred out or that the mateace actvtes are poor ad addtoal measures must be take to accout. Lecturer, eg. Ph.. at Uversty of Petroşa, _dosa@hotmal.com Lecturer, eg. Ph.. at Uversty of Petroşa, dcpetrlea@yahoo.com

2 Eergy Characterstcs of Pp-330/0-P55 Steam oler 9. A RIEF PRESENTATION OF STEAM GENERATOR ult 968 the USSR the Pp-330/0-P55 [] steam geerator s a ocethrough coal-fred boler. Its costructo s carred out two dstct bodes, symmetrcal wth the axs of the group, ad ca be operated parallel to steam turbe, but they ca work depedetly wth the turbe as they are equpped wth adequate valves to be solated. Steam output for oe body s 330 t h -, at a pressure of 0 bar ad 550 C for lve steam ad. bar at 550 ºC temperature for reheat steam. Each steam geerator body (Fg. ) s desged wth two flue gas paths - the shape of Π - oe ascedg ad oe descedg, ted together wth a reverse room. Fg.. Pp-330/0-P55 steam boler []. SCAA - steam-steam heat exchager; ZSR II - upper radato secto; ZMR meda radato secto; ZIR lower radato secto; SCP - prmary covecto superheater; SCI - termedate covecto superheater; ZT trasto secto; ECO ecoomzer; PA regeeratve ar heater (SCAA ad SCI are part of the reheater crcut).

3 30 oşa, I., Petrlea,.C. The ascedg path s the furace chamber area, where the radato heat exchagers are located ad the descedg path cossts the covecto heat exchage surfaces. Combusto ar ad the ar used for the trasport of pulverzed coal are blow by a cetrfugal ar fa. The basc fuel s crushed coal, obtaed hammer mlls for each body of the steam geerator. To start ad support the flame, auxlary fuel s used (atural gas). Oe mll, delvers crushed coal for two burers placed cross o each sde of the furace chamber. Flow of coal grdg mll s provded by the raw coal feeder (wth scraper bad) whose speed ca be adjusted remotely by the voltage appled to the C drve motor. oler effcecy at rated load reaches 90,07% (by project) especally by placg partcular areas of regeeratve covecto heat exchagers (ecoomzer ad ar preheater), leadg to lower flue gas temperature to a value of 5 C, whe operatg exclusvely o pulverzed coal. Supply water parameters at steam geerator rated load are: pressure 88 bar, temperature C. 3. ENERGY CHARACTHERISTICS OF STEAM GENERATORS Eergy characterstc of a boler represets the fuel cosumpto (deoted wth ) depedg o boler load. epedg o load ad how the fuel cosumpto s calculated, eergy characterstcs ca be: - gross eergy characterstc f(q u ) of f() where Q u s the useful heat of steam or hot water suppled by the boler ad s the steam flow rate provded by the steam geerator. - et eergy characterstc, et f(q u ) of et f() where et cotas the fuel equvalets of supplemetal eergy cosumpto of blowers ad other equpmet eeded for proper boler fuctog. The gross eergy characterstc s the most commoly used for characterzg the operatoal level of the boler. Forms of eergy characterstc equatos are [3]: a + b + c a + b Q + c Q () depedg o what form we would lke to use, the steam flow rate provded by the steam geerator or the useful heat of steam or hot water suppled by the boler Q. I order to establsh the actual characterstc of steam boler at a gve momet coeffcets a, b, ad c or a, b ad c must be evaluated. Measuremets ca be carred out for ths purpose or data obtaed whe

4 Eergy Characterstcs of Pp-330/0-P55 Steam oler 3 eergy balace measuremet are doe, ca be used. A mmum of three measuremets must be carred out same as regulatos for eergy balace states [], [5], [6]. ased o measured data eergy balace s calculated ad values for ad are determed. ase o values ad, where stads for umber of measuremets performed, coeffcets a, b ad c ca be calculated as follows: 5 3 c () 3 5 b (3) c b a () where: (5) 3 (6) 3 (7) (8) 5 (9)

5 3 oşa, I., Petrlea,.C. where stads for the fuel cosumpto for measuremet ad for steam output for the same measuremet. Relatos () (9) ca be used for the secod form of eergy characterstc, replacg wth Q. The method used for calculatg the coeffcets equatos () - (9) s the method of the smallest squares, as values ad are ot accurate values order to corroborate the eergy characterstc curve, but close values, sce measuremet errors occur.. MEASUREMENTS AN RESULTS ata for aalyss was provded by the strbuted Cotrol System (CS) of ut. As requred, measuremets must be carred out for least 3 dfferet loads. The loads were fxed to 60 t h %, 560 t h - 85% ad 60 t h - - 9% of rated steam flow rate t h -. Sce measured parameters vary aroud the values set above, the ed a umber of 363 uque data sets were acqured. Aalyzg obtaed data a major varato atural gas flow rate betwee 66 to 90 m 3 N h - (used for flame support) ca be observed. Coal qualty ad flow rate also vares; as a result the lower heatg value of coal-methae gas mxture vares too. Ths creates a problem whe eergy characterstcs for the same boler were establshed usg fuel havg dfferet lower heatg values, ad the they eed to be compared. Soluto to ths problem s to express the fuel cosumpto relatve to a stadard qualty coal lets say a coal havg lower heatg value 7,000.0 kcal kg -. Aother specfc feature that must be cosdered s that part of the steam suppled to the turbe, s recycled ad reheated the boler so that oly secod form of equato () ca be used, the oe that s cosderg the useful heat Q u. The useful heat Q u s the sum of the heat of steam suppled to the turbe ad the heat suppled to the steam at reheat. Results obtaed are preseted Table. Table. Coeffcets of eergy characterstc equato Coeffcet oler ody A oler ody a -0, , b e-0,363980e-0 c E-07 -, E-07 ata Table shows that coeffcet values for the eergy characterstc equato for ody A ad are very close except coeffcet a. I Fgure the polyomal equatos are graphcally represeted order to vew how close the two characterstc curves are oe to aother.

6 Eergy Characterstcs of Pp-330/0-P55 Steam oler 33 Fg.. Eergy characterstcs for body A ad of Pp-330/0-P55 steam boler 5. CONCLUSION Comparso of eergy characterstc for body A ad of Pp-330/0-P55 steam boler show that although workg smlar codtos, eergy characterstc curves are close to but do ot overlap. Ths s due to the fact that there are a lot of varables that fluece fuel cosumpto ad useful heat output. Ther teractos are dffcult to predct, ad adjustg parameters that flueces the operato of the boler at a fxed load for a log tme s t possble, rather t wll work aroud the desred load value.i order to develop a eergy characterstc curve for the steam boler more data must be acqured. Usg addtoal data, aalyss ca be performed order to dscover f a relatoshp ca be foud, suffcetly precse to descrbe the eergy characterstc for Pp-330/0-P55 steam boler, so that ths characterstc ca be used to predct accurately fuel cosumpto for a plaed operatg regme. REFERENCES []. []. ***, Istrucţu tehce petru îtreţerea geeratorulu de abur Pp-330/0-P55. [3]. Mereuţă, C., Athaasovc, V., Vasluţă, V., Îdreptarul gerulu eergetca d treprderle dustrale, Edtura Tehcă, ucureşt, 98. []. ***, Ghdul de elaborare ş aalză a blaţurlor eergetce, M.O. al Româe, part.i, r.79/ [5]. erde, T., Ioaşcu, T., Resga, R., ş.a., Îtocmrea ş aalza blaţurlor eergetce î dustre. Vol. II. Edtura Tehcă, ucureşt, 976. [6]. Carabogda, G.I., Alexe, F., Athaasovc, V., adea, A., ş.a. laţur eergetce. Probleme ş exercţ petru ger. Edtura Tehcă, ucureşt, 986.