Design of Air Turbine Flow Passage and Analysis of Energy Efficiency

Transcription

1 Available online a Energy Proedia 7 (0 ) 7 0 Inernaional Conferene on Fuure Elerial Power and Energy Sysems Design of Air Turbine Flow Passage and Analysis of Energy Effiieny PAN Hong-gang a, HENG Wei a,feng Zhao-xing b,he Miao-miao a Deparmen of Power and Energy Engineering, Shenyang Insiue of Engineering,SIE,Shenyang,China b Naional Power Plan Combusion Engineering Researh Cener,NPCE,Shenyang,China Norheas China Grid Company Limied,NEG,Shenyang,China Absra I is possible o use ompressed air o drive air urbine, hus make he urbine drive generaors o power. This paper makes a researh on he feasibiliy of he air urbine experimenal equipmen wih a brief inroduion o is omposiion. The design of he nozzle flow passage and flow passage, measuremen of airflow and alulaion of power generaion effiieny are desribed emphaially. Based on he resul of alulaion and experimen, his paper shows ha he air urbine experimenal equipmen an generae eleriiy safely and seadily. Besides, measuring he effiieny of he air urbine generaor se helps o promoe he undersanding of he engineering appliaion of heoreial formula. 0 0 Published by by Elsevier Ld. Ld. Seleion and/or and/or peer-review under under responsibiliy of Hainan of [name Universiy. organizer] Open aess under CC BY-NC-ND liense. Keywords: Air urbine; Design of flow passage;air flow alulaion.inroduion Measuring he effiieny of seam urbine is one of imporan experimens involved in he ourse priniple of seam urbine. When he experimen is arried ou, suffiien seam supply for normal operaion of seam urbine mus be provided o ensure measuremen; likewise, raed revoluion speed of seam urbine generaing uni (000 rpm) mus be mainained for measuring he effiieny of generaor. These requiremens make diffiulies o hoose he experimenal equipmen. Firs of all, failiy ha is used o produe seam wih high emperaure and high pressure is high in os, eh and risk. Seond, he air urbine roaing a a high speed is also osly and high-risk. Taking hese faors ino onsideraion, we pu forward he air urbine experimenal equipmen, of whih he main omponens are fan, single-sage air urbine and auomai alernaor. While he experimenal equipmen is working, high-pressure air from he fan drives he air urbine generaing uni onsising of air urbine and alernaor o produe eleriiy. Governing devie, emergeny proeion devie and lubriaing oil sysem are also adoped as he experimenal equipmen o guaranee is safey Published by Elsevier Ld. Seleion and/or peer-review under responsibiliy of Hainan Universiy. Open aess under CC BY-NC-ND liense. doi:0.06/j.egypro.0.0.9

2 8 PAN Hong-gang e al. / Energy Proedia 7 ( 0 ) 7.Overview of he Air Turbine Experimenal Equipmen As shown in Fig., main equipmens and sysems of he experimenal equipmen inlude: fan, air urbine, generaor, oil supply sysem, lubriaing oil sysem, governing sysem, monioring sysem, piping sysem and onrol abine. Fig. shemai diagram of he air urbine experimenal equipmen. Fan. Main valve.governing valve 4. Air urbine 5. Shaf oupling 6.Generaor 7. Main oil pump 8.Reepor 9. Bypass valve Afer dus removing, oudoor air is drawn ino he fan and ompressed here, and hen, goes hrough he main valve and governing valve; ompressive air from he fan flows ino he air urbine generaing uni, o drive he roor and produe eleriiy. Finally, he exhaus air disharges auomaially ino amosphere hrough pipeline. A bypass sysem is designed in his generaing uni o ensure sar-up safey and o regulae inake flow rae of he air urbine ino an auxiliary means. During uni s se-up, he bypass valve is open. Meanwhile, he main valve and governing valve is losed. When he fan is operaing seadily, open he main valve and he governing valve gradually and lose bypass valve a he same ime. The uni is also equipped wih regulaing-preserving sysem. Regulaing and preserving funion of he sysem is realized by is various omponens in suh way. Firs, he radial pump onneing wih fron-end of he urbine provides a pulse signal of oil pressure. Then, he pulse signal be amplified in pressure onverer and sliding valve is sen o servomoor in urn. Finally, servomoor regulaes he open of governing o realize funion of he sysem by onneing rods. If he generaing uni is in emergeny, main valve and governing valve ould be losed by pressing he sop buon of he emergeny proeion devie o proe uni s safey. Oil supply sysem is grea imporane for smooh running of generaing uni. Oil in he anker is sen o bearings, governing devie and proeion devie of he generaing uni by he main pump of oil supply sysem. The sar-sop buons of main oil pump, fan, digial revoluion indiaor and digial power indiaor are plaed in he onrol abine of he experimenal equipmen. The air urbine is a parial admission urbine wih single pure pulse sage. The nozzle seion, aouning for quadran, onsiss of small nozzles.the blade of air urbine is made of glass fiber reinfored plasi, whih is heap and easy o be proessed.

3 PAN Hong-gang e al. / Energy Proedia 7 ( 0 ) 7 9 Fig. Componens of air urbine generaing uni. Generaor. Af bearing box.air urbine 4. Emergeny proeion devie 5. Fore bearing box 6.Radial oil pump 7.Inake pipe 8. Sop buon 9.Synhronizer 0. Saring valve Fig. Some omponens of air urbine generaing uni. Main shaf.wheel.blade 4. Af bearing box 5.Shaf oupling 6. Generaor 7.Adjusor valve 8.Hydrauli servomoor 9.Sliding valve Roor of he urbine operaes seadily in experimen, of whih he highes roor speed is up o,000r/min. Fig. and Fig. presen he omponens of air urbine generaing uni..design of Flow Passage Usually, seam is inrodued o he seam urbine around he full ar. As blade heigh is he only sruure parameer, when parameers suh as average diameer, profile, pih are hosen, deerminaion of blade heigh is main work of he design of flow passage. Average blade diameer and blade heigh is respeively 0.6m and 0mm in he air urbine. Considering he lowes generaing speed of auomobile alernaor is 400rpm, hose500rpm as raed roaion speed of he air urbine. So he remaining work is o deermine he oal widh k of nozzles hroa. Calulaion seps are as follow

4 0 PAN Hong-gang e al. / Energy Proedia 7 ( 0 ) 7 Soluion of irular veloiy dn u 8.7m Solving he heoreial veloiy a he oule of he nozzle k k P k RT k P0 Where he adiabai exponen of air k is.4 Universal gas onsan R is 8.4 KJ / Kmol k m Air mass per kilo mole M is 8.964kg Air gas onsan Rm R 0.87kJ / kg k 87J / kg k M Tesing emperaure is 0and he hermo dynamial emperaure is 9K Disharge pressure of air urbine P 0. is Mpa Pressure pre-nozzle P Mpa Subsiue parameers above o equaion and we ge m Solving he aual veloiy a he oule of he nozzle Work ou Aording o he heigh of nozzle [] m Solving w w by veloiy riangles Blade oule angle of he pure impulse sage is 5 is w u u os 74.8m sin arsin w w w w Aording o he - - m w relaion's urve w m ~ 4 less han approximaely,so sele w u uw os 44.55m w arsin sin Soluion of veloiy raio x and rown effiieny 9 as he value of u

5 PAN Hong-gang e al. / Energy Proedia 7 ( 0 ) 7 u x 0.8 os os 7.5% os u x x Solving air mass flow G P u Gu os os The design power of he experimenal equipmen is 500Wso ake 500W as he value of Pu G 0.96kg u os os Solving air volume flow V A 0 and 760mmHgair densiy is.9 kg / m Pu So, volume flow G 0.96 V 0.m.9 Considering ha generaing effiieny of air urbine generaor is 5%, revised value V of volume flow V is V 0. V 0.4m oal widh k of nozzles hroa is worked ou as follow V 0.4 k 0. m l Flow passage of he nozzle an be designed afer exerminaing he oal widh k of nozzles hroa. For air urbine in his paper, he parial admission nozzle seion has ses of nozzles in oal. 4.Flow Calulaion To redue he in-aking friion head loss of he air urbine, he flow measuring devie wih a large diameer hrole orifie is adoped in his experimenal equipmen, as shown in Fig 4. Fig.4 Shemai diagram of flow meer. Flow du. Throle orifie.ondui4. Pressure differene5. U-ube 4 Equaion for solving volume flow Q is

6 PAN Hong-gang e al. / Energy Proedia 7 ( 0 ) 7 Where Q volume flow Q A0 P m / expansion oeffiien flow oeffiien A 0 inner orifie area of he hrole orifie, m densiy m / kg P s pressure differene in fron and bak of he hrole orifie, Pa As ompressible fluid has differen densiy in fron and bak of he hrole orifie, regard he fluid as inompressible and flow equaion for inompressible fluid is used for he sake of onveniene. is he fluid densiy before hrole; flow oeffiien and disharge oeffiien hoose he value of ompressible fluid. All influenes of ompressibiliy are refleed in expansion oeffiien. In his paper, he energy loss is no onsidered and sign o disharge oeffiien. When waer level differene of he U-ube is 0mmHg, he raio of pressure in fron and bak of he hrole orifie is Take 0.88 as he value of, he raio of orifie diameer d o ondui inner diameer D (00mm, so And expansion oeffiien =. Where flow oeffiien is alulaed wih he following equaion 4 And air densiy.9kg / m. Aording o equaion ().4 00 Q / m 7.75m h In fa, wo hrole orifies, wih =0.8, 0.7 respeively, are made o ensure measuremen auray and redue he hrole loss of working fluid. 5.Calulaion of Generaing Effiieny Generaing effiieny is he raio of eleri power generaed by generaing se o heoreial r, el power P produed by air urbine ha is o say P 5 el r, el. P For he air urbine wih pure impulse sage, he power P disharged by air flowing hrough he nozzle is heoreial enhalpy drop of he urbine. When air is onsidered as ideal gas, heoreial power onsan. Energy equaion for he nozzle is 0 h0 h h h h h Enhalpy drop of ideal gas in he proess of isenropi expansion is P an be expressed direly wih gas

7 k k PAN Hong-gang e al. / Energy Proedia 7 ( 0 ) 7 k T P V PV h0 h R T0 0 0 So k k k k P P0 V0 k P0 P Gh G By using he orresponding parameers measured in he experimen, we an work ou ha he air volume flow is68. m / h is 08 m/ sand eleri power P el indiaed by power meer is 487w, herefore, generaing effiieny an be solved as follow Pel 487 r, el 5.7% P Conlusions Main work of his paper inludes seleion of experimenal equipmen, design of flow passage and alulaion of air flow rae and hermal effiieny. On he basis of he work menioned above, following onlusions an be reahed: Adoping air as working fluid is feasible ompleely. Afer debugging he designed air urbine, experimenal resul indiaes ha air urbine running a a required roaion speed an produe eleriiy and ligh he bulb. Compuing mehod in his paper is proved orre by he oinidene of flow passage area heoreially and experimenally. Two hrole orifies are seleed in flow measuremen, and eah measuremen resul is onsisen wih he alulaion resul perfely. Illuminan bulb and displayed power helps o alulae he generaing effiieny of air urbine uni. For he low generaing effiieny, air urbine is no unsuiable for power-generaing equipmen used in a large sale. Referenes [] Zhang Yanfeng.The sruure of seam urbine [M].Beijing: Workers eduaion press987:8-4. [] Shen Shiyi, Zhuang HeQing, Kangsong, e al. Basi priniple of seam Turbine [M]. Beijing: China eleri power press, 007: p60-7. [] Hou Manxi. Indusrial seam urbine [M].Chongqing: Chongqing Universiy press, 995:p-8. [4] Lv Chongde. Measuremen and proessing of hermal parameers [M]. Beijing: Tsinghua Universiy Press, 00: 6-0. [5] Cheng Mingyi, Yan Honghuan, Shi Qiguang. Thermal power plan [M]. Beijing: China eleri power press, 998: p6-5.