IS 12800(‘Part 1 ) : 1993 ( Reaffirmed 1998 ) Indian Standard GUIDELTNBSFOR SELECTJONOFTURBINES, PRELIMINARYDIMENSIONINGAND LAYOUTOFSURFACEHYDRO-ELECTRIC POWERHOUSES PART 1 MEDIUM AND LARGE POWER HOUSES UDC 627.85 : 621.224~2 o BIS 1993 BUREAU MANAK OF BHAVAN, INDIAN 9 BAHADUR STANDARDS ZAFAR MARG Price Group 8 SHAH NEW DELHI I 10002 August 1993 Hydro-electric Power House Structures Sectional Committee, RVD 15 FOREWORD This Indian Standard ( Part 1 ) was adopted by the Bureau of Indian Standards, after the draft finalized by the Hydro-electric Power House Structures Sectional Committee had been approved by the River Valley Division Council. So far as to generate electrical energy from Hydroelectric Power Houses, Selection of Turbines, Preliminary Dimensioning and Layout is necessary in designing of such Power Houses, requirement Requirements are, therefore, will be different from large, medium and micro ( small ) Power Houses. laid down separately for large and medium Power Houses and small Power Houses. This standard is, therefore, formulated into three parts - Part 1 covering Medium and Large Power Houses, Part 2 covering Storage Power Houses and Part 3 Mini and Micro Power Houses. Guidelines covered in this standard are applicable after fixing the data with regard to the capacity, type, number of units and discharges. Departure from the guidelines will be necessary to meet such special requirements and condition of individual site based on judgement and experience. _ For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1960 <Rules for rounding off numerical values ( revised )‘. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. turbine output in kW. tt is given by: 2 REFERENCES The Indian Standards listed below are necessary adjuncts to this standard: IS No. the definitionsgiven in IS 4410 ( Part IO ) : 1988.electric powel Guidclincs for selection Spherical valves for hydropower stations and systems: Part 1 Criteria for structural and hydraulic design The selection in accordance 4. I corresponding to available rated head of site.IS 12800 ( Part 1 ) : 1993 Indian Standard GUIDELINESFORSELECTION OFTURBINES.p. trial synchro110~s speed/rotational speed II’ can bc computed from the following formula: 7332 ( Fart 1 ) : 1991 3 TERMINOLOGY 3.1 Determine trial specific speed by Fig.2 After ascertaining trial specific speed as mentioned in the foregoing para.2 Alternatively. 4.m. Yl= rated speed of turbine in revolutions/ minute. and P= H= rated head in metres. 4. .2.2 Minimum Tail Water Level It is the water level in the tail race preliminary Guide for dimensioning and layout of elbow type draft tubes for surface hydel power stations Criteria for design o’ spiral casing ( concrete and steel ) (first revision ) at the exit end of the draft tube corresponding to a discharge required to run one machine at no load. OF TURBINE 7418 : 1991 4 MAlN PARAMETERS 4.1 Specific Speed ( n.2. if the runner were reduced to a size which would develop one metric horse power under one metre head.2 Speed of type of turbine should be made with TS 12837 : 1989. ) This standard (Part 1) lays down guidelines for preliminary dimensioning for surface hydroelectric power houses with reaction turbines having vertical shaft arrangement. suitable speeds rrom economical considerations may be decided in consultation with the manufacturer.These guidelines will generally unit capacities from 5 MW to 500 MW.2. 4.2. NOTE . apply to It is the speed in r. 3.0 For the purpose of this standard. speed can be detcrmi~~etl by the following steps.1 Type of Turbine 7326 ( Part 1 ) : 1992 Penstock and turbine inlet butterfly valves for hydropower stations and systems: Part 1 Criteria for structural and hydraulic design for Hydraulic turbines and large hydromedium houses .2. IS 7418 : 1991 and following should apply. Title where IZS= Glossary of terms relating 4410 ( Part 10 ) : 1988 to river valley projects : 10 Hydro-electric Part including station power system conductor water (first 5496 : 1969 revision ) specific speed of turbine in revolutions/ minute. PRELIMINARY DIMENSIONING AND LAYOUTOFSURFACEHYDRO-ELECTRIC POWER HOUSES PART 1 SCOPE 1 MEDIUM AND LARGE POWER HOUSES 3.1 Rated head and output 12837 : 1989 per machine being known.2. 4. at which a turbine of homologous design would operate. 1.1 In reaction turbines. 3A and Fig. A head varying in excess of 10% from the design head suggests the next lower speed. 2 for a given altitude above mean sea level and for a given temperature which is generally taken as 30°C. which can be obtained from Fig. The selection of formula is subject lions: a rated speed by the above lo the following considera- 7 -.3. 10 The positive value of Hs indicates that the 1 cm 200 300 400 500 100 50 centre line of the distributor may be placed up to Ha metres above the minimum tail water SPECIFIC SPEED (ns~ level.. < H. 4. 100 where Ha s Hb = e G (r 2 s! 50 40 Suction head in metres. $ a.3 The rotational/synchronous/rated speed of the turbine in revolutions per minute is determined from the following formula:* Hated speed in r. account of heavy silt abrasion is apprehended then a lower value may be adopted.’ = : 000 600 500 400 trial specific speed.4 If on .3 Turbine Setting 4. H. Barometric pressure in water column.p.~ r 7 7. z! g 2 h) . the next greater speed should be chosen. ) 20 0= Thoma’s cavitation coefficient.2. 3B. 6 ~~~~. = Vapour pressure. frequency 50 cycles per second ).3 After determining the rated speed as mentioned above. through standard generators with odd number of pairs of poles are also available.number of pairs of pOkS.oH Hv * w g 200 z 9 I .m.2. 4. -. The suction height of distributor centre line above the minimum tail water level can be determined from the following formula: H. 4.5 where . 1 REL.f = frequency ia cycles per second ( In Indian Power systems. and metres of ( In the absence of specific data the value of Hb . can be determined 30 from Fig.~TIONSHIPBETWEENSPECIFIC SPBED the centre line of the distributor is to be placed at an elevation of at least HB metres below AND RATBDHEAD minimum tail water level. the specific speed can be determined by the formula given in 3. the setting of turbine with respect of minimum tail water level should be fixed from the consideration of cavitation.2. and If the head is expected to vary less than 10% from the design head. and ]J . The negative value of Hs indicates that FIG. 2 HEIGHT OF BAROMETRIC: WATER COLUMN AT DIFFERENTTEMPERATURES WATERAND OF ALTITuDBS Anov~ SRA L~VFI. 4. II 60 x f ~--P $ % 5 ‘.IS 12800 ( Part 1 ) : 1993 where II.2. <\1 ALflTClDE ABOVE SEA LEVEL (metres) FIG. 65 a) An even number of pairs of poles should be preferred for the generator.H. 9 and 10. to have a cavitation free runner at a given specific speed. the specific speed may be reduced by decreasing the speed of rotation. 7.5.2 In case the turbine setting.3 04 05 THOMAS 06 COEFFICIENT 07 (0 1 08 09 10 FIG.4.) of machine and peripheral vclocit>’ coefficient ( KU ) . where D is & ia case of Francis turbine in case of Kaplan turbine. 5 for Kaplan for Francis turbines. is found to be very low resulting in uneconomical construction of power house. ‘l‘hc radius I( OF the inlet portion and the \l.idth B of the open portion of the casing. refcrrcd to runner diameter I>. 1 I can 3 The relationship between specific speed ( 11. 4. 3B THOMA’S COEFFICIENT FOR DIPFBRBNTSPECIFICSPEEDFOR KAPLAN TURBINES 4. 4. indicxtcd in Fig. The major dimensions of the spiral casing indicated in Fig. 3A THOMA’S COEFFICIENT DIFFBRL~NT AT SPECIFIC SPEEDFOR FRANCIS TURBINE ooc 800 600 500 400 0.4. 6 is shown in Fig.4 Runner 4.5 Spiral Casing 4. turbines and in 4.1 The runner discharge diameter LJ~ for Francis turbine and runner diameter & for Kaplan turbine ( shown in Fig.2 The other runner dimensions of Francis turbine indicated in Fig. 3 ) are both determined by the peripheral velocity cocfficient K. which is defined a’s: x D I18 Fig. 8 may be obtained as a function of YIP.ecl for gross heads generally above 30 metrcs. or D!: from the curves shown in Fig. and D. 4 may be obtained with respect to the diameter D3 and specific speed 17~ from the curves shown in Fig.IS 12800 ( Part 1 ) : 1993 600 60 ': 04 006 008 01 02 03 THOMA’S COEFFICIENT FIG.: Concrete spiral casing shouid bc designed in accordance with lS 7418 : 1991..1 Mefallic Spiroi Ccrsitrg Metallic spiral casing should bc ur.3. .2 300 400 500 fml SPECIFIC 7OCJ SPEED rli 800 900 1000 11x FIG.X$ 12800 ( Part 1 ) : 1993 KAPLAN -lbRBINE FIG. 5 RELATIONSHIP BETWEEN SPECIFIC SPEED ( nH) AND PBRIPHERAL VHL()~~TY COEFFICIENT k'. 4 TYPICAL SHAPES OF REACTION TURBINE RUNNERS 22 2.0 18 1. FOR KAPLI\N TURBINE .6 14 1. 0 50 150 200 250 SPECIFIC SPEED n. FIG. 7 RUNNBR DIMBNSIONS WITH RESPWT TO THE DIAMETER L+ AND SPBCIFIC SPEED FOR FRANCIS TURBINE 5 . SPBED ( ns ) AND PBRIPHBRAL VBLOCITY FOR FRANCIS TURBINE 2.6 0. 6 RELATIONSHIP BETWBEN SPECIFIC COEFFICIENT K.4 02 0.IS 12800 ( Part 1 ) : 1993 06 0 100 20Q 300 SPECIFIC SPEED ns 400’ 500 FIG.8 0.0 18 16 14 12 10 0. 6 Draft Tube diameter is ‘F’ as determined 100 150 SPFCIFIC 200 SPEED -: 250 'cjr. evaluated by the following conditions: P = P- O”.5 x stayvane outside 0 = 4. 5 4' cc 7 12 10 08 06 50 Stayvane outside from Fig. and can be 14 KI.4 where K = 0. The values of constants K1 and K. :.1 The air gap diameter OF HYDRO- ( D. = constants.r) Major dimensions of the draft tube are given in Fig. IB = ++----I D-1 : - 5-J FIG. 8 MAJOR DIMENSIONS THE SPIRAL OF CASING be determined by the following formula: R = 1..3 to 3.6 D1. The maximum value of air gap diameter ‘3 D.1 for 4 = 200” to 225’.6 2. at rated speed can be read from Fig. SPIRAL CASING DINENSIONS WII II RESPECT TO RUNNER DIAMETER OR I).3 for Francis turbine and 2.2 for Kaplan turbine ( higher speed ratio for lower head ) the value of maximum peripheral rotor velocity V. and K = 1. Assuming the runaway ratio to be 1. 4. & m g 5 5 5 I 2.95 for # = 180” to 200”.4 22 20 16 16 1.1.8 OGL 50 A 100 I 150 SPECIFIC I 200 SPEtD 2% 71s / I 300 350 The equation of semispiral is given below: P = K1 KI -8’ where P= radius of curvature of the semispiral at an angle 8 in radians. ) ( see Fig. K. This condition is likely to be limiting only with large Kaplan turbines of low speed where a clearance of at least 5 cm should be allowed. is governed by the maximum permissible stresses in the rotor parts and rim and these are directly linked with the peripheral velocity on runaway speed. R at 0 = diameter at w 0. : 0 5 2 u 03 a 12 10 0. SPECIFIC: SPEED 11~ 9 .( AND D. 15. and R + KD1. 12 and should be determined in accordance with IS 5496 : 1969.85 to 2. 10. and 0. 6 FIG. should be large enough to allow the turbine runner top cover to pass through the stator bore.1 Air Gap Diameter 5.IS 12800 ( Part 1 ) : 1993 5 MAIN PARAMETERS GENERATORS 5. 13 and 14 ) can be determined from the following criteria: a) The air gap diameter D. 4 1.4 2. ) Outer core diameter Do of the stator ( see Fig.IS 12800 ( Part 1 ) : 1993 This curve relates to sheet steels having a yield point of 525 N/mm*.0 1. 13 SUSPENDED TYPE CONSTRUCTION 7 .0 2.9 1.6 0. 13 and 14 ) can be determined by the following formula: 1.6 1. 0 -f $ n U? 0. For better quality steels peripheral velocity be increased in direct ratio of yield strength. = D.0 50 100 150 SPECIFIC -+-----I H = Depth of the draft tube L = Length of the draft tube B = Width of the draft tube 200 250 300 350 FIG.2 2.2 1. in metres can be obtained from the following formula: &=60x TE v..8 2.8 where p = number of pairs of poles.7 0. 12 in 1 OF GUIDE APPARATUS ----_-__ where velocity peripheral v.8 1.1 0.p. zi I ii . The peripheral velocity thus settled.5 0.m. the value of D.6 2. 11 CONCRETE SPIRAL CASING FIG.4 03 0. (1 +-$-)metres g L 0.2 I 50 100 150 200 I 250 300 I 350 SPECIFIC SPEED ns FIG.0 D. a & 2 2 L 6 z! i ii 4 ii a ul 3. RESPECT TO 10 SPIRAL CASING DIMENSIONS WITH RUNNER DIAMETER& OR Dn AND SPECIFIC SPEEDns FIG. = maximum metreslsec. and n = rated speed of machine in r. 12 MAJOR DIMENSIONSOF DRAFT TUBE SPEED ns r\ r: 8 0) g 5.2 Outer Core Diameter ( D. 3 to 2.1 C see Fig.3 Stator Frame Diameter 5. 5. 13 and 14 .5. K V’ Df for suspended 5. ) L.5 to 1.1 Inner diameter ( DI. ( see 5.IS 12800 ( Part 1) : 1993 can be determined IO the stator frame i.0 ) metres l-6 to 2. + 5. + 3-S to 4.7. = by adding 2. 15 MAXIMUM PEIUPHBRAL ROTOR VELOCI. to be and determined K.3 to 2.8 ) metres ( De + = Db = i i . 13 following where W = Rated KVA of machine. II~ = and umbrella K 4 Dgfor tion.1 Stator frame diameter Df ( see Fig. ) barrel across barrel ) Height of load bearing bracket Hj 13 and 14 ) can be determined by the following formula: __-.2) metres.8 to 3.~Y If. Lt = ( L. hj = of Load Bearing Bracket ( h. 13 and 14 ) can be determined by adding I.6 Leogth FIG.7 Height 5. = Output coefficient from Fig.4.4 Inner Diameter of Generator type construetype construc- 5. NUMaER FIG. 14 of Stator Frame ( Lr ) UMBRELLA/SEMI-UMBRELLA TYPE CONSTRUCTION ( Df ) Length of stator frame Lf ( see Fig. D. 16.5 to I.0 ) metres ( D.2 metres to the outer core diameter.5 Core Length of Stator 5.3. 13 and 14 ) ( across flat dimension in case of polygonal shape ) can be determined by adding 1. ) 1.6 ) metres. Barrel ( DI. i.2 ) metres ( L. D.e. + 2.e.1 Core length of stator and 14 ) can be determined formula: by the Fig. ) of generator ( see Fig. 5. + 2.8 across flat dimensions metres ( Df ) ( D.e. OF PAIRS OF POLES (P. I I I = ( D. Df = ( Do + 1. AT RATED SITED 8 .Inner dimensions aat faces in case of polygonal shaped tion.6 metres to the length of stator core i. erection 01‘ . and 0. in the power house. Total axial load for use in the determination of height and number of load bearing brackets should comprise the hydraulic thrust and the weights of rotor and runner..9 Axial Hydraulic Thrust 5. dimensions of units of the Axial hydraulic thrust P. 6 OVERALL HOUSE DIMENSIONS OF POWER power turbine. 50 tonnes per per and 5.85 for a load of 100 tonnes above per arm of the bracket.8 Number of Arms of Brackets The number of the arms of the bracket are to be decided on the basis of the total load on the thrust bearing that is maximum hydraulic thrust of the turbine runner and weight of rotating parts. 16 DETERMINATION OUTPUT COBFFICIENT OF . 5. determined 5.75 for load of 50 to 100 tonnes arm of the bracket.1 The overall dimensions of mainly depend upon the following: a) Overall dimensions tube and scroll-case. of the generator.< on ihe turbine runner may be determined by the following formula: PH = K D. 2nd d) Size of the erection NOTE -.. K= in tonnes. 19A and runner 19B. otor and untanking of transformers should be made in such a \vay that the space required is minimum without impairing the operational and maintenance requirements. of runner in D1 = inlet diameter and H max = maximum head in metres.10 Weight of Generator Rotor Weight W?: of generator rotor in relation with air gap diameter DR and active core length LC can be determined from Fig 18. 17A and Fig. l<o OUTPUT 171~. to be Weight of turbine from Fig. house draft 6.65 for load of less than arm of the bracket. Load per arm of the bracket as given hereunder. Generally 4 to 8 arms of the bracket are taken. 5.Provision for inlel valve.IS 12800 ( Part 1 ) : 3993 where K = KG K I 0.12 Weight of machine rotating parts comprises the weights of rotor and runner.‘J H.. bay. b) Overall c) Number from metres. 17B.11 Weight of Turbine Runner can be determined 0. where a constant to be determined Fig. COEFFICIENT. IS 12800 ( Part 1 ) : 1993 0.10 0 05 0 50 100 150 SPECIFIC 200 SPEED (n s) 250 300 350 FIG.25 0. 17B DETERMIXATION OF AXIAL HYDRAULIC TI~RIJS~.COEFPXCIENT KAPLAN FOR T~JRRINH . 17A DETERMINATION OF AXIAL HYDRAULIC THRUST COEFFICIENT FOR FRANCIS TURBINE 1 I I - i- )L FIG.30 0.20 0.15 0.40 0 35 0. 19A RELATIONSHIP kk'WREN RUNNERWI-IGHT FRANCIS TURBINE 11 AND RUNNER FOR . A clearance of l-5 to 2. AND ACTIVE CORB LENGTH L. For determining the outer dimensions of the generator barrel.2 Length of Power House It depends upon the unit spacing. crane to handle the last unit. length of erection bay and the length required for the E. These clearances should be such that a concrete thickness on either side of scroll case should be at least 2.IS 12800 ( Part 1 ) : 1993 2 4 6 8 10 12 14 it‘ AIR GAP DIAMETER (D Q ) IN METRES FIG.2.O. 18 WEIGHT DkI OF GENERATOR ROTOR IN RELATION WITH AIR GAP DIAMETER D.the inner diameter of the generator barrel may be increased by 0.0 m should be added on either side of the extremities of the above drawn figures to determine the unit spacing.5 to 15 m depending upon the size of the machine.1 Unit Spacing For determining the distance between the centre lines of the successive units? a plan showing the overall dimensions of the spiral casing..0 to 2. 6.T. 6.5 m in case of fully-embedded steel scroll cases.5 m in case of concrete scroll cases and 1. I I J (1 5 tl I a DIAMETER RUNNER DIAMETER (Dl) IN METRES FIG. the draft-tube and the hydro-generator should be drawn with respect to the vertical axis of the machine.0 IO I. T. . b) A gallery of 1.3.IS 12800 ( Part 1 ) : 1993 C 1 2 3 4 5 (Dl) IN METRES 6 7 6 RUNNER DIAMETER FIG.3 gives the internal width of the Power Honse ( exclutiing column width ).5 times the unit bay size as per erection requirements.3 The total length L of the power can then be determined as follows: houses On the upstream side provision should be made for the following: a) A clearance of about I. 6.2 The cirteria laid down in 6.O. = Length of erection bay. and e) The spaces as indicated against item (a) to (d) are supposed to be sufficient for accommodating the auxiliary equipment also but may have to be reviewed considering the layout of essential equipment and operational requirements.IZ)lle to special topographical tail conditions it may become necessary to provide tionzl unloading bay at different levels.2.3.. if provided.0 to 2.1 The inlet valve gallery. crane. 12 6.5 to 2~0 m width approaching the draft tube manhole. K = Length required for the E. if required. 19B RBLATIONSHIPBETWBBN RUNNER WEIGHT AND RUNNBRDIAMETERFOR KAPLAN TURBINES 6.T.5 to 2-O m for concrete the upstream of scroll case. = Number of units. cl In for L = No x ( unit spacing ) + LB + K where N. water addi- d) A clearance of about l-5 to 2. and case the main inlet valve is also accommodated in the power house.0 to 1.0 to 5. crane to handle the last unit.O. NOTE .3 Width of Power House Super structure For determining the width of the power house superstructure. 6.0 metres for pressure relief valve in the scroll case. Depending upon the number and size of the E.5 metres. can be utilized for approaching the draft-tube man-hole also and hence no separate gallery is needed for this purpose. 62.2 The length of erection bay may be taken as 1. a valve pit of appropriate size should have to be provided as per IS 7326 ( Part 1 ) : 1992 and IS 7332 ( Part 1 ) : 1991.0 metres. Superstructure clear of the downstream extremities of the above drawn figure by about 2. this length is usually 3. the overall dimensions of the spiral casing and the hydrogenerator may be drawn with respect to the vertical axis of the columns should be machine. L. SPEED IO m 0.4. 20 ) can be determined.3.O.4.O. c) Clearance required transformers. for untaking of d) Unloading of largest package from the trailors.O. Further the height should depend upon the height of the service bay floor from where the equipment is to be handled.3. ( see Fig. The value of K may be taken as 5. b) Hauling the main transformer with bushing into the erection bay under the E. 6. backfill conditions and size of the power house.4.4 Height of Power House height of power house from the bottom of the draft-tube to the centre line of the spiral casing H.0 to 2. can be determined in accordance with IS 5496 : 1969.7. Keeping a clearance of O-3 metre between the highest part of the gantry crane and the ceiling of the power house. specific be taken as 205.5 m depending upon the width of the power house superstructure and capacity of E.IS 12800 ( Part 1) : 1993 6. and the clearance required between the ceiling and the top of the crane. crane hook may generally vary from 4 to 6. crane rail level.1 The 6. rotor assembly and even entire generator stator.4 m 0.1 respectively. crane hook level and the correspondmg E. A height of 7 to 8. A typical example for calculating FIG.9 may speed of machine . 20 CROSS SB~TION THROUGH GENERATING the overall dimensions of the power house is given in Annex A.5 to 7. 1.O.2 ) TYPICAL EXAMPLE FOR CALCULATING THE OVERALL POWER HOUSE DIMENSIONS OF A-l DATA Type of Machine Total Number of Machines Unit Capacity Maximum Head Rated Head Minimum Head Francis Turbine 4 100 MW 105 111 100 m 75 m 13 Barometric Pr-essure at Power House site Vapour Pressure at Power House site Power Factor A-2 SYNCHRONOUS From Fig.6 and 5.T. 6.4. crane hook level and the corresponding crane rail level are determined by providing adequate clearance for the following cases: a) Hauling moving major items of equipment viz. turbine runners assembly.2 The height of the power house ceiling above the highest level of the E. The thickness of the concrete below the lowest point of draft-tube may be taken from 1. UNIT ANNEX A ( Clause 6. 6.T.T. 6.0 m depending upon the type of foundation strata. = Lt + hj + K Lt and hj have been defined in 5.3.4. as follows: H. crane girder.O. 20 ).0 depending upon the size of the machine.5 metres between the top erection bay floor and the highest hook level may be sufficient.4.T.3 The height of the machine hall above the top bracket of the generator depends upon the E.2 The height of power house from the centre line of the spiral-casing up to the top of the generator H2 ( see Fig.1 The E.O.T.T. crane. .m. h = 1.32 &.87 m L = 0.6 to 3.74 x 3.11 m x 3.65 m Depth of draft tube ‘Iit’ for Francis Turbine = 2.5 metres below minimum tailrace level as in 3.4 m 3-O m.7 metres.~. Say 3.44 m H 6 1. .65 x 3.11 m G = I. :.7 = 0.7 r.81 x 105 )O*t x 0.70 m. f and 10 work out to be as shown below: A = I.63 m M = O-61 x 3. n = 166.2 m.5 to 3.p.14 x 166.69 m.94 0s to 1.5 Dj. metallic spiral casing should be used.0.:* ~-2. Since the clear width of the draft-tube is cxcessive.25 J!&.7 = 5.14 m I.e.7. [ Same as adopted where n.71 o3 60 ( 2 x 9.. 18 speed for 16 pairs of poles 60 x 50 16 = 187. Trial synchronous speed machine 205 x 1005/r . ‘h’ will be on the higher side.7 = ____. t!l~. a synchronous speed of 166. The total width of the ciraft-tub: n.7 = 5.IS 12800 ( Part 1 ) : 1993 Synchronous speed of machine ns . is being adopted. 8.26 m A-6 SIZE OF DRAFT-TUBE The various dimensions of the draft-tube shown in Fig. The main dimensions of the spiral casin as determined in accordance with Fig.m..29 x 3. = H = P= 205 r.5 x 3.m.5 met% the centre the distributor should be set 3-O + 0.7 = 4. 4 106:358 .and a specific H = G m from Fig.2 I.5 r.71 _-.3 Da.m.7 = 4. Hs < IO < With a line of = 3. As the specific speed of the turbine is on the lower side. be 12.44 m E = 1.7 = 4.12 :.3. Taking L = 4. A-4 SIZE OF RUNNER Discharge diameter. L r 4. Taking H1 5 2.98 x 3.7 r. further margin of 0. Synchronous As the head variation from the rated head is mOre than 10% lower synchronous speed i.p..iII.38 x 3. and 100 xl OOOkW where H = 105 m.5 metros \vidth shuulti be introduced in the cenlrc of the drnft-tube.7 = 6. A-5 DIMENSIONS OF SPIRAL CASE :.12 x 105 . Length of draft-tube Z_ = 4 to 5 &._ 1005/4 A-3 TURBINE SETTING Hs < HbaH-HH. O-4 m 105 m. 14 166..7 = 2. Since.7 7 5.7 = 3. 12 as determined in accordance with IS 5496 : 1969 should be as below: end draft-tube at exit Height of h = 0.p.5 m. 6 corresponding to a specific speed of 194 = 0.39 x 3.81 m c= D = 1.7 . power 111 kW :: 9. = 10 m. Corrected specific speed cI 194 As the gross head above the turbine is more than 30 metres.6o ( 2 gH)“‘6~& as in 7xI1 IS 12800 ( Part 2 ) : 1989.1 x 3. a pier til‘ 1.p.R x Q x i/ :c .v 106 x 1.07 m B = 1.2. Here Hb = H. and Ku = from Fig. Hbl4 =L/ P x l-358by IS 12800 ( Part 2) : 1989 1.l.p.O-235 x 3.7 = 16.7 = 4. & =.m.358 = 176 r. Cleat width ‘B’ of the druft-tube at exit end = 2. NL = 10.77 m F = 1. 100 m.7 = 6. 3 corresponding speed of 194 = 0.57 x 3.5 defined 0.0 Dy.75 D3. Synchronous speed for 18 pairs of poles 60 x 50 zzz = 166..25 x 3. Taking it _ 1.. minimum submergence at the outlet end of drafttube should be greater than 0. Velocity at the exit end of draft-tube.3 metre.5 + 10.5 m :. A-7. Total number of pair of poles = 18 = 100 000/o-9 Rated kVA of generator = 111 000.2. = -a-&$-ic = 2.8 t_ l-2 = IO. = IO accordance with 2. From Fig. 17.6 x (8.6 = 105.5 of IS 5496 : 1969.5 metres below minimum tail water level..2 metres = 8.5 = 3.8 metres.2 . and = JKZ. 100 x 1 000 _. 21 drawn with 6.0 + l-8 = 11. ( 1 + -5 _ 8. Top of exit end of draft-tube will be 1. = Dg = 11000 kVA. which is in order.9.7 m.0 m _: IO. and -_. for umbrella type construction where K0.9 :.7 Axial in tonnes. Assuming efficiency of machine to be 0. A-7 GENERATOR PARAMETERS A-7. Da = 8-i m A-7. Let there be 6 arms in the bearing bracket.85 dlO construction.6 to 2.1)’ x 166. Dg’ I.32 ) = 7.XP 2x18) ’ A-7. = 2. = 0. hydraulic thrust PH = KD$ Hmax Say 0. turbine 225 x runner = 23 tonnes A-7.m.IS 12800 ( Part 1 ) : 1993 where Q = discharge in cumecs. L. I).0 m A-7.8 Weight of generator rotor Wn 1. the exit end of draft-tube will be 1. Keeping bed slope 1 vertical to 10 horizontal at the bottom of the draft-tube.9 Weight of ( from Fig. 19 ).85 4 8. where K = Ds = H max 0. :. PlI = 0.67 metres above the bottom of draft-tube.19 x 3.5 to 1. in accordance A-8. + 1. :.85 ( see 5. where W = K.5 tonnes ( from Fig.1 metre II = 166._ = 113.0 m.1 == 2. Height of load bearing bracket ‘hj = K J-i% for suspended type construction. _. 634 Load on each arm . 11 000 6.64 for suspended type :. 18 ) .42 for umbrella type construction.7 Say 106 tonnes.81 2g -_ O-251 nl A-7.7 x 105 = 273 tonnes. the top of the exit end of draft-tube will be ( 3.65 = 6. or Vc” i e i_?f??.1.7 = 1’54m Say 1.3 m. + 1.19 from Fig. V.32 m above the bottom of the draft-tube. 16 ).5 Core length of stator ‘Lc) = W K. the extremities of scroll case/draft tube/generator in longitudinal direction are at 15 .5 + 1.F ___ ’ ’ 2 x 9. H= rated head in metres. 15.6 m E 1.7 r.6 Length of stator frame ‘~~9 c L. and 105 m. Since height of draft-tube below centre line of guide apiaratus is 10. 8.10 Height of load bearing bracket ‘hi’ = Total weight of rotating parts + axial thrust = 338 + 23 f 273 w 634 tonnes.1 1 1.6.p.1 Air Gap Diameter ‘DR’ 3.8 m.2 Outer core diameter G D.3 Stator frame diameter Df = D. + I.1 From Fig.807 m Say 8.219 m/set.67 + d1.338 tonnes A-7.1 ).5 cumecs e = -!GG x 100__---_ x 0.4 Inner diameter A-8 OVERALL DIMENSIONS STATION OF POWER of generator - barrel Db D. ) metres = 8. A-7.7.38 metres below minimum tail water level. 6. A-7. and r) = efficiency of machine.6 ( from Fig. hj = 0.2 metres and the centre line of guide apparatus itself is 3. 21 and 22 and 6. Lr = 3.T. station = 4 x 17 + 17 Hz = Lr + hi + K ( see 6.5 times the generator barrel ) + 4.O.0. Say 6. Length of erection bay = 0.89 m. :.69 ( For suspended type machine ).0 m. 20 ) = HI + H. Total height 21. 21 dimensions in millimetrrs. the distance of the inner face of downstream columns from the longitudinal centre line of machine works out to be 6.T.5 to 2.10.3.5 + ( 1.3 Total height of machine hall will depend upon type of foundation. From the size of draft-tube ted in A-6.69 - From Fig. As already calculated.IS 12800( Part 1 ) : 1993 7-l 15 on spiral inlet side and 6. PLAN SHOWING MAIN DIMENSIONS OF UNIT BAY 16 . the same space can also be used for approaching draft-tube ) = 10.5 m. crane. = 3. :.00 ( For accommodating control valve. type of roof and can be determined accordingly.O. H.69 m.0 + 2. Total length of power + 4 = 89 m.0 metres hj = 2.2 ). size of assemblies. height of E.4.5 to 7.69 + 6 :-= 11.7 to unit bay size = 1 x 17 = 17 m.5 ( extremity of draft-tube/scroll-case/ A-8.1 I. A-8.2 Total height of machine ( see Fig. Adding l-5 to 2 metres to these dimensions. Distance of the inner face of upstream columns from the longitudinal centre line of machine = 6. as already calcula- Space required for the E.0. crane to handle the last unit will depend upon the number and size of the crane.2 m.0 ) = 8. Say 2. I. HI . of machine IO.2 -i. All FIG.5 m. K = and 5.5 m on opposite side of the transverse centre line of the machine. the size of the unit bay in longitudinal direction or unit spacing work out to be 17 metres. For preliminary purpose assuming it to be 3 to 5 metres ( 4 metres in the present case). FIG. 22 CROSS SECTIONOF POWER HOUSE 17 .-d35oo --13500--y SPIRALCASING n <ENSTOCK ’ Y All dimensions in millimetres.IS 12800 ( Part 1 ) : 1993 --lo75o~-+. Details of conditions under which a licence for the use of the Standard Mark may be granted to manufacturers or producers may be obtained from the Bureau of Indian Standards. 1986 and the Rules and Regulations made thereunder._~~~~ ___. The Standard Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well defined system of inspection.. ~_.. Standard marked products are also continuously checked by BIS for conformity to that standard as a furlher safeguard. testing and quality control which is devised and supervised by BIS and operated by the producer. . _ Standard Mark The use of the Standard Mark is governed by the provisions of the Bureau of Indian Standards Act. New Delhi 110002 Telephones : 331 01 31. Maniktola CALCUTTA 700054 Northern Southern : SC0 445-446. I. 235 04 42 23 15 632 78 58 632 78 92 Western : Manakalaya. V. type or grade designations. I. j 632 92 95.~~NTI-IAPURAM. E9 MIDC. 53 16 40 53 23 X4 : C. goods and attending to connected matters in the country. I. RVD 15 ( 1345 ) Amendments Issued Since Publication Amend No. T. 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