Document zdd1Oyvpy3Jgajo7Z1EEeg8Yg

TO MfttOQOtotOSOft fembar of ifvom qwwratort Mtm oarinory hooltq writes 100] [TT| 900h 99$F, Cconen4rr d dr twotir 50 25 <S> 600to $99* roofo r$$k ptrtwotor only gcenomtnronV NeoualUoryiurtoea NMTOsr dram dr-lwawr trra dBItsd 0 25 90 ` 75 too 125 tawesrOf twtlns ttoo* pmat 490 729 899 >090 099 099 M99 <999 1999, . SMem-pr*uwr $wpt,p*tg jUj fooo to eoGQfift :} 800 to 99$ pit . ffJll ffoo/o ns &- \ 100 to 450 pt! GROUPING BY CAPACITIES show* the 60* ond 80*mw turbine* contribute lorgett blocks of kw; units under 10 mw lowest kw 749 799 89 999 949 999 049 Stown-tomporaturo giops,? PRESSURES IN THE 600* ore most frequently oppllec temperatures ronglnp frpm 900 to 949 F strongly P"** Survey Spots Utility Design Trends] Roexirurc msds hr more genernt- tlon on about 7S to 80% of now units. log capacity are strikingly shown by New Practices. The tremendous ex the record number oi returne received pansion all systems are experiencing, In Power's present eteom central-sta- coupled with inflated prices, leads tiaa surrey. In the tobies on pp 92*97 Qaturally to emphasis on designs that are brood details o{ 233 units installed . will hold down' overall costs. About alnee Jenaary 1947 aod projected up two-thirds of the reported units will use to 1951. These units total close to 6.5 team pressures of 600 pilg and above,, million kw, representing about 55 to and temperatures of 900 F and above. (fi% of announced expansions. Power's Only so Insignificant number of boilers 1947 Surrey, published in the June, do not use either or both economiser 1947 Issue, reported on 79 units repre and oir heater; these are in small Mu senting almost 35 million kw for the nicipal plants. same period- as the current survey. Ef The predominant use o! one boiler forts were made to avoid reporting the per turbine directly reflects the cost* same installation in both surveys. cutting aim as well as the Increased re The two studies together give informs* liability of equipment operation. No information was collected os' bar of pure single-unit tosi Probably most of these units are Interconnected wilh other same station at the steam bead^ boiler-feed header. The trend to utilisation of points and more continues. M< plants using less than four operating at pressures of 4SO, below. About 65% of the rc?J her of boilers will have fuM release rates less than 25,000 cu It per hr and 45% 20,000 Btu. While this tic* largely on iho furnace destg? theless shows an allowance,f 72 (SB4) ROWER Octyl NumbsrolWill* withocw.twoontflhrrateflsrs pot twNra 0 29 90 75 100 t <50 T9 Iboqsrpor hrttno .9 botito HHurdM t bdlsrs par turdna 3 faabsri por furbtao COAL WILL BE MOST USED fUlL with utmost universal op. plication of oir hooters; note high uso of I boiler per unit in iue) quality to the poorer side. Tbs present group of installations in* 'tlndes eight topping turbines, only e tall percentage of the entire group 233; last year's aurvey had fire topri out of 81 units. A definite try for increased, over-all *nomy appears in the 12'teheot in"`ion* reported, most of them at nd reheat temperatures of 1000 V0 F, reheat being applied for its "'best rate rather than moisture ol at turbine exhaust. 167 turbines 20,000 kw and larger, 7 three are air cooled, the remainder ! hydrogen. Of a total ol 233 Cfive are crow-compound with the rotor turning at 3600 rpm and (ho totar at 1600 rpm; there are 17 t> tunning at 1800 rpm and one at - Hun, rest operate at 3600 rpm. 7.4 n*t majority mbit of tha instab 3* niU use electrically driven S- '*^-.,with perhaps a standby tor- feed pump. ' Only 16 have Iven pomps exclusively. For rot on fans and pumps s total of 80 hydraulic couplings and 25 mag netic couplings were reported. .Rodlcoi Deporfwras. Projected instal lations that are radically different and will bo watched with interest by the power field are (1) the mercury-steam station being Installed by tbe Public Service Co of Now Hampshire (2) the aimple-oyele gas turbine with exhaust heat recovery being installed by the Oklahoma Cbs and Electric Co. The . first Installation will consist of two "standard" 7500-kw mercury turbines and boilers 'supplying steam to a 25,000kw steam turbine, making a total unit capacity of 40,000 kw. ' The gas turbino reported in Sept 1948 Power, pp 64-71. is a 3500-kw unit working with existing stesm-sistiori heat balance to raise station capability over 6000 kw and improve total beat rate. ADDITIONAL DATA oppear in Flo- 6-9 ot right; not# portlculorfy the conserva tive heat releases in Ftg. 9, showing provision (or changes In coot Quolities El October 40 200 400 800 800 COO > to to to to to 199 599 999 799 990 1100 Boter-capacltf groups,OOO lb port* 100, ( *o to to to 14.9 19.9 24.9 29.9 94.9 400 Piweoeo Boot- rotooss-reto groups, 1000 BN por Or por cu II (S55) 73