Document OE2Kbz7m3bxezZgd2LKr14aL1

Otfef&vn fctton turbmtt -1 *i ; * fc: , y t 1 y< f' I h:l `ti p Turbine floor plan of the powerhoute. Pelton turbines havo oppaslto sides of Ihe powerhouse. Pump dhcli#.~_ two nosiles, one connected to ooch of two penstocks olong coma up between the two groups of vertkol.hoh -fv* apeeiee ____(wronaemsnt of the fuel-control mechonism for 4 The combined octlon of speed-measuring ond fucl-chonglr>Q tend ond dual-fuel engines. Volvo shown Is simplified m mechonism during load increase In a mechanical governor PUMPED STORAGE (ontinutd because of the pumps' th^st bearings. This could have been done by different valve schemes but, again, the turbines conuoi shutting down the pumps. This '~\L r?la probably the first time litis method has been used. With this system, when electric power, to a pump (ails and it starts to stow down, the governor opens the turbine's Lott Sit/> nrr* * pKiftiBr -Am rV ifi ji: noales. The turbine then brings the unit to speed ready to synchronise the generator lor connection to the power system. To adapt tho turbine governors to Jt > lUft \ Is 1J APN this type of control they ate supple* moated by a safety governor driven by the exciter shaft. This governor has J------------- 1 UiUi r l! switches that trip lire generator-motor ofl the power system If speed drops 5% below normal and that start closing Plon ond profito of the Etiel hydroelectric development. It hot 120,6 Installed capacity in tlx 20,000-hp units operating under a 1300-hM the isolating valve in the discharge line If pump speed drops to 60% normal. Pumping-Plant Benefits. Only during dry summers, when natural drainage (alia to fill Lake Sihl are the pumps needed to help fill the lake. Normally they aerve principally to balance the power supply over short periods, gen erally a few weeks each year. Never theless, the storage pumps have substan tially improved performance of the power station. Government regulations are quite rigid as to the dale when Lake Sihl must be filled in summer. The pumps make it possible to meet these requirements always, If surplus night and weekend power is available from base-load sta tions, pumping during these periods may be valuable to improve load factor of the power system. This la true In spring, summer and autumn, and also In winter when water is lowest In the rivers sup- plying other plants on tho power system. low-Wotar Operation. Decause of ex tremely low water during the winter of 1949-50, Switzerland was threatened with a power shortage. Every avail able means was needed to meet these conditions without seriously restricting power use. Including Importing power from systems outside the country. Much of the imported power was available during nights snd weekends only. For example, Holland furnished power from 10 pm to 6:30 am, and on Sundays. Part of this power was used in the Waggltal and Etzel stations to drive pumps to store water for peakload generation during week days. Water was also stored in the reservoir of the Oberhaslt power station of the Bemische Kraftwerke for week days. During week-day nights part \ power generated in the Beouo-.S plant pumped water into <lor>~~ this way the Etzel pumped-Uam and others like It have given < servioe, not only during powr!ft ages but sfso in normal tioAW the ayttem can easily carry ll peak and peak loads. Conclusions. Hydroelectric I storage plants have on tdnitotM most large power systems. crease the output of many bydiP" nd use power surpluses tbs* *i otherwise go to waste. The **jJL. station is an interesting eiiOP"jS high-head phnt where storsi* improve performance ond er6 pile of natural ranotl that filb J* ervoir during normal year*. ENGINEERIN') AND management section hat Does peed Regulation ean? 3 Action In o simple mechonkol governor during decree** In engine lood. Governor reduce* fual supply to' 'engine S'lhe job of your governor to keep engine whhln desired limits for load carried, ft second arftcte of our serfe* shows you jw mechanical governors are applied-today XBy CDOAR i KATES, Cenuiltinf Enginaer, N#w York Ust mouth we discussed the vortype* of governor* available for tit ud other blgh-compreaaion en* _ a We're oow rcody to lake a cleaer at what happens when o governor "ppead regulation is the change in an spat's "Heady'' speed (its final or suefbed speed) when load ia changed gam the (oil-rated value to xero, or vice without governor adjustment. fOiiage ta needy speed Is expressed ir* percent of full-load speed by: , Speed regulation, % -- * (ao-load rpm-foJMosd rpm) * y rated full-load rpm [Note that speed regulation refer* to a "ie,!n steady speed. This means that governor and engine are given enongh time to reach a stable position and speed, respectively, for the given load. For partial changes in load, steadyspeed change ii proportional to the speed regulation. Example. Suppose our engine runs at 600 rpm at full load, and at 624 rpm steady, speed when ill load is removed. Slnee speed increase is 24 rpm between full end no load, apeed regulation ia (100) (24)' + 600 - 4%. Knowing the speed regulation we oan easily compute speed change (or any partial load change. With e load change of one-quarter rated load, aay from 4/4 to or 94 l V4 load, resulting speed change it one quarter that from full to no load. For this engine it Is 94(24) -- 6 rpm. Table below summarizes change of speed with load, for this engine." Load Full (4/4) ft % 0 Speed, rpm 600 606 612 618 624 Speed change, % 0 1 2 3 4 Speed regulation U important (or many reasons. One is that it determines how two or more engines driving the same load will share any load change. An engine's speed regulation is directly related to the governor speed droop. , Speed droop la the change In rotating ENOINEERINO and manaoemeni section