Document badgaoDn07rvoGwyzX0NKbygk

jh.iDi'iftWSr.V.s OUTDOOR STATION HAS THREE ENCLOSEO AREAS, turbine, opparotui outdoors hos suitable weolherproof cosing. AbScngj] generator units, ouxillary room and control room; all other of architectural treatment makes plant appear very dlfferm Texas Electric Service Co in stalls outdoor station near PERMIAN BASIN Monahans, Texas. Cooling towers serve condensers of four units. Two unjts forming heat balance group have one common deaerating heater The WesTcnn Divuion of Texas Elec tric Service Co serves a portion ol the rich Texas oil.and gas 6elds. Their extensive development during end since World Wer II has created a demand for additional electric power, and predic tions indicate a substantial increase in the future. Avenge load factor in this area reaches 65% annually and the monthly maximum is 74%. To meet rioing power demand Texas Electric . Service is adding new capacity, repre senting an increase In system capability of over 170,000 lew, at fl) Handley, near Fort Worth (2) Permian Basin (3) Wichita Falls. Permian Basin will be rated at SO,* 000 kw when completed in 1949. Two 12,500-kw turbine-generators and two boilers have just been installed, with two mora similar units scheduled (or next year. The plant stands in a sparsely settled region of the plains country near' Monahans in west Texas,on the Texas 6 Pacific RR. A full section of land was purchased, partly to have adequate area for spacing wells that supply IS (590). makeup water. Considering the station as a "kilowatt-hour factory" no archi tectural .embellishments are necessary. Company engineers and executives have taken the broad view in accepting ad* vanced practice io outdoor design. Climate generally favors outdoor eon* etruction, rainfall averaging only about 15 in. annually. Design precautions guard against eflects ol moisture and low temperatures. With enclosures-pro* vided only for control room, auxiliary room and turbine-generators, large sta tion-construction savings are realised, the main, objective In outdoor designs. Providing a water supply for coolingtower and general plant makeup poses a real problem in west Texas. Water at Permian Basin comes from a considerable number of wells drilled ol widely spaced intervals to minimise the effect of one well on others. Cooling towers provide theonly means of meeting cir culating-water needs in this location. The two present and two future steam generators are of outdoor design, the boilers being completely enclosed by an insulated steel casing with removablepanel side walls and root, and weldedcasing rear wall. Each unit delivers rated output of 150,000-lb-per-hr steam at 650 psig and 835 F. Full-load heal release equals 33,000 Btu per hr per cu ft, or 132,500 Btu per hr per sq ft of projected watercooling surface. Naturalgas fuel permits this relatively high unit heat release in the four boiler furnace Natural gas provides the ehiel^ with oil as standby. Both are svsiUH in the vicinity. Each boiler bu-fJTj] combination gas-and-oil burners loJ rows. Oil burners are widc-'ragie] mechanical type. A SSjOOO-bbl tank and 2000-bbl day tank hold oil supply. A Ljungstrom air Ik with vertical shah forms part ol;i^ steam-generating unit. Constant-sjw^ motor-driven forced-draft and induetdj draft fana, one for each boiler,j mounted on outdoor concrete p between boiler and stack. Each driven by a'150-hp motor, delivers* 500 cfm. An i-d fan, driven by 25 motor, handles 90,500 elm. The h lined steel stacks, 10 It 8 In. Inside, .stand 150 ft above grade. 0ae serves two boilers. A eomewhst unusual system of* and water connection serves ihes*,** relatively small units. Boilers 1 feed steam to a header supplyio bines 1 and 2. A single deat heater and intermediate-pressor feedwater heater, fed by 8lb-aUge[ traction steam, are provided pair of turbines to avoid unhaUnj^j steam extracted from two units. boiler pair has one common driven boiler-feed pump with a ' driven feed pump for standby (or the first pair and a motor-4 standby pump for the aecood-P8^ J ROWER Octobofjijj solenoid-operated shutofl valves cut fuel aupply to the boilers. The 3-element feedwater control ays- tem responds to (1) water level in boiler drum (2) steam flow leaving boiler (3) feedwater flow into boiler. The piston-actuated control valves have valve pooltion Indicators. An Integrally mounted regulator operates each con trol valve, being loaded from the ele ments meaaurod. Manual adjustment* are provided. Tfblna4nRiien. The impulse-type turbine with three bleed points ha ' a rating of 11,500/12,650 kw with throt tle steam at 600 psig, 825 F. Ralhei than the standard 13,529-kva machine; an oversixed generator rated 15,625 kvo was specified. This operates at 13,200 v, 3-phase, 60 cycles. The air-cooled generator uses a fin-type cooler. Steel and concrete enclosures protect the turbines on an open deck. Turbine units 1 and 2 are In one enclosure, 3 .and 4 in another. A 25-ton gantry crane * runs overhead, for general use in han dling the turbine and other machinery parti.. Sliding steel hatches in the tur bine-enclosure root permit access lot . maintenance. MAIN CONDENSERS STAND OUTDOORS to one side of turbines, reducing turbinepvdestol height. Hsolar* and deoorotors ore locoted outdoors above control room' Condensers are of 2-pass non-dlvided waterbox construction with %-In. tubes, 20 ft long. The 11,000-sq-ft condensers re roted 106 million Btu per hr each when provided'with 29.8 efs oooling water at 80 F. Condensers are not dl- .rcctly under the turbine exhaust,.but well to one side, and connected by an - elbow. This arrangement permits re ducing height of pedestal above base slab; this reduces construction costs. Two cooling towers, capable of han dling about 65 cfs each, cool the con densing water. Six 184-in. 3-blade ad justable-pitch axial-flow fans serve six . 2-cell cooling'towers. Each fan delivers 375.000 efm. Guaranteed approach to a 74-F wet bulb' is 14 F. Cooling water Bows b yravity from cooling tower through concrete tunnels, provided with screens at the entrance, to the circulot- Ing-purap suctions adjacent to the con densers. ' One 13,350-gpm circulator serves each-cgndenser. Makeup water from the wells passes through settling basins and various coolers before going _*V*NCt ARRANGES TWO TURBINES ond two boiler, os o.group hoylno - . "*arotor, one evaporator, one tntcrmediato-pveuure hooter for two units to cooling-tower basin. An air-to-air heat pump air-condi tions the control room because of dust and high temperatures. The pump, *utomaltc combustion-control laraar^ f easier controller, gur^drafi regulator, steamflow-oir- assistance from the operators. Each control mechanism may be operated manually without disturbing any auto- with a 10-hp compressor, handles i heat gain of 106,000 Btu per hr and a. heat loss of 165,000 Btu per hr with two changes of air per hr from a volume of operates the boilers- mstlo linkago or other connections. In 14.000 cu ft. Unit coefficient of per ance *llh steam load withoot case of boiler-fan power-supply failure. formance equals 3.5. The unit Is not ($99) <7