Document JJoNajX7nqZmNNGQMJwNgKn96

HOW TO ORGANIZE YOUR NEW POWER PLANT-1 313 Items to Follow Up in Designing a New Plant First installment of a practical series on selecting, design* ing, constructing, starting, operating and maintaining modern electric-generating stations to give most economical service '* By 0 C SWIFT, ffrosco Services Incorporated Tilt omic* of etch power plant (rows out of a series of compromises. Adjustments must be made according to the location, climate, usable space, fuel, equipment availability and price. Ideas of both designer and owaer in* fluence plant arrangement, equipment selected and the building. These com* promises frequently produce features undesirable from en operating, mainte nance or testing standpoint.. The person responsible for starting and testing the new plant should, if possible, hove the opportunity to review the plans as they progress. He may save considerable time and expense by (1) suggesting changes to make operation simpler, safer or more economics!, and .(2) checking to see that lest points and instruments are properly located and available. Even more important, those who ere to supervise operation and maintenance should review and eritclse the'plans as they become available, and are revised. Tills should keep everyone satisfied end happy with the setup in years to come. local conditions end practices, or likes and dislikes, may indicate the de* stability of altering plant design in greater or lesser degree from usual ar rangements. A list of special features desired should be prepared. After checking on the costs involved, and discussion and approval by all interested parlies, theto additions should be in corporated in the design. Chock list on pp 79*81 lias shown by long experience to include desirable features of plant design. As the design progresses a periodic review of the plans, using the check list end a list of special features as guides, will show whether items are being satisfactorily taken care of. Those that ore not should be studied to arrive at the best possible compromise. This list will not replace capable de sign knowledge anil experience, but it can help considerably in insuring lhai items are not overlooked. Incorporation of these items Into the de'eign si the earliest possible point saves consider able time and expense in getting the plant into operation. Representatives from the owner's engineering or oper ating organisation should be designated to follow design closely. They should carefully scrutinize purchase orders and design prints to check on the vsrious features before actual construction goes too far to allow changes. Models built prior to construction are often used to assure satisfactory ap pearance and adequate operating and maintenance clearances. White the cost of model construction may seem rather largo, it usually runs much less than one percent of total plant cost. Without first cheeking in model form, more than this omount may be spent in redesigning and making field changes to correct un foreseen conflicts of piping, ducts, ond building steel. Even with o model, closest coopera tion between structural, mechanical, and electrical design engineers is needed It prevent interferences of equipment fa the field. Ab prints reoch the plant oadcr construction, they are often checked for interference by the men who uifl he responsible for running the pism. Last-minute field changes cause dslij and expense, and at times other oafnc seen complications. .1 Specification preparation U om-qdJ many important services rendered bj designers and consultants. Specification* lor equipment and bulldlm nut bt quite complex, requiring considerab1l1y experience to prepare satisfactory ones. Preliminary specifications are uiosll] revised to describe more execlly ihcmj to be eventually purchased. The revbtj form usually is included as psrt of lb purchase contract, giving Informstio nn details of equipment design andpa formnnee. A complete set of parch** orders and specifications should bein', able to the testing crew* end epertW for thetr information. Purchase orders should specify w* the manufacturer furnllh an adeqotf number of instruction books and eW struction prints. These should bo * available to operators and rePj5oeB.iJ sponsible for the machines, where manufacturer is to supply BP6** . vice or Instruction, <hc detail* to should be Included in the order. The form and legal provisions^ payment, delivery, guarantees, alhe carefully worded, and *"0U prepared !y an experienced purcb E| Deti0n Considerations mis rite ores for present tnd future expiation. .Jrn*i* *ter supply for present and future needs, sbove Hood level or protected against high water. jLgi oriented for best railroad, trsnimlssJon-llne approach. feTj luiuts expansion considered In plant general design. iTiturs (ye) ehsnges considered in plant design. Irj wu and srailsblliiy, load-factor variation, tnskeup-wster operating personnel, prevailing conditions considered i footing equipment and steam conditions, biter, turbine, electrical operating levela on same floor. Itgfvnicnt passageway between main operating areas. Kdeqaite room for operation, maintenance around equipment. Headways accommodate large trailer trucks in melting tur* blae-room crane. folpraenl numbering system agreed on and used in design, jeratlng, maintenance instructions, parts lists msde available K operating personnel before plant starts. {adequate quiet space for office and meeting areas. Judcquate locker rooms with plan for future needs worked out. %b supply of drinking water throughout plant. [Adequate, convenient apace for shop and maintenance needs, ftojep end shelving layout built befdre plant starts. itjMI Equipment spare parts to be delivered before plant starts. Handling, Storage and Preparation A Elevated-tank level indicator visible from plans. 9 High- and low-level alarms for denied isnk. 10 Altitude valvo (or elevated lank. 11 Elevated-tank overflow piped so tank may be overflowed con tinuously during winter. 12 Service-water pump head si full load only slightly above do- vated-taak static head. 13 Water meters ahead ol teolile softeners. . 14 Cheek solve to prevent hot water reaching teolile material. 15 Representative samples of water obtained st earliest date. 16 Minimum water-treatment equipment Installed Initially with provision for later amplification if needed. 17 Minimum chlorination equipment. 18 Water-testing apparatus, chemicals ordered lor early delivery. 19 Ample apace for water apparatus storage and use. 20 Provide for convenient truck, rallrond delivery of chemicals. 21 Ample space for dry storage of chemicals. 22 Platforms or holtta for easy chemical handling. 23 Hose connection, floor sumps to clean chemical use areas. 24 Zeolite materiel suitable for incoming water condition. 25 Chemical food tank, pumps to supply chemicals to boiler or boiler leedweter. 26 Phosphate feed direct to boiler drums. 27 Safe handling, good distribution by acid feed system. 28 Cage hoards or sesles to show condensate storage-tank con tents in thousands of pounds. 29 Cooling coils and layout for steam and hot-water samples. rSptly* on low points of-gas lines, ibp |i* linei run level in solid ground, or are carefully prided and drained to avoid pockets cutting o0 gas flow. Hitn gas-line shutoff valve on outside ol boilerhouse. "Cue lino for incoming gas-preisure run to control room. Hans for recording gas flow, temperature, apecilie gravity, IBto provided by gas supplier or in plant design, ill-capacity regulator for gas supply ol light loads, ins to heat regulators if pressure drop Is more than 5:1. 'feeler line (or gas regulator runs downstreem to give steady `pressure at most essential point. [Bypass valve around gai-eontrol valve, ixontroi valve and main bypass operable from control I bypass valve around gas-control valve operable from r os for lighting off. I^Biroer header ol ample site to reduce velocity eflects. DcBeth ends of burner supply header vented, Oat pressure taps st header inlet, both ends of header end to inditHduel burner.. ,p*0iMank heaters of ample lire with unrestricted flow areas, - thermostatically controlled. barer heating lines for oil lines in cold climates. Nam for gaging storage and oil tanks. iFteilillea for unloading daily lull-load fuel In 8 hours. Methods (or moving oil and coal cars. ^Csti-csr trackage' reduces inlerferenco from unloaded cart, proaomlcal arrangements for moving fuel to or from storage, `Adequate area' for present and future coal storage. [Coal preparation and handling arranged for minimum dust. tfCoa] supply, handling, milling equipment interlocked (nr lately. Coal bunker ond chutes arranged for free flow of wet coal. 'Crier and pulveriser capacity to handle maximum wet, hard '(ieesL JWverited fuel piping for good distribution and minimum rtttiling eul. ,3paee and layout for fuel sampling, preparation, testing. CirculotIng*Water System 1 Log boom st intake to keep floating trash sway. 2 Intake equipment o! corrosion-resistant materials or finish. 3 Traveling screens end auxiliaries installed where needed. 4 Ample screen area, screens in aeries for dirty water. 5 Means for safely cleaning and washing screens. 6 Necessary equipment for screen hoisting. 7 Stop logs or other method for complete rapid unwatering of circulating-water tunnels. 6 Intake screens ond rocks removable for repair aod inspection. 9 Screen chamber and elreulating-water tuooeb avoid sodden turns to minimize eddies. 10 Pump auction pipes carried fairly close to tunnel bottom. 11 Circulating pump-suction piping arranged to avoid air pockets, spins or uneven distribution to pump inlet. 12 Circulating pumps to be self-prlmlng where feasible. 13 Motor-operated or butterfly valves for pump, condenser piping. 14 Rubber expansion joints for pipo and condenser expansion. 15 Check valve or other means to prevent pump reversal with cooling tower or parallel pump installation. 16 Cooling tower separated to minimize recirculation. 17 Tower location minimizes traffic, plant hazards from fog. spray. 18 Towers have best expect to wann-wcathcr vindi 19 Tower approach and water capacity sized with condenser for best over-all economy. 20 Tower makeup inlet where cool Incoming water does most good. 21 Tower blowdown easily observed, messurtd by weir. 22 Tower overflow adequate In size and non-slpbonlng. 23 Convenient method for reguleting water to tower sections. 24 Tower basin volume equals 8 to 12 br normal evaporation. 25 Tower basin sloped to drain to clean-out sump for easy drain age tnd cleaning. 26 Tower basin constructed to be essentially leakproof. LUV nd Water Treotment t*P wells far apart, minimising water table drawdown, fJAto-depth gage linos for wells. Hpports for discharge lines near pumps. fSettling-basin level control for at least one pump. "***1 gages In settling basin. '?PS for draining and cleaning settling basin. ip outlet from settling basin set few inches above bottom. Condenser ond Auxiliaries 1 Most economical condenser design for water supply available. 2 Condenser tubes arranged to avoid subcooling of condensate. 3 Divided wsterbos or backwashing method if needed. 4 Room for condenser tube removal. 5 Means for handling waierbox covers. 6 Walerboies without sir pockets or lurhulenee-produclng cor ners. 7 Waierbox drain valves adequate In size. fCttnax-c ft