Loading...
HomeMy WebLinkAbout1994-10-26; Water Commission Ad Hoc; MinutesMINUTES MEETING OF: WATER COMMISSION DATE OF MEETING: TIME OF MEETING: 1:30 p.m. PLACE OF MEETING: Wednesday, October 26,1994 (Regudr Meeting) Ci Council Chambers CALL TO ORDER: Chairman Louis called the Meeting to order at 1:32 p.m. ROLL CALL Present: Commissioners Louis, Kubota, Maerkle and Melideo. Absent: Commissioner Henley. PLEDGE OF ALLEGIANCE was led by Commissioner Maerkle. COMMENTS FROM THE AUDIENCE: There were no requests to address the Commission on a non-agenda item. NEW BUSINESS: 1. 1026-1 PRESENTATION ON PROPOSAL FOR "PILOT COGENERATION DESALINATION FACILITIES' - BY SUPERSYSTEMS, INC. Bob Greaney introduced Sam Tadros, President of Supersystems, Inc., and Frank Ducey, Marketing Manager, who gave a presentation on combined cogeneration desalination as proposed by their company. Mr. Tadros made the presentation, stating his company has an agreement with the Bureau of Reclamation for palt of the funding of facilities, and they intend to construct a pilot plant somewhere in southern California, preferably in San Diego County. Mr. Tadros stated there is a bill in the Congress at this time, and if it is approved, early in December of this year there would be one hundred million dollars assigned for desalination research. This is S-617, Desalination bill, introduced by Paul Simon, Democrat from the State of Illinois Mr. Tadros explained that Supersystems has cogeneration desalination plants in Saudi Arabia, Egypt, the Virgin Islands, and are studying the development of power desalination plants in Mexico, Hawaii, the Middle East and South America. He showed slides of plants in operation in Santa Monica, California, stating the one at St. John's Hospital would probably be similar to the one proposed for this area. October 26, 1994 WATER COMMISSION Page 2 NEW BUSINESS: (Continued) Mr. Tadros stated that desalination alone without the power utilization makes the cost of the water too expensive and beyond the affordable range. When desalination is combined with the use of the power, the cost of the water is competitive. Distillation uses the heat from the cogeneration or heat generation, and the fuel is not being used just for desalination. The heat that would be lost normally is saved and used to operate the distillation plant. There are two products; electricity and distilled water. Mr. Tadros stated the technology is well-known and has been in commercial operation for over 30 years--but not in the United States. By using this system, the distilled water can be blended with other sources of water in the area, and by blending them, the quality of the other water can be improved. Mr. Tadros explained how the system works, showing the cycles and sequences of operation. He also showed the water cost breakdown, with energy costing 60 percent; fixed charges, 21 percent; chemicals 6 percent and labor 13 percent. He showed the comparison of water costs, and stated that his company would like to have a pilot plant in this area, in cooperation with SDG&E, using the turbines from the Solar Company, in San Diego, which are very reliable and effective. That pilot plant would operate for two years, and then if successful, the full plant would be built. Mr. Tadros stated his company is able to finance this facility, together with the Bureau of Reclamation. If Carlsbad is interested, they could indicate this by sharing in one third of the cost for a study to be made to determine the proper site. After the study is made, the site would be determined for a pilot plant. A copy of Mr. Tadros’ agenda is on file with the original Minutes at the Water District Offices. The Commission queried Mr. Tadros about working with SDG&E, and he indicated he has talked with them. He indicated the Bureau of Reclamation needs a feasibility study before April 30, 1995, and a recommendation to start a pilot plant for their budget. Mr. Tadros stated that if they were at the Encina plant, they would get electricity at a reduced rate and the City of Carlsbad would also get part of the electricity at a reduced rate. What is left would be sold to SDG&E--and they must buy it--per Federal regulations. Mr. Tadros stated that they cannot discharge waste into the ocean over 10 degrees above the ocean water temperature, and their brine would be allowed into the ocean, as they stay within those limits. Mr. Tadros stated also that they deal only with sea water, and not with reclaimed water, as their contract with the Bureau of Reclamation is for sea water. Mr. Greaney asked Mr. Tadros what commitment he would want out of the Water District to be part of the feasibility study. Mr. Tadros stated there is $40,000 available now from the Bureau of Reclamation and Supersystems, Inc. He would need a commitment of another third, or $20,000 from the Water District. He stated that SDG&E and other power companies are forming R & D groups to get into other areas of business, as they feel that in the future their main product will not be power generation. October 26, 1994 WATER COMMISSION Page 3 NEW BUSINESS: (Continued) Mr. Greaney stated he wanted Commission input whether to pursue this any further. He stated there could be a benefit on the reclaimed water. The quality of the reclaimed water the District has now is very high in TBS and if the water stays that high, will need to do some form of desalting for it to be used. He stated he would like to write an agenda bill for the Board of Directors and present it to the Commission for their perusal and recommendation whether to present it to the Board to seek permission to participate in the feasibility study. The consensus of the Commission was that they would like to see this, and also the feasibility of doing something with the Cannon wells and San Luis Rey well fields. As a concept, the Commission felt this is an excellent time to start this study. ACTION: On motion by Commissioner Kubota, the Water Commission directed the General Manager to proceed with the concept presented by Supersystems, Inc., and Mr. Tadros, and make a presentation to the Board of Directors. AYES: Louis, Kubota, Maerkle and Melideo Mr. Rick Graff, General Manager of the Encina Plant, was introduced. WATER COMMISSION: Presidents & Manaqers Council of Water Utilities Meetinq Bob Greaney reported on the October 18, 1994, meeting at Stoneridge Country Club, 7:30 a.m., and stated the speaker was Dana Smith, LAFCO Assistant Executive Officer. Commissioner Maerkle added that there are three Districts that overlap near Dana Point, and that was discussed at the meeting. WARAC MEETING Commissioner Kubota reported on a September 26 WARAC meeting and stated that the California Health Department has given conditional approval to the new north city reclamation plant to pump the water 20 miles to the San Vincente Reservoir, which is a raw water supply for San Diego. The water will be blended with the water in that shed and the treatment process begun. The reclaimed water will be piped into the drinking water supply, with the conceptual approval of the Health Department. Mr. Kubota asked to have the 20 page report copied and distributed to the Commissioners. GENERAL MANAGER REPOFITS: CWA GENERAL MANAGER’S MEETING Bob Greaney reported on a recent meeting, stating the rate restructuring by Metropolitan was discussed, with the staff working on the ready to serve charge and the new demand charge. He stated that Metropolitan’s Board will discuss this at their Board Meeting next Tuesday, and the General Managers and Water Authority Meetings will be canceled so the General Managers can attend the Metropolitan Meeting to get a feeling on how the Board is going on this. October 26, 1994 WATER COMMISSION Page 4 GENERAL MANAGER REPORTS: (Continued) In reply to Commission query regarding the reimbursement of expenses to attend meetings and conferences, Mr. Greaney stated that the letter addressed to Commissioner Maerkle was the final word on that, and added that if Mr. Maerkle would permit it, he will have that letter copied and given to the Commissioners. He also stated that budget limitations do not allow reimbursement for the breakfast meetings. Commissioner Melideo stated that she felt that if any Commissioner attends a conference for the Water District, as part of their program, the Water District should be inclined to reimburse the basic costs. APPROVAL OF MINUTES: On motion by Commissioner Maerkle, the Minutes of the Regular Meeting held September 28, 1994, were approved as presented. AYES: Louis, Kubota, Maerkle and Melideo NEXT MEETING DATE: The next regular meeting of the Water Commission will be Wednesday, November 9, 1994, at 2:OO p.m. Mr. Greaney stated that Don Rideout will present an update on the Habitat Management Plan and how it affects the Water District. ADJOURNMENT: By proper motion, the Regular Meeting of October 26, 1994, was adjourned at 3:25 p.m. wi$rln arriett Babbi Minutes Clerk SUPERSYSTEMS, INC.. 17561 TEACHERS AVE. FAX (714) 733-3430 SUPERSYSTEMS IRVINE. CA 92714 TELEX 710 11 1 5328 (714) 786-7117 (MBE246) ENGINEERS * DEVELOPERS MEETING AGENDA CITY OF CARLSBAD & SSI OCTOBER 26,1994 1. 2. 3. A 4. 5. 6. 7. 8. 9. PHASE ONE: Current desalination research program co-funded with the Bureau of Reclamation (c&funding ratio: 55% SSI / 45% Bureau). Location: Any suitable site in San Diego county. PHASE TWO: Pilot Demonstration Seawater Desalination Bureau of Reclamation current program: $500,000 in two years , new program: $l000,OOO or more n FINAL PHASE: Full Scale Power Desalination Plant. WHY COMBINED COGEN DESALINATION: Economics (Refer to handouts) Technology History Overseas SSI experience SLDDES: Cycles and Technology Actual operating plants SYSTEM SIMULTANEOUS PRODUCTS: Distilled Water Drinking water Electricity steam RECOMMENDATION: Start Feasibility Study Evaluate, Study, Construct Pilot Demo Plant Evaluate Pilot Plant / Construct Full Scale Plant A number of Utilities and largesize Companies are interested in financial contribution to the Pilot-Demo Plant construction. Questions / Discussion COGENERATION + SMALL POWER DESALINATION + HEATING & COOLING ENVIRONMENTAL STUDIES + DESIGN + CONSTRUCTION SUPERVISION + FINANCE TURNKEY PROJECT .- Brine Discharge WASTE H EAT Main Gas Main Water Pipeline 4 To Desal Pumps I ~ Drinking Water ' . Seawater Desalination Plant or Distilled Water) Pipeline KWH Electricity - L Public Electrical' Grid Gas Cogeneration Oil Power Plant Solid Fuels c or CONCEPT OF COMBINED P OWER -D ESALINATION SYSTEM - Steam (SSI Traditional design since 1982) SCltB. IILC: wxs. I I 6LGa I 'POWEWDESAL CONCEPT I ECONOMICS A combined Cogen-Desalination has good economics due to the fact that the waste heat from power generation (otherwise lost to the atmosphere) is saved and supplied to desalinate the water. Fuel is needed only for power generation. No additional fuel is needed for desalination. 1. WATER ECONOMICS 0 Competitive Price for High Purity Distilled Water Lowest Price of producing Distilled Water from any known Commercially Proven Technology 2. ELECTRICAL RATES The economics of the High Fuel Utilization Efficiency Technology would support selling electricity at reduced prices compared to the existing utility rates. TECHNOLOGY HISTORY 0 Technology Invented by USA "OSW" in 1965 Hundreds of Distillation Plants with Single Unit Capacity in the range of 1-8 Million Gal of Waterlin Commercial Operation in Over 50 Countries (including Virg%slands) 1970-1990 QUALITY OF WATER High Purity Distilled Water at less than 5 ppm on the average 0 Add Salts to Supply Drinking Water Quality Produce Distilled and Drinking Water at any combination BENEFITS TO THE CITY Additional Reliable Source of Water (24hrs/d) for 20 Years 0 Does not Depend on Rain, Snow, or other Unpredictable Weather Conditions 0 Improve the General Quality of Water in the Area (by blending this high quality water with existing drinking or brackish water) Buying electricity (KWH) at reduced cost (less than SDG&E) IMPLEMENTATION 1. SITE Determine the Site (e.g. inside Encino Wastewater Plant, inside SDG&E Plant, any location along the coast, etc.) 2. FEASIBILITY PHASE Perform Site Specific Technical and Economical Study Studv Phase Cost will be equally shared among: . Bureau of Reclamation, BUREC (Dept. of Interior) SSI The City 3. PILOTPLANT Seawater Desalination Pilot Plant Cost will be shared among: BUREC, SSI, The City 4. SELL WATER and ELECTRICITY for 10 years 5. FULL-SCALE DESALINATION 1. DESALINATION 0 three power plants for LADWP: Harbor Generating Station repowering project, Scattergood, and Haynes power plant, 1993. Technical and economical feasibility studies for’integrating desalination plant with 0 Baramos Monastery, Egypt, 1989. Detailed engineering and specification of one brackish water desalination for 0 Harbor Cogeneration Company - Enhanced Oil Recovery Plant, Long Beach, Ca., 1992. Detailed studies and conceptual design for a desalination plant for the 80 MW 0 Performed all the studies, specifications, detailed engineering, integration with power plant, start up, and testing of 10 MGD/80 MW, Jeddah, Saudi Arabia in 1977. 0 Performed all the studies, specifications, detailed engineering, integration with power plant, start up, and testing of 7.5 MGD/480 MW, Yanbu Industrial Complex, Saudi Arabia in 198 1. 0 in Saudi Arabia in 1978. And for Jubail phase 11 : 220 MGD/2000 MW in 1981. Conceptual design and master specifications for Jubail Phase I: 20 MGD/200MW 0 Six years operation and maintenance contract with the government of Saudi Arabia in charge of operating 25 desalination units of various types and sizes and 5 power plants 1971-1977. 0 Etiwanda Power Plant, 1985 - study. Desalination integration with Etiwanda Units 1 and 2, Southern California Edison, 0 SSI Principals have 28 years of hands on experience engineering and modmg many power and desalination plants in four countries overseas and in the VirginIslands. 0 SSI Bureau of Reclamation are jointly co-developing desalination facilities in Southern California. SSI is currently studying the development of power desalination plants in Mexico, Hawaii, the Virgin Islands, Middle East, and South America. 2. COGENERATION Extensive experience in Cogeneration in California, Oregon, Arizona, Hawaii, Saudi Arabia, Egypt, Poland, and other countries. In California, SSI has 8 operating Cogeneration facilities. SSI in the News Published newmaper and Drofessioiial iournal articles c Electric Power and- Desalinated 3 eaw ater tw Sam iciros. RE. costs, cogeneration planls huve acquired a new significance. Receni studies and applications huve shotcn results reletrant to the design ad economy of cogeneration phnts fir the produetion of electric pomr and desaLinaied seawater. Pm 1 is included here, to be &hwed in the next issue qf Cogeneration World with the W?l.Clruion, Thesuwerdesalindoncycle &ued for detaikd comparison m this audy is the mlI-lrrown mulbslsgr fksh evPpomior (MSF). which uses brine mcimhion and acid or polyphcsphste for de pmccction. Inurn Intee in a dud-purpose ph-or cogencdon d e- powa and scam- smns hm its inhacnr thmwdynamic &my. Fod.Toelhd ad ststions comrtO~d~irlputto elccrricitybut.ilomthemmining~ tD escape in the form dthamrl didmges By usinstherrjccted hea co!per&rr--or &&ncynhighu8096. widesped uy d cqpadon dd-purpose themugysharedhepro&ur*.lcrcoatis high. In the Unid SUDCS in 19% k aeam wnsundnr indh WI 4.14% Tor d4-p- plnng-am & I thvmal This is the rtlon i%r recent pLmr d b .bo rmibd to he Iba thm am in the d p8duLYion CaI d rckrod pulp Ad 5.62%. for the chlo& industry. In 1972. the enem &are of pdua water cost wa~ up to 35%. and in 1984 the ekgy share of product water cost was higher than 50%. boikr is ruppbjed dkdy to the daPlinetion pk.1 vi8 a prrsuur ducing athn and a desuperhcater. Pomr rrquired lor ph operetion could h provided hm I sump dieselgene~ract. . by approprhe modifhion d the *am flow. A conlrol\7lh.e kcMd on the iurbine is arranged to muict the flow d SICMI through the low pmrnvr sdon so 1)M the don *am mu be nis;lt.ined through the low p- eun maximum extraction rslc~. to pmn~ wrheating of the dine blsda 'This minimum OOW corresponds to about 10 to 15% d thc rplrd capecity dthe bw preasun seclion. k this minimum ibw condition. the atradon &me will hnve ita maximum water produdion capecity. This maximum water pducdon could be obtained continuously and independently of the power load. If we psrumcd I turbine thde condition of 900' F and 850 psig. ihis =heme could haw a WsKr ID pamr do &UI 11.6 &kWh or 1 mgd for ewy 3.7MW. The cogencrabon index. arpmsed in kWh geneaed per million Btu crbsartmi by thc brine heater. would be about 104 kWhflO. Bu for M atid dosing plant et a performance do 'R" equal to 10 pounds of distillate per 1.OOO Btu. Honaer. he water IO powcr mi0 \arks with the priiobnnance do et the same cogrmratjon index. For R in the m~ of7 to 15 lbn.OO0 Bu. the wetcr to per ratio for his &me would vary from 8.1 g$.kWh to 27.3 gdMVh. 900° FBO p.ip thmak umditio~, 1OMW/mgd pmer to w~ba do and 10 R tpcAormanoe do) for an acid doaing dcariinationphnfthe maximum SIC MI^ hi 1.5 times the steam fbw m M bed cmKLhions dthe dud pwpe ~ryam. AI a armn Qw rdo in thebw pawrr wetion dthe iurbinewould be .ppordmlcly 12. To allow for this c0"lition in ph des& uarld d in a aI* iaaev in bothcapitnlmdopntLyapmrs Evcry earn silodd be mde nd 0 OW!&thC~*Ad mdyaia lhould be mde d the k and ekuIicd bdsm Cwmb muitn~ uac hmadeddjunity~'Ihenadfor this dolt is h!dy econo& The Jocr the equipment 6ize is lothe &mm& the higkrthecrpdtyLdorvinbeThe capital ma d the plani h a timuion dthe rinorqacitydthepknSblatherennue camed by the phi is a hdon dthe A change in pomr demand is met For cogmedon ~yaenm opraing at m the low prrrurr turbine cltegn (ic. When the pb is in the pomtonly mode) win be pcwr ID w&!r rstio d3.7Mwhgd. hi8 Gn1611uedona27 ~ Cogeneration World, StptemberK)aober 1984 Dtdimied Serwl~r Gnonwdlrumpp20 d he bad. bd -ling on the ekctricd idc or the w~er si& ~m OI$ be rtrievtd mthearpmrcdbwrchumodynuru 'C -. schan+EooMmy For the mne atem and feedwater conditions u for regeneAliK cy& this scheme will hsve a wiabk hey ~tc and CfIicicnCy depending on thc pmpoiiion of *am cNpc(cd for the consumption of the desalindon plpm. When thr atradon steam to desalination plant is zem the turbi hem me will be ~SKUI~& the me 01 for thc regmmihe cyck (neglechng he mall p~um dmp acmss ttK atmction control uh). When thc mardmum steam is cxtreaed. i.c. ~l a maximum water to per ratio of about 027 mgd per MU. dosing dcsdinmion plant. *em hemal ef6ciem-y jumps to eppnaima!ely 76%. as hn on fw 2 where 1 kUh rm taken qquiuknt to one unit. Bawd on one unit of in he form ob fuel and 2.82 units in the form of *am would be urpplird to the brine heater. kupcrhcated and supplied to an acid ekctririp outpu 5.04 uniu aR heat input The economic features am bawd on to the dcsolinmion ph can br included as A posih dw in thc ?ar~m's diic;ncy qwtion. Aba the rmpermum d bok feedrater rpd mmed qual IO the brine heater conde~ tern- Howorcc for bo& condensing and bockp~~~~-nrhemes. ku. kedw*er ~lmpcr*w mi& cause a thermd shock @ the boikr and aci up undesirabk The retuning condensate mi& pbo be comaminped hhd pes through thc &up wer or lhmugh bline k+ in he tninc heatecr. For thrv reascms the inclusion dthe fedwater hem and denerstor md he fad thal the heat m he PCam supplied polishin# ?*ems win be rrquirrd. ph when using the condmsing scheme 4 hm A z)stcm heat rY dabout 4.600 buAcWh. Apprmdmdy 69% d he kaothawwwrrcdinthirrhmnis The combined powerkhdinmion lccoved in the fonn dumm supplied to the de&lmiolbphnL Thir hut lecaney dccrriciy dqlpmhdy 2.8 to 1.0. wing the condlming~chrmc muhsinardodrrcrmrtdhutto In erns dprimuy energy mom cnch million kwh produced by thirrhtme the mme .morn d pmer md wrlrr md 29.OOO gDOm d oil (or 157 IOIU d copl of PLnrr Prodm the Yme fuel M .M A hu nhK d u.oO0 6db). To asee~ the mnud dollar wing. the foIlowing rrumptions AIE de: 1. l0OW cogemdon q~~m using the COndeMingaresfao * n scheme 2. Water to porn ntio d0.27 mgd/MW. 3. Pomronly pknr thcrmd &my d 4. Dedinaion plant pedorm~a do of 36%. 10. SAM UDROS EXPERIENCE . LOCLVION COGENERBNON UolBusincssRrk~th Suite 210 6021265-2741 60212654259 Telex 165017 - 805/321-2234 - 2833 N. 3rd Scmt - &trsAclQcalifornii93309 phocni~,~nz~~am Ggedon World. SeptemberlOaober 1984 -I. - -. L. 27 I 1 Electric B ower ana Desalinate-a 1 1. 1 A new significance has been in the production of electric power and desalinated seawater. Included is the conclusion of a two part series on the design and economy of cogeneration plants on desalinated seawater. - Car Turbiue/MSF Scheme Flexibility and Design Feiturer In today’s gas turbine application, the exhaust heat of gas turbine combus- tion of the type fnquently used for utilities pou~sscs features that can be used effectively in cogeneration (dual purpose installation) for the produc- tion of power and desalinated water. by adding a heat recovery boiler for generating the steam required for desalting plant operation. Conventional boilers arranged for the latter are essentially to accept the exhaust &ac~s. However, the net heat rate improved with ao increase in the amount of refirin%. The hion and figures presented in this paper will be limited to un6red heat recovery boilers. heat recovery would vay with gas tur- bine electrical output, an additional source of steam is needed to enable the daahation plant output to be maintained at times of low electrical bad or when the gns turbine b shut down in case this system was design- ed to operate at its mudmum water to power do. . The gas &me ddnation pht scheme hps a water to power ratio of murid 6.2 gaykwh or ap proximately 1.50 md per 10 MW at R=10. h R varier between 7 and IS, the power to water ratio varies between 4.3 and 9.2 @Wh. This ratio is influenced by the exhaust gas from the heat recovery boiler. This, in I acquired by cogeneration plants Since the steam available from I .- by Sam Tadros, RE. turn, h controlled by the sulphur con- tent of the fuet as cooling below the dew point must not take place to avoid corrosion. Currently, the max- imum size available for a gas turbine is 130 MW. gas turbine is not as high steam turbines, one main advantage is the capability for quick start and quick delivery of power and process heat. components of a combined gas turbineldesalination plant. This arrangement enables the gas turbine to operate while the desalination plant is shut down. The supplemental fuel to the waste heat boiler, if added, will enable the gas turbine and the desalination plant to operate separate- ly while one is shut down and also to operate at various water to power ratios. However, at low values of the water to power ratio, suppIemental fir- ing for the heat recovery boiler may not be nquirrd for the full-load pro- duction of water, provided the water plant heat demand is within the limit of the cogeneration index. Scheme Economy plants operate at thermal efficiencies well below 30%. The heat rate is 12,OOO to 14.000 BtukWh. A short time is needed for it to reach M load conditions. This combination of factors Although the reliability of the that of \ Figure 1 demonstrates the main Cumnt gaa turbine power tends to reserve the simpk gas turbine cycle for gas peaking and standby we. Future development of the turbine will reduce the heat rate, probably to 10,000 BtukWh or even lower. Ato, research is under way to enable the gas turbine to use other types of fuels. - In a dual purpow cogeneration system, advantage b taken of the hot exhaust gaa to provide steam for the desalination plant. In Figure 1 for each 3.6 hd units’ heat input in the gaa turbine combustion system, 1.5 uNta are saved from the exhaust gaa’ stream and arc absorbed by the brine recycle stream in the brine heater. Approximately 57% of the heat other- wise wasted through the exhaust system is recovered in the form of steam supplied to the brine heater. The recoverable heat rate of the scheme shown in Fv 4 is approx- imately 4950 BtukWh. efficiency is now approximately 69% or a system heat rate of SO00 BtukWh when operating at design full load conditions, for an acid dosing desalination plant with 250° F maximum brine temperature. The cogeneration index for this scheme under the above conditions would be 1% kWh/lObBtu as shown in Table 1. In general, the ideal, most economic situation for any cogenera- tion system is to have steady year-round demands for both eIectrici- ty and water so that both demands can be met &om a correctly sized dual purpoa syrtem operating at the highest possible system thermal efficiency. In terms of primary energy resources, ea& don kWh produced by this scheme, as compared to separate gas turbine and desaIinotion plant producing the sMe amount of The combined overall system ~amw.27 Cu Turbine; MSF Scheme Cogeneration WorId NovernberlDecember 1984 35 .. Conunwd lmm pap 25 power and water and wing the same fuel. can have a net annual saving of approximately 40,000 gallons of oil. in terms of net annual dollar savings, if a cogeneration system of this tvpe having a capacity of 100 MW and a 'water to power ratio of 0.15 mgdW is compared to a separate garr turbine unit-of thermal efficiency 27% and a separate seawater desalination plant of 10 performance ratio (assuming that this cogeneration .system will be operating at 90% capacity factor for 11 months every year), at 83 cents per gallon of. oil, this cogeneration scheme would save approximately $26 million each year in the form of fuel oil. Diesel EneinelMSF Scb erne Derign Futunr The concept of diesel engine scheme is shown in FF 2. The generator. procesS steam far the desalting plants is made in the heat recovery boiler that uses the engine exhaust and jacket cooling as heat soources. The back-prescurr exhaust win result in a slight decrease in the eleceic power generation from this set. Diesebcumnttyue* petr0kum-W fuels. Raearch is under way for a duaEfuel system that can use both liquid and &aseous fuels such as propane and methane. Research has ab0 atartcd an the use of ly expand the cogeneration ha diesel enejm &a an electric dduived fuels The Win -t- &rough did spplicatjons. DieselrBecumntfyav*up The arcey, air OT the air/fuel to 25 MW. Basic thud &ciencia range hm 30 to 35%. ratio for the diesel engine is much lower than that for gas turbines. Therefore, the did engine has the lowest steam to power rad0 and conse- quently the lowest water to power ratio. Diesel engine cogenemtion cycle is recommended for smaIl dags located on the #a, and where the watw demand b not rtlatively high or where the demand on ekctrid power issign&xn*high. Table 2 Thermal Efficiency and Performance Values for Died EnainelMSF Scheme Water/power ratio (gaUkWh)' Heat recovered (waste heat) 38% 2.2 to 4.6 System thermal esciency 57% Cogeneration index (kWhllWBtu) 390 Scheme Economy -. If we assume, as previously mentioned, that the nhowt steam hm the heat recovery boiler dl be supplied to the brine heater where it would be condensed at inkt brine heater saturation pressure and returned as boiler feedwater at that temperature, the system efficiency jumps hm 35 to 57% approximately, as shown in Table 2. If we assume 1 kwh power output hm the generator or one unit output, then the fuel rrquired for this I combined cycle win be equivalent to 2.97 units. Process heat supplied io desalination plant is 0.75 unit with system.heat rate of 5800 BtuAcWh. Refer to FF 2. The cogeneration index for this cogekdon system would reach $15 don per year when compared to the diesel generator set and desalination working separately, using the same fuel and having the same capecity. (1) The extraction turbineMSF scheme heat rate and the& &cimcy arc * highly sensitive to the spread been throttle and exhaust conditions, in both ideal and mal cycles. This scheme is the most flexible regarding load cycling, but has the disadvantage of relatively high cost. (2) The badpressure turbineMSF scheme has the highest water to power ratio, highest thermal e6ciency and lowest cogeneration index. This scheme has a limited response to load cycling COnChUionr scheme is around 390 kWhMBtu heat to the process for an acid dosing ddbationplant.Thedieselengine eogenedon system pda the high* &&city to water ratio. or least water production per kwh. In the above ligure, the waterlpower ratio is approximately 3.1 g&ns/kwh or 13.3 MW per mgd wata production. 38% of the heat othawise wasted is recovexed in the fonn d steam supplied to the desalination plant. hsuming a 100 MW/8 mgd combii cyck, with a desalination Inthisscheme,appdmatdy plant performpnce ratio ob 10, plant capacity Lctor of 90% and availability of 92%, the net annd mhg d fuel consumption of this (otherwise wasted) - Table 1 Thermal E5amcy and Performance Values for Gu TurbineNKarte Heat BoilerlMSF Scheme Wltcr/powa ratio (gd/kWh)* Syatem thermal efiiciency 69% 4.3 to 9.2 Heat recovered (waste heat) 57% Ggeneration index (IrWhllO'Btu) . 1%' Cogeneration World NovemberlDeccmber 1984 because the MSF needs sufiicient to rrspond to change in its output. (3) The gas turbineMSF sdreme has the lowest hdkd costs and the highest rate of rehun. OnIy when gas or distilled fuel h unavailable can other schemes be justified on M economic basis. (4) The diesel engine/MSF rcheme has the highest per to water ratio. Its hitation on unit size and der amount of recoverable heat has restricted its apphioi in the cogemration field. (5) Inlightafxapidly&ingfuelcmta the optimum performance ratio b tion scheme. The design of mukistap flash maporaton should be revimed m view of the requirements of more stages, more heat trarnfuuea and higher pumping coats. New ixak pmtdon edditiva which arc &&e at higher &um brim temperamu ue needed to mhunx the economical prpectr of this process.. expeaedto-for.nyaw=-- 27 Desalinafion, 87( 1992)137-137 Elsevier Science Publishers D.V., Amsterdam Desalination plant integration with 137. cogeneration systems for EOR/commercial/industrial applications SAM TADROS President, Supersystems hc., Consulting EngineerslDesigners, 17561 Teachers Ave., Irvine, CA 92714 .\ SUMMARY Several studies, designs, and feed back- of cogeneration systems integration with desalination plants -here called Multi- purpose system- indicated that significant reduction in operat- ing costs together with system reliability and efficiency im- provement have been achieved. This paper addresses a number of multi-purpose plants for the simultaneous production of electric- ity, process steam,. heating, cooling, and desalinated water. These facilities either have been designed and are already in operation, or in the conceptualjpermitting phase, or in the detailed ~. design phase. -2 - ,.c . The .purpose of the desalination process portion of the multi-purpose facility was to produce potable water for hotel/housing complex, process make up and drinking water quali- ty for oil+business, and relatively high h purity water for an industrial application. Specifically, this paper will address the economics and process design feature for the following three - simultaneous - power/water/energy production applications: .. ., , -., Multi-purpose Multi-purpose Multi-purpose - ./. system for commercial application system for nEnhanced Oil Recoveryn for industrial application * 'Water=PoweP by Sam Tadros Bechtel Power Corporation With water and energy-produc- ing resources' becoming scarcer and costlier, two steam-turbine- based topping cycles-backpres- sure turbines and extraction tur- bines-offer the possibility of pro- viding energy for desalinating wa- ter and generating electricity while saving subslantial amounts of money through greater fuel effi- ciency. In examining the thermodynam- ics and economics of each lopping cycle by focusing on the relation- ship between the process and the cogeneralion index (kilawslthoura per million 6tu). we find lhat a 100- megawatt (MW) backpressure/ multi-stage flash (MSF) scheme could save $1 7 miltion in oil. based on a fuel cost of 83 cents per ga!lon. A steam extractionlMSF scheme of the same size could save $15 mil- lion per year at the same fuel cost. The savings come from the de- sign options afforded by cogener- ation. More than 50 percent of the heat input of a power generating plant normally is rejected in Ihe condenser at about 100°F. But be- cause the cogeneration cycle can be designed to reject its heat at the higher temperature required by the water plant. the condenser loss can be eliminated with the use of a back-pressure turbine/MSF system or minimized wilh an automatic steam extraction turbine/MSF sys- tem. Fuel efficiency for the cogener- ation scheme could reach 80 per- cent, and the fuel chargeable toco- generated power would be only 7.000 BtulkWh instead of 10,500 6tulkWh or more for an electric power plant. This attractive thermal performance level. possible wilh eilher steam or gas cogeneration lurbines. has brought a good deal *- of attention to the processes in the United Slates, Europe, the Middle East and Japan, where MSF has been the dominant desalination process. Selection Factors The choice of topping cycle for use wilh the desalination process 'depends largely on the relation- ship between water and heat (power) output. The more energy- efficient backpressure turbine scheme is the botter choice when the electric power and water loads peak at the same time. When the peaks vary, the system can meet the electricity load and excess wa- ter can be stored or dumped as waste depending on needs and storage capacity. Some of that vari- ation can.be reduced by planning production according to monthly electrical needs. In the Middle East, for example, power and water demands peak during the summer. In any event, the desalination pro- cess requires a large brine recy- cling flow rate. making its ability to respond to load changes very slow. Although the automatic extrac- tion turbine is not as fuel efficient, it is proven more economical under operating conditions in which elec- tric power demand is expected to vary continuously or in which peak water demand does not match the power peak. In other cases, this scheme provides a continuity of service often considered critical for applications in which a loss of power andlor water can cause a major disruption in linked-process operations. Either scheme can be used with the MSF process. as shown in Fig- ure 1. For cogeneration purposes, the boiler normally produces steam at 900 psig at 830°F, ,but for our study, we assumed and applied, a throttle condition of 850 psig at 825°F. As the steam comes out of the boiler, it can be fed to the power-producing cycle at 15 1bs.l kWh. Either scheme will produce steam at 20 psig when it comes out of the power-production cycle, wilh slight variations in the pathway. be- fore il goes to the desuperheater and then to the brine where it is raised lo a maximum temperature of 233°F. In the MSF process, the vapor formed in the flashing chambers condenses on the condenser, or heat recovery tubes. heating the in- coming brine recycle feed. The brine heater supplies the remain- der of Ihe energy required to raise the feed temperature to the maxi- mum before flashing begins. The 233°F maximum was selected for this study to allow for additives to prevent pipe scaling. The energy required to operate Ihe MSF plant represents more than 45 percent of the desalinated wa- ter's cost. depending on the plant performance ratio, which may be defined as the ratio of pounds of water per 1,000 Btu to the temper- ature of the brine heater. For evap- orator plants, such as MSF, the con- tinuous increase of fuel costs will result in higher values of the per- formance ratio (less steam con- sumption for the same water ca- pacity). But on the other hand, higher performance ratios will re- quire more heat transfer area and a greater number of stages at the same maximum brine temperature. Therefore, it will be necessary lo optimize the value of the perfor- mance ratio in cogeneration . systems. . 24 COOENERATION WORLD f. - from 6.2% in 1990 to 9.05% in 2000. a 46% increase. Comparing the 1991 forecast to the 1990 report shows that utilities now plan to add 24.068 MW of cfs in 1990- 99, up from a planned 19,844 MW for the me period in CT additions would average 2,674 MW a year in P 9 ' thel990report. 1990t99, but would total 3336 MW between summu 1999 apd summer 2000. The biggest increase percentage-wise would be in "other" utility generation, which is now expected to rise capacity in 2o00, a 1,77 1 96 increase. Combined-cycle capacity would increase by 182%. from 6,332 MW in 1990 to 17,872 MW in 2000. Com- bined-cycle additions would total 9,612 MW in 1990-99, up from a predicted 8,656 Mw in the 1990 report. Another 1,928 MW would be added between summer . . from 504 MW of capacity in 1990 to 8,928 MW of , t', ' .... .. US. NON-COINCIDENT SUMMER PEAK DEMAND Actual VI. ullllty prodlcUonr (an imwnta in mgnmr) Aclual Pndlctrd by ullRhr' Yeu-to-Year You-RYoar Peak Qrtmth POI Qra*rlh" 1986 476.893 4.58% 475.093 +3.1?% 1 987 496.185 4.02% 464,4611 r1.5774 1988 529,460 +6.?1% 500,270 4.82% 1989 523,432 -1.14% 521 $35 -1.42% 1 e90 545,537 4.22% 539.308 r3.03% 1991 ' - 55lJlQ +ldW '85-90 ivg. +3.48% +1.43% 'As mwed m annual &flh herican Electie h/iatifily carnd wEhwbici~ SW 1 Dmand'm~ *' Pmdkted peak compared lo rmel peak kr peviws LU~W Road East, Princeton. NJ. 08540-6601, or call 609-452- -8060. MONTANA POWER stioPPiNQ FOR ms mw BY 1996 IN ALL-SOURCE SQUCtT'ATRQJt Montana Power is shopping for Is0 MW needed by 1996 and has invited notices of intent from prospective suppiy- and demand-side bidders by Sept. 6.199 1. The , request for proposals will be based on he company's load forecast and ieast-cost power planning process. Bob Gannon, Montana Power's Utility Division presi- dent, said the utility wants the additional fesourcw be- cause of system growth and the need to replace two power-purchase contracts that expire within leu than five years. Those purchases include 77 MW from the Washington Public Power Supply System and 75 MW from ldaho Power. The two contracts cost approximately $36-miIIion annually and renewal is unlikely, Gannonsaid. "Additionally," he said, "we expect our eleclric sys- tem generally will need between 12 MW and 18 MW an- nually to meet system loads through this decade." Gannon said generation and DSM proposals will be evaluated *'on an equal footing." in a resource portfolio with planned hydropower upgrades at the company*s existing dams. Gannon said the DSM programs should complement the utility's ongoing residential, commercial and industrial conservation ef- forts. ' ;. A pre-bid confecnce will be held in October. Inter- connection information must be sent to Montana Power no later than Nov. 1. The deadline for receiving proposals is . : The oCfcrcd supply-side resources will be considcred 1999 ahd summer 2000. Non-utility generator capacity available to utility systems to meet peak load is now expected to total 35.352 MW in 2000, up from 18.156 MW in 1990, or a 17,196- MW increase. NUGs would represent 4.57% of U.S. capacity, up from 2.65% in 1990. In the 1990 forecast. utilities said they planned to add 14,635 MW of NUG capacity in he 19h-99 period. The. 1991 report shows 17,185 MW added in that period-but virtually all of that would be on-line by 1996, when total NUG capacity is expeclcd to be 35301 MW. NUG capacity would actually top out in 1998 at 35.706 MW, and then drop. only 229 million kWh in 1990. the 1991 report shows, far less thai the 36,665,000,000 predicted for 1990 in the Net electricity imports (mohy from Canada) totaled 1990 report Both forecasts show a skady increase in imports. The 1991 rem shows an increase from 37.094,000,000 kWh ' in 1991 (down from a predicted 44,986,000,000 in thc 1999 report), to 65,708,OOO,OOo in 1999 (down from 66.920.000,OOO in the 1990 report), with a further increase -3 'J LADWP STUDIES ADDING DESALINATION . FEATURE TO EXISTING POWER PLANTS The Los Angeles Dep~ of Water dc Power has signed a contract to study the feasibility of integrating new - desalination plants into the operations of lhtee of its .* power plants located next to Qe Pacific Ocean in tos An- gela. Sam Tadros, president of Supersystems Inc., Irvine, Calif., said the company signed the contract last monlh and is now at work on the technical and ecmomic feasibility study. He said combining a desalination prucess with an operating power plant would make the plant more efficient because it would powa the desalination opera- tion during off-peak hours when electricity demand nor- mally is very low. During peak petiods the desalination plants would not operate while the power plants were producing elecUicily for utility customers..Using he waste heat from the power plants in the desalination process further increases powff .- plant efficiency, said Tadros. 1' ?'ah, who has experience designing and building desalination plants in Saudi Arabia, said lhis is not a typi- . to 66,014,000,000 kWh in 2060. These totals cover all The report is available from NERC at I01 College ELECTRIC UTILITY WEEK -A~pos( 12,1991 DOE would slash coal generation costs DOE has authorized Foster Wheeler Development Cop. of Livingston, NJ, to begin the second phase of a program designed to cut costs of coal-fired gener- ation by 22 percent. A team led by Foster Wheeler will now begin developing and testing individual components of an advanced pressurized fluidized bed coal combustion system. Foster Wheeler was chosen in 1986 to lead a three-phase $26 million program to develop asecond generation of a pres- surized fluidized bed combustor. The first phase was design. This second phase will test individual components. The third phase will link the key parts in an integrated subsystem. First-generation svstems are nearing boost efficiency to as much as 45 percent University of Tennessee Space Institute whilecutting size and cost of thecombus- in Tullahoma. It will test combustor tor. The"team"of Foster Wheeler, West- exhaust gases for nitrogen oxides and inghouse Electric, Gilbert/ Common- other impurities that can damage turbine wealth Inc. and the Institute of Gas blades. Technology hopes to accomplish this by If this phase is successful, the Institute introducing a'carbonizern to preheat the of Gas Technology will assemble and test coal before it enters the combustion bed. all parts except the turbines beginning in In the carbonizer, volatile matter re- 1990. leased from the coal forms a fuel gas that DOE'S Morgantown (WV) Energy is burned in aseparate topping combus- Technology Center is managing the tor at the entrance to the gas turbine, project- ,c p ,-~ - increasing the turbine inlet temperatures 7 from the normal 1600OF to 2100OF and Super Systems unit higher. for new CA hotel ~', ) Foster Wheeler will build a 30-foot Serve as a carbonizer Or as a COmbustor- 4 refractory-lined pressurized vessel to A 1.1 MW cogeneration system supplied by Super Systems Inc. of Irvine, CA, will Y commercialization. &e such has been It will be used to test fuel-feeding sys-' funded under DOES clean coal tech- tems along with ash and particie-remov- nology program. These systems are ex- ing components during 100 hours of pected to convert up to 40 percent of carbonization and another 100 hours of coal's energy into electricity as compared combustion testing. to 35 percent or less today. Westincghouse will build a prototype The second-generation version could system of a topping combustor at the A control room technician checks operating performance of Stanford University's new 49 M W cogeneration system. The facility, designed and built by General Electric and Kaiser Engineers, supplies all of the university's needs for electricity and steam and provides emergency backup power to the Stanford Medical Center. provide electricity and high pressure steam for the new Santa Monica Bay Hotel. The system will use two Garrett gas turbines with heat recovery steam generators, according to Sam Tadro, president of Super Systems. A 100 hp coil-tube Clayton steam generator will provide back-up and peak load steam for kitchen, housekeeping and an absorption chiller. The Clayton unit was specified because of its compact size and ability to produce steam in five hinutes. The hotel is scheduled to open next March. theft in construction The growing problem of vandalism and theft in construction is attacked in a new manual, "Protecting Profits - and Jobs - Against Theft and Vandalism" from the Mechanical Contractors Association of America. Included in the manual are I) how to begin an anti-theft. anti-vandalism pro- gram. 2) sources of security assistance. 3) physical security (fences, alarm sys- tems, rewards, inventory controls) and 4) a security checklist. The manual is available for $8 for MCAA members and $24 for non- members. Contact 301-897-0770. 10 .COGENERATION October 1988