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HomeMy WebLinkAboutKotzebue District Heat Study 1989mE ES mH HE HEH HE EE EE EE EF ru oy 7 KOTZEBUE DISTRICT HEAT STUDY PREPARED FOR State of Alaska ay Alaska Energy Authority 701 East Tudor Road P.O. Box 190869 Anchorage, Alaska 99519-0869 NOVEMBER 1989 polarconsult alaska, inc. ENGINEERS ¢ SURVEYORS e ENERGY CONSULTANTS 1503 WEST 33RD AVE.e ANCHCRAGE, ALASKA 99503 PHONE: (907) 258-2420 FAX: (907) 258-2419 polarconsult Kotzebue District Heat Study Table of Contents ROC VS SUNITIMEY rete tere onerd) «+ ile Mueueusue: oie aieteasneny Pais eyes = sia Seis I I. Introduction ALPURDOME: os aicacctia © fs % 5 Brailes F.00 G Somes w Ws Fee iere © 6 4 wer 1 B, District Heating System Description... «<6 occa 9 0 50 vistas ow woe ae 1 Ca Data Somes tas sich s = wescecssiels ape otepteecele) ola wgeuexerecele: = « 2 0 Fneiisie 3 IL. Assumptions .........-. 00sec ee eee eee POUTeTT ETS TTT eTT 4 LI MOUNOUOIO GY 33. cn.aks 6 8 Sah se Lb 1s Ee Oe SR eeee ewes SoRS « 5 IV. Technical Pcs PIG Wore cs: iaiiecw over v 6) oi tretotip: 6 © wulcoyedel sree (eittioeones «; # s\n elginne 7 Bs ORUEROHONOOTS sccce) exe's ofolavages 0 + & @ odsyeueusls & © Pueeeels § Sa Sais 11 Co Temmpernntes: ci sceic «= 2 5 sieiee se 1S se ereisiein « Baeieee s ss sees 11 DrOw Displaced! «3, srscnw ote « ween oes ota 9 os etree «6 ot 13 Be OY SIiy PICRU EONS iss & eee ew chete & 6 Fu recone © 6 6 0 lorie «6 + wie 0 15 I MEGIR xs, 5 G5 le tevecentens & ¥ wuctPieash) 0, vow Sileveie Me edelfovemerene: » euene Moles 17 GaTIGATAMNCE fore cilocecel «so 5 & cxeutuel Gf © lepine! Shanes ov Gps Wes 18 RA PUMUe” so. «¢ oetesere © & dm Sree 8 Seis es os ar okewrn oe Ome 18 LS WARE NBAUING: = oe paveren © 4 & Sawyers He ER GeeRng «000 Bs foiwsene: o ex¥ 0 19 i SOUS! a2 x axe & Sieeese of s dive wcglene: Y Siro whe ode otete ednevatiae ore fa legen 19 Weep COMRECION G5 tire Sitcorsoie: 9:10 fe loneoueret eee Mveneninel aes Fuck IGG = > 20 SAUTER) coy sisosceen o Sustanerescsl.cig Ass Miners wim FNsethay Gale 3 cere eiey's! 4 21 V. Operation ae Maintenance 5 5 5 eiciore 6 0.6 steers cone © Sictersie o ois 2 yeu 22 VI. Project Estimate SCHOUTEN Sree g ANG ccesearlle: «: n 4a 10 sessocen «7 cas Me eheeshece Hi Momee EONS. y OUI 24 B. Assumptions AOUUSASE 7. 5 5s 5 GS LS RA © Be eases Sih os arwrertn 25 Cr BSENMIOS 2) oe 5 oeiacw: & & 5G ievensadl Oe doe eaters wo & a relee tees wa we toe 27 VANS ComnctabOes 85 cs idetorete: « 6 + wieponensts: 0 os lagererey tea ielevehonsllens: « Suslinioxs 28 VIC RECONMIMIMMIBNONS, 8 oe ecesose: «, os & Gisueiele suas siekereed © ea eer Y & 29 Pipe IMStAl AONE INSITCHONBY 6.5. co concizes cole! 0 lyerentin's 4 oneNteERe oa © Appendix A Cost Haenriaee: co. 2c sins © 5 Gisiae | ae 2 Gheetele a = = etoile 4 + ware Appendix B polarconsult Kotzebue District Heat Study Tables IV.C.1 Ambient Air Temperatures and Heating Degree Days ............ 11 IV.D.1 Gallons of Oil Usedand Displaced: 3. .cccenc 6s a0 sere oo 6 0 eterna 14 IV.E.1 Main Transmission Pipeline Heat Losses ......... 000 ee eeeee 15 VI.B.1.1 Annual Building Heating Oil Usage ......... 0... ce eee eee 26 VI.C.1 Syarer Coats) 5.cisciee x @ Sictacevs « 5 ss errand Sowers sev a wo 27 Figures I.1 District Heating Piping Layout. i... ened. 0. 0 0 60 esos gt 8 2% ORNS 6 IV.A.1 Typscal Distract eaune SYSIEM: 2... oo aioe ds 16 eae ele x 8 Oi 8 IV.A.2 Typepal User Hook-Up for Heating: jiicsa: ss os eos v6 ea wrens 9 IV.A.3 Typical User Hook-Up for Domestic Hot Water ..........00005 10 IV.B.1 Typical Installation of District Heating Pipe .............0005 12 IV.D.1 Seasonal Heat Requirements and Availability .............005 13 Lt rt polarconsult Kotzebue District Heat Study Executive Summary o A district heating system at Kotzebue can save the community in excess of 547,000 gallons of fuel, which at current prices, translates to $711,100 savings per year. This savings would come from using waste heat, equivalent to about 613,000 gallons of oil, which is now lost at the KEA power plant. The district heating om will reduce energy costs and free money for other uses. o A district heating system is similar to a heating system used in a car. The car engine gives off heat to the cooling water, which is then carried in a hose from the engine to the heater where it produces heat for the passengers or to the radiator where it is "wasted" by being rejected to the air. o Hot water carried in two buried steel insulated pipes will circulate the heat throughout the City. The heat will come from heat exchangers at the power plant which will extract radiator water heat and exhaust gas heat from the diesel engines driving the generators. A second set of heat exchangers will transfer this heat from the circulating water to the connected building's hot water heating system. o The system can provide economical potable water heat, which will keep water and sewer lines from freezing and reduce water heating costs throughout the community. o Construction of the system will provide jobs. o The system will pay for itself and reduce the effects of increased_oil prices on the community. o The complete system with three loops, which will serve almost all of the major public buildings and heat the potable water, will cost $3,955,320 and save about 540,000 gallons of fuel per year. o The school-new hospital loop will save about 480,000 gallons of oil per year and will have a capital cost of near $2,052,000. It will use two steel insulated buried pipes 9,160 feet in length, ranging in inside diameter from 8 to 4 inches. o Operational costs are low, requiring meter reading, billing, electricity for pumping and Tepairs. o Construction of the system will take one summer and half of a winter. o Building the system will be low in risks and high in rewards. The risks are if oil prices drop and stay down or the system construction costs are much higher than estimated. o The gains for the community are substantial and can be made even greater with a topping boiler, use of heat during the summer for swimming pools, meat and fish drying or a green houses as is done at Nome and Kaktovik. : rm polarconsult Kotzebue District Heat Study I. Introduction A. Purpose The purpose of this report is to determine if there is a means of reducing the high energy costs for the people of Kotzebue through the use of waste heat. The heat would be distributed around the city through a district heating system. The primary source of the heat will be waste heat captured from Kotzebue Electric Association's diesel electric generators. B. District Heating S Descrinti A brief description of a "District Heating System" follows. A district heating system is not complicated. Our familiar baseboard heated buildings have a boiler which transfers heat to water, and the water is circulated by a pump to radiators. At the radiators the heat is transferred to the air in the building. A district heating system works in the same manner with water circulated around a diesel generator acting as the boiler. Another example is a car heater where water is circulated by a pump through the engine block where it picks up heat, then goes through hoses to the heater where a fan blows warm air into the car. The district heating system discussed in this report is very similar in nature to a heater in a car as they both take energy that would otherwise be thrown away and convert it to beneficial use for the people. The district heating system as used in this report obtains its energy from the rejected heat from diesel-electric generators which are generating electric power for Kotzebue. The heat is extracted from the water used to cool the engine block and from the hot exhaust gas given off by the engines. This heat transfer is accomplished by circulating cooling water, or a water-glycol mix, through the engine block and around the exhaust silencer and hence through a heat exchanger where the heat is transferred to the district heating loop (See Figure IV.A.1 for a diagram of a typical district heat system). Hot water produced by the heat exchanger will be circulated by pumps through a heating loop in the city. Each loop will consist of two parallel insulated pipes of the same diameter. One pipe carries the hot pressurized water from the heat exchanger at the power plant out to the consumer, and the second pipe returns the somewhat colder water at a lower pressure to the power plant to be reheated. At buildings along the loop there will be a connections me Ee HE Ee we ee Se Se Se SS SS we ee eS ee ee polarconsult Kotzebue District Heat Study to both pipes. The hot water will flow from the higher pressure hot pipe, through a heat exchanger inside of the building, and return to the lower pressure return pipe. Heat will be transferred to the buildings heating system at one heat exchanger. The heat exchanger in the building will also be connected to the building's domestic hot water heating system which is also served from the building's boiler. Whenever the thermostat calls for heat, the building's circulation pump will turn on and water will be circulated through the heat exchanger to remove heat from the district heating system. This heat will be conveyed throughout the building to the base boards or other heating units. (See figures IV.A.2 and IV.A.3 for an illustration of a typical building connection). The amount of heat available at any given time depends on the number of engines running in the power plant and their electrical load. During the day, for example, the electric load is greater so there will be more heat available. During the evening the electric load drops, so the amount of heat will drop also. For Kotzebue there is not enough heat during parts of the winter to supply all of the building requirements for the three loops analyzed. During the summer there is a great deal more heat than the buildings need. One of the critical analysis items is to find out how much heat can be sold, so the value of a heating system can be established. This is one of the key objectives of this report. Excess heat during summer, spring and fall can be used for fish and meat drying, or for a green house like in Kaktovik. Boilers can be added at the power plant, or at intermediate points, which would increase the amount of heat available from the district heating system for additional heat during the winter. This option will be addressed in more detail later. It can be seen that the purpose of a District Heating System is to take the heat now being thrown away and make it usable by the people in Kotzebue to lower their energy costs. polarconsult Kotzebue District Heat Study C. Data Sources Data was acquired from a number of sources. The most accurate and recent consists of actual oil usage records from targeted larger scale users in Kotzebue. Weather data was acquired from U.S. Government sources and was then correlated with the reported fuel consumption. Information for the piping material was obtained from representative manufacturers of pipe and heat exchangers. Cost information was obtained from State sources, equipment manufacturer's and from work done for the Nome District Heating Feasibility study on Diesel Waste Heat by Polarconsult Alaska, Inc. in 1987 for the Department of Energy, and the Nome/Kotzebue Coal Fired District Heat Study by Polarconsult Alaska, Inc.. in 1989. Polarconsult also designed and did the construction management for the district heating system for Tanana in 1985. This system was the first to use the ic. Moller type pipe in Alaska. The piping at Tanana is buried in the center of a road in ice rich silty ground. To date they have had no problems with thaw settlement or shown any signs of leakage. Polarconsult also acquired data during field visits to Kotzebue. Discussions were held with personnel from the school complex, water utilities, power plants and others. In addition the estimated heat and temperature requirements of the water circulation system for the new hospital in Kotzebue were obtained from the engineers designing the project. polarconsult Kotzebue District Heat Study II. Assumptions It was assumed that heat for the system would come from the existing power plant in the southwest section of the city. The limitation on the quantity of heat and the temperature of the fluid that could be used will be regulated by the output of the engines at the power plant. The cost of money used in the study is 9.5% interest over 20 years and the approximate cost of fuel oil at the plant is $0.62 per gallon of #2 and $1.30 for Arctic Grade Diesel supplied to the buildings in town. The district heating system will only be connected to the larger structures which are mostly public or institutionally owned. The construction cost of the district heating system is based on using contract labor paid Little Davis Bacon Wages. The cost is for a complete system using only waste heat rejected from the engines. No costs are included for increased heat capacity by adding boiler(s). m_eHe Hee Hee eee He se ES eS eee se ee Oe Ce polarconsult Kotzebue District Heat Study III. Methodology The basic criteria was to develop a district heating layout and conceptual design that was practical and had reasonable construction and operational costs. The methodology was concerned with arriving at a cost estimate that is substantially correct. During the full design phase of the project more detailed studies and analyses will need to be made to arrive at the most economical pipe sizes, connections and other factors. This will result in selecting the most economical project. Where there was a question of component size or costs, this study used the greater. The basic methodology resulted in the majority of the effort being expended in technical analysis of systems and costs. All of the calculations are done using the gallons of oil used per year rather than Btu's. This is to make it easier to understand the system and to relate to savings, costs and to future changes in the price of oil. Consequently Figure III.1 showing the district heating pipe layout also shows the gallons of oil that were used in the individual structures during the base year. The amounts of oil used in some of the structures were estimated as the data could not be obtained. The amount of oil used is important because this determines the size of the waste heat equipment and the amount of heat which must be furnished at the plant which in turn determines the cost of the project. The quantity of oil used also determines the cost the community currently pays for heat. This amount is the upper limit for costs of alternative means of supplying heat. It is evident that replacing a highly flexible system, such as the one currently in use, would not be advisable unless there are some substantial economic gains and community benefits. 1503 WEST 33RD AVE.* ANCHORAGE, ALASKA 99503 | ENGINEERS ¢ SURVEYORS « ENERGY CONSULTANTS 6 & 2 wo 8 2 7 a 5 2 § ° a KOTZEBUE WASTE HEAT polarconsult Kotzebue District Heat Study IV. Technical A. Pipe The pipe selected for this analysis was that manufactured by i.c. Moller in Europe. This pipe was used as it is likely the type, and perhaps the brand, of pipe that will be selected for this project. The inner pipe is made up of ERW (electric resistance welded) steel pipe with a yield point near 33,000 pounds per square inch. This pipe is surrounded by high density polyurethane foam insulation. The foam ranges from 1-1/2 to 2 inches thick, weighs 5 to 6.2 pounds per cubic foot, and has a compressive strength near 71 pounds per square inch. The "k" value for this foam is about 0.05 Btu/ft-hr-°F. This "k" value is higher than that used for the typical 2.2 pound density foam which is common in Alaska. Protecting the foam is a outer jacket pipe which is comprised of high density polyethylene (see Figure IV.B.1 for a section view of the pipe). The pipe system can be equipped with two tin plated copper wires which will serve as an alarm if water leaks from the carrier pipe or through the jacket. These alarm wires are read by a $1,500 alarm device which can connect to as many as four individual pipe loops. These devices also will aid in locating the position of leaks which reduces expensive excavation and assures the pipe is repaired rapidly. The steps to assemble two sections of this pipe are: electric weld the steel carrier pipe sections together; bolt an outside jacket over the carrier pipe joints, which covers the space between the two outer jackets; then fill the space between the jacket and the pipe with foam. The pipe is subjected to high operational stresses because the temperature can vary from 25 °F to 210 °F. These temperature differences cause the pipe to expand and contract. Compensation for the large differential temperature conditions is dealt with by bringing the pipe to a neutral stress level at a position about half way between the two temperature extremes. (See Figure IV.B.1 for an illustration of a typical cross section of the buried district heating piping). WALSAS IWOIdAL Siameenns Platacumenaie casaeeees ‘ "9u 6 oe ONILVSH LOIWLSIG SNAZLOM | eysEIe yNsUCSZOd ADVYHOLS AlddNS HALVM YOLVHANAD NIUaLvM SNIIO09 ANIONS atemeiain SNILSIXS YADNVHOXS LaxOve SANIDNS 1W3H SLV1d WOus HADHVHOXS LW3H HIONVHOXS av (Wasn) ‘LV3H ; ONiaTING yOVIS S.5018 YAHLO OL 1W3H LOIWLSIG LSNVHXA MOVLS ' marae eH Ee HeHeH ee eH Eee He EE HE EE EF Z VAL aynota £0986 VASVTV ‘SDVUOHONY “"3AV Guee 13M cost NILV3SH 4 SLNVLINSNOO ADUING * SHOAZAUNS + SHISNIDNI aE ONILV3H YO4 dN-NOOH Y3SN IVOIdAL “OUI ‘BySEIe yNsUCoAEjOd ava ONILVSAH LOIWLSIG — ANEGAZLOm (€'V'Al SUNDIS 33S) YaLVM 91LS3N00 M) ssvdAg @) uaSNOL AlddNS ONILV3H (S) uanivuls © NUNL3Y ONY AlddNS ONILV3H Loluisia @) 3A1VA ONIONVIVE © 438M WOU NYNL3Y OLH @) BAVA ONILV10SI@) YOLV 1NDNID®| YBONVHOXS LV3H 3Lv1d© uanune @ 3A1VA Nivuad © 4¥313W Lv3H © QN39317 W3LSAS ONILV3H Q somisia = AS YSLVM LOH SILSSWOGd HOS dN-MOOH YASN WOIdAL ae ee ONILWSH LOIWWLSIG ANGAZLOM 6861 ‘AON :3.Lva ) > eo ee 15 aoa ee ee ALM LOH O1LSaWOG HO4 IONVHOXG LV3H (SEE FIGURE IV.A.2 a ONILVSH LOIWLSIG OL NYNLAY HALVM 0109 Y3TIO8 ONILSIX3 ALSAS ONILVSH LOIWLSIG | WO8s H3LVM LOH £0986 VSV TV ‘SDVHOHONY *"3AV Guee 1S3M cDSt SLNVLINSNOO ADUANG © SHOAZAUNS ° SUISNIDNI “oul ‘eyseje WNsUuOCZiLjod Y3LVM 0109 mn HE EE Ee Se lULUelUlUelCUe CU polarconsult Kotzebue District Heat Study B. Heat Exchangers Heat exchangers were assumed to be the plate type and made of stainless steel. All of the buildings connected were assumed to be hydronic heating systems, i.e. hot water baseboard, although forced air heat could possibly be accommodated as well. For each service, one plate heat exchanger would be used to heat the water circulated to the base boards to a temperature of 195 °F and return it to the exchanger at a temperature of 170 °F, A second heat exchanger was included for domestic hot water. This heat exchanger was priced as a double wall type to prevent contamination of the domestic water supply by the district heating fluid. All of the systems are to be equipped with valves, temperature indicating devices and a Btu meter of the electronic type which is currently used in the U.S. and Europe. To take meter readings without entering the utility room, wires can be run to a jack outside the buildings, or the meters can be connected to a computer for remote reading. C. Temperatures Ambient temperatures and degree days for Kotzebue are given in degrees Fahrenheit, ¥F, below. Air Temperature Heating Degree Days Minimum Average Max. Day Avg. Day Total/Yr -52°F 20.9 °F 117 44 16,032 Table IV.C.1 The temperature of the working fluid in the main district heating distribution piping depends on the minimum temperatures used in the typical hot water heating system in the buildings to be served. The minimum temperature was assumed to be 170 °F and the maximum temperature was set at 205 °F for calculating fluid flows and pipe capacity, The actual temperatures at some points in the system could be as high as 210 F or as low as 155 °F. The soil temperature used for determining pipe heat losses was 29.8 °F. ad = = oe ® KOTZEBUE eosin . * a - ws cas | a: ip: : . tee * e. e oon % . . a le - © ee \ . . Gogh % CLASSIFIED FILL GEOFABRIC STEEL CARRIER PIPE HIGH DENSITY URETHANE INSULATION polarconsult alaska, inc. ENGINEERS ¢ SURVEYORS « ENERGY CONSULTANTS 1503 WEST 33RD AVE.* ANCHORAGE, ALASKA 99503 WITH POLYETHYLENE JACKET KOTZEBUE DISTRICT HEATING 4" DIA. DISTRICT HEATING PIPE (TYPICAL INSTALLATION) DATE: NOV. 1989 FIG. IV.B.1 polarconsult Kotzebue District Heat Study D. Oil Displaced The total amount of recoverable heat available from the engines, using both jacket water and exhaust stack heat recovery, has an equivalent oil heating value of about 613,000 gallons, based on the 1988 records. Figure IV.D.1 shows that all of this heat cannot be recovered because there is substantial heat available during the summer when the demand for heat is low. Seasonal Heat Requirements and Availability ” aS School + Front St. + Airport Loop 80 ae + Front Street Loop Ls 70 0 100 Gallons of Oil s Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Month Figure IV.D.1 This excess heat suggests that there may be other uses for the waste heat in the summer. These could include meat and fish drying, a seasonal green house or possibly a swimming pool. The amount of heat recovered from the engines is given in the following Table. These loops are added incrementally to the School Loop, which is assumed to be the base case, Ls polarconsult Kotzebue District Heat Study so the only heat displacement gained is during the summer. There is not enough heat available from the engines during the winter to displace this addition heat load. Loop School Loop Front Street Loop Airport Loop Total Present Gallons System Gallons of Oil Used/yr of Oil Displaced 539,700 479,620 100,770 30,530 80,300 29,850 720,770 540,000 Table IV.D.1 14 zz Ha = = mH polarconsult Kotzebue District Heat Study E. System Heat Losses Heat losses, in district heating systems, are almost exclusively from the main transmission pipe which generally should be buried in the ground for mechanical and freezing protection. District heating piping systems have one pipe that carries the hot fluid from the heat exchanger at the power plant out along the loop to the user and another pipe which returns the somewhat colder fluid back to the plant for reheating. The fluid can be water or a water anti-freeze mixture. See Section IV.E, Media, for discussion of working fluids. For this report it was assumed that water was used. (See Figure IV.B.1 for typical cross section of buried piping). Heat losses for the i.c. Moller "Plus" pipe range in value from 20 Btu's per foot for 1 inch diameter pipe, to 47 Btu's per foot for 12 inch diameter pipe. This is based on the hot water in the pipe being about 200 °F higher than the temperature of the ground. The heat losses for the district heating system vary with the pipe diameter, length and this differential temperature. The heat loss for the loops, given in gallons of oil and a percentage of the total, is shown in the following table to put these losses in perspective. The heat losses in the table are based on an average operating temperature of 190 °F and are given in equivalent gallons of oil which is assumed to yield 95,400 Btu's per gallon. Main Transmission Line Heat Losses Loop Gal. Oil Displaced Gal. Oil Lost/yr Percent Lost School Loop 479,620 44,500 9.3% Front Street Loop 30,530 19,680 64.6% Airport Loop 29,850 15,980 53.5% Total 540,000 80,160 14.8% * Note: These loops are added incrementally to the School loop. Table IV.E.1 Figure IV.D.1 in the previous section also showed that the heat losses in the pipeline are not all relevant as there is more heat available off the engines during the summer than the community can use. Hence only about half of the heat losses from the pipe lines can be counted as a financial loss as the engines need to be cooled anyway. LS polarconsult Kotzebue District Heat Study At the current cost of fuel oil of $1.30 per gallon, the cost of the fuel to replace one half of the total pipeline losses would be $52,100 per year. The value of that amount of losses in todays dollars, assuming this condition continues for 20 years, is about $460,000. This means an improvement which decreases the pipeline heat losses, such as increased pipe insulation, could afford to spend up to $460,000. When compared to peak loadings, the percentages of the losses are substantially reduced. Heat losses from the pipes can also be reduced by decreasing the temperature of the media. A decrease in fluid temperature is possible, provided the demand for heat is reduced. If the demand is not reduced than the quantity, hence the velocity, of the fluid has to be increased. Doubling the fluid velocity will cut the differential temperature in half. As an example it can alter it from 70 °F to 35 °F. In that event the average pipe temperature can drop 17.5 °F. This represents a change in percentage of about 17.5/175 or a 10% reduction in heat losses. To accomplish this requires an 8 time increase in the pumping power, which will increase the cost of electricity. Tradeoffs such as these will be made during design and when programing the operations computer. The fluid temperature can be decreased when the demand for heat is reduced, such as in the spring, summer and fall. As a practical matter the minimum temperature of the high side would average near 195 °F and the low side near 175 °F for an average temperature of 185 °F during the lower demand periods. This would reduce the pipe losses shown in the table above, which are calculated at 190 °F, by up to 7%. An additional method of reducing the losses is to increase the insulation thickness. As this will increase pipe costs, there is not a one to one correspondence between system cost savings and increased insulation thickness. During the more detailed design phase, calculations will be made to determine the value of the losses versus the cost of insulation. This will result in a more optimized pipe/insulation selection. During the design phase detailed computer simulations of operating conditions will be utilized to aid in selecting the optimum pipe sizes and insulation configurations. The detailed tradeoffs between pumping costs and heat losses will also be made at that time. A computer will be installed to operate the district heating system. The computer will calculate temperatures and pumping costs for the system and translate these into output temperatures and fluid flow rates. This will result in the lowest cost operation for the selected system. 16 polarconsult Kotzebue District Heat Study E. Media Different media can be used to transfer the heat in a district heating system. The traditional media used in district heating systems is water with some form of inhibitor to prevent pipe corrosion. In Alaska the systems have used a mixture of ethylene, or propylene glycol, and water to prevent damage to the system if it is shut down and freezing occurs. The problem with using a water-glycol mixture is it reduces the ability of the fluid to carry heat, which increases pumping and heat exchanger costs. In addition, the glycol has a higher viscosity than water which requires greater pumping pressures and causes higher energy losses. The glycol itself costs money and if there are leaks the system has to be shut down and the leak found to prevent fluid loss. In Alaska, with permafrost ground such as is under Kotzebue, the spilled glycol will cause melting and settlement of the area. With a buried pipeline the ground around the pipe is heated well above the freezing temperature even during the winter. The temperature at three foot of depth without heating of any kind is about 25 °F minimum temperature during the latter part of the winter. This means that a district heating pipe that is buried can be shut down for a long period of time before there is a danger of freezing. The critical location is the service connections where the pipes pass from the ground through open air into the buildings. The services are less at risk than those of standard water systems as the fluid they carry is hot. The system would be designed and operated so that there is always a small flow through the two service pipes through the heat exchanger so the lines will not freeze. The main pumps could be equipped with an engine powered emergency system pump to assure circulation in the event of system failure. Another type of failure is a large leak which requires the pipeline being shut off and repairs completed prior to being put back into service, because water in the low sections would have time to freeze. For small systems without full time experienced operators it would not generally be good judgement to operate a district heating system without some form of freeze protection. Because this district heating system is in a sizable city, where operators are available and knowledgeable, it is not believed that the use of glycol is either cost effective or necessary. If there is an emergency which shuts down electricity, pumping, and/or heating, a contingency plan will need to have been thought out to take care of the problem. For this study it was assumed that the media was water. ver polarconsult Kotzebue District Heat Study G, Hydraulics Pipe hydraulics are based on a flow rate that will result in a pressure loss of about 4.4 psi per 1,000 feet of pipeline length. The pressure drops were calculated from charts given by icc. Moller for their pipe. Larger head losses were evaluated but conservative values were selected. In terms of hydraulics it was assumed that the head losses took place over the entire loop in a uniform fashion with the quantity of water flowing throughout the individual pipe that caused the drop. In actuality the losses diminish as water is taken from the pressure pipe, and are increased when they are added to the receiving pipe. As a result, head losses diminish based on the use of water throughout a particular section. This means the results of the study are conservative values. When the system is designed these intermediate designated taps will be accounted for in calculating the tradeoffs between pumping costs, heat losses and pipe costs. Pressure drops are accounted for through the exchangers. It is assumed that there will be a 3 psi drop through the main exchanger and 3 psi through the individual exchangers. H. Pumping The pumping power requirements for the system are low. The values are based on the flow rate multiplied by the head losses as described above. Since the cost of electricity is a function of fuel and plant cost, the annual pumping cost is given at 15 cents per kilowatt hour using a 70% efficient pumping system. Based on these values the annual pumping cost for all three loops would be $14,300 per year. 18 polarconsult Kotzebue District Heat Study 1 Water heating Kotzebue currently does not heat its domestic water supply and has problems with services freezing. A connection was included to the domestic water supply so the water can be heated. It is estimated that it would take about 130,000 gallons of oil to heat the water in Kotzebue based on a similar system in use in Nome. If this connection proves feasible the cost for the equivalent amount of oil to heat water will only be the cost of the heat exchanger equipment, some small lengths of pipe and annual pumping costs. Based on water system experience the amount of heat added can be greater or less. The final determination of the amount of heat transferred to the water is an economic and community decision. Heating the domestic water supply will have considerable advantages as it will prevent the water system from freezing and will reduce the cost to the residents who have to heat the water to higher temperatures before use. As a result residences who can not afford to connect to the district heating system can receive some of the benefits. Because district heating, with the exception of the distribution piping, has no losses, savings in heat as compared to inefficient hot water heaters are substantial. L Soils Kotzebue is in a discontinuous, marginal, permafrost area which means the permafrost is not very cold. It is reported that water runs from the Beaufort Sea to the Lagoon through permeable gravel layers under the City. If this is the case, there are unfrozen zones in Kotzebue. In this report the tops of the pipe will be approximately three feet underground and located off the roads. The pipes will only cross the roads when necessary. The utility people report the soils in the selected areas are mostly silty sands and are suitable for pipe backfill. They also said, however, that parts of the city are constructed on dredged materials which may be high in organics. In general, district heating pipe is not heavy and will not require restraint, anchors and weights, for overbends when laid in straight lines over level terrain such as in Kotzebue. The pipe trenches in Kotzebue are assumed to be uninsulated. In the study the only use of insulated pipe trenches is for road crossings where settlement could result in problems with the road surface and more importantly, pipe integrity. 19 polarconsult Kotzebue District Heat Study K. Construction Construction of a district heating system utilizing the type of piping systems that are produced in Europe is fairly simple. All of the steps have been considered in great detail and are illustrated graphically. Ditch excavation to the shallow depths, about four feet, will be quite rapid and easy during the summer when the ground is thawed. The problem of significance will be the avoidance of other underground utilities. In Kotzebue the water and sewer lines can be fairly shallow. Therefore, it is anticipated that making crossings will be a little more difficult. The electric system is overhead so buried wires should not have to be contended with. After the ditch is excavated the pipe is welded together. In many cases where the terrain is flat, long sections can be assembled on the bank of the ditch using roll welding. Because of the importance of the system, it is proposed to radiograph about 10% of the welds for quality control. The emphasis will be placed on assuring that the welders are qualified, have current certifications, follow procedures and produce quality work. After welding, but prior to covering the weld, the pipe will be pressure tested. After passing these tests, the joint insulation and jacket will be assembled. This assembly for the i.c. Moller type pipe involves connecting the alarm wires, bolting on the two metal half shells and air pressure testing them to make certain the shells are well sealed. Foam is then mixed in measured bags, sized for each pipe diameter and type of fitting at the specified temperature, and is poured into the shells. After expansion is complete the openings are capped and the pipe can be placed in the ditch or backfilled if already there. During construction, parts of the pipeline will be left exposed and the pipe will be expanded or pulled to develop a tension that will set the pipe stresses at a intermediate level during operation. One pipe manufacturer expands the pipe with hot water utilizing a special fitting which is then welded fixing the temperature stress. This technique is similar to that employed during the construction of the Trans Alaska Pipeline. Some typical installation sheets have been provided in Appendix A to illustrate in part some of the procedures which are followed and the depth of detail provided by the manufacturer's. 20 polarconsult Kotzebue District Heat Study L.Ubiliti Utility crossings will generally be done with the district heating pipe on top. The district heating pipe is very strong and tough and will not be harmed by high surface loadings. Where the pipe has to go under another utility it will generally be bent in the field to fit. Bending is possible in the field for pipe diameters up to 4 inches in diameter. 21 polarconsult Kotzebue District Heat Study V. Operation & Maintenance Operation of the system will primarily be under control of a master programmable logic controller or small computer. The computer will sense outside temperatures and set the pumping rates and temperature conditions according to algorithms which will determine the optimum output of the system. Returning water temperature will also be used to determine the degree that heat is being removed from the system. A district heating system can be very reliable if properly designed and constructed. Piping systems are one of the most reliable forms of transportation in the world, and a district heating system is simply a means of utilizing pipes to transport hot water to the consumer. To prevent internal corrosion of the steel carrier pipe district heating systems can have organic inhibitors added to the water. These inhibitors do not create environmental problems if leaked or spilled. To be certain the pipe is not corroding the addition of corrosion coupons will show if there are problems. The outside of the steel pipe is protected by the tough non corrosive external jacket. With the alarm system, failure of the external jacket at any location will be shown and remedies can be taken to repair the problem before it becomes serious. Operation of a district heating system is not difficult. Once the values for the computer algorithms are set, the system will operate automatically. Normal maintenance procedures will call for periodic checks of equipment and the pipeline. Just after project startup the pipeline and individual exchanger systems should be checked frequently. Leaks or operations malfunctions are more likely to occur at the beginning of operation. Systematic checks to determine if the pipeline alarm system is functioning are advised. Many of the pumps now used for district heating systems operate without seals and do not require lubrication. As a result they have long lives and almost no maintenance. The fourth edition of the "District Heating Handbook": published by the IDHA states that piping failure of hot water heating systems range from 0.048 to 0.32 per mile per year. With the 5.6 miles of piping in the three proposed loops this is from .3 to 1.8 failures per year. With the modern piping systems it is likely the number of failures will be nearer the 0.3 figure. The most likely cause of failure is from the pipe being punctured during an excavation near the pipeline where the pipes location is not accurately known or where carelessness occurs. Ze polarconsult Kotzebue District Heat Study It is estimated that the piping system would have 1 failure per year. If an average repair costs $5,000, maintenance would cost $5,000 per year. In addition it is likely that there will be work required on services. This work could be done by the building owner, however it would probably be better if it is done by the utility. With a repair rate of one out of 20 per year and $500 in cost per incident, the repair costs would be $25 per service per year. The cost of inspection is estimated to be somewhere near $10 per year. Meter reading is an additional cost of running the system. Assuming 15 minutes to read and bill for each meter per month, 3 hours would be used per meter per year. Paying a meter reader and clerk $15 per hour, the cost per service would be $45 per year. This amount can be reduced by making the reading once each three months. The annual cost of operating and the maintaining the system adds up to about $7,800 per year. 23 polarconsult Kotzebue District Heat Study VI. Project Estimate A. General The project estimate is based on experience with many projects in western Alaska and in Nome with underground utilities and waste water systems. Project estimates are arrived at by calculating the material quantities, installation labor and equipment hours for each significant work item and summing them to arrive at unit cost of construction. Exchanger systems are priced on the basis of two heat exchangers per each service, all valves, Btu meters, and associated piping. The costs of heat extraction from the engines was based on using a plate heat exchanger and exhaust gas heat recovery units for each engine. The estimate for the power plant was deliberately kept very conservative as it is not known in detail the extent of the alterations which will need to be made to the plant. 24 polarconsult Kotzebue District Heat Study B. Assumptions LQil usage Oil used was assumed to result in a net Btu production of 96,000 per gallon for each structure served. This was based on the fact that most of the buildings utilized a so called arctic grade diesel, which is similar to No. 1 fuel oil, and have boiler efficiencies of about 75%. This figure provided the number of Btu's of heat that are required to displace one gallon of fuel oil at the building. The peak Btu's required by the system were based on a constant day at the minimum recorded temperature, compared to the year in which the measurements were made. All of the above values provide the information necessary to determine the number of Btu's required over the year and the peak load in the system. The gallons of oil used in each building and piping loop served is presented in Table VI.B.1.1. The gallons of usage can, in a general sense, be used to determine the project income for that particular subset. As an example, given oil at the current price of $1.30 per gallon and the School loop which uses 479,620 gallons of oil per year, the income would be $623,500 per year, the value of displaced oil. Using the estimated $7,800 annual operation and maintenance cost from Section V. Operation & Maintenance, the annual income from the system would be $615,700. This means the payback period for the School loop, with a capital cost of $2,640,000 would be less than 5 years if interest were neglected. Based on the above it is evident that the major variables are the current and projected cost of oil, the cost of the district heating system and the cost of borrowed capital. Of these costs the future price of oil is the one with the greatest uncertainty. It is for this reason that the project is broken down on the basis of oil which would be consumed to provide the heat for the project. The cost of energy for a waste heat recovery system is free up to the amount given off by the electric load. The capital cost of the system is fixed by the construction costs. Operation and Maintenance are minor costs. The variable, the displaced cost of oil has two components. The purchase cost, $/Btu of energy, and the cost of storage and delivery. Unless it is expected that the cost of either of these components will be reduced, it is not likely that the cost of oil will decline and therefore using a flat oil price is a conservative measure. 25 polarconsult Kotzebue District Heat Study The oil used, the peak Btu's and the service pipe sizes for each individual structure to be served are presented in the table below. Building Served | Gallons! Peak | Pipe | | /Year | Btu/HR | Size | Warehouse (est) | 5,000 | 144,000 | STI Week's Apartments (est) | 10,000 | 287,000 | an City Hall | 5,400 | 155,000 | 1.5"1 Kotz. Fire Dept. | 2,000 | 57,000 | 171 Kotz. Police | 500 | 14,000 | 17) Kotz. Jail | 10,000 | 287,000 | 2 Hospital, New | 100,000 | 2,300,000 | 6"1 KIC Apt. (29) | 18,300 | 526,000 | 25° 1 AC Store | 26,000 | 747,000 | 4" | Kotz. Sr. Center | 22,000 | 632,000 | 2.5" 1 Public Works | 13,500 | 388,000 | 2521 Water Bldg. | 32,200 | 925,000 | 4" | Domestic Water | 130,000 | 2,800,000 | 6" | Community College | 9,400 | 270,000 | 21 Elementary | 15,000 | 430,000 | 2:5" Middle | 30,000 | 860,000 | 4"| High School 2 @ ea. | 45,000 | 1,290,000 | 4" | Borough | 30,000 | 860,000 | 4" | Armory (est) | 25,000 | 720,000 | 4"1 Rec. Center | 10,400 | 299,000 | 20 EOM Value House (est) I 10,000 | 290,000 | 2") OTZ Radio Station (est) | 3,000 | 90,000 | 15" Golden Whale (est) | 9,000 | 260,000 | 2" Hanson's Store | 5,000 | 144,000 | 1 Nul-Lukvick Hotel | 47,270 | 1,360,000 | 4" | C.Forstner (est) | 6,000 | 170,000 | Sc Baptist Church (est) | 4,000 | 110,000 | LS Eskimo Bldg. | 16,500 | 474,000 | 25° 1 KIC Apt (41) | 22,000 | 632,000 | 25" Museum, NANA | 20,000 | 575,000 | 251) School Dist Office (est) | 5,200 | 150,000 | 15°) D.O.T. (est) | 5,200 | 150,000 | 1S*'I Mark Air Terminal | 6,500 | 187,000 | Ses Civil Air Patrol (est) | 5,200 | 150,000 | 157 Alaska Airlines | 11,000 | 316,000 | ani A.LA. (est) | 5,200 | 150,000 | 1:5" 4 Subtotal | 720,770 | 19,199,000 | | Table VI.B.1.1 polarconsult Kotzebue District Heat Study C. Estimates The following estimates of project costs are presented as extracted from the economic spread sheets. The estimates are broken down so the systems can be assembled in sections as funds become available. The Kotzebue system is well suited to break into three or more individual sections. Presented below is a table that provides the costs of the district heating systems. The cost of heat is based on that quantity of Btu's delivered to the pipeline after corrections have been made for efficiency. The relatively low loss values for pumping costs represent the fact that losses are a function of the square of the velocity or the quantity of fluid being pumped. The pipe was sized for the peak values; as a result pumping losses over the year are low. However since peak flows are about 2.7 times the average flow, losses at that time are in excess of 7 times the average. System Costs | Capital! Annual | Annual | Annual | Gallons | Loop | Cost | HeatLoss! Pumping! O&M | Displaced! School Loop | $2,640,000! $28,925! $12,700! $4,520! 479,620! School + | | | | | | Front St. Loop | $3,334,000! $41,720! $13,500! $6,030! 510,150! School + Front | | | | | | St.+ Airport Loop | $3,955,000! $52,100! $14,300! $7,820! 540,000! Table VI.C.1 27 polarconsult Kotzebue District Heat Study VII. Conclusions Kotzebue is an ideal candidate for district heating. It has cold weather, a large diesel electric plant with substantial waste heat, flat terrain and the permafrost soils are not bad so pipeline construction will be fairly economical, and it has a considerable number of large heating loads. In addition, due to the far sightedness of KEA, the cooperative purchase of fuel, and the use of #2 fuel makes it possible for KEA to provide the lowest priced heat in the City. The total district heating system has a payback period of about 6 years with only a 2 percent increase in the cost of oil. The district heating system will help to insulate Kotzebue from potential increases in oil prices which will likely come in the future. Construction of the district heating system will result in additional jobs for local workers. District heating can increase the reliability of heating systems as it does not, at this stage, remove the local heating source, but injects the heat ahead of the boiler. This keeps the boiler controls from operating as the controls sense the returning hot water, so they do not turn on the burners. If there is a failure or lack of capability in a district heating system connected in this manner, the boiler burners will run, providing heat to the building. District heating also has the advantage of decreasing the personal need for heating system technical repair skills and places these requirements in the hands of the utility experts who are much more experienced with the systems. As a result, the total operation of a district heating system which depends on experts making the repairs to the piping and the interior distribution system can be more efficient and effective. District heating also has the advantage of reducing the amount of environmental discharges because the individual boiler outputs are reduced. Adding central boilers to displace load would also lower the amount of discharge as a larger plant working under optimum conditions is more efficient and uses less fuel. 28 polarconsult Kotzebue District Heat Study VIII Recommendations: It is evident that a district heating system can save money for Kotzebue, and that it will make a good State and local investment. What has to be decided are the details to define the system. Some of these details are listed as follows: o Who will build the system? KEA, the Community or another? This decision will effect financing and interest rates. © Distribution of profits? How much to KEA and how much to the consumers of the heat? o The extent of the system? For example, the optimum rate of return per dollar of invested capital would be to design and build the system up to Bison Street and Sth Avenue, and serve only the new hospital and the structures in the vicinity. Or should it be designed and built to extend to the schools? Or should the leg to Front Street or to the Airport be built even though the rate of return on these two legs is lower? In our opinion to waste the heat by not extending the line from the hospital on to the water system and the schools would be wrong. As an absolute minimum, the system should be designed and constructed with such an extension in mind. The other legs are more questionable however. If consideration of a topping boiler is made, outside the scope of this report, it is likely the economy of these extensions will improve. o How much heat should go to the water system and how should it be paid for? The heat to the water system will be dispersed to all entities connected to the domestic water system and will represent a universal savings. o A design and final cost estimate is needed. Based on the answers to the preceding questions, data on soils, locations of utilities, detailed location of services, power plant asbuilts and verification of amounts of oil used over time are needed. Of considerable importance to the economic model and the design is to get daily information on the heating loads of some of the major structures such as the school. This data can be obtained by installing recording devices to provide time based information . 29 polarconsult Kotzebue District Heat Study o The construction of the system should be done during the summer after the ground is thawed. Main line construction will proceed quite rapidly because the pipe is buried at shallow depths outside of the road. Interconnections at the services and at the power plant will take more time but they are indoors and can be done during inclement weather. o It is recommended that all services be installed by the constructor of the main lines, so the economies of scale can be achieved and quality control can be assured. With a district heating system, the major failure of a single pipe can effect the entire systems operation. At some time in the future connections to the system may be made with structures that no longer have their own individual boilers, as is done elsewhere. In this event, reliability of the system becomes more important. o It is recommended that consideration of a topping boiler be used as KEA purchases fuel for about 62 cents per gallon versus costs to individual users of $1.30. These savings can readily be transferred to district heat users. 30 polarconsult Appendix A Pipe Installation Instructions L.C. Moller Pipe Kotzebue District Heat Study a _ & | hard ) It is easier to make a correct joint if the joint area is sufficiently exposed. This is ensured if the prescribed trench dimen- sions are used as indicated above. The easiest way of joining pipes up to dimension © 4"/7. a" (114.3/200 mm) is to place the pi es on supports. For pipes larger than © 4"/7.87” the ground beneath the joint is excavated, so that the joint area is completely clear of the bottom of the trench. Lin (400 mm) = 16” (400 mm) Before starting the insulation procedure the outer pipe ends are wiped clean and dry and all burrs are removed. Insulation should not be carried out during wet weather unless the pipes are under cover. If the pipes are moist or wet prior to insulation they can be dried off using a soft gas flame. If the joint area has been under water before the joint couplings have been fitted, the wet polyurethane foam should be removed from the pipe ends using a sharp knife. : VAR . taper lock joint | After butt-welding the pipe lengths together, Sealing compounds applied to the lower joint the joints are insulated in asimple andsafe way _ half, which is pressed against the outer casing by means of i.c.mgller taper lock joints. and supported with wedges. The sealing com- pound is applied to the polyethylene casing at = the points of contact between the joint coupl- ing and the outer casing. a a 4 - Taper lock joint —_ Casing © out. in 3.54 4.33 4.92 5:51 6.3 7.87 8.86 9.84 12.4 || mm 90 110 125 140 | 160 200 225 250 315 rf + +—_—— Part no. 1030 1031 1032 1033 1034 1036 2036 1037 1038 Sealing comp. {a| each joint ft.) Gas" Te ar 7'10" 8'2” 8'10” 910” 10'6” 11'10"_ m Ral a2 2:3 2.4 2 27 3.0 3.2 3.6 ts The i.c.mgller pipes are supported/excavated The upper joint part is then placed into posi- and the joint surfaces are wiped clean. Then tion. The two joint parts are pressed together the sealing compound is applied to the outer and the four taper locks are fitted loosely. | Pipe ends, allowing an overlap. Note: One of the taper locks with an anode for cathodic protection must be fitted. ic. maller a/s fredericia dk tel 455996711 198611 32.2. taper lock joint | | | | The taper locks are then driven into position, using a hammer. Each taper lock must not be forced home in one operation, but in stages, in sequence as shown in the diagram. The i.c.mgller dual plug is inserted. The joints should now be insulated. See section 14 Foam liquids. To ensure electrical connection between the four taper locks and the joint, it is important to check that they have been fully driven home. There should be no gap between the taper locks and the top of the stop. 5) iB alee ee eee the. eal ia ine een 1O@K 11 Kotzebue District Heat Study Appendix B Cost Estimate KOTZEBUE DISTRICT HEATING SYSTEM School Loop Capital Cost Gal. of Fuel Disp. / Yr $ /Gallon Displaced School + Front St. Loop Capital Cost Gal. of Fuel Disp. / Yr $ /Gallon Displaced School + Front Street Capital Cost + Airport Loops Gal. of Fuel Disp. / Yr $ /Gallon Displaced POWER PLANT MODIFICATIONS | COST/UNIT DESCRIPTION | QTY. | Unit | LABOR | MATERIAL| ee ears eae eee (SS eee (a See eS ee ee | | | | | Power Plant Conn. | 1 | Each | | | | | | | ; Subtotal Hydrotest Radiagraphy Overhead+Profit @ 20% Contingencies @ 20% Engineering @ 8% Total LOOP: TO SCHOOL COMPLEX | COST/UNIT | DESCRIPTION | QTY. | Unit | LABOR | MATERIAL| S<Sseer ees =s=— [Sea ee= | Se Saee Saas eee ee | MAIN PIPING | | | | | 8 Inch | 2,170. |. Ft | $15 | $158 | 6 Inch [Sbpet0 |. Bess I $13 | $120 | 4 Inch | 100 (kt... $12 | $83 | | | | | | Road Crossings | i2 | Each: | $581 | $3,691 | | | | | | Building Conn. | 20 | Each | $4,597 | $28,335 | ew ee wo ww ow ww ww wo oo oo oo wee ee = | Subtotal Hydrotest Radiagraphy Overhead+Profit @ 20% Contingencies @ 20% Engineering @ 8% Total Gal. of Fuel Disp. / Yr $ /Gallon Displaced 11/22/89 $2,639,800 539,700 $4.89 $3,334,160 640,470 $5.21 $3,955,320 720,770 $5.49 $390,000 $2,500 $5,000 $79,500 $79,500 $31,200 $374, 667 $228,480 $66,403 $51,271 $658, 645 $1,379,465 $2,500 $5,000 $277,390 $277,390 $110,360 $2,052,100 539,700 $3.80 KOTZEBUE DISTRICT HEATING SYSTEM 11/22/89 LOOP: TO FRONT STREET COST/UNIT | DESCRIPTION | QTY. | Unit | LABOR | MATERIAL] TOTAL See ee ae (Sess 5 oe) ee ee ee MAIN PIPING | | | | | 6 Inch | 620 | Ft. 41 $13 | $120 | $82,841 4 Inch | 2,910 | Ft. | $i2 + $83 | $181,185 | | | | | Road Crossings | 6 | Each | $633 | $5,198 | $34,989 | | | | | Building Conn. | 6 | Each | $3,652 | $23,524 | $163,053 ee a ee ee = | eww ew ew ew we ee = Subtotal $462,068 Hydrotest $2,500 Radiagraphy $5,000 Overhead+Profit @ 20% $93,910 Contingencies @ 20% $93,910 Engineering @ 8% $36,970 Total $694,360 Gal. of Fuel Disp. / Yr 100,770 $ /Gallon Displaced $6.89 LOOP: TO AIRPORT | COST/UNIT | DESCRIPTION | QTY. | Unit | LABOR | MATERIAL| TOTAL Sean aromas a eee I ees eect | ce ea | mec ae MAIN PIPING | | | | | 4 Inch | 2,590 | “Ft | | $83 | $245,690 | | | | | Road Crossings | 2 | Each | $569 | $3,399 | $7,935 | | | | | Building Conn. | 6 .| Each | $2,713-|5S17,159 | $158, 982 mmm m mmm ew ee ee ew oe oe www ww ww ww ww wn wo wo we wo ww ww ow wo oo ow wo ww oe ee = | wwe eww eww nwnwnn— Subtotal $412,608 Hydrotest $2,500 Radiagraphy $5,000 Overhead+Profit @ 20% $84,020 Contingencies @ 20% $84,020 Engineering @ 8% $33,010 Total $621,160 Gal. of Fuel Disp. / Yr 80,300 $ /Gallon Displaced $7.74 Pg. 2 Kotzebue District Waste Heat Study Loop To School |Gal. Fuel] Building Served | /Year Warehouse (est) | 5,000 Weeks Apts. (est) | 10,000 City Hall | 5,400 Kotz. Fire Dept. | 2,000 Kotz. Police | 500 Kotz. Jail | 10,000 Hospital, New | 100,000 KIC Apt. (29) | 18,300 Alaska Commercial Store| 26,000 Kotz. Senior Center | 22,000 Public Works | 13,500 Water Treatment Bldg. | 32,200 Domestic Water Heat | 130,000 Community College 9,400 Elementary 15,000 Middle | 30,000 HS 2@ea. 45,000 Borough | 30,000 Armory (est) 25,000 Recreation Center 10,400 Subtotal 539,700 Loop to Front Street Gal. Fuel| Building Served /Year EOM Value House (est) 10,000 OTZ Radio Station (est) 3,000 Golden Whale (est) 9,000 Hanson’s Store & Whse | 5,000 Nul-Lukvick Hotel { 47,270 C. Forstner (est) | 6,000 Baptist Church (est) | 4,000 Eskimo Bldg. | 16,500 Subtotal 100,770 Loop to Airport |Gal. Fuel| Building Served | /Year KIC Apt (41) | 22,000 Museum, NANA | 20,000 School Dist. (est) | 5,200 DOT (est) | 5,200 Mark Air Terminal | 6,500 Civil Air Patrol (est) | 5,200 Peak BTU/HR 144,000 287,000 155,000 57,000 14,000 287,000 2,870,000 526, 000 747,000 632,000 388,000 925,000 2,800,000 270,000 430,000 860,000 1,290,000 860,000 720,000 299,000 14,561,000 Peak BTU/HR 290,000 90,000 260,000 144,000 1,360,000 170,000 110,000 474,000 632,000 575,000 150,000 150,000 187,000 150,000 316,000 150,000 11/15/89 Service Pipe | Lgth, ft |Connection| Alaska Airlines | 11,000 AIA (est)| 5,200 Subtotal 80,300 Total / Average 720,770 Peak BTU/Hr = (Gal. Fuel / Yr) * 2,310,000 549,139 ((T hot - T cold) / | Dia. Jone way| Cost..." e==SSo= (=a ee | [eee | 200 | $19,732 | | he | 200 | $25,011 | ) 21.8" "| 60 | $127;728 | | Ler 60 | $9,852 | | re 60 | $9,852 | | an. | 60 | $16,269 | | 6" | 350 | $87,025 | | aes" | 100 | $22,941 | | 4° | 120 | $30,083 | gee” | 360 | $42,283 | ogee” | 220 | $29,407 | | =. 150: |. -$335:929 || | oo; 100 | $40,621 | | 2 | 130 | $19,640 | [-o2n5*. | 350 | $39,578 | | an 320 | $50,056 | ae] 610 | $81,565 | a? | 110 | $30,135 | an) 200 | $36,672 | an. | 140 | $21,265 | 195 | $658,645 | Service| Service| |Pipe Si|Length, | Total | | an. | 80 | $20,485 [ S2e8* | 80 | $14,626 | | an] 80 | $19,485 | foelsS” | 100 | $16,770 | ar | 100 | $38,459 | [= des | 70 | $16,055 ke ee} 70 | $14,055 isuece | 70 | $23,119 | 81 | $163,053 | Service |Service| |Pipe Si|Length, | Total baeg <5": -| 130 | $29,351 i eco. | 130 | $28,351 | ie Lea | 160 | $20,200 lL Se | 80 | $15,626 (= 2.8 -| §0..1-°"9i67 911 | f= 1.5" | 80 | $15,626 | | an | 70 | $19,8612- | (4stS™ ol 70 | .$257056> | | 96 | $158,982 | 147.78 $27,241 Deg Days) * (1/24)