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HomeMy WebLinkAboutSelawik Waste Heat Project Letter of Non-Objection (AVEC) August 3, 1995Alaska Energy and Engineering,Inc.Mailing address -P.O.Box 111405 1217 East Klatt Road,Suite AAnchorage,AK 99511-1405(907)349-0100349-8001 fax August 3,1995 Mr.David Birney Construction Engineer Office of Environmental Health &Engineering 3925 Tudor Center Drive Anchorage,AK 99508 SUBJECT:Selawik Waste Heat Project Letter of Non-Objection (AVEC) Dear Mr.Birney: Please find enclosed a Letter of Non-Objection from the Alaska Village Electric Cooperative,Inc.(AVEC)for the above referenced project. Please note that AVEC has provided several conditions with which the "the City ofSelawikmustcomply(please refer to attached Letter of Non-Objection).AlsoattachedisacopyofthereferencedAVECcorrespondence(#93-M-408E)and thecorrespondencefromAlaskaEnergyandEngineeringtoAVECdatedJanuary23,1995 in response to the #93-M-408E AVEC correspondence. We have still not received a Letter of Non-Objection from the Northwest Arctic Borough at this time.We will again contact the Borough and request the status of the Letter. If you have any questions please call me at (907)349-0100,or fax your comments to (907)349-8001. oy ak Inc.A P.E. Sincerely, Alaska Ene attachments ALASKA VILLAGE ELECTRIC COOPERATIVE,INC. July 31,1995 Mr.Steven J.Stassel,P.E. PresidentAlaskaEnergy and Engineering,Inc.P.O.Box 111405 Anchorage,AK 99511-1405 RE:Letter of Non-Objection -Selawik Waste Heat Project Dear Mr.Stassel: Alaska Village Electric Cooperative has no objection to providing access to the City of Selawik for the placement of a waste heat module,tie-in to the AVEC cooling systems,and routing of arctic piping across AVEC property in Selawik under the following condi- tions: 1.Prior to initiating the installation of the equipment,AVEC is notified and informed that all of.the equipment will be installed according to the originally approved design or that specific equipment will be installed according to a revised design. 2.In the case of a revised installation design,AVEC shall review and approve the design =before proceeding»with theinstallation. 3.AVEC shall be provided the name and background qualifications of the supervisor on the project. 4.AVEC will be notified in advance and allowed adequate lead time to have a representative on-site when the actual tie-ins are made to the AVEC cooling system. 5.The City will be responsible for any damage to the prime movers due to loss of coolant as a result of'leaks or inadver- tent operation of the improper valve. 6.The City will be responsible for cleaning up and replacing any ethylene glycol cooling mixture lost when connecting into the AVEC cooling system. 4831 Eagle Street «Anchorage.Alaska 99503-7497 *Phone (907)561-1818 ©In State (800)478-1818 ©Fax (907)361-225 The City will be responsible for providing their own metered source of electric power for operation of construction tools and shall not utilize AVEC station power. The City shall take all precautions necessary to avoid personnel injury or damage to the power plant while workingaroundenergized,high temperature,and/or combustible equip- ment. The City shall be aware of and comply with items 17,18,19, 20,21,22,23,24,25,26,28,29 and 34 of correspondence 93-M-408E previously provided. Sincerely,fYa©eer Mark E.Teitzel Assistant General Manager MET/sm letterl0.95 letter1l0.95 Alaska Energy and Engineering,Inc. Mailing Address -P.O.Box 111405 1217 East Klatt Road,Suite A Anchorage,AK 99511-1405 (907)349-0100 349-8001 fax January 23,1995 Mr.Mark Teitzel,P.E. Manager Engineering Alaska Village Electric Coop,Inc. 4831 Eagle Street Anchorage,AK 99503-7497 SUBJECT:Selawik Waste Heat System Design Questionnaire Response Dear Mr.Teitzel: This letter is in response to the Questionnaire provided by AVEC regarding design considerations for the Selawik Waste Heat System (ref.:93-M-408E,attached). Question 1. The waste heat system connection to the Butler Building is on the exterior of the building.A line size Amot valve with 180F thermostats will be installed in addition to two tees,six line size butterfly valves,and a 3/4”normally open Amot bypass valve.The connection is shown on sheet M2.The waste heat system connection to the SMI Module has been coordinated with AVEC's new cooling system design and will consist of theinstallationoftwobutterflyvalvesinplaceofblind-flanges. Question 2. See sheets M1 and M2. Question 3. See sheets M1 and M2 Question 4. Due to the limited head capability of the cooling water pumps and the corresponding high pressure drop in the existing cooling systems,our design incorporates secondary pumped loops from the Butler Building and SMI Module to the Waste Heat Module.The design includes 4”schedule 40 piping and line size lug-style butterfly valves with Viton seals. No valves are included between the supply and return connections to the existing coolingsystemssuchthatnoadditionalheadisimposedontheexistingcoolingsystems. Question 5. Not provided since secondary pumped loops are used. Question 6. This question is addressed at question #8. Question 7. See the Waste Heat Utilization spreadsheet included in the 95%Design Submittal. Question 8. Calculations are not provided. The control strategy incorporated in our design is to limit the heat removed from the waste heat system by the Water Treatment Plant (WTP).Our design separates the existing hydronic system at the WTP into two distinct loops:A high temperature loop and a low temperature loop.The high temperature loop serves the hot water generator and the hydronic dryers.The low temperature loop serves the building heating load,circulating potable water loops,and utilidor heat trace loops (basically all "critical”heat loads). Only the low temperature loop will receive waste heat. The low temperature loop boiler will be set to fire between 165F and 175F.When the WTP load exceeds the available waste heat,the low temperature boiler will fire.With the low temperature boiler set to fire at 165F,and the waste heat loop designed for a 20F delta-T,the minimum waste heat return temperature (WHR)back to the WHM at peak design loads will be 145F (peak design loads will occur less than 2%of the time).With a WHR temperature of 145F at 65 gpm and the secondary pumped loop flow rate at 100 gpm,the minimum Engine Cooling Return (ECR)temperature from the WHM to the SMI Module cooling system will be about 165F.Since the flow rate from the WHM to the SMI module is less than 50%of the SMI minimum cooling system flow rate,and assuming that the AVEC hydronic system uses 5F of the 190F,the minimum mixed ECR temperature to the engine will be (165 +185)/2 =175F. In the event of a low temperature boiler failure,and the WTP heating supply temperature drops below 165 (to about 160F),an aquastat in the low temperature loop heating supply line will activate a pump to provide emergency heat from the high temperature boiler. CP-12 will provide heat from the high temperature boiler to the low temperature loop via a shell and tube heat exchanger.This will help prevent the low temperature loop from exceeding the available heat from the waste heat system.An alarm will sound to notify the WTP operator that the emergency backup system has been activated to add heat to the low temperature loop. Question 9. See Question #8. Question 10 and 11. Our approach to the design of a waste heat system is to minimize any impact to the generation system caused by a waste heat system shutdown or failure.If the WTP suddenly stops taking heat from the power plant cooling system,the engine cooling water returm temperature will increase.The cooling system Amot valve will start to cycle the C-port open and the B-port closed.As the temperature of the coolant returning to the engine approaches 180F,the open C-port will allow 100%coolant flow to the radiators. The power plant radiator(s)will cycle as required to reject the excess heat to the ambient. Adequate antifreeze (50/50 propylene glycol/water in the arctic piping and 60/40 premixed Fleetguard Complete in the secondary pumped loops)will be used to provide freeze protection to the piping systems.In the event of a complete waste heat system shut down in the dead of winter,the O&M Manual will instruct the WTP operator to heat the arctic piping loop with the WTP boilers on start-up prior to allowing engine coolant to flow to the WHM heat exchanger.Once the arctic piping is up to normal operating temperature,hot engine coolant will slowly be allowed to circulate to the WHM heat exchanger until the secondary loop is up to temperature.At that time the secondary loop will be allowed to go to full flow. Question 12. Based on information provided by David Biegel on Thursday,January 12,1995,the existing expansion tanks in the SMI module are sized for a cooling system volume of 257 gallons.The existing SMI cooling system volume is approximately 108 gallons.The estimated coolant volume added for the waste heat system is approximately 45 gallons. The additional coolant added for the Butler Building cooling system is approximately 65 gallons which requires an additional expansion tank capacity of about 5 gallons (Please verify adequate existing expansion tank capacity). Question 13. See Sheet M2.The secondary piping loops are attached to the power plant buildings (wall of the SMI Module and floor of the Butler Building).4”diameter by 36”live length stainless steel flex connectors are provided to allow for differential movement between the power plant buildings and the Waste Heat Module. Question 14. See Sheets M1 and M2,and reference the request to AVEC for a Letter of Non-objection to provide authorization to locate the WHM and associated piping on AVEC property, and to provide access to the City of Selawik for construction and maintenance of the waste heat system. Question 15. No motor operated valves are used in the cooling system piping.See design submittal information for material specifications and cutsheets.Also,a copy of the waste heat O&M Manual will be provided to AVEC upon completion of the project. Question 16. It is unclear at this time if the SMI Module cooling system modifications by AVEC will include the exterior piping penetrations.If not,approximately 30”x 16”,20 gauge stainless steel escutcheon plates will be installed,siliconed,and screwed to the SMI interior and exterior walls. Question 17. Yes,two drums of premixed 60/40 Fleetguard Complete will be provided. Question 18. Yes. Questions 19 thru 25. OK. Question 26. At this time,Alaska Energy and Engineering has not been retained to provide as-built drawings of the competed system. Question 27. All high points will be vented through existing cooling system venting,with the exception of approximately 2 auto air vents in the WHM (this was discussed with and approved by David Biegel,January 12,1995). Questions 28-30,33,34,36-40,42 and 43. OK. Questions 31 and 32. All circulating pumps and system fill point will be located in the Waste Heat Module.A electrical service connect request will be completed to provide 120/230 volt,1 phase service to the WHM,as discussed and approved on January 12,1995. Questions 35 and 41. This is accomplished by keeping the low temperature boiler at the WTP set below 180F (165F to 175F),and isolating the high temperature loop from the waste heat system, .(except during failure of the low temperature boiler). A section of3”pipe will be provided that can be removed to provide room for the installation of a BTU meter. If you have any questions please call me at (907)349-0100 or fax your comments to(907)349-8001. Sincerely, yyyb and Engineering,Inc.JduclLtvisLS President attachment © @ 9. prec [Sei raf A clear as-built of the existing piping,valves,fittings,hangers and supports of the existingcoolingsystemincludingdimensionsshowingtheclearanceoftheexistingsystemfromthe walls and ceiling of the existing enclosures and also other equipment. Specific drawings and details showing the proposed location for additional piping,fittings,hangers and supports including dimensions showing the clearances of the proposed system from the walls and ceiling of the existing enclosures and also other equipment. Schematic showing normal flow directions. we Clear calculations showing projected pressure drops with the existing engine. £ @ @ © Y a 6 Clear calculations showing projected pressure drops with a future Cummins KTA 38 1200 RPM engine. Clear heat-loss calculation showing the projected amount of heat necessary to keep: 1.the coolant circulating within each of the offline engines at a minimum of 100°F,+ 2.the chest-high ambient air temperature inside each of the engine modules at a minimum | of 70°,: 3.the chest-high ambient air temperature inside the control module at a minimum of 70°, 4.the chest-high ambient air temperature inside the storage van at a minimum of 70°, all at the lowest outside ambient air temperature expected at Gambell along with the expected wind effects. The expected amount of heat available from the engine jacket water. Clear calchfations and £xpfanatiop>showing that adequate heat will be available to keepAVECfacilitiesheatedaccordingtotheconditionslistedin#6 any time heat is being removed from the school. Clear calculations and explanation showing that the heat recovery system is designed to prevent the return coolant temperature to the engine from dropping below 175°after the system has come up to normal operating conditions. .Clear explanation of how the system would respond following any extended shutdown. ,Clear explanation of how the system would respond should the school suddenly stop taking ne re Q4 oxKERamonrehavenrersmi +tSciescalculationsshowingmaximumexpansionofneoncoolant(ot Seeverification of adequate expansion volume. A clear detail showing that adequate allowance has been made for differential movement oftheengine,piping,enclosure and heat exchanger. Page #2 93-M-408E fa 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. ay Ga)a clear detail showing that the new equipment will not obstruct access to any existing & equipment requiring periodic maintenance. oe Catalog specifications for all materials to be usedin the primary loops especially any three- way modulating valves or motor-operated valves to be added. Details showing how any wall penetrations will be made and methods used to seal the wails from moisture. An adequate supply of Fleetguard Complete premixed to a 60/40 ratio of ethylene glycol to water shail be provided by the contractor to recharge the system after modifications. The existing engine coolant mixture shall be drained into a clean container,protected from contamination and reused after modifications. Do not boil out the engine coolant system with sodium hydroxide and sodium tripolyphosphate;simply flush with clean water using care to not allow any water in the engine to freeze.Do not allow the engines to be pressure tested. Please be certain that the contractor(s)is(are)aware of electrical shock and burn hazards - associated with working near power generation and control equipment. Please be certain that the contractor(s)is(are)aware of the engine-related hazards,such as hot manifolds,rotating fans,pulleys,belts,etc.Be aware that the sound level in the plants is such that hearing protection is required. The contractor(s)shall be responsible for any and all damage incurred to the engine sets and buildings while connections and modifications are being made.The contractor(s)is(are) responsible for leaving the plant in an orderly condition,consistent of that when he arrived. Coordination for this project must be made with the AVEC Engineering office and AVEC Operation and Maintenance department regarding project schedule,current schedule updates,and start up activities. Coordination for this project must be made with the AVEC Plant Operator at the site location. Contractors shall not be ailowed to shut down and start engines at their own discretion;this is the Plant Operator's responsibility. AVEC shall be notified a minimum of one week prior to start up of the heat recovery system. At this point AVEC shall have an opportunity to require field changes deemed necessary for the safe and reliable operation of the waste heat system. Within two weeks of project completion,AVEC shail be given a complete set of as-builts. All high points in the primary loop shall be vented to the expansion tank with steel pipe nothose.-wep hn UWA ©wiki _L Wun "Ss pit x py .The contractor shall not utilize any AVEC fuel. Page #3 93-M-408E 31. 32. 33. 34. 35. 36. 37. . 39. 40. 41, 42. 43. .The contractor shail not utilize AVEC station service for powering a welder or any other large restive or motor load. Drains shail be installed on all piping low points so the system can be completely drained if necessary. The required circulating pump on the secondary loop shail be located inside the school and connected to the school's electrical distribution system. The fill point for the secondary loop shall be located inside the school and will be the school's responsibility. The proposed routing,burial depth and installation procedure for the secondary loop piping shall be clearly shown. Following refilling of the engine cooling loop,special care shall be exercised to assure that all air has been evacuated from the engine before load is applied. Clear calculations and explanation showing that the system is designed to prevent the coolant return temperature from rising above the temperature of the coolant leaving the heat - exchanger,ie heat being transferred from the school to the power plant. No hoses shall be used on any part of the primary loop. All fittings shall be either welded or bolted together between flanged faces. A full-size bypass on each primary loop of the heat exchanger is required. All valves shall be specifically tagged with a unique number. Permanently attached flow direction arrows indicating the normal direction of flow shall be supplied and installed. Ports on the secondary side of the heat exchanger located at the AVEC plant for future installation of a BTU meter shall be installed and plugged. A 3/4"bypass around the AMOT-vaive has been used to temper the temperature of the coolant in the remote radiators at any time to prevent cold shocking and to help keep the existing victaulic seals from leaking.If there is a desire to utilize this heat associated with the flow through the 3/4"bypass then at a minimum all of the victaulic fittings inside the radiator rooms should be replaced with welded flanged connections and an explanation provided describing how cold shocking of the radiators can be prevented. No heat recovery off of the engine exhaust is authorized at this time. Page #4 93-M-408E