Model YPC Two-Stage Steam-Fired Absorption ... - Usair-eng.com

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Mechanical SpecificationsGENERALThe YORK YPC Two-Stage Absorption Liquid Chiller iscompletely factory-packaged, including a first-stage (hightemperature) generator, solution heat exchangers, mainshell, hot water heater, microprocessor controls and allinterconnecting unit piping and wiring.All models are shipped as a single piece complete witha factory balanced lithium-bromide (LiBr) and refrigerantcharge inside of the unit to simplify and expedite start-up.The unit is also shipped with a nitrogen charge to eliminatethe possibility or air entering the machine during shipment.The burner and burner panel on each unit are factorymounted, wired and tested and shipped pre-installed asintegral components of the Chiller-Heater.The purchase price includes services of a JohnsonControls factory-trained, field service representative tosupervise the initial start-up of the machine.SOLUTION FLOWThe solution flow is divided into two parallel paths, oneleading to the first-stage generator and one to the secondstagegenerator. In this way, each stream is concentratedonly once, allowing for a more safe and efficient operation.The balance of flow between the two streams is factory-setduring the performance test to ensure maximum efficiencyfor any given application.MAIN SHELLThe main shell consists of four separate shell and tubeheat exchangers: the absorber, evaporator, condenserand second-stage (low temperature) generator, all housedin a single carbon steel shell divided into low pressureand intermediate pressure sections. The shell is fabricatedfrom formed carbon steel plates with fusion weldedseams. Carbon steel tube sheets, drilled and reamed toaccommodate the tubes, are welded to the end of theshell. Intermediate tube supports are fabricated of carbonsteel plates. Each tube is roller expanded into the tubesheets to provide a leak tight seal; each tube is individuallyreplaceable. The solution side of the shell is designed fora working pressure of 60 mm Hg absolute.The portion of the main shell opposite the generatorhouses the low pressure section of the machine whichincludes the evaporator and the absorber. Both the absorberand the evaporator are drip-type heat exchangerswith 5/8” (16 mm) OD, 0.025” (0.635 mm) wall, coppertubing for the 14SC and 3/4” (19 mm) OD, .028” (0.71mm) wall copper tubing for the 16SL and larger. Tubes areexternally enhanced where necessary to achieve desirecapacity. The absorber and evaporator are separated byfinned eliminator baffles designed to allow only water inthe vapor state to pass to the absorber.The side of the main shell closer to the generator containsthe intermediate pressure section of the machine consistingof the condenser and second-stage generator. Thesecond-stage generator is a drip-type heat exchangerwith 5/8” (16 mm), 0.025” (0.6 mm) wall, copper tubingfor the 14SC, and 3/4” (19 mm) OD, 0.028 (0.7 mm) wallfor the 16SL and larger. Generator and condenser areseparated by baffling which prevents liquid carryover tothe condenser. Condenser tubing is 5/8” (15.9 mm) 0.025”(0.6 mm) wall copper tubing for the 14SC, and 3/4” (19.05mm) OD, 0.028” (0.7 mm) wall for the 16SL and larger.The removable compact water boxes are fabricated ofsteel. The design working pressure is 150 PSIG (10.3 bar)and the boxes are tested at 225 PSIG (15.5 bar). Integralsteel water baffles are located and welded within the waterbox to provide the required pass arrangements. Stub-outwater nozzle connections with ANSI/AWWA C-606-stylegrooves are welded to the water boxes. These nozzlesare suitable for ANSI/AWWA C-606 couplings, welding orflanges, and are capped for shipment. Plugged vent anddrain connections and lifting lugs are provided on eachwater box.FIRST-STAGE GENERATORThe first-stage generator is a single flooded shell and tubeheat exchanger. The shell side is fabricated from carbonsteel plate with fusion welded seams, and is designed fora working pressure of 13.5 psia (0.9 bar) (the unit burstingdisk is designed to fail at 10 PSIG (0.7bar)). Carbon steeleliminator baffles laid out in a serpentine fashion preventsolution carryover over with the refrigerant vapor. Thegenerator has a single drilled and reamed carbon steeltube sheet and uses a “U” shaped tube bundle to minimizethermal stress. The “U” tubes are 5/8” (16 mm) OD, .035”(0.9 mm) wall, 70/30” cupro-nickel and are roller expandedinto the tube sheets. The tube side of the generator isdesigned for working pressures up to 150 PSIG (10.3 bar)and is ASME approved and stamped in accordance withASME Boiler and Pressure Vessel Code, Section VlII. Thehigh temperature generator contains a solution float valvewhich controls the level of solution in the generator. Thislimits the amount of sensible heating at part load conditions,resulting in much better performance.SOLUTION HEAT EXCHANGERThe solution heat exchanger is a shell and tube designwith geometrically-enhanced 5/8” (16 mm) OD for the14SC and 0.58” (14.7 mm) OD for the 16SL and larger,90/10 cupro-nickel tubing. The shell is formed from carbon8 JOHNSON CONTROLS
FORM 155.19-EG3 (1108)steel plate with fusion welded seams. Tubes are rollerexpanded into carbon steel tube sheets.DRAIN COOLERSYPC Absorption steam units come equipped with a condensatedrain cooler, eliminating the need for a separatecondensate cooler on the job site. Each drain cooler is ashell and tube heat exchanger with a tube side DWP of150 PSIG (10.3 bar) and a shell side DWP of 29 PSIG(2 bar). The drain cooler is fabricated from rolled carbonsteel plate with welded seams. Tubes are 5/8” (16 mm)OD, .030” (0.8 mm) wall, 90/10 cupro-nickel and are geometricallyenhanced to minimize heat stress. Each tubeis roller expanded into a drilled and reamed carbon steeltube sheet.PUMPSSolution and refrigerant pumps are hermetically sealed,self-lubricating, totally enclosed, liquid cooled, factory-mounted,wired and tested. Motor winding are notexposed to LiBr or water. The suction and dischargeconnections for each pump are fully welded to the jointpiping to minimize the opportunity for leaks. Suction anddischarge connections are also equipped with factoryinstalled isolation valves to permit quick and easy servicingof pumps. All YPC units include two solution pumpsand a refrigerant pump. Pumps are designed to operatefor a total of 55,000 operating hours between serviceinspections.VALVESAll valves used for adjusting the solution are fully weldedor brazed to prevent leakage of air into the unit. Valveoperators are covered with a seal cap to eliminate thepossibility of air leakage through the stem. Additionally, allconnections of valves to unit piping are fully welded.SOLUTION AND REFRIGERANTEach YPC unit is charged with lithium-bromide (LiBr)solution with non-toxic lithium molybdate as a corrosioninhibitor. Refrigerant is deionized water. A small amountof 2-ethyl hexanol is added as a heat and mass transferenhancer.PURGE SYSTEMThe purge system automatically and constantly removesnoncondensible vapors generated in the absorption processthorough the use of a eductor. Noncondensibles arethen stored in a purge chamber until they can be removedthrough the use of a purge pump. The purge pump is anoil, rotary, two-stage vacuum pump with a 1/4 HP, 3-Phase,ODP motor.The chiller control panel includes a SmartPurge systemthat will automatically sense the amount of non-condensiblesin the purge chamber and empty the tank whenevernecessary. The SmartPurge system eliminates the needfor an operator to ever manually empty the purge chamber.In addition, the control panel monitors the frequencyof purge cycles and alerts the chiller operator through aunique control panel warning message if the number ofpurges exceeds normal levels.CAPACITY CONTROLCapacity control is accomplished by modulating the steamvalve position. The YPC Steam-Fired unit is capable ofmodulating capacity from 20% to 100%.The YPC chiller design incorporates a float valve thatlimits solution flow to the generator as the cooling load decreases.This maintains optimum solution level throughoutthe operating range. In addition, manual control valves areused by YORK technicians in the factory and/or at start-upto fine tune solution and refrigerant flows to match the jobsite needs at peak efficiency.POWER PANELThe power panel enclosure includes the following: singlepoint wiring connection for the incoming power supply;non-fused disconnect switch; motor starters, completewith current and thermal-overload protection for solutionpump(s), refrigerant pump, and purge pump (currentoverloads only); 115VAC 50/60 Hz control power transformer.MICROCOMPUTER CONTROL CENTERThe microprocessor-based control center is factory-mounted,wired and tested. The electronic panel automaticallycontrols the operation of the unit in meeting system coolingrequirements while minimizing energy usage. Chilleroperating parameters are sensed by either thermistorsor transducers and displayed on the keypad. All pressuresare taken as absolute to alleviate typical gaugepressure inaccuracies. Temperatures and pressures canbe displayed in English (F, PSIA) or metric (C, KPa) unitsdepending on the application. Display of all informationis shown in the English language on a 40-character alphanumericdisplay.Available operating information includes return/leavingchilled water temperatures, return/leaving tower watertemperatures, first-stage generator pressure and temperature,refrigerant and solution temperatures, operatinghours, steam valve position and number of starts andpurges.JOHNSON CONTROLS9
Page 1 and 2: FORM 155.19-EG3 (1108)Model YPC Two
Page 3 and 4: IntroductionFORM 155.19-EG3 (1108)M
Page 5 and 6: FORM 155.19-EG3 (1108)4. CondenserR
Page 7: FORM 155.19-EG3 (1108)WARNING CONDI
Page 11 and 12: Optional FeaturesFORM 155.19-EG3 (1
Page 13 and 14: FORM 155.19-EG3 (1108)start/stop fl
Page 15 and 16: FORM 155.19-EG3 (1108)limit switch
Page 17 and 18: DimensionsFORM 155.19-EG3 (1108)YOR
Page 19 and 20: Nozzle Arrangement 16SL and LargerF
Page 21 and 22: FORM 155.19-EG3 (1108)PURGING SYSTE
Page 23 and 24: FORM 155.19-EG3 (1108)Remote reset

Model YPC Two-Stage Steam-Fired Absorption ... - Usair-eng.com

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