Presentation on theme: "Waste Heat Generator (WHG)"— Presentation transcript:
0 2010 Regional Distributor Review & Conference Organic Rankine Cycle (ORC) Waste Heat Generator (WHG) Presented by Grant Terzer and Marc Rouse2010 Regional Distributor Review & ConferenceAmericasJune 14-17, 2010
1 Waste Heat Generator (WHG) Converts waste heat into electricityCapable of using ‘low grade’ waste heatWaste Heat Generator (WHG)
2 Turbines Devices that convert fluid flow into work Gas turbine Working fluid is combustion products and airWater turbine (hydro)Working fluid is waterSteam turbineRankine Cycle – water is boiled to vapor before passing through turbineWorking fluid is water vapor (steam)
3 Rankine Cycle Thermodynamic cycle which converts heat into work Working fluid is often steamRequires high temperatures to vaporize water80% of all power in the world is produced with this technologyLow Temperature heat sources produce little useable steamInherent problem is high latent heat of water in liquid-vapor phase changeCONDENSERWater
4 Organic Rankine CycleFor many (low temperature) waste heat applications, we need a fluid that boils at a lower temperature than waterHistorically, such fluids have been hydrocarbons - hence the name OrganicModern Working Fluids include: Propane / Pentane / Toluene / HFC-R245faThese Working Fluids allow use of Lower-Temperature Heat Sources because the liquid-vapor phase change, or boiling point, occurs at a lower temperature than the water-steam phase change
5 Waste Heat SourcesWaste heat is any source of otherwise unused heat – that is why ‘fuel’ is freeWaste heat from MicroTurbine exhaustWaste heat from industrial processesProcess stacks from drying or heating processesHeat from waste fuelBiomass or Biogas is burned to produce heat directlyNot waste heatA boiler creates heat for vaporization in a closed loop system – not free fuel
6 Integrated Power Module Evaporative Condenser The Complete SystemIntegrated Power ModuleGenerate125 kWR245faHeat Source375F (190C)3 MBTU/HEvaporative CondenserEvaporatorPump
7 Integrated Power Module Evaporative Condenser How it Works - 1Integrated Power ModuleGenerate125 kWR245faLiquid85F (29C)26psig (1.8bar)Heat Source375F (190C)3 MBTU/HEconomizerEvaporative CondenserEvaporatorLiquid85F (29C)230psig (16bar)ReceiverPumpThe working fluid is in the receiver as a liquid at the condensing pressure and temperature. It enters the pump where the working fluid’s pressure is raised to the evaporating pressure.
8 Integrated Power Module Evaporative Condenser How it Works - 2Integrated Power ModuleGenerate125 kWR245faLiquid85F (29C)26psig (1.8bar)Heat Source375F (190C)3 MBTU/HEconomizerEvaporative CondenserLiquid118F (48C)220psig (15bar)EvaporatorLiquid85F (29C)230psig (16bar)ReceiverPumpThe working fluid passes through a heat exchanger (Economizer) to take heat out of the gas leaving the Integrated Power Module. This improves system efficiency. The working fluid is now a warmer, high pressure liquid.
9 Integrated Power Module Evaporative Condenser How it Works - 3Integrated Power ModuleGenerate125 kWR245faVapor240F (115C)220psig (15bar)Heat Source375F (190C)3 MBTU/HLiquid85F (29C)26psig (1.8bar)EconomizerEvaporative CondenserLiquid118F (48C)220psig (15bar)EvaporatorLiquid85F (29C)230psig (16bar)ReceiverPumpThe working fluid enters the Evaporator, where the working fluid is exposed to waste heat which evaporates the fluid to a high pressure vapor.9
10 Integrated Power Module Evaporative Condenser How it Works - 4Integrated Power ModuleGenerate125 kWR245faVapor240F (115C)220psig (15bar)Vapor145F (63C)26psig (1.8bar)Liquid85F (29C)26psig (1.8bar)Heat Source375F (190C)3 MBTU/HEconomizerEvaporative CondenserLiquid118F (48C)220psig (15bar)EvaporatorLiquid85F (29C)230psig (16bar)ReceiverPumpThe working fluid (now a vapor) enters the turbine of the IPM. The working fluid’s pressure drops across the turbine to the condensing pressure, spinning the turbine (which is connected to the generator) in the process. The driving force is the pressure difference across the turbine.
11 Evaporative Condenser How it Works - 5R245faVapor240F (115C)220psig (15bar)Vapor85F (29C)26psig (1.8bar)Vapor145F (63C)26psig (1.8bar)Liquid85F (29C)26psig (1.8bar)Heat Source375F (190C)3 MBTU/HEconomizerEvaporative CondenserLiquid118F (48C)220psig (15bar)EvaporatorLiquid85F (29C)230psig (16bar)ReceiverPumpThe working fluid still has an enormous amount of heat, some of which is transferred to the pumped liquid in the economizer. This helps in two ways: 1) this heat would have otherwise been extracted in the condenser and; 2) there is less heat required at the evaporator due to the liquid being pre-warmed.1111
12 Evaporative Condenser How it Works - 6Vapor85F (29C)26psig (1.8bar)R245faVapor240F (115C)220psig (15bar)Vapor85F (29C)26psig (1.8bar)Vapor145F (63C)26psig (1.8bar)Liquid85F (29C)26psig (1.8bar)Heat Source375F (190C)3 MBTU/HAmbient Air 75F (24C)Wet BulbEconomizerEvaporative CondenserLiquid118F (48C)220psig (15bar)EvaporatorLiquid85F (29C)230psig (16bar)ReceiverPumpThe working fluid (still a vapor) then flows to the condenser where heat is extracted and the working fluid condenses to a liquid.
13 Evaporative Condenser How it Works - 7Vapor85F (29C)26psig (1.8bar)R245faVapor240F (115C)220psig (15bar)Vapor85F (29C)26psig (1.8bar)Vapor145F (63C)26psig (1.8bar)Liquid85F (29C)26psig (1.8bar)Heat Source375F (190C)3 MBTU/HAmbient Air 75F (24C)Wet BulbEconomizerEvaporative CondenserLiquid118F (48C)220psig (15bar)EvaporatorLiquid85F (29C)230psig (16bar)ReceiverPumpThe low pressure, liquid working fluid drains back to the receiver and is ready to be pumped to high pressure and flow towards the integrated power module.
14 Applications Turbines Exhaust Industrial Stack Gas Waste heat from exhaustIndustrial Stack GasRefineriesIncineratorsDrying processes
15 Applications Geothermal Solar Thermal Water or Steam After steam processIndirect evap source
16 The ORC Power Skid Capstone supplies the ORC ‘Power Skid’ Includes electronics, receiver, economizer, power module and various pumpsNeeds external evaporator and condenser
17 Power Skid Fluid Connections Hot Vapor from EvaporatorCool Liquid from CondenserWarm Liquid to EvaporatorWarm Vapor to Condenser
18 Integrated Power Module Power Skid ComponentsIntegrated Power ModuleInlet Control ValveSlam ValveSeparatorProgrammable Logic Controller (PLC) & Magnetic Bearing Controller (MBC)ReceiverField ConnectionsPowerElectronicsBypass ValveVFD for PumpEconomizerSeparator Drain ValvePump
19 Power Skid Specs Turbine Expander and Generator Hermetically sealed power module – no leaksMagnetic Bearings – no lubricants26,500 rpm – no vibrationPower electronics – 125 kWGrid Connect onlyV, 3 phase, 3 wire 50/60 HzWorking fluid HFC-R245faDry weight 7,000 lbs46” w x 112” l x 79.5” h
20 EvaporatorTransfers waste heat energy to refrigerant, resulting in vaporizationDirect, heat transfers directly from the waste heat source to the working fluidLikely choice for a Microturbine application where waste temperatures are low and exhaust stream is cleanHeat source needs to be near ORCIndirect, thermal transfer medium is used between the heat source and the working fluid (e.g. thermal oil, hot water, steam)Requires more ancillary equipmentLess efficient overallGood fit if heat source is far from ORC
21 CondenserRejects latent heat of working fluid, resulting in condensationDirect – The working fluid passes through a heat exchanger that rejects heat directly to the environment.Indirect – A medium such as water is passed through a heat exchanger and takes the rejected heat out of the working fluid. The medium then transfers the heat somewhere else.Cooling towers, air cooled condenser (Dry Cooler), ground water, evaporative condenserCooling towers (if already existing) and direct evaporative condensers are likely the best match for MicroTurbine applications
22 Installation Considerations Evaporator & Condenser must be within 50ft of the ORC power skidMinimize refrigerant run lengthMinimize heat loss / absorptionMinimize amount of R245fa usedCondenser must be elevated (flow to receiver)Qualified technician required to handle R245faInternal cleanliness (of R245fa loop) important
24 Heating, Cooling, PowerCycle effectiveness is determined by the heat source and condensing sourceDetermine total heat and temperature availableDetermine total cooling availablePower available is determined by multiplying the heat available by the cycle effectivenessMore heat available => less cooling requiredLess heat available => more cooling required
25 Available Power Output More heat is required for a given power production as condensing temp increases.Size heat source and condenser for ambient conditions.125kW nominal is at generator terminals (inverter loss approx. 8 kW)
26 ORC with MicroTurbines Typical MicroTurbine implementation6 to 8 Capstone C65 MicroTurbinesOne ORC WHG Power SkidOne direct MT exhaust to refrigerant heat exchangerOne direct evaporative cooling tower or piggyback on existing cooling tower.
27 Free Electricity? Or, how to build a ORC WHG value proposition System uses low grade heat that is usually wasted – no other good useIncrease overall efficiency of systemsConsumes no additional fuelProduces no additional emissionsWasted energy into electric power mayReduce demand chargesCapture carbon creditsQualify for renewable energy incentives
28 Calculating New Efficiency Using waste heat to generate electric power increases overall system efficiencyLow grade waste heat is used, so assume it can not be used for any other purposeExample, 6 Capstone C65sProduce 390kW at 29% Electric EffA 125kW ORC WHG is addedAssume net output is 110kW (due to system losses, heat source and condensing source.500kW is produced, using no added fuelnew efficiency is(New power/old power)*old Efficiency = 37%The ORC increases electric efficiency to over 37%
29 Case StudyBiomass boiler test site in the south east USA.
30 Case Study Payback Free fuel and low Maintenance Cost provide payback Annual Run Hours ,400Net Electrical Output kWeAnnual Production ,400 x 107 = 898,800 kWhGross Revenue ,800 x $0.18 = $161,784Maintenance Cost 898,800 x $ = $6,741Net Annual Revenue $155,043Cost of Project $298,000Simple Payback < 2 years
31 Technology Advantages Very similar to those of Capstone MicroTurbinesHigh Speed GeneratorIncreased Efficiency, Reliability, no gear boxMagnetic BearingsIncreased Efficiency, Reliability, Reduced lossesPower ElectronicsEfficient variable speed operationNo lubrication or lubrication systemIncreased Reliability, Reduced parasitic losses, No contamination of process fluidNo couplingIncreased reliability, fewer componentsVariable speed operationOptimized cycle efficiency operating pointHermetically sealedHigher reliability, fewer wear componentsSingle moving partIncreased reliabilityModular DesignSimple Integration into system (like standard piping)
32 For More InformationContact Capstone Applications or Sales