Numerical simulations of evacuated- tube solar collectors - School of ...
Numerical simulations of evacuated- tube solar collectors - School of ... Numerical simulations of evacuated- tube solar collectors - School of ...
Numerical simulations of evacuatedtubesolar collectorsGerardo DiazSchool of Engineering,University of California, MercedDan David FoundationSolar Energy: Today and TomorrowSeptember 26, 2008
- Page 2 and 3: Configurations of Evacuated-Tube So
- Page 4 and 5: Thermal Analysis for each Configura
- Page 6 and 7: Design #3 - Metal absorber with gla
- Page 8 and 9: Future DirectionsMinichannel and mi
- Page 10: Q & A
<strong>Numerical</strong> <strong>simulations</strong> <strong>of</strong> <strong>evacuated</strong><strong>tube</strong><strong>solar</strong> <strong>collectors</strong>Gerardo Diaz<strong>School</strong> <strong>of</strong> Engineering,University <strong>of</strong> California, MercedDan David FoundationSolar Energy: Today and TomorrowSeptember 26, 2008
Configurations <strong>of</strong> Evacuated-Tube Solar Collectors(a)(c)(a) (b) (c) (d)U-TubeCounterflowHeatpipeAll glassDewar
Heat InputA ray trace analysis was performed using TracePro optical modeling s<strong>of</strong>tware(a)(b)
Thermal Analysis for each Configuration
Design #1 - All glass dewar: Direct FlowDirect Flow Dewar0.700Collector Efficiency0.6000.5000.4000.3000.200e = 0.05e = 0.100.1000.00050 75 100 125 150 175 200Collector Inlet Temperature (C)Design #2 - All glass dewar: Indirect Flow -- Dewars filled with thermal fluid0.600Dewar with FluidRed: Highly Conductive FluidBlue: Paraffinic Hydrocarbon Fluid0.500Collector Efficiency0.4000.3000.200e = 0.05e = 0.10e = 0.05e = 0.100.1000.00050 75 100 125 150 175 200Collector Inlet Temperature (C)
Design #3 - Metal absorber with glass-to-metal seal0.700Glass-to-Metal Seal TubeBlue: copper fin thickness <strong>of</strong> 0.2mmRed: copper fin thickness <strong>of</strong> 0.6mmGreen: copper fin thickness <strong>of</strong> 1.2mm0.600e = .050.500e = 0.10e = 0.05Collector Efficiency0.4000.300e = .10e = 0.05e = 0.100.2000.1000.00050 75 100 125 150 175 200Collector Inlet Temperature (C)
Model validation (U-<strong>tube</strong>)160 g/s140 g/sThermal efficiency0.70.650.60.550.50.450.4Eff160Model160Thermal efficiency0.70.650.60.550.50.450.4Eff140Model1400 50 100 150 200 2500 50 100 150 200 250T_average [oC]T_average [oC]120 g/s100 g/sThermal efficiency0.70.60.50.40.30 50 100 150 200 250Eff120Model120Thermal efficiency0.70.60.50.40.30 50 100 150 200 250Eff100Model100T_average [oC]T_average [oC]
Future DirectionsMinichannel and microchannel-based <strong>solar</strong> <strong>collectors</strong>WHPorts(a)Webs(b)Aluminum Minichannel Condenserversus RTPF CondenserEqual Capacity: 7 kW
Proposed DesignEvacuatedglass <strong>tube</strong>Mini-channelsSelectivecoating0.760.740.720.70.680.660.640.620.60 50 100 150 200Efficiency Round-TubeEfficiency M-C Tube No-Abs
Q & A
Change language