TRNSYS SEGSVI Modeling Peter Schwarzbozl Scott Jones Bob Cable Robert Pitz-Paal Nathan Blair 1
Other Trough Models Luz system performance model KJC performance model Flagsol Easy Many more Complexity varies Simple model can give reasonable annual predictions More complexity required for shorter time scales Accurate modeling of temporal effects lacking Many Tower and Dish models also
TRNSYS Modeling objectives Flexibility in system models Model typical daily transients Detailed subsystem simulations Annual performance simulations Tool to evaluate performance and operation issues with thermocline storage systems that have been proposed Foster international collaboration, common basis for comparison Simulation environment University of Wisconsin Historically used for buildings, low-temperature solar Modular & Flexible Create new components Easily Create new systems by linking components (e.g. Hybrid) Both detailed and simplistic models possible Open environment moderate cost Windows graphical interface Version 15 a big improvement
STEC Library Solar Thermal Electric Component model library Developed by DLR and Being adopted by SolarPACES: Russians, CIEMAT, ANU involved State property models (ODE s) Not just energy Temperature, Pressure, Enthalpy
SEGS VI 3 MW Model Solar-only, no fossil burning modeled Detailed, quasi-steady state, property model of solar side and steam cycle Detailed model capable of simulating steady state operation and transients like startup, shutdown Steam cycle startup recirculation modeled Needed for accurate modeling of storage systems (e.g thermocline)
TRNSYS Schematic SEGSVI
Validation Comparison with measured plant data Emphasis was on short time scales Daily comparisons, not annual
July 18, 1991 Weather Ambient Temperature (C), Wind Velocity (m/s) 5 45 4 35 3 25 2 15 1 5 Temperature Wind Velocity DNI 1 9 8 7 6 5 4 3 2 1 DNI (W/m 2 ) 2 4 6 8 1 12 14 16 18 2 22 24
HTF Flow Rate July 18 1,8, 1,6, HTF Flowrate (kg/hr) 1,4, 1,2, 1,, 8, 6, 4, Measured Predicted 2, 2 4 6 8 1 12 14 16 18 2 22 24
HTF Temperatures 45 4 35 Tin Measured Tout Measured Tin Predicted Tout Predicted HTF Temperature (Deg. C) 3 25 2 15 1 5 2 4 6 8 1 12 14 16 18 2 22 24
HP Turbine Steam Temperatures 4 HP Turbine Temperature(Deg. C) 35 3 25 2 15 1 Tin Measured Tout Measured Tin Predicted Tout Predicted 5 2 4 6 8 1 12 14 16 18 2 22 24
HP Turbine Steam Pressures 9 8 7 Pin Measured Pout Measured Pin Predicted Pout Predicted HP Turbine Pressure (bar) 6 5 4 3 2 1 2 4 6 8 1 12 14 16 18 2 22 24
Gross Power Output 35 Gross Power Output (MW) 3 25 2 15 1 Measured Predicted 5 2 4 6 8 1 12 14 16 18 2 22 24
Parasitic Power Consumption 3.5 Parasitc Power Consumption (MW) 3. 2.5 2. 1.5 1. Measured Predicted.5. 2 4 6 8 1 12 14 16 18 2 22 24
September 19, 1991 Weather 5 1 45 Temperature 9 Amb. Temperature (C), Wind Velocity (m/s) 4 35 3 25 2 15 1 5 Wind Velocity DNI 8 7 6 5 4 3 2 1 DNI (W/m 2 ) 2 4 6 8 1 12 14 16 18 2 22 24
HTF Flow Rate 1,8, 1,6, HTF Florate (kg/hr) 1,4, 1,2, 1,, 8, 6, Measured Predicted 4, 2, 2 4 6 8 1 12 14 16 18 2 22 24
HTF Temperatures 45 4 35 Tin Measured Tout Measured Tin Predicted Tout Predicted HTF Temperature (Deg. C) 3 25 2 15 1 5 2 4 6 8 1 12 14 16 18 2 22 24
HP Turbine Steam Temperatures 4 HP Turbine Temperature (Deg. C) 35 3 25 2 15 1 Tin Measured Tout Measured Tin Predicted Tout Predicted 5 2 4 6 8 1 12 14 16 18 2 22 24
HP Turbine Steam Pressures 9 8 7 Pin Measured Pout Measured Pin Predicted Pout Predicted HP Turbine Pressure (bar) 6 5 4 3 2 1 2 4 6 8 1 12 14 16 18 2 22 24
Gross Power Output 3 Gross Power Production (MW) 25 2 15 1 5 Measured Predicted 2 4 6 8 1 12 14 16 18 2 22 24
Parasitic Power Consumption 2.5 Measured Parasitic Power Consumption (MW) 2. 1.5 1..5 Predicted. 2 4 6 8 1 12 14 16 18 2 22 24
Gross Energy Production 35 3 Measured Predicted 25 Electric Power (MWh) 2 15 1 5 Gross Energy Production Parasitic Energy Consumption
Improved Trough Model New model still under development HTF residence time in trough loop (1 min 6 minutes) Field piping residence time Currently model field thermal capacitance in the expansion vessel SEGSVIII (and new plants?) have exp. vessel downstream of SGS Accuracy required for storage modeling
Remaining Work Fine tune system parameters Advanced trough model Controls issues