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To view the Trough System Costs page, click Parasitics on the main window's navigation menu. Note that for the trough input pages to be available, the technology option in the Technology and Market window must be Concentrating Solar Power - Dish Stirling System.
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The input variables on the Parasitics page are used to calculate the compression space temperature and the electrical power consumption of pumps, cooling fans, and tracking controls.
The relevant sections of the thesis Stirling Dish System Performance Prediction Model (Fraser 2008) https://www.nrel.gov/analysis/sam/pdfs/thesis_fraser08.pdf (4.1 MB) are:
| • | 2.5 Cooling System, p 55 |
| • | 3.4 Cooling System Analysis for Total System Optimization, p 92 |
| • | Appendix A: TRNSYS Parasitic Power Model, p 158 |
Input Variable Reference
Parasitic Parameters
Variable
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Description
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Units
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Control System Parasitic Power, Avg.
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Average power required by the tracking control system.
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W
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Cooling System Pump Speed
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Cooling fluid pump operating speed. Used to calculated parasitic losses due to cooling fluid pumping.
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rpm
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Cooling System Fan Speed 1
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Fan operating speed when the cooling fluid temperature is less than the fan speed 2 cut-in temperature below.
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rpm
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Cooling System Fan Speed 2
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Fan operating speed when the cooling fluid temperature is greater than the fan speed 2 cut-in and less than fan speed 3 cut-in temperature below.
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rpm
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Cooling System Fan Speed 3
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Fan operating speed when the cooling fluid temperature is greater than fan speed 3 cut-in temperature below.
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rpm
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Cooling Fluid Temp. for Fan Speed 2 Cut-In
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Cooling fluid temperature set point. Used to determine fan operating speeds.
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°C
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Cooling Fluid Temp. for Fan Speed 3 Cut-In
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Cooling fluid temperature set point. Used to determine fan operating speeds.
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°C
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Cooling Fluid Type
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Fluid used in the cooling system. Options are water, 50% ethylene glycol (EG), 25% ethylene glycol, 40% propylene glycol (PG), and 40% propylene glycol. Percentages are by volume.
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--
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Cooler Effectiveness
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Used to calculate working fluid temperatures in the cooling system as part of the compression space temperature calculation.
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--
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Radiator Effectiveness
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Used to calculate cooling fluid temperature at the cooling system outlet as part of the compression space temperature calculation.
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‘b_cooler’ Parameter
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‘b_radiator’ Parameter
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