A Heat exchanger surface area [m2]
Aabs Outer area of the absorber [m2]
Ac Collector aperture area [m2]
APP Approach point[°C]
C Capital cost [$]
Cc Concentration ratio
Cpa Specific heat of the air in the compressor section
\({\overset{\overline{}}{C}}_{\text{pg}}\) Mean specific heat of the exhaust gases in the HRSG [J/kg.K]
CpHTF Heat capacity of the Heat transfer fluid HTF [kJ/kg.K]
DNI Direct normal irradiation [W/m2]
F Correction factor
h Enthalpy [kJ/kg]
hs Steam enthalpy [kJ/kg]
hw Water enthalpy [kJ/kg]
LCOE Levelized cost of energy [$/kWh]
\(f\) fuel by air ratio
\({\dot{m}}_{a}\) Air mass flow [kg/s]
\({\dot{m}}_{f}\) Fuel mass flow [kg/s]
\({\dot{m}}_{g}\) Mass gas flow [kg/s]
\({\dot{m}}_{s}\) Steam mass flow [kg/s]
\({\dot{m}}_{\text{SF}}\) HTF mass flow rate [kg/s]
NL Number of line in the solar field
\(P_{a}\) Atmospheric pressure [bar]
pp Pinch point [°C]
Q Heat exchanger duty [W]
\(Q_{a}\) Assumed duty [W]
\(Q_{\text{PTC}}\) Useful energy gained by the collector per unit of time [MW]
\(L_{\text{cv}}\) Natural gas calorific value [kJ/kg]
\(Q_{\text{SF}}\) Total useful energy gained in the SF per unit of time [MW]
PFP Pressure feed pump
PSPT Steam turbine output [MW]
PGT Gas turbine output [MW]
sfc specific fuel consumption of the gas turbine [kJ/kg]
ST Solar time [hour]
T Temperature [K]
Ta Ambient temperature [°C]
Tabs Mean absorber pipe temperature [°C]
Ts Steam temperature [°C]
Tsat Water saturation temperature [°C]
U Overall heat transfer coefficient [W/m2 K]
UA Product of U and surface area A [W/K]
Uabs Absorber thermal loss coefficient [W/m2 K]
ΔTpp Pinch point [°C]
ΔTap Approach point  [°C]
∆TSF Temperature difference between inlet and outlet of HTF [°C]
TLM Logarithmic mean temperature difference [°C]