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Westmead International School
College of Engineering
Nuclear Power Plant Design Project
COMPUTATION FOR THERMAL EFFICIENCY
~TURBINECOMPRESSOR
2
1
RECUPERATOR
3
4
5
6
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Westmead International School
College of Engineering
Nuclear Power Plant Design Project
3
1
2
4
5
6
T
S
T-S DIAGRAM FOR HELIUM MODULAR HIGH TEMPERATURE GAS COOLED
REACTOR
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8/12/2019 Thermal Efficiency Computation
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Westmead International School
College of Engineering
Nuclear Power Plant Design Project
MHTGR @ Direct Cycle Nuclear Power Plant
Reactor Power 250MWe
Fuel Type Peeble Bed
Core Temperature (In/Out) 576/8500C or 849/1123K
Core Coolant Flow rate 245.6kg/s
Core Coolant Pressure 8Mpa
Turbine Inlet Pressure 7.80Mpa
Turbine Efficiency (nt) 93%
Turbine Cycle Pressure Ratio 2.2
Turbine Inlet Temperature 8500C
Turbine Flow rate 245.6kg/s
Compressor Efficiency (nc) 89%
Helium Specific Heat Ratio 1.66
Cycle Pressure Drop 0.07
Compression Ratio 1.85Ratio of Specific Heat for He 1.66
Recuperator effectiveness 95%
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Westmead International School
College of Engineering
Nuclear Power Plant Design Project
Thermal Efficiency FormulaAnalysis of a Helium Brayton Power
Cycle for Direct Drive IFE Power Reactor (From
R.Schleicher, R.Raffray, C. Wong 2001)
[ ]
Where:
Tin - temperature out
Toutminimum cycle temperature
coverall compression ratio
( ) rpindividual component compressor ratio
nc/ntadiabatic efficiencies of compressor/turbine
P/Poutcycle pressure drop
recu - recuperator effectiveness
Ratio of specific heats (Cp/Cv)
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Westmead International School
College of Engineering
Nuclear Power Plant Design Project
Solving for Overall Compression Ratio
( )
Solving for the Thermal Efficiency
[ ]
[ ]
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Westmead International School
College of Engineering
Nuclear Power Plant Design Project
Therefore, Thermal Efficiency of the Cycle is:
Note:
Thermal Efficiency computation of the Helium Brayton Power Cycle
for a Direct Drive can only be calculated by
using the above equation by R. Schleicher, R. Raffray, C. Wong
(2001).
CATT2 Software is not applicable for the design of nuclear power
plant since thermodynamic properties for Helium
is not available.
