2528df0f75
These changes make it unnecessary to copy header files around during the build process, which tends to confuse IDEs and debuggers. The headers which comprise Cantera's external C++ interface are now in the 'include' directory. All of the samples and demos are now in the 'samples' subdirectory.
94 lines
2 KiB
Python
94 lines
2 KiB
Python
#
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# A Rankine vapor power cycle
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#
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from Cantera import *
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from Cantera.liquidvapor import Water
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########################################################
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#
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# parameters
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#
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eta_pump = 0.6 # pump isentropic efficiency
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eta_turbine = 0.8 # turbine isentropic efficiency
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pmax = 8.0e5 # maximum pressure
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########################################################
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#
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# some useful functions
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#
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def pump(fluid, pfinal, eta):
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"""Adiabatically pump a fluid to pressure pfinal, using
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a pump with isentropic efficiency eta."""
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h0 = fluid.enthalpy_mass()
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s0 = fluid.entropy_mass()
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fluid.set(S = s0, P = pfinal)
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h1s = fluid.enthalpy_mass()
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isentropic_work = h1s - h0
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actual_work = isentropic_work / eta
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h1 = h0 + actual_work
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fluid.set(H = h1, P = pfinal)
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return actual_work
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def expand(fluid, pfinal, eta):
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"""Adiabatically expand a fluid to pressure pfinal, using
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a turbine with isentropic efficiency eta."""
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h0 = fluid.enthalpy_mass()
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s0 = fluid.entropy_mass()
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fluid.set(S = s0, P = pfinal)
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h1s = fluid.enthalpy_mass()
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isentropic_work = h0 - h1s
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actual_work = isentropic_work * eta
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h1 = h0 - actual_work
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fluid.set(H = h1, P = pfinal)
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return actual_work
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def printState(n, fluid):
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print '\n\n***************** State '+`n`+' ******************\n', fluid
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###############################################################
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# create an object representing water
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w = Water()
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# start with saturated liquid water at 300 K
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w.set(T = 300.0, Vapor = 0.0)
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h1 = w.enthalpy_mass()
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p1 = w.pressure()
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printState(1,w)
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# pump it adiabatically to pmax
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pump_work = pump(w, pmax, eta_pump)
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h2 = w.enthalpy_mass()
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printState(2,w)
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# heat it at constant pressure until it reaches the
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# saturated vapor state at this pressure
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w.set(P = pmax, Vapor = 1.0)
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h3 = w.enthalpy_mass()
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heat_added = h3 - h2
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printState(3,w)
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# expand back to p1
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turbine_work = expand(w, p1, eta_turbine)
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printState(4,w)
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# efficiency
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eff = (turbine_work - pump_work)/heat_added
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print 'efficiency = ',eff
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