OFWH.py

#!/usr/bin/env python
from model.State import State
from model.Turbine import Turbine
from model.Condensor import Condensor
from model.Reheater import Reheater
from model.Pump import Pump
from model.OFeedWater import OFeedWater

import util.plotting as plot

class OFWH(object):
    def __init__(self, t0, p0, p_1, t_1, p_2, eta_t, eta_p, p_cond, TL, TH):
        self.one = State('Water', P=p_1, T=t_1)
        self.one.define()
        self.two = State('Water', P=p_2)
        self.turb_one = Turbine(self.one, self.two)
        self.turb_one.isentropic(eta_t)
        self.turb_one.exergyBalance(p0, t0)

        self.three = State('Water', P=p_cond)
        self.turb_two = Turbine(self.two, self.three)
        self.turb_two.isentropic(eta_t)
        self.four = State('Water', P=p_cond)
        self.condensor = Condensor(p_cond, self.three, self.four)

        self.five = State('Water', P=p_2)
        self.pump_one = Pump(self.four, self.five)
        self.pump_one.isentropic(eta_p)
        self.six = State('Water', P=p_2, Q=0)
        if self.six.define():        
            y = ((self.six.properties['h']-self.five.properties['h'])
                /(self.two.properties['h']-self.five.properties['h']))
        else:
            print 'Failed to define state 6'
        self.y = y

        self.seven = State('Water', P=p_1)
        self.pump_two = Pump(self.six, self.seven)
        self.pump_two.isentropic(eta_p)
        self.pump_two.exergyBalance(t0, p0)
        self.turb_two.exergyBalanceY(t0, p0, y)
        self.pump_one.exergyBalanceY(t0, p0, y)
        self.superHeater = Reheater(self.seven, self.one)
        self.eta = (sum([self.turb_one.w, self.turb_two.w, self.pump_one.w, self.pump_two.w])/
                    sum([self.superHeater.q]))
        self.E = self.eta*(1/(1-float(TL)/float(TH)))
        self.ofwh = OFeedWater([self.two, self.five], [y, (1-y)], self.six, [1], t0, p0)


def ofwh(p_2):
    TL = 300
    TH = 650
    p_1 = 100*10**5 # Pa
    t_1 = 620 # K
    p_cond = 10*10**3 # Pa
    eta_t = 0.9
    eta_p = 0.95
    t0 = 300 # K
    p0 = 100*10**3 # P
    return OFWH(t0, p0, p_1, t_1, p_2, eta_t, eta_p, p_cond, TL, TH)

if __name__ == '__main__':
    pLow = 10*10**3
    pHigh = 100*10**5
    results = []
    int_p = []
    for x in range(pLow+1, pHigh-1, 10000):
        int_p.append(x/1000)
        results.append(ofwh(x))

    thermal = [res.eta for res in results]
    exergetic = [res.E for res in results]

    idx = thermal.index(max(thermal))
    print 'Max Thermal Efficiency of {} with an Intermediate pressure of {} kPa'.format(
            max(thermal), int_p[thermal.index(max(thermal))])
    print 'Max Exergetic Efficiency of {} with an Intermediate pressure of {} kPa'.format(
            max(exergetic), int_p[exergetic.index(max(exergetic))])
    print 'Turbine one: {}'.format(results[idx].turb_one.ef)
    print 'Turbine two: {}'.format(results[idx].turb_two.ef)
    print 'Pump One: {}'.format(results[idx].pump_one.ef)
    print 'Pump Two: {}'.format(results[idx].pump_two.ef)
    print 'Y {}'.format(results[idx].y)
    print 'CFWH: {}'.format(results[idx].ofwh.ef)

    plot.plotData('Thermal Efficiencies of a OFWH Cycle', 'Intermediate Pressure (kPa)',
                    'Thermal Efficiency', [int_p, thermal])
    plot.plotData('Exergetic Efficiencies of a OFWH Cycle', 'Intermediate Pressure (kPa)',
                    'Exergetic Efficiency', [int_p, exergetic])
    plot.plotComponent('OFWH Turbine One', [res.turb_one for res in results], int_p)
    plot.plotComponent('OFWH Turbine Two', [res.turb_two for res in results], int_p)
    plot.plotComponent('OFWH Pump One', [res.pump_one for res in results], int_p)
    plot.plotComponent('OFWH Pump Two', [res.pump_two for res in results], int_p)
    plot.plotComponent('OFWH Feed Water', [res.ofwh for res in results], int_p)