from pyXSteam.XSteam import XSteam
import matplotlib.pyplot as plt

steamTable = XSteam(XSteam.UNIT_SYSTEM_BARE)

batch_time = 5  # timmar

dm_eth = 11.37  # [m^3/h]
T1 = [74.3, 72, 70, 75, 70]  # [C] dynamisk
T2 = [13, 14, 15, 13, 12]  # [C] dynamisk
P2 = 0.3  # MPa

dQ_C_list = []
dQ_H_list = []


def heat_sink(P2, h2, dm_h2o):  # Function heat sink
    h3 = steamTable.hL_p(P2)
    dQ_H = dm_h2o*(h2-h3)  # [kW]
    return dQ_H


def heat_exchange(T1, T2):
    # density of ethanol
    den = 785.3  # kg/m^3

    # specific heat capacity {isobaric gas} should be dynamic
    c_eth = 2.18  # [kJ/kg K]

    # heat transferred to cooling agent
    dQ_C = dm_eth * c_eth * (T1 - T2) * den

    # enthalpy at saturated steam
    h_H = steamTable.hV_p(0.101325)

    s_L3 = steamTable.sL_p(0.3)
    s_low = s_L3

    h_low = steamTable.h_ps(0.101325, s_low)

    dm_h2o = dQ_C / (h_H-h_low)

    # entropy of water at atmospheric pressure
    s1 = steamTable.sV_p(0.101325)

    # entropy after compression given ideal conditions
    s2 = s1

    # enthalpy entering heat exchanger
    h2 = steamTable.h_ps(P2, s2)

    return dQ_C, h2, dm_h2o


for x in range(batch_time):
    dQ_C, h2, dm_h2o = heat_exchange(T1[x], T2[x])
    dQ_C_list.append(dQ_C)
    dQ_H_list.append(heat_sink(P2, h2, dm_h2o))


fig, ax = plt.subplots()
ax.plot(range(batch_time), dQ_C_list, '--o', label= 'Värmeöverföring Eth/kyl [kJ/timme]')
ax.plot(range(batch_time), dQ_H_list, '--o', label= 'Värmeöverföring kyl/ånga [kJ/timme]')
ax.set_xlabel('Tid [timme]')
ax.set_ylabel('Värmeöverföring [kJ/timme]')
ax.set_title('Kylbehov per timme under en körning')
ax.axis([0, batch_time, 0, 1.1*max(dQ_C_list)])
ax.legend()
plt.show()