Add temperature correction factor to solution conductivity in REDstack.py

Author: tristantc

gdplib/reverse_electrodialysis/REDstack.py

@@ -79,6 +79,13 @@ def build_REDstack():
         mutable=True,
     )
 
+    m.temperature_coeff = pyo.Param(
+        doc='Temperature correction factor [-] of the solution conductivity',
+        default=0.02,
+        initialize=0.02,
+    )  # Mehdizadeh, et al. (2019) Membranes, 9(6), 73. https://doi.org/10.3390/membranes9060073
+    # Linear temperature dependence of the solution conductivity. The temperature coefficient of the solution conductivity is 0.02 K-1.
+
     m.pump_eff = pyo.Param(doc='Pump efficiency [-]', default=0.75, initialize=0.75)
 
     # =============================================================================
@@ -188,6 +195,7 @@ def iems_permsel_avg(m):
     m.vel_lb = pyo.Param(
         m.SOL, doc='Min. linear crossflow velocity [cm s-1]', initialize=0.01
     )
+
     m.vel_init = pyo.Param(
         m.SOL,
         doc='Min. linear crossflow velocity [cm s-1]',
@@ -710,6 +718,7 @@ def _ksol_b(m, x, sol):
         """
         This function sets the bounds of the solution conductivity based on the feed concentration in the high and low concentration compartments.
         The expression is derived from the linear regression of the experimental data.
+        Tristán et al. (2020) Desalination, 496, 114699. https://doi.org/10.1016/j.desal.2020.114699
 
         Parameters
         ----------
@@ -773,10 +782,11 @@ def _ksol(m, x, sol):
         m.SOL,
         domain=pyo.NonNegativeReals,
         bounds=lambda _, x, sol: (
-            m.ksol[x, sol].lb * (1 + 0.02 * (m.T - m.Tref)),
-            m.ksol[x, sol].ub * (1 + 0.02 * (m.T - m.Tref)),
+            m.ksol[x, sol].lb * (1 + m.temperature_coeff * (m.T - m.Tref)),
+            m.ksol[x, sol].ub * (1 + m.temperature_coeff * (m.T - m.Tref)),
         ),
-        initialize=lambda _, x, sol: m.ksol[x, sol] * (1 + 0.02 * (m.T - m.Tref)),
+        initialize=lambda _, x, sol: m.ksol[x, sol]
+        * (1 + m.temperature_coeff * (m.T - m.Tref)),
         doc="Temperature corrected sol. conductivity per unit length [S m-1]",
     )
 
@@ -1227,7 +1237,9 @@ def _sol_cond_T(m, x, sol):
         pyomo.Constraint
             The temperature corrected solution conductivity per unit length constraint
         """
-        return m.ksol_T[x, sol] == m.ksol[x, sol] * (1 + 0.02 * (m.T - m.Tref))
+        return m.ksol_T[x, sol] == m.ksol[x, sol] * (
+            1 + m.temperature_coeff * (m.T - m.Tref)
+        )
 
     @m.Constraint(
         m.length_domain,