RHSpH:
--------------------------------------------------------------------------
Simulates a simple model of a pH process. The process consists of an
acid (HNO3) stream, buffer (NaHCO3) stream, and base (NaOH) stream that
are mixed in a stirred tank. The chemical equilibria is modeled by
introducing two reaction invariants for each inlet stream.
+ - - =
wAi = [H ]i - [OH ]i - [HCO3]i - 2[CO3]i
- =
wBi = [H2CO3]i + [HCO3]i + 2[CO3]i
--------------------------------------------------------------------------
Form:
xDot = RHSpH( x, t, d )
--------------------------------------------------------------------------
------
Inputs
------
x (3,1) State [wA4;wB4;h] h is liquid level
t (1,1) Time
d (1,1) Structure
.wA1 (1,1) See above
.wA2 (1,1)
.wA3 (1,1)
.wB1 (1,1)
.wB2 (1,1)
.wB3 (1,1)
.pK1 (1,1) Base 10 log of equilibrium constant
.pK2 (1,1) Base 10 log of equilibrium constant
.a (1,1) Crosssectional area of mixing tank
.cV (1,1) Valve coefficient
.n (1,1) Valve exponent
.z (1,1) Vertical distance between bottom of
tank and outlet of effluent
.q1 (1,1) Volumetric flow of HNO3
.q2 (1,1) Volumetric flow of NaHCO3
.q3 (1,1) Volumetric flow of NaOH
-------
Outputs
-------
xDot (3,1) State derivative
--------------------------------------------------------------------------
Reference: Henson, M. A. and D. E. Seborg. (1997.) Nonlinear Process
Control, Prentice-Hall. pp. 207-210.
--------------------------------------------------------------------------
