Abstract
A method of analysis of the stochastic behaviour of electrolyzers due to stationary random fluctuations in current and inlet electrolyte concentration is presented. The analysis is illustrated by means of a numerical example.
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Abbreviations
- c :
-
electrolyte concentration;c i inlet electrolyte concentration;c E exit electrolyte concentration (mol dm−3)
- F :
-
Faraday's constant (96487 C mol−1)
- I :
-
current (A)
- j :
-
imaginary unit = √(−1)
- K :
-
equivalent gain
- N(A) :
-
nonlinear function of amplitudeA of an independent variable
- n :
-
number of electrons participating in the electrode process
- P(z):
-
probability density function of random variablez
- Q :
-
electrolyte volumetric flow rate (dm3 min−1)
- R z(λ):
-
autocorrelation function
- S z(ω):
-
power spectrum of random variablez
- T 0,T 1 :
-
Frequency characteristic parameters (obtained from process reaction curve)
- u :
-
shorthand for the product αz 1 (see Equation 30)
- V :
-
active volume of electrolyzer (dm3)
- v :
-
shorthand for the product βz 2 (see Equation 30)
- χ:
-
dimensionless exit electrolyte concentration
- z 1 :
-
dimensionless electrolyte inlet concentration
- z 2 :
-
dimensionless current
- α:
-
lumped parameter defined as-c *i /c *E
- β:
-
lumped parameter defined asI */nFQc *E
- γ:
-
lumped parameter defined as aI */nFVc *E
- λ:
-
dummy' integration variable
- σ 2x :
-
variance (or mean power) of random variablez
- τ:
-
mean residence time in electrolyzer, equal toV/Q (min)
- ϕ(jω):
-
frequency spectrum
- ω:
-
angular frequency
- *:
-
steady state (superscript)
- erf:
-
error function, defined as\(erf (z) = \frac{2}{{\surd \pi }}\int_0^z {\exp ( - \lambda ^2 ) d\lambda }\)
- o:
-
step magnitude (superscript)
- H :
-
Heaviside's shifting function, defined asH(t−τ)=0 fort<τ;H(t−τ)=1 fort≥τ
- Γ:
-
gamma function, defined as\(\Gamma (z) = \int_0^\infty { \lambda ^{z - 1} } \exp ( - \lambda ) d\lambda\)
- CSTER:
-
acronym for continuous flow stirred tank electrolytic reactor
- PFER:
-
acronym for plug-flow electrolytic reactor
References
V. V. Solodovnikov, ‘Introduction to the Statistical Dynamics of Automatic Control Systems’, Dover, New York (1960).
V. S. Pugachev, ‘Teoriya Sluchainikh Funkciy’ (Random Function Theory) Fizmatgiz, Moscow (1960).
A. A. Pervozvanskii, ‘Random Processes in Nonlinear control Systems’, Academic Press, New York (1965).
J. H. Laning Jr. and R. H. Battin, ‘Random Processes In Automatic Control’, McGraw Hill, New York (1956).
H. W. Smith, ‘Approximate Analysis of Randomly Excited Nonlinear Controls’, MIT. Press, Cambridge, Mass. (1966).
D. Graham and D. McRuer, ‘Analysis of Nonlinear Control Systems’, Dover, New York (1961).
J. C. West, ‘Analytical Techniques for Non-Linear Control Systems’, Van Nostrand, Princeton, NJ (1960).
T. Z. Fahidy,J. Appl. Electrochem. 17 (1987) 57.
17 (1987) 841.
,Symp. Series, Inst. Chem. Engrs. (UK)112 (1989) 119.
Idem, J. Appl. Electrochem. The Effect of Random Perturbations On The Performance of Tank Electrolyzers, in press.
J.-C. Gille, M. J. Pélegrin and P. Decaulne, ‘Feedback Control Systems’, McGraw Hill, NY (1959).
K. H. Lee and T. Z. Fahidy,Instrum. Control Syst. 40 (1967) 141.
Y. Sawaragi, N. Sugai and Y. Sunahara, ‘Statistical Studies of Nonlinear Control Systems’, Nippon Printing and Publishing Co. Osaka, Japan (1962).
J. G. Ziegler and N. B. Nichols,Trans. ASME 64 (1942) 759.
C. L. Smith, ‘Digital Computer Process Control’, Intext Scranton PA (1972).
C. A. Smith and A. B. Corripio, ‘Principles and Practice of Automatic Process Control’, John Wiley and Sons, NY (1985).
G. H. Cohen and G. A. Coon,Trans. ASME 75 (1953) 827.
T. W. Weber, ‘An Introduction to Process Dynamics and Control’, John Wiley and Sons, NY (1973).
T. Z. Fahidy, ‘Principles of Electrochemical Reactor Analysis’, Elsevier, Amsterdam (1985).
R. W. Yeo and T. Z. Fahidy,Electrochim. Acta 31 (1986) 1397.
M. Klerer and F. Grossman, ‘A New Table of Indefinite Integrals’, Dover, New York (1971).
I. S. Gradshtein and I. M. Ryzhik, ‘Table of Integrals, Series and Products’, 2nd edition, Academic Press, New York (1980).
R. W. Yeo and T. Z. Fahidy,Electrochim. Acta 32 (1987) 277.
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Fahidy, T.Z. An analysis of random perturbations in electrolyzers. J Appl Electrochem 20, 901–906 (1990). https://doi.org/10.1007/BF01019563
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DOI: https://doi.org/10.1007/BF01019563