Spatial temperature profiles in an aluminum reduction cell under different anode current distributions

Abstract

The development of a thermal model to estimate energy distribution in an aluminum reduction cell and its impact on local conditions based on anode current signals are presented. In the Hall-He´roult process, routine practices carried out during operation give rise to spatial energy imbalances and consequently temperature variation in the cell. This phenomenon has been ignored in thermal models developed to date as they are only concerned with overall process dynamics. Implementing anode current signals as model inputs along with the discretization method allows the change of spatial conditions caused by current distribution to be calculated. Simulation studies have been performed to investigate the cell thermal balance affected by anode shorting. The article shows the potential of using anode current signals as model inputs to compute spatial thermal conditions based on the proposed model structure that are not considered in traditional modeling approaches. Figure 1. Schematic diagram of a reduction cell and a resistance network.where R sw and R L are the thermal resistance of the cell sidewall and the ledge, respectively. Resistance of the sidewall can vary due to the design of different cell technology. Figure 23. Deviation of ledge thickness d 0 , at upstream at the center of the cell (Case S3).

Spatial thermal condition in aluminum reduction cells under influences of electrolyte flow

“…Details on q n at Level k = 1 have been provided by Cheung et al (2013). Mass, m (i,j,k) , and specific heat capacity,c (i,j,k) are characterized based on the subsystem location and can include more than one component depending on the particular region.…”

“…The three-dimensional model is built based on the twodimensional conduction model developed previously by Cheung et al (2013). The two-dimensional model considered three major regions: the liquid, the ledge and the sidewall regions.…”

“…While work practices and individual anode current distribution are factors contributing to local thermal variations in an aluminum reduction cell (McFadden et al, 2001;Cheung et al, 2013), experimental works (Kristensen et al, 2005;Whitfield, 2003) have demonstrated that spatial convective heat transfer induced by electrolyte circulation also generates localized effects on the cell thermal condition (Utne, 1982;Haupin, 1997;Romerio et al, 2005). For instance, spatial temperature differences in an industrial reduction cell can range from an average of 971 • C at one end located away from feeding zones, to an average of 958 • C in the middle of the side channel at the same time under normal cell operation (Whitfield, 2003).…”

Weak solutions for a thermoelectric problem with power-type boundary effects

“…gwds, a.e. in ]0, T [, (6) for every v ∈ V ℓ (Q T ) and w ∈ V , where ·, · accounts for the duality product, and T M is the M-truncation function defined by T M (z) = max(−M, min(M, z)).…”

Variable Selection Method for Aluminum Electrolytic Process Based on FNN and RM in KPLS Feature Space

“…Aluminum electrolysis process has the multiple characteristics, which gather the multivariate, strong coupling, strong interference and the time-varying parameters in integral whole [1] [2]. When the model of aluminium electrolysis process is established, the complexity of the model will increase exponentially along with decision variables [3].…”