2.2.2. Solid section

The solid section in this work consists of three components, namely, the aluminium block, the wall of the helix coil and the battery module. When the velocity is set to zero in Eq. (20), the equation governing pure conductive heat transfer by diffusion is obtained, that is,

$$\frac{\partial}{\partial t}(\rho \boldsymbol{\varphi}) = \frac{\partial}{\partial \boldsymbol{\mathfrak{x}}\_i} \left( \boldsymbol{\Gamma}\_{\boldsymbol{\varphi}} \frac{\partial \boldsymbol{\varphi}}{\partial \boldsymbol{\mathfrak{x}}\_i} \right) + \boldsymbol{\mathcal{S}}\_{\boldsymbol{\varphi}} \tag{37}$$

value of 20, so complying with recommendations given in the literature that Y<sup>þ</sup> should be between 11.5 and 300 to ensure accuracy when using a high-Reynolds turbulence model [37].

The overall change in the residual for each variable between the last two numbers of elements was less than 0.1%, indicating grid independence had been achieved. The calculations were performed on a Dell T5500 workstation with 32 nm six-core Intel Xeon 5600 series processor and main memory of 24 GB. A typical CPU time for a transient run with a grid having 10<sup>6</sup>

The thermal characteristics of a Li-ion battery cell are first investigated using Eqs. (1)–(19), which form thermal-electrochemical coupled model. The cell used in these calculations has an electrolyte consisting of zinc and lithium salts dissolved in water. When the battery is fully charged, the anode consists of nonporous zinc and the cathode of porous Mn2O4. It is important to note that some of the electrochemical calculations are strongly dependent on coefficients, which are in turn strongly dependent of experimental results. For example, for the electrolyte just described, the specific conductivity Eq. (11) of the electrolyte is a function of temperature and the concentration of the electrolyte in the liquid phase, and so the ionic conductivity, κ<sup>i</sup> had to be determined by experiment, the results of which are summarised in

, 2.0�10<sup>6</sup> and 1.0� 107

Effectiveness of a Helix Tube to Water Cool a Battery Module

http://dx.doi.org/10.5772/intechopen.74113

.

137

Tests for grid independent solutions were carried out using 2.0 �105

Figure 4. Ionic conductivity of electrolyte consisting of a ZnCl2 and LiCl aqueous solution.

nodes was just over 24 h.

3.1. Heat generation within a single cell

3. Results

Figure 4.

Conjugate heat transfer was used between the solid domain and fluid domain.

### 2.3. Boundary conditions and settings

The cooling fluid is modelled using the material properties of water calculated using the inlet temperature. The settings and boundary conditions are set out in Tables 2 and 3.
