8. Conclusions

(15)

<sup>0</sup>:<sup>8</sup> (16)

<sup>2</sup> ð Þ <sup>W</sup> <sup>þ</sup> <sup>H</sup> (17)

<sup>2</sup> Nu Kf L Wð Þ <sup>þ</sup> <sup>H</sup> (18)

Cpr<sup>c</sup> <sup>f</sup> (19)

kLH (21)

<sup>h</sup> <sup>¼</sup> NuKf Dh

where Kf is coolant thermal conductivity, Nu is the Nusselt number calculated with the Dittus-

in which Pr is Prandtl number and Re is Reynolds number. Dh, the hydraulic diameter, is

<sup>0</sup>:<sup>4</sup> Re

perimeter <sup>¼</sup> <sup>4</sup> WH

Nu ¼ 0:023 Pr

Rconv <sup>¼</sup> Dh

Rheat <sup>¼</sup> <sup>1</sup>

where Cp is the coolant specific heat and r<sup>c</sup> is coolant density. f is the volumetric flow rate for

The coolant viscosity and thermal conductivity vary according to the temperature [114]. The

Rcond <sup>¼</sup> <sup>W</sup>

For fluid dynamical and thermal phenomena that occur in the channels with corrugated walls, different heat transfer characteristics can be observed. Generally, the wall corrugation enlarges the surface of the channels and creates turbulence. However, most studies stated that the rise in temperature of the walls along the direction of the flow is almost linear

Recently, heat sinks with nano-fluid have shown potential to achieve lower thermal resistance [118, 119]. In addition, cooling technologies based on heat removal from the heat sinks using

where k is the thermal conductivity of the channels plates material.

synthetic jet [120], either single-phase or two-phase flow, are noticeable.

<sup>f</sup> <sup>¼</sup> coolant velocity<sup>∗</sup> cross sectional area <sup>¼</sup> vWH (20)

Dh <sup>¼</sup> <sup>4</sup> ð Þ cross sectional area

Boelter equation [113],

258 Bringing Thermoelectricity into Reality

Hence the convective can be expressed as:

The heat resistances can be expressed as:

conductive resistances can be expressed as:

each channel which is defined as:

defined as:

[115–117].

In this chapter, a short review of technologies related to the TE cooling was presented. The new methodologies of system design and system analysis have enabled the design of highperformance TE cooling systems. This includes the use of the basic physical properties of TE modules and the flow equations to identify the TE cooling design parameters to maximize the COP of the TE cooling systems. To minimize the energy demands in TE cooling systems and increase their energy effectiveness, solar TE cooling technologies such as active building envelope, solar thermoelectric coolers are suggested to be used in zero-energy environments.
