Thermal Management

**References**

[1] K. Thulukkanam (2013) Heat Exchanger Design Handbook, sec. ed., CRC Press, Boca Raton, 312–314.

[2] M. Stewart, O. T. Lewis (2013) Heat Exchanger Equipment Field Manual. Gulf Professional Publishing, Oxford.

*Heat Transfer - Design, Experimentation and Applications*

[3] F. Perrone, M. Brignone, G. Micali, M. Rottoli (2014). Grid geometry effects on pressure drops and heat transfer in

International CAE Conference 2014,

[4] J. M. Chenoweth, FIVER – A new design concept to prevent tube damage from flow-induced vibration in shelland-tube heat exchangers, Research Brief 1–10, Heat Transfer Research, Inc.,

an EMbaffle heat exchanger.

27/28.10. 2014 Verona, Italy.

College Station, TX (1983).

Italy.

**346**

[5] D. Agazzi, T. Odry, M. Rottoli (2016). CFD analysis of annular distributors for shell & tube heat exchangers. International CAE

Conference 2016, 17/18.10. 2016 Parma,

[6] E.J.J. van der Zijden, M. Brignone, M. Rottoli, C.F.J.M. van Lint (2013). EMbaffle® Heat Exchanger in fouling operation. Proceed. Int. Conf. Heat Exchangers Fouling and Cleaning, 324– 328, 9/14.6.2013, Budapest, Hungary.

[7] M. Brignone, F. Perrone, M.Rottoli, S.J. Pugh, E.M. Ishiyama (2015). EMbaffle® in refinery service. On-field study and data validation through SMARTPM®. Proceed. Int. Conf. Heat Exchangers Fouling and Cleaning, 7/12.6.2015, Enfield (Dublin), Ireland.

[8] Tubular Exchanger Manufacturers Association, Inc. – Standards of the Tubular Exchanger Manufacturers Association – 9th Edition, 2007.

**Chapter 18**

*and Luis Fonseca*

the active materials in device performance.

silicon nanowires, heat exchangers

derived from them would be [3, 4].

**1. Introduction**

**349**

**Keywords:** thermoelectricity, silicon technology, micromachining,

It is quite evident that extending or improving human senses has enabled human societies to prosper by acquiring information from their surroundings and gaining knowledge from it. Internet of Things (IoT) embody this trend today combining distributed sensing with high connectivity so that wise decisions and actions follow information gathering and analysis [1, 2]. Trillion Sensors is another paradigm onto which IoT is further exploited on the basis that the more extensive or intensive the deployment of sensor networks is, the more fruitful the knowledge that can be

**Abstract**

Managing Heat Transfer Issues in

*Joaquin Santander, Denise Estrada-Wiese, Jose-Manuel Sojo,*

This chapter deals with heat transfer challenges in the microdomain. It focuses on practical issues regarding this matter when attempting the fabrication of small footprint thermoelectric generators (μTEGs). Thermoelectric devices are designed to bridge a heat source (e.g. hot surface) and a heat sink (e.g. ambient) assuring that a significant fraction of the available temperature difference is captured across the active thermoelectric materials. Coexistence of those contrasted temperatures in small devices is challenging. It requires careful decisions about the geometry and the intrinsic thermal properties of the materials involved. The geometrical challenges lead to micromachined architectures, which silicon technologies provide in a controlled way, but leading to fragile structures, too. In addition, extracting heat from small systems is problematic because of the high thermal resistance associated to heat exchanged by natural convection between the surrounding air and small bare surfaces. Forced convection or the application of a cold finger clearly shows the usefulness of assembling a heat exchanger in a way that is effective and compliant with the mechanical constraints of micromachined devices. Simulations and characterization of fabricated structures illustrate the effectiveness of this element integration and its impact on the trade-off between electrical and thermal behavior of

Thermoelectric Microgenerators

*Marc Salleras, Inci Donmez-Noyan, Marc Dolcet,*

*Gerard Gadea, Alex Morata, Albert Tarancon*
