An Adsorption Based Cooling Solution for Electronics used in Thermally Harsh Environments

Industries such as automobiles, oil exploration, military hardware, etc. often deal with harsh environment (temperatures 150°C--200°C), which makes it difficult to use conventional electronics for tasks such as performance monitoring, and data acquisition. Commercial-off-the-shelf electronics can survive up to 125°C, hence the electronics currently used are pre-screened for the desired temperature and assembled with or without cooling systems that are limited in cooling capacity and/or need to be reset/recharged. This offsets cost benefits and hinders continuous operation. While high temperature compatible electronics could provide a solution in future, immediate concerns could be addressed by compact thermal management systems that should work without having to be reset and require less maintenance (human interference during system operation must be ruled out). Also, the system should be scalable to smaller sizes without loss of performance.;In this backdrop this research aims at realization of an adsorption based cooling system for evaporator temperatures in the range of 140°C--150°C, and heat rejection temperature in the range of 160°C--200°C. Adsorption cooling systems have few moving parts, and the use of ThermoElectric (TE) devices to regenerate heat of adsorption in between adsorbent beds enhances the compactness and performance efficiency of the overall 'ThermoElectric-Adsorption' (TEA) system. The work presented identifies the challenges involved and respective technical solutions for high temperature application. Performance deterioration of TE device at high temperatures (> 150°C) and its thermal operating limits have been identified as major challenges, and a two-step adsorption cycle proposed to accommodate the thermal needs of the TE device. Methods of operation have been proposed that enable the system to manage varying thermal load while accommodating TE device thermal operating requirements. An experimental set up was fabricated to demonstrate operation of the TEA cooling system at high temperature. Mathematical system models were also developed to benchmark experimental results.;Also, it is worth noting that TEA cooling system comprises of TE and Adsorption cooling systems. A TE cooler can be a compact thermal management system in its own right. Hence a comparison of the performance of TEA and TE cooling systems has also been presented.;This research will help in achieving a reliable and compact high temperature cooling system that should extend the working envelope of existing conventional electronics.