Hybrid thermal management strategy with PCM and insulation materials for pulsed-power source controller in extreme oil-well thermal environment

Abstract

• Thermal management strategy for PPS controller are experimentally investigated. • Metal PCM can lower thermal resistance from 1.7 to 1.1 K/W compared to paraffin. • Silica aerogels can alleviate heat transfer from external environment by 59.9%. • Chip operating time can be prolonged when using present thermal management strategy. The application of pulsed-power source (PPS) can effectively improve the efficiency of shale oil exploitation. However, the severe underground environment with high temperature, pressure and viscosity will bring great challenges to electronic components. This study presents a hybrid thermal management strategy (HTMS) for the PPS controller. The heat storage unit filled with phase change materials (PCMs) is applied for internal thermal management, and the performance of PPS is evaluated when paraffin and low melting temperature alloy (LMTA) are respectively used as PCMs. On the other hand, glass wool, phenolic foam and silica aerogels are implemented to construct a sandwich structure for external thermal protection. Results show that the LMTA can extend the safe operating time of equipment from 50 min to over 250 min in comparison to paraffin while lowering the average equivalent thermal resistance from 1.7 K/W to about 1.1 K/W. Besides, the application of glass wool and phenolic foam is eligible to extend the operating time by 63 % and 57 %, respectively, with external ambient temperature at 100 °C. After replacing by the silica aerogels, the thermal insulation effect can be further improved. As the result, with the application of HTMS, the PPS controller is tested under more severe thermal environment with ambient temperature of 150 °C. It is noticed that the operating time prolongs to 50 min within the maximum junction temperature of 80 °C.