Study on performance and mechanisms of a novel integrated model with Power & Thermal Management system and turbofan engine

With the improvement of modern aircraft performance, thermal management has become increasingly challenging. The power and thermal management system (PTMS) proposed by Honeywell is an integrated approach to solve this problem. Although the PTMS has inevitable mass and energy interactions with the engine, the existing PTMSs are usually designed based on limited flight states without considering the full engine condition. Therefore, we first propose a novel integrated model combining PTMS and engine based on a semi-precise heat exchanger submodule. Parametric analysis is conducted to find out the impact of the engine and PTMS design variables on the propelling and cooling performance of the integrated system, and energy and exergy analyses are adopted to evaluate the degree of coupled effects between PTMS and engine over the whole flight envelope. Results show that the influence of FAN and HPC pressure ratio on refrigerating performance is more significant than the bypass ratio and inlet temperature of HPT at the design point. The cooling efficiency of PTMS is improved by 4.1% and 1.2%, respectively, as the pressure of HPC and FAN rises by 50%. Besides, the refrigerating performance of PTMS gradually weakens with the increasing flight Mach number, while the cooling efficiency reduces by 50% as the Mach number increases from 0 to 1.8. This trend indicates that the working condition and flight environment of the engine need to be considered in the design process of the PTMS system. As for the control variables of PTMS, the refrigerating efficiency of PTMS decreases by 60% when the pressure ratio of PTMS compressor (PTMS_COMP) changes from –33.3% to 33.3%. Inconsistently, the refrigerating efficiency shows a positive correlation with the heat transfer capacity of the kerosene heat exchanger (PTMS_KEHEX) and primary heat exchanger (PTMS_PRHEX). Meanwhile, the impact of the second heat exchanger (PTMS_SEHEX) on the cooling performance of PTMS can be neglected. Above all, in future PTMS designs, the influences of the pressure ratio of PTMS_COMP, the heat transfer capacity of PTMS_KEHEX and PTMS_PRHEX, as well as the engine control variables need to be considered simultaneously.