Suggestion of Intercooled and Recuperated Jet Engine Using Already Equipped Components as Heat Exchangers

Abstract

Aviation engines are strongly desired to reduce CO2, carbon dioxide, emission in the worldwide trend of CO2 reduction. Gas turbine engines are bound to remain as aviation jet engines in the next 20 years at least because of its high power density. So, the jet engines definitely have to enhance their efficiency and to reduce fuel consumption because the reduction in CO2 emission corresponds to the reduction in fuel consumption for a gas turbine engine. One of the likely solutions is an intercooled and recuperated jet engine. Some researchers have confirmed that the overall efficiency certainly increases by employing an intercooler and a recuperator, however, the increase of weight is not acceptable as aviation engine. Therefore, this paper proposes a new concept of an intercooled and recuperated jet engine using already equipped components as heat exchanger to save its weight. In this concept, the intercooler and recuperator require no additional space except a heat transfer system between each heat exchanger. Super-critical carbon dioxide (which is pure substance, not exhaust gas) is qualified as a heat transfer medium for this system. It is larger density and larger specific heat than air, it is smaller viscosity and more flexibility than liquid, it has no surface tension, and phase change never occurs against large heat input. It is circulated inside a heat transfer system by pumps. Hereby, the new intercooler and recuperater including a heat transfer system can be much smaller and lighter than the conventional ones. Therefore, they might be directly applied to the current jet engine without configuration change. This paper roughly designs the new intercooled and recuperated jet engine, and theoretically evaluates its performance, weight, and feasibility.