A NOVEL AXIAL ENERGY-IMPARTING TURBOMACHINE FOR HIGH-ENTHALPY GAS HEATING: ROBUSTNESS OF THE AERODYNAMIC DESIGN

Abstract

Abstract Hard-to-abate industrial processes, such as petrochemicals, have long been considered technically challenging to decarbonize. In response to the urgent demand to eliminate industrial CO2 emissions, a new class of energy-imparting turbomachines has been developed. These devices aim to convert mechanical into internal energy instead of pressurizing the gas, which enables high-temperature gas heating for a variety of applications. This paper is organized into three parts. First, the paper demonstrates the capabilities of the novel, customizable, repeating-stage axial turbo-heater for a hydrocarbon cracking example application. The study presents the new design requirements and working principles of this energy-imparting concept. The radically different objectives compared to a compressor enable ultra-high loading stage designs by avoiding the stability and efficiency constraints imposed on compressors. Within this new design space, the turbo-heater can achieve a loading coefficient ψ ≥ 4.0. Second, detailed numerical simulations of a multistage turbo-reactor with various vaneless space lengths are conducted. This work conclusively demonstrates the robustness of the aerodynamic design to maintain nominal work-input conditions even for the most compact arrangements despite employing a uniform blade design. Finally, having confirmed that the aerothermal restrictions on the vaneless space length can be removed, the designer is free to tailor the design to optimize the chemical reaction by (1) tailoring the residence time distribution (2) homogenizing reaction progress by mixing-out concentration gradients and (3) adjusting the rotational speed to account for variations in the reaction dynamics for different feedstocks.