Design of Fuel Cell Systems in Aviation - Part I

The development of novel propulsion systems is essential to achieve the zero-emissions goals in aviation. One promising approach is the electrification of aircraft engines using hydrogen-based polymer electrolyte membrane fuel cells (PEMFC). In addition to the fuel cell stack, the propulsion system includes several subsystems, which determine the mass and volume and thus the feasibility of the architecture. A key subsystem is the cathode air supply, which preconditions the air for efficient and reliable operation. The compressor work required to pressurize the air has a significant impact on the power requirements, efficiency, and mass of the overall system. In addition, the operating range of the compressor influences the possible operating strategy of the fuel cell system. Another crucial subsystem of PEMFC-aircraft is the thermal management system, which manages the heat rejection of all heat sources. The paper is organized into two parts. In this part, Part I, a design approach for the air supply system and its components is presented. The objective is to apply the design method to a reference medium-range aircraft with a variable number of cathode air supply systems. This is an important decision point that influences both the design of the individual components of the cathode air supply system and the aircraft design, and thus the performance during the entire flight mission. The design points and boundary conditions are derived from an overall system simulation. Based on this, the compressor, turbine, and thermal management system are designed for the identified design points.