Investigation of Different Cathode Path Topologies for Water Recovery
in a Heavy-Duty Polymer Electrolyte Membrane Fuel Cell Vehicle 2024-01-5050
Heavy-duty vehicles equipped with polymer electrolyte membrane fuel cells
(PEM-FC) are an environmentally friendly alternative to vehicles powered by
internal combustion engines. A major challenge for heavy-duty fuel cell vehicles
is the potential cooling deficit under high load conditions at high ambient
temperatures. To solve this problem, a spray cooling system can be utilized, in
which liquid water is sprayed on the main cooler at the front end of the
vehicle. The evaporation of the sprayed liquid water results in an increased
cooling power. In this paper, the recovery of liquid water within the cathode
loop of a mobile PEM-FC system is presented and discussed. For this purpose,
three different topologies of the cathode subsystem of the PEM-FC are
investigated for recovering liquid water directly from the fuel cell exhaust
gas. To obtain liquid water, vapor in the exhaust gas is cooled below the
saturation temperature in an additional heat exchanger. Three possible positions
of such a heat exchanger in the exhaust gas system are analyzed and discussed in
this study. The first investigated position is at the outlet of the turbine and
the other two are either upstream or downstream of the membrane humidifier. For
the position upstream of the humidifier, a control and operating strategy is
established. To investigate the water recovery of the three topologies, a
simulation study is conducted using a validated physics-based model of the
entire fuel cell system. The result of the study is a recommendation that the
additional cooler should be placed upstream of the membrane humidifier.