A comparison of evaporative and liquid cooling methods for fuel cell vehicles

Abstract

Available online xxxKeywords: Thermal management Water balance Fuel cell vehicle PEM Heat transfer Cooling a b s t r a c tDespite having efficiencies higher than internal combustion engines, heat rejection from fuel cells remains challenging due to lower operating temperatures and reduced exhaust heat flow. This work details a full system simulation which is then used to compare a conventional liquid cooled fuel cell system to two types of evaporatively cooled fuel cell systems. Both steady state and transient operation are considered. Results show the radiator frontal area required to achieve thermal and water balance for an evaporatively cooled system with an aluminium condensing radiator is 27% less than a conventional liquid cooled system at 1.25 A/cm 2 steady state operation. The primary reason for the reduction is higher heat transfer coefficients in the condensing radiator due to phase change. It is also shown that the liquid water separation efficiency has a significant influence on the required radiator frontal area of the evaporatively cooled system.

Determination of Electrical and Efficiency Parameters of Air Cooling of Low-Temperature PEM Fuel Cell Stack with Power of 5kW

“…Thus, in the case of the tested device, in addition to electricity of 5 kW, also the heat of 5 kW was received, which must be removed from fuel cells in this H5000 PEMFC stack. The most commonly used methods of waste heat collection include: a) air cooling using fans, b) cooling using the liquid medium, c) cooling using the passive elements [29][30][31].…”

Parametric analysis of simultaneous humidification and cooling for PEMFCs using direct water injection method

“…Phase change cooling uses the enthalpy of vaporization, or the latent heat, to remove the generated heat from the stack. The latent heat is usually very higher than the sensible heat absorbed by the coolant [8,18]. Silva et al [19] developed a two-phase heat transfer cooling system consisted of a capillary pumped loop (CPL) with heat pipes as an alternative for the liquid cooling system.…”

“…The proposed system removed heat successfully for power inputs up to 50 W, maintaining the operation temperature of stack in the range from 70 to 90 C. However the coupling of the proposed system to a real fuel cell was not conducted. Flow boiling method is considered as a significant cooling technique especially due to its high cooling capability [8,18]. Garrity et al [20] designed a microchannel cooing plate and developed two-phase thermosiphon cooling system with HFE-7100.…”

“…Lately, evaporative cooling has become a subject of special interest. One of the most attractive strength of evaporative cooling is that this method can remove the generated heat from the stack by evaporation, and additionally it could be used for inner humidification of PEMFCs [8,18,22]. Designing porous water transport bipolar plates was studied, and inner humidification and cooling effect were investigated [17,23].…”

“…Numerical study of evaporative cooling has been conducted as well. Fly and Thring [18,25] numerically investigated temperature control ability of direct water injection method and compared it with convectional liquid cooled fuel cell system. While many studies of evaporative cooling method have been conducted, there are still many points to be studied in order to apply this technology to automotive PEMFC system.…”