Abstract: A heat exchanger for a fuel cell includes first and second heat exchanger portions that provide a fluid flow passage. The second heat exchanger portion is arranged downstream from the first heat exchanger portion. The first and second heat exchanger portions include a coolant flow passage, which is provided by tubes in one example. The first and second heat exchanger portions are configured to transfer heat between the fluid flow and coolant flow passages. The first heat exchanger portion is configured to provide a first heat transfer rate capacity. The second heat exchanger portion includes a second heat transfer rate capacity that is greater than the first heat transfer rate capacity. In one example, the first heat exchanger portion includes tubes and does not include any fins, and the second heat exchanger includes spaced apart fins supporting the tubes.

Abstract: A fuel cell system is disclosed that includes a heat exchanger having first and second heat exchanger portions arranged in a fluid flow passage. The second heat exchanger portion is arranged downstream from the first heat exchanger portion. The first and second heat exchanger portions include a coolant flow passage and are configured to transfer heat between the fluid flow and coolant flow passages. The first heat exchanger portion includes a first corrosion-resistant material and the second heat exchanger portion includes a second corrosion-resistant material that is less corrosion-resistant than the first corrosion-resistant material. A collector, which includes a tray and/or a mist trap, is configured to collect acid in the first heat exchanger portion from a gas stream in the fluid flow passage. Collected acid can be sprayed into a gas stream upstream from a flow field of the fuel cell.