抄録
We have developed a new heat recovery method that uses a heat exchanger in which there is direct contact between the fuel cell exhaust gas and the heat recovery water. Estimates of the heat recovered from the exhaust gas of a 50-kW fuel cell show that the amount of the recovered heat decreased due to the decrease in latent heat when the temperature of the heat recovery water increased. Futhermore, more heat was recovered from the reformer exhaust gas than from the cathode exhaust gas. The amount of recovered heat was confirmed to be hardly influenced by the diameter and the mass of the packed column, and the angle of the perforated plate in the direct contact heat exchanger, nevertheless the pressure drop was influenced remarkably. The amount of recovered heat agreed well with the estimated value, and the maximum temperature of the heat recovery was 78°C. The efficiency of heat recovery from the reformer exhaust gas was 9% at the heat recovery temperature of 65°C, so it can supply an absorption refrigerator with steam and hot water.
