FUEL CELL SYSTEM

To provide a fuel cell system capable of accurately measuring a flow rate of water required for reforming by a thermal flow rate sensor and appropriately controlling the flow rate of water.SOLUTION: A fuel cell system including a fuel cell which generates power on the basis of a reformed gas containing hydrogen and an oxidant gas containing oxygen comprises: a reformer which generates a reformed gas by reforming a raw fuel gas; a water tank which stores the water used for reforming by the reformer; a water pump which sends the water in the water tank to the reformer side through a water pipe; a thermal flow rate sensor which is provided on a downstream side of the water pump in the water pipe and measures a flow rate of water passing the water pipe; a metallic buffer tank which is provided between the water pump in the water pipe and the thermal flow rate sensor and temporarily stores the water passing the water pipe; and a control device which drives and controls the water pump on the basis of the flow rate of the water measured by the thermal flow rate sensor.SELECTED DRAWING: Figure 1 【課題】燃料電池システムにおいて改質に必要とされる水の流量を熱式流量センサで精度よく計測して水の流量制御を適切に行う。【解決手段】水素を含む改質ガスと酸素を含む酸化剤ガスとに基づいて発電する燃料電池を備える燃料電池システムは、原燃料ガスを改質して改質ガスを生成する改質器と、改質器の改質に用いられる水を貯留する水タンクと、水配管を通して水タンク内の水を改質器側へ送る水ポンプと、水配管における水ポンプの下流側に設けられ水配管を通る水の流量を計測する熱式流量センサと、水配管における水ポンプと熱式流量センサとの間に設けられ水配管を通る水を一時的に貯留する金属製のバッファータンクと、熱式流量センサにより計測される水の流量に基づいて水ポンプを駆動制御する制御装置と、を備える。【選択図】図１