Abstract: An exhaust gas purification device for purifying exhaust gas of nitrogen oxides includes: a catalyst that is provided in an exhaust pipe (exhaust passage) for transporting exhaust gas, discharged from an engine, in a predetermined exhaust direction, and promotes the reduction of the exhaust gas; and an injection nozzle that is provided in the exhaust pipe so as to be upstream of the catalyst in the exhaust direction, and injects a reducing agent for reducing the exhaust gas. The injection nozzle includes an injection hole for injecting the reducing agent toward the catalyst, and a discharge hole for discharging a cooling medium in at least the direction opposite the exhaust direction.

Abstract: A urea water supply device supplying urea water to purify exhaust gas from an electric power generating engine. The urea water supply device includes: a urea water injector; a urea water flow route in which urea water flows; a clean water supply route in which clean water flows; and a urea water amount adjustment valve and a urea water flow meter provided in the urea water flow route. The clean water supply route merges with the urea water flow route on the downstream side of the urea water amount adjustment valve and the urea water flow meter.