HEAT RECOVERY UNIT, EXHAUST GAS ECONOMIZER, AND WASTE HEAT RECOVERY SYSTEM

摘要

A branch pipe (21) branches from the exhaust pipe (15) of an exhaust gas economizer (10), a secondary heat recovery unit (22) being installed on the branch pipe (21) to recover exhaust gas heat. When an engine (1) uses residual oil or other high-sulfur fuel, a first condition occurs in which a switching means (23) causes exhaust gas flowing into the exhaust pipe (15) to be discharged from the exhaust pipe (15) without passing through the branch pipe (21), and when the engine (1) uses low-sulfur fuels such as distillate oil, light oil, or the like, a second condition occurs in which the switching means (23) causes exhaust gas flowing into the exhaust pipe (15) to pass through the branch pipe (21) and then be discharged.