Control device for internal combustion engine and control method for internal combustion engine

A control device for an internal combustion engine including a fuel reformation device capable of generating reformed fuel through a fuel reforming operation and an output cylinder to which the reformed fuel generated in the fuel reformation device is supplied, the output cylinder being configured to yield an engine power by combusting the reformed fuel, the control device comprising:

• a reforming operation control unit configured not to execute the fuel reforming operation in the fuel reformation device, and configured to execute a warming operation for raising a temperature of the fuel reformation device, when a gas temperature in the fuel reformation device is estimated to fall short of a reforming operation allowable lower limit gas temperature set based on a lower limit value of a reforming reaction enabling temperature;
• and
• an output cylinder bypass passage which communicates an outlet passage of the fuel reformation device with an exhaust passage of the output cylinder, the output cylinder bypass passage including a bypass amount adjusting valve;
• wherein the bypass amount adjusting valve is opened in the warming operation, and when the warming operation is terminated and a fuel reforming operation in the fuel reformation device is started, the bypass amount adjusting valve is closed.