Components and systems for reducing thermal stress of heat recovery steam generators in combined cycle power plant systems

A heat recovery steam generator (HRSG) comprising:

• a manifold receiving a working fluid of the HRSG;
• a plurality of piping links in fluid communication with the manifold;
• an enclosure including an interior, the enclosure surrounding the manifold and at least a portion of the plurality of piping links;
• and
• a supplemental heating system in fluid communication with the interior of the enclosure, the supplemental heating system including:
• a heater for heating fluid;
• and
• an inlet conduit in fluid communication with and positioned downstream of the heater, the inlet conduit formed through the enclosure to provide the heated fluid to the interior of the enclosure.

A combined cycle power plant system comprising:

• a gas turbine system including a turbine component discharging an exhaust gas;
• and
• a heat recover steam generator (HRSG) in fluid communication with the turbine component for receiving the exhaust gas, the HRSG including:
• a manifold receiving a working fluid of the HRSG;
• a plurality of piping links in fluid communication with the manifold;
• a enclosure including an interior, the enclosure enclosing the manifold and at least a portion of the plurality of piping links;
• and
• at least one of:
• at least one thermal element positioned within the enclosure, the at least one thermal element surrounding the manifold, or
• a supplemental heating system in fluid communication with the interior of the enclosure, the supplemental heating system including:
• a heater for heating fluid;
• and
• an inlet conduit in fluid communication with and positioned downstream of the heater, the inlet conduit formed through the enclosure to provide the heated fluid to the interior of the enclosure.