System and method for top platform assembly of heat recovery steam generator (hrsg)

A top platform auxiliary module of a heat recovery steam generator (HRSG), the top platform auxiliary module comprising:

• a frame;
• a terminal connection disposed within the frame and configured to couple to a corresponding terminal connection disposed within a base of the HRSG;
• and
• a mounting assembly extending outwardly from the frame and configured to receive a mounting feature of the base of the HRSG, the mounting assembly being spaced from the terminal connection a distance;
• wherein, when the mounting assembly interfaces with the mounting feature, the terminal connection of the top platform auxiliary module is aligned with the corresponding terminal connection.

A method of constructing a heat recovery steam generator (HRSG), comprising:

• forming a first top platform auxiliary module having a first frame with a first generally flat bottom surface, and having a steam manifold disposed in the first frame;
• forming a second top platform auxiliary module having a second frame with a second generally flat bottom surface, and having a high pressure (HP) drum disposed in the second frame;
• forming a third top platform auxiliary module having a third frame with a third generally flat bottom surface, and having a low pressure (LP) drum and intermediate pressure (IP) drum disposed in the third frame;
• lifting the first top platform auxiliary module to elevation, and disposing the first top platform auxiliary module on a base of the HRSG such that the first generally flat bottom surface of the first top platform auxiliary module is disposed in a plane formed by the base;
• lifting the second top platform auxiliary module to elevation, and disposing the second top platform auxiliary module on the base of the HRSG such that the second generally flat bottom surface of the second top platform auxiliary module is disposed in the plane formed by the base;
• and
• lifting the third top platform auxiliary module to elevation, and disposing the third top platform auxiliary module on the base of the HRSG such that the third generally flat bottom surface of the third top platform auxiliary module is disposed in the plane formed by the base.