scope:

Purpose and scope

Guidelines VDI/VDE 3501 to 3506 contain Instruc¬ tions for the proper design of control circuits for boil¬ ers of a conventional power Station. Each of these is an independent Guideline but the content of the Guidelines is largely harmonized. A description of the controlled system is followed by the formulation of the control task. Suitable arrangements of the control circuit are described in a following clause and the measuring devices and Controlling Clements required for the design of the control unit are dealt with in a further clause.

The associated Guidelines 3500, 3507 and 3508 refer to the complete power Station. The fmdings and experience contained in these Guidelines is of course widely known and acknowledged, but has never before been assembled in this manner.

The terms and presentations used correspond to the definitions and symbols of DIN 19227 "Symbols and code letters for process engineering", DIN 2481 "Thermal electric stations" and ISO 3511/3 "Process measurement control functions and instrumentations - symbolic representation". This Guideline Covers feedwater control for once-through boilers.

Part I of this Guideline describes normal operation and Part II describes start-up and low-load operation.