TG308 - Steam Turbine Starting & Loading Instructions

2 days - 1.9 Continuing Education Units Awarded

The intent of this Seminar is to enhance the participants understanding of Steam Turbine Starting, Loading and Shutdown Instructions (or procedures). These instructions and their interpretation have a direct impact upon the unit life-span, starting, and shut-down times.  The goal is to optimize the starting conditions and minimize the time required for a turbine roll-up.  It is our experience, not to be critical, but, all too often the startup procedures utilized in the plant have lost focus.  Knowledge is the key.  Personnel need to understand “why” and the better they understand the “why” the better they may implement procedures.   Recently, at a restart, one of our instructors was present for supportive purposes.  An operator, when asked why the 1^st stage pressure/temperature was maintained at this value during pre-warming, told us that this is how the unit had been operated for 30-years.  Again, we asked the question, “Why?”  The control room operator did not have an answer.  If this operator understood why the OEM recommends particular conditions, he would have understood that the procedure implemented was consuming far more life than necessary (holding all else constant).  After attending this Seminar, this operator will understand why recommendations are what they are.

The Seminar emphasizes why and how steam turbine parts are damaged; interpretation of the OEM recommendations; and what an operator can do (or cannot do) to optimize the start-up situation.  A topical outline includes:  Review of Steam Turbine Fundamentals, Use of TSI, Thermal Stress, Starting and Loading Instructions, Abnormal Events.

This Seminar is recommended for Control Room Operators, Shift Supervisors, Operations Superintendents, and Engineers. The Seminar specifically targets GE or W steam turbines (see open enrollment schedule for dates), and due to their similarities applies to Toshiba, Hitachi and Mitsibushi units as well.  Other manufacturers can only be represented in on-site customized Seminars.

OBJECTIVES

1. Describe thermal stress; how it is derived and what is the impact upon steam turbine components.
2. Describe how personnel can minimize the negative impact of thermal stress while minimizing start-up times.
3. Describe the importance of the Fracture Appearance Transition Temperature.
4. Describe those Turbine Supervisory Instruments typically found to support starting and loading decision making.
5. Demonstrate the ability to interpret the OEM starting and loading instructions.
6. Demonstrate the knowledge necessary to apply the OEM starting and loading instructions to his/her application.
7. Demonstrate an understanding of causes, indications, and required actions for common abnormal steam turbine operational events.

Seminar OUTLINE

1. Review of Steam Turbine Fundamentals: Energy Transfer, Theory of Operation, Turbine Components
2. Turbine Supervisory Instruments important to Starting & Loading Instructions: Eccentricity, Shell (Casing) Expansion, Differential Expansion, Rotor Expansion, Metal Temperatures
3. Thermal Stress: Definition, Tensile versus Compressive, Temperature Differentials, Cyclic Duty
4. Starting Instructions: Prewarming (where applicable), Drains, Temperature Mismatch, Acceleration, Speed Holds, Synchronizing, Loading, Unloading (Normal), Unloading (Emergency)
5. Abnormal Conditions:  Excessive time off turning gear, vibration incidents (evaluation and action), rotor long, rotor short, water induction awareness, excessive temperature/pressures, loss of vacuum.