REAL TIME SIMULATION OF A STEAM RANKINE CYCLE FOR CSP OPERATOR TRAINING

Abstract

Concentrating solar power technologies is an evolving electrical power production tech­ nology that utilize multiple parabolic trough or a heliostat field to collect renewable energy thermally for driving thermodynamic cycles to produce electrical power. Because of their inherent dynamic and uncontrolled nature of the primary energy input, managing the operation of a solar field and power block of a CSP plant can be a daunting task for experienced operators. Control Room Operators in a CSP plant must track hundreds of sensors throughout the plant, stay updated on current and incoming weather conditions, and accurately direct plant employees while maintaining close communication with grid coordinators. Currently, new control room operators shadow experienced operators in order to learn key tasks required for ensuring efficient and effective daily plant operation until they gain enough knowledge and confidence to transition to managing the overall plant operation themselves. Presented in his thesis, are the results of the development and validation of a steam-Rankine cycle power block as part of a larger plant simulator intended to serve as a training environment for control room operators. The goal of the simulator is to enable incoming control room operators to become proficient in plant op­ eration by experiencing various normal and abnormal operational scenarios in a low-risk environment. The training simulation is developed using TRNSYS, a transient simulation solver. Models of plant components and piping are connected together to create one large power block model. This model features complex heat transfer fluid and turbine bypass piping networks allowing operators to adjust the flow through various branches of the steam system by updating valve positions. Dynamic tank models of the condenser, deaerator, and steam drum provide the complexity needed so operators can manage drum pressures and liquid levels. Other features include realistic pump models where operators can adjust pump speed and power inputs, quasi-steady state heat exchangers, and a turbine model capable of predicting the performance of a high-pressure and low-pressure turbine with or without steam extractions for boiler feedwater heating. All models are developed to run at design and off-design conditions. Data from the Solana power block are used to validate the simulation model. The validated power block model is illustrated by running two demonstrations that require interaction with the control room operator to make appropriate adjustments to avoid a plant trip and ensure an expedient plant start-up, respectively. The first demonstration requires the control room operator to use the turbine bypass network to avoid a low-superheat turbine failure when a cold-slug of HTF enters the power block from the solar field. The second demonstration shows an operator performing the plant's start-up procedures for a sunny day.