Session: 09-01 Compressed Air Energy Storage

Paper Number: 127833

127833 - Speed Strategy on High-Pressure Compressor for the Charging Process of Advanced Adiabatic Compressed Air Energy Storage During Dynamic Shutdown 

Advanced adiabatic compressed air energy storage (AA-CAES) starts and shutdowns frequently. The default operation of the high-pressure compressor (HP) connected to the cavern is to reduce the speed of the inverter motor during shutdown. Whether the default speed strategy is safe or not has not yet been focused on. To this end, a detailed charging process comprising three series of centrifugal compressors with intercoolers was constructed within the framework of UniSim® Design. The safety measures were meticulously considered by integrating anti-surge circuits, vent valves, and check valves. PI controllers were allocated to the primary component to govern the shutdown procedure. The speed strategy of the HP inverter motor during the load shedding stage is the focus of research. Six speed strategies including decreasing speed, normal speed and increasing speed were discussed respectively. Changes in air injection, inlet mass flow of the HP, inlet and outlet pressure of the medium-pressure compressor (MP) and HP, and energy efficiency are discussed. The study found that both the strategy with the inverter motor speed (IMS) to the minimum allowable speed and with increasing speed in the load shedding stage will cause fluctuations in the air injection. As IMS increases at the end of load shedding stage, the pressure anomalies at the MP outlet and the HP inlet become weaker, and the energy efficiency of the shutdown process becomes better. The HP inlet flow fluctuations caused by various strategies are within an acceptable range. This study reveals that there is mutual influence between components in the charging process of AA-CAES. Appropriate speed strategy of HP inverter motor can mitigate the operational hazards. The results of this study can provide guidance for similar AA-CAES shutdowns.

Presenting Author: Yi Wang Xi'an Jiaotong University

Presenting Author Biography: Yi Wang is a doctoral student in Xi’an Jiaotong University. Her major is steady and dynamic performance of advanced adiabatic compressed air energy storage.

Authors:

Yi Wang Xi'an Jiaotong University
Guoliang Qin Xi'an Jiaotong University
Cheng Jia Xi'an Jiaotong University
Qin Cui Xi'an Jiaotong University