A Bypass Control System Applicable to Expansion Units of Caes System

Abstract

The invention discloses a bypass control system suitable for an expansion unit of a CAES system. Aiming at the characteristics of frequent start-up and shutdown of various CAES systems and the operation of various working conditions, the bypass passage and valve structure of the expansion machine are changed to realize the pressure at all levels. Control and regulation, on the one hand, can shorten the start-up time, improve the start-up conditions, and prolong the life of the expander; It is suitable for frequent starting and stopping and rapid lifting of loads; finally, under sliding pressure operating conditions, the expansion ratio can be achieved in an expander with high medium and low pressure efficiency. In addition, the invention can also effectively adjust the operating conditions of the expansion unit according to the different intake (gas storage) pressures of the CAES system and the different load requirements of the user end, and can be adapted to the operation of a wide range of variable operating conditions, and can effectively improve its variable operating conditions. range, regulation safety and reliability while improving unit operating efficiency.

Description

technical field [0001] The invention belongs to the field of compressed air energy storage (CAES), and relates to a bypass control system of an expansion unit, in particular to a valve combination structure of a bypass pipeline in the CAES expansion unit. Background technique [0002] In recent years, with the country's emphasis on energy security and sustainable development, renewable energy such as wind energy and solar energy has developed rapidly, but wind energy and solar energy have greater volatility and instability. Energy storage technology is a major renewable energy The urgent need for large-scale utilization is also an essential key technology to improve the efficiency, safety and economy of conventional power systems, as well as smart grids and distributed energy systems, and is known as the supporting technology of the energy revolution. Compressed air energy storage (CAES) has the advantages of large energy storage capacity, long period, and small unit investm...

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Problems solved by technology

The high-pressure air directly drives the expander to start, which will cause a large impact, which is not good for the life of the equipment; on the other hand, if there is a mechanical failure or instantaneous load rejection during operation, due to the cavity effect, the residual high-pressure gas will still drive the expander at high speed. operation, which is not conducive to equipment safety; finally, under the sliding pressure operating condition, due to the sharp decrease in the total pressure ratio, the efficiency of the low-pressure stage drops sharply and even operates as a load condition, and the system efficiency deteriorates

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