A system and method for realizing safe control of pressure energy utilization of natural gas pipeline network

Abstract

The invention provides a safe operation realizing system and method using a pressure energy of a natural gas pipeline network. The system comprises an expansion power generation module, a low-temperature natural gas cold energy utilization module and a monitoring and regulating module, wherein the expansion power generation module is used for reducing the pressure of high pressure natural gas flowing out of a high voltage grid and converting the pressure energy obtained by pressure reduction to electric energy; the low-temperature natural gas cold energy utilization module is used for supplying a cold energy after heat exchange is performed on the low-temperature natural gas expanded by the expansion power generation module and a refrigerant; and the monitoring and regulating module is used for monitoring the expansion power generation module in real time, switching the expansion power generation module to a pre-determined pressure regulating system when the expansion power generation module is emergently shut down or the natural gas power generation load is suddenly reduced, and supplementing a back end pressure of the expansion power generation module to the front end. The system provided by the invention realizes seamless joint of a pressure energy expansion power generation system and an original pressure regulating system, effectively copies with impact by sudden working conditions, and prolongs the service life of an expansion machine, so that the whole set of system operates safely and stably.

Description

technical field [0001] The invention relates to the technical field of recovery and utilization of residual pressure and residual energy of natural gas, in particular to a system and method for realizing safe control and utilization of natural gas pipeline network pressure energy. Background technique [0002] Long-distance natural gas pipelines generally use high-pressure transmission. For example, the gas transmission pressures of the "first line" and "second line" of the West-East Gas Pipeline are 10MPa and 12MPa respectively. A lot of pressure energy is generated in the process. For example: when the pressure of the natural gas pipeline network is 4MPa and the pressure of the end user is 1.6MPa, and this part of the pressure can be used for power generation, the recoverable electric energy per square meter of gas is about 12W, and the annual gas transmission volume of the "first line" is 12 billion Calculated in cubic meters, the annual recoverable pressure energy is 13...

AI Technical Summary

Problems solved by technology

However, in the natural gas pipeline network pressure energy recovery and utilization system, there are special working conditions such as emergency gas shutdown or power generation load reduction, which have problems such as impact loss on the key equipment expander, which eventually leads to damage to the expander and affects the stable output of the downstream natural gas supply system.

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