S-CO2 power generation system and method for developing geothermal energy of hot dry rock based on finned casing pipe

Abstract

The invention discloses an S-CO2 power generation system and method for developing geothermal energy of hot dry rock based on a finned casing pipe. The finned casing pipe is a coaxial casing pipe, andthe system is composed of an outer-layer descending pipe segment, an outer-layer enhanced heat exchanging pipe segment, an inner backflow pipe, an S-CO2 gas turbine, a power generator, a compressor and the like. According to the innovation point of the S-CO2 power generation system and method for developing the geothermal energy of the hot dry rock based on the finned casing pipe, by means of closed-loop circulation of S-CO2 in the finned casing pipe, the geothermal energy is transmitted to the gas turbine from a hot dry rock layer; the finned casing pipe and the gas turbine both adopt the S-CO2 as circulating work media, and the heat exchanger end difference is eliminated; and fins are added outside a hot dry rock segment, the heat transfer area is increased, and the single well output is improved. The S-CO2 flows to the bottom of a heat taking well from the outer layer of a heat taking casing pipe to be collected to the inner layer, the geothermal energy in the hot dry rock is absorbed in the descending process, temperature ceaselessly rises, the S-CO2 then flows back to the ground from the inner layer, and the geothermal energy is converted into high-grade electric energy through the S-CO2 gas turbine and the power generator. After being detected by a work medium detecting unit and pressurized by the compressor, the S-CO2 starts new circulating, and sustainable exploitationof the geothermal energy of the hot dry rock is achieved.

Description

technical field [0001] The invention relates to the field of hot dry rock geothermal exploitation, in particular to S-CO2 based on finned casings for developing hot dry rock geothermal energy 2 (supercritical CO 2 ) power generation system and method. Background technique [0002] Geothermal energy is a green, low-carbon, recyclable and renewable energy. It has the characteristics of large reserves, wide distribution, cleanness, environmental protection, stability and reliability. It is a feasible and competitive clean energy. Geothermal energy is divided into shallow geothermal resources, hydrothermal geothermal resources and thermal dry rock resources. At present, both shallow and hydrothermal geothermal resources have been widely used, and thermal dry rock resources account for more than 95% of geothermal energy storage in my country. Not yet exploited. Hydrothermal geothermal resources have the problem of water level drop or resource depletion. The total amount of shal...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the deficiencies of the existing enhanced geothermal power generation system, the purpose of the present invention is to provide S-CO based on the development of hot dry rock geothermal energy based on fin casings. 2 Power generation system and method and method, the fin casing is divided into inner and outer layers, S‐CO 2 It flows from the outer layer to the bottom of the well to absorb the heat energy of dry rock, returns to the ground through the inner return pipe and enters the gas turbine to do work, and then flows from the outer layer of the heat extraction well pipe to the bottom of the well to absorb the heat energy of dry rock; S‐CO 2 Closed circulation inside the heat extraction well tube, the outer surface of the fins enhance heat transfer to absorb the heat energy of the hot dry rock formation, and only one geothermal well can ensure the sustainable development of hot dry rock thermal power generation

Images