Van Tuyl Lecture: Chunan Tang, Dalian University of Technology
November 15 @ 4:00 pm - 5:00 pm
Chunan Tang, Dalian University of Technology, China
241 Berthoud Hall, 4PM
Topic: Conceptual Model of Enhanced Geothermal System Based on Excavation Technology (EGS-E)
Abstract: The current technology for Enhanced Geothermal System (EGS) typically involves drilling of deep injection and production wells to inject cold water into the injection well to the EGS reservoir depth, to extract heat by permeating through the fractured hot rock masses, collected by the production well and return to the surface as heated water. In this presentation, a new approach is proposed to develop EGS based excavation technology (EGS-E). This method consists of (i) deep rock excavation, including a deep shaft from surface to the EGS depth, caverns, and tunnels radially out and downwards, together to create a large underground reservoir for hot water heated by the hot rocks; (ii) enhanced heat extraction from rock, aided by additional drilling holes spreading out and down from the tunnels, induced fracturing of the surrounding rocks for enhanced rock-water heat transfer; (iii) enclosed heat transmission from hot water reservoir to the power plant by using independent heat conducting pipes running between them, continuously supplying the heat for power generation, without water exchange between the inside and outside of the piples in the reservoir. EGS-E offers the following advantages: (i) utilizing mechanized rock excavation technology; (ii) greatly increasing heat extraction volume by easily extending vertically and horizontally; (iii) maximize the energy transfer through the hot water reservoir and water circulation; and (iv) separated heat transmission from EGS to power plant to minimize environmental pollution.