The recovery of low temperature geothermal energy(30-79℃) in Korea was investigated by injecting air seasonally for local community heating without heat exchanges, when a gas storage development was planned.
Geological informations such as permeability, formation compressibility and leakage identification necessary for underground gas storage development, can be obtained through Air-Injection method.
A preliminary design was conducted for economic feasibility study and aquifer dynamic was experimentally studied to confirm the basic idea. "pore-volume creation and dynamic by compressibility".
Cement powder used as a packing material, it was discovered that permeability behaved as a controlling parameter of aquifer dynamic and hysteresis phenomena became greater as permeability got lower.
And it was found from economic analysis that Air-Injection method, solely for energy recovery purpose, was uneconomical owing to high operating costs, but the overall economic advantage of gas storage system made the energy recovery attractive.
國內 低溫地熱 에너지 (30~79℃)을 工業的으로 回收함과 同時 Gas 地下貯藏 開發을 할 수 있는 Air-Injection 方法을 論하였다. 즉, 壓縮機을 利用하여 여름에 空氣를 溫泉구멍에 加壓, 投入한 後 겨울에 더워진 空氣를 뽑아서 直接溫房에 活用하는 方法으로, 地下貯藏開發에 必要한 地質資料(透過率, 壓縮率) 및 安全問題를 解決할 수 있다.
一次設計를 通하여 經濟性을 分析하였으며, 本案의 基本理論인 "壓縮率에 依한 Pore-Volume 創造 및 Dynamic"을 實驗的으로 確認하였다.
세멘트 粉末을 Packing 物質로 使用함으로써, 透過率이 Aquifer Dynamic 의 가장 重要한 因子가 되며 透過率이 低下될수록 Hysteresis 現象이 深해짐을 發見하였다.
높은 動力費로 말미암아 低溫에너지 回收策 單獨으로써는 非經濟的이지만, 地下貯藏開發의 높은 收益性 때문에 充分히 實現性이 있다고 判斷된다.
