Renewable energy storage technologies are critical for transitioning to sustainable energy systems,with salt caverns playing a significant role in large-scale solutions.In water-soluble mining of low-grade salt format...Renewable energy storage technologies are critical for transitioning to sustainable energy systems,with salt caverns playing a significant role in large-scale solutions.In water-soluble mining of low-grade salt formations,insoluble impurities and interlayers detach during salt dissolution and accumulate as sediment at the cavern base,thereby reducing the storage capacity and economic viability of salt cavern gas storage(SCGS).This study investigates sediment formation mechanisms,void distribution,and voidage in the Huai'an low-grade salt mine,introducing a novel self-developed physical simulation device for two butted-well horizontal(TWH)caverns that replicates compressed air injection and brine discharge.Experiments comparing“one injection and one discharge”and“two injections and one discharge”modes revealed that(1)compressed air effectively displaces brine from sediment voids,(2)a 0.5 MPa injection pressure corresponds to a 10.3 MPa operational lower limit in practice,aligning with field data,and(3)sediment voidage is approximately 46%,validated via air-brine interface theory.The“two injections and one discharge”mode outperformed in both discharge volume and rate.Additionally,a mathematical model for brine displacement via compressed air was established.These results provide foundational insights for optimizing compressed air energy storage(CAES)in low-grade salt mines,advancing their role in renewable energy integration.展开更多
以天津滨海新区吹填泥浆为研究对象,对初始含水率w_0=200%~2000%的泥浆开展长达100 d的自然沉降模型试验,研究吹填泥浆的自重沉降固结规律与形成土的微观结构特性,据此提出吹填工程设计的控制指标,为吹填工程的设计与施工提供可靠的技...以天津滨海新区吹填泥浆为研究对象,对初始含水率w_0=200%~2000%的泥浆开展长达100 d的自然沉降模型试验,研究吹填泥浆的自重沉降固结规律与形成土的微观结构特性,据此提出吹填工程设计的控制指标,为吹填工程的设计与施工提供可靠的技术支撑。结果表明,天津吹填泥浆的沉降类型主要是沉积沉降和固结沉降,沉积沉降过程分为絮凝阶段、阻碍沉降阶段、自重固结阶段。含水率临界值(或土的形成含水率)w_0*=400%,且w_0*与液限w_L具有较好的线性关系。初始含水率w_0≤w_0*,发生固结沉降,沉降量可以用一维固结理论计算;w_0>w_0*,发生沉积沉降,沉降量可以用沉积规律计算。土的形成孔隙比e_0*=10.92;沉降稳定时间Tc可用Tc=159(w_0/w_L)^(-1)计算;稳定孔隙比e_c可由分段公式计算,e_c=0.08+5.4(e_0≥13.65),e_c=0.4+1.03(e_0<13.65);絮凝屈服应力P_s=0.3 k Pa,界限孔隙比e_s=6.4。研究还表明,泥浆沉降过程其实是絮凝屈服应力与有效应力相互影响的过程,进而产生不同的沉降特征;吹填形成土在平行于沉降方向为絮凝结构,而垂直沉降方向呈堆叠结构。展开更多
基金financial support from the National Key Research and Development Program of China(No.2024YFB4007100)the Basic ForwardLooking Project of the Sinopec Science and Technology Department,“Research on the Long-Term Sealing Mechanism of Multi-layer Salt Cavern Hydrogen Storage”(No.P24197-4)。
文摘Renewable energy storage technologies are critical for transitioning to sustainable energy systems,with salt caverns playing a significant role in large-scale solutions.In water-soluble mining of low-grade salt formations,insoluble impurities and interlayers detach during salt dissolution and accumulate as sediment at the cavern base,thereby reducing the storage capacity and economic viability of salt cavern gas storage(SCGS).This study investigates sediment formation mechanisms,void distribution,and voidage in the Huai'an low-grade salt mine,introducing a novel self-developed physical simulation device for two butted-well horizontal(TWH)caverns that replicates compressed air injection and brine discharge.Experiments comparing“one injection and one discharge”and“two injections and one discharge”modes revealed that(1)compressed air effectively displaces brine from sediment voids,(2)a 0.5 MPa injection pressure corresponds to a 10.3 MPa operational lower limit in practice,aligning with field data,and(3)sediment voidage is approximately 46%,validated via air-brine interface theory.The“two injections and one discharge”mode outperformed in both discharge volume and rate.Additionally,a mathematical model for brine displacement via compressed air was established.These results provide foundational insights for optimizing compressed air energy storage(CAES)in low-grade salt mines,advancing their role in renewable energy integration.
文摘以天津滨海新区吹填泥浆为研究对象,对初始含水率w_0=200%~2000%的泥浆开展长达100 d的自然沉降模型试验,研究吹填泥浆的自重沉降固结规律与形成土的微观结构特性,据此提出吹填工程设计的控制指标,为吹填工程的设计与施工提供可靠的技术支撑。结果表明,天津吹填泥浆的沉降类型主要是沉积沉降和固结沉降,沉积沉降过程分为絮凝阶段、阻碍沉降阶段、自重固结阶段。含水率临界值(或土的形成含水率)w_0*=400%,且w_0*与液限w_L具有较好的线性关系。初始含水率w_0≤w_0*,发生固结沉降,沉降量可以用一维固结理论计算;w_0>w_0*,发生沉积沉降,沉降量可以用沉积规律计算。土的形成孔隙比e_0*=10.92;沉降稳定时间Tc可用Tc=159(w_0/w_L)^(-1)计算;稳定孔隙比e_c可由分段公式计算,e_c=0.08+5.4(e_0≥13.65),e_c=0.4+1.03(e_0<13.65);絮凝屈服应力P_s=0.3 k Pa,界限孔隙比e_s=6.4。研究还表明,泥浆沉降过程其实是絮凝屈服应力与有效应力相互影响的过程,进而产生不同的沉降特征;吹填形成土在平行于沉降方向为絮凝结构,而垂直沉降方向呈堆叠结构。
