Liquid air energy storage(LAES)has been regarded as a large-scale electrical storage technology.In this paper,we first investigate the performance of the current LAES(termed as a baseline LAES)over a far wider range o...Liquid air energy storage(LAES)has been regarded as a large-scale electrical storage technology.In this paper,we first investigate the performance of the current LAES(termed as a baseline LAES)over a far wider range of charging pressure(1 to 21 MPa).Our analyses show that the baseline LAES could achieve an electrical round trip efficiency(e RTE)above 60%at a high charging pressure of 19 MPa.The baseline LAES,however,produces a large amount of excess heat particularly at low charging pressures with the maximum occurred at~1 MPa.Hence,the performance of the baseline LAES,especially at low charging pressures,is underestimated by only considering electrical energy in all the previous research.The performance of the baseline LAES with excess heat is then evaluated which gives a high e RTE even at lower charging pressures;the local maximum of 62%is achieved at~4 MPa.As a result of the above,a hybrid LAES system is proposed to provide cooling,heating,hot water and power.To evaluate the performance of the hybrid LAES system,three performance indicators are considered:nominal-electrical round trip efficiency(ne RTE),primary energy savings and avoided carbon dioxide emissions.Our results show that the hybrid LAES can achieve a high ne RTE between 52%and 76%,with the maximum at~5 MPa.For a given size of hybrid LAES(1 MW×8 h),the primary energy savings and avoided carbon dioxide emissions are up to 12.1 MWh and 2.3 ton,respectively.These new findings suggest,for the first time,that small-scale LAES systems could be best operated at lower charging pressures and the technologies have a great potential for applications in local decentralized micro energy networks.展开更多
Between 2018 and 2020, an average of 15 TWh of energy peat was consumed in Finland. Energy peat is used in 260 boilers in Finland, which produce district heat and heat and steam for industry, as well as electricity as...Between 2018 and 2020, an average of 15 TWh of energy peat was consumed in Finland. Energy peat is used in 260 boilers in Finland, which produce district heat and heat and steam for industry, as well as electricity as cogeneration (CHP) in connection with district heating and industrial heat production. Peat accounts for 3% - 5% of the energy sources used in Finland, but its importance has been greater in terms of security of supply. With current use in accordance with the 2018-2020 average, the emissions from peat are almost 6 Mt CO<sub>2</sub> per year in Finland, which is 15% of emissions from the energy sector. In this study, the technical limitations related to peat burning, economic limitations related to the availability of biomass, and socio-economic limitations related to the regional economy are reviewed. By 2040, the technical minimum use of peat will fall to 2 TWh. The techno-economical potential may be even lower, but due to socio-economic objectives, peat production will not be completely ceased. The reduction in the minimum share assumes that old peat boilers are replaced with new biomass boilers or are alternatively replaced by other forms of heat production. Based on the biomass reserves, the current use of peat can be completely replaced by forest chips, but regional challenges may occur along the coast and in southern Finland. It is unlikely that the current demand for all peat will be fully replaced by biomass when part of CHP production is replaced by heat production alone and combustion with waste heat sources.展开更多
针对当前纯电微网运行效率较低,且单独参与市场交易时缺乏竞争力等问题,构建了考虑微网间电能交互的多微网联合调度模型。首先,构建含冷热电联供(combined cooling heating and power,CCHP)系统的微网基本调度模型,并通过“以热/冷定电...针对当前纯电微网运行效率较低,且单独参与市场交易时缺乏竞争力等问题,构建了考虑微网间电能交互的多微网联合调度模型。首先,构建含冷热电联供(combined cooling heating and power,CCHP)系统的微网基本调度模型,并通过“以热/冷定电”的方式提高微网调度策略的灵活性;其次,考虑到微网间可直接进行点对点(peer to peer,P2P)交易,建立了考虑P2P交易的多微网联合调度模型;最后,对一个市场运营商与三个CCHP型微网的案例进行仿真。结果表明,所提出的调度方式进一步降低了系统的运行成本。展开更多
因具有经济环保、多能转换等特点,今后热电联产(combined heat and power,CHP)系统将进入规模化应用阶段,优化CHP系统规模与选址有助于解决电网故障时关键负荷保电难题,提升电网运行弹性。为此,在构建考虑动态能效的CHP系统和电-气耦合...因具有经济环保、多能转换等特点,今后热电联产(combined heat and power,CHP)系统将进入规模化应用阶段,优化CHP系统规模与选址有助于解决电网故障时关键负荷保电难题,提升电网运行弹性。为此,在构建考虑动态能效的CHP系统和电-气耦合能源系统网络模型基础上,提出了以经济性最优为目标的电-气综合能源系统关键负荷供应优化方法。以IEEE 14节点系统为例提出CHP系统最佳配置方案,验证内外部故障下所提CHP系统配置方案的有效性和可行性。最后,对CHP系统电效率、能源价格等因素对成本的影响进行敏感度分析。展开更多
基金the partial support from UK EPSRC Manifest Project under EP/N032888/1,EP/P003605/1a UK FCO Science&Innovation Network grant(Global Partnerships Fund)an IGI/IAS Global Challenges Funding(IGI/IAS ID 3041)。
文摘Liquid air energy storage(LAES)has been regarded as a large-scale electrical storage technology.In this paper,we first investigate the performance of the current LAES(termed as a baseline LAES)over a far wider range of charging pressure(1 to 21 MPa).Our analyses show that the baseline LAES could achieve an electrical round trip efficiency(e RTE)above 60%at a high charging pressure of 19 MPa.The baseline LAES,however,produces a large amount of excess heat particularly at low charging pressures with the maximum occurred at~1 MPa.Hence,the performance of the baseline LAES,especially at low charging pressures,is underestimated by only considering electrical energy in all the previous research.The performance of the baseline LAES with excess heat is then evaluated which gives a high e RTE even at lower charging pressures;the local maximum of 62%is achieved at~4 MPa.As a result of the above,a hybrid LAES system is proposed to provide cooling,heating,hot water and power.To evaluate the performance of the hybrid LAES system,three performance indicators are considered:nominal-electrical round trip efficiency(ne RTE),primary energy savings and avoided carbon dioxide emissions.Our results show that the hybrid LAES can achieve a high ne RTE between 52%and 76%,with the maximum at~5 MPa.For a given size of hybrid LAES(1 MW×8 h),the primary energy savings and avoided carbon dioxide emissions are up to 12.1 MWh and 2.3 ton,respectively.These new findings suggest,for the first time,that small-scale LAES systems could be best operated at lower charging pressures and the technologies have a great potential for applications in local decentralized micro energy networks.
文摘Between 2018 and 2020, an average of 15 TWh of energy peat was consumed in Finland. Energy peat is used in 260 boilers in Finland, which produce district heat and heat and steam for industry, as well as electricity as cogeneration (CHP) in connection with district heating and industrial heat production. Peat accounts for 3% - 5% of the energy sources used in Finland, but its importance has been greater in terms of security of supply. With current use in accordance with the 2018-2020 average, the emissions from peat are almost 6 Mt CO<sub>2</sub> per year in Finland, which is 15% of emissions from the energy sector. In this study, the technical limitations related to peat burning, economic limitations related to the availability of biomass, and socio-economic limitations related to the regional economy are reviewed. By 2040, the technical minimum use of peat will fall to 2 TWh. The techno-economical potential may be even lower, but due to socio-economic objectives, peat production will not be completely ceased. The reduction in the minimum share assumes that old peat boilers are replaced with new biomass boilers or are alternatively replaced by other forms of heat production. Based on the biomass reserves, the current use of peat can be completely replaced by forest chips, but regional challenges may occur along the coast and in southern Finland. It is unlikely that the current demand for all peat will be fully replaced by biomass when part of CHP production is replaced by heat production alone and combustion with waste heat sources.
文摘针对当前纯电微网运行效率较低,且单独参与市场交易时缺乏竞争力等问题,构建了考虑微网间电能交互的多微网联合调度模型。首先,构建含冷热电联供(combined cooling heating and power,CCHP)系统的微网基本调度模型,并通过“以热/冷定电”的方式提高微网调度策略的灵活性;其次,考虑到微网间可直接进行点对点(peer to peer,P2P)交易,建立了考虑P2P交易的多微网联合调度模型;最后,对一个市场运营商与三个CCHP型微网的案例进行仿真。结果表明,所提出的调度方式进一步降低了系统的运行成本。
文摘因具有经济环保、多能转换等特点,今后热电联产(combined heat and power,CHP)系统将进入规模化应用阶段,优化CHP系统规模与选址有助于解决电网故障时关键负荷保电难题,提升电网运行弹性。为此,在构建考虑动态能效的CHP系统和电-气耦合能源系统网络模型基础上,提出了以经济性最优为目标的电-气综合能源系统关键负荷供应优化方法。以IEEE 14节点系统为例提出CHP系统最佳配置方案,验证内外部故障下所提CHP系统配置方案的有效性和可行性。最后,对CHP系统电效率、能源价格等因素对成本的影响进行敏感度分析。
