Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power gen...Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power generation. Cascade utilization of energy is realized in the two thermal cycles, where low-level waste heat,low-temperature exergy and pressure exergy of LNG are utilized efficiently through the system synthesis. The simulations are carried out using the commercial Aspen Plus 10.2, and the results are analyzed. Compared with the conventional Brayton cycle and Rankine cycle, the two novel cycles bring 60.94% and 60% in exergy efficiency, respectively and 53.08% and 52.31% in thermal efficiency, respectively.展开更多
The diffusion of chemical species down concentration gradient is a ubiquitous phenomenon that releases Gibbs free energy.Nanofluidic materials have shown great promise in harvesting the energy from ionic diffusion via...The diffusion of chemical species down concentration gradient is a ubiquitous phenomenon that releases Gibbs free energy.Nanofluidic materials have shown great promise in harvesting the energy from ionic diffusion via the reverse electrodialysis process.In principle,any chemicals that can be converted to ions can be used for nanofluidic power generation.In this work,we demonstrate the power generation from the diffusion of CO_(2) into air using nanofluidic cellulose membranes.By dissolving CO_(2) in water,a power density of 87 mW/m^(2) can be achieved.Using monoethanolamine solutions to dissolve CO_(2),the power density can be increased to 2.6 W/m^(2).We further demonstrate that the waste heat released in industrial and carbon capture processes,can be simultaneously harvested with our nanofluidic membranes,increasing the power density up to 16 W/m^(2) under a temperature difference of 30°C.Therefore,our work should expand the application scope of nanofluidic osmotic power generation and contribute to carbon utilization and capture technologies.展开更多
The customarily discarded exhaust from the fossil fuel-based power plants of the off-grid mines holds the thermal potential to fulfill the heating requirement of the underground operation.This present research fills i...The customarily discarded exhaust from the fossil fuel-based power plants of the off-grid mines holds the thermal potential to fulfill the heating requirement of the underground operation.This present research fills in an important research gap by investigating the coupling effect between a diesel exhaust heat recovery and an intake air heating system employed in a remote mine.An integrative approach comprising analytical,numerical,and experimental assessment has been adapted.The novel analytical model developed here establishes the reliability of the proposed mine heating system by providing comparative analysis between a coupled and a decoupled system.The effect of working fluid variation has been examined by the numerical analysis and the possible improvement has been identified.Experimental investigations present a demonstration of the successful lab-scale implementation of the concept and validate the numerical and analytical models developed.Successful deployment of the fully coupled mine heating system proposed here will assist the mining industry on its journey towards energy-efficient,and sustainable mining practices through nearly 70%reduction in fossil fuel consumption for heating intentions.展开更多
The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consi...The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consideration can be made by energy self-sufficient when all fish waste oil is processed into biodiesel and further converted to electricity and heat （for cooling） in a CHP （combined heat and power） unit. The purpose of the present paper is to discuss the profitability of such plants in southeast Asia. The economic model shows that electricity production is, due to the low electricity tariff, uneconomical （except during electricity blackout）, even if cogeneration heat can be utilized. This prompt a design of the plant whereby the necessary heat for the biodiesel process is taken from the waste heat produced by the compressors of a CO2 cooling system. According to the calculations and assumptions of the present study, the profitability of biodiesel production from fish cleaning wastes in Vietnam depends strongly on the market prices for fish waste and fish oil. Different business case scenarios are described.展开更多
基金the Science and Technology Foundation of Shaanxi Province (No.2002K08-G9).
文摘Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power generation. Cascade utilization of energy is realized in the two thermal cycles, where low-level waste heat,low-temperature exergy and pressure exergy of LNG are utilized efficiently through the system synthesis. The simulations are carried out using the commercial Aspen Plus 10.2, and the results are analyzed. Compared with the conventional Brayton cycle and Rankine cycle, the two novel cycles bring 60.94% and 60% in exergy efficiency, respectively and 53.08% and 52.31% in thermal efficiency, respectively.
基金National Natural Science Foundation of China(22272194)Key R&D Projects of Shandong Province(2022CXGC010302)+1 种基金Shandong Provincial Natural Science Foundation(ZR2021YQ12)Shandong Energy Institute(SEI202124).
文摘The diffusion of chemical species down concentration gradient is a ubiquitous phenomenon that releases Gibbs free energy.Nanofluidic materials have shown great promise in harvesting the energy from ionic diffusion via the reverse electrodialysis process.In principle,any chemicals that can be converted to ions can be used for nanofluidic power generation.In this work,we demonstrate the power generation from the diffusion of CO_(2) into air using nanofluidic cellulose membranes.By dissolving CO_(2) in water,a power density of 87 mW/m^(2) can be achieved.Using monoethanolamine solutions to dissolve CO_(2),the power density can be increased to 2.6 W/m^(2).We further demonstrate that the waste heat released in industrial and carbon capture processes,can be simultaneously harvested with our nanofluidic membranes,increasing the power density up to 16 W/m^(2) under a temperature difference of 30°C.Therefore,our work should expand the application scope of nanofluidic osmotic power generation and contribute to carbon utilization and capture technologies.
文摘The customarily discarded exhaust from the fossil fuel-based power plants of the off-grid mines holds the thermal potential to fulfill the heating requirement of the underground operation.This present research fills in an important research gap by investigating the coupling effect between a diesel exhaust heat recovery and an intake air heating system employed in a remote mine.An integrative approach comprising analytical,numerical,and experimental assessment has been adapted.The novel analytical model developed here establishes the reliability of the proposed mine heating system by providing comparative analysis between a coupled and a decoupled system.The effect of working fluid variation has been examined by the numerical analysis and the possible improvement has been identified.Experimental investigations present a demonstration of the successful lab-scale implementation of the concept and validate the numerical and analytical models developed.Successful deployment of the fully coupled mine heating system proposed here will assist the mining industry on its journey towards energy-efficient,and sustainable mining practices through nearly 70%reduction in fossil fuel consumption for heating intentions.
文摘The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consideration can be made by energy self-sufficient when all fish waste oil is processed into biodiesel and further converted to electricity and heat （for cooling） in a CHP （combined heat and power） unit. The purpose of the present paper is to discuss the profitability of such plants in southeast Asia. The economic model shows that electricity production is, due to the low electricity tariff, uneconomical （except during electricity blackout）, even if cogeneration heat can be utilized. This prompt a design of the plant whereby the necessary heat for the biodiesel process is taken from the waste heat produced by the compressors of a CO2 cooling system. According to the calculations and assumptions of the present study, the profitability of biodiesel production from fish cleaning wastes in Vietnam depends strongly on the market prices for fish waste and fish oil. Different business case scenarios are described.
