The isobaric energy recovery device can significantly reduce the energy consumption of the seawater reverse osmosis system by recycling the residual pressure energy of high-pressure concentrated brine.Three-cylinder v...The isobaric energy recovery device can significantly reduce the energy consumption of the seawater reverse osmosis system by recycling the residual pressure energy of high-pressure concentrated brine.Three-cylinder valve-controlled energy recovery device(TC-ERD)solves the fluid pulsation of traditional two-cylinder devices,but the use of a“liquid piston”exacerbates the mixing between brine and seawater.Herein,the evolutionary law of“liquid piston”and the relationship between volumetric mixing degree and operating conditions are explored.The results show that the“liquid piston”first axially expands and then gradually stabilizes,isolating the brine and seawater.Additionally,as long as the volume utilization ratio(U_(R))of the pressure exchange cylinder remains constant,there will not be much difference in the volumetric mixing degree after stabilization of the“liquid piston”(Vm-max)regardless of changes in the processing capacity(Q)and cycle time(T_(0)).Therefore,the equation for Vm-max with respect to the operating parameters(Q,T_(0))is derived,which can not only predict the Vm-max of the TCERD,but also provide an empirical reference for the design of other valve-controlled devices with“liquid piston”.When the Vm-max is 6%,the efficiency of the TC-ERD at design conditions(30 m^(3)·h^(-1),5.0 MPa)is 97.53%.展开更多
Compressed air energy storage(CAES)is an important technology in the development of renewable energy.The main advantages of CAES are its high energy capacity and environmental friendliness.One of the main challenges i...Compressed air energy storage(CAES)is an important technology in the development of renewable energy.The main advantages of CAES are its high energy capacity and environmental friendliness.One of the main challenges is its low energy density,meaning a natural cavern is required for air storage.High-pressure air compression can effectively solve the problem.A liquid piston gas compressor facilitates high-pressure compression,and efficient convective heat transfer can significantly reduce the compression energy consumption during air compression.In this paper,a near isothermal compression method is proposed to increase the surface area and heat exchange by using multiple tube bundles in parallel in the compression chamber in order to obtain high-pressure air using liquid-driven compression.Air compression with a compression ratio of 6.25:1 is achieved by reducing the tube diameter and increasing the parallel tube number while keeping the compression chamber cross-sectional area constant in order to obtain a high-pressure air of 5 MPa.The performances of this system are analyzed when different numbers of tubes are applied.A system compression efficiency of 93.0%and an expansion efficiency of 92.9%can be achieved when 1000 tubes are applied at a 1 minute period.A new approach is provided in this study to achieve high efficiency and high pressure compressed air energy storage.展开更多
基金supported by the Natural Science Foundation of Fujian Province(2023J011020)the Education Department of Fujian Province/Sanming University(JAT220348/B202202)Sanming University(22YG12,PYT2202).
文摘The isobaric energy recovery device can significantly reduce the energy consumption of the seawater reverse osmosis system by recycling the residual pressure energy of high-pressure concentrated brine.Three-cylinder valve-controlled energy recovery device(TC-ERD)solves the fluid pulsation of traditional two-cylinder devices,but the use of a“liquid piston”exacerbates the mixing between brine and seawater.Herein,the evolutionary law of“liquid piston”and the relationship between volumetric mixing degree and operating conditions are explored.The results show that the“liquid piston”first axially expands and then gradually stabilizes,isolating the brine and seawater.Additionally,as long as the volume utilization ratio(U_(R))of the pressure exchange cylinder remains constant,there will not be much difference in the volumetric mixing degree after stabilization of the“liquid piston”(Vm-max)regardless of changes in the processing capacity(Q)and cycle time(T_(0)).Therefore,the equation for Vm-max with respect to the operating parameters(Q,T_(0))is derived,which can not only predict the Vm-max of the TCERD,but also provide an empirical reference for the design of other valve-controlled devices with“liquid piston”.When the Vm-max is 6%,the efficiency of the TC-ERD at design conditions(30 m^(3)·h^(-1),5.0 MPa)is 97.53%.
文摘Compressed air energy storage(CAES)is an important technology in the development of renewable energy.The main advantages of CAES are its high energy capacity and environmental friendliness.One of the main challenges is its low energy density,meaning a natural cavern is required for air storage.High-pressure air compression can effectively solve the problem.A liquid piston gas compressor facilitates high-pressure compression,and efficient convective heat transfer can significantly reduce the compression energy consumption during air compression.In this paper,a near isothermal compression method is proposed to increase the surface area and heat exchange by using multiple tube bundles in parallel in the compression chamber in order to obtain high-pressure air using liquid-driven compression.Air compression with a compression ratio of 6.25:1 is achieved by reducing the tube diameter and increasing the parallel tube number while keeping the compression chamber cross-sectional area constant in order to obtain a high-pressure air of 5 MPa.The performances of this system are analyzed when different numbers of tubes are applied.A system compression efficiency of 93.0%and an expansion efficiency of 92.9%can be achieved when 1000 tubes are applied at a 1 minute period.A new approach is provided in this study to achieve high efficiency and high pressure compressed air energy storage.
