The application of solar thermal energy to preheat cold fresh air for mechanical ventilation could save a lot of energy and ensure the stable operation of the ventilation system.In this paper,a kind of collector-stora...The application of solar thermal energy to preheat cold fresh air for mechanical ventilation could save a lot of energy and ensure the stable operation of the ventilation system.In this paper,a kind of collector-storage solar air heating system(CSSAHS),in which the thermal storage unit(TSU)is characterized by a dual S-channel for heat transfer,is proposed and the mathematical model for the integrated system was established.The model including the TSU,solar air collector,heat recovery device,and the fan was verified by an experimental study set up in a typical cold city in China.The model has been verified by experiments.The simulation results demonstrate that fresh air is the most important factor affecting storage/release efficiency.The increasing rate of heat release efficiency in the range of fresh air temperature-6-18°C is about 1.58%/°C.The solar heat collector area and the size of the TSU suitable for representative cities in cold regions are optimized based on multi-condition simulation analysis.The CSSAHS can preheat fresh air for 5 h after heat storage and the release efficiency is between 52 and 74%.Compared with other systems,the energy-saving rate of the CSSAHS is 26.5-33.3%in cold winter,and the heat supply ratio of the TSU is 24.4-35.1%.展开更多
Expanding the application scenario for rechargeable batteries is the key to the terminal utilization of renewable energy.Enabling zinc–air batteries at low temperatures is drawing increasing attention,yet the low-tem...Expanding the application scenario for rechargeable batteries is the key to the terminal utilization of renewable energy.Enabling zinc–air batteries at low temperatures is drawing increasing attention,yet the low-temperature working feasibility of zinc–air batteries with noble metalfree electrocatalysts remains indistinct.In this contribution,the low-temperature performances of zinc–air batteries with noble metal-free electrocatalysts are comprehensively investigated.Armed with a representative noble metal-free bifunctional oxygen electrocatalyst,the zinc–air batteries demonstrate satisfactory yet relatively depressed performance at low temperatures,compared with that at room temperatures.The reduced electrolyte conductivity is identified as one of the limiting factors for the reduced low-temperature performance.Furthermore,electrolyte engineering via solvation structure regulation is performed on the zinc–air batteries with noblemetal-free electrocatalysts,where an improved low-temperature performance is achieved.This work reveals the compatibility between noble metal-free electrocatalysts and low-temperature feasibility/low-temperature performance enhancement strategies for zinc–air batteries and affords new opportunities to satisfy low-cost and efficient energy storage at harsh working conditions.展开更多
为解决压缩空气储能电站中储气装置容积庞大、制约系统经济性的问题,采用定压供气方案,使储气装置的容积缩减至常规方案的49.63%,从而降低投资成本。通过使用Aspen Plus V11软件模拟计算后,系统的电—电转换效率达到62.48%。综合分析结...为解决压缩空气储能电站中储气装置容积庞大、制约系统经济性的问题,采用定压供气方案,使储气装置的容积缩减至常规方案的49.63%,从而降低投资成本。通过使用Aspen Plus V11软件模拟计算后,系统的电—电转换效率达到62.48%。综合分析结果表明,该系统具有广泛的应用前景,可为清洁能源应用和能源转型提供经济可行的解决方案。展开更多
基金This research was supported by the National Natural Science Fund of China(Grant Nos.52178082 and 51708365)innovative talents project of colleges and universities in Liaoning Province(2020389)Shenyang Science and technology planning project(21-108-9-03).
文摘The application of solar thermal energy to preheat cold fresh air for mechanical ventilation could save a lot of energy and ensure the stable operation of the ventilation system.In this paper,a kind of collector-storage solar air heating system(CSSAHS),in which the thermal storage unit(TSU)is characterized by a dual S-channel for heat transfer,is proposed and the mathematical model for the integrated system was established.The model including the TSU,solar air collector,heat recovery device,and the fan was verified by an experimental study set up in a typical cold city in China.The model has been verified by experiments.The simulation results demonstrate that fresh air is the most important factor affecting storage/release efficiency.The increasing rate of heat release efficiency in the range of fresh air temperature-6-18°C is about 1.58%/°C.The solar heat collector area and the size of the TSU suitable for representative cities in cold regions are optimized based on multi-condition simulation analysis.The CSSAHS can preheat fresh air for 5 h after heat storage and the release efficiency is between 52 and 74%.Compared with other systems,the energy-saving rate of the CSSAHS is 26.5-33.3%in cold winter,and the heat supply ratio of the TSU is 24.4-35.1%.
基金the Key Research and Development Program of Yunnan Province(grant no.202103AA080019)S&T Program of Hebei(grant no.22344402D)+1 种基金National Natural Science Foundation of China(grant no.22109007)Beijing Institute of Technology Research Fund Program for Young Scholars,and the Tsinghua University Initiative Scientific Research Program.
文摘Expanding the application scenario for rechargeable batteries is the key to the terminal utilization of renewable energy.Enabling zinc–air batteries at low temperatures is drawing increasing attention,yet the low-temperature working feasibility of zinc–air batteries with noble metalfree electrocatalysts remains indistinct.In this contribution,the low-temperature performances of zinc–air batteries with noble metal-free electrocatalysts are comprehensively investigated.Armed with a representative noble metal-free bifunctional oxygen electrocatalyst,the zinc–air batteries demonstrate satisfactory yet relatively depressed performance at low temperatures,compared with that at room temperatures.The reduced electrolyte conductivity is identified as one of the limiting factors for the reduced low-temperature performance.Furthermore,electrolyte engineering via solvation structure regulation is performed on the zinc–air batteries with noblemetal-free electrocatalysts,where an improved low-temperature performance is achieved.This work reveals the compatibility between noble metal-free electrocatalysts and low-temperature feasibility/low-temperature performance enhancement strategies for zinc–air batteries and affords new opportunities to satisfy low-cost and efficient energy storage at harsh working conditions.
文摘为解决压缩空气储能电站中储气装置容积庞大、制约系统经济性的问题,采用定压供气方案,使储气装置的容积缩减至常规方案的49.63%,从而降低投资成本。通过使用Aspen Plus V11软件模拟计算后,系统的电—电转换效率达到62.48%。综合分析结果表明,该系统具有广泛的应用前景,可为清洁能源应用和能源转型提供经济可行的解决方案。
