本文以上海某建筑为研究对象,采用Trnsys对该建筑现有地板辐射供冷系统进行模拟研究。根据该建筑的实际状况,为该建筑设计了顶板辐射供冷系统,将两者进行对比分析。结果表明:相比于地板辐射供冷系统,顶板辐射供冷系统对室内热环境调节更...本文以上海某建筑为研究对象,采用Trnsys对该建筑现有地板辐射供冷系统进行模拟研究。根据该建筑的实际状况,为该建筑设计了顶板辐射供冷系统,将两者进行对比分析。结果表明:相比于地板辐射供冷系统,顶板辐射供冷系统对室内热环境调节更快,热惰性更小。整个供冷季节,地板辐射供冷系统能耗为35 826. 2 k W·h,顶板辐射供冷系统能耗为34 181. 9 k W·h,减少了4. 59%。针对该建筑空调系统运行中存在的问题,对顶板辐射供冷空调系统设计了运行时间表,在满足室内热环境标准的前提下,降低系统能耗。在此基础上,针对该建筑空调系统长期定工况运行的问题,分别设计了变水流量控制系统和变水温度控制系统,对比了两种控制系统的实际运行效果。结果表明:变水温度控制系统对室内热环境变化响应更快,且能耗较低。改进系统运行时间表,并采用变水温度控制后,顶板辐射供冷系统供冷季节总能耗为14 665. 3 k W·h,相比于原系统能耗大幅降低。展开更多
A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a va...A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow（VRF）air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.展开更多
Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a su...Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.展开更多
文摘本文以上海某建筑为研究对象,采用Trnsys对该建筑现有地板辐射供冷系统进行模拟研究。根据该建筑的实际状况,为该建筑设计了顶板辐射供冷系统,将两者进行对比分析。结果表明:相比于地板辐射供冷系统,顶板辐射供冷系统对室内热环境调节更快,热惰性更小。整个供冷季节,地板辐射供冷系统能耗为35 826. 2 k W·h,顶板辐射供冷系统能耗为34 181. 9 k W·h,减少了4. 59%。针对该建筑空调系统运行中存在的问题,对顶板辐射供冷空调系统设计了运行时间表,在满足室内热环境标准的前提下,降低系统能耗。在此基础上,针对该建筑空调系统长期定工况运行的问题,分别设计了变水流量控制系统和变水温度控制系统,对比了两种控制系统的实际运行效果。结果表明:变水温度控制系统对室内热环境变化响应更快,且能耗较低。改进系统运行时间表,并采用变水温度控制后,顶板辐射供冷系统供冷季节总能耗为14 665. 3 k W·h,相比于原系统能耗大幅降低。
文摘A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow（VRF）air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.
基金Supported by the "863" Foundation under Grant No.2002AA401000
文摘Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.
