Use of the low temperature (less than 100°C) energy contributes to effective use of heat resources. The cost recovery by power generation is difficult by using an existing system (the binary cycle or the thermoel...Use of the low temperature (less than 100°C) energy contributes to effective use of heat resources. The cost recovery by power generation is difficult by using an existing system (the binary cycle or the thermoelectric conversion element), because the initial investment is large. The final purpose of this research is development of the low temperature difference drive engine supposing use in a hot-springs resort as a power source for electric power generation. In order that a traveler may look at and delight a motion of an engine, it is made to drive at low-speed number of rotations. An engine cycle of this study is aimed at the development of Stirling cycle engine which can maintain high efficiency in small size. This kind of engine has simple structure;it brings low cost, and it is easy to perform maintenance. However, it is difficult to obtain enough output by this type of engine, because of its low temperature difference. This paper deals with the heat transfer characteristic that the working fluid including a phase change material flows into the heating surface from the narrow path. In order to increase the amount of the heat transmission, Diethylether is added to the working fluid. Diethylether is selected as a phase change material (PCM) that has the boiling point which exists between the heat source of high temperature and low temperature. The parameters of the experiment are additive amount of PCM, rotational speed of the displacer piston and temperature of heat transfer surface. It is shown that it is possible to make exchange of heat amount increase by adding phase change material. The result of this research shows the optimal condition of the difference in temperature in heat processing, number of revolutions, and addition concentration of PCM.展开更多
The characteristics and microstructural changes of cyclic softening in hot-working die steels 5CrNiMo and 5Cr2NiMoVSi were studied under strain controlled low-cycle fatigue.The re- sults show that the cyclic softening...The characteristics and microstructural changes of cyclic softening in hot-working die steels 5CrNiMo and 5Cr2NiMoVSi were studied under strain controlled low-cycle fatigue.The re- sults show that the cyclic softening is featured in both steels hardened in different conditions under the strain controlled amplitude range of Δε_t/2=0.6-1.8×10^(-2).The softening effect mainly occurs in some initial cycles and the stress amplitude varies slightly in the sequential cycles,i.e.the softening effect is minified.No obvious stress saturation phenomenon was ob- served during the whole cyclic deformation.The TEM analysis shows that the cyclic softening is related to heterogenity of plastic deformation.The softening of the tested steels is caused by the formation of the dislocation cell structure with low density and low internal stress,and by the fragmentation and redissolution of fine carbides into matrix.展开更多
The preparation process of the CO gas sensor used at normal temperature is presented.The electric conductance of this type of sensor evolved oscillation from regularly when the sensor is exposed to low level CO gas.Th...The preparation process of the CO gas sensor used at normal temperature is presented.The electric conductance of this type of sensor evolved oscillation from regularly when the sensor is exposed to low level CO gas.The gas sensing mechanism was investigated by its crystalline structure.The mechanism of information sensing,which was the concurrence of the grain boundary barrier control and the crystal surface control,is discussed.展开更多
Due to the rapid development of China＇ s rail transportation equipment manufacturing industry and related international distribution, important material suppliers such as Baoshan Iron ＆ Steel Co., Ltd. carries on in...Due to the rapid development of China＇ s rail transportation equipment manufacturing industry and related international distribution, important material suppliers such as Baoshan Iron ＆ Steel Co., Ltd. carries on investigating the stability of material under extremely cold conditions. In this study, mechanical properties and secondary work embrittlement of weathering steel 05CuPCrNi were tested at low temperature. Compared to the mechanical properties at room temperature, the yield and tensile strength increase slightly with decreasing temperature. However, the variation of elongation is not obvious. The experimental results also show that the secondary work embrittlement transition temperature of 05CuPCrNi is lower than - 60 ℃. These results provide the basis for the use of this train body material in extremely cold regions.展开更多
该文针对智能装配管理系统第二阶段的优化,主要关注系统高度定制性、用户交互和信息管理效率的提升。系统支持10 k V断路器和ZW32高压交流真空断路器等生产线,具备集中部署、独立服务和自定义表单等功能。系统设计重点包括多生产线并行...该文针对智能装配管理系统第二阶段的优化,主要关注系统高度定制性、用户交互和信息管理效率的提升。系统支持10 k V断路器和ZW32高压交流真空断路器等生产线,具备集中部署、独立服务和自定义表单等功能。系统设计重点包括多生产线并行支持、用户角色管理、订单处理流程优化和与现有生产信息系统的集成。同时,通过流程优化改善用户交互体验,增加更高效的数据录入方法和订单追踪功能。展开更多
文摘Use of the low temperature (less than 100°C) energy contributes to effective use of heat resources. The cost recovery by power generation is difficult by using an existing system (the binary cycle or the thermoelectric conversion element), because the initial investment is large. The final purpose of this research is development of the low temperature difference drive engine supposing use in a hot-springs resort as a power source for electric power generation. In order that a traveler may look at and delight a motion of an engine, it is made to drive at low-speed number of rotations. An engine cycle of this study is aimed at the development of Stirling cycle engine which can maintain high efficiency in small size. This kind of engine has simple structure;it brings low cost, and it is easy to perform maintenance. However, it is difficult to obtain enough output by this type of engine, because of its low temperature difference. This paper deals with the heat transfer characteristic that the working fluid including a phase change material flows into the heating surface from the narrow path. In order to increase the amount of the heat transmission, Diethylether is added to the working fluid. Diethylether is selected as a phase change material (PCM) that has the boiling point which exists between the heat source of high temperature and low temperature. The parameters of the experiment are additive amount of PCM, rotational speed of the displacer piston and temperature of heat transfer surface. It is shown that it is possible to make exchange of heat amount increase by adding phase change material. The result of this research shows the optimal condition of the difference in temperature in heat processing, number of revolutions, and addition concentration of PCM.
文摘The characteristics and microstructural changes of cyclic softening in hot-working die steels 5CrNiMo and 5Cr2NiMoVSi were studied under strain controlled low-cycle fatigue.The re- sults show that the cyclic softening is featured in both steels hardened in different conditions under the strain controlled amplitude range of Δε_t/2=0.6-1.8×10^(-2).The softening effect mainly occurs in some initial cycles and the stress amplitude varies slightly in the sequential cycles,i.e.the softening effect is minified.No obvious stress saturation phenomenon was ob- served during the whole cyclic deformation.The TEM analysis shows that the cyclic softening is related to heterogenity of plastic deformation.The softening of the tested steels is caused by the formation of the dislocation cell structure with low density and low internal stress,and by the fragmentation and redissolution of fine carbides into matrix.
文摘The preparation process of the CO gas sensor used at normal temperature is presented.The electric conductance of this type of sensor evolved oscillation from regularly when the sensor is exposed to low level CO gas.The gas sensing mechanism was investigated by its crystalline structure.The mechanism of information sensing,which was the concurrence of the grain boundary barrier control and the crystal surface control,is discussed.
文摘Due to the rapid development of China＇ s rail transportation equipment manufacturing industry and related international distribution, important material suppliers such as Baoshan Iron ＆ Steel Co., Ltd. carries on investigating the stability of material under extremely cold conditions. In this study, mechanical properties and secondary work embrittlement of weathering steel 05CuPCrNi were tested at low temperature. Compared to the mechanical properties at room temperature, the yield and tensile strength increase slightly with decreasing temperature. However, the variation of elongation is not obvious. The experimental results also show that the secondary work embrittlement transition temperature of 05CuPCrNi is lower than - 60 ℃. These results provide the basis for the use of this train body material in extremely cold regions.
文摘该文针对智能装配管理系统第二阶段的优化,主要关注系统高度定制性、用户交互和信息管理效率的提升。系统支持10 k V断路器和ZW32高压交流真空断路器等生产线,具备集中部署、独立服务和自定义表单等功能。系统设计重点包括多生产线并行支持、用户角色管理、订单处理流程优化和与现有生产信息系统的集成。同时,通过流程优化改善用户交互体验,增加更高效的数据录入方法和订单追踪功能。
