谷物冷却机回风利用与节能

分析了谷物冷却机采用回风型冷却的节能原理及优点，回风型冷却具有重要的节能意义。     

Effect of cooling rate on high temperature mechanical properties of weathering steel

High temperature mechanical properties are key factors which affect fracture production during deforming process of continuous casting. High temperature properties of weathering steel Q450NQR1 are tested in 3 cooling rates (1.65, 5, 10 ℃/s) using Gleeble thermo-mechanical simulator. Specimens appear austenite dynamic recrystallization at 1 050 ℃, and the ductility reaches the lowest point and the reduction of area approaches 23% at 850 ℃ in 3 cooling rates. As the cooling rate increases, the low ductility area where cracks are easy to be produced in slabs is enlarged and extended towards low temperature, and the ductility troughs are deepened. The increase of the cooling rate decreases the tensile stress and yield stress, while when the cooling rate increases to some degree, it doesn’t affect the stress. The low cooling rate decreases the film or network ferrite producing in austenite grain boundary, and the carbonitride of microalloy is enwrapped in matrix, which is helpful to improve the ductility of steel.     

Development of HRB500E seismic grade rebars by using VN microalloyed and controlled cooling process

In order to reduce the production cost of HRB500E seismic grade rebars, promote its production and application, HRB500E seismic grade rebars are developed by using VN microalloyed and controlled cooling process in domestic steel plant. The mechanism and effect of precipitation strengthening and fine-grain strengthening, the relationship between termination temperature after controlled cooling and mechanical properties of rebars, microstructure, welding and aging properties, high-strain and low-cycle fatigue properties for rebars are researched by using metallographic microscopy, scaning electron microcopy, transmission electron microscopy, X-ray diffraction apparatus, flash-butt welding, materials testing machine and mechanical properties testing. The results show that V(C,N) precipitation amount accounts for 66.67% of the total amount of vanadium by adding VN alloy in liquid steel, effect of microalloy precipitation strengthening is remarkable; when termination temperature after controlled cooling is controlled at 680～710 ℃, the amount of strength surplus for rebars is more than 25 MPa, R m/ R eL ratio is greater than 1.26, uniform elongation ( A gt) is more than or equal to 11.5%, good effect of fine grain strengthening and seismic performance are obtained; rebars have some good features such as low strain aging, good welding performance, high-strain and low-cycle fatigue properties; compared with VN microalloyed and hot-rolled process,the production cost is reduced by RMB 82 Yuan/t, and economic benefit is obvious.     

Study on Underground Hot Water Storage Tank Cooling of Solar Energy Heating System

In view of the different of the underground heat storage water tank of solar position arrangement, make use of the Fluent software program numerical simulation and calculation, it is concluded that under different conditions the heat storage water tank temperature field distribution of the soil around. At the same time, establishing physical model and mathematical model of underground heat storage water tank and combined with practical engineering, verify the underground storage tank for heat and energy storage, to obtain the relationship between the tank roof loss and total heat release. Calculation results show that under the same conditions, outdoor storage tank at the top of the heat dissipating capacity to reduce, so the method can be used to offset at the top of the energy required collector to reduce, so the method can be used to offset this part of the energy required collector area of the cut, improve thermal efficiency and reduce the user store hot water tank of the store.     

Analysis of Yangtze River Water as a Potential Source for Developing a Water Source Heat Pump in Chongqing

Characteristics of smoke flow and fire spread in a patio space of a high-rise building were studied to investigate their influences on fire compartment and safety evacuation. Fire development model was established and fire scenarios were designed to simulate fire and smoke spread by CFD software numerically based on concepts of fire performance-based design in a high-rise building with double patio space, whose height are 74. 65 m and 55. 95 m, respectively. Simulation results show that in all fire scenarios, performance targets for safety evacuation for people in each floor was satisfied, if smoke was extracted naturally using the patio space. Hang walls mounted in corridors around the patio space prevent smoke flowing out smoothly, shorten the coming of the risk time and increase fire danger. Using chimney effect, it is preferred to adopt natural smoke exhaust method in a high rise building with patio space.     

太阳能制冷低温储粮应用效果初探

从降低机械压缩式制冷低温储粮能耗及运行成本的角度出发,设计、建造了一台太阳能吸附式制冷系统,并将该系统在高温季节进行了低温储粮的实仓实验。测试结果表明:在夏秋高温季节,采用太阳能制冷系统冷却粮仓上部空气隔离层,可有效降低仓温,抑制粮温回升,实现准低温储粮。经济性分析表明太阳能制冷系统用于低温储粮的运行成本明显低于压缩式制冷谷物冷却机。     

Analysis About the Coupling Circuit of the Communication With Low-voltage Power Line

In the interest of realizing carrier communication using LVPL, it is sticking point to analyse and design the coupling circuit of the communication. Higher efficiency of loading carrier signals is necessary. On the other hand, disturbs from LVPL should be overcome. Penman commendably resolved the difficult problem with the "complex-coupling-technology" of combining " electromagnetism - coupling" to "RC-coupling". Based on the " complex - coupling-technology" , "the interface circuit of the communication is analyzed and designed with LVPL. Simulation results and experimentation results show : the coupling circuit not only has higher efficiency of loading carrier signals but also can completely close off 50 Hz signal from LVPL. Therefore, the coupling circuit can apply to communication systems on LVPL.     

我国畜禽舍机械式降温系统的研究与发展现状

论述了我国畜禽舍机械式降温系统的研究与应用现状;比较分析了各种降温系统的优缺点与应用条件;考虑到设备投资与应用成本,认为采用正压送风的湿帘冷风机具有较大的应用潜力,集中式雾化降温系统和喷雾冷风机具有一定的优势;同时,指出了喷雾降温系统的研究重点是开发低成本的设备和完善适用于低压喷雾的集中式雾化降温系统的水雾分离装置.     

矿用高压开关电器短路开断与关合试验电源

针对国内冲击发电机性能参数不足,以国外冲击发电机作为试验电源,建立基于直接试验法的矿用高压开关电器短路开断与关合试验系统,提出了一种新的技术解决方案。仿真试验结果表明,该方案满足综合性煤矿高压电气实验室建设项目技术指标和试验标准要求,为大容量开断与关合试验系统设计和建造提供一种技术思路。     

Design of wireless inductive power receiver circuit in artificial subretinal chip

A scheme of inductive wireless receiver circuit is put forward, according to special requirement of inductive wireless power supply in artificial subretinal prosthesis circuit. The proposed receiver circuit can be divided into CMOS rectifier, regulator and self-biasing circuit. The CMOS rectifier is used to provide power supply for regulator and self-biasing circuit. The self-biasing circuit furnishes the regulator with bias voltage and bias current which is independent from power supply. The proposed receiver circuit is designed by Cadence tool and Chartered 0.35 μm CMOS device model, and oscillator in artificial subretinal chip is used as the proposed receiver circuit’s load. The results show that the proposed receiver circuit can provide load capacity of 3.3 V and >1 mA,with a layout size of 62 μm×195 μm.