基于CPLD的柴油机高压共轨电控系统控制信号的产生

文章主要用CPLD实现了柴油机高压共轨电控系统主要控制信号的产生。运用MAX7000S系列的CPLD和支持该CPLD的MAX plus II 10.2 BASELINE开发软件,结合硬件描述语言VHDL,通过设计输入、编译、调试和仿真,完成了所需实现的硬件功能,并将程序固化到CPLD中,最后通过了电路实验的验证。CPLD的使用,可缩短硬件开发周期,便于程序修改,提高ECU的集成度,减小电路板的体积,增强抗电磁干扰性能,便于进行程序修改。     

基于DSP+CPLD模式的变电站电气设备在线监测采集系统

讨论了基于DSP CPLD模式的变电站电气设备在线监测采集系统。以断路器为例介绍了系统硬件结构、工作原理，提出利用DSP CPLD模式扩展系统外围器件，并分析了这种硬件结构的优势。最后得出结论。基于DSP CPLD模式的硬件系统将以其高速度、高集成度和高可靠性在电气设备在线监测中发挥重要作用。     

基于DSP+CPLD+PLC的凝壳炉电源控制器的设计

针对现有凝壳炉用直流电源晶闸管导通的一致性不高,输出电流稳定性不好等问题,文中提出了一种使用DSP与CPLD相结合对电源进行控制的方案。该系统以DSP进行信号的调理,CPLD进行脉冲分配,两者分工明确。使用PLC对整个系统进行监控与保护,保障了系统运行的稳定性。最后的仿真与调试结果证明了设计的可行性。     

基于CPLD的柴油机高压共轨控制系统硬件的开发

主要介绍了基于CPLD的柴油机高压共轨燃油控制系统的硬件开发。其中用到CPLD器件MAX7000S系列的EPM7128SLC84—6来对硬件电路的逻辑部分进行集成开发，使得电路板体积紧凑，模块化强，增强了硬件电路板的抗干扰能力，在调试中易于随时更改。用verilong HDL语言对所需实现的硬件功能进行编程、调试、仿真，最后固化到器件上实现原电路板中相应的逻辑功能。     

基于可编程逻辑器件的电喷控制单元

根据机车用多缸大功率柴油机对于电喷控制系统的要求,提出了采用可编程逻辑器件扩展电喷控制通道的方案,具体讨论了基于CPU＋CPLD架构的新型电喷控制单元的控制原理和实现方式。     

采煤机变频器的软件设计与实验研究

为提高采煤机利用电能的效率,针对SPWM脉宽调制的变频器直流电压利用率低、输出电流的谐波含量高的问题,以数字信号处理器TMS320F2812为核心,CPLD为辅助控制电路,DSP完成算法设计,CPLD实现逻辑控制与键盘显示,最大发挥各自的性能.采用软件法实现空间矢量脉宽的调制.实验结果表明：该方法比硬件法谐波含量相对减少,电机电流的谐波小,实现了频率调节范围为1～50 Hz,低的电机高频噪声,高的电压利用率.     

基于CPLD的三相晶闸管数字移相触发器设计

介绍一种应用于三相晶闸管整流或逆变电路的数字移相触发电路,该电路以CPLD为核心,产生的触发脉冲稳定性好,可靠性高;同时不需要同步变压器,实现了相序自适应。     

发动机台架采集系统多功能接口研究

在发动机试验台架数据采集系统中,需要处理不同类型的大量数据信号,要求数据采集系统提供大量的多功能接口.在采集模块设计上,需要对ARM微控制器(MCU)进行功能接口扩展,本文应用CPLD技术扩展接口可以发挥CPLD逻辑编程强、占用资源少的优势.本文设计的并行、串行接口具备多功能的需要,能够充分发挥微控制器性能,实现发动机台架试验检测系统的需要.     

基于CPLD的共轨喷油器电磁阀电流调制系统

根据共轨喷油器电磁阀驱动特点,设计了基于复杂可编程逻辑器件(CPLD)的电流调制系统,实现了对电磁阀的驱动电流控制和短路保护,系统仅需要微控制器(MCU)提供时钟和驱动脉宽即可完成喷油时序,与MCU直接控制的驱动系统相比,降低了硬件资源要求和软件设计复杂度。     

非线性励磁控制器的研究

同步发电机励磁控制器是电厂中十分重要的控制设备,结合传统PID控制对非线性励磁控制方式进行有效的改进.DSP控制器与可编程逻辑器件CPLD为核心组成的微机励磁控制器,具有很好的应用前景.     

储运油泥热解机理研究

利用管式炉,通入氯气和二氧化碳两种不同气氛,研究储运油泥的热解特性.分析油泥的气、液、渣的不同特性,探讨两种气氛下的不同热解特点.二氧化碳气氛下油泥热解的最佳温度为450℃,而氮气气氛下为500℃2.二氧化碳气氛下的渣是致密性渣,氮气气氛下是薄壁型渣.冷凝液中的低烷烃类、单环芳烃,二氧化碳气氛下比氮气气氛下高.而气体成分中甲烷和氢气含量氮气气氛比二氧化碳下高.得出同温度下,氮气的热解程度大于二氧化碳,而且二氧化碳参与了热解反应.     

Development of a mathematical model for predicting water vapor mass generated in micro-explosion

This paper describes a mathematical model for predicting the mass of water vapor generated in micro-explosion. First, a single droplet experiment was carried out. A W/O (water/oil) emulsified fuel droplet suspended by a thermocouple was heated by a halogen spot heater, and micro-explosion was observed using a high-speed video camera. The progress of the coalescence of the dispersed water droplet was observed while droplet was heated, and an aggregated water droplet was formed in the oil layer. Based on the measured micro-explosion characteristics, a mathematical model for predicting water vapor mass generated in micro-explosion was proposed. The size of the aggregated water droplet just before micro-explosion was measured to verify the proposed mathematical model. Under certain assumptions, mass and energy conservation equations were applied to micro-explosion process, and an equation to calculate water vapor mass generated in micro-explosion was derived. The derived equation and some measurement results provide enough information to calculate water vapor mass generated in micro-explosion. The calculated diameter of the water droplet, which changed to vapor in micro-explosion, was compared to that of the aggregated water droplet just before micro-explosion. The calculated results roughly agreed with experimental ones, and the validity of the proposed model was verified.     

某300MW发电机滑环烧损事故分析与处理

某电厂300MW机组发生发电机滑环碳刷烧损,针对发电机的实际烧损情况进行详细分析证明:集电环处风道堵塞、散热不好、弹簧特性改变、压力不均匀、电流分配不均、碳刷及弹簧片频繁跳动和报警信息没有及时发现等诸多因素,造成整个滑环及碳刷温度迅速升高,产生弧光,在滑环的高速旋转下形成环火,使碳刷、刷握、铜支架等烧软、烧熔,造成发电机滑环烧损事故,针对上述原因采取相应的措施,使发电机运行正常。     

Feasible pretreatment of textile wastewater for dark fermentative hydrogen production

In this study, the yield of hydrogen production was investigated under different feedstock pretreatment conditions. The feedstock for dark fermentative hydrogen production was textile wastewater which was obtained from the de-sizing process in a textile factory, located in northern Taiwan. The wastewater was pretreated with activated carbon, cation exchange resin or was not pretreated before being fed into the batch bottles. Biohydrogen production was carried out in a batch reactor with the sludge of mixed-culture using the feedstock from the pretreated wastewater. The sludge was obtained from the Taichung municipal wastewater treatment plant. The yield of hydrogen production using the two pretreatment methods or non – treatment were compared.     

Denitrification from diesel by triethylammonium hydrogensulfate ionic liquid under microwave irradiation

The basic nitrogen compounds (BNC) in diesel were removed using triethylammonium hydrogensulfate ionic liquid as the complexing agent under microwave irradiation, and alcohol was used as the extractant. The effect of factors on removing BNC from diesel was reviewed systematically. The result showed that the optimum denitrification process was as follows: microwave power was 300 W, microwave irradiation time was 6 min, volume ratio of ionic liquid to diesel was 10:1, the volume ratio of hydrogen peroxide to ionic liquid was 3:1, and the volume of extractant was 15 mL. The BNC in diesel was reduced from 85.79 μg/g to 3.26 μg/g and the denitrification rate reached 96.2%.     

Mercury emission and adsorption characteristics of fly ash in PC and CFB boilers

The mercury emission was obtained by measuring the mercury contents in flue gas and solid samples in pulverized coal (PC) and circulating fluidized bed (CFB) utility boilers. The relationship was obtained between the mercury emission and adsorption characteristics of fly ash. The parameters included unburned carbon content, particle size, and pore structure of fly ash. The results showed that the majority of mercury released to the atmosphere with the flue gas in PC boiler, while the mercury was enriched in fly ash and captured by the precipitator in CFB boiler. The coal factor was proposed to characterize the impact of coal property on mercury emissions in this paper. As the coal factor increased, the mercury emission to the atmosphere decreased. It was also found that the mercury content of fly ash in the CFB boiler was ten times higher than that in the PC boiler. As the unburned carbon content increased, the mercury adsorbed increased. The capacity of adsorbing mercury by fly ash was directly related to the particle size. The particle size corresponding to the highest content of mercury, which was about 560 ng/g, appeared in the range from 77.5 to 106 µm. The content of mesoporous (4–6 nm) of the fly ash in the particle size of 77.5–106 µm was the highest, which was beneficial to adsorbing the mercury. The specific surface area played a more significant role than specific pore volume in the mercury adsorption process.     

建筑保温隔热材料的研究及应用进展

建筑隔热保温是实现建筑节能和降耗减排的重要手段。对几种常用保温隔热材料的分类与发展进行了概述和评价,着重介绍了新型气凝胶保温隔热材料的特性与研究进展。概述了气凝胶超级隔热材料在建筑隔热保温中的应用进展,并对其建筑节能应用前景进行了展望。     

Emission factors and thermal efficiencies of cooking biofuels from five countries

The aim of the study was to compare the environmental and thermal performance of cooking biofuels from five countries. The standard water boiling test was used to determine thermal parameters. The fuels were burnt in a metal stove in a test chamber in accordance with standard protocol. Low-flow air samplers were used for particulate matter measurements, both TSP and RSP. Later, benzo(a)pyrene was determined using the high performance liquid chromatography (HPLC) technique after extraction from particulate samples in benzene. CO was measured using an electronic datalogger and HCHO using a passive sampler. The ventilation conditions during the experiments were manipulated by using different combinations of doors, windows and fans to ensure minimum stratification of pollutants in the chamber. The indirect method of deriving emission factors was used. Levels of most of the pollutants measured was found to be higher than that reported by previous studies, especially that of benzo(a)pyrene. The thermal efficiency was found to be in the range 10-15%. The emission per task of RSP was 0.27-0.77 g and that of B(a)P in RSP was 1.87-4.17 mg.     

Numerical and experimental investigation of melting of ice involving natural convection

Two‐dimensional transient melting of ice in a rectangular enclosure was numerically and experimentally investigated. Natural convection in the liquid phase due to the temperature dependency of water density was considered in the numerical model. The implicit finite difference method with fixed staggered grid approach was utilized. The SIMPLER algorithm was followed for the solution of pressure and velocity fields in the liquid phase. The prediction of the model was found to be satisfactory through preliminary experimentation. Copyright © 2002 John Wiley & Sons, Ltd.     

基于FLIC的油泥焚烧产物模拟研究

文章对含油污泥的焚烧过程进行了数值模拟,并建立了含油污泥焚烧过程的一维数学模型,采用SIMPLE算法对离散方程进行求解,计算了焚烧产物、炉内固体残留物,以及气体和固体温度特性。结果表明:在炉体床层的上部,CO2浓度在700 s时出现峰值;随着风从鼓风机中引入,含油污泥中的水分迅速蒸发;含油污泥的挥发分均出现先升高再下降的趋势,最大挥发分含量达到82.4%;固定碳是燃烧过程中的一个中间产物,灰分中的残留量较少;不同床层高度的气体温度随着反应的延续而升高。