用流化床焚烧造纸污泥的热态试验

在一床截面积为０．２３ｍ×０．２３ｍ的流化床热态试验台上,造纸污泥在无辅助燃料助燃的情况下,对影响稳定燃烧的各种因素进行试验。试验表明当水分不大子５０％时能稳定燃烧。     

应用微压探测诊断燃烧状况的试验研究

利用压力传感器进行了燃烧状态诊断的试验研究。提出了一种通过压力脉动信号分析燃烧状态的简单有效方法，该方法对归一化后压力脉动信号作线性回归并计算回归直线斜率Ｋ，根据Ｋ值对燃烧状态进行分类判断。研究发现，随Ｋ值的增大燃烧状态趋于不稳定，对于本实验炉当│Ｋ│〉０．６时为燃烧状态处于的熄火和点火剧变过程，而│Ｋ│∈「０．３，０．６」则燃烧处于不稳定状态，只有│Ｋ│〈０．１５时燃烧状态才基本稳定。     

粉煤流化床燃烧（PCF—FBC）的热态试验研究

提出了一种新型高效、清洁煤燃烧方法，即粉煤流化床燃烧，并在一个热输入为０．３ＭＷ的试验装置上进行了热态试验研究。该方法全部燃用粉煤，具有粉煤燃烧高效率和流化床燃烧低污染的特点。     

粉煤流化床（PCF—FBC）燃烧特性的试验研究

本文首次提出一种新型的高效、清洁煤燃烧方法，即粉煤流化床（ＰＣＦ－ＦＢＣ）燃烧技术，并在０．３ＭＷ的试验台上系统研究了其燃烧特性。该项技术全部燃用煤粉，且同时具有煤粉炉和流化床锅炉的特点。研究结果表明：煤粉能在ＰＣＦ－ＦＢＣ中温度为８５０￣８８０℃的流化床区（ＦＢＣＺ）稳定着火，释放出５７．７％￣８４．２％的挥发份，并完成部分炭及部分挥发份的燃烧（约７０％左右）；ＰＣＦ－ＦＢＣ的炉内最高烟温为１１     

煤粉气流着火存在最佳煤粉浓度的试验研究

在小型煤粉燃烧试验台上，在冷风（常温）、热风（３００℃左右）和各种不同煤粉浓度（０．２－０．３ｋｇ煤粉／ｋｇ空气）条件下，对５种曲型煤种的煤粉气流着火特性进行了燃烧试验及实测分析，获得了阳佳煤粉浓度与煤质特性和热风温度之间的关系，其结果具有重要的实际意义和一定的参考价值。图２表５参５     

粉煤流化床（PCF－FBC）燃烧特性的试验研究

本文首次提出一种新型的高效、清洁煤燃烧方法，即粉煤流化床（ＰＣＦ－ＦＢＣ）燃烧技术，并在０．３ＭＷ的试验台上系统研究了其燃烧特性。该项技术全部燃用煤粉，且同时具有煤粉炉和流化床锅炉的特点。研究结果表明：煤粉能在ＰＣＦ－ＦＢＣ中温度为８５０～８８０℃的流化床区（ＦＢＣＺ）稳定着火，释放出５７．７％～８４．２％的挥发份，并完成部分炭及绝大部分挥发份的燃烧（约７０％左右）；ＰＣＦ－ＦＢＣ的炉内最高烟温为１１００℃左右，平均烟温为９５０～１０００℃；燃烧效率为９８％。     

沼气浮罩的结构设计及安装调试

沼气浮罩的结构设计及安装调试安徽省农村能源科研所童有怀浮罩沼气池是一种较好的池型，其一，它产气率高，达到０．３～０．４ｍ３／ｍ３．ｄ，而水压沼气池产气率只有０．１～０．１５ｍ３／ｍ３．ｄ；其二，它的沼气压力稳定，能够使得灶具燃烧达到热效率最高的状况；...     

工业锅炉分层燃烧脱硫技术研究

针对造成工业锅炉散煤燃烧固硫效率低的原因和特点,提出了分层燃烧脱硫技术以克服层燃炉燃烧固硫条件下固硫剂在高温床层中停留时间过长的矛盾,并在０．５ｔ／ｈ链条炉上进行了分层燃烧脱硫试验,结果表明：分层燃烧脱硫实现了煤层内和煤层上方空间同时脱硫的目的,使链条炉脱硫效率得到大幅度的提高,是一种很有前途的燃烧固硫技术。     

火花点火发动机压力循环变动特性研究

作由连续循环的压力示功图求出各循环的平均指示压力及燃烧百分率，取得了平均指示压力变动率随转速，负荷，空燃比，点火提前角的变化曲线。并分析了从火花跳火到燃烧百分率为０．１，０．５，０．９时曲轴所转过角度之间的自相关系数。最后还研究了平均指标压力同从点火到燃烧百分率为０．１，０．５，０．９时曲轴转过角度之间的自相关系数。     

运行参数对粉煤流化床（ＰＣ—ＦＢ）燃烧效率的影响

在一座０．３ＭＷ热输入的ＰＣ－ＦＢＣ试验台上进行了试验研究,获得了不同操作ＰＣ－ＦＢ燃烧效率的试验数据,详细讨论了这些参数对ＰＣ－ＦＢ燃烧效率的影响规律。研究结果表明,粉煤流化床的燃烧效率最高达９８％－９９％,可与煤粉炉相媲美。本试验研究亦首次,提出,只要燃烧温度、颗粒停留时间、火焰湍流度（３Ｔ）及炉内氧浓度、颗粒浓度（２Ｃ）合理匹配,就能够实现煤粉的低温度高效燃烧。     

Performance assessment of some ice TES systems

In this paper, a performance assessment of four main types of ice storage techniques for space cooling purposes, namely ice slurry systems, ice-on-coil systems (both internal and external melt), and encapsulated ice systems is conducted. A detailed analysis, coupled with a case study based on the literature data, follows. The ice making techniques are compared on the basis of energy and exergy performance criteria including charging, discharging and storage efficiencies, which make up the ice storage and retrieval process. Losses due to heat leakage and irreversibilities from entropy generation are included. A vapor-compression refrigeration cycle with R134a as the working fluid provides the cooling load, while the analysis is performed in both a full storage and partial storage process, with comparisons between these two. In the case of full storage, the energy efficiencies associated with the charging and discharging processes are well over 98% in all cases, while the exergy efficiencies ranged from 46% to 76% for the charging cycle and 18% to 24% for the discharging cycle. For the partial storage systems, all energy and exergy efficiencies were slightly less than that for full storage, due to the increasing effect wall heat leakage has on the decreased storage volume and load. The results show that energy analyses alone do not provide much useful insight into system behavior, since the vast majority of losses in all processes are a result of entropy generation which results from system irreversibilities.     

Effect of co-cultivation of Chlamydomonas reinhardtii with Azotobacter chroococcum on hydrogen production

Chlamydomonas reinhardtii cc124 and Azotobacter chroococcum bacteria were co-cultured with a series of volume ratios and under a variety of light densities to determine the optimal culture conditions and to investigate the mechanism by which co-cultivation improves H₂ yield. The results demonstrated that the optimal culture conditions for the highest H₂ production of the combined system were a 1:40 vol ratio of bacterial cultures to algal cultures under 200 μE m^?2 s^?1. Under these conditions, the maximal H₂ yield was 255 μmol mg^?1 Chl, which was approximately 15.9-fold of the control. The reasons for the improvement in H₂ yield included decreased O₂ content, enhanced algal growth, and increased H₂ase activity and starch content of the combined system.     

Aerodynamic performance effects of leading-edge geometry in gas-turbine blades

The purpose of this paper is to illustrate the advantages of the direct surface-curvature distribution blade-design method, originally proposed by Korakianitis, for the leading-edge design of turbine blades, and by extension for other types of airfoil shapes. The leading edge shape is critical in the blade design process, and it is quite difficult to completely control with inverse, semi-inverse or other direct-design methods. The blade-design method is briefly reviewed, and then the effort is concentrated on smoothly blending the leading edge shape (circle or ellipse, etc.) with the main part of the blade surface, in a manner that avoids leading-edge flow-disturbance and flow-separation regions. Specifically in the leading edge region we return to the second-order (parabolic) construction line coupled with a revised smoothing equation between the leading-edge shape and the main part of the blade. The Hodson–Dominy blade has been used as an example to show the ability of this blade-design method to remove leading-edge separation bubbles in gas turbine blades and other airfoil shapes that have very sharp changes in curvature near the leading edge. An additional gas turbine blade example has been used to illustrate the ability of this method to design leading edge shapes that avoid leading-edge separation bubbles at off-design conditions. This gas turbine blade example has inlet flow angle 0°, outlet flow angle −64.3°, and tangential lift coefficient 1.045, in a region of parameters where the leading edge shape is critical for the overall blade performance. Computed results at incidences of −10°,   −5°,   +5°,   +10° are used to illustrate the complete removal of leading edge flow-disturbance regions, thus minimizing the possibility of leading-edge separation bubbles, while concurrently minimizing the stagnation pressure drop from inlet to outlet. These results using two difficult example cases of leading edge geometries illustrate the superiority and utility of this blade-design method when compared with other direct or inverse blade-design methods.     

Natural-gas fueled spark-ignition (SI) and compression-ignition (CI) engine performance and emissions

Natural gas is a fossil fuel that has been used and investigated extensively for use in spark-ignition (SI) and compression-ignition (CI) engines. Compared with conventional gasoline engines, SI engines using natural gas can run at higher compression ratios, thus producing higher thermal efficiencies but also increased nitrogen oxide (NO_x) emissions, while producing lower emissions of carbon dioxide (CO₂), unburned hydrocarbons (HC) and carbon monoxide (CO). These engines also produce relatively less power than gasoline-fueled engines because of the convergence of one or more of three factors: a reduction in volumetric efficiency due to natural-gas injection in the intake manifold; the lower stoichiometric fuel/air ratio of natural gas compared to gasoline; and the lower equivalence ratio at which these engines may be run in order to reduce NO_x emissions. High NO_x emissions, especially at high loads, reduce with exhaust gas recirculation (EGR). However, EGR rates above a maximum value result in misfire and erratic engine operation. Hydrogen gas addition increases this EGR threshold significantly. In addition, hydrogen increases the flame speed of the natural gas-hydrogen mixture. Power levels can be increased with supercharging or turbocharging and intercooling. Natural gas is used to power CI engines via the dual-fuel mode, where a high-cetane fuel is injected along with the natural gas in order to provide a source of ignition for the charge. Thermal efficiency levels compared with normal diesel-fueled CI-engine operation are generally maintained with dual-fuel operation, and smoke levels are reduced significantly. At the same time, lower NO_x and CO₂ emissions, as well as higher HC and CO emissions compared with normal CI-engine operation at low and intermediate loads are recorded. These trends are caused by the low charge temperature and increased ignition delay, resulting in low combustion temperatures. Another factor is insufficient penetration and distribution of the pilot fuel in the charge, resulting in a lack of ignition centers. EGR admission at low and intermediate loads increases combustion temperatures, lowering unburned HC and CO emissions. Larger pilot fuel quantities at these load levels and hydrogen gas addition can also help increase combustion efficiency. Power output is lower at certain conditions than diesel-fueled engines, for reasons similar to those affecting power output of SI engines. In both cases the power output can be maintained with direct injection. Overall, natural gas can be used in both engine types; however further refinement and optimization of engines and fuel-injection systems is needed.     

Exergetic evaluation of 5 biowastes-to-biofuels routes via gasification

This paper presents the exergy analysis results for the production of several biofuels, i.e., SNG (synthetic natural gas), methanol, Fischer–Tropsch fuels, hydrogen, as well as heat and electricity, from several biowastes generated in the Dutch province of Friesland, selected as one of the typical European regions. Biowastes have been classified in 5 virtual streams according to their ultimate and proximate analysis. All production chains have been modeled in Aspen Plus in order to analyze their technical performance. The common steps for all the production chains are: pre-treatment, gasification, gas cleaning, water–gas-shift reactions, catalytic reactors, final gas separation and upgrading. Optionally a gas turbine and steam turbines are used to produce heat and electricity from unconverted gas and heat removal, respectively. The results show that, in terms of mass conversion, methanol production seems to be the most efficient process for all the biowastes. SNG synthesis is preferred when exergetic efficiency is the objective parameter, but hydrogen process is more efficient when the performance is analyzed by means of the 1st Law of Thermodynamics. The main exergy losses account for the gasification section, except in the electricity and heat production chain, where the combined cycle is less efficient.     

Hydrogen production by steam-gasification of carbonaceous materials using concentrated solar energy – V. Reactor modeling,optimization, and scale-up

A chemical reactor for the steam-gasification of carbonaceous particles (e.g. coal, coke) is considered for using concentrated solar radiation as the energy source of high-temperature process heat. A two-phase reactor model that couples radiative, convective, and conductive heat transfer to the chemical kinetics is applied to optimize the reactor geometrical configuration and operational parameters (feedstock's initial particle size, feeding rates, and solar power input) for maximum reaction extent and solar-to-chemical energy conversion efficiency of a 5 kW prototype reactor and its scale-up to 300 kW. For the 300 kW reactor, complete reaction extent is predicted for an initial feedstock particle size up to 35 μm at residence times of less than 10 s and peak temperatures of 1818 K, yielding high-quality syngas with a calorific content that has been solar-upgraded by 19% over that of the petcoke gasified.     

液压系统常见的故障诊断及处理

任何工程机械式液压设备使用时出现故障是不可避免的。但是怎样确定故障的原因及找到好的解决方法,这是使用者最关心的问题。讲述了液压系统常见的故障及其排除方法。     

汽轮机数字电液调节系统挂闸异常的技术完善

分析了200MW汽轮机数字电液调节系统在运行中存在的挂闸异常问题,采取了相应的技术处理措施,且运行实践效果良好。     

新型高压共轨ECU升压模块的数字化开发与优化

为了提高喷油器电磁阀的响应速率,提出了一种基于CPLD(复杂可编程逻辑器件)应用于高压共轨ECU的数字升压模块。鉴于该升压电路结构参数多,其升压电压的恢复响应要求高等特征,基于Pspice建立了升压电路的仿真模型,研究了不同电路参数下升压模块的输出特性,全面优化了该升压模块的性能。结果显示,该升压模块的最大转换效率可以达90%以上。在柴油发动机上对ECU的试验表明,升压电压最大波动不超过10%,其恢复时间仅为1.3ms,功率管最大温升仅为41℃,满足整机运行范围内ECU的需求。     

Trace metal chemistry and silicification of microorganisms in geothermal sinter, Taupo Volcanic Zone, New Zealand

As part of a pilot study investigating the role of microorganisms in the immobilisation of As, Sb, B, Tl and Hg, the inorganic geochemistry of seven different active sinter deposits and their contact fluids were characterised. A comprehensive series of sequential extractions for a suite of trace elements was carried out on siliceous sinter and a mixed silica-carbonate sinter. The extractions showed whether metals were loosely exchangeable or bound to carbonate, oxide, organic or crystalline fractions. Hyperthermophilic microbial communities associated with sinters deposited from high temperature (92–94°C) fluids at a variety of geothermal sources were investigated using SEM. The rapidity and style of silicification of the hyperthermophiles can be correlated with the dissolved silica content of the fluid. Although high concentrations of Hg and Tl were found associated with the organic fraction of the sinters, there was no evidence to suggest that any of the heavy metals were associated preferentially with the hyperthermophiles at the high temperature (92–94°C) ends of the terrestrial thermal spring ecosystems studied.