消声器优化设计及其性能分析方法的研究

本文介绍了一种消声器设计及其性能分析方法。该方法用传统的传递矩阵法形成初步设计方案,然后借助于CFD软件进行性能分析,从而达到消声器的结构优化设计。GT-Power是一种新的发动机性能仿真软件,该软件基于一维流体动力学的原理对包括消声器在内的发动机系统进行性能模拟和仿真。本文讨论了应用该软件对消声器的流体动力特性和声学性能进行分析的方法。实例模型的模拟结果显示,该方法具有良好的预测性能。     

车用汽油机消声器计算机模拟的应用研究

作者应用不稳定流动计算机模拟方法,不仅能估算排气消声器特性,还能模拟不同消声器结构对发动机性能的影响。本文从工程应用角度出发,以开发的消声器特性模拟软件为分析工具,探求优化设计排气消声器的方法。结合软件分析,提出了消声器性能分析的简易判断准则并予以实际应用。作者设计了性能良好的消声器,使发动机的动力性和消声性能均优于原产品,取得实际效果。     

汽油机排气消声器对动力性影响的模拟分析

为了在设计开发中预测消声器内部结构对发动机动力性的影响,利用数值模拟软件GT-POWER建立了捷达发动机和其配套消声器的联合模型,并且通过实验进行了模型的验证,利用验证好的模型,研究了排气系统对发动机动力性的影响,并且研究了消声器内部压差分布情况,结果表明在发动机中低转速时,消声器对发动机造成的功率损失很小.在高转速时...     

排气消声器消声性能仿真分析

本文利用GT-POWER软件对一款摩托车排气消声器的插入损失进行了数值模拟。通过分析试验得到消声器的消声频率特性,建立消声器模型并对发动机模型进行验证后,计算了排气消声器的插入损失,取得了计算结果与试验值吻合的良好效果。     

阻性消声器穿孔率和吸声材料填充密度对发动机性能的影响研究

用GT—power软件建立了一个包含阻性前消声器的排气系统,结合已存在的一个直列4缸汽油机GT—power模型,预测发动机性能。通过改变穿孔率、吸声材料填充密度等阻性消声器设计参数,研究这些参数对发动机性能的影响。并总结了如何有效选择阻性消声器设计参数以提高发动机性能。     

迷宫式消声器分析

为了研究迷宫式消声器的降噪效果,利用GT-power软件,建立发动机仿真模型,模拟发动机工作并与消声器耦合,得到与实际工况接近的消声器人口边界条件,计算出消声器排气口噪声,并用FULENT软件对其内部速度流场进行分析.最终说明迷宫式消声器比传统内插管消声器降噪效果明显.     

面向对象发动机仿真软件的设计

将面向对象技术应用于发动机仿真软件的设计,使用Visual C++实现了该软件。D6114柴油机的仿真计算结果和试验测试结果比较表明:该软件具有较好的精度,与传统的发动机仿真软件相比,该软件性能良好,用户使用方便。     

新型阻抗复合式消声器的研制

随着环保意识的日益增强,发动机的噪声污染和排放物污染越来越被人们所重视。针对ZS1105型单缸柴油机排气噪声的特点,设计出一种新型阻抗复合式消声器,利用流体分析软件Fluent和声学分析软件Sysnoise对其内部空气动力性能和声学性能进行数值模拟,并与原厂抗性消声器进行对比,通过台架试验进行验证,研制出降噪效果明显、净烟功能好的新型消声器,为指导消声器设计提供了有力的参考依据。     

内燃机消声器特性试验装置的研制及应用

研制了一种用于消声器声学性能研究的试验装置，该装置可研究在气流条件下内燃机进气消声器和在热气流条件下排气消声器的声学性能，为研究和分析消声器声学性能提供了坚实的试验基础。初步的试验结果表明：该装置能向试验管道内提供稳定的流动气体，对管内气流的加热温度能达到设计要求，能很好地模拟内燃机消声器内的声学条件。     

B231发动机性能优化及循环模拟计算

以改善发动机的燃油经济性为目的，采用发动机台架试验和模拟计算的方法对B231发动机性能进行研究开发。首先利用AVL的BOOST软件对发动机进行建模，通过试验确定边界条件，与试验结果比较表明了该模型有较高的模拟精度。利用所建模型预测喷油时间对发动机性能的影响，筛选出最佳方案，并通过试验验证。在满足欧-Ⅱ排放法规的前提下，使B231发动机在标定点油耗率降低5％。     

Unerroric of control of mutual compliance of the efficiency of hydrogen engines of unmanned vehicles in the conditions of mass production

The issues related to the reliability of hydrogen engines of unmanned vehicles and increasing the efficiency of using hydrogen as fuel when using the method of its production during the decomposition of hydrogen-containing molecules of liquid-phase organic compounds in a plasma discharge under the action of intense ultrasonic exposure are considered. Experiments have shown that as a result of decomposition in the acoustoplasma discharge of liquid hydrocarbons, solid-phase carbon-containing products are formed, chemical transformations occur in the liquid phase and hydrogen-containing combustible gas is formed. Hydrogen-containing gas can be used as fuel immediately after synthesis, i.e. it does not require separation, since in addition to hydrogen it contains only impurities of CO₂ and water vapor. The purpose of the study is to formalize the basic conditions for tightening the control of mutual compliance with the efficiency of hydrogen engines of the same series in the conditions of their mass production. Methods of mathematical statistics and hardware-software modeling were used in the study. The term “unerroric of quality mutual compliance control” is introduced to describe a set of hardware and software tools for such control. The principle of in-depth testing of the technical condition of such engines of one series is described in a multidimensional formulation of the quality control problem for three of their operating parameters at once. The conditions for increasing the mutual correspondence of the measured values of such parameters in the conditions of serial production of hydrogen engines are formalized.     

小型锅炉烟尘测试时锅炉出力的计算

锅炉烟尘测试时,必须对锅炉出力进行测试。但监测中,许多小型锅炉往往不具备相关的计量装置和仪表,为解决这一问题,文章提出了用烟气量和空气过剩系数来计算锅炉的出力的公式,在实际使用中,该方法简单易行,其结果和实测值具有很好的一致怀。     

MgO膨胀剂细度对MgO水化和水泥浆体膨胀的影响

基于《水工混凝土掺用氧化镁技术规范》中的Ⅰ型氧化镁（MgO）,研究了该型MgO膨胀剂（MEA）细度对掺粉煤灰水泥浆体膨胀性能的影响。即采用X射线衍射分析(XRD)及同步热分析（TG DSC）分析了掺MEA水泥浆体中MgO的水化性。结果表明,养护温度相同时,MEA的细度对水泥浆体内MEA中MgO的水化和水泥浆体的膨胀无显著影响,产生的膨胀均能补偿水泥浆体的收缩;MEA的细度可从试验设计采用的45 μm筛筛余15%左右增加到30%左右,这将有利于MEA生产企业的节能降耗。     

Heat of vaporization of mixtures

General expressions for the heat of vaporization of mixtures at constant pressure; at constant temperature; and at constant pressure, temperature, and composition are proposed. The last one is related to the liquid-vapor interface where steady vaporization or condensation is taking place. Numerical examples by the proposed expressions are shown for binary mixtures of HCFC22(R22) and (HCFC123(R123) © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(1): 12–24, 1996     

生物质催化热裂解技术的研究进展

生物质催化裂解是生物质热化学转化的一种重要途径。综述了生物质催化热裂解技术使用的反应器、催化剂类型,以及催化热裂解过程中热裂解温度、吹扫气、升温速率、生物质原料等条件的影响,展望了生物质催化热裂解技术的发展趋势。     

燃烧流化床气泡能量分布模型

应用瞬态谱分析方法对燃烧流化床声波信号进行了频谱分析,发现气泡能量分布呈Ｇａｍｍａ分布形式,在Ａｒｇｙｒｉｏｕｓ和Ｙｏｓｈｉｄａ等人提出的模型的基础上,发展了燃烧流化床气泡能量分布模型,并通过优化迭代对模型参数进行求解,在实验和理论的基础上得出了更加切合实际的燃烧流化床气泡能量分布模型     

中国煤炭地下气化技术的发展

本文综述了煤炭地下汽化技术的国内外发展现状,对我国“长通道、大断面”煤炭地下气化新工艺给予了技术经济评述,并提出了发展煤炭地下汽化技术的政策建议。     

促进城镇生活污水处理装置产业化

城镇生活污水处理装置是由农村户用沼气地发展演变而来，是一种小型、分散化处理污水的装置 ，是环境建设的需要。文章着重从我国环保政策及目标、生活污水造成的污染状况、急需整治的公共设施、生活污水净化装置的演变以及社会经济效益和环境效益等方面，阐述了其产业化的重要性。     

Review of theory of distortion and disintegration of liquid streams

Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined.     

Investigation of effect of variation of cycle parameters on thermodynamic performance of gas-steam combined cycle

The paper deals with second law thermodynamic analysis of a basic gas turbine based gas-steam combined cycle. The article investigates the effect of variation of cycle parameters on rational efficiency and component-wise non-dimensionalised exergy destruction of the plant. Component-wise inefficiencies of the combined cycle have been quantified with the objective to pin-point the major sources of exergy destruction. The parameter that affects cycle performance most is the TIT (turbine inlet temperature). TIT should be kept on the higher side, because at lower values, the exergy destruction is higher. The summation of total exergy destruction of all components in percentage terms is lower (44.88%) at TIT of 1800 K & r_p,c = 23, as compared to that at TIT = 1700 K. The sum total of rational efficiency of gas turbine and steam turbine is found to be higher (54.91%) at TIT = 1800 K & r_p,c = 23, as compared to that at TIT = 1700 K. Compressor pressure ratio also affects the exergy performance. The sum total of exergy destruction of all components of the combined cycle plant is lower (44.17%) at higher value of compressor pressure ratio (23)& TIT = 1700 K, as compared to that at compressor pressure ratio (16). Also exergy destruction is minimized with the adoption of multi-pressure-reheat steam generator configuration.