共查询到20条相似文献，搜索用时 46 毫秒
1.
The paper concludes the characters of methanol as a fuel in engines. Based on the kiva 3v program, it conducts the multi dimensional numerical simulation of the operation process in cylinder of a methanol fueled engine to obtain the detail information and performance graphic charts, as well as the real time data of pressure, temperature and so on. It is helpful for the research on methanol fueled engines. The results indicate that the methanol is a green alternative fuel and the methanol fueled engines have steady operations and lower emissions by comparing the numerical results with the data of gasoline engine. 相似文献
2.
It is very difficult for small and medium sized motorcycle engine to use the combination of closed-loop control electronic fuel injection system and three-way catalytic converter for emission controlling due to the high cost. In order to strengthen emission controlling of the carburetor motorcycle engines, the metering characteristics of carburetor are adjusted, combustion chamber as well as intake and exhaust ducts are further optimized, and secondary air injection system and oxidation type catalytic converter are developed, and moreover a simplified positive crankcase ventilator is employed to eliminate the gas blowby from crankcase. It is verified by test cycle testing that pollutant emissions of the carburetor motorcycle engines can be effectively controlled within the emissions limits by taking the above technical approaches. 相似文献
3.
A fuel system evaluation method was introduced to select the proper high pressure injection system for diesel engines. Using this method, the second generation common rail system of BOSCH Company was selected for use in the 4JB1 diesel engine. Based on this common rail system, a fuel supplying model was built using AMESim. The model included a high pressure pump sub module, a pressure control valve sub module, an injectors sub module, and a connecting pipes sub module. Through model simulation, the influences of parameters (e.g., rail volume, high pressure pipe length and diameter) on pressure fluctuations and pressure building were studied. Rail pipe system parameters were selected based on simulation results. Experimental results show the rail pipe parameters could satisfy the needs of rapid pressure response and low pressure fluctuations for common rail diesel engines. 相似文献
4.
Geometry of port-combustion chamber has an important effect on the performance of gasoline engines. Methods and approaches in reverse engineering are introduced into surface reconstruction and modification of a port-combustion chamber structure. Free-form surfaces of the port-combustion chamber structure for a gasoline engine with 4-valves and dual-ball type combustion chamber are successfully reconstructed in the reverse way through data processing, surface modeling, surface verifying, surface re-modeling and smooth evaluating etc., based on laser-scanned point cloud data of a sample work piece. It lays a foundation for imitation innovation of gasoline engine by changing the local structural characteristics and dimensions of a prototype model. 相似文献
5.
生物柴油作为燃油替代品可以从食用油中大量获得,从而解决将来石油匮乏问题。针对菜籽油制备生物柴油酯的交换反应中,甲醇与菜籽油呈两相不互溶的主要问题,研究了添加共溶剂,使反应体系均相来提高反应速率与效率。以所选溶剂与甲醇的混合液为溶剂,菜籽油作溶质,分别在常温和60℃下做三元溶解度试验,选出乙醇、乙醚、四氢呋喃、1,2-环氧丙烷进行下一步比较;以普通菜籽油为原料,以甲醇为酰基受体,在加入不同共溶剂的条件下,进行碱催化酯交换反应,以酯化率和反应时间为考察指标,对共溶剂进行优选,发现以乙醇为共溶剂时,酯化率比空白提高了21.0%,且高于其他溶剂。研究结果表明,甲醇与乙醇的最佳摩尔比为3∶1。 相似文献
6.
Owing to increasingly strict emission regulation, gasoline properties not only satisfy the needs of high performance for the engine, but also attain the requirement of vehicles exhaust control. The gasoline from gas stations around China is sampled and its properties are analyzed. The distribution of gasoline quality in different zones is listed. At the same time, the difference of properties between domestic and oversea gasoline is compared. After establishing the emission model of the engine, the reference value of vehicle emissions in different zones is obtained. At last, some measurements are proposed to reduce the emissions: improving gasoline quality and controlling the related parameters for engine according to the distribution of gasoline properties. 相似文献
7.
Zhou Luowei Li Zaihua Hou Zhencheng 《保鲜与加工》1993,(2):19-23
The dynamical modelling of the new converter with the cross double-fed control system is set by using the averaging techniques. The dynamical quality and the stability of the new system are analyzed with the modelling,and compared with the ordinary converter. The results show that the dynamical quality and the stability of the new converter are much better than those of the ordinary one. 相似文献
8.
环保部2016年发布了GB 15097—2016《船舶发动机排气污染物排放限值及测量方法（中国第一、二阶段）》,该标准相较于《渔业船舶法定检验技术规则（船长大于或等于12 m国内海洋渔业船舶2017）》的要求增加了一氧化碳、碳氢化合物、颗粒物3个控制项目,氮氧化物的排放限值也明显提高。为获知当前中国主流渔船柴油机排放的技术现状、了解履行新标准的差距,对2种典型的渔船柴油机进行了排放污染物测试试验和劣化试验验证。试验结果显示：典型渔船柴油机可满足新标准一阶段的要求,但距离二阶段要求有较大差距。其中颗粒物的排放超出二阶段限值25%~53%。通过两型柴油机试验数据的对比分析发现,燃油喷射方式是改善颗粒物排放和有效降低柴油机劣化程度的关键因素。针对渔船柴油机如何更好的履行二阶段排放要求给出建议：推迟新标准二阶段生效;鼓励研发新产品,促进先进技术引进;控制实船使用燃油质量,提高渔民的环保意识;加强实船监管力度。 相似文献
9.
Through construction market survey, the paper proposes the way of the control system of construction quality of building engineering and establishes objective system of its on becoming core of quality control spot. It puts forward many grade control and evaluation net and expounds the method to produce quality evaluation form, control system of quality ordinary question and quality analysis. It determines technology way and movement foundation on system development. The paper introduces the model and its function on the control system of construction quality of building engineering. This system is a opening system, it may be filled and complemented with new content at any time. It has better adaptable to change of construction code. 相似文献
10.
In a toroidal CVT, power transmission is accomplished by means of a special traction oil that displays high shear resistance under a state of high pressure . A toroidal CVT can be used even with engines that generate large torque and provide excellent ratio change response and high efficiency . The history of research of the toroidal CVT are summarized and the toroidal CVT up to date is reported. The varieius aspects on the toroidal CVT are summarized ,including EHL theory , toroidal double cavity system,traction fluid ,ratio control system, traction drive system , efficiency analysis ,and so on. Finally ,The development of the toroidal CVT in the future is indicated. 相似文献
11.
Hybrid electric vehicle (HEV) is a mixture of electric vehicle and conventional vehicle, which has the merits of reducing exhaust gas and the consumption of gasoline HEV is the new development way of automobile industry. This paper introduces HEV, and discusses the essential framework of HEV drive system,the basic types of the electrical drive and their features and the present state of the development at home and abroad.Some key technologies are also proposed which determine the drive and control performance of HEV. 相似文献
12.
Automatic mechanical transmissions (AMT) are suitable for use in heavy duty vehicles. Bench testing is an important task of the research and development. Many objectives, such as AMT performance testing, matching AMTs with engines, and optimizing control rules, can be achieved through bench testing, thereby laying a foundation for AMT application. An AMT testing bench is built up based on a developed AMT. By analyzing the performance requirements of AMT bench testing for heavy duty vehicles, a testing controlling system scheme is proposed and methods of data acquisition and communication are analyzed. Control methods for actuators are proposed based on analyzing the characteristics of AMT actuators. A testing control program for AMT bench testing is developed based on the Delphi platform. The entire bench testing system possesses advances test functions. 相似文献
13.
采用平板对峙结合生长速率法测定分析了红树内生细菌AmS2菌株及其甲醇粗提液对香蕉炭疽病菌的抑制活性,并对其甲醇粗提液的防病效果进行了研究。结果表明,红树内生细菌AmS2菌株及其甲醇粗提液对香蕉炭疽病菌的抑菌带宽分别为12.0 mm和11.5 mm;毒力测定结果表明,AmS2甲醇粗提液对香蕉炭疽病菌的菌丝生长和孢子萌发均有较强的抑制作用,EC50分别为1.007 6 mg/mL和1.902 8 mg/mL;AmS2菌株的甲醇粗提液对香蕉炭疽病具有较好的防治效果,且随着提取液浓度的加大,防治效果不断提高,当AmS2甲醇粗提液使用浓度为4.0 mg/mL时,对接种香蕉炭疽病菌10 d后的防治效果为79.83%。 相似文献
14.
为研发高效低毒的防治南方根结线虫(Meloidogyne incognita)的新途径,通过毒力测定及盆验研究了牛心朴子叶甲醇提取物对南方根结线虫的生物活性。结果表明牛心朴子叶甲醇提取物具有较强的杀线虫活性,3000mg/L牛心朴子叶甲醇提取物处理48h后,线虫校正死亡率达93.30%,LC50为418.7mg/L,而盆栽试验表明牛心朴子叶甲醇提取物稀释100倍、1000倍、5000倍后处理接种了南方根结线虫的番茄苗,植株平均根结数分别为11.4±2.24、24.6±3.78和41.2±4.46,均显著低于对照（5%甲醇水溶液）的平均根结数67.5±6.18,株高分别比对照提高26.5%、18.7%和6.6%,地上部鲜重分别比对照增加31.4%、12.7%和1.5%,根长分别比对照增加32.6%、28.8%和20.9%,表明牛心朴子叶甲醇提取物对线虫具有较好的防效,并能促进植株生长,显示出一定的开发价值。 相似文献
15.
A method of solving the problem of shoe leather lumen measurement in shoe CAD/CAM by industrial CT technology is introduced,X ray industrial CT technology is studied. The paper gives a rational scheme of system dispose. This scheme can be not only meet the need of shoe leather lumen measurement, but also achieve ordinary measurement. An uncomplicated and practicable movement control system are proposed also. This scheme achieves high precision of movement position without expensive direct current servo-control. A new simple method measurement is developed and accurate control of position in movement of detector data insert is achieved. The image resolving power can meet shoe leather lumen measurement. 相似文献
16.
Engine power performance of fuel economy and emission characteristics with a JL368Q engine run on ethanol/ gasoline blends was experimentally investigated. The results show that with the same structure and parameter of the engine, at the low speed, the power output or torque of blended fuels are almost similar to that of 93 # gasoline. But with the speed increasing, the E15W and E50W power outputs are lower than that of 93# gasoline while E30W remains the same. The brake specific fuel consumption of E15W is lower than that of gasoline about 0.35%. With the increase of ethanol volume fraction in the blended fuel, the specific fuel consumption increases gradually. When fueled with ethanol/ gasoline blends, the engine NOx emission increases and CO emission decreases. E30W gives the lowest CO emission in this test. With the increase of ethanol volume fraction, HC can be improved gradually. 相似文献
17.
双层对向正反燃烧单体供热技术在烤烟烘烤中的应用研究 总被引：2，自引：1，他引：1
为提高烤烟烘烤中燃料利用率,降低烘烤成本,减少环境污染,研究采用1个供热炉设上下2个炉膛,实现正向和反向同时对向燃烧,对比研究了双层对向正反燃烧单体供热设备和普通加热设备烤房烤烟烘烤性能。煤的燃烧充分,传统烟气中所含CO、CH4、碳粉尘等可燃物能得到充分、高效燃烧及利用。空载测试升温速率60℃/h,比普通烤房提高34℃;烘烤实载时,各阶段实测温湿度与目标温湿度吻合度高,完全能满足烘烤工艺的控制要求。双层对向正反燃烧单体供热设备烤房平均每千克干烟耗煤量、耗电量、综合能耗成本分别比普通烤房减少0.31 kg、0.05 kWh和0.33元,降幅分别为17.73%、14.36%和17.46%;烘烤操作等日常用工成本较普通供热设备少0.52元,降幅43.93%,且对烟叶烘烤质量无明显影响。双层对向正反燃烧单体供热设备升温速度快,平面温度均匀,烘烤过程中温湿度控制精准,能有效降低烘烤能耗和用工成本。 相似文献
18.
Present meta search engines are key-based information retrieve. A plenty of irrelevant information is returned when user search some professional knowledge because Simple combination of key can not express accurately user's purpose. Subject meta search engines solve the problem. Based on the study of present technologies of meta search engines and domain knowledge base, an information retrieve strategy is put forward which is fit for subject meta search engines. It effectively improves efficiency and precision of information retrieve. The main content of this paper are to introduce the key idea and technologies of the retrieve strategy. 相似文献
19.
Taking into the feature of computer computing method, using Stress solution of elasticity theory and according to different method of solving of system of second order ordinary differential equations , this article provides two numerical value computing method as for the stress and deformation of the turbine impeller which is within the scope of elasticity . One combines the initial value computing method of system of ordinary differential equations (Runge-Kutta Method) with optimization method, another combines the boundary value computing method of system of ordinary differential equations difference method-with optimization method and three points interpolation method . The proposed method can eliminate the deficiencies of Secondary Calculation method and is particularly suited for programmable computer-based solution . The sample show that results gotten by two methods is nearly equal to the precise results,so they are practicable. They completes the quick and precise calculating of stress and deformation . They have some general meaning , large commonality and the project employing value. 相似文献
20.
控失肥与普通化肥对夏玉米养分积累与生长发育的影响 总被引：1，自引：0，他引：1
为了比较研究控失肥和普通化肥对夏玉米养分累积与生长发育的影响,于2014-2015年在河北农业大学辛集试验站进行了大田试验。采用玉米杂交种郑单958为试材,测定了不同时期玉米形态和生理性状及其养分吸收效率。结果表明:在施入相同养分含量(N 144 kg/hm~2,P2O572 kg/hm~2,K2O 72 kg/hm~2)的控失肥和普通肥料后,玉米生长发育、干物质积累和营养元素累积量均发生了显著的变化,控失肥处理玉米产量显著高于普通肥料。与普通肥料相比,控失肥可提高玉米千粒质量、干物质和产量分别为12.3%,12.8%和6.9%;控失肥处理的器官营养元素含量高于对照肥料。控失肥处理提高了玉米灌浆期叶面积指数和光合强度。同时,控失肥处理增加了基部茎秆粗度和抗穿刺强度,抗倒伏性大为提高。控失肥作为一种新型肥料将对提高玉米产量、提高施肥效益和保护资源环境起到重要作用。 相似文献