具有CeO_2-ZrO_2-Y_2O_3固态参考层的新型氧传感器的制备

传统浓差型汽车氧传感器结构上必须有参比空气通道以提供恒定的氧分压,故其工艺复杂、成本高、不便于微型化,同时空气通道会极大降低传感器的整体强度。文章利用CeO_2-ZrO_2-Y_2O_3固溶体(CZYO)具有的储氧特性,使其作为固态氧分压参考层,制备了一种用于监测汽车尾气排放的新型浓差型氧传感器,并对传感器分别在工作温度350,450,550℃进行测试,结果显示在空燃比为1附近输出电压发生突变,突变范围为700~-100 mV。     

氧化锆氧传感器浓差电势的测试研究

针对氧敏材料氧化锆氧浓差电势受工作温度及本底电势影响很大的特性,设计并制作了氧化锆氧传感器浓差电势的测量和检测系统,重点实现了不同工作温度的精确、稳定及迅速测量。在此基础上,完成了温度从400℃到800℃、氧气浓度从0%到6%时,氧化锆传感器浓差电势的测量的试验。对试验数据进行作图比较、回归分析等并得出结论。     

新型平板式汽车氧传感器的结构设计与数值模拟

设计了利用铈基储氧材料作为固态储氧参比层的新型平板式浓差型汽车氧传感器的多层结构,采用APDL建立其参数化有限元模型,通过热传导分析,对加热器进行优化设计。对优化模型施加阶跃电压,通过对电热耦合场模拟显示:t=4 s时,传感器活性区域温度均达到工作温度(300℃)以上,t=63 s时,各层温度趋于稳定,其中t=5 s时,各层温度梯度最大。热力耦合结果显示:各层最大等效应力先增大再缩小,最后趋于稳定,在t=5 s时,各层热应力值最大,但均小于相应温度下的断裂强度。     

氧传感器的检测与常见故障分析

电喷车为获得高排气净化率,降低排气中一氧化碳（CO）、碳氢化合物（HC）和氮氧化合物（NOx）成份,必须利用三元催化器。但为了能有效地使用三元催化器,必须精确地控制空燃比,使它始终接近理论空燃比。在理论空燃比（14.7∶1）附近氧传感器输出的电压有突变,这种特性被用来检测排气中氧气的浓度并反馈给ECU。ECU根据来自氧传感器的电动势差别来精确地控制空燃比,并相应地控制喷油持续的时间。但是,如氧传器有故障使输出的电动势不正常,电脑（ECU）就不能精确控制空燃比。会造成三元催化转化器（TWC）寿命下降,耗油量和尾气排放超标。     

氧传感器对电喷发动机性能影响试验分析

采用切断氧传感器的方法,研究发动机性能的变化.试验发现,由于怠速时发动机温度较低,氧传感器在发动机怠速时在空燃比反馈控制中不起作用.怠速时断开氧传感器对发动机影响不大,在负荷试验中,断开氧传感器后,发动机不受空燃比反馈控制,耗油变大,混合气比有氧传感器时变浓,排放恶化明显.     

一种氧化锆氧传感器测氧系统的设计

分析了氧化锆传感器的测氧原理,对能斯特方程做了修正。基于STM32 F3系列单片机设计了传感器加热电阻丝的温度检测和补偿电路、温度控制电路、氧浓差电势检测电路及恒流输出电路。系统采用PID算法,能有效精确地控制传感器的工作温度,具有一定的实用价值。     

汽车排放控制系统中的氧传感器现状及展望

介绍了浓差型(Nernst型)、极限电流型和半导体电阻型等汽车排放控制系统中的氧传感器原理及结构。在综合该领域国内外研究现状的基础上,对氧传感器的发展进行了展望。     

汽车用氧传感器介绍与研究进展

介绍了汽车用氧传感器的原理、结构、发展情况及国内外研究新动向，并简要分析了其发展趋势。汽车尾气中的有害物造成的污染，给人类赖以生存的大气环境带来了越来越严重的危害。发达国家从六、七十年代就开始探索汽车尾气净化的途径，并取得了非常满意的净化效果。在我国，无铅汽油已经开始推广使用，但还只是汽车尾气净化工程的一个开端，相关的研究工作还需要全面展开。汽车用氧传感器在控制汽车尾气排放、节省燃料、净化空气中起着重要的作用。经掺杂稳定的立方相氧化锆（ZrO2)固体电解质材料，具有良好的高温氧离子导电性，是制造汽车用氧传感器的关键部件。氧传感器有氧浓差型和极限电流型类型，国内汽车用氧传感器的研究和制造已达到一定的规模，国外新近还研究出了一种化学扩散障型氧传感器。     

限流型氧传感器

制作了具有快速响应和高度灵敏特点的限流型氧传感器,传感器再现性好,功耗小,在使用氧２范围（０－１０％）内输出线性良好。氧传感器应用温度范围是６８０－８００℃,最佳使用温度是７５０℃。     

平板式极限电流型氧传感器热应力数值分析

对平板式极限电流型氧传感器冷启动时的热应力耦合场进行了模拟。通过施加阶跃电压取代恒定电压的方法,解决了响应时间和稳定工作温度的矛盾。电热耦合模拟分析结果显示,设计的传感器响应时间为5 s,稳定工作温度为800℃。热力耦合模拟分析显示,在氧传感器实际安装使用时,热应力主要取决于装配应力,由于LSCM/3YSZ扩散障材料的热膨胀系数与YSZ电解质材料相近,用它制备氧传感器,其最大热应力小于各层材料的断裂强度,解决了LSM与YSZ热不匹配的问题。     

硅PN结基底TiO2氧传感器的特性研究

采用薄膜工艺及MEMS工艺研制了一种以硅PN结为基底材料的TiO2氧传感器,阐述了该传感器的工作原理、工艺流程及射频磁控溅射制备银电极及TiO2薄膜的方法.利用XRD、SEM分析了薄膜的表面形貌及晶粒结构.基于该结构的氧传感器具有良好的感特性及响应特性,具有响应时间短、信号线性度好、灵敏度高等优点.     

工艺用氧压机Ⅱ段排气阀改造

针对某工艺用氧压机Ⅱ段排气阀寿命低的问题，进行了分析，提出了调整气阀弹簧力及改进阀座进气通道结构的方案。经长期运行，效果良好。     

Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

For capturing and recycling of CO_2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO_2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO_2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52 FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation(EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52 FMI engine is transformed and the CO_2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80–437.40 g is imported into the device and last 1–20 min, respectively, 21.50–701.30 g dry ice is obtained. This research proposes a new design method which can capture CO_2 for vehicular internal combustion engine.     

高压氧舱用氧气传感器故障检测方法的研究

氧气传感器对医用高压氧舱的安全性起着至关重要的作用。本文从神经网络的特点出发,研究了基于神经网络的氧气传感器的故障预测方法,经实验表明,该方法简单、实用,也可应用于同类的气体传感器。     

K/DZZ-2型制氮车及除氧干燥设备流程改进

介绍K/DZZ—2型制氮车的基本结构、原理流程、主要技术性能参数以及控制与安全系统。分析了K/DZZ—2型制氮车原流程在节能降耗方面存在的不足,并对除氧干燥设备流程进行改进。     

A comparison of oxidation and oxygen substitution in MoS2 solid film lubricants

Significant advancements in the production of low friction, long wear life, sputter-deposited MoS₂ lubricant coatings have been made in the last decade. The introduction of multi-layered coatings, the establishment of careful controls on doping during DC and magnetron sputter deposition, and the implementation of ion assisted deposition have resulted in lubricants with substantially longer wear lives (up to a factor of ten greater than in the early 1980s) and lower sliding friction coefficients. A major research effort, designed to improve the performance of solid lubricants, involved a number of laboratories during this time period, resulting in these major breakthroughs. However, even with this concentrated effort, the typical investigation involved making an educated guess, based on previous experience, of the deposition conditions, target compositions, or post treatments that might be expected to provide improved performance of resulting coatings. One notable discovery during this time period was that typical MoS₂ films contain large quantities (up to 20 atom %) of oxygen substituted for sulfur in individual crystal lattices. In this paper we will compare the effects of this oxygen substitution with the effects of oxidation which involves a change in the oxidation number of the central molybdenum atoms within the crystals. A discussion of the relationship(s) between chemistry and coating structure and tribological performance will be presented with emphasis on defect chemistry and multiple phase interactions. Speculations on the role of coating chemistry in determining coating performance in applications such as in ball bearings will be presented.     

氧分析仪在退火炉氧含量自动检测系统中的应用

介绍某进口退火炉使用一套氧分析仪对多个炉区氧含量进行自动检测的系统。一般氧分析仪测量精度为ppm,该氧分析仪测量精度达到10-20vol.%以下。该文介绍了该氧分析仪的测量原理。通过对氧分析仪初始化的描述,使读者了解氧分析仪的使用方法。通过对自动检测系统的分析,使读者了解氧分析仪和自动化系统的集成方法。     

磁动式氧含量分析仪的研制

对磁动式测氧仪的测量池、光路和数据采集系统进行了研究。从气体磁性推导出了哑铃球在非均匀梯度磁场中受到的转动力矩公式,给出测量池系统的设计方案,采用镀银刻蚀方案实现哑铃球系统的转动阻尼,分析了非均匀梯度磁场系统的技术要求。介绍线阵CCD光点位置探测光路和CCD数据采集与处理电路系统。为满足仪器定标、温度补偿和校正的需要,设置了五个功能按键,列表说明其功能。给出了仪器的校正方案和检测数据。实验结果表明:仪器在不同的温度点测量精度均可达0.2%以上,仪器的温度补偿性能、精度和稳定性达到了设计要求。     

Low-energy linear oxygen plasma source

A new version of a constricted plasma source is described, characterized by all metal-ceramic construction, a linear slit exit of 180 mm length, and cw operation (typically 50 kHz) at an average power of 1.5 kW. The plasma source is here operated with oxygen gas, producing streaming plasma that contains mainly positive molecular and atomic ions, and to a much lesser degree, negative ions. The maximum total ion current obtained was about 0.5 A. The fraction of atomic ions reached more than 10% of all ions when the flow rate was less then 10 SCCM O(2), corresponding to a chamber pressure of about 0.5 Pa for the selected pumping speed. The energy distribution functions of the different ion species were measured with a combined mass spectrometer and energy analyzer. The time-averaged distribution functions were broad and ranged from about 30 to 90 eV at 200 kHz and higher frequencies, while they were only several eV broad at 50 kHz and lower frequencies, with the maximum located at about 40 eV for the grounded anode case. This maximum was shifted down to about 7 eV when the anode was floating, indicating the important role of the plasma potential for the ion energy for a given substrate potential. The source could be scaled to greater length and may be useful for functionalization of surfaces and plasma-assisted deposition of compound films.