共查询到20条相似文献,搜索用时 156 毫秒
1.
大型低温液体贮罐设计制造 总被引:1,自引:0,他引:1
介绍了大型低温液体贮罐的结构特点,以及结构尺寸、内罐、外罐、保温和基础等设计要点,阐述了大型低温液体贮罐抗震设计、施工安装、清洗和试验等有关问题。 相似文献
2.
3.
4.
5.
图1为一低温贮罐结构图。贮罐主要有内容器、外壳、真空夹层、内外管路及内外支撑等组成内容器用来盛装低温液体,其外表面包扎有多层绝热材料,并通过绝热性能良好的内支撑与外罐连接,外罐与内容器构成密闭的真空夹层绝热空间,外管路及操作系统置于外罐的下部。管路系统具有加排液、自增压、安全保护、液面高度及压 相似文献
6.
7.
20000m~3双层金属低温液体贮罐的设计 总被引:1,自引:0,他引:1
介绍20000m3双层金属低温液体贮罐的主要设计参数、外形结构和设计程序,阐述了内罐、保冷措施、外罐以及阀门和仪表等的设计方案和特点。 相似文献
8.
20 0 1年 6月由上海交通大学承担的“九五”国家重点项目———抗强冲击低温液罐技术通过鉴定。该课题研究中对液氧贮罐的焊接工艺与焊缝低温性能、高真空多层绝热结构与工艺、抗强冲击的内部支承结构、隔振系统与整体抗冲击技术、贮罐制造工艺等五大关键技术进行了深入细致的研究 ,并成功地应用于 6m3 液氧贮罐的制造与试验中 ,并为工程化贮罐的制造与试验提供了技术支撑。上海交通大学与兰州真空设备厂等单位合作 ,成功地制造出具有高阻尼隔振抗冲击系统的 6m3 液氧贮罐样机和抗冲击试验装置 ,其蒸发率和抗冲击性优于技术任务书规定的指… 相似文献
9.
10.
11.
A. Horibe S. Fukusako M. Yamada K. Fumoto 《International Journal of Thermophysics》1997,18(2):387-396
The paper is concerned with measurements of the surface tension of aqueous binary solutions at low temperatures. The effects
of both temperature and concentration on the surface tension of CaCl2, NaClO3, and propylene glycol have been investigated. A differential capillary-rise method was employed for the measurements. The
results showed that the surface tension of CaCl2 and NaClO3 increases monotonically as the concentration of the solution increases, while for the propylene glycol solution the surface
tension decreases with increasing concentration. The surface tension of the testing liquids was found to be an almost-linear
function of temperature from 20°C to just above the freezing temperature. Equations for the surface tension of the three aqueous
binary solutions as a function of temperature and concentration are presented.
Paper presented at the Fourth Asian Thermophysical Properties Conference, September 5–8, 1995, Tokyo, Japan. 相似文献
12.
The leakage currents which cause information loss in dynamic random access memories (DRAMs) at room temperature disappear at liquid nitrogen temperature, permitting operation of the circuits without the need for refresh (quasi-static operation). The current drive characteristics of the MOS transistor also improve significantly at liquid nitrogen temperatures. Combining these factors leads to an exploration of high speed dynamic RAM design based upon cells with non-destructive readout. This paper describes an experimental high speed RAM based upon a new two-transistor (2T) memory cell designed to exploit the unique advantages of operation at low temperature. Non-destructive readout coupled with a large d.c. sensible output current yields a high speed RAM with low power consumption. An experimental 4 kbit memory, fabricated using a 2 μm CMOS technology, exhibits an access time of 7 nS at 77 K. 相似文献
13.
在3200 m3/h空分设备运行过程中,发生了常温水流量偏大导致常温水泵和低温水泵同时跳车、冷冻水温度调节旋钮脱落导致冷冻水温度太低的两起故障。介绍故障发生时的现象、故障原因以及故障发生时的应急操作。 相似文献
14.
利用自制弹簧训练装置对Cu-Al-Mn低温形状记忆合金进行了约束训练,测定了训练前后弹簧低温形变量及马氏体相变点的变化。结果表明:进行适当的约束训练可以有效地提高弹簧的低温形变量,训练次数为30左右达到最好效果。训练对弹簧的马氏体相变点影响不大。 相似文献
15.
Daniel P. Foty 《低温学》1990,30(12)
The physics of freeze-out in conventionally doped silicon is examined. A dynamic equilibrium theory, similar to that used in deep level transient spectroscopy, is developed to describe the time dependence of thermal ionization. The theory is extended to include field-dependent ionization, which accounts for impurity ionization at very low temperatures. The specific mechanisms (Poole - Frenkel ionization and tunnelling) are discussed, and the temperature and field dependences of the mechanisms are described. It is then shown that MOS capacitors and MOSFETs have very different behaviour at very low temperatures. Experimental results are examined, showing a distinct change in the behaviour of long term current transients at very low temperatures, as predicted by the model. The theoretical model developed here, when used in a simple one-dimensional simulation, agrees with substrate current measurements. Finally, some implications for very low temperature MOSFET operation are considered. 相似文献
16.
Effect of substrate temperatures on the electrical resistivity of thermally evaporated Mn thin films
Resistivity measurements have been performed on three samples of Mn thin films from 300 to 1.4 K using the van der Pauw four probe technique. The films were grown by thermal evaporation onto glass substrates held at 523, 323 and 77 K, respectively in a bell jar held at 6 × 10−6 Torr. The resistivity-temperature results of the three specimens reveal a variety of low temperature behaviours. A behaviour typical of the bulk α-Mn is obtained with the film grown at a substrate temperature of 523 K whilst with the film grown at a substrate temperature of 323 K, the resistivity tends to a saturation at low temperatures exhibiting a behaviour reminiscent of Kondo scattering. The resistivity-temperature behaviour of the sample held at a substrate temperature of 77 K may be regarded as typical of a metallic alloy glass with a negative temperature coefficient of resistivity at high temperatures and this turns to a T2 dependence of resistivity at very low temperatures. 相似文献
17.
通过具体工程的设计和测试来详尽说明如何在肉鸡深加工车间实现低温空调以及在低温空调工况下的操作工人建立一个比较舒适的工作环境.经过二年多的运行实测证明,各项设计参数均达到要求. 相似文献
18.
碳材料以其低成本、良好的化学稳定性和热稳定性等优异特性被广泛应用于各种催化反应中。本研究利用来源广泛的天然脱脂棉为原材料, 通过原位气相掺杂的方法制备了N掺杂、B掺杂、BN共掺杂的生物质碳材料, 并将其应用在丙烷直接脱氢制丙烯反应中。研究发现, 与未掺杂的生物质碳相比, 杂原子掺杂的生物质碳均表现出更高的丙烷转化率和丙烯选择性, 而且N、B单独掺杂的生物质碳材料催化性能优于BN共掺杂的生物质碳材料, 其中N掺杂的生物质碳具有最优催化性能: 在600 ℃反应温度下, 丙烷转化率达到17.6%, 总烯烃收率达14.8%, 且经过12 h的脱氢反应后, 催化剂性能无明显的衰减。通过对这些碳材料的化学结构和催化性能的对比分析, 发现N掺杂和B掺杂使得碳材料表面的大量C-O基团转变为具有丙烷脱氢活性的C=O基团, 抑制反应过程中的C-C键断裂, 从而提高目标产物丙烯的选择性。生物质碳材料成本低廉且来源广泛, 以其作为催化剂可以极大地推动丙烷脱氢工业的发展。 相似文献
19.
在调研国外低温运载火箭抑制纵向耦合振动方案及结构的基础上,对各种可行性方案进行分析研究,从贮气型结构的气腔结构选型、消除温度对能量值的影响、低温绝热、低温结构密封、低温充气测压方案及注气型结构的注入气总量和单位流量的控制、充气测压方案等关键难点技术分析,对比双层整体套装波纹式蓄压器、双侧金属膜盒式蓄压器、囊式蓄压器、注气型蓄压器的先进性、继承性、复杂性、工作寿命、工艺性、经济性、使用维护性、可靠性等方面情况,分析对比结果表明,双侧金属膜盒式蓄压器是中国低温运载火箭抑制纵向耦合问题的最为合理可靠的方案. 相似文献
20.
张龙爱 《制冷空调与电力机械》2006,27(6):21-24
分析了引起风冷热泵冷热水机组运行中经常出现的蒸发器(板式换热器)冻裂的原因;由于造成板换冻裂的最根本原因是冷媒蒸发温度过低,提出了采用单风机运行模式来提高机组蒸发温度进而防止蒸发器冻裂;通过不同机型的实验分析表明,采用单风机模式可有效提高系统蒸发温度,从而防止蒸发器冻裂. 相似文献