降低天然气压缩机组单位能耗的研究

文章以探索提某站4台伴生气天然气压缩机组运行时效作为研究目的,针对压缩机组运行过程中出现的机组排量低、运行参数偏离设计值等问题开展研究,采取调整余隙和增大动力缸上止点时燃烧室容积等措施,实现机组提高处理量、降低单位能耗的目的,在为企业节省生产运行成本的同时,实现节能减排。     

一种求解地下结构顶板频率和振型的方法

采用欧拉梁横向自由振动理论,发展了一种求解浅埋地下结构顶板频率和振型的方法.鉴于地下结构顶板频率求解问题的复杂性,首先将该问题假定为平面应变问题求解,推导出浅埋地下结构顶板梁的自由振动方程;然后根据顶板梁的边界条件,得到了顶板梁的频率方程,从而得出了顶板梁的频率和振型;进一步得出了墙体转动刚度对顶板频率影响的规律,即转...     

绕流对称性破缺诱发柔细结构振动研究——以Tacoma大桥风振致毁事故为例

绕流对称性破缺往往对柔细结构产生很大的作用效应,诱发结构振动,严重影响其可靠性和安全性.基于圆柱平面绕流模型,系统分析了实际流体圆柱绕流纵向对称性破缺以及各种情况的横向对称性破缺现象.为了更加深入地理解理论分析的结果,利用Fluent软件对圆柱绕流模型进行了计算机模拟,详细分析了雷诺数为10、20、40、100、200...     

Risk Assessment in the Working Environment in Estonia

The first step to chart hazards in the working environment in Estonia (labour force: 0.65 million) was taken by the National Board of Health Protection in the beginning of 1996.

The existing chemical, physical, and biological agents in the working environment were investigated with the help of local health inspectors in all counties. An identification of hazards and workers at risk was carried out. The results of the analysis showed that 16% of Estonian industrial workers are exposed to different hazards: 20,000 persons are exposed to noise, 11,000 are working in the conditions of vibration, 10,000 are affected by unsatisfactory microclimate, 6,000 complain about long-lasting work in a compulsory posture, the overexertion of eyes is suffered by 5,500 persons, and physical overload by 3,500 workers. In the group of chemical hazards the greatest numbers of workers are exposed to organic dust (6,500) and welding aerosols (5,400), followed by petroleum products (2,700), and oil-shale dust (4,300). The measurements of working conditions showed that an average of 30.3% of the results are above the standards. Proposals for the improvement of the situation in occupational safety and health are presented.     

Evaluation and Optimization of Handle Design Parameters of a Grass Trimming Machine

The grass trimming machine is a widely used agricultural machine for cutting grass by the roadside and in other areas in Malaysia. Hand-arm vibration (HAV) syndrome is very common among workers operating power tools and performing similar work for extended periods. Grass trimming involves the use of a motorized cutter spinning at high speed, resulting in high levels of HAV among its operators. The existing D-shape handle causes HAV-related stress and operational load in operators. This research proposes a new design of a handle of the grass trimming machine. When this new design was compared with the old one, it was found that the new handle resulted in 18% lower HAV. To find the lowest HAV, 3 critical parameters of the new handle (length, angle and material of the cap of the handle) were optimized using the Taguchi quality tool. Appropriately selected parameters of the new handle significantly reduced the occurrence of HAV among grass trimmers.     

A Study on the Combined Effect of Noise and Vibration on Operators’ Performance of a Readability Task in a Mobile Driving Environment

This paper presents a study in which the main objective was to investigate the combined effect of noise and vibration on the performance of a readability task in a mobile driving environment. Subjects performed a readability task on a laptop computer in a sitting posture with their backs supported with a backrest under varying levels of noise and vibration. The data in terms of the mean number of characters read per minute were collected and statistically analyzed. Results showed that the individual effect of noise, vibration, and the operators’ gender as well as the interaction between gender and noise, and gender and vibration were statistically significant. However, the combined effect of noise and vibration was not found to be statistically significant. Results also indicated that gender was statistically significant at all levels of noise as well as vibration, and noise and vibration were statistically significant at both levels of gender.     

天然气增压站噪声和振动治理效果分析

分析了天然气增压站噪声的主要来源,在阐述降噪原理的基础上,根据增压站所在地区实际情况,采用更换消声器、修建减振沟、修建降噪厂房、优化降噪厂房墙体等不同措施,结合治理前后噪声监测数据分析,对不同措施降噪减振的效果进行评价,同时综合了采取不同措施的合理性,为类似增压站噪声和振动治理提供借鉴。     

特殊环境下清障爆破方法研究

分析了地下军事设施战损抢修清障爆破的环境特点,在分析多种影响因素的基础上确定了高能燃烧剂爆破和聚能切割爆破2种清障方法,并介绍了各自的作用原理和基本设计。爆破试验结果表明,高能燃烧剂爆破和聚能切割爆破在地下军事设施战损抢修清障爆破中的应用是可行的。     

大庆油田取缔非法炼油点的爆破作业及其安全管理

详细介绍了大庆油田采用外敷药包爆破技术来爆破拆除非法炼油点的设计和施工过程,并通过对爆破作业安全管理的分析,提出严密的安全管理体系是顺利完成爆破取缔非法炼油点工作的保证.     

隧道掘进爆破载荷作用下埋地管道的振动峰值速度预测研究*

为研究隧道掘进爆破过程中地震效应对邻近埋地管道安全性的影响,建立平行于隧道的埋地管道数值模型,将管道视为薄壳圆柱体,定义管道在动载荷作用下的塑性破坏准则,并利用无量纲分析法构建管道表面质点的振动速度关于振动频率与爆破持续时间的数学模型,从而研究埋地管道受震特性。结果表明:隧道掘进爆破作业下成洞侧的管道应力峰值低于非成洞侧的管道应力峰值,爆炸载荷下邻近埋地管道表面最大振动速度位于爆源与管道表面最近点处,在该点两侧45度范围内为管道易受损位置。将预测公式计算所得振速峰值与数值模型提取的振速峰值进行比较,得出二者的平均误差约为17.7 %。