气流智能管理技术在数据机房控温中的应用探析

当前信息技术迅猛发展,全球数据中心建设步伐明显加快。新建数据网络机房正逐步实现智能管理、绿色节能、高效环保,但当前业内对于旧机房控温系统改造案例较少,考虑如何立足旧机房现实情况,有益借鉴国内外先进数据中心控温技术,选择可本地化灵活应用并加以改造,将进一步提高机房使用寿命,降低设备运行风险,具有一定研究意义。文章以江西省防灾减灾科技中心数据机房为研究对象,分析该机房建设基本情况、控温效能不高的原因,引用气流智能管理控温技术,并对改造方法进行探析。

热泵型干燥室气流组织综述

在过去的十年中,由于对干燥农产品的高需求,在全球范围内引发了高密度热泵型干燥技术快速扩张.干燥室内物料的干燥速率与气流分布有很大的关系,已提出了多种配置和方法来提高干燥室内的气流分布.阐述了热泵干燥系统的运行原理和特点,分别从干燥室内部结构、工况设计、节能形式三大方面对国内外相关研究和案例进行综述.指出了干燥室内气流分布不均匀是造成物料干燥效率低、不均匀和品质差的主要原因,分析了各种空气管理的办法,包括采用不同的送回风方式可避免干燥室内部形成回流,应用优化的几何结构可减小流体流动过程中的阻力,提高热泵干燥室内的综合性能.指出需要进一步探索如何合理设计排湿口位置并对应设计不同的管道布置,以改善干燥室内热量及湿度的合理分布.

高炉热风炉自动烧炉控制

钢铁工业是支撑我国经济发展的基础产业,同时也是高能耗、高排放的行业,而其中炼铁工序能耗又占了钢铁能耗的70%左右。在炼铁工序中,高炉高风温具有降低焦比燃耗,增加喷煤效果,降低生产成本的作用。通过热风炉自动烧炉控制,有利于整个钢铁企业的节能降耗。本文通过介绍热风炉烧炉理论,为钢铁企业热风炉自动燃烧控制提供参考意见。

公安部沈阳消防科学研究所研发出新型火灾探测报警系统

近日，公安部沆阳消防科学研究所研制开发出高灵敏度吸气型感烟火灾探测报警系统，为特殊场所的火灾探测报警提供了可能。

Design and parametric optimization of thermal management of lithium-ion battery module with reciprocating air-flow

Single cell temperature difference of lithium-ion battery(LIB) module will significantly affect the safety and cycle life of the battery. The reciprocating air-flow module created by a periodic reversal of the air flow was investigated in an effort to mitigate the inherent temperature gradient problem of the conventional battery system with a unidirectional coolant flow with computational fluid dynamics(CFD). Orthogonal experiment and optimization design method based on computational fluid dynamics virtual experiments were developed. A set of optimized design factors for the cooling of reciprocating air flow of LIB thermal management was determined. The simulation experiments show that the reciprocating flow can achieve good heat dissipation, reduce the temperature difference, improve the temperature homogeneity and effectively lower the maximal temperature of the modular battery. The reciprocating flow improves the safety, long-term performance and life span of LIB.

Impact of Meteorological Drought on Streamflow Drought in Jinghe River Basin of China

Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or socio-economic drought. Among the different categories of drought, hydrological drought, especially streamflow drought, has been given more attention by local governments, researchers and the public in recent years. Identifying the occurrence of streamflow drought and issuing early warning can provide timely information for effective water resources management. In this study, streamflow drought is detected by using the Standardized Runoff Index, whereas meteorological drought is detected by the Standardized Precipitation Index. Comparative analyses of frequency, magnitude, onset and duration are conducted to identify the impact of meteorological drought on streamflow drought. This study focuses on the Jinghe River Basin in Northwest China, mainly providing the following findings. 1) Eleven meteorological droughts and six streamflow droughts were indicated during 1970 and 1990 after pooling using Inter-event time and volume Criterion method. 2) Streamflow drought in the Jinghe River Basin lagged meteorological drought for about 127 days. 3) The frequency of streamflow drought in Jinghe River Basin was less than meteorological drought. However, the average duration of streamflow drought is longer. 4) The magnitude of streamflow drought is greater than meteorological drought. These results not only play an important theoretical role in understanding relationships between different drought categories, but also have practical implications for streamflow drought mitigation and regional water resources management.

Study of Models for Heating Power Station Operator Training Systems

This paper is devoted to development and study of models for operator training systems of heating power station processes management. It proposed a mathematical model describing the management processes of heating power units of the technological complex considering the relationship of technological variables in deviations effective in real time. A software complex is developed for the system of training of operators controlling processes in heating station units. Obtained results may be used in the course of development of computer training systems for operators of heating power stations with cross-linkage.

Modeling the pressure drop of wet gas in horizontal pipe

A model for gas–liquid annular and stratified flow through a horizontal pipe is investigated, using the two-phase hydrokinetics theory. Taking into consideration the flow factors including the void fraction, the friction between the two phases and the entrainment in the gas core, the one-dimensional momentum equation for gas has been solved. The differential pressure of the wet gas between the two tapings in the straight pipe has been modeled in the pressure range of 0.1–0.8 MPa. In addition a more objective iteration approach to determine the local void fraction is proposed. Compared with the experimental data, more than 83% deviation of the test data distributed evenly within the band of ± 10%. Since the model is less dependent on the specific empirical apparatus and data,it forms the foundation for further establishing a flow measurement model of wet gas which will produce fewer biases in results when it is extrapolated.

Eutrophication of Aquatic Ecosystems： A Viewpoint on the Environmental Impact of Climate Change

Environmental concerns associated with nutrient-oriented eutrophication phenomenon have become a serious issue and a major cause of water quality deficiency nowadays. This necessitated eutrophication to occupy a front seat in research accompanied with climate change. Climate change has revealed to be a key player and a main contributor in the occurrence of such phenomenon. This paper discusses the ever-growing concern about eutrophication as a cause of climate change. Climate change affects storms intensity, changing the precipitation regime and increasing temperature. These effects increase the nutrient loading diffusion and cause excessive nutrients accompanied with storm water runoff, domestic wastewaters, and agricultural discharges to pour into water bodies. Eutrophication conversely contributes in the global wanning by releasing greenhouse gases from deoxygenated waters and sediments. Some control and mitigation measures are needed to fight climate change and achieve desired water quality goals. These measures include mitigation of climate change causes, enhancement of natural ecohydrological processes, application of proper integrated water resource management and participation of communities and governments.

消除数据中心热点的各种技术措施

数据中心运维人员采取了各式各样消除热点的措施，有些颇为奏效并可在短期内解决问题，但同时也会导致能源损耗增加；有些措施不但未能奏效，还会引发更多热点。气流管理是一种简单易行而又经济有效的热点解决方案，不但能消除热点，一劳永逸，还能减少能耗，避免因增添制冷单元数量产生的相关费用。该研究探讨了热点产生的根本原因，介绍识别热点的方法，评估典型的应对措施，并阐述了消除热点的新技术新方法。

Comparative study of pressure-control ventilation and volume-control ventilation in treating traumatic acute respiratory distress syndrome

Objective: To observe the clinical therapeutic effect and side effect of pressure-control ventilation (PCV) on traumatic acute respiratory distress syndrome (ARDS) compared with volume-control ventilation (VCV). Methods: Forty patients with traumatic ARDS were hospitalized in our department from June 1996 to December 2002. Twenty were treated with PCV (PCV group) and 20 with VCV (VCV group). The changes of the peak inflating pressure and the mean pressure of the airway were observed at the very beginning of the mechanical ventilation and the following 12 and 24 hours, respectively. The transcutaneous saturation of oxygen pressure, the pressure of oxygen in artery, the mean blood pressure, the central venous pressure, the heart rate and the incidence of the pressure injury were also monitored before ventilation and 12 hours after ventilation. Results: The pressure of oxygen in artery, the transcutaneous saturation of oxygen pressure, the heart rate and the respiratory rate in the PCV group were obviously improved after ventilation treatment. The peak inflating pressure, the mean pressure of the airway and the central venous pressure in the PCV group were lower than in the VCV group. The incidence of pressure injury was 0 in the PCV group while 10% in the VCV group. Conclusions: The clinical effect of PCV on traumatic ARDS is better and the incidence rate of pressure injury is lower than that of VCV. PCV has minimal effects on the hemodynamics.

Thermal Modeling and Cooling Analysis of High-power Lithium Ion Cells

The heat generation model and three-dimensional computational fluid dynamics model for lithium ion cells were established with boundary conditions defined.In order to provide a better insight about the behaviors of high-power lithium ion cells under realistic discharge conditions,the temperature difference of the cells and an active thermal management system with a pure air-cooling mode were analyzed and predicted with the factors affecting the unevenness of temperature field discussed.The results show a significant effect of the cooling flow rate on the temperature rise of the cells for all discharge rates.Average surface temperatures are relatively uniform at lower discharge rate that makes it easier to control the temperature of the pack.Cell temperatures are expected to rise significantly toward the end of discharge and they show non-uniformity at higher discharge rates.Adequate air flow rate of active cooling is required at high discharge rate and high ambient temperature for practical pack thermal management system.