发布时间 : 星期六 文章煤矿矿井通风系统中英文对照外文翻译文献更新完毕开始阅读
这种关系。
然而，我们必须对造成通风系统效率低下的因素的复杂性有清楚的认识。如前所述，众所周知的是高风机风压可以催生更多的漏洞和低通风效率。但是，也必须记得的是大型矿井往往拥有最高的风压这一假定，也不得不假设大型矿井一般会有更多的密封处（用来封住那些潜在的漏洞）和大量可能的煤矿采空区。这些密封处和采空区仍然需要通风和密封。因此，诸多这些因素也在影响风机风压和容积效率的关系上扮演重要的角色。
我们发现容积效率和缝隙高度、连续工作矿工组数、煤矿产量以及煤矿密封数并没有任何必然的联系。因此影响通风系统效率、漏洞和采空区漏风的主要因素和当前所述的参数并没有密切的关系就不足为奇了。
总结
本次研究阐述了美国煤矿通风系统的平均效率，大致能够达到38%，但是仍然有相当大的提升空间，通风效率有望超过70%。房柱式采煤法的煤矿通风系统效率稍高，大约为44%，而采用长壁式采煤法的煤矿这一效率则平均为34%。较低的通风效率一般是由于主要通风机风压过高所致，这也意味着大型煤矿在提高矿井通风系统效率方面面临更大的挑战。
由于安全是构建一个高效的矿井通风系统所要考虑的首要问题，所以一个良好的通风系统和合理的通风设计在高效生产中是必须重点考虑的课题。此外，提高通风系统效率对降低煤矿生产成本也意义非凡。因此，促进一个良好的通风系统也能使采矿作业和活动大大受益。
可以左右通风系统效率高低的因素不仅数量繁多而且关系复杂。从以上研究所得的数据来看，影响通风系统效率的因素很明显不是单方面的。最普通也最常见的因素主要有：矿井漏洞的年久失修、填塞物老化、高风机风压引起的漏风、大量采空区以及密封区所需的风。影响每一个煤矿通风系统效率高低的因素都是上述方面的综合，因此，如果一个矿井有提高矿井通风系统效率的打算，通风系统的设计者需要在识别、期望以及避免这些可能导致通风系统效率低下的因素上
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耗费大量的心血。
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COAL MINE VENTILATION EFFICIENCY: A
COMPARISON OF US COAL MINE VENTILATION SYSTEMS
Abstract
With ever rising energy costs, it is increasingly important for mines to operate with energy efficiency. As a large portion of a mine’s energy consumption is often attributed to the operation of mine ventilation fans,maintaining an efficient ventilation system is a critical pro-active way for mining companies to reduce power costs. A common way to measure a mine’s ventilation system efficiency is to calculate the volumetric efficiency,which is simply a calculation of the percentage of total mine air that is usefully employed for production. The purpose of this study is to document a nationwide comparison of the volumetric efficiency of U.S.underground coal mining operations. The results will aim to show just how efficient today’s coal mine ventilation systems are and what factors may be causing their various efficiencies and inefficiencies.
Definition of Volumetric Efficiency
Mine ventilation volumetric efficiency is defined as the percentage of total mine air that is “usefully employed” for production. There can be room for discrepancies when considering what constitutes being“usefully employed” for air in a mine. McPherson defines air that is usefully employed as “the sum of airflows reaching the working faces and those used to ventilate equipment such as electrical gear, pumps or battery charging stations” (McPherson, 1993). Hartman considers usefully employed ventilation air to be the sum of air at the last open crosscut and belt air (Hartman,1997).For this study, mine air that is considered to be usefully employed consists of air that is used for ventilating working faces as well as air that is used for
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equipment that is critical to production (such as electrical gear, pumps, battery charging stations). After determining the total mine air quantity at the main fans and calculating the summation all air that is usefully employed in a mine, the following equation can be used for calculating ventilation volumetric efficiency: Equation 1. Volumetric Efficiency
Volumetic?Efficiency?Airflow?Useful?100%Total?Airflow
Values for ventilation volumetric efficiency fall in a wide range. McPherson states values may range from 75% down to 10% (McPherson, 1993). In this study, mines had efficiency values which fell within the range of 14.5% to 71.6% (shown below in Table 2). Mines with efficiency values in the lower part of this range indicate that large volumes of air are not being employed effectively, creating a potentially large and wasteful energy expense
Factors Affecting Efficiency Loss
The two most significant factors that can cause lower volumetric efficiency include losses from leakage as well as the use of ventilation air to ventilate old workings,pillared/gob areas, or seals.
Leakage through stoppings and doors can be minimized through good construction and maintenance. However,leakage is certainly inevitable when large numbers of stoppings are present in a mine, no matter how well-constructed. Additionally, the potential for leakage naturally increases with fan pressure, so mines with high operating pressure are more prone to leakage. A reliable method for avoiding leakage in a mine is to minimize connections between entries having flows in opposite directions. This can be accomplished by dividing intake and return entries with a neutral entry or entries, or by geographically separating intake and return entries with barrier pillars (McPherson, 1993). This, of course, requires incorporation of ventilation design at the mine planning stage, but such planning can save future fan power costs.
Young mines often have a volumetric efficiency advantage over mines that have
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