通风管道设计阻力平衡
Design resistance balance of ventilation duct
一、在通风系统中的通风管道是相互连接的一个整体,必然得遵循各支路阻力平衡规律,当风管系统的结构形式、管道尺寸一经确定,在一定的风机作用下,各段的风量是按阻力平衡规律自动分配的。在设计计算时未经阻力平衡计算,会导致系统实际风量分配与设计不符。当然我们也可以通过调节风阀来分配风量,但这样一来就又使非不利环路的风压多余。所以在设计计算时考虑各环路的阻力平衡具有现实意义。
1、 The ventilation duct in the ventilation system is an interconnected whole, which must follow the resistance balance law of each branch. Once the structural form and pipe size of the air duct system are determined, under the action of a certain fan, the air volume of each section is automatically distributed according to the resistance balance law. If the resistance balance calculation is not carried out in the design calculation, the actual air volume distribution of the system will be inconsistent with the design. Of course, we can also adjust the air valve to distribute the air volume, but in this way, the air pressure of the non adverse loop is redundant. Therefore, it is of practical significance to consider the resistance balance of each loop in the design and calculation.
然而,不少设计人员在进行风道水力计算及阻力平衡过程中仅仅凭经验估算或查图手算,这样费时费力还达不到理想效果。笔者所设计的计算软件以excel为工作平台,用vba语言为开发工具,从而确保了程序的执行效率。
However, in the process of hydraulic calculation and resistance balance of air duct, many designers only rely on empirical estimation or manual calculation by looking up drawings, which is time-consuming and laborious and can not achieve the ideal effect. The calculation software designed by the author takes excel as the working platform and VBA as the development tool, so as to ensure the execution efficiency of the program.
二、阻力自动平衡计算的基本步骤
2、 Basic steps of resistance automatic balance calculation
风道系统阻力平衡自动计算的执行过程基本延用常规设计的计算步骤,主要如下:
The execution process of automatic calculation of resistance balance of air duct system basically follows the calculation steps of conventional design, mainly as follows:
①将各节点间的逻辑关系、管段的相关参数依次输入并保存,然后根据技术要求初步选定各管段的假定风速;
① Input and save the logical relationship between nodes and relevant parameters of pipe sections in turn, and then preliminarily select the assumed wind speed of each pipe section according to the technical requirements;
②根据假定风速自动计算管段当量水力直径及阻力损失;
② Automatically calculate the equivalent hydraulic diameter and resistance loss of the pipe section according to the assumed wind speed;
③用节点逆寻法自动查找系统各环路的路径及阻力损失,并确定系统不利环路;
③ The node reverse search method is used to automatically find the path and resistance loss of each loop of the system, and determine the unfavorable loop of the system;
④对非不利环路进行自动阻力平衡。
④ Automatic resistance balancing for non adverse loops.
⑤对计算结果进行校核。
⑤ Check the calculation results.
以上过程中只有工作量不大①、⑤需人工干预,而其他步骤全部由计算机自动完成。从而不但确保其计算速度及准确性,而且还可根据需要进行适当的手工调整。
In the above process, only the workload is small, ① and ⑤ need manual intervention, while other steps are completed automatically by the computer. Thus, it can not only ensure the calculation speed and accuracy, but also make appropriate manual adjustment according to the needs.
The above is the detailed introduction of Jinan ventilation duct. I hope it will be helpful to you If you have any questions, please contact us We will provide you with professional service http://www.jntfgd.com
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