英语翻译As previously mentioned,the common problem withreducing

英语翻译
As previously mentioned,the common problem with
reducing the transverse spacing in order to increase heat
transfer surface area is that the flow passage area also
decreases resulting in increased pressure drop and blockage
of the heat exchanger due to deposit build up between
the closely spaced tube rows.Fig.8 shows how
the five tube bundle arrangements numerically investigated
perform in terms of deposition rate and deposition
rate distribution between the tube rows.Comparing the
arrangements at the larger transverse spacing,it is evident
that the streamlined tube shapes of the elliptic
and the DDEFORM tubes lead to a reduction in the
overall deposition rate,which is most evident in the
downstream tube rows,although even the first row
shows a reduction in the order of 30–50%.However,
as shown previously,at the large transverse spacing
the benefits with regards to both heat transfer rate and
pressure drop are not favourable.On the other hand,
by looking at the closely spaced arrays,it can be seen
that the deposition rates are still at 26% and 44% of
those of the standard arrangement with circular crosssectional
tubes but heat transfer is significantly higher
(see Fig.6) and pressure drop lower (see Fig.7).The
DDEFORM tube shows a superior performance over
the elliptic one in terms of deposition rates.The different
behaviour of the bundles with non-circular tubes is further
explored in the next section
明天就要交差了 自己这几天有事没来得及翻 翻译的好的话我再给+100分!

如前所述,为了增加传热表面积而减小横向间隔的共同问题是由于沉淀堆积在靠近的管道列之间液流通道面积减少导致压力下降和热交换器堵塞.图8所示,由在数字调查而来的五组管束排列在管束列之间如何依据沉淀比率和沉淀比率分配运行.
比较以宽大横向间隔方式的排列,显而易见,椭圆形的和异形管的流线型管导致在整个沉淀率上的减少,尽管甚至第一根管道显示以30–50%顺序的减少,但是这一点在下游管束列中更为明显.无论如何,如前面所显示,以宽大横向间隔的方式兼顾传热比率和压力下降两个方面的效益是不利的.
另一方面,通过观察靠近间隔的编组排列,可以发现沉淀率在那些具有圆形代表性管道的标准排列中依然是26% 和44%,但是热传导值得注目的是较高（见图6）而且压力下降较低（见图7）.异形管道显示出的高性能在沉淀率方面超过椭圆形管道.以非圆形管捆扎管束的不同的运转状况将在下一个章节中研究.