换热器在折流或错流操作时的平均温差如何计算？

GB151-1999《管壳式换热器》中规定：双壳程换热器、纵向隔板的宽度允许偏差（）折流板外直径允许偏差。

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore.

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

列管式换热器壳程压降与折流板数的关系是（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

列管式热交换器内用饱和水蒸汽加热管程的空气，为提高换热器的K值，在管外装设折流挡板。

由管箱、管板、壳体、换热管、折流板组成的换热器是（）换热器。

一台换热器未设折流板和支持板，其管板间距为L，则换热管受压失稳的当量长度Lcr为（）。

折流板用于（）介质的折流。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。