пучок труб(As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes inside it. WAD Alexander Demidov)
пучок труб(more hits: ... transfer heat between the two fluids. The set of tubes is called a tube bundle, and may be composed by several types of tubes: plain, longitudinally finned, etc. WAD Alexander Demidov)