| Popis: |
Heat transfer can be intensified in shell-and-tube heat exchangers for improved heat transfer performance. Such intensification has been widely studied from the point of view of individual heat exchangers (HEs). The use of heat transfer enhancement in Process Integration has many benefits. First, enhanced heat exchangers require less heat transfer area for a given heat duty because of higher heat transfer coefficients. Second, the heat transfer capacity for the given HE can be increased without changing physical size of the exchanger. Third, the use of enhancement can reduce pumping requirement in some cases, as enhanced HE can achieve higher overall heat transfer coefficients with lower velocities, which may lead to lower friction losses. Using enhancement techniques has practical advantages in Heat Exchanger Network (HEN) retrofit, as it can avoid modification of the network structure. The implementation of enhancement is a relatively simple task that can be easily achieved within a normal maintenance period, allowing production losses to be kept to a minimum level and no civil engineering requirement. This chapter provides an introduction to the enhancement methods of commercial shell-and-tube heat exchangers and their engineering application. The key aspects of enhancing shell-and-tube heat exchangers in HEN retrofit are presented and illustrated with examples involving both energy saving and fouling considerations. |
