Structural Analysis of Heat Exchanger Supports

We performed structural analysis on heat exchanger supports due to loads including wind, seismic and gravity loads.

A contract engineering firm design and built a Heat Exchanger System for a plant project located in Mailliao, Taiwan. Equipment comprising the system includes: the heat exchanger, ductwork and structure associated with the waste gas inlet and outlet and expansion joints. The Heat Exchanger System is supported above grade by structural steel designed and constructed by others.

We determined the resultant forces on the heat exchanger supports (where it is attached to the top of the structural steel) for wind, seismic and gravity loads. An evaluation of the structural integrity of the heat exchanger system, its supports and connections are not considered. Stresses and loads in equipment, individual components and their supports are also not considered in this evaluation.

The heat exchanger system is supported by a structural steel frame at sixteen locations. The finite element method was used to determine the loads on the supports since the system is statically indeterminate. The heat exchanger system was assumed to act as a rigid body due to the relative stiffness of the various structural components.

The model was divided into three sections: waste gas inlet, waste gas outlet, and the heat exchanger. The waste gas inlet and outlet sections were modeled as solid rectangular blocks using solid elements. The heat exchanger section was modeled as a solid cylinder using solid elements. The Heat Exchanger System was modeled as being rigid.

The density of each of the sections was defined such that the weights of the waste inlet, waste outlet and heat exchanger sections were 11,000 pounds, 7,000 pounds, and 52,000 pounds, respectively. Details such as the expansion joints, tubes, tubesheets, nozzles, and miscellaneous hardware were not modeled. Their weight however, was included in the overall assembly weight. Rigid massless beam elements were used to attach the Heat Exchanger System to its support locations.

O’Donnell Consulting Engineers Performs Design and Analysis for Clients in Industries including Manufacturing, Petrochemical and Energy.