Double Pipe Heat Exchanger Design with Counterflow or Parallel Flow

A double pipe heat exchanger consists of one pipe inside another. It can be operated as a parallel flow or as a counterflow heat exchanger. Double pipe heat exchanger design requires use of the heat transfer rate, the log mean temperature difference, and an estimate of the overall heat transfer coefficient to calculate the estimated heat transfer surface area. An advantage of the double pipe heat exchanger over some other heat exchanger types is the fact that it can operate with true counterflow, leading to the highest log mean temperature difference, the the best heat transfer efficiency, the highest overall heat transfer coefficient, and the smallest required heat transfer area, in comparison with parallel flow or crossflow.