Investigation of a submerged oscillating heat exchanger

The present work investigates a new concept of ocean energy production which combines wave and thermal energies to explore Deep Ocean Waters. This concept is a Submerged Oscillating Heat Exchanger that consists of a bundle of horizontal pipes hanged by an elastic cable and connected to a floating unit. The heat transfer takes place as it oscillates in response to the exciting forces imposed by an elastic cable. The body motion can be amplified in accordance with hydrodynamic properties of the drag and added mass coefficients, and by mechanical properties of the system, as the geometry and stiffness of the lifting cable. This amplification in resonant state tends to increase the Heat transfer. To achieve the maximum heat transfer, the combination of hydrodynamic and mechanical properties of the submerged heat exchanger shall be determined in accordance with the expected environmental loads. Experimental results from the literature are used as reference to develop and validate a numerical routine in Python. An analytical harmonic motion amplification model is used as reference to calculate the body response at several water depths ranging from 200 to 1200 m. Twelve Submerged Heat Exchanger types are analyzed. The Submerged Heat Exchangers are set up in groups in accordance with the number of pipes, pipe diameter and pipe length. The results show a relationship between heat convection and hydrodynamic response, strongly influenced by porosity. Submerged Oscillating Heat Exchanger is assumed as a condenser of an Organic Rankine Cycle and provides the energy required to condense the working fluid.