COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF NEW CONCEPT HEAT EXCHANGER FOR OTEC APPLICATION

This paper presents a comprehensive analysis of a new concept of heat exchanger for Ocean Thermal Energy Conversion (OTEC) applications. The study utilizes Computational Fluid Dynamics (CFD) simulations to evaluate the performance of different heat exchanger designs for extracting thermal energy from oceanic sources, specifically using water and R717 liquid. Key performance parameters including cold vapor fraction, temperature difference, and pressure drop are evaluated through a combination of numerical simulations and experimental validations. The analysis of the cold vapor fraction provides insights into evaporation rates and their distribution across multiple prototypes, highlighting the impact of the wetted area on heat transfer effectiveness. The evaluation of temperature differences reveals variations in discharge fluid temperatures, with some prototypes deviating from thermodynamic principles at a default evaporation frequency of 0.1. Various evaporation frequencies are simulated and compared with experimental data to select the optimal frequency for each prototype. The simulations and experiments, conducted under similar conditions, ensure accurate validation despite inconsistencies arising from variations in heat exchanger design and boundary conditions. The performance evaluation demonstrates the effectiveness of the three prototypes, with Prototype 2 achieving the highest effectiveness up to 59% for OTEC applications. The findings contribute to a better understanding of heat exchanger performance in OTEC and provide valuable insights for design optimization and future application development. This paper emphasizes the significance of efficient heat transfer and highlights the potential of ocean thermal energy as a renewable and sustainable resource.