Mathematical Modeling and Performance Analysis of Seawater Heat Exchanger in Closed-Loop Seawater-Source Heat Pump System

Abstract

The seawater source heat pump (SWHP) utilizes low-grade energy from seawater to satisfy heating/cooling requirements of coastal buildings. Compared with the open-loop SWHP system, the closed-loop system is more stable and reliable when used in cold regions because the seawater heat exchanger can mitigate icing and corrosion problems. This study established mathematical modeling for the seawater heat exchanger, which was validated by the experimental results, to estimate the heat transfer performance. The thermal performance of the seawater heat exchanger under different operating conditions was predicted, and the effects of several key parameters on thermal resistance were analyzed. The results revealed that the pipe wall thermal resistance of the original heat exchanger was the most important factor limiting the heat transfer. Hence, a cost analysis of the heat exchangers with different pipe materials was conducted, and the steel pipe with anticorrosive coating was proven to be optimal in reducing pipe wall thermal resistance and economy. The findings are useful in designing and optimizing the seawater heat exchanger and promoting the application of ocean thermal energy.