水下热滑翔机的温差能热机性能分析与相变材料选择

相变材料作为温差能热机的工作流体,其热力学状态对周围海水温度非常敏感,且其融点对水下热滑翔机的运行范围影响很大.基于焓法模型,在不同大洋温度剖面下,对以3种相变材料为工作流体的温差能热机进行性能分析;并考虑到不同大洋温度剖面的特点,为温差能热机选择合适的相变材料,以拓宽水下热滑翔机的应用范围.结果表明：在给定的大洋温度剖面下,3种工作流体的相变过程时间不同;以正十五烷为温差能热机工作流体的水下热滑翔机具有更广的运行范围.

Performance Analysis of Ocean Thermal Engines and the Selection of PhaseChange Materials for an Underwater Thermal Glider

As a working fluid for ocean thermal engines,the Phase Change Material（PCM）is very sensi-tive to the surrounding seawater temperature in terms of thermodynamic state,and its melting point hasgreat influences on the operating range of underwater thermal gliders. Based on the enthalpy method,thispaper analyzes the performances of ocean thermal engines with three types of PCM under different oceantemperature profiles. An optimal PCM is then selected for each temperature profile to broaden the operatingrange of the underwater thermal glider. The results show that the transition time of the phase change pro-cesses may vary for different working fluids under the same ocean temperature profile. Also,it is observedthat the n-pentadecane is a desirable working fluid for the ocean thermal engine as the underwater thermalglider in this case has the widest operating range.