基于余热利用的反渗透淡化热机及其效率

Reverse osmosis desalination thermo engine with waste heat and its utilization efficiency

提出一种利用低品位余热驱动反渗透淡化的方法,以实现将低品位热能转换成为可驱动海水反渗透的机械能.对低品位余热驱动反渗透淡化的机理进行分析并建立系统的工艺模型,研究温敏淡化热机工作周期内的运动模式,并基于温熵图分析工质的热力循环过程.理论分析温敏淡化热机的能量传递和分配过程,建立基于显热法和焓差法的热机热功转换效率的计算公式.结果表明:以R143a为温敏工质的热机效率为13.6%,该方法拓展了反渗透淡化驱动方式,为其应用于太阳能、地热、工业余热在内的能源梯级利用系统奠定了基础.

A method of reverse osmosis desalination based on the power from low grade heat is put forward to achieve the conversion from low grade heat to mechanical energy. Firstly, the driving mechanism of reverse osmosis desalination by low grade heat is analyzed, based on which, system model is established. Then, the motion mode of thermo engine is discussed, and thermodynamic circle of working medium is analyzed based on tephigram. Finally, the energy transformation and allocation of thermo engine is theoretically analyzed, and the calculation formulas of thermo conversion efficiency based on sensible heat method and erithalpy potential method are constructed respectively. The result shows that the efficiency of thermo engine with working fluid R143a is 13.6%. This method extends the driving modes of reverse osmosis desalination, and provides technology support for cascade utilization of energy including solar energy, geothermal energy and industrial waste heat.