The osmotic heat engine is a promising technology for harvesting low-grade heat from different heat sources. However, a better understanding of the system performance, thermodynamic efficiencies, and suitable application circumstances (type of heat sources, system energy generation capacity, etc.) is needed before the transition can be made from conceptual design to practice. Firstly, the energy efficiency (ƞ_th) and exergy efficiency (ƞ_X) of a thermolytic osmotic heat engine (NH₄HCO₃ solution as the working fluid) were investigated in this study. It was found that the osmotic heat engine performs better when the operating temperature (heat source temperature) is lower (323 K). Additionally, a higher draw solution concentration and a lower feed solution concentration can increase both ƞ_X and ƞ_th. Subsequently, the energy return on investment with either low-grade industrial waste heat or solar thermal energy acting as the heat source was calculated. It was found that different energy return on investment values can be obtained with different heat sources. The results show that when industrial waste heat is used as the heat source, a much higher energy return on investment value (approximately 55) can be obtained. This finding indicates that it is suitable to generate electricity from industrial waste heat using the osmotic heat engine. When solar thermal energy is used as the heat source the energy return on investment value is 1.3–2.2 because there is a large amount of embodied energy in the flat-plate solar collector. This study represents a step forward towards the practical application of the osmotic heat engine.

渗透热机是一种从不同热源收集低级热量的有前途的技术。但是，在可以从概念设计过渡到实践之前，需要对系统性能，热力学效率和合适的应用环境（热源类型，系统能量产生能力等）有更好的了解。首先，能量效率（ƞ_日）和火用效率（ƞ _X）一个热分解渗透热机的（NH ₄ HCO ₃溶液作为工作流体）在本研究中进行了研究。发现当工作温度（热源温度）较低（323 K）时，渗透热机的性能更好。此外，较高的驱动溶液浓度和较低的进料溶液浓度可以增加两者ƞ _X和ƞ_第。随后，以低品位工业废热或太阳能为热源，计算了投资的能源回报。发现使用不同的热源可以获得不同的能源投资回报值。结果表明，当使用工业废热作为热源时，可以获得更高的能源投资回报率（约55）。该发现表明使用渗透热机从工业废热发电是合适的。当将太阳能热能用作热源时，由于平板太阳能收集器中包含大量的体现能量，因此能量投资的投资回报值为1.3–2.2。这项研究代表了向渗透热机的实际应用迈出的一步。