一种热能梯级利用型温差发电系统的优化设计

Optimization Design of a Cascading Thermoelectric Generation System

天然气作为一种清洁、高效、供应范围广的能源,被广泛地应用于分布式发电中,而结构简单、输出稳定性强、热源适用性广的温差发电技术可以较好地结合天然气应用于分布式能源当中,但温差发电系统热电转化效率的低下阻碍了其发展与应用。为了提高系统的发电效率,本文提出了一种热能梯级利用型温差发电系统。通过将高、中、低温温差发电模块合理地布置于一个以天然气燃烧产生的高温烟气为热源的系统中,以此形成对热能的梯级利用。使用CFD计算的手段实现了系统的优化设计计算,并依据优化结果搭建了实验台。模拟和实验研究的结果表明,优化后的系统能够有效地实现对热源的梯级利用,相比于传统的单级高温温差发电系统,系统的发电效率增加了1.93个百分点,增幅达到37.7%。

The natural gas is clean,high-efficiency and accessible so that it is wildly used in the field of distributed energy.Meanwhile,the thermoelectric generation(TEG)with simple structure,stable output and wide heat resource adaptability can be applied to the distributed energy combining with natural gas.However,the low efficiency of the TEG system hinders the development and the application of it.In order to increase the system efficiency,a cascading thermoelectric generation system is designed.The system is able to make full use of the heat source produced by the combustion of the natural gas based on the rational arrangement of the high,medium and low temperature thermoelectric modules.The CFD method has been used to optimize the design of the system and a test bed has been established based on it.The simulative and experimental results show the optimized system can make the cascading utilization of the heat source,and also the efficiency of the system is 1.93% more than the conventional single-stage high temperature TEG system which weighs 37.7% of it.