Abstract

Utilizing energy efficiently could greatly relieve current energy crisis. Therefore, in this article, a simple supercritical CO₂ Brayton cycle for waste heat recovery from gas turbine is presented. The system uses ambient air as its cold source, which is more convenient and economic. Considering temperature difference between heat source and turbine inlet, it is of great significance to research the effects of turbine inlet temperature on the system performance due to the high temperature range of the exhaust gas from gas turbine. For this purpose, a control strategy is proposed and a mathematical model is established on off-design conditions to predict system performance when turbine inlet temperature increases from 673.15 K to 773.15 K. Results indicate that both turbine power output and system net power output increase with the rise of turbine inlet temperature, as well as total heat transfer in heater and cooler. Furthermore, the system thermal efficiency also increases until it becomes maximum on design point. In addition, the efficiency of turbomachinery varies slightly.

摘要

有效利用能源可以大大缓解当前的能源危机。因此，在本文中，一个简单的超临界 CO ₂介绍了用于从燃气轮机中回收废热的布雷顿循环。该系统采用环境空气作为冷源，更加方便、经济。考虑到热源与汽轮机入口温差，研究汽轮机入口温度对燃气轮机排气温度范围较高的系统性能的影响具有重要意义。为此，提出了一种控制策略，并在非设计条件下建立了数学模型，以预测涡轮入口温度从 673.15 K 增加到 773.15 K 时的系统性能。结果表明，涡轮功率输出和系统净功率输出均随着涡轮进口温度的升高，以及加热器和冷却器的总传热。此外，系统热效率也会增加，直到达到设计点的最大值。此外，涡轮机械的效率略有不同。