超临界CO2循环驱动的空气压缩系统研究

Study on Air Compression System Driven by Supercritical CO2 Cycle

工业用大型压缩机能耗高,节能降耗需求迫切。简单回热循环超临界CO2循环可用于驱动压缩机并可以大量集成压缩机余热。针对空气压缩过程,构建了超临界CO2循环驱动的空气压缩系统,空气压缩机分为4级压缩3次中间冷却方案和2级压缩1次中间冷却方案,对4种情况进行了热力学分析。结果表明:采用4级压缩空气压缩机,可回收的余热量小,对于降低热源能耗的作用有限;而采用2级压缩空气压缩机,可大量回收余热,对于降低能耗的作用显著,特别是提高2个压缩级的进气温度,可进一步提高余热回收量,降低热源能耗。超临界CO2循环驱动的空气压缩系统相比现有技术水平的汽轮机机组驱动系统,有望达到更低的热源能耗。

The energy consumption of large industrial compressors is high,and there is an urgent demand for energy consumption reduction.The simple regenerative supercritical CO2 cycle can be used to drive the compressor and integrate large amount of waste heat of the compressor.For the air compression process,an air compression system driven by supercritical CO2 cycle is constructed.The air compressor is divided into 2 types,one has 4 compression stages with 3 intermediate cooling,and the other has 2 compression stages with 1 intermediate cooling.The thermodynamic analysis for 4 cases is carried out.The results show that using 4-stage compressed air compressor can recover only a small part of the waste heat and slightly reduce the energy consumption of heat source,while using 2-stage compressed air compressor can recover a lot of waste heat,which has a significant effect on the reduction of energy consumption.Especially,increasing the inlet air temperature of the 2 compression stages can further improve the amount of waste heat recovery and reduce the energy consumption of heat source.The air compression system driven by supercritical CO2 cycle is expected to obtain lower energy consumption of heat source compared with the steam turbine driving system at the existing technical level.