含硫烟气余热智能相变回收系统性能实验研究

Experimental study on performance of intelligent phase change recovery system for sulfur-containing flue gas waste heat

关键词:  余热回收  相变换热  运行特性

Key words:  waste heat recovery  phase change heat transfer  operating characteristics

摘要:

为掌握含硫烟气余热智能相变回收系统的运行特性,设计并搭建了性能测试实验台,测试了烟气热负荷率、LiBr溶液质量浓度和循环泵频率等参数对系统运行特性的影响。结果 表明:系统热回收系数随烟气热负荷率的增大呈线性增长；系统火用效率随烟气热负荷率的增大而减小,但火用效率较小,仅约为0.15～0.20,表明该系统不适用于做功,而适用于生产生活供热等用途；系统热回收系数和火用 效率受LiBr溶液质量浓度和循环泵频率的影响均较小。LiBr溶液进出换热器温度差随烟气负荷率的增大先增大,再趋于平缓,后又增大,并在溶液质量浓度为53%低负荷运行时,对换热器壁面及烟气出口温度受烟气热负荷率影响较小。以上结论为智能相变系统运行提供了理论依据。 

Abstract:

In order to master the operation characteristics of the intelligent phase change recovery system for sulfur-containing flue gas waste heat, a performance test bench was designed and built to test the influence of flue gas heat load ratio, LiBr solution mass concentration and circulating pump frequency on the operation characteristics of the system. The results show that the energy efficiency increases linearly as the flue gas heat load ratio rises. And the exergy efficiency decreases with the increase of flue gas heat load ratio, but the exergy efficiency is only about 0.15-0.20, indicating that the system is suitable for production and living heating rather than work. Meanwhile, LiBr solution mass concentration and circulating pump frequency have a little influence on the energy efficiency and exergy efficiency. In addition, the temperature difference of LiBr solution at inlet and outlet of the heat exchanger first increases, then tends to be flat, and increases again with the increase of flue gas load ratio. When the system operates at low heat load ratio condition with the 53% of LiBr solution mass concentration, the wall temperature of heat exchanger and the outlet temperature of flue gas are less affected by the flue gas heat load ratio. The above conclusions can provide a theoretical basis for the operation of intelligent phase change recovery system for sulfur-containing flue gas waste heat.