新型压缩机排热涡流管-ORC系统热力性能分析

Thermal performance analysis of a new type compressor heat discharge vortex tube-ORC system

为了高效回收压缩机排气余热余压,利用涡流管的特性,与有机朗肯循环(organic Rankine cycle, ORC)耦合,提出一种新型涡流管-有机朗肯循环系统(VT-ORC)。以343.15~373.15 K,0.30~0.65 MPa的排气为热源,对VT-ORC系统进行模拟,对模拟结果进行分析。结果表明:VT-ORC系统相较于传统ORC模型,系统热效率相近,但系统净输出功得到较大提升。对选用工质进行模拟,得到不同蒸发压力下工质R236fa最高系统热效率16.66%;而在许用蒸发压力范围内,采用工质R1234yf能得到最高净输出功590.23 kW;通过改变涡流管阀门开度,调节涡流管出口冷、热流比,分析得到热流比较小时,系统净输出功较大,系统[火用]损失随热流比的增加而减少;而随着压缩机排气压力的提升,涡流管出口热流温度提升,系统的吸热量增加,但同时蒸发器换热温差提升,系统[火用]损失增加。

In order to efficiently recover the exhaust waste heat and residual pressure of the compressor,a new vortex tube organic Rankine cycle(VT-ORC)system was proposed by combining vortex tube and organic Rankine cycle(ORC).The VT-ORC system was simulated taking the exhaust gas of 343.15-373.15 K and 0.30-0.65 MPa as the heat source,and the simulation results were analyzed.The results show that compared with the traditional ORC system,the thermal efficiency of VT-ORC system is similar,but the net output work of VT-ORC system is greatly improved.R236fa has the highest system thermal efficiency of 16.66%under different evaporation pressures.Within the allowable evaporation pressure range,the highest net output power of 590.23 kW can be obtained by using R1234yf.By changing the valve opening of the vortex tube and adjusting the cold and heat flow ratio at the outlet of the vortex tube,a larger net output power of the system can be achieved when the heat flow ratio is small,and the system exergy loss decreases with the increase of the heat flow ratio.With the increase of compressor exhaust pressure,the heat flow temperature at the outlet of vortex tube increases,and the heat amount of the system absorption increases,but the heat exchange temperature difference of the evaporator also rise and the system exergy loss increases.