透平入口压力对ORC系统的影响摘要.pptVIP

4.2 主要热力学参数的灵敏度 4.2.2 透平入口压力对ORC系统的影响 新能源1201班 陈斯 林晋仪 Assuming that the turbine inlet temperature is 70℃ and condensation temperature 20℃.Figs.9 and 10 respectively show that the enthalpy drop across turbine increases and the mass flow rate with different working fluids decreases with an increase in turbine inlet pressure. 假定透平入口温度是70℃，冷凝器温度是20℃，图9和图10分别表示各种工质的焓降和质量流率与透平入口压力的关系。 Because the vapor evaporator temperature can increase with an increase in turbine inlet pressure, the water temperature (hot side) leaving vapor evaporator is elevated with the limitation of pinch point temperature difference and the heat transfer rate in vapor evaporator falls, resulting in a decrease in mass flow rate in ORC. 因为蒸汽的沸点会随透平入口压力的上升而上升，流出蒸发器的水温会由于夹点温差的限制而上升，然后蒸发器的传热速率会下降，导致ORC系统中的质量流率降低。 Fig.11 shows the variation of net power output with turbine inlet pressure. As the turbine inlet pressure increases, the net power output increases firstly, reaches to its peak and declines when the enthalpy gains across turbine do not make up for the decrease in mass flow rate of working fluid across the turbine for different working fluids 图11表示不同工质的净输出功先增加，到达顶点后又减小，这是因为焓增不足以弥补质量流率的下降所导致的净输出功的下降。 Since the differences of net power output among four different fluids are not very great, R123 or R245fa could be good candidate working fluids owing to their lower operating pressure. 因为四种不同流体的净输出功差别不大，而R123和R245fa的工作压力更低，所以它们是好的备选工质。