进汽参数对拉伐尔喷管中水蒸气自发凝结的影响

In view of the spontaneous condensation laws of water steam expanding from the superheated zone into the wet steam zone under different inlet parameters, a numerical simulation method is adopted to study the condensation characteristics of water steam flowing through a Laval nozzle under non-equilibrium and equilibrium conditions. Effects of inlet steam parameters on the supercooling, droplet number, humidity, pressure ratio and Mach number of the water vapor in the non-equilibrium condensation process are analyzed. And then the differences between the equilibrium condensation characteristics and non-equilibrium condensation characteristics are contrasted. Results show that the supercooling of non-equilibrium condensation is greater, and the changes in pressure and Mach number are more significant when the inlet pressure is lower. With the increase of the inlet pressure, the changes in pressure and Mach number are reduced gradually, and the outlet humidity increases and exceeds 20% when p/p_c reaches to 0.8. By comparing the equilibrium condensation and non-equilibrium condensation, it is found that when the inlet pressure is low, the calculation results of non-equilibrium condensation and equilibrium condensation are significantly different, and the humidity of Wilson point reaches to 8.40% in equilibrium condition. When the inlet pressure is close to the critical pressure, the result of equilibrium condensation is basically close to that of non-equilibrium condensation, and the humidity of Wilson point in equilibrium condition is only 1.98%.