摘要
文中从范德瓦尔状态方程导出了工质状态的气液相尖点突变机理。从自复叠循环低温节流阀的阀前工质状态入手,以自动复叠式循环的两个节流阀开度作为控制变量,分析了低温节流阀前工质状态的突变,进而针对自复叠试验中的突变现象进行了分析和解释。结果表明,随着自复叠循环的高温节流阀开度不断减小,低温节流阀前工质将由液相状态朝着气化突变方向变化。当低温节流阀前工质气化突变后,低温节流阀的阻力将突然变大,引起壅塞,从而导致蒸发压力急剧降低而冷凝压力急剧升高,从而使系统失稳瘫痪。尖点突变的逆向不重复性决定了当高温节流阀的开度减小引起系统失稳时,直接使节流阀开度回复至失稳前的状态无法使系统稳定下来,只有使高温节流阀和低温节流阀的开度同时增大一个较大的量,才可以使系统趋于稳定。
The cusp - type catastrophe mechanism of gas - liquid state variation was deduced by Van der Wall equation. With the control parameters of throttle valves＇opening, the refrigerant state catastrophe before low- temperature throttle valve in Auto -cascade refrigeration （ACR） system was analyzed, and the catastrophe phenomenon in ACR system experiments was analyzed and explained. The result shows that, with the decrement of high -temperature throttle valve＇s opening, the state of the re- frigerant before low - temperature throttle valve in ACR system will trend to gasifying catastrophe from liquid state. After the gasi- fying catastrophe of the refrigerant before low - temperature throttle valve, the resistance of low - temperature throttle valve will quickly grow up, which will cause choked flow, then evaporation pressure quickly decreases while condensation pressure quickly increases, which will lead to instability and paralysis of the system. When the system＇s instability caused by the decrement of high - temperature throttle valve＇s opening, reverse non - repetition of cusp - type catastrophe makes it impossible to stabilize the system by directly reverting the throttle valve＇s opening, it has to have a relative more increase of the opening of two valves in ACR system to stabilize the system.
出处
《低温与超导》
CAS
CSCD
北大核心
2011年第10期62-66,共5页
Cryogenics and Superconductivity
关键词
突变
自复叠
节流阀开度
失稳
Catastrophe, Auto - cascade, Opening of throttle valves, Instability
