發(fā)布時(shí)間：2018-11-20 15:18

【摘要】：安全閥是承壓系統(tǒng)中重要的安全附件之一。本文使用計(jì)算流體力學(xué)軟件CFx研究核電安全閥內(nèi)的過(guò)熱蒸汽臨界流和過(guò)冷水氣穴流,所得到的結(jié)論對(duì)核電安全閥結(jié)構(gòu)設(shè)計(jì)和優(yōu)化具有借鑒意義。本文的主要工作如下： (1)在蒸汽安全閥出口處接一圓柱形容器獲得計(jì)算用幾何模型,模擬了不同開(kāi)高、入口壓力和下調(diào)節(jié)圈位置時(shí)過(guò)熱蒸汽的臨界流場(chǎng),以及以理想水蒸氣作流體介質(zhì)時(shí)的臨界流場(chǎng)。通過(guò)分析發(fā)現(xiàn)：安全閥內(nèi)出現(xiàn)臨界流時(shí),音速面出現(xiàn)在上下調(diào)節(jié)圈組成的環(huán)形區(qū)域內(nèi),而不是在喉徑橫截面上；該音速面的范圍隨著入口壓力、下調(diào)節(jié)圈高度的增大而增大；臨界流抑制了閥門的泄放能力,排量系數(shù)隨著開(kāi)高增大出現(xiàn)震蕩,隨著音速面范圍的增大而減�。哼^(guò)熱蒸汽物性對(duì)速度場(chǎng)模擬結(jié)果影響不大,對(duì)溫度場(chǎng)模擬結(jié)果有嚴(yán)重影響。 (2)使用蒸汽安全閥作為氣穴流模擬的幾何模型,研究了恒定物性的過(guò)冷水的流場(chǎng)分布情況。通過(guò)模擬和分析不同結(jié)構(gòu)、出口壓力和入口流速的氣穴流場(chǎng)發(fā)現(xiàn)：氣穴主要發(fā)生上下調(diào)節(jié)圈組成的環(huán)形區(qū)域內(nèi)；當(dāng)氣穴發(fā)生在閥瓣和反沖盤受力面與密封面組成的環(huán)形區(qū)域內(nèi)時(shí),氣穴流嚴(yán)重消弱安全閥動(dòng)作性能；氣穴數(shù)量隨著出口壓力和開(kāi)高的增大而減小,隨著入口流速的增大而增大。
[Abstract]:Safety valve is one of the important safety accessories in the pressure system. In this paper, the superheated steam critical flow and supercooled cavitation flow in the nuclear power safety valve are studied by using the computational fluid dynamics software CFx. The conclusions obtained are useful for the design and optimization of the nuclear power safety valve structure. The main work of this paper is as follows: (1) the critical flow field of superheated steam at different opening heights, inlet pressures and the position of the lower regulating ring is simulated by using a geometric model for the calculation of a cylindrical vessel at the outlet of the steam safety valve. And the critical flow field when ideal water vapor is used as fluid medium. It is found that when the critical flow occurs in the safety valve, the sonic surface appears in the annular region composed of the upper and lower regulating rings rather than on the throat cross section, and the range of the sonic plane increases with the inlet pressure and the height of the lower regulating ring. The critical flow inhibits the discharge capacity of the valve, and the displacement coefficient oscillates with the increase of the opening height and decreases with the increase of the sonic surface. The physical properties of superheated steam have little effect on the simulation results of the velocity field, but have serious influence on the simulation results of the temperature field. (2) using steam relief valve as the geometric model of cavitation flow simulation, the flow field distribution of supercooled water with constant physical properties is studied. By simulating and analyzing the cavitation flow field with different structures, outlet pressure and inlet velocity, it is found that the cavitation mainly occurs in the annular region composed of upper and lower regulating circles; When the cavitation occurs in the annular region composed of the disc and the recoil disc, the cavitation flow seriously weakens the performance of the relief valve, and the number of the cavitation decreases with the increase of the outlet pressure and opening height, and increases with the increase of the inlet velocity.
【學(xué)位授予單位】：華東理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類號(hào)】：TH134

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 胡建華;超（超）臨界蒸汽疏水閥空化與熱流固耦合研究[D];蘭州理工大學(xué);2013年

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本文編號(hào)：2345257