绝缘材料耐低温溢出性的测定第3部分:射流释放

[中文适用范围]： 该文件描述了一种用于确定低温溢出保护（CSP）系统对低温喷射的抵抗力的方法，该抵抗力是由于加压释放而不会导致浸没条件。 它适用于 CSP 系统安装在碳钢上并与低温流体接触的情况。 低温射流可在从在压力下操作的工艺设备释放时形成（例如，一些液化工艺利用40至60巴的操作压力）。 由于高压放电，大动量和极端低温可能会损害低温溢出保护。 尽管该测试使用液氮作为低温液体，但本文件中描述的测试代表 LNG 通过 20 mm 或更小的孔口、在 6 barg 或更低的释放压力下释放，基于 1 m 处的模拟参数。 释放点。 该测试具有代表性的置信度基于模拟释放的预期动态压力与根据本文件的释放的动态压力的比较。 在该测试中覆盖真实工厂条件下的全部低温工艺条件是不切实际的；特别是，该测试不涵盖制冷回路和液化后液化天然气流中可能发现的高压低温喷射释放。 液氮被用作低温介质，因为它能够在本文件中描述的压力下安全地处理材料。 测试条件在标称 8 barg 压力下运行。 由于液化天然气或液氮的喷射释放或低压释放而受到低温溢出保护的保护。 ISO 20088-2 涵盖由于 LNG 或液氮喷射释放或低压释放而导致的气相暴露条件。 [外文原描述]： This document describes a method for determining the resistance of a cryogenic spill protection (CSP) system to a cryogenic jet as a result of a pressurized release which does not result in immersion conditions. It is applicable where CSP systems are installed on carbon steel and will be in contact with cryogenic fluids. A cryogenic jet can be formed upon release from process equipment operating at pressure (e.g. some liquefaction processes utilize 40 to 60 bar operating pressure). Due to high pressure discharge, the cryogenic spillage protection can be compromised by the large momentum combined with extreme cryogenic temperature. Although the test uses liquid nitrogen as the cryogenic liquid, the test described in this document is representative of a release of LNG, through a 20 mm orifice or less, at a release pressure of 6 barg or less, based upon simulated parameters 1 m from the release point. Confidence in this test being representative is based upon a comparison of the expected dynamic pressure of the simulated release in comparison with dynamic pressure from releases in accordance with this document. It is not practical in this test to cover the whole range of cryogenic process conditions found in real plant conditions; in particular the test does not cover high pressure cryogenic jet releases that might be found in refrigeration circuits and in LNG streams immediately post-liquefaction. Liquid nitrogen is used as the cryogenic medium due to the ability to safely handle the material at the pressures described in this document. The test condition is run at nominally 8 barg pressure. ISO 20088-1 covers cryogenic release scenarios which can lead to pooling conditions for steel work protected by cryogenic spill protection as a result of a jet release or low pressure release of LNG or liquid nitrogen. ISO 20088-2 covers vapour phase exposure conditions as a result of a jet release or low pressure release of LNG or liquid nitrogen.