Abstract:

Since the clearance of the seal end face for high-pressure, high-rotate-speed and dry gas in the stationary and rotating rings is only 3 to 5 microns, the test technology of face temperature in dry gas seal is difficult, and furthermore, it is key point to study the thermal fluid mechanics of micro-scale face. In this paper the face temperature in dry gas seal is tested and the face temperature distribution and cause are studied under different pressure, rotational speed, and starting and stopping phases in the dry gas seal system by using LabVIEW test system software to establish the face temperature test program of dry gas seal, selecting the requirements of sensor and other appropriate hardware devices, determining the corresponding test technology of face temperature, and taking methods to restrain interference. The results show that under different pressure and different rotational speed, the face temperature distribution is as follows. The temperature of the root diameter is the highest and that of the outside diameter is the lowest, while the temperature of the inner diameter is between those of the root and outside diameters. At the pressure of 4 MPa and rotational speed of 10000 r•min^-1, the highest temperature of 90.90℃ occurs in the root diameter. It reflects that when the dry gas seal system is steady operated, the root diameter is in the maximum pressure change point and rotating and static rings are in the non-contact state. Thus, the main reason of rising temperature is that a large pressure drop of the root diameter region causes thermal dissipation in the face. Under dry gas seal starting and stopping phases, the distribution of the face temperature shows that the temperature of the outside diameter is the highest, while that of the inner diameter is the lowest and that of the root diameter is between the temperature of the outside and inner diameters. It indicates that when the dry gas seal system is in the started and stopped phases, rotating and static rings are in the contact state, resulting in rising temperature because of friction between the solid walls. The results are consistent with our previous theoretical results obtained by using thermal dissipation deformation, and verify the root diameter region is the highest temperature point. The results provide a basis for optimizing groove design under thermal dissipation.

Key words: dry gas seal, microscale, thermodynamics, face temperature, high-pressure and high-rotate-speed, test technology, LabVIEW software, compressor

摘要：

由于高工况和端面间隙3~5 μm, 因而对端面温度的测试技术是个难点, 更是研究端面微尺度热流体力学的关键点。采用LabVIEW对端面温度编写测试程序, 选定符合要求的传感器等设备, 确定相应的测试技术, 采取抑制干扰的措施, 对端面温度进行测试, 研究不同工况和启停阶段下端面温度的分布和其原因。试验结果表明:不同压力和转速下, 端面的温度分布:根径大于内径大于外径, 最高温度发生在根径处, 为90.90℃, 说明非接触状态下, 以根部大压降引起的热耗散所产生的温升为主。启停阶段外径温度最高, 说明接触状态下, 以固体壁面间摩擦产热为主。这与先前利用热耗散变形得到的理论结果相吻合, 验证了根径区域为温度最高点。试验结果为今后考虑热耗散下的槽形优化提供了依据。

关键词: 干气密封, 微尺度, 热力学, 端面温度, 高速高压, 测试技术, LabVIEW软件, 压缩机