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

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