Research On Flow Field Theory Of Gas Relay

Gas protection as an important part of the relay protection, Because of problems in the internal structure of the core components of the Buchholz relay, the gas protection frequently refuse to move and occur malfunction. This leads to huge economic losses. This problem has been described Buchholz relay reliability and stability. The root causes of fact, the gas relay malfunction occurs, tripping phenomenon is its basic theoretical research, there are still shortcomings and deficiencies. Leading to the setting value set unreasonable. So this paper desire from the CFD point of view to explore Buchholz relay internal flow field-flow state and to solve the problem of setting the speed setting value.Firstly, this paper do the numerical simulation based on Fluent dynamic grid method, make a fine study of the internal flow field of Buchholz relay. Adapt the dynamic method to simulate the shutter open process. for further research of analysissing Buchholz relay provides a basis platform. And experimental data to verify the accuracy of the CFD simulation platform.Then, this paper analyzes the idea of the relation of the steady-state torque and damping baffle opening and an oil flow velocity. And combined resistance of the spring torque and the relationship of the opening angle, as well as re-opening of the gas alarm to give the size of the gas flow rate of the relay setting values. This is essentially determined different tuning velocity, the angle corresponding to different alarms.Finally, From the standpoint of the features of transformer internal fault, It generates source of explosion inside the transformer, and generates shock waves subsequently, when Buchholz relay occurs heavy gas alarm. Shock reflects many times in the transformer internal flow path. The pressure wave via two ways to release its carried energy. First, through the gas relay, and eventually through the oil pillow respirator pressure energy release. Second, it via the pressure relief valve or pipe explosion, the press release. In the case of unknowning the specific overpressure that flows through the Buchholz relay, using the relationship inherent shock, combined with relay current industry standard flow rate setting value range, this paper gives out a semi-empirical theory method to determine the speed setting value, and with the CFD method to simulate the whole process.