Analysis Of Flow Field Characteristics Of Pneumatic Control Valve

Pneumatic piston motor is the mine winch’s center power plant for mine exploitation, pipe laying, roof bolt handling and so on,it is very important for the study of air motor’s working process.Pneumatic control valve is air motor’s key control element,it’s structure affects air motor’s power take-off and performance characteristic directly. The distribution of the flow field inner pneumatic control valve and motor in-cylinder is complex and changeful,it has strong three-dimensional character and randomness. To analyze and study the flow field inner pneumatic control valve and motor in-cylinder by numerical simulation method, and analyze the connection of their flow field distribution rules and motor output characteristics.According the flow characteristic and influence factor of flow field inner pneumatic control valve, combining aerodynamics’ s basic theory and study method, to establish the 3D model of flow field inner pneumatic control valve. According different working condition, to make the flow field’s numerical simulation of pneumatic control valve by flow field analysis sofeware Fluent. We get the pressure,speed, mach number and other associated parameters which can present flow field characteristics inner pneumatic control valve. Firstly, the inner flow field of safety valve and pneumatic motor output power were analyzed under the different lift, and then the reasonable lift value for safety valve could be determined in order to reduce pressure loss in safety valve inlet on the basis of the guarantee with sufficient air inflow in the cylinder.Secondly, in order to have an analysis of the law on distribution of the flow field of different outlet and energy loss, a simulation on the flow field distribution were made at the interface of air distribution valve spool intake pipe and valve body circular-type pipe with the different cylinder inlet; then a contrastive comparison on the flow field distribution at the intake pipe outlet were made under the working condition of counter-rotating motor. Next the connection between cam phase angle and air distribution valve intake pipe outlet were identified; and the relationship between distribution of the flow field in the cylinder could be understood.In the mean while, the process of pneumatic motor first and second exhaust were analyzed; then the three groups of cross sectional diameter of second exhaust pipe were selected to study the influence of the cross sectional diameter had on the second exhaust, so the cause of hernia phenomena existing in the process of second exhaust can be found out.Finally, the cylinder inlet pipe diffusion angle were determined according to the relationship between the cylinder pressure loss coefficients in inlet pipe and its diffusion angle; the relationship between phase angles of air inlet and exhaust, the pressure in in-cylinder and motor output torch were set up, then the reasonable cam phase Angle was optimized. Finally, under the same conditions, the output power of the pneumatic motor is compared under different pneumatic control valve structure, so as to verify the rationality of the structure optimization.Through systematic study and analysis to the aerodynamic performance of pneumatic control valve inner air by numerical simulation method,we get the pneumatic control valve inner flow field’s detailed physical parameter, make structure optimization to several key position of pneumatic control valve according the parameter gotten. The research results have theoretical reference value to pneumatic control valve’s structure design and promotion.