Constructions of the experimental-estimation model for releasing combustion products at thermal pulse processing

Резюме

The object of this study are ways to ensure the speed and repeatability of the valve for the release of combustion products from the thermal-pulse unit, which are the most important parameters that enable the precision of the finishing treatment with detonating gas mixtures. The study is aimed at analyzing the process of releasing combustion products in the valve of the proposed design; identification of factors that affect the speed of its opening; establishing the nature of the change in gas dynamic parameters in the combustion chamber. Experimental studies were carried out on a specialized bench simulating the operation of a valve with pressure measurement in gas cavities and controlling the movement of a movable glass of the valve with an incremental encoder. Information on the position of the movable cup is obtained in real time with a decisive ability of 3 microns. The experimental study showed that an increase in the response rate of the valve of the design under consideration to the values required for precision thermal pulse treatment (0.01 s) is possible subject to the use of compressed air. To study the flow processes of high-temperature gases during the operation of the controlled outlet valve, partially immersed in water, a numerical model has been built. A feature of the model is to take into account the real values of the friction force acting on the moving part of the valve, due to the introduction of resistance force acting on the movable glass. The magnitude of this force under the specified initial conditions is assigned from the condition of ensuring the coincidence between the estimated opening time of the valve and its average value obtained from full-scale experiments. For the range of design conditions, based on the lower limit of the working pressure of the combustion products, the water level is determined in the chamber of the thermal pulse equipment, on which the valve must be partially immersed for safe operation