Numerical Simulation Of Pressure Swirl Nozzle Interference

The cloth liquid system as an important part of horizontal tube falling film evaporation device, it has a direct affect the heat transfer effect in the process of falling film. The spray type cloth liquid system has many advantages, such as difficulty to jam convenient maintenance and small occupied space, so the system is widely used, especially in the large and super large devices. The performance of the spray system is determined by the nozzles. And the spray system is composed of multiple nozzles. At present, the study of the nozzle mostly concentrated in a single nozzle. So numerical studies of nozzle interference are very important.In this paper, the author has made the numerical calculations of internal and outside flow field of the two nozzles and four nozzles by using Euler-Euler method. The author also analyses the distribution characteristics, speed characteristics and pressure characteristics of the gas-water two-phase flow in the nozzle and out the nozzle. This paper also analyzes the difference between different models as well as the reasons. In addition. the author made the two nozzles calculation of the outside flow field. The paper analyzes the influences of pressure and the distance between the two nozzles (L) to spray form, the diameter of the droplet distribution, evenness and the velocity distribution.Study found:for the hollow cone nozzle, when there are the same nozzle structure, the same calculation condition, the same inlet velocity, and the opposite direction, the inlet velocity vector parallels are not on the same straight line. But when the inlet velocity vector perpendicular to the vertical plan that made by the two nozzle interference arrangement. The square arrangement has four nozzles. The shape that composed by the four nozzle spray center is not a rule square. With the increase of Z, the shape is more irregular. With the increase of the Z, the gap that in the center of the spray is smaller. The overall distribution of spray is very uneven. Near the interference area (which is composed of four nozzle spray center square), the liquid phase volume fraction is larger. There are two triangles among the four spray nozzles in the lozenge arrangement of the four nozzle model. With the increase of Z, the gap is smaller. The overall distribution of the spray is uneven. Near the interference area (which is composed of four nozzle spray center square), the liquid phase volume fraction is larger.For the solid cone nozzle, the SMD in the nozzle spray center is minimum. With the increase of the radial jet distance, the SMD increase gradually. But this trend decrease with the increase of pressure. The SMD values decrease with the increase of pressure. The SMD of double nozzle interference is smaller than that of single nozzle. And the difference is inconspicuous. The SMD of two nozzle interference basically remain unchanged with the increase of the distance between the two nozzles. With the increase of Z, the DPM concentration in the nozzle jet center decreases. In the area of interference, with the increase of Z, DPM concentration increased gradually. With the increase of pressure, the maximum concentration of DPM increases gradually, the position of the DPM concentration peak also gradually far away from the injection center. With the increase of pressure, DPM concentration range increase gradually, and the evenness deviate gradually. Along with the rising of the parallel distance L, the range and the peak of the DPM concentration decrease. When L=30mm, the uniformity of spray is beast.