Experimental Research On The Condensation Characteristics Of Steam Flowing In A Horizontal Pipe Under Dynamic Load

In this thesis the centrifugal force resulted from a rotational platform was used to simulate the flying load, and an experimental system for steam condensation in a horizontal pipe had been established on the platform. The test pipe was installed in the radial direction of the rotating platform, and the flow direction of vapor in the pipe was opposite to the dynamic load. The parameters such as dynamic load, pressure, pressure drop, flow rate, temperature and void fraction were adjusted and measured in the experiment. Therefore some characteristics of steam condensation in a horizontal pipe under dynamic load were obtained. The experimental data could be added to the database in the characteristics of steam condensation in a horizontal pipe under dynamic load, and could be a reference in developing the vapor-cycle cooling system for flying vehicles.The results show that the dynamic load dramatically influences the condensation process of the steam in a horizontal pipe. The greater the dynamic load in the range 0 to 2g, the higher of the inlet pressure and the outlet pressure of the steam. However the inlet pressure increases more significantly than the outlet pressure so that the pressure drop increases. When the flow rate of the cooling water is kept constant, the condensation flux increases with the increase in dynamic load. The flow rate also influences the condensation process, and its effect becomes more obvious under high dynamic load. As the dynamic load becomes larger, the heat flux and the condensation coefficient would increase under different temperature differences between the vapor and the cooling water , and the tendency is more serious when the temperature difference is at a small value. It reveals that smaller temperature difference can enhance condensation. The condensation efficiency is higher when the inlet pressure of vapor is greater under the same dynamic load. And both of the condensation coefficients increase significantly with the increase in dynamic load. In addition, the stability of the condensation was analyzed in the thesis.