Cavitation Performance Of Thermal Energy Generator And Thermal Fluid-solid Coupling Analysis

With the development of Chinese oil industry, the demand for liquid nitrogen pump truck has increased dramatically. Before, this technology was completely mastery and monopoly by foreign professional companies. Its key equipments mainly rely on imports in domestic.lt is significant to research liquid nitrogen pump truck products with completely independent intellectual property rights and realize the height localization for liquid nitrogen pump truck product.Heat generator is the key equipment of heat-recovery-type liquid nitrogen pump truck. Its performance directly affects the use of liquid nitrogen pump truck. So the research on the properties of heat generator is the key technologies of liquid nitrogen pump truck. At the scene of the oilfield, the existing heat generator has short service life and the stator and rotor blade prone to failure. In order to improve the heat generator performance and service life, cavitation and the thermal-fluid-structural coupling of heat generator was systematically studied based on the theoretical analysis, numerical calculation and experimental study, considering heat generator manufacturing materials and structural factors. The research process and methods are as follows:(1) The usage of oil field heat generator was deeply analyzed to find the failure parts of heat generator through extensive research literature at home and abroad. Compared the results of cavitation simulation with the results of field failure analysis and found the main factor causing heat generator failure.(2) In the working speeds, the single phase flow numerical calculations of heat generator models with different structures (blade angle, blade number, blade thicknesse, axial clearance and vortex pit depth) are done. The stress distribution and flow mechanism in heat generator under no-cavitation condition are obtained by simulation.(3) On the basis of water liquid/vapor two-phase flow movement rule, the rotational cavitation flow numerical calculations for heat generator under different structures are done. The distribution of water vapor volume fraction is obtained and the cavitation phenomenon in heat generator is revealed.(4) The cavitation rates of four kinds of material are determined through the experiment. The using cost and failure time of these materials making into heat generator are obtained. According to cavitation degree and the economic situation, a suitable material is chosen.(5) Through the safety margin analysis for different materials of heat generator, the best processing material is further selected combining with experiment. Thermal-fluid-structural coupling analysis for different structures of heat generator is carried out. The structures that could satisfy the requirement of strength are chosen. Through the combinatorial optimization analysis, the optimal combination parameter of heat generator is got.