Numerical Simulation On Shell Side Performance And Optimization Research On Design Of Marine Condenser

Condenser is one of the key equipment in the ship waste heat recovery system.The working performance of the condenser can directly affect the working efficiency of the steam turbine,and even the stability of the whole waste heat recovery system.In this paper,according to the host host waste heat recovery system requirements and given design parameters,designed a N-163 condenser.The two dimensional numerical model of the thermodynamic performance of the condenser is established.The structural optimization of the condenser is carried out by using the FLUENT software platform simulation results and the field synergy theory.Firstly,the engineering design of N-163 condenser was carried out according to the requirements of the main engine waste heat recovery system and given design parameters,according to the industry standard of HEI "Surface Condenser".Engineering design includes thermal calculation,vibration calculation and the design and selection of the structure.The method of thermal calculation,the calculation method of span of support plate,the method of avoiding vibration and vibration of tube bundle,the design method of water chamber,tube bundle,shell,vacuum desuperheater,bearing and hot well are given respectively.And finally draw a set of CAD engineering drawings,initially get the N-163 condenser structure.Secondly,after the analysis of the condenser structure and the complexity of the flow,the reasonable simplification and assumptions are made.The governing equations and the auxiliary relations of the porous medium model are introduced to simulate the tube bundle in the condenser into porous media,and the obstruction effect and condensation effect of the tube bundle on the steam flow are dealt with by the distribution resistance and distribution mass sink,the two-dimensional numerical model of the condenser then established.And the rationality of the two-dimensional numerical model was verified by the structural parameters and numerical simulation results of Al-sanea experimental condenser.Thirdly,based on the N-163 condenser structural parameters,physical modeling and meshing were carried out,and a numerical simulation program for N-163 condenser was established.By setting up the porous media region,UDF program is written and imported and activated in FLUENT,and the distribution of shell side vortex and air gathering point of the initial structure is finally known.And then optimize and simulate the initial design and structure,and compare the thermal performance before and after optimization.The results show that the optimized structure is more reasonable in the flow field,the number of dead zones is reduced,the pressure loss is reduced,the condensation rate is increased,the air concentration is decreased,and the structure optimization effect is good.Finally,based on the basic idea of field synergetic theory,the synergetic theory of three fields of velocity field,temperature field and pressure field is deduced and the evaluation index and method of field synergy are deduced.Then,according to the definition of TECPLOT function language,we get the distribution of the synergy angle.The results show that the velocity field,temperature field and pressure field of the optimized structure are better,and the effect of the optimization method is reflected.