| Medium pressure steam generator for coal hydrogen production,also known as heat exchanger,is the hot and cold fluid through convection and heat conduction of an industrial components,especially related to the medium pressure steam generator for coal hydrogen production,medium pressure steam generator for coal hydrogen production is a part of the significant equipment for petrochemical enterprises.The steam generator involved in this paper is a special heat exchanger with U-shaped heat exchange tubes on both sides.Its main components are shell,heat pipe bundle,tube plate,baffle and tube,pipe fluid and shell.The tube-flow fluid exchanges heat with the shell-side fluid,and the tube sheet simultaneously receives loads,pressures,and thermal expansions from the fluid,the casing,and the tube bundle.As a result,The study of tubesheets is of great significance and value for improving the performance of heat exchangers.In this paper,the heat exchanger is study object,using numerical simulation method to establish the finite element model of the steam generator tube plate and numerical analysis.Using finite element software for the steam generator tube plate temperature field,stress field and temperature loads and pressure loads under temperature load simultaneously when the stress field numerical simulation.Through comparative analysis,you can analyze that the maximum stress is located at the junction of the pipe sheet and the pipe bundle and the thermal stress generated by the temperature load has a great influence on the steam generator pipe sheet and tube bundle stress.Through the review of the heat exchanger standards to determine the main causes of fluid-induced vibration,separate models of different types of tube bundles and modal analysis of these bundles using finite element software.Compared with the provisions in the heat exchanger standard,you can analysis that all pipe bundles on both sides of the steam generator will not vibrate or break due to excessive cross flow speed and the large amplitude.There may be vibration and damage caused by the Karman vortex on both sides of the coal-to-hydrogen medium-pressure steam generator,and there may be turbulent chattering on both sides.Therefore,in the four aspects of fluid-induced vibration on the tube bundle,only karman vortex and turbulent chattering may lead to the vibration and destruction of the pipe bundle.In this paper,the safety factor in fracture mechanics and the mathematical formula of life(Mason-Coffin formula)are applied to evaluate the fatigue life of the location subjected to the maximum stress and the highest temperature.In summary,the thermal stress induced by the temperature load and the fluid force induced by the pressure load have a certain influence on the total stress distribution of the pipe bundle and the pipe sheet of the heat exchanger.However,the thermal stress caused by the temperature difference has a great influence on the stress distribution of the steam generator pipe bundle and the pipe sheet.In contrast,fluid shock load induced by stress is small.In the meantime,the shell-side fluid in the heat exchanger may induce the vibration of the pipe bundle,and the principle of causing the vibration includes the Karman vortex and the turbulent chattering.It can be observed that the maximum stress of the steam generator tube bundle appears at the connection of pipe bundle and pipe sheet,and the local stress concentration of the steam generator tube bundle at the baffle plate also occurs.These can cause cracks and damage at the connection of pipe bundle and pipe sheet. |
