Thermal Stress Simulation on a Stainless-steel Submersible Water Heater design

Abstract

A new design of immersion heater is proposed for common household use and is checked for stress induced due to heating and the corresponding factor of safety (FOS). Temperature distribution with time is obtained by building a finite element model of the simplified heater geometry (body) while considering conduction and convection due to buoyancy effect. For realistic results, a two-step analysis is done. Firstly, the temperature distribution with time, is calculated in Solidworks® Flow Simulation software by considering the conduction in heater body and convection in the surrounding water. Secondly, the calculated temperatures are exported into Solidworks structural simulation and thermal stresses are calculated. An effort is made to study the effect of purely thermal stresses on the heater body as it is heated under 3000 W power and visualize the flow trajectory of fluid particles as it is heated. The results are used to assess the stress, strain, and FOS of the design and to finalize its geometry. It is concluded in the study that buoyancy effects and flow trajectory of fluid particles is paramount in determining the thermal stresses in a heater design.