Produktutveckling av en rörbrottsventil

Sammanfattning

This thesis was the final part of a Bachelor of Science in Engineering degree within the Product and Process Development programme at Mälardalen University, during the spring semester of 2026. The work includes a product development project for a pipe break valve at the start-up company H2Hive AB, which develops hydrogen storage systems. With support from literature, a recognized and well-established product development process (Ulrich and Eppinger, 2021) has been implemented to provide a structured and appropriate method. The product development process and its phases have mainly been applied as a quantitative method to structure the work and to define the activities included in each phase. The project includes concept generation for several alpha prototypes, the majority of which were modelled in SolidWorks as digital alpha prototypes. The digital alpha prototypes were then transferred into analytical alpha prototypes, which later got through a screening process until one final pipe break valve concept remained. The screening decisions were based on factors within Design for Assembly (DFA), Design for Manufacturing (DFM), Design for Reliability (DFR), as well as the results from the Computational Fluid Dynamics (CFD) simulations. The CFD simulations were performed in both open and closed positions to ensure that the purpose of the project was accomplished. Based on the simulation results, a requirements specification for a spring was also established, based on how great the force acting on the valve body is when the hydrogen reaches a velocity corresponding to the requirements specified by the company. The purpose of the project is to develop a pipe break valve design that can be implemented in the company’s hydrogen storage system. The project also aims to investigate the force at which the pipe break valve closes, as well as to identify suitable spring properties for an implementable spring in the pipe break valve. Based on this, the following research questions were formulated: To what extent does the developed design fulfil the functional requirements according to the requirements specification in a CFD simulation? Which spring properties and requirements should be specified to ensure that the pipe break valve closes and fulfils the requirements set by the company? Results: The developed design, alpha prototype 4, fulfils the functional requirements according to the company’s requirements specification to a great extent. This was verified through CFD simulation and complementary research to support research question 1. Alpha prototype 4 served as a basis for the further development of the beta prototype for H2Hive. The spring properties and requirements addressed in research question 2 resulted in values for the unloaded length, maximum loaded length, maximum load, spring constant, maximum suspension length and the required end configuration of the spring. Keywords: CFD simulation, hydrogen, hydrogen storage, product development process, product design, prototype development, pipe break, SolidWorks, valve.