Hydrogen Storage Design: Simulating Composite Tanks

Welcome everybody, this is Edwin Rodriguez from OCE Ozen Engineering. We are going to start with this hydrogen storage design webinar for today. Thank you to everybody to be here with us today.

We are going to talk about simulation techniques for hydrogen storage tanks in order to understand better how we can do it using the ANSYS tools we are available for you today. Okay, we're going to start then with our presentation.

OCE Ozen Engineering is an ANSYS Elite Channel Partner and has been named America's Channel Partner of the Year from 2015 to 2023. We are experts in simulation in several physics, including structural, thermal, and fluid fields.

We provide software tools, consulting, training, mentorships, and technical support. Hydrogen tanks can be used in many applications, such as by producers, backup power supplies, transport fleet operations, and anywhere hydrogen needs to be stored as a product.

Hydrogen can be stored as gas or liquid. If stored as gas, high pressure capacity is required, typically between 300 and 750 bar. If stored as liquid, cryogenic temperatures are needed due to the boiling point of hydrogen at atmospheric pressure being -252 Celsius.

During the refueling process, tank temperatures can rise up to 65 Celsius. Designers must consider this to ensure tank quality during the refueling process.

There are five types of pressure vessels composite tanks: 1. Metallic tank (steel or aluminum) 2. Steel tank with a glass or carbon fiber cover around the midsection 3. Composite material and metal liner 4. Composite material with a polymer liner 5. All composite with metal outliners The type 3 and 4 tanks have metal inserts for connecting to other installations.

The high flow of heat transfer during refueling is managed by using 24 water cells and quieting and its wider system. The capacity of the oil chakra helps prevent any autumn change. Each two actual weld were of separate chemical compositions and adds to an ABV of the whole process.

The same kind of time is ensured by having the same kind of time for each two channels, which are forged by the collector. The type 3 tank is the most used type of hydrogen tanks and is the focus of our presentation today.

We want to have a methodology to model this construction using the finite element approach. We need to take into account all wrapping orientations and do it using ANSYS. Composite parts can be filament wound, and the laminate design depends on manufacturing and process parameters.

For example, friction, pretensions, and winding angle define what is producible. Manufacturers of wound structures work with winding software tools that focus on the production action. Finite element packages are mostly used for structural verification but less for the design itself.

We need to join the production site and the finite element packages to define the layers, orientations, and constructability of the tank and make an analysis of them.

We have three approaches to model our composite tank using ANSYS tools: 1. ANSYS Composite Prepost (ACP) with Winding Wizard 2. ANSYS Composite Prepost (ACP) with Python scripting interface 3. External tool, such as CatWin or CatWint We can choose any of these approaches based on our preference and go to the simulation part.

In ANSYS Workbench, we can construct our model using several cells, including engineering data, mechanical models, ACP definition, and structural analysis.

We can define our winding structure, angles, thickness, and other parameters in the ACP definition and join them with the mechanical model to solve the structural analysis. The winding wizard creates a lookup table for dropping, taking into account the ends of the tank and non-cylindrical surfaces.

It creates a modeling group using geodesic paths, which is an approximate way to define the winding but helps create complex geometry easily. We can also use the Python script capability of ACP to create our own dropping angle and modify our thickness.

This allows us to customize the winding theory and see the results immediately in the model. We can use HDF5 files from external software to define our simulation directly in ACP. This is useful if we have access to specific software for defining a winding structure.

In ANSYS, we can define our structure by creating a mechanical model for the surface of our vessel and another mechanical model for the solid metal inserts. We can then go to the ACP Preprocessor to define all our structures, including fabrics, element sets, rosettes, and modeling groups.

We can create layers using the winding wizard and define the reference measures of our tank, such as the radius and direction. We can add epoxy fabrics with a nominal angle and mirror ply to create multiple layers.

We can evaluate several aspects of our model, such as deformation, principal stresses, equivalent stresses in solid parts, and composite behavior. We can evaluate the entire section using the inverse reserve factor and see how our structure will behave under composite material criteria to failure.

Thank you for your participation, and we want to see you in the next events like this.