# Gung Bayu Aji Alam Saputra

## Introduction

Hai,

Gung Bayu Aji Alam Saputra 2206100243 Class of MetNum-03

## Designing A Storage System For Hydrogen

Designing a storage system for hydrogen at 8 bar involves several important considerations. Here are some general steps in designing a storage system for hydrogen at 8 bar:
If you have a hydrogen tank with a volume of approximately 1 liter and you want to compress the hydrogen to 8 bar, there are a few considerations to keep in mind:

1. Tank Selection: Choose a hydrogen tank that is suitable for the desired volume and pressure. Ensure that the tank is designed and rated for the specific pressure of 8 bar. Consider factors such as the material of the tank, its structural integrity, and any safety features it may have.

2. Tank Capacity: Confirm that the tank's volume of approximately 1 liter is sufficient for your storage needs. Keep in mind that hydrogen under high pressure will occupy less volume than at standard conditions. Compression to 8 bar will significantly reduce the volume of the hydrogen.

3. Safety Measures: Compressing hydrogen to 8 bar involves potential safety hazards. Ensure that the tank and associated equipment are designed with appropriate safety measures, such as pressure relief valves and other safety mechanisms, to handle the higher pressure and mitigate any potential risks.

4. Regulatory Compliance: It's important to comply with applicable regulations and standards for hydrogen storage and handling. Make sure that the tank and the overall storage system meet the necessary regulatory requirements to ensure safe operation.

*When considering the material for a hydrogen tank that will be compressed to 8 bar, there are several options to consider. The choice of material is crucial as it needs to be able to withstand the pressure and ensure the safety and integrity of the tank. Here are some common materials used for hydrogen storage:*

1. Steel: High-strength steel alloys are commonly used for hydrogen storage tanks. They offer good mechanical properties and can withstand high pressures. Steel tanks are relatively cost-effective and widely used in various applications.

2. Aluminum: Aluminum alloys are lightweight and have good corrosion resistance. They are often used for lightweight portable hydrogen tanks. However, aluminum has lower strength compared to steel, so thicker walls or additional reinforcement may be required to handle the higher pressure.

3. Carbon Fiber-Reinforced Polymer (CFRP): CFRP tanks consist of carbon fiber-reinforced composite materials combined with a polymer matrix. They offer high strength-to-weight ratios and good resistance to corrosion. CFRP tanks are lightweight and suitable for portable or automotive applications.

4. Glass Fiber-Reinforced Polymer (GFRP): GFRP tanks are similar to CFRP tanks but use glass fiber instead of carbon fiber. They offer good strength and corrosion resistance but are generally heavier than CFRP tanks. GFRP tanks are used in various industrial and automotive applications.

5. Composite Materials: Other composite materials, such as fiberglass composites or hybrid composites, may also be used for hydrogen storage tanks. These materials offer a combination of strength, weight savings, and corrosion resistance.

The fabrication process for hydrogen tanks involves the construction and assembly of the tank using the chosen material and appropriate manufacturing techniques. Here are the general steps involved in the fabrication of a hydrogen tank:

1. Design and Engineering: The fabrication process begins with the design and engineering phase. This includes determining the dimensions, shape, and structural requirements of the tank based on its intended use, capacity, and pressure rating. Design considerations also involve incorporating safety features, such as pressure relief valves and inspection points.

2. Material Preparation: The chosen material, whether it is steel, aluminum, CFRP, or another composite material, is prepared for fabrication. This may involve cutting, shaping, or molding the material into the desired form for the tank components.

3. Component Fabrication: The tank components, such as the cylindrical body, end caps, and fittings, are fabricated. This can be done through various processes, including welding, machining, forming, or composite layup techniques, depending on the material and design specifications.

4. Welding or Bonding: If the tank material is weldable, welding processes are used to join the components together. For non-weldable materials like CFRP, bonding techniques may be employed. Specialized welding methods and bonding agents suitable for the chosen material are used to ensure strong and leak-free connections.

5. Quality Control and Testing: Throughout the fabrication process, quality control measures are implemented to ensure the integrity and safety of the tank. Non-destructive testing methods, such as visual inspections, ultrasonic testing, or pressure testing, are performed to verify the structural integrity and identify any defects or leaks.

6. Surface Treatment and Coating: After fabrication, the tank's surfaces may undergo surface treatment and coating processes to enhance corrosion resistance, improve durability, and provide additional protection against environmental factors.

7. Final Assembly: Once all the individual components are fabricated, they are assembled to form the complete tank. This includes attaching fittings, valves, and any additional accessories necessary for the tank's functionality.

8. Inspection and Certification: The finished tank undergoes a final inspection to ensure it meets the required standards, regulations, and specifications. Certification may be obtained to verify compliance with industry standards and safety regulations.

In the design of a hydrogen tank with a maximum pressure of 8 bar and a volume of 1 liter, we can define the following:

1. Design Variable: The design variable represents a parameter that can be adjusted during the design process. In this case, a relevant design variable could be the material used for the tank construction. Options could include carbon fiber-reinforced composites, aluminum alloys, or steel.

2. Objective Function: The objective function quantifies the goal or target to be achieved in the design process. In this case, the objective could be to minimize the weight of the tank while meeting the specified pressure and volume requirements. The objective function, therefore, could be to minimize the weight of the tank.

3. Constraint: A constraint is a condition or limitation that must be satisfied during the design process. For this hydrogen tank, some possible constraints could include:

4. Pressure Constraint: The maximum pressure of the tank should not exceed 8 bar. This constraint ensures the tank can safely contain the hydrogen at the specified pressure.

5. Volume Constraint: The tank volume should be equal to or less than 1 liter. This constraint ensures the tank can store the desired amount of hydrogen.

6. Safety Factor Constraint: The tank design should meet the required safety factor, which is typically between 3 and 5. This constraint ensures the tank has sufficient structural integrity and can withstand the expected loads and conditions.

7. Material Constraint: The selected tank material should meet the necessary strength and compatibility requirements for hydrogen storage.

These are just a few possible examples of constraints that could be considered. Depending on the specific design requirements and regulations, additional constraints related to safety, manufacturing, or environmental factors may need to be included.

The optimization process would involve finding the optimal design variable(s) and shape/configuration of the tank that minimizes the objective function (weight) while satisfying all the specified constraints.

To calculate the specifications of a hydrogen tank with a maximum pressure of 8 bar and a volume of 1 liter, we need to consider certain factors such as the material, safety factors, and applicable standards.

Material: Hydrogen tanks are commonly made of high-strength materials like carbon fiber-reinforced composites, aluminum alloys, or steel. Let's assume we are using a carbon fiber composite material, which is widely used for high-pressure hydrogen storage.

Safety Factor: Hydrogen tanks are designed with safety factors to ensure reliable operation. A typical safety factor for hydrogen tanks ranges from 3 to 5, depending on the design and applicable standards. Let's assume a safety factor of 4 for this calculation.

Now, let's calculate the wall thickness and other specifications of the tank:

1. Step 1: Convert pressure from bar to Pascal (Pa):

8 bar = 8 x 10^5 Pa

2. Step 2: Calculate the minimum burst pressure:

Minimum burst pressure = Maximum pressure x Safety factor Minimum burst pressure = 8 x 10^5 Pa x 4 = 3.2 x 10^6 Pa

3. Step 3: Determine the material properties:

Carbon fiber composites have various properties, such as tensile strength and modulus of elasticity. For this calculation, let's assume the tensile strength of the carbon fiber composite material is 1.8 GPa (1.8 x 10^9 Pa) and the modulus of elasticity is 230 GPa (230 x 10^9 Pa).

4. Step 4: Calculate the required wall thickness:

Wall thickness = (Minimum burst pressure x Volume) / (Tensile strength x Safety factor) Wall thickness = (3.2 x 10^6 Pa x 0.001 m^3) / (1.8 x 10^9 Pa x 4) ≈ 0.00177 meters or 1.77 mm

Therefore, for a hydrogen tank with a maximum pressure of 8 bar and a volume of 1 liter, made of a carbon fiber composite material with a safety factor of 4, the required wall thickness would be approximately 1.77 mm. However, it is important to consult with a professional engineer and adhere to applicable standards for an accurate and safe design.

Code for Hydrogen Tank
from scipy.optimize import minimize

def objective(x):

radius = x[0] length = x[1] # Calculate the weight of the tank based on dimensions # You can use appropriate equations based on the material and tank shape weight = calculate_tank_weight(radius, length) return weight

def volume_constraint(x):

radius = x[0] length = x[1] # Calculate the volume of the tank based on dimensions # You can use appropriate equations based on the tank shape volume = calculate_tank_volume(radius, length) return volume - desired_volume

def pressure_constraint(x):

radius = x[0] length = x[1] # Calculate the maximum allowable pressure based on dimensions # You can use appropriate equations based on the material and tank shape max_pressure = calculate_max_pressure(radius, length) return max_pressure - desired_pressure

- Initial guess for tank dimensions (radius and length)

x0 = [1.0, 2.0]

- Desired volume and pressure constraints

desired_volume = 100.0 desired_pressure = 10.0

- Define the optimization problem

constraints = [

{'type': 'ineq', 'fun': volume_constraint}, {'type': 'ineq', 'fun': pressure_constraint}

]

result = minimize(objective, x0, constraints=constraints)

- Print the optimized dimensions and weight of the tank

if result.success:

print("Optimization successful!") print("Optimized radius:", result.x[0]) print("Optimized length:", result.x[1]) print("Optimized weight:", result.fun)

else:

print("Optimization failed:", result.message)

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