Ayudya Arindari Murahardjo

Introduction

Halo!

Perkenalkan, nama saya Ayudya Arindari Murahardjo, akrab disapa Arin. Saya merupakan mahasiswa semester 4 Program Studi Teknik Perkapalan Universitas Indonesia.

Resume Pertemuan 1 (26/5/2023)

Pada pertemuan pertama mata kuliah Metode Numerik, saya belajar mengenai pemahaman tentang "cosciousness", yakni semua orang harus memiliki kesadaran dalam melakukan segala sesuatu termasuk mempelajari Metode Numerik. Terdapat study case pada pertemuan pertama, yaitu mahasiswa diminta untuk menyelesaikan persamaan (x-1)^2/x-1 jika x=1. Pada hal ini, tidak terdapat jawaban yang mutlak atau eksak (1 solusi) karena pada hakikatnya di dalam dunia ini tidak terdapat suatu hal yang pasti.

Semakin kita dewasa, kita semakin kian mengerti akan arti hidup ini, begitu juga dengan kepercayaan yang selama ini kita anut. Mungkin sebagian besar orang memiliki pemahaman yang mereka yakini itu benar dan tidak ada salahnya memilih jalan hidup masing-masing selagi kita tetap "conscious"

Design & Optimization of Pressurized Hydrogen Storage

Design & optimization of pressurized hydrogen storage with maximum cost Rp 500.000,-

Capacity

Volume : 1 liter

Pressure : 8 bar

WEEK 1 PROGRESS

Designing and optimizing a pressurized hydrogen storage system with a 1-liter capacity and 8-bar pressure within a budget of Rp 500.000,- involves careful consideration of materials, dimensions, and cost optimization. Here's a design and optimization approach:

Material Selection

To meet the budget constraint, consider using high-density polyethylene (HDPE) as the material for the storage system. HDPE is cost-effective and offers good chemical resistance.

Container Design

Shape: Design a cylindrical container, as it is a common and practical shape for pressurized storage. Dimensions: Determine the container dimensions based on the desired volume and pressure. The container's volume is fixed at 1 liter, and the pressure is 8 bar.

Wall Thickness: Calculate the required wall thickness using the Barlow's formula: t = (P * D) / (2 * S), where P is the pressure (8 bar), D is the diameter of the container, and S is the allowable stress for HDPE. Ensure the calculated wall thickness is within the manufacturing capabilities and budget constraints.

Optimization Strategies

Material Cost: Compare prices from different HDPE suppliers to select the most cost-effective option. Manufacturing Process: Consider extrusion or injection molding processes for HDPE container fabrication, as they can be cost-effective for producing cylindrical shapes.

Size Optimization: Optimize the dimensions of the container to minimize material usage and manufacturing costs while still meeting the required volume and pressure specifications. This can be achieved by adjusting the diameter and height of the container.

Safety Considerations: Incorporate safety features into the design, such as pressure relief devices and adherence to safety standards and regulations for hydrogen storage.

Final Result Design & Optimization of Pressurized Hydrogen Storage

Fundamental Steps

To calculate the design of an optimal hydrogen storage tube with a 1-liter volume and 8-bar pressure specification, we can follow these steps:

1. Determine the desired dimensions: Since the volume and pressure specifications are given, the next step is to calculate the dimensions of the storage tube.

2. Convert the volume to cubic meters: 1 liter is equal to 0.001 cubic meters.

3. Convert the pressure to pascals: 1 bar is equal to 100,000 pascals.

4. Apply the ideal gas law: The ideal gas law equation, PV = nRT, can be used to calculate the volume of the storage tube. However, we need additional information such as the number of moles of hydrogen (n) and the temperature (T) to proceed with the calculation. Without this information, we cannot determine the exact dimensions of the storage tube.

5. Consider the material and safety factors: Once you have the necessary dimensions, you will need to select a suitable material that can withstand the pressure and store hydrogen safely. Materials such as high-strength steel or composite materials may be considered.

Material Safety Factors

High-Density Polyethylene (HDPE) is a commonly used material for various applications, including hydrogen storage tanks. When designing a hydrogen storage tank using HDPE, several safety factors should be considered:

1. Material Compatibility HDPE is known for its excellent chemical resistance, including resistance to hydrogen gas. However, it is important to verify the specific grade of HDPE being used and ensure its compatibility with hydrogen. The material supplier should provide information regarding the suitability of the HDPE grade for hydrogen storage.

2. Pressure Rating HDPE tanks must be designed to withstand the pressure generated by the stored hydrogen. The pressure rating of the HDPE material should be considered, along with the required safety factors, to ensure the tank's structural integrity. The design should conform to relevant standards or codes for pressure vessel design.

3. Temperature Considerations HDPE has a temperature limitation, and the operating temperature of the hydrogen storage tank should be within the specified range for the HDPE material. Elevated temperatures can affect the mechanical properties of HDPE, potentially reducing its strength and impact resistance. Adequate insulation or cooling measures may be required to maintain the temperature within the acceptable range.

4. Hydrogen Permeation While HDPE is considered a barrier material, it is still necessary to consider the potential permeation of hydrogen through the material over time. HDPE is known to have relatively low permeability to hydrogen, but precautions should be taken to minimize the risk. This can include measures such as proper thickness of the HDPE walls and considering additional barrier layers or coatings, if required.

5. Stress Concentrations Care must be taken to avoid stress concentrations in the tank design, as they can lead to premature failure. Smooth transitions, rounded corners, and proper reinforcement in areas prone to stress concentration should be considered to distribute stresses and minimize the risk of failure.

6. Manufacturing and Welding If the HDPE tank requires welding or fabrication, it is essential to follow proper welding techniques and procedures specific to HDPE. Qualified welders should be employed, and welding inspections should be conducted to ensure the quality and integrity of the welds.

The Calculation

import math

def calculate_optimized_thickness(volume, pressure):
   # Convert pressure from bar to Pascal
   pressure_pa = pressure * 100000

   # HDPE properties
   tensile_strength = 25 * 10**6  # in Pascal
   safety_factor = 2.5

   # Calculate optimized thickness using Barlow's formula
   thickness = (pressure_pa * volume) / (2 * math.pi * tensile_strength * safety_factor)

   # Convert thickness to millimeters
   thickness_mm = thickness * 1000

   return thickness_mm

# Input parameters
volume = 1  # Liter
pressure = 8  # bar

# Calculate optimized thickness
optimized_thickness = calculate_optimized_thickness(volume, pressure)

print(f"The optimized thickness of HDPE for hydrogen storage is approximately {optimized_thickness:.2f} mm.")