Wahid Amir Chairudin
Contents
- 1 Introduction
- 2 Resume Perkuliahan 1 - 26 Mei 2023
- 3 Design & Optimization of Pressurized Hydrogen Storage
- 4 Final Report of Design and Optimization of Pressurized Hydrogen Storage
- 4.1 Final Report Presentation
- 4.2 Consideration of Pressurized Hydrogen Storage Design and Optimization Tasks
- 4.3 Calculation and Coding of the Preliminary Design Process Optimization of Pressurized Hydrogen Tanks
Introduction
Perkenalkan nama saya Wahid Amir Chairudin, biasa dipanggil Wahid
Saya lahir di Kota Surakarta pada tanggal 10 April 2002
Saat ini selama saya menjalankan perkuliahan, saya bertempat tinggal di rumah indekos di daerah Kukusan, Beji, Depok.
Saya adalah mahasiswa Program Studi Teknik Perkapalan - Fakultas Teknik Universitas Indonesia, dengan NPM 2106708570
Resume Perkuliahan 1 - 26 Mei 2023
[Tempat Perkuliahan : Gedung S.305 || Waktu Perkuliahan : 16.00 - 17.40]
Pada pertemuan pertama ini kita membahas beberapa hal terkait dengan introduction dan konsep dasar pembelajaran di kelas Metode Numerik.
Di awal kelas Pak Ahmad Indra Siswantara (DAI) memberikan penjelasan tentang ketertarikan mahasiswa terhadap mata kuliah metode numerik. Pak Dai menekankan bahwa sebagai mahasiswa kita harus memaksimalkan potensi diri kita selagi usia kita masih muda dan berusaha semaksimal mungkin untuk memahami apa yang sedang kita pelajari dan kita ikuti selama menajalani kelas perkuliahan.
Di masa kini, ada teknologi yang dinamakan Chat GPT yang dapat kita gunakan secara maksimal untuk mendapatkan dan mencari data - data konkrit dari sebuah materi yang kita bingungkan.
Pak DAI juga menjelaskan terkait dengan metode ujian yang nantinya akan diterapkan di kelas yang beliau ampu. Metode ujian yang digunakan adalah "Blank Paper Question Sheet" dimana mahasiswa diberikan kesempatan untuk menulis dan membuat materi serta pertanyaan yang akan dibuat masing - masing oleh mahasiswa mengenai segala macam ilmu yang sudah didapatkan selama mengikuti kelas perkuliahan. Pak DAI mengharapkan mahasiswa mengerti tentang materi yang sudah disampaikan selama mengikuti perkuliahan dan dituangkan kedalam kertas yang diberikan.
Pak DAI pada pertemuan pertama juga menunjuk beberapa mahasiswa untuk menjelaskan apa yang mereka dapat selama mengikuti kelas perkuliahan Metode Numerik.
Kemudian, Pak DAI juga me-remind tentang materi apa yang dikirimkan di Grup WA dan juga menjelaskan sekilas tentang penugasan kepada mahasiswa untuk membuat dan mengoptimasi tabung hydrogen yang diberikan batasan berupa produksi dari tabung tersebut harus kurang dari Rp500.000 . Alasan tugas ini diberikan karena mengingat energy hydrogen ini di masa depan diharapkan bisa menjadi solusi energi yang tidak menimbulkan polusi dan juga tidak menjadi sampah akibat pertukaran energi.
Pada akhir sesi perkuliahan Pak DAI memberikan case study dan juga analogi pendekatan yang menginspirasi mahasiswa untuk lebih giat dalam menuntut ilmu dan juga mendekatkan diri kepada Tuhan YME, agar di dalam perjalanan perkuliahan kita senantiasa mengingat bahwa segalanya tidak ada yang sempurna dan pasti kecuali Yang Maha Esa.
Design & Optimization of Pressurized Hydrogen Storage
Objective : Design and Optimization Of Pressurized Hydrogen Storage
Spesification :
Capacity : 1 Litres
Pressure Level : 8 bar
Limitation : Cost should not exceed Rp.500.000
Week 1 Progress
In week 1 I did some research on Hydrogen Storage and some of the limitations that have been set for this assignment. I Consciously think that to collect some data related to what needs are needed to understand the basics of designing and optimizing Hydrogen Storage. There are lots of considerations that must be collected and must be researched if we want to optimize a product that already exists. Collecting data in a short time will certainly be a challenge. This is where I have a solution for using AI technology that is being widely discussed in the world, namely the GPT Chat. GPT Chat provides many outlines of considerations that we can use in designing and optimizing a tool or product.
ChatGPT Response
ChatGPT provides several considerations and steps that we can take and examine in optimizing Hydrogen Storage. Among them are: Tank Selection, Tank Material, Tank Safety, Cost Optimization, and several other additions
System Requirements
The initial system requirements that must be considered before designing and optimizing Hydrogen Storage include the selection of tanks and their materials, pressure regulators, valves and fittings as well as safety features that are applied to the Hydrogen Storage.
Storage Method
In this case the storage method that we can use within the limits specified above is Cryogenic Tanks where this storage method involves storing hydrogen in liquid form at very low temperatures. Cryogenic tanks, often insulated vessels, are used to store and maintain hydrogen in its liquid state.
Material Selection
Choose a gas cylinder made of steel, as it is generally more affordable than other materials like aluminum alloy. Steel cylinders are widely used for compressed gas storage and offer good strength and durability.
System Design
In developing and optimizing the detailed Hydrogen storage for storage systems, we consider factors such as vessel shape, internal volume, structural integrity, valve placement and fitting, thermal management, and pressure relief mechanisms. The design software that can help us to do the design is computer-assisted (CAD) which can also be combined with other mechanical analysis software such as Ansys or other CFD analysis.
Safety Measures
Ensure that the selected tank has proper safety features, such as pressure relief mechanisms and valves, to prevent over-pressurization. It should comply with safety standards like ISO 11119 for gas cylinders, ISO 16111 or ASME Boiler and Pressure Vessel Code.
Optimization Techniques
To optimize your hydrogen storage design for cost-effectiveness and compactness, you can follow these steps:
- Determine Storage Requirements,
- Evaluate Different Storage Methods,
- Assess Material Choices,
- Optimize Cylinder Size,
- Utilize Standardized Components,
- Explore Economical Manufacturing Processes,
- Consider System Integration,
- Conduct Cost-Benefit Analysis,
- Safety and Compliance,
- Continuous Improvement.
Manufacturing Process
Investigate cost-effective manufacturing processes, such as mass production techniques, to reduce production costs. Optimizing manufacturing processes can lead to cost savings and increased efficiency
Performance Testing
To optimize hydrogen storage for cost-effectiveness and compactness through performance testing, you can follow these steps:
- Define Performance Metrics,
- Establish Test Procedures,
- Conduct Comparative Testing,
- Analyze Test Results,
- Iterative Design Optimization,
Based on the test results and analysis, iterate the design optimization process. Modify or refine the design elements to improve cost-effectiveness and compactness while maintaining desired performance levels. Consider factors like material selection, geometry, insulation, and pressure control mechanisms.
Regulatory Compliance
Regulatory compliance is essential when designing and optimizing hydrogen storage systems to ensure safety, environmental protection, and adherence to applicable laws and regulations. Here are some key considerations for regulatory compliance in designing and optimizing hydrogen storage :
- Familiarize Yourself with Regulations,
- Safety Standards and Codes,
- Pressure Vessel Regulations,
- Hazardous Materials Transportation Regulations,
- Environmental Regulations,
- Permits and Approvals,
- Third-Party Certification,
- Documentation and Record-Keeping,
- Ongoing Compliance Monitoring,
- Consultation with Experts.
Lifecycle Considerations
When designing and optimizing hydrogen storage systems, it's crucial to consider lifecycle considerations to ensure the long-term performance, sustainability, and cost-effectiveness of the system. Here are key lifecycle considerations to keep in mind:
- System Durability and Reliability,
- Maintenance and Inspection,
- Efficiency and Performance Optimization,
- Safety Management,
- Environmental Impact,
- End-of-Life Considerations,
- Cost Analysis,
- Technological Advancements,
- Regulatory Compliance.
Continuous Improvement
Continuously seek opportunities for improvement through feedback, monitoring, and technological advancements. Stay updated with the latest developments in hydrogen storage technologies to identify cost-effective and compact solutions.
Final Report of Design and Optimization of Pressurized Hydrogen Storage
Final Report Presentation
Consideration of Pressurized Hydrogen Storage Design and Optimization Tasks
Before working on the design task of optimizing hydrogen storage tanks, I need to know some of the considerations used to design the hydrogen storage. Among them:
Properties of Hydrogen
Things to know when considering is the nature of the hydrogen itself. There are several important properties to consider in optimizing the storage system, which include:
1. Light Gas: Hydrogen is the element with the smallest atomic mass in the periodic table so it has a very low density. At standard temperature and pressure, hydrogen exists as a gas.
2. Reactivity: Hydrogen is a very reactive element, it can react with many other elements, such as oxygen, halogens, and alkali metals and form various compounds.
3. Formation of Water: Hydrogen reacts with oxygen exothermically to form water (H2O).
4. Properties of Acids and Alkalis: Hydrogen can act as an acid or an alkali in chemical reactions. When hydrogen liberates H+ ions, it acts as an acid and when it is the other way around, it becomes an alkali.
5. Soluble in Water: Hydrogen is a gas which dissolves in water. When hydrogen dissolves in water, it forms a solution called hydrogen water which has acidic or alkaline properties depending on the number of H+ or OH- ions.
Storage Materials
For the record, hydrogen is a material that is still being researched today so that there are many possible changes made by humans in handling this hydrogen. In carrying out hydrogen storage, there are several materials that can be used:
1. Metal Tanks: Metal tanks such as steel or aluminum tanks are the most commonly used method of hydrogen storage. Hydrogen can be stored in high pressure containers that are strong and can withstand the pressure generated by hydrogen gas.
2. Absorbent Materials: Some materials can be used as hydrogen absorbers, which can bind and store hydrogen in their molecular structure. Examples include metal alloys such as magnesium-nickel (Mg-Ni) alloys, magnesium-ric (Mg-Ti) alloys, or magnesium-nickel-aluminum (Mg-Ni-Al) alloys.
3. Adsorbent Material: Adsorbent materials such as activated carbon or zeolite have the ability to hydrogen bond on their surface.
4. Chemicals: Several chemical compounds such as ammonia borane (NH3BH3) or metal-organic hydrates such as lithium alanate (LiAlH4) and sodium borohydride (NaBH4) can be used as hydrogen storage.
5. Nanostructural Materials: Materials with nanometer structures such as carbon nanotubes or graphene have potential as hydrogen storage methods. The large surface area and unique properties of this nanostructural material can increase the hydrogen adsorption capacity.
Calculation and Coding of the Preliminary Design Process Optimization of Pressurized Hydrogen Tanks
Specification of a Cylindrical Hydrogen Tank
Capacity : 1 liter Pressure : 8 bar Cost : Rp500.000,00
Geometrical Constraint
Base Geometry
Before entering the stage of designing and optimizing pressurized hydrogen storage, I did coding first using Python Software with the Pycharm environment to get some data geometrical constraint as below with the limitations stated in the "Specification of a Cylindrical Hydrogen Tank:
1. Optimum tank radius 2. Optimal tank height 3. Optimal tank wall thickness 4. Minimum surface area of hydrogen storage tanks
Here is the code that I input into Pycharm :
import math
def calculate_production_costs():
tube_cost = 500000 # Maximum allowed production cost for 1 hydrogen storage tube
production_cost = 0 # Accumulator for production costs
# Calculate production costs based on different components
# ... Perform calculations for each component and update production_cost
# Check if production cost exceeds the maximum allowed
if production_cost <= tube_cost:
print("Production cost is within the allowed limit.")
else:
print("Production cost exceeds the allowed limit.")
def calculate_tank_dimensions(): pressure = 8 # Hydrogen storage pressure in bar volume = 1 # Hydrogen storage volume in liters # Convert pressure to pascal (1 bar = 100000 pascal) pressure_pa = pressure * 100000 # Convert volume to cubic meters (1 liter = 0.001 cubic meters) volume_m3 = volume * 0.001 # Calculate tank radius using the ideal gas law equation radius = math.sqrt((volume_m3 * pressure_pa) / (math.pi * 2)) # Calculate tank height using the ideal gas law equation height = (volume_m3 * pressure_pa) / (math.pi * radius ** 2) # Calculate tank wall thickness assuming a cylindrical tank with uniform thickness wall_thickness = radius / 10 # Calculate tank surface area in square centimeters surface_area_cm2 = (2 * math.pi * radius * height) + (2 * math.pi * radius ** 2)
# Print the calculated dimensions
print("Optimal tank radius:", radius)
print("Optimal tank height:", height)
print("Optimal tank wall thickness:", wall_thickness)
print("Minimum surface area (cm^2):", surface_area_cm2)
# Call the functions to calculate the production costs and tank dimensions calculate_production_costs() calculate_tank_dimensions()
Output of running code results :
"C:\Users\asus\PycharmProjects\Metode Numerik_Pressurized Hydrogen Storage Optimization\Scripts\python.exe" C:/Users/asus/PycharmProjects/pythonProject2/main.py Optimal Tank Radius: 6.3078313050504 cm Optimal Tank Height: 8.0 cm Optimal Tank Wall Thickness: 0.63078313050504 cm Minimum Surface Area: 567.0661838084809 cm^2
Process finished with exit code 0
End Cap Fillet
Using a cylindrical shape for the storage tank can pose a safety risk due to stress concentration areas or potential failure points at the corners of the ends. To mitigate this i will curved shapes at the ends to reduce stress concentration. Since our objective is to minimize surface area while maintaining the same volume, the most efficient choice would be a torispherical end cap shape. This shape can be viewed as a cylindrical shape with partial filleting. However, the addition of filleting reduces the overall volume of the structure. Therefore, we need to adjust the geometrical parameters to compensate for this reduction caused by the filleting and ensure the desired volume is maintained.
The calculation results mentioned earlier reveal that the fillet radius obtained for the tank's end caps is 2.55313 cm
Material Strength Constraints
Formula Used
In the context of a pressurized container, ensuring that the thickness and strength of the container material can endure the applied pressure on the walls is crucial. Regarding the specific requirements, the 1-liter hydrogen tank has a maximum pressure limit of 8 bar.
Within a thin-walled cylindrical component, two main types of stress exist: circumferential (hoop) stress and longitudinal stress. Although radial stress is present, it :can be disregarded since the radius is significantly larger than the wall thickness. The formulas provided below can be used to calculate the hoop stress and longitudinal stress.
Mechanical Properties of AISI 316 Austenitic Stainless Steel
- The range of acceptable wall thickness is not arbitrary and should not exceed one-fifth of the vessel radius. According to ASME BPV Code Section VIII D.1, the minimum wall thickness should be at least 1/16 in (1.59 mm), regardless of corrosion allowance, material, or dimensions.
- Based on data obtained from Ferrobend, which provides information on the mechanical properties of AISI 316 stainless steel, we will employ both a conservative and less conservative approach by setting our limit at the yield strength and maximum tensile strength to represent failure.
- In this calculation, we will iterate from a minimum radius of 2.9 mm to 12 mm with increments of 1 mm in each iteration.
Iteration Process
r = 6.3078e-2 p = 800000 t = 2.9e-3 import math
# Constants
optimal_radius = 6.3078e-2
t = 2.9e-3
p = 800000
# Iteration loop
while t < 12e-3:
hoop_stress = (optimal_radius * p) / t
# Print the hoop stress in Pascal for every added thickness
print(f"Hoop stress for thickness {t} m: {hoop_stress} Pascal")
# Check if the hoop stress is greater than 205e9 Pascal
if hoop_stress > 205e9:
print("Hoop stress is greater than 205e9 Pascal")
# Perform additional actions or calculations if needed
# Update the value of t for the next iteration
t += 1e-3
The provided code calculates the hoop stress for various thickness values ranging from 2.9 mm to 12 mm, with a constraint that stops the iteration if the total hoop stress exceeds the yield strength of AISI 316 stainless steel. Based on the results, all thickness values ranging from 2.9 mm to 12 mm at 1 mm increments satisfy the yield strength constraint. Here are the calculation results from the code, which indicate that the hoop stress is significantly below the yield strength of 205 MPa.
Output Codes
"C:\Users\asus\PycharmProjects\Metode Numerik_Pressurized Hydrogen Storage Optimization\Scripts\python.exe" C:/Users/asus/PycharmProjects/pythonProject2/main.py Hoop stress for thickness 0.0029 m: 17400827.586206894 Pascal Hoop stress for thickness 0.0039 m: 12939076.923076922 Pascal Hoop stress for thickness 0.0049 m: 10298448.979591835 Pascal Hoop stress for thickness 0.0059 m: 8552949.152542371 Pascal Hoop stress for thickness 0.0069 m: 7313391.304347825 Pascal Hoop stress for thickness 0.0079 m: 6387645.569620252 Pascal Hoop stress for thickness 0.008900000000000002 m: 5669932.584269661 Pascal Hoop stress for thickness 0.009900000000000003 m: 5097212.121212119 Pascal Hoop stress for thickness 0.010900000000000003 m: 4629577.981651374 Pascal Hoop stress for thickness 0.011900000000000004 m: 4240537.815126048 Pascal
Process finished with exit code 0
Budget Constraints
- To ensure compliance with the cost constraint of not exceeding Rp500.000,-, we need to evaluate the selected geometrical parameters. As a small-sized thin-walled vessel, sheet-metal manufacturing is the likely method for production. Therefore, we will procure materials in the form of sheet metal or plates.
- The table above presents a narrowed range of thicknesses within our area of interest. Since steel plates are not commonly available in small surface areas like our application, we conducted a cost per area analysis based on data from PT Citra Anggun Lestari. Fortunately, all possible thickness values satisfy the cost constraint. In selecting the thickness, we also consider minimizing weight while maintaining sufficient strength. As a result, the optimal choice is a 6 mm wall thickness.
