DESIGN AND ANALYSIS OF LARGE TRANSPORTABLE VACUUM INSULATED CRYOGENIC VESSEL

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 7, Issue 6, November December 2016, pp.45 57, Article ID: IJMET_07_06_006 Available online at Journal Impact Factor (2016): (Calculated by GISI) ISSN Print: and ISSN Online: IAEME Publication DESIGN AND ANALYSIS OF LARGE TRANSPORTABLE VACUUM INSULATED CRYOGENIC VESSEL Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G Student, Mechanical Engineering, Sri Venkateswara College of Engineering, Andhra Pradesh, India ABSTRACT Cryogenic engineering is concerned with low temperatures and the equipment used in producing, storing and using of fluids at low temperatures. Due to the increasing use of cryogenicfluids in industrial applications, the storage and transport of cryogenic fluids has become a necessity. Because of low temperatures, the storage of cryogenic fluids is difficult. Cryogenic fluids must be maintained at low temperatures and high pressures, otherwise the change of phase may occur, and storage of cryogenic fluids is possible with insulated chambers. Mainly, damage of inner vessel's surge plates and edges are happened due to uneven conditions of transportation leads in creating variable pressure impacts inside the walls and plates. This creates the deformation of tank's edges and surgical plates which are not repairable for that application. So, in order to overcome such issues, we changed the surgical plate design and material properties. Finally the modified design is tested in Ansys with new materials to analyse and aiming to reduce the stress locations and deformation. Key words: Cryogenic Vessel, Surge Plate designs, Deformation, Aluminium alloy, Safe Material, Stress Reduction. Cite this Article: Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G, Design and Analysis of Large Transportable Vacuum Insulated Cryogenic Vessel. International Journal of Mechanical Engineering and Technology, 7(6), 2016, pp CRYOGENICS Cryogenics is the science that addresses the production and effects of very low temperatures. The word originates from the Greek words 'kryos' meaning "frost" and 'genic' meaning "to produce." Under such a definition it could be used to include all temperatures below the freezing point of water (0 C). However, Prof. Kamerlingh Onnes of the University of Leiden in the Netherlands first used the word in 1894 to describe the art and science of producing much lower temperatures. He used the word in reference to the liquefaction of permanent gases such as oxygen, nitrogen, hydrogen, and helium. Oxygen had been liquefied at -183 C a few years earlier (in 1887), and a race was in progress to liquefy the remaining permanent gases at even lower temperatures. The techniques employed in producing such low temperatures were quite different from those used somewhat earlier in the production of artificial ice. In particular, efficient heat exchangers are required to reach very low temperatures. According to the laws of 45 editor@iaeme.com

2 Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G thermodynamics, there exists a limit to the lowest temperature that can be achieved, which is known as absolute zero. Molecules are in their lowest, but finite, energy state at absolute zero. Such a temperature is impossible to reach because the input power required approaches infinity. However, temperatures within a few billionths of a degree above absolute zero have been achieved. Absolute zero is the zero of the absolute or thermodynamic temperature scale. It is equal to C or F. The metric or SI (International System) absolute scale is known as the Kelvin scale whose unit is the kelvin (not Kelvin) which has the same magnitude as the degree Celsius. The symbol for the Kelvin scale is K, as adopted by the 13th General Council on Weights and Measures (CGPM) in 1968, and not K. Thus, 0 C equals K. The production of cryogenic temperatures almost always utilizes the compression and expansion of gases. In typical air liquefaction process the air is compressed, causing it to heat, and allowed to cool back to room temperature while still pressurized. The compressed air is further cooled in a heat exchanger before it is allowed to expand back to atmospheric pressure. The expansion causes the air to cool and a portion of it to liquefy. The remaining cooled gaseous portion is returned through the other side of the heat exchanger where it pre cools the incoming high-pressure air before returning to the compressor. The liquid portion is usually distilled to produce liquid oxygen, liquid nitrogen, and liquid argon. other gases, such as helium, are used in a similar process to produce even lower temperatures, but several stages of expansion are necessary. This project is aimed at the design and analysis of a transportable cryogenic vessel composed of several parts. Methane is kept in an inner vessel covered by an outer jacket of the same shape. Between both vessels, a vacuum insulation system is located. There are also beams which are used as connections between the inner vessel and the outer jacket and these are designed, analyzed and optimized in order to obtain stress values within margins. Apart from this, the project also addresses the frame to which vessels are attached, as well as its supports, which are the connections between the vessels and the frame. Finally, pipes and valves are taken into consideration in order to complete the design of the cryogenic vessel. This project is structured around two parts. The first part contains a background on methane, the truck with the hook-lift mechanism and the insulation system. The second part focuses on the design and finite element analysis of the cryogenic vessel assembly Flow Chart Figure 1.3 Project Work Flow Diagram 46 editor@iaeme.com

3 Design and Analysis of Large Transportable Vacuum Insulated Cryogenic Vessel 2. LITERATURE REVIEW Shafique M.A. Khan presents analysis results of stress distributions in a horizontal pressure vessel and the saddle supports. The results are obtained from a 3D finite element analysis. He showed the stress distribution in the pressure vessel, the results provide details of stress distribution in different parts of the saddle separately, i.e. wear, web, flange and base plates. A value of 0.25 for the ratio A/L is favored for minimum stresses in the pressure vessel and the saddle. The slenderness ratio (L/R) of less than 16 is found to generate minimum stresses in the pressure vessel and the saddle. The highly stressed area, beside the pressure vessel at the saddle horn, is the flange plate of the saddle. Aceves S.M. et al shows an evaluation of the applicability of the insulated pressure vessels for light duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current analysis and experimental plans for testing insulated pressure vessels. The most important results can be summarized that. Insulated pressure vessels do not lose any hydrogen for daily driving distances of more than 10 km/day for a 17 km/l energy equivalent fuel economy. Since almost all cars are driven for longer distances, most cars would never lose any hydrogen. Losses during long periods of parking are small. Due to their high pressure capacity, these vessels retain about a third of its full charge even after a very long period of inactivity, so that the owner would not risk running out of fuel. Also previous testing has determined the potential of low-temperature operation of commercially available aluminium -lined wrapped vessels for a limited number of cycles. Further testing will extend the number of cycles to the values required for a light-duty vehicle. Additional analysis and testing will help in determining the safety and applicability of insulated pressure vessels for hydrogen storage in light-duty vehicle. Mr. Abdul Sayeed et al worked on solid structural analysis of vacuum chamber. The analysis is done for electron microscopy applications, for scanning electron microscope it require vacuum atmosphere for viewing of the specimen. The specimen is to be viewed in vacuum. The vacuum level required for that is in the range of 700 torr, which is less than atmospheric pressure lead to compressive forces on the chamber They made vacuum chamber model in Catia and Simulation is done in Ansys. The Vacuum chamber is safe from buckling failure as applied p is very small in comparison to max theoretical buckling pressure. Compressive yield strength of structural steel is greater than Von Mises stress is calculated by solid structural analysis so it is safe from this criterion. Aceves S.M.et al. worked on high pressure and evalution of insulated pressure vessel for cryogenic hydrogen storage. The work described in this paper directed at verifying that commercially available pressure vessels can be safely used to store liquid hydrogen. This paper describes a series of tests which are shown below, that have been done with aluminium lined, fiber-wrapped vessels to evaluate the damage caused by low temperature operation. In FEM testing Cyclic, ultrasound and burst testing of the pressure vessels is being complemented with a finite element analysis, which will help to determine the causes of any potential damage to the vessel during low temperature operation. N.Vukojeviæ et al presented Vertical pressure vessels according EN are supported on four different kind of supports. In paper is presented stress-strain analysis of pressure vessel supported by brackets. Problems with supports are specially marked by great pressure vessels and without correctly choosing, supports type can become potentially weak point in construction. The Results based on presented analysis shown that great pressure vessel supported on bracket supports demonstrate poor solution in relation to continual cofigutared supports (scirt supports). Bracket type of supports is unfavorable in case of initial crack failures with growth tendention. Results deviaton between numerical experimental analysis are implication of different wall thickness of pressure vessel made by forging. A.Th. Diamantoudis et al. tried comparative study for design by analysis and design by formula of a cylinder to nozzle intersection has been made using different finite element techniques. The cylinder to nozzle intersection investigated is part of a typical vertical pressure vessel with a skirt support. For the study the commonly used ductile P355 steel alloy and the high strength steel alloy P500 QT were considered. The application of Design by Analysis (DBA) leads to much less conservative design parameters. The high strength steel P500 is severely punished when Design by Formula (DBF) rules are applied, instead of DBA methodology editor@iaeme.com

4 Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G 3. SPECIFICATIONS 3.1. Dimensions of Cryogenic Vessel Table 3 Dimensions of vessel PARAMETER Distance between inner and outer vessel Inner vessel length Inner vessel ellipse major radius Inner vessel ellipse minor radius Inner vessel thickness Surge plate thickness Distance between surge plates VALUE 150mm 3320mm 1900mm 1100mm 18mm 4mm 550mm Figure 3.1 Dimensions of Cryogenic Vessel 4. MODELLING In computer-aided design, geometric modelling is concerned with the computer compatible mathematical description of the geometry of an object. The mathematical description allows the model of the object to be displayed and manipulated on a graphics terminal through signals from the CPU of the CAD system. The software that provides geometric modelling capabilities must be designed for efficient use both by the computer and the human designer. To use geometric modelling, the designer constructs the graphical model of the object on the CRT screen of the ICG system by inputting three types of commands to the computer. The first type of command generates basic geometric elements such as points, lines, and circles. The second type command 48 editor@iaeme.com

5 Design and Analysis of Large Transportable Vacuum Insulated Cryogenic Vessel is used to accomplish scaling, rotation, or other transformations of these elements. The third type of command causes the various elements to be joined into the desired shape of the object being created on the ICG system. During this geometric process, the computer converts the commands into a mathematical model, stores it in the computer data files, and displays it as an image on the CRT screen. The model can subsequently be called from the data files for review, analysis, or alteration. The most advanced method of geometric modelling is solid modelling in three dimensions Modelling of Cryogenic Vessel Cryogenic vessel deign is a key point and no errors must be done. Hence, it is done with knowing all the considerations. This is first designed in CATIA V5R20, then analysed for static load conditions in ANSYS Tools Used for Designing Reference Elements To create a new plane, choose the Plane button from the Reference Elements (Expanded) toolbar. The Plane Definition dialog box is displayed, as shown in the figure Pads Tool Used to add material for the element designed. PADS toolbar is present in sketch features of CATIA Fillet Tool Fillet tool used for filling sharp edges to curved edges and also for filling materials. This tool is present in dress up features Steps Invoved in Modelling Choose part deign in mechanical design present in tool bar. Then select the plane in which model is to be present. Using sketching tools draw an ellipse of major radius 1900mm and minor radius 1100mm and using pad tool give thickness of 18mm to the ellipse. Later create datum planes by using reference element tool each at a distance 550mm from each other. Create Datumn planes with plane offset distances of mmDesign of Surge plates with Thickness 4mm 49 editor@iaeme.com

6 Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G Closing the Edges with Plates and filleting the edges with diameter 50mm 4.4. Comparision of Old and New Model of Cryogenic Vessel 5. ANALYSIS Figure 4.4 Old and New Surge Plate Designs 5.1. Static Analysis A static analysis calculates the effects of steady loading conditions on a structure, while ignoring inertia and damping effects, such as those caused by time-varying loads. A static analysis s can, however, include steady inertia loads (such as gravity and rotational velocity), and time-varying loads that can be approximated as static equivalent loads (such as the static equivalent wind and seismic loads commonly defined in many building codes). If the stress values obtained in the analysis crosses the allowable values it result in the failure of the structure in the static condition itself. To avoid such a failure, this analysis is necessary. Static analysis determines the displacements, stresses, strains, and forces in structures or components caused by loads that do not induce significant inertia and damping effects. Steady loading and response conditions are assumed; that is, the loads and the structure's response are assumed to vary slowly with respect to time editor@iaeme.com

7 Design and Analysis of Large Transportable Vacuum Insulated Cryogenic Vessel 5.2. Analysis Methodology Finite element model is prepared in CAD geometry. Ansys software used to create mesh. Then project is prepared in Project Window Ansys preparation steps Apply material properties Apply boundary conditions. Apply load. Solving Figure 5.1 Ansys Work Bench Figure 5.2 Imported Geometry Sectional View 51

8 Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G 5.3. Analytical Calculations Applied Conditions: Pressure = 0.4 Mpa (Inside the vessel) Temperature =-170 degree MATERIALS EQUIVALENT STRESS(MPa) Figure 5.3 Meshed Model TOTAL EQUIVALENT STRAIN THERMAL STRAIN TOTAL DEFORMATION(mm) Stainless steel Austenitic stainless steel grade 310s Aluminium grade ANALYSIS OF CRYOGENIC VESSEL DESIGN ON DIFFERENT MATERIALS To enhance the properties of the presently following design and materials of cryogenic vessel a new design is modelled and some new materials are used to observe the difference compared to old one. Three materials are compared including the presently using stainless steel, aluminium grade, and austenitic steel grade editor@iaeme.com

9 Design and Analysis of Large Transportable Vacuum Insulated Cryogenic Vessel 6.1. Stainless Steel Figure 5.4 Equivalent Stress On Stainless Steel Vessel Figure 5.5 Thermal Stain on Stainless Steel Vessel Figure 5.6 Total Eqivalent Strain on Stainless Steel Vessel 53

10 Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G 6.2. Austenitic Stainless Steel of Grade 310S Figure 5.7 Total Deformation of Stainless Steel Vessel Figure 5.8 Equivalent Stress on Austenitic 310s Grade Stainless Steel Vessel Figure 5.9 Therml Strain on Austenitic 310s Grade Stainless Steel Vessel 54 editor@iaeme.com

11 Design and Analysis of Large Transportable Vacuum Insulated Cryogenic Vessel Figure 5.11 Total Equivalent Strain on Ausenitic Grade 310sstainless Steel Vessel Figure 5.12 Total Deformation of Austenitic Grade 310s Grade Stainless Steel Vessel 6.3. Aluminium Grade 5083-O Figure 5.13 Equivalent Stress on Aluminium 5083-O 55

12 Tejaswini N, Poorna Sai R, Reddy Babu Naik B and Naveen G Figure 5.14 Thermal Strain on Aluminium 5083-O Figure5.15 Total Equivalent Strain Onaluminium 5083-O Vessel Figure 5.16 Total Deformation of Aluminium 5083-O Vessel 7. CONCLUSION By comparing stress locations in both the designs, our new surge plate design have less stresses than the old one. So the new model is preferable then old model. On comparison of total equivalent strain and total 56 editor@iaeme.com

13 Design and Analysis of Large Transportable Vacuum Insulated Cryogenic Vessel deformation for the materials like stainless steel, austenitic 310s, aluminium 5083-o on new surge plate design both the properties are low for aluminium 5083-O. We can observe that, based on the designs that we used, mostly stainless steel for new surge plate is not suitable but aluminium alloys holds better than it. Taking strain, deformation and other mechanical properties of the vessel for different materials into consideration on new surge plate design aluminium 5083-o is the perfect material. Aluminiumis huge in quantity that available in nature. It is lower in cost when compared to stainless steel and austenitic stainless steel. Among cost analysis it is clear that aluminium 5083-O is of low cost. Aluminium 5083-O alloyis light weight compared to other materials. Hence, total weight of vessel is reduced which is an advantage for transporting vessel from one place to other. So, to be clear, Aluminium 5083-O is best suitable material for cryogenic tank vessel. Eventually in analysis process we can conclude that the hybrid CAE software package ANSYS V15 has helped in our project resulting in enhanced outcomes with less total deformation, less total equivalent strain and less stress locations. So, in this project we came across a better output with design and analysis of large transportable vacuum insulated cryogenic vessel. REFERENCE [1] Swedish standards, SS-EN : Cryogenic vessels - Large transportable vacuum insulated vessel; Part 1: Fundamental requirements. Swedish Standard Institute, [2] Swedish standards, SS-EN : Cryogenic vessels - Large transportable vacuum insulated vessel; Part 2: Design, fabrication, inspection and testing. Swedish Standard Institute, [3] Gases background, [accessed ] [4] Truck specifications, [accessed ] [5] Hook-lift mechanism specifications, [accessed ] [6] Vacuum insulation methods, [accessed ] [7] Vacuum insulation methods, [accessed ] [8] Vacuum insulation methods, [accessed ] [9] Material specifications, [accessed ] Carbon steel AISI 1040, ge_title=aisi%2010xx; [10] Material specifications, [accessed ] Stainless steel UNS S30400: [11] S. Madhukar, A. Shravan, P. Vidyanand Sai and Dr. V.V. Satyanarayana, A Critical Review on Cryogenic Machining of Titanium Alloy (Ti-6Al-4V). International Journal of Mechanical Engineering and Technology (IJMET), 7(5), 2016, pp [12] V. V. Wadkar, S.S. Malgave, D.D. Patil, H.S. Bhore and P. P. Gavade, Design and Analysis of Pressure Vessel Using Ansys. Journal of Mechanical Engineering and Technology (JMET), 3(2), 2015, pp editor@iaeme.com