Development of Filament Winding-Produced Hybrid Composite Pressure Vessels for Hydrogen Storage

Development of Hybrid Composite-Based Pressurized Vessels Produced with Filament Winding Technique for Hydrogen Storage

Abstract

Composite-wrapped pressurized vessels are used for high-pressure hydrogen storage due to their excellent mechanical properties and low weight. In this study, Type-III composite high-pressure vessels with a metallic inner liner were manufactured using the filament winding technique and [±11°/90°]3 winding orientation. Two types of composite pressurized vessels were produced; the first was a fully glass fiber-wrapped pressurized vessel, and the second was a hybrid pressurized vessel with two carbon circumferential layers in the cylindrical section. The burst pressures of all inner liners and composite-wrapped pressurized vessels were determined experimentally, and their deformations in axial and radial directions were measured using strain gauges during the burst test. Additionally, a finite element model with progressive damage capability was developed to compare experimental and numerical results.

Introduction and Objective

Today, 25% of global CO2 emissions are caused by the transportation system. According to current trends, the number of automobiles is expected to double by 2050 due to increasing population and income [1]. Preventing carbon emissions from the transportation system is one of the most important factors in reducing climate change. Hydrogen is considered the new energy source for the coming century due to zero greenhouse gas emissions, high energy efficiency, and abundance in nature. There are generally three ways to store hydrogen. These are: (i) storage within solid materials, (ii) storage as cryogenic liquid, (iii) storage as compressed gas in a pressurized tank. However, storage in pressurized tanks is the most popular method compared to the others due to technical simplicity and fast filling-emptying operations [2]. The most important performance criterion for composite pressurized vessels is the burst test. There are few studies in the literature regarding the burst behavior of composite pressurized vessels. Shao et al. manufactured high-pressure composite pressurized vessels using epoxy and polyester matrix materials and carbon fiber as reinforcement. Helical winding at 1 mm and circumferential winding at 1.5 mm were applied over the metal inner liner with a ±15° winding angle. Burst tests were applied to carbon/polyester and carbon/epoxy specimens. The burst pressure for carbon/polyester composite specimens was found to be 870 bar, while for carbon/epoxy composite specimens this value was 720 bar [3]. Cohen (1997) and Cohen et al. (2001) examined the effects of filament winding parameters and fiber volume fraction on the performance of composite pressurized vessels. The results showed that lamina orientation, winding tension, and winding speed directly affect the performance of composite tanks [4,5]. The finite element method is the most effective numerical method used to predict burst pressure and damage progression in composite pressurized vessels. Xu et al. proposed a 3D parametric finite element method to predict damage modes in composite hydrogen storage pressurized vessels. They developed a solution algorithm to investigate progressive damage characteristics of the composite structure with increasing internal pressure [6]. Alcántar et al. developed two methods for weight reduction in hydrogen storage pressurized vessels [7]. In this study, Type-III composite pressurized vessels with a metal inner liner were manufactured. Two different types of composite pressurized vessels were produced. In one type, only glass fiber was used, while in the other, hybrid tanks were produced by applying 2 circumferential carbon fiber wraps in the cylindrical section. The effects of the hybrid effect on the burst pressure of composite tanks were investigated experimentally and numerically.

Experimental Studies

In this study, 1200 tex glass fibers obtained from Cam Elyaf Sanayi A.Ş. and produced suitable for the filament winding method were used as glass fiber, while 800 tex carbon fibers obtained from DowAksa A.Ş. were used as carbon fiber. Hunsan Araldite MY740 epoxy system, which is cured at high temperature and suitable for the filament winding method, was used as the resin system. 34CrMo4 steel inner liners with an average wall thickness of 4.5 mm were obtained and used in the filament winding method. Composite helical and circumferential wraps were wound onto the steel inner liner using a filament winding machine as shown in Figure 1.

a

b

Figure 1. Composite pressurized vessel manufacturing steps (a) dry winding, (b) wet winding, (c) cured storage tank.

Composite pressurized vessels were subjected to internal pressure to determine the burst pressure. Strain gauges were used to calculate axial and radial local strains during the burst test (Figure 2).

Figure 2. Pressurized vessel ready for burst test Finite Element Analysis

The burst pressure of composite pressurized vessels and axial and radial local strains during the burst test were also measured using a finite element model. The inner liner material was defined in ANSYS as a non-linear, elastic-plastic material. The burst pressure was determined based on sudden changes in equivalent stress. Progressive damage analysis was applied for the composite structure. A 1/16 model was used to reduce computation time (Figure 3).  

Figure 3. 1/16 composite pressurized vessel model

Results and Discussion Experimental Results

Burst tests were applied to steel inner liners, glass fiber pressurized vessels, and hybrid pressurized vessels. The average burst pressure of steel inner liners was found to be 657 bar. For glass fiber specimens this value was 899 bar, while for hybrid specimens it was 905 bar. One test specimen after burst is shown in Figure 4.

Figure 4. Test specimen after burst test

Numerical Results

In order to determine the burst pressure of composite pressurized vessels with steel inner liners, curves of internal pressure versus equivalent stress were generated using the numerical model. As seen in Figure 5, after the initial linearly elastic region with no permanent damage, a plateau is formed, and it is clearly visible that during this period the steel, which has significant load-bearing characteristics, yields and the composite layers undergo progressive damage. The sudden increase in equivalent stress following this plateau region is considered an indication that failure will occur predominantly at this internal pressure. According to this approach, burst pressures were predicted as 701 bar for the steel inner liner alone, 799 bar for the composite pressurized vessel with 3 helical and 3 circumferential glass fiber layer wraps, and 775 bar for the hybrid composite pressurized vessel based on finite element analysis. Experimental and numerical results are presented in Table 1.

Figure 5. Equivalent stress variation with respect to internal pressure on the pressurized vessel from finite element analysis

During the burst test, axial and circumferential strains obtained from strain gauges were compared with strain results obtained from the finite element analysis conducted on the numerical model (Figure 6).

Figure 6. Comparison of experimental and finite element analysis results for strain gauge (L2, T2) at the front section, (a) steel inner liner, (b) glass fiber pressurized vessel, (c) hybrid pressurized vessel

Table 1. Experimental and numerical burst pressure results

In this study, glass fiber and hybrid (glass/carbon) fiber composite-wrapped pressurized vessels containing the same number of helical and circumferential layers were manufactured. A finite element model with progressive damage capability was developed. When the finite element model was compared with experimental data, it produced very close results. However, it was found that carbon-containing hybrid pressurized vessels had no effect on experimental burst pressure. Additionally, numerically predicted strain values in hybrid tanks showed greater deviation compared to other pressurized tanks. This can be attributed to the stiffness difference between consecutively arranged carbon and glass fiber layers and the failure to maintain integrity during the manufacturing of composite layers. As seen in this study, validation of a numerical model containing the basic approaches of composite-wrapped pressurized vessels experimentally is important for these pressurized vessels operating at high pressure and will enable widespread use of composite-wrapped pressurized vessels. Research Assistant Osman Kartav İzmir Yüksek Teknoloji Enstitüsü Faculty of Engineering Department of Mechanical Engineering     Prof. Dr. Metin Tanoğlu İzmir Yüksek Teknoloji Enstitüsü Faculty of Engineering Department of Mechanical Engineering   Associate Professor Dr. H. Seçil Artem İzmir Yüksek Teknoloji Enstitüsü Faculty of Engineering Department of Mechanical Engineering       Research Assistant Serkan Kangal İzmir Yüksek Teknoloji Enstitüsü Faculty of Engineering Department of Mechanical Engineering   Associate Professor Dr. Engin Aktaş İzmir Yüksek Teknoloji Enstitüsü Faculty of Engineering Department of Civil Engineering    

References [1] Ellerman, D. and Marcantonini, C. (2013). The Cost of Abating CO2 Emissions by Renewable Energy Incentives in Germany. MIT CEEPR Working Paper. [2] Zheng, J., Liu X., Xu, P., Liu, P., Zhao, Y., Yang, J. 2012. "Development of high pressure gaseous hydrogen storage technologies", International Journal of Hydrogen Energy, 37, 1048-1057. [3] Shao, Y., Betti, A., Carvelli, V., Fujii, T., Okubo, K., Shibata, O., Fujita, Y. Y. "High pressure strength of carbon fibre reinforced vinylester and epoxy vessels," Compos. Struct., vol. 140, pp. 147–156, Apr. 2016. [4] D. Cohen, "Influence of filament winding parameters on composite vessel quality and strength," Compos. Part A Appl. Sci. Manuf., vol. 28, no. 12, pp. 1035–1047, Jan. 1997. [5] D. Cohen, S. C. Mantell, and L. Zhao, "The effect of fiber volume fraction on filament wound composite pressure vessel strength," Compos. Part B Eng., vol. 32, no. 5, pp. 413–429, Jan. 2001. [6] P. Xu, J. Y. Zheng, and P. F. Liu, "Finite element analysis of burst pressure of composite hydrogen storage vessels," Mater. Des., vol. 30, no. 7, pp. 2295–2301, Aug. 2009. [7] V. Alcántar, S. Ledesma, S. M. Aceves, E. Ledesma, and A. Saldaña, "Optimization of type III pressure vessels using genetic algorithm and simulated annealing," Int. J. Hydrogen Energy, vol. 42, no. 31, pp. 20125–20132, Aug. 2017.