Pavlos K. Pandis a, Stamatoula Papaioannou a, Maria K. Koukou b, Michalis Gr. Vrachopoulos b, Vassilis N. Stathopoulos a. Pafos, Cyprus, Oct 2018

Transcription

1 Differential scanning calorimetry based evaluation of 3D printed PLA for phase change materials encapsulation or as container material of heat storage tanks Pavlos K. Pandis a, Stamatoula Papaioannou a, Maria K. Koukou b, Michalis Gr. Vrachopoulos b, Vassilis N. Stathopoulos a a Department of Electrical Engineering, School of Technological Applications,, 344 Psachna campus, Evia, Greece b Energy and Environmental Research Laboratory, Department of Mechanical Engineering, School of Technological Applications,, 344 Psachna campus, Evia, Greece Pafos, Cyprus, Oct 218

2 Presentation Layout Introduction Energy today Thermal Energy Systems PCMs 3D printing (FFD) - PLA Concept Experimental Procedure Results Conclusions 2

3 Energy facts and figures Energy consumption is increasing every day The energy model used by our society is not sustainable Industry is consuming about 28% of energy demand 5% of generated heat is wasted polluting technologies, fossil fuels renewable energy not technically & economically viable global storage market of 1.4 GW/y by 22 The use of Energy Storage (ES) systems often result in such significant benefits as: Reduced energy costs & consumption Increased flexibility of operation Reduced initial and maintenance costs The storage of energy in suitable and clean forms is today a challenge to the technologists H. Jouhara, et al, Thermal Science and Engineering Progress, 6 (218) H. Jouhara, A.G. Olabi, Editorial: Industrial waste heat recovery, Energy, 16 (218) 1-2. International Energy Agency (IEA) s, World Energy Outlook, 217 World Energy Council, World Energy Resources Full Report 216 A large variety of ES techniques are under development, which can be grouped as follows: Mechanical, Thermal, Chemical, Biological, Magnetic 3

4 Thermal Energy Storage (TES) Thermal Energy Storage 3 major categories Latent Heat Energy Storage PCMs Eutectics Steam Sensible Heat Energy Storage Molten Salt Steam Hot water Storage tanks Hot rocks Thermochemical Salt dissolution 4

5 Phase Change Material (PCM) PCM: material with capacity to store and release large amounts of energy (latent heat) via phase transition Applications: Construction, Textile, Food packaging industry, Medical packaging industry, Automobile, Transportation, aerospace, photovoltaics etc SOLID LIQUID Phase Change: Heat Storage LIQUID SOLID Phase Change: Heat release Benefits: Higher storage density than sensible heat Smaller temperature change between storing and releasing energy Open issues: shape stabilization Corrosiveness (materials compatibility) Low thermal conductivity High cost 5

6 Materials & PCMs in TES systems Compact - tanks Smaller size-encapsulated M.K. Koukou, et al., Thermal Science and Engineering Progress, 7 (218) Materials investigated Metals: Cu and Al alloys, Carbon Steel, Stainless Steel Polymers: PP, PET, HDPE, LDPE, Perspex TES encapsulated PCMs textiles building materials food sector Chalkia et al., RSC Adv., 8 (218) J. Giro-Paloma et al., Renewable and Sustainable Energy Reviews, 53 (216) Z. Liu, et al., Building and Environment, 144 (218) X. Huo et al.,carbohydrate polymers, 2 (218)

7 Encapsulated PCMs High density polyethylene (HDPE) spheres with PCM A58 in 65 o C before after Benefits Prevent reactivity towards environment Control volume as phases change Prevent large drops in heat transfer rates Undesired results obtained in the water tank set-up PCM leakage Suggestion of 25 heating cooling cycles to reach a stable state of the HDPE spheres to prevent leakage L. Navarroet al, High density polyethylene spheres with PCM for domestic hot water applications: Water tank and laboratory scale study, Journal of Energy Storage, 13 (217)

8 Concept Metal fabricated tank materials Availability, price, manufacturability (carbon steel, Al and/or Cu alloys ) Organic PCMs: not aggressive to metal container Inorganic PCMs: aggressive to metal container No corrosion of stainless steel (but expensive!!) Polymer materials PP, PET, HDPE and LDPE PET and PP proved to be the best encapsulation materials for the organic PCM while HDPE for the inorganic PCM tested Issues to address: cost, materials availability, corrosiveness, manufacturability The use of PLA in contact with two organic PCMs (A44 & A58) for the first time PLA based latent heat storage tanks and encapsulation core material via 3D printing 8

9 Green polymer PLA (Poly(lactic acid)) environmentally friendly nontoxic recyclable good mechanical & thermal properties versatile in terms of manufacturability 3D printing - PLA 3D printing technology towards the replacement of standard structural parts on various industrial processes PLA material State of the art for additive manufacturing NOT TESTED for use in PCM/TES bioactive thermoplastic aliphatic polyester derived from renewable resources, such as corn starch cassava roots sugarcane Structure & shape stabilization on-demand for encapsulation & tank design by PLA 3D printing additive manufacturing 9

10 Experimental Prusa i3 3D printer FFD technique 2 o C (1.75mm) heated bed (6 o C) nozzle (Ø.4 mm).2 x.2 x.15 m In contact with two organic PCMs linear hydrocarbons (A44) fatty alcohols (A58) 1. Samples treatment PCM / PLA PLA 65 o C A44 A58 65 o C 2. Cleaning Procedure rinsed/mildly scrubbed H 2 O rinsed with ethanol rinsed H 2 O Drying No cleaning for plain PLA 3. Evaluation Mass uptake Thermal properties DSC experiments (14-22 o C) 2 ml/min flow of N 2 1 K/min ramp (crystallinity) Optical Contact Angle 1

11 Results Mass change Mass Uptake [% cm -2 ] %/cm 2 for A44/PLA and.45%/cm 2 for A58/PLA from day 28 A44 A Time days] very small mass increase practically stable in terms of mass Mass change [%] Comparison with HDPE A44/PLA A44/HDPE A58/PLA A58/HDPE Day 1 Day 4 V. Chalkia, N.Tachos, P.K. Pandis, A. Giannakas, M. Koukou, M.Vrachopoulos, L. Coelho, A. Ladavos, V. N. Stathopoulos, Influence of organic phase change materials on the physical and mechanical properties of HDPE and PP polymers, RSC Advances, 8 (218)

12 Results - DSC on A44/PLA & A58/PLA -1 A44/PLA 4 days B peak -1 A58/PLA 4 days days days -2-2 Heatflow [mw] days 7 days C peak Heatflow [mw] days 7 days A B C days -1-2 A B C days Temperature [ o C] Temperature [ o C] 12

13 Results DSC on 65 o C -5-1 days Heatflow [mw] A 1 day B 2 days 3 days days C Temperature [ o C] 4 days Disappearance of A peak Elimination of B peak 13

14 Optical observation & Contact Angles A44 A58 A44 A58 7 days 14 days 28 days 4 days 14

15 Discussion-Results PLA does not absorb PCM as seen in previous work with other polymers e.g HDPE, PP 3D printed PLA improves its crystallinity over working time at 65 o C 3D printed PLA structure is found stable and inert towards the two organic PCMs PLA proved so far very promising for organic PCM encapsulation or latent heat storage tank structural material Future work Further tests are needed for long term stability. Contact with other types of PCMs are currently under investigation. Mechanical properties Morphology observation 15

16 Publications and other work EW-4 - ERCOM WORKSHOP SESSION 4 (Thursday 18 Oct) 11:35 Recent advances in phase change materials for thermal energy storage V.N. Stathopoulos 1. V. Chalkia, N. Tachos, P.K. Pandis, A. Giannakas, M.K. Koukou, M.G. Vrachopoulos, L. Coelho, A. Ladavos, V.N. Stathopoulos, Influence of organic phase change materials on the physical and mechanical properties of HDPE and PP polymers, RSC Advances, 8 (218) M.K. Koukou, M.G. Vrachopoulos, N.S. Tachos, G. Dogkas, K. Lymperis, V. Stathopoulos, Experimental and computational investigation of a latent heat energy storage system with a staggered heat exchanger for various phase change materials, Thermal Science and Engineering Progress, 7 (218) POSTER SESSION Bioelectricity production from fermentable household waste extract using a single chamber microbial fuel cell Goals Waste room temperature Electricity production 16

17 Thank you for your attention! lcmt.teiste.gr 17