NANOFLUID ADDITIVE FOR HEAT EXCHANGER (HE) Imran Syakir Mohamad COMBICAT, UM

2 Objectives To design a nanofluid formulation using the proprietary CNT-based additive for OYL mini chiller which will improve heat transfer efficiency by 1 o C (current:  T=5 o C, target:  T=6 o C), thus allowing to:- Scale down heat exchanger system Increase energy efficiency (  10%)

3 Info (OYL Air-Cooled Mini Chiller)

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5 Schematic Diagram: Test Rig P: Diff. Pressure F: Flow meter : Thermometer SSR Chiller SSR P F F PID UUT: Unit under test PID: Proportional Integral Derivative controller SSR: Heater controller UUT BPHE Hot side (Vary Flow) Cold side (Fixed Flow) Stainless Steel Tank Pump Stainless Steel Tank Pump

6 Specification of BPHE The specifications of the BPHE used is as follows: Model: SWEP B25-26 Effective Length, Leff = Lv (m)0.479 Effective channel width, Lw (m)0.117 Number of plates26 Number of Passes, Np (single pass)1 Number of channels per pass, Ncp13 Plate pitch, p (mm)2.34 Plate thickness, t (mm)0.4 Channel Spacing, b (m) (b = p - t) Port Diameter, Dp (m)0.024 Surface enlargement factor1.2(assumed) Hydralic Diameter, Dh = 2b/1.2 (m) Single channel flow area = b*Lw (m^2) Chevron angle,  70 deg. LpLv Lw Lh 2b Dp

7 WaterCNT-Water Entering water temp 12 o C Leaving water temp7oC7oC6oC6oC ∆T5oC5oC6oC6oC Fluid flow rate2m 3 /hr Cooling capacity11.61kW13.93kW Power input4.56kW4.625kW % Energy efficiency254.6%301.3% Power: Compressor3970W Waterpump350W385W fanmotor270W Total4590W4625W Comparison Data

8 Scope of Work This project would be divided into five sub-phases (Phase I-V). Phase I: Review heat-exchanger fluid technology and IP landscape. Phase II:Develop additive for nanofluid a) Selection of suitable primary additive b) Formulation of nanofluid c) Screening Test: Thermal conductivity d) Heat transport property evaluation Phase III:Process Simulation a) Process simulation b) Target optimization Phase IV:Optimization of HE nanofluid formulation a) Conceptual engineering design for pilot plant b) Establish pilot plant c) Reproducibility Phase V:Field test

9 Project Flow Diagram Flow Chart 1: Summary of Research Project

10 Possible Primary Additive CNT Spherical nanocarbon Non-abrasion metal oxide

11 CNT Development Route Washing (removes impurities; eg: Al, Si, Fe, K) Washing (removes impurities; eg: Al, Si, Fe, K) Catalyst Development Nanocarbon Growth (Thermal-CVD) Characterization Monometallic (Iron, Ni) Compositional analysis (EDX,XRF) Morphology/Structure analysis (SEM, HRTEM) Texture/Surface Area analysis (BET) Mechanical & Electrical Properties Analysis Compositional analysis (EDX,XRF) Morphology/Structure analysis (SEM, HRTEM) Texture/Surface Area analysis (BET) Mechanical & Electrical Properties Analysis Carbon source (C 2 H 4 ) Carrier gas (H 2, N 2 ) Carbon source (C 2 H 4 ) Carrier gas (H 2, N 2 ) Substrate (NC100) Substrate (NC100) Treatment Impregnation CNT CNT After Treatment Nanofluid Formulation treat with 5M HNO 3, T=30 o C, 24 hr wash with deionized water, dried T=200 o C, 2 hr treat with 5M HNO 3, T=30 o C, 24 hr wash with deionized water, dried T=200 o C, 2 hr Cat. + acetic acid under ultrasonic, 30 min, 25 o C (water bath) aging 12 hr, 45 o C Cat. + acetic acid under ultrasonic, 30 min, 25 o C (water bath) aging 12 hr, 45 o C Use acid treatment (HCl) to remove catalyst & amorphous C. 1 2

12 Parameter concerned NC100 AC Pretreatment Catalyst Precursor Achiev ed Cat. Weight Ratio Achiev ed Growth Parameter Impregnation Temperature Gas Loading Ratio Growth Time Characterization Achiev ed Modified CNT End Characterization Achiev ed Characterization Achiev ed Optimization Achiev ed No Yes Bulk Preparation of CNT Synthesis Precursor (Fe) AB Wt % Cat. 135 UTP Parameter % H2 loading 5%10%20% Red. Temp ( o C) Growth Time (min)

13 Criteria of CNT modification High purity of nanofiber/nanotube Special modified surface charges to avoid agglomeration Functionality (oxygen-containing functional group)

14 Other Potential Additive Soot ZnO CuO MoO

15 Formulation of Nanofluid Modified CNT Sonication Nanofluid FormulationDistilled Water Dispersant Dispersant Concentration Achiev ed CNT Weight Loading Temperature Viscosity Testing & Measurement Optimization Achiev ed CNT+ Standard Portable Water Nanofluid Testing & Measurement Yes No End To re-entangle the modified CNT 2 types of dispersant will be chosen: Purpose: To prepare a stable dispersion of CNT in liquid form. Criteria of dispersant: able to disperse CNT and stable for 24hr Main Substance: CNT, Distilled water and Dispersant Parameter concerned

16 Formulation of Nanofluid Modified CNT Sonication Nanofluid FormulationDistilled Water Dispersant Dispersant Concentration Achiev ed CNT Weight Loading Temperature Viscosity Testing & Measurement Optimization Achiev ed CNT+ Standard Portable Water Nanofluid Testing & Measurement Yes No End 3 different weight percent 3 different concentration 3 different temperature High to low shear rate Parameter Wt % CNT DEF Nanofluid Temp GHI Wt % Dispersant ABC Viscosity HighLow pH JLK

17 Formulation of Nanofluid Modified CNT Sonication Nanofluid FormulationDistilled Water Dispersant Dispersant Concentration Achiev ed CNT Weight Loading Temperature Viscosity Testing & Measurement Optimization Achiev ed CNT+ Standard Portable Water Nanofluid Testing & Measurement Yes No End Testing and measurement Heat transfer coefficient Thermal conductivity Dispersion of CNT Stability

18 Formulation of Nanofluid Modified CNT Sonication Nanofluid FormulationDistilled Water Dispersant Dispersant Concentration Achiev ed CNT Weight Loading Temperature Viscosity Testing & Measurement Optimization Achiev ed CNT+ Standard Portable Water Nanofluid Testing & Measurement Yes No End To optimize nanofluid formulation best method using standard portable water. Testing and measurement Heat transfer coefficient Thermal conductivity Dispersion of CNT Stability

19 Optimization of HE Nanofluid Formulation CNT & Nanofluid Formulation Reproducibility Fluid dynamics and Heat Transfer Test Achiev ed Stability Sample scale up & Performance Repeatability Testing & Measurement Optimized nanofluid ready for field test End Yes No Scale up of CNT Scale up of HE Nanofluid Formulation Performance repeatability Performance stability for 100 hours Corrosion

20 Thank you

21 Info HE System (water) Entering water temp = 12 o C Leaving water temp = 7 o C ∆T = 5 o C Water flow rate=2m3/hr Cooling capacity = 11.61kW Power input=4.56kW % Energy efficiency= 11.61/4.56x100%=254.6% Power:Compressor=3970W (Fixed) Waterpump=350W (depend on viscosity of fluid) fan motor=270W(Fixed) Total=4590W

22 Info HE System(CNT+water) Entering water temp = 12 o C Leaving water temp = 6 o C (expected) ∆T = 6 o C Cooling capacity = 13.93kW Power input=4.625kW % Energy efficiency= 13.93/4.625x100%=301.3% Power:Compressor=3970W (Fixed) Waterpump=385W (depend on viscosity of fluid) fan motor=270W(Fixed) Total=4625W

23 Apendix: Preparation of Nanofluids The process could possible to be proceeding as: Step 1: Sonicating CNT sample with a known weight in an ultrasonic bath Step 2: Dispersing the sonicated CNTs into a present amount of distilled water containing suitable dispersant Step 3:Treating the mixture with high shear homogenizer for 30 minutes. Parameters concerned:  Solution: distilled water, SYABAS  Dispersant: Gum Arabic and Sodium Laurate  Dispersant Concentration: 0.1wt% - 0.5wt%  CNT Concentration: 0.1wt% - 5wt%  Nanofluids Temperature: 25oC – 35oC  Nanofluid Viscocity: High - slow shear rate