Scope and Objectives

1. To screen and synthesize the DES (Deep Eutectic Solvents) as per combination of Inorganic salt and Hydrogen Bond Donor 2. Synthesis of NDDES (Nanoparticle Dispersed DES) using Alumina and Titanium nanoparticles 3. Experimental Studies with the prepared NDDES and DES in a forced circulation heat transfer loop. 4. Measurement and validation of thermal conductivity and heat capacity. 5. Quantification of steam properties as absorbed by NDDES and DES from concentrated solar power. 6. Comparison of the economic efficiency with respect to thermal stability of commercial solvents

Deliverables

The bracket represents the deliverable achieved so far: 1.Low cost Heat Transfer Fluid with DES 2. Heat Transfer Fluids with temperature range greater than 400 degree C and freezing point below 1 degree C ( Formulated Menthol+Oleic Acid based DES with 300 degree C) 3. To obtain enhanced thermal conductivity and specific heat capacity as compared to commercial solvents. ( Formulated DL-Menthol+Oleic Acid based DES with thermal conductivity as 0.237 W/m.K as compared to 0.136 W/m.K for Therminol VP1. Further Menthol:+Oleic Acid based DES gave specific heat capacity as 899.65 J/mol.K as compared to 620.6 J/mol.K for Therminol VP1.) Therminol VP1 is the commercial thermal fluid. 4. Viscosity (ASTM D-445) less than 2.5 centistokes(cSt) at 313 K and less than 1 cSt at 373K (Formulated Menthol + Oleic Acid based DES with viscosity as 1.74 cP as compared to 0.585 cP for Therminol VP1) 5. Compute turbine power in KW using enhanced steam properties as generated by DES (Underway first by ASPEN and then Experimentation)

Videos

Scientific Output

In our first phase, we have reported the thermophysical and flow measurements of novel thermal solvents based on Deep Eutectic Solvent (DES) and spherical alumina based Nanoparticle Dispersed Deep Eutectic Solvents (NDDES). The DES was synthesized using a Hydrogen Bond Donor (HBD) i.e. Oleic Acid and an Hydrogen Bond Acceptor (HBA) namely DL-menthol by using an equimolar ratio at a temperature of 350.15 K. NDDES or Nanofluids was formed by dispersing different volume fraction (0.001, 0.005, 0.0075, and 0.01) of Al2O3 nanoparticles (less than 40 nm) in the DES. The optimum volume fraction (0.005) of Al2O3 nanoparticles were decided by the optimizing the thermophysical properties (density, viscosity, thermal conductivity and specific heat capacity) and its agglomeration behavior. As expected NDDES with 0.005 volume fraction gave a higher enhancement in thermal conductivity, viscosity, heat capacity and density as compared to DES. From the shear stress and strain curve both the DES and NDDES were found to be of Newtonian in nature. In order to evaluate the heat transfer coefficient, forced convection experiments were conducted in circular test section for both DES and NDDES under laminar condition (Re=124, 186 and 250). A hydrodynamically fully developed flow was observed after steady state. In the final section, the heat transfer coefficient and the Nusselt number were also validated with COMSOL Multi-physics simulation. In our second part, we have also synthesized a menthol-based Deep Eutectic Solvent (DES), using a Hydrogen Bond Donor (HBD) i.e. Oleyl Alcohol and an Hydrogen Bond Acceptor (HBA) namely menthol. The thermophysical properties namely viscosity, density, thermal conductivity and specific heat capacity are measured and compared with both conventional and commercial solvents. The performance of the solvent has been evaluated in a forced convective heat transfer configuration under laminar flow conditions. The convective heat transfer experiments demonstrated the fact that the thermal entrance length of the DES is very large due to its high viscosity and low thermal conductivity. The convective heat transfer results were compared with the in-house AnuPravaha CFD simulator.

Results and outcome till date

1. Formulated Menthol+Oleic Acid based DES with 300 degree C as its thermal stability. 2. Formulated DL-Menthol+Oleic Acid based DES with thermal conductivity as 0.237 W/m.K as compared to 0.136 W/m.K for Therminol VP1. Further Menthol:+Oleic Acid based DES gave specific heat capacity as 899.65 J/mol.K as compared to 620.6 J/mol.K for Therminol VP1.) Therminol VP1 is the commercial thermal fluid. 3. Prepared Menthol + Oleic Acid based DES with viscosity as 1.74 cP as compared to 0.585 cP for Therminol VP1 4. Currently computing turbine power in KW using enhanced steam properties as generated by DES (Underway first by ASPEN and then Experimentation)