Effects of graphene ethylene glycol/water nanofluids on the performance of a brazed plate heat exchanger

• Effects of graphene ethylene glycol/water nanofluids as the hot side fluid on heat transfer and pressure drop characteristics in a brazed plate heat exchanger (BPHE) were experimentally investigated. Nanofluid properties, especially thermal conductivity and viscosity of the graphene nanofluids were measured at various graphene concentrations (0.01 to 1.0% wt.) and temperatures (10 to 60 °C). Dimensionless Nusselt number and friction factors were used to compare the performances of the BPHE with and without graphene addition. Experimental analysis showed that the heat transfer performance is improved by an increase in Reynolds number and flow velocity and with a decrease in nanofluid concentration. The graphene nanofluids at 0.01 to 0.1% wt. brings an acceptable pressure drop penalty, but with a higher heat transfer performance than the base fluid in the BPHE. At a fixed flow velocity, the graphene nanofluids with proper concentrations give an increase about 4% to 7% in the heat transfer coefficients, which reveals that the graphene nanofluids can be a useful working medium in the BPHE. The increase in pressure drop is moderate under these experimental conditions which favours graphene nanofluids to be used in BPHEs for thermal systems.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Nyckelord

Brazed plate heat exchanger

Ethylene glycol

Graphene nanofluids

Heat transfer enhancement

Pressure drop

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art (ämneskategori)

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