3.4 EXPERIMENTAL
SETUP
The photograph and schematic of the
experimental setup, fabricated to investigate the heat transfer characteristics
of nanofluids in Double Pipe heat
exchanger for different flow conditions are shown in Fig 3.4 and Fig 3.5 respectively.
The schematic of the experimental apparatus
is shown in figure 1.This setup
is built as two closed loop systems
consists of two
cycles. The nanofluid cycle contains collection tank 5 litres. A pump
with bypass line, heat transfer test section of length 1 Meter. The inner
copper tube has inner diameter of 7mm
and outer diameter of 10mm and a total length of 3meters.The heated length of
copper tube is1 Meter. The outer tube made of GI with inner diameter of 22mm
and outer diameter of 27.5mm. 2 k type sensors were measured bulk temperature
of the flow at the inlet and outlet of the test section having the gap of 6 cm
from each end. 3 k type thermocouple were installed at a distance of
24cm,42cm,60cm from the left end of the system, on the surface of the test section, so that the temperature of
the inner surface of the tube measured without affecting the flow. The test
section was heated by hot water which flows over copper tube. The heat transfer
section is isolated by a 1cm thick puff material in order to minimize the heat
loss to the surroundings. An air cooling radiator after the test section is
used to control the temperature of nanofluid and keep it constant at inlet of
the test section. The second cycle
contains equipments to create and control the flow rate of hot water at desired
temperature. The reservoir tank made of two sections in order to create hot
with uniform temperature and lowest variation of hot water temperature at the
inlet of the test section as shown in the photo. The capacity of the reservoir
tank is 15 litres. The reservoir tank is
fitted with 1500w kettle heater to heat the water. The temperature of the water
is measured by multi point temperature digital display unit. 2 , k type sensors
are used to measure inlet and outlet
bulk temperature of hot water supply to the test section. A rota meter is used
to measure and adjust the hot water flow rate. In our experiment the flow rate
has been fixed to 4lpm for all concentrations. A slop ccl4 manometer was used to measure
the pressure drop. The angle of manometer with horizontal line was 48.5°.
The essential parameters that are to be measured include hot water flow rate,
nanofluid flow rate, temperatures and heights of manometer coloums.The flow
rate through loops were controlled with a main valve and by pass line. All of
the thermocouples and sensors have a precision of 0.1°C and were
calibrated before they are attached to the test section. The hot water rota
meter calibrated in different temperature of hot water. An ordinary thermometer
was used to measure the temperature of ambient. The complete experimental setup is
thermally insulated to prevent heat loss. The insulation material used is
Styrofoam.
