Description of DIDAC Water to Water Turbulent Flow Heat Exchanger:
Water to Water Turbulent Flow Heat Exchanger is a highly advanced concentric tube heat exchanger with hot water flowing through the central tube while cooling water flows through the annular space. The heat exchanger has been divided into three equal sections in order to allow examination of the intermediate stream temperature conditions and temperature distribution through the heat exchanger. Thermocouples sense the hot and cold stream temperatures at the four stations and the inner tube wall temperatures on entry and exit. The addition of the central tube surface temperatures at inlet and exit allow detailed investigation of the surface heat transfer coefficient inside and outside the central tube.
Specification of Water to Water Turbulent Flow Heat Exchanger:
- Heat Exchanger: Concentric tube type with inlet, outlet and two intermediate measuring points plus pipe temperature. Area 0.0288m2.
- Water Heater: 3kW with electronic control .
- Pump: Continuous rated to circulate hot water.
- Flow Meters (1+1):- For hot and cold water.
- Digital Thermometer: 0.1ºC resolution, with multi-way selector switch.
- Cold water flow reversal valves: To establish concurrent and counter-current flow.
- The PID temperature control on the Heat Exchanger Service Unit allows investigation of turbulent flow conditions at a range of fixed Prandtl numbers.
- Investigations using these two methods of control allow students to experimentally determine the constants in one of the classic empirical equations for turbulent heat transfer in a tube.
Experimental Capability of Water to Water Turbulent Flow Heat Exchanger:
- Determination of heat transfer rate, logarithmic mean temperature difference, overall heat transfer coefficient and 4 point hot and cold stream temperature profiles.
- Determination of surface heat transfer coefficient inside and outside the tube, and of the effect of fluid velocity.
- Comparison of performance in concurrent and in counter-current flow.