Heat Transfer Laboratory

Address:

SL-210

Overview:

This lab is used for the ME341 course (ME 341). Heat Transfer laboratory provides fundamental and industrial knowledge about modes of heat transfer, like conduction, convection and radiation, and their application. Heat Transfer Lab consists of the following equipments. Pin Fin Apparatus: This setup is designed to study the heat transfer in a pin fin. It consists of cylindrical fin fitted to the base in rectangular duct. A blower is provided on one side of duct to conduct experiments under forced convection heat transfer mode. Five thermocouples are embedded along the axis of the cylindrical fin at five different locations and one thermocouple placed in the air stream at the exit of the test section to measure the outlet air temperature. Digital Temperature Indicator is provided to read temperatures distribution along the fin. Test pipe is connected to the delivery side of the blower along with the Orifice to measure flow of air through the pipe. A heater heats one end of fin and heat flows to another end. Heat input to the heater is given through variac. Students will be expected to develop the following skills/understanding upon the successful completion of this experiment.

  • To plot surface temperature distribution along the length of fin

  • To determine average surface heat transfer coefficient for a fin losing heat by forced convection.

  • Calculation of effectiveness and efficiency of the fin for different heat fluxes.

Heat transfer through extended surface: In this experiment heat transfer from the extended surface relies on natural convection and radiation.This experimental set up consists of HT15 extended surface heat transfer accessory alongside HT10X heat transfer service unit on a suitable bench. Power lead is connected from the HT15 to the HT10x heat transfer service unit. There are 9 thermocouples on the HT15 connected to the appropriate sockets on the front side of the service unit. Voltage controller, manual/remote switch, thermocouple selector and digital temperature indicator are provided on the front panel of the service unit. The following things can be studied by performing this experiment.

  • Measuring the temperature distribution along an extended surface and comparing the results with theoretical analysis

  • Finding average heat transfer coefficient loosing heat by natural convection and radiation only.

  • Finding thermal conductivity of the material of extended surface

Emissivity measurement apparatus: This experimental set up consists of two circular aluminium plates, plate one blackened by thick layer of lamp black to form the idealised black surfaces where as the plate 2 is the test plate whose emissivity is to be determined, identical in size and provided with heating coils at the bottom. The heat input to the heater is varied by separate dimmer stats and is measured by an ammeter and a voltmeter. Separate wires are connected to diametrically opposite points to get the average surface temperature and one thermo couple is placed in the enclosure to measure ambient temperature. The heater inputs to the two plates are dissipated by conduction, convection and radiation. The experimental set up designed in such a way that under steady state conditions the heat dissipated by conduction and convection in the same for the two plates.

Heat transfer in natural convection: The setup consists of a brass tube fitted in a rectangular duct in a vertical fashion. The duct is open at the top and bottom, and forms an enclosure and serves the purpose of undisturbed surrounding. One side of the duct is fitted with a transparent good quality Acrylic window for visualization. An electric heating element is kept in the vertical tube that in turns heats the tube surface. The heat is lost from the tube to the surrounding air by natural convection. The temperature of the vertical tube is measure by Temperature Sensors and displayed by a digital

temperature Indicator with multi-channel switch. The heat input to the heater is measured by a ammeter and a Voltmeter and is varied by a variac. The tube surface is polished to minimize the radiation losses.

  • To determine average heat transfer coefficient for a vertical tube losing heat by natural convection

Critical heat flux measurement apparatus: This experimental set up is designed to study the pool boiling phenomenon up to critical heat flux point. The apparatus consists of a cylindrical glass container housing the test heater ad a hater coil for the initial heating of the water. This heater coil and test heater connected to mains via dimmer stats. An ammeter is connected in series while a voltmeter across it to read the current and voltage, respectively. The glass container is kept on an iron stand which could be fixed on a platform. There is provision of illuminating the test heater wire with help of a lamp projecting light from behind the container. A computer is facilitated for observing formation of bubbles and to identify the different regimes of pool boiling phenomenon. The following things can be studied by performing this experiment.

  • To observe variation of critical heat flux with bulk temperature of the fluid

  • To compare the experimental value of critical heat flux at the saturation temperature with that value obtained by Zuber's correlation

HT17 Unsteady state heat transfer:

This experimental set up is used to observe unsteady state conduction of heat to the centre of a solid shape when a step change is applied to the temperature at the surface of the shape. This apparatus consists of a HT17 unsteady state heat transfer unit, a PC running windows with available USB socket and a HT10XC computer compatible heat transfer unit. The method of experiment is allowing solid shapes of different sizes, form and materials of construction to stabilise at room temperature and then dropped into a bath of hot water. The change in temperature at the centre of each shape is continuously logged using a PC connected to the HT10XC.



Equipments

  • Pin Fin Apparatus

  • HT15 extended surface

  • HT10X heat transfer service unit

  • Emissivity measurement apparatus

  • Heat transfer in natural convection

  • Critical heat flux measurement apparatus

  • HT17 unsteady state heat transfer unit

  • HT10XC computer compatible heat transfer unit

  • Thermocouple calibration system

Experiments:

  • Heat transfer in a pin fin under forced convection heat transfer mode

  • Heat transfer from the extended surface relies on natural convection and radiation.

  • Emissivity measurement

  • Natural convection heat transfer for a vertical tube

  • Pool boiling phenomenon up to critical heat flux point

  • Unsteady state conduction of heat


Faculty: Dr. Umesh Madanan

Staff: Mr. Farhan Babu

Contact Person:
Mr. Farhan Babu
HT Lab
Phone: 7987
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.


Critical Heat Flux Apparatus

Thermocouple Calibration System


Unsteady Conduction Equipment

Emissivity Measurement Apparatus


Pin Fin Appratus

Natural Convection Heat Transfer Appratus




Extended Surface System