final project enercon.docx

TECHNOLOGICAL INSTITUTE OF THE PHILIPPINES 938 Aurora Blvd., Cubao, Quezon City

College of Engineering and Architecture Department of Electronics Engineering

Principle Characteristics of a Peltier Device

In Partial Fulfillment of the Requirements for the completion of the subject Electromechanical Energy Conversion (EEC423L1)

Submitted by:  AQUINO,  AQUINO, Ronalyn Ronalyn C. BERIOSO, Ian Carlo L. DY, Ervin John Y. VARGAS, Emmanuel Christopher D.T. EC41FB1

Submitted to: Engr. Alvin T. Dela Cruz Instructor

OCTOBER 1, 2013 Date

Principle Characteristics of a Peltier Device

1. Objectives(s):

This activity aims to determine the properties of a peltier and its temperaturevoltage relationship. 2. Intended Learning Outcomes (ILOs)

 At the end of the experiment, the students shall be able to: 1. Explain the properties of peltier. 2. Know the advantages and disadvantages of peltier. 3. Identify peltier characteristic curves and operation. 3. Materials and Equipment:

Power Supply TEC1-12715 Heat Sink Cooling Fan Thermal Tape Temperature Reader 4. Theory/Discussion:

In 1821, J.T. Seebeck discovered that when two not similar metals are connected in two different points and those points are held in different temperatures, a micro-voltage will be developed. This ef fect is called “Seebeck effect”. Some years later, a scientist discovered the opposite of the Seebeckeffct. He discovered that if someone applies voltage to a thermo-couple, one junction shall be heated and the other shall be cooled. The scientist was called Peltier and thus, the effect was called the “Pelitier effect”.  A peltier thermo-element is a device that utilizes the peltier effect to implement a heat pump. A peltier has two plates, the cold and the hot plate.

Between those plates there are several thermo couples. All those thermo couples are connected together and two wires come out. If voltage is applied to those wires, the cold plate will be cold and the hot plate, hot.

Elements of Peltier

Peltier thermo-elements are mainly made of semi conductive material. This means that they have P-N contacts within. Actually, they have a lot of P-N contacts connected in series. They are also heavily doped, meaning that they have special additives that will increase the excess or lack of electrons. The illustration below shows the P-N contacts are connected internally within a peltier TEC.

Now imagine tens or hundreds of those P-N materials between two plates. The following drawing show how many P-N contacts exist in a rectangular area like a Peltier TEC.

Peltier Markings

TECs have identification markings on their face.

TEC1-12709  

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The first two digits will always be “TE” The next digit will be “C” or “S”. “C” stands for standard size and “S” for small sized. The following digit is a number and it indicates the number of stages that the TEC has. In the example is a one-stage TEC. Right next is a dash. After the dash, the three first digits indicate the number of couples that the TEC has inside. In the example, it has 127 couples. Next comes two more digits that indicate the rating current of operation for the Peltier. In the example, this is 9 Amperes. Some times follwos a “T” and three numbers. This indicates the maximum operating temperature for the TEC.

TEC Calculations 

Peltier Hot Plate Temperature

TH = T AMB + (C/W)(QH) QH = PE + QC PE = V x I

where: TH = Peltier Hot Plate Temperature T AMB = Ambient temperature C/W = Heat sink efficiency (Degrees C/watts) QH = Total Heat Sink Load (Watts) PE = Peltier electrical power input (Watts) QC = Heat load needed to be cooled (Watts) V = Volatage (Volts) I = Current (Amperes) 5. Procedures:

1. Se the power supply to 5 Volts. 2. Mount the TEC1-12715 in the heat sink and cooling fan using thermal tape. 3. Connect the power supply probes with the TEC1-12715. 4. Switch on the power supply. 5. Point the laser light of the temperature reader in the TEC1-12715. 6. Record the readings in Table 2. 7. Gradually adjust the voltage supply and repeat the steps above to complete the table 2. 6. Data and Results:

Complete the table below: Table 1: TEC1-12715 Markings Standard Size Size One Number of Stages 127 Number of Couples 15 Amperes Current Rating Operation

Trial 1 2 3

Table 2: Operating Characteristics of TEC1-12715 Supply Current Temperature Power Voltage Drawn 15.4 V 15 A 76.6 ˚F  24.67 ˚C 231 Watts 14.2 V 12.7 A 80 .0 ˚F  26.67 ˚C 180.34 Watts 13.2 V. 12.1 A 88.6 ˚F  31.44 ˚C 159.72 Watts

4 5 6 7 8

12.1 V 10.8 V 8.6 V 8V 7.5 V

89.0 ˚F  92.3 ˚F  92.4 ˚F  93 .0 ˚F  95.6 ˚F 

10.4 A 9.87 A 7.54 A 6.34 A 5.76 A

31.67 ˚C 33.5 ˚C 33.56 ˚C 33.89 ˚C 35.33˚C

125.84 Watts 106. 596 Watts 64.844 Watts 50.72 Watts 43.2 Watts

Graphical Sketches 

Temperature (˚F) VS Voltage (V)

18 16 14 12 10 Voltage

8 6 4 2 0 76.4



80

88.6

89

92.3

92.4

93

95.6

Temperature (˚F) VS Current (A)

16 14 12 10 8

Current

6 4 2 0 95.6

93

92.4

92.3

89

88.6

80

76.4

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Temperature (˚F) VS Power (W)

250

200

150 Power 100

50

0 95.6

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93

92.4

92.3

89

88.6

80

76.4

Temperature (˚F) VS Voltage (V), Current (A), and Power (W)

250

200

150 Voltage Current 100

Power

50

0 95.6

93

92.4

92.3

89

88.6

80

76.4

Table 2 – Analysis of Characteristic of a Peltier Device

CHARACTERISTIC GRAPH

INTERPRETATION

Temperature vs Voltage

 As the supply voltage is increased, the temperature decreased.

Temperature vs Current

The current increased as the temperature increased.

Temperature vs Power

Power increased as the temperature increased.

7. Interpretation of Data

During the experiment, the data and results above were obtained and these can be interpreted as follow: 

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Peltier elements can give more than 80˚C temperature difference between their plates. TEC1-12715 is a one stage peltier with 127 couples. Its current rating operation is 15 Amperes. As the voltage supplied to the peltier is increased, the current and power also increased while the temperature is decreased. When the ambient temperature raise or fall 1˚C, the module resistance will raise or fall 0.015 accordingly.

8. Observations

During the experiment, it was observed that: 

A peltier thermo element must be mounted on the surface of a heat-sink with a cooling fan to keep it working. The peltier generates a lot of heat on the hot surface, far more than the heat they dissipate and that is because the TEC itself draws a lot of current that generates itself heat due to I 2R heat losses.

9. Conclusion

 After conducting the experiment, we have concluded the following: Peltier devices use the peltier effect to transfer heat from one side of the device to the other. Thus, one side gets heat removed (and become cooler), and the other side receives the heat. As the voltage supplied to the peltier is increased, the current and power also increased while the temperature is decreased.   TEC1-12715’s maximum operating temperature is