Peltier module

Structure

• • A series of semiconductors (n-type & p-type) arranged in a specific conformation.
  • A series of thermocouples connected electrically in series and thermally in parallel.

How does it work?

The Peltier effect

• • When a current flows through the module, heat is absorbed from the environment on one side, cooling it down, and then expelled on the opposite side, warming it up.
  • The performance of the module is dependent on the heat dissipation from the hot side using a heat sink and fan.

Cooling system

Components:

• • One TEC12706 Peltier module + one CPU cooler
  • Secured with a 3D-printed stand

Efficiency of Peltier cooling:

• • Testing results:
    1.3l of water took 30 mins to cool from 24.2ºC to 21.1ºC
    ∂T = 3.1ºC
    Q = 1.3 x 4200 x 3.1 = 16,926 J
  • What is required:
    Assuming the overestimate of 2.5l of water to be cooled from 37ºC to 25ºC
    ∂T = 12ºC
    Qreq = 2.5 x 4200 x 12 = 126,000 J
  • Conclusion:
    Time taken = 126,000/16,926 x 30 = 223.3 mins = 3.7 hours
    Which is sufficient for the prototype

Water circulation

Components:

• • One diaphragm pump (3.8l/min)
  • 23×42 Waterproof water pouch
  • PE tubing connected from water tank to pump inlet; pump outlet to the water pouch
  • Silicon tubing as the return line from pouch to tank

Efficiency of water circulation:

• • Able to support the head (approximately 5 kg)

Vibrotactile alarm

Components:

•  3V DC vibration motor

Settings:

• 3 Different Vibration Settings (Low, Medium, High)