Blog#7-->>
Performance Curves
The graph between temperatures Ambient, Inner BOX, Heat-sink with reference set temperature,dT
Here curves shows cooling saturated after 2hr and not able to cross 15*C after system off due to Backheat flow through TEC to cool side attached inside cooling box
Energy increase as dT increase
This shows energy is dissipating as the rate of dT increases to maintain cooling
TEC- V v/s I curve for TEC in overall system
Q(W)-Heat transfer & Qk Heat transfer via Thermocol V/s seconds(0-10hr)
Q decrease as with time increases
Qk conduction heat transfer rate (W) during system ON
Performance curves for selecting TEC and operating specification
CONCLUSION (as per current setup)
- Not suitable for refrigeration(0-10*c) if sample is from room temperature 20-40*c
- The current system works for room temperature below temperature 20*C (i.e more dependent on room temperature)
- More TEC with proper hardware fixing and insulation around them is required for current system to work fast.
- Heat backflow rate will act just after System OFF which lead temperature will increase rapidly than decrease in temperature when system ON also one of the reason for slow system and saturate at certain temperature.
CHALLENGES (as per current setup)
- Mechanical issues like adjustment of TEC module due to limitation of tool resources leading to assembly issue for TEC module placement is cumbersome.
- As the layer of partition between container box with surround heatsink with fan assembly require to be insulated within left space available
- Due to insulating material (thin due to space availability between TEC module and heatsink) and fixing issue on increase in voltage of TEC module to fast the overall system but due to this hot side temperature rises which pick by cooling side mostly therefore the supply voltage is low for TEC which leads the system slower than expected even if increase the number of TEC module to lower down the overall temperature of the box inside the fitting issue arise.
- Movable copper plate required to interposed between the block and the TEC, acting as a thermal diode to prevent backflow of heat from the TEC into the vaccine holder.
- To transported heat away from the hot side of the TEC to a remote heat exchanger.