Discussion and Conclusions
Discussion
During this project, the Peltice system has gone through extensive testing. Preliminary tests were done with half the system equipment to further test the theories of the Peltier modules from our research and MATLAB code from RIPACS. The tests used a small heat sink, the size of the modules and 1-inch-tall, to test the cooling. The graph of Temperature Stabilizing of Certain Devices is design to in a way that the left vertical axis represents Fahrenheit of the temperature drops (Direct contact on Peltier Cold Side and Direct contact of Heat Sink on Cold Side {1-inch distance from module}). The right vertical axis represents Fahrenheit of the temperature rises (Direct contact on Water block (Hot Side), Water Reservoir, and Ambient Temperature near the Radiator). This was done to show the rate of temperature change in a single graph. This data concluded that Peltier modules have superior results with solid objects rather than gaseous spaces. This further pushes the reason RIPACS would not have been successful and why they are more favorable to CPU cooling. The next step was to test the in between, in other words, liquids and see the results were still favorable for the Peltice system.
The data in Stabilization Temps. Vs. Number of Modules graph used different amounts of Peltier modules to test a small water loop to see the capabilities of the Peltier modules with liquid cooling. When looking at Stabilization Temps. Vs. Number of Modules graph, the temperatures for all sections rise as more modules are added into the system. This was to no surprised with looking from the heat dissipation side. One theory was more modules, more heat production, but it was expected that the values from the cooling portions would be higher with more modules as well. Then with more research, the answer was found. Peltier modules can only displace so much temperature from side to the other. When the test with three Peltier modules was conducted, all three of the “hot sides” shared the same contact. That means all three were heating the same source meaning the temperature would be higher than if there was one module doing the heating thus making the “cold side” not achieve as low of a temperature.
The data for Peltice vs Peltice (w/o Peltiers) vs Traditional Method graph comes from Table 6. Table 6 is the data collected from the Peltice system and its two controlled variables, traditionally placing ice inside the cooler, and the Peltice system with the modules turned off. A temperature sample was recorded from the serial monitor from the Arduino on the Window Arduino program every 2 minutes for 3 hours for each variable. The Peltice system was able to bring the product’s temperature from 68 F to 49 F in 2 hours’ time. In addition, the data showed that the temperature in the Cooling Loop Water Reservoir was held at 33 F for about 2 hours before giving away quickly to the heat from the juice. A test was then conducted to see how the Peltier modules affect the cooling action in the system since they are used to absorb the heat from the cooling loop before the water returns to the reservoir. The Peltice system without the Peltier modules was able to bring the product’s temperature from 66 F to 51 F in 2 hours’ time. The data showed that the temperature in the Cooling Loop Water Reservoir was held at 33.8 F for about 1 hour before giving away quickly to the heat from the juice.
Comparing Peltice with the modules on and off shows that the Peltier modules in this system acts as an” electric insulation” for the Cooling Loop reservoir. The modules prevent the temperature in the Cooling Loop water reservoir from rising linearly for nearly 2 hours while 1 hour without. This means a user will need to replace the ice in the Peltice system every 2 hours instead of 1 hour which makes Peltice more user friendly, but this extra hour allows the cooler to achieve a two degree Fahrenheit difference inside the cooler which is not much.
During the complete operation, the Peltice system average about a 15.4 Amps current draw meaning the system ran about a constant 180 watts, as shown in Current & Wattage over Time graph. The data recorded for Current & Wattage over Time graph are located in Table 7. This table recorded a sample of the voltage, current, and wattage through the Digital Multi-Meter installed on the front face of the Peltice system for every 10 minutes for 3 hours. When the Peltier modules are not operation, the current usage is at 1.55 Amps meaning the 6 modules draw up to 14 Amps of current. The current peaked as the temperature difference between the product and the Cooling Loop Water Reservoir was at its greatest. This could have happened because the Liquid Cooling temperature and Cooling Loop temperature were at a higher separation during the cooling process thus using more current to keep that high-temperature spread between both sides. This current drain was only a difference of 15.36 Amps and 15.42 Amps though meaning this situation could not have been a huge strain on the system. for Peltice vs Peltice (w/o Peltiers) vs Traditional Method graph shows the comparison of Peltice to the ordinary way of adding ice into the cooler. The same variables were applied to both tests: Room Temperature of 71 F, 5 gallons of water in the container, 1 gallon of ice inserted in the system, and 3 hours of operation data. This data shows that the ordinary method works better than the Peltice system. The Ordinary method averaged a temperature of 40.5 F by 30 minutes after the insertion of ice while the Peltice averaged a temperature of 49 F by 2 hours after insertion of ice in the Cooling Loop Water Reservoir.
Conclusions
In conclusion, when it comes to the numbers, the Peltice system was beaten by the ordinary means of cooling juice in a 10-gallon Gatorade cooler by an 8 degree Fahrenheit temperature difference and achieving max cooling 1.5 hours faster Peltice. But when numbers are put aside and taste buds are put into the test, the Peltice system achieves cooling without adding a gallon of water into the product in which can water it down unlike the ordinary means of cooling. To properly use this system, one would have to replace the ice every two hours and should not use the system until the first two hours have passed to achieve maximum satisfaction. The Peltice system could achieve more superior results if more modules were used and all areas that are affected by ambient temperature had higher quality insulation (e.g. the Cooling Loop tubing). This insulation will help keep the cooling efficiency of the Peltice at max potential. If the Peltice system were taken into production, the design for the top and reservoir could be majorly improved to make it easier for one to take the top off and insert product inside or clean the container.