The most critical component of our experiment is the calorimeter. This device will be used to determine the energy density of the biodiesel as it combusts. Before implementing our own design, we will first analyse an industrial grade machine to determine its mechanics and efficiency. We will design our machine based on this information with a relatively low budget in mind. Our greatest concern for the design is to eliminate wasted energy from the burning fuel. Our goal is to transfer 100% of the heat from the burning fuel to the water.
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| Figure 1 |
The design shown in Figure 1 is a relatively simple setup that shows a given mass of water containing a thermometer, elevated above a spirit burner containing a fuel source. There is a shield surrounding the reaction base that prevents loss of heat, and a insulator at the top of the device to maximize the amount of heat contained. We realize, however, that this process is highly inefficient and is susceptible to a large amount of energy loss. A more accurate solution is a bomb calorimeter, which encapsulates the reaction under the water. This sealed container will retain the heat and transfer it to the surrounding water. In order to maintain the reaction, we must introduce an oxygen source.
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| Figure 2 |
The bomb calorimeter shown in Figure 2 is considerably more efficient. With consideration to Figure 1, the bomb calorimeter requires an oxygen supply, ignition source, and an internal encapsulation device that is able to resist the heat of combustion, and water sealed to prevent the inlet of water during the reaction process. The heat of the reaction is not let into the atmosphere, but to the surrounding water instead. Thus, increasing efficiency. For our purposes, we may utilize a Styrofoam enclosure as the insulating jacket; an aluminum soup can that will enclose the reaction; and a model rocket fuse to initiate the burning process.
Although it may be minimal, do you plan to account for heat lost to the surroundings?
ReplyDelete-Alex, Group 5
Alex, we have pondered over the idea of heat loss during the reaction process of the calorimeter. To counteract, we will be using two different types of devices. Our bomb calorimeter provides an almost airtight seal that will theoretically eliminate any possible loss of heat.
DeleteOur second calorimeter is naturally less efficient comparable to the bomb calorimeter. So to assist in the loss of energy, we will contain the system within a styro-foam enclosure. This will eradicate energy loss to the atmosphere.
-Jake
isn't it impossible to have a 100% conversion of energy? The variables are to uncontrollable. Do you plan to have a control machine to compare results with?
ReplyDelete-Group 2
Group 2, of course it isn't possible to get a 100% conversion of energy, especially with cheap materials, but the goal here is to make the most efficient calorimeter that is also cost-efficient. A control would be using one of the more expensive calorimeters at Drexel just to compare the results so we know we might be in the ball park for our energy amounts.
DeleteAlso, we are attempting to control these uncontrollable variables as best we can. We are using medium sized Styrofoam buckets to insulate the whole process of burning the fuel and heating up the water. Hopefully these sealed buckets will keep in as much heat as possible, which we'll be testing in the next week or so.
-Nikolai, Group 4