Refrigeration Calculations and Analysis
Located below are the calculations that our group performed for each process within the Refrigeration Cycle. Also provided is a line diagram of the Refrigeration Cycle Superimposed
Analysis
The coefficient of performance is a very useful value to obtain. The COP of a refrigeration system tells us how much cooling is provided compared to the amount of work put into the system. A higher COP value means that the system will work more efficiently ideally at a lower cost. During our initial analysis of the system, we made some simplifying assumptions about the system in order to simplify our calculations and the system as a whole. The value we have obtained at this point in the project would be what we would expect out of an ideal Refrigeration Cycle. Some of the simplifying assumptions that we made came both from lecture and from the textbook. The first simplifying assumption that we made was that we assumed no friction affected the flow throughout the system. Obviously, this is not the case but we have not yet discussed how to take friction into account within a piping system. Later, in our further calculations, we will be able to account for the friction and because of this, the COP will go down. As discussed in the textbook, another assumption we made is that there is no heat lost in the compressor and the expansion valve. These are adiabatic processes under an ideal Refrigeration Cycle, but as we know in reality, this is not the case. Heat will always be lost in a system, but we made this assumption to simplify the calculations. Because we have not taken into account the energy losses that would stem from these assumptions, we have a COP that is higher than what the actual Campus Chiller Plant would have. Based on some quick research, the average COP for a typical chiller plant would be around 5. Our initial analysis has given us a COP of 10.175, however, this is not taking into account the energy losses from friction, pressure losses, or heat lost into the environment. All in all, our value is reasonable for the assumptions that we have made and we expect it to decrease as we remove our assumptions, such as friction, and move the system into the real world environment.
P-H Line Diagram with Pictures
