You are to design a heat exchanger to heat the water for a large athletic center. The exchanger must be able to heat water with flowrates up to $120gpm$ from $50F$ to $140F.$ The exchanger will be heated by combusted natural gas. You can choose the fuel$/$gas ratio. The available pressure drop for the water is $5($exceeding this value would require the addition of a pump$).$ The available pressure drop for the other stream is $10.$ For the economics, you can assume the center needs the water at maximum capacity for $6$ hours per day for $360$ days per year, but you may want to consider how the exchanger will operate during non$-$peak times.

Submit a design with a schematic and a summary of input$/$output flow rates and temperatures for all streams. Your summary should include the initial cost of the exchanger$($s$)$ and the annual operating costs. Give reasons for your assumptions and design choices. Provide the total cost for $1,3,$ and $10$ years of operation.

You may design a system from scratch. You may research existing designs for ideas. At minimum, you must show a heat exchanger design calculation by hand and a computer design $($using the HTFS$+/$ TASC Module in Aspen$).$ Typically, students will design their exchanger in Aspen, and verify calculations by hand. You may research alternative heat exchange systems in addition if you wish. You may create multiple design options, but you must make a final recommendation for which design to use.

You may use a single heat exchanger or an array of units as you see fit. Submit your design as a typed report and cite references $($if used$).$ Calculations validating the design may be turned in neatly hand$-$written and thoroughly explained. There are no maximum$/$minimum page length restrictions, but a $3-5$ page report $($excluding calculations$)$ is expected. You will be graded on the quality and the organization of the content, not by the mass or volume of the report.