Scenario In whisky distillation, the working fluid passes through several processes before it is casked and matured for a number of years. In the wash phase, pot ale (the waste by-product of wash still distillation, with little or no alcohol left
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B50TE Heat Exchangers and Heat Transfer: Assignment #1 (Session 2026/27)
| Course | B50TE Heat Exchangers and Heat Transfer |
| Institution | Heriot-Watt University |
| Assessment | Assignment #1, Session 202627 (design report submitted as PDF) |
| Total marks | 20 (10 + 4 + 2 + 4) |
| Software | HTRI Xchanger Suite, with manual calculations to confirm results |
| GenAI | Not permitted for any part of the assignment |
This B50TE assignment is a heat exchanger design project set in whisky distillation. Students design a TEMA AEU U-tube shell and tube exchanger that uses hot pot ale to preheat wash, justify the geometry they choose in HTRI, test how two parameter changes affect performance, and check HTRI’s duty, tube-side heat transfer coefficient and surface area with hand calculations.
Scenario
In whisky distillation, the working fluid passes through several processes before it is casked and matured for a number of years. In the wash phase, pot ale (the waste by-product of wash still distillation, with little or no alcohol left and containing solids and residues) can be used to heat the wash (beer brewed for distillation, average ABV about 9%) before further distillation.
| Stream | Inlet temperature | Volume flow rate* | Outlet temperature | Tank volume |
|---|---|---|---|---|
| Wash (9% ABV water and ethanol mix) | 35 °C | 550 L/min | 70 °C (must be above 66 °C) | 15,000 L |
| Pot ale (treat as water) | 85 °C | 400 L/min | Unimportant (goes to waste) | 9,900 L |
*You may choose your own flow rates based on the capacity of the storage tanks.
Assumptions you may make
- The fluids are always in the liquid phase.
- The hot fluid should be on the tube side.
- Pressure losses of 50 kPa are acceptable in both fluids; pumps move the fluids through the exchanger.
- An allowance for fouling should be included.
Task 1: Propose a Fully Justified Design [10 marks]
Design a suitable TEMA AEU U-tube shell and tube heat exchanger for heat recovery that maximises the wash outlet temperature. The wash can be brought to the final temperature with supplementary heating after the exchanger if required, and your design must justify any supplementary heating. Experiment with different geometries and arrangements, and justify your final recommendation against clearly defined criteria of your own.
Task 2: Effect of Parameter Changes [4 marks]
For your chosen design, explain how two given parameter changes would affect the performance of the exchanger, first individually and then together. HTRI may be used to validate, but the effects must be explained. Keep the original dimensions and parameters constant where possible, although some changes will require a different exchanger size.
Task 3: Manual Heat Balance and Tube-Side Coefficient [2 marks]
Perform a manual heat balance (duty) to confirm the HTRI calculation, remembering that one stream is a mixture of two fluids. Use an appropriate forced convection correlation to estimate the tube-side heat transfer coefficient and comment on how it compares with the HTRI value.
Task 4: Surface Area Check [4 marks]
Using the heat transfer coefficients and tube data from HTRI, confirm the surface area by manual calculation (corrected LMTD or ε-NTU method) and comment on any difference between the manual and computer results.
