27 Table 3.2 MSDR primary heat exchanger design data Type
Rate of heat transfer per unit MW Btu/hr Tube-side conditions Hot fluid Entrance temperature, 'F Exit temperature, " F Pressure drop across exchanger, psi Mass flow rate, lb/hr Shell-side conditions Cold fluid Entrance temperature, O F Exit temperature, F Pressure drop across exchanger, psi Mass flow rate, lb/hr Tube material Tube OD, in. Tube thickness, in. Tube-sheet-to-tube-sheet distance, ft Shell material Shell thickness, in. Shell ID, in. Tube sheet material Number of tubes Pitch of tubes, in. Total heat transfer area, ft2 Basis for area calculation Type of baffle Number of baffles Baffle spacing, in. Disk OD, in. Doughnut ID, in. Overall heat transfer coefficient, U, Btu hr-' ft-2 VoIume of fuel salt in tubes, ft3
exchanger is shown i Fig. 3.3. Use of the
salt altered the he from those of previous concepts. In order to keep the r small, for ease of afterheat removal and we found it desirable to use two primary gers in parallel in each of the three fuel-salt oops. The exchangers have a bolted, inverted dished head over a seal-welded membrane. A metal ring gasket in the head flange provides backup containment in the event of a leak in the membrane. This design makes maintenance easier than in the
U-tube, U-shell, countercurrent, one-pass shell and tubes with disk-and-doughnut baffles 125 4.2687 X lo8 Fuel salt 1250 1050 127.4 6.588 X lo6 Coolant salt (2LiF-BeF2) 900 1100 114.7 3.744 x 106 Hastelloy N 0.375 0.035 29.96 Hastelloy N 0.5 26.32 Hastelloy N 1368 0.672 (triangular) 4023.6 Outside of tubes Disk and doughnut 47 7.66 19.0 18.6 700.7 20.18
previously reported concept that involved plasma arc cutting of a 1-in.-thick heat exchanger head. The secondary heat exchanger design data are given in Table 3.3. The configuration is like that of the primary heat exchanger. Since the LiF-BeF2 heat transport circuits will become much less radioactive than the primary salt circuits, the remote maintenance requirements for this exchanger are not nearly as restrictive as for the primary units. The different parameters that can now be considered in design of the steam generators were mentioned in Sect. 3.2.2. We are investigating conceptual designs for