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Diffstat (limited to '1309/CH9/EX9.6/ch9_6.sce')
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1 files changed, 42 insertions, 0 deletions
diff --git a/1309/CH9/EX9.6/ch9_6.sce b/1309/CH9/EX9.6/ch9_6.sce new file mode 100755 index 000000000..6e0435f4c --- /dev/null +++ b/1309/CH9/EX9.6/ch9_6.sce @@ -0,0 +1,42 @@ +clc; +clear; +printf("\t\t\tChapter9_example6\n\n\n"); +// Using the effectiveness-NTU method to calculate the outlet temperatures of the fluids +// Data from Example 9.5 +// properties of (distilled) water at 104°F +m_1=170000; // mass flow rate in lbm/hr +T1=110; // temperature in degree F +cp_1=0.998; // specific heat BTU/(lbm-degree Rankine) +// properties of (raw) water at 68°F +m_2=150000; // mass flow rate in lbm/hr +t1=65; // temperature in degree F +cp_2=0.9988; // specific heat BTU/(lbm-degree Rankine) +Uo=350; // exchanger coefficient +Ao=703.7; +// The effectiveness-NTU approach is used when the overall heat transfer coefficient is known +// determining the capacitances +mcp_raw=m_2*cp_2; +mcp_distilled=m_1*cp_1; +printf("\nThe capacitance value of raw water is %d BTU/(hr. degree R)",mcp_raw); +printf("\nThe capacitance value of distilled water is %d BTU/(hr. degree R)",mcp_distilled); +if mcp_raw>mcp_distilled then + mcp_max=mcp_raw; + mcp_min=mcp_distilled; + printf("\nDistilled water has minimum capacitance"); + else mcp_max=mcp_distilled; + mcp_min=mcp_raw; + printf("\nRaw water has minimum capacitance"); +end +// determination of parameters for determining effectiveness +mcp_min_max=mcp_min/mcp_max; +UA_mcpmin=(Uo*Ao)/(mcp_min); +printf("\nThe required parameters are mcp_min/mcp_max=%.3f and (UoAo/mcp_min)=%.2f",mcp_min_max,UA_mcpmin); +effectiveness=0.58; //value of effectiveness from figure 9.15 corresponding to the above calculated values of capacitance ratio and (UoAo/mcp_min) +qmax=mcp_min*(T1-t1); +printf("\nThe maximum heat transfer is %.2e BTU/hr",qmax); +q=effectiveness*qmax; // actual heat transfer +printf("\nThe actual heat transfer is %.2e BTU/hr",q); +t2=(q/mcp_raw)+t1; +T2=T1-(q/mcp_distilled); +printf("\nThe Outlet temperatures are:\n\tRaw Water:%.1f degree F\n\tDistilled Water:%.1f degree F\n",t2,T2); + |