LEADER 00000nam  2200361   4500 
001    AAI1492778 
005    20111005095711.5 
008    111005s2011    ||||||||||||||||| ||eng d 
020    9781124654492 
035    (UMI)AAI1492778 
040    UMI|cUMI 
100 1  Hazell, Daniel 
245 10 Modeling and Optimization of Condensing Heat Exchangers 
       for Cooling Boiler Flue Gas 
300    108 p 
500    Source: Masters Abstracts International, Volume: 49-06, 
       page:  
500    Adviser: Edward K. Levy 
502    Thesis (M.S.)--Lehigh University, 2011 
520    A large amount of water is present in vapor form in the 
       flue gas of a coal power plant. Reduction of total water 
       usage in power plants is the goal of this investigation. A
       secondary goal is to recover the heat that exists in the 
       flue gas and transfer it to the feed water for usage 
       elsewhere. To accomplish both of these goals a heat 
       exchanger is used with bundles of in-line circular tubes. 
       Cooling water is pumped through these tubes and flue gas 
       is forced around these tubes resulting in convective heat 
       transfer. Eventually the flue gas temperature drops below 
       the water vapor dew point and water is condensed out of 
       the flue gas. In addition, heat is transferred from the 
       hot flue gas (135°F -- 300°F) to the cooling water
       (90°F -- 105°F) that is being pumped through the 
       tubes 
520    A previously developed computer simulation code was 
       modified to predict heat transfer, condensation and 
       pressure drop through a full scale heat exchanger. The 
       heat exchanger was designed to carry the load of a 550 MW 
       power plant producing 6 million lb/hr of flue gas. Tube 
       spacing optimization was carried out and it was determined
       that relatively small transverse spacings and large 
       longitudinal spacings resulted in the best heat transfer 
       to cost ratio 
520    Heat exchanger cost consisted of capital cost and 
       operating cost. Capital cost was considered as a function 
       of tube material. Stainless steel 304 was the most cost 
       effective material in regions of water condensation. 
       Nickel Alloy 22 was the most effective material in regions
       before water condensation where there was sulfuric acid 
       condensation 
520    Two different operating locations for the heat exchanger 
       were considered: downstream of an ESP unit and downstream 
       of an FGD unit. Use of the heat exchanger downstream of 
       the FGD unit gave better water condensation per cost and a
       better heat transfer rate per cost. Operating conditions 
       and different flow rate ratios were considered and 
       predicted condensation efficiencies of up to 59% were 
       attained with some configurations 
590    School code: 0105 
650  4 Engineering, Mechanical 
650  4 Energy 
690    0548 
690    0791 
710 2  Lehigh University.|bMechanical Engineering 
773 0  |tMasters Abstracts International|g49-06 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/
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