Question

1. In a counterflow heat exchanger, the heat loss to the environment is to be included in the mathematical model. Considering the case of the hot fluid on the outside and the colder fluid on the inside, as shown in Figure below, sketch qualitatively the change that the inclusion of this consideration will have on the temperature distribution in the heat exchanger. Also, give the energy equation taking this loss into account. Hot Cold Energy loss

please help for thermal design subject

Answer 1

Countion Griven Counter fdow heat ex Let assume ine, ne mass flow rate of hot and cold fluid This = gniet temp of hot finid Tho - Outlet temp of hot fluid greet temp of cold fauid Tao = cold fluid Specific heat capacity frid Specific heat capacity of hot & fluid Tei d outlet temp of cold Cpc - Cpn = * Determine logarithmic mean temp of body (LMTD ) - use energy conservation law Ein Bout Fenergy loss na Con This - The) - inch ETce - Tc;) = hA (Tm - To ) Where Too = enivisonnent temp h = theat transfer coefficient b/w sussounding & heat exchanger.