Analysis of Heat Exchangers and Heat Exchanger Coefficients Group 2 Maria Useche Franco, Mikayla Haynes, Mitchell Horn, Jackie Landoski, Will Seidel Agenda Background Methods Calculations Results Recommendations Background A steady state balance around the heat exchanger gives this equation to calculate heat transfer. Heat exchangers are divided into categories based on • Flow arrangement • Construction of heat exchanger Configurations (a) Parallel flow (b) Countercurrent flow The temperature differences are used to calculate ΔT(LMTD) which is subsequently used to calculate other quantities. Heat Transfer Coefficients Overall Heat Transfer Coefficient (U) Film heat transfer coefficient (h) Can be experimentally determined using one of 3 empirical Equations based on Re ThTheis This equation is dependent on diameters, thermal conductivity, film coefficients, and tube wall thickness. 1. 2. Sieder-Tate Equation (Re <2100) Hausen Equation (2100 < Re < 10,000) 3. Dittus-Boelter Equation (Re > 10,000) Flow Regimes Based on this equation and the parameters of the experiment, the Reynolds number changes from the velocity of the fluid. Re<2100 laminar 2100 ≤Re <4000 transitional Re≥ 4000 turbulent Methods - Equipment Setup Shell and Tube Heat Exchanger Concentric Tube Heat Exchanger Methods - Schematic Concentric-tube heat exchanger Shell-and-tube heat exchanger Methods • Set temperatures of cold and hot water to 10 ℃ and 50 ℃ • Measure steady state temperatures Three hot water flow rates Three cold water flow rate Countercurrent and Parallel Flow • Conduct experiment for both heat exchangers Calculations ● ● ● ● ● ● Steady State Energy Balance Overall Heat Transfer Coefficient Reynolds Number & Prandtl Number Wilson Plot Heat Exchanger Efficiency Film Heat Transfer Coefficient Data and Results Shell-and-Tube Heat Exchanger • Overall Heat Transfer Coefficients • Outside Film Heat Transfer Coefficients Data and Results Shell-and-Tube Heat Exchanger • Inside Film Heat Transfer Coefficients Data and Results Shell-and-Tube Heat Exchanger • Efficiency of Hot Stream • Efficiency of Cold Stream Data and Results Concentric-Tube Heat Exchanger • Overall Heat Transfer Coefficients • Outside Film Heat Transfer Coefficients Data and Results Concentric-Tube Heat Exchanger • Inside Film Heat Transfer Coefficients Data and Results Concentric-Tube Heat Exchanger • Efficiency of Hot Stream • Efficiency of Cold Stream Recommendations ● Prevent valve leaking ○ Replace O-rings ● Exchanger Design ○ Different number of tubes Questions Are there any questions?
