Simulation of Dynamics of Heat Exchangers

Dynamical response of a counter flow double pipe heat exchanger is studied. A
mathematical model is constructed by applying the energy and heat transfer
equations with some preliminary assumptions. The dynamic behavior of the heat
exchanger is approximated by solving the governing equations via numerical method
of solving and discretization. The numerical method applied is the forward finitedifference
scheme. Sets of explicit finite-difference equations were used to represent
fluid and wall temperature distributions. It is assumed that the temperature
distribution can be expressed by a combination of initial and final temperature
distributions and a determined time function. Transient response of the system is
considered for three cases which is step change, ramp change and exponential change
of shell side fluid inlet temperature. Transient response at different no. of transfer
units, NTU was tested. Comparison of results with the numerical solutions and
results of other researchers is done to ensure that the model is acceptable to be used.