Abstract:
To date supertargeting which is the industrial software available for targeting,
designing and simulation of heat recovery network has only been able to trade off
energy and capital ahead of designing and to give optimum minimum driving force
(Atj^jn opt). The new targeting method suggested in this work identifies different heat
transfer conditions such as boiling, condensation and sensible heat transfer in the heat
recovery network and explores all the feasible stream shifting schemes to identify an
alternative optimum for the given energy consumption.
As an outcome, new graphical tools to screen and scope the design options at the
targeting stage are introduced. It identifies ±e different optima for the different
process heat recovery levels instead of identifying single optima for the entire heat
recovery network. This leads to the new range targeting procedure. New insight can
then be used to utilise the capital cost of the process in an economical manner. If the
energy requirement is a constraint, new method suggests the range of area that can be
best utilised to achieve the given energy consumption.
The newly developed tools are built on the combined thermodynamic and
mathematical programming approaches. Following the judgement on the optimal
individual stream contributions and minimum capital at the targeting stage, the initial
network structure obtained from the mathematical optimisation is next subjected to
non linear cost optimisation which gives the optimum design parameters for final
design. The effectiveness of the new method has been demonstrated by the case study
solved.
