Page 222 - Sustainability in the Process Industry Integration and Optimization

S o f t wa r e T o o l s 199

FIGURE 9.5 Refrigeration composition options and ideal composition profi les
(WORK user interface).

heat loads and temperature levels can be optimized relative to the
background process in order to minimize overall shaftwork.
Optimizing mixed-refrigerant systems: WORK can optimize the
composition of mixed refrigerants to minimize shaftwork
requirements. This goal is achieved by matching the composition of
the mixed refrigerant to the cooling profile (see Figure 9.5). The
software outputs a visual representation of the shaftwork losses in
refrigeration cycles, including both mechanical and thermal losses.

9.3.6 HEXTRAN
HEXTRAN is a steady-state simulator that provides a view of heat
transfer systems (IPS, 2009a). It is used to design new systems,
monitor current systems, optimize existing operations, and solve (or
prevent) heat transfer problems. The program simulates integrated
processes and allows engineers to monitor the performance of
individual exchangers or an entire heat transfer network. It also
offers superior postprocessing displays, plotting Grand Composite
Curves as well as the results from network targeting and zone
analysis. HEXTRAN provides new efficiencies in all types of design
and operational analysis work, such as individual exchanger and
network designs, Pinch Analysis, exchanger zone analysis, split
flows, area payout, and optimal cleaning cycles.
HEXTRAN analyzes factors that can make the difference between
profits and losses. These factors include: (1) improved process heat
transfer, product yield, and quality; (2) increased energy efficiency
and significantly reduced operating costs; (3) increased plant flexibility
and throughput; (4) optimized cleaning schedule for exchangers;
(5) optimal antifouling selection and usage; and (6) improved process
designs and revamps. The HEXTRAN simulator for process heat
transfer offers features that facilitate straightforward evaluations of
complex design, operational, and retrofit situations; in particular, it:
(1) enables the design of both simple and complex heat transfer
systems that result in cost-effective, flexible processes; (2) allows the