Low
grade heat still widely exists in energy-intensive industrial
parks, although good energy integration has been accomplished for
individual processes or plants. Low grade heat is notably large but
difficult to utilize because of the limitation of heat transfer and
the scarcity of low grade heat sinks. Large scale utilization of low
grade heat is very challenging for energy-intensive industries or
industrial parks. A large scale low grade heat recovery, refrigeration,
and utilization network system is introduced in this study to improve
energy performance for industrial parks. In order to model the large
scale system, the system is decomposed into three levels: pipe networks,
refrigeration stations and absorption chillers. A mixed integer nonlinear
programming model is presented that considers mass and energy networks,
pipes, refrigeration stations, absorption chillers, and economic performance.
The mathematical model is applied to the optimization and economic
analysis for the low grade heat utilization in a petrochemical industrial
park in China. The model can be solved in available time using the
global solver. The solution results demonstrate the good economic
performance of the new low grade heat recovery, refrigeration, and
utilization network system for the industrial park.