Locating exchangers in an EIP-wide heat integration network

- Multi-plant multi-enterprise collaborative heat integration in an eco-industrial park.
- Simultaneous intra-plant and inter-plant direct heat integration.
- Heat exchangers distributed at plants and centralized sites.
- Accounting of ambient heat losses/gains and piping, exchanger, and pumping costs.

Inter-plant heat integration offers an energy-saving opportunity in eco-industrial parks (EIPs) beyond the traditional intra-plant integration. The economic feasibility of this integration depends critically on the locations of heat exchangers. In this work, we generalize our previous study on centralized HENS (Heat Exchanger Network Synthesis) for EIPs to allow exchangers to be located at either plant or central sites facilitating both intra-plant and inter-plant heat integration in a seamless manner. We propose a mixed integer non-linear programming (MINLP) model that synthesizes a maximum-NPV (Net Present Value) EIP-wide HEN, while accounting for all the capital (e.g. heat exchangers, pumps, and pipelines) and operating (pumping costs, utility savings) cash flows along with the ambient heat gains/losses during transports. The model is tested on five examples from the literature and gives better HENs compared to the previous results. This work highlights and quantifies the impact of heat exchanger locations in an EIP-wide HEN.