Spatial total site heat integration considering energy losses

Abstract

Energy Efficiency has been a research-intensive topic for almost four decades, initially driven by the expense of fossil fuels and then by environmental concerns. As one of the largest energy consumers, the industrial sector, particularly the process industry, has become the focus of energy efficiency research. Process Integration utilising Pinch Analysis plays a crucial role in improving the profitability and sustainability of industrial operations. Total Site Heat Integration (TSHI) is one of the primary branches of Process Integration based on Pinch Analysis, an industrial energy-saving method across individual process boundaries. However, the issue of plant layout has not been well addressed in the current Total Site (TS) targeting approaches. In this research, the Spatial Utility Problem Table Algorithm (SUPTA) is applied to the TSHI targeting methodology to account for the logistics of the process plants as well as the pressure drop, and heat losses caused by the effect of plant layout to achieve more accurate results that more accurately represent the actual plant situation. This enhanced tool can aid the designer in designing a Total Site Utility System that considers a new system's operational and capital costs by factoring in energy losses. A case study is performed to compare the maximum insulation (without energy losses) and conventional insulation with boiler condition adjustment (with energy losses). The result shows that the simple payback period has not significant difference at about 3 - 4 y, however, the scenario with maximal insulation has generally 3 times higher annual energy saving. The location of the utility plant is also found to be very significant in the TS utility system design, the results show that the simple payback period differs by 20 % when the utility plant is assumed at the middle of the industrial zone.