Numerical pinch analysis for pressurised water reactor total site trigeneration system for continuous and batch processes

Abstract

The progressive development of industrialisation and rising of populations has led to the depletion of energy resources, global environmental pollution and climate changes. This challenges can be reduced by using trigeneration and total site systems. The trigeneration system is one of the innovations that can increase the performance of power systems by using waste energy for heating and cooling applications to meet the demand requirements. Total site system, on the other hand, is a technology that can integrate intra-processes of utility at multiple sites. However, the combination of trigeneration and total site systems has not yet been established. This work proposed a new methodology for developing an insight-based numerical pinch analysis methodology to simultaneously target the minimum cooling, heating and power requirements for continuous and batch processes of total site systems of the centralised trigeneration pressurised water reactor (PWR) system. The new proposed methodology is called trigeneration system cascade analysis (TriGenSCA). The procedure of TriGenSCA for the trigeneration PWR system in continuous processes of total site system consists of six steps which are data extraction, problem table algorithm (PTA), multiple utility problem table algorithm, total site problem table algorithm, TriGenSCA and trigeneration storage cascade table. Based on case study 1, the overall energy production, energy losses and equivalent annual cost of the optimal trigeneration PWR system are 122.6 GWh/day, 75.3 GWh/day and USD 400.0 M, respectively. As for the batch processes of total site system, additional of time slice as step 2 in case study 2 is proposed to show the batch processes of the total site system. The results found that the overall energy production, energy losses and equivalent annual cost for the optimal trigeneration PWR system are 9.0 GWh/day, 2.3 GWh/day and USD 367.5 M, respectively. This shows that energy production, energy losses and annual equivalent cost are reduced by 21.0%, 17.3% and 8.0%, respectively. Consideration of transmission energy losses while transferring the energy from the trigeneration PWR system to the demands were incorporated into the TriGenSCA methodology to improve the sizing utility in the system. The findings indicated that 1.0 MW of extra energy is required in 5.0 km of transmission lines. Additional step in a method which is called as trigeneration system sensitivity table is used to analyse the sensitivity of the centralised trigeneration PWR system if some of the industrial plants in the Total Site system are shut down. The results showed that additional 100.7 MW of hot water (HW) are needed if Plant C is shut down for continuous processes, whilst 12.6 MW of HW and 50.2 MW of cool water are required if Plant B and Plant C are shut down in batch processes.