Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Cogeneration of Electricity and Water using a Small PWR of 75 MWth coupled to a DCMD Desalination System with Heat Recovery
Submission Author:
Paulo Augusto Berquo de Sampaio , RJ , Brazil
Co-Authors:
Paulo Augusto Berquo de Sampaio, LUIZ FLAVIO ALVES, Maria de Lourdes Moreira
Presenter: Paulo Augusto Berquo de Sampaio
doi://10.26678/ABCM.ENCIT2022.CIT22-0697
Abstract
Fresh water scarcity is a concerning issue in a world facing rapidly growing population. The development of desalination technologies can help to mitigate the problem by means of producing fresh water from seawater. Multistage Flashing (MSF), Multi-Effect Distillation (MED) and Reverse Osmosis (RO) are the state-of-the-art technologies for desalination. In recent years, though, Membrane Distillation (MD) is emerging as a desalination technology which is becoming increasingly attractive for its adequacy to use low-grade waste heat or renewable energy sources. There are also some specific advantages regarding the use of MD. Essentially, no additives are needed to prevent fouling of the MD module, in contrast with RO technology. Besides, as MD produces less than 10% of the feed stream as distillate in a single pass system, the environmental impact of a brine discharge directly to the sea can, in most cases, be considered low or negligible. In this work we consider the use of a small PWR of 75 MWth for cogeneration of water and electricity. The nuclear power plant is coupled to a Direct Contact Membrane Distillation (DCMD) desalination plant with heat recovery. Part of the external heat used in the process is waste heat from the power plant, as the desalination plant collects warm seawater from the power plant condenser instead of taking water directly from the sea. The program DE-TOP of the IAEA is used to simulate the secondary system of the small PWR. Furthermore, DE-TOP also allows the selection of the points of steam extraction from the nuclear power plant secondary system. These steam extractions, taken at the low pressure turbines, after the steam has done most of its mechanical work, provide the additional heating required by the DCMD desalination plant. The performance of the desalination plant is simulated using the Desal_Plant program developed at IEN/CNEN, which adopts a multiscale approach, combining modelling of mass and heat transfer across hollow fibre membranes, plus balances of mass and energy at the level of a DCMD module, and thermodynamic analysis of the whole desalination plant with heat recovery. Our computational simulations indicate that the 75 MWth nuclear power plant, in cogeneration of electricity and water, can provide 24.80 MWe of electricity simultaneously with 1502.4 m3/day of fresh water, compared with the 25.41 MWe production of the reference nuclear power plant dedicated exclusively to electricity production.
Keywords
nuclear desalination, small modular reactors, Reactor Technology
