اتصال حرارتی HTGRs و کارخانه های آب شیرین کن MED و عملکرد و هزینه تجزیه و تحلیل آن برای نمک زدایی هسته ای
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|23399||2012||6 صفحه PDF||سفارش دهید||5234 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Desalination, Volume 303, 1 October 2012, Pages 17–22
The nuclear desalination based on the high temperature gas-cooled reactor (HTGR) with gas turbomachinery and multi-effect distillation (MED) has been drawing attention, because it can utilize waste heat for desalination. In this paper, research objectives are as follows: (a) proposing an optimal design of HTGR + MED systems and (b) performance and cost analysis for the HTGR + MED system. In the first step, the KAIST coupling scheme was proposed. It uses printed circuit heat exchangers (PCHE) instead of conventional heat exchangers without any intermediate loop and has the independent structure between MED plants and heat sink. In the second step, the KAIST version of DEEP (K-DEEP) code was developed for more practical cost and performance analysis of the KAIST HTGR + MED system. The desalination performance and cost analysis with the K-DEEP code were performed for the Gas Turbine-Modular Helium cooled Reactor (GT-MHR) + MED system. The maximum desalted water production capacity increases by 258% compared to the production capacity using the previous coupling scheme. The desalted water cost could be reduced by 9.0%. Finally, from the comparison of various nuclear MED desalination systems we confirmed the potential of the KAIST HTGR + MED system that may be one of the best desalination options in mass production of desalted water.
Water crisis is one of the most serious problems that humans are facing. Desalination technologies are attractive and sustainable solutions for water crisis. Desalination processes can be divided by two categories: distillation processes and membrane processes. Recently a multi-effect distillation (MED) process in distillation processes and a reverse osmosis (RO) process in membrane processes are in the limelight because these processes can be improved further and their desalted water costs are commonly lower than water costs of other processes . Desalination processes need energy sources: heat or electricity. Nuclear energy, fossil energy, renewable energy can be candidates. If we consider global warming, low cost, and sustainability, nuclear can be one of the best energy options. Researches on nuclear desalination systems are very active because nuclear power plants can provide low cost, carbon free, and sustainable energy to desalination plants. Since the 1960s IAEA and several countries have carried out technical and economic feasibility studies for desalination technologies utilizing the nuclear energy and demonstration programs of nuclear desalination are in progress in several countries ,  and . There are various options in nuclear power plants and in desalination processes. Specially, we pay close attention to coupling MED plants and high temperature gas-cooled reactors (HTGRs) with gas turbomachinery. Because of thermodynamic reasons, there is unavoidable waste heat in all nuclear power plant systems, so researchers have tried to utilize the waste heat for other purposes. Desalination is one of the options. In the case of light water reactors (LWRs), the temperature ranges of the waste heat are too low to utilize for desalination, so in order to get enough temperature ranges of the waste heat, modification of thermodynamic conditions and a significant decrease of electrical power are inevitable . Fortunately, however, in the case of HTGRs, the temperature ranges of the waste heat are ideal for desalination, and so modification of the existing thermodynamic conditions is not needed and there is no penalty. Free heat can be utilized for desalination processes. From literature survey, we could find a Desalination Economic Evaluation Program (DEEP) developed by the International Atomic Energy Agency (IAEA) ,  and . The DEEP is the software linked Microsoft Excel spreadsheets and for estimating the desalination performances and costs for various alternative energy and desalination process configurations. Dardour et al.  selected the coupling scheme of HTGR + MED systems used in both EURODESAL and TUNDESAL projects  and . At that time, actual versions of DEEP did not have models for HTGR + MED systems, and so they developed the models from basic thermodynamic considerations and integrated them in the new, CEA version of the DEEP code. However utilization of waste heat from HTGRs is limited to only 23% due to characteristics of their HTGR + MED coupling scheme. KAIST is conducting the research on the WHEN (Water-Hydrogen-Electricity Nuclear gas-cooled reactor) system that is an integrated system based on the nuclear power system coupled with desalination and hydrogen generation systems. The WHEN system is based on high temperature gas-cooled reactors (HTGRs) which have passive safety features and generates power through gas turbomachinery. The WHEN system utilizes electricity and waste heat from a power conversion system for producing fresh water through a desalination system. A hydrogen production system produces hydrogen by receiving the high temperature heat produced by HTGRs and/or the electricity produced by an electric generator. This study focused on the thermal coupling of HTGRs and thermal desalination systems which utilize the waste heat. Research objectives are as follows: 1) Proposing an optimal design of HTGR + MED systems 2) Safety, performance, and cost analysis for the HTGR + MED systems There are three steps for achieving the research objectives. The first step is a design step of HTGR + MED systems based on understanding for each of them: HTGRs and MED desalination plants. In this step, the previous design for HTGR + MED systems was improved in the aspects of safety, performance, and cost. The second step is developing a KAIST Desalination Economical Evaluation Program (K-DEEP) code reflecting the coupling scheme proposed in the first step and evaluating the performance and cost of desalted water production. In this step, on-design performance value of HTGRs is used as HTGRs performance input data of the K-DEEP code. The third step is to analyze the safety and performance of HTGRs due to failures or accidents of desalination plants coupled with the HTGRs. For transient analysis, the GAMMA-T (GAs Multidimensional Multicomponent mixture Analysis–Turbomachinery) code is used, which was developed for transient analysis of an HTGR with an emphasis on a gas turbine through a two-dimensional approach  and . This paper is focused on the first and second research steps.