96/01890 An integrated CHP and desalination plant

CHP (combined heat and power) retrofit for a large MED-TVC (multiple effect distillation along with thermal vapour compression) desalination plant: high efficiency assessment for different design options under the current legislative EU framework

Techno-economic assessment of a hybrid RO-MED desalination plant integrated with a solar CHP system

In this study, optimization of Qeshm power and water desalting cogeneration plant has been investigated. The objective functions are related to maximizing exergetic efficiency and minimization of exergoeconomic and exergoenvironmental parameters. Also, the integration of RO desalination with the existing plant has been evaluated based on these analyses. This plant includes two MAPNA 25 MW gas turbines, two heat recovery steam generators, and two MEDTVC desalination units. Thermodynamic modeling and simulation of the plant have been performed in MATLAB software. The thermodynamic simulation verified by Thermoflex software and plant data with high accuracy. Also, the computer code has been developed to perform exergetic, exergoeconomic and exergoenvironmental analysis. Multi-Objective Genetic Algorithm (MOGA) has been applied to find optimum objective functions and decision variables based on exergetic, exergoeconomic and exergoenvironmental parameters. Results show that in the optimum plant overall exergetic efficiency of the plant has been increased by 27.78%, and total exergetic cost and total exergoenvironmental impacts have been decreased by 0.93% and by 0.89%.

Flaring of gas often having high heating value results in considerable economic and energy losses in addition to significant environmental impacts. Power generation through combined gas and steam turbine cycles may be considered as a suitable flare gas recovery process. Thermal sea-water desalination is a process that requires a considerable amount of heat; hence it may be used in downstream of power generation cycles. Energy is the largest section of the water generation cost of all desalination processes. The energy cost of thermal distillation sea-water plants is close to 50-60% of water generation costs. In the current study, the generation of power and desalinated water through the gas turbine cycle, steam cycle, and multistage flash (MSF) method using flare gas of cheshmeh khosh are investigated. The economic parameters related to the different scenarios considered for the production of power and water are evaluated in the current research. According to the economic evaluation carried out, the most economically profitable scenarios for the investigated co-generation plant is generating as much as possible power in the steam turbine and using the remaining heat in the low-pressure outlet steam in the MSF desalination process. The results show that by increasing steam turbine outlet pressure from 3 bar to 78 bar, power and water generation is changed from 697 to 581 MW and 1557 to 2109 m3/h, respectively. Also, by increasing the outlet pressure of the steam turbine from 3 to 78 bar, the total capital cost is changed from 1177 to 1192 MUSD, and the operating cost is changed from 117.85 to 117 MUSD/year. Finally, operating profit will decrease from 300 to 50 MUSD/year, and payback time will change from 3.92 to 4.75 years.

Nuclear cogeneration projects where apart from electricity, valuable products like desalinated and purified water, hydrogen and oxygen gases from electrolysis of the water are produced are capable of providing water and energy security in developing and developed nations. They can also potentially become sources of additional revenue for the power plant operators. A simple approach using energy and economics data from published literature is used in this work to develop a model and a parametric search based solution algorithm by which the optimal dispatch of a given quantity of energy to the various co-located or cogeneration plants from a typical nuclear power reactor in India can be determined. The objective function for optimization is chosen to be the overall benefit to cost ratio of the cogeneration projects. The effect of energy cost, plant capital cost and target revenue from each product on the optimal fractions of energy to be provided to each plant is also studied.

Desalination of sea water through thermal and membrane based techniques and production of hydrogen through low temperature water electrolysis at facilities co-located with nuclear power plants are two areas identified for deploying co-generation projects in India in the near term. Nuclear desalination meets the requirements of clean drinking water in and around the nuclear facility, as well as to the in-house demand for high purity water for steam generation and other processes like hydrogen generation, coupled to it. Nuclear assisted hydrogen production also provides means to generate and distribute clean hydrogen which is envisaged as an important component of the decarbonized energy system of the near future. Currently the technologies for indigenous design, manufacture and quality assurance of desalination and medium scale compact water electrolysis plants are commensurate with the 220 MW(e) PHWRs presently operating in India. This work provides an overview of the research, development and deployment work carried out in these two areas in India, analyses the applicability of the IAEA Milestones Approach to nuclear cogeneration projects and discusses the problems and prospects of setting up and integrating more such facilities all over the country.

With the ever-growing frequency of natural catastrophe occurrences such as hurricanes, floods, earthquakes, etc., the idea of resilient microgrids (MGs) has attracted more attention than before. Providing the opportunity for a multi-carrier energy supply after a natural catastrophe can lessen power losses and improve power resiliency and reliability. Critical loads within the MG can be prioritized and restored in the shortest possible time based on the condition of the network after the damaging occurrence by considering the energy hub (EH) systems and the optimum design and allocation of these multi-carrier systems. To this end, this paper aims to address the resilience framework in MGs considering sets of water and EHs (WEHs) consisting of CHP (combined heat and power), a boiler, energy storage, and a desalination unit. This study focused on considering an effective resilient scheme to restore critical loads in a short period after a natural catastrophe when the MG experiences an unpredictable event. By applying the idea of WEHs, there would be a chance of restoring the system by using two sets of WEH systems in the appropriate islanded points to restore the system and critical loads of electricity, heat, and water. For this purpose, different scenarios were considered for assessing the resiliency of the system against a natural catastrophic event that causes serious damage to the network by analyzing the energy-not-supplied (ENS) factor. Moreover, the allocated WEHs can adequately supply the electrical, water, and thermal demand loads throughout the day after the natural catastrophe. To mitigate the unforeseen variations in the renewable sources, a battery is located in the WEH, which can attend to the optimal scheduling effectively. A scenario-based method is also introduced to improve the resiliency of MGs in an uncertain environment such as electrical, heat, and water stochastic demands. The appropriate efficiency of the offered model was considered on a modified IEEE test system.

In a non-interconnected area, a water-energy microgrid with distributed energy (e.g., solar panels, wind turbines, combined heat power, generators, batteries) and water resources (e.g., desalination plant, atmospheric water generator, water storage tank) could serve the demand of a discrete geographic footprint (i.e., a small town). This paper proposes an optimal management model of this type of microgrids under the minimum operation cost goal. The mathematical formulation is presented in detail, which involves constraints related to the operation of the system over a time horizon of a week. The proposed model is validated using an estimation of the water-energy demand of a generic small town located in La Guajira Department of Colombia, which is known as Ranchería. The numerical results show the effectiveness of the management model under four study cases.

An integrated CHP and desalination plant

Nowadays, several technologies for desalination processes are available and widely employed. However, they consume a considerable amount of energy and involve high capital and operating costs. Therefore, the techno-economic analysis of a system coupling different energy sources with the desalination processes is of value. The possibility of coupling a small gas turbine combined heat and power system (GT CHP) with hybrid desalination plants (HDPs) has been assessed in this study. The proposed gas turbine power generation system, based on a single-stage centrifugal compressor and an uncooled centripetal turbine, provides design simplicity and reasonable installation costs for the power generating plant. The hybrid desalination technique, based on the use of two different desalination technologies, i.e., Reverse Osmosis (RO) and a thermal desalination process, has been chosen to better exploit the electrical and thermal energy produced by the mini CHP plant. The proposed solution is numerically investigated from both thermodynamic and economic points of view, and the results of the thermodynamic analysis of the cycle are used as input for the evaluation of the amount of freshwater produced and of costs. The economic assessment of standalone desalination systems is also shown for the comparison with the hybrid solutions here proposed. Results show that the total cost of the water produced by MED + RO was less than the total cost of the water obtained by MSF + RO, and that the energy cost of MED + RO hybrid desalination system was about 15% less than that for stand-alone RO desalination technology. Thus, the MED + RO hybrid desalination system can be considered a promising solution for the coupling with the proposed mini GT CHP plant, which, due to the small size and cost, as well as the easy installation, can be easily applied in off-grid or remote areas.

Geothermal source potential for water desalination – Current status and future perspective

Chapter 4 - Geothermal Source for Water Desalination—Challenges and Opportunities

The global call for an environmentally friendly, sustainable, and reliable energy system looks for the optimal integration of different technologies to allow a smooth and economically viable transition towards electrification. In this context, small, medium, and large industrial processes are relevant contributors to global CO2 emissions production due to the simultaneous requirement of electricity, heating, and cooling power generally obtained through fossil fuel combustion. In this context, Combined Heat and Power Energy converters based on internal combustion engines, such as reciprocating engines, gas turbines, and gas turbine combined cycles, and external combustion, such as backpressure and condensing steam power plants, are the most suitable solutions for the efficient and reliable generation of the above-mentioned assets. Typically, the industrial demand for heat and electricity differs in terms of heat-to-power ratio when compared to the heat-to-power ratio of the CHP plant, and this has led to requiring the selection of a control strategy to follow, partially or fully, the heat load or the electric load. In this paper, the authors propose an operating and design strategy addressed to fully covering the heat load demands by the heat generated by the CHP, allowing the system to have an excess of electricity generated. This electricity can be used for different purposes, as regards the novel electrification roadmap. Indeed, the authors have explored four configurations in which the excess of the CHP-generated electricity can be exported to the national grid, used for high-tension fast-charging electromobility systems, for running reverse osmosis desalination plants, and for the production of alternative fuels such as hydrogen. The authors propose a methodology for providing an extensive environmental techno-economic assessment that looks at 2050 CO2 targets. Accordingly, the environmental techno-economic assessment results are presented and discussed by considering the Net Present Value, payback period, and CO2 emission savings.