Introducing a hybrid renewable energy system for production of power and fresh water using parabolic trough solar collectors and LNG cold energy recovery
Introduction
In the past, using fossil fuels and groundwater resources, two major problems of water crisis and energy crisis were solved, but today, with reduced groundwater resources and increased carbon dioxide levels, humans are forced to use renewable energies [1,2]. One of the ways to reduce carbon dioxide in the plant is to use the flat-plate solar collectors instead of fossil fuels in boilers [3,4]. In recent years, numerous studies have been carried out for cogeneration of power and fresh water. Javidmehr et al. [5] used an air storage system, flat-plate solar collectors, gas turbines, ORC, and Multi effect desalination for cogeneration of power and fresh water. This integrated structure has a thermal efficiency of 65.2% and exergy efficiency of 41.67%. Pouyfaucon et al. [6] examined the water desalination technology using solar collectors to identify the key parameters for market supply. The integrated structures of fresh water generation were investigated using parabolic collectors, parabolic trough solar collectors, ORC, RO water desalination, PV/RO water desalination, PTC/MED. Ahmadi et al. [7] developed an integrated structure of cogeneration of power using solar dish collectors and Stirling. The economic analysis and NSGA-II optimization algorithm were used to examine the developed integrated structure. Mehrpooya et al. [8] used a parabolic collector to provide the heat of integrated structures of power generation. They showed that the use of nanoparticles as the heat carrier fluid in the collector increases the efficiency of the power plant. Loni et al. [9] focused on the numerical modeling of a flat-plate solar collector with different nanofluids as a working fluid of the solar system. The results of the modeling showed that with an increase in concentration of nanoparticles, the thermal efficiency of the flat-plate solar collector is reduced and the exergy efficiency is increased. Mohammadi et al. [10] developed a gas-turbine hybrid system, ORC, and absorption system for the generation of power, heat, and refrigeration in the building. This integrated structure with an efficiency of 67.6% is capable of generating 30 kW and 8 kW power and 7.2 tons of hot water. Argun et al. [11] developed an integrated structure of flat-plate collectors and solar dish collectors for the generation of fresh water. The thermal efficiency of the water desalination is varied from 23 to 57% over the year. This integrated structure can at maximum generate the fresh water by 1038 ml/m2h in the fall and 1402 ml/m2h in the summer. The investment return period is 3 years and the prime cost of the product (PC) is 0.018 US$/Litre. Alfellag et al. [12] developed a suitable method to calculate solar radiation at different times of the year. Furthermore, using the laboratory model and numerical model, the solar parabolic collector was analyzed and examined. They showed that the amount of thermal efficiency and useful energy absorbed by the system are the highest possible value in hot hours of the year.
Ansari et al. [13] developed an integrated structure of a steam power plant by multi effect desalination. The input fuel providing the heat of the boiler in this power plant is an atomic fuel of 1000 MW. This integrated structure is capable of generating fresh water by 24000 ton/day. Also, for this 7-stage water desalination, the GOR is equal to 8.81. Meratizaman et al. [14,15] presented several integrated structures for power and heat generation of heavy fuel oil gasification to be used in the fuel cell and multi effect desalination. The sensitivity analysis, exergy analysis, and economic analysis were used to evaluate this developed integrated structure. Ghorbani et al. [16] developed a cogeneration system of fresh water, carbon dioxide separation, power generation, and LNG. This integrated structure consists of the combustion process with pure oxygen, multi effect desalination, two-stage LNG cycle (pre-cooling by absorption refrigeration system and liquefaction by mixed refrigerant). The period of return is 2.87 years and the exergy efficiency of the integrated structure is 62.33%. Mehrpooya et al. [17] developed an integrated structure of cogeneration of power, refrigeration, and fresh water using flat-plate solar collectors. This integrated structure has a total exergy efficiency of 66.05% and a total thermal efficiency of 80.7%. The economic analysis of the integrated structure by the annualized cost of system method shows that the period of return is 5.738 years. Mehrpooya et al. [18] dynamically developed a new integrated structure of power generation using solar collectors at various times of the day. The total exergy efficiency and electrical efficiency of the power cycle are 38.7% and 47%, respectively. Ansarinasab et al. [19] developed an integrated structure of power generation using molten carbonate fuel cell, Stirling engine, and gas turbine. The economic analysis and advanced exergy analysis have been used to investigate the second law of thermodynamics and evaluate the developed integrated structure. The re-gasification operation is used in the power cogeneration cycles. Mehrpooya et al. [20] analyzed the exergy of an integrated structure of power generation using the re-gasification operation in the condenser. The exergy efficiency and exergy destruction rate in this process are 59.4% and 159.60 MW, respectively. Ashouri et al. [21] used parabolic trough solar collectors to replace the heat source of the Kalina power generation cycle. In this integrated structure, 36800 kg of fuel is annually saved by replacing the parabolic trough solar collectors. The highest rate of exergy destruction occurs in this integrated structure in the parabolic collector. Besides, to supply cooling in the integrated cycles of air separation and power generation with pure oxygen, the re-gasification operation is used. In these papers, HYSYS software was used to simulate an integrated structure [22,23]. Ahmadi et al. [24] used the solar collectors instead of boiler in the Isfahan power plant. Using solar collectors instead of natural gas in the boiler, the exergy efficiency is increased and the power and carbon dioxide generated in the steam plant is decreased. Khoshgoftarmanesh et al. [25] developed an MSF water desalination coupled with Bushehr power plant with a capacity of 3000 MW. The exergy analysis and economic exergy analysis were used to evaluate the developed integrated structure. Habibi et al. [[25], [26], [27]] developed a new power generation. In order to supply the input heat, an integrated structure of parabolic trough solar collectors, and to supply the condenser cooling of the power cycle, the re-gasification operations have been used. Tomkow [20,28] investigated the new methods for power production using re-gasification operations. The new improvement is proposed for an absorption power cycle by coupling it with an organic Rankine cycle. In this paper, an integrated structure of cogeneration of fresh water and power has been developed hourly over a year using a multi effect desalination and organic Rankine cycle in the climatic conditions of Tehran. In order to provide the heat input to the integrated structure and condenser cooling of the organic Rankine cycle, the parabolic trough solar collectors, boiler and re-gasification auxiliary operation have been used, respectively.
Section snippets
Cycle description & configurations
In this study, in order to calculate the equilibrium of steam and liquid phases and to predict the enthalpy and entropy, the Peng-Robinson state equation is used. In order to simulate the integrated structure, the HYSYS, TRNSYS, and MATLAB have been used. The integrated structure of the cogeneration of power and fresh water has been developed in Tehran with a hot and dry climate. The city of Tehran is located at 51° 6 min to 51° and 38 min east longitude and 35° and 34 min to 35° and 51 min
Exergy analysis
The exergy of an energy source is the highest amount of work that can be achieved when the source reaches the dead state from its specified thermodynamic state during a process. The dead state is, in fact, the same as environmental conditions, usually considered as the temperature of 25 °C and pressure of 1 atm [41]. In the absence of kinetic, potential, nuclear, electrical, and magnetic energies, and the surface tensile effects, the total exergy rate of the system can be considered as the sum
Examining first law of thermodynamics
The temperature-entropy and pressure-enthalpy diagrams for cycle 100 of the organic Rankine cycle have been shown in Fig. 4. In this diagram, the variations in entropy and enthalpy of propane single-component refrigerant are shown in terms of temperature and pressure along the path, and the deviation from the ideal state is determined. Deviation from the ideal state is directly related to the irreversibilities in the process. All of the real refrigeration cycles have some kind of
Sensitivity analysis of the developed integrated structure
The appropriate system modeling is subject to the identification of the key parameters of the system and an accurate understanding of the system behavior in response to their variations. The sensitivity analysis, while identifying key and sensitive parameters of integrated structure, examines their regular behavior and continuity, which is one of the methods for verifying the proper design of process structures. Fig. 12 demonstrates the hourly variations in exergy destruction and the exergy
Economic analysis
Annualized cost of system is selected for the economic evaluation of the integrated structure. In this method, all costs of a system are calculated over its estimated lifetime. The costs involve the annualized costs of capital, replacement, maintenance, and operating. Marshal and Swift cost index is used to update the price equations.
Table 11, Table 12 present the cost functions of the equipment and the process of
Conclusion
In this paper, the solar parabolic collectors are used to provide the heat of organic Rankine cycle and multi-stage thermal water desalination system. Moreover, to provide the refrigeration of the power generation cycle of 3164 MW, the re-gasification operation is used. This integrated structure has used 225201 solar parabolic collectors on a particular day (June 29th) in Tehran for generating the power of 459.9 MW and water desalination of 3628 kgmol/h. In this paper, the level of received
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References (67)
Thermodynamic analysis and multi objective optimization of performance of solar dish Stirling engine by the centrality of entransy and entropy generation
Int. J. Electr. Power Energy Syst.
(2016)- et al.
Integrated power generation cycle (Kalina cycle) with auxiliary heater and PCM energy storage
Energy Convers. Manag.
(2018) - et al.
Introducing a hybrid photovoltaic-thermal collector, ejector refrigeration cycle and phase change material storage energy system (Energy, exergy and economic analysis)
Int. J. Refrig.
(2019) - et al.
Thermodynamic and economic analyses and optimization of a multi-generation system composed by a compressed air storage, solar dish collector, micro gas turbine, organic Rankine cycle, and desalination system
Energy Convers. Manag.
(2018) - et al.
Solar thermal-powered desalination: a viable solution for a potential market
Desalination
(2018) Thermo-economic multi-objective optimization of solar dish-Stirling engine by implementing evolutionary algorithm
Energy Convers. Manag.
(2013)- et al.
Optical and thermal analysis of a parabolic trough solar collector for production of thermal energy in different climates in Iran with comparison between the conventional nanofluids
J. Clean. Prod.
(2018) Thermodynamic analysis of a solar dish receiver using different nanofluids
Energy
(2017)Thermodynamic analysis of a combined gas turbine, ORC cycle and absorption refrigeration for a CCHP system
Appl. Therm. Eng.
(2017)- et al.
Thermoeconomic optimization of a hybrid pressurized water reactor (PWR) power plant coupled to a multi effect distillation desalination system with thermo-vapor compressor (MED-TVC)
Energy
(2010)