Novel parabolic trough solar collector and solar photovoltaic/thermal hybrid system for multi-generational systems
Introduction
Novel concepts in energy saving, pollution reduction, environmental protection, in-situ energy supply, and comprehensive utilization have been rapidly emerging in the last decade and attracting global attention. One of the promising solutions is the usage of renewable energy-based multi-generational systems. Multi-generational energy systems are characterized by the integration of various processes and systems, which can be used either in a single input energy system or multiple systems [1]. The idea of integrating such energy systems for multi-generational purposes is relatively new [2]. These multi-generational systems fulfil vital demands for various residential applications and domestic needs, which can be cooling, space heating, and drying, fresh water production, and electric power [3]. This integration of renewable energy resources can also be utilized for desalination of sea water for drinking purposes [4]. In addition, hydrogen gas or liquefied hydrogen, which is produced in these systems, is one of the most important and useful assets that can be utilized as a direct fuel [5]. It can also be utilized as an energy storage medium or catalyst for various processes, such as Haber’s process and hydrogenation of fats. Some closely related research on multi-generational systems has been carried out in the past, keeping in view the vital energy concerns and environmental apprehensions. A solar and geothermal hybrid system was proposed by Song et al. [6]. A mathematical model was developed for the efficiency of the collector, as well as the temperature of the heat transfer oil on the basis of heat transfer characteristics of the parabolic trough solar collector (PTSC). A solar-geothermal energy coupled organic Rankine cycle (ORC) power generation experimental platform was also established. The theoretically and experimentally evaluated maximum efficiencies were 55.3% and 53.2%, respectively. However, for the geothermal based systems, the requirements of finding potential sites, extensive land surveying, high installation costs, depletion of resources with respect to time, and transportation losses were all possible drawbacks. Yuan et al. [7] and Yilmaz et al. [8] investigated ocean thermal energy conversion (OTEC) for multi-generational applications. OTEC technology has been tested only on a small-scale; as of now, large-scale energy production plans are not feasible or financially viable. A novel solar and wind-based hybrid system was structured by Zhang et al. [9] for power production and cooling applications. They also performed system modeling and output optimization. However, wind is an unreliable continuous source of energy, hard to store, and furthermore, suffers from a paucity of potential sites.
In contrast, researchers have been more interested in exploiting the solar-based multi-generational systems. An early study by Omer and Infield [10] analyzed the thermal performance of dual stage solar energy concentrators comprising a PTSC and a compound parabolic concentrator for heat and electricity generation. Ozturk and Dincer [11] structured a solar-based multi-generational system with power, cooling, heating, and hydrogen production with an exergy efficiency of 57.35%. An analysis indicated that parabolic dish collectors have the highest exergy destruction rate among the constituent parts of the system, owing to high temperature variance between the working fluid and the collector receivers. Han et al. [12] proposed a combined solar heat and power plant and its parametric analysis showed that these energy-benign resources can be utilized for various useful applications, such as building heating, cooling, and power production with an improved system exergy efficiency of approximately 30%. Earlier studies have proposed that the system efficiency could be improved by employing advanced design models and components. Yuksel et al. [13] designed a PTSC-based multi-generational system, which comprised a proton exchange membrane (PEM) electrolyzer for hydrogen production, a two-stage ORC for power generation, and a quadruple-effect absorption cooling system for cooling applications. Their analysis indicated that the largest exergy destruction occurred across the PTSC, PEM electrolyzer, and turbine. Most recently Yilmaz et al. [14] proposed a solar-based system with a PEM electrolyzer as well, which had overall system energy and exergy efficiencies of 48.19% and 43.57%, respectively. El-Emam and Dincer [15] structured a solar heliostat-based multi-generational system with a hydrogen production rate of 1.25 kg/h, which could be utilized for further domestic and industrial purposes. Modi et al. [16] conducted an extensive review on solar energy-based heat and power generation systems with PTSC as an important part of the solar multi-generational systems. They concluded that improving the collector models and reflector geometry could improve the heat transfer rate exponentially, aided by a higher effective heat transfer efficiency of the collector. In a review article by Kasaeian et al. [17] on solar energy-based heat and power generation systems, the authors pointed out that PTSCs were the best performing collectors among all the solar thermal collectors. They also proposed that the key to enhancing the solar energy conversion is to improve the solar collector’s performance by optimizing the collector geometry, switching the working fluid, and selecting a suitable material for the absorber tube.
Compared to the PTSC systems, the solar photovoltaic/thermal (PV/T) collector systems have the capability of converting solar irradiation into thermal and electrical energy simultaneously. The dual capabilities make it more adaptable, cost-effective, and hence attractive for applications. Water or air is normally applied as the cooling fluid for the collector panels. Hazi et al. [18] presented a numerical study based on the energy efficiency of a water-based PV/T system in an industrial application. Xu and Ortmanns [19] presented a new class of rectifiers and clarified that the cell temperatures in both solar PV/T and PV collector systems were an important factor, when considering the performance of the panels. Tiwari et al. [20] presented an analytical expression for the temperature-dependent electrical efficiency of N-PV/T water collectors, connected in series. Tsai et al. [21] enhanced the thermal efficiency of a novel PV/T air collector by proposing a reciprocal aid. Yazdanpanahi et al. [22] experimentally evaluated the exergetic efficiency of a water-based solar PV/T collector. A review on hybrid solar PV/T systems was conducted by Charalambous et al. [23] and concluded that higher efficiency can be achieved by reducing the back surface temperature of the panels and utilizing better cooling fluid for thermal panels. Bianchini et al. [24] experimentally proved that using a hybrid PV/T collector system for useful purposes is more sustainable and economically viable as compared to utilizing a standalone solar PV system. Al-Waeli et al. [25] concluded that for future energy and preheating applications, the solar PV/T air heating systems are more promising than the standalone PV systems.
In addition to the PTSC and PV/T systems, small plants based on ORC are frequently coupled in multi-generational systems. Karellas and Braimakis [26] performed an energy–exergy analysis and economic investigation of a Rankine-vapor compression cycle-based hybrid system, utilizing biomass fuel and solar power, and obtained nominal energy and exergy efficiencies of 5.54% and 7.56%, respectively. This hybrid system, in spite of having a low efficiency, can be utilized for multiple applications. A numerical model was presented by Potenza et al. [27] for a co-generation system integrated with an ORC system for both hot water and power production. Rady et al. [28] suggested a conceptual design of a small-scale multi-generation concentrated solar plant for a medical center in Egypt. They discovered that the operating hours of the ORC system and the thermally driven absorption chiller could be reduced by approximately 50% and 30%, respectively, by using linear Fresnel reflector solar collectors. Borunda et al. [29] analyzed a concentrated solar power plant integrated with an ORC unit for industrial processes in Spain and demonstrated the commercial usage potential of such hybrid systems. Islam and Dincer [30] proposed a new solar-based system with a dual ORC system, with which an overall exergy efficiency of 62% was achieved. Based on the above-mentioned studies, it should be noted that selecting a proper working fluid for the ORC definitely would lead to an increase in the efficiency, in light of the cycle operating temperature.
In summary, extensive research and innovation have been applied to the advancement of renewable energy-based multi-generational systems. Although integration of multiple types of renewable energy improves the versatility of the system, it also significantly increases the system complexity from a practical stand point. It would be much simpler if one standalone input energy source satisfies the requirement of the end applications. Solar energy is considered as the most favorable one to fulfill the demand; however, its intermittent nature should be considered. Since hydrogen has been recognized as one of the most promising green energy carriers, the multi-generational systems are suggested to place additional emphasis on hydrogen production, particularly with the aim of producing hydrogen much more efficiently, while simultaneously minimizing emissions to the environment. In the present study, a novel PTSC and solar PV/T based hybrid multi-generational system is proposed for electricity generation, space heating purposes, cooling, fresh water production, and hydrogen production. The structure comprises mature technologies that enhance the feasibility of the system. The objectives of the current study are as follows:
- •
Conduct a comprehensive energy efficiency assessment of the proposed hybrid renewable energy-based multi-generational system (first law of thermodynamics).
- •
Identify the exergy flow rates of all the streams and evaluate the rates of exergy destruction, rates of exergy loss, and exergetic efficiencies of the overall system, subsystems, and individual components (second law of thermodynamics).
- •
Study the effects of design parameters on the performance and operation of the hybrid system.
Section snippets
System description
A schematic of a cohesive PTSC and PV/T collector multi-generation system is shown in Fig. 1. The system acts as a single generation system when the electric power output is considered and becomes a cogeneration system when cooling is added. When heating is included, it behaves as a tri-generation system. Furthermore, the addition of hydrogen and oxygen gases, and fresh water to the system enables it to become a multi-generation system. The designed structure mainly consists of essential
Thermodynamic analysis
For the proposed multi-generational system, energetic and exergetic analyses have been carried out to deliver information regarding the performance of the system, in terms of efficiency and the exergy destruction rates. Valid and feasible assumptions made for the hybrid energy system are as follows:
- •
The ambient conditions are set to be the following: temperature T0 = 298 K and pressure P0 = 100 kPa.
- •
Steady flow devices are used and the processes are steady state.
- •
The working fluid of the ORC is
Results and discussion
In this section, detailed energetic and exergetic analyses are presented for the multi-generational renewable energy system. In this system the values of temperature (K), pressure (kPa), specific enthalpy (kJ/kg), mass flow rate (kg/s), specific exergy (kJ/kg), and entropy (kJ/kg K), determined for each individual state are provided in Table 3. A detailed analysis was conducted, and the thermodynamic values were evaluated using the Engineering Equation Solver (EES®) software by Klein (Academic
Conclusions
A solar energy-based multi-generation system was proposed and analyzed energetically and exergetically. Parametric analyses were carried out to evaluate how the incident solar radiation, solar fluid mass flow rate, ambient temperature, different ORC working fluids, and subcomponent efficiencies affected the performance of the hybrid system. The following concluding remarks could be drawn from the study:
- •
The highest exergy destruction rate and exergy destruction ratio were observed in Evaporator
CRediT authorship contribution statement
Ammar Ahmed Raja: Conceptualization, Methodology, Investigation, Visualization, Writing-original draft. Yonghua Huang: Supervision, Writing - review & editing.
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.
Acknowledgement
The authors gratefully acknowledge the guidance being provided by Professor Ruzhu Wang. This work is supported by National Natural Science Foundation of China (No. 51676118 and 51936006), and Shanghai Aerospace Advanced Technology Joint Research Foundation, China (USCAST2019-4).
References (47)
- et al.
Investigation and assessment of a novel solar-driven integrated energy system
Energy Convers Manage
(2018) - et al.
Integration of renewable energy based multigeneration system with desalination
Desalination
(2017) - et al.
Experimental research on solar and geothermal energy coupling power generation system
Energy Procedia
(2019) - et al.
Performance analysis of a solar-assisted OTEC cycle for power generation and fishery cold storage refrigeration
Appl Therm Eng
(2015) - et al.
Thermodynamic performance assessment of ocean thermal energy conversion based hydrogen production and liquefaction process
Int J Hydrogen Energy
(2018) - et al.
Research on the configuration and operation effect of the hybrid solar-wind-battery power generation system based on NSGA-II
Energy.
(2019) - et al.
Design and thermal analysis of a two stage solar concentrator for combined heat and thermoelectric power generation
Energy Convers Manage
(2000) - et al.
Thermodynamic analysis of a solar-based multi-generation system with hydrogen production
Appl Therm Eng
(2013) - et al.
Thermodynamic performance assessment of a novel environmentally-benign solar energy based integrated system
Energy Convers Manage
(2016) - et al.
Energy and exergy performance assessment of a novel solar-based integrated system with hydrogen production
Int J Hydrogen Energy
(2019)
Development and assessment of a novel solar heliostat-based multigeneration system
Int J Hydrogen Energy
A review of solar energy based heat and power generation systems
Renew Sustain Energy Rev
Solar collectors and photovoltaics as combined heat and power systems: A critical review
Energy Convers Manage
Experimental investigation of exergy efficiency of a solar photovoltaic thermal (PVT) water collector based on exergy losses
Sol Energy
Photovoltaic thermal (PV/T) collectors: A review
Appl Therm Eng
Photovoltaic/thermal (PV/T) solar system: Experimental measurements, performance analysis and economic assessment
Renewable Energy
Photovoltaic/Thermal (PV/T) systems: Status and future prospects
Renew Sustain Energy Rev
Energy–exergy analysis and economic investigation of a cogeneration and trigeneration ORC–VCC hybrid system utilizing biomass fuel and solar power
Energy Convers Manage
Conceptual design of small scale multi-generation concentrated solar plant for a medical center in Egypt
Energy Procedia
Organic Rankine cycle coupling with a parabolic trough solar power plant for cogeneration and industrial processes
Renewable Energy
Development, analysis and performance assessment of a combined solar and geothermal energy-based integrated system for multigeneration
Sol Energy
Exergy analysis of parabolic trough solar collectors integrated with combined steam and organic Rankine cycles
Energy Convers Manage
Solar assisted multi-generation system using nanofluids: A comparative analysis
Int J Hydrogen Energy
Cited by (35)
A review of the photothermal-photovoltaic energy supply system for building in solar energy enrichment zones
2024, Renewable and Sustainable Energy ReviewsInvestigation of the effects of various nanoparticles on improvement of hydrogen production rate in a solar energy driven alkaline electrolyzer
2024, International Journal of Hydrogen EnergyA comprehensive review on the application of nanofluids and PCMs in solar thermal collectors: Energy, exergy, economic, and environmental analyses
2023, Journal of the Taiwan Institute of Chemical Engineers