•A novel parabolic trough solar-nuclear combined (SNC) system is proposed.•This SNC system is used for power generation and sea water desalination.•Exergy analysis of the SNC system is conducted.
A ...novel solar-nuclear combined (SNC) system is proposed for both electricity production and sea water desalination. A parabolic trough solar thermal system and a small modular reactor (SMR) based on pressurized water reactor technology are coupled in this system. By using the Ebsilon code, the operation behavior and exergy evaluations of the SNC system are launched under both the design point and varying solar irradiance conditions. The results demonstrate that the output electric power and electric efficiency of the SNC system are 258.4 MW and 35.2% when the solar irradiance is 900.0 W·m−2. The output electric power, incremental electric power and electric efficiency of the SNC system all increase as the solar irradiance increases. The maximum exergy loss occurs in the parabolic trough solar receiver. The exergy efficiency of the parabolic trough solar receiver is 51.7% when the DNI increases to 1000.0 W·m−2.
A numerical model for a solar water heating system (SWHS) used in industrial process heat in warm climates was carried out and validated with experimental data. The experimental set up consisted in ...18 evacuated tube solar collectors, 700 lt thermal storage tank, 10 kW back up auxiliary heating system (electrical), plate heat exchanger coupled to a 25 kW chiller (in order to simulate the industrial process heat), differential temperature control and recirculation pumps. In this work, a TRNSYS type was developed in order to take into account the thermal losses in connecting pipes between the storage tank and the solar collector array.
A global validation of the SWHS coupled to a thermal load was carried out; the mean deviation obtained for temperatures was lower than ±3.6% and ±5.8% for the useful energy gain at the collector array.
The numerical model validated was applied to the evacuated tube solar heating system installed in the Instituto de Energías Renovables; it showed that it is possible to operate an 8 kW adsorption cooling system with an annual solar fraction of 86%. The numerical results obtained showed that it could be technically feasible for Temixco, Morelos, Mexico and similar warm regions.
•A numerical model for a solar heating system in industrial process heating was developed.•The model was validated with experimental data for different working conditions.•A TRNSYS type was developed for take into account thermal losses in connecting pipes.•The model can be used as a tool for the analysis for industrial process heating.•The solar systems can be a profitable investment in industrial process heating.
Polygeneration configurations for small power generation systems offer significant potential for energy saving and reducing carbon emissions in wastewater treatment facilities. In this work, a ...biogas-fed solid oxide fuel cell system operating in a wastewater treatment plant (located in Turin, Italy) is analyzed in terms of its potential improvements through novel polygeneration systems. In its present combined heat and power configuration, along with electrical power, thermal energy from the exhaust gas is recovered to provide required heat to the plant’s anaerobic digester. The analysis is focusing on different energy efficiency solutions for this type of plant by using solar thermal collectors, microturbines, a trilateral Rankine cycle, and an absorption chiller. Results reveal that, despite of higher efficiency for the trigeneration case using both trilateral Rankine cycle and absorption chiller (up to 88.4%), the solar integrated system results in the lowest natural gas consumption, which is 38.5% lower than the baseline scenario. This same scenario is also the worst in economic terms due to the high capital costs of solar collectors. In a short-term cost trajectory of the solid oxide fuel cell technology, the most economically favorable scenario is the microturbine integrated case in which the calculated levelized cost of electricity is 0.11 €/kWh, lower than grid electricity price, and with payback time of 6.5 years. Long-term cost trajectory is indeed generating effective investments for all of the four scenarios with payback time between 3 and 5 years in all cases. The analysis has been developed to the entire European Union area: the most suitable market conditions are found in Germany, Denmark, Slovakia, and Italy.
•Different polygeneration solutions for installation at WWTP are analyzed.•Thermodynamic and techno-economic models are created for polygeneration systems.•Integration of microturbines is the most economic solution with LCOE of 0.11 €/kWh.•The techno-economic analysis is extended for the entire EU area.•Suitable market conditions are found in Germany, Denmark, Slovakia, and Italy.
•Overview of PCM and PCS for better thermal storage performances in solar systems.•A new concept of solar thermal system using PCS as heat transfer fluid is defined.•Experimental setup of a full ...scale innovative solar thermal system prototype.•The monitoring and control system of the PCS based solar collector is presented.
Flat-plate solar thermal collectors are the most common devices used for the conversion of solar energy into heat. Water-based fluids are frequently adopted as heat carriers for this technology, although their efficiency is limited by certain thermodynamic and heat storage constraints. Latent heat, which can be obtained from microencapsulated Phase Change Slurry (mPCS) – that is a mixtures of microencapsulated Phase Change Materials (mPCM), water and surfactants – is an innovative approach that can be used to overcome some of the aforementioned limitations. The viscosity of these fluids is similar to that of water, and, as a result, they can be pumped easily. Some of the thermo-physical and rheological properties and the material behaviour of flat-plate solar thermal collectors with an mPCS as the heat carrier fluid are analysed in the present work. Solar thermal systems filled with an mPCS are proposed and a prototypal system is presented. The possible advantages and drawbacks of this technology are also discussed.
•A spectrum splitting, transmissive CPV module is shown in a hybrid PV-thermal system.•Module has conversion efficiency exceeding 43.5% for above bandgap (in-band) light.•Module cooling (<110°C) is ...maintained with high transmission of IR light (>75%).•System is designed for dispatchable electricity or industrial process heat generation.
A spectrum splitting, transmissive concentrating photovoltaic (tCPV) module is proposed and designed for a hybrid photovoltaic-solar thermal (PV/T) system. By utilizing III–V triple junction solar cells with bandgaps of 2.1eV/1.7eV/1.4eV, ultraviolet (UV) and visible light will be absorbed and converted to electricity, while infrared (IR) light will pass through and be captured by a solar thermal receiver and stored as heat. The stored thermal energy may be dispatched as electricity or process heat, as needed. According to the numerical analysis, the tCPV module can perform with overall power conversion efficiency exceeding 43.5% for above bandgap (in-band) light under a standard AM1.5D solar spectrum, under an average concentration ratio of 400 suns. Passive and active cooling methods, keeping cells below 110°C, are also investigated and discussed, indicating that a transparent active cooling design could improve the CPV module efficiency by around 1% (absolute), relative to a passive design, by reducing the maximum cell working temperature by around 16°C. Furthermore, cost analysis shows that installation cost of around $1.9/W–$2.2/W could be reached for the tCPV based PV/T system, which shows a competitive economic advantage compared to a more conventional PV with battery system.
An innovative energy optimization algorithm is employed for an existing office building. This optimization is done to decrease energy usage and increase the building's energy efficiency. Apart from ...this optimization, an efficient solar thermal system is used for reducing building CO2 emissions. In addition, to achieve more significant CO2 reductions, the feasibility of transforming the existing building to a zero-energy building is analyzed. Optimization is done using accurate data and DesignBuilder simulation software. Then, by detecting inefficiencies, objective functions are proposed for the case study. Based on the air heating and domestic hot water loads, an efficient solar thermal system is modeled. Various energy resources are considered to supply hot water and space heating, including solar energy, electricity, and natural gas. Finally, the feasibility of converting the building to a zero-energy building is evaluated using TRNSYS software. A feasibility analysis is performed using electricity consumption data from DesignBuilder software. The building optimization results in a significant reduction in fuel consumption and carbon dioxide emissions. Adding a solar thermal scenario raised the thermal efficiencies of the system to 47%. Economic calculations demonstrated the solar thermal system's financial merits. In this case, the solar thermal system can save about $318 annually. To convert the building to a zero-energy building, at least twenty-four 2 kW wind turbines, three 9 kW wind turbines, and 460 m2 of photovoltaic panels must be used. These values are obtained by assuming efficiencies of 100% for inverters and transformers. But to achieve zero energy building status on a monthly basis, a higher number of renewable energy suppliers must be used. Based on the rooftop area (340 m2), separate land close to the building must be considered for mounting some of these renewable energy suppliers, apart from the rooftop.
Liquid desiccant dehumidification (LDD) system is an emerging technology with energy-saving benefit in HVAC applications. It removes moisture from the inlet air stream and handles the latent load ...without overcooling and reheating. The most energy-intensive process of the LDD system, the desiccant regeneration process, can be driven by renewable solar thermal energy with a temperature lower than 100 °C. However, the integration of solar heat needs to consider the inconsistent availability of solar radiation and regeneration heat demand.
In this study, a pinch-based Cascade Analysis (CA) approach is used to optimally size the solar thermal collectors and thermal energy storage (TES) water tanks, which are the main components of the solar thermal system. From the analysis, the overall system efficiency, minimum area of solar thermal collectors and total TES volume are 78.8%, 59.83 m2 and 7.10 m3, respectively, with an average daily regeneration heat demand of 213.48 kWh. The overall system installation and operating cost is approximately 14219.98 USD or 948.00 USD annually over 15 years. This work serves as a preliminary study to provide an overview of the implementation of solar thermal systems for decision-makers who intend to implement solar-based LDD systems in HVAC or drying applications.
•The desiccant regeneration process of the LDD system is driven by solar heat.•Cascade Analysis (CA) is used to optimally size the solar thermal system.•System installation and operating cost estimation is included.•An overall system efficiency of 78.8% is achieved for the solar-LDD system.
Summary
Delivering reliable and adequate power to the consumer is essentially critical. Standard quality of power is measured by its frequency stability and power flow between different control ...areas. Therefore, power‐system‐control is generally attained with load‐frequency‐control (LFC). This paper presents the LFC of a hybrid power system comprising of conventional‐thermal, solar‐thermal and electric vehicle (EV). The inclusion of EVs into the utility grid, generation‐rate‐constraint of thermal plants and time‐delay in all three control areas makes the proposed power system more realistic and a practical one. This makes the system a bit complex and requires a robust controller to function optimally. An integral‐double‐derivative (IDD) controller is applied for this study and the system responses are compared with those of classical controllers. The controller gains are optimized using the powerful magnetotactic bacteria optimization (MBO) technique, which find its maiden application in power system studies. MBO optimized IDD controller performs better in contrast to other classical controllers. Further, a fuzzy logic control (FLC) is developed to optimize the gains of optimal IDD controller. System dynamic responses comparison of both fuzzy optimized IDD and MBO optimized IDD controller reveals an inclination towards the performance of fuzzy optimized IDD controller. This is validated with the help of demerit index. Robustness analysis is also done to highlight the strength of IDD controller optimized with both MBO and FLC for various system changes, such as load perturbation, system loading and solar irradiance. The critical review of all these analysis infers the effective performance of fuzzy optimized IDD controller.
A realistic multi‐source three‐area electrical power system incorporating solar thermal and electric vehicle (EV) for LFC studies.
Applying magnetotactic bacteria optimization (MBO) technique for the first time in LFC studies.
Optimize and compare the controller gains with fuzzy and MBO technique.
Dynamic response comparison of the proposed power system with different optimization techniques.
Fuzzy optimized integral double derivative (IDD) controller for the proposed system.
Robustness analysis to compare the strength of MBO‐IDD and fuzzy‐IDD controller gains.
Impact of electric vehicles (EVs) in regulating system stability.
•Solar thermal system and energy storage using Phase Change Material slurry.•Hybrid Economic Model Predictive Control analysis for latent heat storage.•Strategy to enhance the exploitation of the ...benefits due to fusion/solidification.•Adoption of Mixed Logical Dynamical formulation to deal with latent heat exchange.•Optimization objective function calibration to enhance controller performance.
Model predictive control has proved to be a promising control strategy for improving the operational performance of multi-source thermal energy generation systems with the aim of maximising the exploitation of on-site renewable resources. This paper presents the formulation and implementation of a model predictive control strategy for the management of a latent heat thermal energy storage unit coupled with a solar thermal collector and a backup electric heater. The system uses an innovative Phase Change Material slurry for both the heat transfer fluid and storage media. The formulation of a model predictive controller of such a closed-loop solar system is particularly desirable but also challenging mainly due to the nonlinearity of the heat exchange and thermal storage processes involved. A solution for the model predictive control problem to regulate a system with intrinsic nonlinearities is introduced using a mixed logic-dynamical approach. The model predictive control regulation is tested and compared with a baseline rule-based controller considering both ideal and estimated disturbance predictions. Results demonstrate the capability of the predictive controller in anticipating future disturbances and in optimising the utilisation of the more efficient energy sources. When compared to the rule-based controller, the model predictive control algorithm leads to reductions of the system primary energy demand ranging from 19.2% to 31.8% as a function of the variation of a soft constraint on meeting demand constraints. The work contributes to new knowledge on how model predictive control algorithms can be implemented to maximise the benefits of integrating thermal energy storages that employ latent heat of fusion with solar thermal technologies.
The photochromic norbornadiene/quadricyclane system is among the most promising candidates for molecular solar thermal (MOST) energy storage. As in this context there is still the need for new ...tailor-made derivatives, borylated norbornadienes were synthesized that may be used as versatile building blocks. Thus, the 4,4,5,5-tetramethyl-2-(bicyclo2.2.1heptadien-2-yl)-1,3,2-dioxaborolane was prepared and shown to be a suitable substrate for Pd-catalyzed Suzuki-Miyaura coupling reactions with selected haloarenes. It was demonstrated exemplarily that the novel monosubstituted 2-(1-naphthyl)norbornadiene, that is accessible through this route, is transformed to the corresponding quadricyclane upon irradiation, whereas the back reaction can be accomplished by thermal treatment.
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