Luis Hern'andez is a reviewer of research projects and reviewer of scientific journals with a high impact factor. This reality focuses on the integration of solar energy in cities (smart cities), buildings (smart buildings), microgrids, smart rural grids and other similar environments.
Simulation of a Solar-Assisted Air-Conditioning System Applied to a Remote School
- Introduction
- System Description
- Methodology
- Results and Discussion 1. Operation at Nominal Capacity
- Conclusions
The TRNSYS software was used to perform the operational simulation of the solar thermal cooling system. Being a coastal community, the relative humidity plays a very important role in the proper operation of the cooling water circuit and therefore the system in general.
Thermal Evaluation of Graphene Nanoplatelets
Nanofluid in a Fast-Responding HP with the Potential Use in Solar Systems in Smart Cities
Experimental 1. Test Rig
The amount of working fluid filled into the system was precisely measured using a syringe pump. The internal pressure of the HP was continuously monitored to ensure that it was not pressurized during the filling process.
Results and Discussion 1. Temperature Profile
With the addition of more nanomaterials to the working fluids, the thermal resistance of the HP is more suppressed. Figure 4 represents the change of the HTC of the evaporator with the applied heat flow to the evaporator.
Conclusions
Effect of structural character of gold nanoparticles in nanofluid on heat pipe thermal performance. Mater. Application of Nanofluids in Thermal Performance Improvement of Parabolic Trough Solar Collector: Advanced. Application. Thermal Performance Analysis of a Flat Heat Pipe Working with Carbon Nanotube-Water Nanofluid for Cooling a High Heat Flux Heater. Heat mass transfer.
Experimental Investigation of the Thermal Performance and Efficiency of a Copper Fabricated Thermosyphon Heat Pipe Loaded with Alumina - Glycol Based Nanofluids. Powder technology. Low-frequency vibration for mitigating fouling and intensifying the thermal performance of a plate heat exchanger operating with CuO/water nanofluid. Thermal Performance of a Heat Sink Microchannel Working with Biologically Made Silver-Water Nanofluid: Experimental Assessment. Ex.
Potential of Solar Collectors for Clean Thermal
Energy Production in Smart Cities using Nanofluids
Sarafraz 1 , Iskander Tlili 2 , Mohammad Abdul Baseer 3 and Mohammad Reza Safaei 4,5, *
- Experimental
- Results and Discussion
They demonstrated that the TP of the collector can be improved by 21% for the nanofluid. Also, the efficiency of the system increased by 23% compared to the system without nanofluid. Using zeta potential values, they stabilized the nanofluid and quantified the TP of ETSC.
It has been demonstrated that the TP of the collector can be improved for the case of the nanofluid. Set pH of the nanofluid to a value in which the highest zeta potential was observed. Schematic diagram of the test facility used in the present study, (a) the structure of the evacuated tube used in the solar collector, (b) the test rig [40].
Impedance Measurement and Detection Frequency Bandwidth, a Valid Island Detection Proposal for
Control Fundamentals
This impedance enables a third main control circuit corresponding to the control of the AC current droop in the GSCI. Figure 1 shows a grid-connected inverter with the type of resonant load proposed in the mentioned AI standards [7,11,12]. They suggest that the concept of resonant load occurs when the local consumption is almost equal to the active power delivered by the inverter in terms of current, not taking into account the reactive power, but with a resonance between the reactive components equal to the grid frequency. .
Note that the resonance concept is linked to a voltage driven by the current supplied by the inverter. In other words, this is because the voltage and frequency are maintained by the control law of the inverter. When power is lost, the voltage on PCC,UPCC is not released and is conditioned by the inverter.
Main Anti-Islanding Detection Methods
Impedance measurement (IM): An impedance measurement mechanism detects the utility disconnection thanks to the impedance change of the PCC. Based on communication [25,26]: Some signal generator based on different carriers aims to provide the state signals of the main line. Some examples of such possibilities are radio, power line carrier communication, power signals or wireless alternatives.
They usually require a remote transmitter and receiver, which is the answer to why it is considered a remote AIDM. However, some examples can be found based on the electrical device itself under a local conceptualization [25].
Limitations of AIDMs When Applied with the Presence of GSCI
When the inverter switches from grid-connected to off-grid, the voltage and frequency behavior in the PCC is directly related to the impedance and power consumption of the resonant load. To achieve this objective, Ohm's law can be applied, then the voltage and current values of the PCC are needed. Analyzing the PCC impedance transfer function, the asymptotic magnitude Bode diagram for grid-connected and grid-disconnected modes of operation is parameterized.
The asymptotes shown in Figure 9 are directly related to the network weakness and to the quality factorq of the resonant load. Frequency (rad/s) Bode size diagram: power grid and quality factor 1. Frequency and impedance change analysis of PCC impedance transfer function for power grid scenario and 30 kW/phase with q= 1 resonant load. This is due to the vertical shift (upward) of the grid resistance asymptote and the horizontal.
Improved Performance of Harmonic Injection by the Phase Perturbation Method
This is due to the shift of the load inductance asymptote to the right and the load capacitor asymptote to the left. It should be noted that the main idea of the proposal is to detect the change in terms of impedance and not to be precise in the exact value of the impedance of the PCC. However, the cosine argument is directly θ∗and avoids the inner product (2·π·ωr), where ω is the nominal angular frequency of the grid.
In [29], the islanding detection method is based on quadrature synchronous reference voltage variations considering a symmetrical and balanced system. According to all previous sections of the algorithm (A-C), at this point, it is possible to assume that the impedance in the PCC has undergone a change. However, the last step of the algorithm is shown in Figure 16 to give a more stable decision for the island episode.
Experimental Results
According to all the previous subsections, it is proposed to apply the algorithm shown in Figure 12, but dividing the calculations with two frequency rates: one with high frequency regarding the implications of the internal control loop and one with low frequency for the detection of cost-heavy functions such as DFT. , as depicted in Figure 17. The total time for the high-frequency calculations represented less than 4% of the available 125μs, and for the low-frequency case, less than 0.5% of the available 1ms. This section evaluates the detection time in the experimental setup by separating the analysis of the ZPF and NZPF scenarios.
Figure 22a,b shows the detection trigger when the converter was delivering less power than required by the resonant local load. Finally, Figure 22c,d shows the detection trigger when the inverter has exceeded the power required to supply the local load. This is the key point of the need to disregard AIDM based on voltage or frequency drifts.
Conclusions
In Proceedings of the 17th European Conference on Power Electronics and Applications 2015, EPE-ECCE Europe 2015, Geneva, Switzerland, 8–10 September 2015. In Proceedings of the 2015 IEEE 10th International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives (SDEMPED), Guarda, Portugal, 1–4 September 2015;. In Proceedings of the IEEE Power and Energy Society, National Harbor, MD, USA, 27–31 July 2014; p.
In Proceedings of the APEC, Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. In Proceedings of the 2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), Genève, Switserland, 8–10 September 2015; pp. In Proceedings of the PESC Record—IEEE Annual Power Electronics Specialists Conference, Aken, Duitsland, 20–25 Junie 2004; Volume 4, pp.
Contribution of Smart Cities to the Energy Sustainability of the Binomial between City
Concepts Review 1. Energy Sustainability
In his calculation, 75% corresponds to the analysis of the energy performance of the countries, where energy security, energy equity and environmental sustainability are evaluated. Group-II is the only group that has countries from all six regions of the study. The SMART criterion emerged in the 1980s and is an acronym of the objectives of a business management proposal: specific, measurable, achievable, relevant, time-bound [14].
In this sense, since the energy service is a transversal element in the efficient delivery of urban services, the smart cities exist within the framework of the urban energy transition. These networks are essential for achieving energy security, affordable energy and climate change mitigation – the three elements of the “energy trilemma” of energy sustainability [53]. The deployment of smart grids has had different goals in the main economic regions (for the countries of the European Union (and the bill "clean energy for all Europeans"), the United States and Canada, the main driving forces in the development of Smart grids have been decarbonization and energy efficiency.
Smart city Strategy to Energy Sustainability
DG can be defined as electricity generation within distribution networks on the customer side of the network [64]. This type of generation makes it possible to take advantage of the renewable energy sources in cities. New services emerge from the smart technological development in the distribution grids that help to increase the energy efficiency of the system through the economic incentive for new market entrants.
The smart city strategy for city management aims to contribute to the energy sustainability of the planet [6]. Thus, the emergence of generation systems benefiting from renewable energy sources in cities will bring about a whole range of changes to the electricity system, including the loss of value of existing infrastructure and the functioning of the energy sector [71]. However, with the superimposition of the SMART and ICT criteria, the electricity system gains efficiency to achieve economic and environmental benefits.
Urban Population and Urban PV Generation vs. Energy Sustainability
Furthermore, most of the countries that move down the ranking do so with a high negative correlation (Q4). The specific objective was to study the effect of the increase of this generation in the indicators. Reducing the concentration of electricity generation will enable 113 of the 125 countries to achieve a better position in the ETI and; thus better energy sustainability.
Minimum variation results: Two countries (Dominican Republic and Iraq) would get a lower position and 10 countries would keep the same position (Denmark, Greece, Hungary, Netherlands, Niger, Portugal, Romania, Sweden, Switzerland and United Kingdom). Table 2 summarizes the averages of the obtained results, and Figure 11 graphically shows the results of each segment of the countries in the ranking. In short, countries respond to their energy sustainability by managing the energy needs of their cities.
