Energy/Economic Analysis and Optimization of On-Grid Photovoltaic System Using CPSO Algorithm

Develop a New Correlation between Thermal Radiation and Heat Source in Dual-Tube Heat Exchanger with a Twist Ratio Insert and Dimple Configurations: An Experimental Study

The goal of this research was to convey an outlook of heat transfer and friction factor study in experimental detail with a double-pipe heat exchanger (DPHE). In process heat transformation (HT) and friction factor(f) in a (DPHE) counter-flow with a twisted tape (TT) arrangement by dimple inserts. The grooves were a kind of concavity that enhanced thermal transfer while only slightly degrading the lower pressure. Heat transmission (HT) and friction factor(f) were investigated employing dimples and protrusions of varying diameters and a uniform diameter (D) to the diameter-to-depth ratio (D/H). The impact of using twisted tape with various dimpled diameters D = 2, 4, and 6 mm at a uniform (D/H) = 1.5, 3 and 4.5 on heat transmission and friction factor properties were discussed. The dimple diameter (D) was directly connected to the friction coefficient (f), hence the highest value of friction factor was established at (D) = 6 mm. Furthermore, the best performance of Nusselt number (Nu) and performance evaluation criteria (PEC) was determined at a diameter of D = 4 mm. As a result, dimpled twisted tape additions are an excellent and cost-effective approach to improve heat transformation in heat exchangers. With fluid as a water, lower parameters, and higher Reynolds number (Re) resulted in better thermal conditions. Thermal performance and friction factor(f) correlations were developed with regard to the geometry of the dimple diameter (D) and its ratio (D/H) and ‘Re’, and a good correspondence with the experimental data was achieved. The novel geometry caused a smaller pressure drop despite its higher convection heat transfer coefficient. The results also showed that raising the ‘Re’ and nanofluid concentration, the pressure drop increased.

Research on the Operational Strategy of the Hybrid Wind/PV/Small-Hydropower/Facility-Agriculture System Based on a Microgrid

The use of renewable energy sources, such as wind, photovoltaics (PV), and hydropower, to supply facility agriculture may effectively mitigate food and environmental pollution problems and ensure continuity of the energy supply. The operating conditions of a hybrid system are complex, so the operating strategy is very important for system configuration and scheduling purposes. In the current study, first, a hybrid wind/PV/small-hydropower/facility-agricultural system was constructed. Then, the chaotic particle swarm method was applied to optimize hybrid system operation, and a scheduling strategy of the hybrid system was proposed. Finally, combined with an example, according to wind and PV power output and load curves, supply-to-load curves for wind, PV, and small hydropower were obtained. The operational strategy proposed in this study maximizes the utilization of wind and solar resources and rationally allocates hydropower resources. The aforementioned operational strategy provides a basis for hybrid system capacity allocation and scheduling.

A Two-Stage Approach to Locate and Size PV Sources in Distribution Networks for Annual Grid Operative Costs Minimization

This paper contributes with a new two-stage optimization methodology to solve the problem of the optimal placement and sizing of solar photovoltaic (PV) generation units in medium-voltage distribution networks. The optimization problem is formulated with a mixed-integer nonlinear programming (MINLP) model, where it combines binary variables regarding the nodes where the PV generators will be located and continuous variables associated with the power flow solution. To solve the MINLP model a decoupled methodology is used where the binary problem is firstly solved with mixed-integer quadratic approximation; and once the nodes where the PV sources will be located are known, the dimensioning problem of the PV generators is secondly solved through an interior point method applied to the classical multi-period power flow formulation. Numerical results in the IEEE 33-bus and IEEE 85-bus systems demonstrate that the proposed approach improves the current literature results reached with combinatorial methods such as the Chu and Beasley genetic algorithm, the vortex search algorithm, the Newton-metaheuristic algorithm as well as the exact solution of the MINLP model with the GAMS software and the BONMIN solver. All the numerical simulations are implemented in the MATLAB programming environment and the convex equivalent models are solved with the CVX tool.

Investigation and Optimization of the Performance of Energy Systems in the Textile Industry by Using CHP Systems

With the general progression of small communities toward greater industrialization, energy consumption in this sector has increased. The continued growth of energy consumption seen in Iran, along with the low efficiency of production, transmission, and the distribution of energy, has led to the projection of an unfavorable future for this sector. The purpose of this study is to reduce fuel consumption and increase system efficiency by considering the optimal position of the turbine. In this regard, turbine modeling has been performed by considering different positioning scenarios. Afterward, the result from applying each scenario was compared with another scenario in terms of the parameters of electrical energy production, gas consumption, the final energy produced by the system, and the ratio of energy produced to overall gas consumption. After comparing different scenarios, considering all 4 parameters, Scenario 7 was selected as the most suitable positioning for gas turbine placement. Scenario 7 showed the highest gas consumption; of course, high power generation is the most desirable, the most reliable and, ultimately, the most profitable outcome of energy production. According to our results, the amount of electrical energy produced in the selected scenario is 4,991,160.3 kWh; the gas consumption in this case is 0.22972 kg/s.