نشریه مهندسی مکانیک تبدیل انرژی
سال یازدهم شماره 3 (پیاپی 41، پاییز 1403)

In this study, feasibility study of using renewable energy of wind and solar sources for Technical and Vocational University of Shahid Chamran in Guilan has been performed using HOMER software. The feasibility study has been conducted based on three scenarios including the combination of electricity grid with wind turbine, combination of electricity grid with solar cells and combination of electricity grid with hybrid wind turbine and solar cells system. Moreover, an economic analysis based on the discount rate of 8 and 18 percent and the inflation rate of 45 percent has been conducted. The results show that among the three designed scenarios, the hybrid system of solar cell and electricity grid is economical based on the net present value of money. In this system, the maximum output power equal to 263 kW and equalization cost was 0.00812 dollars for each kilowatt hour.Also, the emission of harmful environmental gases was investigated, which shows that the hybrid system of electricity network and wind has a lower percentage of carbon and pollution emissions.

To calculate the nuclear spectroscopic properties and solve the structure of element f oxides and other strongly correlated powders, it is necessary to use more accurate quantum chemical methods. For the actual modeling of nuclear-electron spectroscopy, it is necessary to consider the Britt interaction, so it is necessary to use the Gantt expression, which shows the rotation of the spin of an electron on its axis and is responsible for creating a vector potential that is equal to the vector potentials produced by all other electrons. will interact in the system and the gauge term that describes the retardation effects caused by the mutual interaction between the spin vector fields of the two electrons will be added to the Hamiltonian. In this paper, the full implementation of the four-component Dirac-Coulen-Britt Hamiltonian according to multi-resolution analysis with multi-wavelength basis has been done. The accuracy of the work is checked by comparing the ground state energies of charged helium-like ions in the increase of Z,X^((Z - 2)+) which is done with Python code (VAMPyR) and numerical radial interference in GRASP and Gaussian basis set calculations in DIRAC program. It was observed that the obtained results are independent of the selected nuclear charge model and depend on the tolerance and polynomial order of the selected multiwavelength legend. Moreover, the results confirmed that in the two-electron species, the magnetic and gauge contributions of the s orbitals are the same in value.

Among the progresses to reduce fuel consumption, combined cycle type is a useful attempt to generate electricity and achieve a thermal efficiency of 60 percent in Iran,combined cycle power plant type is vastly utilized .Identification of the places having process improvement potential is the first step in modification of the networkIn this paper, energy and exergy analysis of combined cycle power plant of Abadan with heat recovery steam generator of double pressure along with additional combustion has been done for two types of fuel: gas andgas oil. Abadan Combined Cycle Power Plant possesses two units, included two gas turbines, a boiler and a steam turbine in each unit. Based on the design information, The results of the simulation and power plant’s energy  and exergy analysis by means of the Thermoflow software showed that the energy and exergy efficiencies of the combined cycle based on the natural gas are about 6% higher than that achieved for gas oil. Also, the highest amount of the exergy loss occurs in the gas turbine combustion chamber of 27.66% and then in the heat recovery steam generator about 8.89%.

In this research, the energy, exergy, economic, and environmental analysis of a new hydrogen and electricity production system was discussed. A new system was designed by using the combination of compressed air energy storage units and proton exchange membrane electrolyzer, as well as using the combination of methane and hydrogen fuel to provide the necessary energy required for the modified Brayton cycle. To model the system, thermodynamic software for solving engineering equations was used. R123 organic fluid was used in the Rankine cycle. The parametric study showed that the inlet temperature of the gas turbine and the inlet pressure of the compressed air energy storage are among the most influential parameters on the system performance. The performance of the system was investigated in the three cities of Dezful, Tehran, and Tabriz. The results showed that changes in ambient temperature have an effect on the performance of the system and the system works better in cities with cold weather than in hot cities. The analysis of the consumption load required by one person throughout the year in Tabriz City showed that the system can supply the electricity required by 889 people throughout the year.

In this article, using traditional and unnecessary methods, the energy consumption in ventilation and cooling of the building has been numerically analyzed. By considering a model of the wind deflector, the influence of effective parameters on the performance of the wind deflector has been investigated and the results have been presented. Two general cases were considered, one of the models included a heat absorbent surface (corresponding to the pond or wet surfaces in traditional wind deflectors) and the other was simple. In this research, it was observed that increasing the height of the wind deflector has improved its performance and also the wind speed has a positive role in the efficiency of the wind deflector. Also, the presence of a heat absorbing surface reduced the internal temperature to a greater extent than in the normal case. From the modeling carried out in this research, it was found that the presence of wind deflectors can reduce the temperature inside the residential house by 11 degrees and also the amount of air conditioning inside the building can be significantly improved.

In this work, the COP/exergy analysis of a Heat Pump System Coupled with a Scroll Compressor (HPSCSC) is investigated. The experimental data was used to analyse the energy/exergy of HPSCSC at different Relative Intermediate Pressure (RIP) and wintry temperature to make clear the optimum operating condition based on more COP and extra capability. Moreover, an Energy Input Capacity (EIC) was defined to suggest the optimum operating of the system. The investigation of irreversibility in the components of the heat pump shows that the most important losses are generated in the Compressor (65-80%) and the condenser (12-15%).Also, the results confirm that even at very low ambient temperatures (-15oC) -where the COP drops-, the use of less RIP leads to an acceptable EIC and improvement in COP. The results further indicated that when the RIP exceeds 1.2, the energy transfer from the condenser remains relatively constant across various winery temperatures. Furthermore, in this study, a relation for the optimum RIP against wintry ambient temperature for an acceptable EIC and higher COP has been presented, which falls between 1.1 and 1.5.