جستجوی مقالات مرتبط با کلیدواژه « سیکل تبرید » در نشریات گروه « برق »

One of the main issues of Iran is power deficiency in hot months. Due to the ever-increasing demand for energy and its consumption, it is of critical importance to optimize power-generating systems, improve their efficiency, address their drawbacks. This research aims at studying the effect of adsorption systems on the performance of the unit (its production power and efficiency) in the climate of Yazd by simulating a G13 Alstom generator in thermoflow. The results showed that using absorption systems-reduced the inlet air temperature by 20ºC, which, in turn, increased overall production power by 20.38% in comparison to when there was no cooling of the inlet air. This system also improved the aforementioned unit’s efficiency by 1.88%. The fog system was also simulated in this research. The results demonstrated that the absorption system showed a better efficiency in comparison to the fog system by 5.32%. To ascertain the validity of the model, it was validated against the real operational data for the G13 unit in base load and in different environmental conditions, as well as against the data present in the documents associated with the Yazd Power Plant. One of the novelties of this study is using heat in the craft unit outlet, which is currently released to air. If this system is applied to the unit, the efficiency of the craft unit and power plant will be improved. Moreover, this will reduce the emission of environmental pollutants into the air, which will ultimately cause a major reduction in social expenses.

In this paper, parametric analysis and optimization of the transcritical ejector refrigeration cycle using different working fluids have been proposed which can be employed in the parts of solar energy processes. The main advantages of using ejector in the refrigeration cycles, which often use instead of the compressor, are simplicity in construction and maintenance, high reliability and low cost. In this study, the transcritical ejector refrigeration cycle is modelled using EES software and the effects of different parameters such as temperature and pressure of different parts of cycle on the coefficient of performance and entrainment ratio are investigated. In continued, the coefficient of performance of the transcritical ejector refrigeration cycle for four different working fluids is optimized using the combination the Artificial Neural Network and Particle Swarm Optimization algorithm.

In this work, a compression type HVAC (heating, ventilating, and air conditioning) system has been studied. The aim of the work was improving the cooling operation and performance of the system, elimination of the freezing problem of the compressor, increasing the efficiency, decreasing the energy consumption and reducing the working duration of the compressor. The results of numerical solution of the computational fluid dynamics has been crosschecked with and interpreted according to the experimental data. The results of the exploited modifications based on the numerical solution have been presented in the form of contours and velocity-temperature plots. Eventually, troubleshooting of the HVAC system resulted in the elimination of the compressor freezing accompanied with convenient air conditioning and ventilation. The temperature and flow of the provided air, decreased 7 oC and increased by %13, respectively.

The obtained gas from refinery units is sent to torches for burning which not only pollutes the environment but also destroys valuable materials. The suggested method of using cryogenic cycle not only solves the environmental problem but also makes the gradual producing of HydroCarbon, Nitrogen, Hydrogen and finally heavy water possible. According to the exiting technology, the by-products produced in the process of oil refining are waste gas mixtures that mainly consist of hydrogen, hydrocarbons nitrogen and other components. The composition of those mixtures depends on oil deposit, refining technology and varies significantly. Relatively low results of oil refining in the national refineries are explained by the use of traditional technologies and equipment. The greatest amount of waste gases is burnt in the fuel ring and in the flame. The burning of waste gases may create a complicated ecological situation when vast territories should be determined as refinery sanitary protection zones. At present we know various methods of the separation of oil-refinery and waste gases. Those methods, however, do not allow to completely solve the problem of their utilization. The technical and economic analysis has shown, that the use of low-temperature technology holds the greatest promise for separating gas mixture into pure components including the release of nitrogen, hydrogen, deuterium and helium. Such an approach would improve the process of oil refining by 5 percent, raise considerably economic feasibility of production and improve ecological situation: that would lead to the reduction of sanitary protection zone and raise the cadastr cast of cleaned lands.