milad fili

The two-level cooling output is the main framework of the bi-evaporator technology by which the refrigeration cycles’ capability enhances. Hence, the current study is motivated to assess the feasibility of thermal energy utilization of geothermal energy for an innovative trigeneration system encompassing a bi-evaporator-based refrigerator, a heating terminal, an electricity generation setup. In this paper, a tri-generation system of cooling, heating, and power generation is proposed, which can simultaneously produce all three outputs. The Rankine cycle is combined with an improved ejector refrigeration cycle, where the outlet flow from the second evaporator creates suction in the ejector and activates the ejector refrigeration cycle. In addition, binary working fluids are used instead of pure working fluids to enhance the system's performance. The proposed system is thermodynamically analyzed based on the first and second laws of thermodynamics for various mixtures. The highest power, refrigeration capacity, and heating output are found to be 33 kW, 214 kW, and 306 kW, respectively, for the R236fa/Pentane mixture. Additionally, the highest energy and exergy efficiencies are 54.7% and 27.48%, respectively, for the R142b/Pentane mixture.

This paper presents a novel multi-generation system based on biogas fuel for simultaneous production of goods such as electricity, cooling, freshwater, and hydrogen using smart heat recovery of combustion gases. The performance of the proposed system is investigated in terms of the first and second laws of thermodynamics. Also, to acquire a comprehensive evaluation of operation costs, an exergoeconomic analysis has been performed. Furthermore, a comprehensive parametric study has been conducted to understand the behavior of the system performance parameters with the design parameters. In the following, to show the superiority of using a Stirling engine, the investigation of the present study is performed under two different scenarios. The proposed system could produce 986 kW, 137.5 kW, 8.39 m3/h, and 2.96 kg/h, net output electricity, cooling load, distilled water, and hydrogen while working with the Stirling engine. In this case, the energy and exergy efficiencies of the proposed system are obtained at 37.3% and 32.08%, which are improved by about 2.96% and 7.89%, respectively. In terms of cost metrics, the total unit cost of the products is about 0.1086$/kWh which has increased by 8.1% compared to the non-sterling engine mode.

In the present research, a novel bi-evaporator combined cooling and power cycle based on the integration of a double-stage organic Rankine cycle and an ejector refrigeration cycle is devised to recycle heat from the exhaust gas of a marine diesel engine. Instead of using conventional pure organic fluids, various appropriate zeotropic mixtures are screened for the proposed system and the results are discussed in terms of the first and second laws of thermodynamics. The results indicated that by recycling 434kW energy from the exhaust gases and using R142/Pentane with 51/49 percent a maximum thermal efficiency of 43.28% and an overall cooling load of 166.36 kW can be achieved. In this case, the net produced electricity and exergy efficiency are obtained as 21.83 kW and 20.22% which can be increased by selecting other appropriate mixtures. Additionally, using R142/Pentane with 51/49 percent as the working mixture, it is figured out that the auxiliary vapor generator contributes to the highest exergy destruction by 62.3 kW out of overall exergy destruction of 122.15 kW. Also, the energy and exergy efficiencies of the system can be increased simultaneously by increasing the evaporator bubble point temperature.