## 1 Introduction
In their study, exergy efficiency and overall cost rate are selected as the objective functions and the design parameters are compressor isotropic pressure ratio, inlet temperature, isotropic efficiency of the turbine, regenerator effectiveness, number of concentrating mirrors and outlet temperature. Their optimization results show that the amount of exergy efficiency and the cost rate are 52.73% and 10,851.47 $/hv respectively for fossil fuel alone and the 41.6% and 20,296.9 $/hr for hybrid Brayton gas cycle. [PERSON] et al. [16] examined the Brayton gas cycle from the perspective of the first law of thermodynamics. In their study, they used the regenerator, concentrated solar collector and combustion chamber to increase the temperature of the compressor exhaust gas such that the hot fluid and gas output from the collector and the combustion chamber transfer heat energy by means of two separate heat exchangers to the Brayton cycle operating fluid. By a complicated mathematical and thermodynamic model, the performance of the solar collector, combustion chamber, heat exchangers and other major components of the cycle is related to the overall energy efficiency. In addition, the effect of various factors such as ambient temperature and compressor pressure ratio on the energy efficiency are examined. A utilization of the waste heat and geothermal heat sources in a centralized domestic heating, cooling and electricity network was carried out by [PERSON] et al. [17]. In their study, both geothermal and waste heat are applied to run domestic-scale combined cooling, heating and power (CCHP) units to meet the thermal and electrical demands of a residential area as the case study. It is showed that the designed CCHPs not only meets the local energy demand in a sustainable way, but also delivers surplus thermal and electrical energy to the main grids. [PERSON] et al. [18] investigated the combined cycle of gas turbine and organic Rankine cycle with middle-heater to generate heat and power simultaneously from the perspective of energy and exergy. In their studied cycle, the high temperature dissipated outlet gas from the gas turbine enters the steam generator and after generating the output heat and lowering the temperature, is used as the organic Rankine cycle actuator. [PERSON] et al. [19] evaluated and optimized the performance of a new triple production system from the exergoeconomic and environmental perspective. They showed that dissipated energy of gas turbine and solar energy can be used as a driving for steam cycle and also dissipated steam energy is applied for hot water heat exchanger and absorption chiller. The results showed that the optimum unit cost of exergy products decreased by 11.5% and overall exergy efficiency increased from 44.38% to 56.07%. A combined Brayton and Rankine cycle with a capacity of 50 MW from an energy and economic perspective was examined by [PERSON] et al. [20]. In their work, the heliostat collector and combustion chamber are used as the simultaneous stimulation of the Brayton cycle and the hot exhaust gases from the gas turbine are used as the vapor cycle actuator. [PERSON] et al. [21] investigated a co-generation system of power, heat and cooling including the upper Brayton gas cycle, organic Rankine cycle and the lower absorption cryogenic cycle from a thermodynamic perspective. In the next step, parametric analysis is performed to study the effect of different factors on the output parameters of cycle. Their results indicated that the proposed hybrid system could produce 30 kW of power, 8 kW of cooling and 7.2 ton of hot water with an overall efficiency of 67.6%. In addition, the results of parametric analysis showed that compressor pressure ratio and turbine inlet temperature are two important factors in changing system performance. The impact of using two different types of fuel, namely natural gas and diesel fuel, on the performance of the Brayton-Rankine hybrid system from the perspective of energy, exergy, economic and environmental examined and compared by [PERSON] et al. (2020).