applied sciences  
An Optimization Study to Evaluate the Impact of the Supercritical CO\({}_{2}\) Brayton Cycle's Components on Its Overall Performance  
[PERSON],* [PERSON], [PERSON], [PERSON] and [PERSON] Department of Automotive and Marine Engineering Technology, College of Technological Studies, The Public Authority for Applied Education and Training, Shuwaiikh, Kuwait City 70654, Kuwait; [EMAIL_ADDRESS] (B.B. ); [PERSON]ESS] (Y.A. ); [EMAIL_ADDRESS] (A.M.) Automotive Department, Industrial Institute at Sabah Alsalam, The Public Authority for Applied Education and Training, Sabah Alsalam, Kuwait City 70654, Kuwait; [EMAIL_ADDRESS] Correspondence: [EMAIL_ADDRESS]  
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compressor power requirements [4]. In contrast, the compressor of the sCO\({}_{2}\)-BC operates close to the critical point where compressibility of the supercritical CO\({}_{2}\) is comparable with the compressibility of liquids [2]. This is the reason why, unlike the air Brayton cycle, the compression work requirements of sCO\({}_{2}\)-BC are substantially smaller than those of the former. Furthermore, sCO\({}_{2}\)-BC is capable of operating at very high turbine inlet temperatures to achieve a significantly high conversion efficiency by blending the benefits of both air and steam cycles. Moreover, operation of sCO\({}_{2}\)-BC above the critical point eliminates the necessity of condensing the system, leading to a comparatively basic cycle layout. Lastly, the sCO\({}_{2}\)-BC operates at very extremely high pressures due to which the cycle's components are much more compact compared with the air Brayton and steam Rankine cycle. It has been frequently reported in the literature that the turbine, compressors, and printed circuit heat exchanger (PCHE) sizes become at least tenfold more compact compared with the steam Rankine cycle [5,6]. The sCO\({}_{2}\)-BC is regarded as one of the most promising approaches to meet with tight emission standards. In this regard, integration of the sCO\({}_{2}\)-BC with concentrated solar power plants (CSPs) is highly pertinent as it is cost-effective for the next-generation CSP plants operating at temperatures above 600 \({}^{\circ}\)C [7, 8, 9]. Along with this, sCO\({}_{2}\)-BC accounts for an ideal power block of the next-generation nuclear reactor [10] and waste heat recovery [5,11] based on its excellent integration capabilities with low-temperature heat sources [5,12, 13, 14]. A list of potential applications of sCO\({}_{2}\)-BC along with their sizes and motivations is listed in Table 1.  
Several combinations of sCO\({}_{2}\)-BC were analyzed in the literature [3,4,15, 16, 17, 18] to furth improve its efficiency [3,4,15, 16, 17, 18]. Among various cycle configurations, the most naive sCO\({}_{2}\)-BC layout is known as a recuperated/regenerative cycle. It comprises three heat exchangers (a regerative, an intermediate heat exchanger, and a precooler), an expander, and a compressor. The cycle was initially suggested by [PERSON] [16]. Other variants of the regenerative sCO\({}_{2}\)-BC involve a reheated compression cycle (with an additional heat exchanger between stages of the turbine) and intercooled compression (an intercooler between two stages of the compressor) [15,19]. The single recuperator in the cycle was replaced with two smaller recuperators in series to overcome the pinch-point issues linked with the regenerative cycle. The subsequent cycle is known as the recompression cycle and involves two compressors, i.e., main-compressor and re-compressor. Recompressional sCO\({}_{2}\)-BC has been referred to as the most efficient layout amount other available layouts of the supercritical cycle [8,20,21]. Numerous studies have been performed to optimize the boundary conditions of sCO\({}_{2}\)-BC.