How to select regenerative configurations of CO ₂ transcritical Rankine cycle based on the temperature matching analysis

Abstract

Summary CO2 transcritical Rankine cycle is regarded as a potential technology for internal combustion engines waste heat recovery, and its regenerative configurations present great prospect to increase the power output capacity. This paper proposed different regenerator layout configurations based on the temperature matching analysis, including low temperature regenerative transcritical Rankine cycle (LR‐TRC), high temperature regenerative transcritical Rankine cycle (HR‐TRC), dual regenerative transcritical Rankine cycle (DR‐TRC) and split dual regenerative transcritical Rankine cycle (SR‐TRC). Afterward, the thermodynamics, electricity production cost (EPC) and miniaturization performance are implemented. The results show that regenerative configurations have an effect on improving net power output and SR‐TRC obtained optimal value of net power output. For the perspective of economic performance, the greatest value is obtained for HR‐TRC among four regenerative configurations. As for the miniaturization performance, the total heat transfer area increment of LR‐TRC is the lowest. The comparative analysis results offer guidance for selecting optimal regenerative configurations.

Energetic and exergetic efficiency comparison of recuperative transcritical organic Rankine cycles under different pure and mixture fluids

“…Sánchez and Silva 29 indicated the size of a heat exchanger (namely evaporator and condenser) can be reduced by a recuperator. Tian et al 30 indicated a high impact of regenerative configurations on improving net power output, especially for split dual regenerative TRC. However, Ramy et al 31 indicated the recuperator had negative effects on compactness and performance.…”

Fluid Selection of Transcritical Rankine Cycle for Engine Waste Heat Recovery Based on Temperature Match Method

“…In this research, a split dual regenerative transcritical Rankine cycle (SR-TRC) is investigated shown in Figure 1. Due to the design of split branches and two regenerators, the SR-TRC system can meet the requirement of recovering the jacket water and exhaust gas simultaneously and improve the temperature matching in the whole heat absorption process, and has been proved to be a novel cycle configuration to achieve better temperature match between the system and heat sources [36]. The concrete working process of SR-TRC is: the working fluid transferring heat from jacket water in the preheater (2-3) is split into two parts, namely, high-temperature branch (H-branch) and low-temperature branch (L-branch).…”