Effect of working fluids on the performance of a novel direct vapor generation solar organic Rankine cycle system

Abstract

A novel solar organic Rankine cycle (ORC) system with direct vapor generation (DVG) is proposed. A heat storage unit is embedded in the ORC to guarantee the stability of power generation. Compared with conventional solar ORCs, the proposed system avoids the secondary heat transfer intermediate and shows good reaction to the fluctuation of solar radiation. The technical feasibility of the system is discussed. Performance is analyzed by using 17 dry and isentropic working fluids. Fluid effects on the efficiencies of ORC, collectors and the whole system are studied. The results indicate that the collector efficiency generally decreases while the ORC and system efficiencies increase with the increment in fluid critical temperature. At evaporation temperature of 120 o C and solar radiation of 800 Wm-2 , the ORC, collector and overall thermal efficiencies of R236fa are 10.59, 56.14 and 5.08% while their values for Benzene are 12.5, 52.58 and 6.57 % respectively. The difference between collector efficiencies using R236fa and Benzene gets larger at lower solar radiation. The heat collection is strongly

Design and Manufacturing of Organic Rankine Cycle (ORC) System Using R-134a as Working Fluid with Solar Collector as Source Energy

“…On the other hand, if the HTF mass flow rate is lower, the higher the HTF inlet temperature. So it is hard to reduce the mean temperature of HTF which results in the operation of solar collectors it causes a loss that is efficient reduction at high temperatures rather than operating at low temperatures [10].…”

“…To found the velocity value of fluid flow (9) Then the value of Reynold Numbers (10) To found the Nusselt Number value (11) To calculate convection coefficient inner and outer (12) To determine Thermal Resistance (R) and Overall heat transfer coeficient (U) (13) (14)…”

Thermodynamic investigation of organic Rankine cycle energy recovery system and recent studies

“…Some of the preferred physical and chemical properties are non-flammability, stability, non-corrosiveness, non-fouling, and non-toxicity. Moreover, the low boiling point of the working fluid is another property to be used in a binary power cycle as involving with low-temperature geothermal waters [25][26][27].…”

Thermodynamic Performance and Optimization Analysis of a Modified Organic Flash Cycle for the Recovery of Low-Grade Heat

“…Combined cycles based on ORC also can utilize the energy source more efficiently. Various cycles, such as the combined cycle of an ORC and refrigeration [6]; combined cycle of ORC and liquefied natural gas (LNG) cold energy [7]; combined cooling, heating, and power generation cycle [8]; and solar ORC [9] have been proposed and investigated. Bao and Zhao [10], Recompte et al [11], Pethrrajan et al [12], Mahmoudi et al [13], Shi et al [14], and Garcia et al [15] have reviewed the studies, both theoretical and experimental, on ORC.…”