Definition of a general performance map for single stage radial inflow turbines and analysis of the impact of expander performance on the optimal ORC design in on-board waste heat recovery applications

Manfredi, Marco; Spinelli, Andrea; Astolfi, Marco

doi:10.1016/j.applthermaleng.2022.119857

Cited by 9 publications

(5 citation statements)

References 16 publications

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“…Once the indicated power is evaluated, to assess the mechanical power produced by the expander, from Pind the mechanical losses should be subtracted as in Equation (2).…”

Section: Theoretical Modelmentioning

confidence: 99%

“…One of the most important technological solutions to exploit low-temperature hot sources is the power unit based on Organic Rankine Cycle (ORC) [1]. These, indeed, allow production of mechanical power recovered from the thermal power of waste heat in internal combustion engines [2][3][4] and the industrial sector [5,6]. Moreover, ORC-based power units can recover low-and medium-grade thermal energy of renewable hot sources like solar [7][8][9], geothermal [10,11] and biomasses after combustion [12].…”

Section: Introductionmentioning

confidence: 99%

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Development of Dual Intake Port Technology in ORC-Based Power Unit Driven by Solar-Assisted Reservoir

Fatigati,

Cipollone

2024

Energies

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The ORC-based micro-cogeneration systems exploiting a solar source to generate electricity and domestic hot water (DHW) simultaneously are a promising solution to reduce CO2 emissions in the residential sector. In recent years, a huge amount of attention was focused on the development of a technological solution allowing improved performance of solar ORC-based systems frequently working under off-design conditions due to the intermittence of the solar source availability and to the variability in domestic hot water demand. The optimization efforts are focused on the improvement of component technology and plant architecture. The expander is retained as the key component of such micro-cogeneration units. Generally, volumetric machines are adopted thanks to their better capability to deal with severe off-design conditions. Among the volumetric expanders, scroll machines are one of the best candidates thanks to their reliability and to their flexibility in managing two-phase working fluid. Their good efficiency adds further interest to place them among the best candidate machines to be considered. Nevertheless, similarly to other volumetric expanders, an additional research effort is needed toward efficiency improvement. The fixed built-in volume ratio, in fact, could produce an unsteady under- or over-expansion during vane filling and emptying, mainly when the operating conditions depart from the designed ones. To overcome this phenomenon, a dual intake port (DIP) technology was also introduced for the scroll expander. Such technology allows widening the angular extension of the intake phase, thus adapting the ratio between the intake and exhaust volume (so called built-in volume ratio) to the operating condition. Moreover, DIP technology allows increasing the permeability of the machine, ensuring a resulting higher mass flow rate for a given pressure difference at the expander side. On the other hand, for a given mass flow rate, the expander intake pressure diminishes with a positive benefit on scroll efficiency. DIP benefits were already proven experimentally and theoretically in previous works by the authors for Sliding Rotary Vane Expanders (SVRE). In the present paper, the impact of the DIP technology was assessed in a solar-assisted ORC-based micro-cogeneration system operating with scroll expanders and being characterized by reduced power (hundreds of W). It was found that the DIP Scroll allows elaboration of a 32% higher mass flow rate for a given pressure difference between intake and expander sides for the application at hand. This leads to an average power increase of 10% and to an improvement of up to 5% of the expander mechanical efficiency. Such results are particularly interesting for micro-cogeneration ORC-based units that are solar-assisted. Indeed, the high variability of hot source and DHW demand makes the operation of the DIP expander at a wide range of operating conditions. The experimental activity conducted confirms the suitability of the DIP expander to exploit as much as possible the thermal power available from a hot source even when at variable temperatures during operation.

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“…Once the indicated power is evaluated, to assess the mechanical power produced by the expander, from Pind the mechanical losses should be subtracted as in Equation (2).…”

Section: Theoretical Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Development of Dual Intake Port Technology in ORC-Based Power Unit Driven by Solar-Assisted Reservoir

Fatigati,

Cipollone

2024

Energies

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“…Song et al [17] simulated a heat pump with an intermediate economizer and the ground source energy drive using EES software and then examined the effect of different parameters on environmental parameters using five working fluids (R134a, R12, R152a, R1234ze(E), and R1234yf). Some researchers have focused on performance optimization to achieve the optimal performance of the ORC system [18,19]. Le et al [20] introduced the system efficiency optimization scheme of basic and regenerative supercritical ORCs (organic Rankine cycles) using low-GWP organic compounds as the working fluid.…”

Section: Introductionmentioning

confidence: 99%

Thermal-Economic Analysis of an Organic Rankine Cycle System with Direct Evaporative Condenser

Yu,

Geng,

Gao

2023

J. Adv. Therm. Sci. Res.

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The organic Rankine cycle (ORC) system for power generation has proven to be an effective technology for low-temperature waste heat utilization. Accurate prediction and comprehensive comparison of system performance under different conditions are necessary for the development and application of suitable ORC configurations. This paper proposed an organic Rankine cycle (ORC) system using a direct evaporative condenser to realize performance enhancement and analyzed its dynamic performance based on the actual climatic condition, which is beneficial for the performance optimization of this system. This study begins with an introduction to the thermal economics model of the proposed system and evaluates the performance of the system based on the 3E (energy, exergy, economy) analysis method. Secondly, four candidate working fluids were compared and analyzed, leading to the selection of R142b as the best working fluid for the proposed system. Finally, the dynamic performance of the proposed system using the working fluid of R142b was analyzed based on the hourly environment temperature. The result showed that the net thermos-electric conversion efficiency of the system was negatively correlated with the ambient wet-bulb temperature. The annual average exergy efficiency of the system is about 65.79%, and the average exergy loss of the heat absorption unit, evaporative condenser, pump, and expander account for 61.07%, 6.92%, 2.99%, and 29.01% of the exergy loss of the system respectively. In the case 8760 h of operation per year, the payback period of the proposed ORC system using direct evaporative condenser is about 2.14 years.

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“…First, a lowtemperature organic mass is pressurized and its physical properties, such as boiling point and flow, are modified using a mass pump. Then, under the influence of the pump, the circulating mass in the system absorbs heat at medium pressure in the evaporator, causing it to vaporize and form saturated steam [1][2][3][4].This steam then transforms into high-temperature and highpressure gases. Finally, these gases are further heated by the superheater.…”

Section: Introductionmentioning

confidence: 99%

Research on Organic Rankine Cycle-Based Industrial Circulating Water Cogeneration System

Yang

2023

JERR

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A fertilizer plant wastewater recycling as a research object, the establishment of ORC (Organic Rankine Cycle, referred to as ORC) cogeneration system, using MATLAB software to simulate the operation of the system was found to change the evaporation temperature, condensing temperature, superheat and subcooling degree of the four factors will have an impact on the performance of the system, in which the evaporation temperature and degree of superheat to improve the performance of the system, the condensing temperature and degree of subcooling have a negative effect on the system efficiency. The evaporation temperature and superheat are favorable factors for improving the system performance, while the condensation temperature and subcooling degree adversely affect the system efficiency. Through the verification calculation of specific working conditions, under the conditions of evaporating temperature 110℃, condensing temperature 27℃, superheating degree 8℃ and subcooling degree 3℃, the thermal efficiency of the system can reach about 25%, and the energy efficiency reaches about 45%. The experimental results show that this designed ORC cogeneration system is able to recycle industrial waste heat to a greater extent, which is of great significance to improve the efficiency of energy utilization.

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Definition of a general performance map for single stage radial inflow turbines and analysis of the impact of expander performance on the optimal ORC design in on-board waste heat recovery applications

Cited by 9 publications

References 16 publications

Development of Dual Intake Port Technology in ORC-Based Power Unit Driven by Solar-Assisted Reservoir

Development of Dual Intake Port Technology in ORC-Based Power Unit Driven by Solar-Assisted Reservoir

Thermal-Economic Analysis of an Organic Rankine Cycle System with Direct Evaporative Condenser

Research on Organic Rankine Cycle-Based Industrial Circulating Water Cogeneration System

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