Quasi-dynamic model for an organic Rankine cycle

Bamgbopa, Musbaudeen O.; Uzgoren, Eray

doi:10.1016/j.enconman.2013.01.040

Cited by 41 publications

(18 citation statements)

References 22 publications

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“…The ORC is considered to be one of the most economic and efficient ways to convert low grade thermal energy, such as geothermal energy, solar thermal energy, waste heat recovery, biomass energy, and ocean thermal energy, to electricity [2]. In recent years, ORCs are being studied in many contexts, including technical-economical-market surveys [1,3], selection of the working fluid [4][5][6], proof of concept demonstrations [7,8], models for optimal control strategies [9], quasi-dynamic models [10], and running tests of prototypes for ORC systems [11,12].…”

Section: Introductionmentioning

confidence: 99%

Performance of a 250 kW Organic Rankine Cycle System for Off-Design Heat Source Conditions

Liu

2014

Proceedings of 1st International E-Conference on Energies

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An organic Rankine cycle system with a preheater, evaporator, condenser, turbine, generator, and pump was used to study its off-design performance and operational control strategy. R245fa was used as a working fluid. The net power output is 243 kW and the system thermal efficiency is 9.5% under the design conditions. For an off-design heat source flow rate (m W ), the operating pressure was controlled to meet the condition that the R245fa reached the saturation liquid and vapor states at the outlet of the preheater and evaporator, respectively. The analytical results demonstrated that the operating pressure increased with increasing m W ; a higher m W yielded better heat transfer performance of the preheater and required a smaller evaporator heat capacity; and the net power output and system thermal efficiency increased with increasing m W . The net power output increased by 64.0% while the total heat transfer rate increased by only 9.2% for the studied range of m W . To conclude, an off-design operation is studied for a heat source flow rate which varied from -39.0% to +78.0% from the designed rate, resulting in -29.2% to +16.0% and -25.3% to +12.6% variations in the net power output and system thermal efficiency, respectively.

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Section: Introductionmentioning

confidence: 99%

Performance of a 250 kW Organic Rankine Cycle System for Off-Design Heat Source Conditions

Liu

2014

Proceedings of 1st International E-Conference on Energies

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“…Similarly, Bamgbopa and Uzgoren [93] developed a dynamic model for the heat exchangers and static models for the pump and the expander and studied the power output for varying flow rate and temperature for the hot and cold sources in a system that employed R245fa as the working fluid. In a subsequent article by Bamgbopa and Uzgoren [94] the models were utilized to evaluate the steady state efficiency of a solar ORC system.…”

Section: Dynamic Modelsmentioning

confidence: 99%

Systematic Methods for Working Fluid Selection and the Design, Integration and Control of Organic Rankine Cycles—A Review

2015

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Efficient power generation from low to medium grade heat is an important challenge to be addressed to ensure a sustainable energy future. Organic Rankine Cycles (ORCs) constitute an important enabling technology and their research and development has emerged as a very active research field over the past decade. Particular focus areas include working fluid selection and cycle design to achieve efficient heat to power conversions for diverse hot fluid streams associated with geothermal, solar or waste heat sources. Recently, a number of approaches have been developed that address the systematic selection of efficient working fluids as well as the design, integration and control of ORCs. This paper presents a review of emerging approaches with a particular emphasis on computer-aided design methods.

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“…The selection criteria require the organic fluids to have low environmental impact (low ODP and low GWP), favourable thermodynamic properties (high enthalpy drop through the expander, favourable boiling temperature, large latent heat, good heat transfer, low viscosity and good thermal stability), high safety (low toxicity, low corrosion and non-flammability) and low cost [32]. Based on these requirements, R245fa was chosen as a working fluid that is also widely used in many studies such as [33][34][35]. As mentioned Energies 2016, 9, 527 4 of 21 above, the decomposition temperature of R245fa is relative low, so an ORC-MC system is applied as the WHRS.…”

Section: Orc-mc Systemmentioning

confidence: 99%

Part-Load Performance Prediction and Operation Strategy Design of Organic Rankine Cycles with a Medium Cycle Used for Recovering Waste Heat from Gaseous Fuel Engines

2016

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Abstract:The Organic Rankine Cycle (ORC) is regarded as a suitable way to recover waste heat from gaseous fuel internal combustion engines. As waste heat recovery systems (WHRS) have always been designed based on rated working conditions, while engines often work under part-load conditions, it is quite significant to analyze the part-load performance and corresponding operation strategy of ORC systems. This paper presents a dynamic model of ORC with a medium cycle used for a large gaseous fuel engine and analyzes the effect of adjustable parameters on the system performance, giving effective control directions under various conditions. The results indicate that the intermediary fluid mass flow rate has nearly no effect on the output power and thermal efficiency of the ORC, while the mass flow rate of working fluid has a great effect on them. In order to get a better system performance under different working conditions, the system should be operated with the working fluid mass flow rate as large as possible, but with a slight degree of superheating. Then, with the control of constant superheat degree at the end of the heating process, the performance of the combined system that consists of ORC and the engine at steady state under seven typical working conditions is also analyzed. The results indicate that the energy-saving effect of WHRS becomes worse and worse as the working condition decreases. Especially at 40% working condition the WHRS nearly has no energy-saving effect anymore.

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Quasi-dynamic model for an organic Rankine cycle

Cited by 41 publications

References 22 publications

Performance of a 250 kW Organic Rankine Cycle System for Off-Design Heat Source Conditions

Performance of a 250 kW Organic Rankine Cycle System for Off-Design Heat Source Conditions

Systematic Methods for Working Fluid Selection and the Design, Integration and Control of Organic Rankine Cycles—A Review

Part-Load Performance Prediction and Operation Strategy Design of Organic Rankine Cycles with a Medium Cycle Used for Recovering Waste Heat from Gaseous Fuel Engines

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