THE POSSIBILITY OF USING LOW-POTENTIAL HEAT BASED ON THE ORGANIC RANKINE CYCLE AND DETERMINATION OF HYDRAULIC CHARACTERISTICS OF INDUSTRIAL UNITS BASED ON THE THEORY OF STOCHASTIC EQUATIONS AND EQUIVALENCE OF MEASURES

2020 ◽  
Vol 21 (1) ◽  
pp. 125-132 ◽  
Author(s):  
A. V. Dmitrenko
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Stochastic Equations ◽  
Hydraulic Characteristics ◽  
Equivalence Of Measures ◽  
Industrial Units

scholarly journals OPTIMAL EVAPORATING AND CONDENSING TEMPERATURES OF ORGANIC RANKINE CYCLE IN A HOT AND HUMID ENVIRONMENT

2016 ◽  
Vol 36 (1) ◽  
pp. 110-118
Author(s):  
UV Ihuoma ◽  
EO Diemuodeke
Keyword(s):  
Heat Input ◽  
Figure Of Merit ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Thermodynamic Theory ◽  
Development Environment ◽  
Evaporation Temperature ◽  
Humid Environment ◽  
Theoretical Procedure

This paper presents a thermodynamic analysis of an organic Rankine cycle (ORC) in a hot and humid environment. A theoretical procedure is proposed for the determination of the optimal evaporation temperature (OET) and optimal condensing temperature (OCT) of a subcritical ORC plant, which is based on thermodynamic theory; the heat input is selected as the objective function. The OETs and OCTs of 21 working fluids, which comprise wet, isentropic and dry fluids, are determined under given environmental conditions– hot and humid environment. The Engineering Equation Solver (EES) integrated development environment is used to optimize the heat input of the ORC plant. Results suggest that the wet fluids (namely R717, Methanol and Ethanol) have the potential of producing better thermodynamic figure of merit over the other fluid types.   http://dx.doi.org/10.4314/njt.v36i1.14

scholarly journals Determination of Critical Reynolds Number for the Flow Near a Rotating Disk on the Basis of the Theory of Stochastic Equations and Equivalence of Measures

Fluids ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 5
Author(s):  
Artur Dmitrenko
Keyword(s):  
Reynolds Number ◽  
Power Plants ◽  
Critical Reynolds Number ◽  
Thermal State ◽  
Rotating Disk ◽  
Stochastic Equations ◽  
Analytical Dependence ◽  
Steam Turbines ◽  
Equivalence Of Measures

The determination of the flow regime of liquid and gas in power plants is the most important design task. Performing the calculations based on modern calculation methods requires a priori knowledge of the initial and boundary conditions, which significantly affect the final results. The purpose of the article is to present the solution for the critical Reynolds number for the flow near a rotating disk on the basis of the theory of stochastic equations of continuum laws and equivalence of measures between random and deterministic motions. The determination of the analytical dependence for the critical Reynolds number is essential for the study of flow regimes and the thermal state of disks and blades in the design of gas and steam turbines. The result of the calculation with using the new formula shows that for the flow near a wall of rotating disk, the critical Reynolds number is 325,000, when the turbulent Reynolds is 5 ÷ 10 and the degree of turbulence is 0.01 ÷ 0.02. Therefore, the result of solution shows a satisfactory correspondence of the obtained analytical dependence for the critical Reynolds number with the experimental data.

Model, simulation and experiments for a Buoyancy Organic Rankine Cycle

2020 ◽  
Vol 92 (1) ◽  
pp. 10906
Author(s):  
Jeroen Schoenmaker ◽  
Pâmella Gonçalves Martins ◽  
Guilherme Corsi Miranda da Silva ◽  
Julio Carlos Teixeira
Keyword(s):  
Model Simulation ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Test Body ◽  
Working Fluid ◽  
Proof Of Concept ◽  
Energy Scenario ◽  
New Type ◽  
Fluid Reservoir

Organic Rankine Cycle (ORC) systems are increasingly gaining relevance in the renewable and sustainable energy scenario. Recently our research group published a manuscript identifying a new type of thermodynamic cycle entitled Buoyancy Organic Rankine Cycle (BORC) [J. Schoenmaker, J.F.Q. Rey, K.R. Pirota, Renew. Energy 36, 999 (2011)]. In this work we present two main contributions. First, we propose a refined thermodynamic model for BORC systems accounting for the specific heat of the working fluid. Considering the refined model, the efficiencies for Pentane and Dichloromethane at temperatures up to 100 °C were estimated to be 17.2%. Second, we show a proof of concept BORC system using a 3 m tall, 0.062 m diameter polycarbonate tube as a column-fluid reservoir. We used water as a column fluid. The thermal stability and uniformity throughout the tube has been carefully simulated and verified experimentally. After the thermal parameters of the water column have been fully characterized, we developed a test body to allow an adequate assessment of the BORC-system's efficiency. We obtained 0.84% efficiency for 43.8 °C working temperature. This corresponds to 35% of the Carnot efficiency calculated for the same temperature difference. Limitations of the model and the apparatus are put into perspective, pointing directions for further developments of BORC systems.

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