Optimum Design of Shell and Tube Heat Exchangers using Modified Kinetic Gas Molecule Optimizer for the use of Low Temperature in Organic Rankine Cycles

Shell and Tube Heat Exchangers (STHEs) plays a crucial role in an effective design of Organic Rankine Cycle (ORC) power plants.The main aim of this research work is to design a cost-effective ORC in order to exploit low to medium temperature geothermal fluid or low grade industrial waste heat. In this research work, modified Kinetic Gas Molecule Optimization (KGMO) algorithm was developed forfinding the optimized parameter settings of the power plant. In modified KGMO algorithm, feedback learning stage was included for improving the fitness of individual worst particles. In addition, the proposed optimization algorithm was tested on two dissimilar fluids such asR245fa and R134a in order to show the effectiveness of proposed scheme. The experimental investigation showed that the proposed scheme effectively improved the heat exchanger performance as related to the existing schemes.The enhancement factor of proposed scheme was 2.8063 for R245fa fluid and 1.9346 for R134a fluid, which was better compared to the existing schemes; KGMO and Bell-Delaware method.

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Design and Analysis of the Scroll Expander with Next Generation Refrigerant in an ORC

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b3106.078219 ◽

2019 ◽

Vol 8 (2) ◽

pp. 5687-5693

Keyword(s):

Power Output ◽

Waste Heat ◽

Research Work ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Working Fluid ◽

Slight Variation ◽

Cfd Analysis ◽

Medium Temperature ◽

Scroll Expander

Organic Rankine Cycle (ORC) system is used to extract the waste heat from low to medium temperature heat source. The ORC system works as a reverse process of refrigeration. It has the four basic components of Condenser, Refrigerant pump, Evaporator and the Expander. The waste heat is absorbed in the Evaporator and the energy gained is used to rotate the expander which generate the power. The Expander used in the ORC are of different types like the scroll, Screw, Rotary, Turbo. Various refrigerants are used as the working fluid in the ORC system depending upon its physical and thermodynamic properties like R134a, R245fa etc. R245fa is currently used refrigerant in the ORC system. In recent research and development of the refrigerants, R1233zd(E) is also having suitable properties to be used in the ORC system. This refrigerant has zero ODP and very low GWP. This research work includes the analytical and the CFD analysis over the working fluid in the Scroll Expander of the ORC system. The working fluids considered for the analysis is R245fa which currently has a wide usage, and another is R1233zd(E) which has the suitable properties for ORC and is a green refrigerant. A specification for ORC system is considered and the p-h chart is plotted on the refrigerant charts for R245fa & R1233zd(E). The Scroll Fluid Geometry is drafted using ANSYS Design Modeller & Mesh. The Analytical & CFD analysis method is used to find the Force, Torque & Power output parameters for both the refrigerants under consideration at different operating angular positions. The results projected using the Analytical & the CFD method is almost similar with slight variation. The efficiency and the power output using the refrigerant R1233zd(E) is slightly less in comparison with the refrigerant R245fa. Considering the power output results from the scroll expander with both the working fluid under analysis, the refrigerant R1233zd(E) is a good alternate working fluid over the refrigerant R245fa in the ORC system with its Zero ODP and low GWP with a slight compromise over the power output from the ORC system.

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Performance Analysis of Organic Rankine Cycle for Low-Grade Waste Heat Recovery in Industry

CSAA/IET International Conference on Aircraft Utility Systems (AUS 2018) ◽

10.1049/cp.2018.0213 ◽

2018 ◽

Author(s):

RuiJie Wang ◽

JingQuan Zhao ◽

Lei Zhu ◽

DongHai Zhang ◽

GuoHua Kuang

Keyword(s):

Performance Analysis ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Low Grade

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Meanline Analysis and CFD Study of a Radial Inflow Turbine With Vaneless Distributor for Low Temperature Organic Rankine Cycle

Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine ◽

10.1115/gt2020-14792 ◽

2020 ◽

Author(s):

M. Deligant ◽

S. Braccio ◽

T. Capurso ◽

F. Fornarelli ◽

M. Torresi ◽

...

Keyword(s):

Energy Demand ◽

Waste Heat ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Operating Conditions ◽

Low Grade ◽

Heat Sources ◽

Turbine Wheel ◽

Good Efficiency ◽

Low Grade Heat

Abstract The Organic Rankine Cycle (ORC) allows the conversion of low-grade heat sources into electricity. Although this technology is not new, the increase in energy demand and the need to reduce CO2 emissions create new opportunities to harvest low grade heat sources such as waste heat. Radial turbines have a simple construction, they are robust and they are not very sensitive to geometry inaccuracies. Most of the radial inflow turbines used for ORC application feature a vaned nozzle ensuring the appropriate distribution angle at the rotor inlet. In this work, no nozzle is considered but only the vaneless gap (distributor). This configuration, without any vaned nozzle, is supposed to be more flexible under varying operating conditions with respect to fixed vanes and to maintain a good efficiency at off-design. This paper presents a performance analysis carried out by means of two approaches: a combination of meanline loss models enhanced with real gas fluid properties and 3D CFD computations, taking into account the entire turbomachine including the scroll housing, the vaneless gap, the turbine wheel and the axial discharge pipe. A detailed analysis of the flow field through the turbomachine is carried out, both under design and off design conditions, with a particular focus on the entropy field in order to evaluate the loss distribution between the scroll housing, the vaneless gap and the turbine wheel.

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