Design and Operation Strategy of Micro Organic Rankine Cycle with Zeotropic Binary Mixtures for Low Grade Geothermal Energy

2021 ◽  
Author(s):  
Ryosuke Akimoto ◽  
Masaru Nakaiwa ◽  
Keigo Matsuda
Keyword(s):  
Binary Mixtures ◽  
Geothermal Energy ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Low Grade ◽  
Operation Strategy

scholarly journals Thermo-Economic Comparison Between Organic Rankine Cycle and Binary-Flashing Cycle for Geothermal Energy

2021 ◽  
Vol 9 ◽  
Author(s):  
Yuan Zhao ◽  
Bowen Du ◽  
Shunyi Chen ◽  
Jun Zhao ◽  
Yulie Gong ◽  
...  
Keyword(s):  
Geothermal Energy ◽  
Heat Recovery ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Payback Period ◽  
Low Grade ◽  
Recovery Efficiency ◽  
Net Power Output ◽  
Full Utilization ◽  
Economic Comparison

Geothermal energy is a characteristic of widely distributed, high capacity factor, high reliability, and lower environmental impact potential values. And it will play an important role in achieving the goal of carbon neutral carbon peak. Nonetheless, geothermal energy presents its own particular challenges, i.e., the high investment cost and long payback period. The binary flashing cycle (BFC) system is proved to be a promising power generation technology due to the efficient and full utilization of a low-grade heat source. While the economic performance still needs further evaluation, in the present study, the thermo-economic comparison between organic Rankine cycle (ORC) and the BFC for geothermal energy has been investigated. R245fa has been chosen as the working fluid. Considering the thermodynamic and economic performance simutaneously, several evaluation indicators were selected including thermal efficiency, exergy efficiency, net power output per ton geothermal water, heat exchanger area, and heat recovery efficiency, and the system modeling and comparison were presented. The simulation results reveal that the BFC system obtains 32% more net power output than the ORC system under the working conditions investigated. The heat recovery efficiency of the BFC is 1.96 times as much as that of the ORC, which indicates that the BFC can realize the full utilization of low-grade energy. And more heat exchanger areas are required in the BFC system. What is more, the preliminary discussion of the economic feasibility of BFC system applied in the FengShun geothermal power plant is presented. The payback period of the BFC is just 6.0 years under the generation pressure of 600 kPa. It is indicated that the BFC system has obvious economic benefits, especially in a nonflowing geothermal well.

Low grade waste heat recovery with subcritical and supercritical Organic Rankine Cycle based on natural refrigerants and their binary mixtures

Energy ◽  
2015 ◽  
Vol 88 ◽  
pp. 80-92 ◽  
Author(s):  
Konstantinos Braimakis ◽  
Markus Preißinger ◽  
Dieter Brüggemann ◽  
Sotirios Karellas ◽  
Kyriakos Panopoulos
Keyword(s):  
Binary Mixtures ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Low Grade

1-D Model Analysis of Tesla Turbine for Small Scale Organic Rankine Cycle (ORC) System

2017 ◽  
Author(s):  
Jian Song ◽  
Chun-wei Gu
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Organic Rankine Cycle ◽  
Axial Flow ◽  
Rankine Cycle ◽  
Expansion Ratio ◽  
Working Fluid ◽  
Small Scale ◽  
Low Grade ◽  
D Model

Energy shortage and environmental deterioration are two crucial issues that the developing world has to face. In order to solve these problems, conversion of low grade energy is attracting broad attention. Among all of the existing technologies, Organic Rankine Cycle (ORC) has been proven to be one of the most effective methods for the utilization of low grade heat sources. Turbine is a key component in ORC system and it plays an important role in system performance. Traditional turbine expanders, the axial flow turbine and the radial inflow turbine are typically selected in large scale ORC systems. However, in small and micro scale systems, traditional turbine expanders are not suitable due to large flow loss and high rotation speed. In this case, Tesla turbine allows a low-cost and reliable design for the organic expander that could be an attractive option for small scale ORC systems. A 1-D model of Tesla turbine is presented in this paper, which mainly focuses on the flow characteristics and the momentum transfer. This study improves the 1-D model, taking the nozzle limit expansion ratio into consideration, which is related to the installation angle of the nozzle and the specific heat ratio of the working fluid. The improved model is used to analyze Tesla turbine performance and predict turbine efficiency. Thermodynamic analysis is conducted for a small scale ORC system. The simulation results reveal that the ORC system can generate a considerable net power output. Therefore, Tesla turbine can be regarded as a potential choice to be applied in small scale ORC systems.

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

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.

Investigations on experimental performance and system behavior of 10 kW organic Rankine cycle using scroll-type expander for low-grade heat source

Energy ◽  
2019 ◽  
Vol 177 ◽  
pp. 94-105 ◽  
Author(s):  
Chih-Hung Lin ◽  
Pei-Pei Hsu ◽  
Ya-Ling He ◽  
Yong Shuai ◽  
Tzu-Chen Hung ◽  
...  
Keyword(s):  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Low Grade ◽  
System Behavior ◽  
Experimental Performance ◽  
Low Grade Heat

Thermo-economic optimization of small-scale Organic Rankine Cycle: A case study for low-grade industrial waste heat recovery

Energy ◽  
2020 ◽  
Vol 213 ◽  
pp. 118898
Author(s):  
Bernardo Peris ◽  
Joaquín Navarro-Esbrí ◽  
Carlos Mateu-Royo ◽  
Adrián Mota-Babiloni ◽  
Francisco Molés ◽  
...  
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Small Scale ◽  
Low Grade ◽  
Economic Optimization ◽  
Industrial Waste Heat

Multi-Vane Expanders as Prime Movers in Low-Grade Energy Engines

1986 ◽  
Vol 200 (2) ◽  
pp. 117-125 ◽  
Author(s):  
O Badr ◽  
D Probert ◽  
P W O'Callaghan
Keyword(s):  
Low Temperature ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Low Grade ◽  
Small Power ◽  
Operating Variables ◽  
Positive Displacement ◽  
Temperature Heat ◽  
Prime Movers ◽  
Power Outputs

Multi-vane expanders possess many advantages, over turbines and other positive-displacement machines, as prime movers for low-grade energy engines of small power outputs. It has been found that the performances of such expanders can be improved considerably by optimizing their design and operating variables. For an organic Rankine-cycle engine, utilizing low-temperature heat as the input, a multi-vane expander with isentropic efficiencies exceeding 73 per cent at rotational speeds up to 3000 r/min was designed, built and demonstrated.

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