Investigation of the Combination of Bypass System and OPC Logic for ORC System Stability Under Load Reduction Disturbance

2014 ◽  
Author(s):  
Pan Zhao ◽  
Mingkun Wang ◽  
Jiangfeng Wang ◽  
Yiping Dai
Keyword(s):  
Control System ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
System Stability ◽  
Small Scale ◽  
Low Grade ◽  
Load Reduction ◽  
Drum Boiler ◽  
Axial Turbine ◽  
Unit Model

Organic Rankine cycle (ORC) is recognized as a promising technology for converting the energy from low grade heat sources into electricity. From a general perspective, the ORC system mainly operates in island mode and also has a small scale power capacity. When this type of system sustains the disturbance of load reduction, the overpressure protection in drum boiler and overspeed protection in axial turbine are the two big challenges for ORC system’s stability. In the present study, the configuration type by combining the bypass system and overspeed protection control (OPC) logic is proposed in ORC system for solving these problems. Firstly, the ORC unit model consisting of the drum boiler, boiler control system, axial turbine, bypass system, turbine control system and OPC logic is established. Then, the drawback and improvements of current OPC logic in China are carried out. Finally, the simulation of this configuration type of ORC system is investigated under load reduction disturbance. The results show that the proposed configuration of ORC system has excellent performance in purpose of power system stability. The axial turbine in the simulation model operates in constant pressure mode.

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.

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

Cost Effective Small Scale ORC Systems for Power Recovery From Low Grade Heat Sources

2006 ◽  
Author(s):  
H. Leibowitz ◽  
I. K. Smith ◽  
N. Stosic
Keyword(s):  
Organic Rankine Cycle ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Small Scale ◽  
Low Grade ◽  
Full Potential ◽  
Heat Sources ◽  
Capacity Cost ◽  
Power Recovery ◽  
Low Grade Heat

The growing need to recover power from low grade heat sources, has led to a review of the possibilities for producing systems for cost effective power production at outputs as little as 20-50kWe. It is shown that by utilizing the full potential of screw expanders instead of turbines, it is possible to produce Organic Rankine Cycle (ORC) systems at these outputs, which can be installed for a cost in the range of $1500 to $2000 /kWe of net output. This low capacity cost combined with the ORC's fuel-free specification results in a very favorable value proposition.

Small scale Organic Rankine Cycle testing for low grade heat recovery by using refrigerants as working fluids

2018 ◽  
Vol 79 (3) ◽  
pp. 70-78
Author(s):  
Emanuele Fanelli ◽  
Simone Braccio ◽  
Giuseppe Pinto ◽  
Giacinto Cornacchia ◽  
Giacobbe Braccio
Keyword(s):  
Heat Recovery ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Small Scale ◽  
Low Grade ◽  
Working Fluids ◽  
Low Grade Heat

scholarly journals Performance Analysis of a Small-Scale ORC Trigeneration System Powered by the Combustion of Olive Pomace

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2279 ◽  
Author(s):  
Andrea Colantoni ◽  
Mauro Villarini ◽  
Vera Marcantonio ◽  
Francesco Gallucci ◽  
Massimo Cecchini
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Energy System ◽  
Small Scale ◽  
Low Grade ◽  
Olive Pomace ◽  
Working Pressure ◽  
Medium Temperature ◽  
Combustion Tests ◽  
Combined Cooling

The utilisation of low- and medium-temperature energy allows to reduce the energy shortage and environmental pollution problems because low-grade energy is plentiful in nature and renewable as well. In the past two decades, thanks to its feasibility and reliability, the organic Rankine cycle (ORC) has received great attention. The present work is focused on a small-scale (7.5 kW nominal electric power) combined cooling, heating and power ORC system powered by the combustion of olive pomace obtained as a by-product in the olive oil production process from an olive farm situated in the central part of Italy. The analysis of the employment of this energy system is based on experimental data and Aspen Plus simulation, including biomass and combustion tests, biomass availability and energy production analysis, Combined Cooling Heat and Power (CCHP) system sizing and assessment. Different low environmental impact working fluids and various operative process parameters were investigated. Olive pomace has been demonstrated to be suitable for the energy application and, in this case, to be able to satisfy the energy consumption of the same olive farm with the option of responding to further energy users. Global electrical efficiency varied from 12.7% to 19.4%, depending on the organic fluid used and the working pressure at the steam generator.

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