The Application of Rotary Vane Expanders in Organic Rankine Cycle Systems—Thermodynamic Description and Experimental Results

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Zbigniew Gnutek ◽  
Piotr Kolasiński
Keyword(s):  
Power Systems ◽  
Thermodynamic Description ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Test Stand ◽  
Working Fluid ◽  
Cycle Systems ◽  
Set Up ◽  
Domestic Power ◽  
Small Capacity

Small (10–100 kW) and micro (0.5–10 kW) Organic Rankine Cycle (ORC) power systems are nowadays considered for local and domestic power generation. Especially interesting are micropower applications for heat recovery from dispersed low potential (85–150 °C) waste and renewable heat sources. Designing and implementing an ORC system dedicated to energy recovery from such a source is difficult. A proper working fluid must be selected together with a suitable expander. Volumetric machines can be adopted as a turbine alternative in small-capacity applications under development, like, e.g., domestic cogeneration. Scroll and screw expanders are a common choice. However, scroll and screw expanders are complicated and expensive. Vane expanders are mechanically simple, commercially available and cheap. This paper documents a study providing the preliminary analysis of the possibility of employing vane-expanders in mini-ORC systems. The main objective of this research was therefore a comprehensive analysis of the use of a vane expander for continuous operation with a low-boiling working fluid. A test-stand was designed and set up starting from system models based on thermodynamic analysis. Then, a series of experiments was performed using the test-stand. Results of these experiments are presented here, together with a model of multivane expanders and a thermodynamic-based method to select the working fluid. The analysis presented in this paper indicates that multivane expanders are a cheap and mechanically simple alternative to other expansion devices proposed for small-capacity ORC systems.

scholarly journals Organic Rankine Cycle Power Systems: From the Concept to Current Technology, Applications, and an Outlook to the Future

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Piero Colonna ◽  
Emiliano Casati ◽  
Carsten Trapp ◽  
Tiemo Mathijssen ◽  
Jaakko Larjola ◽  
...  
Keyword(s):  
Power Systems ◽  
Research And Development ◽  
Thermal Energy ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Biomass Combustion ◽  
Main Stream ◽  
Advantages And Disadvantages ◽  
The Many

The cumulative global capacity of organic Rankine cycle (ORC) power systems for the conversion of renewable and waste thermal energy is undergoing a rapid growth and is estimated to be approx. 2000 MWe considering only installations that went into operation after 1995. The potential for the conversion of the thermal power coming from liquid-dominated geothermal reservoirs, waste heat from primary engines or industrial processes, biomass combustion, and concentrated solar radiation into electricity is arguably enormous. ORC technology is possibly the most flexible in terms of capacity and temperature level and is currently often the only applicable technology for the conversion of external thermal energy sources. In addition, ORC power systems are suitable for the cogeneration of heating and/or cooling, another advantage in the framework of distributed power generation. Related research and development is therefore very lively. These considerations motivated the effort documented in this article, aimed at providing consistent information about the evolution, state, and future of this power conversion technology. First, basic theoretical elements on the thermodynamic cycle, working fluid, and design aspects are illustrated, together with an evaluation of the advantages and disadvantages in comparison to competing technologies. An overview of the long history of the development of ORC power systems follows, in order to place the more recent evolution into perspective. Then, a compendium of the many aspects of the state of the art is illustrated: the solutions currently adopted in commercial plants and the main-stream applications, including information about exemplary installations. A classification and terminology for ORC power plants are proposed. An outlook on the many research and development activities is provided, whereby information on new high-impact applications, such as automotive heat recovery is included. Possible directions of future developments are highlighted, ranging from efforts targeting volume-produced stationary and mobile mini-ORC systems with a power output of few kWe, up to large MWe base-load ORC plants.

scholarly journals Performance modelling and greenhouse impact assessment of a micro-ORC energy system working with HFCs, low GWP fluids and mixtures

2021 ◽  
Vol 238 ◽  
pp. 10002
Author(s):  
Michele Bianchi ◽  
Lisa Branchini ◽  
Andrea De Pascale ◽  
Francesco Melino ◽  
Saverio Ottaviano ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Energy System ◽  
Working Fluid ◽  
Performance Modelling ◽  
Cycle Systems ◽  
Greenhouse Impact ◽  
Greenhouse Emission ◽  
Fluid Leak

The worrying effects of climate change have led, in the last decades, to the improvement of innovative solutions for low greenhouse emission energy conversion, among which, is the use of micro-ORC (Organic Rankine Cycle) systems for distributed generation, in the framework of combined heat and power applications and renewables exploitation. However, micro-ORCs environmental impact, due to high GWP (global working potential) working fluid leak rate, is an issue still to overcome. Neverthless the interest in using new low GWP refrigerants and their blends is increasing, new fluids have not yet been properly tested into ORC. Numerical studies reveal that low GWP fluids do not always guarantee the same performance of typically used fluids, leading to indirect emissions related to the use of fossil fuels to compensate the lower power production. This study proposes to investigate performance and impact of an innovative micro-ORC test bench when working with HFCs (HydroFluoroCarbons), low GWP fluids and mixtures, with the main aim of comprehensively evaluating its impact due to both direct and indirect greenhouse gas emissions produced in a typical annual operation.

High-Efficiency Solar Dynamic Space Power Generation System

1991 ◽  
Vol 113 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Aristide Massardo
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Generation System ◽  
Dynamic Power ◽  
Power Generation System

Space power technologies have undergone significant advances over the past few years, and great emphasis is being placed on the development of dynamic power systems at this time. A design study has been conducted to evaluate the applicability of a combined cycle concept—closed Brayton cycle and organic Rankine cycle coupling—for solar dynamic space power generation systems. In the concept presented here (solar dynamic combined cycle), the waste heat rejected by the closed Brayton cycle working fluid is utilized to heat the organic working fluid of an organic Rankine cycle system. This allows the solar dynamic combined cycle efficiency to be increased compared to the efficiencies of two subsystems (closed Brayton cycle and organic fluid cycle). Also, for small-size space power systems (up to 50 kW), the efficiency of the solar dynamic combined cycle can be comparable with Stirling engine performance. The closed Brayton cycle and organic Rankine cycle designs are based on a great deal of maturity assessed in much previous work on terrestrial and solar dynamic power systems. This is not yet true for the Stirling cycles. The purpose of this paper is to analyze the performance of the new space power generation system (solar dynamic combined cycle). The significant benefits of the solar dynamic combined cycle concept such as efficiency increase, mass reduction, specific area—collector and radiator—reduction, are presented and discussed for a low earth orbit space station application.

scholarly journals Heat Exchanger Sizing for Organic Rankine Cycle

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3615 ◽  
Author(s):  
James Bull ◽  
James M. Buick ◽  
Jovana Radulovic
Keyword(s):  
Heat Exchanger ◽  
Power Systems ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Two Phase ◽  
Operational Conditions ◽  
Shell And Tube

Approximately 45% of power generated by conventional power systems is wasted due to power conversion process limitations. Waste heat recovery can be achieved in an Organic Rankine Cycle (ORC) by converting low temperature waste heat into useful energy, at relatively low-pressure operating conditions. The ORC system considered in this study utilises R-1234yf as the working fluid; the work output and thermal efficiency were evaluated for several operational pressures. Plate and shell and tube heat exchangers were analysed for the three sections: preheater, evaporator and superheater for the hot side; and precooler and condenser for the cold side. Each heat exchanger section was sized using the appropriate correlation equations for single-phase and two-phase fluid models. The overall heat exchanger size was evaluated for optimal operational conditions. It was found that the plate heat exchanger out-performed the shell and tube in regard to the overall heat transfer coefficient and area.

scholarly journals Integrated working fluid-thermodynamic cycle design of organic Rankine cycle power systems for waste heat recovery

2017 ◽  
Vol 203 ◽  
pp. 442-453 ◽  
Author(s):  
Stefano Cignitti ◽  
Jesper G. Andreasen ◽  
Fredrik Haglind ◽  
John M. Woodley ◽  
Jens Abildskov
Keyword(s):  
Power Systems ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Working Fluid

scholarly journals Application of the Multi-Vane Expanders in ORC Systems—A Review on the Experimental and Modeling Research Activities

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2975 ◽  
Author(s):  
Kolasiński
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Operating Principle ◽  
Working Fluid ◽  
Promising Alternative ◽  
Research Activities ◽  
Cycle Systems ◽  
Micro Power ◽  
Geometrical Dimensions

This paper reviews the applications of the multi-vane expanders in ORC (organic Rankine cycle) systems. The operating principle and design of the ORC systems are addressed in the introduction. Then, there is a brief review of the expanders applied in small-power and micro-power ORCs, and a discussion of the multi-vane expander design and operating principle as an introduction to a comprehensive review on the applications of the multi-vane expanders in ORC systems. The different features of the multi-vane expanders—i.e., the design of the expander, its geometrical dimensions and operating conditions, durability, applied working fluid, obtained power output, and efficiency—are analyzed in this paper. This review clearly indicates that multi-vane expanders are a promising alternative to the different types of the expanders applied in ORC systems.

scholarly journals Domestic Organic Rankine Cycle-Based Cogeneration Systems as a Way to Reduce Dust Emissions in Municipal Heating

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3983
Author(s):  
Piotr Kolasiński
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Fuel Combustion ◽  
Test Stand ◽  
Experimental Results ◽  
Working Fluid ◽  
Operating Pressure ◽  
Dust Emissions ◽  
Central Heating ◽  
Combustion Processes

Environmental issues are nowadays of great importance. In particular air and water quality should be kept at as high levels as possible. Energy conversion systems and devices which are applied for converting the chemical energy contained in different fuels into heat, electricity and cold in the industry and housing are sources of different gases and solid particle emissions. Medical data show PM2.5 dust in particular is highly dangerous for human health. Therefore, limiting the number of low-quality fuel combustion processes is a key issue of modern energy policy. Statistical data show that domestic heating systems account for a large share of the total emissions of PM2.5 and PM10 dust. For example in Poland in 2017, the share of households in the total annual emissions of PM2.5 dust was equal to ca. 35.8%, while the share of PM2.5 emission in industry (i.e., power generating plants, industrial power plants and technologies) was equal to only 23.6%. A possible way of solving this problem is by the successful replacement of old domestic furnaces by combined heat and power (CHP) or multigeneration boilers which can be used for heating the rooms and sanitary water and generating electricity and cold. Such systems can possibly contribute in the future to significant reductions of dust emissions and air pollution in urban and rural areas by limiting the number of low-quality fuel combustion processes. This article presents design considerations and experimental results related to a domestic micro-CHP unit which is based on organic Rankine cycle (ORC) technology. The main aim of the design works and experiments was therefore the analysis of the possibility of integrating the ORC system with a standard domestic central heating gas-fired boiler. The specially designed micro-ORC system was implemented in the laboratory and experiments were performed using this test stand. The main design aims of the test-stand were: low operating pressure, small working fluid flow, low price and compact dimensions. To meet these aims, volumetric machines were chosen as the expander and working fluid pump. The experimental results were positive and show that it is possible to integrate an ORC system with a standard domestic central heating gas boiler. For different heat source temperatures, the obtained expander power ranged from 109 W to 241 W and the thermodynamic cycle efficiency ranged from 4.3% to 8.8%. These positive research results were achieved partly thanks to the positive features of the different system subassemblies.

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