A direct manipulation interface for water-based Rankine Cycle heat engines

1988 ◽  
Vol 19 (4) ◽  
pp. 340-342
Author(s):  
L. Beltracchi
Keyword(s):  
Rankine Cycle ◽  
Direct Manipulation ◽  
Heat Engines ◽  
Water Based

Solar Thermal Energy

2018 ◽  
Author(s):  
E. L. Wolf
Keyword(s):  
Solar Cells ◽  
Thermal Energy ◽  
Fossil Fuel ◽  
Rankine Cycle ◽  
Carnot Cycle ◽  
The Sun ◽  
Solar Thermal Energy ◽  
Heat Engines ◽  
Direct Use ◽  
Fossil Fuel Energy

The Sun’s spectrum on Earth is modified by the atmosphere, and is harvested either by generating heat for direct use or for running heat engines, or by quantum absorption in solar cells, to be discussed later. Focusing of sunlight requires tracking of the Sun and is defeated on cloudy days. Heat engines have efficiency limits similar to the Carnot cycle limit. The steam turbine follows the Rankine cycle and is well developed in technology, optimally using a re-heat cycle of higher efficiency. Having learned quite a bit about how the Sun’s energy is created, and how that process might be reproduced on Earth, we turn now to methods for harvesting the energy from the Sun as a sustainable replacement for fossil fuel energy.

Thermal Analysis of Heat Recovery Unit to Recover Exhaust Energy for Using in Organic Rankine Cycle

2013 ◽  
Vol 393 ◽  
pp. 781-786 ◽  
Author(s):  
Aman M.I. bin Mamat ◽  
Wan Ahmad Najmi Wan Mohamed
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Gas Temperature ◽  
Maximum Heat ◽  
Heat Engines ◽  
Exhaust Energy ◽  
R 134A ◽  
Exhaust Gas Temperature

Heat engines convert only approximately 20% to 50% of the supplied energy into mechanical work whereas the remaining energy is lost as rejected heat. Although some of the energy lost is intrinsic to the nature of an engine and cannot be fully overcome (such as energy lost due to friction of moving parts), a large amount of energy can potentially be recovered. This paper presents a heat transfer analysis of a WHE for recovering wasted exhaust energy whilst transferring energy to different organic working fluid used in the OrganicRankine Cycle. The types of considered fluids are R-134a, Propane and Ammonia. The results show that the Ammonia has the highesteffectiveness of 0.25. The maximum heat transferrate of 48.5 kW was recovered using the Ammonia at the exhaust gas temperature of 700°C.

Analysis and Optimization of an Ammonia Based Transcritical Rankine Cycle for Power Generation

2008 ◽  
Author(s):  
Jahar Sarkar ◽  
Souvik Bhattacharyya
Keyword(s):  
Power Generation ◽  
Low Temperature ◽  
Thermal Efficiency ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Heat Sources ◽  
High Side ◽  
Water Based ◽  
Temperature Heat ◽  
Transcritical Rankine Cycle

This study presents the potential of ammonia as a working fluid in transcritical Rankine cycle for power generation using both high and low temperature heat sources. Higher heat capacity value and superior heat transfer properties of ammonia compared to water are the motivating factors behind its use as a working fluid. A thermodynamic analysis for the ammonia based transcritical Rankine cycle and its comparison with the water based Rankine cycle is presented. Analyses with several cycle modifications are also presented to study the thermal efficiency augmentation. It is observed that an optimum high side pressure exists for near critical operation. In case of low temperature heat sources such as solar energy or waste heat, where water based systems are not suitable, ammonia based Rankine cycle is applicable with attractive thermal efficiency, although cycle modification is not possible. The results with high temperature heat source such as boiler or nuclear reactor, where the turbine outlet is in superheated zone, show that simple ammonia systems yield lower efficiency than water, although a recompression cycle with regenerative heat exchangers exhibits higher efficiency than water. Significant thermal efficiency improvement can be achieved by increasing the high side cycle pressure. Recompression Rankine cycle can be a potential alternative with proper design measures taken to avoid toxicity and flammability.

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.

Direct Manipulation Interface for 3D Agents Based on Stretched Word-end Voice Commands

2013 ◽  
Vol 133 (12) ◽  
pp. 2257-2263
Author(s):  
Tomohisa Kawasaki ◽  
Takahiro Shinozaki ◽  
Sadaoki Furui
Keyword(s):  
Direct Manipulation
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