Efficiency Analysis on Low Temperature Energy Conversion System Based on Organic Rankine Cycle

2011 ◽  
Vol 347-353 ◽  
pp. 498-503
Author(s):  
Wei Wang ◽  
Yu Ting Wu ◽  
Chong Fang Ma ◽  
Jian Yu
Keyword(s):  
Low Temperature ◽  
Thermal Power ◽  
Power Conversion ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Single Screw ◽  
Conversion System ◽  
Temperature Heat ◽  
The Impact

The amount of low temperature heat resources is very huge, efficient utilization that energy is very important issue for improving energy efficiency, saving energy and protecting environment. Due to the small available energy of low temperature heat source, how to improve thermodynamic efficiency is the key problem. In this paper, the thermodynamic model of low temperature thermal power conversion system based on organic Rankine cycle was described firstly. Turbine, single screw and piston expanders were briefly described. R123, R245fa and R134a were chose as working fluid because of quite different critical temperature. Based on this model, the influence of thermodynamic property of organic working fluid on the efficiency of low temperature thermal power conversion system was discussed. The calculating result showed that R123 is the best choice if no considering the impact of expander types and that R245fa is the best choice if considering the impact of expander. This conclusion indicated that it is very important to investigate the match relationship between working fluid and expander. Moreover, single screw expander was proved to be more suitable than turbine and piston expanders for low temperature heat power conversion system.

scholarly journals A Simple Method of Finding New Dry and Isentropic Working Fluids for Organic Rankine Cycle

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 480 ◽  
Author(s):  
Gábor Györke ◽  
Axel Groniewsky ◽  
Attila Imre
Keyword(s):  
Low Temperature ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Electricity Production ◽  
Working Fluid ◽  
Heat Sources ◽  
Simple Method ◽  
Working Fluids ◽  
Temperature Heat

One of the most crucial challenges of sustainable development is the use of low-temperature heat sources (60–200 °C), such as thermal solar, geothermal, biomass, or waste heat, for electricity production. Since conventional water-based thermodynamic cycles are not suitable in this temperature range or at least operate with very low efficiency, other working fluids need to be applied. Organic Rankine Cycle (ORC) uses organic working fluids, which results in higher thermal efficiency for low-temperature heat sources. Traditionally, new working fluids are found using a trial-and-error procedure through experience among chemically similar materials. This approach, however, carries a high risk of excluding the ideal working fluid. Therefore, a new method and a simple rule of thumb—based on a correlation related to molar isochoric specific heat capacity of saturated vapor states—were developed. With the application of this thumb rule, novel isentropic and dry working fluids can be found applicable for given low-temperature heat sources. Additionally, the importance of molar quantities—usually ignored by energy engineers—was demonstrated.

scholarly journals Experimental investigation and performance analysis of an Organic Rankine Cycle for low-temperature heat to electricity generation

2019 ◽  
Vol 14 (4) ◽  
pp. 500-507
Author(s):  
Lili Wei ◽  
Zhenjun Ma ◽  
Xuemei Gong ◽  
Xiujuan Guo
Keyword(s):  
Energy Efficiency ◽  
Low Temperature ◽  
Heat Source ◽  
Electricity Generation ◽  
Extraction Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Energy And Exergy ◽  
Temperature Heat

Abstract This paper presents experimental investigation of low-temperature heat to electricity generation system based on Organic Rankine Cycle (ORC) using R152a as the working fluid. Both energy efficiency and exergy efficiency were analyzed based on the experiments. Although energy efficiency was low to 5.0% when the evaporating and cooling temperatures were 65°C and 11°C, respectively, the exergy efficiency reached 25%, which showed great competitiveness among low-temperature heat utilization technologies. To reveal the energy recovery proportion from the waste heat, both energy extraction efficiency and exergy extraction efficiency as well as energy and exergy loss paths were analyzed. When the heat source was 65°C, 14.9% of the maximum possible thermal energy in the heat source was absorbed by the organic working fluid, and 10.7% was transferred to the cooling medium. The power output contributed 0.64%. A total of 1.8% of the exergy in the heat stream flowed to the cooling medium. The start-up work takes dramatically 0.16% and 1.7% of energy and exergy, respectively. Other energy and exergy loss occurs due to the irreversibility of the heat transfer process and expansion process. Cascade ORC system could enlarge the temperature difference of the heat stream and raise the power output. However, the energy efficiency of the multi-stage ORC system is lower than single-stage system, since there was a downward trend of the temperature of heat source for the latter stage. ORC cycle can lower the temperature of heat source to 45°C.

Heat Recovery Using Organic Rankine Cycle

Vestnik MEI ◽  
2021 ◽  
pp. 51-57
Author(s):  
Dakkah Baydaa Bo ◽  
◽  
I′ldar A. Sultanguzin ◽  
Yuriy V. Yavorovsky ◽  
◽  
...  
Keyword(s):  
Low Temperature ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Test Bench ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Losses ◽  
Working Fluid ◽  
Gear Pump ◽  
Temperature Heat

Heat losses in industrial processes can be divided into three sections (high-, medium-, and low-temperature heat), depending on the temperature of the exhaust gases. This heat is usually recovered either by heat exchangers or by a closed Rankine cycle. However, about 60% of low-temperature heat losses remain irreplaceable. Currently, the organic Rankine cycle has become a promising method of low-temperature energy recovery, and several theoretical studies on this topic have appeared, but a small number of experimental studies have been performed. In our work, we have built a 2 kW heat recovery laboratory test bench using tube-type heat exchangers, a gear pump and a turbo expander on the working fluid R141b. As a result, we found that the efficiency of the cycle increases as the boiling point and pressure increase, but an increase in overheating at the inlet of the expander leads to a decrease in efficiency due to the use of the working fluid R141b. At the inlet of the evaporator and the outlet of the condenser, respectively, overheating and supercooling of the working fluid occurs, which negatively affects the efficiency of the cycle. The amount of useful heat obtained was 45.4 W with an efficiency of 2.24%. as a result of low efficiency of the expander and pump, as well as leaks during the test. The development of an experimental test bench with working on organic Rankin cycle requires long-term research work and great scientific potential. In the future, it will be necessary to create a new test bench based on a deeper study, so that we can get a higher efficiency of the expander and pump, which would affect the efficiency of this cycle. Also, we need to replace the working fluid in the cycle with a more efficient one.

scholarly journals Thermodynamic analysis of a Carbon Carrier Cycle (CCC) for low temperature heat recovery

2021 ◽  
Vol 238 ◽  
pp. 01002
Author(s):  
Diego Micheli ◽  
Mauro Reini ◽  
Rodolfo Taccani
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Recovery ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Performance Comparison ◽  
Working Fluid ◽  
Power Cycle ◽  
Carbon Carrier ◽  
Temperature Heat

The aim of the paper is to study the thermodynamic behavior of a non-conventional power cycle, named Carbon Carrier Cycle (CCC), which is expected to obtain interesting performance with low temperature heat source. The CCC may be regarded as derived from an absorption machine, where an expander replaces the condenser, the throttling valve and the evaporator. The working fluid is a mixture of CO2 and a proper absorber. In the paper, the thermodynamic model of this kind of cycles is described, and the results obtained considering Acetone as the absorber are discussed. A first performance comparison is then conducted with a more conventional Organic Rankine Cycle (ORC).

MODELING OF AN ORGANIC RANKINE CYCLE FOR LOW TEMPERATURE HEAT SOURCES

2018 ◽  
Author(s):  
Arthur Batista Martins Lott ◽  
Arthur Pacheco Luz ◽  
João Arthur Daconti Silva ◽  
Cristiana Maia ◽  
Sergio Hanriot
Keyword(s):  
Low Temperature ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Sources ◽  
Temperature Heat

A Totally Heat-Driven Refrigeration System Using Low-Temperature Heat Sources for Low-Temperature Applications

2019 ◽  
Vol 27 (02) ◽  
pp. 1950012 ◽  
Author(s):  
Zeynab Seyfouri ◽  
Mehran Ameri ◽  
Mozaffar Ali Mehrabian
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Water Mixture ◽  
Refrigeration System ◽  
Power Requirement ◽  
Temperature Heat

In the present study, a totally heat-driven refrigeration system is proposed and thermodynamically analyzed. This system uses a low-temperature heat source such as geothermal energy or solar energy to produce cooling at freezing temperatures. The proposed system comprises a Rankine cycle (RC) and a hybrid GAX (HGAX) refrigeration cycle, in which the RC provides the power requirement of the HGAX cycle. An ammonia–water mixture is used in both RC and HGAX cycles as the working fluid. A comparative study is conducted in which the proposed system is compared with two other systems using GAX cycle and/or a single stage cycle, as the refrigeration cycle. The study shows that the proposed system is preferred to produce cooling at temperatures from 2∘C to [Formula: see text]C. A detailed parametric analysis of the proposed system is carried out. The results of the analysis show that the system can produce cooling at [Formula: see text]C using a low-temperature heat source at 133.5∘C with the exergy efficiency of about 20% without any input power. By increasing the heat source temperature to 160∘C, an exergy efficiency of 25% can be achieved.

Exergoeconomic comparison and optimization of organic Rankine cycle, trilateral Rankine cycle and transcritical carbon dioxide cycle for heat recovery of low-temperature geothermal water

2019 ◽  
Vol 233 (8) ◽  
pp. 1068-1084 ◽  
Author(s):  
Afsaneh Noroozian ◽  
Abbas Naeimi ◽  
Mokhtar Bidi ◽  
Mohammad Hossein Ahmadi
Keyword(s):  
Sensitivity Analysis ◽  
Low Temperature ◽  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Cost Ratio ◽  
Exergetic Efficiency ◽  
Geothermal Heat ◽  
Product Cost

Depleting fossil fuel resources and the horrible environmental impacts due to burning fossil fuels emphasize the importance of using renewable energy resources such as geothermal and solar energies. This paper compares performance of CO2 transcritical cycle, organic Rankine cycle, and trilateral Rankine cycle using a low-temperature geothermal heat source. Thermodynamic analysis, exergetic analysis, economic analysis, and exergoeconomic analysis are applied for each of the aforementioned cycles. In addition, a sensitivity analysis is performed on the system, and the effects of geothermal heat source temperature, evaporator pinch point temperature, and turbine inlet pressure on the cycle's performance are evaluated. Finally, the systems are optimized in order to minimize product cost ratio and maximize exergetic efficiency by using the genetic algorithm. Results indicate that the maximum thermal efficiency is approximately 13.03% which belongs to organic Rankine cycle with R123 as working fluid. CO2 cycle has the maximum exergetic efficiency, equals to 46.13%. The minimum product cost ratio refers to the organic Rankine cycle with R245fa as working fluid. Moreover, sensitivity analysis shows that increasing geothermal heat source temperature results in higher output power, product cost ratio, and exergy destruction ratio in all cycles.

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