scholarly journals CORRECT SELECTION OF THE ORC SYSTEM PARAMETERS FOR THE EXHAUST GASES HEAT SOURCE

2020 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Artur Rusowicz ◽  
Tomasz Ziąbka
Keyword(s):  
Heat Source ◽  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Correct Selection ◽  
Maximum Efficiency ◽  
Source Power ◽  
System Parameters ◽  
Working Medium ◽  
Cycle Systems

Contrary to appearances, ORC (Organic Rankine Cycle) systems should not be selected for the highest available temperature of the upper heat source. This approach allows, of course, to achieve the highest energy efficiency, but this happens at the expense of the electrical power obtained. This solution would be good for an infinite heat source. In practice, there is always a finite heat source power. Therefore, the analysis should take into account other aspects than just maximum efficiency. The article presents a method of selecting ORC system parameters for a heat source in the form of waste gases, enabling the highest electrical power to be obtained. The analysis shows that even a significant reduction in the evaporation temperature of the working medium in the ORC system compared to the source temperature is beneficial for the profitability of investing in an ORC system. The analysis showed that for flue gases with temperatures of 300, 400, 500 and 600 °C, the best evaporating temperatures of the working medium in the ORC system are 145 °C, 185 °C, 214 °C and 250 °C, respectively. The highest level of generated electricity is obtained for these temperatures.

Working Fluid and Parametric Optimization of a Two-Stage ORC Utilizing LNG Cold Energy and Low Grade Heat of Different Temperatures

2017 ◽  
Author(s):  
Zhixin Sun ◽  
Shujia Wang ◽  
Fuquan Xu ◽  
Tielong Wang
Keyword(s):  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Cycle Performance ◽  
Maximum Efficiency ◽  
Working Fluid ◽  
Low Grade ◽  
Two Stage ◽  
Cold Energy ◽  
Low Grade Heat

Natural gas is considered as a green fuel due to its low environmental impact. LNG contains a large amount of cold exergy and must be regasified before further utilization. ORC (Organic Rankine Cycle) has been proven to be a promising solution for both low grade heat utilization and LNG cold exergy recovery. Due to the great temperature difference between the heat source and LNG, the efficiency of one-stage ORC is relatively small. Hence, some researchers move forward to a two-stage Rankine cycle. Working fluid plays a quite important role in the cycle performance. Working fluid selection of a two-stage ORC is much more challenging than that of a single-stage ORC. In this paper, a two-stage ORC is studied. Heat source temperatures of 100,150 and 200°C are investigated. 20 substances are selected as potential candidates for both the high and low Rankine cycles. The evaporating, condensing and turbine inlet temperatures of both Rankine cycles are optimized by PSO (Particle Swarm Optimization). The results show that the best combination for heat source temperature of 100°C is R161/R218 with the maximum exergy efficiency of 35.27%. The best combination for 150°C is R161/RC318 with the maximum efficiency of 37.84% and ammonia/ammonia with the maximum efficiency of 39.15% for 200°C. Fluids with intermediate critical temperature, lower triple point temperature and lower normal boiling temperature are good candidates.

scholarly journals Studies on the possible application of heat storage devices for powering the ORC (Organic Rankine Cycle) systems

2019 ◽  
Vol 116 ◽  
pp. 00035
Author(s):  
Piotr Kolasiński
Keyword(s):  
Heat Source ◽  
Power Plants ◽  
Heat Storage ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Storage Device ◽  
Heat Sources ◽  
Storage Devices ◽  
Cycle Systems ◽  
Output Characteristics

Some of the heat sources (such as e.g. waste or renewable), are characterized by floating thermal and output characteristics. Thus, their application for powering vapor power plants, such as ORCs, which should utilize the heat sources having steady thermal and output characteristics is difficult. The floating heat source characteristics may potentially be improved using the heat storage devices providing the thermal energy accumulation at stable output and temperature level. Heat storage device can be adopted as a e.g. steady-level heat source for ORC system. In this paper different applications of the heat storage devices in ORCs were proposed and the results of experiments on powering the ORC system via heat storage device are presented. The results showed that adopting the heat storage devices for powering the ORC systems is possible and it is a promising way of utilizing the waste and renewable heat sources featuring floating characteristics.

Selection of Working Fluids for Different Temperature Heat Source Organic Rankine Cycle

2012 ◽  
Vol 614-615 ◽  
pp. 195-199
Author(s):  
Guang Lin Liu ◽  
Jin Liang Xu ◽  
Bing Zhang
Keyword(s):  
Power Generation ◽  
Heat Source ◽  
Flue Gas ◽  
Thermal Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Source Power ◽  
Working Fluids ◽  
Cycle System ◽  
Temperature Heat

In the current paper, under the condition of different flue gas temperatures and constant flue gas thermal power, the influence of different organic working fluids on the efficiency of sub-critical organic Rankine cycle system were studied. The efficiency and other parameters of the simple system were calculated. The results show that the efficiency of sub-critical organic Rankine cycle system could reach maximum when the parameters of the working fluids in the expander inlet are dry-saturation. Flammability, toxicity, ozone depletion and other factors of the working fluids should be considered in the organic Rankine cycles. R245fa is considered a better choice for low-temperature heat source power generation, and the efficiency of the system is about 10.2%; for the high-temperature heat source, R601a can be considered; however, due to its high flammability, novel working fluids should be further discovered for power generation.

scholarly journals Thermo-Economic Analysis on Integrated CO2, Organic Rankine Cycles, and NaClO Plant Using Liquefied Natural Gas

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2849
Author(s):  
Tri Tjahjono ◽  
Mehdi Ali Ehyaei ◽  
Abolfazl Ahmadi ◽  
Siamak Hoseinzadeh ◽  
Saim Memon
Keyword(s):  
Natural Gas ◽  
Heat Source ◽  
Potable Water ◽  
Net Present Value ◽  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Electrical Energy ◽  
Rankine Cycle ◽  
Payback Period ◽  
Liquefied Natural Gas

The thermal energy conversion of natural gas (NG) using appropriate configuration cycles represents one of the best nonrenewable energy resources because of its high heating value and low environmental effects. The natural gas can be converted to liquefied natural gas (LNG), via the liquefaction process, which is used as a heat source and sink in various multigeneration cycles. In this paper, a new configuration cycle is proposed using LNG as a heat source and heat sink. This new proposed cycle includes the CO2 cycle, the organic Rankine cycle (ORC), a heater, a cooler, an NaClO plant, and reverse osmosis. This cycle generates electrical power, heating and cooling energy, potable water (PW), hydrogen, and salt all at the same time. For this purpose, one computer program is provided in an engineering equation solver for energy, exergy, and thermo-economic analyses. The results for each subsystem are validated by previous researches in this field. This system produces 10.53 GWh electrical energy, 276.4 GWh cooling energy, 1783 GWh heating energy, 17,280 m3 potable water, 739.56 tons of hydrogen, and 383.78 tons of salt in a year. The proposed system energy efficiency is 54.3%, while the exergy efficiency is equal to 13.1%. The economic evaluation showed that the payback period, the simple payback period, the net present value, and internal rate of return are equal to 7.9 years, 6.9 years, 908.9 million USD, and 0.138, respectively.

scholarly journals Experimental Investigation of a 560 Watt Organic Rankine Cycle System using R134a as Working Fluid and Plat Solar Collector as Heat Source

2021 ◽  
Vol 4 (3) ◽  
pp. 169-172
Author(s):  
Awaludin Martin ◽  
Muhammad Nur
Keyword(s):  
Energy Source ◽  
Solar Energy ◽  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Maximum Efficiency ◽  
Working Fluid ◽  
Energy Sources ◽  
Small Scale ◽  
Cycle System

New and renewable energy sources such as solar, geothermal, and waste heat  are energy sources that can be used as a source of energy for Organic Rankine cycle system because the organic Rankine cycle (ORC) requires heat at low temperatures to be used as energy source. The experimental of Organic Rankine Cycle (ORC) systems with solar energy as a heat source was conduct to investigate a small-scale ORC system with R134a as a working fluid by varying the heat source at temperature 75⁰C-95⁰C. The experiment resulted a maximum efficiency, power of system is 4.30%, and 185.9 Watt, where the temperature of heat source is 95⁰C, the pressure and temperature of steam inlet turbine is 1.38 MPa and 67.9oC respectively. Solar energy as the main energy source in the ORC system can reduce energy use up to 49.9% or 4080.8 kJ where the temperature of the water as the heat source in the evaporator is 51°C.

Theoretical and experimental investigation of an organic Rankine cycle for a waste heat recovery system

2009 ◽  
Vol 223 (5) ◽  
pp. 523-533 ◽  
Author(s):  
W Gu ◽  
Y Weng ◽  
Y Wang ◽  
B Zheng
Keyword(s):  
Heat Source ◽  
Entropy Generation ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Entropy Generation Rate ◽  
Working Fluid ◽  
Total Entropy ◽  
Waste Heat Recovery System ◽  
Cycle Efficiency

This article describes and evaluates an organic Rankine cycle (ORC) for a waste heat recovery system by both theoretical and experimental studies. Theoretical analysis of several working fluids shows that cycle efficiency is very sensitive to evaporating pressure, but insensitive to expander inlet temperature. Second law analysis was carried out using R600a as a working fluid and a flow of hot air as a heat source, which is not isothermal, along the evaporator. The result discloses that the evaporator's internal and external entropy generation is the main source of total entropy generation. The effect of the heat source temperature, evaporating pressure, and evaporator size on the entropy generation rate is also presented. The obtained useful power is directly linked to the total entropy generation rate according to the Gouy—Stodola theorem. The ORC testing system was established and operated using R600a as a working fluid and hot water as a heat source. The maximum cycle efficiency of the testing system is 5.2 per cent, and the testing result also proves that cycle efficiency is insensitive to heat source temperature, but sensitive to evaporating pressure. The entropy result also shows that internal and external entropy of the evaporator is the main source of total entropy generation.

Categorization and analysis of heat sources for organic Rankine cycle systems

2016 ◽  
Vol 64 ◽  
pp. 790-805 ◽  
Author(s):  
Huixing Zhai ◽  
Qingsong An ◽  
Lin Shi ◽  
Vincent Lemort ◽  
Sylvain Quoilin
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Sources ◽  
Cycle Systems
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