Thermodynamic and comparative analysis of ERC and ARC integrated wet-ethanol fueled HCCI engine for cogeneration of power and cooling

Abstract This study attempted for the proposal and analysis of a combined cycle consists of a wet-ethanol fueled and turbocharged HCCI engine coupled to ejector refrigeration cycle (ERC) and absorption refrigeration cycle (ARC) for the simultaneous generation of two distinct outputs namely power and refrigeration. Both first and second laws of thermodynamics were employed to develop a thermodynamic model which has been applied to investigate the performance of combined cycle. Further, performance of the combined cycle for ERC versus ARC was compared and assessed after altering operating parameters (turbocharger pressure ratio, turbocharger compressor efficiency, ambient temperature, and the entrainment ratio of ERC and generator temperature of ARC) to study their effect on engine power output, refrigeration load, exergy of refrigeration, energy and exergy efficiencies of the cooling-power cogeneration cycle. Results show that elevated pressure of turbocharger results in the enhancement of HCCI engine power and increase of the refrigeration of thermal load, simultaneously. However, ambient temperature rising shows the decline of HCCI engine efficiencies and energy efficiency of cogeneration while the cogeneration cycle exergy efficiency is found increasing. Furthermore, the results are reported for the refrigeration performed by LiBr-H2O operated ARC, and R134a and R290 operated ERC, respectively. Mapping of exergy destruction for the presented cogeneration cycle discovered HCCI engine, boiler of ERC, generator of ARC, and catalytic convertor as the components of significant exergy destruction. Entrainment ratio and type of refrigerant employed in ERC and the generator temperature of ARC shows a marginal impact on the COPs.

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Performance Analysis of a Combined Cycle Power Plant with Simultaneous Cooling of Inlet Air Streams to the Compressor and Condenser

No 1 - International Journal of Advanced Thermofluid Research ◽

10.51141/ijatr.2018.4.1.1 ◽

2018 ◽

Vol 4 (1) ◽

pp. 2-25

Author(s):

Ifeanyi Henry Njoku ◽

Chika Oko ◽

Joseph Ofodu

Keyword(s):

Power Plant ◽

Performance Analysis ◽

Waste Heat ◽

Combined Cycle ◽

Integrated System ◽

Refrigeration Cycle ◽

Exergy Destruction ◽

Combined Cycle Power Plant ◽

Absorption Refrigerator ◽

Air Streams

Abstract: This paper presents the thermodynamic performance analysis of an existing combined cycle power plant to be retrofitted with a waste heat driven aqua lithium bromide absorption refrigerator for cooling the inlet air streams to the compressor and air-cooled steam condenser. The power plant is located in the hot and humid tropical region of Nigeria, latitude 4°45′N and longitude 7°00′E. This was achieved by performing energy and exergy analysis of the integrated system. Using the operating data of the existing combined cycle power plant, the results of the analysis showed that by cooling the inlet air streams to 15oC at the compressors, and to 29oC at the air-cooled steam condenser, the net power output, thermal and exergy efficiencies of the combined cycle plant increased by 7.7%, 8.1% and 7.5% respectively while the plant total exergy destruction rate and specific fuel consumption dropped by 10.8% and 7.0% respectively. The stack flue gas exit temperature reduced from 126oC to 84oC in the absorption refrigerator, thus reducing the environmental thermal pollution. The COP and exergy efficiency of the refrigeration cycle was 0.60 and 27.0%, respectively. Results also show that the highest rate of exergy destruction in the combined cycle power plant occurred in the combustion chamber while the highest rate of exergy destruction in the absorption refrigeration cycle occurred in the evaporator followed by the absorber.

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A boil-off gas utilization for improved performance of heavy duty gas turbines in combined cycle

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650918772658 ◽

2018 ◽

Vol 233 (1) ◽

pp. 96-110 ◽

Cited By ~ 2

Author(s):

Stefano Mazzoni ◽

Srithar Rajoo ◽

Alessandro Romagnoli

Keyword(s):

Heat Transfer ◽

Natural Gas ◽

Ambient Temperature ◽

Gas Turbine ◽

Gas Turbines ◽

Liquefied Natural Gas ◽

Combined Cycle ◽

Cooling Power ◽

Heavy Duty ◽

Cold Energy

The storage of the natural gas under liquid phase is widely adopted and one of the intrinsic phenomena occurring in liquefied natural gas is the so-called boil-off gas; this consists of the regasification of the natural gas due to the ambient temperature and loss of adiabacity in the storage tank. As the boil-off occurs, the so-called cold energy is released to the surrounding environment; such a cold energy could potentially be recovered for several end-uses such as cooling power generation, air separation, air conditioning, dry-ice manufacturing and conditioning of inlet air at the compressor of gas turbine engines. This paper deals with the benefit corresponding to the cooling down of the inlet air temperature to the compressor, by means of internal heat transfer recovery from the liquefied natural gas boil-off gas cold energy availability. The lower the compressor inlet temperature, the higher the gas turbine performance (power and efficiency); the exploitation of the liquefied natural gas boil-off gas cold energy also corresponds to a higher amount of air flow rate entering the cycle which plays in favour of the bottoming heat recovery steam generator and the related steam cycle. Benefit of this solution, in terms of yearly work and gain increase have been established by means of ad hoc developed component models representing heat transfer device (air/boil-off gas) and heavy duty 300 MW gas turbine. For a given ambient temperature variability over a year, the results of the analysis have proven that the increase of electricity production and efficiency due to the boil-off gas cold energy recovery has finally yield a revenue increase of 600,000€/year.

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Exergy and Exergoeconomic Analysis of a Cogeneration Hybrid Solar Organic Rankine Cycle with Ejector

Entropy ◽

10.3390/e22060702 ◽

2020 ◽

Vol 22 (6) ◽

pp. 702

Author(s):

Bourhan Tashtoush ◽

Tatiana Morosuk ◽

Jigar Chudasama

Keyword(s):

Electrical Power ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Combined Cycle ◽

Coefficient Of Performance ◽

Working Fluid ◽

Refrigeration Cycle ◽

Refrigeration System ◽

Entrainment Ratio ◽

Temperature And Pressure

Solar energy is utilized in a combined ejector refrigeration system with an organic Rankine cycle (ORC) to produce a cooling effect and generate electrical power. This study aims at increasing the utilized share of the collected solar thermal energy by inserting an ORC into the system. As the ejector refrigeration cycle reaches its maximum coefficient of performance (COP), the ORC starts working and generating electrical power. This electricity is used to run the circulating pumps and the control system, which makes the system autonomous. For the ejector refrigeration system, R134a refrigerant is selected as the working fluid for its performance characteristics and environmentally friendly nature. The COP of 0.53 was obtained for the ejector refrigeration cycle. The combined cycle of the solar ejector refrigeration and ORC is modeled in EBSILON Professional. Different parameters like generator temperature and pressure, condenser temperature and pressure, and entrainment ratio are studied, and the effect of these parameters on the cycle COP is investigated. Exergy, economic, and exergoeconomic analyses of the hybrid system are carried out to identify the thermodynamic and cost inefficiencies present in various components of the system.

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Thermodynamic and Exergoeconomic Analyses of a Novel Combined Cycle Comprised of Vapor-Compression Refrigeration and Organic Rankine Cycles

Sustainability ◽

10.3390/su11123374 ◽

2019 ◽

Vol 11 (12) ◽

pp. 3374 ◽

Cited By ~ 3

Author(s):

Nima Javanshir ◽

S. M. Seyed Mahmoudi ◽

Marc A. Rosen

Keyword(s):

Unit Cost ◽

Combined Cycle ◽

Cycle Performance ◽

Working Fluid ◽

Cooling Power ◽

Vapor Compression ◽

Exergy Destruction ◽

Destruction Rate ◽

Organic Rankine Cycles ◽

Vapor Compression Refrigeration

In this study, a cooling/power cogeneration cycle consisting of vapor-compression refrigeration and organic Rankine cycles is proposed and investigated. Utilizing geothermal water as a low-temperature heat source, various operating fluids, including R134a, R22, and R143a, are considered for the system to study their effects on cycle performance. The proposed cycle is modeled and evaluated from thermodynamic and thermoeconomic viewpoints by the Engineering Equation Solver (EES) software. Thermodynamic properties as well as exergy cost rates for each stream are found separately. Using R143a as the working fluid, thermal and exergy efficiencies of 27.2% and 57.9%, respectively, are obtained for the cycle. Additionally, the total product unit cost is found to be 60.7 $/GJ. A parametric study is carried out to determine the effects of several parameters, such as turbine inlet pressure, condenser temperature and pressure, boiler inlet air temperature, and pinch-point temperature difference, on the cycle performance. The latter is characterized by such parameters as thermal and exergy efficiencies, refrigeration capacity, produced net power rate, exergy destruction rate, and the production unit cost rates. The results indicate that the system using R134a exhibits the lowest thermal and exergy efficiencies among other working fluids, while the systems using R22 and R143a exhibit the highest energy and exergy efficiencies, respectively. The boiler and turbine contribute the most to the total exergy destruction rate.

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EFFECT OF AMBIENT TEMPERATURE ON THE PERFORMANCE OF A COMBINED CYCLE POWER PLANT

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2013-0099 ◽

2013 ◽

Vol 37 (4) ◽

pp. 1177-1188 ◽

Cited By ~ 12

Author(s):

Arvind Kumar Tiwari ◽

Mohd. Muzaffarul Hasan ◽

Mohd. Islam

Keyword(s):

Power Plant ◽

Ambient Temperature ◽

Thermal Power ◽

Combined Cycle ◽

Inlet Temperature ◽

Exergy Destruction ◽

Combined Cycle Power Plant ◽

Combined Cycle Plant ◽

Gas Turbine Cycle ◽

Cycle Efficiency

The aim of the present paper is to examine the effect of ambient temperature on the performance of a combined cycle power plant. For this work, the combined cycle plant chosen is NTPC (National Thermal Power Corporation) Dadri, India where a gas unit of 817 MW is installed. The effect of ambient temperature on combined cycle efficiency, gas turbine cycle efficiency, exergy destruction in different components, exergy loss via exhaust and air fuel ratio at lower and higher turbine inlet temperature are reported. The results show that the net decrease in combined cycle efficiency is 0.04% and the variation in exergy destruction of different plant components is up to 0.35% for every °C rise in ambient temperature.

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Effect of Operational Parameters on a Novel Combined Cycle of Ejector Refrigeration Cycle and Kalina Cycle

Journal of Energy Resources Technology ◽

10.1115/1.4044220 ◽

2019 ◽

Vol 142 (1) ◽

Cited By ~ 1

Author(s):

Candeniz Seckin

Keyword(s):

Energy Content ◽

Power Production ◽

Exergy Efficiency ◽

Combined Cycle ◽

Working Fluid ◽

Refrigeration Cycle ◽

Entrainment Ratio ◽

Extensive Discussion ◽

Kalina Cycle ◽

Operation Conditions

A Kalina cycle is coupled to an ejector refrigeration cycle to generate power and refrigeration outputs, simultaneously. Ejector refrigeration cycle is driven by the heat which is extracted from a high-temperature/pressure stream of Kalina cycle working fluid since the energy content of this fluid stream is not directly utilized in power production in the Kalina cycle. Supplied heat to the proposed combined cycle is produced by combustion of biomethane which is obtained from anaerobic digestion of biomass, namely, food waste. System reactions to altering operation conditions (entrainment ratio, condenser pressure, evaporator pressure, and superheating degree) in terms of refrigeration production, power production, energy efficiency, exergy efficiency, and exergy of produced power and refrigeration are analyzed. The results are reported for R290, R134a, and R152a working fluids of the ejector refrigeration cycle and an extensive discussion of the results are provided. It is shown that the entrainment ratio strongly affects the thermal and exergy efficiency results. The highest thermal and exergy efficiency results are performed when R290 and R134a are used, whereas the lowest thermal and exergy efficiencies are obtained when R152a and R290 are used as the refrigerant, respectively.

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Performance of Ejector Refrigeration Cycle for Automotive Air Conditioning

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.819.202 ◽

2016 ◽

Vol 819 ◽

pp. 202-206

Author(s):

Reza Maziar ◽

Kasni Sumeru ◽

M.Y. Senawi ◽

Farid Nasir Ani

Keyword(s):

Compression Ratio ◽

Air Conditioning ◽

The Other ◽

Coefficient Of Performance ◽

Refrigeration Cycle ◽

Entrainment Ratio ◽

Automotive Air Conditioning ◽

Average Improvement

In this study, two experiments were performed, one with the conventional compression refrigeration cycle (CRC) and the other with an ejector refrigeration cycle (ERC). The CRC system for automotive air conditioning was designed, fabricated and experiments were conducted. The system was then retrofitted with an ejector as the expansion device and experiments were repeated for the ERC system. Calculations of the entrainment ratio, compressor compression ratio and coefficient of performance (COP) were made for each cycle. The calculations showed that ERC has some advantages over the CRC. In this study, an average improvement of 5% in COP has been obtained for the ERC compared with the CRC.

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Ambient temperature does not affect the tactile sensitivity of mystacial vibrissae in harbour seals.

Journal of Experimental Biology ◽

10.1242/jeb.201.22.3023 ◽

1998 ◽

Vol 201 (22) ◽

pp. 3023-3029 ◽

Cited By ~ 6

Author(s):

G Dehnhardt ◽

B Mauck ◽

H Hyvärinen

Keyword(s):

Ambient Temperature ◽

Thermal Emission ◽

Normal Skin ◽

Cold Season ◽

Cooling Power ◽

Difference Threshold ◽

Tactile Sensitivity ◽

Camera System ◽

Width Difference ◽

Harbour Seals

Vibrissae provide pinnipeds with tactile information primarily in the aquatic environment, which is characterized by its high thermal conductivity and large potential cooling power. Since studies of thermal effects on human tactile sensitivity have revealed that cooling below normal skin temperature impairs sensitivity, the present study investigates the tactile sensitivity of the vibrissal system of harbour seals at varying ambient temperatures. Using plates bearing gratings of alternating grooves and ridges, the texture difference thresholds of two adult seals were determined under water. We took advantage of the natural difference in ambient temperature between summer and winter. Mean water temperature was 1. 2 degreesC during the winter and 22 degreesC during the summer. During the cold season, the thermal status of both seals was examined using an infrared-sensitive camera system. The texture difference threshold of both seals remained the same (0.18 mm groove width difference) under both test conditions. The thermographic examination revealed that the skin areas of the head where the mystacial and supraorbital vibrissae are located show a substantially higher degree of thermal emission than do adjacent skin areas. This suggests that, in the vibrissal follicles of harbour seals, no vasoconstriction occurs during cold acclimation, so that the appropriate operating temperature for the mechanoreceptors is maintained.

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