scholarly journals Investigations of the synergy of Composite Cycle and intercooled recuperation

2018 ◽  
Vol 122 (1252) ◽  
pp. 869-888 ◽  
Author(s):  
Sascha Kaiser ◽  
Markus Nickl ◽  
Christina Salpingidou ◽  
Zinon Vlahostergios ◽  
Stefan Donnerhack ◽  
...  
Keyword(s):  
High Pressure ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Low Pressure ◽  
Low Pressure Turbine ◽  
The Core ◽  
Fuel Burn ◽  
Piston System ◽  
Temperature Levels

ABSTRACTThe synergistic combination of two promising engine architectures for future aero engines is presented. The first is the Composite Cycle Engine, which introduces a piston system in the high pressure part of the core engine, to utilise closed volume combustion and high temperature capability due to instationary operation. The second is the Intercooled Recuperated engine that employs recuperators to utilise waste heat from the core engine exhaust and intercooler to improve temperature levels for recuperation and to reduce compression work. Combinations of both architectures are presented and investigated for improvement potential with respect to specific fuel consumption, engine weight and fuel burn against a turbofan. The Composite Cycle alone provides a 15.6% fuel burn reduction against a turbofan. Options for adding intercooler were screened, and a benefit of up to 1.9% fuel burn could be shown for installation in front of a piston system through a significant, efficiency-neutral weight decrease. Waste heat can be utilised by means of classic recuperation to the entire core mass flow before the combustor, or alternatively on the turbine cooling bleed or a piston engine bypass flow that is mixed again with the main flow before the combustor. As further permutation, waste heat can be recovered either after the low pressure turbine – with or without sequential combustion – or between the high pressure and low pressure turbine. Waste heat recovery after the low pressure turbine was found to be not easily feasible or tied to high fuel burn penalties due to unfavourable temperature levels, even when using sequential combustion or intercooling. Feasible temperature levels could be obtained with inter-turbine waste heat recovery but always resulted in at least 0.3% higher fuel burn compared to the non-recuperated baseline under the given assumptions. Consequently, only the application of an intercooler appears to provide a considerable benefit for the examined thermodynamic conditions in the low fidelity analyses of various engine architecture combinations with the specific heat exchanger design. Since the obtained drawbacks of some waste heat utilisation concepts are small, innovative waste heat management concepts coupled with the further extension of the design space and the inclusion of higher fidelity models may achieve a benefit and motivate future investigations.

Performance evaluation of low-pressure turbine, turbo-compounding and air-Brayton cycle as engine waste heat recovery method

Energy ◽  
2019 ◽  
Vol 166 ◽  
pp. 895-907 ◽  
Author(s):  
A.E. Teo ◽  
M.S. Chiong ◽  
M. Yang ◽  
A. Romagnoli ◽  
R.F. Martinez-Botas ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Low Pressure ◽  
Brayton Cycle ◽  
Recovery Method ◽  
Low Pressure Turbine

scholarly journals Design methodology of a low pressure turbine for waste heat recovery via electric turbocompounding

2016 ◽  
Vol 107 ◽  
pp. 1166-1182 ◽  
Author(s):  
Aman M.I. Bin Mamat ◽  
Ricardo F. Martinez-Botas ◽  
Srithar Rajoo ◽  
Liu Hao ◽  
Alessandro Romagnoli
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Design Methodology ◽  
Waste Heat ◽  
Low Pressure ◽  
Low Pressure Turbine

Application of a low pressure economizer for waste heat recovery from the exhaust flue gas in a 600 MW power plant

Energy ◽  
2012 ◽  
Vol 48 (1) ◽  
pp. 196-202 ◽  
Author(s):  
Chaojun Wang ◽  
Boshu He ◽  
Shaoyang Sun ◽  
Ying Wu ◽  
Na Yan ◽  
...  
Keyword(s):  
Power Plant ◽  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Low Pressure

scholarly journals Parametric Study of a Supercritical CO2 Power Cycle for Waste Heat Recovery with Variation in Cold Temperature and Heat Source Temperature

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6648
Author(s):  
Young-Min Kim ◽  
Young-Duk Lee ◽  
Kook-Young Ahn
Keyword(s):  
Heat Source ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Low Pressure ◽  
Power Cycle ◽  
Cooling Temperature ◽  
Source Temperature ◽  
Heat Source Temperature

The supercritical carbon dioxide (S-CO2) power cycle is a promising development for waste heat recovery (WHR) due to its high efficiency despite its simplicity and compactness compared with a steam bottoming cycle. A simple recuperated S-CO2 power cycle cannot fully utilize the waste heat due to the trade-off between the heat recovery and thermal efficiency of the cycle. A split cycle in which the working fluid is preheated by the recuperator and the heat source separately can be used to maximize the power output from a given waste heat source. In this study, the operating conditions of split S-CO2 power cycles for waste heat recovery from a gas turbine and an engine were studied to accommodate the temperature variation of the heat sink and the waste heat source. The results show that it is vital to increase the low pressure of the cycle along with a corresponding increase in the cooling temperature to maintain the low-compression work near the critical point. The net power decreases by 6 to 9% for every 5 °C rise in the cooling temperature from 20 to 50 °C due to the decrease in heat recovery and thermal efficiency of the cycle. The effect of the heat-source temperature on the optimal low-pressure side was negligible, and the optimal high pressure of the cycle increased with an increase in the heat-source temperature. As the heat-source temperature increased in steps of 50 °C from 300 to 400 °C, the system efficiency increased by approximately 2% (absolute efficiency), and the net power significantly increased by 30 to 40%.

scholarly journals Estimating the waste heat recovery in the European Union Industry

2019 ◽  
Vol 4 (5) ◽  
pp. 211-221 ◽  
Author(s):  
Giuseppe Bianchi ◽  
Gregoris P. Panayiotou ◽  
Lazaros Aresti ◽  
Soteris A. Kalogirou ◽  
Georgios A. Florides ◽  
...  
Keyword(s):  
European Union ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Primary Energy ◽  
The European Union ◽  
Industrial Sectors ◽  
Energy Flows ◽  
Energy Consumptions ◽  
Temperature Levels

Abstract Industrial processes are currently responsible for nearly 26% of European primary energy consumptions and are characterized by a multitude of energy losses. Among them, the ones that occur as heat streams rejected to the environment in the form of exhausts or effluents take place at different temperature levels. The reduction or recovery of such types of energy flows will undoubtedly contribute to the achievement of improved environmental performance as well as to reduce the overall manufacturing costs of goods. In this scenario, the current work aims at outlining the prospects of potential for industrial waste heat recovery in the European Union (EU) upon identification and quantification of primary energy consumptions among the major industrial sectors and their related waste streams and temperature levels. The paper introduces a new approach toward estimating the waste heat recovery in the European Union industry, using the Carnot efficiency in relation to the temperature levels of the processes involved. The assessment is carried out using EU statistical energy databases. The overall EU thermal energy waste is quantified at 920 TWh theoretical potential and 279 TWh Carnot potential.

scholarly journals Optimisation of power generation cycles using saturated liquid expansion to maximise heat recovery

2016 ◽  
Vol 231 (1) ◽  
pp. 57-69 ◽  
Author(s):  
MG Read ◽  
IK Smith ◽  
N Stosic
Keyword(s):  
Power Generation ◽  
High Pressure ◽  
Heat Recovery ◽  
Volume Ratio ◽  
Low Pressure ◽  
Working Fluid ◽  
Two Stage ◽  
Low Pressure Turbine ◽  
Screw Machine ◽  
Temperature Heat

The use of two-phase screw expanders in power generation cycles can achieve an increase in the utilisation of available energy from a low-temperature heat source when compared with more conventional single-phase turbines. The efficiency of screw expander machines is sensitive to expansion volume ratio, which, for given inlet and discharge pressures, increases as the expander inlet vapour dryness fraction decreases. For single-stage screw machines with low inlet dryness, this can lead to underexpansion of the working fluid and low isentropic efficiency. The cycle efficiency can potentially be improved by using a two-stage expander, consisting of a machine for low-pressure expansion and a smaller high-pressure machine connected in series. By expanding the working fluid over two stages, the built-in volume ratios of the two machines can be selected to provide a better match with the overall expansion process, thereby increasing the efficiency. The mass flow rate though both stages must be matched, and the compromise between increasing efficiency and maximising power output must also be considered. This study is based on the use of a rigorous thermodynamic screw machine model to compare the performance of single- and two-stage expanders. The model allows optimisation of the required intermediate pressure in the two-stage expander, along with the built-in volume ratio of both screw machine stages. The results allow specification of a two-stage machine, using either two screw machines or a combination of high-pressure screw and low-pressure turbine, in order to achieve maximum efficiency for a particular power output. For the low-temperature heat recovery application considered in this paper, the trilateral flash cycle using a two-stage expander and the Smith cycle using a high-pressure screw and low-pressure turbine are both predicted to achieve a similar overall conversion efficiency to that of a conventional saturated vapour organic Rankine cycle.

Economic Analysis of Wet Flue Gas Desulfurization System with the Application of Low Pressure Economizer for Waste Heat Recovery

2015 ◽  
Vol 1092-1093 ◽  
pp. 491-497 ◽  
Author(s):  
Jing Hui Song ◽  
Yan Lin ◽  
Yan Fen Liao ◽  
Xiao Qian Ma ◽  
Shu Mei Wu
Keyword(s):  
Economic Analysis ◽  
Power Consumption ◽  
Water Consumption ◽  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Low Pressure ◽  
Flue Gas Desulfurization

The data of wet flue gas desulfurization (WFGD) power and water consumption, from two different coal-fired power plants (100 MW and 1000 MW) under full load operation, are studied for the WFGD economic analysis of waste-heat-recovery transformation with the installation of low pressure economizer (LPE). The results of 100MW unit show that, WFGD inlet flue gas temperature drops from 155°C to 110°C, the benefits generated include power consumption of fans declines by 23.85% and water consumption of the smoke desulfurization absorption tower declines by 34.88%. In another case, the temperature of inlet flue gas from WFGD of 1000 MW unit drops from 130°C to 84°C, power consumption of fans increases by 15.04% while water consumption of the smoke desulfurization absorption tower declines by 73.1%. Besides, the flow resistance is increased in LPE water side due to the installation of LPE. This makes power consumption of condensate pump enhanced, which slightly decreases the benefits from waste heat recovery.

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