scholarly journals Thermodynamic Analysis and Optimization of a Novel Power-Water Cogeneration System for Waste Heat Recovery of Gas Turbine

Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1656
Author(s):  
Shunsen Wang ◽  
Bo Li
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Exergy Efficiency ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Turbine Inlet Temperature ◽  
Split Ratio ◽  
Preheating Temperature ◽  
Cogeneration System ◽  
Dual Stage

A power-water cogeneration system based on a supercritical carbon dioxide Brayton cycle (SCBC) and reverse osmosis (RO) unit is proposed and analyzed in this paper to recover the waste heat of a gas turbine. In order to improve the system performance, the power generated by SCBC is used to drive the RO unit and the waste heat of SCBC is used to preheat the feed seawater of the RO unit. In particular, a dual-stage cooler is employed to elevate the preheating temperature as much as possible. The proposed system is simulated and discussed based on the detailed thermodynamic models. According to the results of parametric analysis, the exergy efficiency of SCBC first increases and then decreases as the turbine inlet temperature and split ratio increase. The performance of the RO unit is improved as the preheating temperature rises. Finally, an optimal exergy efficiency of 52.88% can be achieved according to the single-objective optimization results.

A Parametric Analysis for Optimal Selection of a Gas Turbine Cogeneration System

2004 ◽  
Author(s):  
K. Sarabchi ◽  
A. Ansari
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Computer Code ◽  
Primary Energy ◽  
Inlet Temperature ◽  
Fuel Cost ◽  
Energy Usage ◽  
Turbine Inlet Temperature ◽  
Cogeneration System ◽  
Selection Of

Cogeneration is a simultaneous production of heat and electricity in a single plant using the same primary energy. Usage of a cogeneration system leads to fuel energy saving as well as air pollution reduction. A gas turbine cogeneration plant (GTCP) has found many applications in industries and institutions. Although fuel cost is usually reduced in a cogeneration system but the selection of a system for a given site optimally involves detailed thermodynamic and economical investigations. In this paper the performance of a GTCP was investigated and an approach was developed to determine the optimum size of the plant to meet the electricity and heat demands of a given site. A computer code, based on this approach, was developed and it can also be used to examine the effect of key parameters like pressure ratio, turbine inlet temperature, utilization period, and fuel cost on the economics of GTCP.

Thermodynamic and Economic Analysis and Multi-Objective Optimization of Supercritical CO2 Brayton Cycles

2015 ◽  
Author(s):  
Hang Zhao ◽  
Qinghua Deng ◽  
Wenting Huang ◽  
Zhenping Feng
Keyword(s):  
Supercritical Co2 ◽  
Exergy Efficiency ◽  
Temperature Cycle ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Multi Objective Optimization ◽  
Turbine Inlet Temperature ◽  
Multi Objective ◽  
Turbine Inlet ◽  
Thermodynamic Performance

Supercritical CO2 Brayton cycles (SCO2BC) offer the potential of better economy and higher practicability due to their high power conversion efficiency, moderate turbine inlet temperature, compact size as compared with some traditional working fluids cycles. In this paper, the SCO2BC including the SCO2 single-recuperated Brayton cycle (RBC) and recompression recuperated Brayton cycle (RRBC) are considered, and flexible thermodynamic and economic modeling methodologies are presented. The influences of the key cycle parameters on thermodynamic performance of SCO2BC are studied, and the comparative analyses on RBC and RRBC are conducted. Based on the thermodynamic and economic models and the given conditions, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used for the Pareto-based multi-objective optimization of the RRBC, with the maximum exergy efficiency and the lowest cost per power ($/kW) as its objectives. In addition, the Artificial Neural Network (ANN) is chosen to establish the relationship between the input, output, and the key cycle parameters, which could accelerate the parameters query process. It is observed in the thermodynamic analysis process that the cycle parameters such as heat source temperature, turbine inlet temperature, cycle pressure ratio, and pinch temperature difference of heat exchangers have significant effects on the cycle exergy efficiency. And the exergy destruction of heat exchanger is the main reason why the exergy efficiency of RRBC is higher than that of RBC under the same cycle conditions. Compared with the two kinds of SCO2BC, RBC has a cost advantage from economic perspective, while RRBC has a much better thermodynamic performance, and could rectify the temperature pinching problem that exists in RBC. Therefore, RRBC is recommended in this paper. Furthermore, the Pareto front curve between the cycle cost/ cycle power (CWR) and the cycle exergy efficiency is obtained by multi-objective optimization, which indicates that there is a conflicting relation between them. The optimization results could provide an optimum trade-off curve enabling cycle designers to choose their desired combination between the efficiency and cost. Moreover, the optimum thermodynamic parameters of RRBC can be predicted with good accuracy using ANN, which could help the users to find the SCO2BC parameters fast and accurately.

scholarly journals Exergy Efficiency Optimization for Gas Turbine Based Cogeneration Systems

2013 ◽  
Author(s):  
Ana C. Ferreira ◽  
Senhorinha F. Teixeira ◽  
José C. Teixeira ◽  
Manuel L. Nunes ◽  
Luís B. Martins
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Exergy Efficiency ◽  
Plant Performance ◽  
System Component ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet

Energy degradation can be calculated by the quantification of entropy and loss of work and is a common approach in power plant performance analysis. Information about the location, amount and sources of system deficiencies are determined by the exergy analysis, which quantifies the exergy destruction. Micro-gas turbines are prime movers that are ideally suited for cogeneration applications due to their flexibility in providing stable and reliable power. This paper presents an exergy analysis by means of a numerical simulation of a regenerative micro-gas turbine for cogeneration applications. The main objective is to study the best configuration of each system component, considering the minimization of the system irreversibilities. Each component of the system was evaluated considering the quantitative exergy balance. Subsequently the optimization procedure was applied to the mathematical model that describes the full system. The rate of irreversibility, efficiency and flaws are highlighted for each system component and for the whole system. The effect of turbine inlet temperature change on plant exergy destruction was also evaluated. The results disclose that considerable exergy destruction occurs in the combustion chamber. Also, it was revealed that the exergy efficiency is expressively dependent on the changes of the turbine inlet temperature and increases with the latter.

Effects of Steam Injection on the Performance of Gas Turbine Power Cycles

1979 ◽  
Vol 101 (2) ◽  
pp. 217-227 ◽  
Author(s):  
W. E. Fraize ◽  
C. Kinney
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Steam Injection ◽  
Combined Cycle ◽  
Thermodynamic Efficiency ◽  
Inlet Temperature ◽  
Exhaust Gas ◽  
Turbine Inlet Temperature ◽  
Power Cycles ◽  
Determine Effect

The effect of injecting steam generated by exhaust gas waste heat into a gas turbine with 3060°R turbine inlet temperature has been analyzed. Two alternate steam injection cycles are compared with a combined cycle using a conventional steam bottoming cycle. A range of compression ratios (8, 12, 16, and 20) and water mass injection ratios (0 to 0.4) were analyzed to determine effect on net turbine power output per pound of air and cycle thermodynamic efficiency. A water/fuel cost tradeoff analysis is also provided. The results indicate promising performance and economic advantages of steam injected cycles relative to more conventional utility power cycles. Application to coal-fired configuration is briefly discussed.

scholarly journals Parametric Investigation and Thermoeconomic Optimization of a Combined Cycle for Recovering the Waste Heat from Nuclear Closed Brayton Cycle

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Lihuang Luo ◽  
Hong Gao ◽  
Chao Liu ◽  
Xiaoxiao Xu
Keyword(s):  
Mass Fraction ◽  
Waste Heat ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Overall Efficiency ◽  
Economic Analyses

A combined cycle that combines AWM cycle with a nuclear closed Brayton cycle is proposed to recover the waste heat rejected from the precooler of a nuclear closed Brayton cycle in this paper. The detailed thermodynamic and economic analyses are carried out for the combined cycle. The effects of several important parameters, such as the absorber pressure, the turbine inlet pressure, the turbine inlet temperature, the ammonia mass fraction, and the ambient temperature, are investigated. The combined cycle performance is also optimized based on a multiobjective function. Compared with the closed Brayton cycle, the optimized power output and overall efficiency of the combined cycle are higher by 2.41% and 2.43%, respectively. The optimized LEC of the combined cycle is 0.73% lower than that of the closed Brayton cycle.

Application of Gas Bearings to Closed-System Brayton-Cycle Turbomachinery—Recent Accomplishments and Potential Problem Areas

1966 ◽  
Vol 88 (4) ◽  
pp. 367-376 ◽  
Author(s):  
P. W. Curwen ◽  
H. F. Jones ◽  
H. Schwarz
Keyword(s):  
Gas Turbine ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Test Results ◽  
Development Programs ◽  
Closed Loop System ◽  
Turbine Inlet Temperature ◽  
Gas Bearings ◽  
Shaft Power ◽  
Gas Bearing

Several development programs to demonstrate application of gas-lubricated bearings to gas turbine machinery are presently under way. This paper presents design and initial test data for a 24,000 rpm, 1300 F (turbine inlet temperature) gas-bearing Brayton-cycle turbocompressor operating in a closed-loop system. The bearing system design for a two-shaft power plant, consisting of a 50,000 rpm, 1490 F turbocompressor and a 12,000 rpm turboalternator, is also described. Test results to date demonstrate that gas lubrication, per se, of gas turbine machinery is definitely feasible. However, considerable data are still needed to prove the practical utility of gas bearings. A brief discussion of the needed investigations is presented.

scholarly journals Performances of Transcritical Power Cycles with CO2-Based Mixtures for the Waste Heat Recovery of ICE

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1551
Author(s):  
Jinghang Liu ◽  
Aofang Yu ◽  
Xinxing Lin ◽  
Wen Su ◽  
Shaoduan Ou
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Cycle Performance ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Power Cycles ◽  
Split Ratio ◽  
Turbine Inlet ◽  
Organic Fluids

In the waste heat recovery of the internal combustion engine (ICE), the transcritical CO2 power cycle still faces the high operation pressure and difficulty in condensation. To overcome these challenges, CO2 is mixed with organic fluids to form zeotropic mixtures. Thus, in this work, five organic fluids, namely R290, R600a, R600, R601a, and R601, are mixed with CO2. Mixture performance in the waste heat recovery of ICE is evaluated, based on two transcritical power cycles, namely the recuperative cycle and split cycle. The results show that the split cycle always has better performance than the recuperative cycle. Under design conditions, CO2/R290(0.3/0.7) has the best performance in the split cycle. The corresponding net work and cycle efficiency are respectively 21.05 kW and 20.44%. Furthermore, effects of key parameters such as turbine inlet temperature, turbine inlet pressure, and split ratio on the cycle performance are studied. With the increase of turbine inlet temperature, the net works of the recuperative cycle and split cycle firstly increase and then decrease. There exist peak values of net work in both cycles. Meanwhile, the net work of the split cycle firstly increases and then decreases with the increase of the split ratio. Thereafter, with the target of maximizing net work, these key parameters are optimized at different mass fractions of CO2. The optimization results show that CO2/R600 obtains the highest net work of 27.43 kW at the CO2 mass fraction 0.9 in the split cycle.

scholarly journals Parametric Optimisation of an ORC in a Wood Chipboard Production Facility to Recover Waste Heat Produced from the Drying and Steam Production Process

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3656 ◽  
Author(s):  
Yıldız Koç
Keyword(s):  
Thermal Efficiency ◽  
Waste Heat ◽  
Saturated Steam ◽  
Maximum Temperature ◽  
Inlet Temperature ◽  
Drying Process ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Cogeneration System ◽  
Steam Production

The wastes in wood industries (waste chips) are commonly used as fuel for burners to produce steam and to use the remaining heat in the drying process. However, in spite of that, there is a considerable amount of heat evaluated from the burn of waste chips still released to the atmosphere without use. Therefore, in the present study, a cogeneration cycle design by used of ORC was designed and parametrically optimised for six organic working fluids (acetone, ethanol, R11, RE245fa2, R365mfc and R601a). During the ORC optimisation, the ORC turbine inlet temperature was changed from the saturated steam temperature of the fluid to the maximum temperature of the fluid. The ORC turbine inlet pressure was increased from 7.5 bar to the critical pressure of the fluid. As a result of the study, the maximum net power, net thermal efficiency and exergy efficiency of the ORC were found as 453.91 kW, 30.01% and 67.56% at 340 °C and 62.5 bar from the ORC with ethanol. This means that almost 30% of the waste heat could be recovered by use of the ORC with ethanol. By using the designed cogeneration system, it was calculated that the thermal efficiency of the system can be increased up to 74.01%.

Investigation of the Bottoming Cycle for High Efficiency Combined Cycle Gas Turbine System With Supercritical Carbon Dioxide Power Cycle

2015 ◽  
Author(s):  
Seong Kuk Cho ◽  
Minseok Kim ◽  
Seungjoon Baik ◽  
Yoonhan Ahn ◽  
Jeong Ik Lee
Keyword(s):  
Gas Turbine ◽  
Flow Rate ◽  
High Efficiency ◽  
Waste Heat ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Power Cycle ◽  
Turbine Inlet ◽  
Steam Cycle

The supercritical CO2 (S-CO2) power cycle has been receiving attention as one of the future power cycle technology because of its compact configuration and high thermal efficiency at relatively low turbine inlet temperature ranges (450∼750°C). Thus, this low turbine inlet temperature can be suitable for the bottoming cycle of a combined cycle gas turbine because its exhaust temperature range is approximately 500∼600°C. The natural gas combined cycle power plant utilizes mainly steam Rankine cycle as a bottoming cycle to recover waste heat from a gas turbine. To improve the current situation with the S-CO2 power cycle technology, the research team collected various S-CO2 cycle layouts and compared each performance. Finally, seven cycle layouts were selected as a bottoming power system. In terms of the net work, each cycle was evaluated while the mass flow rate, the split flow rate and the minimum pressure were changed. The existing well-known S-CO2 cycle layouts are unsuitable for the purpose of a waste heat recovery system because it is specialized for a nuclear application. Therefore, the concept to combine two S-CO2 cycles was suggested in this paper. Also the complex single S-CO2 cycles are included in the study to explore its potential. As a result, the net work of the concept to combine two S-CO2 cycles was lower than that of the performance of the reference steam cycle. On the other hand, the cascade S-CO2 Brayton cycle 3 which is one of the complex single cycles was the only cycle to be superior to the reference steam cycle. This result shows the possibility of the S-CO2 bottoming cycle if component technologies become mature enough to realize the assumptions in this paper.

Analysis and Assessment of a Gas Turbine-Modular Helium Reactor for Nuclear Desalination

2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Farrukh Khalid ◽  
Ibrahim Dincer ◽  
Marc A. Rosen
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Electricity Generation ◽  
Waste Heat ◽  
Inlet Temperature ◽  
Generation Process ◽  
Work Output ◽  
Turbine Inlet Temperature ◽  
Electric Generation ◽  
Temperature Recovery

A thermodynamic analysis of the coupling of a reverse osmosis (RO) process with the gas turbine-modular helium reactor (GT-MHR) is presented in which the waste heat is utilized for the generation of steam as it is expanded in a steam turbine. A comprehensive parametric study is carried out to reveal the effect of some parameters such as compression ratio, turbine inlet temperature, recovery ratio, and preheated feed seawater inlet temperature on the exergy efficiencies of the RO process, electricity generation process, electricity generation without steam turbine work output, and overall system. The analysis shows that the exergy efficiency of the electric generation process is increased by 10.3%, if the waste heat from the reactor is utilized. The exergy efficiencies of the RO process, electricity generation process, electricity generation without steam turbine work output, and overall system are found to be 89.0%, 40.0%, 29.7%, and 41.0%, respectively.

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