Thermo-Economic Analysis of an Intercooled, Reheat and Recuperated Gas Turbine for Cogeneration Applications: Part II — Part-Load Operation

2001 ◽  
Author(s):  
R. Bhargava ◽  
G. Negri di Montenegro ◽  
A. Peretto
Keyword(s):  
Economic Analysis ◽  
Gas Turbine ◽  
The Other ◽  
Load Range ◽  
Part Load ◽  
Full Load ◽  
Performance Loss ◽  
Low Load ◽  
Cogeneration System ◽  
Load Conditions

The knowledge of off-design performance for a given gas turbine system is critical particularly in applications where considerable operation at low load setting is required. This information allows designers to ensure safe operation of the system and determine in advance thermo-economic penalty due to performance loss while operating under part-load conditions. In this paper, thermo-economic analysis results for the intercooled, reheat (ICRH) and recuperated gas turbine, at the part-load conditions in cogeneration applications, have been presented. Thermodynamically, a recuperated ICRH gas turbine based cogeneration system showed lower penalty in terms of electric efficiency and Energy Saving Index over the entire part-load range in comparison to the other cycles (non-recuperated ICRH, recuperated Brayton and simple Brayton cycles) investigated. Based on the comprehensive economic analysis for the assumed values of economic parameters, this study shows that, a mid-size (electric power capacity 20 MW) cogeneration system utilizing non-recuperated ICRH cycle provides higher return on investment both at full-load and part-load conditions, compared to the other same size cycles, over the entire range of fuel cost, electric sale and steam sale values examined. The plausible reasons for the observed trends in thermodynamic and economic performance parameters for four cycles and three sizes of cogeneration systems under full-load and part-load conditions have been presented in this paper.

Thermoeconomic Analysis of an Intercooled, Reheat, and Recuperated Gas Turbine for Cogeneration Applications—Part II: Part-Load Operation

2002 ◽  
Vol 124 (4) ◽  
pp. 892-903 ◽  
Author(s):  
R. Bhargava ◽  
G. Negri di Montenegro ◽  
A. Peretto
Keyword(s):  
Gas Turbine ◽  
The Other ◽  
Safe Operation ◽  
Load Range ◽  
Part Load ◽  
Full Load ◽  
Performance Loss ◽  
Low Load ◽  
Cogeneration System ◽  
Load Conditions

The knowledge of off-design performance for a given gas turbine system is critical particularly in applications where considerable operation at low load setting is required. This information allows designers to ensure safe operation of the system and determine in advance thermoeconomic penalty due to performance loss while operating under part-load conditions. In this paper, thermoeconomic analysis results for the intercooled reheat (ICRH) and recuperated gas turbine, at the part-load conditions in cogeneration applications, have been presented. Thermodynamically, a recuperated ICRH gas turbine-based cogeneration system showed lower penalty in terms of electric efficiency and Energy Saving Index over the entire part-load range in comparison to the other cycles (nonrecuperated ICRH, recuperated Brayton and simple Brayton cycles) investigated. Based on the comprehensive economic analysis for the assumed values of economic parameters, this study shows that a midsize (electric power capacity 20 MW) cogeneration system utilizing nonrecuperated ICRH cycle provides higher return on investment both at full-load and part-load conditions, compared to the other same size cycles, over the entire range of fuel cost, electric sale, and steam sale values examined. The plausible reasons for the observed trends in thermodynamic and economic performance parameters for four cycles and three sizes of cogeneration systems under full-load and part-load conditions have been presented in this paper.

Simulation of Full and Part-Load Performance Deterioration of Industrial Two-Shaft Gas Turbine

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
E. Mohammadi ◽  
M. Montazeri-Gh
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Generator ◽  
Simulation Accuracy ◽  
Part Load ◽  
Load Variations ◽  
Full Load ◽  
Performance Deterioration ◽  
Main Components ◽  
Load Conditions

In this paper, common faults in main components of an industrial two-shaft gas turbine are simulated, and the fault signatures are determined in both part and full-load conditions. As fouling and erosion are the most important and effective causes of performance deterioration in gas turbines (GTs), the effects of these faults on the performance of all three main components including compressor, gas generator turbine, and power turbine are studied and their effects on the overall efficiency of the whole system are analyzed. In this study, the faults simulation is performed by changing the health parameters (flow capacity and isentropic efficiency) of each GT components via modification of the compressor and turbines characteristic curves. The results obtained from the compressor fouling simulation are validated against the published experimental data; the validation results represent acceptable simulation accuracy in estimation of the measurement parameters deviation. Moreover, the fault signatures are determined in full-load conditions, and the effects of the examined faults on the main GT parameters are analyzed; in this way, the key measurement parameters in identification of these faults are introduced. Finally, in order to identify the fault signatures in part-load conditions, the fault implantation process is performed for each 10% reduction in gas turbine loads. Simulation results demonstrate that the fault signatures have different sensitivity to load variations, and thus, these are in general a function of the GT loading conditions.

scholarly journals The Effect of Pure Oxygenated Biofuels on Efficiency and Emissions in a Gasoline Optimised DISI Engine

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3908
Author(s):  
Tara Larsson ◽  
Senthil Krishnan Mahendar ◽  
Anders Christiansen-Erlandsson ◽  
Ulf Olofsson
Keyword(s):  
Internal Combustion Engines ◽  
Negative Impact ◽  
The Other ◽  
Nox Emissions ◽  
Combustion Engines ◽  
Engine Efficiency ◽  
Spark Timing ◽  
Low Load ◽  
Oxygenated Fuels ◽  
Load Conditions

The negative impact of transport on climate has led to incentives to increase the amount of renewable fuels used in internal combustion engines (ICEs). Oxygenated, liquid biofuels are promising alternatives, as they exhibit similar combustion behaviour to gasoline. In this article, the effect of the different biofuels on engine efficiency, combustion propagation and emissions of a gasoline-optimised direct injected spark ignited (DISI) engine were evaluated through engine experiments. The experiments were performed without any engine hardware modifications. The investigated fuels are gasoline, four alcohols (methanol, ethanol, n-butanol and iso-butanol) and one ether (MTBE). All fuels were tested at two speed sweeps at low and mid load conditions, and a spark timing sweep at low load conditions. The oxygenated biofuels exhibit increased efficiencies, even at non-knock-limited conditions. At lower loads, the oxygenated fuels decrease CO, HC and NOx emissions. However, at mid load conditions, decreased volatility of the alcohols leads to increased emissions due to fuel impingement effects. Methanol exhibited the highest efficiencies and significantly increased burn rates compared to the other fuels. Gasoline exhibited the lowest level of PN and PM emissions. N-butanol and iso-butanol show significantly increased levels of particle emissions compared to the other fuels.

Response Time Optimisation of the Rankine Compression Gas Turbine (RCG)

2006 ◽  
Author(s):  
H. Ouwerkerk ◽  
H. C. de Lange
Keyword(s):  
Response Time ◽  
Gas Turbine ◽  
Combined Cycle ◽  
Short Response Time ◽  
Part Load ◽  
Full Load ◽  
Ship Propulsion ◽  
Power Turbine ◽  
New Type ◽  
Set Up

The Rankine Compression Gas turbine (RCG) is a new type of combined cycle that delivers all power on one free power turbine. With its free power turbine the intended fields of application of the RCG are mechanical drives and ship propulsion. For the RCG to become successful in these fields of application a short response time from part-load to full-load is vital. Experiments with an experimental set-up at the Technische Universiteit Eindhoven showed that the response time would benefit from after-spray and supplementary firing. Therefore, these items were implemented in an overdrive controller that was designed to accelerate the RCG cycle more quickly. Simulations showed that the overdrive controller dramatically reduces the response time of the modeled RCG-cycle in a transient from 50% part-load to full-load from 20 minutes down to about 2 minutes. This is an impressive improvement of the response time and is believed to make the RCG suitable for mechanical drives and ship propulsion.

Thermo-Economic Analysis of an Intercooled, Reheat and Recuperated Gas Turbine for Cogeneration Applications: Part I — Base Load Operation

2000 ◽  
Author(s):  
R. Bhargava ◽  
M. Bianchi ◽  
G. Negri di Montenegro ◽  
A. Peretto
Keyword(s):  
Economic Analysis ◽  
Energy Saving ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Waste Heat ◽  
Pressure Ratio ◽  
Gas Temperature ◽  
Minimum Value ◽  
Maximum Value ◽  
Cogeneration System

This paper presents a thermo-economic analysis of an intercooled, reheat (ICRH) gas turbine, with and without recuperation, for cogeneration applications. The optimization analyses of thermodynamic parameters have permitted to calculate variables, such as low-pressure compressor pressure ratio, high-pressure turbine pressure ratio and gas temperature at the waste heat recovery unit inlet while maximizing electric efficiency and “Energy Saving Index”. Subsequently, the economic analyses have allowed to evaluate return on the investment, and the minimum value of gross payout period, for the cycle configurations of highest thermodynamic performance. In the present study three sizes (100 MW, 20 MW and 5 MW) of gas turbines have been examined. The performed investigation reveals that the maximum value of electric efficiency and “Energy Saving Index” is achieved for a large size (100 MW) recuperated ICRH gas turbine based cogeneration system. However, a non-recuperated ICRH gas turbine (of 100 MW) based cogeneration system provides maximum value of return on the investment and the minimum value of gross payout period compared to the other gas turbine cycles, of the same size and with same power to heat ratio, investigated in the present study. A comprehensive thermo-economic analysis methodology, presented in this paper, should provide useful guidelines for preliminary sizing and selection of gas turbine cycle for cogeneration applications.

Oil Ring Design Influence on Lube Oil Consumption of SI Engines

2004 ◽  
Author(s):  
Andre´ Ferrarese ◽  
Fernando F. Rovai
Keyword(s):  
Thermal Stability ◽  
The Other ◽  
Oil Consumption ◽  
Ring Type ◽  
Full Load ◽  
Sealing Capacity ◽  
Other Hand ◽  
Actual Use ◽  
Si Engines ◽  
Load Conditions

2-piece and 3-piece oil ring designs were tested in dynamometer and vehicles in order to evaluate the ring type influence on lube oil consumption of spark ignited (SI) engines. The dynamometer tests were executed according a typical durability cycle of SI engines. This cycle is predominantly in full load conditions. Under these conditions, 2-piece oil ring design showed lower lube oil consumption than 3-piece. Two different vehicle tests were also run: urban and mountain circuits. The purpose of the urban circuit test was to simulate the actual use of the engine. The mountain circuit was selected to verify the rings behavior under motoring conditions. In vehicle tests, 3-piece showed lower or equivalent oil consumption than 2 piece, which disagreed with the dynamometer tests. This difference can be explained by the better side sealing capacity of the 3-piece oil ring. On the other hand, 2-piece oil rings present better conformability, important for applications with larger bore distortion. So, the most appropriate application of oil ring type depends on the load and speed conditions, in which the engine would predominantly operate. Ring wear and thermal stability are compared using bench and vehicle tests.

Strategies to Enhance the Part-Load Performance of a SOFC/GT Hybrid System

2007 ◽  
Author(s):  
Jin Sik Yang ◽  
Jeong L. Sohn ◽  
Sung Tack Ro
Keyword(s):  
Gas Turbine ◽  
Hybrid Systems ◽  
Hybrid System ◽  
High Performance ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Part Load ◽  
Performance Loss ◽  
High Level ◽  
Level Performance

In spite of the high performance characteristics of the solid oxide fuel cell / gas turbine (SOFC/GT) hybrid system, it is very difficult to maintain the high level performance under real application conditions, which generally require part-load operations. The performance loss of SOFC/GT hybrid systems under part-load operating conditions is closely related to that of the gas turbine. The power generated by the gas turbine in a hybrid system is much smaller than that generated by the SOFC. However, its contribution to the system efficiency is very important especially at part-load operating conditions. Therefore, to enhance the part-load performance of hybrid systems, it is useful to reduce the relative amount of power generated by a gas turbine that delivers lower performance than a SOFC. In the present study, several part-load operation strategies related to the gas turbine are studied and their impacts on the performance of a SOFC/GT hybrid system are discussed.

Prediction and Mitigation of Thermally Induced Creep Distortion in Gas Turbine Combustors

2007 ◽  
Author(s):  
Hany Rizkalla ◽  
Page Strohl ◽  
Peter Stuttaford
Keyword(s):  
Gas Turbine ◽  
Design Process ◽  
Optimal Operation ◽  
Operating Conditions ◽  
Thermal Loads ◽  
Thermally Induced ◽  
Part Load ◽  
Gas Turbine Combustors ◽  
Over Time ◽  
Load Conditions

In an effort to maximize efficiency and decrease emissions, modern gas turbine combustors are exposed to extreme operating conditions which if not accounted for during the design process, can lead to premature failure of the combustion components. Of interest to this article are some operating conditions that, in many instances can expose the gas turbine combustion chambers (liners) to asymmetric thermal loads. Highly asymmetric thermal loads at high temperatures can inflict severe distress on combustion liners attributing to thermal creep distortion and Thermo-Mechanical Fatigue (TMF). Modern low emission pre-mix combustion systems such as the Dry Low NOx (DLN) 2.6 in the GE F Class machines and PSM’s FlameSheet combustor employ firing curves that involve “staging” when the gas turbine is ramping up or down in load or is simply operating in part-load condition. During such staging process, the flame resides in only certain sectors of each combustor while the other sectors are cold, these part load conditions can cause high thermal gradients leading to high thermally induced stresses in the liners. High thermal stresses at high metal temperatures can induce severe visco-plastic (creep) geometric distortion in liners upon prolonged exposure to such conditions. Extreme thermally induced creep distortion can eventually lead to liners’ catastrophic failures due to buckling and/or rupture. Under mild circumstances permanent creep distortion of liners can lead to non-optimal combustion and hence attributing to non optimal operation of the gas turbine. Several means can be employed during the design process to avoid and/or account for creep distortion, some of which are discussed in this article. Although linear elastic analysis is usually used by design engineers to predict liner thermal deflection under part load conditions, it is important to note that even though the resulting stresses may be within the material’s elastic range, creep relaxation leading to permanent liner deformation may still occur over time causing non-optimal base load operation and degradation to the gas turbine efficiency. In most cases predicting thermally induced creep distortion over time can only be done using iterative numerical techniques such as FEA coupled with the material specimen creep testing. A case study involving a F class FlameSheet liner will be discussed and used for illustrative purposes. ANSYS non-linear creep FEA modeling was used to predict the creep deformation results over time using Haynes 230 specimen test data. The predicted numerical analytical results matched well with actual hardware characterized data, thus validating the analytical technique.

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