Control Strategy Development for Optimized Operational Flexibility From Humidified Micro Gas Turbine: Saturation Tower Performance Assessment

2021 ◽  
Author(s):  
Ward De Paepe ◽  
Alessio Pappa ◽  
Diederik Coppitters ◽  
Marina Montero Carrero ◽  
Panagiotis Tsirikoglou ◽  
...  
Keyword(s):  
Control Strategy ◽  
Gas Turbines ◽  
Waste Heat ◽  
Injection System ◽  
Working Fluid ◽  
Electrical Load ◽  
Operational Flexibility ◽  
Test Rig ◽  
Water Steam ◽  
Control Matrix

Abstract Waste heat recovery through cycle humidification is considered as an effective tool to increase the operational flexibility of micro Gas Turbines (mGTs) in cogeneration in a Decentralized Energy System (DES) context. Indeed, during periods with low heat demand, the excess thermal power can be reintroduced in the cycle under the form of heated water/steam, leading to improved electrical performance. The micro Humid Air Turbine (mHAT) has been proven to be the most effective route for cycle humidification; however, so far, all research efforts focused on optimizing the mHAT performance at nominal electrical load, and no thermal load. Nevertheless, in a DES context, the thermal and electrical load of the mGT needs to be changed depending on the demand, requiring both optimal nominal and part load performances. To address this need, in this paper, we present the first step towards the development of a control strategy for a Turbec T100 mGT-mHAT test rig. First, using experimental data, the global performance, depending on the operating point as well as the humidity level, has been assessed. Second, the performance of the saturation tower, i.e. the degree of saturation (relative humidity) of the working fluid leaving this saturator, is analyzed to assess the optimal water injection system control parameter settings. Results show that optimal mHAT performance can only be obtained when the working fluid leaving the saturation tower is fully saturated, but does not contain a remaining liquid fraction. Under these conditions, a maximal amount of waste heat is transferred from the water to the mGT working fluid in the saturation tower. From these data, some general observations can be made to optimize the performance; being maximizing injection pressure and aiming for a water flow rate of ≈5 m3/h. However, having a specific control matrix, that allows setting the saturation tower control parameters for any set of operational setpoint and the inlet conditions would be of more interest. Therefore, future work involves the development of a control matrix, using advanced data post-processing for noise reduction and accuracy improvement, as well as an experimental validation of this methodology on the actual test rig.

Power Recovery From Gas Turbines: A Review of the Limitations, and an Evaluation of the Use of “Organic” Working Fluids

1970 ◽  
Author(s):  
Stephen Luchter
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Waste Heat ◽  
Power Level ◽  
Working Fluid ◽  
Working Fluids ◽  
Valuable Source ◽  
Power Recovery

Gas-turbine waste heat appears to be a valuable source of energy, yet the number of installations in which this energy is utilized is minimal. The reasons for this are reviewed and a typical nonafterburning cycle is examined for both steam and an “organic” working fluid. The power level range over which each is attractive is obtained, and the costs of each are compared on a relative basis.

scholarly journals Design and Operational Control Strategy for Optimum Off-Design Performance of an ORC Plant for Low-Grade Waste Heat Recovery

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5846
Author(s):  
Fabio Fatigati ◽  
Diego Vittorini ◽  
Yaxiong Wang ◽  
Jian Song ◽  
Christos N. Markides ◽  
...  
Keyword(s):  
Power Unit ◽  
Control Strategy ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Combustion Engine ◽  
Working Fluid ◽  
Thermal Source ◽  
Low Grade ◽  
Gear Pump

The applicability of organic Rankine cycle (ORC) technology to waste heat recovery (WHR) is currently experiencing growing interest and accelerated technological development. The utilization of low-to-medium grade thermal energy sources, especially in the presence of heat source intermittency in applications where the thermal source is characterized by highly variable thermodynamic conditions, requires a control strategy for off-design operation to achieve optimal ORC power-unit performance. This paper presents a validated comprehensive model for off-design analysis of an ORC power-unit, with R236fa as the working fluid, a gear pump, and a 1.5 kW sliding vane rotary expander (SVRE) for WHR from the exhaust gases of a light-duty internal combustion engine. Model validation is performed using data from an extensive experimental campaign on both the rotary equipment (pump, expander) and the remainder components of the plant, namely the heat recovery vapor generator (HRVH), condenser, reservoirs, and piping. Based on the validated computational platform, the benefits on the ORC plant net power output and efficiency of either a variable permeability expander or of sliding vane rotary pump optimization are assessed. The novelty introduced by this optimization strategy is that the evaluations are conducted by a numerical model, which reproduces the real features of the ORC plant. This approach ensures an analysis of the whole system both from a plant and cycle point of view, catching some real aspects that are otherwise undetectable. These optimization strategies are considered as a baseline ORC plant that suffers low expander efficiency (30%) and a large parasitic pumping power, with a backwork ratio (BWR) of up to 60%. It is found that the benefits on the expander power arising from a lower permeability combined with a lower energy demand by the pump (20% of BWR) for circulation of the working fluid allows a better recovery performance for the ORC plant with respect to the baseline case. Adopting the optimization strategies, the average efficiency and maximum generated power increase from 1.5% to 3.5% and from 400 to 1100 W, respectively. These performances are in accordance with the plant efficiencies found in the experimental works in the literature, which vary between 1.6% and 6.5% for similar applications. Nonetheless, there is still room for improvement regarding a proper design of rotary machines, which can be redesigned considering the indications resulting from the developed optimization analysis.

scholarly journals Combined Cycles for Pipeline Compressor Drives Using Heat

1979 ◽  
Author(s):  
W. F. Malewski ◽  
G. M. Holldorff
Keyword(s):  
Gas Turbines ◽  
Waste Heat ◽  
Working Fluid ◽  
Exhaust Gas ◽  
Working Fluids ◽  
Ambient Temperatures ◽  
Working Medium ◽  
Medium Range ◽  
Combined Cycles ◽  
Optimum Working

Combined cycles for pipeline-booster stations using waste heat from gas turbines exhaust can improve the overall efficiency of such stations remarkably. Several working fluids are suitable. Due to existing criteria for selecting a working medium under mentioned conditions, water, ammonia, propane and butane can be considered as practical working fluids. The investigations have shown that: (a) ammonia is advantageous at low exhaust gas and ambient temperatures, (b) water is most effective at high exhaust gas and ambient temperatures, and (c), additionally, hydrocarbons are suitable in a medium range for exhaust gas and condensing temperatures. Not only thermodynamic but also operational features have to be considered. There is not one optimum working fluid but a best one suitable according to the prevailing site conditions.

Thermo-Economic Evaluation of ORC System in Off-Shore Applications

2014 ◽  
Author(s):  
R. K. Bhargava ◽  
M. Bianchi ◽  
L. Branchini ◽  
A. De Pascale ◽  
F. Melino ◽  
...  
Keyword(s):  
Economic Analysis ◽  
Gas Turbines ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Gas Production ◽  
Working Fluid ◽  
Bottom Line ◽  
Cycle System ◽  
Engineering Team

This paper presents a study related with off-shore oil & gas production and processing facilities, where required energy, for electric power, mechanical power and process heat, is mostly produced using gas turbines, as the fuel source (natural gas) is available onsite. Since size and weight of all equipment on an offshore facility are critical, it becomes necessary for the facility engineering team to ensure that all equipment are sized and selected appropriately to obtain better return on the investment. Therefore, any approach which could help in utilizing energy resources effectively will influence the bottom-line of the project, namely reduced capital cost and/or increased return on investment. In this paper, one such approach of recovering power and thermal energy through the use of Organic Rankine Cycle system is discussed. A detailed thermo-economic analysis, conducted considering a system with four gas turbines operating, shows that power recovery equivalent to one topping gas turbine is achievable with a suitable working fluid. The presented thermo-economic analysis clearly shows that use of the Organic Rankine Cycle system for waste heat recovery is a technically viable and economically attractive solution for the offshore applications.

Stall and Surge in Wet Compression: Test Rig Development and Experimental Results

2018 ◽  
Author(s):  
Enrico Munari ◽  
Gianluca D’Elia ◽  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina
Keyword(s):  
Gas Turbines ◽  
Water Injection ◽  
Experimental Results ◽  
Low Flow ◽  
Injection System ◽  
Data Sampling ◽  
Test Rig ◽  
State Tests ◽  
Dry Conditions ◽  
Wet Compression

Wet compression is a strategy adopted to increase the power output of gas turbines, with respect to dry conditions, usually also incrementing the operating range of the compressor. However, stall and surge are two aerodynamic instabilities which depend on many factors, and they are expected to occur even in wet compression at low flow rates. Despite the many studies carried out in the last 80 years, literature does not offer many works concerning these instability phenomena in wet compression. In this paper, an experimental analysis of stall and surge in wet compression conditions is carried out on an axial-centrifugal compressor installed in an existing test rig at the Engineering Department of the University of Ferrara. Some modifications of the test rig were necessary. The intake duct was implemented with a water injection system which, by means of water spray injectors, allows the uniform mixing of air and water before the compressor inlet. The control and data acquisition system of the test bench was updated with new hardware and software to obtain faster data sampling. Transient and steady-state tests were carried out to make a comparison with the experimental results in dry conditions. The analysis was carried out using traditional thermodynamic sensors, by means of both classic post-processing techniques, and cyclostationary analysis. The aim is to i) evaluate the influence of wet compression on the stable performance of the compressor ii) qualitatively identify the characteristics of stall and surge in wet compression by means of sensors which were shown to capture these phenomena well and iii) demonstrate the reliability of cyclostationary analysis in wet compression conditions for stall and surge analysis.

A General-Purpose Test Facility for Evaluating Gas Lubricated Thrust Bearings

2020 ◽  
Author(s):  
Keith Gary ◽  
Bugra Ertas ◽  
Adolfo Delgado
Keyword(s):  
Gas Turbines ◽  
High Performance ◽  
Load Capacity ◽  
General Purpose ◽  
Test Facility ◽  
Working Fluid ◽  
Test Rig ◽  
Auxiliary Equipment ◽  
Thrust Bearings ◽  
Low Viscosity

Abstract The design, construction, operational capabilities, and proof of concept results are presented for a test rig used to evaluate gas-lubricated thrust bearings. The following work is motivated by a desire to utilize the working fluid of high-performance turbomachinery, such as gas turbines, for bearing lubricant. Auxiliary equipment required to cool, pump, and clean oil for a typical thrust bearing is eliminated by taking advantage of the turbomachinery’s working fluid as bearing lubricant. The benefit of removing such auxiliary equipment is obvious when considering cost and weight of turbomachines, yet the working fluid of gas turbines typically has very low viscosity compared to oil which introduces load capacity and stability challenges. It is therefore necessary to build a facility capable of testing gas-lubricated thrust bearings to advance the technology. The test rig design in this work allows for 7 to 15 inch (180–380 mm) diameter thrust bearings, static loads up to 30,000 lbf (135 kN), and speeds up to 20 krpm. The test facility also provides up to 500 psig (3.45 MPa) static air pressure to enable testing of hydrostatic and hybrid (hydrodynamic combined with hydrostatic) bearings. This paper describes the test rig operating principle, details experimental procedures to obtain measurements, and provides test results necessary to prove the test rig concept by means of a hybrid gas bearing.

Thermodynamic Optimization and Off-Design Performance Analysis of a Toluene Based Rankine Cycle for Waste Heat Recovery From Medium-Sized Gas Turbines

2012 ◽  
Author(s):  
Carlo Carcasci ◽  
Riccardo Ferraro
Keyword(s):  
Gas Turbines ◽  
Waste Heat ◽  
Water Cycle ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Industrial Applications ◽  
Working Fluid ◽  
Main Process ◽  
Thermal Source ◽  
Medium Temperature

In the last years, the accelerated consumption of fossil fuels has caused many serious environmental problems such as global warming, the depletion of the ozone layer and atmospheric pollution. Similarly, low-temperature waste heat which is discharged in several industrial processes, contributes to thermal pollution and damages the environment. Furthermore, many industrial applications use low enthalpy thermal sources, where the conventional systems for the conversion of thermal energy into electrical energy, based on a Rankine water cycle, work with difficulty. Thus, the Organic Rankine Cycle can be considered a promising process for the conversion of heat at low and medium temperature whenever the conventional water cycle causes problems. Using an organic working fluid instead of water, the ORC system works like the bottom cycle of a conventional steam power plant. This kind of cycle allows a high utilization of the available thermal source. Moreover, the choice of the working fluid is critical, because it should meet several environment standards and not only certain thermophysical properties. This paper illustrates the results for the simulations of an Organic Rankine Cycle based on a gas turbine with a diathermic oil circuit. The selected working fluid is toluene. The design is performed with a sensitivity analysis of the main process parameters, the organic Rankine cycle is optimized by varying the main pressure of the fluid at different temperatures of the oil circuit. The off-design is performed by varying the temperature of the air condenser.

scholarly journals Installation of a Waste Heat Recovery System at a Gas Turbine-Driven Compressor Station

1983 ◽  
Author(s):  
Charles J. Tateosian ◽  
George K. Roland
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Working Fluid ◽  
Compressor Station ◽  
Water Steam ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

A waste heat recovery system for generation of electricity has been added to a natural gas pipeline compressor station. The heat recovery system, utilizing a dual pressure Rankine cycle with water/steam as the working fluid, increases the overall thermal efficiency of the 12,500 hp simple cycle gas turbine from 25.3% to 36.1%. The system will generate power for the local electric distribution system.

scholarly journals Evaluation of Using Gas Turbine to Increase Efficiency of the Organic Rankine Cycle (ORC)

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1499 ◽  
Author(s):  
Dominika Matuszewska ◽  
Piotr Olczak
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Low Grade ◽  
System Efficiency ◽  
Steam Quality ◽  
The Impact

Power conversion systems based on the Organic Rankine Cycle (ORC) have been identified as a potential technology especially in converting low-grade renewable sources or waste heat. However, it is necessary to improve efficiency of ORC systems. This paper focuses on use of low geothermal resources (for temperature range of 80–128 °C and mass flow 100 kg/s) by using modified ORC. A modification of conventional binary power plant is conducted by combining gas turbines to increase quality of steam from a geothermal well. An analysis has been conducted for three different working fluids: R245fa, R1233zd(E) and R600. The paper discusses the impact of parameter changes not only on system efficiency but on other performance indicators. The results were compared with a conventional geothermal Organic Rankine Cycle (ORC). Increasing of geothermal steam quality by supplying exhaust gas from a gas turbine to the installation has a positive effect on the system efficiency and power. The highest efficiency of the modified ORC system has been obtained for R1233zd(E) as a working fluid and it reaches values from 12.21% to 19.20% (depending on the temperature of the geothermal brine). In comparison, an ORC system without gas turbine support reaches values from 9.43% to 17.54%.

Perspectives for Waste Heat Recovery by Means of Organic Fluid Cycles

1973 ◽  
Vol 95 (2) ◽  
pp. 75-83 ◽  
Author(s):  
G. Angelino ◽  
V. Moroni
Keyword(s):  
Gas Turbines ◽  
Heat Recovery ◽  
Waste Heat ◽  
Combined Cycle ◽  
Working Fluid ◽  
Specific Work ◽  
Power Turbine ◽  
Basic Characteristics ◽  
Working Media ◽  
Power Recovery

Organic compounds, employed as working fluids for low temperature heat recovery, are shown to exhibit a performance better than that of steam cycles. The potential influence on efficiency and specific work of organic fluid power recovery applied to existing open cycle gas turbine, diesel and gas engines is illustrated on the base of a statistical documentation. The basic characteristics of a typical combined cycle layout are analyzed with respect to fuel economy, air consumption and heat exchange surface requirements. The possibility of improving the performance of closed cycle (helium) gas turbines by means of an organic fluid heat recovery cycle is then examined. The potential benefits deriving from the use of the power turbine of the organic fluid cycle as a direct driver for the compressor of a refrigerating cycle or heat pump employing the same working fluid are discussed. The basic results of a test program aiming to determine the decomposition rates and the corrosion characteristics of some organic working media are presented.

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