Cogenerative Performance of a Wind–Gas Turbine–Organic Rankine Cycle Integrated System for Offshore Applications

2016 ◽  
Author(s):  
Michele Bianchi ◽  
Lisa Branchini ◽  
Andrea De Pascale ◽  
Francesco Melino ◽  
Valentina Orlandini ◽  
...  
Keyword(s):  
Power System ◽  
Gas Turbines ◽  
Oil And Gas ◽  
High Reliability ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Heat And Power ◽  
Combined Cycle ◽  
Integrated System ◽  
Offshore Wind

Gas Turbines (GT) are widely used for power generation in offshore oil and gas facilities, due to their high reliability, compactness and dynamic response capabilities. Small heavy duty and aeroderivative units in multiple arrangements are typically used to offer larger load flexibility, but limited efficiency of such machines is the main drawback. A solution to enhance the system performance, also in Combined Heat and Power (CHP) arrangement, is the implementation of Organic Rankine Cycle (ORC) systems at the bottom of the gas turbines. Moreover, the resulting GT-ORC combined cycle could be further integrated with additional renewable sources. Offshore wind technology is rapidly developing and floating wind turbines could be combined with offshore GT-ORC based power plants to satisfy the platform load. The pioneering stand alone power system, for an oil and gas platform, examined in this paper comprises a 10MW offshore wind farm and three gas turbines rated for 16.5MW, each one coupled with an 4.5MW ORC module. The ORC main parameters are observed under different wind power fluctuations. Due to the non-programmable availability of wind and power demand, the part-load and dynamic characteristics of the system should be investigated. A dynamic model of the power system based on first principles is used, developed in the Modelica language. The model is integrated with a time series-based model of two offshore wind mills. Various thermodynamic indexes, available in the literature, are identified and evaluated to compare the actual combined heat and power performances of single components and of the overall integrated system in the considered wind scenarios.

Biomass combined cycles based on externally fired gas turbines and organic Rankine expanders

2011 ◽  
Vol 225 (8) ◽  
pp. 1066-1075 ◽  
Author(s):  
C M Invernizzi ◽  
P Iora ◽  
R Sandrini
Keyword(s):  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Economic Feasibility ◽  
Maximum Efficiency ◽  
Working Fluid ◽  
Inlet Temperature ◽  
System A ◽  
Combined Cycles

This article investigates the possibility to enhance the performance of a biomass organic Rankine cycle (ORC) plant by adding an externally fired gas turbine (EFGT), yielding a combined EFGT + ORC system. A typical ORC configuration is first modelled and validated on data available from an existing unit 1.5 MW reference plant. Then, different working fluids belonging to the methyl-substituted benzene series and linear methylpolysiloxanes have been evaluated for the ORC section on the basis of both thermodynamics considerations and design issues of the regenerator and the turbine. Results of the simulations of the combined cycle (CC) referred to a furnace size of about unit 9 MW, assuming a maximum GT inlet temperature of 800 °C, show a maximum efficiency of 23 per cent, obtained in the case where toluene is adopted as a working fluid for the bottoming section. This value is about 4 points per cent higher than the efficiency of the corresponding simple ORC. Finally, to conclude, some preliminary considerations are given regarding the techno-economic feasibility of the combined configuration, suggesting the need of a further investigation on the possible technological solution for the furnace which represents the main uncertainty in the resulting costs of the CC.

Energy Recovery in Natural Gas Compressor Stations Taking Advantage of Organic Rankine Cycle: Preliminary Design Analysis

2017 ◽  
Author(s):  
M. Bianchi ◽  
L. Branchini ◽  
A. De Pascale ◽  
F. Melino ◽  
V. Orlandini ◽  
...  
Keyword(s):  
Natural Gas ◽  
System Performance ◽  
Gas Turbines ◽  
Energy Recovery ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Integrated System ◽  
Specific Power ◽  
Condensation Temperature ◽  
Power Recovery

Gas compressor stations represent a huge potential for exhaust heat recovery. Typical installations consist of open cycle configurations with multiple gas turbine units, usually operated under part-load conditions during the year with limited conversion efficiency. At least, one of the installed unit serves as back-up to ensure the necessary reserve power and the safe operation of the station. Organic Rankine Cycle (ORC) has been proven as an economical and environmentally friendly solution to recover waste heat from gas turbines, improving the overall energy system performance and reducing the CO2 emissions. In this context, taking as reference typical gas compressor stations located in North America, the paper investigates the potential benefit of ORC application, as bottomer section of gas turbines, in natural gas compression facilities. Thus, ORC converts gas turbines wasted heat into useful additional power that can be used inside the compression facility reducing the amount of consumed natural gas and, consequently, the environmental emissions, or directed to the grid, thus furthermore earning economic benefits. Different case studies are examined with reference to two typical compressor station size ranges: a “small-medium” and a “medium-high” size range. Two different gas turbine models are considered according to most common manufacturers. Typical gas compressor stations and integrated cycle configurations are identified. Based on Turboden experience in development and production of ORCs, specific design options and constraints, layout arrangements and operating parameters are examined and compared in this study, such as the use of an intermediate heat transfer fluid, the type of organic fluid, the influence of superheating degree and condensation temperature values. Emphasis is given on thermodynamic performance of the integrated system by evaluating thermal energy and mechanical power recovery. Several key performance indexes are defined such as, the ORC power and efficiency, the specific power recovery per unit of compression power, the integrated system net overall power output and efficiency, the ORC expander and heat exchangers size parameters, the carbon emission savings, etc. The performed comparison of various configurations shows that: (i) the energy recovery with ORC can be remarkable, adding up to more than 35% of additional shaft power to the compression station in the best configuration; (ii) the ORC condensation temperature value has a significant impact on the ORC bottomer cycle and on the integrated system performance; (iii) in case of Cyclopentane, keeping the same ORC cycle operating parameters, the max specific power recovery is achieved in the direct configuration case, (iv) the bottomer cycle size can be reduced with the use of a refrigerant fluid (R1233zd(E)), compared to hydrocarbon fluids; (v) the max environmental benefit can be up to 120 kg CO2/h saved per MW of installed compression power.

Flexible Combined Cycle Gas Turbine Power Plant Utilising Organic Rankine Cycle Technology

2016 ◽  
Author(s):  
Michael Welch ◽  
Nicola Rossetti
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Operational Flexibility

Historically gas turbine power plants have become more efficient and reduced the installed cost/MW by developing larger gas turbines and installing them in combined cycle configuration with a steam turbine. These large gas turbines have been designed to maintain high exhaust gas temperatures to maximise the power generation from the steam turbine and achieve the highest overall electrical efficiencies possible. However, in today’s electricity market, with more emphasis on decentralised power generation, especially in emerging nations, and increasing penetration of intermittent renewable power generation, this solution may not be flexible enough to meet operator demands. An alternative solution to using one or two large gas turbines in a large central combined cycle power plant is to design and install multiple smaller decentralised power plant, based on multiple gas turbines with individual outputs below 100MW, to provide the operational flexibility required and enable this smaller power plant to maintain a high efficiency and low emissions profile over a wide load range. This option helps maintain security of power supplies, as well as providing enhanced operational flexibility through the ability to turn turbines on and off as necessary to match the load demand. The smaller gas turbines though tend not to have been optimised for combined cycle operation, and their exhaust gas temperatures may not be sufficiently high, especially under part load conditions, to generate steam at the conditions needed to achieve a high overall electrical efficiency. ORC technology, thanks to the use of specific organic working fluids, permits efficient exploitation of low temperatures exhaust gas streams, as could be the case for smaller gas turbines, especially when working on poor quality fuels. This paper looks at how a decentralised power plant could be designed using Organic Rankine Cycle (ORC) in place of the conventional steam Rankine Cycle to maximise power generation efficiency and flexibility, while still offering a highly competitive installed cost. Combined cycle power generation utilising ORC technology offers a solution that also has environmental benefits in a water-constrained World. The paper also investigates the differences in plant performance for ORC designs utilising direct heating of the ORC working fluid compared to those using an intermediate thermal oil heating loop, and looks at the challenges involved in connecting multiple gas turbines to a single ORC turbo-generator to keep installed costs to a minimum.

scholarly journals New Mobile Gas Turbine with a Wide Range of Applications

2018 ◽  
Vol 140 (03) ◽  
pp. S54-S55
Author(s):  
Uwe Schütz
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Large Power ◽  
Power Stations ◽  
Wide Range ◽  
Term Basis

This article describes features and advantages of new mobile gas turbine with a wide range of applications. The market for mobile gas turbines is continuously growing. Mobile units are also an ideal choice when it comes to making large power capacities available on a short-term basis, for example, for major events, prolonged downtimes at other power stations, or power-intensive applications such as mining or shale gas extraction. If the electricity requirements exceed the level that can normally be demanded of a mobile application, an SGT-A45 installation can be modified to form a combined-cycle power plant to further improve its efficiency. In remote locations, this can be achieved using an Organic Rankine Cycle (ORC), to eliminate the need for water and water treatment systems, and to optimize energy recovery from the SGT-A45 off-gas stream at a relatively low temperature. The use of a direct heat exchanger, in which the ORC working fluid is evaporated by the off-gas stream from the gas turbine, can boost the system’s output capacity by more than 20 percent.

Bottoming Organic Cycle for Gas Turbines

2005 ◽  
Author(s):  
Lucien Y. Bronicki ◽  
Daniel N. Schochet
Keyword(s):  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Processing Plant ◽  
Steam Turbines ◽  
Practical Applications ◽  
Gas Processing ◽  
The Past ◽  
Exhaust Heat

Organic Rankine Cycle (ORC) systems are not new; prototypes have been tested for about a century. The theoretical investigation and practical applications in the past are briefly presented and referenced. This paper presents the applications of this technology, which matured mainly in geothermal applications, to the recovery of exhaust heat of simple cycle gas turbines driving compressors on gas pipelines and gas processing plant. Most of the compressor stations have a capacity below 50 MW and operate basically unattended. The complexity and the necessity of an operator prevents the use of bottoming steam systems (combined cycle) on this size of plant. In these applications, which are mainly retrofits, the ease of operation of the ORC made its use possible where steam turbines were unsuccessful. Two applications are described: the Enterprise Products’ Neptune plant in Louisiana, and the Gold Creek gas compressor station in Alberta, Canada.

A Supercritical CO2 Brayton Cycle Micro Turbine for Waste Heat Conversion: Optimization Layout in Cogenerative Applications

2021 ◽  
Author(s):  
Fabrizio Reale ◽  
Raniero Sannino ◽  
Raffaele Tuccillo
Keyword(s):  
Gas Turbines ◽  
Supercritical Co2 ◽  
Waste Heat ◽  
Mechanical Energy ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Thermal Source ◽  
Brayton Cycle ◽  
Micro Turbine

Abstract Waste heat recovery (WHR) can represent a good solution to increase overall performance of energy systems, even more in case of small systems. The exhaust gas at the outlet of micro gas turbines (MGTs) has still a large amount of thermal energy that can be converted into mechanical energy, because of its satisfactory temperature levels, even though the typical MGT layouts perform a recuperated cycle. In recent studies, supercritical CO2 Brayton Cycle (sCO2 GT) turbines were studied as WHR systems whose thermal source was the exhausts from gas turbines. In particular, subject of this study is the 100 kW MGT Turbec T100. In this paper, the authors analyze innovative layouts, with comparison in terms of performance variations and cogenerative indices. The study was carried out through the adoption of a commercial software, Thermoflex, for the thermodynamic analysis of the layouts. The MGT model was validated in previous papers while the characteristic parameters of the bottoming sCO2 GT were taken from the literature. The combined cycle layouts include simple and recompression sCO2 bottoming cycles and different fuel energy sources like conventional natural gas and syngases derived by biomasses gasification. A further option of bottoming cycle was also considered, namely an organic Rankine cycle (ORC) system for the final conversion of waste heat from sCO2 cycle into additional mechanical energy. Finally, the proposed plants have been compared, and the improvement in terms of flexibility and operating range have been highlighted.

Techno-Economic Optimization of Electricity and Heat Production in a Gas-Fired Combined Heat and Power Plant With a Heat Accumulator

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Piotr Żymełka ◽  
Marcin Szega ◽  
Paweł Madejski
Keyword(s):  
Gas Turbine ◽  
Heat Production ◽  
Optimization Algorithm ◽  
Gas Turbines ◽  
Heat Recovery ◽  
High Reliability ◽  
Combined Heat And Power ◽  
Combined Cycle ◽  
Time Step ◽  
Heat Accumulator

Abstract At present, power systems based on gas turbines are mainly used for electricity and heat generation. Gas turbines are used in industrial and institutional applications due to high-temperature exhaust, which can be used for heating, drying, or process steam production. The combined cycle gas turbine plants are a mature technology with high reliability and offering rapid response to changing demand for electricity and heat. The combination of a gas turbine with a heat recovery system and a heat accumulator makes the combined heat and power (CHP) plant a flexible unit. The paper presents the optimization tool for the planning process of electricity and heat production in the gas-fired CHP plant with a heat accumulator. The detailed mathematical model of the analyzed cogeneration plant was developed with the EBSILON®Professional and verified based on the results from on-site tests and warranty measurements. The implemented optimization algorithm is used to maximize the profits of the CHP plant operation. The presented solution is based on an evolutionary algorithm. The optimization algorithm is applied to the production determination for the day-ahead planning horizon, with 1-h time step. The obtained results show that the developed optimization model is a reliable and efficient tool for production planning in a CHP plant with gas turbines. The comparative exergy analysis for different technologies of heat recovery from gas turbine exhaust gases was performed to evaluate the quality of the energy conversion process in the CHP plant.

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