Model-Based Analysis of a Combined Heat and Power System Featuring a Hydrogen-Fired Gas Turbine with On-Site Hydrogen Production and Storage

Author(s):  
Thomas Bexten ◽  
Manfred Wirsum ◽  
Björn Roscher ◽  
Ralf Schelenz ◽  
Georg Jacobs

Abstract Hydrogen-fired gas turbines can play an important role in carbon neutral energy and industry sectors. However, the required demand-oriented supply of CO2-neutral hydrogen is technically and economically challenging. These challenges arise due to interdependencies between the volatility of renewable power generation, available hydrogen production capacities, available hydrogen storage capacities and the operational demands to be met by gas turbines. The present study aims to quantify these interdependencies by conducting a model-based analysis of an exemplary CHP system featuring a hydrogen-fired industrial gas turbine with on-site hydrogen production via electrolysis and on-site hydrogen storage. To identify the sought-after interdependencies, simulation runs featuring various system parameterizations are analyzed. If only local power surpluses are utilized for the operation of electrolyzers, the results show a non-linear impact of both the hydrogen production capacity and the hydrogen storage capacity on the hydrogen-based gas turbine operation. Furthermore, the results indicate that an exclusive utilization of local power surpluses leads to limited periods of hydrogen-based gas turbine operation. If additional power for the operation of electrolyzers is supplied by the grid, prolonged periods of hydrogen-based gas turbine operation can be achieved. However, to realize an overall reduction of CO2 emissions, this mode of operation requires the supply of large quantities of renewable power by the grid. The results of an additional economic assessment reveal that both investigated operational modes are not economically viable within the considered economic framework.

Author(s):  
Thomas Bexten ◽  
Manfred Wirsum ◽  
Björn Roscher ◽  
Ralf Schelenz ◽  
Georg Jacobs

Abstract Hydrogen-fired gas turbines have the potential to play an important role in decarbonized energy sectors. However, a demand-oriented supply of CO2-neutral hydrogen for the operation of gas turbines is technically and economically challenging. These challenges mainly arise due to various interdependencies between the volatility of renewable power generation, available hydrogen production capacities, available hydrogen storage capacities and the operational demands to be met by gas turbines. The present study aims to quantify these interdependencies by conducting a detailed model-based analysis of an exemplary combined heat and power system featuring a hydrogen-fired industrial gas turbine with on-site hydrogen production via electrolysis and on-site hydrogen storage in pressure vessels. In order to identify the sought-after interdependencies, simulation runs featuring various combinations of available hydrogen production and storage capacities are analyzed. If only local power surpluses are utilized for the electrolysis, the obtained results reveal a strong non-linear impact of both the hydrogen production capacity and the storage capacity on the ability to provide hydrogen for the gas turbine. Furthermore, the results indicate that an exclusive utilization of local power surpluses leads to very limited periods of hydrogen-based gas turbine operation and low utilization rates of the available hydrogen production and storage capacities. If additional power for the operation of electrolyzers is supplied by the grid, increased utilization rates and prolonged periods of hydrogen-based gas turbine operation can be achieved. However, in order to realize an overall reduction of CO2 emissions, this mode of operation requires the supply of large quantities of renewable power by the grid. Furthermore, the results of an additional economic analysis reveal that both investigated operational modes are currently not economically viable within the considered economic framework.


Author(s):  
Jason John Dennis ◽  
Thomas Bexten ◽  
Nils Petersen ◽  
Manfred Wirsum ◽  
Patrick Preuster

Abstract One of the main challenges currently hindering the transition to energy systems based on renewable power generation is grid stability. To compensate for the volatility of wind- and solar-based power generation, storage facilities able to adapt to seasonal and short term differences in energy production and demand are required. Liquid Organic Hydrogen Carriers (LOHCs) represent a viable method of chemically binding elemental hydrogen, offering opportunities for largescale and safe energy storage. In times of energy shortage, flexible and dispatchable power generation technologies such as gas turbines can be fueled by hydrogen stored in this manner. Hydrogen can be released from its liquid carrier via an endothermic dehydrogenation reaction using waste heat provided by the gas turbine. This gaseous hydrogen can be supplied to the gas turbine combustion chamber using a hydrogen compressor. In the present study a steady state model is developed in order to analyse the heat-integrated combination of a 7.7 MW hydrogen-fired gas turbine and a H18-DBT/H0-DBT LOHC system. For the best-performing parameter set the effective storage density of the LOHC oil comes to 1.5 kWh/L. This value is situated in-between that of compressed hydrogen at 350 bar (1.01 kWh/L) and liquid hydrogen (2.33 kWh/L). Concurrently, the corresponding energy required for hydrogen compression reduces the overall system efficiency to 22.00 % (ηGT = 30.15%). The resulting optimal electricity yield, being a product of these two values, amounts to 0.33 kWhel/L.


Author(s):  
Thomas Bexten ◽  
Sophia Jörg ◽  
Nils Petersen ◽  
Manfred Wirsum ◽  
Pei Liu ◽  
...  

Abstract Climate science shows that the limitation of global warming requires a rapid transition towards net-zero emissions of greenhouse gases (GHG) on a global scale. Expanding renewable power generation is seen as an imperative measure within this transition. To compensate for the inherent volatility of renewable power generation, flexible and dispatchable power generation technologies such as gas turbines are required. If operated with CO2-neutral hydrogen or in combination with carbon capture plants, a GHG-neutral gas turbine operation could be achieved. An effective leverage to enhance carbon capture efficiency and a possible measure to safely burn hydrogen in gas turbines is the partial external recirculation of exhaust gas. By means of a model-based analysis of a gas turbine, the present study initially assesses the thermodynamic impact caused by a fuel switch from natural gas to hydrogen. Although positive trends such as increasing net electrical power output and thermal efficiency can be observed, the overall effect on the gas turbine process is only minor. In a following step, the partial external recirculation of exhaust gas is evaluated and compared both for the combustion of natural gas and hydrogen, regardless of potential combustor design challenges. The influence of altering working fluid properties throughout the whole gas turbine process is thermodynamically evaluated for ambient temperature recirculation and recirculation at an elevated temperature. A reduction in thermal efficiency can be observed as well as non-negligible changes of relevant process variables. These changes are more distinctive at a higher recirculation temperature


2021 ◽  
Author(s):  
Thomas Bexten ◽  
Tobias Sieker ◽  
Manfred Wirsum

Abstract Hydrogen-fired gas turbines have the potential to play an important role in future CO2-neutral energy and industry sectors. A prerequisite for the operation of hydrogen-fired gas turbines is the availability of sufficient quantities of hydrogen. The combination of electrolysis and renewable power generation is currently considered the most relevant pathway for the large-scale production of CO2-neutral hydrogen. Regarding the fuel supply of hydrogen-fired gas turbines, this pathway is associated with various technical and economic challenges. This applies in particular to configurations in which electrolyzers and hydrogen storage capacities are installed directly at gas turbine sites to avoid hydrogen transport. Considering an exemplary system configuration, the present study extends prior model-based investigations by focusing on the economic viability of the on-site fuel supply of hydrogen-fired gas turbines. The impact of various design parameters and operational strategies is analyzed using the Levelized Cost of Hydrogen as the main economic indicator. The study reveals that the investigated on-site hydrogen production is not economically viable within the current (2019) framework of the German energy sector. Assuming the extensive availability of renewable power generation in the long-term, additional investigations indicate that on-site hydrogen production and storage systems for gas turbines could potentially become economically viable if various advantageous conditions are met. These conditions include a sufficient availability of inexpensive renewable power for the operation of electrolyzers as well as a sufficient utilization of on-site hydrogen storage capacities to justify corresponding capital expenditures.


Author(s):  
Thomas Bexten ◽  
Tobias Sieker ◽  
Manfred Wirsum

Abstract Hydrogen-fired gas turbines have the potential to play an important role in future CO2-neutral energy and industry sectors. A prerequisite for the operation of hydrogen-fired gas turbines is the availability of sufficient quantities of hydrogen. The combination of electrolysis and renewable power generation is currently considered the most relevant pathway for the large-scale production of CO2-neutral hydrogen. Regarding the fuel supply of hydrogen-fired gas turbines, this pathway is associated with various technical and economic challenges. This applies in particular to configurations in which electrolyzers and hydrogen storage capacities are installed directly at gas turbine sites to avoid hydrogen transport. Considering an exemplary system configuration, the present study extends prior model-based investigations by focusing on the economic viability of the on-site fuel supply of hydrogen-fired gas turbines. The impact of various design parameters and operational strategies is analyzed using the Levelized Cost of Hydrogen as the main economic indicator. The study reveals that the investigated on-site hydrogen production is not economically viable within the current (2019) framework of the German energy sector. Assuming the extensive availability of renewable power generation in the long-term, additional investigations indicate that on-site hydrogen production and storage systems for gas turbines could potentially become economically viable if various advantageous conditions are met. These conditions include a sufficient availability of inexpensive renewable power for the operation of electrolyzers as well as a sufficient utilization of on-site hydrogen storage capacities to justify corresponding capital expenditures.


2018 ◽  
Vol 173 ◽  
pp. 113-122 ◽  
Author(s):  
D.G. Oliva ◽  
M. Fuentes ◽  
E.M. Borzone ◽  
G.O. Meyer ◽  
P.A. Aguirre

Author(s):  
Koldo Zuniga ◽  
Thomas P. Schmitt ◽  
Herve Clement ◽  
Joao Balaco

Correction curves are of great importance in the performance evaluation of heavy duty gas turbines (HDGT). They provide the means by which to translate performance test results from test conditions to the rated conditions. The correction factors are usually calculated using the original equipment manufacturer (OEM) gas turbine thermal model (a.k.a. cycle deck), varying one parameter at a time throughout a given range of interest. For some parameters bi-variate effects are considered when the associated secondary performance effect of another variable is significant. Although this traditional approach has been widely accepted by the industry, has offered a simple and transparent means of correcting test results, and has provided a reasonably accurate correction methodology for gas turbines with conventional control systems, it neglects the associated interdependence of each correction parameter from the remaining parameters. Also, its inherently static nature is not well suited for today’s modern gas turbine control systems employing integral gas turbine aero-thermal models in the control system that continuously adapt the turbine’s operating parameters to the “as running” aero-thermal component performance characteristics. Accordingly, the most accurate means by which to correct the measured performance from test conditions to the guarantee conditions is by use of Model-Based Performance Corrections, in agreement with the current PTC-22 and ISO 2314, although not commonly used or accepted within the industry. The implementation of Model-based Corrections is presented for the Case Study of a GE 9FA gas turbine upgrade project, with an advanced model-based control system that accommodated a multitude of operating boundaries. Unique plant operating restrictions, coupled with its focus on partial load heat rate, presented a perfect scenario to employ Model-Based Performance Corrections.


2018 ◽  
Vol 22 (Suppl. 3) ◽  
pp. 809-817
Author(s):  
Umit Unver ◽  
Alper Kelesoglu ◽  
Muhsin Kilic

Gas turbines are widely used in the energy production. The quantity of the operating machines requires a special attention for prediction of power production in the energy marketing sector. Thus, the aim of this paper is to support the sector by making the prediction of power production more computable. By using the data from an operating power plant, correlation and regression analysis are performed and linear equation obtained for calculating useful power production vs atmospheric air temperature and a novel method, the gas turbine degree day method, was developed. The method has been addressed for calculating the isolation related issues for buildings so far. But in this paper, it is utilized to predict the theoretical maximum power production of the gas turbines in various climates for the first time. The results indicated that the difference of annual energy production capacity between the best and the last province options was calculated to be 7500 MWh approximately.


Author(s):  
Jae Hong Lee ◽  
Tong Seop Kim ◽  
Do Won Kang ◽  
Jeong Lak Sohn ◽  
Jung Ho Lee

Abstract Gas turbines are most widely used for power generation and operate under various conditions and loads. Gas turbine control is important to cope with various situations, and the turbine inlet temperature (TIT) is the most important parameter because it is directly related to the power output and life cycle of the turbine. Thus, precise prediction and control of the TIT are important in terms of the stable operation and life cycle management of gas turbines. This paper proposes a new method to predict non-measured parameters such as the air flow and TIT using Kalman filter techniques. The Kalman filter is widely used for estimating the instantaneous state of a system and can estimate non-measured parameters. The Kalman filter algorithm was implemented in a gas turbine analysis program using MATLAB. The reliability of the new method was verified through various case studies using virtual data and real operating data. The results were compared with those of a model-based gas turbine diagnostics program. The computing time of the Kalman filter and model-based diagnostics program were also compared to confirm the capability of the new method. The results indicate that the new method is more suitable for diagnostics and monitoring applications than the model-based analysis program. Finally, two case studies were performed to confirm the feasibility of the new method using two virtual datasets. The results confirm that the Kalman filter can predict the non-measured parameters precisely.


2017 ◽  
Vol 139 (06) ◽  
pp. 32-37 ◽  
Author(s):  
Lee S. Langston

This article highlights technological performance improvements in the gas turbine industry and its likely future course. While the outlook for commercial aviation gas turbines is bright, the non-aviation segment is decidedly clouded. While analysts have focused on the growing demand for electricity worldwide, the average output of each individual gas turbine unit is also increasing, and at a rate that is faster than that of electricity demand. Gas turbine power plants also have the advantage of dispatchability, which wind, hydroelectric, and solar often do not. A recent econometric study of renewable electric power implementation shows that the use of fast-reacting fossil technologies such as gas turbines to hedge against variability of electrical supply made it more likely to result in the successful investment and use of renewables. The article suggests that gas turbine power plants are cost-effective and can provide a necessary backup to the variability of renewable power plants. Gas turbines combine low cost and fast reaction time in a way that will enable the grid to handle winds dying down unexpectedly or unpredicted heavy clouds diminishing solar power output.


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