Dynamic Analysis of a Recuperated mGT Cycle for Fuel Cell Hybrid Systems

2016 ◽  
Author(s):  
Luca Larosa ◽  
Alberto Traverso ◽  
Aristide F. Massardo
Keyword(s):  
Fuel Cell ◽  
Dynamic Behaviour ◽  
Simulation Tool ◽  
Performance Gap ◽  
Warm Up ◽  
Transient Phenomena ◽  
Transient Behaviour ◽  
Micro Gas Turbine ◽  
Experimental Campaign ◽  
Start Up

This work presents the dynamic behaviour of a new recuperated micro gas turbine (mGT) coupled with a large volume. Such system, called “emulator”, has been purposely designed for the future upgrade into a fuel cell mGT hybrid system. The tests, carried out by LG Fuel Cell Systems (LGFCS), aimed both at understanding the dynamic behaviour of the system and validating the dynamic simulation tool. Within the wide experimental campaign, a subset of data has been selected to identify the key transient phenomena and characterise the dynamic behaviour of the system: in this respect, the focus is on start-up, warm-up and shutdown phases. A dynamic model of the emulator was developed, based on the original software TRANSEO. The model was used to characterise the mGT performance and identify a performance gap in the expander. For this purpose, the machine was upgraded and substituted. Final results show that, after refinement of input data, the model is capable to predict accurately the overall system transient behaviour.

Emergency Shutdown Management in Fuel Cell Gas Turbine Hybrid Systems

2014 ◽  
Author(s):  
Fabio Lambruschini ◽  
Mario L. Ferrari ◽  
Alberto Traverso ◽  
Luca Larosa
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Control Strategies ◽  
University Campus ◽  
Time Dynamic ◽  
Micro Gas Turbine ◽  
Emergency Shutdown ◽  
Start Up ◽  
Pressure Stress ◽  
The University

A real-time dynamic model representing the pressurized fuel cell gas turbine hybrid system emulator test rig at Thermochemical Power Group (TPG) laboratories of the University of Genoa has been developed to study the fuel cell behavior during different critical operative situations like, for example, load changes (ramp and step), start-up and shut-down and, moreover, to implement an emergency shutdown strategy in order to avoid any damage to the fuel cell and to the whole system: focus has been on cathode/anode differential pressure, which model was validated against experimental data. The real emulator plant (located in Savona University campus) is composed of a 100 kW recuperated micro gas turbine, a modular cathodic vessel (4 modules of 0.8 m3 each) located between recuperator outlet and combustor inlet, and an anodic circuit (1 module of 0.8m3) based on the coupling of a single stage ejector with an anodic vessel. Different simulation tests were carried out to assess the behavior of cathode-anode pressure difference, identifying the best control strategies to minimize the pressure stress on fuel cell stack.

scholarly journals Simulations of a flexible 100 kWel PEM Fuel Cell power plant for the provision of grid balancing services

2021 ◽  
Vol 238 ◽  
pp. 04003
Author(s):  
Elena Crespi ◽  
Giulio Guandalini ◽  
Stefano Campanari
Keyword(s):  
Fuel Cell ◽  
Power Plant ◽  
Power Plants ◽  
Maximum Load ◽  
Variable Load ◽  
Renewable Energy Resources ◽  
Continuous Growth ◽  
Warm Up ◽  
Start Up ◽  
Flexible Resources

The continuous growth of non-programmable renewable energy resources penetration leads to unpredictable oscillations of the net load faced by dispatchable power plants, hindering the reliability and stability of the electric grid and requiring additional flexible resources. The EU project GRASSHOPPER focuses on MW-scale Fuel Cell Power Plant (FCPP) based on low temperature PEM technology. The project aims to setup and demonstrate a 100 kWel PEM FCPP, flexible in power output and designed to provide grid support. This work presents a dynamic simulation model of the FCPP, developed to simulate plant flexible operation and identify the best management strategy, aiming at optimizing the efficiency while reducing the degradation rate. Cold start up simulations, according to a warm-up procedure limiting stack degradation, result in a time to operation equal to 26 minutes. A sensitivity analysis is performed to determine which parameters mostly influence the warm-up duration, showing that it is possible to reduce start-up time substantially (e.g. down to 3 minutes with component preheating). On the other hand, simulations at variable load along the entire range of operation (20-100 kWel), according to grid balancing requirements, show that the plant is able to ramp up and down between the minimum to the maximum load in about 40 seconds.

scholarly journals Introduction of a New Numerical Simulation Tool to Analyze Micro Gas Turbine Cycle Dynamics

2016 ◽  
Author(s):  
Martin Henke ◽  
Thomas Monz ◽  
Manfred Aigner
Keyword(s):  
Fuel Cell ◽  
System Dynamics ◽  
Automatic Control ◽  
Gas Turbine ◽  
Cell Hybrid ◽  
Simulation Tool ◽  
Micro Gas Turbine ◽  
Novel Applications ◽  
Component Models ◽  
Fuel Cell Hybrid

Micro gas turbine (MGT) technology is evolving towards a large variety of novel applications, like weak gas electrification, inverted Brayton cycles and fuel cell hybrid cycles; however, many of these systems show very different dynamic behaviors compared to conventional MGTs. In addition, some applications impose more stringent requirements on transient maneuvers, e.g. to limit temperature and pressure gradients in a fuel cell hybrid cycle. Besides providing operational safety, optimizing system dynamics to meet the variable power demand of modern energy markets is also of increasing significance. Numerical cycle simulation programs are crucial tools to analyze these dynamics without endangering the machines, and to meet the challenges of automatic control design. For these tasks, complete cycle simulations of transient maneuvers lasting several minutes need to be calculated. Moreover, sensitivity analysis and optimization of dynamic properties like automatic control systems require many simulation runs. To perform these calculations in an acceptable timeframe, simplified component models based on lumped volume or one-dimensional discretization schemes are necessary. The accuracy of these models can be further improved by parameter identification, as most novel applications are modifications of well-known MGT systems and rely on proven, characterized components. This paper introduces a modular in-house simulation tool written in Fortran to simulate the dynamic behavior of conventional and novel gas turbine cycles with real-time calculation speed. Thermodynamics, gas composition, heat transfer to the casing and surroundings, shaft rotation and control system dynamics as well as mass and heat storage are simulated together to account for their interactions. The simulation tool is explained in detail, including a description of all component models, coupling of the elements and the ODE-solver. Finally, validation results of the simulator based on measurement data from the DLR Turbec T100 recuperated MGT test rig are presented, including cold start-up and shutdown maneuvers.

scholarly journals Introduction of a New Numerical Simulation Tool to Analyze Micro Gas Turbine Cycle Dynamics

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Martin Henke ◽  
Thomas Monz ◽  
Manfred Aigner
Keyword(s):  
Fuel Cell ◽  
System Dynamics ◽  
Automatic Control ◽  
Gas Turbine ◽  
Cell Hybrid ◽  
Simulation Tool ◽  
Micro Gas Turbine ◽  
Novel Applications ◽  
Component Models ◽  
Fuel Cell Hybrid

Micro gas turbine (MGT) technology is evolving toward a large variety of novel applications, such as weak gas electrification, inverted Brayton cycles, and fuel cell hybrid cycles; however, many of these systems show very different dynamic behaviors compared to conventional MGTs. In addition, some applications impose more stringent requirements on transient maneuvers, e.g., to limit temperature and pressure gradients in a fuel cell hybrid cycle. Besides providing operational safety, optimizing system dynamics to meet the variable power demand of modern energy markets is also of increasing significance. Numerical cycle simulation programs are crucial tools to analyze these dynamics without endangering the machines, and to meet the challenges of automatic control design. For these tasks, complete cycle simulations of transient maneuvers lasting several minutes need to be calculated. Moreover, sensitivity analysis and optimization of dynamic properties like automatic control systems require many simulation runs. To perform these calculations in an acceptable timeframe, simplified component models based on lumped volume or one-dimensional discretization schemes are necessary. The accuracy of these models can be further improved by parameter identification, as most novel applications are modifications of well-known MGT systems and rely on proven, characterized components. This paper introduces a modular in-house simulation tool written in fortran to simulate the dynamic behavior of conventional and novel gas turbine cycles. Thermodynamics, gas composition, heat transfer to the casing and surroundings, shaft rotation and control system dynamics as well as mass and heat storage are simulated together to account for their interactions. While the presented models preserve a high level of detail, they also enable calculation speeds up to five times faster than real-time. The simulation tool is explained in detail, including a description of all component models, coupling of the elements and the ODE solver. Finally, validation results of the simulator based on measurement data from the DLR Turbec T100 recuperated MGT test rig are presented, including cold start-up and shutdown maneuvers.

Emulation of Hybrid System Start-Up and Shutdown Phases With a Micro Gas Turbine Based Test Rig

2008 ◽  
Author(s):  
Mario L. Ferrari ◽  
Matteo Pascenti ◽  
Loredana Magistri ◽  
Aristide F. Massardo
Keyword(s):  
Control System ◽  
High Temperature ◽  
Fuel Cell ◽  
Power Systems ◽  
Gas Turbine ◽  
Hybrid System ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Start Up ◽  
Critical Phases

The aim of this work, focused on natural gas fired distributed power systems, is the experimental analysis of the start-up and shutdown for high temperature fuel cell hybrid systems. These critical phases have been emulated using the micro gas turbine test rig developed by TPG at the University of Genoa, Italy. The rig is based on the coupling of a modified commercial 100 kWe recuperated gas turbine with a modular volume designed to emulate fuel cell stacks of different dimensions. It is essential to test the dynamic interaction between the machine and the fuel cell, and to develop different operative procedures and control systems without any risk to the expensive stack. This paper shows the preliminary experimental results obtained with the machine connected to the volume. The attention is mainly focused on avoiding surge and excessive stress on the machine components during the tests. Finally, after the presentation of the valve control system, this paper reports the emulation of the hybrid system start-up and shutdown phases. They have been performed to produce a gradual heating up and cooling down of the fuel cell volume, using the cold bypass line, three high temperature valves, and the machine load control system. This approach is necessary to avoid high thermal stress on the cell material, extremely dangerous for the plant life.

Exergy Analysis of a Hybrid Micro Gas Turbine Fuel Cell System Based on Existing Components

2012 ◽  
Author(s):  
D. P. Bakalis ◽  
A. G. Stamatis
Keyword(s):  
Fuel Cell ◽  
Hybrid System ◽  
Exergy Analysis ◽  
Cell System ◽  
System Component ◽  
Utilization Factor ◽  
Fuel Cell Stack ◽  
Micro Gas Turbine ◽  
Partial Load ◽  
Set Up

A hybrid system based on an existing recuperated microturbine and a pre-commercially available high temperature tubular solid oxide fuel cell is modeled in order to study its performance. Individual models are developed for the microturbine and fuel cell generator and merged into a single one in order to set up the hybrid system. The model utilizes performance maps for the compressor and turbine components for the part load operation. The full and partial load exergetic performance is studied and the amounts of exergy destruction and efficiency of each hybrid system component are presented, in order to evaluate the irreversibilities and thermodynamic inefficiencies. Moreover, the effects of various performance parameters such as fuel cell stack temperature and fuel utilization factor are investigated. Based on the available results, suggestions are given in order to reduce the overall system irreversibility. Finally, the environmental impact of the hybrid system operation is evaluated.

Sign in / Sign up

Export Citation Format

Share Document