Gas Turbine Set Research Articles

Improving bioethanol production from sugarcane: evaluation of distillation, thermal integration and cogeneration systems

Demand for bioethanol has grown considerably over the last years. Even though Brazil has been producing ethanol from sugarcane on a large scale for decades, this industry is characterized by low energy efficiency, using a large fraction of the bagasse produced as fuel in the cogeneration system to supply the process energy requirements. The possibility of selling surplus electricity to the grid or using surplus bagasse as raw material of other processes has motivated investments on more efficient cogeneration systems and process thermal integration. In this work simulations of an autonomous distillery were carried out, along with utilities demand optimization using Pinch Analysis concepts. Different cogeneration systems were analyzed: a traditional Rankine Cycle, with steam of high temperature and pressure (80 bar, 510 °C) and back pressure and condensing steam turbines configuration, and a BIGCC (Biomass Integrated Gasification Combined Cycle), comprised by a gas turbine set operating with biomass gas produced in a gasifier that uses sugarcane bagasse as raw material. Thermoeconomic analyses determining exergy-based costs of electricity and ethanol for both cases were carried out. The main objective is to show the impact that these process improvements can produce in industrial systems, compared to the current situation.

Procedure for the Design of a Hybrid-Series Vehicle and the Hybridization Degree Choice

For years, the interest of the UDR1 research group has focused on the development of a Hybrid Series (HS) vehicle, different from the standard one thanks to the use of a Gas Turbine set (GT) as a thermal engine. The reason for this choice resides in the opportunity to reduce weight and dimensions, in comparison to a traditional Internal Combustion Engine (ICE). It is not possible to use the GT engine set directly for the vehicle traction, therefore the UDR1 HS configuration shows the GT set connected with the electric generator only. The result is that the traction is purely electric. The resulting engine configuration is a commonly defined Hybrid Series. Many efforts are spent in the definition of a generic scientific method to define the correct ratio (Degree of Hybridization) between the installed power of the battery pack and that of the GT electric generator, which simultaneously guarantees the life of the battery pack and the capacity of the vehicle to complete a common mission without lack of energy or stopping. This article reports a method to define the power ratio between battery pack and GT generator, applied to a recent commission for the development of a mini city bus.

State Prediction of Huge Gas Turbine Machine Based on Multi-Level Recursive Method and Experimental Study

Gas turbine machine,Multi-level recursive,Prediction,Experimental study Abstract. Take the huge gas turbine set of Beijing Yanshan Petrochemical Refinery as the research object. The most important feature of machine is the vibration characteristic,and vibration displacement is the most important parameter of the machine,based on the historical vibration displacement datas,use multi-level recursive method to predict the state of the machine.With this method,fault prediction is divided into two parts:forecast of time-varying parameters and forecast based on the former forecast,the prediction precision is improved. Through the analysis of gas turbine failure mechanism,use Bently rotor bench,effectively simulate the mechanical failure of the rotor imbalance.

Reliability Assessment of a Backup Gas Turbine Generation System for a Critical Industry Load Using a Monte Carlo Simulation Model

The Alberta Interconnected Electric System (AIES) forms a single integrated transmission network serving the Province of Alberta, Canada. A number of large critical industrial loads are served by the AIES. These loads operate 24 h a day and seven days a week. This paper deals with a critical industrial load which is normally supplied by the Alberta provincial grid through two 72-kV lines. This load also maintains a backup generation system consisting of a set of gas turbines to meet its operating demands in the case of Alberta grid failure. The basic objective of this paper is to derive the optimal number of gas turbines that this critical load should maintain in order to satisfy the plant's reliability criteria in the case of grid failure for continuity of its operation. A Monte Carlo simulation model is developed to assess the adequacy of the backup gas turbine system, and the results of a series of case studies performed using the developed model are presented in this paper.

The LETHE™ Gas Turbine Hybrid Prototype Vehicle of the University of Roma 1: Drive Cycle Analysis of Model Vehicle Management Unit

The paper describes the logic of the vehicle’s power management unit (VMU) for the prototype configuration of the LETHE™ (low emissions turbo hybrid electric) vehicle designed by the University of Roma 1. The theoretical and practical feasibility of the concept (a series hybrid in which the thermal engine is a small turbo-gas and the traction is fully electric) was demonstrated in a series of previous works by the same authors, and some experimental tests were conducted at the ENEA-Casaccia Laboratories on a small 45 kW gas turbine set, to investigate the performance of the propulsive unit (turbine plus batteries and electrical motor) under the European vehicular emission (ECE) tests. After successful completion of these tests, a further analysis was carried out to identify an optimal hybridization ratio with respect both to driveability and fuel consumption: the results led to the conclusion that such an absolute optimal configuration does not exist, because not only the system performance, but also the absolute and relative sizes (i.e., nameplate power) of turbines and battery pack depend largely on the type of the proposed driving mission of the car. In the final configuration discussed in this paper, the vehicle is equipped with an additional energy storage device, a compact ultra-fast flywheel, to partially compensate for the low recharge capability of the Pb-acid batteries and to exploit better brake recovery for futher reduction of the fuel consumption. The present status report describes the VMU control logic, the individual components of the propulsive system and the proposed chassis configuration for the prototype.

The concept of the gas turbine-based hybrid vehicle: system, design and configuration issues

The object of this study is a theoretical and experimental analysis of a new hybrid propulsion system for a passenger sedan in which the thermal engine is a small gas turbine set. Some preliminary results on the possibility of replacing the conventional ICE of a hybrid ‘series’ configuration by a turbogas were presented and discussed in previous papers by the same authors: several possible designs were examined under both a thermodynamic and an operative point of view. This paper presents a summary of the project and constitutes an attempt to put things in a proper engineering perspective: the technical feasibility of the project is assessed via a calculation of the required mission loads, a preliminary design of the most important elements of the propulsive system, the choice of the mission control strategy and the implementation of a numerical system simulator. The experiments that provided a verification for the assumed component efficiencies were carried out, in cooperation with the Research Centre of ENEA-Casaccia, on an ELLIOTT TA-45 group. Our results, though only preliminary, allow for a direct comparison between a GT-hybrid vehicle and a modern diesel car, and indicate that the GT-hybrid may be actually a competitor for the FC-powered vehicle concept. Our ‘optimal’ configuration is a combination of a 100 kg battery pack and two turbogas set of 5 and 16 kW, respectively. Copyright © 2005 John Wiley & Sons, Ltd.

An Innovative Solution for Suburban Railroad Transportation: The Gas Turbine-Hybrid Train

The paper reports the latest results of a study conducted on a hybrid train in which a gas turbine, operating in several alternative control modes (fixed point, on-off or load-following), generates the electrical energy for recharging a battery package and for driving the electric motors of a suburban train. The model, originally developed for automotive applications, has been validated by experimental tests performed on an ELLIOTT TA-45 GT group in the ENEA-Casaccia Research Center. This paper describes the preliminary design of the traction system and the choice of the energy flow control strategy. Numerical simulations have been carried out, based on an actual train mission (the Norwegian railroad track between Asker and Lillehammer) and on industrial data for the single components. Following two different approaches, separate optimizations of the gas turbine set and battery package are performed, in which the objective function is the monetary cost per mission or, which is equivalent, the kWh/(t·km) for a given mission profile.

Humid Air Turbine as a Primary Link PRIVATE of a Conventional Gas Turbine Set

The effectiveness of the primary link of a conventional gas turbine set has been expressed by means of the incremental energy efficiency, defined as the ratio of the attained increase of power to the increase of chemical energy consumption. The calculations performed for the humid air turbine (HAT) applied as a primary link indicate a high effectiveness of the utilization of the additionally consumed fuel. The compression ratio in both parts of the considered gas turbine set has been optimized in order to attain maximum energy efficiency.

Influence of the ambient temperature on the operational indices of the gas turbine set

Influence of the ambient temperature on the operational indices of the gas turbine set

Influence of the ambient temperature on the operational indices of the gas turbine set

Applying the volumetric characteristics of the compressor and the equation of Stodola, formulae have been developed expressing the influence of the changes of ambient temperature on the mass output of the compressor and compression ratio in the set of gas turbine. Influence on the mechanical power and energy efficiency of the set as well as on the thermal power of the waste heat boiler has been determined too.

Gas turbines and the Nigerian grid systems

The grid system in which generating stations and major consumer centres are integrated is employed by the National Electric Power Authority in generating and distributing electricity in Nigeria. Gas turbines constitute more than half of the generating sets. The Nigerian grid is prone to instability which causes disturbances in the system and gas turbines are known to be sensitive to such disturbances. This paper is the result of a study of the effects of the instability of the grid on the gas turbine sets.

排気再燃型ガスタービン・リパワリングシステム導入 高効率コージェネレーションシステム

As an example at recent Co-generation system for industry use, we introduce its characteristic and operational result of Repowering system with exhaust gas reburning which was first applied in Japan. The repowering system is composed of power boiler and steam turbine which were in use, and of 4 MW class heavy-duty gas turbine set newly. The power boiler was reformed to convert heavy oil into city gas, and for conduction gas turbine exhaust gas. This system produces reduction of energy use about 15%, and of NOx, CO2 emission about 30%.

Multi-Power Port Gas Turbine Configurations for Solar Cogeneration Applications

Solar energy, unlike fossil fuel energy, is a constrained source of power. It is constrained by its diurnal and seasonal variations and by weather upsets. Solar energy, unlike fossil fuel energy, which is highly concentrated and highly commandable, cannot be directly commanded. The only means to control the solar power input to a gas turbine is the flow rate of the fluid which acquires the converted solar heat and conveys it, passing through the turbine stages on its way to the exhaust. A conventional gas turbine set has one power input port, the combustion heat-compressed gas at the gas turbine inlet, and one controlled power power output port, the mechanical variable shaft torque of the power turbine. For cogeneration applications, two power controlled ports are necessary: the mechanical shaft torque--usually used to drive a generator--and the exhaust fluid--usually compressed clean air for industrial or topping cycle uses.

Equivalent tests of gas-turbine sets for ships

Equivalent tests of gas-turbine sets for ships

Main Propulsion Gas-turbine Set for the Oil Tanker Auris

In order to obtain operating experience with a main propulsion gas turbine under service conditions at sea, the Diesel electric oil tanker Auris has been equipped with a gas-turbine set which replaces one of the four Diesel engines originally installed. A description is given of the set which operates on the simple open cycle with a heat exchanger and independent (low pressure) power turbine. The set thus has one compressor and two turbines in series, the high-pressure turbine driving the compressor and the low-pressure turbine driving the alternator which supplies power to the propeller motor. In the design the emphasis was laid on high component efficiencies which necessitated the use of multi-stage uncooled turbines. A moderately high initial gas-temperature was adopted in order to ensure adequate length of life. The experience during test operation, which covered a running time of 680 hours, is fully recorded, and complete performance figures for all conditions are given. The set was operated with some success on heavy (residual) fuel oil. The total running time on heavy fuel oil was 363 hours, which included a continuous run of 270 hours, mainly at full load.