Innovative Starting Procedure of Siemens SGT-600 in Cold Climate Conditions

2011 ◽  
Author(s):  
Mats Blomstedt ◽  
Ha˚kan Lindgren ◽  
Hans-Lennart Olausson ◽  
Johan Moverare
Keyword(s):  
Cold Climate ◽  
Control Logic ◽  
Climate Conditions ◽  
Ambient Temperatures ◽  
Auxiliary Power ◽  
Start Up ◽  
Critical Components ◽  
Hardware Costs ◽  
The Cost ◽  
Additional Hardware

A start-up of a gas turbine means that stress and forces are put on the machine. A start-up in cold climate conditions means that the forces are more critical since the material in the machine becomes more brittle. At a certain temperature the material is utilized to its limits (with appropriate margins applied) and for the SGT-600 ambient temperatures below −30°C (−22°F) become critical. In earlier installations in an arctic climate, an electric pre-heater has been utilized to prevent the critical components from becoming too brittle. This additional hardware costs money, is consuming auxiliary power and may contribute to unavailability. Another way to solve this issue may be to install material that is less brittle, but this will also increase the cost of the installation. Siemens is now applying an improved control logic during start-up, solving this issue in the software, without any additional hardware and avoiding unnecessary material changes. This new innovative start-up procedure is performing an automatic check of the stress levels before loading the machine, resulting in a safe and reliable start at temperatures below −30°C (−22°F).

Start-up performance of a full-scale bioreactor landfill cell under cold-climate conditions

2008 ◽  
Vol 28 (12) ◽  
pp. 2623-2634 ◽  
Author(s):  
Xianda Zhao ◽  
Reem Musleh ◽  
Seth Maher ◽  
Milind V. Khire ◽  
Thomas C. Voice ◽  
...  
Keyword(s):  
Full Scale ◽  
Cold Climate ◽  
Bioreactor Landfill ◽  
Climate Conditions ◽  
Start Up

PERSIAN GARDENS IN COLD AND DRY CLIMATE: A CASE STUDY OF TABRIZ’S HISTORICAL GARDENS

2016 ◽  
Vol 10 (3) ◽  
pp. 193
Author(s):  
Ahad Nejad Ebrahimi ◽  
Farnaz Nazarzadeh ◽  
Elnaz Nazarzadeh
Keyword(s):  
Comparative Study ◽  
Water Supply ◽  
Field Study ◽  
Cold Climate ◽  
Natural Substrate ◽  
Garden Design ◽  
Climate Conditions ◽  
North West ◽  
Special Expertise

Throughout history, gardens and garden designing has been in the attention of Persian architects who had special expertise in the construction of gardens. The appearance of Islam and allegories of paradise taken from that in Koran and Saints’ sayings gave spirituality to garden construction. Climate conditions have also had an important role in this respect but little research has been done about it and most of the investigations have referred to spiritual aspects and forms of garden. The cold and dry climate that has enveloped parts of West and North West of Iran has many gardens with different forms and functions, which have not been paid much attention to by studies done so far. The aim of this paper is to identify the features and specifications of cold and dry climate gardens with an emphasis on Tabriz’s Gardens.  Due to its natural and strategic situation, Tabriz has always been in the attention of governments throughout history; travellers and tourists have mentioned Tabriz as a city that has beautiful gardens. But, the earthquakes and wars have left no remains of those beautiful gardens. This investigation, by a comparative study of the climates in Iran and the effect of those climates on the formation of gardens and garden design, tries to identify the features and characteristics of gardens in cold and dry climate. The method of study is interpretive-historical on the basis of written documents and historic features and field study of existing gardens in this climate. The results show that, with respect to natural substrate, vegetation, the form of water supply, and the general form of the garden; gardens in dry and cold climate are different from gardens in other climates.

Failure Analysis of the Tripping Operation and its Impact on Well Control

2015 ◽  
Author(s):  
Majeed Abimbola ◽  
Faisal Khan ◽  
Vikram Garaniya ◽  
Stephen Butt
Keyword(s):  
Human Error ◽  
Integrated Control ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Well Control ◽  
Lost Circulation ◽  
Critical Elements ◽  
Open Hole ◽  
Critical Components ◽  
The Cost

As the cost of drilling and completion of offshore well is soaring, efforts are required for better well planning. Safety is to be given the highest priority over all other aspects of well planning. Among different element of drilling, well control is one of the most critical components for the safety of the operation, employees and the environment. Primary well control is ensured by keeping the hydrostatic pressure of the mud above the pore pressure across an open hole section. A loss of well control implies an influx of formation fluid into the wellbore which can culminate to a blowout if uncontrollable. Among the factors that contribute to a blowout are: stuck pipe, casing failure, swabbing, cementing, equipment failure and drilling into other well. Swabbing often occurs during tripping out of an open hole. In this study, investigations of the effects of tripping operation on primary well control are conducted. Failure scenarios of tripping operations in conventional overbalanced drilling and managed pressure drilling are studied using fault tree analysis. These scenarios are subsequently mapped into Bayesian Networks to overcome fault tree modelling limitations such s dependability assessment and common cause failure. The analysis of the BN models identified RCD failure, BHP reduction due to insufficient mud density and lost circulation, DAPC integrated control system, DAPC choke manifold, DAPC back pressure pump, and human error as critical elements in the loss of well control through tripping out operation.

Catchment-scale evaluation of pollution potential of urban snow at two residential catchments in southern Finland

2013 ◽  
Vol 68 (10) ◽  
pp. 2164-2170 ◽  
Author(s):  
Nora Sillanpää ◽  
Harri Koivusalo
Keyword(s):  
Snow Water Equivalent ◽  
Hydrological Cycle ◽  
Cold Climate ◽  
Road Maintenance ◽  
Catchment Scale ◽  
Small Surface ◽  
Climate Conditions ◽  
Snow Water ◽  
High Level ◽  
Mass Loads

Despite the crucial role of snow in the hydrological cycle in cold climate conditions, monitoring studies of urban snow quality often lack discussions about the relevance of snow in the catchment-scale runoff management. In this study, measurements of snow quality were conducted at two residential catchments in Espoo, Finland, simultaneously with continuous runoff measurements. The results of the snow quality were used to produce catchment-scale estimates of areal snow mass loads (SML). Based on the results, urbanization reduced areal snow water equivalent but increased pollutant accumulation in snow: SMLs in a medium-density residential catchment were two- to four-fold higher in comparison with a low-density residential catchment. The main sources of pollutants were related to vehicular traffic and road maintenance, but also pet excrement increased concentrations to a high level. Ploughed snow can contain 50% of the areal pollutant mass stored in snow despite its small surface area within a catchment.

Development of Reliable NARX Models of Gas Turbine Cold, Warm and Hot Start-Up

2017 ◽  
Author(s):  
Hilal Bahlawan ◽  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina ◽  
Mauro Venturini
Keyword(s):  
Gas Turbine ◽  
Training Data ◽  
Series Data ◽  
Data Sets ◽  
Control Logic ◽  
Start Up ◽  
Hot Start ◽  
Narx Models ◽  
Set Up ◽  
Rapid Transients

This paper documents the set-up and validation of nonlinear autoregressive exogenous (NARX) models of a heavy-duty single-shaft gas turbine. The considered gas turbine is a General Electric PG 9351FA located in Italy. The data used for model training are time series data sets of several different maneuvers taken experimentally during the start-up procedure and refer to cold, warm and hot start-up. The trained NARX models are used to predict other experimental data sets and comparisons are made among the outputs of the models and the corresponding measured data. Therefore, this paper addresses the challenge of setting up robust and reliable NARX models, by means of a sound selection of training data sets and a sensitivity analysis on the number of neurons. Moreover, a new performance function for the training process is defined to weigh more the most rapid transients. The final aim of this paper is the set-up of a powerful, easy-to-build and very accurate simulation tool which can be used for both control logic tuning and gas turbine diagnostics, characterized by good generalization capability.

scholarly journals High-quality eddy-covariance CO2budgets under cold climate conditions

2017 ◽  
Vol 122 (8) ◽  
pp. 2064-2084 ◽  
Author(s):  
Fanny Kittler ◽  
Werner Eugster ◽  
Thomas Foken ◽  
Martin Heimann ◽  
Olaf Kolle ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Cold Climate ◽  
High Quality ◽  
Climate Conditions

scholarly journals Cross-Platform Analysis and Development of Online Catering Platform (Kunyahku)

2021 ◽  
Vol 7 (2) ◽  
pp. 79-89
Author(s):  
Indra Swarna ◽  
James Purnama ◽  
Randy Anthony
Keyword(s):  
Coming Out ◽  
Development Time ◽  
Development Cycle ◽  
Start Up ◽  
Code Base ◽  
Cross Platform ◽  
Multiple Platform ◽  
Suitable Framework ◽  
Faster Development ◽  
The Cost

Kunyahku is an online catering platform that provides catalogs of menus from local caterer near the user and become the distributor that will take the order and deliver them. In developing an application, the most important aspect for small start-up companies is to have a development stack that can deliver the app into multiple platform by using a single code base to reduce the cost of developers, improve efficiency and reduce the time to develop the application itself. To provide the necessity of building an application for Kunyahku, this paper is aimed to find the most suitable cross platform framework for developing the Kunyahku application. This research focuses on comparison between existing popular cross-platform and proving the suitable one to be used in development cycle in the case of Kunyahku requirements. Sets of test and comparison were conducted in order to compare the most suitable cross platform between React Native and Flutter such as render test and comparing each advantage coming out from using each of the cross-platform.After all the requirements are gathered and then the most suitable framework will be chosen which is Flutter. Performance analysis and the benefits of using Flutter framework are elaborated and thus proving it is the most suitable development stack to be used in Kunyahku case and the development time can be reduced since it is a cross-platform technology that output the application into three different platform rather than managing separate platform for each different one. Testing shows that flutter also met all the requirements thus proving flutter address the problems of scalability and faster development compared to developing each native platform one by one.

scholarly journals Method of coordinating air starter and auxiliary power unit joint operation

2020 ◽  
pp. 5-13
Author(s):  
Grigory Popov ◽  
◽  
Vasily Zubanov ◽  
Valeriy Matveev ◽  
Oleg Baturin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Power Unit ◽  
Gas Turbine Engine ◽  
Working Process ◽  
Joint Operation ◽  
Turbine Engine ◽  
Auxiliary Power Unit ◽  
Auxiliary Power ◽  
Start Up ◽  
Air Turbine

The presented work provides a detailed description of the method developed by the authors for coordinating the working process of the main elements of the starting system for a modern gas turbine engine for a civil aviation aircraft: an auxiliary power unit (APU) and an air turbine – starter. This technique was developed in the course of solving the practical problem of selecting the existing APU and air turbine for a newly created engine. The need to develop this method is due to the lack of recommendations on the coordination of the elements of the starting system in the available literature. The method is based on combining the characteristics of the APU and the turbine, reduced to a single coordinate system. The intersection of the characteristic’s lines corresponding to the same conditions indicates the possibility of joint operation of the specified elements. The lack of intersection indicates the impossibility of joint functioning. The calculation also takes into account losses in the air supply lines to the turbine. The use of the developed method makes it possible to assess the possibility of joint operation of the APU and the air turbine in any operating mode. In addition to checking the possibility of functioning, as a result of the calculation, specific parameters of the working process at the operating point are determined, which are then used as initial data in calculating the elements of the starting system, for example, determining the parameters of the turbine, which in turn allow providing initial information for calculating the starting time or the possibility of functioning of the starting system GTE according to strength and other criteria. The algorithm for calculating the start-up time of the gas turbine engine was also developed by the authors and implemented in the form of an original computer program. Keywords: gas turbine engine start-up, GTE starting system, air turbine, methodology, joint work, auxiliary power unit, power, start-up time, characteristics matching, coordination, operational characteristics, computer program.

scholarly journals Energisation Method for Offshore Wind Farms Connected to HVdc via Diode Rectifiers

2021 ◽  
Author(s):  
Oscar Saborío-Romano ◽  
Ali Bidadfar ◽  
Jayachandra Naidu Sakamuri ◽  
Ömer Göksu ◽  
Nicolaos Antonio Cutululis
Keyword(s):  
Reactive Power ◽  
Wind Farms ◽  
Offshore Wind ◽  
Proof Of Concept ◽  
Offshore Wind Farms ◽  
Suitable Alternative ◽  
Active And Reactive Power ◽  
Auxiliary Power ◽  
Additional Sequence ◽  
Additional Hardware

Diode rectifiers (DRs) have been recently suggested as a viable alternative for connecting offshore wind farms (OWFs) to HVdc, eliciting growing interest from both industry and academia. However, energisation of DR-connected OWFs is not straightforward. The present study constitutes a proof of concept of a novel energisation method for DR-connected OWFs, in which auxiliary power is provided from the shore through the HVdc link and the dc bus bar of one or more WTs. The proposed method provides an alternative with minimal additional hardware, which can be easily extended to more WTs in the OWF, increasing reliability by providing redundancy. The study includes coinciding auxiliary loads with active and reactive power components and a semi-aggregated OWF model, in which every WT is individually represented in the string containing the energising WT. An additional sequence of simulation events is considered following the initial energisation sequence. Such sequence comprises wind power taking over the provision of the auxiliary power. The simulation results indicate that the proposed method is a suitable alternative for energising OWFs connected to HVdc via DRs.<br><br>The manuscript has been submitted to the CIGRÉ Symposium 2021.

scholarly journals Evaluation of the Cost-Optimal Method Applied to Existing Schools Considering PV System Optimization

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 611
Author(s):  
Cecilia Ciacci ◽  
Neri Banti ◽  
Vincenzo Di Naso ◽  
Frida Bazzocchi
Keyword(s):  
Optimization Procedure ◽  
Cost Effective ◽  
Heating System ◽  
System Optimization ◽  
Cold Climate ◽  
Design Parameters ◽  
Design Environment ◽  
Pv System ◽  
Optimal Method ◽  
The Cost

In Italy in 2020, only 15.5% of school building heritage was retrofitted from an energy and environmental point of view. In this paper, the cost-optimal method was applied to two different school buildings belonging to the same Italian cold climate zone but characterized by different structural and technological solutions. The research aims at defining the cost-effective redevelopment solution among several ones proposed to apply to this building type. At the same time, this paper provides a critical analysis of the methodology applied, highlighting deficiencies related to a not proper evaluation of environmentally friendly retrofitting measures. In a cost-effective context, the main results show that the intervention on the heating system is more convenient than the retrofitting of the envelope. The energy saving is equal to about 35% for both considered schools. Among the different proposed requalification configurations, the adoption of PV (photovoltaic) electric generation is included. In this regard, an optimization procedure was implemented in a generative design environment to maximize energy production with reference to different design parameters. As a result, a solution with south oriented PV modules with a tilt angle of 42° and arranged in 0.7 m spaced rows proved to be the most effective.

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