Search Results

You are looking at 1 - 10 of 43 items for :

Clear All
Open access

Charchalis Adam and Krefft Jerzy

Economizer Selection Method with Reference to its Reliability at Preliminary Design Stage of Seagoing Vessels

The economizers are used for production of steam heating on en route ships. The economizers are producing steam in a heat exchange process from the ship's main engine exhaust gas. Products of the incomplete combustion of the heavy fuel oil remaining in engines, passing the boiler, collect on the heat exchange surface of the economizer. When the incorrect assumptions are made for the boiler operation conditions, the boiler steam capacity drops and fire and burning of the incomplete combustion products can occur in the economizer. To minimize combustion product quantity that collects on the boiler surface, the allowable exhaust gas pressure drop in the boiler should be taken into consideration, as well as the results from recommended exhaust gas flow velocity that is determined by main engine service load determined in the preliminary design phase of the ship. The remaining operating conditions are made in such a way to obtain high steam capacity of the boiler. It is essential at the design stage to take into consideration the future operating parameters of the combustion-steam-water installation, since these parameters depend on the choice of boiler and determined at the design stage production of steam. On the basis of operation parameters of contemporary container ships, an attempt was made to select economizer capacity in the preliminary design stage taking into consideration operation conditions of the propulsion system-steam installations unit in aspect of economizer reliability.

Open access

Nadine Arnold and Isabel Hammer

8 Literatur Akyel, Dominic. 2013. Die Ökonomisierung der Pietät . Frankfurt a. M.: Campus. Arnold, Nadine. 2017. Standardisierungsdynamiken im Fairen Handel . Wiesbaden: VS Springer. Aspers, Patrik. 2015. Märkte . Wiesbaden: Springer Fachmedien. Becchetti, Leonardo und Benjamin Huybrechts. 2008. The Dynamics of Fair Trade as a Mixed-form Market. Journal of Business Ethics 81(4): 733–750. Çalışkan, Koray und Michel Callon. 2010. Economization, Part 2: A Research Programme for the Study of Markets. Economy and Society 39(1): 1

Open access

Jelena Ziemele, Dagnija Blumberga, Normunds Talcis and Ilze Laicane

Abstract

In the course of work industrial research was carried out at the boiler plant A/S “Imanta” where a 10MW passive condensing economizer working on natural gas was installed after the 116MW water boiler. The work describes the design of the condensing economizer and wiring diagram. During the industrial experiment, the following measurements were made: the temperature of water before and after the economizer; the ambient temperature; the quantity of water passing through the economizer; heat, produced by the economizer and water boilers. The work summarizes the data from 2010-2011.

Open access

Economising Early Prints on Fight Books by Multiple Using Movable Half Page Woodcuts.

Insights into the layout work on the illustrations of Andre Paurnfeindt’s Fight Book of 1516 published by Hieronymus Vietor

Matthias Johannes Bauer

Open access

J. Mlnařík and J. Hruška

V důsledku poklesu teploty spalin pod teplotu rosného bodu dochází u řady energetických celků k problémům s korozí vlivem zkondenzovaných kyselin. Dochází tak k značným korozním napadením a poškozením zejména na ohřívácích vzduchu, ekonomizérech, vedeních kouřovodů, ale i v samotném komíně. Ve SVÚM se vyvíjí automatický systém pro kontinuální měření teploty rosného bodu spalin přímo ve spalovacím zařízení. V této práci jsou shrnuty výsledky z dosavadních příprav pilotního provozu v uhelné elektrárně.

Open access

I. Pikos, R. Kocurek and J. Adamiec

ABSTRACT

Modern design solutions of power boiler using the welded fin tubes for heat exchangers. Depending on thermal parameters (pressure and temperature), the heat transfer fluid and flue gas these constructions can be preheater, economizers or superheaters. Their use can significantly increase the energy efficiency of boilers. For the manufacture of welded fin tubes are used non-alloy steels and low-alloy C-Mo, C-Cr-Mo. Analysis of project assumptions supercritical blocks indicates that the range of conventional steel for power and martensitic steels has been depleted. Designing higher performance outlet of steam to 720°C and 35MPa requires the use of austenitic steels and nickel alloys. These materials are not easily available and not fully recognized, both technologically and in terms of materials, especially in the area of their weldability. In this work, performed the review of probably directions of development of materials for the finned tubes, with a particular focus on laser welding technology.

Open access

Charlene Ramsunkar, Chris van Tonder and Walter Schmitz

Abstract

Boiler combustion air is generally controlled by the excess air content measured at the boiler economiser outlet using oxygen (O2) analysers. Due to duct geometry and dimensions, areas of high and low O2 concentrations in the flue gas duct occur, which poses a problem in obtaining a representative measurement of O2 in the flue gas stream. Multipoint systems as opposed to single point systems are more favourable to achieve representative readings. However, ash blockages and air leakages influence the accuracy of O2 measurement. The design of multipoint system varies across ESKOMs’ Power Stations. This research was aimed at evaluating the accuracy of the multipoint oxygen measurement system installed at Power Station A and to determine the systematic errors associated with different multipoint systems designs installed at Power Stations' A and B. Using flow simulation software, FloEFDTM and Flownex®, studies were conducted on two types of multipoint system designs This study established that significantly large errors, as high as 50%, were noted between the actual and measured flue gas O2. The design of the multipoint system extraction pipes also introduces significant errors, as high as 23%, in the O2 measured. The results indicated that the sampling errors introduced with Power Station A’s system can be significantly reduced by adopting the sampling pipe design installed at Power Station B.

Open access

Christos Emmanouilides

Abstract

Cancer is becoming a major public health issue as patients enjoy longer survivals than ever before due to the introduction innovative but expensive drugs in the clinic. In addition, the ageing of the population in Greece is expected to increase the absolute incidence of cancer. The National Health System should rapidly and efficiently adapt to the new challenges, including increased pharmaceutical costs. Resources ought to be allocated rationally and efficiently while maintaining adequate coverage for the insured population. Economising due to large-scale operations should be pursued by the governmental single payor (EOPYY), so that affordable coverage remains feasible. Establishment of mechanisms to deal with new and very costly drugs should be put in place. The major changes in anchor oncologic hospitals are needed in order to play a role as regional leaders in oncologic care, including merging of similar divisions, subspecialisation of services and promotion of clinical research. These major centres could coordinate a host of satellite oncology services in other urban hospitals and in the provinces. In addition, joint operations in training and patient care should be pursued with major private centres, without mutual mistrust or obsolete inflexibilities. The current financial crisis represents an excellent opportunity for revisioning and restructuring oncologic care in Greece, taking into account the societal needs and based on flexibility and efficiency.

Open access

J Mlnařík and J Hruška

Přímé měření kyselého rosného bodu ve spalovacích zařízeních

V důsledku poklesu teploty spalin pod teplotu rosného bodu dochází u řady energetických celků k problémům s korozí vlivem zkondenzovaných kyselin. Dochází tak k značným korozním napadením a poškozením zejména na ohřívácích vzduchu, ekonomizérech, vedeních kouřovodů, ale i v samotném komíně. Ve SVÚMu byla vyvinuta a vyzkoušena sonda pro přímé měření teploty rosného bodu spalin. Pomocí této metody je možné rychle zjistit teplotu rosného bodu bez nutností složitých výpočtů, analýz spalin, náročných odběrů spalin, atd. Následnou úpravou teploty spalin je tak možné předejít značným korozním problémům.

Open access

Azem Duraku

Abstract

Treaty of Rome of 1957 and following treaties on amending the Treaty of Rome contain a number of basic principles on which the EU is founded. Among these principles, the most important ones related to the public procurement are: prevention of discrimination based on nationality, free movement of goods; right and freedom of establishment of a business; the right to provide services. Spending of public money in Kosovo pursuant to the Law on Procurement is found on the following principles: economization and efficiency; equal treatment and non-discrimination; transparency; value for money. The average of open procedure application in EU countries is 73% based on notices, whereas in Kosovo is 82.80% based on notices. In the end of 2014, Kosovo commenced the development of electronic procurement platform. This project takes place within the Public Sector Modernization Project. The importance of the electronic procurement is stated in the statement of European Commission: “Modernization and opening of procurement markets across borders - including through the electronic procurement expansion - are crucial for the competition in Europe and creating new opportunities for businesses in EU”. A good procurement system in Kosovo will have an impact on elimination of negative phenomena (corruption and bad management) in the management of public expenditures from spending agencies, as well as an impact on increase of budget saving.