Generic modeling and speed control approach of hydraulic power plants: Start-up operating mode

2020 ◽  
Vol 160 ◽  
pp. 1-15
Author(s):  
Amgad Mohamed ◽  
Mazen Alamir ◽  
Quentin Alloin
Author(s):  
A M Boulos ◽  
K J Burnham

Use of combined cycle power generation plant has increased dramatically over the last decade. A supervisory control approach based on a dynamic model is developed, which makes use of proportional-integral-derivative (PID), fuzzy logic and fuzzy PID schemes. The aim is to minimize the steam turbine plant start-up time, without violating maximum thermal stress limits. An existing start-up schedule provides the benchmark by which the performance of candidate controllers is assessed. Improvements regarding possible reduced start-up times and satisfaction of maximum thermal stress restrictions have been realized using the proposed control scheme.


2010 ◽  
Vol 31 (3) ◽  
pp. 55-72
Author(s):  
Piotr Duda ◽  
Dariusz Rząsa

A new method for determining allowable medium temperature during transient operation of thick-walled elements in a supercritical power plantConstruction elements of supercritical power plants are subjected to high working pressures and high temperatures while operating. Under these conditions high stresses in the construction are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stress limit. The goal is to find optimum operating parameters that can assure safe heating and cooling processes [1-5]. The optimum parameters should guarantee that the allowable stresses are not exceeded and the entire process is conducted in the shortest time. In this work new numerical method for determining optimum working parameters is presented. Based on these parameters heating operations were conducted. Stresses were monitored during the entire processes. The results obtained were compared with the German boiler regulations - Technische Regeln für Dampfkessel 301.


2015 ◽  
Vol 6 (3) ◽  
pp. 35-46
Author(s):  
Tamas Koplyay ◽  
Brian Mitchell ◽  
Sorin Cohn ◽  
Maria Fekete ◽  
Abdelkader Jazouli

Abstract That supply chain management and logistics are a determining factor for the long term success of a company was well documented by Forrester over a half century ago [1], with the importance of the statement only growing through the intervening years.Whether consciously factored into the operating mode or not, logistics and distribution channel management plays a critical role in the life, and death, of a firm. From the rudimentary beginnings of the start-up company to the hectic world of the growth company and onto the relatively secure existence in mature markets, the value chain consisting of logistics and distribution channel linkages follows the firm, until it solidifies into immutable form of the mature value chain and begins to exert an inexorable pressure on the survival of the entire chain, and conversely the chain imposes its will on the members. The emergence of mature industry value chains is often driven by the need to monopolistically control logistics and distribution channels which provides a competitive advantage but also introduces a serious exposure to pending shock loadings of the chain.


2020 ◽  
Vol 23 (2) ◽  
pp. 48-51
Author(s):  
V. KONDRATENKO ◽  
◽  
V. KALYNYCHENKO ◽  

Mine drainage systems, which are used at the main drainage of mining enterprises, have a drive capacity of up to 1600kW. To reduce non-productive energy losses, as well as for the continuous operation of the mining company, mine pumps must be energy efficient and reliable. Analysis of downtime of drainage systems shows that the weak point is the unloading device. This fact can lead not only to the failure of the pumping unit, but also to possible prolonged downtime of the mine. The main disadvantage of the existing disk unloading devices of mine pumps is their low reliability and low service life, due to the rapid wear of the components of the unloading unit. The most vulnerable elements of the unloading device are the unloading rings. The need for frequent replacement and adjustment of the elements of the discharge unit is associated with disassembly and assembly of the pump directly in the pump chamber. Such actions require significant costs of unproductive manual labor of service personnel, and rapid wear of parts of the unloading device necessitates their constant replenishment. Malfunctions in the unloading device can cause significant pump failures. To increase the reliability and energy efficiency of mine drainage systems, the method of control of the unloading device was used. During the experimental studies it was found that cavitation phenomena during the operation of pumping units are absent and, accordingly, can not be the cause of wear of the elements of the unloading unit. When the pumps are operating in steady state, the displacement of the rotors was monitored for 3-4 hours on each pump unit. After data processing, it was obtained that the wear of the surface of the unloading rings occurs at a rate of 0.05-0.15mm in one hour. To determine the wear of the rings of unloading during start-up - stop of the pump, at first the indicators of measuring devices at the established mode of operation of the pump unit were fixed. Then the pump was turned off and on again. After starting the pump unit, we made sure that the operating mode of the unloading device did not change and compared the readings of the shaft position indicator before stopping and after starting the pump. From the measurements made it followed that stopping and starting the pump does not lead to noticeable wear of the unloading device. Therefore, it can be assumed that mainly the wear of the discharge rings occurs during the steady operation of the pump unit.


Solar Energy ◽  
2018 ◽  
Vol 176 ◽  
pp. 589-603 ◽  
Author(s):  
Davide Ferruzza ◽  
Monika Topel ◽  
Björn Laumert ◽  
Fredrik Haglind

Author(s):  
Un Bong Baek ◽  
Hae Moo Lee ◽  
Yun-Hee Lee ◽  
Seung Hoon Nahm

A severe thermal stress occurs during start up/shutdown transients in thick walled components of high temperature power plants. Thus, a precise consideration of this issue is very important. Many researchers have studied low-cycle fatigue at high temperatures and small box-type electrical resistance furnaces have been developed for small-sized fatigue specimens. However, these small-scale electrical resistance furnaces need precise temperature calibrations because temperature control is difficult in a small space. Thus, a method for the temperature calibration of a box-type electrical resistance furnace is investigated and calibration procedures are proposed in this study.


Author(s):  
Baba Dzhabrailovich Babaev ◽  
Vladimir Panchenko ◽  
Valeriy Vladimirovich Kharchenko

The main objective of the work is to develop principles for the formation of the optimal composition of the energy complex from all the given power plants based on renewable energy sources for an autonomous consumer, taking into account the variable energy loads of the consumer, changing climatic conditions and the possibility of using local fuel and energy resources. As a result of solving this optimization problem, in addition to the optimal configuration of the power complex, it is also necessary to solve the problem of optimizing the joint operation of different types of power plants from the selected optimal configuration, that is, it is necessary to determine the optimal modes of operation of power plants and the optimal share of their participation in providing consumers at every moment in time. A numerical method for analyzing and optimizing the parameters and operating mode of the energy complex with the most accurate consideration of the schedule of changes in consumer load and software that automates the solution of this optimization problem are also presented.


Sign in / Sign up

Export Citation Format

Share Document