Bogdan Żółtowski

Vibrations in the Assessment of Construction State

The knowledge of the dynamic state and structure of the system allows to describe its behavior, and allows creating prognosis models of the system behavior in the function of dynamic evolution time, based on the model of the technical state symptoms growth. Most often, however, there are no known equations describing behaviors of the system in the function of dynamic evolution time, which accounts for the need to apply new tools to examine the dynamic state. There is, therefore, the requirement to experimentally verify analytical technical models as the proper one is a model which is verified in practice. An experiment is, therefore, often only an inspiration for further researches leading to the optimization of the construction. In this work presented are chosen problems of machines’ technical state diagnosis with the use of identification and technical diagnostics methods. Relations between methods of dynamic state evaluation and methods of technical state evaluation were indicated. Example modal analysis results illustrate the complexity of projecting dynamic state researches into diagnostic researches of machine state evaluation.

A method for determining the usability potential of ship steam boilers

Abstract Ship large-power steam boiler may serve as an example of complex critical technical system. A basis for rational control of operation of such system is knowledge on its capability of fulfilling the tasks to which it was intended. In order to make it possible to apply computer aiding to operational decision-making the capability should be described analytically. In this paper it was proposed to express the capability of ship steam boiler ( considered a complex system) to perform service tasks, by calculating components of its usability potential in a given instant t. To this end , was distinguished a set of steam boiler fundamental features which formulate space of its technical states. Values and characteristic intervals of the features were defined and this way sub-spaces of serviceability and non-serviceability states of the object in question were determined. Next, in the considered space, technical state of the boiler and its usability potential was determined. Owing to this it become possible to quantitatively express the steam boiler functioning capability which served as a basis for elaborating an algorithm for controlling the operational processes of a complex technical system under action. In this paper is also described a way of application of the presented method to calculation of ship steam boiler usability potential, which may be especially instrumental in the case of operational control of the boilers of the kind , equipped with interstage reheaters, i.e. those operating with high values of operational parameters.

Method of Building a Model of Operational Changes for the Marine Combustion Engine Describing the Impact of the Damages of This Engine on the Characteristics of Its Operation Process

Abstract This article deals with the modeling of the processes of operating both marine main and auxiliary engines. The paper presents a model of changes in operating conditions of ship’s internal combustion engine. The semi-Markov decision process was used to mathematically describe the process model of the engine. The developed model describes the effect of engine damage on the characteristics of its operation. A change in the input parameters of the model can simulate the influence of internal and external factors on the course of the analyzed process. A simplified calculation example is also presented for illustration purposes. The presented method together with developed algorithms and IT tools can be used to solve a wide range of problems related to the operation of marine main engines and other marine equipment as well as maritime and port facilities. This concerns primarily the economic, risk management and operational security issues of complex technical systems, as well as the readiness and reliability analysis of technical facilities.

Truss harbor cranes modal design elements research

Abstract Dockside cranes must meet the relevant strength requirements that provide usefulness and not endanger the safety of their use. The vibration effect on structural safety hazard results from the impact of horizontal forces caused by the transport of goods for loading and transverse forces caused by wind, which can be dangerous for correct functioning. In addition, there are often serious effects of climate-related impacts of the environment, material fatigue, which actuates the degradation state of the object. Dynamic loads may therefor cause random effects that devastate the structures or lead to their catastrophic destruction. Recognizing the need to improve the testing methods of crane structures in order to assess their condition and assess their safety factors - this paper attempts to develop a methodology for testing the degradation of the selected portion of a construction crane - using experimental modal analysis, realized in simulation tests in the Inventor environment as well as at test stand research.

Study of the state a Francis turbine

Abstract This paper presents a methodology to evaluate the technical state of a Francis turbine by shaft rotor dynamic simulation. There are several rotor dynamic criteria that define the technical state of a turbo-machine. To feed the shaft rotor dynamic model this delivers the required information to accomplish the technical assessment. The numerical rotor dynamic model uses as input, the field forces obtained by the fluid-solid interaction analysis undertaken over the blades of the runner. The rotor dynamic numerical simulations allow to determinate the record-in-time of the displacements of any point along the shaft. This information is relevant for diagnosis tasks, because it is possible to decompose it spectrally and to estimate the severity of the vibrations. Comparing the results of the numerical model against those obtained from machines that operates under normal conditions, it is possible to determinate the technical state of the turbo-machine. This allows studying the stability of the turbine working on several operation ranges. A Francis turbine is a very complex machine that involves many physical phenomena of different nature. In this way, the hydraulic input forces needed by the rotor dynamic model should not be assumed but calculated directly from the fluid interaction over the turbine structure.

A Hydrogenic Electrolyzer for Fuels

Abstract In this work - in view of still decreasing crude oil resources and increasing fuel prices - are presented issues concerning research on development of other, alternative fuel sources including those used in water, land and air transport means. One of them is hydrogen which, while burning, does not produce noxious carbon dioxide but only side effects such as heat and clean water. It is almost true that along with sudden drop of availability and rising price of crude oil many countries face economical paralysis. Any of alternative sources is not capable of supplying even only a basic amount of such energy, not mentioning the whole amount of energy demanded by our civilization. Hydrogen as an independent fuel for internal combustion engines has yet to go a long way to commercialization. to be Co-burning systems (combustion of mixtures)of today used hydrocarbon fuels combined with hydrogen seem closer to this aim. As proved in many investigations the substitution of a part of hydrocarbon fuel by hydrogen enables to make use of beneficial features of both the fuels. One of possible solutions of the problem may be application of an innovative hydrogenic fuel electrolyzer which is presented and evaluated in this paper.

Improvement the systems of exploitation machine/Doskonalenie strategii utrzymania zdatności maszyn

Abstract It this work was talked over chosen and the new problems of exploitation of folded machine engines, helped with methods of technical diagnostics and monitoring the state. This concerns more and more often: the questions perfecting the effectiveness of methods of diagnosing, systems of preventive exchanges, new solutions of software on stage co-ordinating the decision (one - and the multi - dimension), as and the dedicated systems of diagnosing in engineering of diagnostics. Introduced problems of this study finds in processes of destruction of machine engines his reason, concurrent every machine engine near at hand after her producing, until to liquidation. The be shaping the costs of exploitation of machine engines and the possibilities of applying of well-known strategies of exploitation differentiate in this area the variety of organizational workings. The developing technical diagnostics gives to rational exploitation of machine engines the basis in newly created or the perfected diagnostic systems of exploitation. Streszczenie W pracy omówiono wybrane problemy utrzymania zdatności złożonych maszyn, wspomagane metodami diagnostyki technicznej. Dotyczy to zagadnień doskonalących skuteczność metod diagnozowania, nowych rozwiązań oprogramowania na etapie uzgadniania decyzji (jedno- i wielo- wymiarowej), jak i dedykowanych systemów diagnozowania w inżynierii diagnostyki. Przedstawiona problematyka tego opracowania znajduje swoje uzasadnienie w procesach destrukcji maszyn, towarzyszących każdej maszynie po wytworzeniu, aż do jej likwidacji. Kształtowanie się kosztów eksploatacji maszyn i różnorodność działań organizacyjnych w tym obszarze różnicują możliwości stosowania znanych strategii eksploatacji. Rozwijająca się diagnostyka techniczna daje podstawy do racjonalnej eksploatacji maszyn w nowo tworzonych lub doskonalonych diagnostycznych systemach eksploatacji.