Papers by Author: Bogdan Pojawa

Abstract: The paper presents the results of study concerning the determination of operating characteristics of the examined engine in steady states. The study concerned main propulsion engines of an Oliver Hazard Perry class frigate operated by the Polish Navy. The studies were conducted in the ship's engine room when the ship was at sea. Operating characteristics were determined on the basis of the measurements recorded over the entire load range of the engine, from minimum to rated load. During the studies, the load of both engines of the ship was simultaneous and balanced. In order to facilitate the comparison of the operating characteristics of the tested engines, as well as to make a reference to various weather conditions, the data obtained was reduced to standard reference state. For the aforementioned characteristics approximation relations were determined using statistical analysis. The relations obtained may be utilized in energy modeling and simulations, as well as technical diagnostics concerning this kind of engines.

Abstract: Broadly understood technological progress, growth of the world's population and striving of individual countries for economic growth cause increased demand for energy. That energy is mainly obtained conventionally, from mineral fuels [16]. Limited fuel resources and high demand for fuels, which accompanies the increased demand for energy, result in continuous growth of fuel prices and, what it involves, the price of energy [6,16]. Another effect of the increased production of energy results is also the increased emission of combustion products which are harmful for the natural environment, mainly CO₂ and NO_x [6,9,10,]. Because of the above-mentioned factors, the importance of the assessment of energy efficiency, at the stage of energy production, distribution and end use as well as the problem of environmental protection gain more and more importance [4,5,15]. The idea of energy efficiency lies not only in energy conservation but also in finding ways for the present activities of producers and consumers to require reduced demand for primary energy expressed in tonnes of oil equivalent [3,7,13,14,17,19,21]. Energy companies must therefore respect a number of legal regulations concerning energy efficiency and environmental protection [3,4,5,15]. An energy company such as a cogeneration plant may achieve an improvement of energy efficiency mainly as a result of energy cogeneration itself but also as a result of improving the efficiency of internal processes (energy transformations) in the producing unit (in this case heating unit). Ensuring the maximum possible energy efficiency of the internal processes within the heating unit requires performing constant assessment of the entire unit and its components [7,11,12,13]. Even though energy cogeneration has been in use for a long time now [7,12,21], the problem of conducting a running energy efficiency assessment of the components of the heating unit still remains open [12].

Abstract: In the process of the routine exploitation of naval gas turbine the most important, for the exploiter, is the nature of the cooperation between the engine and its power receiver. In particular, if it is a controllable pitch propeller. Due to the fact that ship's documentation does not often contain that type of characterization, there was an attempt to its designation. Given the preliminary nature of the research, it was decided to perform them on gas turbine engine GTD-350. Appointment of a mathematical model of the above characteristics is a complex issue, requiring the application of the theory of planning experiments. The article demonstrates how to implement the preliminary tests and their results, the results of statistical analysis and substantive research results obtained and formulated on the basis of their conclusions.