Eugeniusz Ihnatowicz

A review of expanders for power generation in small-scale organic Rankine cycle systems: Performance and operational aspects

The article discusses various types of expanders used in the organic Rankine cycle systems to turn thermal energy into electrical energy. In addition to basic information on scroll, screw, vane, piston, and turbine expanders, the paper also describes the principles of their operation as well as major advantages and disadvantages. The following characteristics of expanders have been developed on the basis of the most recent scientific publications and own experimental research conducted at the IFFM PASci, in Gdansk. The analysis of various expansion devices available on the market, including those that are still in the development phase, revealed a wide variety of problems related to their operation. The design differences between them have a significant impact on their efficiency and reliability when operating with different working fluids. The article is an authoritative compendium of research-based information about designs and performance of various types of expansion devices. It may be useful for people who want to apply such devices in different types of cogeneration systems.

The Experimental Investigation of the Biomass-Fired ORC System with a Radial Microturbine

The paper presents the results of experimental investigation of the ORC system with a droplet separator (which was used to improve the quality of working medium vapour), a radial microturbine and a multi-fuel boiler. The research aimed at verifying the correctness of prototype microturbine performance in the ORC installation, equipped with a heat source in the form of the multi-fuel boiler. During these tests, a detailed assessment of the functioning of the microturbine and the boiler has been devoted more attention. The paper contains the characteristics of the heat exchangers installation that were obtained for the ORC system variant using a regenerative cycle. The multi-fuel boiler was fired with biomass (wood pellets). Two series of measurements were conducted for various flow rates and several selected temperatures of the working medium, glycol solution and thermal oil. On the basis of research carried out on the ORC with a radial microturbine, one can say that, physicochemical parameters of the HFE7100 medium obtained during the first measuring series, were as follows: temperature at the microturbine inlet 158.9 °C, pressure at the microturbine inlet 9.66 bar, flow rate 178.9 g/s at the microturbine discharge pressure of 1.75 bar. The second series of measurements gave the following results: temperature at the microturbine inlet 163.2 °C, pressure at the microturbine inlet 9.86 bar, flow rate 179.2 g/s at the microturbine discharge pressure of 1.88 bar. The maximum electrical power generated with the use of radial microturbine working in the regenerative ORC system reached about 1150 We.

Experimental investigation of the ORC system in acogenerative domestic power plant with a scrollexpanders

Abstract The paper presents the results of experimental investigations of the ORC system with two scroll expanders which have been used as a source of electricity. Theworking fluidwas HFE7100 – a newly engineered fluid with a unique heat transfer and favourable environmental properties. In the ORC system three heat exchangers were used (evaporator, regenerator, condenser) and before expanders the droplet separator was installed. As a source of heat an innovative biomass boiler was used. Studies have been carried out for the expanders worked in series and in parallel. The paper presents the thermal and fluidflow properties of the ORC installation for the selected flow rates and different temperatures of the working medium. The characteristics of output electrical power, operating speed and vibrations for scroll expanders were also presented.

The Experimental Investigation of Scroll Expanders Operating in the ORC System with HFE7100 as a Working Medium

The paper presents the results of experimental investigation on the ORC system with a droplet separator (which was used to improve the quality of working medium vapour) and two scroll expanders, which operated individually. The research aimed at verifying the correctness of scroll expanders performance in the ORC installation, equipped with the electric flow heater for thermal oil as a heat source. The paper contains the characteristics of the heat exchangers installation that were obtained for the ORC system variant using a regenerative cycle. The tests were conducted for selected flow rates and various temperatures of the working medium HFE7100, glycol solution and thermal oil. The unit with a gear pump and a magnetic coupling functioned as a circulating pump. Following the results of tests carried out on two scroll expanders it may be concluded that the electric power output that was measured at the generator terminals was approximately 750 W. The maximum voltages generated by the expanders amounted to around 200 V and the maximum current was about 4 A.

The use of modern plastics for the construction of high speed fluid-flow machinery

* Dr inż. Grzegorz Żywica (gzywica@imp.gda.pl), dr inż. Tomasz Z. Kaczmarczyk (tkaczmarczyk@imp.gda.pl), dr inż. Eugeniusz Ihnatowicz (gieihn@imp.gda.pl) – Instytut Maszyn Przepływowych Polskiej Akademii Nauk Omówiono zagadnienia związane z doborem tworzyw sztucznych na wybrane elementy wysokoobrotowych maszyn przepływowych. Oprócz kryteriów stosowanych przy doborze materiału przedstawiono przykład analizy wytrzymałościowej tarczy wirnikowej z tworzywa sztucznego. Celem tych prac było zastąpienie powszechnie stosowanych stopów metali nowoczesnymi tworzywami sztucznymi, co może się przełożyć na skrócenie czasu produkcji i obniżenie kosztów. SŁOWA KLUCZOWE: budowa maszyn, tworzywa sztuczne, polimery wysokotemperaturowe, maszyny przepływowe, mikroturbiny