Wyniki wyszukiwania - BazTech

1

Rola biomasy toryfikowanej na rynku tradycyjnych paliw kopalnych

Poskart A., Szwaja S., Magdziarz A., Musiał D., Zajemska M.

Rynek Energii

|

2018

|

Nr 1

65--71

PL

Z uwagi na fakt, iż produkcja energii z biomasy wiąże się z występowaniem pewnych barier technologicznych, w szczególności w układach bezpośredniego jej współspalania z węglem, w ostatnich latach przedmiotem zainteresowania wielu naukowców stały się metody poprawiające jej właściwości energetyczne. Jedną z bardziej obiecujących metod waloryzacji biomasy jest toryfikacja. W niniejszej pracy przedstawiono wyniki badań wpływu toryfikacji prowadzonej w atmosferze CO2 w zakresie temperatury od 250 do 350°C na właściwości energetyczne ślazowca pensylwańskiego. Badania przeprowadzono w reaktorze śrubowym, służącym do toryfikacji ciągłej. Otrzymane karbonizaty (tzw. biowęgiel) poddano analizie elementarnej (zawartość pierwiastków C, H, N) oraz technicznej, tj. oznaczono zawartość wilgoci, popiołu i części lotnych oraz wyznaczono ciepło spalania i wartość opałową. Wyniki badań wykazały, że proces toryfikacji przyczynił się do wzrostu wartości opałowej o około 39% (od 16,1 MJ/kg do 22,4 MJ/kg) i zawartości pierwiastka węgla o około 28% (od 45,9% do 58,6%), podczas gdy zawartość wilgoci uległa zmniejszeniu o 63% (od 9,4 do 3,4%). Przeprowadzone analizy potwierdziły, że toryfikacja ślazowca pensylwańskiego, w szczególności w temperaturze 350°C może w znacznym stopniu poprawić jego właściwości fizykochemiczne, a tym samym doprowadzić do uzyskania dobrej jakości surowca do celów energetycznych, stanowiącego alternatywę dla tradycyjnych paliw kopalnych.

EN

Due to the fact that the energy production from biomass is associated with certain technological barriers, in particular in the systems of its direct co-combustion with coal, in recent years methods of improving its energy properties have become the subject of interest of many scientists. One of the more promising methods of biomass valorization is torrefaction, involving drying at a temperature of 200 to 350°C in an inert atmosphere. This paper presents the results of studies on the impact of torrefaction carried out in the atmosphere of CO2 in the temperature range from 250 to 350°C on the energy properties of Virginia mallow. The research were carried out in a screw conveyor reactor for continuous torrefaction. The samples of obtained biochars were subjected to elemental analysis (content of C, H, N). The physicochemical properties were also evaluated, i.e. the calorific value, moisture content, ash content and volatiles fractions were determined. The research showed that as a result of torrefaction, the heating value increased by approx. 39% (from 16.1 MJ/kg to 22.4 MJ/kg) and the carbon content by approx. 28% (from 45.9% to 58, 6%), while the moisture content was reduced by 61% (from 9.4 to 3.6%). The carried out analyzes confirmed that torrefaction of Virginia mallow performed in particular at temperature of 350°C can significantly contribute to improving its physicochemical properties, and thus to obtain a good quality raw material for energy purposes, which is an alternative to traditional fossil fuels.

2

Torgas condensate combustion in the SI engine

Chwist M., Szwaja S., Grab-Rogaliński K., Poskart A.

Journal of KONES

|

2018

|

Vol. 25, No. 3

33--38

EN

The article presents results from IC engine tests on combustion of alcohol fuel with the addition of torgas condensate. Torgas is a by-product created from the torrefaction of Sida hermaphrodita. It was obtained from torrefaction carried out at a temperature of 400°C. Torgas was condensed in a tubular cooler. The basic fuel was butanol. This fuel was chosen, because regular hydrocarbon based fuels got delaminated while blended with torgas condensate. The condensate dissolves in alcohol therefore the choice was justified. In the mixture, the volume ratio of alcohol to condensate was 4:1. The combustion was carried out in a spark-ignition, single-cylinder engine with a cubic capacity of 650 cm3. The engine was able to vary its compression ratio. The engine worked at full load at maximum open throttle. The engine body was heated to a temperature of 95°C and this temperature was maintained throughout the testing period. The engine was running at 850 rpm. The first stage of the experiment included determination of the optimal ignition angle for butanol as a reference fuel and for a mixture of butanol and torgas condensate. The optimal spark angle was estimated based on the maximum indicated work. Three compression ratios, i.e.: CR=8.8, 10 and 11.2 were used. All tests were performed for a stoichiometric air fuel ratio. The obtained in-cylinder pressure diagrams for the reference fuel and the fuel with the addition of condensate were compared with each other. The rate of pressure increase inside the cylinder was calculated. For all tests, the following exhaust components were measured: CO2, CO and HC.

3

Thermodynamic analysis of combustion events in the natural gas fuelled SI engine with VVT

Szwaja M., Mazuro P., Szwaja S.

Journal of KONES

|

2018

|

Vol. 25, No. 4

421--427

EN

The main aim of the research was to investigate influence of overlap of the natural gas fuelled spark ignited engine on the following parameters: Indicated Mean Effective Pressure (IMEP), heat rate release including combustion phases (ignition lag, main combustion phase). The content of the study includes results from processing in-cylinder pressure measurements, heat release rate analysis, combustion phases, and finally the conclusions. The tests were carried out on the test bed including the single cylinder research engine with a displacement volume of 550 cm3. The engine was equipped with independent cam phasors for both intake and exhaust valves, but for this investigation, the exhaust valve timing was fixed (the exhaust cam centre line was fixed at -95 crank angle (CA) deg before Top Dead Centre) and intake valve timing was changed (the intake cam centre line was varied from 90 to 150 CA deg after Top Dead Centre). The overlap was changed in the range from 85 to 25 CA deg. 8 tests series were performed, each singular series consisted of 300 consecutive engine combustion cycles. As observed, by varying the valve overlap it contributes to significant change in the peak combustion pressure, peak of heat release rate, and combustion phases. Summing up, variable valve timing affects compression and expansion strokes by changing polytropic indexes due to various amounts of exhaust residuals trapped in the cylinder. It affects not only engine volumetric efficiency but also the heat release rate and IMEP, so it does engine performance. Thus, variable valve timing can be considered as valuable tool that can be applied to the natural gas fuelled internal combustion engine.

4

Investigation of knock suppression characteristics in a boosted methane : gasoline blended fuelled SI engine

Yang Z., Miganakallu N., Rao S., Harsulkar J., Naber J., Lonari Y., Szwaja S.

Journal of KONES

|

2018

|

Vol. 25, No. 3

517--525

EN

Natural gas has a higher knock suppression effect than gasoline which makes it possible to operate at higher compression ratio and higher loads resulting in increased thermal efficiency in a spark ignition engine However, using port fuel injected natural gas instead of gasoline reduces the volumetric efficiency from the standpoints of the charge displacement of the gaseous fuel and the charge cooling that occurs from liquid fuels. This article investigates the combustion and engine performance characteristics by utilizing experimental and simulation methods varying the natural gas-gasoline blending ratio at constant engine speed, load, and knock level. The experimental tests were conducted on a single cylinder prototype spark ignited engine equipped with two fuel systems: (i) a Direct Injection system for gasoline and (ii) a Port Fuel Injection (PFI) system for compressed natural gas. For the fuels, gasoline with 10% ethanol by volume (commercially known as E10) with a research octane number of 91.7 is used for gasoline via the DI system, while methane is injected through PFI system. The knock suppression tests were conducted at 1500 rpm, 12 bar net indicated mean effective pressure wherein the engine was boosted using compressed air. At 60% of blending methane with E10 gasoline, the results show high knock suppression. The net indicated specific fuel consumption is 7% lower, but the volumetric efficiency is 7% lower compared to E10 gasoline only condition. A knock prediction model was calibrated in the 1-D simulation software GT-Power by Gamma Technologies. The calibration was conducted by correlating the simulated engine knock onset with the experimental results. The simulation results show its capability to predict knock onset at various fuel blending ratios.

5

In-cylinder combustion analysis of a SI engine fuelled with hydrogen enriched compressed natural gas (HCNG) : engine performance, efficiency and emissions

Juknelevičius R., Mehra R.K., Ma F., Szwaja S.

Journal of KONES

|

2018

|

Vol. 25, No. 3

253--260

EN

The main objective of this study was to investigate the effect of hydrogen addition on spark ignition (SI) engine’s performance, thermal efficiency, and emission using variable composition hydrogen/CNG mixtures. The hydrogen was used in amounts of 0%, 20%, 40% by volume fraction at each engine speed and load. Experimental analysis was performed at engine speed of 1200 rpm, load of 120 Nm corresponding BMEP = 0.24 MPa, spark timing 26 CAD BTDC, and at engine speed of 2000 rpm, load of 350 Nm corresponding BMEP = 0.71 MPa, spark timing 22 CAD BTDC. The investigation results show that increasing amounts of hydrogen volume fraction contribute to shorten ignition delay time and decrease of the combustion duration, that also affect main combustion phase. The combustion duration analysis of mass fraction burned (MFB) was presented in the article. Decrease of CO2 in the exhaust gases was observed with increase of hydrogen amounts to the engine. However, nitrogen oxides (NOX) were found to increase with hydrogen addition if spark timing was not optimized according to hydrogen’s higher burning speed.

6

Flame propagation in gas feeding pipelines to the IC engine

Gruca M., Szwaja S., Pyrc M.

Journal of KONES

|

2018

|

Vol. 25, No. 3

205--212

EN

Results from experimental investigation on flame propagation in a pipeline filled with gaseous combustible mixture consisted of hydrogen, methane or 20% hydrogen-methane is presented in the article. The mixture was prepared in separate cylinders and premixed before filling the pipeline. The tests were conducted under various relative equivalence ratio – lambda from 1.0 to 3.0 at pressure of 1 bar and temperature of 25ºC. Hydrogen and methane were selected because these gases are main combustible fractions in several gaseous engine fuels (e.g. natural gas, syngas, biogas). Additionally, the mixture 20% hydrogen and methane, as potential engine fuel, was also under investigation. Flame front was detected with aid of IR photodetectors. Hence, the flame speed was resulted from distance divided by time. As observed, the flame propagation speed was over 100 m/s for both hydrogen and methane premixed mixtures. It was several times higher if compared with the laminar flame speed for these gases. It can be explained by additional acoustic effects (standing waves) taking place inside the pipeline. Results from this investigation can be useful in design and construction of the gas feeding system in the gas fuelled internal combustion engine.

7

Combustion of RME – diesel and NExBTL – diesel blends with hydrogen in the compression ignition engine

Juknelevičius R., Szwaja S., Pyrc M., Gruca M., Pukalskas S.

Journal of KONES

|

2018

|

Vol. 25, No. 3

261--274

EN

The article presents the test results of the single cylinder compression ignition engine with common rail injection system operating on biofuels and conventional diesel blends with hydrogen. Two types of liquid fuels were tested: blend of the 7% Rapeseed Methyl Ester (RME) with conventional diesel fuel and Neste Pro Diesel – blend of the 15% Hydrotreated Vegetable Oil (HVO), produced by Neste Oil Corporation with conventional diesel fuel. The purpose of this investigation was to examine the influence of the hydrogen addition to biofuels and diesel blends on combustion phases, autoignition delay, engine performance efficiency and exhaust emissions. Hydrogen fraction was changed within the range from 0 to 43% by energy. Hydrogen was injected into the intake manifold, where it created homogeneous mixture with air. Tests were performed at both fixed and optimal injection timings at low, medium, and nominal engine load. After analysis of the engine bench tests and simulation with AVL BOOST software, it was observed that increasing hydrogen fraction shortened the fuel ignition delay phase and it affected the main combustion phase. Moreover, decrease of carbon monoxide (CO), carbon dioxide (CO2) and smoke opacity was observed with increase of hydrogen amounts to the engine. However, increase of the nitrogen oxide (NOx) concentration in the engine exhaust gases was observed.

8

Conception of a hybrid pneumatic-combustion rotary vane engine - challenge and reality

Szwaja S., Rzadkosz K.

Combustion Engines

|

2018

|

R. 57, nr 4

35--39

EN

The paper presents a new concept of applying a rotary vane engine working as the hybrid system including both a combustion engine and a pneumatic motor, which were working simultaneously. In the beginning, review on both unconventional piston engine designs and similar like solutions on rotary vane engines were conducted. Next, description of the conceptual engine was presented. The concept was realized in practice. The prototype engine was built and it was preliminary investigated focusing on problems with cold start and misfiring events which occurred. The engine was tested on LPG and gasoline, however, its main target is to feed it with natural gas. This approach is justified as far as the engine finally might work in natural gas reduction stations and would provide electricity of 1kW power for station’s own demands.

9

Bio-oil blended butanol as a fuel to the spark ignition internal combustion reciprocating engine

Chwist M., Szwaja S., Grab-Rogaliński K., Pyrc M.

Combustion Engines

|

2017

|

R. 56, nr 2

93--96

EN

The article presents results on combustion of the bio-oil blended butanol in the spark ignition engine. Bio-oil is a mixture of hydro-carbons condensing to liquified phase while cooling it down to ambient temperature. In general, the liquid called bio-oil is a byproduct of the pyrolysis process of organic matter. Results from analysis presented in the manuscript include the following: in-cylinder pressure traces and toxic exhaust emissions. Finally, comparison of these results with results from combustion of n-butanol reference fuel were provided. Obtained results indicate satisfactory, eco-friendly possibility for utilization of bio-oil in the internal combustion engine.

10

Odzysk ciepła odpadowego za pomocą silnika Stirlinga

Szwaja S., Skrobek D.

Rynek Energii

|

2016

|

Nr 6

76--79

PL

W artykule omówiono skrótowo rodzaje silnika zewnętrznego spalania zwanego powszechnie silnikiem Stirlinga. Następnie przedstawiono autorską koncepcję dwu-modułowego silnika w wersji „alfa” o konfiguracji cylindrów w układzie widlastym z kątem rozłożenia cylindrów 90º. Przedstawiono analizę termodynamiczną obiegu tego silnika oraz zamieszczono wyniki analizy oraz osiągów silnika. Na podstawie uzyskanych wyników wywnioskowano, że zaprezentowane rozwiązanie będzie można zastosować do konwersji ciepła odpadowego spalin silnika gazowego na energię elektryczną ze sprawnością na poziomie około 10% co jest wynikiem satysfakcjonującym, jeśli uwzględni się, że pozostałe ciepło odpadowe zostanie zutylizowane do obiegu grzewczego mikrobiogazowni rolniczej.

EN

Several versions of the external combustion piston engine, commonly known as the Stirling engine, have been presented in the paper. Furthermore, the own original conception of double-module engine in “alpha” version with 4 cylinders in V configuration of 90 deg has been proposed. Next, thermodynamic analysis of the engine working cycle, its results and engine performance have been included. The engine works on compressed air, but tests with several gases as argon, CO2 and hydrogen are foreseen. The preliminary tests of the functional model showed that power output of this 4 cylinder V90 engine can reach nearly 2 kW at heat source temperature of 550°C and cooling temperature of 80°C. Additionally, impact of the regenerator’s charge will be tested. On the basis of these results, it was concluded, that the proposed engine can be applied as the effective device for waste heat recovery from exhaust gases generated by a gas fueled internal combustion engine with efficiency of approximately 10%. This is considered as satisfactory achievement, if someone takes into account that the heat from the engine cooling system can be utilized by a heating system in the micro biomass-to-biogas power plant.

11

Karbonizat ślazowca pensylwańskiego jako paliwo do kotłów węglowych c.o.

Poskart A., Szwaja S., Musiał D.

Rynek Energii

|

2016

|

Nr 6

104--108

PL

W artykule przedstawiono możliwości wykorzystania ślazowca pensylwańskiego - uprawy energetycznej, która w wyniku wysokiego plonowania może być źródłem biomasy na cele opałowe. W celu wyeliminowania wad biomasy, jako paliwa stałego do kotłów węglowych, przeprowadzono proces uwęglania (toryfikacji) ślazowca, co spowodowało uzyskanie materiału palnego o składzie chemicznym, w tym składników palnych, zbliżonym do węgla kamiennego. Uwęglona biomasa może zastąpić węgiel w kotłach węglowych bez konieczności ich modyfikacji. Przeprowadzone badania laboratoryjne potwierdziły, że uwęglanie w przedziale temperatury 300-350ºC (toryfikacja) ślazowca pensylwańskiego ma pozytywny wpływ na poprawę jego właściwości jako potencjalnego paliwa, które może zastąpić węgiel np. w domowych kotłach węglowych C.O. Toryfikacja w istotny sposób przyczyniła się do zwiększenia ciepła spalania i wartości opałowej toryfikowanych próbek poprzez znaczne zmniejszenie zawartości wilgoci w odniesieniu do próbki surowej. Ponadto, w wyniku badań okazało się, że czas wyprażania można skrócić nawet do 20-30 minut w temperaturze 300ºC bez znaczącego uszczerbku na walorach opałowych powstałego paliwa.

EN

The paper presents possibilities of applying Virginia Mallow plant – considered as energetic crops – as solid fuel for boilers due to its high growing yield. Torrefaction process was introduced to Virginia Mallow to eliminate typical drawbacks of biomass as direct fuel to coal fired boilers. In this way, a satisfactory good carbonized material, on the basis of chemical analysis similar to coal, was obtained. Carbonized biomass can be directly applied to coal fired boilers without their modification. Laboratory research confirmed that carbonization of Virginia mallow within the temperature range 300-350°C (torrefaction) has a positive impact on improvement of its properties as a potential fuel that can replace coal in domestic boilers. Torrefaction significantly contributes to increase in the heat of combustion as well as heating value of torrefied samples by reduction in the moisture content in comparison to a crude sample. Furthermore, as a result of this research it was found that the carbonization time can be reduced up to 20-30 minutes at 300°C without significant loss of heating values of the received fuel.

12

Analiza opłacalności ekonomicznej mikrobiogazowni rolniczej

Szwaja S.

Rynek Energii

|

2016

|

Nr 6

94--97

PL

W artykule omówiono rozwój mikrobiogazowni rolniczych w Polsce. Przedstawiono argumenty sprzyjające i niesprzyjające tego typu instalacjom do wytwarzania ciepła i energii elektrycznej na potrzeby gospodarstwa rolnego. Następnie przedstawiono charakterystykę zbudowanej mikrobiogazowni o mocy 7 kW opartej konstrukcyjnie o kontener morski typu 40HC. Dla tej instalacji przeprowadzono analizę opłacalności ekonomicznej jej długoterminowego eksploatowania. Z analizy tej wynika, że mikrobiogazownia rolnicza ze względu na swoje relatywnie wysokie jednostkowe koszty inwestycyjne jest przedsięwzięciem nieopłacalnym, jeśli uwzględni się w niej wyłącznie produkcję energii elektrycznej. Produkcja ciepła na potrzeby gospodarstwa poprawia nieznacznie kondycję ekonomiczną instalacji. Znaczącą korzyść może przynieść taka mikrobiogazownia, gdy wykorzysta się z niej produkt uboczny, jakim jest woda pofermentacyjna, jako wartościowy nawóz bogaty w związki azotu.

EN

Development in micro-size biomass power plants in Poland has been discussed in the paper. Several pros and cons have been presented due to their practical implementations in agricultural farms. Next, a micro biomass power plant of 7 kW based on a ship container HQ40 has been described. The power set applied to the power plant is a cogeneration set with two heat recovery units installed on the exhaust gas pipeline and the engine cooling system. The cogeneration unit finally is built in the container, in which 5 sqm for this purpose were reserved. Economic analysis for this power plant in long-term operation was conducted on the basis of LACE and LCOE indicators. The LCOE was determined at level of 1.65 PLN/kWh. The LACE was taken directly as cost of power price of 0.65 PLN/kWh from the electric state grid. As found, this micro power plant with respect to its relatively high costs of both investment and operation cannot be considered as profitable venture, unless not only production of electrical power would be taken into account. Heat generation can slightly increase profits, but the most crucial improvement in economical condition of this power plant is to utilize additionally post-fermented water, which from one side is treated as a by-product, but from another side, this water is valuable organic fertilizer rich in nitrogen derivatives.

13

The possibility of use a waste product of biofuels production-glycerol as a fuel to the compression ignition engine

Grab-Rogaliński K., Szwaja S.

Journal of KONES

|

2016

|

Vol. 23, No. 3

157--164

EN

The article presents results of tests performed in a combustion research unit (CRU) with the two following fuels: light fuel oil (LFO) and glycerol. The CRU is a constant volume combustion chamber machine equipped with an injection system based on that used in common-rail diesel engines with electromagnetic injectors. This machine allows to compare various combustion properties between fuels for specified parameters of injection and a combustion chamber as well. As it is known glycerol is a substance which is obtained from several technological processes such as production of biofuel thus in this way it can be treated as an alternative renewable fuel. The glycerol is characterized by low heating value of 16MJ/kg and relatively high density of 1261 kg/m3. However, its heating value by volume is higher if compared to other liquid fuels. From that reason decrease in energy that can be delivered with fuel is smaller which is approximately 16% lest than for LFO. The parameters measured during this research were: pressure increase, rate of pressure increase (ROPR), ignition delay (ID), main reaction delay (MRD), main combustion period (MCP), end of main combustion (EMC), end of combustion (EC), position of max ROPR (PMR) and max ROPR. The tests were performed with different injection parameters such as injection pressure, injection duration and injection delay as well as under various conditions in the CRU combustion chamber expressed by pressure and temperature. On the basis of these tests the comparison between LFO and glycerol was done. The results were presented in diagrams. The research shows that glycerol used as a fuel, to obtain the same output power, should be injected at higher amounts. Glycerol as a fuel cannot ignite itself, hence to provide combustion the pilot injection of another fuel have to be applied.

14

Skojarzone wytwarzanie energii elektrycznej, ciepła i chłodu w instalacji z biogazowym silnikiem tłokowym

Pyrc M., Grab-Rogaliński K., Szwaja S.

TTS Technika Transportu Szynowego

|

2015

|

R. 22, nr 12

2835--2838

PL

Tematyka pracy związana jest z systemami trójgeneracyjnymi. Zawarto w niej opis paliwa biogazowego jako alternatywę do zasilania silników stacjonarnych, elementy układu trójgeneracyjnego, cele stosowania trójgeneracji. Zaprojektowano koncepcyjny model takiego układu o mocy 80kWe z przeznaczeniem dla hali sportowej. Przedstawiono podstawowe elementy tego układu z jego parametrami i kosztami zużywanego paliwa. Jako podsumowanie dołączono bilans energijny tej koncepcji. W podsumowaniu zawarto możliwości wdrożenia takiego układu z uwzględnieniem zużywanego paliwa, a także korzyści płynące z użytkowania tego typu urządzeń. Przedstawiono, gdzie i kiedy można używać takich układów i czy warto inwestować w tego typu urządzenia.

EN

The subject matter of this thesis refers to trigeneration systems. The thesis includes a description of biogas as an alternative to powering reciprocating engines, the elements of trigeneration systems, the purpose of using trigeneration. Additionally, a conceptual model of such a system with a power of 80kW has been designed for the sports hall. The thesis presents the essential elements of this system along with its parameters and costs of the fuel used. At the end, the energy balance of this concept has been attached. The conclusion includes the possibilities of implementing such a system considering the fuel used as well as the benefits of using such devices. The thesis presents where and when these systems can be used and whether it is worth investing in this type of equipment.

15

Silnik biogazowy z układem odzysku ciepła odpadowego

Grab-Rogaliński K., Szwaja S., Pyrc M.

TTS Technika Transportu Szynowego

|

2015

|

R. 22, nr 12

605--609, CD

PL

W niniejszym artykule przedstawiono analizę zespołu kogeneracyjnego wyposażonego w układ odzysku ciepła odpadowego opartego na siłowni parowej pracującej na zasadzie obiegu Clasiusa-Rankina. Przeprowadzona analiza opierała się na określeniu ilości energii zawartej w spalinach silnika gazowego a następnie na zaprojektowaniu instalacji odzysku ciepła odpadowego, z którego wytwarzana będzie energia elektryczna oraz wykonaniu bilansu energijnego wykorzystanego do tego celu zespołu kogeneracyjnego i siłowni parowej. Na podstawie analizy bilansu energijnego oszacowano również koszty inwestycyjne potrzebne do stworzenia takiej instalacji oraz czas amortyzacji wyżej wymienionej inwestycji w zależności od sposobu dofinansowania oraz cen sprzedaży wyprodukowanej energii elektrycznej.

EN

The paper presents an analysis of cogeneration unit with a waste heat recovery system based on a stem power plant which work with Clasius-Rankin cycle. To conducted the analysis the waste heat energy of the gas engine was determined. Next the waste heat recovery system which will be producing the electric energy was designed. At the end the energetic balance was done for the gas engine and the waste heat recovery system. On a base of this analysis the investments cost for such installation and time needed to it full amortization, which depends of financing method and energy price, were determined.

16

The effect of methanol-diesel combustion on performance and emissions of a direct injection diesel engine

Tutak W., Szwaja S.

Journal of KONES

|

2015

|

Vol. 22, No. 2

259--266

EN

The results of CFD modelling a dual fuel diesel engine powered with both methanol and diesel fuel is presented in the paper. Modelling was performed with 20 and a 50% energetic share of methanol in the entire dose. The analysis was conducted on both the thermodynamic parameters and exhaust toxicity of dual fuel engine. It was found that the various share of methanol influences the ignition delay of the combustion process and after start of main phase of combustion, the process occurs faster than in case of the diesel engine. It was found that the time of 10-90% burn of the fuel is much shorter than it is in the diesel engine. The dual fuel engine was characterized by higher indicated mean pressure in the whole range of diesel fuel injection timings. While analysing toxic exhaust emission from the dual fuel engine powered with methanol, it was found that the rate of NO formation was significantly higher than from the diesel engine. The combustion process in the dual fuel engine occurs more rapidly than in the conventional diesel engine, which contributes to form areas with high temperature, and in combination with presence of oxygen from the air and oxygen bonded in the methanol, promotes the NO formation. In the case of the dual fuel engine, it was found that soot emission was reduced. The engine running with diesel injection start at 8.5 deg before TDC, the soot emissions were more than twice lower in the dual fuel engine, while the emission of NO was much higher.

17

Influence of intake valve closure angle on IC engine indicated parameters

Grab-Rogaliński K., Szwaja S.

Journal of KONES

|

2015

|

Vol. 22, No. 3

29--35

EN

The paper presents results of modelling study of influence of an intake valve closure angle on IC engine indicated parameters. The modelled engine was Andoria S231, which was working on methane. At first, optimizations of the model were done by comparison of the indicated mean effective pressure for real engine and modelled engine. Next, modelling was done for early intake valve closure angle in comparison to original closure angle. The engine was simulated as a naturally aspirated one and for the cases such indicated; parameters as indicated efficiency, mean indicated pressure, fuel consumption were calculated. During the modelling ignition, timing and air-fuel ratio were fixed. For better comparison for two cases of early intake valve closure angle the engine was modelled as super-charged one where mean indicated pressure was fixed at the same level as for the naturally aspirated engine working with original valve timing and indicated parameters were calculated and compared with in parameters determined from this naturally aspirated engine. Because of the calculations, characteristics of indicated parameters vs. intake valve closure angle were computed. As a result of this research, both the decrease in indicated efficiency, indicated mean effective pressure were shown, temperature of fresh charge, end of compression stroke and maximum in-cylinder temperature were observed for naturally aspirated engine with early intake valve closure angle.

18

Konstrukcja małej turbiny parowej typu Elektra dla energetyki rozproszonej

Kryłłowicz W., Liśkiewicz G., Szwaja S.

Energetyka

|

2015

|

nr 11

719--722

PL

Opisano konstrukcję prototypowej małej turbiny parowej przeznaczonej do pracy w instalacji stacjonarnego silnika spalinowego zasilanego biogazem. Omówiono zasady doboru układu przepływowego (dwustopniowy układ Electra) oraz przedstawiono budowę podstawowych podzespołów konstrukcyjnych. Artykuł zawiera wnioski dotyczące doświadczeń osiągniętych w trakcie projektowania i budowy prototypu.

EN

Described is the construction of a prototype small steam turbine dedicated to co-operate with a stationary biogas-fuelled combustion engine. Discussed are main principles that contributed to a selection of the flow system (two-stage Electra turbine) and presented is the construction of basic subassemblies. Contained are conclusions concerning the experience gained during designing and construction of the prototype.

19

Miller cycle application to the gaseous supercharged SI engine

Grab-Rogaliński K., Szwaja S.

Combustion Engines

|

2015

|

R. 54, nr 3

881--885

EN

The paper contains results of tests on the spark ignited (SI) engine modified to work as the engine with the overexpanded thermodynamic Miller cycle. Investigation was particularly focused on thermodynamic properties of the applied Miller cycle as well as combustion progress in the supercharged engine fuelled with various gaseous fuels as follows: coke gas, natural gas and hydrogen. Crucial conclusions deal with experimental investigation. The conclusions showed the following: IMEP was maintained at the same level with aid of supercharging, thermal indicated efficiency increased.

PL

W artykule przedstawione zostały wyniki stanowiskowych silnika o zapłonie iskrowym przystosowanym do pracy na zasadzie obiegu Millera. Badania skupiały się na właściwościach termodynamicznych wykorzystanego obiegu Millera jak również przebiegu spalania w doładowanym silniku zasilanym różnymi paliwami gazowym takimi jak: gaz koksowniczy, gaz ziemny, wodór. Główne wnioski uzyskane zostały w wyniku badań eksperymentalnych i wskazały wzrost odporności na spalanie stukowe przy wykorzystaniu obiegu Millera oraz podwyższenie sprawności indykowanej.

20

Produkcja energii elektrycznej z ciepła spalin agregatu kogeneracyjnego

Szwaja S.

Rynek Energii

|

2014

|

Nr 6

74--77

PL

W artykule przedstawiono analizę termodynamiczną obiegu Rankine’a z turbiną kondensacyjną pracującą na czynniku roboczym para-woda i opłacalność takiej inwestycji w przypadku zastosowania instalacji do agregatu kogeneracyjnego. Przedstawiono bilans energijny całego obiegu oraz poszczególnych jego elementów. Potwierdzono celowość stosowania takiego sposobu odzysku ciepła i konwersji na energię elektryczną przy założeniu utrzymania kosztów inwestycyjnych na niezbędnym minimum i dążenia do uzyskania maksimum opłat ekologicznych w tym certyfikatów energetycznych. Praca wykonana w ramach projektu PBS II nr 210698 pt. Utylizacja osadu pofermentacyjnego z biogazowni na potrzeby produkcji energii elektrycznej.

EN

Both thermodynamic analysis of the steam Rankine cycle with a condensing turbine and economical benefits coming from applying this system to a heat and power cogeneration set have been presented in the paper. Energy balance for the complete system as well as for particular devices has been calculated. Economical profits from this business has been discussed and confirmed as the attractive venture under terms of minimum investment costs and maximum financial support by ecological certificates.