prof. dr hab. inż. Dariusz Mikielewicz
Zatrudnienie
- Kierownik zakładu w Zakład Systemów i Urządzeń Energetyki Cieplnej
- Prorektor d/s Organizacji i Rozwoju w Politechnika Gdańska
- Profesor w Instytut Energii
Publikacje
Filtry
wszystkich: 284
Katalog Publikacji
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A thermodynamic criterion for selection of working fluid for subcritical and supercritical domestic micro CHP
PublikacjaW pracy przedstawiono kryterium termodynamiczne doboru czynnika roboczego dla mikrosiłowni pracującej w warunkach podkrytycznych i nadkrytycznych. Przeanalizowano 20 płynów możliwych do wykorzystania w mikrosiłowni ORC. Z analizy wynika, że najlepszym płynem roboczym jest etanol, R123 oraz R141b.
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Utilisation of waste heat from the power plant by use of the ORC aided with bleed steam and extra source of heat
PublikacjaUtilization of waste heat recovered from the exhaust gases of the power generation unit by means of ORC (organic Rankine cycles) installation is considered. The waste heat is available in the form of a stream of hot water having temperature of 90 stC in the amount of 200 MWt. To increase evaporation temperaturę of ORC working fluid the heat of steam from the extraction points from the low-pressure part of steam turbine is used....
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Improved semi-empirical method for determination of heat transfer coefficient in flow boiling in conventional and small diameter tubes
PublikacjaPraca dotyczy przedstawienia poprawionego modelu umożliwiającego wyznaczanie współczynnika przejmowania ciepła w kanałach o małych średnicach jaj i tych tradycyjnych. Model zweryfikowano na 6 czynnikach chłodnuiczych uzyskując bardzo zadowalającą zgodność.
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Air-cooled photovoltaic roof tile as an example of the BIPVT system – An experimental study on the energy and exergy performance
PublikacjaThe air-cooled photovoltaic tile is a subject of presented investigations, which focused on improving the overall system efficiency of PV tiles with heat recovery. The operational efficiency of a PV roof tile, together with the construction optimising the air cooling efficiency, were the main points of plans realized at this research stage. The article describes the experimental research consisting of the assessment of electrical,...
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A New Approach for the Mitigating of Flow Maldistribution in Parallel Microchannel Heat Sink
PublikacjaThe problem of flow maldistribution is very critical in microchannel heat sinks (MCHS). It induces temperature nonuniformity, which may ultimately lead to the breakdown of associated system. In the present communication, a novel approach for the mitigation of flow maldistribution problem in parallel MCHS has been proposed using variable width microchannels. Numerical simulation of copper made parallel MCHS consisting of 25 channels...
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Performance of the very high-temperature heat pump with low GWP working fluids
PublikacjaTraditional heat pumps are a very attractive pro-ecological solutions for a number of applications, including providing of heating or heat recovery from industrial processes. The application range of heat pumps could be greatly enlarged when the operating temperature would be increased to 130-150°C and/or the temperature lift can be increased to 50-100 K. In the paper, the very high temperature vapour-compressor based single stage...
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Influence of metallic porous microlayer on pressure drop and heat transfer of stainless steel plate heat exchanger
PublikacjaThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The metallic porous layer was created on the heat transfer surface of analyzed unit. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one – the identical heat exchanger but with the modified...
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Influence of metallic porous microlayer on pressure drop and heat transfer of stainless steel plate heat exchanger
PublikacjaThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. On the heat transfer surface of heat exchanger the metallic porous layer was created. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one – the identical heat exchanger but with the modified...
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Thermodynamic Analysis of Negative CO2 Emission Power Plant Using Aspen Plus, Aspen Hysys, and Ebsilon Software
PublikacjaAbstract: The article presents results of thermodynamic analysis using a zero-dimensional mathematical models of a negative CO2 emission power plant. The developed cycle of a negative CO2 emission power plant allows the production of electricity using gasified sewage sludge as a main fuel. The negative emission can be achieved by the use this type of fuel which is already a “zeroemissive” energy source. Together with carbon capture...
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Performance of the domestic micro ORC equipped with the shell-and-tube condenser with minichannels
PublikacjaIn this paper, the original compact shell-and-tube heat exchanger with circular minichannels of in-house design and manufacturing is presented as the condenser for the domestic micro heat and power plant investigations as well as other future technical applications. The heat exchanger is equipped with turbulizing baffles inside the shell. The shell itself is made of a tubular sleeve having an inner diameter of 0.067 m and the length...
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Innovative Turbine Intake Air Cooling Systems and Their Rational Designing
PublikacjaThe improved methodology of the engine intake air cooling system designing based on the annual effect due to cooling was developed. It involves determining the optimal value of cooling capacity, providing the minimum system sizes at maximum rate of annual effect increment, and its rational value, providing a close to maximum annual effect without system oversizing at the second maximum rate of annual effect increment within the...
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Numerical Study on Mitigation of Flow Maldistribution in Parallel Microchannel Heat Sink: Channels Variable Width Versus Variable Height Approach
PublikacjaMicrochannel heat sink on one hand enjoys benefits of intensified several folds heat transfer performance but on the other hand has to suffer aggravated form of trifling limitations associated with imperfect hydrodynamics and heat transfer behavior. Flow maldistribution is one of such limitation that exaggerates temperature nonuniformity across parallel microchannels leading to increase in maximum base temperature. Recently, variable...
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Experimental investigation of dryout of SES36, R134a, R123 and ethanol in vertical small diameter tubes
PublikacjaW publikacji przedstawiono wyniki badań eksperymentalnych kryzysu wrzenia typu dryout podczas wrzenia w przepływie czterech czynników (SES36, R134a, R123, alkohol etylowy) w kanałach o średnicy wewnętrznej 1.15 mm i 2.3 mm. Badania przeprowadzono w szerokim zakresie zmian stopnia suchości pary (0.65-1), gęstości strumienia masy (40-900 kg/(m2s)) i gęstości strumienia ciepła (20-220 kW/m2). W badaniach wykorzystano technikę termowizyjną...
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Selected studies of flow maldistribution in a minichannel plate heat exchanger
PublikacjaAnalysis of the state of-the-art in research of minichannel heat exchangers, especially on the topic of flow maldistribution in multiple channels, has been accomplished. Studies on minichannel plate heat exchanger with 51 parallel minichannels with four hydraulic diameters, i.e., 461 μm, 574 μm, 667 μm, and 750 μm have been presented. Flow at the instance of filling the microchannel with water at low flow rates has been visualized. The...
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Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels
PublikacjaAttention is focused on the issues of flow resistance and pressure drop of perspective refrigeration fluids during condensation in the two-phase flow in minichannels. The case of the flow through a cylindrical single channel of 2.3 mm inner diameter was carefully analyzed. Pressure drop tests have been performed in diabatic flow conditions. The effect of heat flux, mass flux, vapour quality and saturation temperature on the two-phase...
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Channel Blockage and Flow Maldistribution during Unsteady Flow in a Model Microchannel Plate heat Exchanger
PublikacjaThis paper describes the problem of channel blockage as a result of flow maldistribution between the channels of a model mini channel plate heat exchanger consisting of one pass on each leg. Each leg of the heat exchanger contains 51 parallel and rectangular minichannels of four hydraulic diameters namely 461 μm, 571 μm, 750 μm and 823 μm. In addition, a more complex geometry has been investigated where for the sake of breaking...
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A common method for calculation of flow boiling and flow condensation heat transfer coefficients in minichannels with account of nonadiabatic effects
PublikacjaW pracy przedstawiono metodę ogólną wyznaczania współczynników przejmowania ciepła podczas wrzenia w przepływie i kondensacji w przepływie w minikanałach z uwzględnieniem efektu nieadiabatycznego. Uwzględnia ona wpływ modyfikacji naprężeń stycznych na granicy ciecz-para na wymianę ciepła.
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Mathematical modelling of gasification process of sewage sludge in reactor of negative CO2 emission power plant
PublikacjaSewage sludge is a residue of wastewater processing that is biologically active and consists of water,organic matter, including dead and alive pathogens, as well as organic and inorganic contaminants suchas polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Due to the nature of sewage sludge and itspossible influence on human health and wellbeing, it is a subject of various regulations. Currently,sewage sludge is considered...
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Structural optimization of microjet array cooling system
PublikacjaThe single phase heat transfer from an upward facing, horizontal copper surface to arrays of impinging water jets was experimentally investigated. Experimental configuration allows for a free-surface unconfined jets flow. Square nozzles 50 × 100 μm arranged in four different geometries were used. Additionally, for the set of two jets array geometry was varied by adjusting the nozzle to nozzle distance. The area averaged heat transfer...
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Experimental investigation of domestic micro-CHP based on the gas boiler fitted with ORC module
PublikacjaThe results of investigations conducted on the prototype of vapour driven micro-CHP unit integrated with a gas boiler are presented. The system enables cogeneration of heat and electric energy to cover the energy demand of household. The idea of such system is to produce electricity for own demand or for selling it to the electric grid – in such situation the system user will became the prosumer. A typical commercial gas boiler,...
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