Wyniki wyszukiwania - BazTech

1

Wpływ odzysku ciepła odpadowego spalin z kotła energetycznego na prace instalacji mokrego odsiarczania spalin

Rączka Paweł

Rynek Energii

|

2023

|

Nr 1

21--27

PL

W pracy przedstawiono wyniki obliczeń wpływu odzysku ciepła jawnego i utajonego spalin wylotowych z kotła energetycznego bloku o mocy 900 MW zasilanego węglem brunatnym na pracę instalacji mokrego odsiarczania spalin (IOS). Obliczenia przeprowadzono na podstawie modelu matematycznego wykorzystującego dane z prawdziwej rośliny. Oprócz pozytywnego wpływu układu odzysku ciepła (HRS) na sprawność cieplną bloku energetycznego oraz wstępnego oczyszczenia spalin z pyłów i gazów kwaśnych, wyniki obliczeń wykazały bardzo istotny wpływ na pracę bloku energetycznego. IOS. Główna zmiana dotyczy masowego przepływu wody stosowanej w absorberze w celu schłodzenia spalin do wymaganej temperatury. Obliczony maksymalny spadek zapotrzebowania elektrowni na wodę uzupełniającą (przy 167,5 MW odzysku ciepła) wynosi 185,9 Mg/h. Gdy do uzupełniania używany jest kondensat HRS, zapotrzebowanie na wodę surową będzie zerowe. Dodatkowo HRS w wyniku kondensacji części pary wodnej zawartej w spalinach powoduje częściowe zasiarczenie spalin w wymienniku HRS. Zmniejsza to obciążenie IOS, w tym mniejsze zapotrzebowanie na sorbent i wodę technologiczną używaną do przygotowania roztworu sorbentu. Strumień spalin kierowany do instalacji i odprowadzany do atmosfery przez chłodnię kominową zmniejsza się o ok. 9%. Wartością dodaną proponowanego rozwiązania jest zabezpieczenie wnętrza pochłaniaczy IOS przed wysoką temperaturą spalin w przypadku awarii zasilania instalacji (blackoutu) lub innej tego typu awarii, odcinającej dopływ prądu do pomp IMOS.

EN

This paper presents the results of calculations of the influence of sensible and latent heat recovery from ﬂue gas of a 900 MW power unit Bieled with lignite on the operation of the wet ﬂue gas desulfurization plant (FGD) The calculations based on the mathematical model using data from the real plant. In addition to the positive Impact of the heat recovery system (HRS) on the thermal efﬁciency of the power unit and the initial cleaning of flue gas from dust and acid gases, the results of the calculations showed a very signiﬁcant impact on the operation of the FGD. The main change concerns the water mass ﬂow used in the absorber to cool the ﬂue gas to the required temperature. The calculated maximum decrease in the demand for make-up water by the plant (with 167.5 MW of hęatgrecovery) is 185.9 Mg/hr. When HRS condensate is used for top-up, the raw water requirement will be zero. In addition, the HRS with condensation of part of the water vapor contained in the ﬂue gas causes partial ﬂue gas dęsulfurization in the HRS exchanger. This reduces the load on the FGD, including the lower need of sorbent and process water used to prepare the sorbent solution. The ﬂue gas stream directed to the installation and discharged to the atmosphere through the cooling tower is reduced by approx. 9%. The added value of the proposed solution IS thc protection of the interior of the FGD absorbers against high ﬂue gas temperature in the event of a system power failure (blackout) or other such failure, cutting off the power supply to FGD pumps.

2

Exploration of a model thermoacoustic turbogenerator with a bidirectional turbine

Korobko Volodymyr, Serbin Serhiy, Le Huu Cuong

Polish Maritime Research

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2023

|

nr 4

102--109

EN

The utilisation of the thermal emissions of modern ship power plants requires the development and implementation of essentially new methods of using low-temperature waste heat. Thermoacoustic technologies are able to effectively use lowtemperature and cryogenic heat resources with a potential difference of 500–111 K. Thermoacoustic heat machines (TAHMs) are characterised by high reliability, simplicity and environmental safety. The wide implementation of thermoacoustic energy-saving systems is hampered by the low specific power and the difficulties of directly producing mechanical work. An efficient approach to converting acoustic energy into mechanical work entails the utilisation of axial pulse bidirectional turbines within thermoacoustic heat engines. These thermoacoustic turbogenerators represent comprehensive systems that consist of thermoacoustic primary movers with an electric generator actuated by an axial-pulse bidirectional turbine. The development of such a thermoacoustic turbogenerator requires several fundamental issues to be solved. For this purpose, a suitable experimental setup and a 3D computational fluid dynamics (CFD) model of a thermoacoustic engine (TAE) with bidirectional turbines were created. The research program involved conducting physical experiments and the CFD modelling of processes in a TAE resonator with an installed bidirectional turbine. The boundary and initial conditions for CFD calculations were based on empirical data. The adequacy of the developed numerical model was substantiated by the results of physical experiments. The CFD results showed that the most significant energy losses in bidirectional turbines are manifested in the output grid of the turbine.

3

Wykorzystanie wody dołowej w odbiorze i wykorzystaniu ciepła skraplania z podziemnych układów klimatyzacji w kopalniach

Szlązak Nikodem, Obracaj Dariusz, Korzec Marek

Inżynieria Mineralna

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2023

|

no. 1

225--234

PL

Stosowanie różnych systemów chłodzenia powietrza w kopalniach podziemnych wynika z trudnych warunków klimatycznych panujących na stanowiskach pracy. Podziemne instalacje chłodnicze z agregatami sprężarkowymi są szeroko stosowane w systemach chłodzenia powietrza. Sprawne działanie agregatów chłodniczych zależy od właściwego odprowadzania ciepła skraplania. Moc chłodnicza i lokalizacja instalacji chłodniczej mają największy wpływ na podjęcie decyzji o odprowadzeniu ciepła skraplania do powietrza lub wody. W artykule skoncentrowano się na zastosowaniu urządzeń chłodniczych zabudowanych w wyrobiskach podziemnych. Przedstawiono rozważania dotyczące ograniczeń przekazywania ciepła skraplania do powietrza kopalnianego oraz warunki sprzyjające wykorzystaniu wody dołowej w odbiorze ciepła skraplania z układów klimatyzacji. Omówiono uwarunkowania i możliwości wykorzystania ciepła odpadowego zawartego w pompowanej na powierzchnię wodzie dołowej.

EN

Using various air cooling systems in underground mines results from harsh climatic conditions at workplaces. Underground refrigeration plants with compressor chillers are widely used in air cooling systems. The efficient operation of refrigeration units depends on the proper condensation heat rejection. Cooling capacity and localization of a refrigeration plant have the most significant influence on deciding of rejecting condensation heat to air or water. The limitation of the heat rejection capacity of return air streams in a typical mine and conditions facilitative to using underground water from an underground mine dewatering system is presented. Determinants and opportunities for heat recovery from water discharged to the surface are also discu

4

Reliability and availability modelling of a retrofitted Diesel-based cogeneration system for heat and hot water demand of an isolated Antarctic base

Coronado Miguel, Kadoch Benjamin, Contreras Jorge, Kristjanpoller Fredy

Eksploatacja i Niezawodność

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2023

|

Vol. 25, no. 3

art. no. 169779

EN

The reduction of greenhouse gas emissions is a relevant challenge for a sustainable development. Waste heat could be used to produce hot water by using a recovery system. This article studies the availability of a combined heat and power systems (CHP) in extreme area (Antarctic) through the integration of a waste heat recovery system with a diesel generator to produce hot water. The reliability and availability principles are incorporated to explore how the profile of hot water consumption and the hot water storage tank size affect system availability. Different combined heat and power systems are thus classified, and their availability indexes modelled by adopting the continuous Markov approach and the state space model. The results indicate that the CHP systems availability is strongly influenced by the daily hot water demand profile. As a useful recommendation, one of the considerations for increasing availability, reducing costs and greenhouse gas emissions with the CHP system is to include a hot water tank in the analysis.

5

Resources and potential for utilization of low-exergy heat from mung bean sprouts cultivation – case study

Mirek Paweł, Panowski Marcin, Słomczyńska Klaudia, Stanek Michał, Bąkowski Tomasz

Archives of Thermodynamics

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2023

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Vol. 44, no 4

507--534

EN

Poland is a significant producer of vegetable sprouts, which, due to the high content of nutrients, are produced for food purposes. The cultivation cycle of these plants, especially the mung beans (Vigna radiata), is associated with significant exploitation of natural resources (as much as 275 dm3 of water per 1 kg of dry seeds) and requires appropriate temperature conditions. However, since producing of vegetable sprouts is an exothermic process, there are reasons to organize the growth conditions of these plants in a quasi-autonomous manner. Estimated preliminary studies show that during the entire period of sprout growth, as much as 2.86 MJ of heat from 1 kg of dry seeds can be used, which, taking into account the scale of production of these plants, places them among the significant sources of low-temperature waste heat. The paper presents the results of temperature measurements carried out in a growth chamber used for the industrial production of the mung bean vegetable sprouts. Based on the prepared energy balance, the total amount of heat generated (4.9 GJ) and recovered (3.3 GJ) in the seed germination process was determined. The amount of energy lost in the process of imbibition and the amount of heat needed to ensure optimal plant growth conditions were determined. The study shows that the use of low-temperature heat generated by plants allows for a significant reduction in the energy consumption of the production process.

6

Analysis of the Potential for Reducing the Energy Consumption of a Vegetable Sprouts Production Using Flownex Simulation Softwar

Słomczyńska Klaudia, Mirek Paweł, Panowski Marcin

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 5

163--173

EN

Using the waste energy generated in any production process is the one of possible ways of increasing energy efficiency. In the industrial cultivation of vegetable sprouts for food purposes, significant amounts of low-temperature waste heat are released, the source of which is the metabolic processes taking place inside the seeds. In typical installations, this energy is lost to the environment, while it could be utilised, for example, to heating the water used to irrigate the plants. This paper presents a concept of utilizing waste heat generated during the germination process of seeds using plate heat exchangers and the analysis of the potential for reducing the energy consumption of installations for vegetable sprout production. For this purpose, transient simulations were conducted using a developed simulation model of the technological line in Flownex Simulation Environment. In order to formulate a reliable simulation model, relevant device parameters and process data were collected. After building the model and calibrating it appropriately, an analysis of the variability of the values of all process parameters was performed, and the potential for recovering waste heat was determined. The results obtained from numerical modelling were verified against the results obtained from the production line and shows, that the amount of recoverable waste heat in the entire production cycle was about 5 GJ.

7

Niekonwencjonalne metody odzysku ciepła w układach przemysłowych

Matysko Robert, Wiśniewska Weronika

Chłodnictwo i Klimatyzacja

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2022

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nr 1

40--45

PL

W artykule przedstawiono przegląd metod niekonwencjonalnych systemów odzysku ciepła. Opisano możliwości odzysku ciepła z wykorzystaniem układów absorpcyjnych, sprężarkowych oraz ORC. Przybliżono również klasyczne metody odzysku ciepła z procesu spalania. Zastosowanie metod konwencjonalnych oraz niekonwencjonalnych odzysku ciepła sprzyja poprawie efektywności energetycznej realizowanych procesów. Odzysk ciepła pozwala również zmniejszyć zużycie coraz droższych paliw kopalnych oraz redukuje negatywny wpływ na środowisko naturalne.

8

An innovative method for waste heat recovery from flue gas treatment system through an additional economizer

Iliev Iliya Krastev, Kowalczyk Tomasz, Beloev Hristo Kvanov, Terziev Angel Kostadinov, Jesionek Krzysztof Jan, Badur Janusz

Archives of Thermodynamics

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2022

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Vol. 43, no 2

37--59

EN

The usage of wet methods for flue gas dedusting from coalfired boilers is associated with significant heat losses and water resources. Widespread emulsifiers of the first and second generation are satisfactory in terms of flue gas cleaning efficiency (up to 99.5%), but at the same time do not create conditions for deeper waste heat recovery, leading to lowering the temperature of gases. Therefore, in the paper, an innovative modernization, including installing an additional economizer in front of the scrubber (emulsifier) is proposed, as part of the flue gas passes through a parallel bag filter. At the outlet of the emulsifier and the bag filter, the gases are mixed in a suitable ratio, whereby the gas mixture entering the stack does not create conditions for condensation processes in the stack.

9

Bezpośrednie wykorzystanie gazów wylotowych z turbiny gazowej w przemyśle przetwórczym – przegląd zastosowań i możliwości wdrożenia na polskim rynku

Cichocki Marek, Salamonik Ilona, Bielecki Marcin, Fadlun Ever, Rusowicz Artur

Rynek Energii

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2021

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Nr 5

68--77

PL

Klasyczne układy ze skojarzonym wytwarzaniem energii elektrycznej i ciepła wymagają wprowadzenia dodatkowego medium grzejnego. Alternatywnym rozwiązaniem jest bezpośrednie wykorzystanie gazów wylotowych z silnika cieplnego. Dzięki wysokiej temperaturze oraz znacznym strumieniem ciepła w stosunku do mocy, gazy wylotowe z turbiny Gazowej (TG) zostały z powodzeniem zastosowane w skali przemysłowej jako: podgrzane powietrze w piecach przemysłowych, źródło ciepła do bezpośredniego osuszania oraz w absorpcyjnych urządzeniach chłodniczych. W artykule zawarto przegląd udokumentowanych zastosowań TG w przemyśle przetwórczym z uwzględnieniem uwarunkowań technicznych i ekonomicznych, jak również, kryteria doboru TG. Opisane rozwiązania pozwoliły na obniżenie energochłonności w zakresie od 7% do 20% oraz redukcję kosztów zużywanej energii na poziomie 15-30%. Redukcja energochłonności obniża ilość emitowanego CO2. Osiągnięto także całkowitą sprawność układów kogeneracji powyżej 90%. Dokonano również wstępnej oceny możliwości integracji gazów wylotowych dla TG produkowanych przez Baker Hughes w polskim przemyśle.

EN

The typical combined heat and power plants require the introduction of additional heating medium. The alternative solution is the direct integration of the exhaust gases from heat engine. High temperature and high exhaust energy to power ratio, enabled the integration of Gas Turbine (GT) exhaust gases at industrial scale as: preheated combustion air for industrial furnaces, heat source for direct drying and for absorption chillers. The article comprises the review of documented applications of GTs with direct exhaust gas integration in the process industry focusing on technical and economic considerations, as well as GTs selection criteria. The described solutions allowed to reduce specific energy consumption by 7-20% or the costs of energy consumption by 15-30%. The reduction of specific energy consumption allows to decrease the amount of CO 2 emitted. The overall efficiency of cogeneration plant above 90% was achieved. The preliminary feasibility assessment of the opportunities to integrate exhaust gases in the polish industry for the Gas Turbines produced by Baker Hughes is done.

10

Efektywna metoda dekarbonizacji krajowego sektora ciepłowniczego za pomocą innowacyjnego systemu odzyskiwania ciepła skraplania pary wodnej ze spalin powstającej ze spalania wilgotnej biomasy oraz absorpcyjnej pompy ciepła

Malicki Marcin, Gądek Maksymilian, Gidziela Przemysław, Kabiesz Jarosław, Piotrowski Wojciech, Wong Muñoz Carlos Esteban

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2021

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T. 52, nr 4

9--16

PL

Biomasa stanowi ponad połowę potencjału energii na potrzeby sektora ciepłowniczego w Polsce. Opracowywane technologie efektywnej zamiany wilgotnej biomasy na ciepło, stanowią realną szansę na dekarbonizację krajowego sektora ciepłowniczego. Zastosowanie Absorpcyjnych Pomp Ciepła umożliwia odzyskanie ciepła ze spalin znacząco poprawiając efektywność procesu wytwarzania ciepła. Wzrost kosztów emisji dwutlenku węgla sprawia, że taka inwestycja jest wysoce opłacalna. W artykule opisano studium przypadku polegającego na porównaniu czterech wariantów technologicznych modernizacji kotłowni o mocy cieplnej 15 MW.

EN

Biomass accounts for more than half of the heating potential in Poland. The developed technologies for the effective conversion of wet biomass into heat constitute a real opportunity to decarbonize the domestic heating sector. The use of Absorption Heat Pumps enables deep recovery of energy from exhaust gases, significantly improving the efficiency of the overall process. The increase in the cost of carbon dioxide emissions makes such an investment highly profitable. Paper presents four technological options of 15 MW boiler station.

11

Waste Heat Recovery by Electric Heat Pump from Exhausted Ventilating Air for Domestic Hot Water in Multi-Family Residential Buildings

Cepiński Wojciech, Kowalski Piotr, Szałański Paweł

Rocznik Ochrona Środowiska

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2020

|

Tom 22, cz. 2

940--958

EN

The article discusses the possibility of recovering waste heat from the exhaust air from the ventilation system of multi-family residential buildings. A system of waste heat recovery from the extracted air with an electric heat pump was proposed for the preparation of domestic hot water (DHW). The proposed system has been analysed in TRNSYS 17 software for exemplary multi-family residential building. The influence of exhaust air humidity and heat pump outlet temperature on the energy effect was analysed. For the analysed case and the Polish conditions of electricity production, a possible reduction of the final energy amount for DHW preparation (EKW) by 35.1% and primary energy consumption (EPW) by 9.1% was determined in comparison with the use of a gas condensing boiler only. The factors influencing the energy effect of the system for the recovery of waste heat from the exhaust air were indicated. The authors specified directions of further research aimed at determining how to recover available waste heat from the exhaust air with lower energy expenditure and for which installations in the building they should be used.

PL

W artykule podjęto temat możliwości odzyskania ciepła odpadowego z powietrza wywiewanego z systemu wentylacyjnego budynków wielorodzinnych mieszkalnych. Zaproponowano system odzysku ciepła odpadowego z powietrza wywiewanego elektryczną pompą ciepła dla potrzeb przygotowania ciepłej wody. Zaproponowany system przeanalizowano w oprogramowaniu TRNSYS 17 dla przykładowego budynku wielorodzinnego. Przedstawiono wpływ wilgotności względnej powietrza wywiewanego i temperatury zasilania pompy ciepłej na efekt energetyczny. Dla analizowanego przypadku i polskich warunków produkcji energii elektrycznej, wyznaczono możliwe zmniejszenie zapotrzebowania energii końcowej na przygotowanie ciepłej wody użytkowej (EKW) o 35,1% i energii pierwotnej (EPW) o 9,1% w porównaniu z zastosowaniem tylko gazowego kotła kondensacyjnego. Wskazano czynniki wpływające na efekt energetyczny systemu do odzysku ciepła odpadowego z powietrza wywiewanego. Autorzy podali kierunki dalszych badań zmierzających do określenia jak odzyskać dostępne ciepło odpadowe z wywiewu przy mniejszym nakładzie energetycznym i do jakich instalacji w budynku je wykorzystać.

12

Gazowe promienniki podczerwieni w nowoczesnych magazynach spedycyjnych

Dudkiewicz Edyta

Nowoczesne Hale

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2020

|

Nr 2

34--39

PL

Magazyny ze względu na różne sposoby funkcjonowania wymagają indywidualnego podejścia do systemu grzewczego. W artykule przedstawiono znaczenie funkcjonalności magazynów w aspekcie ogrzewania i dane dotyczące zużycia w nich energii. Omówiono zasady projektowania ogrzewania z promiennikami gazowymi, parametry tych urządzeń i nowoczesne rozwiązania odzysku ciepła.

EN

Due to various functionalities, warehouses need an individual approach to the design of a heating system. The article presents the importance of the functionality of warehouses in the aspect of heating as well as data on their energy consumption. The principles of designing a heating system with gas-fired radiant heaters, the parameters of these devices and modern solutions of waste heat recovery are discussed.

13

Theoretical and Experimental Analysis of Thermoelectric Power Generation

Ruciński Adam, Rusowicz Artur

Journal of Power Technologies

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2020

|

Vol. 100, nr 3

250--254

EN

This paper deals with thermoelectric technology. Selected new semi conductors with improved figures of merit are presented. Peltier modules are used to generate electric current through temperature difference. The paper indicates applications of thermoelectric modules, as interesting tools for various waste heat recovery. There are zero dimension equations describing the conditions of electric power generation including voltage and current with characteristics of the above parameters. The authors are also interested in the efficiency of electric current generation. The experimental stand, on going research and experimental measurements are described. The authors explore the resistance of the receiver placed in the electric circuit with thermoelectric elements. Finally, the experimental results are analyzed and theoretical conclusions made. Voltage generationof about 1.5 to 2.5 V was observed in the range of temperaturę difference ΔT from 65 to 85K. Measurements were taken from a bismuth telluride thermoelectric couple, which is traditionally used in cooling technology.

14

Materiały termoelektryczne w odbiorze ciepła odpadowego

Zawadzka Ewa

Inżynieria Elektryczna

|

2020

|

nr 3

44--47

15

Improving the efficiency of a gas-fueled ship power plant using a Waste Heat Recovery metal hydride system

Cherednichenko Oleksandr, Tkach Mykhaylo, Timoshevskiy Boris, Havrysh Valerii, Dotsenko Serhii

Zeszyty Naukowe Akademii Morskiej w Szczecinie

|

2019

|

nr 59 (131)

9--15

EN

Due to environmental, energy, and operating cost constraints, the number of liquefied natural gas (LNG)–powered ships is increasing. To avoid decreasing the thermal efficiency of two-stroke, low-speed diesel engines, high-pressure gas injection is used. The specific energy consumption of a gas fuel compressor is around 0.35 kWh/kg, which has a negative impact on the efficiency of ship power plants. To reduce the primary energy consumption of a gas fuel supply system, waste heat recovery (WHR) technologies may be used. This study investigated whether WHR metal hydride technology was suitable for improving the efficiency of low-grade heat waste in marine diesel engines. The key factors of this technology were revealed, and the design scheme was described. Working fluids were also analyzed, and a mathematical model of a WHR metal hydride plant was developed, and the results were represented. The calculations showed that the above technology could increase the operating power of a propulsion plant by 5.7–6.2%. The results demonstrate the possibility of applying WHR metal hydride equipment for gas fuel compressor drives in LNG-powered ships. The novelty of this study lies in the investigation of metal hydride technology for application in the waste heat recovery systems of LNG-powered ships.

16

Controlling of train’s interior heating system for maximum energy efficiency

Bušs Dāvis, Eiduks Jānis

Transport Problems

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2019

|

T. 14, z. 3

121--134

EN

Heating systems in diesel multiple unit (DMU) trains often use additional mechanical and/or electrical auxiliary power, increasing fuel consumption, while waste heat is available from the diesel engine. Delivery of waste heat for heating of multiple carriages is analysed as realized in DR1 and D1 series trains, in light of the current standards of passenger comfort and in-depth testing of DR1B trains. A new hybrid hot air and electrical heating system and its control algorithm is reviewed for modernized DR1AC trains of Latvian railways, capable of extracting waste heat from three different sources and supplemented by two additional sources in case of shortage, for full conformance to EN 14750-1 standard. Results of factory testing are included.

17

Significant waste properties in terms of applicability in the power industry

Nowak Martyna, Stelmach Sławomir, Sajdak Marcin

Environment Protection Engineering

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2019

|

Vol. 45, nr 4

75--85

EN

The aim of the article is to present the physical and chemical properties of the refuse derived fuel (RDF) substrates, which have a significant impact on the energy recovery process in power plants. The experimental part includes technical (moisture and ash content, net and gross calorific values) and elemental analyses (sulfur, chlorine and mercury content), biomass and non-biomass concentration in the samples. In order to carry out the analysis of reactor slagging and fouling risk, chemical composition of the ash and characteristic ash fusion temperatures were determined. The waste samples are heterogeneous material and their properties are diversified – the moisture content ranges from 1.8 to 29.2 wt. %, the net calorific value from 17.231 to 28.307 MJ/kg, the ash content in the samples from 7.7 to 31.2 wt. %. The S content is in the range from 0.04 to 0.58 wt. %, the Cl content from 0.58 to 2.11 wt. % and the Hg content in the samples from 0.09 to 0.20 mg/kg. It can be observed, that the tested waste is a demanding fuel, because of its unfavorable fouling and slagging properties, which are directly related to the content of oxides with the basic properties.

18

Waste heat recovery from the air preparation room in a paint shop

Adamkiewicz Andrzej, Nikończuk Piotr

Archives of Thermodynamics

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2019

|

Vol. 40, no 3

229--241

EN

The policy of sustainable development seeks to improve energy efficiency of industrial equipment. Efforts to improve energy efficiency also apply to the paint shops, where the recovery of waste heat is sought. The main source of a large amount of low-temperature waste heat in the paint shop is the spray booth. The second place where a large amount of low temperature waste heat is released is the room where the compressed air is prepared. Low energy efficiency of air compressors requires a large electric power supply. As a result, the emitted large heat fluxes become waste energy of the technological process. Heat is equivalent to up to 93% of the electric power supplied in the air compression process. There are solutions for recovering heat from compressors coming from the oil cooling water, but then the waste heat from the cooling of the compressed air and from the electric motor is released into air in the room. A method for recovering low-temperature waste heat from the air preparation room by means of an air-source heat pump has been proposed. An energy balance of the air compression and dehumidification process for the paint shop was made. A Matlab’s built-in numerical model includes air compressor and dehumidifier, heat recovery and accumulation for the purposes of use in the spray booth. A simulation experiment was carried out on the effectiveness of heat recovery from the air preparation room. The use of combined energy management in paint shops was proposed.

19

Comparison of an impulse and a reaction turbine stage for an ORC power plant

Zaniewski Dawid, Klimaszewski Piotr, Witanowski Łukasz, Jędzejewski Łukasz, Klonowicz Piotr, Lampart Piotr

Archives of Thermodynamics

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2019

|

Vol. 40, no 3

137--157

EN

Turbine stages can be divided into two types: impulse stages and reaction stages. The advantages of one type over the second one are generally known based on the basic physics of turbine stage. In this paper these differences between mentioned two types of turbines were indicated on the example of single stage turbines dedicated to work in organic Rankine cycle (ORC) power systems. The turbines for two ORC cases were analysed: the plant generating up to 30 kW and up to 300 kW of net electric power, respectively. Mentioned ORC systems operate with different working fluids: DMC (dimethyl carbonate) for the 30 kW power plant and MM (hexamethyldisiloxane) for the 300 kW power plant. The turbines were compared according to three major issues: thermodynamic and aerodynamic performance, mechanical and manufacturing aspects. The analysis was performed by means of the 0D turbomachinery theory and 3D computational aerodynamic calculations. As a result of this analysis, the paper indicates conclusions which type of turbine is a recommended choice to use in ORC systems taking into account the features of these systems.

20

A case study of working fluid selection for a small-scale waste heat recovery ORC system

Klimaszewski Piotr, Zaniewski Dawid, Witanowski Łukasz, Suchocki Tomasz, Klonowicz Piotr, Lampart Piotr

Archives of Thermodynamics

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2019

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Vol. 40, no 3

159--180

EN

The paper illustrates a case study of fluid selection for an internal combustion engine heat recovery organic Rankine cycle (ORC) system having the net power of about 30 kW. Various criteria of fluid selection are discussed. Particular attention is paid to thermodynamic performance of the system and human safety. The selection of working fluid for the ORC system has a large impact on the next steps of the design process, i.e., the working substance affects the turbine design and the size and type of heat exchangers. The final choice is usually a compromise between thermodynamic performance, safety and impact on natural environment. The most important parameters in thermodynamic analysis include calculations of net generated power and ORC cycle efficiency. Some level of toxicity and flammability can be accepted only if the leakages are very low. The fluid thermal stability level has to be taken into account too. The economy is a key aspect from the commercial point of view and that includes not only the fluid cost but also other costs which are the consequence of particular fluid selection. The paper discusses various configurations of the ORC system – with and without a regenerator and with direct or indirect evaporation. The selected working fluids for the considered particular power plant include toluene, DMC (dimethyl carbonate) and MM (hexamethyldisiloxane). Their advantages and disadvantages are outlined.