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A simulation study for single and double effect absorption solar cooling systems operated under Taiwan climateShen, Jyun-long 09 September 2010 (has links)
Abstract
There is much rich solar energy in Taiwan situated at the subtropics;Therefore it¡¦s suitable for solar energy is utilized as the driving energy for
absorption cooling system. Simultaneously the use of solar energyreduces our dependence on fossil fuel ,and reaches the goal of energy conservation and reduction of carbon footprint deeply.After establishing
absorption cooling system in TRNSYS.16 platform, climate data TMY2 form for several cities of Taiwan are input to the simulation program. As a result of Taiwan climate variation, summer is getting more and more longer ; winter is getting shorter gradually .Hence we simulated program from March to October .Then system operating the parameters of solar collector area and the volume of the storage tank are varied to research those effects on the system performance. The research focuses on the simulation data for monthly solar fraction(f),seasonal solar fraction(F) as well as how much solar energy
saved could transform carbon dioxide content for single effect and double effect absorption cooling system operated under the climate of the major
cities in Taiwan .Those data could provide the design needs.
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The Application of Absorption Cooling Systems in Enhancing Power Generation CapacityLin, Dung-Lung, 09 June 2000 (has links)
It takes 3~5 years to finish a power plaint project including location, reliability, environment evaluating, investigation, etc. In addition, it is difficulty to get a right place and hinder by the environment protection. So, it is an important class on boosting the existing power generation capacity.
It was used to enhance power generation capacity by increasing the combustion chamber temperature in traditional way. However, it not only increases the exhaust temperature of gas turbine, but also increase the compressor ration. However, it is more difficulty on the design of gas turbine. And then we consider the other way in this thesis by reducing inlet air temperature of compressor to increase the density and flow of air and the power generation capacity. The result is magic that the power generation capacity enhance 10% ~20%.
The analysis of Combustion Turbine Inlet Air Cooling System by Absorption refrigerant system(CTIAC-ABS) describe in chapter 2 including fundamental of a gas turbine, the absorption refrigerant chiller, the inlet cooling coil and cogeneration system. It lets us know how to select the style of cogeneration and specification of an absorption refrigerant chiller.
It is important to consider the mass condensate water in the air side of inlet cooling coil. The author suggest to use the analysis method of wet-coil developed by Threlkeld(1970).
The CTIAC system could be used to the Gas Turbine System, Gas Turbine with HRSG System and Combined System. Because of there is not high pressure steam, we can use the fired-gas absorption refrigerant system as the source of chiller on the CTIAC-ABS system. There is the high pressure steam of Gas Turbine with HRSG System and Combined System. So we can divided the high pressure steam into two part, one to process and the other could be used as the heat source of absorption refrigerant chiller There are two advantages of using CTIAC-ABS on cogeneration power plaint.
1.The new purpose of mass high pressure steam could be used in cogeneration power plaint in Taiwan.
2.Reduction operational cost of CTIAC-ABS
The author finished the sensibility of power generation capacity with the analysis of practical operative data, classification of gas turbine and the power plaint Simulation program (GateCycle). When the compressor inlet temperature decrease from 30OC to 10OC, the results are : air flow rate increase 6.3%, fuel flow rate increase 5.95%, exhaust air temperature decrease 1.7% and exhaust air flow rate increase 6.3%, net power output increase 12.2%, heat rat decrease 3.7% and thermal efficiency upward 1.32%.Then, the author got a simulative equation of power capacity.
The typical gas turbines operate at full-load condition, 52.25% of annual hours, in 1998 in Taiwan. Gas turbines were almost full load on daytime and half-load or closed at night.
If we apply the CTIAC-ABS system on TPC's combined power plant, it can operate at 8:00~18:00 on daytime and shutdown at night. If there is high pressure steam in the cogeneration with HRSG, the CTIAC-ABS system can operate at the time that the cogeneration power plant is operative.
How to decide the capacity of absorption refrigerant chiller? The author decided the maximum capacity of absorption refrigerant chiller operating at 31OC , 80%RH of weather condition that limit by 2.5% ***. The author forecasts the lowest compressor inlet air temperature will be 10OC.
The steam double-effect CTIAC-ABS system could make the compressor inlet air temperature decrease from 30OC to 10 OC and enhances the heat rate 3.8%, the thermal efficiency 1.2%. The fired-direct CTIAC-ABS system also enhances the heat rate 5% and the thermal efficiency 1.5%. The results are close to the simulation of GateCycle program. So, the author compared the result of simulation with real data that the optimumal operative point of the CTIAC-ABS system is 10OC.
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Förutsättningar för absorptionskyla i Härnösand : En undersökning av tekniken samt en investeringskalkylStrömsten, Marcus January 2016 (has links)
Denna studie undersöker absorptionstekniken i syfte att ta reda på förutsättningarna för absorptionskyla i Härnösand. En investeringskalkyl har genomförts för att bedöma lönsamheten. I huvudsak har en litteraturstudie genomförts och för investeringskalkylen har nuvärdesmetoden använts samt att produktspecifikationer har efterfrågats från de största leverantörerna i världen. Resultatet visar att det finns två typer av kommersialiserade absorptionskylmaskiner på marknaden, varav den ena är tillämpbar för decentraliserad kylproduktion i fjärrvärmenät vid temperaturer kring 75 °C, och den andra för högre temperaturer kring 120-150 °C och lämpar sig därmed inte för decentraliserad kylproduktion. Det forskas och utvecklas kring andra mer avancerade tekniker och investeringskalkylen visar att en investering är lönsam beroende på storleken på absorptionskylmaskinen och försäljningspriset på kylan som levereras till kunden. Slutsatsen är att säljargument och en motivering måste tas fram varför kunden ska välja att få sin kyla levererad via en absorptionskylmaskin istället för en kompressorkylmaskin. / This study examines the absorption cooling technology in order to find the prerequisites of absorption cooling in Härnösand. An investment appraisal has been completed to ensure profitability. Mainly, a literature review has been conducted and the net present value decision rule has been used for the investment appraisal and product specifications have been requested from the main global suppliers. The result shows that there are essentially two absorption chillers commercialized in the market, one of which is applicable for decentralized cooling production in a district heating network at temperatures around 75 °C, and the second which is applicable for temperatures in the range of 120-150 °C and thus not suitable for decentralized cooling production. Research and development for more advanced techniques is ongoing and the investment appraisal shows that the profitability is depending on the size of the chiller unit and the selling price for the cooling energy. The conclusion is that a sale proposal and a motivation are needed on why the customer should choose to have their cooling delivered from an absorption chiller instead of a compressor chiller.
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Study on solar driven office cooling systemAlmouayad Alazm, Zafer January 2019 (has links)
No description available.
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Potential for Absorption Cooling Generated from Municipal Solid Waste in Bangkok : A Comparison between Waste Incineration & Biogas Production with CombustionHedberg, Erika, Danielsson, Helén January 2010 (has links)
This master’s thesis has been performed in Bangkok, Thailand at the company Eco Design Consultant Co., Ltd. The aim is to investigate the possibilities to generate absorption cooling from municipal solid waste in the Bangkok area. The investigation includes a comparison between waste incineration and biogas production with combustion to see which alternative is preferable. During the investigation, a Swedish perspective has been used. The research for the report mainly consisted of published scientific articles from acknowledged sources as well as information from different Thai authorities. Also, experts within different areas were contacted and interviewed. In order to determine which of the two techniques (waste incineration or biogas production with combustion) that is best suited to generate absorption cooling, a model was designed. This model involved several parameters regarding e.g. plant efficiency, amount of treated waste and internal heat usage. As for the results of the model, three parameters were calculated: the generated cooling, the net electricity generation and the reduced greenhouse emissions. The overall Thai municipal solid waste generation in Thailand is estimated to approximately 15 million tons per year and the majority of the waste ends up at open dumps or landfills. There are only two to three waste incinerators in the country and a few projects with biogas generation from municipal solid waste. The main electricity is today generated from natural gas which makes the majority of the Thai electricity production fossil fuel based. As for absorption cooling, two applications of this technique has been found in Thailand during the research; one at the Naresuan University and one at the Suvarnabhumi airport in Bangkok. The model resulted in that the best alternative to power absorption cooling technique is waste incineration. This alternative has potential to generate 3200 GWh cooling per year and 1100 GWh electricity per year. Also, this alternative resulted in the largest decrease of greenhouse gas emissions, ‐500 000 tons per year. The model also showed that the same amounts of generated cooling and electricity can never be achieved from biogas production with combustion compared to waste incineration. Regardless, waste incineration has an important drawback: the citizens of Thailand seem to oppose further development of waste incineration in the country. The biogas technique seems more approved in Thailand, which benefits this alternative. Due to the high moisture and organic content in the municipal solid waste, a combination between the two waste handling alternatives is suggested. This way, the most energy can be withdrawn from the waste and the volume of disposed waste is minimized. Our overall conclusion is that the absorption cooling technique has great potential in Thailand. There is an increasing power‐ and cooling demand, absorption cooling generated from either or both of the alternatives can satisfy these demands while reducing greenhouse gas emissions. We also believes that the cost for using absorption cooling has to be lower than for the current compression cooling if the new technique is to be implemented further.
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Adição de nanopartículas em um refrigerante secundário e sua influência no consumo específico de combustível em um grupo gerador dieselSANTOS, Kamylla Alexandre Leite dos 24 February 2016 (has links)
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Previous issue date: 2016-02-24 / A redução da disponibilidade de combustíveis e o aumento das restrições ambientais à emissão de poluentes, inerente à geração de energia, têm justificado o investimento em projetos industriais que minimizem seu consumo energético. A Petrobras é um dos maiores consumidores de energia do país e, dados os custos decorrentes das tarifas de energia, a geração própria sempre foi uma preocupação da Companhia. Nesse contexto os fluidos refrigerantes secundários, que possuem propriedades de transmitir calor a longas distâncias, são de especial interesse para unidades nessa área de desenvolvimento tecnológico. Os sistemas de refrigeração são empregados em diversos setores industriais, como nas petroquímicas, e em termelétricas utilizadas como unidades de cogeração em refinarias. Esses sistemas são constituídos, comumente, por compressores, trocadores de calor, torres de resfriamento, tubulações, bombas, ventiladores e instrumentação para controle. Uma “Unidade de Refrigeração” utiliza refrigerantes primários para armazenamento e transporte de calor ou frio a curtas distâncias em sistemas à compressão de vapor ou por absorção. Para o transporte de energia calorífica a longas distâncias são geralmente utilizados os refrigerantes secundários compostos de água e glicóis (anti-congelantes) ou salmouras e aditivos. Contudo, essas substâncias anticongelantes reduzem a capacidade calorífica e a condutividade térmica da água. Por outro lado, nanopartículas metálicas têm a propriedade de aumentar a condutividade térmica do meio onde são adicionadas. O presente trabalho investigou, através de experimentos em um arranjo experimental de bancada de testes de um grupo gerador diesel, a influência da adição de nanopartículas em uma solução de etilenoglicol utilizada como refrigerante secundário. Para isso utilizou-se injeções de água gelada, produzida por um chiller de compressão de vapor (R22), na linha de alta temperatura (HT) do motor do grupo gerador. Para armazenamento e registros dos dados foi utilizado um equipamento do tipo datalogger. Foram testadas diferentes set-points de temperatura de entrada da água da linha de HT no motor (64oC, 67 oC, 70 oC, 73 oC e 76 oC). Essas temperaturas foram testadas com água pura e com solução aquosa de etilenoglicol a 30%, sem e com a adição de nanopartículas (2%, 4% e 6%). Em todas as condições foram realizadas medidas do consumo específico de combustível e avaliadas as velocidades de resposta no sistema. Um percentual de 2,0% de nanopartículas, em volume, apresentou-se como ideal para o desempenho do nanofluido. Em função da ausência, no mercado brasileiro, de unidades de refrigeração por absorção com potência menor que 64 TR, foi elaborado um modelo dinâmico e simulado um chiller de absorção (H2O-LiBr), visando uma construção futura e utilização desse tipo de equipamento em escala piloto. / The reduced availability of fuel and increasing environmental restrictions on emissions, inherent in the power generation, have justified the investment in industrial projects that minimize their energy consumption. Petrobras is one of the country's largest energy consumers and, given the costs of the tariffs, the very generation has always been a concern of the Company. In this context the secondary refrigerants, which have properties of transmitting the heat over long distances, are of particular interest for technological development units in this area. Cooling systems are employed in various industrial sectors such as the petrochemical, and power plants used as cogeneration units in refineries. These systems are made, usually for compressors, heat exchangers, cooling towers, pipes, pumps, fans and instrumentation control. A "cooling unit" uses primary refrigerant for storage and transport of heat or cold at close range systems in the vapor compression or absorption. For the heat energy transport over long distances are usually used secondary refrigerants composed of water and alcohols (anti-freeze) or pickles and additives. However, such antifreeze substances reduce the heat capacity and thermal conductivity of water. Moreover, metal nanoparticles have the property of increasing the thermal conductivity of the medium in which they are added. This study investigated through experiments in an experimental test bench arrangement of a diesel generator set, the influence of the addition of nanoparticles in a solution of ethylene glycol used as secondary coolant. For this used ice water injections, produced by a vapor compression chiller (R22), in the high temperature line (HT) of the engine generator set. For storage and records of the data was used an equipment type datalogger. They tested different set-points for the HT line of the engine inlet water temperature (64 °C, 67 °C, 70 °C, 73 °C and 76 °C). These temperatures were tested with pure water and ethylene glycol 30% aqueous solution, with and without the addition of nanoparticles (2%, 4% and 6%). In all conditions were performed measurements of specific fuel consumption and evaluated the response speeds in the system. A percentage of 2.0% nanoparticles by volume was presented as ideal for the performance of nanofluid. Due to the absence, in the Brazilian market of refrigeration units by absorbing less power than 64 TR, it designed a dynamic model and a simulated absorption chiller (H2O-LiBr), aimed at future construction and use of such equipment in pilot scale.
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Design of a solar cooling system for Iraq climateFakhraldin, Shahen Mohammed January 2016 (has links)
With the objectives of designing a solar cooling system with cold storage unit for the Iraqi climate, solar energy resources were assessed and methods were proposed to enhance harvesting the solar energy in the Iraqi climate. Where the results showed that adopting monthly average optimal tilt angles led to an increase in the amount of useful solar energy gained nearly 9%. A methodology of multi objective optimisation of solar absorption cooling system was then developed and demonstrated by applying it in a domestic application in Baghdad. Maximising the system performance in exergy, economic and environment were the objectives of the project. A decision-making tool was then implemented to select the most suitable design. The optimal proposed system has exergy efficiency of 56%, total cost rate of 4.19US$/hr, annual CO2 emission of 32199kg and payback period of 18.7years. After analysing the optimal configuration of the system, a cold thermal energy storage unit with the solar absorption cooling system was suggested in order to store the cold energy produced by the system at times when the solar energy is available (at daytime) and use (discharge) it at times when there is no solar energy available (at night). Next, a new control strategy was developed and applied in the system to make it more cost effective. Five scenarios were considered to manage the quantity of charging of the cold storage tank according to the splitting rate of the mass of the supplied chilled water by the chiller to the cold storage tank and the building. Finally, the chosen optimal system that uses an efficient controlled cold thermal energy storage, has exergy efficiency of 69.4%, total cost rate of 4.25US$/hr and total avoided annual CO2 emissions of 33.9% less than system without cold storage tank. Additionally, without any government incentive, the payback was recorded 9.3years, which was 50% less than the system without cold storage tank.
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Absorption cooling in district heating network: Temperature difference examination in hot water circuitYuwardi, Yuwardi January 2013 (has links)
Absorption cooling system driven by district heating network is relized as a smart strategy in Sweden. During summer time when the heating demand is low, the excessive hot water can be directly sold to drive absorption chillers instead of decreasing its production. In addition, this is also one answer to satisfy the cooling demand in more environmentally way since currently only around 26% of cooling demand in Sweden is satisfied by district cooling, the rest is fulfilled by individual air conditioning. Realizing this potential, the purpose of this study is to examine the returning hot water temperature in the district heating network with supply temperature of 70°C and also the effect to the absorption chiller’s COP. Through the simulation result, it is found out that the lowest possible returning water temperature is 55 °C at COP 0,69 with heat rejection (re-cooling) temperature water at 22 °C. This implies that the desired returning hot water temperature of 47 °C cannot be achieved. The lower returning hot water temperature is preferable since it gives the district heating network benefit in term of less distribution pump work, and energy recovery for the condensation process at central heating plant.
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Techno-Economic Assessment of Solar PV/Thermal System for Power and Cooling Generation in Antalya, TurkeyKumbasar, Serdar January 2013 (has links)
In this study a roof-top PVT/absorption chiller system is modeled for a hotel building in Antalya, Turkey to cover the cooling demand of the hotel, to produce electricity and domestic hot water. PVT modules, an absorption chiller, a hot storage tank and a natural gas fired auxiliary heater are the main components of the system. Elecetrical power produced by the system is 94.2 MWh, the cooling power is 185.5 MWh and the amount of domestic hot water produced in the system is 65135 m3 at 45 0C annually. Even though the systems is capable of meeting the demands of the hotel building, because of the high investment costs of PVT modules and high interest rates in Turkey, it is not economically favorable. Using cheaper solar collectors, integrating a cold storage unit in the system or having an improved conrol strategy are the options to increase the system efficiency and to make the system economically competitive.
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Energy supply system for a high-rise building in Germany : Optimization of a heating and cooling supply system made with plant simulationsAlmén, Ida, Johansson, Elin January 2022 (has links)
The building sector has great potential for energy savings since it is responsible for nearly a third of the global energy use. As oil, coal and natural gas continues to hold a big share of the energy mix it is important to work towards introducing more renewable energy alternatives. For an energy supply system, it is common to use a multi-energy system to increase efficiency. By increasing efficiency and the use of renewable energies, the total energy consumption can be lowered, and emissions can be reduced. The purpose of this thesis was to design a multi-energy supply system for a high-rise building in Germany with low emissions. This was executed by constructing a simplified design used as a reference, also referred to as option 1, and two other designs with different energy sources, called design 1 and design 2. The design layout was constructed in collaboration with Transsolar. Design 1 is using a compression chiller and is presented as three different variants, option 2, 3 and 4. The three options were created to evaluate the pros and cons of a larger cold water storage tank and sizing of the compression chiller. Design 2, option 5, is using an absorption chiller and this option was created to investigate the opportunity to use district heating. Simulations were made of the designs with the simulation tool TRNSYS and presented in graph form. Values provided from the simulations were then used to calculate emissions, investment costs and net present value over a period of 40 years. For the net present value, three different variants were presented. One without carbon costs taken into consideration, one with low carbon costs and one with high carbon costs. The result was evaluated, and comparisons were made to suggest the most sustainable option for the building. The result of design 1, which has a natural gas boiler for peak heating demand and a compression chiller as cold energy source, shows that the chiller produces a higher capacity compared to the installed value during the summer and a lower value during the winter. The norm capacity of the chiller in design 1 was 175 kW when combined with a larger cold water storage and 410 kW with no cold water storage. Comparison of those options showed that it is economical to install a cold water storage since the investment cost of the chiller is lowered. However, it also showed that a higher capacity of the chiller lowered the need for the gas boiler, because of the parallel heating and cooling characteristic of the chiller, which reduces emissions. Another option was made with a larger cold water storage implemented and an over dimensioned capacity of 340 kW for the chiller to reduce the gas needed for heating. For the option with the 175 kW compression chiller the gas boiler needed to supply 15% of the heating load of the building, while the option with the 340 kW compression chiller needed 3% of the buildings heating load to be provided by the gas boiler. This decrease in the gas boiler dependency reduced the emissions for heating from 52 ton/year to 41 ton/year, while still having comparable cost over time with low carbon costs and lower cost with high carbon costs. Therefore, the option with an over dimensioned chiller with an implemented big cold water storage is the favourable one, since it has the lowest emissions of the options of design 1 and is economically justifiable. Design 2 has one of lowest investment cost and the lowest emissions which was 61% lower than the reference design and 19% lower than design 1. With higher carbon costs option 5 is the cheapest, otherwise it is relatively similar to the other options. Hence, Design 2 is the system that is suggested to use for the building. / Byggnadssektorn står för nästan en tredjedel av den globala energianvändningen och har därför stor potential till energibesparing. Eftersom en stor del av energimixen består av olja, kol och naturgas är det viktigt att sträva mot att introducera mer hållbara energikällor. För ett energisystem är det vanligt att använda sig av mer än en energikälla för att öka effektiviteten. Med ökad effektivitet i kombination med förnyelsebara energikällor kan den totala energikonsumtionen, samt utsläppen, minska. Målet var att designa ett energisystem med fler än en energikälla och låga utsläpp för ett höghus i Tyskland. För att göra det konstruerades en förenklad design, också kallad option 1, som användes som en referensdesign samt två andra designer, kallade design 1 och design 2, med olika energikällor. Designförslagen togs fram i samarbete med Transsolar. Design 1 använder sig av en kompressionskylmaskin och har tre olika varianter, option 2, 3 och 4, som gjordes för att utvärdera för- och nackdelar med en stor kallvattentank för energilagring och för att bestämma storleken på kompressionskylmaskinen. Design 2, option 5, använder sig av en absorptionskylmaskin och skapades för att undersöka möjligheten att använda sig av fjärrvärme. Simuleringar gjordes för design 1 och 2 med hjälp av simuleringsverktyget TRNSYS där resultatet presenterades i grafer. Värdena tagna från simuleringarna användes till att beräkna utsläpp, investeringskostnad och nuvärdet för den totala kostnaden över 40 år. Nuvärdet beräknades utan att ta emissionskostnader i åtanke, med en lägre emissionskostnad samt med högre emissionskostnad. Resultatet utvärderades och jämfördes för att kunna framföra ett förslag om vilket av alternativet som passar byggnaden bäst. Resultatet från design 1, som har en naturgaspanna för att försörja toppvärmebehovet och en kompressionskylare för kylbehovet, visar att kompressionskylaren uppnår en högre kapacitet jdän den installerade kapacitet under sommaren och lägre kapacitet under vintern. För varianten med en större kallvattentank kunde kylarmaskinens kapacitet bestämmas till 175 kW medan den behövde en kapacitet på 410 kW för varianten med en liten kallvattentank. Vid jämförelse av de två varianterna visas att kostnaderna minskades för alternativet med kallvattentanken eftersom den krävde en lägre kapacitet för kompressionskylaren. Däremot visades det att utsläppen minskar vid användning av en större kylmaskin eftersom det minskar värmebehovet från gaspannan eftersom kylaren kyler och värmer parallellt när den är i drift. Den tredje varianten som både använder en stor kallvattentank samt en överdimensionerad kylare på 340 kW skapades för att minska gasanvändningen. Alternativet med en kylare på 175 kW behövde att 15% av värmebehovet kom från gaspannan, medan kylaren på 340 kW behövde att 3% av värmebehovet kom från gaspannan. Reduceringen av gasanvändningen sänkte utsläppen från 52 ton CO2-ekv./år till 41 ton CO2-ekv./år, med en jämförbar kostnad över tid med ingen eller låg emissionskostnad och lägre kostnad över tid med hög emissionskostnad. Alternativet med en stor kallvattentank och överdimensionerad kompressionskylare är därför det mest passande alternativet av design 1 eftersom den har lägst utsläpp medan den är ekonomiskt försvarbar. Design 2 har en av de lägsta investeringskostnaderna och har lägst utsläpp som är 61% lägre än referensdesignen och 19% lägre än design 1. Med högre emissionskostnader är design 2 billigast, annars har den jämförbara kostnader. Därmed föreslås att byggnaden ska använda design 2.
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