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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

ANALISYS AND ENERGY SAVING MEASURES OF KASTVALLEN ICE HOCKEY RINK ARENA

Igual Bueno, Mario, Bielsa Azcona, Jose Enrique January 2012 (has links)
Nowadays efficiency measures are more and more important because the price of the energy is increasing every year. Moreover, saving energy it is also important for decrease the environmental impact. Kastvallen is a hockey arena built in 1997 that cools the hockey rink with electric compressors. The changing rooms are heating by using district heating. Actually the total invoice of electricity is above the 800000 SEK. Meanwhile the district heating invoice reaches the 60000SEK. The aim of this project is reducing the amount of the electricity and heat invoice promoting smart energy improvements. The improvements proposals can be divided in three sections; energy savings of the changing rooms, efficiency increase of the compressors and dehumidifier energy savings. For heat the tap water and the changing room’s ventilation it is suggested to take profit from the heat released at the condenser and so reduce its heat load requirements. For this proposal two different configurations are studied. In order to increase the efficiency of the compressors the possibility of reducing the condenser temperature will be studied. Three proposals will be studied to carry out this commitment; Installing a condensing temperature control, installing a evaporate cooler and having a snow storage. Finally, one of the largest consumers of electricity in Kastvallen ice hockey rink is the dehumidifier. The current dehumidifier works with a desiccant wheel. The desiccant material extract the moisture from the processed air flow, after that the desiccant has to be reactivated with ‘fresh air’. This reactivation air needs to be heated 95ºC, so the waste air released after the reactivation of the desiccant is air at high temperature. The first proposal is preheat the reactivation air with the hot waste air in order to reduce the heating requirements, conducting this proposal the total money saved each year would be 41811 SEK with a Pay-back around 1 year. The second step is studied the possibility of heating the air with district heating, taking into account that district heating is three times cheaper than electricity, conducting this proposal the total money saved each year would be 45629 SEK with a Pay-back around 1 year. The last proposal is to combine preheating and heating with district heating, conducting this proposal the total money saved each year would be 61553 SEK with a Pay-back around 1.6 years. All the previous energy improvements proposals are studied with empirical and analytical methods and using the knowledge gained during the previous years of studies. The study concludes that the best proposal for the dehumidifier is combine the preheating and heating with district heating. In addition of the money saved, this measure allows to save 2.71 Tm of CO2 each year. For the refrigeration cycle, the study concludes that installing a controlled temperature control is the best option if the price of that is lower than 334726 SEK. If not the best option is heating the rooms and the ventilation with the condenser of the refrigeration cycle. These measures could reduce between 8% and 20% of the total energy invoice plus a considerable reduction of CO2 emissions. Evaporative cooling and snow storage would be studying after with the data of the first year of the condensing temperature control; if it is installed.
2

EVALUATION OF THE MOISTURE APPEARENCE IN THE ICE RINK FACILITIES BASED ON OBSERVATION STUDIES AND PERFORMED SIMULATIONS IN HYGROTHERMAL SOFTWARE

Kucharczyk, Lukasz January 2017 (has links)
In the paper, there are presented issues related to the ice rink venues. These widely known objects,all around the world,are one of the most complex types of the public buildings. It is caused mainly by the thermal conditions, which prevails in such objects but also energy demand needed for operational processes. Range of indoor temperatures may vary from -5oC in place of ice pad and close to it, up to +20oC in dressing rooms, offices or tribunes for the spectators. Like any other buildings, the same ice rink venues should meet the conditions and provide proper indoor environmental quality (IEQ) for every user of the object. It is mainly performed by the appliance of the newest technology, which is taking care and control aspects like: temperature, relative humidity, energy usage, lighting etc. In this document, there are presented 5 ice rink facilities,which were taken into account, in order to check if there are providing comfortable and proper conditions indoors. All the investigated halls were in the City of Stockholm. In order to obtain require data, some professional tools were used including infrared camera and moisture meter. The registered data was including the average temperature of the indoor air and level of relative humidity. Based on this data, the dew point temperature has been calculated. Another aspect of the work was carrying out simulations of the typical ice rink wall construction and finding the best possible placement for the vapour barrier. In these case, the simulation had been performed in the different cities located in Sweden. Function of this layer is mainly to inhibit the migration of the water vapor and to protect the thermal insulation layer from dampness. However, installed in wrong place in the wall composition may give rise to serious problems related to moisture and humidity. By using WUFI software, it was possible to present hygrothermal conditions like: relative humidity, dew point temperature and water content of the individual component of designed wallin relation to different placement of damp proofing material.
3

Konstrukce zastřešení kluziště / Roof construction over scating ring

Pospíšilová, Lenka January 2015 (has links)
This document describes the design of the roof structure for the dimensions of the rink. It was designed and evaluated three roofing solutions – steel truss structure, concrete arch with external prestress and prestress truss roof girder with concrete roof panel. One option was selected – prestress truss girder. This variant has been further developed. In the beginning was drafted several proposals geometry respecting the demands on the type of construction. Within the static calculation was created a mathematical model of the structure of the program Scia Engineer. Using this model were obtained values needed for the assessment of individual elements of construction and design assessment as a whole for the ultimate limit state and usability. According to the proposed geometry and opinions parts of the structure was drawing documentation structure as a whole and individual parts of the structure solved in this thesis. The last proposal was visualized structures together with the phases of the construction by program ArchiCAD and rendered by program Artlantis.
4

Carbon dioxide in ice rink refrigeration

NGUYEN, TUYET January 2013 (has links)
The average energy consumption of one ice rink is around 1000MWh/year, which approximately69% is occupied by the refrigeration unit and heating demand. With the aim of decreasing theenergy consumption, a new concept of refrigeration system with CO2 as a refrigerant has beendeveloped and it is promising to become a high potential next generation for refrigeration systemin ice rink.This thesis is to evaluate a new refrigerant application in ice rink refrigeration system underthree different aspects; energy performance, heat recovery potential and economic efficiency. Inorder to make this evaluation, three main tasks are executed. Firstly, literature review and marketstatistic are processed to give a general picture of the CO2 development as a refrigerant. Secondly, asoftware Pack Calculation II is used for the simulations of CO2 refrigeration system and traditionalice rink refrigeration system. Älta ice rink located in Sweden, is chosen as a reference case forsimulation’s input data. The simulation results is to compare these system in terms of energyperformance and heat recovery potential. Finally, life cycle cost of these systems is calculated toinvestigate the economic benefits from this new application.Results from this study show good benefits of the new CO2 application in ice rink. Fromthe market statistics, CO2 has become a successful refrigerant in supermarket food and beverageindustry with 1331 CO2 refrigeration system installed until 2011 in Europe (Shecco2012). In icerink industry, 24 ice rinks have been applied CO2 in the second cycle of refrigeration system; oneice rink in Canada applied a refrigeration system with only CO2 in the first cycle and the distributionsystem.From the simulation’s result, CO2 full system has been proven as the most efficiency sys-tem with the lowest energy consumption (30% lower than NH3/Brine system and 46% lower thanCO2/Brine system) and the highest COP (6.4 in comparison with 4.9 of NH3/Brine system and4.37 of CO2/Brine system). Regarding heat recovery potential, CO2 full system has highest energysaving in comparison with the other two systems.Due to lower energy cost and service cost, the life cycle cost of CO2 full system is loweraround 13% than the traditional NH3/Brine system, furthermore, the component cost of CO2 sys-tem is promising to decrease in the next years thanks to the rapid development of this market insupermarket industry.To conclude, CO2 full system has high potential to become a next generation of refrigerationsystem in ice rink, however, because of its transcritical working, this application can be restrictedin the regions of warm climate.
5

MEASUREMENT AND MODELLING OF ICE RINK HEAT LOADS

Karampour, Mazyar January 2011 (has links)
Ice rinks are among the most energy intensive public buildings in developed and developing countries. According to a research on Swedish ice rinks; a typical ice rink consumes approximately 1185 MWh/year which leads to more than 300 GWh/year for the 342 Swedish indoor ice rinks. The refrigeration system is usually the largest consumer by 43% average share of the total energy consumption.  To decrease the refrigeration system energy demand, there are a variety of energy efficiency techniques known and available but the key to select the best ones is finding the major heat loads on the ice sheet and refrigeration system, which is unique for each ice rink. To fulfil this objective and in addition to review literature, this study has two main approaches. The first approach is to measure and evaluate the performance of the refrigeration system in two ice rinks, called Norrtälje and Älta. The estimated cooling capacity is approximately equal to the total heat load on the ice plus the heat gains in the distribution system. This goal has been accomplished by using a performance analyser called “ClimaCheck” which is based on an “internal method” because it uses the compressor as an internal mass flow meter and consequently, there is no need for an external one. The refrigerant mass flow rate is calculated by an energy balance over the compressor. By knowing the mass flow, enthalpy of the refrigerant, etc. the cooling capacity and COP of the system can be calculated. While the total heat load is known by the first approach, the second approach tries to discover different heat loads shares by analytical modelling. The measured physical and thermodynamical parameters plus the ice rink geometrical characteristics are input to the heat transfer correlations to estimate the heat load magnitude. The results of the measurements show that the total energy consumption in Norrtälje is about two third of Älta. The main reasons for this less energy consumption are smarter control systems for compressors and pumps, better ventilation distribution design and 1°C-2°C higher ice temperature.      Analytical modelling for a sample day has estimated that about 84% of the total heat loads is originated from the heat loads on ice sheet while the distribution system causes the remaining 16%. Moreover, calculations show that convection plus small portion of condensation (altogether 36%), radiation (23%), ice resurfacing (14%) and lighting (7%) are the largest heat loads in winter while in summer condensation is another significant heat load (10%). Comparing two six-hour periods, one without ice resurfacing and four resurfacings in the second one, 30% more cooling demand has been calculated for the second period. Furthermore, it has been shown that the evaporator to brine is the contributor for 66% of the heat transfer resistances from ice to evaporator while brine to bottom ice and bottom to top ice accounts for 27% and 7% respectively. To conclude, a parallel “performance analysis of the refrigeration system” and “heat loads estimation” proves to be a useful tool for adopting proper design and control for energy efficient operation. / Stoppsladd financed by Swedish Energy Agency (Energimyndigheten) and Swedish Ice Hockey Association
6

Technology and Energy Inventory of Ice Rinks

Makhnatch, Pavel January 2011 (has links)
Currently 341 ice rinks are in operation in Sweden with an estimated total energy consumption of 384 GWh/year. As it has been revealed in previous studies, most of the ice arenas are constructed and/or not operated efficiently. Thus it is considerable energy saving potential, which could be achieved in this area. The potential is even more significant if one can consider the savings in the ice rinks all over the world. This report is an in-depth study, which aims at analysing the Swedish ice rinks energy consumption and estimation of the corresponding energy saving potential. The report analyses the energy statistics obtained through the Stoppsladd study, which includes the ice rinks inventory, data collection and compilation of energy relevant data for 100 ice rinks located in Sweden. The inventory has revealed a number of important statistical figures, such as total energy consumption average in total (estimated to be 1,137 MWh/year) and for different ice arenas categories in particular. Relevant specific energy consumption values as well as a number of other important figures are also provided in the paper, thus giving an idea on the way to minimise energy consumption at each specific ice rink. The results are additionally supported by statistical multifactor regression analysis, which resulted in a relation between the ice rink’s total energy consumption and some known factors values affecting it. Two in-depth studies fulfil the Stoppsladd project by analysing water quality and ice quality effect on the ice rink’s energy consumption and investigation of the static and dynamic heat flow distribution in ice rink slab. A static heat flow distribution model of an ice rink evaluated the effect of concrete  with different properties on temperature and heat flow distribution within an ice rink floor slab. The study proves that the ice rink refrigeration system COP2 could be increased with 3.5 % just implementing new high thermal conductivity concrete layer into the conventional concrete ice rink floor. The static analysis results were further completed with dynamic analysis, which adequately reflects the thermodynamic response of the concrete ice rink floor to a varying heat load. As a result, the thesis represents a holistic approach to the ice rink energy efficiency increase problem and provides a good basis for further studies in relevant areas. It is proved that modified concrete allowing higher (efficient) secondary refrigerant tempera­tures and also provides better response to change in heat load to the system. / Stoppslad
7

Stora författare från periferin : En jämförande studie mellan minoritetslitteratur från Friesland och Svenskfinland, med romanerna de fûke (1966) och Där vi en gång gått (2006) som utgångspunkt

Deelstra, Oetze Theodoor January 2016 (has links)
This master’s thesis considers the differences between the minority literature from Friesland, a province in the northwest of the Netherlands, and that of the Swedish-speaking part of Finland. The author of this paper tries to draw attention to the literatures of those minorities, which often are not well-known outside their own regions. The main issue discussed in this paper is: How is minority culture problematized in the novels de fûke (1966) by the Frisian author Rink van der Velde and Där vi en gång gått (2006) by the Finland-Swedish author Kjell Westö? The Frisian population in the Netherlands is considered by many as a very old people, because famous writers of the Roman Empire, such as Pliny the Elder, wrote specifically about their region and its people. Despite this, the Frisian language has been in a peripheral situation for many centuries. The Swedish minority in Finland, on the contrary, is much younger. Finland gained autonomy in 1809 and before that time the region currently known as Finland, was the eastern part of the Kingdom of Sweden. This meant that Swedish was the predominant language until that year. Later on Finnish became the main language in Finland. However, both the Frisian and the Finland-Swedish literature were not established before the nineteenth century. This changed partially as a result of ideas of the Romanticism, but also because of historical reasons. By analyzing the previously mentioned novels, Oetze Deelstra shows how the minorities in both countries fare in opposite situations. The Swedish-speaking population has often been, and continues to be, examined as upper-class. On the other hand, in Frisia should a very old countryside culture has been preserved. Those ideas have been important in forming the images of both minorities. A noticeable distinction is that the Frisian literature is defined by language, while the Finland-Swedish literature is characterized by political and ideological arguments. / Dizze masterskripsje rjochtet him op de ferskillen tusken de literatuer fan Fryslân en dy fan de Sweedsktalige minderheid yn Finlân. De skriuwer fan dit wurk besiket op dy wize mear omtinken te freegjen foar de literatuer fan dizze minderheden, dy’t faak net sa bekend is bûten de eigen regio. De fraach dy’t sintraal stiet is: Op hokker wize wurdt stal jûn oan minderhedeproblematyk yn de romans de fûke (1966) fan de Fryske skriuwer Rink van der Velde en Där vi en gång gått (2006) fan de Finlânsweedske skriuwer Kjell Westö? Faak wurde de Friezen beskôge as in âld folk. Mooglik komt dat trochdat se al neamd wurde soene troch ferneamde skriuwers fan it Romeinske Ryk, lyk as Plinius de Aldere. Dochs hat it Frysk iuwenlang in net al te wichtige rol spile yn Fryslân en dêrbûten. De Sweedske minderheid yn Finlân is lykwols folle jonger. Finlân is pas sûnt 1809 autonoom en foar dy tiid wie dat wat wy hjoed-de-dei Finlân neame, it eastlike diel fan it Sweedske Ryk. Dat betsjut ek dat it Sweedsk oant doe ta de oerhearskjende taal wie. Letter waard it Finsk de wichtichste taal yn Finlân. Sawol de Fryske as de Finlânsweedske literatuer wiene lykwols net fêstige foar de njoggentjinde iuw. Dat feroaret pas yn de Romantyk, foar in diel fanwege de idealen út dy tiid, mar ek om politike redenen. Troch de earderneamde romans te analysearjen, lit Oetze Deelstra sjen hoe’t de minderheden fan beide lannen eins yn tsjinstelde situaasjes operearje. De Sweedsktalige befolking fan Finlân is faak, en wurdt no noch hieltyd, besjoen as de boppeklasse. Yn Fryslân soe oan ’e oare kant in iuwenâlde lanboutradysje bewarre bleaun wêze. Dizze opfettings hawwe wichtich west foar de byldfoarming fan beide minderheden. In opfallend ferskil is dat de Fryske literatuer fan de eigen taal út definiearre wurdt, wylst de Finlânsweedske literatuer karakterisearre wurdt troch politike en ideologyske útgongspunten.
8

Analýza zimního stadionu Mělník a návrh marketingového plánu / Analysis of the ice hockey stadium in Mělník and the proposal of marketing plan

Krejsa, Jiří January 2015 (has links)
Title: Analysis of the ice hockey stadium in Mělník and the proposal of marketing plan Objectives: The aim of this work is to elaborate analyzes of the state of the ice hockey stadium in Melnik and to create a proposal of a marketing plan for the stadium. The plan should serve to a more efficient functioning of the entire ice rink in the following years. Methods: The work analyzes years 2011-2013 where it focuses on the utilization of the ice surface, public skating hours and skating schools and analysis revenues and expenditures in the same period. Interviewing visitors, and competitive analysis of stadiums around Melnik were carried out. All values obtained from analyzes were subsequently compared with the national average values obtained from KPMG research. Results: The analyses identified the potential in greater efficiency of utilization of the ice surface and rental of advertising space. When comparing public financing is Melnik's stadium to the national average in the same size cities it turns out that Melnik's stadium is underfunded. The whole proposal of the marketing plan was compiled into 4 main sections aimed at attracting potential sponsors, increased use of ice rinks in the months of September to March, an increase in attendance of public skating and skating schools in the same...
9

Modeling the evolution of agricultural land markets / Žemės ūkio paskirties žemės rinkų raidos modeliavimas

Aleknavičius, Marius 04 December 2007 (has links)
This is a summary of doctoral dissertation. Dissertation represents analysis of agricultural land markets development. The analysis was performed by proposing a complex analytical model system and applying it for the investigation of land market development and evolution in Lithuania. / Tai yra daktaro disertacijos santrauka. Disertacijoje pateikiama žemės ūkio paskirties žemės rinkų raidos analizė, pagal apžvelgtą teorinę medžiagą pasiūlant kompleksinę tyrimų schemą ir pritaikant ją Lietuvos žemės rinkos kūrimuisi ir vystymuisi tirti.
10

Secondary Fluids Impact on Ice Rink Refrigeration System Performance / IMPACT DES PROPRIETES THERMO-PHYSIQUES DES FRIGOPORTEURS SUR LES PERFORMANCES DE LA PRODUCTION DE FROID DANS LES PATINOIRES

Mazzotti, Willem January 2013 (has links)
Sweden has 350 ice rinks in operation which annually use approximately 1000 MWh each. Therefrigeration system usually accounts for about 43 % of the total energy consumption which is the largestshare of the major energy systems. Besides improving the facilities one-by-one, it is important todistinguish common features that will indicate the potential energy saving possibilities for all ice rinks.More than 97 % of the Swedish ice rinks use indirect refrigeration systems with a secondary fluid.Moreover, the thermo-physical properties of secondary fluids directly impact the heat transfer andpressure drop. Thus, assessing and quantifying their influence on the refrigeration system performance isimportant while estimating the energy saving potential for the ice rinks.A theoretical model as well as two case studies focusing on the importance of the secondary fluid choiceare investigated. The theoretical model calculations are performed assuming the steady-state conditionsand considering a fixed ice rink design independently on the secondary fluid type. Hence, they can becompared on the same basis. According to this theoretical model, the refrigeration efficiency rankingstarting from the best to the worst for secondary fluid is: ammonia; potassium formate; calcium chloride;potassium acetate; ethylene glycol; ethyl alcohol; and propylene glycol. Secondary fluids can be ranked inexactly the same order starting from the lowest to the highest value in terms of the dynamic viscosity. Itwas shown that potassium formate has the best heat transfer properties while ammonia leads to the lowestpressure drops and pumping power. Propylene glycol shows the worst features in both cases. Ammoniaand potassium formate show respectively 5% and 3% higher COP than calcium chloride for typical heatloads of 150 kW. When controlling the pump over a temperature difference ΔT, the existence of theoptimum pump control or optimum flow was highlighted. For common heat loads of 150 kW thisoptimum pump control ΔT is around 2,5 K for calcium chloride while it is around 2 K for ammonia. It isshown that the secondary fluids having laminar flow in the ice rink floor pipes have a larger share in theconvection heat transfer resistance (~20-25 %) than the secondary fluids experiencing turbulent flow (~3%).One of the case studies shows a potential energy saving of 12 % for the refrigeration system whenincreasing the freezing point of the secondary fluid. An energy saving of 10,8 MWh per year was foundfor each temperature degree increase in the secondary fluid freezing point.

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