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4110 Uppsatser om Heat stress - Sida 1 av 274

Äldreboendet på Zakrisdal : En studie om solvärme med säsongslagring

A home for elderly is planed to be built at Zakrisdal, Karlstad, Sweden. The heat source for the building was at the time not determined. In order by the local government of Karlstad this report is meant to examine if the need of heat could be provided only by solar heat combined with a seasonal heat storage. The problem to solve is, if the need of heat from the home for elderly is provided from only solar heat, whitch dimensions of the solar collectors and the storage is needed?.

Norrkila arena : visuell beskrivning av arena

A home for elderly is planed to be built at Zakrisdal, Karlstad, Sweden. The heat source for the building was at the time not determined. In order by the local government of Karlstad this report is meant to examine if the need of heat could be provided only by solar heat combined with a seasonal heat storage. The problem to solve is, if the need of heat from the home for elderly is provided from only solar heat, whitch dimensions of the solar collectors and the storage is needed?.

En studie av Uppsala stads värmeö

The urban heat island is an area restricted to a city center where the temperatureis higher than its surrounding environment. The greatest temperature difference isfound at night when the weather is calm and the sky is clear of clouds. There are twomajor causes behind this phenomena and the first one is the use of energy forheating of houses. The heat leaks through the walls of the buildings and warms upthe surrounding mass of air. The second one is the use of building material whichstore the suns radiation on daytime and releases the heat during night.

Kylapotentialen i Drefviken för Vattenfall Heat AB

Vattenfall Heat AB is a district heat provider in Drefviken, but has yet to establish any cooling systems in this area. This thesis examines the potential client base within the area today and over the coming 20 years. The feasibility of the most common cooling technologies is evaluated and results show a total potential for an installed capacity of 30 MW providing 50 GWh of cooling per year. One of the examined areas shows good prospect for heat driven absorption chillers during the summer months when the heat load is limited..

Frånluftsvärmepumpens möjligheter i flerbostadshus

If a building is heated by a heat pump, it is of high importance that the heat pump has a high coefficient of performance. An exhaust air heat pump extracts heat from the building?s exhaust air. The air has a relatively high and constant temperature all year around, leading to a high seasonal coefficient of performance. This thesis examines whether it is profitable to complement an exhaust ventilation system with an exhaust air heat pump in an apartment block that already has geothermal heat pump, district heating, oil- or biofuel heated system.

Restvärmeåteranvändning från absorptionsvärmepumpar : en kartläggning av möjligheter och begränsningar vid Vattenfall Värme Uppsala Block 5

Vattenfall district Heating power plant in Uppsala produces district cooling with absorption heat pumps which leads to a large amount of waste heat that has to be cooled with evaporative cooling towers. The Environmental Court has ordered Vattenfall to survey the possibilities to recover the heat, which is the focus of this thesis.The study begins with an overview of the system, and conditions and limitations for waste heat recovery is examined. In the next step alternatives to recycle the heat is evaluated, either by direct recovering or by upgrading.First, the technical possibility of each alternative is discussed, and then the operation time and the amount of recovered heat is calculated. Those alternatives which are possible are brought further to an economic analysis.The cost of investment for each alternative constitutes the basis for a present value analysis. The results are put together in a table where the total amount of recovered heat is compared with the present value for the different alternatives.

Kartläggning av material flödesflaskhals i ICA butik.

In the spring of 2014 Sweco Systems AB were commissioned to design a ventilation system for a newly built preschool in Linköping. Terms from the client was that it cost efficiency would cope with the energy demands that are placed on the building. The unit chosen was a cross-flow heat exchanger, and this work is to compare it with two other heat exchangers to see if a more energy and cost efficient could have been chosen. The heat exchangers that was chosen for the comparison was a rotating- and a counterflow heat exchanger. Simulations have been made to the different heat exchangers by the manufacturers.

Datormodellering av en värmelagrande betongväggs inverkan på det termiska klimatet i ett växthus

This report describes the building of a computer model that makes it possible to simulate the thermal climate in a greenhouse. The computer model is built on the physical theory of heat exchange that occur in a greenhouse, such as radiation and convective heat exchange. The model also includes the heat storage that is active in a greenhouse.The computer model is used to simulate the thermal climate in a greenhouse under three periods, winter, spring and summer. It also investigates which effect a concrete wall has on the thermal climate in a greenhouse. The purpose of putting a concrete wall in the greenhouse model is to investigate the possibility to store heat during the day and then use this heat when the temperature drops during the night.The result from the simulations shows that a concrete wall levels the big difference in temperature that normally occurs under a day in a greenhouse.

Värmepumpars inverkan på elkvaliten

Modern technology and fast development of heat pumps, the hunt for savings in energy consumption and the strive for environmentally friendly energy sources, convenience, and financial profit, have made heat pumps a reasonable alternative for the heating of houses.When the heat pump starts it will consume a considerable amount of current, which may result in a short-lived voltage-drop if the power grid is weak compared to the start-up current.The company Fortum Distribution which owns and administrates electrical network is interested in an investigation that deals with heat pumps affect on the quality of electricity.The purpose of this investigation is to study fast electrical fluctuations (flicker) as a result of start-up currents for single as well as multiple heat pumps on the same electrical station and from this evaluate whether there will be any problems installing heat pumps..

Värmestyrning I Handske

This rapport is result of a project. The purpose of which was to design a circuit that is used in a heat glove. The heat glove is the technical aid which provides heat inside a glove.It is specially suited for old people who have problems with cold hands because of decreased blood circulation.There already was an old circuit in the glove that gives a constant current which develops heat from battery to glove through a circuit. The temperature is between 32 and 34 degrees.The problem with the existing circuit was to regulate the temperature. There is only on/off switch and there is no way to adjust desirable value of the temperature.In order to solve the problem the old circuit was investigated.

Inventering av värmelager för kraftvärmesystem

When a combined heat and power plant produces heat and power it often faces a deficit of heat load during the summer or other periods of time. This heat is often unnecessarily cooled away or the power production has to be reduced or shut off. If it is possible to store heat from periods with low heat demand to periods with high heat demand one can get many benefits. Among these benefits are: increased power production, decreased operation with partial load, uniformly distributed load.To be able to store heat in situations like this long-term thermal heat storages are needed. In this thesis five different types of stores are presented: rock cavern storage, tank storage, pit water storage, borehole storage and aquifer storage.

Värmeåtervinning på förskolan Rymdattacken 1 : En jämförelse av värmeväxlare

In the spring of 2014 Sweco Systems AB were commissioned to design a ventilation system for a newly built preschool in Linköping. Terms from the client was that it cost efficiency would cope with the energy demands that are placed on the building. The unit chosen was a cross-flow heat exchanger, and this work is to compare it with two other heat exchangers to see if a more energy and cost efficient could have been chosen. The heat exchangers that was chosen for the comparison was a rotating- and a counterflow heat exchanger. Simulations have been made to the different heat exchangers by the manufacturers.

Samkörning mellan värmepumpar och fjärrvärme : Bostadsrättsföreningen Bogården

This diploma work covers an investigation over the heat - and hot water systems of thetenant-owner's association, Bogården. The heat - and hot water needs of Bogården aresatisfied by both district heating as well as three heat pumps. Implemented investigationshows that the heat pumps are not used in a profitable way. Apart from that, the reservepossibilities are small. There is also a risk of the growth of Legionella bacterium in thehot water system.Since the heat pumps are already installed, HSB-Gävleborg (responsible for Bogården)has a wish to investigate possible proposed actions for optimization of existing plant.After completed investigation, a new proposed action is presented.

Effects of shade on milk production in Swedish dairy cows on pasture

Heat stress negatively influences the performance of dairy cattle such as lactation and reproduction. Heat stress can cause production losses as well as welfare problems. Years of research have shown that Heat stress is a huge problem for dairy cattle in both the tropics and temperate zones but no such research have so far been done in northern European countries. It seems like shade is an important tool when improving pasture conditions and therefore deserves more attention. The aim with this study was to investigate whether there is a need of providing shade for grazing dairy cows during the summer in Sweden. Two groups of lactating Swedish Red dairy cows (n=15 per group) were kept on pasture.

Att balansera vågskålen - En studie i lärarens stress

Detta arbete handlar om stress, hur stress uppstår och hur lärare ute i verksamheten hanterar stress. Med dessa utgångspunkter har vi undersökt hur ett antal lärare och förskollärare i grundskolan tänker och resonerar kring begreppet stress..

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