For a district heating company it is of importance to have an efficient and well performing system. A central part in the work to lower temperature levels in district heating networks is to acknowledge and improve cooling capability in substations. The aim of this thesis is to analyse substations in Polish district heating systems in order to identify reasons of poor cooling and to present suggestions of implementable measures. Furthermore, the economical saving potential from an improved cooling is evaluated. The analysis was carried out for two of the five Polish companies included in this report; Sydkraft EC Slupsk and MEC Koszalin. It was followed by two scenarios created for evaluation of improvement possibilities based on calculated financial savings from reduction of distribution heat losses and distribution pumping. The results show that there are significant improvement possibilities. From the carried out scenarios a saving potential between 15 000 to 20 000 PLN/substation is possible to achieve for selected worst substations, if their individual annual average cooling is set to 30°C. The analysis further shows that causes of poor cooling in substations are highly individual but points out that customer owned substations are represented in the majority of worst substations.

The municipality of Knivsta plans to expand from 15,000 to 25,000 inhabitants until the year 2025. In order to do so the municipality is planning to build a new residential area, Nydal. The purpose of this bachelor thesis is to estimate the heat demand for the new district and to investigate the advantages and disadvantages of using a common or an individual heat solution. The common solution consists of a pipe grid system connecting each building with a central heat source and in the individual solution each building has its own heat source. The heat units that have been used are combined heat and power and solar thermal heating. The total yearly heat demand for Nydal was calculated to total 21.6 GWh for the common solution and 19.4 GWh for the individual solution. This implies that the losses in the pipe grid are 2.2 GWh. The heat demand peaks are largest in January, about 7600 kW, and smallest in July, about 300 kW. To cover the heat demand for the common solution during summer, solar panels need to cover 6.5 per cent of the roof area. To be able to cover the heat demand for the larger buildings in the individual solution up to 45 per cent of the roof area needs to be covered with solar panels. Furthermore, the total installed heat power from CHP plants is 4320 kW in the common solution and 7375 kW in the individual solution. In conclusion, a common solution is to prefer because less CHP needs to be installed despite heat losses in the pipe grid.

In this thesis project, a building in Vegagatan 12, Gävle has been analysed. The main objective has been to find why it consumes more energy than it was expected and to solve theoretically the problems.This building is a low energy building certified by Miljöbyggnad which should use less than 55kWh/m2 year and nowadays it is using 62.23 kWh/m2. In order to find why the building is using more energy than the expected several different things has been measured and analyzed.First of all, the heat exchanger of the ventilation unit has been theoretically examined to see if it works as it should and it does. This has been done using the definition of the heat exchangers.Secondly, the heating system has been analysed by measuring the internal temperature of the building and high temperatures have been found (around 22°C) in the apartments and in the corridors. This leads to 5-10% more use of energy per degree.Thirdly, the position and the necessity of all the heaters have been checked. One of the heaters may not make sense, at least in the way the building has been constructed. This leads to bigger heating needs than the expected.Fourthly, the taps and shower heads have been checked to see if they were efficient. Efficient taps and shower heads, reduce the hot water use up to 40%. The result of this analysis has been that all taps and shower heads are efficient.Fifthly, the hot water system has been studied and some heat losses have been found because the lack of insulation of several pipes. Because of this fact 8.37kWh/m2 are lost per year. This analysis has been carried out with the help of an infra red camera and a TA SCOPE.Sixthly, the theoretical and real U values of the different walls have been obtained and compared (concrete and brick walls). As a conclusion, the concrete wall has been well constructed but, the brick wall has not been well constructed. Because of this fact 1 kWh/m2 of heat are lost every year. Apart from that, windows and thermal bridges have also been checked.

<p>This project has been developed at the company Gavlegardarna. The companyowns a large part of the buildings of Gävle and two of them are the objective ofthe project. Gavlegardana is highly concerned about the environment; for thisreason, they cooperate on the subject with the energy management from theirtechnical department.</p><p>Gävle is one of the Swedish cities where the DH (district heating) network isdistributed, arriving to most of the dwellings, industries and commercialbuildings. As DH uses environmentally friendly sources of energy,Gavlegardana is introducing it in its buildings.</p><p>Electrical radiators and boilers were installed in the buildings when the price ofelectricity was more affordable than nowadays. The price of the electricity canbe considered 1,23 SEK/kWh while the DH price is 0,45 SEK/kWh.</p><p>Consequently, this is another reason why the objective of the company at thepresent time is to replace electrical space heating systems by means of districtheating.</p><p>The energy balance of the buildings is analysed in order to study their currentenergy situation. This entails the consideration of heat gains and lossesinvolved. The heat gains of the building are the heat from solar radiation whicharrives at the building trough the windows, the heat internally generated (bypersons, lighting and other devices) and the heat supplied. The heat losses are composed by the transmission trough walls and windows, the infiltrations, the heat used for hot tap water and the ventilation losses.</p><p>An important part of the work required to calculate the energy balance hasconsisted of the collection and organization of all the data (areas, types ofmaterial, electrical devices, lighting, number of employees, opening hours...).This data comes from the drawings of the buildings provided by the companyand from the information gathered during the visits to the installation. In addition, the ventilation flows were measured in-situ using the tools provided by Theorells.</p><p>Gavle Energi, the DH distributor company, has been contacted in order to fixthe cost and other details related to the district heating connection. The heatexchanger models, selected from Palmat System AB, are TP20 for Building Aand TP10 for Building B. TP20 provides 100 kW of heating and 0,4 l/s of hot tap water and TP10 provides 50 kW and 0,31 l/s respectively. The capital cost is 187500 SEK which includes the heat exchangers and the connection cost.</p><p>As the secondary circuit is not currently installed because the existing system iscomposed by electrical radiators, the installation of the piping network in thebuilding has been designed. The radiators’ power is calculated taking intoaccount the need of heat in each room which is estimated as the transmissionlosses. This need of heat calculated is higher than the energy currently supplied which means that the thermal comfort is not achieved in all the rooms of the buildings.</p><p>In spite of using more energy for space heating, the change of heat sourceentails a lower energy cost per year. The selected radiators are from Epeconand the investment cost (including the installation) is 203671 SEK. The brand of the selected pipes is Broson and the investment cost of the total piping system is 66000 SEK.</p><p>The initial investment of the new installation is 457171 SEK, considering the DHconnection, heat exchangers, radiators and pipes. If the initial investment istotally paid in cash by the company the payback will be fulfilled in 6 years. Incase of borrowing the money from the bank (considering an interest rate of 5%), two possibilities can be considered: paying back the money in annual rates over 15 years or 30 years of maturity. The paybacks are 11 and 8 years respectively.</p><p>After designing the DH piping system in the buildings, estimating the total costs of the investment and studying the project’s feasibility by suggesting different payment options, some possible energy savings are recommended.</p><p> </p><p>The first of the options refers to the transmission losses trough the windowswhose values’ are considerably high. Using a glass with a lower U-value, theselosses can decrease until 66% (with triple glass windows). Consequently, thepower required for space heating can also be reduced until 26%.</p><p>Regarding the ventilation, rotating heat exchangers are currently used, whichentails the problem of smells mixture detected by the users of the buildings. By changing them with flat-plate heat exchangers, the problem is solved and the efficiency is increased from 66% to 85%. The new heat exchanger cost is340387 SEK and it has a payback of 10 years.</p>

<p><strong></strong>The aim of this Project is to study the influence of high return temperatures in district heating on the costs for heat and power production in a CHP plant.When the temperatures of the water coming back to the heating plant are so high, the overall performance of heat and power production is decreased and, consequently, also the production costs. Along the project, the influence of this temperature on the different parts of a CHP plant are analysed as well as the economical impact it has. At the same time, some general impacts on the entire network are mentioned.</p><p> </p><p>A real network is used in this project, and it is the net of district heating in Gävle (Sweden), and the most of the study is focus in its bigger combined heat and power production plant (CHP), called Johannes.</p>

<p>Electricity and district heating are the most important energy carriers for the residential and service sector in Sweden. Today, district heating supplies about half of the total heating requirement of residential and commercial premises in Sweden. The aim of this paper is the analysis of the heating system of a school, placed in Gävle, Sweden. The heat is delivered to the school by a district heating network.</p><p>First of all, the Heat Balance must be done, with the purpose of obtain the best knowledge of the present situation in the school. The calculations about the transmission and ventilation losses and the internal heating generated have been showed. After this, the point of view has been focused on the district heating system itself. It is means, the distribution pipe system inside the school. The efficiency and accuracy of the net will be analysed and discussed.</p><p>Three possible ways to improve the net will be showed. The first of all is the most simple: just take the pipe system and try to reduce the waste heat, the heat losses; the second choice is to make a new connection to the district heating network, joining all the buildings with one connection for each building –five more- instead of only the connection that exists at the moment when this paper was written; the third option seems as a different model of the second, it is means to divide all the school in two bigger parts and make another connection to the district heating network with the purpose of dividing the heating system in two equal parts.</p><p>Thanks to the heat balance done in the school and in the district heating system, it is possible to know the waste of heat. Mainly, these losses are found in the district heating net. The amount of waste is around 17%, a really high amount of energy wasted, which must be reduced. According to the data of the company Gävle Energy, the waste in old buildings like the school which is under study in this paper, usually is between 15% and 20% of the supplied energy. So, this showed the accuracy of the method used to make this paper.</p><p>According to the possibilities of improvement, it will depend on the ultimate decision of the Gävle Fastigheter, company which owns the school, to choose the way that could be better for their own interest. However, in this paper the prices and possible pay-back times are showed, in order to provide better information.</p><p>Although the best solution has a total cost of 1750000 Swedish crowns (186289 €) and a pay-back time of 21 years –talking about making five new connections-, another cheaper possibility is also commented: improving the isolation of the pipe system, with a cost of 549000 SEK (58441 €) and a pay-back time near 7 years.</p>

This project has been developed at the company Gavlegardarna. The companyowns a large part of the buildings of Gävle and two of them are the objective ofthe project. Gavlegardana is highly concerned about the environment; for thisreason, they cooperate on the subject with the energy management from theirtechnical department. Gävle is one of the Swedish cities where the DH (district heating) network isdistributed, arriving to most of the dwellings, industries and commercialbuildings. As DH uses environmentally friendly sources of energy,Gavlegardana is introducing it in its buildings. Electrical radiators and boilers were installed in the buildings when the price ofelectricity was more affordable than nowadays. The price of the electricity canbe considered 1,23 SEK/kWh while the DH price is 0,45 SEK/kWh. Consequently, this is another reason why the objective of the company at thepresent time is to replace electrical space heating systems by means of districtheating. The energy balance of the buildings is analysed in order to study their currentenergy situation. This entails the consideration of heat gains and lossesinvolved. The heat gains of the building are the heat from solar radiation whicharrives at the building trough the windows, the heat internally generated (bypersons, lighting and other devices) and the heat supplied. The heat losses are composed by the transmission trough walls and windows, the infiltrations, the heat used for hot tap water and the ventilation losses. An important part of the work required to calculate the energy balance hasconsisted of the collection and organization of all the data (areas, types ofmaterial, electrical devices, lighting, number of employees, opening hours...).This data comes from the drawings of the buildings provided by the companyand from the information gathered during the visits to the installation. In addition, the ventilation flows were measured in-situ using the tools provided by Theorells. Gavle Energi, the DH distributor company, has been contacted in order to fixthe cost and other details related to the district heating connection. The heatexchanger models, selected from Palmat System AB, are TP20 for Building Aand TP10 for Building B. TP20 provides 100 kW of heating and 0,4 l/s of hot tap water and TP10 provides 50 kW and 0,31 l/s respectively. The capital cost is 187500 SEK which includes the heat exchangers and the connection cost. As the secondary circuit is not currently installed because the existing system iscomposed by electrical radiators, the installation of the piping network in thebuilding has been designed. The radiators’ power is calculated taking intoaccount the need of heat in each room which is estimated as the transmissionlosses. This need of heat calculated is higher than the energy currently supplied which means that the thermal comfort is not achieved in all the rooms of the buildings. In spite of using more energy for space heating, the change of heat sourceentails a lower energy cost per year. The selected radiators are from Epeconand the investment cost (including the installation) is 203671 SEK. The brand of the selected pipes is Broson and the investment cost of the total piping system is 66000 SEK. The initial investment of the new installation is 457171 SEK, considering the DHconnection, heat exchangers, radiators and pipes. If the initial investment istotally paid in cash by the company the payback will be fulfilled in 6 years. Incase of borrowing the money from the bank (considering an interest rate of 5%), two possibilities can be considered: paying back the money in annual rates over 15 years or 30 years of maturity. The paybacks are 11 and 8 years respectively. After designing the DH piping system in the buildings, estimating the total costs of the investment and studying the project’s feasibility by suggesting different payment options, some possible energy savings are recommended.   The first of the options refers to the transmission losses trough the windowswhose values’ are considerably high. Using a glass with a lower U-value, theselosses can decrease until 66% (with triple glass windows). Consequently, thepower required for space heating can also be reduced until 26%. Regarding the ventilation, rotating heat exchangers are currently used, whichentails the problem of smells mixture detected by the users of the buildings. By changing them with flat-plate heat exchangers, the problem is solved and the efficiency is increased from 66% to 85%. The new heat exchanger cost is340387 SEK and it has a payback of 10 years.

The aim of this Project is to study the influence of high return temperatures in district heating on the costs for heat and power production in a CHP plant.When the temperatures of the water coming back to the heating plant are so high, the overall performance of heat and power production is decreased and, consequently, also the production costs. Along the project, the influence of this temperature on the different parts of a CHP plant are analysed as well as the economical impact it has. At the same time, some general impacts on the entire network are mentioned.   A real network is used in this project, and it is the net of district heating in Gävle (Sweden), and the most of the study is focus in its bigger combined heat and power production plant (CHP), called Johannes.

Det här är ett examensarbete som handlar om en fastighet som står på Norra Kungsgatan 37-43 som har både en värmepump och fjärrvärme för uppvärmning. Värmepumpen används i första hand och fjärrvärmen används som spets när värmepumpen inte räcker till. Detta är en ganska ovanlig kombination. Syftet med arbetet är att ta reda på om detta är en bra lösning och om lösningen är lönsam. För att få fram hur stort fastighetens energibehov är så görs beräkningar utifrån fjärrvärmedata från tidigare år samt en gammal värmepump som är utbytt sedan 2011. Byggnadens energibehov uppskattas vara ungefär 895 MWh/år och värmepumpen beräknas täcka 54 % av värmebehovet. Utifrån detta jämförs sedan kostnaden för uppvärmning av fastigheten med endast fjärrvärme med kostnaden för uppvärmning med både värmepumpen och fjärrvärme. Genom att använda värmepumpen så sparas drygt 140 000 kr per år. Det innebär att värmepumpen är lönsam rent ekonomiskt. Däremot kan användningen av högkvalitativ energi för uppvärmning diskuteras. Värme som är energi med lägre kvalitet borde i första hand användas för uppvärmning. Det för att inte slösa på våra dyrbara energiresurser och på så sätt få en hållbar utveckling. / This is an essay about a property at Norra Kungsgatan 37-43 who is heated with both a heat pump and district heating. The heat pump is used primarily and district heating is used as a tip when the heat from the heat pump is not enough. This is a pretty rare combination. The purpose of this essay is to find out if this is a good solution and if the solution is economically viable. To determine the heat demand of the property, calculations based on district heating data and heat pump data from previously years has been used. The heat demand of the building is estimated to be approximately 895 MWh/year and the heat pump is estimated to cover 54% of the heat demand. Based on this, the cost for heating the building with district heating is compared with the cost of heating the building with the heat pump and district heating. By using the heat pump, more than 140 000 kronor per year can be saved. This means that the heat pump is economically viable. However, the use of high-quality energy for heating is discussed. Heat is energy with lower quality and should be used primarily for heating. We can not waste our precious energy resources if we want to achieve sustainable development.

This study investigates the status and potential of the low temperature district heating system in Lyckebo, focusing on the distribution losses in the culvert system and in the heat exchangers. The Lyckebo system was built in the 1980’s as a test system with heating from a solar field and an electrical boiler. The unique features with this system were a cavern for storage of excess heat combined with a low temperature system. Today, the solar field has been substituted with two pellet boilers, but the cavern is still in service. Low temperature district heating systems are built in order to lower the losses, due to a smaller temperature difference between the medium in the culvert and the soil. This technology is used in newly built energy efficient residential areas, which makes it interesting to investigate the status of a system that was built in the 1980’s, in comparison to the possibilities of low temperature systems today. A simulation model has been developed to calculate the theoretical losses in the culvert system with production data from 2013. The total instantaneous losses in the culvert system were between 210- 280 kW and the highest losses in  can be found in the secondary system. There are heat exchangers in the system that has a return temperature of approximately 8°C lower than the return temperature in the system, which leads to the conclusion that many of the exchangers in the system probably have poor energy utilization.