Högtempererat borrhålslager för fjärrvärme
HT-BTESBTESTESHigh TemperatureBoreholeDuctThermalEnergy StorageDistrict HeatingSeasonal StorageStoragePelletHeatPlantEnergyPowerFlowMartesEnvironmental impactFinanceInvestment CostTechnologyDrillingSavingGothenburgHeat TransferBedrockReviewFeasibility StudyLoadPeak loadBase loadDistrict Heating ProductionNetworkGridPipeBorehole Heat exchangerCollectorNewFutureGenerationLow temperatureBottle neckSystemSuccessiveCalculationMatlabComputorProgrammingScienceHT-BTESBTESTESBorrhålslagerSäsongslagerFjärrvärmeMartesVärmelagerPelletsPannaEnergiEffektFlödeMiljöpåverkanEkonomiInvesteringskostnadTeknikBorrningBesparingGöteborgVärmeöverföringBerggrundReviewFörstudieBorrhålLastSpetslastBaslastFjärrvärmeproduktionHög temperaturProduktionNätRörKollektorBorrhålsvärmeväxlareNyFramtidGenerationLåg temperaturFlaskhalsSystemSuccessiveKalkyleringMatlabDataProgrammeringVetenskap
The district heating load is seasonally dependent, with a low load during periods of high ambient temperature. Thermal energy storage (TES) has the potential to shift heating loads from winter to summer, thus reducing cost and environmental impact of District Heat production. In this study, a concept of high temperature borehole thermal energy storage (HT-BTES) together with a pellet heating plant for temperature boost, is presented and evaluated by its technical limitations, its ability to supply heat, its function within the district heating system, as well as its environmental impact and economic viability in Gothenburg, Sweden, a city with access to high quantities of waste heat.The concept has proven potentially environmentally friendly and potentially profitable if its design is balanced to achieve a good enough supply temperature from the HT-BTES. The size of the heat storage, the distance between boreholes and low borehole thermal resistance are key parameters to achieve high temperature. Profitability increases if a location with lower temperature demand, as well as risk of future shortage of supply, can be met. Feasibility also increases if existing pellet heating plant and district heating connection can be used and if lower rate of return on investment can be accepted. Access to HT-BTES in the district heating network enables greater flexibility and availability of production of District Heating, thereby facilitating readjustments to different strategies and policies. However, concerns for the durability of feasible borehole heat exchangers (BHE) exist in high temperature application.