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En numerisk analys av den ringformade koaxiala borrhålsvärmeväxlaren
The borehole heat exchangers of today suffer from poor thermal and hydrodynamic performance. The purpose of this thesis is to improve the performance of ground source heat pump systems and thermal energy storages by increasing the energy efficiency of the borehole heat …
The thermal response of a borehole field is often described by non?dimensional response factors called gfunctions.The g?function was firstly generated as a numerical solution based on SBM (Superposition BoreholeModel). An analytical approach, the FLS (Finite Line Source), is …
… 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 …
… storage in Tekniska verken’s energy system. The investigated technology is borehole thermal energy storage using two different kinds of borehole heat exchangers; u-pipe and annular coaxial heat exchanger. To evaluate how Tekniska verken’s energy system changes through …
En utredning av påverkan från möjliga osäkerheter i befintlig information
… calculated based on two types of information: descriptions of the layers in borehole profiles and information from sieve analyses. The obtained values were then compared to a rough estimate based on information about groundwater flow and hydraulic gradient. The compilation of …
… to financial performance. The technology forrecovering the waste heat is a Borehole Thermal Energy Storage (BTES) which is aconstruction consisting of 140 vertical boreholes, 150 meters deep with an internal spaceof four meters.The calculated amount of energy for storage is …
… holes of 210 meters wish provide an investment cost of 307 050 sek for the boreholes and an total investment of 446050 sek with a pay-off time of 5,6 years without cooling and 471050 sek with cooling wish give a pay-off time of 5,9 years. If a special double U-piping were to be …
In this thesis proposals for different designs of a borehole thermal energy storage (BTES) have been developed for the building DN-huset in Stockholm, Sweden. To build a BTES results in savings in energy costs by approximately 44 %, i.e. 2 million Swedish crowns annually …
… an investigation of the possibilities of using seasonal storage in the form of boreholes stock was made. Various cases were analyzed, and the biggest focus was on a case about the amounts of waste heat obtained from Akademiska Hus added to the excess heat Umeå Energi have in the …
… a geothermal heat pump system leakage of an antifreezing agent can appear in a borehole and leak out in surrounding groundwater. To guarantee high quality drinking water for generations to come Sweden has dedicated some areas as water protection areas. The local authority gives …
… of stores are presented: rock cavern storage, tank storage, pit water storage, borehole storage and aquifer storage. In this thesis the principles of the different storages is presented and experiences from operation in Sweden, Germany and Denmark are also presented. The thesis …
… modes. When there is an excess of solar energy from the solar collectors the borehole should be recharged and be stored in the ground for a shorter period of time. The heat pump refrigerants should also be preheated in the storage tank where the heat from solar collectors is not …
… round heat supply from solar energy. This report will focus on heat storage in boreholes. At the present here is only a preliminary plan of how the neighborhood is supposed to be designed. This plan has been used in all the calculations regarding the potential areas where solar …
Kan borrhålskyla ersätta en kylmaskin?
Syftet med rapporten är att göra en jämförelse av två olika metoder för att kyla ett fiktivt kontorshus som är 2 000 m² stort och beläget i Västerås. För att representera ett normalt kontorshus har kyleffektbehovet valts till 50 W/m² vilket ger totala kyleffektbehovet 100 kW. I …
… a system with heat pumps to upgrade the 31?C water from a 1.8 kilometre deep borehole. In order to achieve the desired water flow, hydraulic fracturing will be necessary since it is assumed that the rock would be relatively solid at that depth. Water at 10?C will be pump down …
