Heat Exchanger World Magazine February 2023 | Page 39

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Project Report
Thermal subsystem
15 fan coils units
Heat exchanger ( HXI )
Cooling circuit Heat exchanger ( HXC )
Hot / Cold water Storage tank ( 2000L )
12 Borehole Heat Exchanger ( BHE ) 100m deep
Legend
Geo fluid loop
Cold Water Electricity ( DC ) Electricity ( AC ) Hot
The Demo-site block diagram of the Bucharest setup shows the connection of the thermal and the electrical subsystem and its implementation into the UPB district heating network .
In Bucharest , the University Politehnica is testing the integration of renewable energy sources in the university ' s existing heating network , which is currently operated by a gas cogeneration system . This existing network is arborescent , meaning it can be seen as a tree . The outer branches are not supplied with an appropriate thermal level of heat , and this problem is getting worse with time as the network is used to supply heating for more and more clients . WEDistrict has proposed the integration of a hybrid system based on geothermal energy , employing the use of heat pumps and solar energy . The solar panels are meant to power the geothermal unit and the hybrid photovoltaic thermal collectors , the latter of which is intended to supply domestic households with hot water during summer . These photovoltaic panels are installed on the roof of the building and have an estimated power output of 66 kWp . The borehole heat exchanger connected to the heat pumps can , in turn , be used for cooling the building during summer . These geothermal heat pumps produce about 63 kW of heat and 50 kW of cold . The heat produced by the heat pumps is stored in the buffer tank and is available for use depending on the need to heat the spaces of the target building . The heat overproduced by the system and not consumed by the building is injected into the local district heating network . To oversee everything , WEDistrict employs an intelligent management system for Supervisory Control and Data Acquisition ( SCADA ). In Bucharest , they employ Danfoss SONDEX gasket plate heat exchangers for water / water and water / glycol .
Luleå site – The south of Sweden has a humid continental climate . Luleå , however , is located in the northern part of the country , which experiences a subarctic climate . This climate provides long , ( very ) cold winters and short , warm to cool summers . Sweden has already met the climate goals as stated in the Kyoto protocol . The country employs nation-wide efficient district heating , which is supplied by non-fossil energy sources . District heating currently accounts for 50 % of Swedish heating , whereas in 1980 , it was almost exclusively powered by fossil fuels . In 2017 , 90 % of its heating demand was accounted for by renewable energy and recycled heat .
The structure of the heat exchanger pipes that were implemented into the twelve 100m deep bore holes . www . heat-exchanger-world . com Heat Exchanger World February 2023
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