Obtaining a water permit for direct use of water for heat production
Investment value: € 26.705,24
Role: Design, project management
Year of the design of technical documentation: 2010
Izvedba črpalnega poskusa na vodnjakih Brn in ponikanje v ponikovalni vodnjak
Project description
In the construction of the new building of the Air Traffic Control of the Republic of Slovenia, heating and cooling is planned using a water-to-water heat exchanger system. The maximum final pumping flow rate is expected to be up to 40 l/s. The mining designs for the implementation of the works for the construction of two pumping wells, one sinking well, a 70 m deep structural boreholes and their inventory were carried out in the conceptual design phase, in which IRGO was not involved. Groundwater abstraction, as well as groundwater recharge, was planned from a depth of between 40 and 70 m.
Due to the short distance between the pumping wells and the sinking well, the future sinking well has also been included in the pumping wells. According to the findings, the pumped water will be returned to the newly constructed dug sinking wells, which extend to a depth of 24 m or to the upper open aquifer. On the basis of the works and investigations carried out, a report has been prepared for obtaining a water permit for the direct use of water for heat production.
Technical properties
As part of the water permit acquisition project, we supervised drilling operations, analysed leachate, monitored activation, carried out chemical analysis of groundwater samples, etc. Based on that, a report on the drilling works carried out was produced. After completion of the drilling operations, a drawdown analysis and a longer pumping test were carried out on each well. The maximum pumped flow rate from each well was approximately 21 l/s. Finally, a combined pumping experiment was carried out, simulating the future situation by pumping approximately 45 l/s from the two wells and returning the water to the sinking wells. As part of the interpretation of the results of the pumping experiments, we have calculated the total depression at the peaks, which will not exceed 0.5 m. During the pumping experiments, it was found that the upper open aquifer, into which the heat-treated pumped water sinks, and the lower closed aquifer, from which it is pumped, are hydraulically separated.