TYPES OF GEOTHERMAL SYSTEMS
The basic characteristics of the two types of geothermal systems, closed and open circuit are the following:
1. CLOSED CIRCUIT GEOTHERMAL SYSTEMS
Closed circuit geothermal heat exchangers can be: a) horizontal geo-heat exchangers, b) vertical geo-heat exchangers (drillings), depending on the way the pipes are placed in the ground.
A) Horizontal geothermal systems use a geothermal exchanger, which is placed parallel to the ground at a depth of usually 1.2-1.8 m in one or more layers of pipes.
B) Vertical geothermal systems the geothermal exchanger is placed perpendicular to the ground surface, in drill holes drilled and at depths usually ranging from 50-150 m.
A closed circuit continuously recirculates, under pressure, the heat transfer fluid. A circulator is necessary for the smooth supply of the heat pump. The circuit of the earth and the house is closed and consequently no deposits of salts occur, with the result that the requirements for maintenance of the system are small.
Vertical systems (drilling) have the advantage over the horizontal ones, because they need less space for their installation and are more “stable”, because they are hardly affected by seasonal changes, due to greater installation depth.
2. OPEN CIRCUIT GEOTHERMAL SYSTEMS
Open circuit geothermal heat exchangers use groundwater (from wells) or surface water (from a lake, well, river, or sea) as a source of heat – cooling and water storage.
They pump water from an underground reservoir using drilling and an intermediate water / water exchanger interposed between the geothermal heat pump and the open circuit, supplying or absorbing energy to the system before the water returns to the reservoir from another well.
This system is suitable in areas with shallow aquifer depth, so that small water wells are required.
These wells utilize the property of the constant temperature that the waters of the underground reservoir have throughout the year, regardless of the prevailing atmospheric conditions.
Shallow open circuit geothermal requires at least two boreholes. From the first one, water is pumped from the underground aquifers and channeled to the geothermal pump where it supplies or absorbs energy to our system before the water returns to the reservoir from the second borehole.
Our company with the help of cooperating companies of mechanical engineers undertakes:
- the execution of the entire project, from the first stage to its delivery, ready for use
- the elaboration of the study of installation of heating – cooling system, the hydrogeological study
- the preparation and editing of the file for the issuance of the single permit for the execution and operation of the facilities