Geothermics

• 11/16/2009
• Number of comments: 0

CGS is currently working on several line of research in the area of applied geothermics specifically, what is known as low enthalpy geothermics. Enthalpy is a variable which allows the amount of heat in a certain system to be measured and, consequently, a low enthalpy system is one which the transfer of heat is low level. As a result, it is appropriate for surface infrastructure which takes advantage of the stability of the subsoil temperature, determined by the land itself, for carrying out preliminary fluid treatments at surface level due to the different temperatures at ground level and underground. Therefore, in summer it makes use of the lower temperatures of the earth at certain depths and, in winter, does the opposite.

One typical uses of low enthalpy geothermal heat is to support HVAC systems so that they are more efficient, and thereby leading to quick amortization of the initial investment. The main advantage is that this type of resource is available regardless of geographic location and does not require any type of natural geothermal anomaly.

Although there are other less frequent configurations, it involves the drilling of wells that are spaced differently and have different diameters and depths depending on the case, where certain fluid is circulated in a closed circuit throughout the wells, exchanging temperature with the land which, due to its nature, has greater inertia when faced with specific changes in liquid.

The most important aspects to consider in the project and dimensioning phase of this type of system are, in addition to those related to the aforementioned well field, the design of the pumping installation which manages them, the pump or heat exchanger which connects the geothermal system with the normal HVAC systems, the performance level of each element, the thermal transfer rates of the exchangers (whether it be the underground exchanger between the refrigeration fluid and the land or that which is carried out at surface level between the refrigeration fluid and the refrigerating gas itself in the circuit located in the compressor element).

In addition to the purely technical aspects, it is also necessary to consider the economic aspects such as the depreciation periods depending on the tax advantages arising from the use of this type of energy, those related to company accounting and even those related to the improvement to the image of a company which uses this type of technology and which is an added value to be considered.