Thermal Heat

Advanced energy source

Since the beginning of industrialization in the 19th century, the continuously growing demand for electricity, transport and heat lead to an overexploitation of the earth’s raw materials. Within no more than 100 years the energy requirement of mankind has increased by 16 times and the air pollution has increased by 5 times.

(Quelle: http://www.tfz.bayern.de/sonstiges/16459/07brs006_weltenergieverbrauch.pdf)

In the next few years, this trend is unstoppable. An end of the continuously growing world population and the striving for comfort is not in sight.

Meanwhile irreversible damages on the environment have been proven and documented in many cases. They will change our living environment sustainably.

No certain prognosis can be made about for example the greenhouse effect and relating thereto the rising sea level through the global warming of the atmosphere. Neither about the effect of the immense CO2 emission on our climate.

The exploitation of the fossil deposits represents an underestimated risk for us and the next generations. The explosion of energy prices for oil and gas leads to unexpected costs for heating and warm water.

In addition, the dependence on producing countries of fossil energy sources is leading to political tensions.
In order to maintain our current standard of living, the usage of renewable energy sources is pushed even by the federal politics.

For a long time, the sun provides us with heat-giving-rays. The heat stored in the earth could satisfy the energy demand of the entire world for 20 million years. (Source: Geothermal energy for North Rhine-Westphalia, a brochure from the ministry of transportation, energy and land use planning in North Rhine-Westphalia, 2003 p4)

At our discretion, this natural source of energy is available endlessly and has no negative impact on our nature.
ENREGIS is specialized in the development, the construction and the production of various heat sources and very efficient heat pump technology. We are able to respond to every request of architects, planning offices, departments and especially operators.


The heatpump

The enormous amount of energy, which has been supplied to us from the sun all over the years, and which are stored in the earth, could be promoted and extracted by means of heat pumps. By using heat pump technology heating costs for buildings could be reduced, in some cases up to 75%. It is not necessary to maintain or to fill the heat pump with fuel. The life time is about several decades.

The principle of energy generation by a heat pump is comparable with a refrigerator. But with opposite objective, the pump has to heat and not to cool.
For this a thermo dynamical process and of course the ENREGIS know-how will be used.

In a circuit (geothermal downhole heat exchange or collector) flows the heat transfer, in this case brine, transport a small quantity of heat of ca. 10°C from the earth to the pump. However the temperature of 10 °C is not sufficient to heat. For this reason the heat is transformed by means of an evaporator to a refrigerant with extremely low boiling point.

Contrary to water which is solid at 0 degree becomes this refrigerant steam at subfreezing temperature. This steam is compressed by using an electrical compressor. The pressure and temperature will be increased. Thanks to this procedure, heat energy from the earth is raised to a higher usable temperature level. The condenser liquefies the steam and the thus gained thermal energy (40 – 80 °C) will be transformed to the heating circuit. At the end of the cycle, the refrigerant, which is now again liquid, will be brought down my means of an expansion devise, to a low temperature and pressure value. The cycle starts from the beginning. The only necessary energy is the electricity for the compressor.

The needed energy here for is about ca. ¼ of the obtained energy. Exp. for 8 KW heat require you need only 2 KW of electrical energy, the remained 6 KW are from the earth.


Basics of geothermal energy

The near surface geothermal is the usage of geothermal energy at depths up to 400. At these depths the solar radiation still contributes to a warming of the subsoil.
The seasonal temperature level is depending on the depth.

For exp. the soil temperature in 2 m depth is between 7 and 13 °C, and in 5m depth only between 8,5 and 11,5 °C. As shown the soil temperature swings at deeper depths at ca. 10 °C.

The temperature rises as soon the effect of the geothermal is noticeable. The average temperature in 100 m depth is of ca. 12 °C and in 200 m depth of ca. 15 °C. In general raises the soil temperature each 100 by 2-3 °C.

Geothermal energy can be developed and used by means of for exp. downhole heat exchanger, spiral collectors or surface collectors.
The dimensioning of a geothermal system is depending on the possible extraction performance of the soil or rock. The thermal conductivity is between 1 to 3 W/m*k. The surrounding soil serves as a thermal buffer, therefore it is possible to extract larger capacities for short periods.

However a sufficient long regeneration time must be planned, so that the geothermal heat flow from the earth’s interior can make this deficit good. By using spiral- or surface collectors affects the surface near installation, that the solar radiations are available and helpful for regeneration.

Geothermal system under 30 KW overall performances could be designed by means of a DVI 4640 guidelines. This guideline allows a simplified application of the possible extraction performance.

For larger systems, the possible extraction performance should be determined by means of soil experts. For this purpose are mainly the thermal response tests used, in order to determine the actual local soil conditions.

An insufficiently dimensioned downhole heat exchanger and collectors and with it an increase of the extraction performance each unit of area, leads to limited local impacts on the vegetation. In the past, a generously consideration of the soil’s conductivity leads to permanent appearances of icing.

A limited ice radius around the pipes has essentially a positive effect on the heat conduction. On the other hand a complete icing leads to a drastic falling of the annual heating capacity.