3399
Numerical simulation of the process of geothermal low-potential ground energy
extraction in Perm region (Russia)
Modélisation numérique du procès de la sélection géothermale d’énergie potentielle basse du sol
dans les conditions de la région de Perm (Russie)
Ponomaryov A., Zakharov A.
Perm national research polytechnical university
ABSTRACT: The aim of our research is to study the interaction of energy foundations with the ground mass and to develop methods
for their construction on the example of the city of Perm. Field studies of ground were carried out in a specially chosen pilot site to
determine temperature distribution in the ground mass, change of ground-water level and physical-mechanical and thermal-physical
characteristics of the ground mass. The diagrams of depth temperature distribution in the ground and its seasonal variations were
obtained on the results of monitoring, and also the average groundwater level. To carry out numerical simulation, software-complex
“GeoStudio” was selected. Its basic differential equation is the fundamental heat conduction equation with an internal heat source.
The purpose of the numerical simulation was quantitative evaluation of the thermal energy extracted from different energy
foundations under soil conditions in the city of Perm. By results of the spent numerical experiments the equations of regress and
nomographs dependences of size of received thermal energy on geometrical parameters of the projected power bases to hydro-
geological and climatic conditions of the Perm region are constructed.
RÉSUMÉ : Le but de notre recherche est l’étude de l’interaction des fondations énergétiques avec le sol et l’élaboration de leur
méthode de construction sur l’exemple de la ville de Perm (Russie). Des études de la répartition des températures dans le sol, des
changements du niveau de nappe aquifère, des propriétés physico-mécaniques et thermo physiques sont faites au cours de recherches
in-situ sur un terrain expérimental choisi. Les résultats obtenus ont permis de déterminer des diagrammes de répartition des
températures dans le sol et leurs changements saisonniers, ainsi que les changements du niveau des nappes aquifères. Pour la
modélisation numérique nous avons choisi le logiciel Geostudio, dont l’équation différentielle de base est l’équation de conductivité
de la chaleur avec une source de chaleur intérieure. Le but de la modélisation numérique était l’évaluation quantitative de l’énergie
thermique en provenance des fondations énergétiques de différents types de sols de la ville de Perm. Selon les résultats des
expériences numériques, nous avons construit des équations de régression et des nomogrammes de dépendance de la valeur de
l’énergie thermique en fonction des paramètres géométriques des fondations énergétiques en conditions hydrogéologiques et
climatiques de la région de Perm.
KEYWORDS: geothermal ground energy, ground thermal energy, energy foundation.
1 INTRODUCTION
One of the ways of increasing energy consumption efficiency
when heating buildings is the use of renewable (alternative)
energy sources. In developed countries ground thermal energy
makes up a considerable proportion of energy used for heating.
Although studies of this problem have taken much time,
technologies based on them are rather young. Nowadays, these
technologies are widely used in many countries, such as
Canada, Australia, the United States, and most European
countries. Energy geothermal systems together with important
environmental aspect have a great number of advantages:
- They allow reduced energy consumption for heating
buildings by 50-70 %.
- The use of foundations as ground heat exchangers
necessary from the structural point of view becomes possible.
- They have fewer current costs in operation.
Technologies that use geothermal energy have been used
very rarely in Russia so far. Taking into account the advantages
of the technology given and the state policy in the area of
energy consumption we think that the problem of ground
thermal energy investigation when laying foundations and
building underground structures is pertinent.
The aim of our research is to study the interaction of energy
foundations with the ground mass and to develop methods for
their construction based on the example of the city of Perm.
2 PROBLEM STATEMENT
Heating system using ground thermal energy consists of three
main parts: the system of pipelines embedded in the ground
mass or in contact with the ground (primary circuit); the system
of pipelines intended for heating or conditioning (secondary
circuit) and a heat pump combining these pipeline systems
(Grigorjev V.A. et al. 1982, Katzenbach R. et al. 2007).
The primary circuit is used to generate ground thermal
energy and is located in the body of energy foundations. Piles,
foundation plates, “slurry walls”, diaphragms, anchors, walls of
the underground floors and other constructions being in contact
with ground can be used as energy foundations.
The advantage of energy foundations is that these structures
(piles, foundation plates, etc.) are required for the conditions of
constructional safety (that is, to ensure bearing capacity and
deformability). Correspondingly, there is no need in their
additional construction. Therefore, they are double-purpose
structures acting as load-bearing elements and ground heat
exchangers.
The secondary circuit is a closed heating system in the walls
and slabs of a building.
The functions of the heat pump are to increase the
temperature of the primary circuit heat carrier to the necessary
one.
Ground is a multiphase system with a complex mechanism
of heat transmission, which includes (Grigorjev V.A. et al.
