Utilization Of Thermal Waters Research Articles

Geotermikus energia korszerű felhasználása Nagyszénás településen (Esettanulmány)

Békés megyében található Nagyszénás településen geotermikus energiafelhasználásra épülő projekt került átadásra 2015. december 20.-án. Az építési beruházások az Európai Unió támogatásával a 2007-2013-ös pénzügyi, finanszírozási ciklusban elnyert pályázati forrásból valósultak meg 1,578 milliárd forint összértékben. A termálvíz-hasznosítási beruházás országos viszonylatban is egyedülálló műszaki megoldásokkal valósult meg és eredményeképpen a meglévő geotermikus lehetőségek kihasználásával, zöld energiaforrásra épülő, korszerű, gazdaságos fűtési rendszer lett kiépítve a település közintézményeiben és az újonnan létesített parkfürdő-komplexumban. A kivitelezés során és az üzemeltetés közben, számos előre nem ismert műszaki probléma merült fel, amelyek megoldása csak új technikai elemek alkalmazásával vált lehetővé. A kitermelt termálvíz magas sótartalma és a magas hőfoka különleges gépészeti és építészeti megoldásokat követelt. Az üzemeltetés során számos ponton átalakításra és technológiai elemek megváltoztatására volt szükség a biztonságos üzemeltetés érdekében. A cikk célja ezen műszaki beavatkozások bemutatása, amelyek eredményeképpen napjainkban a rendszer megbízhatóan üzemel, és megfelelő alternatívát nyújt a földgáz hátterű fűtési rendszerek helyett.

Geochemistry and Utilization of Water from Thermal Springs of Tawang and West Kameng Districts, Arunachal Pradesh

ABSTRACT The hydrogeochemical studies provide insights about reservoir conditions of geothermal springs along with utilization of thermal waters for domestic, livestock and irrigation purposes. Most of the hot springs of Tawang and West Kameng districts of Arunachal Pradesh emanated through garnet bearing high grade gneissmigmatite-schist-quartzite sequence of the Se La Group, except for Dirang hot springs which emanate from river terrace deposits lying on the footwall of deformed quartzite-phyllite. The thermal waters are of mixed Na-Ca-HCO3-SO4-Cl type, meteoric in origin and at the same time immature in nature, moving sluggishly towards mineral-fluid equilibration zone with slow rock-water interactions. Chemical geothermometry showed wide variation in estimation of sub-surface reservoir temperature and quartz geothermometry model fits prominently to provide the most reliable reservoir temperature varying within 90±40°C. The studies recorded highest reservoir temperature of Thingbu hot spring with 133°C with very high fluoride concentration in all the hot springs except Bishum and Phudung as per BIS (2012) IS: 10500 specifications. High fluoride and sulfate concentration in thermal spring waters make it unsuitable for drinking purpose. The applicability of thermal waters for irrigation is predicted through sodium adsorption ratio (SAR) calculations which showed that waters of Dirang-2, Sorbe and Kitpi-1&2 are not suitable for irrigation purpose due to high salinity and SAR values.

Integrated development of low-temperature thermal waters

The research concerns the efficient development of low-potential thermal waters in the East-Ciscaucasian artesian basin. A technology is proposed for the integrated development of low-temperature thermal water, using its heat potential for district heating and hot water supply, as well the water itself for various water management purposes, with its quality previously brought to the standards of drinking water. Various chemical water treatment units are suggested for this purpose, with their design and technological features being formed depending on the quality of the source water. The system will enable the maximization of the resource potential of the geothermal well and its all-year-round operation. The paper shows the efficiency of using the potential of geothermal energy resources in energy- biological complexes. The geothermal-biogas technology with the integrated application of thermal waters for various needs is presented. Such thermal water utilization provides for the most efficient use of its thermal potential with a decrease in temperature to a value close to the ambient temperature.

For Medical or Industrial Purposes? Issues of the Utilization of Thermal Waters in Southern Transdanubia in the Age of Socialism

For Medical or Industrial Purposes? Issues of the Utilization of Thermal Waters in Southern Transdanubia in the Age of Socialism

Hydrochemical characterization of thermal waters in Shipkovo thermal field

“Shipkovo” thermal water field is one of the few in the country formed in karstified carbonate rocks. Initially, there was a natural spring with elevated temperature, located at the boundary of Triassic karstified limestones and dolomites and Lower Cretaceous terrigenous rocks, sinking in depth to the east. Later, drilling operations were carried out in the area, which resulted in the discovery of additional quantities of water with different temperatures and chemical composition, which led to the discovery of additional water of different temperature and chemical composition. Eight wells were drilled east of the natural spring with a depth from 174 to 1315 m, with thermal waters from different depths found in the Triassic karst aquifer and the fissured Jurassic terrigenous rocks. The characterization of the chemical composition of the waters was made based on 55 water samples analyzes. It is established that the chemical composition is specific to the individual water sources and varies over time. The natural spring is characterized with the most significant fluctuations in the concentrations of some hydrochemical indicators – the maximum and minimum values of the total dissolved solids (TDS) differ approximately twice, and the pH – by about 2 units. As the flow rate of the spring increases and its temperature decreases, the type of water changes from HCO3-SO4–Ca-Mg to HCO3–Ca, and the concentrations of indicators characterizing the deep origin of thermal water decrease – fluorine (from 1.5÷1.6 to 0.1÷0.3 mg/l) and metasilicic acid (from 20÷25 to 10 mg/l). In periods when mainly deep mineral water flows from the spring, rather than mixed thermal and atmospheric waters, the concentrations of Ba, Sr, Al, Li are significantly higher. Comparison of the chemical composition of groundwater from individual wells shows the influence of geological and hydrogeological factors on its formation and changes in depth. The mixing of the waters formed by active water exchange in the karst environment of the Triassic limestones and dolomites with HCO3-Ca and HCO3-Ca-Mg type with the water formed in fractured rocks with stagnant character and SO4-Ca-Mg type in the Jurassic deposits and within the reach of the Shipkovo Fault, the fieldspecific SO4-HCO3-Ca-Mg waters are formed. With respect to the microcomponents, there is a slight tendency to increase the concentration of F, Sr, Ti, Ba, Mo, Ni, Mn in depth, but in the deepest wells they are relatively lower. The results obtained are useful in support of management decisions for the utilization of thermal waters from the Shipkovo field.

Thermal water utilization in the Hungarian greenhouse practice

This article focuses on the usage of geothermic energy in greenhouses, its energy-, economic efficiency- and sustainability-related questions. The most notable cost greenhouses produce during operation is the usage of heat energy, which is why when planning a system for this purpose, the energetic analysis of the solution to be used is one of the most important factors. The presented analyses suggest that of the energy resources currently available and usable, geothermic energy has the lowest unit cost. In the case of greenhouse heating, this method turned out to be the most cost-effective among all solutions using any of the energy resources. Regarding the environmental aspect, the CO2 emission rates of the various heating methods have been examined as well. Using the thermal water of the greenhouses before reinjection is an efficient way of energy utilization. Even though the firewood and pellet boilers look the most efficient forms for the first time, past experiences proved them to be the most expensive ones as well. Therefore, it can be stated that the utilization of geothermal energy is the best solution for greenhouse heating, from the perspectives of economic and environmental aspects as well. Based on the previous observations in terms of environmental and economic efficiency this paper aims to discover the opportunities for high-scale thermal utilization in Hungary in order to meet its future renewable targets.

Regional underpressure: a factor of uncertainty in the geothermal exploration of deep carbonates, Gödöllő Region, Hungary

Hungary has a remarkable geothermal potential, and there are ongoing projects investigating the possibilities of thermal water utilization. The regional hydrodynamic assessment of one of the most promising geothermal sites of Hungary, the Godollő Hills Region, could provide valuable additional information to them. The aim of this research was not only to carry out a regional study but also to demonstrate the relevance of the hydrodynamic approach in the reconnaissance phase of exploration. Regional evaluation was carried out based on the created database of preproduction wells’ hydraulic, temperature, and geochemical data. Based on the dataset from the depth extending to −2300 m asl, it could be shown that the temperature field (up to 120 °C) and the reservoir conditions are favorable: structurally influenced Triassic Main Dolomite and Dachstein Limestone, Miocene, and Upper Pannonian formations, and fluid flow is basically topography induced. The recharge and discharge zones of the gravity-driven system, the basement elevation, and the temperature distribution show good correlation. The vertical connections between Pannonian and Eocene-Triassic basement reservoirs could be followed through the changes of pressure regimes and by the interaction of “fresh” and “basinal” fluids of the region. It has been revealed that, due to the differentiated uplifting of the region in the Pliocene and the Quaternary, the pore pressures in the aquitards and in the basement reservoir have been shifted toward subhydrostatic, indicating geologically transient pore pressures. The detected subhydrostatic pressure gradients cause downward vertical groundwater flow in the Hills characterized by restricted recharge across low permeability strata. Upward vertical flow appears from the basement carbonate reservoir toward the highest negative pressure increment values in the aquitards. The underpressure in the basement carbonate reservoir causes an uncertainty factor in the exploration of a potential geothermal site. The area was differentiated based on flow and pressure conditions for geothermal exploitation.

Some experiences in tapping deep thermal waters of the Triassic karstic aquifer in the Pannonian Basin of Serbia

The Triassic karstic aquifer is the system with the greatest potential for the utilization of thermal waters in Serbia. As an integral part of the Dinaric tectonic unit, the Triassic aquifer extends widely over the western part of the Serbian territory and is characterized by cold waters. In contrast, the same but confined type of aquifer overlain by thick Tertiary sediments in the Pannonian Basin has significant geothermal potential. The major potential for tapping geothermal flow is in the southern and southwestern parts of the Pannonian Basin (Srem) and in the adjacent areas of Macva and Semberija in the Sava tectonic graben. In these areas the Triassic karstic aquifer has been tapped by several boreholes with depths ranging from 400 m to 2400 m. The temperature of the hottest water exceeds 75 °C, while maximal discharge is 40 l/s. Although the prospect of wider utilization of geothermal energy undoubtedly exists, some Serbian national plans count on a limited contribution of geothermal energy in renew...

Sustainability aspects of thermal water production in the region of Hajdúszoboszló-Debrecen, Hungary

As geothermal energy usage becomes more conspicuous the long-term effects of thermal water extraction become more significant. The greatest extent of exploitation in East Hungary occurs in the area of Hajduszoboszlo and Debrecen. The extracted thermal water is utilized mainly by their baths. In this paper, the sustainability of this system was examined with a steady state hydrodynamic model. The solid model is based on sequence stratigraphic interpretation while the hydraulic conductivity values were estimated based on the values of geophysical well-logs. The closely spaced wells cause a great subregional decrease of hydraulic head, particularly in the most intensively extracted layer, i.e. the layer of the delta front facies. The effects of extraction by the two spatial groups of wells intersect resulting in decreased profitability of subsequent wells. However, rationalizing thermal water utilization using water from shallower zones simultaneously may have beneficial effects on the yield distribution among the different layers.

Aspects of current geothermal application in Bulgaria

The territory of Bulgaria is rich in thermal water of temperature in the range of 20 °C–100 °C. Electricity generation from geothermal water is not currently available in the country. Direct thermal water use nowadays is mainly for balneology, space heating and air-conditioning, greenhouse heating, geothermal ground source heat pumps (GSHP), direct thermal water supply, and bottling of potable water and soft drinks. Several applications such as balneology and geothermal ground source heat pumps show more stable development in the current period, while geothermal energy used for heating of buildings and greenhouses has considerably decreased. The update information on hydrothermal fields is based on issued permits and concessions by the state since 2000 and concerns mainly state-owned hydrothermal fields. The current installed capacity amounts to about 85.8 MW (excl. GSHP). A progress has been recently made in the state policy promoting thermal water utilization. According to the latest amendments of the Water Act taxes for thermal water application are considerably reduced, and many state-owned reservoirs are made available for use by the municipalities.

Cooled and desalinated thermal water utilization in the Podhale heating system

Streszczenie Woda obiegowa w instalacjach ciepłowniczych musi posiadać odpowiednie parametry fizykochemiczne, uzależnione od wymagań technicznych producentów urządzeń, przez które przypływa. Nie powinna powodować powstawania kamienia kotłowego, pienić się oraz korozyjnie oddziaływać na elementy instalacji. W pracy przedstawiono badania dotyczące oceny możliwości wykorzystania odpadowych wód termalnych w celu uzupełnienia ubytków wody sieciowej w największym polskim geotermalnym systemie ciepłowniczym zlokalizowanym w obrębie niecki podhalańskiej. Obszar ten cechuje się dużymi zasobami wód termalnych, a jednocześnie deficytem wód zwykłych. Odpadowe wody termalne ze względu na wykazywane parametry fizykochemiczne mogą być wykorzystane w systemie dopiero po uzdatnieniu. Podczas badań zagospodarowana i uzdatniana była jedynie część całkowitego strumienia wody geotermalnej (do 5 m3/h), odpowiadająca mniej więcej zapotrzebowaniu systemu ciepłowniczego na świeżą uzdatnioną wodę obiegową (ok. 550 m3/miesiąc). Ubytki wody sieciowej wynikają z nieszczelności sieci, prowadzenia remontów, modernizacji lub obsługi sieci. Oczyszczanie przeprowadzone zostało z wykorzystaniem procesów membranowych w zintegrowanym systemie złożonym z ultrafiltracji (UF) i dwóch niezależnych stopni odwróconej osmozy (RO-1 i RO-2) połączonych szeregowo. Uzdatnianie prowadzone było przy częściowym wykorzystaniu artezyjskiego ciśnienia złożowego, co pozwoliło zredukować moc pomp obiegowych eliminując zużycie energii o około 0,7-0,9 kW. Dzięki pod­wyższonej temperaturze wody uzdatnionej zredukowana została moc cieplna o około 30 kW oraz efektywniej prowadzone były procesy oczyszczania i odgazowania wody. Uzyskano redukcję: zawartości żelaza ze stężenia około 4 do 0,013 g/m3, twardości ogólnej z 13,5 val/m3 do <0,02 val/m3, zasadowości z 4,45 val/m3 do <0,01 val/m3, fosforanów z 0,03 do <0,006 g/m3, uzyskując spełnienie wymagań określonych w normach, co po korekcie pH i odgazowaniu pozwala wykorzystać uzdatnione wody geotermalne dla uzupełnienia ubytków wody sieciowej w systemie ciepłowniczym. Polska Norma PN-85/C-04601 nie specyfikuje wymagań w zakresie dopuszczalnego stężenia m.in. chlorków i siarczanów w wodzie obiegowej, a więc anionów wpływających nakorozyjność wody, głównie wżerową. Jony te tworzą rozpuszczalne związki z metalami, utrudniając powstawanie i wytrącanie tlenków metali. Zastosowanie przedstawionej technologii membranowej w odsalaniu wód termalnych pozwoliło na uzyskanie wysokiego stopnia retencji. Wynosi on dla chlorków 97% po RO-1 i 99 % po RO-2, natomiast dla siarczanów 99% już po RO-1.

Analysis of thermal water utilization in the northeastern Slovenia

The presented research aims at identification of thermal water users in NE Slovenia, at finding type and amount of the produced thermal water as well as its utilization practice. The energetic overview has been upgraded by a description of current observational monitoring practice and thermal waste water management, but technological problems of thermal water use and their mitigation are discussed also. We have ascertained that 14 of 26 active geothermal wells tap the Mura Formation aquifer in which the only reinjection well is perforated also. Total thermal water abstraction summed to 3.29 million m3 in 2011. Cascade use of thermal water is abundant, where individual space and sanitary water heating is followed by heating of spa infrastructure and balneology. Greenhouse heating systems and district heating were also identified. Operational monitoring of these geothermal wells is generally insufficient, and geothermal aquifers are overexploited due to decades of historical water abstraction. All these facts indicate the need for applying appropriate measures which will improve their natural conditions as well as simultaneously enable further and even higher thermal water utilization in the future.

The hydrogeothermal basin of Sofia graben (Bulgaria)

In the Mesozoic basement and Neogene filling of Sofia tectonic graben a non-homogenous system of thermal water reservoirs connected to a united hydrogeothermal basin occurred. The basin contains and reproduces five types of low mineralized thermal waters and four types of mineralized thermal waters with exotic composition. The water temperatures are 30–80(90) °C. The total potential of the basin is assessed at 500 l/s thermal waters and 48 MWt thermal power. The utilization of thermal waters in the area of the Bulgarian capital has its roots and traditions in antiquity, and a promising future. The new town plan of Sofia provides construction of 35 centers for developing a versatile and prosperous hydrothermal business.

Development and utilization of thermal waters in Hungary

The object of this study is to provide information on the utilization of thermal waters and the conditions of thermal well development. A brief summary is given of the different branches of thermal water utilization in Hungary. The location of thermal wells according to the three important fields of use is shown in the Figures. The economic advantages and multipurpose utilization of thermal waters are mentioned. Finally, one the most important problems is considered, namely, the elimination of the precipitation of salts together with scaling control which greatly influences the certainty of continuous water production. In addition, the importance of compulsory measurements in the wells, and their scientific and practical advantages are also mentioned.

Utilization of thermal waters from oil deposits of the caucasus

During the exploitation of many gas-oil fields of the Caucasus a great quantity of thermal water is obtained. This water, with great economical effect, is sometimes used for hot water supplying of industrial and agricultural enterprises and for heating different commercial services etc. Great prospects for a wide utilization of thermal waters are opened in connection with the developing of the oil deposits, namely of the productive horizons of the Middle Miocene deposits. From only one oil field (in the October district of the north Caucasus) 5.6–6.2 million m 3 of water is annually extracted together with the oil. During the whole period of development up to the 1st of January 1969, 260 million m 3 of water at the head of many wells is higher than 80 °C. The extraction of heat by water out of the interior of the oil field amounted to 15.8·10 12 cal for the 55 year period. For generating the same quantity of heat it would be necessary to burn 1.58 million tons of mazut, or 2.3 million tons of coal, or about 2.0 billion m 3 of natural gas. The development, over many years, of Middle Miocene deposits led to a considerable decrease of hydrodynamic levels and expansion of cones of depressions for scores of kilometers. As a result of this there followed the reduction of yield and even the exhausting of many thermal springs. Approximately 90% of the large total recovery of the aggregate amount of liquid from Middle Miocene deposits was from 3–4 levels. A sharp reduction in the recovery of liquid from levels and in connection with the considerable development of some deposits resulted in the increase of hydrodynamic levels. Water of the earlier productive horizons are now the source of thermal supplying of some industrial enterprises. Long regime observations of thermohydrodynamic parameters showed high reliability of hydrodynamic systems in the Neogene deposits. It was observed that while using thermal waters it is necessary to make up their reserves artificially. To determine allowable recovery of thermal water and, in connection with this, to determine the quantity of water injected into the stratum for the recovery of its resources, thermal calculations have been made according to the scheme including convection, transportation of heat in the stratum and heat transfer of the surrounding rocks in the vertical direction. The calculations showed that the most favourable conditions of work of the considered hydrodynamic system, the Black Mountains - Peredovoy ridges, can be created by recovery and injection of 100,000 or 50,000 m 3 water per day. The linear distance between the injected and exploited wells is 5000 meters. At the injection and the extraction of 25,000 m 3 water/day, the temperature of the level will not appreciably decrease. In the near future in the Caucasus, side by side with the direct utilization of thermal energy of the underground waters, the extraction from them of iodine, bromine and other elements can be organized. Thermal mineral waters can have a still wider use for balneology purposes.

Occurrence and utilization of thermal waters in Poland

This paper describes the conditions in which thermal waters occur in Poland and their utilization. The possibilities for obtaining thermal waters in Poland are interesting though the exploitation temperatures are rather low. It is possible that, along with the extension of deep prospection borings, zones of hot waters occurrence may be discovered in the next future.

Geothermal resources of the USSR and prospects for their practical use

Planning of geological exploration for thermal waters and exploitation of geothermal fields should be preceded by: — establishment of bulk possible reserves of thermal waters all over the country — rating of technical-economical efficiency of thermal waters utilization and their share in the fuel-power budget of any particular district. Studies of main principles governing the area extent of thermal waters all over USSR territory; together with the estimation of their heat potential, mineralization and composition, have allowed us to distinguish over ten promising territories of thermal waters for practical utilization. Among them are the platform regions, where the thermal waters are in stratified position, as well as folded areas, where fissurevein type hot waters are found. Within these promising regions possible reserves have been estimated for thermal waters with a mineralization not exceeding 35 g/l and a temperature above 40°C, and associated to thermal aquifers occurring at a depth not exceeding 3000 m (for fissure-vein type waters no deeper than 300–500 m). These reserves seem to be over 250 m 3/sec. A primary condition for a paying exploitation of thermal resources to the end of geothermal heat supply (as a main kind consumption) to be obtained is a combined utilization of thermal waters, together with adequately selected and arranged consumers, application and working through of most progressive technical problems favouring and increasing the operation effect of heat potential. The mass introduction of geothermal heat supply should be preceded by large-scale experimental construction and checking of various heat-supply schemes on pilot-exploitational plants. This testing should be carried out within a wide range of hydrothermal, heat-engineering and climatic conditions. Some power-engineering characteristics are suggested (a geothermal heat-supply system efficiency factor, ratio of wells utilization), which allow us to characterize the efficiency of a particular devised scheme.

Technical-economic estimation of geothermal resources

Tremendous underground heat resources and simplicity of geothermal installations attracts ever more attention of power engineers in many countries of the world. To determine conditions and possible scale of earth heat effective utilization it is necessary to compare thoroughly geothermal sources with other energy sources. 1. 1. Classification of geothermal installation schemes. When utilizing thermal water for purposes of heat supply four different schemes can be used: 1) direct use of thermal water; 2) rising of geothermal temperature level in peak boiler shops; 3) rising of geothermal temperature level in heat pump installations; 4) combined schemes. There are comparative characteristics of these schemes given and conditions of their expedient application considered in the paper. Two schemes of geothermal power stations differ principally: 1) with vapour cycle of thermal water; 2) with secondary fluid cycle. Comparison of these schemes from the point of view of their power effectiveness, possibility of using water with different composition and operational conditions shows that none of the schemes is absolutely predominant. The choice of this or that scheme must be done with regard to local conditions. 2. 2) Technical-economical indices of geothermal heat sources. The direct heat source in systems of geothermal heat supply is the operational drill-well. Its useful heat output is determined by yield, depth, temperature gradient and geothermal conditions of the region. With increasing depth the thermal water temperature rises as well as the heat output of the well. Non-linearity of the well cost dependence from its depth predetermines the presence of optimal depth at which the best technical-economical characteristics of the well as an energy source are achieved. Generalization of data on investment in oil and gas wells drilling allows to obtain empirical dependences for determination of wells cost in prospected areas of thermal water utilization. Equations for determination of optimal well depth, of specific rated expenses and net cost of thermal water are obtained. Data on geothermal conditions, well's yield and the influence of the depth on basic economical characteristics of geothermal heat sources are presented in the paper. 3. 3. Comparison of geothermal heat sources with installations using organic fuels. As a criterion of the energy source effectiveness the value of specific reduced expences is accepted, which is determined as the relation of rated annual expenses sum to the annual power output. Comparing the specific reduced expenses for geothermal installations, heating boiler shops and thermal power stations it became possible to find conditions of economically expedient use of thermal water for heat supply and electric power generation. The main factors are geothermal conditions, well yield, drilling cost and the economical conditions of the region.