1、Designation: E 957 03Standard Terminology Relating toGeothermal Energy1This standard is issued under the fixed designation E 957; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses in
2、dicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.aquifer, na water-bearing, permeable body of rock orgranular material below the surface of the earth.binary cycle plant, na facility that generates electric powerby trans
3、ferring heat from produced geothermal fluids to anon-aqueous working fluid that vaporizes and causes aturbine to rotate the shaft of a generator.brine, nin geothermal, fluids in a liquid phase that have beenproduced from geothermal wells or from hot springs and thatcontain appreciable amounts of sod
4、ium chloride and othersalts.capacity, nthe power which a component of a geothermalfacility (e.g., a well, a reservoir, a power plant, or adirect-use facility) is capable of supplying at a point in time,assuming that other required components of the geothermalfacility are available. Capacity is expre
5、ssed in units of power(e.g., Megawatts, kilowatts).direct-use facility, na facility which uses geothermal energyfor purposes other than the generation of electricity (e.g.,space heating, greenhouses, bathing, and industrial pro-cesses).fumarole, na vent at the earths surface that emits steam orgaseo
6、us vapor.DISCUSSIONSuch vents are usually found in volcanic areas.geochemistry, nthe study of the chemistry of the rocks andfluids of the earth for the purpose of understanding theircomposition, their temperature, and their origin.geothermal, adjrelating to or derived from the natural heatof the ear
7、th.geothermal anomaly, na conspicuous deviation of theearths temperature, geothermal gradient, or heat flow fromaverage values; an area where such a deviation exists.geothermal energy, nthe thermal energy contained in therocks and fluids of the earth.geothermal facility, nthe physical components nec
8、essaryfor the utilization of geothermal energy, including thereservoir, production and injection wells, pipelines, and thepower plant or direct-use facility.geothermal fluid, nwater in a vapor or liquid phase or in amixture of these phases that exists within or has been emittedfrom a geothermal rese
9、rvoir, together with any entrained ordissolved substances.geothermal gradient, nthe change in temperature of theearth with depth, expressed either in degrees of temperatureper unit depth, or units of depth per degree.geothermal power plant, na facility for the production ofelectricity using geotherm
10、al energy, typically including aturbine, a generator, and associated surface equipment.geothermal heat pump, na heat pump that transfers energyto or from the earth.geothermal reserves, nthe amount of energy anticipated tobe economically recoverable from a geothermal facility overa specified time per
11、iod (e.g., the project life) using existingtechnology. Geothermal reserves are expressed in units ofenergy (e.g., terajoules in SI units), which are dimensionallyequivalent to units of power multiplied by units of time (e.g.,Megawatt-years or kilowatt-hours). Geothermal reservesmay also be expressed
12、 as an equivalent amount of anotherenergy source (e.g., barrels of oil equivalent).DISCUSSIONGeothermal reserves can also be characterized as to thedegree of certainty of recovery. By analogy to usage in the mining andpetroleum industries, reserves may be qualified as proved, probable, orpossible.Ex
13、ample of Usage:This facility has geothermal reserves of 4,000 Megawatt-years, recoverable over a project life of 30 years.geothermal reservoir, nan aquifer of sufficient temperatureand permeability to support the economic use of geothermalenergy.DISCUSSIONThe extent of a geothermal reservoir is dete
14、rmined bythe degree of hydrologic interconnection. When an aquifer containsboth hot portions and portions that are too cool for economic use, thoseportions that are sufficiently interconnected to have a significant1This terminology is under the jurisdiction of ASTM Committee E44 on Solar,Geothermal
15、and Other Alternative Energy Sources and is the direct responsibility ofSubcommittee E44.15 on Geothermal Field Development, Utilization and Materials.Current edition approved March 10, 2003. Published May 2003. Originallyapproved in 1983. Last previous edition approved in 2002 as E 957 02.1Copyrigh
16、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.hydrologic or thermal impact on each other are considered part of thesame geothermal reservoir.geothermal steam, na geothermal fluid in the vapor phase.geothermometer, na method of estimating th
17、e temperatureof a geothermal reservoir based on the minerals in thereservoir rock or the concentration of chemical species ingeothermal fluids that have come from the reservoir.geyser, na spring that intermittently blows forth hot waterand steam.heat flow, ndissipation or transfer of heat coming fro
18、mwithin the earth by conduction, convection or radiation at thesurface; usually reported in units of energy per unit time perunit area, for example, joules per second per square metre orwatts per square metre.hot spring, na thermal spring whose temperature is abovethat of the human body. Meinzer (19
19、23)magma, nmolten rock within the earth or within otherplanets.moisture content, nthe percentage by mass of liquid-phasewater in a two-phase mixture of vapor-and liquid-phasewater.DISCUSSIONThe moisture content of a two-phase mixture is equiva-lent to 100 minus the steam qualitynoncondensible gas co
20、ntent, nthe concentration of noncon-densible gas in a geothermal fluid.DISCUSSIONThe principal geothermal noncondensible (NC) gasesinclude carbon dioxide, hydrogen sulfide, ammonia, nitrogen, methane,hydrogen, and argon. Standard usage is to express NC gas content as apercentage by mass in the refer
21、ence fluid; that is,(NC gas content = mass NC gas/ (mass fluid + mass NC gas) 3100, where fluid = water vapor, or water vapor + liquid (total fluid)Other units for NC gas content (such as percentage by volume ormole ration) may also be used. The units and the reference fluid for NCgas content should
22、 always be explicitly stated.noncondensible gases, nin geothermal, chemical species(such as carbon dioxide or hydrogen sulfide) that areconstituents of geothermal fluids, that partition primarilyinto the vapor phase when geothermal fluids boil, and that donot condense along with geothermal steam whe
23、n put througha condenser in a geothermal power plant.permeability, nthe ability of a rock to transmit fluid.DISCUSSIONThe amount of permeability of a rock depends on thesize, shape, and degree of interconnection of the rocks pores andfractures. Permeability is expressed as the ability to transmit fl
24、uid of aspecified viscosity at a specified flow rate through a specified areaunder the influence of a specified pressure gradient. The traditional unitof permeability is the darcy or the millidarcy. The SI unit is the squaremicrometer. These units have the dimension of length squared.phreatic erupti
25、on, nan explosion of the surface of the earththat results from a sudden increase in the volume ofgroundwater when it flashes to steam due to contact with hotrocks.DISCUSSIONTypically in an area of hot springs or fumaroles, and nolava or other materials derived from magma are erupted.porosity, nthe r
26、atio of the aggregate volume of interstices ina rock or soil to its total volume, usually stated as a percent.project life, nthe time period over which the economicviability of a geothermal facility is evaluated.reinjection/injection, nthe process of conveying geothermalfluids to sub-surface formati
27、ons through wells.DISCUSSIONAfter such fluids have been processed by a geothermalpower plant or its associated facilities, or both, this process issometimes referred to as “reinjection” when injected water circulatesback through the geothermal reservoir to the production wells.steam purity, nthe pro
28、portion by mass of pure vapor-andliquid-phase water in a fluid mixture that consists primarilyof steam.DISCUSSIONGeothermal steam may contain impurities, such assilica, sodium, chloride, iron and solid particulates. Steam purityexpresses the proportion by mass of pure water (in both liquid andvapor
29、phases) in this mixture. Typically, only steam impurity isdiscussed in quantitative terms; the impurities are expressed in units ofconcentration by mass in the steam mixture.Impurities such as sodium and chloride may be present as dissolvedspecies in liquid water, or as particulate material, such as
30、 solid NaCl.Likewise, silica may be dissolved in water or present as a solidparticulate. In cases where volatile chloride exists (HCl and/or NH4Cl),the volatile and nonvolatile species of chloride may be listed indepen-dently. Baron is a semi-volatile species that partitions between thevapor and liq
31、uid phases and is typically not grouped with the othernon-volatile species. Noncondensible gas is not usually classified as asteam impurity, but is considered separately.Example Geothermal steam purity may be expressed in terms ofthe known impurities in the steam:Chloride 0.75 ppmSodium 0.30 ppmSili
32、ca 0.05 ppmIron 0.02 ppmOther non-volatile dissolved impurities 0.18 ppmTotal Dissolve Solids (TDS, sum of nonvoaltile, dissolved impurites 1.3 ppmParticulate matter 0.50 ppmTotal Solids (TS, sum of all non-volatile impurities 1.8 ppmBoron (semil-volatile impurity, considered separately 35.0 ppmstea
33、m quality, nthe percentage by mass of vapor-phasewater in a two phase mixture of vapor- and liquid-phasewater.DISCUSSIONGeothermal steam may contain a small amount ofliquid-phase water, as well as non-aqueous constituents, such asnoncondensible gas and silica. Steam quality expresses the proportiono
34、f vapor-phase water relative to the mixture of vapor-and liquid-phasewater only. The term “steam quality” is synonymous with the term“steam dryness”.Example A two-phase geothermal fluid consists of thefollowing mass percentages: 90% vapor-phase water, 6%liquid-phase water, 3% noncondensible gas, 1%
35、total dissolvedsolids.The steam quality of this mixture is 90/(90+6)3100 =93.75%.sustainable capacity, nthe power which a component of ageothermal facility (such as a reservoir or a power plant) iscapable of sustaining for a specified period of time.DISCUSSIONThe period of time over which a certain
36、capacity can besustained may be different than the project life.Examples of Usage:This reservoir has a sustainable capacity of 100 MW for atleast 30 years.This reservoir has a capacity of 50 MW, sustainable for atE957032least the first 20 years of a 30-year project life.With proper maintenance, this
37、 power plant has a sustainablecapacity of 30 MW for 30 years.total dissolved solids content of steam, nthe concentrationby mass of non-volatile, dissolved impurities in geothermalsteam.DISCUSSIONGeothermal steam may contain non-volatile impurities,such as silica, sodium, chloride and iron, that may
38、be considereddissolved in droplets of liquid water. The total dissolved solids content(TDS) of steam expresses the sum of these impurities as a concentrationby mass in the water vapor and liquid mixture. Semi-volatile constitu-ents such as boron (boric acid, H3BO3) are not usually considered partof
39、the total dissolved solids in steam.warm spring, nthermal spring whose temperature is appre-ciably above the local mean annual temperature but belowthat of the human body. Meinzer (1923)This standard is subject to revision at any time by the responsible technical committee and must be reviewed every
40、 five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technic
41、al committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E957033
