1、Designation: E957 03 (Reapproved 2011)1Standard Terminology Relating toGeothermal Energy1This standard is issued under the fixed designation E957; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTETypographical errors were corrected editorially in September 2011.aquifer, na water-bearing, permeable body of rock orgranular material below the sur
3、face of the earth.binary cycle plant, na facility that generates electric powerby transferring 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 beenproduc
4、ed from geothermal wells or from hot springs and thatcontain appreciable amounts of sodium 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 th
5、at other required components of the geothermalfacility are available. Capacity is expressed 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
6、industrial pro-cesses).fumarole, na vent at the earths surface that emits steam orgaseous 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,
7、 and their origin.geothermal, adjrelating to or derived from the natural heatof the earth.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 containe
8、d in therocks and fluids of the earth.geothermal facility, nthe physical components necessaryfor 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 i
9、n amixture of these phases that exists within or has been emittedfrom a geothermal reservoir, 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 deg
10、ree.geothermal power plant, na facility for the production ofelectricity using geothermal 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 antici
11、pated tobe economically recoverable from a geothermal facility overa specified time period (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
12、 time (e.g.,Megawatt-years or kilowatt-hours). Geothermal reservesmay also be expressed 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 minin
13、g andpetroleum industries, reserves may be qualified as proven, probable, orpossible.Example 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
14、economic use of geothermalenergy.DISCUSSIONThe extent of a geothermal reservoir is determined 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 significan
15、t1This terminology is under the jurisdiction of ASTM Committee E44 on Solar,Geothermal and Other Alternative Energy Sources and is the direct responsibility ofSubcommittee E44.15 on Geothermal Field Development, Utilization and Materials.Current edition approved Sept. 1, 2011. Published September 20
16、11. Originallyapproved in 1983. Last previous edition approved in 2003 as E957 03. DOI:10.1520/E0957-03R11E01.1Copyright 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 g
17、eothermal reservoir.geothermal steam, na geothermal fluid in the vapor phase.geothermometer, na method of estimating the 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.geys
18、er, na spring that intermittently blows forth hot waterand steam.heat flow, ndissipation or transfer of heat coming fromwithin 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 met
19、re orwatts per square metre.hot spring, na thermal spring whose temperature is abovethat of the human body. (Meinzer 1923)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.D
20、ISCUSSIONThe moisture content of a two-phase mixture is equiva-lent to 100 minus the steam quality.noncondensible gas content, nthe concentration of noncon-densible gas in a geothermal fluid.DISCUSSIONThe principal geothermal noncondensible (NC) gasesinclude carbon dioxide, hydrogen sulfide, ammonia
21、, nitrogen, methane,hydrogen, and argon. Standard usage is to express NC gas content as apercentage by mass in the reference 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
22、(such as percentage by volume ormole ratio) may also be used. The units and the reference fluid for NCgas content should always be explicitly stated.noncondensible gases, nin geothermal, chemical species(such as carbon dioxide or hydrogen sulfide) that areconstituents of geothermal fluids, that part
23、ition primarilyinto the vapor phase when geothermal fluids boil, and that donot condense along with geothermal steam when 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
24、, and degree of interconnection of the rocks pores andfractures. Permeability is expressed as the ability to transmit fluid 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
25、or the millidarcy. The SI unit is the squaremicrometre. These units have the dimension of length squared.phreatic eruption, 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.DISCUSSIONTypical
26、ly in an area of hot springs or fumaroles, and nolava or other materials derived from magma are erupted.porosity, nthe ratio 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 g
27、eothermal facility is evaluated.reinjection/injection, nthe process of conveying geothermalfluids to sub-surface formations through wells.DISCUSSIONAfter such fluids have been processed by a geothermalpower plant or its associated facilities, or both, this process issometimes referred to as “reinjec
28、tion” when injected water circulatesback through the geothermal reservoir to the production wells.steam purity, nthe proportion by mass of pure vapor-andliquid-phase water in a fluid mixture that consists primarilyof steam.DISCUSSIONGeothermal steam may contain impurities, such assilica, sodium, chl
29、oride, iron and solid particulates. Steam purityexpresses the proportion by mass of pure water (in both liquid andvapor 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.Impuri
30、ties such as sodium and chloride may be present as dissolvedspecies in liquid water, or as particulate material, such as 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 spe
31、cies of chloride may be listed indepen-dently. Boron is a semi-volatile species that partitions between thevapor and liquid 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 Ge
32、othermal steam purity may be expressed in terms ofthe known impurities in the steam:Chloride 0.75 ppmSodium 0.30 ppmSilica 0.05 ppmIron 0.02 ppmOther nonvolatile dissolved impurities 0.18 ppmTotal Dissolved Solids (TDS, sum of nonvolatile, dissolved impuri-ties)1.3 ppmParticulate matter 0.50 ppmTota
33、l Solids (TS, sum of all nonvolatile impurities) 1.8 ppmBoron (semi-volatile impurity, considered separately) 35.0 ppmsteam 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
34、 water, as well as non-aqueous constituents, such asnoncondensible gas and silica. Steam quality expresses the proportionof 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 geotherma
35、l fluid consists of thefollowing mass percentages: 90% vapor-phase water, 6%liquid-phase water, 3% noncondensible gas, 1% 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 o
36、r a power plant) iscapable of sustaining for a specified period of time.DISCUSSIONThe period of time over which a certain 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.E957 03 (2011)12This re
37、servoir has a capacity of 50 MW, sustainable for atleast the first 20 years of a 30-year project life.With proper maintenance, this 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
38、geothermalsteam.DISCUSSIONGeothermal steam may contain non-volatile impurities,such as silica, sodium, chloride and iron, that may 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 t
39、he water vapor and liquid mixture. Semi-volatile constitu-ents such as boron (boric acid, H3BO3) are not usually considered partof 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 bod
40、y. (Meinzer 1923)This standard is subject to revision at any time by the responsible technical committee and must be reviewed every 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 ad
41、dressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical 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, a
42、t 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E957 03 (2011)13
