Zafin jiki

Therm (alama, thm)  SI  ne  na naúrar zafi daidai da 100,000 British thermal units (BTU),  kuma kusan  megajoules,  kilowatt-hours, 25,200 kilocalories da  thermies. Ɗaya daga cikin zafin jiki shine ƙarfin makamashi na kusan 100 cubic feet (2.83 cubic meters) na iskar gas a daidaitattun zafin jiki da matsin lamba. Koyaya, BTU ba a daidaita shi a duk duniya ba, tare da ƙimar da ta bambanta a cikin EU, Burtaniya, da Amurka, ma'ana cewa abubuwan da ke cikin makamashi na zafin jiki sun bambanta da yankin.

Mita na iskar gas na halitta yana auna girma ba ma'anar makamashi ba, kuma idan aka ba da cewa yawan makamashi ya bambanta tare da cakuda hydrocarbons a cikin iskar gas, kamfanonin iskar gas suna amfani da "ma'anar zafi" don canza girman iskar gas da aka yi amfani da ita zuwa daidai da zafi, yawanci ana bayyana shi a cikin raka'a na "ma'a ta CCF" (CCF taƙai ce ga 100 na ma'aunin cubic feet). Fiye da matsakaicin maida hankali na ethane, propane ko butane zai kara yawan zafin jiki kuma hadawar ƙazanta marasa wuta, kamar carbon dioxide ko nitrogen zai rage shi. Ana amfani da Wobbe Index na iskar gas a wasu lokuta don ƙididdige adadin zafi a kowane ɗayan ƙonewa.

 Ma'anar 

 Therm (EC)=  BTU<sub id="mwLw">ISO</sub> 
 =  joules
 ≈  kWh
 Injiniyoyi a Amurka suna amfani da zafin jiki (EC).
 Therm (US)  BTU59 °F 
 =  joules
 ≈ 29.30011111111 kWh.
 Therm (UK)  joules 
 Sashen  kWh

 Rashin sutura 
A decatherm or dekatherm (dth or Dth) is 10 therms, shine 1,000,000British thermal units or 1.055 GJ.  a hade ne na prefix na 10 (deca, sau da yawa tare da rubutun "deka") na Amurka da sashin makamashi.  Akwai wasu shubuha, kamar yadda “decatherm” ke amfani da prefix “d” wajen nufin 10, inda a ma’aunin ma’auni “d” na nufin “deci” ko kashi daya bisa goma, sai kuma “da” na nufin “deca”, ko 10.  ko da yake decatherm na iya amfani da babban "D".  Abubuwan makamashi na ƙafafu iskar gas da aka auna a daidaitaccen yanayi yana kusan daidai da dekatherm ɗaya. 

Ana amfani da wannan rukunin makamashi da farko don auna iskar gas. Gas na halitta cakuda ne na iskar gas wanda ke dauke da kusan 80% methane (CH4) kuma darajar dumama ta bambanta daga kusan 10.1 zuwa 11.4 kilowatt-hours a kowace cubic mita (975 zuwa 1,100 Btu / cu , dangane da cakuda iskar gas daban-daban a cikin iskar gas. Gir iskar gas tare da darajar dumama na dekatherm ɗaya kusan 910 zuwa 1,026 cubic feet (25.8 zuwa 29.1 m). Noncombustible carbon dioxide (CO2) yana rage ƙimar dumama na iskar gas. Hydrocarbons masu nauyi kamar su ethane (C2), propane (C3), da butane (C4) suna ƙara ƙimar dumama. Tunda abokan ciniki da ke sayen iskar gas a zahiri suna sayen zafi, kamfanonin rarraba iskar gas waɗanda ke biyan kuɗi ta hanyar girma suna daidaita farashin su don biyan wannan.

Kamfanin Texas Eastern Transmission Corporation, kamfanin bututun mai, ya fara amfani da dekatherm a cikin shekara ta 1972. Don sauƙaƙa biyan kuɗi, ma'aikatan Texas Eastern sun kirkiro kalmar dekatherm kuma sun ba da shawarar amfani da calorimeters don auna da lissafin gas da aka ba abokan ciniki a dekatherms. Wannan zai kawar da lissafin gyare-gyare na yau da kullun zuwa dala a kowace ƙimar cubic feet 1000 don tabbatar da cewa duk abokan ciniki sun sami adadin zafi iri ɗaya a kowace dala. An gabatar da yarjejeniyar sulhu da ke nuna sabon tsarin biyan kuɗi da ƙimar sulhu a cikin 1973. Hukumar Kula da Wutar Lantarki ta Tarayya ta ba da umarni da ta amince da yarjejeniyar sulhu da sabon farashi ta amfani da dekatherms daga baya a wannan shekarar,  Sauran kamfanonin rarraba gas suma sun fara amfani da wannan tsari.

Duk da bukatar gyare-gyare, kamfanoni da yawa suna ci gaba da amfani da daidaitattun ƙafafun cubic maimakon dekatherms don auna da lissafin iskar gas.

 Amfani da shi 
An yi gyare-gyare na ka'idojin Burtaniya don maye gurbin therms tare da joules tare da tasiri daga 1999, tare da iskar gas yawanci ana siyar da ita a cikin na'urar da aka samo, kilowatt-hours. Duk da wannan, kasuwar gas ta Burtaniya tana kasuwanci a cikin therms. A Amurka, ana yawan biyan iskar gas a cikin CCFs (daruruwan ƙafafun cubic) ko therms.

 Saurin carbon 
A cewar EPA ƙonewar zafi ɗaya na iskar gas yana samar da matsakaicin    na carbon dioxide.

 Dubi kuma 

 Baril na mai daidai
 Conversion of units § Energy
 Cubic Mile na Man Fetur

 Bayanan da aka ambata 

Category:Kiwon Lafiya