Tsarin aiki na ma'aunin zafi da sanyio

Ma'aunin zafi da wutan lantarki yana amfani da thermocouple a matsayin ma'aunin auna zafin jiki don auna ƙarfin thermoelectromotive wanda ya dace da yanayin zafi kuma ƙimar mizanin ana nuna ta mita. Ana amfani dashi ko'ina don auna yawan zafin jiki a cikin kewayon -200 ℃ ~ 1300 ℃, kuma a ƙarƙashin yanayi na musamman, zai iya auna babban zazzabi na 2800 ℃ ko ƙarancin zafin jiki na 4K. Yana da halaye na tsari mai sauƙi, ƙarancin farashi, daidaito mai girma, da kuma kewayon auna zafin jiki mai faɗi. Saboda thermocouple yana canza zafin jiki zuwa wutar lantarki don ganowa, yana da dacewa don auna da sarrafa zafin jiki, kuma don haɓaka da canza alamun zafin jiki. Ya dace da ma'aunin nesa da sarrafa atomatik. A cikin hanyar auna yanayin zafin lamba, aikace-aikacen ma'aunin zafi da zafi ya fi amfani.

DS-1
(1) Tsarin ma'aunin ma'aunin zafin jiki na Thermocouple
Ka'idar ma'aunin yanayin zafin jiki na thermocouple ya dogara ne akan tasirin thermoelectric.
Haɗa mahaɗan A da B na abubuwa biyu mabanbanta a jere zuwa madaidaiciyar madauki. Lokacin da zafin jikin lambobin biyu 1 da 2 suka bambanta, idan T> T0, za a samar da ƙarfin thermoelectromotive a cikin madauki, kuma za a sami wani adadi a cikin madauki. Manya da ƙananan raƙuman ruwa, ana kiran wannan lamarin tasirin kwayar halitta. Wannan karfin wutar lantarki shine sanannen "Seebeck thermoelectromotive force", wanda ake kira da "thermoelectromotive force", wanda aka nuna a matsayin EAB, kuma ana kiran masu tafiyar da A da B thermoelectrodes. Ana yin hulɗa da lamba 1 galibi tare, kuma ana sanya ta a wurin auna zafin don jin yanayin zafin da aka auna yayin aunawa, saboda haka ana kiransa ƙarshen aunawa (ko ƙarshen ƙarshen ƙarshen aiki). Mahimmin mahaɗar 2 yana buƙatar zazzabi mai ɗorewa, wanda ake kira mahaɗar ma'anar (ko mahaɗar sanyi). Wani firikwensin da ya haɗu da masu jan wuta biyu kuma ya mai da zafin jiki zuwa ƙarfin thermoelectromotive ana kiransa thermocouple.

Thearfin thermoelectromotive ya ƙunshi ƙarfin tuntuɓar masu jagoran biyu (Peltier yuwuwar) da yuwuwar bambancin yanayin zafin jiki na madugu guda (Thomson m). Girman ƙarfin thermoelectromotive yana da alaƙa da kaddarorin kayan kayan adawar biyu da yanayin mahaɗan mahaɗar.
Thearfin lantarki a cikin mai gudanarwa ya bambanta. Lokacin da masu jagoranci biyu A da B tare da nau'ikan lantarki daban-daban suke mu'amala, yaduwar lantarki yana faruwa a farfajiyar sadarwar, kuma wutan lantarki suna gudana daga mai gudanarwa tare da karfin wutar lantarki mai yawa zuwa ga mai gudanar da low density. Adadin yaduwar wutar lantarki yana da alaƙa da ƙarfin lantarki na mahaɗan biyu kuma yana dacewa da yanayin zafin jiki na yankin tuntuɓar. Idan aka ce yawancin electron na masu gudanar da A da B sune NA da NB, da NA> NB, sakamakon yaduwar wutan lantarki, madugu A yayi asaran electrons sai yayi chaji mai kyau, yayin da adaida B ya sami electron sai yayi chaji mara kyau, ya samar da lantarki fili a farfajiyar sadarwar. Wannan filin lantarki yana hana yaduwar kwayoyin wutan lantarki, kuma idan aka samu daidaituwar sikeli, sai a samu daidaitaccen bambancin yanayi a yankin da za'a iya tuntuɓar, ma'ana, yuwuwar tuntuɓar, wanda girmansa yake

(8.2-2)

Inda k-Boltzmann yake akai, k = 1.38 × 10-23J / K;
e – adadin cajin lantarki, e = 1.6 × 10-19 C;
T – Zazzabi a wurin tuntuɓar, K;
NA, NB - su ne nau'ikan lantarki na kyauta na masu gudanar da A da B, bi da bi.
Electarfin wutar lantarki wanda ya haifar da bambancin yanayin zafin jiki tsakanin iyakar biyu na mai gudanarwar ana kiransa tasirin thermoelectric. Saboda kwandon zazzabi, an canza rabon makamashin lantarki. Babban zazzabin karshen (T) wutan lantarki zai yaɗu zuwa ƙarshen ƙarancin zafin jiki (T0), ya haifar da ƙarshen zazzabin da za a ɗora masa caji mai kyau saboda asarar wutan lantarki, da kuma ƙarshen ƙananan zazzabin da za a caji mara kyau saboda wutar lantarki. Sabili da haka, ana haifar da banbanci mai yuwuwa a gefuna biyu na mai gudanarwar kuma yana hana electron yaɗuwa daga ƙarshen zafin jiki zuwa ƙarshen ƙarshen zafin jiki. Sannan electrons suna yaduwa don samar da daidaitattun daidaito. Bambancin yiwuwar da aka kafa a wannan lokacin ana kiransa thermoelectric potential ko Thomson potential, wanda ke da alaƙa da zafin jiki Domin

(8.2-3)

JDB-23 (2)

A cikin dabara, σ shine Thomson coefficient, wanda yake wakiltar ƙimar ƙarfin electromotive da aka samu ta banbancin zafin jiki na 1 ° C, kuma girmanta yana da alaƙa da kayyakin kayan ƙasa da yanayin zafin jiki a ƙarshen ƙarshen.
Hanyoyin rufe thermocouple wanda ya kunshi masu jagoranci A da B yana da damar sadarwa guda biyu eAB (T) da eAB (T0) a cikin lambobin biyu, kuma saboda T> T0, akwai damar thermoelectric a cikin kowane mai gudanarwa A da B. Saboda haka, jimillar ƙarfin wutar lantarki mai ƙarfi EAB (T, T0) na rufaffiyar madauki ya zama adadin algebraic na ƙarfin electromotive lamba da ƙarfin zafin wutar lantarki, wato:

(8.2-4)

Ga thermocouple da aka zaɓa, lokacin da zafin zafin yake nuni akai-akai, jimillar ƙarfin thermoelectromotive ya zama aiki mai daraja guda ɗaya na ƙarfin zafin jiki na ma'auni T, wato, EAB (T, T0) = f (T). Wannan shine ƙa'idar ma'aunin ma'aunin thermocouple.


Post lokaci: Jun-11-2021