Kichik o'lchamlari va mukammal issiqlik samaradorligi tufayli, kartrijli isitgichlar nozik qolib isitish sanoatida kichik qolib teshiklarida isitish uchun juda mos keladi. Isitish effekti va xizmat muddatini muvozanatlash uchun muhandislar cheklangan hajmdagi isitgichning diametri va uzunligiga aniq mos kelishi kerak. Ushbu maqolada kartrijli isitgichlarning o'lchamiga mos keladigan tushunchalar, hisoblash texnikasi va haqiqiy{2}}qo'llanilishi ko'rib chiqiladi.
Metall qobiq, isitish simi, magniy oksidi kukuni izolyatsion qatlam va muhrlangan uchi bitta uchli elektr isitish trubkasini tashkil qiladi. Ishlayotganda, oqim Joule issiqligini ishlab chiqarish uchun isitish simidan oqib o'tadi, keyinchalik u magniy oksidi kukuni orqali metall qobiqqa o'tkazilgandan so'ng qolipga etkaziladi. Samarali issiqlik uzatishni ta'minlash va termal kengayish natijasida yuzaga keladigan mexanik stressni oldini olish uchun tor qolib teshiklarida isitish trubkasi va teshik devori o'rtasida mos bo'sh joy bo'lishi kerak.
Uchta fikr birinchi navbatda diametr tanlashni cheklaydi. Birinchidan, qolip teshigi diametri: isitish trubasining tashqi diametri odatda teshik diametridan 0,1-0,3 mm kichikroq bo'ladi, bu g'ilof materialiga (304 zanglamaydigan po'lat uchun 17,3 × 10⁻¹ / daraja), ish harorati oralig'iga (umuman 150-500 daraja) va issiqlik kengayish koeffitsientiga (umumiy ravishda qolib ketgan materialga) bog'liq. Po'lat qoliplar uchun 11,5×10⁻¹/ daraja). Ikkinchidan, quvvat zichligi balansi: kichikroq diametr sirt quvvati zichligini oshiradi, bu esa haddan tashqari issiqlikka olib kelishi mumkin. Standart quvvat zichligi havoda 5–15 Vt/sm² va qolipni isitish uchun 15–30 Vt/sm². Uchinchidan, ishlab chiqarish cheklovlari: zanglamaydigan po'latdan yasalgan qobiqlarning minimal diametri 3 mm dan katta yoki teng bo'lishi kerak, Inconelning minimal diametri 2,5 mm dan katta yoki teng bo'lishi kerak va titanium qotishmasining minimal diametri 2 mm dan katta yoki teng bo'lishi kerak.
Uzunlikni aniqlashda muhandislik omillarini hisobga olish kerak. Issiqlik balansi formulasi L=P/(p·D·q), bu erda P - kerakli umumiy quvvat (Vt), D - isitish trubkasi diametri (m) va q - sirt quvvati zichligi (Vt/m²), L uzunligini baholash uchun ishlatilishi mumkin. 15–30 mm lik isitish zonasi simlarni o'tkazish uchun,{5}}bo'lmagan isitish zonasi, suv o'tkazgichlari yoki suv o'tkazmalari bo'shliqlari va ichki o'rnatish moslamalari kabi xususiyatlarni chetlab o'tish. strukturaviy cheklovlarga misollar. Harorat taqsimotiga uzunlik-diametr nisbati (L/D): L/D ham ta'sir qiladi<10 produces clear end effects with a temperature difference of 30–50°C; L/D = 15–25 is the uniform range; and L/D >30 oraliq qizib ketishiga olib kelishi mumkin.
Coordinated diameter and length optimization depends on technical expertise and thermodynamic principles. Typical matching references include a 6mm hole with a 5.8mm tube (50-120mm, 100-300W), a 4mm hole with a 3.8mm tube diameter (30-80mm length, 50-150W), etc. Segmented heating is advised for deep holes (L/D>30); mikro-isitish uchun quvvat zichligi 8–12 Vt/sm² ga tushirilishi kerak (D<3mm). Important installation considerations include preserving expansion gaps, distributing electricity sensibly, and enhancing heat transmission using thermally conductive silicone grease. Power density, L/D ratio, and installation accuracy can be adjusted to address common issues including short service life and inconsistent temperature. Future trends will include sophisticated temperature control and downsizing when new materials and techniques are developed.
