Zana ya Uhandisi Isiyolipisha
Kikokotoo cha Kipindi cha Kubadilisha Mafuta
Hesabu vipindi vya kubadilisha mafuta vilivyorekebishwa kutoka saa za msingi kwa kutumia mambo ya joto la uendeshaji, uchafuzi, uzito wa mzigo, aina ya mafuta, na ubora wa kichujio. Inajumuisha ulinganisho wa gharama na mapendekezo ya uchambuzi wa mafuta.
Matokeo ya Muda
Fomula ya Muda Uliorekebishwa
Kila kipengele hurekebisha muda wa msingi juu au chini. Thamani >1 huongeza muda; thamani <1 hupunguza muda.
Kipengele cha Joto (Kanuni ya Arrhenius)
Oil oxidation rate approximately doubles for every 10°C increase above 60°C. This is the single most important factor.
| Temperature | Factor | Effect |
|---|---|---|
| < 50°C | ×1.3 | Uoksidishaji polepole sana |
| 50–70°C | ×1.0 | Msingi wa kawaida |
| 70–85°C | ×0.7 | Kuzeeka kwa kasi |
| 85–100°C | ×0.5 | Half life |
| > 100°C | ×0.3 | Uharibifu wa haraka |
Kipengele cha Uchafuzi
Uchafuzi wa chembe husababisha asilimia 70–80 ya hitilafu zote za mifumo ya majimaji. Hata viwango vidogo vya maji (>200 ppm) huharakisha mmomonyoko kwa kiasi kikubwa.
Kipengele cha Aina ya Mafuta
Synthetic oils have better oxidation stability, lower pour points, and higher VI. PAO synthetics typically last 2× longer; ester-based 2.5× longer than mineral oils under same conditions.
Mfano wa Vitendo
Given: Base 4000 h, hot (×0.5), dusty (×0.75), heavy load (×0.7), mineral oil (×1.0), standard filter (×1.0)
Factor = 0.5 × 0.75 × 0.7 × 1.0 × 1.0 = 0.2625
Adjusted = 4000 × 0.2625 = 1050 hours
→ With synthetic oil (×2.0): 2100 hours — still economical.
⚠️ Important: Mambo haya ni mwongozo tu. Daima thibitisha kwa uchambuzi wa mafuta. Vifaa vya dharura vinapaswa kuwa na mpango wa uchambuzi wa mafuta bila kujali muda uliohesabiwa.
Vipindi vya Kawaida vya Msingi
| Equipment | Base (hours) | Notes |
|---|---|---|
| Gearbox ya viwandani | 4000–8000 | Ulainishaji wa kunyunyizia au wa kulazimishwa |
| Mfumo wa majimaji (hydraulic) | 2000–4000 | Hatari kubwa ya uchafuzi |
| Diesel engine | 250–500 | Mkusanyiko wa masizi/asidi |
| Compressor | 2000–4000 | Msongo wa joto kali |
| Mabeba ya motor za umeme | 8000–16000 | Kulainisha tena kwa grisi |