25 Karno dvigateli (termodinamikaning ikkinchi qonunining qo'llanilishi) – muammolar va yechimlar
1. Dvigatel 1200 Kelvin va 300 Kelvin oralig'ida ishlaydi. Bu dvigatelning samaradorligi qancha?
Ma'lum:
Yuqori harorat (T H ) = 1200 K
Past harorat (T L ) = 300 K
Kerakli: Samaradorlik (e)
yechim:

2. Dvigatel 727 oralig'ida ishlaydioC va 127oC. Dvigatelning issiqlik sarfi 6000 Joul. Dvigatelning samaradorligi va har bir siklda bajaradigan ishi qancha?
Ma'lum:
baland harorat (TH) = 727oC + 273 = 1000 K
Past harorat (T)L) = 127oC + 273 = 400 K
Issiqlik sarfi (QH ) = 6000 Joul
Kerakli: Samaradorlik (e) va dvigatel tomonidan bajarilgan ish (Vt)
yechim:
ning samaradorligi Carnot dvigateli :

Ish Carnot dvigateli tomonidan bajariladi:
W = e QH
W = (0.6)(6000)
W = 3600 Joul
3. Dvigatel 527 oralig'ida ishlaydioC va 127oC. Dvigatelning issiqlik sarfi 10 000 Joulni tashkil qiladi. Bu dvigateldan qancha issiqlik chiqindi issiqlik sifatida chiqariladi?
Ma'lum:
Yuqori harorat (T H ) = 527 o C + 273 = 800 K
Past harorat (T)L) = 127oC + 273 = 400 K
Issiqlik kiritish (QH ) = 10,000 Joul
Qidirilgan: Issiqlik chiqishi (Q)L)
yechim:
Carnot dvigatelining samaradorligi:

Ish Carnot dvigateli tomonidan bajariladi:
W = e Q 1
W = (0.5)(10.000)
W = 5000 Joul
Issiqlik chiqishi (Q)L) = Issiqlik kiritish (QH) – Ish (W)
QL = QH - V
QL = 10,000 - 5,000
Q L = 5000 Joul
4. Quyidagi diagrammaga muvofiq dvigatelning samaradorligi va dvigatel tomonidan bajarilgan ish qanday.
Ma'lum:
Yuqori harorat (T H ) = 800 K
Past harorat (T L ) = 300 K
Issiqlik sarfi (QH ) = 1000 Joul
Kerakli: Samaradorlik (e) va ish (W) dvigatel tomonidan bajarilgan
yechim:
Carnot dvigatelining samaradorligi:

Ish Carnot dvigateli tomonidan bajariladi:
W = e QH
W = (0.625)(1000)
W = 625 Joul
5. Agar Carnot dvigateli �(500\,K \) va �(300\,K \) oralig'ida ishlayotgan bo'lsa, uning samaradorligini hisoblang.
Yechim: \( \eta = 1 – \frac{T_C}{T_H} = 1 – \frac{300}{500} = 0.4 = 40\% \)
6. Carnot sovutgichining √(300,K) va √(250,K) oralig'ida ishlashining samarali samaradorligini toping.
Yechim: \( \eta = \frac{T_C}{T_H – T_C} = \frac{250}{50} = 5 = 500\% \)
7. Carnot dvigatelining samarali samaradorligi �(30% ga teng). Agar �(T_C = 300,K \) bo'lsa, �(T_H \) ni toping.
Yechim: \( T_H = \frac{T_C}{1 – \eta} = \frac{300}{0.7} \taxminan 428.57\,K \)
8. Agar Carnot issiqlik nasosi 270 K va 330 K oralig'ida ishlayotgan bo'lsa, unumdorlik koeffitsientini (COP) toping.
Yechim: \( \text{COP} = \frac{T_H}{T_H – T_C} = \frac{330}{60} = 5.5 \)
9. 50% samaradorlikka va 400 K ga teng bo'lgan Carnot dvigateli uchun ni aniqlang.
Yechim: \( T_C = T_H \marta (1 – \eta) = 400 \marta 0.5 = 200\,K \)
10. \( 373\,K \) va \( 273\,K \) oralig'ida ishlaydigan Carnot dvigatelining samarali ish faoliyatini hisoblang.
Yechim: \( \eta = 1 – \frac{273}{373} \taxminan 0.268 = 26.8\% \)
11. Carnot sovutgichining mоslama qiymatini toping, bunda mоslama qiymati ...
Yechim: \( \text{COP} = \frac{T_C}{T_H – T_C} = \frac{260}{40} = 6.5 \)
12. Carnot dvigateli 25% samaradorlikka va 200% samaradorlikka ega. (T_C = 200 K) ni toping.
Yechim: \( T_H = \frac{T_C}{1 – \eta} = \frac{200}{0.75} \taxminan 266.67\,K \)
13. Agar Carnot issiqlik nasosi 220K va 320K oralig'ida ishlayotgan bo'lsa, COP ni toping.
Yechim: \( \text{COP} = \frac{T_H}{T_H – T_C} = \frac{320}{100} = 3.2 \)
14. 60% samaradorlikka va 500 K ga teng bo'lgan Carnot dvigateli uchun ni aniqlang.
Yechim: \( T_C = T_H \marta (1 – \eta) = 500 \marta 0.4 = 200\,K \)
15. \( 600\,K \) va \( 400\,K \) oralig'ida ishlaydigan Carnot dvigatelining samarali ish faoliyatini hisoblang.
Yechim: \( \eta = 1 – \frac{400}{600} \taxminan 0.333 = 33.3\% \)
16. Carnot sovutgichining mоslama qiymatini toping, bunda mоslama qiymati ...
Yechim: \( \text{COP} = \frac{T_C}{T_H – T_C} = \frac{280}{50} = 5.6 \)
17. Carnot dvigateli 40% samaradorlikka va 250% samaradorlikka ega. (T_C = 200 K) ni toping.
Yechim: \( T_H = \frac{T_C}{1 – \eta} = \frac{250}{0.6} \taxminan 416.67\,K \)
18. Agar Carnot issiqlik nasosi 270K va 370K oralig'ida ishlayotgan bo'lsa, COP ni toping.
Yechim: \( \text{COP} = \frac{T_H}{T_H – T_C} = \frac{370}{100} = 3.7 \)
15. 75% samaradorlikka va 800 K ga teng bo'lgan Carnot dvigateli uchun ni aniqlang.
Yechim: \( T_C = T_H \marta (1 – \eta) = 800 \marta 0.25 = 200\,K \)
16. \( 700\,K \) va \( 300\,K \) oralig'ida ishlaydigan Carnot dvigatelining samarali ish faoliyatini hisoblang.
Yechim: \( \eta = 1 – \frac{300}{700} \taxminan 0.571 = 57.1\% \)
17. Carnot sovutgichining mоslama qiymatini toping, bunda mоslama qiymati ...
Yechim: \( \text{COP} = \frac{T_C}{T_H – T_C} = \frac{250}{100} = 2.5 \)
18. Carnot dvigateli 10% samaradorlikka va 150% samaradorlikka ega. (T_C = 200 K) ni toping.
Yechim: \( T_H = \frac{T_C}{1 – \eta} = \frac{150}{0.9} \taxminan 166.67\,K \)
19. Agar Carnot issiqlik nasosi 200K va 400K oralig'ida ishlayotgan bo'lsa, COP ni toping.
Yechim: \( \text{COP} = \frac{T_H}{T_H – T_C} = \frac{400}{200} = 2 \)
20. 80% samaradorlikka va 1000 K ga teng bo'lgan Carnot dvigateli uchun ni aniqlang.
Yechim: \( T_C = T_H \marta (1 – \eta) = 1000 \marta 0.2 = 200\,K \)