Bai tap trac nghiem ky thuat

ThOng sOtrqng thdi Cdc thOng sO" trqng thdi co bdn CO 2 thang nhiCt dO: Thang nhiCt dO bdch phan.. kY hieu t, dO "C Celcius; Thang nhiCt dO tuyet d6i, kY hjeu t... d Nang luQng ddy ld na

Chdt mOi gicYi sinh cOng I > D: chdt mOi gidi nhiin cOng (bi nCn) / < 0 COng sudt ld cOng trong mOt don vi thdi gian:

N = J/s = W (watt), I KW = 1000 W 1.2.2 ThOng sOtrqng thdi

Cdc thOng sO" trqng thdi co bdn

CO 2 thang nhiCt dO:

Thang nhiCt dO bdch phan kY hieu t, dO "C (Celcius);

Thang nhiCt dO tuyet d6i, kY hjeu t dC) K ( Kelvin)

Quan he giUa cdc thang nhiet dO nhu sau:

T=273,l5+t=273+tNgodi ra a My vd cdc nude khdc cOn diing thang nhiCt dO Farenheit "F:

1.2.3 Cdc thOng s0"nhiet

a) Noi nang

U, j; u, J/kg ld nang luqng dqc trung cho hC kin

U = G.u.jVC9i khi iy tuOng, nOi nang ciia m(?i cha't khi Iii nhu nhau vd biing:

C/ll = C,,d7"

AU = GAu = GC,.(T, - I)b) Entanpy

I, j; i, jlkg ld nang luQng dac trung cho hc hO

/= G.i,jV8 khi iy tOng, entanpy cUa mQi cha"t khi ld nhu nhau vd bdng:

di = C,dT

Al = GAl = GC,(T - I)C) Entropy

ky hieu s j/k; s J/kg.k tinh cho 1 kg

S = G.s, J/K

d, = dq cITTrong dO T Id nhiet dO tuyCt deli ciia mOi cha't.

d) Nang luQng ddy ld nang luQng chi cO trong hc hO

D = pV vd cl = pi' tinh cho I kgC) Exergy ld nang luqng cO thC biCn dOi hoiin thiinh cOng trong qudtrinh thuqn nghjch, kY hiCu E, J: e, J/kg

CO thC viCt phucmg trinh sau day:

q=e+aTrong dO: a - anergy (phh nhiet nang khOng thC bie'n dOi thdnh cOngtrong qud trinh khOng thUn nghjch)

1.3 Phuong trinh djnh luQt nhiet @ng thU nhdt

1.3.1 Nhiet dung riCng vd cdc t/nh nhiet Iupng theo nhiet dung riCng

NhiCt dung rieng thuc

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