12.97 At steady state, air at 42C, 1 atm, 30% relative humidity is mixed adiabatically
with a second moist air stream entering at 1 am. The mass flow rates of the two streams
are the same. A single mixed stream exits at 29C, 1 atm, 40% relative humidity w
0 = m 1 h1 + m 2 h2 m 3 h3
Substituting for m 3 from the mass rate balance
0 = m 1 h1 + m 2 h2 ( m 1 + m 2 )h3
Solving for m 2
m 2 =
m 1 h3 h1
At inlet 1, the water is compressed liquid. From Table A-2, h1 hf1 = 209.33 kJ/kg
s. _ Air enters the compressor of an air-standard regenerative
gas turbine at p, = 14.7 lbflin T, = 530R with a mass flow
rate of 90,000 lblh. The compressor pressure ratio 18 10, the
turbine inlet temperature is 2200R, and the regenerator
9.51: Solve Problem 9.55 on a cold air-standard basis with
specic heats evaluated at 520R.
MAL! A We ts Mn: is and 7.0. on a cold awasi-auhd Sui: .
Th_Mhb-u Monks Min M Wu Mintaalm
edudes are. known. 11.: Co or m radio and
1h. W 03- Ha. Min
Problem 9.61 (Continued) - Page 2
ANALYSIS: (8.) The T -s diagram for the cycle is shown below.
For the cycle with a regenerator effectiveness of less than 100%, all pncipw states are
unchanged from Problem 9.60 except for states x and y.
State X c
Problem 9.80 (Continued) Page 3
(a) The mass ow rate of air is found as follows. Mass and energy rate balances for control
volumes enclosing the turbine stages and compressor stages give
W11 = M": hc)
W12: (he 74)
WeZ = (12 hb)
The net power
Air at 1 bar and 15"C enters the compressor of an ideal
cold air-standard regenerative Brayton cycle. The pressure at
the compressor exit is 10 bar and the maximum cycle
temperature is 1100C. For k = 1.4\ determine
(a) the net work developed. i
9.69 Air enters the compressor of a regenerative gas turbine
at 14.5 lbf/in.z, 77F. and is compressed to 60 lbf/in? The air
then passes through the regenerator and exits at 1120R.The
temperature at the turbine inlet is i700R. 'lhe compressor
PROBLEM 9. 108
M: A cfw_-uvbojcl- emuu. is analqzed on an. air-gum; (co-sis. M
are known 4+ VArtous locahbm.
ELM:- Calculah Hap. #rust
' (AT) =zso m3Is VI :03:
cuemagmg 3_ " gash?
Moggg: Sam: as m EXawvlc m, excap+ hf- 0.
f PROBLEM 4-85
W AJ-wvbojdengfne .5 and ad on. m m andcml bar-"5.11%.
are knmnocl- vmimloca swat ma ow-Mia 5pc F -
m. 'Dc+-m\necm+kc Mmssmrzsazti whmd- a? Mai-ca WE) riquicud
head- AJ'L MCc) z veloci
3M1 ch) ~Haz Me
quxmuPlc 9 [3, cro
P108 LEM ccfw_72.
The schematic and Ts diagram of a two-stage turbine
operating at steady state with reheat at pressure pf between I
the two stages is shown in Fig. P912. Values for 111, T1 and [
p; are known. The temperature at the inlet to each turbin
Corrected October, 2011
The analysis on a mass basis of an ideal gas mixture at 50oF, 25 lbf/in.2 is 60% CO2, 25%
SO2, and 15% N2. Determine
(a) the analysis in terms of mole fractions.
(b) the apparent molecular weight of the mixture.
PROBLEM I2.3-'i CCm+d-)-P3.2
a, ; sum-tam 3:!th , [ 9MP'"% - a I cfw_:5
I ._ -u I
:7;- 3. to NA!-
ou lb . cs 2.51122 _ I. amm-
_1 43044-473w- ImJ-u I, ) .g (H J[ No (rr)]
'5 no. HM
Fu- 5 guns-d Vow-me Inlflftlj 1"- VIWC; M euwap t 94"9
12.10 A gas mixture with a molar analysis 20% C3H3 (propane) and 80% air enters a
control volume operating at steady state at location 1 with a mass ow rate of 5 kg/min,
as shown in Fig. 12.10 A stream of pure air enters as a separate stream at 2 and dilu
Problem 12.41 (Continuing) Page 2
E = 0.7511. + 0.2552 = 0.7SI7H2(1T,)+ 0.255! (T2) (2)
The enthalpy of the mixture per kmol of mixture, is
E. = 0.755H2(T3)+0.255N1(T3) (3)
Substitute Eq. (3) into Eq. (2) and use data from Table A-23
0.755,.) (T3 )+ 0.255
KNOWN: A Mlvlhklg h|*|\l_ speech-ed 0"! H-IHEtI .nlcp: Q. QCHPFCIIIY QP'IAH'I
u snub, sh. at s mired nun cfw_Ia-u ran. and HM; And ".er
H- a. :peu-M Mupudure. and n (91-417, T. R a-F he. hunt!"-
6 4"- COMpv-Hur h if: hurl-man: :1" also , 3F
Problem 12.17 (Continued) Page 3
AU = [(5)(10.361)+ (4X0.686)[kg][210 K]
= [54.549i](210 K)
kg - K
= 1- 1455.3 k1
Q = AU+W =11455.3kJ-7580.1kJ = 3875 [d
(b) To nd AS
AS: mt an +ln
mc +m c
PROBLEM H.114 (Conh'n Ova/3.22
dtr +99 44m+m Pfya [Gilawn) p.4- Flared T:
4'4: Pivo,P'7-r ET, '+g-,.>,i.
=z_:.u.\_. - ~ (at M)
EBM) um '01 NW'HCH uhna +1. Radbch- [1:00:39
: El _._:.- 1:, E: E a.
V 77 7% ET v-u d
12.47 A lecture hall having a volume of 106 it3 contains air at 80F, 1 atm, and a humidity ratio
of 0.01 lb of water vapor per lb of dry air. Determine
(a) the relative humidity.
(b) the dew point temperature, in F.
(0) the mass of water vapor contained i
12.43 A stream of oxygen (02) at 100F, 2 atm enters an insulated chamber at steady
state with a mass ow rate of 1 lblmin and mixes with a stream of air entering separately
at 200F, 1.5 atm with a mass flow rate of 2 lb/min. The mixture exits at a pressure
PROBLE M t1-3
xwowN: Th; molar arm-hr: of- 34: huh": I'3 Spun'fr'od.
FWD" '+"'" +" MW! " *"w If MAI-I Fvuhanl; u. Hr-l Press-u" of acts.
Couponcu't, "N. VII-June, occu'md by [Olb of msgmre.
swear: it much: DATA:
50 F Auk-M 03L
W 5 co1 035
Three phase is a system produced by a generator consisting of three sources having the same
amplitude and frequency but out of phase with each other by 120.
The generation of electricity is either done by a power station or from renewable energy