Exam 2 Cheat Sheet | Thermodynamics | ENSC 2213, Study notes of Thermodynamics

Download Exam 2 Cheat Sheet | Thermodynamics | ENSC 2213 and more Study notes Thermodynamics in PDF only on Docsity! Equations: Chapter 1:  F=m*a/gc  P=F/A  ρ=m/Volume  ΔP=ρgL/gP=ρgL/gc  T(K)=T(oC)+273  T(oR)=T(oF)+460  T(oR)=1.8*T(K)  (specific) v=Volume/m o v=1/ ρ  (spec weight) γ= ρg/gc  SG= ρρfluid/ ρρwater o γfluid/ γwater Pressures:  Pgage=Pab-Patm  Pvac=Patm-Pab ρwater:  62.4 lbm/ft3  1000 kg/m3 Chapter 2:  Work o p(V2-V1) (p=const) o pavg(V2-V1) (linear) o (p2V2-p1V1)/(1-n) o W>0- BY system o W<0- ON system  pV=ZmRT  R=Rideal/MW  Q>0 energy added  Q<0 energy removed  ΔP=ρgL/gE=PE+KE+ΔP=ρgL/gU  ΔP=ρgL/gE=Q-W Chapter 3:  U=mgug+mfuf  u=uf+x(ug-uf) [or h or v]  x=(u-uf)/(ug-uf) o x=(v-vf)/(vg-vf)  % Vapor= mgvg/V  h=u+pv (enthalpy)  pR=p/pc  TR=T/Tc  v′ = v /(RT /p ) (pseudo- reduced volume)  ΔP=ρgL/gu=cv(T2-T1)  ΔP=ρgL/gh=cp(T2-T1) Chapter 4:  ṁo=ṁf  Q=Ẇ+m2(h2+gz2+½(V2)2)- ṁ1(h1+gz1+½(V1)2)  Ẇ= ṁ(h1-h2) (adiabatic Q=0, KE=PE=0)  ṁ= ρVA or VA/v Turbine:  Q=0, ṁ1= ṁ2, p2<p1, Ẇ= ṁ (h1-h2) >0 Pump/Compressor:  Q=0, ṁ1= ṁ2, p2>p1, Ẇ= ṁ (h1-h2) < 0 Heat Exchangers:  Q=0, ṁ1= ṁ2, p2>p1, Ẇ= 0  Q1= ṁ1(h2-h1)1 = -Q2 = ṁ2(h2-h1)2 Oxygen gas is stored in a tank with a volume of 5 ft3 at a temperature of 400oR and pressure of 4000 psia. Determine the mass in the tank in lbm. Justify your calculations and any assumptions you make. Ammonia is stored in a tank having a volume of .21 m3. Determine the pressure in kPa and the mass of ammonia in the tank assuming saturated liquid at 20oC. Three lbm of water is contained in a rigid container having a volume of 4.5 ft3. Initially the pressure is measured to be p1= 350 psia. The container is then cooled until the pressure drops to p2=100 psia. a) What is the initial internal energy u1 of the water in Btu/lbm b) Find the quality c) How much total heat was transferred? Water is enclosed in a container at 75oC. If the specific volume of the water in the container is 2.4 m3/kg ; determine the quality. Determine the enthalpy of steam at a pressure of 60 lbf/in2 and temperature of 631oF. Determine the internal energy of steam at a pressure of 23.7 bar and a temperature of 385oC. AJ has a piston cylinder system that contains air at 640oF, 29.4 psia and an initial volume of 7000 ft3. The air is heated at constant pressure until the volume is doubled. Assume ideal gas, calculate the work, heat transfer, and change in internal energy. (on multiple exams) Water is enclosed in a container at 120 bar. If the internal energy of the water in the container is 2201.5 kJ/kg determine the quality. Determine the specific volume of steam in ft3/lbm at a pressure of 450 lbf/in2 and a temperature of 491oF. Determine the specific volume of propane at 60oF and 10 psia. Nitrogen gas is stored in a tank with a volume of 5ft3 at a temperature of 261oR and a pressure of 2,000 psia. Determine the mass in the tank in lbm. Steam enters an adiabatic (Q=0) turbine at 10 MPa and 500oC and leaves at 10KPa with a quality of x=.9. KE=PE=0. Determine the mass flow rate for a power output of 5MW. You have been asked to finish the design of a steam turbine. The design calls for steam to flow into the turbine through an inlet pipe having a diameter of 0.2 m. At the inlet, the velocity is 100m/s at conditions of 14 MPa and 600oC. The steam exits the turbine through a pipe of diameter 0.8 m at conditions of 500 kPa and 180oC. PE=KE=Q=0. Calculate power output of the turbine in kW. Butane gas is stored in a tank with a volume of 1.2 m3 at a temperature of 165oC and a pressure of 19 bar. Determine the mass in the tank in kg. Steam enters the turbine at 1600 lbf/in2 and 1000oF. The adiabatic (Q=0) turbine operates at steady state. 25% of the steam entering is extracted midway through the expansion process in the turbine at 160 lbf/in2 and 450oF. The rest of the steam exits as saturated vapor at 1 lbf/in2. The turbine develops a power output of 9*108 BTU/hr. KE=PE=0. Determine mass flow rate entering the turbine. Given ρTemperature ρand ρPressure ρ (T, ρp) Go to the saturated temperature table and determine if: p > ps(T) - Subcooled (compressed) liquid p = ps(T) - Saturated state (may be saturated vapor, saturated liquid, or two-phase mixture) p <ps(T) - Superheated vapor OR T < Ts(p) - Subcooled (compressed) liquid T = Ts(p) - Saturated state (may be saturated vapor, saturated liquid, or two-phase mixture) T > Ts(p) - Superheated vapor Given ρTemperature ρand ρSpecific ρ Volume ρ(T, ρv) Go to the saturated temperature table Given ρPressure ρand ρVolume ρ(p, ρv) Go to the saturated pressure table and determine if: Nitrogen gas is stored in a tank with a volume of 5 ft3 at a temperature of 400oR and a pressure of 4,000 psia. Determine