A current of methanol flowing at a rate of 5500 standard liters per minute is heated from 65 °C to 260 °C in an adiabatic heat exchanger with a counter-current stream of saturated steam at 300 °C. The steam condenses and leaves the heat exchanger as liquid water at 90 °C. What is the required flow rate of the entering steam in m3/min? What is the rate of heat transfer from the water to the methanol (in kW)?i really need help with this problem!!
I see what you mean. I've adjusted the analysis accordingly. When in doubt, state numerically what is meant by said density, or better yet, state mass flow rate. Answers: Required flow rate of entering steam: V_dot[3] = 1.008 m^3/sec Rate of heat transfer from the water to the methanol: Q_dot = 110 MegaWatts Record of solution panel and array table: img718.imageshack.us/img718/4971/... --------------------------------------... ----Begin EES----- !DATA: State 1: methanol in State 2: methanol out State 3: steam in State 4: steam out Fluid flavors F$[1] = 'Methanol' F$[2] = F$[1] F$[3] = 'Steam' F$[4] = F$[3] Methanol state V_dot_std = 5500 [L/min] * convert(L, m^3)*convert(sec,min) T[1] = 60 [C] T[2] = 260 [C] Steam state T[3] = 300 [C] x[3] = 1 T[4] = 90 [C] Assume Methanol is at 1 bar pressure P[1] = 100 [kPa] P[2] = P[1] !STRATEGY Determine mass flow rate of methanol rho_std = density(F$[1], T=0[C], P=P[1]) m_dot[1] = V_dot_std*rho_std m_dot[2] = m_dot[1] Complete table for steam P[3] = Pressure(F$[3] , T=T[3], x=x[3]) P[4] = P[3] since it is assumed a perfect isobaric condenser x[4] = quality(F$[4] , P=P[4], T=T[4]) Look up enthalpy values We could use a specific heat approach, but why? h[1] = enthalpy(F$[1], T=T[1], P=P[1]) h[2] = enthalpy(F$[2], T=T[2], P=P[2]) h[3] = enthalpy(F$[3], T=T[3], x=x[3]) h[4] = enthalpy(F$[4], T=T[4], P=P[4]) Energy balance on heat exchanger. EES will solve for m_dot_steam Heat absorbed by methanol = heat released by steam m_dot[1]*(h[2] - h[1]) = m_dot[3]*(h[3] - h[4]) m_dot[4] = m_dot[3] Total amount of heat Q_dot = m_dot[1]*(h[2] - h[1]) Complete table duplicate i=1,4 rho[i] = density(F$[i], T=T[i], h=h[i]) V_dot[i] = m_dot[i]/rho[i] end x[1] = quality(F$[1], T=T[1], h=h[1]) x[2] = quality(F$[2], T=T[2], h=h[2]) ----End EES-----
uncertain what a rotameter is yet... One blend is going into the condenser and a couple of issues pop out. 755 ccs of benzene converts to 1510 ccs of benzene according to min popping out and the rotameter (??) tells you that the gasoline which did no longer condense is popping out at 80 3 moles according to min. on account which you recognize that mass is conserved, the mass pass value in is the comparable with the aid of fact the mass pass value out. in simple terms would desire to transform moles according to min to mass according to min. you recognize what the commencing blend is, so convert moles to mass, and the molecular weight that's no longer popping out as organic benzene remains in the exiting gasoline. desire this enables
