Question

A heat exchanger uses saturated steam at 375 K to heat cold water entering at 280 K and leaving at 301 K only the latent heat of vaporization is removed from the steam. i.e. the steam is condensed and saturated water exit the exchanger. a) what is the LMTD for a counter current heat exchanger? b) what is the LMTD for a parallel or cocurrent heat exchanger? c) if the counter current heat exchanger has a duty (Q) of 81000 kJ/hour and an overall heat transfer of coefficient (U) of 500 KJ/m^2K what is the calculated heat transfer area in m^2? d) if the parallel or cocurrent heat exchanger has a duty (Q) of 81000 kJ/hour and an overall heat transfer of coefficient (U) of 500 KJ/m^2K what is the calculated heat transfer area in m^2?

Answer #1

A heat exchanger uses saturated steam at 375 K to heat cold
water entering at 280 K and leaving at 301 K. Only the latent heat
of vaporization is removed from the steam, i.e. the steam is
condensed and saturated water exits the exchanger. (a) What is the
LMTD for a counter-current heat exchanger? (b) What is it for a
parallel heat exchanger (c) If the counter-crrent heat exchanger
has a duty(Q) of 81000 kJ/hour and an overall heat transfer...

The condenser of a large steam power plant is a heat exchanger
in which steam is condensed to liquid water. Assume the condenser
to be a parallel flow shell-and-tube heat exchanger consisting of a
single shell and 10,000 tubes, each executing two passes. The tubes
are of thin wall construction with D = 30 mm and the steam
condenses on their outer surface. The heat transfer rate that must
be effected by the exchanger is Q = 2 × 10^9...

Saturated water vapor leaves a steam turbine at a flow rate of
1.47 kg/s and a pressure of 0.51 bar. The vapor is to be completely
condensed to saturated liquid in a shell-and-tube heat exchanger
that uses city water as the cold fluid. The water enters the
thin-walled tubes at 17oC and is to leave at 57.6
oC. Assuming an overall heat transfer coefficient of
2000 W/m2K, determine the required heat exchanger
surface area and the water flow rate. cp,c...

A counter current double pipe heat exchanger is used to boil but
not superheat water at 100 DegreeC at rate of about 0.1 kg/s. This
is achieved by flowing hot oil at 400 DegreeC through the inner
pipe at a rate of 5 kg/s.
Latent heat of water: 2265 kJ/kg
Heat capacity of water: 4180 J/kgK
Heat capacity of the oil: 1800 J/kgK
What is the temperature of he hot oil leaving the heat
exchanger?
What is the overall heat...

A thin-walled double pipe counter flow heat exchanger is to be
used to cool oil (cp = 2200 j/kg*K) from 150 ℃ to 30 ℃ at a rate of
2.1 kg/s by water (cp= 4180 J/kg*K) that enters at 20 ℃ at a rate
of 1.2 kg/s. The diameter of the tube is 2.5 cm, and its length is
10 m.
Using Excel (a) Determine the overall heat transfer coefficient
of this heat exchanger. (b) Investigate the effects of oil...

Problem #1
Saturated steam at 300°C is used to heat a counter-currently
flowing stream of methanol vapor from 65°C to 260°C in an adiabatic
heat exchanger. The flow rate of the methanol is 5500 standard
liters per minute (at STP), and the steam condenses and leaves the
heat exchanger as liquid water at 90°C.
a) Draw a diagram of the process.
b) Calculate the required flow rate of the entering steam in
m3/min.
c) Calculate the rate of heat transfer...

Cold water enters a counter flow heat exchanger at 20ºC at a
rate of 10 kg/s, where it is heated by a hot water stream that
enters the heat exchanger at 80ºC at a rate of 2 kg/s. Assuming the
specific heat of water to remain constant at Cp=4.18 kJ/(kg.ºC),
determine the maximum heat transfer rate and the outlet
temperatures of the cold and the hot water streams.

saturated steam at 300 C is used to heat countercurrently
flowing stream of methanol vapor from 65C to 260 C in and adiabatic
heat exchanger. The flow rate of the methanol is 5500 standard
liters per minute, and the steam condenses and leaves the heat
exchanger as liquid water at 90 C.
A) calculate the required flow rate of the entering steam in
m^3/min.
B) Calculate the rate of heat transfer from the water to the
methanol (kW).

The fluid in a heat exchanger in a process plant needs to be
warmed up prior to having process startup. The shell side of the
heat exchanger contains the process fluid (water) while the tube
side is supplied with steam at 150°C to facilitate the heating.
Assume the exterior is well insulated such that heat losses are
negligible.
a) Derive the ODE and analytically solve for the function that
describes the temperature of the fluid in the heat exchanger with...

A process fluid having a specific heat of 3500 J/kg?K and
flowing at 2 kg/s is to be cooled from 80 °C to 40 °C with chilled
water, which is supplied at a temperature of 15 °C and a flow rate
of 2.5 kg/s. Assuming an overall heat transfer coefficient of 2000
W/m2?K, calculate the required heat transfer areas for the
following exchanger configurations: (a) Parallel flow; (b) Counter
flow; (c) a 1-2 shell and tube exchanger with the water...

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