Question

An industrial facility needs a flow of 100 gpm of hot water at 180°F, 50 psia. Two designs are being considered to make the hot water. In Design 1, the hot water is produced by injecting steam into an insulated mixing chamber through which the water passes. The water enters the chamber at 50°F, 50 psia. Steam is injected into the chamber at 325°F, 50 psia. The hot water leaves at the required flow rate and temperature. For this system determine

- The mass flow rate of the water entering the chamber (lbm/h)
- The mass flow rate of the steam injected into the chamber (lbm/h)
- The exergy destruction rate in the chamber (Btu/h)
- The exergetic efficiency of the chamber

The second design, Design 2, the water is heated in a heat exchanger with a stream of hot liquid benzene that is available from another process in the facility. The heat exchanger is a parallel flow configuration with a pinch point temperature difference of 10°R. The water enters the heat exchanger at 50°F and leaves at the required flow rate and temperature. The hot benzene enters the heat exchanger at 225°F. For this system determine,

- e. The required mass flow rate of the benzene (lbm/h)
- f. The exergy destruction rate in the heat exchanger
- g. The exergetic efficiency of the heat exchanger
- h. The effectiveness of the heat exchanger

Answer #1

Steam enters an adiabatic turbine at 1,000 psia and 900 F with a
mass flow rate of 6 lbm/s and leaves at 5 psia. The isentropic
efficiency of the turbine is 0.90. Neglect the kinetic and
potential energy changes of the steam.
What is the quality at the isentropic exit state, 2s
(X2s)?
What is the exit temperature of the steam
(T2)?
What is the power output of the turbine?

Water is heated in a mixing chamber by mixing it with hot water
coming from a heater. The mixing chamber loses heat to the
surroundings at a rate of 5 kW. The hot water enters the mixing
chamber at a rate of 1 kg/s.
The mixed water leaves the chamber fully mixed.
- The cold water enters the mixing chamber at 200 kPa and 20°C
at a velocity of 3 m/s
- The hot water enters at a pressure of...

Air enters the evaporator section of a window air conditioner at
14.7 psia and 90°F with a volume flow rate of 200 ft3 /min.
Refrigerant-134a at 20 psia with a quality of 30 percent enters the
evaporator at a rate of 4 lbm/min and leaves as saturated vapor at
the same pressure. Determine (a) the exit temperature of the air
and (b) the rate of heat transfer from the air.

P1:
A plate and frame heat exchanger is used to exchange heat in a
water-to-water flow system. Hot water enters the exchanger at 100 F
with a flow rate of 150 gpm. Cold water also enters at 150 gpm and
50 F.
The exchanger contains 25 plates, the spacing is 0.2 inches, the
plate material is 304SS (stainless steel), the plate thickness is .05 in, the plate
width is 15 in and the plate height is 3 ft.
Find the...

QUESTION 1). A person staying in a caravan on a hot day decides
to close the door and run the fridge with its door open to cool the
interior down. Briefly explain if this will help and
why.
QUESTION TWO)
A large hot water tank is maintained at a constant temperature
of 70°C by a counter flow heat exchanger coil containing hot water.
The heating coil has an outside diameter of 30mm and
U=4500W/m2K. The water enters the heating coil...

An 850-MW Rankine cycle operates with turbine inlet steam at
1200 psia and 1000Â°F and condenser pressure at 1 psia. There are
three feedwater heaters placed optimally as follows: (a) the
high-pressure heater is of the closed type with drains cascaded
backward; (b) the intermediate-pressure heater is of the open type;
(c) the low- pressure heater is of the closed type with drains
pumped forward. Each of the turbine sections has the same
polytropic efficiency of 90 percent. The pumps...

Calculate the mass flow rate of heating medium (water) required
in pasteurization of 1000 kg/h milk from 45°C to 72°C. Water enters
heat exchanger at 90°C and leaves at 75°C. Heat loss from the
exchanger to the ambience is estimated at 1 kJ/s. Take heat
capacities of water and milk as 4.2 and 3.9 kJ/kg°C,
respectively.

Water is the working fluid in an ideal Rankine cycle. Steam
enters the turbine at 1400 lbf/in2 and
1000°F. The condenser pressure is 2 lbf/in.2
The net power output of the cycle is 350 MW. Cooling water
experiences a temperature increase from 60°F to 76°F, with
negligible pressure drop, as it passes through the condenser.
a) Determine the mass flow rate of steam, in lb/h.
b) The rate of heat transfer, in Btu/h, to the working fluid
passing through the...

Hot water enters a counter-flow double-pipe heat exchanger at
180F with a velocity of 5 ft/s. Cold water at 80F flows at 3 ft/s
in the outer section of the exchanger. The diameter of the inner
pipe is 1 inch, the pipe wall thickness is 1/8", and the outer pipe
diameter is 2 inches. The overall heat transfer coefficient times
area per unit length UA/L = 150 Btu/hr-ft-F. If the exchanger is 16
feet long, what is the exit temperature...

Atmosphric air at 40 F and 50% relative humidity enters the heating
section of an airconditioning device at a volumetric flow rate of
100ft^3/min. Water vapor is added to the heated air to increase the
relative humidity to 55%. The temperature after the heating section
is 72F and the temperature at the exit is 74F. Using the
appropriate fomulas:
a) determine the rate of the heat transfer in Btu/min.
b) determine the mass flow of water vapor in lbm/min.

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 19 minutes ago

asked 29 minutes ago

asked 48 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 3 hours ago

asked 3 hours ago

asked 3 hours ago