An expansion valve in a refrigeration cycle throttles R134a from
1.2MPa saturated liquid to 0.32MPa. What...
An expansion valve in a refrigeration cycle throttles R134a from
1.2MPa saturated liquid to 0.32MPa. What is the specific volume at
the exit of the expansion valve in unit of m3/kg. Round the result
to 4 decimal places.
refrigarent-134a enters the expansion valve of a refrigeration
system at 1MPa as a satuarted liquid and leaves at 100kPa.
determine the temperature change across the valve
a.0
b.65.74C
c.640C
d.-26.37C
A well-insulated expansion/throttle valve is designed to operate
with refrigerant R134a. It receives a liquid-gas mixture with a
quality of 0.1 and a pressure of 400 kPa. The refrigerant leaves
with a pressure of 100 kPa. Find the temperature (in Celsius) and
the specific volume (m3/kg) at the exit of the valve.
A vapor-compression refrigeration cycle working with R22
contains a liquid-to-suction heat exchanger. The saturated liquid
refrigerant at 40 °C leaving the condenser and entering the heat
exchanger is used to superheat the saturated vapor refrigerant
leaving the evaporator at 7 °C by 8 °C. If the compressor is
capable of pumping 5 l/s of vapor refrigerant measured at the inlet
to the compressor and the compression processes are considered
isentropic in both cases listed below, determine;
(a) The refrigerating capacity...
Q/ A vapor-compression refrigeration cycle working with R22
contains a liquid-to-suction
heat exchanger. The saturated liquid refrigerant at 40 °C leaving
the condenser and entering
the heat exchanger is used to superheat the saturated vapor
refrigerant leaving the evaporator
at 7 °C by 8 °C. If the compressor is capable of pumping 5 l/s of
vapor refrigerant measured
at the inlet to the compressor and the compression processes are
considered isentropic in
both cases listed below, determine;
(a) The refrigerating...
An ideal vapor compression refrigeration cycle using r134a as
the refrigerant is being used to cool a house. It provides 3
refrigeration tons ≈ 10.5kW of cooling (heat removal from the house
air). The refrigerant in the evaporator operates at 400kPa while in
the condenser it is at 1000kPa. Treat the surroundings as a thermal
reservoir at 33◦C and the air in the house as a thermal reservoir
at 19◦C. All reservoirs are at 100kPa.
1. What is the COPr...
An ideal vapor compression refrigeration cycle with R134a as the
working fluid operates between the pressure limits of 200 kPa and
1200 kPa. Determine
a) the mass fraction of the refrigerant that is in the liquid phase
at the inlet of the evaporator, and
b) the amount of heat transfer (in kJ/kg) to the refrigerant in
the evaporator (??).
Using Ees Program (With the Code and
Output)
Saturated liquid Propane flows in to a valve. It enters at 375
psia, and leaves at 15 psia. Mass flow through the valve is 1.25
lbm/hr. Use EES and ‘Propane’ as your fluid to calculate the
following:
The quality of the Propane exiting the valve
Temperature of the Propane exiting the valve (in °F)
The change in entropy of the Propane (in Btu/lbm-R)
a.__________________ b.____________________
c.____________________
A steady-flow Carnot refrigeration cycle uses refrigerant-134a
as the working fluid. The refrigerant changes from saturated vapor
to saturated liquid at 40 C in the condenser as it rejects heat.
The evaporator pressure is 120 kPa. Determine: (a) the amount of
heat absorbed from the refrigerated space; qL = _______________
kJ/kg (b) the net work input; and wnet = ______________ kJ/kg (c)
the coefficient of performance of the system. COP =
_____________
Saturated liquid Propane flows in to a valve. It enters at 375 psia, and leaves at 15 psia. Mass flow through the valve is 1.25 lbm/hr. Use EES and ‘Propane’ as your fluid. This new device replaces the valve with a ‘magic’ isentropic device. Assuming the device operates at steady state, and PE and KE terms are insignificant, calculate how much power could be generated by the device (hp)?
A vapor-compression refrigeration cycle operates at steady state
with Refrigerant 134a as the working fluid. Saturated vapor enters
the compressor at 2 bar, and saturated liquid exits the condenser
at 10 bar. The isentropic compressor efficiency is 80%. The mass
flow rate of refrigerant is 7 kg/min.
Determine:
(a) the compressor power, in kW.
(b) the refrigeration capacity, in tons.
(c) the coefficient of performance.