1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
NeX [460]
3 years ago
15

An R-134a refrigeration system is operating with an evaporator pressure of 200 kPa. The refrigerant is 10% in vapor phase at the

inlet of the evaporator. The enthalpy and temperature of the refrigerant at the exit of the compressor are 360 kJ/kg and 70 /C respectively. If this system (with the refrigerant flowing at 0.005 kg/s) is used to cool a 750 kg product (initial temperature = 80 /C and specific heat = 3,000 J/kg-K), what will be the temperature of the product after 6 hours?

Engineering
1 answer:
crimeas [40]3 years ago
8 0

Answer:

71.17°C

Explanation:

Please kindly check attachment for the step by step solution of the given problem.

You might be interested in
Air, at a free-stream temperature of 27.0°C and a pressure of 1.00 atm, flows over the top surface of a flat plate in parallel f
Morgarella [4.7K]

Answer:

Explanation:

Given that:

V = 12.5m/s

L= 2.70m

b= 0.65m

T_{ \infty} = 27^0C= 273+27 = 300K

T_s= 127^0C = (127+273)= 400K

P = 1atm

Film temperature

T_f = \frac{T_s + T_{\infty}}{2} \\\\=\frac{400+300}{2} \\\\=350K

dynamic viscosity =

\mu =20.9096\times 10^{-6} m^2/sec

density = 0.9946kg/m³

Pr = 0.708564

K= 229.7984 * 10⁻³w/mk

Reynolds number,

Re = \frac{SUD}{\mu} =\frac{\ SUl}{\mu}

=\frac{0.9946 \times 12.5\times 2.7}{20.9096\times 10^-^6} \\\\Re=1605375.043

we have,

Nu=\frac{hL}{k} =0.037Re^{4/5}Pr^{1/3}\\\\\frac{h\times2.7}{29.79\times 10^-63} =0.037(1605375.043)^{4/5}(0.7085)^{1/3}\\\\h=33.53w/m^2k

we have,

heat transfer rate from top plate

\theta _1 =hA(T_s-T_{\infty})\\\\A=Lb\\\\=2.7*0.655\\\\ \theta_1=33.53*2.7*0.65(127/27)\\\\ \theta_1=5884.51w

7 0
3 years ago
FRIDAY<br> What does a lockbar do?
IrinaK [193]

Answer:

it increases the life of a frame lock

Explanation:

because it decreases wear on the lock face

6 0
2 years ago
Read 2 more answers
A wing component on an aircraft is fabricated from an aluminum alloy that has a plane strain fracture toughness of 27 . It has b
Mamont248 [21]

Answer:

The stress level at which fracture will occur for a critical internal crack length of 6.2mm is 135.78MPa

Explanation:

Given data;

Let,

critical stress required for initiating crack propagation Cc = 112MPa

plain strain fracture toughness = 27.0MPa

surface length of the crack = a

dimensionless parameter = Y.

Half length of the internal crack, a = length of surface crack/2 = 8.8/2 = 4.4mm = 4.4*10-³m

Also for 6.2mm length of surface crack;

Half length of the internal crack = length of surface crack/2 = 6.2/2 = 3.1mm = 3.1*10-³m

The dimensionless parameter

Cc = Kic/(Y*√pia*a)

Y = Kic/(Cc*√pia*a)

Y = 27/(112*√pia*4.4*10-³)

Y = 2.05

Now,

Cc = Kic/(Y*√pia*a)

Cc = 27/(2.05*√pia*3.1*10-³)

Cc = 135.78MPa

The stress level at which fracture will occur for a critical internal crack length of 6.2mm is 135.78MPa

For more understanding, I have provided an attachment to the solution.

4 0
4 years ago
Which is an appropriate type of face and eye protection for resistance welding?
Flura [38]

Answer:

While resistance welding you should wear clear grinding glasses, unbreakable plastic face shields or clear unbreakable plastic goggles. When resistance welding a #10, or more, shade lens should be worn. All hand and portable tools should be inspected for loose parts, cleanliness, or worn power cords.

7 0
3 years ago
Given: There is a rectangular weir that causes the water level in a trapezoidal concrete-lined channel to be 13.1 ft from the ch
Sav [38]

Answer:

The channel distance affected by the weir

Yn ( Normal depth ) = 5.71 ft

Yc ( critical depth ) = 4.11 ft

x = 22794 ft

Explanation:

Attached  below is a detailed solution to the problem

The channel distance affected by the weir

Yn ( Normal depth ) = 5.71 ft

Yc ( critical depth ) = 4.11 ft

x = 22794 ft

4 0
3 years ago
Other questions:
  • Electric heater wires are installed in a solid wall having a thickness of 8 cm and k=2.5 W/m.°C. The right face is exposed to an
    5·2 answers
  • A 1.5-m-long aluminum rod must not stretch more than 1 mm and the normal stress must not exceed 40 MPa when the rod is subjected
    12·1 answer
  • An engineer is working with archeologists to create a realistic Roman village in a museum. The plan for a balance in a marketpla
    9·1 answer
  • A 450 MWt combined cycle plant has a Brayton cycle efficiency of 24% and a Rankine cycle efficiency of 29% with no heat augmenta
    6·1 answer
  • In natural convection, the fluid is forced to flow over a surface or in a tube by an external mean such as a pump or a fan. a)-
    10·1 answer
  • You are NASA. Build a space station on Mars that could support humans to live in for an extended period of time.
    9·1 answer
  • In estimating the mean speed of a roadway segment,a pilot sample of 100 vehicles at this location yield a sample standard deviat
    9·1 answer
  • Discuss why TVET Institutions need advice of the business community in order
    9·1 answer
  • A wooden pallet carrying 540kg rests on a wooden floor. (a) a forklift driver decides to push it without lifting it.what force m
    8·1 answer
  • What are the main factors contributing to the generation of heat in resistance welding (ideally explain based on equation)
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!