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
Naddika [18.5K]
3 years ago
11

Refrigerant 134a enters a horizontal pipe operating at steady state at 40°C, 300 kPa, and a velocity of 25 m/s. At the exit, the

temperature is 90°C and the pressure is 240 kPa. The pipe diameter is 0.1 m. Determine: (a) the mass flow rate of the refrigerant, in kg/s, (b) the velocity at the exit, in m/s, and (c) the rate of heat transfer between the pipe and its surroundings, in kW.
Engineering
1 answer:
salantis [7]3 years ago
3 0

Answer:

a) 2.42 kg/s

b) 37.20 m/s

c) 120.56 kW

Explanation:

Given that:

The fluid in the Refrigerant = R-134a

Diameter (d) = 0.1 m

In the Inlet:

Temperature T_1 = 40^0C

Pressure P_1= 300kPa

Velocity V_1 = 25 m/s

At the exit:

Temperature T_2 = 90^0C

Pressure P_2 = 240 kPa

From the  Table A-12 for Refrigerant R-134a at T_1 = 40^0C and P_1= 300kPa

Specific Volume v_1 = 0.0809 m^3/kg

From the  Table A-12 for Refrigerant R-134a at T_2 = 90^0C and P_2 = 240 kPa

Specific Volume v_2 = 0.12038 kJ/kg

Their corresponding Enthalpy h_1 and h_2 are as follows:

Enthalpy h_1  =284.05 kJ/kg

Enthalpy h_2 = 333 kJ/kg

a) The mass flow rate of the refrigerant can be calculated as :

m_1 = \frac{AV_1}{v_1}

m_1 = \frac{\frac{\pi (0.1)^2}{4}*25}{0.08089}

m_1 = 2.42 kg/s

b) The velocity at the exit point:

we knew that:

m=m_1 =m_2

∴

\frac{AV_1}{v_1} =\frac{AV_2}{v_2}

V_2 = \frac{v_2}{v_1} V_1

V_2 = \frac{0.12038}{0.08089} *25

V_2 = 37.20 m/s

c) Expression for calculating heat transfer (as long as there is no work that is said to be done and the pipe is horizontal) can be represented as:

Q_{cv}= m[(h_2-h_1)+\frac{1}{2}(V_2^2-V_1^2)]

Q_{cv}= 2.42*[(333.49-284.05)+\frac{1}{2}(37.20^2-25^2)]

Q_{cv}= 2.42*[49.44+379.42]

Q_{cv}= 119.6448kW+918.19W(\frac{1kW}{1000W} )

Q_{cv}= 119.6448kW+0.92 kW

Q_{cv} = 120.56 kW

You might be interested in
Explain why Chloe's design needs to be redone in the following scenario, and recommend the techniques she needs to include in he
Alenkinab [10]

Answer:

She believes he's weak and won't do what needs to be done to become a king.

Explanation:

She says ('I fear thy nature') and calls him 'too full o' th' milk of human kindness' which reflects that she feels his kindness makes him weak and may prevent him from proceeding the plan. Thus, she manipulates him to keep his kindness aside and do what she wishes him to do. She rather belittles him to get her purpose solved and

7 0
3 years ago
Read 2 more answers
ILL GIVE BRAINLIEST!!!
Sedbober [7]
Get the app socratic I saw the answer to your question on the app but I ran out of screen time to show you
6 0
2 years ago
A traffic flow has density 61 veh/km when the speed is 59 veh/hr. If a flow has a jam density of 122 veh/km, what is the maximum
antoniya [11.8K]

Since this traffic flow has a jam density of 122 veh/km, the maximum flow is equal to 3,599 veh/hr.

<u>Given the following data:</u>

  • Density = 61 veh/km.
  • Speed = 59 km/hr.
  • Jam density = 122 veh/km.

<h3>How to calculate the maximum flow.</h3>

According to Greenshield Model, maximum flow is given by this formula:

q_{max}=\frac{V_f \times K_i}{4}

<u>Where:</u>

  • V_f is the free flow speed.
  • K_i is the Jam density.

In order to calculate the free flow speed, we would use this formula:

V_f =2 V\\\\V_f =2\times 59\\\\V_f=118\;km/hr

Substituting the parameters into the model, we have:

q_{max}=\frac{118 \times 122}{4}\\\\q_{max}=\frac{14396}{4}

Max flow = 3,599 veh/hr.

Read more on traffic flow here: brainly.com/question/15236911

6 0
2 years ago
The nuclear reactions resulting from thermal neutron absorption in boron and cadmium are 10B5 + 1 n0 ï  7Li3 + 4He2 113Cd48 + 1
kirill115 [55]

Solution :

The nuclear reaction for boron is given as :

$^{10}\textrm{B}_5 + ^{1}\textrm{n}_0 \rightarrow ^{7}\textrm{Li}_3 + ^{4}\textrm{He}_2$

And the reaction for Cadmium is :

$^{113}\textrm{Cd}_48 + ^{1}\textrm{n}_0 \rightarrow ^{114}\textrm{Cd}_48 + \gamma [5 \ \textrm{MeV}]$

We know that it is easier that to shield or stop an alpha particle (i.e. He nucli) as they can be stopped or obstructed by only a few centimetres of the material. However, the gamma rays ( γ ) can penetrate through the material to a greater distance. Therefore, we can choose the first one.

6 0
3 years ago
Scenario* The organization is a regional XYZ Credit Union/Bank that has multiple branches and locations throughout the region.*
fiasKO [112]

Answer:

1) For preparation of plan :

It is to gather the team and creating the timeline. Gathering the inputs for the plan and confirming the mission and vision then launching the strategy.

2) A mission would describe about the company and the specification of the company

A vision is the long term or future state of the organization to achieve in a time frame.

Both would include the OAS statements and strategic shifts.

3) The OAS and strategic shift would help to create a balanced score card that would help for data gathering and analysis

This would include the financial, customers goal, Process goals, people's goals etc.

4) To create and develop the plan's framework:

To set the objective for high level organizational goals

To measure the and accomplish the objectives

To take initiatives to achieve the objectives

Explanation:

8 0
2 years ago
Other questions:
  • Block A is released from rest and slides down the frictionless ramp to the loop. The maximum height h of the loop is the same as
    6·1 answer
  • Complete the following sentence. The skills and content of several subject areas were combined to form a new field known as a me
    12·2 answers
  • At the inlet to the combustor of a supersonic combustion ramjet (or scramjet), the flow Mach number is supersonic. For a fuel-ai
    12·1 answer
  • What is the volume of the rectangular prism shown.
    9·1 answer
  • Applications of fleming hand rule
    6·1 answer
  • Describe two characteristics that bridges and skyscrapers have in common.
    10·1 answer
  • What document should you have from the engine manufacturer when working on an engine
    8·1 answer
  • 2. The speaker argues that more data allow us to see new things. Think about your favorite hobby—skateboarding, listening to mus
    8·2 answers
  • 12. What procedure should you follow when taking measurements?
    11·1 answer
  • 3. (5%) you would like to physically separate different materials in a scrap recycling plant. describe at least one method that
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!