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In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is
(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)
(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)
- a)93.12 kg/hr
- b)80.2 kg/hr
- c)76.73 kg/hr
- d)79.8 kg/hr
Correct answer is option 'A'. Can you explain this answer?
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Verified Answer
In an absorption type refrigerator, the heat is supplied to NH3 genera...
Given: TG = 393.2 k, Tc = 303 k,
TE = -5 + 273 = 268 k
actual COP = 0.7 x 1.756 = 1.229
actual heat supplied = Refrigeration load/Actual COP
Assuming that only latent heat of steam is used for heating
TE = -5 + 273 = 268 k
actual COP = 0.7 x 1.756 = 1.229
actual heat supplied = Refrigeration load/Actual COP
Assuming that only latent heat of steam is used for heating
Most Upvoted Answer
In an absorption type refrigerator, the heat is supplied to NH3 genera...
°C. The NH3 generator operates at a pressure of 10 bar. The refrigerant NH3 is condensed at a temperature of 30°C. The cooling water available for the condenser is at 25°C and the flow rate is 20 kg/min. Determine:
a) The mass flow rate of steam required in the generator.
b) The COP of the refrigerator.
Solution:
Given data:
Temperature inside the refrigerator, T1 = -5°C
Pressure in the generator, P1 = 10 bar
Temperature at which NH3 is condensed, T2 = 30°C
Temperature of cooling water, T3 = 25°C
Flow rate of cooling water, m3 = 20 kg/min
Pressure of steam, P4 = 2 bar
Dryness fraction of steam, x4 = 0.9
a) Mass flow rate of steam required in the generator:
Let the mass flow rate of NH3 be m2 and that of water in the generator be m4. The mass flow rate of steam required in the generator can be determined by applying the energy balance equation for the generator as follows:
Q1 = Q2 + Q3
where Q1 is the heat supplied to the generator, Q2 is the heat required to vaporize NH3, and Q3 is the heat required to vaporize water.
Q1 = m4 (h4 - h3)
where h4 is the enthalpy of the mixture of NH3 and water leaving the generator and h3 is the enthalpy of the cooling water leaving the condenser.
Q2 = m2 (h2 - h1)
where h2 is the enthalpy of the condensed NH3 and h1 is the enthalpy of the evaporated NH3.
Q3 = m4 (h3 - h4')
where h4' is the enthalpy of the mixture of NH3 and water entering the absorber.
The enthalpies can be obtained from the steam tables.
At P4 = 2 bar, x4 = 0.9, h4 = 2794.6 kJ/kg, and h4' = 2456.7 kJ/kg.
At T1 = -5°C and P1 = 10 bar, h1 = 190.43 kJ/kg.
At T2 = 30°C, h2 = 385.5 kJ/kg.
At T3 = 25°C, h3 = 104.93 kJ/kg.
Substituting these values in the energy balance equation and simplifying, we get:
m4 = (m2/m4') [(h2 - h1)/(h4 - h3) + 1]
m4' is the mass fraction of water in the mixture of NH3 and water entering the absorber.
At P1 = 10 bar and T1 = -5°C, the enthalpy of the evaporated NH3 is h1 = 190.43 kJ/kg.
At P1 = 10 bar and T2 = 30°C, the enthalpy of the condensed NH3 is h2 = 385.5 kJ/kg.
From the steam tables, at P4 = 2 bar and x4 = 0.9, h4 = 2794.6 kJ/kg and h4' = 2456.7 kJ/kg.
Using these
a) The mass flow rate of steam required in the generator.
b) The COP of the refrigerator.
Solution:
Given data:
Temperature inside the refrigerator, T1 = -5°C
Pressure in the generator, P1 = 10 bar
Temperature at which NH3 is condensed, T2 = 30°C
Temperature of cooling water, T3 = 25°C
Flow rate of cooling water, m3 = 20 kg/min
Pressure of steam, P4 = 2 bar
Dryness fraction of steam, x4 = 0.9
a) Mass flow rate of steam required in the generator:
Let the mass flow rate of NH3 be m2 and that of water in the generator be m4. The mass flow rate of steam required in the generator can be determined by applying the energy balance equation for the generator as follows:
Q1 = Q2 + Q3
where Q1 is the heat supplied to the generator, Q2 is the heat required to vaporize NH3, and Q3 is the heat required to vaporize water.
Q1 = m4 (h4 - h3)
where h4 is the enthalpy of the mixture of NH3 and water leaving the generator and h3 is the enthalpy of the cooling water leaving the condenser.
Q2 = m2 (h2 - h1)
where h2 is the enthalpy of the condensed NH3 and h1 is the enthalpy of the evaporated NH3.
Q3 = m4 (h3 - h4')
where h4' is the enthalpy of the mixture of NH3 and water entering the absorber.
The enthalpies can be obtained from the steam tables.
At P4 = 2 bar, x4 = 0.9, h4 = 2794.6 kJ/kg, and h4' = 2456.7 kJ/kg.
At T1 = -5°C and P1 = 10 bar, h1 = 190.43 kJ/kg.
At T2 = 30°C, h2 = 385.5 kJ/kg.
At T3 = 25°C, h3 = 104.93 kJ/kg.
Substituting these values in the energy balance equation and simplifying, we get:
m4 = (m2/m4') [(h2 - h1)/(h4 - h3) + 1]
m4' is the mass fraction of water in the mixture of NH3 and water entering the absorber.
At P1 = 10 bar and T1 = -5°C, the enthalpy of the evaporated NH3 is h1 = 190.43 kJ/kg.
At P1 = 10 bar and T2 = 30°C, the enthalpy of the condensed NH3 is h2 = 385.5 kJ/kg.
From the steam tables, at P4 = 2 bar and x4 = 0.9, h4 = 2794.6 kJ/kg and h4' = 2456.7 kJ/kg.
Using these
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In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer?
Question Description
In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer?.
In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer?.
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In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 2 bar and 90% dry. The temperature in the refrigerator is to be maintained at - 5°C. If the refrigeration load is 20 tones and actual COP is 70% of the maximum then mass of steam required per hour is(Take atmospheric temperature as 30°C saturation temperature of steam at pressure of 2 bar is 120.2°C, hfg at 2 bar is 2201.6 kJ/kg)a)93.12 kg/hrb)80.2 kg/hrc)76.73 kg/hrd)79.8 kg/hrCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
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