Engineering Sciences
GATE XE concept:heat-exchangers PYQs
Build your understanding with focused practice from past exam papers.
How to practice concept:heat-exchangers
Attempt a question, record the concept and assumptions, then check the available answer. Rework mistakes after revising the relevant concepts. Topic tags can overlap; review the question context.
Questions 1–6 of 6. Imported answers require independent review unless marked reviewed.
Question 151
Open questionXE-GNAT2 marksNeeds review
Hot oil is being cooled in a countercurrent, double-pipe heat exchanger from 410 K to 340 K by chilled water entering at 290 K and exiting the exchanger at 330 K. The Log Mean Temperature Difference (LMTD) for this heat transfer is ________ K. (Round off to one decimal place)
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 153
Open questionXE-GNAT2 marksNeeds review
Cow milk is pasteurized at a flow rate of 1 kg.s⁻¹ in a counter-current heat exchanger using hot water as the heating medium. The milk enters the heat exchanger at 15 °C and exits at 50 °C. The specific heat of cow milk is 3.5 kJ.kg⁻¹.°C⁻¹ and remains constant at the inlet and exit of the heat exchanger. The inlet and exit temperatures of the hot water are 75 °C and 60 °C respectively. If the overall heat transfer coefficient is 1800 W.m⁻².°C⁻¹, the heat transfer surface area in m² is _____ (rounded off to 2 decimal places). Assume steady state conditions.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 22
Open questionXE-GNAT2 marksNeeds review
An orange juice flowing at 0.80 kg s⁻¹ enters a counter current double pipe heat exchanger at 20 °C and leaves at 72 °C. Inlet and outlet temperatures of the hot water used as heating medium in the exchanger are 81 °C and 74 °C, respectively. The specific heat of the orange juice is 3.74 kJ kg⁻¹ K⁻¹ and overall heat transfer coefficient is 492 W m⁻² K⁻¹. The heat transfer surface area (round off to 2 decimal places) will be ______ m².
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 17
Open questionXE-GNAT2 marksNeeds review
A mixed fruit beverage with 12 °Brix having specific heat of 4298 J kg⁻¹ K⁻¹ is being heated from 30 °C to 95 °C for pasteurization at a flow rate of 1000 L h⁻¹ in a tubular heat exchanger. Steam at 100 °C is used as heating medium which is converted into condensate at 100 °C. If the density of beverage is 1075 kg m⁻³ and the latent heat of steam at the given temperature is 2257 kJ kg⁻¹, the mass flow rate of steam (kg min⁻¹) is ______ (round off to 2 decimal places).
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 18
Open questionXE-GNAT2 marksNeeds review
Fruit juice was cooled in a tubular heat exchanger from 50 °C to 7 °C using water at 2 °C, which gets heated to 5 °C. Assume, Pr = 0.72, Re = 2000 and thermal conductivity = 0.6 W m⁻¹ °C⁻¹ and no viscous effect. If pipe diameter was 10 cm, the convective heat transfer coefficient (W m⁻² °C⁻¹) is ________ (round off to 1 decimal place).
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 9
Open questionXE-GNAT1 markNeeds review
Ambient air at 30°C by bulb temperature and 80% relative humidity was heated to a dry bulb temperature of 80°C in a heat exchanger by indirect heating. The amount of moisture gain (g kg^ dry air) during the process would be ______.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer