Utilities & Energy Integration interview questions
27 real Utilities & Energy Integration questions from the Process Design bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.
1. What is Composite curves?
Junior
A.temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
B.hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
C.plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures
D.back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown
2. Which term means: "hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility"?
A.Composite curves — hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
B.Composite curves — typical plant headers of HP (about 40 bar), MP (about 10 bar) and LP (about 3.5 bar), let down through turbines or PRV-desuperheater stations
C.Composite curves — temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
D.Composite curves — matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
A.matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
B.plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures
C.hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
D.temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
5. Which term means: "temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it"?
A.Pinch point — temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
B.Pinch point — plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures
C.Pinch point — back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown
D.Pinch point — matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
A.hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
B.temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
C.recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide
D.typical plant headers of HP (about 40 bar), MP (about 10 bar) and LP (about 3.5 bar), let down through turbines or PRV-desuperheater stations
8. Which term means: "typical plant headers of HP (about 40 bar), MP (about 10 bar) and LP (about 3.5 bar), let down through turbines or PRV-desuperheater stations"?
A.Steam levels — recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide
B.Steam levels — typical plant headers of HP (about 40 bar), MP (about 10 bar) and LP (about 3.5 bar), let down through turbines or PRV-desuperheater stations
C.Steam levels — smaller minimum approach saves utility but raises exchanger area; supertargeting picks the value that minimises total annual cost
D.Steam levels — hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
11. Which term means: "plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures"?
A.Grand composite curve — plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures
B.Grand composite curve — hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
C.Grand composite curve — back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown
D.Grand composite curve — temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
A.typical plant headers of HP (about 40 bar), MP (about 10 bar) and LP (about 3.5 bar), let down through turbines or PRV-desuperheater stations
B.two refrigerants in series, such as propane then ethylene, because one fluid cannot span from −100 °C to ambient at reasonable pressures
C.recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide
D.matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
14. Which term means: "matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target"?
A.Heat exchanger network design — temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
B.Heat exchanger network design — typical plant headers of HP (about 40 bar), MP (about 10 bar) and LP (about 3.5 bar), let down through turbines or PRV-desuperheater stations
C.Heat exchanger network design — back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown
D.Heat exchanger network design — matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
A.matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
B.hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
C.smaller minimum approach saves utility but raises exchanger area; supertargeting picks the value that minimises total annual cost
D.recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide
17. Which term means: "recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide"?
A.Cooling water system — smaller minimum approach saves utility but raises exchanger area; supertargeting picks the value that minimises total annual cost
B.Cooling water system — plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures
C.Cooling water system — back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown
D.Cooling water system — recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide
20. Which term means: "back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown"?
A.Cogeneration — matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
B.Cogeneration — recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide
C.Cogeneration — typical plant headers of HP (about 40 bar), MP (about 10 bar) and LP (about 3.5 bar), let down through turbines or PRV-desuperheater stations
D.Cogeneration — back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown
A.recirculating tower giving about 33 °C supply and 10 °C range, with cycles of concentration limited by silica and hardness and controlled by blowdown and biocide
B.temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
C.plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures
D.smaller minimum approach saves utility but raises exchanger area; supertargeting picks the value that minimises total annual cost
23. Which term means: "smaller minimum approach saves utility but raises exchanger area; supertargeting picks the value that minimises total annual cost"?
A.ΔTmin trade-off — smaller minimum approach saves utility but raises exchanger area; supertargeting picks the value that minimises total annual cost
B.ΔTmin trade-off — matching hot and cold streams starting at the pinch with CP rules (CP_hot ≤ CP_cold above pinch) and the N−1 minimum-units target
C.ΔTmin trade-off — temperature where hot and cold composite curves are ΔTmin apart; no heat should cross it, no cold utility above it and no hot utility below it
D.ΔTmin trade-off — back-pressure turbine that generates power while letting steam down from HP to process headers, far more efficient than PRV letdown
26. Which term means: "two refrigerants in series, such as propane then ethylene, because one fluid cannot span from −100 °C to ambient at reasonable pressures"?
A.Refrigeration cascade — smaller minimum approach saves utility but raises exchanger area; supertargeting picks the value that minimises total annual cost
B.Refrigeration cascade — hot and cold stream enthalpy-temperature curves overlaid; their closest vertical approach is the pinch and the overhangs give minimum hot and cold utility
C.Refrigeration cascade — two refrigerants in series, such as propane then ethylene, because one fluid cannot span from −100 °C to ambient at reasonable pressures
D.Refrigeration cascade — plot of net heat flow against shifted temperature used to place utilities such as steam levels, furnaces and refrigeration at the right temperatures
Answers, AI explanations, and a free readiness check
Sign up free to check your answers with explanations, ask the AI tutor anything on any question, and take the free 2-minute readiness check for a scored result. The full AI mock interview, scored like a real panel, unlocks with Pro.