Ch. 7

Question 1

477. Co-generation can be defined as:

a. Having two steam generation units in one plant.
b. The utilization of steam for process and power generation purposes.
c. The utilization of waste heat of a steam boiler to heat feedwater.
d. The utilization of one form of input energy to generate two or more forms of output energy.
e. The utilization of two forms of input energy to generate one single form of output energy.

Answer 1

d. The utilization of one form of input energy to generate two or more forms of output energy.

Question 2

478. The primary purpose of cogeneration is_____________________.

a. to reduce the equipment cost
b. to increase the life span of equipment
c. to reduce the prices of natural gas
d. to reduce staffing cost
e. to reduce the energy cost

Answer 2

e. to reduce the energy cost

Question 3

479. The advantages as comparing to conventional facilities of cogeneration at micro (local) level include:

1)     Reduction in the total energy bill when electricity is required at the site
2)     It is generally more compact and less maintenance required as compared to the conventional facilities
3)     Reduction of load demand on heavier polluting, coal-fired facilities
4)     Shorter start up time 

a. 1, 2, 3
b. 1, 2, 4
c. 1, 3, 4
d. 2, 3, 4
e. 1, 2, 3, 4

Answer 3

b. 1, 2, 4

Question 4

480. The applications of cogeneration can befall into which of the following areas:

1)     Institutional establishments
2)     Large scale industries plants
3)     Localized central and heating and cooling plant
4)     Theatres and restaurants 

a. 1, 2, 3
b. 1, 2, 4
c. 1, 3, 4
d. 3, 4
e. 1, 2, 3, 4

Answer 4

a. 1, 2, 3

Question 5

481. Which of the following are the types of simple-cycle cogeneration used today:

1)     Back Pressure Steam Turbine
2)     Waste Heat Cogeneration
3)     Heat Engine Cogeneration
4)     Gas Turbine 
5)     Condensing steam turbine 

a. 1, 2, 3, 5
b. 1, 2, 4, 5
c. 1, 3, 5
d. 2, 3, 4
e. 1, 2, 3, 4

Answer 5

e. 1, 2, 3, 4

Question 6

482. Which one of the following simple-cycle cogeneration systems best describes this process? “Steam produced from a boiler drives a steam turbine, which in turn drives the electric generator. The low pressure exhaust steam from the turbine is supplying the required heat to the process. The condensed steam from the process is then returned to the boiler.”

a. Back Pressure Steam Turbine
b. Condensing Steam Turbine
c. Waste Heat Cogeneration
d. Heat Engine Cogeneration
e. Gas Turbine

Answer 6

a. Back Pressure Steam Turbine

Question 7

483. Which one of the following simple-cycle cogeneration systems best describes this process? “The waste heat produced by the gas turbine passes through an exhaust heat boiler. The steam produced by the boiler is used for heating purposes and for an absorption refrigeration system”.

a. Back Pressure Steam Turbine
b. Condensing Steam Turbine
c. Waste Heat Cogeneration
d. Heat Engine Cogeneration
e. Gas Turbine

Answer 7

e. Gas Turbine

Question 8

484. Which one of the following simple-cycle cogeneration systems best describes the process? “Fuel burned to produce heat for a process and then to use the waste heat from the process to produce steam in the boiler. The steam from the boiler is fed to the steam turbine to turn an electric generator. The low pressure exhaust steam from the steam turbine is used to drive another turbine on to provide heat to the feedwater heaters.”

a. Back Pressure Steam Turbine
b. Condensing Steam Turbine
c. Waste Heat Cogeneration
d. Heat Engine Cogeneration
e. Gas Turbine

Answer 8

c. Waste Heat Cogeneration

Question 9

485. Which one of the following simple-cycle cogeneration system best describes this process? “The heat engine turns and electric generator and the exhaust gases from the heat engine provides the heat source for the heat recovery unit”.

a. Back Pressure Steam Turbine
b. Condensing Steam Turbine
c. Waste Heat Cogeneration
d. Heat Engine Cogeneration
e. Gas Turbine

Answer 9

d. Heat Engine Cogeneration

Question 10

486. Combined cycle cogeneration refers to the production of electricity from __________________________________.

a. one source utilizing one fuel source
b. two sources utilizing two fuel sources
c. two sources utilizing one fuel source
d. one source utilizing two fuel sources
e. three sources utilizing one fuel source

Answer 10

c. two sources utilizing one fuel source

Question 11

487. Which one of the following cogeneration systems best describes this process? “The fuel is burned in a conventional gas turbine combustor. The gas turbine is connected to an electrical generator. The exhaust from the gas turbine is then used as combustion air to mix with fuel burned in the boiler. The steam produced from the boiler is used to drive a steam turbine which is connected to a second electrical generator”.

a. Back Pressure Steam Turbine Cogeneration
b. Waste Heat Cogeneration
c. Gas Turbine Cogeneration
d. Combined-cycle Steam/Gas Turbine Cogeneration
e. Combined-cycle Gas/Steam Turbine Cogeneration

Answer 11

e. Combined-cycle Gas/Steam Turbine Cogeneration

Question 12

488. Which one of the following cogeneration systems requires neither an FD nor ID fans for the boiler?

a. Back Pressure Steam Turbine
b. Condensing Steam Turbine
c. Open Cycle Gas Turbine
d. Combined-cycle Steam/Steam Turbine
e. Combined-cycle Gas/Steam Turbine

Answer 12

e. Combined-cycle Gas/Steam Turbine

Question 13

489. Which one of the following cogeneration systems best describes this process? “The compressor driven by the gas turbine supplies pressurized combustion air to mix with fuel and burned in the boiler. The steam produced by the boiler is used to drive a steam turbine which is connected to an electrical generator. The exhaust gases from the boiler are then fed to the gas turbine which is connected to a second electrical generator.”

a. Back Pressure Turbine
b. Waste Heat
c. Gas Turbine
d. Combined-cycle Steam/Gas Turbine
e. Combined -cycle Gas/Steam Turbine

Answer 13

d. Combined-cycle Steam/Gas Turbine

Question 14

490. The term HRSG stands for:

a. High Return Steam Generator
b. Heat Recovery Superheated Generator
c. Hot Return Steam Generator
d. Heat Recovery Steam Generator
e. Heat Return Steam Generator

Answer 14

d. Heat Recovery Steam Generator

Question 15

491. Which one of the following cogeneration systems best describes this? “The system consists of a gas turbine, steam turbine, electrical generators (driven by the gas and steam turbines) and a fixed HRSG unit.”

a. Fully Fixed Combined-cycle
b. Steam/Gas Turbine Combined-cycle
c. Gas/Steam Turbine Combined-cycle
d. Back Pressure Steam/Gas Turbine Combined-cycle
e. Condensing Steam/Gas Turbine Combined-cycle

Answer 15

a. Fully Fixed Combined-cycle

Question 16

492. A HRSG extracts most of its heat energy from the exhaust of a gas turbine and the remainder of the required heat energy to run the steam turbine is supplied by:

a. The flue gases of the auxiliary boiler
b. Burning fuel in a series of auxiliary burners
c. The heat from the exhaust heat boiler
d. Increasing the input energy to the gas turbine
e. A separately fired heater independent of the HRSG

Answer 16

b. Burning fuel in a series of auxiliary burners

Question 17

493. The advantages of a combined-cycle cogeneration plant as compared to a conventional, steam generating plant:

1)     Higher production of electrical energy
2)     Higher thermal efficiency
3)     Lower emissions to atmosphere
4)     Lower fuel consumption 

a. 1, 2, 3
b. 1, 2, 4
c. 1, 3, 4
d. 2, 3, 4
e. 1, 2, 3, 4

Answer 17

e. 1, 2, 3, 4

Question 18

494. In Combined cycles systems the term pressurized means___________________________________.

a. the HRSG is under steam pressure
b. the gas turbine exhaust is fed into the boiler
c. the combustion chamber is under air pressure
d. the boiler is fed by forced and induced draft fans
e. the gas turbine is pressurized from the boiler

Answer 18

b. the gas turbine exhaust is fed into the boiler

Question 19

495. A single shaft combined-cycle power plan can be arranged so that________________________________.

a. the steam turbine is between the generator and the gas turbine
b. the gas turbine is between the generator and the steam turbine
c. the generator is between the gas turbine and the steam turbine
d. the generator is between the HRSG and the steam turbine
e. the generator is between the HRSG and the gas turbine

Answer 19

c. the generator is between the gas turbine and the steam turbine

Question 20

496. A single shaft combined-cycle power plant can be arranged so that _________________________________.

a. the HRSG unit is between the gas turbine and the steam turbine
b. the HRSG unit is between the generator and the steam turbine
c. the generator is between the HRSG and the steam turbine
d. the gas turbine drives the generator and the exhaust gas from the gas turbine enters the HRSG
e. the boiler flue gases enter the gas turbine which drives the generator with a HRSG providing additional heat energy

Answer 20

d. the gas turbine drives the generator and the exhaust gas from the gas turbine enters the HRSG

Question 21

497. The benefits of a combined-cycle with a single shaft gas/steam turbine arrangement are:

1)     High level of thermal efficiency
2)     Low capital cost
3)     Fast start up and shut down
4)     Short construction time
5)     Low maintenance cost 

a. 1, 2, 3
b. 1, 2, 4
c. 1, 3, 4
d. 1, 2, 3, 4
e. 1, 2, 3, 4, 5

Answer 21

e. 1, 2, 3, 4, 5

Question 22

498. The HRSG used to raise the temperature of the saturated steam before entering the steam turbine in a dual shaft combined-cycle power plant arrangement____________________________.

a. has a series of auxiliary burners
b. receives heat energy from the exhaust gas of the gas turbine
c. receives heat energy from the exhaust gas of the steam boiler
d. receives heat energy from a number of outside sources
e. has separately fired unit to increase heat energy

Answer 22

b. receives heat energy from the exhaust gas of the gas turbine

Question 23

499. Multi-shaft combined-cycle power plant has high efficiency at ______ operation.

a. high load
b. low load
c. base load
d. variable load
e. medium load

Answer 23

c. base load

Question 24

500. When the fuel supplied first produces electrical power with the thermal energy produced as a by-product. This cogeneration system is called the:

a. Waste Heat Cycle
b. Gas Turbine Cycle
c. Heat Engine Cycle
d. Topping Cycle
e. Bottoming Cycle

Answer 24

d. Topping Cycle

Question 25

501. When the fuel supplied produces high temperature thermal energy for processes and the heat exhausted from these processes is used to produce electrical energy from a HRSG. The cogeneration system is called the: a. Waste Heat Cycle b. Gas Turbine Cycle c. Heat Engine Cycle d. Topping Cycle e. Bottoming Cycle

Answer 25

e. Bottoming Cycle

Question 26

502. The ______ system has the electrical production from the cogeneration system fixed at maximum and changing electrical requirements met by the electrical utility grid. a. home based b. base loaded c. set electrical demand d. constant based e. demand based

Answer 26

b. base loaded

Question 27

503. The _____ system has the electrical supply from the utility grid fixed and the cogeneration system looks after changing the electrical requirements. a. home based b. base Loaded c. set electrical demand d. constant based e. demand based

Answer 27

c. set electrical demand

Question 28

504. In a cogeneration system the thermal load can be controlled by which two of the following strategies: 1) Fixed production of a minimum thermal energy 2) Varying requirements for thermal energy 3) Base loaded for maximum thermal energy 4) Topping for minimum thermal energy a. 1, 2 b. 2, 3 c. 1, 3 d. 2, 4 e. 1, 4

Answer 28

a. 1, 2

Question 29

505. Fixed production of a minimum thermal energy for thermal load control strategy of a cogeneration system is achieved by: a. Varying the prime mover output and fixed the thermal energy output. b. Operating the prime mover at constant maximum output and adjust the thermal requirements by other means. c. Operating the prime mover at full load and fixed the thermal requirements by other means. d. Varying both the prime mover and the auxiliary firing equipment outputs. e. Adjusting the thermal energy output of the auxiliary firing equipment.

Answer 29

b. Operating the prime mover at constant maximum output and adjust the thermal requirements by other means.

Question 30

506. During low thermal requirement periods of a cogeneration system a diverter valve is used to: a. Direct the exhaust gases from the HRSG to the atmosphere. b. Direct the thermal energy from the duct burner to the atmosphere. c. Direct the excess electrical energy to another utility grid. d. Direct the thermal energy from the gas turbine to the duct burner. e. Direct the exhaust gases from the gas turbine to the atmosphere.

Answer 30

e. Direct the exhaust gases from the gas turbine to the atmosphere.

Question 31

507. When additional thermal energy is required in a cogeneration system, a _____ is often used for this purpose. a. HRSG b. Gas Turbine c. Boiler d. Duct Burner e. Unit Heater

Answer 31

d. Duct Burner

Question 32

508. The main application for HRSG, WHRG and TEG on a cogeneration system is for: a. Heat generation to drive the gas turbine. b. Mechanical energy generation utilizing the gas turbine exhaust gases. c. Electrical generation utilizing the gas turbine exhaust gases. d. Steam generation utilizing the gas turbine exhaust gases. e. Light energy generation utilizing the gas turbine exhaust gases.

Answer 32

d. Steam generation utilizing the gas turbine exhaust gases.

Question 33

509. The design the HRSG in a cogeneration system depends on: 1) Thermal requirements 2) Mechanical requirements 3) Electrical requirements 4) Volumetric requirements a. 1, 2 b. 1, 3 c. 1, 4 d. 2. 3 e. 2, 4

Answer 33

b. 1, 3

Question 34

510. The duct burners in a cogeneration system with a gas turbine can be used to: 1) Increase the production of steam. 2) Control the temperature of the exhaust gas of the turbine. 3) Control the superheater temperatures 4) Meet process steam temperature requirements. a. 1, 2, 3 b. 1, 2, 4 c. 1, 3, 4 d. 2, 3, 4 e. 1, 2, 3, 4

Answer 34

c. 1, 3, 4

Question 35

511. Some HRSG boilers of the once through forced circulation design equipped with high alloy tubes and it can: a. Operate with high velocity water flow through the tubes. b. Operate with high volume water flow through the tubes. c. Operate with low steam flow through the tubes. d. Operate without water flow through the tubes. e. Operate without chemical treatment for the boiler.

Answer 35

d. Operate without water flow through the tubes.

Question 36

512. Cogeneration systems can be designed to burn various fuels and these fuels can produce the following gases which will affect the environment negatively: 1) SO 2) NOX 3) C2H4 4) CO2 a. 1, 2, 3 b. 1, 2, 4 c. 1, 3, 4 d. 2, 3, 4 e. 1, 2, 3, 4

Answer 36

b. 1, 2, 4

Question 37

513. The production of nitrous oxides leads to_____________________. a. alkaline corrosion b. scaling of the boiler tubes c. high Ph level in the boiler water d. low Ph level in the boiler water e. acid rain

Answer 37

e. acid rain

Question 38

514. _____ and _____ can be used in a HRSG to reduce NOX leaving the HRSG. a. Steam and NH3 b. CO2 and NH3 c. SO2 and NH3 d. H2O and NH3 e. CO2 and SO2

Answer 38

a. Steam and NH3

Question 39

515. _____ is well known for its contribution to the greenhouse effect. a. C4H82 b. CO c. CO3 d. CO2 e. CH3

Answer 39

d. CO2

Question 40

516. In order to counter the corrosion nature of the condensate produced from burning fuel with a high sulphur content, a _________ heat exchanger is installed in the condensing heat recovery systems. a. plastic lined b. mild steel c. high carbon steel d. high alloy steel e. stainless steel

Answer 40

e. stainless steel

Question 41

517. Cogeneration systems with an IC engine connected to a HRWH can obtain good efficiency in ______ systems. a. heavy industry b. normal household c. small industry d. small air conditioning e. large heating

Answer 41

c. small industry

Question 42

518. The water jackets on an IC engine with a HRWH is designed to: 1) Cool the air surrounding the engine. 2) Recover the waste heat from the engine. 3) Cool the engine. 4) Cool the lubricating oil. a. 1, 2, 3 b. 1, 2, 4 c. 1, 3, 4 d. 2, 3, 4 e. 1, 2, 3, 4

Answer 42

e. 1, 2, 3, 4

Question 43

519. When an IC engine is used as part of a cogeneration system, the added advantages are: 1) Higher power to weight rates than the gas turbine. 2) Ambient temperature does not affect the electrical energy output. 3) Higher thermal efficiency than a conventional gas. 4) Capability of intermittent operation. a. 1, 2 b. 2, 3 c. 3, 4 d. 1, 3 e. 2, 4

Answer 43

e. 2, 4

Question 44

520. HRWH stands for: a. Heat Recovery Waste Heater b. Heat Recovery Water Hydrotreater c. Heat Recovery Water Heater d. Heat Recovery Waste Hydrotreater e. Heat Recovery Warming Heater

Answer 44

c. Heat Recovery Water Heater

Question 45

521. HRHWG stands for: a. Heat Recovery High Water Generator b. Heat Recovery Generator Hot Waste c. Heat Recovery High Efficiency Waste Heat Generator d. Heat Recovery Hot Water Generator e. Heat Recovery High Efficiency Water Generator

Answer 45

d. Heat Recovery Hot Water Generator

Question 46

522. Before attempting to start up a combined-cycle cogeneration system, ______ should be consulted first. a. the jurisdictional inspector b. the local fire department c. manufacturers guidelines and operating instructions d. the power company e. the local gas company

Answer 46

c. manufacturers guidelines and operating instructions

Question 47

523. During the start up of a cogeneration system with a gas turbine: a. The gas turbine is normally started up by compressed air. b. The gas turbine is turned/started by a separate starter motor. c. The gas turbine will start up automatically as soon as power is engaged. d. The diverter valve will divert thermal energy from the HRSG to start the gas turbine. e. The auxiliary burner will provide additional thermal energy to start the gas turbine.

Answer 47

b. The gas turbine is turned/started by a separate starter motor.

Question 48

524. When starting a cogeneration system with a gas turbine, the starting motor will disengage from the turbine when the turbine is at approximately ____ % of its rated speed. a. 5 b. 10 c. 25 d. 35 e. 55

Answer 48

e. 55

Question 49

525. When starting a cogeneration system with a gas turbine, the fuel is admitted to the combustor and ignited at approximately ____% of the rated speed of the turbine. a. 5 b. 10 c. 25 d. 55 e. 15

Answer 49

d. 55

Question 50

526. When running up a Cogeneration system the diverter valve is opened 100% when________________________. a. the turbine is at rated load b. the temperature is rising in the turbine blades c. the combustion turbine temperature is at maximum d. the HSSG is pre-warmed and up to temperature e. the HRSG is producing steam

Answer 50

e. the HRSG is producing steam