1-50

Question 1

1. Two kilogram of gas is confined in a 1m^3 tank 200kpa and 88degC. What type of gas is in the tank?

a). Helium
b). Ethane
c). Methane
d). Ethane

Answer 1

b). Ethane

Question 2

2. In Refrigeration, how do you call a heat exchanger in which low-pressure refrigerant boils or vaporizes, thus absorbing heat that was removed from the refrigerated area by the cooling medium (water)?

a) Evaporator
b) Chiller
c) Cooler
d) Flooded Evaporator

Answer 2

b) Chiller

Question 3

3. It is a type of refrigeration system where only part of the circulated refrigerant is evaporated, with the remainder being separated from the vapor and then recirculated. How do you call this system?

a) Absorption refrigeration system
b) Vacuum refrigeration system
c) Vapor-compression refrigeration system
d) Flooded refrigeration system

Answer 3

d) Flooded refrigeration system

Question 4

4. How do you call the mixtures or substances that are used in laboratory methods of producing a drop in temperature? The most common example is the mixture of ice and salt.

a) Calorific mixture
b) Water-ammonia mixture
c) Frigorific mixture
d) Hygroscopic mixture

Answer 4

c) Frigorific mixture

Question 5

5. Which of the following is a scale of temperature in which the melting point of ice is taken as 0 o and the boiling point of water is 800?

a) Reaumur Scale
b) Carrene Scale
c) Genetron Scale
d) Frigorie Scale

Answer 5

a) Reaumur Scale

Question 6

6. What is the amount of heat energy required to raise the temperature of one pound of water one degree Fahrenheit? It is 1/180 of the heat required to raise the temperature of one pound of water from 32 to 212 oF at constant atmospheric pressure of 14,696 psi absolute.

a) Specifc heat
b) British thermal unit
c) Calorie
d) Sensible heat

Answer 6

b) British thermal unit

Question 7

7. It the maximum temperature of any gas or vapor at which it may be condensed into a liquid; above this temperature, it is impossible to condense regardless of the pressure applied.

a) Saturation temperature
b) Superheated temperature
c) Critical temperature
d) Dew point temperature

Answer 7

c) Critical temperature

Question 8

8. Any refrigerant that exists as a liquid under normal atmospheric pressure and temperature must be vaporized in an evaporator under a pressure below atmospheric. This is sometimes referred to as:

a) Halogenated refrigerant
b) Freon refrigerant
c) Vacuum refrigerant
d) Halocarbon refrigerant

Answer 8

c) Vacuum refrigerant

Question 9

9. It is any one of a group of refrigerants that have been developed since about 1925 to overcome the irritating or toxic effects of refrigerants, such as ammonia and sulfur dioxide and the high condensing pressures required with carbon dioxide. How do you call these refrigerants?

a) Halogenated refrigerants
b) Freon refrigerants
c) Vacuum refrigerants
d) Halocarbon refrigerants

Answer 9

a) Halogenated refrigerants

Question 10

10. This refrigeration system component combines the functions of a cooling tower and a condenser. It consists of a casing enclosing a fan or blower section, water eliminators, refrigerant condensing coil, water pan, float valve, and spray pump outside the casing. How do you call this component?

a) Water-cooled condenser
b) Evaporative condenser
c) Atmospheric condenser
d) Chiller

Answer 10

b) Evaporative condenser

Question 11

11. It refers to a factor used in calculating the over- all heat transfer through the tube walls of a condenser tube or other heating surface. It includes the sum of the heat transfer rate of the layer of dirt and foreign material that builds up on the water side of the tube. What is this factor?

a) Cooling factor
b) Contact factor
c) By-pass factor
d) Fouling factor

Answer 11

d) Fouling factor

Question 12

12. It is a refrigeration system evaporator which is arranged with a with a tank or tank or a single drum (accumulator) located above the coil so that the inside of the evaporator is full of refrigerant. How do you call this type of evaporator?

a) Flooded evaporator
b) Dry evaporator
c) Cooing coil evaporator
d) Headered coil evaporator

Answer 12

a) Flooded evaporator

Question 13

13. What is the standardized term used by the industry to describe any device that meters or regulates the flow of liquid refrigerant to an evaporator?

a) Refrigerant control
b) Expansion valve
c) Throttling valve
d) Capillary tube

Answer 13

b) Expansion valve

Question 14

14. Define a “control valve”.

a) The value set on the scale of the control system in order to obtain the required condition
b) The quantity or condition of the controlled medium
c) The flow or pressure of the steam (or fluid) being manipulated
d) The valve of the controlled condition actually maintained under steady state conditions

Answer 14

d) The valve of the controlled condition actually maintained under steady state conditions

Question 15

15. A pneumatic temperature control is used on the steam supply to a non-storage heat exchanger that heats water serving an office heating system. What is referred to as manipulated variable”?

a) The water being heated
b) The air signal from the controller to the valve actuator
c) The steam supplies
d) The temperature of the air being heated

Answer 15

b) The air signal from the controller to the valve actuator

Question 16

16. How do you classify a solenoid valve?

a) A thermal valve
b) A magnetic stop valves
c) A bellows valves
d) A bi-metallic valve

Answer 16

a) A thermal valve

Question 17

17. What is a thermostat?

a) A temperature-operated switch
b) A pressure-operated switch
c) A superheat-operated switch
d) A back pressure-operated switch

Answer 17

d) A back pressure-operated switch

Question 18

18. Which of the following is the one of the main purposes of refractory in a boiler furnace?

a) Help preheat the air for the furnace
b) Help preheat the feed water
c) Protect economizer from excessive heat
d) Prevent excessive furnace heat losses

Answer 18

c) Protect economizer from excessive heat

Question 19

19. Balance pressure traps are what type of steam trap?

a) Thermodynamic
b) Mechanical
c) Thermostatic
d) They do not belong to any specific type of trap family

Answer 19

b) Mechanical

Question 20

20. What is a characteristic feature of thermodynamic steam traps?

a) They pass condensate at steam temperature
b) They operate by holding back condensate until it has cooled
c) They cannot be fitted outside
d) They can only be fitted on low pressure steam systems

Answer 20

b) They operate by holding back condensate until it has cooled

Question 21

21. What are the main considerations for steam trap selection?

a) Price
b) Air venting, plant performance, flow capacity and reliability
c) Connections
d) The trap must be the same size as the condensate drain line

Answer 21

b) Air venting, plant performance, flow capacity and reliability

Question 22

22. Can temperature-controlled applications be trapped?

a) Traps should not be fitted under any circumstances
b) Only if there is no lift after the trap
c) If the pressure on the trap is always higher than backpressure
d.) Pumps should always be fitted to remove condensate

Answer 22

c) If the pressure on the trap is always higher than backpressure

Question 23

23. What are the main considerations for steam trap selection?

a) Price
b) Air venting, plant performance, flow capacity and reliability
c) Connections
d) The trap must be the same size as the condensate drain line

Answer 23

b) Air venting, plant performance, flow capacity and reliability

Question 24

24. Can temperature-controlled applications be trapped?

a) Traps should not be fitted under any circumstances
b) Only if there is no lift after the trap
c) If the pressure on the trap is always higher than backpressure
d) Pumps should always be fitted to remove condensate

Answer 24

c) If the pressure on the trap is always higher than backpressure

Question 25

25. Unless they are designed to flood, what is the important when removing condensate from heat exchangers? a) Condensate is allowed to sub-cool before reaching the trap b) Condensate is removed at steam temperature c) Condensate should back-up into the steam pipe d) That the trap is fatted level with or above the heater outlet

Answer 25

b) Condensate is removed at steam temperature

Question 26

26. How is flash steam produced? a) From condensate passing from high to low pressure systems b) From saturated steam c) From superheated steam d) From steam mixed with high temperature air

Answer 26

a) From condensate passing from high to low pressure systems

Question 27

27. Are steam traps required to pass air? a) Steam traps should not pass air under any circumstances b) Only when the trap has passed all the condensate c) Air should be removed as soon as it reaches the trap d) Only on high pressure steam system

Answer 27

c) Air should be removed as soon as it reaches the trap

Question 28

28. How do you call a system employing open sprinklers attached to a piping system connected to a water supply through which is opened by the operation of a fire detection system installed in the same areas as the sprinklers? a) Mechanical sprinkler b) Automatic system c) Wet pipe system d) Deluge system

Answer 28

d) Deluge system

Question 29

29. What is probably the first consideration when selecting a control system? a) What degree of accuracy is required? b) Is the control for heating or cooling? c) Is a two or three port valve required? d) In the event of power failure, must the valve fail-open or fail-closed?

Answer 29

d) In the event of power failure, must the valve fail-open or fail-closed?

Question 30

30. When adding the refrigerant in a refrigeration system, it shall be charge into which of the following parts of the system? a) High pressure side b) Low pressure side c) low- and high-pressure side d) Compressor discharge line

Answer 30

b) Low pressure side

Question 31

31. Why is a boiler feed tank heated to approximately 85degC? a) To reduce the energy required to raise steam b) To reduce the content of total dissolved solids in the water supplied to the boiler c) To reduce the gas content of the water d) To reduce the content of suspended solids in the water

Answer 31

c) To reduce the gas content of the water

Question 32

32. What is used to dry air? a) A separator b) A strainer c) A steam traps d) A tee pieces

Answer 32

a) A separator

Question 33

33. What causes water hammer in the boiler? a) Suspended water droplets b) An air/water mixture c) Strainers fitted on their sides d) Slugs of water in the steam

Answer 33

d) Slugs of water in the steam

Question 34

34. How does air enter a steam system? a) Through joints, on shut down of the steam system b) With make-up water to the boiler feed tank c) With condensate entering the boiler feed tank d) All items a, b, & c

Answer 34

d) All items a, b, & c

Question 35

35. Why should strainers installed on steam lines be fitted on their sides? a) To prevent the build-up of water in the strainer body b) To trap more dirt c) To reduce the frequency of cleaning d) To provide maximum screening area for the steam

Answer 35

a) To prevent the build-up of water in the strainer body

Question 36

36. What is the result of using a heat exchanger rating to calculate its steam consumption? a) The true connected heat load may be different from the rated figure. b) The rating does not take account of the temperature of the secondary medium c) The rating is based on a steam pressure of 1.0 bar d) The rating does not allow for condensate forming in the heat exchanger

Answer 36

a) The true connected heat load may be different from the rated figure.

Question 37

37. A heat exchanger has a design rating based on a working pressure of 7 bar g. What would be the effect of supplying the exchanger with steam at 3 bar g? a) The heat output would be greater because the enthalpy of evaporation at 3 bar g is higher than at 7 bar g. b) The heat output would be greater because steam at 3bar g has a greater volume than steam at 7 bar g. c) less weight of steam would be required because steam at 3 bar g has a higher enthalpy of evaporation than 7 bar g. d) The output would be reduced because the difference in temperature between the steam and product is reduced.

Answer 37

d) The output would be reduced because the difference in temperature between the steam and product is reduced.

Question 38

38. For any particular tank temperature how does the heat loss from the lid of a closed tank compare with that of bottom? a) They are approximately double those from the bottom b) Losses from the top are approximately double those from the bottom c) losses from the bottom are approximately double those from the top d) losses from the top are approximately 4 times those from the bottom

Answer 38

b) Losses from the top are approximately double those from the bottom

Question 39

39. What is the disadvantage of heating a tank by direct steam injection? a) It agitates the solution b) Some of the enthalpy of water is used c) Steam traps are not required d) It dilutes the tank content

Answer 39

d) It dilutes the tank content

Question 40

40. you are assigned as Engineer, must be replaced. Which of the following types most likely to be installed? a) Screw chiller b) Scroll Chiller c) Reciprocating chiller d) Centrifugal chiller

Answer 40

d) Centrifugal chiller Note: Centrifugal chillers are generally selected for their high coefficient of performance, good part-load performance, and cooling capacity. The economics of large-scale applications (such as hospital) generally favor more efficient machines such centrifugal chillers. In this case, a centrifugal chiller is also the only one of the types listed that can provide the needed capacity.

Question 41

41. Refrigeration condensers are rated based upon their ability to reject the total heat that comes from which of the following? a) Compressor work and net refrigeration effect b) Superheating c) Subcooling d) Compressor work

Answer 41

a) Compressor work and net refrigeration effect

Question 42

42. A published 'U' value from a steam coil to a water-based solution is given as 550 1300 W/m^2-degC. When would be figure near the lower end of the range be used? a) When the steam is known to be of good quality b) For short coils c) For small diameter coils d) When scaling or fouling of the coil takes place

Answer 42

d) When scaling or fouling of the coil takes place

Question 43

43. Steam coils should enter and leave the top of a tank when: a) The tank contains a corrosive solution b) When agitation of the tank solution is required c) When steam locking the trap draining a base coil could occur d) When good heat distribution is required

Answer 43

a) The tank contains a corrosive solution

Question 44

44. A tank is to be heated by direct steam injection. How will the quantity of heat required compare with steam coil heating? a) It depends on the temperature of the water being heated b) More heat will be required c) The same amount of heat will be required d) less heat will be required

Answer 44

c) The same amount of heat will be required

Question 45

45. Which of the following parameters has the greatest? limiting effect on the thermal performance of an open, evaporative cooling tower? a) Wet-Bulb temperature b) Dry-Bulb temperature c)Range d) Approach

Answer 45

a) Wet-Bulb temperature

Question 46

46. It is a space, or several rooms, or units of space having some sort of coincident loads or similar operating characteristics. It may or may not be an enclosed space, or it may consist of many partitioned rooms. How do you call this? a) Zone b) Room c) Space d) Plenum

Answer 46

a) Zone

Question 47

47. In air conditioning, it indicates either a volume or a site without a partition or a partitioned room or group of rooms. How do you call this? a) Zone b) Room c) Space d) Plenum

Answer 47

c) Space

Question 48

48. It is an enclosed or partitioned space that is usually treated as a single load. If conditioned, it often has an individual control system. What is this? a) Zone b) Room c) Space d) Plenum

Answer 48

b) Room

Question 49

49. It represents the rate, in Btu/hr or W, at which heat enters a conditioned space from an external source or is released to the space from an internal source during a given time interval. a) Space heat gain b) Space cooling load c) Space heating load d) Space heat extraction rate

Answer 49

a) Space heat gain

Question 50

50. It is the rate, in Btu/hr or W, at which heat must be removed from a conditioned space so as to maintain a constant temperature and acceptable relative humidity. Its sensible load component is equal to the sum of the convective heat transfer from the surfaces of the building envelope, furnishings, occupants, appliances, and equipment. How do you call this? a) Space heat gain b) Space cooling load c) Space heating load d) Space heat extraction rate

Answer 50

b) Space cooling load