Refrigeration and HVAC Systems Questions PDF

L Two kilogram of gas is confined ina Im”3 200kpa and $8degC. What type of gas is in tank the tank ? a). Helium b). Ethane €)....

L Two kilogram of gas is confined ina Im”3 200kpa and $8degC. What type of gas is in tank the tank ? a). Helium b). Ethane €). Methane d). Ethane 2. In Refrigeration, how do you call a heat exchanger in which low-pressure. refrigerant boils or vaporizes, thus absorbin g heat that was removed from the refrigerated area by the cooling medium (water)? a) Evaporator b) Chiller* ¢) Cooler d) Flooded Evaporator 3. Itis 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 ) Vapor-compression refrigeration system d) Flooded refrigeration system 4. How do you call the mixtures or substances that are used in laboratory methods of producing a drop in temperare? The most common example is the mixture of ice and salt. a) Calorific mixture b) Water-ammonia mixture ¢) Frigorific mixture d) Hygroscopic mixture Which of the following i a scale of temperature o 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 ¢) Genetron Scale d) Frigorie Scale 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 ¢) Calorie d) Sensible heat 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. How do you call this temperature? a) Saturation temperature  b) Superheated temperature ¢) Critical temperature d) Dew point temperature 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 ¢) Vacuum refrigerant d) Halocarbon refrigerant 9. Itisany onc of a group of refrigerants that have been developed since about 1925 to overcome the imitating 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 ©) Vacuum refrigerants d) Halocarbon refrigerants 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 climinators, 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 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 ©) By-pass factor d) Fouling factor 12,1t is a refrigeration system evaporator which is arranged with a 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 ©) Cooing coil evaporator d) Headered coil evaporator 13. whal 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 ©) Throttling valve d) Capillary tube 14. Define a “control valve™. @ The value set on the scale of the contr ol system in order to obtain the required condition b) The quantity or condition of the contr olled medium ©) The flow or pressure of the steam (or fluid) being manipulated d) The valve of the controlled condition actually maintained under steady state conditions 15. A pneumatic temperature control is used on the steam supply 0 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 ¢) The steam supplies d) The temperature of the air being heated 16. How do you classity a solenoid valve? a) A thermal valve b) A magnetic stop valves ©) A bellows valves d) A bi-metallic valve 17. What is a thermostat? a) A temperature-operated switch b) A pressure-operated switch ¢) A superheat-operated switch d) A back pressure-operated switch 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 ¢) Protect economizer from excessive heat d) Prevent excessive furnace heat losses 19. Balance pressure traps are what type of steam trap? a) Thermodynamic b) Mechanical ¢) Thermostatic d) They do not belong to any specific type of trap family 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  ©) They cannot be itted outside ) The y can onl ¥ be fit sleam gystems ted on Joy pressu re 21, L What gy, ¢ the main consideratioi ns for selection? s ) Price e by Air venting, plant capacity and reliabili performance, flow ty ©) Connections &) The trap must be the same size as the condensate drain line 22, Can temperature-con trol| led applications e trapped? ) Traps should not be fitt ed unds ler any cir cumstances b) Only if there is no lifi after the trap ) If the pressure on the trap is always higher than backpressure d.) Pumps should always be fitted to remove condensate 23. What are the main considerations for steam trap selection? a) Price b) Air venting, plant performan ce, flow capacity and reliability ¢) Connections &) The trap must be the same size as the condensate drain line 24.Can temperature-controlled applications be trapped? ) Traps should not be fitted under any circumstances b) Only if there is no lift after the trap ©) If the pressure on the trap is always higher than backpressure d) Pumps should always be fitted to remove condensate 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 ¢) Condensate should back-up into the steam pipe d) That the trap is fatted level with or above the heater outlet 26. How is flash steam produced? 2 a) From condensate passing from high to low pressure systems. b) From saturated steam ¢) From superheated steam d) From steam mixed with high temperature air F T T—  27. Are steam traps required 1o pass air? ) Steam traps should not pass air unde r any circumstances b) Only when the trap h as passed all the condensate €) Air should be remov, edas soonas it reaches the trap d) Only on high pressure steam system 28. How do you call a s ystem:employing open sprinklers attached 10 a piping system supply through which is a) Mechanical sprinkler b) Automatig ystem