PIPE Add'l materials (1-50)

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 are by the cooling medium (water)?

Chiller

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?

Flooded refrigeration system

How do you call the ice formation on a refrigeration system at the expansion device, making the device inoperative?

Freeze-up

In a lithium bromide solution absorption refrigeration system, which of the following is the function of water?

Refrigerant

In the absorption refrigeration system, it is the inlet part of the condenser, cooled by a separate circuit of cooling water or strong aqua. It condenses a small part of the vapor leaving the bubble column and returns it as a liquid to the too of the baffle plate. This ensures that the vapor going to the condenser is lowered in temperature and enriched in ammonia. What is this component?

Rectifier

In the absorption refrigeration system, it is a pressure vessel mounted above the generator through which the vapor leaving the generator pass. How do you call this component?

Analyzer

Which of the following is a scale of temperature in which the melting point of ice is taken as 0° and the boiling point of water is 80°?

Reaumur Scale

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°F at constant atmospheric pressure of 14,696 psi absolute.

British thermal unit

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.

Frigorific mixture

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?

Critical temperature

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:

Vacuum refrigerant

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?

Halogenated refrigerants

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?

Evaporative condenser

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?

Fouling Factor

It 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?

Flooded evaporator

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?

Expansion Valve

Define a “control valve”.

The valve of the controlled condition actually under steady state conditions

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”?

The steam supply

Which of the following valves is the one designed to allow a fluid to pass through in one direction?

Check valve

How do you classify a solenoid valve?

A magnetic stop valve

What is a thermostat?

A temperature –operated switch

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

Prevent excessive furnace heat losses

Balance pressure traps are what type of steam trap?

Thermostatic

What is a characteristic feature of thermodynamic steam traps?

They operate by holding back condensate until it has cooled

What are the main considerations for steam trap selection?

Air venting, plant performance, flow capacity and reliability

Can temperature controlled applications be trapped?

If the pressure on the trap is always higher than back-pressure

Unless they are designed to flood, what is the important when removing condensate from heat exchangers?

Condensate is removed at steam temperature

How is flash steam produced?

From condensate passing from high to low pressure systems

Are steam traps required to pass air?

Air should be removed as soon as it reaches the trap

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?

Deluge system

What is probably the first consideration when selecting a control system?

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

When adding the refrigerant in a refrigeration system, it shall be charge into which of the following parts of the system?

Low pressure side

Why is a boiler feed tank heated to approximately 85°C?

To reduce the gas content of the water

What is used to dry air?

A separator

What causes water hammer in the boiler?

Slugs of water in the system

How does air enter a steam system?

All of the items stated

Why should strainers installed on steam lines be fitted on their sides?

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

What is the result of using a heat exchanger rating to calculate its steam consumption?

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

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?

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

For any particular tank temperature how does the heat loss from the lid of a closed tank compare with that of bottom?

Losses from the top are approximately double those from the bottom

What is the disadvantage of heating a tank by direct steam injection?

It dilutes the tank content

The existing 2000 TR chiller at a large hospital, where you are assigned as Engineer, must be replaced. Which of the following types most likely to be installed?

Centrifugal chiller

Refrigeration condensers are rated based upon their ability to reject the total heat that comes from which of the following?

Compressor work

A published „U‟ value from a steam coil to a water based solution is given as 550 – 1300 W/m²-°C. When would be figure near the lower end of the range be used?

When scaling or fouling of the coil takes place

Steam coils should enter and leave the top of a tank when:

The tank contains a corrosive solution

What range of „U‟ values would you apply for mild steel jacket around a stainless steel tank containing a water and detergent solution?

450 to 1140 kJ/kg-°K

A tank is to be heated by direct steam injection. How will the quantity of heat required compare with steam coil heating?

The same amount of heat will be required

Which of the following parameters has the greatest limiting effect on the thermal performance of an open, evaporative cooling tower?

Wet-Bulb temperature

Air enters a cooling tower at 10°C DB and 9.5°C WB temperature. It leaves the tower saturated at 21°C. Which condition is a likely outcome of this?

Fog

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?

Zone