Industrial Refrigeration Practice Questions

A comprehensive set of vocabulary flashcards covering safety protocols, physical principles of refrigeration, compressor types, and system components based on industrial refrigeration study guides.

Standard Operating Procedure (SOP)

Guidance and specific steps necessary to safely operate a refrigeration system.

PPE Location

Proper Personal Protective Equipment for a job task is found in SOPs and Maintenance Procedures (MPs).

Hot Work Permits

Permits required by OSHA regulations for tasks involving heat or sparks.

Trapped Liquid Pressure Increase

The pressure of trapped liquid can increase between $100$ and $150\,psi$ per degree Fahrenheit ($^{\circ}F$) of temperature increase.

Respiratory Protective Equipment Requirement

OSHA requires a medical evaluation to confirm fitness for persons wearing respiratory PPE.

Lockout/Tagout (LOTO)

A safety procedure required anytime work exposes an employee to hazardous energy.

Arc Flash Conductor

During an arc flash event, the air acts as the conductor.

Arc Flash Expansion Rate

The estimated expansion of an arc flash explosion is $40,000$ to $1$.

Mechanical Refrigeration

A series of steps that moves heat energy from a space or object to an area where it can do no harm.

Sensible Heat

Heat energy that causes a change in temperature but does not cause a change of state.

Latent Heat

Heat energy that causes a change of state but does not cause a change in temperature.

Convection

Heat transfer by the movement of fluids, such as warm air rising and cold air falling.

Rankine

The scale used to measure Fahrenheit temperature absolute.

British Thermal Unit (BTU)

The quantity of heat energy required to change the temperature of one pound of water by one degree Fahrenheit ($1\,^{\circ}F$).

Latent Heat of Vaporization

The heat energy required to cause a liquid to become a vapor.

Pressure

The relationship of a force being applied over a given area ($Pressure = Force / Area$).

Specific Heat

The amount of heat energy required to increase the temperature of a specific substance; it is higher if the substance requires more energy for a temperature change.

Saturated Condition

The state of a boiling liquid where vapor and liquid exist together at the same temperature and pressure.

Ton of Refrigeration

A rate of heat transfer equal to moving $288,000\,BTUs$ per $24\,hours$ (or $12,000\,BTU/hr$).

First Law of Thermodynamics

The principle that energy cannot be created or destroyed.

Subcooled Liquid

Liquid refrigerant at a temperature below its saturation temperature.

Expansion Valve

A device that controls the flow of liquid refrigerant into the evaporator.

Flash Gas

The gas created at the expansion device during the pressure drop.

Pressure Drop

The loss of pressure as a fluid moves down a pipe due to interaction with the inner walls.

Zeotrope / Azeotrope

Two refrigerants blended to create a new refrigerant with its own unique properties.

Lower Explosive Limit (LEL) for Ammonia

The published minimum concentration of ammonia in air that can explode, which is $16\%$.

P&ID

An abbreviation for Piping and Instrumentation Diagram.

Slugging

A damaging condition caused by oil or liquid refrigerant entering a compressor designed only for vapor.

Thermosiphon Oil Cooling

A system that uses a heat exchanger (often using refrigerant) to cool compressor oil.

Coalescing Elements

Components in oil separators used to reduce oil smoke from the discharge gas.

Secondary Coolants

Substances like sodium chloride, calcium chloride, and glycol solutions used to transfer heat.

Induced Draft Fan

A fan that pulls or draws air through the condenser coils.

Desuperheating Coils

Coils used to reduce the discharge gas temperature before it enters the condenser.

Bottling

A condition where liquid refrigerant is held in the condenser due to pressure differences at the outlet.

Non-condensable Gas

A gas, such as air, whose saturation point cannot be reached with the temperatures and pressures in the refrigeration system.

Purging

The process of removing non-condensable gases from the system high side.

Self-Alarming

A property of ammonia due to its distinct odor and irritating properties which alerts people to its presence.

Fatal Current Flow

A current flow of $0.1\,amperes$ across the heart is considered necessary for a fatal shock.

Class A Fire

A fire involving ordinary combustibles such as wood, paper, rags, rubber, or plastics.

Class B Fire

A fire involving oil, gas, grease, or flammable liquids.

Class C Fire

A fire involving energized electrical equipment.