Refrigeration Cycle +Refrigeration (4 Major components)

*Expansion Device*

After condensing, refrigerant flows to expansion device (Orifice Plate, TEV, etc.) which substantially reduces the pressure of the refrigerant flowing through the valve It also separates the High and low side of the system, while controlling flow of liquid refrigerant to the evaporator

Evaporator (Heat exchanger)

Boils refrigerant absorbs building heat from Chilled water, while lowering water temperature in the process.

Refrigerant and Chilled Water temperatures in the Evaporator

Chilled water *entering* the evaporator at 54ºF is releasing sensible heat and its temperature is dropping to 44ºF when *leaving* The refrigerant temperature when in the middle of the evaporator is 40ºF or 69psi When the refrigerant leaves, it is superheated and the temperature increases (ideally) 10ºF superheat

Refrigerant in *Evaporator*

Enters (75% Vapor 25% Liquid) Low Pressure Liquid Boils refrigerant, giving off latent heat, changes state from Liquid to Vapor Leaves 100% Liquid free superheated Vapor

Refrigerant in Compressor

Enters 100% Low Pressure Liquid free Vapor Increases refrigerant 150ºF on average Compresses refrigerant (lowers volume, increasing pressure and temperature) Refrigerant leaving compressor is usually around 200º +/- F, 100% High pressure Vapor

*Compressor* (non-positive displacement)

Made up of prime mover and a centrifugal compressor. Raises pressure and temperature of refrigerant by converting kinetic energy into pressure.

*Condenser* (Heat exchanger)

Removes heat from the refrigerant, to condense from a gas to a liquid Enters 100% Vapor, lowers temperature by giving off heat to water supply, sub-cooling and leaving 50% Liquid 50% Vapor around 125ºF