Powerpoint: Receivers/Evaporators Flashcards
Filling receivers with liquid is ______
illegal
A receiver is essentially a _______ tank for refrigerant
storage
The receiver is a _____ side component
high
The Receiver inlet is from the _________ and the outlet goes to the ______________
condenser, metering device
Refrigerant receiver types;
Full size receiver: holds _______ system charge
holds entire system charge
Refrigerant receiver types;
Oversized receiver: holds ______ system charge (condenser flooding)
excess
Refrigerant receiver types;
Partial receiver: holds a ______ of the system charge and the rest in condenser (not in canada)
portion
What are the inlet and outlet valves called in a full size receiver?
Inlet - Queen valve
Outlet valve quill- King valve
Inlet and Outlet valves in a partial receiver?
Inlet - no valve
Outlet valve quill - King
Receiver capacity as required by B-52:
- Must hold the entire refrigerant charge and only occupy ___% of its volume at ___F
- If refrigerant side head pressure capacity control is used the receiver must be oversized by ___%
- 90%, 90F
2. 50%
A cooling tower is a device for cooling water on a __________ system
recirculating
Cooling towers have no ________
refrigerant
Cooling towers use water to ______ heat from the water
reject
In a cooling tower, water is pushed to the ____ of the tower from the water cooled condenser and heat is rejected and _______ out the top
top
rejected and removed out of the top
Cooling tower low ambient controls;
- _______ valve
- diverting _____
- fan ______ ______
- mixing valve
- diverting valve
- fan speed control
Evaporators _______ heat into the refrigeration system
absorb
Evaporators absorb heat by maintaining the evaporator at a temperature ______ than the medium to be cooled
lower
Evaporators remove both ______ heat and _______ heat from the medium to be cooled
latent heat and sensible heat
Evaporator types:
- Dry (DX): Liquid/Vapour mix to start and a ____ at the exit
- Flooded:
- _____ level of liq ref (used on direct or indirect systems)
- Ref charge of flooded evap is _____than a DX evap
- Used for ______ systems (ie. ice rinks)
- gas
2. Constant, larger, larger
Construction of Evap:
- Bare pipe
- Finned Tube: fins increase surface area and attach to pipe to increase __________
- Plate: (may use eutectic solution) semi trucks and______ low freezers
- Shell and tube: flooded or dry indirect systems seen in chillers
- heat exchange
3. ultra low
Finned tube type: ____ velocity
temperature range is ___F and above
28
Unit cooler temperature range is ____F and above (most common)
-40F and above
Product cooler temp range is ____F and above and is the largest evaporator
-40F and above
- Fin spacing and temperature application:
- Frosting application- product coil must be below ___F (approx __fin/inch)
- Defrost method must have an external heat source to raise temp above ____F
- When in defrost you must shut off the evap ____
- External heat sources could be hot ____, ______, or hot _____
- Frosting application- product coil must be below ___F (approx __fin/inch)
- 32F, 4fin/inch
- 32F
- fan
- hot gas, electric, hot water