Secondary Refrigerants

Question 1

Secondary Refrigerants:

1. Indirect type of systems have a ______ and __________ refrigerant
2. Primary refrigerants change state and use a ______ heat process

Answer 1

1. primary and secondary

2. latent

Question 2

Secondary Refrigerants:

1. Are normally _____ or have water as a base
2. Generally do not change state, _____ heat gain or loss only

Answer 2

1. water

2. sensible

Question 3

Secondary Refrigerants:

1. Some of the substances used to make secondary refrigerants when mixed with water are: name 3;
   BGA

Answer 3

1. Brines
2. Glycol

3, Alcohol

Question 4

Secondary Refrigerants:

1. Water is most commonly at temperatures above __F
2. Brines or refrigerants are used at temperatures below ___F

Answer 4

1. 32F

2. 32F

Question 5

What is a eutectic system?

Answer 5

Mixture of chemical compounds or elements that has a single chemical composition that solidifies at a lower temp than any other composition

Question 6

Eutectic Refrigeration is the continuous process of freezing and _______ a liquid inside a tank and storing the cooling energy

Answer 6

defrosting

Question 7

Brine Selection:

1. Freezing point - brine must be suitable for the lowest operating _____
2. Application - when using an open piping system, the possibility of product ________ by the brine should be considered

Answer 7

1. temp

2. contamination

Question 8

*sodium hydroxide is added to brine to keep it slightly _____

Answer 8

alkaline

Question 9

To overcome corrosion when using brine you may add an _______ to the brine

Answer 9

inhibitor

Question 10

The corrosiveness of a brine is determined by using a ___ tester

Answer 10

PH

Question 11

The PH levels for salt brines should be between 7 and _____

Answer 11

7 and 8.5

Question 12

PH levels indicators run 1 (Acid) to 14 (Alkaline)

1. Ph level 7 =
2. Ph level under 7 =
3. ph level over 7 =

Answer 12

1. neutral
2. more acidic
3. more alkaline

Question 13

Alcohol or glycol Secondary Refrigerants:

1. Systems suing aqueous solutions of alcohol or glycol are more susceptible to ____ than those using salts
2. A disadvantage of alcohol is its _______

Answer 13

1. leaks

2. flammability

Question 14

Corrosion inhibitors should be used with alcohol type brines as recommended by the manufacturer of the _______

Answer 14

alcohol

Question 15

Propylene glycol is used in _____ processing

Answer 15

food

Question 16

Chlorinated and fluorinated hydrocarbons are expensive and are used in very ___ temperature work (below -40F)

Answer 16

low

Question 17

Brine Properties: Important factors for good heat transfer;

1. High values of specific gravity, viscosity, conductivity, specific heat
2. Concentration, freezing, and boiling points
3. ___ values of viscosity

Answer 17

3. low

Question 18

Brine Properties:

1. High values of specific heat and viscosity result in ____ pumping head and consequently high pumping
2. High specific heats are desirable in that they reduce the quantity of _____ required to be circulated or stored for a given duty

Answer 18

1. high

2. liquid

Question 19

Eutectic Mixture:

1. A solution of any salt in water has a specific concentration at which the freezing point is at its minimum. Thus it is called a _______ mixture
2. The temp at which it freezes is the _______ temp
3. The solution at any other concentration will start to ______ at higher temperature than the eutectic temp

Answer 19

1. eutectic
2. eutectic
3. freeze

Question 20

Specific Gravity:

1. Solution mixture is determined with a _________
2. Hydrometer measures _______ ________
3. Recommended specific gravity;
   - Calcium chloride 1.2 @ 60F
   - Sodium chloride 1.17 to 1.2 @ 60F

Answer 20

1. hydrometer

2. specific gravity

Question 21

Types of Hydrometers:

Hydrometers may be used to measure battery acid, glycol solutions, salt brines, alcohol

Name two types of hydrometers:

Answer 21

analog and digital

Question 22

Hydrometers:

Heavy liquids (1.0-2.0) include eutectic solutions, battery acid, glycol

Light liquids (0.7 to 1.0) include water impurities and alcohol

Answer 22

yes

Question 23

Air:

1. Air is extremely _______ in a brine system
2. It will promote an aggressive rate of _______
3. Causes cavitation in the pumps, and can displace brine to the extent that the brine will overflow down the ____
4. After the initial installation there should be no air in the brine system

Answer 23

1. harmful
2. corrosion
3. drain

Question 24

Eliminate Air:

1. The brine discharge service valve is only left ____ until all of the air has worked its way out of the system
2. Occasionally you might have to work air out at the headers
3. The best way to get the air out is to shut the brine pump off and let the air rise to the top of the header, and release it at the header purge valve

Answer 24

1. open