Maricopa Community Colleges  HVA285   19962-20086 
Official Course Description: MCCCD Approval: 07/22/08
HVA285 19962-20086 LEC 3 Credit(s) 3 Period(s)
Industrial Refrigeration Systems
Direct expansion and flooded evaporators, metering devices and their operational characteristics. Suction line accumulators, oil separation-control, liquid level control, surge drum and operation of ammonia refrigeration systems.
Prerequisites: None.
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MCCCD Official Course Competencies:
 
HVA285   19962-20086 Industrial Refrigeration Systems
1. Explain direct expansion and refrigerant behavior under load changes. (I)
2. Describe the operation of specific types of metering devices used on direct expansion evaporators. (II)
3. State the function of suction line accumulators. (III)
4. Compare and contrast the operating characteristics of the flooded system to that of a direct expansion. (IV)
5. Explain the methods of separating oil from refrigerants in a flooded evaporator. (V)
6. Identify the methods of liquid level control. (VI)
7. Describe the purpose and location of a surge drum. (VII)
8. Explain the operation of the overfeed system. (VIII)
9. Explain the operation of the gas pump system. (IX)
10. Describe the maintenance and operation of the double pumper drum system. (X)
11. Describe the operation of specific expansion valves employed in flooded systems. (XI)
12. Select the proper refrigerant pump for a specific application. (XII)
13. Describe the operation of specific controls employed in industrial refrigerant systems. (XIII)
14. Select the correct refrigerant lines and pressure vessels. (XIV)
15. Explain the operation of brine circulation systems. (XV)
16. Explain the operation of booster (two-stage) compression systems. (XVI)
17. Describe procedures for maintenance schedule and readings. (XVII)
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MCCCD Official Course Outline:
 
HVA285   19962-20086 Industrial Refrigeration Systems
    I. Direct expansion and load changes
        A. Direct expansion
        B. Operating characteristics
          1. Increase in load
          2. Decrease in load
          3. Sudden change of pressure
      II. Metering devices
          A. Automatic expansion
          B. Fixed office
          C. Thermostatic expansion
        III. Suction line accumulator
            A. Location
            B. Function
            C. Oil control
          IV. Flooded and direct expansion systems
              A. Flooded system
              B. Flooded versus direct expansion
            V. Oil separation
                A. Ammonia
                B. Other refrigerants
              VI. Liquid level control
                  A. Float valves
                  B. Float switch and solenoid
                  C. Level master control
                VII. Surge drum
                    A. Location
                    B. Purpose
                  VIII. Overfeed system
                      A. Operation
                      B. Advantages and disadvantages
                    IX. Gas pump system
                        A. Gas pressure
                        B. Operation procedure
                      X. Double pumper drum system
                          A. Maintenance of liquid level
                          B. Operation of the two drums
                        XI. Expansion valves
                            A. Hand expansion
                            B. Capillary tubes with thermal expansion
                          XII. Refrigerant pumps
                              A. Mechanical
                              B. Gas pressure
                              C. Injector
                            XIII. Industrial system controls
                                A. Overfeed system controls
                                B. Low pressure float valves
                                C. Float switch-solenoid valve
                                D. Limit function
                                E. Low-level liquid float switch
                                F. Solenoid valves
                              XIV. Line size and pressure vessels
                                  A. Adjustment for overfeed systems
                                  B. Gravity flooded
                                  C. Direct expansion
                                  D. Pressure vessel size
                                XV. Brine circulation system
                                    A. Two pipe
                                    B. Three pipe
                                    C. Defrosting
                                  XVI. Booster (two stage) systems
                                      A. Ammonia systems
                                      B. Halocarbon system
                                      C. Internally compounded compressors
                                    XVII. Maintenance and readings
                                        A. Maintenance
                                          1. Schedule
                                          2. Materials
                                        B. Readings
                                          1. Pressure
                                          2. Temperature
                                          3. Other
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