Official Course
Description: MCCCD Approval: 06/17/03 |
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HVA101 2003
Fall – 2008 Fall |
LEC |
2 Credit(s) |
2 Period(s) |
Refrigeration Components and Applications I |
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Major components of refrigeration systems. Properties of refrigerants and piping practices. Prerequisites: None. Corequisites: FAC/HVA101LL or permission of instructor. |
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Cross-References: FAC101 |
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Go to Competencies Go to Outline
MCCCD Official Course Competencies: |
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HVA101 2003 Fall – 2008 Fall |
Refrigeration
Components and Applications I |
1. |
Identify each component of the refrigeration system and its related function. (I) |
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Determine specific properties of refrigerants based on the pressure temperature chart (p-t). (II) |
3. |
Compare and contrast specific types of evaporators. (III) |
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Calculate the capacity of evaporators, the overall conductance factor and the logarithmic mean temperature difference (LMTD). (III) |
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Evaluate the effect of evaporating temperature difference (TD) on evaporator capacity and humidity. (III) |
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Describe the major types of compressors, methods of compressor construction and the compression ratio. (IV) |
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Describe specific types of condensers. (V) |
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Explain the functions of condensers and how to determine condensing temperatures. (V) |
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Explain the operation of specific refrigerant flow control devices. (VI) |
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Compare and contrast specific methods of defrost. (VII) |
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Describe the specific methods of multistage compression systems and desuperheat the discharge gas between stages. (VIII) |
12. |
Evaluate oil return systems employed in multistage and multicompressor systems. (IX) |
13. |
Explain the operation of multiple temperature evaporator systems. (X) |
14. |
Select proper refrigerant piping. (XI) |
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Go to Description Go to top of Competencies
MCCCD Official Course Outline: |
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HVA101 2003 Fall – 2008 Fall |
Refrigeration
Components and Applications I |
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I. Refrigeration Components A. Compressor B. Evaporator C. Condenser D. Metering Device II. Refrigerants Tables and Properties A. Definition B. Saturated pressure - temperature tables C. Properties 1. non-toxic 2. non-flammable 3. non-explosive 4. mixes well with oil 5. high latent heat content 6. easy to detect D. Safety III. Evaporators A. Temperature ranges 1. high - A/C 2. medium - food storage 3. low temp. - freezer B. Types 1. natural convection a. static or plate b. finned 2. forced convection - finned 3. refrigerant feed a. DX - direct expansion b. flooded C. Evaporator superheat D. Capacity E. Conductance factors F. Logarithmic mean temperature G. Temperature difference 1. temperature difference (TD) verses capacity 2. temperature difference (TD) verses humidity IV. Compressors A. Types 1. reciprocating 2. rotory a. vane b. scroll 3. screw 4. centrifugal B. Methods of construction 1. open drive 2. semi-hemetic 3. hemetic C. Compression ratio - absolute discharge/absolute suction V. Condensers/Functions A. Air cooled 1. static 2. forced convection B. Water cooled 1. tube within a tube 2. shell and coil 3. shell and tube C. Evaporative D. Condenser functions 1. desuperheats 2. condenses 3. subcools E. Condensing Temperature 1. air cooled 2. water cooled VI. Refrigerant Flow Devices A. Refrigerant metering devices 1. operation of specific valves 2. specific applications 3. selection B. Refrigerant distributors 1. operation 2. selection 3. applications C. Metering device performance 1. thermo-bulb location 2. external equalizer location 3. trap location in respect to thermo-bulb location 4. liquid level refrigerant control and pilot control devices D. Liquid level control E. Pilot control devices VII. Defrost Methods A. Time and temperature (off cycle) B. Electric C. Hot gas (reverse cycle) D. Cool gas E. Brine F. Heat bank G. Re-evaporate H. Multiple evaporators VIII. Multistage Compression and De-superheating A. Multistage compression methods B. Intermediate stage de-superheating methods IX. Oil Return Systems A. Multistage systems B. Multi-compressor systems X. Multiple Temperature Evaporator Systems A. Operation B. Evaporator pressure regulators C. Solenoid controlled D. Single compressor E. Multi-compressor XI. Piping A. Evaporator 1. above compressor 2. below compressor 3. multiple evaporators B. Compressors 1. single 2. parallel C. Risers 1. suction a. single b. double 2. hot gas D. Liquid line |