1 / 36

Chapter 6

Chapter 6. Refrigeration Systems. Refrigeration • Mechanical Compression Refrigeration • Absorption Systems • Troubleshooting and Maintaining Refrigeration Systems • Refrigerant Regulations • Refrigerant Handling.

grichmond
Download Presentation

Chapter 6

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 6 Refrigeration Systems Refrigeration • Mechanical Compression Refrigeration • Absorption Systems • Troubleshooting and Maintaining Refrigeration Systems • Refrigerant Regulations • Refrigerant Handling

  2. A refrigeration system controls the absorption and rejection of heat by refrigerant to move heat from inside a cooled space to outside the cooled space.

  3. In a mechanical compression refrigeration system, a compressor is used to produce the refrigeration effect.

  4. Refrigerant vapor pressure charts list the saturation temperature and pressure of refrigerants.

  5. Refrigeration compressors include reciprocating, vane, centrifugal, and screw compressors.

  6. Refrigerant compressors are available in hermetic and semi-hermetic configurations.

  7. An air-cooled condenser removes heat from high-pressure refrigerant vapor by air blown across the condenser coils.

  8. Water-cooled condensers transfer heat from refrigerant vapor to water.

  9. Evaporative condensers reject heat through the evaporation of water.

  10. A fin comb is used for condenser maintenance to straighten damaged or bent fins, which limit airflow and reduce condenser efficiency. Robinair Division, SPX Corporation

  11. A thermostatic expansion valve uses temperature readings at the evaporator outlet to control the rate of refrigerant flow into the evaporator.

  12. The opening and closing of a thermostatic expansion valve is controlled by the pressure in the remote bulb.

  13. An automatic expansion valve controls the temperature of the refrigerant by controlling the pressure in the evaporator.

  14. As refrigerant is forced through the capillary tube, it loses pressure until it is at the desired evaporator pressure.

  15. An evaporator vaporizes low-pressure refrigerant liquid into a low-pressure vapor.

  16. A hot-gas defrost uses hot gas from the compressor to melt frost on the evaporator.

  17. An evaporator pressure regulating valve allows two evaporators running from the same compressor to maintain different temperatures.

  18. Accessories are used for maintaining and controlling the flow of refrigerant in a refrigeration system.

  19. Pressure switches control refrigeration system temperature through changes in system pressure. Ranco Inc.

  20. Ammonia systems operate at high temperatures and pressures and must have special controls and fittings to control the release of ammonia gas.

  21. The direction of refrigerant flow in a heat pump is controlled by a reversing valve.

  22. Heat pumps may use air or water as the heat source.

  23. Chillers use chilled water to cool large building spaces.

  24. A cooling tower cools water from a condenser by the evaporation of water as it cascades through the tower.

  25. Absorption systems use a generator and absorber in place of the compressor to raise system pressure.

  26. Gauge manifolds are used to take pressure readings, add or remove refrigerant, and remove air from a system before it is filled with refrigerant.

  27. Service valves are front-seated for isolating parts of the system, mid-seated for adding or removing refrigerant or taking system pressures, and back-seated during normal operation.

  28. Refrigeration system pressure readings are taken by connecting the blue hose to the low-pressure side service valve and the red hose to the high-pressure side service valve with both gauge manifold valves front-seated.

  29. A head pressure controller prevents the condenser pressure from falling too low and starving the evaporator for refrigerant.

  30. The EPA has established regulations under Section 608 of the Clean Air Act to regulate the handling of ozone-depleting substances.

  31. A recovery unit is used to recover refrigerant for reuse.

  32. A leak detector is a device used to detect refrigerant leaks in air conditioning or refrigeration systems.

  33. A vacuum pump removes all air from a refrigeration system.

  34. The vacuum pump is connected to the system service valves using a gauge manifold and hoses.

  35. Electronic leak detectors are extremely sensitive and indicate the general location of a leak.

  36. The refrigerant container is placed upside down to charge with liquid and right side up to charge with vapor.

More Related