REFRIGERATION AND AIR CONDITIONING

As an EN1 or ENC you have already learned the principles of refrigeration and air conditioning, and the components and accessories that make up the system. You have learned how to start, operate, and secure refrigeration plants. In addition, you have performed routine maintenance jobs such as trouble shooting, and servicing the system, and used correct procedures for leak detecting, and changing the lubricating oil in refrigeration compressors. As you advance in rate, you will be expected to have a greater knowledge of the construction and operating principles of refrigerating equipment. You will be required to perform more complicated maintenance jobs, to make repairs as required, and to determine the causes of inefficient plant operation and accomplish the necessary corrective procedures.

This chapter provides information that supplements related information in other training manuals applicable to your rating and related to the qualifications for advancement. Information is included on the construction and maintenance of refrigeration and air conditioning equipment, and the detection and correction of operating difficulties.

You should refer to the manufacturers technical manual for details of the plant on your ship.

The main parts of an R-12 refrigeration system are shown in figure 6-1. The primary components of the system are the thermostatic expansion valve, the evaporator, the compressor, the condenser, and the receiver. Additional equipment required to complete the plant includes piping, pressure gages, thermometers, various types of control switches and control valves, strainers, relief valves, sight-flow indicators, dehydrators, and charging connections.

In the following discussion, we will deal with the R-12 system as though it had only one evaporator, one compressor, and one condenser. However, a refrigeration system may (and usually does) include more than one evaporator, and it may include additional compressor and condenser units.