An Explanation of the Principle of Marine Refrigeration

Refrigeration plays a large role in many marine ventures. Vacation cruises need refrigeration to store food and drinks for those on the ship. But refrigeration is even more important to fisheries, which must cool or freeze their catches so that they do not spoil. Boat owners have a few extra options over regular refrigerator owners, such as keel coolers. But they can use the same technology as home refrigerators.

  1. Refrigerants

    • The compression system for the marine refrigeration has two systems known as the high side and the low side. The compressor discharges exhaust on the high side and sucks air in through the low side. Electrical or mechanical equipment compresses refrigerants to high pressures, which raises the temperature of the refrigerant. The condenser then cools the gas and transforms it into a liquid using air or water. Boat refrigerators can also use keel coolers, which direct heat from the refrigerator to the water outside. The liquid then travels to the area that needs to be cooled, where the evaporator uses the suction system to rapidly drop the pressure of the liquid, changing the liquid back into a gas at a very low temperature. Through this whole process, the refrigerant absorbs heat from the areas that need to be cooled, cooling those objects to low temperatures. The refrigerator can make ice next to the evaporator plate that can be put in drinks for refreshments.

    Holding Plates

    • Normally, marine refrigerators rely on batteries. However, some refrigerators use holding plates, which remain cold, cooling down anything placed on them. These holding plates can be recharged two or three times a day by attaching to shore power.

    Power Supply

    • On most boats, the refrigeration system is the largest consumer of power, so boat owners who want to use refrigerators need to have very good power supplies. Some boats have hybrid systems for their refrigerators that use both the energy from the boat's engine and also use the shore power, reducing the power demands that the refrigeration system places on the boat engine. Boat owners can also use coolers if they do not have a lot to refrigerate, such as drinks. This may be the only option on smaller boats that have weaker engines that supply less alternating currents. Freezers put even more strain on the boat engine than refrigerators.

    Portable Refrigerators

    • Personal boats often use portable refrigerators, which are similar to the small refrigerators found in homes. These refrigerators use electricity that comes from stored energy on the boat or from internal combustion engines on the boat and use this energy to power the refrigerator. Some of these refrigerators are designed specifically for storing fish caught during fishing ventures.