Refrigerated shipping containers, also known as reefer containers, are designed to maintain a controlled environment for perishable goods. Here’s a simplified explanation of how they work:
Key Components and Process
- Refrigeration Unit: The core of a reefer container is its refrigeration unit, which includes a compressor, condenser, and evaporator.
- Compressor: Compresses refrigerant gas, increasing its pressure and temperature.
- Condenser: Cools the high-pressure gas, turning it into a liquid.
- Evaporator: The liquid refrigerant absorbs heat from the container’s interior, cooling the air inside. The refrigerant then returns to the compressor to repeat the cycle12.
- Insulation: The container walls are insulated to minimise heat exchange with the external environment, ensuring stable internal temperatures
- Temperature Control: Advanced control systems allow operators to set and monitor the temperature, humidity, and ventilation. This ensures optimal conditions for the cargo.
- Power Supply: Reefers can be powered by external electrical sources at ports or on ships or on site. When on the road, they can use diesel-powered generators (gen sets)
- Airflow System: A T-shaped flooring system allows cool air to flow underneath the cargo, ensuring even temperature distribution throughout the container
What’s the Difference between 1 Phase and Three Phase?
Single-Phase Refrigerated Containers
- Power Supply: Operate on a single alternating current (AC) phase.
- Cooling Capacity: Generally have a lower cooling capacity, making them suitable for short-term storage or transportation of smaller quantities of temperature-sensitive goods.
- Size and Footprint: Typically smaller, which makes them ideal for tight spaces or locations with limited space.
- Cost: Usually less expensive to purchase or rent, making them a more affordable option for small businesses or short-term needs.
- Energy Efficiency: Consume less power, making them more energy-efficient and cost-effective to operate.
- Use Cases: Commonly used for events, small businesses, or residential purposes where the power supply is limited to single-phase.
Three-Phase Refrigerated Containers
- Power Supply: Operate on three alternating current (AC) phases, providing a more stable and higher power supply.
- Cooling Capacity: Higher cooling capacity, suitable for long-term storage or transportation of larger quantities of temperature-sensitive goods.
- Size and Footprint: Larger and more robust, designed to handle more demanding conditions.
- Cost: More expensive to purchase or rent due to their higher capacity and durability.
- Energy Efficiency: While they consume more power, they are capable of handling higher loads and maintaining consistent temperatures.
- Use Cases: Ideal for industrial and commercial applications, such as in the food and pharmaceutical industries, where a stable and high-capacity power supply is available.
Key Differences
- Power Supply: Single-phase uses one AC phase, while three-phase uses three AC phases.
- Capacity: Three-phase containers have a higher cooling capacity and can handle larger loads.
- Cost and Size: Single-phase containers are smaller and cheaper, while three-phase containers are larger and more expensive.
- Energy Efficiency: Single-phase containers are more energy-efficient for smaller loads, whereas three-phase containers are better for larger, more demanding applications.