Magic Way of Turing Water into Ice - The Operating Principle of Water-Cooled Ice Makers

A water-cooled ice maker operates on the principles of the refrigeration cycle and ice-making control. The key difference from an air-cooled model lies in its condensing heat dissipation method: it uses water as the cooling medium to remove waste heat, making it more efficient, especially in high-temperature environments.

This is the "heart" of the ice maker, following the classic vapor-compression refrigeration cycle.

Function: The "heart" of the system. It draws in low-pressure, low-temperature refrigerant gas from the evaporator and compresses it, turning it into a high-pressure, high-temperature gas.

Function: The system's "heat radiator." The hot, high-pressure refrigerant gas enters the condenser. Simultaneously, cooling water (typically tap water or from a cooling tower) is pumped through a separate channel within the condenser. The refrigerant transfers its heat to the flowing water, cools down, and condenses into a high-pressure liquid refrigerant.

Key Point: This is the fundamental difference from air-cooled units. Water cooling is generally more efficient, allowing for more heat dissipation in a smaller space and ensuring high performance in hot environments.

Function: The system's "throttle." The high-pressure liquid refrigerant is forced through this narrow passage, causing a drastic drop in pressure and temperature. It becomes a low-pressure, low-temperature mixture of liquid and gas mist.

Function: The system's "heat absorber." In an ice maker, the evaporator also serves as the ice mold. The cold refrigerant mist flows through the evaporator plates, absorbing heat from the water flowing over them, causing the water to freeze. The refrigerant itself evaporates due to this heat absorption, turning back into a low-pressure, low-temperature gas, which is then sucked back into the compressor to restart the cycle.

• Refrigeration Cycle Summary:
  `Compressor` → `Condenser` (Water-cooled) → `Expansion Device` → `Evaporator` (Ice Making) → back to `Compressor`

This is the process of how ice is formed and harvested.

• Water Injection and Spraying

A water pump draws water from a reservoir and sprays it evenly over the surface of the cold evaporator plates.

The water flowing over the frigid surface of the evaporator plates loses its heat rapidly and begins to freeze. Because the water is continuously circulated, it forms clear ice that takes the shape of the evaporator plates (typically half-moon cubes or full cubes).

• Harvesting (Defrost) Process

When the ice reaches a predetermined thickness (controlled by a timer or sensor), the freezing cycle ends, and the harvest cycle begins.

Key Action: The compressor continues to run, but a reversing valve activates, changing the flow of refrigerant. The system temporarily directs the hot, high-pressure refrigerant gas directly into the evaporator. This "hot gas" rapidly warms the evaporator plates, melting the contact surface between the ice and the mold. The ice slabs then slide off due to gravity into the storage bin below.

• Cycle Repetition

After harvesting, the reversing valve resets, the system returns to freezing mode, and the water pump starts spraying again, beginning a new ice-making cycle.

This is the defining feature and a major operational consideration.

• Once-Through System: Connected directly to a potable water supply. The water is used once and then discharged down the drain. This method is simple but wasteful, with high operating costs and is not environmentally friendly.
• Recirculating System with Cooling Tower: The heated water from the condenser is pumped to a cooling tower, where it is cooled through evaporation and heat exchange with air. The cooled water is then recirculated back to the condenser. This system has a higher initial cost but is highly water-efficient in the long run, making it the standard for industrial applications.