The ice is exposed to low heat release a resistor in the heat transfer between the water with ammonia, which is outside of the cooling tubes made of ice.
The condition of the ice will have low thermal conductivity as a resistor in the heat transfer between water and ammonia as a refrigerant pipe on the outside of the ice.
The thermal conductivity of ice is like a low resistance in การถ่ายเทความร้อนระหว่าง water with ammonia as a refrigerant in which the exterior of the tube ice