I would like to ask: what problems might arise if a refrigerant at -25°C is used to cool hot water to room temperature? Will the cooler freeze over?
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I would like to ask: what problems might arise if a refrigerant at -25°C is used to cool hot water to room temperature? Will the cooler freeze over?
-There are two potential problems when using a low-temperature refrigerant at 25°C to cool hot water to room temperature: 1. The hysteresis temperature of the refrigerant； 2. Corrosion of the condenser. At low temperatures of -25°C, the refrigerant forms a layer of ice on the condenser, which may prevent the heat entering the condenser from dissipating quickly. It also lowers the surface temperature of the condenser, thereby affecting its cooling efficiency. Furthermore, if the surface temperature of the condenser is too low, electromagnetic force effects may cause corrosion on the condenser surface. Therefore, when using this low-temperature refrigerant for cooling, the surface temperature of the condenser should be increased to prevent freezing and corrosion. -
There will be no problems during normal operation; energy exchange occurs as the two-phase liquid is in a flowing state. If hot water remains stationary after entering, it will freeze easily.
“-\"Cooling hot water to room temperature using a refrigerant at 25℃\" – this was the idea put forward by some clever boss. -25 degrees is a very valuable amount of cold energy, used to deal with hot water that has no value – isn’t that nonsense?
This practice is not very common, as it can lead to freezing on the hot water side; a slow flow rate on that side may result in freezing. It is best to use indirect cooling, with a medium that is less prone to freezing (such as chilled water with ethylene glycol added) to first exchange heat with hot water, thereby heating the water used for indirect cooling, and then using water at -25 degrees Celsius to cool the water in this indirect circulation. The circulating water volume can be controlled to prevent the water temperature from dropping too low. This is the ideal situation; in practice, it is not recommended to use low-temperature chilled water to cool hot water, as it is not energy-efficient. For cooling hot water, natural cooling or chilled water cooling can be considered.
To cool hot water using a coolant at -25°C, it is necessary to take into account the flow rate of the hot water and the total heat exchange amount. If the amount of hot water is low, over-cooling can occur, leading to freezing of the pipes. If the goal is merely to cool the hot water, low-temperature cooling water or coolant is sufficient; there is no need to use a coolant as cold as -25°C.