How MVR Evaporators Save Circulating Water Consumption

We know that the cooling tower's external heat dissipation method is to transfer heat to the atmosphere by evaporating circulating water to remove heat. Compared to multi effect evaporators, MVR evaporators save a lot of circulating water usage, thus eliminating the need for a large amount of water replenishment to the cooling tower. So how does the MVR evaporator achieve a significant reduction in the use of circulating water?
Operating principle of MVR evaporator: MVR evaporator is an evaporation technology with heat pump properties. During operation, the material boils and evaporates due to heating. The MVR evaporator recovers and pressurizes the evaporated water vapor, increasing its thermal grade and allowing it to be reused as a heat source. The reused steam releases all latent heat in the heater and condenses into water.
There is a significant difference in the operating principle between the MVR evaporator and the multi effect evaporator, that is, all the steam evaporated by the MVR evaporator is reused as a heat source. After being pressurized, the steam heats the material and condenses into water. The steam heat from the MVR evaporator is circulated for the evaporation process, while the secondary steam evaporated from the multi effect evaporator, regardless of its efficiency, always needs to be condensed through the condenser, thus requiring circulating water. From this, it can be seen that the multi effect evaporator always needs to take away the heat of the final effect secondary steam from the circulating water, thereby generating condensation and forming a vacuum. The secondary steam of the MVR evaporator is recycled and does not require external heat release, so there is no need for circulating water. Therefore, the MVR evaporator has a considerable water-saving ability.
Does the MVR evaporator really not require any circulating water? The answer is negative. During the operation of the MVR evaporator, the lubricating oil and pump seals of the system still need to be cooled by circulating water. However, because their heat is very small, the amount of circulating water used is also very small, which is negligible compared to the multi effect evaporator.