Study on numerical simulation of convective heat transfer process of cooling water in Baijiu distillation

The Baijiu distillation cooling system mainly consists of a double-layer cylindrical water cylinder and a multi-tube cooler, which plays a role in condensing the steam of the base liquor using cooling water. In order to study the effects of inlet position and flow direction of the cooling water pipe in the water tank on the cooling effect of the cooler, numerical simulation was conducted on the water-side flow and heat transfer process in the water tank, and the effects of factors such as the inlet water temperature, inlet water flow rate, and cooler surface fouling on the utilization rate of cooling water and the heat transfer process were analyzed. The results showed that the heat transfer effect was the optimal when the cooling water was upward introduced from the center of water tank. The temperature rise rate of the cooling water reached 37.15%. The inlet temperature of cooling water decreased from 32 ℃ to 26 ℃, the heat absorption of the cooling water decreased by 10.2%. The fouling of the cooler surface caused a decrease in the wall temperature, resulting in a decrease in the heat absorption of the cooling water. When the wall temperature of the cooler in the water tank decreased by 10 ℃, the heat absorption of the cooling water decreased by approximately 20%. In order to obtain the same heat transfer of cooling water, compared with the center-upward water inlet method, the cooling water supply volume of the same-side-upward and opposite- side-upward inlet methods increased 54%-61% and 44%-50%, respectively. In conclusion, in order to increase the temperature rise rate of the cooling water in the water tank, it was necessary to reasonably set the water inlet method, control the flow rate of the cooling water, and regularly remove the fouling on the surfaces of inner and outer of the cooler tubes.