A retort containing 500 cans of tomato concentrate was used for sterilization at 121°C. After sterilization, the cans need to be cooled down to 37°C before leaving the retort. The heat capacity of tomato concentrate and the can material are 3750 (J)/(kg°C) and 468 (J)/(kg°C), respectively. Each can weighs 50g and contains 500g of tomato concentrate. The retort wall is made of cast iron and weighs 2500kg. The heat capacity of cast iron is 554 (J)/(kg°C). Calculate the amount of cooling water required if it enters at 20°C and exits at 30°C.