Utilization of waste heat from spraying ammonia with coke oven gas
A coking plant uses plate heat exchangers to recover waste heat from spraying ammonia to cool coke oven gas for heating.
The coke oven gas is cooled by spraying ammonia with alcohol. The sprayed ammonia has a high temperature. After passing through the gas-liquid separator and the sedimentation tank, it is pressurized by the ammonia circulation pump and sent to the plate heat exchanger to heat the secondary heating circulating hot water, raising it from 60℃ to about 80℃. The secondary circulating hot water that absorbs the waste heat of ammonia is sent to the living building for heating by the waste heat recovery circulating water pump.
When the plant recovers the waste heat from spraying ammonia to cool coke oven gas for heating, it adds 7 BR plate heat exchangers of Trip (two of which are used to adjust the load during the peak heating period) on the basis of the original 4 floating head heat exchangers, and the heat transfer area of each is 30m². The heating area of the whole plant using waste heat recovery has reached 80,000 square meters, and the average heat load per square meter of heating building area is 335kJ/h. This waste heat recovery energy-saving measure alone can save more than 2,200 tons of standard coal per heating period. More than 42% of the coke oven gas waste heat is recycled, and 7.6% of cooling water consumption is saved. The infrastructure investment of this energy-saving technical measure has been recovered in just three and a half years.