Coal-fired boilers and thermal power plants are the primary heating resource in the district heating field. However

they have great energy-saving potential because of the significant heat loss from the high-temperature discharging flue gas. In view of the existing problems

a waste-heat recovery system for coal-fired boilers based on a spray tower is presented. It could efficiently recover the latent heat and improve the system efficiency and economic performance by using a spray-tower heat exchanger and absorption heat pump. In this study

a model was built for this system and validated with measured data in a practical project. The system was then evaluated from the points of view of energy saving

emission reduction

and economic feasibility. The results show that the simulation results of the model are roughly in line with the trend of the observed results

and the absolute and relative errors are in a reasonable range

which proves that the model is reasonable. Meanwhile

the boiler thermal efficiency can rise to 104.5%

the pollutant emissions can obviously decrease

and the quantity of collected condensate water can reach 18

000 tons a year. In addition

the payback period is 3.96 years. In summary

the proposed system has higher energy efficiency and better economic benefits than existing systems.