Exergoeconomic Improvement of Power Boiler in Paper Industry at Different Operating Modes

Document Type : Original research articles

Authors

1 Mechanical engineering, Faculty or Engineering, south Valley, University, Qen, Egypt

2 Department of Mechanical Engineering, Faculty of Engineering, South Valley University, Qena, Egypt

Abstract

In the paper, the exergoeconomic improvement of power boiler (PB) at hybrid operating mode (with recovery boiler) and singular operating mode (without recovery boiler) in paper industry is performed. The natural gas (NG) and black liquor (BL) are the main fuels utilized in the power boiler and the recovery boiler (RB), respectively. The chemical black liquor recovery system that has essential benefits to avoid the environmental pollution by burning the organic waste and recycling the soda is comprehensively studied. A soda mass inflow rate of 9.16 kg/s that is required for cooking process is recovered in the chemical pulp (CHP) plant. The exergy analysis for power boiler is studied through one year with different environment ambient temperatures i.e., 290, 295, 305, 310, and 320 K. The outcomes confirmed that the exergy destruction rate of the PB is increasing with increasing of environment temperature at hybrid and singular operating modes. With adjustment the combustion process it found that the exergy destruction for power boiler is reduced within 2 and 4.71% at hybrid and singular modes, respectively. For hybrid mode, the exergy destruction cost rate of PB is decreased from 1304.41 to 1278.28 $/h at environment temperature 290 K. In addition, the exergoeconomic factor is improved from 16.09 to 16.37%. For singular mode the destruction cost rate of PB is reduced from 1470.19 to 1400.95 $/h at environment temperatures of 290 K while, the exergoeconomic factor is improved from 15.32 to 15.96 %.

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