The results of dynamic cost - benefit analysis show that the net present value is 832 . 87 million yuan ; annually net present value is 68 . 37 million yuan ; the benefit - cost ratio is 2 . 8 times ; the investment returns is 4 . 3 years ; and economic internal rate of return is 26 percent 动态费用效益分析结果：净现值83287 . 0万元；年均净现值4164 . 3万元；效益费用比为2 . 8倍；投资回收期为4 . 8年；经济内部收益率为26 。
