ASPEN 在模拟过程中的错误,帮忙解释? block: b1 model: radfrac *** severe error a liquid feed/pumparound to the top stage is required when "q1=0" is specified in "col-specs"; required feed/pumparound has zero flow. * warning rest of block bypassed due to severe error. 以上是我在模拟过程中的错误,那位高手帮忙指点一下查看更多