useless work meaning in English
虚功
Examples
- It depends on the length of delaying closing the valve plate to conduct the varying capacity and avoids some useless work , maintains the work ratio in a little range . in a word , it saves some energy
此调节系统根据延迟吸气阀关闭时间的长短确定排气量的大小，从而避免了压缩机作无用功，在压缩机气量变化的情况下，维持比功率(排气量与功率之比)几乎不变，从而节约了能耗。