Discussion
Yoichi Nakamura (Kawasaki Heavy Industries, Ltd.)
- This is an interesting example since it is thought that the preventive measure was effective.
- Though the cause of the problem originates from heat capacity of SCR, please teach us whether the phenomenon of hunting problem could be avoided if the heat capacity was considered at the time of the SCR design or the phenomenon could be only avoided with the gas extraction valve in the plant with SCR is employed.
- In the Chiba plant of Mitsui Shipbuilding Co. Ltd., probably I think that a gas injection engine with SCR is employed.
Auther's reply:
- If SCR is arranged before turbocharger turbine inlet as our example, it needs to control the delay due to large heat capacity because the delay cannot be avoided.
- In this study, a gas-extraction valve was installed as a control mechanism. Of course, it is presumed to need some control mechanism in actual plant. In the gas injection plant of Mitsui Shipbuilding Co. Ltd. pointed out, we heard an auxiliary bumer was installed instead of a gas-extraction valve. In that case, it is presumed that the system becomes complicated and care must be taken for keeping the plant in good working order as the burner is used.
