shield chamber室温の変動について
1.対象の装置：
試運転完了日：
2.温度異常発生日時：
温度異常の状況：
①水温制御の一時的な変動により、chamber内の温度変動が起きた。
②ポンプユニット内のtwo-way valveから、異音と黒い粉が確認された。
③温度履歴グラフ及び客先の目視により、two-way valveの急激で連続的なon-off動作が確認された。
Regarding room temperature fluctuations of shield chamber
1. Target device:
Test run completion date:
2. Date and time when the temperature abnormality occurred:
Status of abnormal temperature:
(1) Due to the temporary fluctuation of water temperature control, the temperature inside the chamber fluctuated.
(2) Abnormal noise and black powder were confirmed from the two-way valve inside the pump unit.
(3) The rapid and continuous on-off movements of the two-way valve were confirmed by the temperature record graph and by the visual inspection of the customer.
３．原因
①いただいた資料を検討した結果、two-way valveに何らかのトラブルが発生し、two-way valveのon-off動作の制御が一時的に出来ない現象が発生したものと考える。
②黒い粉についてはtwo-way valveの動作過多によるMotorのabrasion powder、又はMotor gearのabrasion powderと考えられる。
3. Cause
(1) As an evaluation result of the materials given, it is considered that some sort of trouble occurred in the two-way valve and the on-off movements of the two-way valve could not be controlled temporarily.
(2) Regarding the black powder, it is considered to be motor abrasion powder or Motor gear abrasion powder made by excessive operation of the two-way valve.
③初期のバルブコントローラーのPID制御設定が、工場設備の増設による供給水の量、圧力、温度等の変化に追随できなかった可能性がある。
4.対策
①two-way valveを交換し、PIDの再調整(オートチューニングにて可能)を行う必要があると考える。
②two-way valveの損傷原因究明のためには、取り外したtwo-way valveをメーカーにて検査することが必要と考える。
(3) There is a possibility that the initial stage PID controller settings of valves could not keep up with changes in the water supply amount, pressure, temperature, etc. of due to the expansion of factory facilities.
4. Countermeasures
(1) I believe it is necessary to replace the two-way valve and readjust the PID (by auto-tuning is possible).
(2) In order to investigate the cause of damage to the two-way valve, I believe it is necessary to let the manufacturer inspect the removed two-way valve.
