PROBLEM TO BE SOLVED: To provide a method for removing marine organisms from a heat exchanger, capable of effectively depleting marine organisms adhered to the inner plane of the heat transfer tube, while suppressing the volume of microbubbles of a carbon dioxide gas dispensed into a heat transfer tube.SOLUTION: In a case where marine organisms adhered to the inner plane of the heat transfer tube 13 of the heat exchanger 12 are depleted, a body of sea water or fresh water including microbubbles of a carbon dioxide gas is dispensed intermittently into the heat transfer tube 13. The timing of the commencement of this intermittent dispensation coincides with the achievement of a control value set in advance as a result of the proliferation of the inlet-outlet pressure difference of the heat exchanger 12. Moreover, it is desirable to confine the pH of the microbubble-containing dispensation water and the dispensation period respectively to 6.5-6.9 and 1-7 days. Moreover, it is desirable to perform an ordinary washing operation such as backwashing, fresh water substitution, etc. during the microbubble dispensation stoppage period. Moreover, it is desirable to intermittently dispense the microbubble-containing dispensation water in a state where the dispensation of sea water into the heat exchanger 12 is being halted.COPYRIGHT: (C)2014,JPO&INPIT【課題】伝熱管内に注入する二酸化炭素ガスのマイクロバブルの注入量を抑制しつつ、伝熱管内面に付着する海生物を効果的に減少させることができる熱交換器における海生物の除去方法を提供する。【解決手段】熱交換器12の伝熱管13内面に付着した海生物を減少させる場合、伝熱管13内に二酸化炭素ガスのマイクロバブルを含む海水又は淡水を間欠的に注入する。この間欠注入の注入開始時期は、熱交換器12の出入口差圧が増大して予め定めた管理値に達したときである。また、マイクロバブルの注入水のpHを6.5~6.9にするとともに、注入期間を1~7日間にすることが好ましい。さらに、マイクロバブルの注入停止期間中には、逆洗、淡水置換等の通常の洗浄を行うことが望ましい。また、熱交換器12への海水の注入を停止した状態で、マイクロバブルの注入水の間欠注入を行うことが好ましい。【選択図】図1
