A new type of integer steel two-side heat transfer enhancement tube, ratchet tube with internal spiral groove (RISG tube) is designed and manufactured.

Enhanced heat transfer mechanism of inner chute spirally corrugated tube is analyzed theoretically, and the heat transfer and frictional characteristics of water in three types of inner chute spirally corrugated tubes are investigated experimentally.

The results of an on site industrial test have shown that the use of internal and outer spiral finned tubes (called IOSF tube for short) with a small spiral angle for power station high pressure heaters can bring about a significant heat transfer intensification effect.

The author succeeds in studying the plastic screw geared tube technology with on-line continuous self cleaning function based on its ultra low flow ratio.

The thesis aimed at the characteristic of the quenched internal helical gear, especially with few number of tooth, big module and high pressure angle hard to hard to manufacture either by cutting or by grinding, the auther carried through a research about the machining of the quenched internal helical gear, adopting a method of shaping internal helical mold gear by EDM.