시스템 수명 연장을 보장하기 위한 재생 터빈 펌프의 유지 보수 방법
While well-selected regenerative turbine pumps offer exceptionally long service life in chiller applications, like all pumps, there are many circumstances that can significantly impact service life. The following items should be carefully considered when installing and using regenerative turbine pumps to ensure a long, trouble-free operating life.
Regenerative turbine pumps are capable of very high pressures, so they have very tight running clearances (typically .002″ ~ .006″) to help prevent internal loss of this pressure. As a result, please be aware that regenerative turbine pumps are very intolerant of grit and abrasive material in the fluid stream. Fluid contamination tends to erode impeller vanes, lodge between the impeller and casing, and cause premature failure in mechanical seals.
시스템 시동
System startup is especially critical because even if fluid is clean and grit free, new piping systems often have solder spatter, pipe dope, and metal chips in them. Older systems may occasionally release clumps of pipe scale and rust into the pump, both causing minor damage that can accumulate over time to reduce performance. In either case, it is important to flush and inspect the system before startup. Installation of a suction strainer is very useful in protecting the pump if the strainer is cleaned regularly. This issue alone is probably the most common mode of failure for regenerative turbine pumps, so proper consideration should be given to protecting the pump from this type of damage.
Protect the pump from “dead-head” conditions where discharge is completely shut off while in operation. While some turbines are tolerant of short periods of zero flow, mechanical seal damage, pump and/or motor overheating, and even system damage due to excessive overpressure may occur as a result of running a pump in this state. Always make sure all system valves are open and piping is restriction-free before pump startup. If you anticipate this condition, use a properly sized relief valve and/or overpressure cutout system to protect the pump and system.
밸브, 압력 충격 및 드라이 런
The use of modulating valves or other conditions that would cause sudden pressure shocks on the system are detrimental to regenerative turbine life. The self-adjusting balanced impeller feature relies on the pump attaining pressure equilibrium within a reasonable period of time. Sudden pressure shocks alter that balance and may cause the impeller to rub against the casing until equilibrium is regained. Continuous repeated pressure shocks from modulating valves or other system components can keep the impeller in a constant state of flux and cause excessive impeller rubbing and eventual failure.
All pumps should be protected from dry running. Please assure that all system valves are open, and pump suction is flooded before startup. Momentary jogging of pumps to confirm proper rotation is permissible.
유효흡입수두(Net Positive Suction Head)
펌프에 적절한 유효흡입수두(NPSH) 가용성을 제공해야 합니다. 일부 재생 터빈 펌프는 열악한 NPSH 조건(열악한 NPSH는 캐비테이션을 유발하고 액체가 증기 상태로 플래시됨)에 대한 상당한 내성을 가지고 있지만 장시간 장치를 가동하면 서비스 수명이 단축됩니다. 유체 내의 증기가 문제가 되는 이유는 증기가 기계적 씰, 무씰링 펌프 베어링 및 임펠러 유체 역할 필름에 필요한 윤활 및 냉각을 제공하지 않기 때문입니다. 이 조건은 드라인 런을 수행하는 것과 기능적으로 같지만 드라이 런보다는 더 적은 영향을 미칩니다. 잘못 선택한 흡착 스트레이너, 불충분한 석션 파이프 크기 및 부분적으로 닫힌 석션 밸브와 같이 흡착 흐름을 방해하는 요소도 캐비테이션, 증기 플래시 및 부분적인 드라이 런 조건을 유발할 수 있으며 이는 곧 성능 저하와 조기 고장으로 이어질 수 있다는 점에 유의해야 합니다.예방적유지보수 일정 실행
Key to avoiding many of the issues above is a good preventive maintenance program. All pumps will eventually fail if maintenance is ignored completely. Mechanical seals, sealless pump bearings, and impellers should be examined for unusual or excessive wear, fluid chemistry should be monitored and maintained, suction strainers should be cleaned regularly, relief valves should be tested, and many other items relating to the system itself should be checked on a regular basis to help prevent problems that could affect pump service life. For common applications, we recommend that you keep a basic spare parts kit on hand at all times. For more critical services, a duplicate pump is often the most expedient and cost effective way to prevent or minimize downtime.
Regenerative turbine pumps have been used successfully for over 35 years in many different applications such as chillers, heat exchangers, boiler feed, spraying, reverse osmosis, fire protection, refrigeration, chemical process and recirculation. Long service life in a pump relates as much to the pump and system design as it does to the quality and execution of the preventive maintenance plan. As with any piece of equipment there is no substitute for using the right tool for the job.
