How you can avoid costly turbine failures and maximize uptime

Steam turbine filtration: Maintaining turbine oil instead of changing it

How you can avoid costly turbine failures and maximize uptime

Steam turbine filtration: Maintaining turbine oil instead of changing it

Steam turbine filtration is a must if you …

desire to avoid turbine stops due to component failure / malfunction, as they cost a lot of money.
want to minimize sticky and sludgy deposits on valves, coolers, pumps, bearings and inline filters.
wish to avert premature wear and maximize the service life of your turbine components.
are tired of short oil service lives and therefore premature oil changes, and want to benefit more from your turbine oil.

Your solution: CJC® Steam Turbine Filters. Achieve application-specific oil cleanliness levels for optimum turbine protection – quickly, efficiently and cost-effectively.

Challenge

Lubrication systems and hydraulic control systems of steam turbines are exposed to a high risk of water ingress. Hot water vapor entering through the labyrinth seals and condensation due to temperature fluctuations increase the water content in the oil and the formation of lubricant-water emulsions is possible. Water and wear particles cause the lubricant to age rapidly (oil degradation, loss of additives), resulting in deposits. Damage and outages are the result and cause interruptions in power generation, which can result in contractual penalties.

With the central lubricating oil supply, all lubrication points and the hydraulic controllers are lubricated with the same lubricant. Due to the tight tolerances in the highly sensitive and complex hydraulic system, the lubricant must be as clean, dry and free of oxidation products as possible. Changing the large-volume oil fillings is time-consuming and expensive.

In a separate hydraulic control system, fire-resistant hydraulic fluids (typically phosphoric acid esters, HFD fluids, soy-based oils) are often used. However, when contaminated with water, ester-based fluids decompose by hydrolysis. The molecules split into their original alcohol and acid components, rendering the fluid unusable.

Damages and consequences of contaminated and prematurely ageing turbine oil

Deposits, oil oxidation and premature additive degradation

The hot steam leads to high temperatures, which leads to a high thermal load on the turbine oil and accelerates oxidation processes. The resulting degradation products precipitate particularly in load zones, stagnant areas or narrow passages in the lubricating and control oil system. Resinous and sludge-like deposits (varnish) form on valves, bearings, heat exchangers, in pipes and in the tank. Acidity and oil viscosity increase. Contaminants such as water and metallic wear particles further increase the speed of oil oxidation. Important additives for wear, corrosion and oxidation protection are used up prematurely, washed out or rendered dysfunctional, which shortens the remaining service life of the oil.

Frequent oil changes, high maintenance costs and turbine failures are the result.

The varnish tendency of the oil as an indicator for the formation of deposits is measured using the MPC test. An MPC value of < 10 is recommende. With a CJC® Steam Turbine Filter, MCP values of < 5 are achieved and ensured for a long time.

Corrosion, rust and vapor bubble formation

Contamination with water is one of the main challenges for steam turbines. Turbine oil for steam turbines has a good water separation capacity, but this is lost over time due to polar impurities, suspended solids and oxidation processes and the associated additive consumption.

If the water is emulsified in the turbine oil, the risk of vapor bubble formation increases. Frictional heat alone can cause the aggregate state of the water molecules in the oil to change very quickly and suddenly. Since steam requires 1000 times more volume and the transformation releases a lot of energy, the oil is displaced and the lubricating film can break off. In close contact and friction zones with pressure fluctuations, the bubbles implode when the pressure rises (cavitation). If this happens close to surfaces, the lubricating film breaks off and metal-to-metal contact occurs, resulting in erosion-like material removal and micro-pitting.

However, water also leads to hydrogen corrosion. Damage to the metal surfaces and sharp edges occur, from which hard, highly abrasive rust particles can detach and contaminate the oil circuit. If particles hit corroded surfaces, additional particles are released. Water and acids (oil oxidation, hydrolysis of esters) together are highly corrosive.

Turbine oil from steam turbines should be kept as dry as possible, e.g. with the help of our CJC® Steam Turbine Filters.

Wear due to solids

Due to the tight tolerances and narrow gap dimensions in the highly sensitive and heavily loaded lubrication and hydraulic control systems, bearings and valves are subject to wear from even the smallest particles. Particles are caused by wear or are introduced into the oil system from the environment. Even fresh oil with a typical ISO class of 19/17/11 does not meet the cleanliness specified for lubrication and hydraulic control systems of steam turbines. Once particles circulate in the oil system, a chain reaction of wear occurs: Particles constantly generate new wear particles and particles adhere to the sticky deposits on bearings and valves, creating an abrasive effect that further accelerates wear.

For a longer valve service life, MOOG recommends an oil cleanliness class of 16/14/11 in accordance with ISO 4406, for example. With a CJC® Steam Turbine Filter, you can achieve cleanliness classes up to ISO 12.

Air release property and foam risk

Water, particles, oxidation products and the increase in viscosity impair the air separation capacity of the oil. Air bubbles in the turbine oil rise less easily and have difficulty leaving the oil. Foaming and insufficient lubrication are possible consequences.

Lubrication effect & energy consumption

Emulsion formation and oil oxidation processes can increase the viscosity, which results in higher tensile forces within the system and higher energy consumption. If the viscosity increases too much, the lubricating film may break off, resulting in contact between the surfaces and increased wear. Even a change of +/- 5-10 % is critical for turbine oil.

Special features of ester-based HDF fluids, e.g. phosphoric acid esters:

Here, water components lead to hydrolysis of the ester, the viscosity decreases and the fluid becomes thinner and loses its lubricity.
Although phosphoric acid esters offer very good viscosity and oxidation stability, water and high temperatures (hot steam) cause the ester molecules to split into their alcohol and acid components. The acid content in the fluid increases (TAN). As hydrolysis progresses, the ester decomposes faster and faster. The high risk of acid corrosion and the loss of the lubricating effect make the fluid unusable.

As CJC® Steam Turbine Filters eliminate water and acids, the hydrolysis of the ester can be significantly slowed down, lubricity is maintained and corrosion and sludge formation are proactive prevented.

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Your solution: efficient steam turbine filtration

Efficient steam turbine filtration means continuously removing water, oxidation residues (varnish, acids) and particles from the turbine oil (24/7). Because the fact is, only with permanently dry and clean turbine oil you …

ensure optimum system protection and a faster return on investment.
minimize the risk of failure, repair costs and maintenance expenditures (OPEX).
avoid contractual penalties due to disruptions in power generation.
optimize the hydraulic control system.
make your turbine oil last longer and reduce the amount of used oil to be disposed of.

steam turbine filtration, low oil consumption for turbines

Less oil consumption

Less maintenance

Higher reliability

steam turbine filtration, higher resource protection for turbines

Better use of resources

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CJC® Steam Turbine Filters for efficient cleaning and maintenance of turbine oil

The water content in your turbine oil keeps rising rapidly, quickly reaches high oxidation rates and acid numbers and/or is contaminated with solids? Do you have to replace or clean bearings, valves, heat exchangers and pressure filters frequently due to deposits? Then the CJC® Steam Turbine Filter is exactly the right solution for your steam turbine. It ensures maximum oil cleanliness in the shortest possible time — optionally documentable via our CJC® Condition Monitoring Systems. Extremely high filter capacities and separation performance make it a safe and cost-optimized solution.

Steam turbine filtration in the offline circuit

Installation in the offline circuit

The separate pump unit enables installation in a separate circuit (offline) and thus continuous depth filtration and maintenance of the turbine oil (24/7). The gear pump draws in the turbine oil from the lowest point of the tank. The return line is depressurized and connected in the near the suction pump so that the lubrication system and hydraulic control system are always supplied with clean oil.

Sensational separation performance

The CJC® Steam Turbine Filter removes all impurities:

Water – free, emulsified and dissolved

Minimize water content to < 100 ppm — far below the saturation limit.

Oxidation products (varnish, sludge)

Permanently reduce the MPC value < 5 and achieve a long-lasting stable oxidation rate.

Particles

Achieve cleanliness classes up to ISO 12 (ISO 4406).

Acids

Absorb / neutralize and prevent acids for a permanently stable acid number (TAN).

High dirt holding capacity and filtration degree

CJC® Fine Filter Inserts are depth filters with a filtration degree of 3 µm absolute and a retention rate of < 1 µm. The whole volume of the insert is made of finely ramified fibres that offer an outer and, in addtion, an inner surface — from 120 to 150 m² per gram. That enables the extremely high dirt holding capacity — the higher, the longer the lifetime of the filter insert.

Fact is, our dirt holding capacity is the market leader.

Condition Monitoring

CJC® Steam Turbine Filters can be optionally equipped with sensors for automatic online condition monitoring of the filter and oil. Depending on the selected system, you can choose up to nine sensors — whether for oil moisture, oil temperature, particles (4-250 µm), wear particles (40-1,000 µm), oxidation rate, filter pressure and/or oil system utilization. Limit values and warning messages can be configured so that you can counteract deviations from the normal state at an early stage.
Our oil condition sensors provide detailed real-time data and enable conclusions to be drawn about the condition of the oil and turbines thanks to the high data density.
Our intuitive operable cloud applications have a clearly arranged dashboard to visualise the sensor data. In the premium version, highly developed algorithms help you with automated data evaluation and interpretation. Ideal for critical steam turbines, where a failure can quickly have cost-intensive consequences. Optionally, the sensor data can be transferred to your own system via various interfaces.

CJC® Steam Turbine Filter for lubrication system and hydraulic control system

steam turbine filter, steam turbine filtration

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Let’s talk: about your steam turbine, your turbine oil and the specific challenges. We filter each oil. Whether you use mineral oils, synthetic fluids or fire-resistant hydraulic fluids. Together with you we maximize the service life of your lubricants and oil-lubricated components.

Receive a personal consultation and a non-binding offer for a CJC® Steam Turbine Filter for efficient oil maintenance.

Write or call us.

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oil sampling, oil care in wind turbines, gearboxes, main bearings, pitch hydraulics

That say our customers

“We have been advocating these secondary CJC® Offline Filters for 2 years. The filters have value for varnish removal to keep in-service oil clean, which is a major concern of us reliability engineers
The also enable fast oil system cleanup after construction, something our project and operations people highly value […] this unit will greatly reduce clean up time and/or eliminate the need to hire expensive rental equipment and contractors to do oil cleanup. The saved time during commissioning a new turbine was reason enough for our purchase decision.”

To the practical report – Steam turbo set

Reliability Engineer, Refinery

„The CJC® Steam Turbine Filter has produced astonishing results. It is an ancillary installation in an independent circuit with a rapid pay back because we have less mechanical breakdowns and less oil and filter changes.

We have now installed another 2 CJC® Offline Filters for the 400 litres hydraulic systems in order to reduce maintenance work saving time and money. I can
highly recommend CJC® Offline Filters.“

To the practical report – Steam turbine

Maintenance Manager, SIRUSA Waste recovery plant

“The turbine lubricating oil in my steam turbines #2 and #3 has never been so clean.”

To the practical report – Steam turbine

Mechanischer Supervisor, Power plant, Ireland

“We are extremely satisfied with the performance. The maintenance of the oil in the offline flow is extremely effective for our steam turbine. The lubricating properties are preserved in the long term by removing the impurities (particles, water). We will also install a CJC® oil maintenance system on each of our two gas turbines to remove oxidation products and wear particles that are not retained by the system filters.”

To the practical report – Steam turbine

Maintenance Superintendent, STORA ENSO, Paper plant

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