BHS UltraCool Bearings to increase system stability. Case Study

Problem

A Sonatrach residual gas facility in Algeria required a gearbox bearing temperature of max. 90 °C in the compressor system, at full load and full speed. Under the spe-cific conditions, conventional bearings would have heated up to a temperature of 105 to 110 °C.

SolutionWith the specially developed BHS UltraCool Bearing by Voith, the bearing temper-ature - depending on bearing construction - is kept between 5 and 20 °C cooler in comparison to other bearings. The oil therefore ages slower. This in turn results in higher system stability and longer service life of the gearbox, which increases profitability and sustainability of the facility.

The maximum permissible temperature in gearbox bearings plays a very important role in critical applications, e.g. in the oil and gas industry. If, for example, the bear-ing becomes too hot, then the oil ages faster and residue accumulates within the bearing. In a worst-case-scenario, the complete system shuts down. The specially developed BHS UltraCool Bearing by Voith achieves top-of-the-line results with pitchline velocities of up to 100 m/s, even in sophisticated applications: With this bearing - depending on the model - the temperature can be kept approx. 5 to 20 °C cooler.

An inquiry by the international oil company Sonatrach initiated the development of the BHS UltraCool Bearing in 2004. A residual gas facility in Africa required a gear-box bearing temperature of max. 90 °C in the compressor system, at full load and full speed. Under the specific conditions, conventional bearings would have heated up to a temperature of 105 to 110 °C. This would have resulted in the faster aging of the oil as well as the accumulation of oil carbon within the bearing, which in turn would have led to shorter oil change cycles and a higher breakdown risk for the complete system.

The systematic modification of the material and design enabled Voith to develop a bearing that fulfills all the requirements of the customer. The BHS UltraCool Bearings use a bearing material with a heat conductivity that is six times higher than that of other materials. The geometric optimization of the bearing body also ensures faster heat discharge. This enables a reduction of the bearing's

BHS UltraCool Bearings to increase system stability.

Product: BHS UltraCool Bearing

Industry: Oil & gas - gas reinjection

Application: Gearbox between “gas turbine and compressor”

Voith customer: Nuovo Pignone, Florence (ITA)

End customer: Sonatrach

Place of installation: In Amenas, Algeria, Africa

Startup operation: 2006

operating temperature by 15 to 20 %. The BHS UltraCool Bearing is an offset sleeve bearing. The special interior shape of the two offset half-shells affixes the shaft, in particular for light-duty or idling speed.

In the case at hand, the “cool bearing” significantly exceeds the customer's expec-tations: Since 2006, the year of commissioning, the measured maximum tempera-ture of the bearings never exceeded 78 °C. Under the following framework condi-tions, it therefore falls well short of the required maximum value of 90 °C: 100 % load, 1.7 bar oil inlet pressure, 49.5 °C oil inlet temperature, 3.3 MPa bearing load at 90 m/s pitchline velocity (see Image 1). The number of oil changes is reduced significantly due to this low temperature, which results in a significantly more sus-tainable use of resources. The advantage of the bearing is even more succinct when it comes to the warming of the oil: we achieved an improvement of 35 % in comparison to the required maximum value of Δ 35 °C. In its test bed in Sonthofen, Voith was able to confirm the customer‘s positive results. Bearing tests were, for the first time, performed at full load and under realistic operating conditions if required and requested by the customer. By 2013, BHS UltraCool Bearings have already been installed at fifteen orders for the oil and gas segment. Classic applications are, for example, gearboxes used in drive trains “electrical motor to compressor” or “gas turbine to compressor”.

Cutting mark for letter fold / Schnittmarke für Wickelfalz

Image 1: Measured bearing temperatures at normal operation in the compressor system of Sonatrach, In Amenas, Algeria

BHS UltraCool Bearings in comparison to the normal version (1) as well as tilting pad bearings (2)

Advantages User benefits

· Fewer oil changes (1) (2)· Lower operating costs (2)· Gearbox efficiency increase (2)· Increased system stability of the train (2)

· Reduction of gearbox bearing temperatures by 5 - 20 °C· Reduction of the oil consumption · Power loss reduction · Higher bearing insulation

Cutting mark for letter fold / Schnittmarke für Wickelfalz

The innovation by Voith is also proven to be of advantage in comparison to tilting pad bearings (see Diagram): the oil requirement is lower, the efficiency is higher, and the bearing insulation is better.

Voith Turbo BHS Getriebe GmbHTome StanicGeneral Manager Service & Business DevelopmentPhone +49 8321 802-535Fax +49 8321 802-685Tome.Stanic@voith.comvoith.com

}

CS

| 06

.001

.02

| en

| file

| 13

10 |

aio

| bax

Voith Turbo BHS Getriebe GmbH Hans-Boeckler-Str. 787527 Sonthofen, GermanyPhone +49 8321 802-0Fax +49 8321 802-689info.bhs@voith.comvoith.com

Voith Turbo BHS Getriebe GmbH is a division of Voith Turbo GmbH & Co. KG. From its location in Sonthofen, Germany, it has been working on high-quality, technically advanced gearboxes, cou-plings, and rotor turning gears for more than 80 years. Until today, more than 20 000 gearbox references and a trans-mitted total load of more than 70 000 MW are documented in the reference lists.

Voith Turbo, the specialist for hydrody-namic drive, coupling and braking sys-tems for road, rail and industrial appli-cations, as well as for ship propulsion systems, is a Group Division of Voith GmbH.

Voith sets standards in the markets energy, oil & gas, paper, raw materials and transportation & automotive. Founded in 1867, Voith employs more than 42 000 people, generates € 5.7 bil-lion in sales, operates in over 50 coun-tries around the world and is today one of the biggest family-owned companies in Europe.