lube oil tank temp is very high for gas turbine unit GE-10 type

[engahmedhassan]

hello all,

my problem is that the temprature of lube oil tank rise from time to another without any new condition of unit operation like bearings drains temp. or turbine load or exhaust temp.
the action that taken is shutdown the unit for one hour and started again then the temp. back to its normal condition and it will take afew days to go back to the high value.

any one can help i will be glad, thanks

 

[speco]

engahmedhassan,

There is probably some type of cooler for the lube oil. I would look at that first. It may be undersized for the conditions.

Regards,

Speco (

http://www.stoneprocess.com)

 

[DRWeig]

Lube oil overtemperature switch intermittently acting up? Loose wire connection? speco's thought is good if you have ambient temperature swings where the oil rejects its heat.

Best to you,

Goober Dave

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[TD2K]

engahmedhassan, are you saying the lube oil temperature is fine for some period of time and then starts rising for no apparent reason?

When you see indications the temperature is rising I'd start checking to see if any lube oil is coming back hotter, how the lube oil cooler is working, the temperature control valve for the lube oil cooler, etc.

If it's just a steady increase in temperature until you reach the high temperature limit it's either the cooler is undersized as said or the bypass valve isn't sending enough oil to the cooler.

 

[rmw]

Describe your lube oil circuit to us. Sounds to me like your LO coolers might be liberting air in the CW outlet (hot)side reducing the CW flow due to two phase flow or air blanketing the cooler reducing your heat transfer surface.

rmw

 

[abeltio]

If the oil temperature in the tank rises steadily to alarm condition is because the cooling is ineffective.

Items i would check:

Most lube oil tanks have lube oil heaters, if these are left on inadvertently they may contribute to the temperature rise

Cooling system: ensure that: 1. there is no bypass, 2. the valves are fully open, 3. the coolers are full of water (the vents do not vent air).

Assuming there is a closed loop cooling water system: also check the coolers of the water for the same three items mentioned above

In case there is a three way valve that regulates the water to the lube oil coolers: check that it works properly, if it is stuck in the position bypassing water to the lube oil coolers, the coolers will be starved from water.


saludos.
a.

 

[GTstartup]

Typically, there is a three way valve that mixes cooled lube oil with warm lube oil to maintain the set temperature. The valve is similar to the thermostat in your car cooling system only inside the valve there are multiple thermostats. If these start to stick the temperature can rise (Basically what was stated in abeltio's post - 4th point.)