roller bearing start to get hot on summer

[181273]

I got an roller bearing on a hydro vertical generator, that is lubricated with oil, and refregerated into a exchanger oil/air, the air used for refrigeration is taken from the plant... that means that in summer the heat inside of the plant is highest than 40º C.... we are thinking into the use of a new exchange, but in this time water/oil, taking the water from the income of the turbine, cause in this way will use the pressure of the water to make force the water to go inside of exchanger... but I don´t know exactly how to calculate the heat to disipate into de exchanger... we use viscosity 100 on the oil, and we got about 50 litres on a temperature of 60ºC and this is the temperature we got on the oil for lubrication... and the bearing temperature trips... I´ll like to know the formulations to calculate the exchange and the heat to disipate.
thank for your attention and sorry for my english

 

[waross]

Look up the specific heat of the oil. this is the amount of heat that must be added or removed to change the temperature of the oil one degree. The specific heat of water is 1. 1 British thermal unit will change the temperature of water 1 degree F.
I assume that your water is cheap and I would use an assumed efficiency of less than 50% and possibly less than 25%.
You may use either SI units or Imperial units but don't mix them.
respectfully

 

[sreid]

Is the oil at 60 deg C causing any problem?

 

[181273]

yes, sreid, this oil too hot is heating the roller bearing and it raise till 95ºC... and this is a high valium..

 

[181273]

now I know to calculate it:
Q= mass* specific heat* (Final temp-initial temp)
but i got one problem i had no tables about the specific heat of an oil VG (SAE) 100, could you tell me some link to a table...or the valium for 65º C

thanks a lot

 

[waross]

google

respectfully

 

[itsmoked]

There is a huge difference between oils. Their types, bases and additives!!

If I were you I'd go look at the drum or bottles of what you are actually using and get the NAME and any other pertinent info. Then go to the maker's web site and look up the data sheet for that actual product. Then you won't always be wondering if the number you're using is correct, or only close, or maybe wrong.

If you have a problem negotiating thru the maker's web site tell us and we can help.

By the way "valium" is a pain drug. You want "value".

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[rmw]

181273,

Don't apologize for your english. You got your point across. For those of us who English is our first language, your use of the word 'valium' instead of 'value' was freudian.

You may need to consider a different viscosity oil for summertime operation.

As others have stated, the website for your current supplier might be the best place to start looking at the temperature ranges for the various viscosities of oil.

Your heat exchanger might not have enough surface area for summertime operations. Can you add an auxiliary cooler?

You will also have to know the flow rate of the oil that you are sending through the cooler(s).

Good luck,

rmw

 

[181273]

thanks to everybody and sorry for my english, yes I admit my mistake...