I am familiar with a hydropower field, but don’t know much about the operational conditions in steam and gas turbines, and nuclear powerplants. Therefore, I would appreciate if someone would share the knowledge. In particular, I’d like to know what are the average temperatures of turbine oil in these applications, and how high the flows are. Thanks.

I have experience with Westinghouse turbines in a nuclear power plant. The flow rate depends on the size of the unit. I worked with an 880 megawatt unit where three turbines (one high pressure and two low pressure) were hooked up in series to a generator. I'm going from memory here so keep that in mind. The turbine driven oil pump had a capacity of around 300 gpm and the oil temperatures didn't get much above 120F. A nuclear steam turbine will run a lot cooler than a steam turbine in a fossil station. Nuclear plants produce a lot of steam at a low pressure as opposed to fossil plants that produce less steam, but at a higher pressure.

As Bill mentioned alot depends on the size of the unit regarding flow rates. Some gas turbines operate with a nominal bearing header temperature of 130 Deg F. (54C) However due to closed loop cooling systems may get as high as 160 Deg F. (71C) The minimum recommended is normally 90 Deg F. (32C) Typically the delta T across the bearings is 25 Deg F to 60 Deg F (14-33C) range. Some turbines have bearings located in areas of high ambient temperature. This ambient and associated sealing air can be over 500 Deg F. (260 C) The tank temperature will be 25 Deg F to 40 Deg F. (14-22 C) above the bearing header temperature. So the bulk tank temperature will vary between 155 Deg F and 200 Deg F. (68-93 C)

Bill and GTG,
Thank you much for the info. That's what I was looking for, just a rough estimate of temps and pressures across a board.