Factorio Forums

Increasing the temperature of hot steam to 515C would fix all the weird ratios (103 steam/s on the heat exchanger, 5.82MW on the turbine) to nice and round numbers (100 steam/s and 6MW) and the next update seems like the perfect opportunity to do it. Heat exchangers should of course only work at above 515C in that case.
It was even done correctly for boilers and steam engines by using 165C steam instead of 150C.

It's an easy fix you can implement by yourself, since it's already exposed by the API:
https://lua-api.factorio.com/latest/pro ... emperature
https://lua-api.factorio.com/latest/pro ... emperature

Currently it's not even 103 steam/s but exactly 100/0.97, as in 103.0927835... (go figures)
Effectively changes the ratio from 5.82/10 to 6/10:

I know it's an easy fix, which is why I'm asking for it to be in vanilla. 2.1 looks like the QoL update with changes that are not backwards compatible for some designs, so might as well fix it now.

Maybe you'll get a reply in time before release if you link this post in a bug report, you can argue it's effectively inconsistent with 150+15 already accouting for the ambient temperature (15°), and likely an oversight more than a conscious design decision (which only fixes the boiler at 10 MW and the turbine at 60/s).

As far as I'm concerned, these buildings not having a clean ratio is a deliberate part of the challenge of setting up a nuclear reactor.

It's not a challenge, because it's no longer a ratio, as 100/0.97 is quite literally non-decimal (uses floating point math).
This is exactly how much steam a heat exchanger produces:
https://www.wolframalpha.com/input?i=100%2F0.97