# Multi-stage compression with intercooling

by exergetic
Tags: compression, intercooling, multistage
 P: 11 Yes,I have some familiarity with thermodynamics.But I know how to represent this process on T-s chart.Instead I would understand,in case of more than 1 intercooling process, how to calculate pressure values at which intercoolers must work for minimizing specific work.Could be correct to state that the minimum specific work is obtained when all pressure ratios equate each other?In other words when: $$\frac{Pinlet}{Pi1}$$=$$\frac{Pi2}{Pi1}$$=$$\frac{Pi3}{Pi2}$$=$$\frac{Poutlet}{Pi3}$$
 P: 561 Multi-stage compression with intercooling Yes, all pressure ratios from each compressor must be the same and it is found this way: $$P_{r}=\sqrt[n]{\frac{P_{out}}{P_{in}}}$$ Where $$n$$ is the number of compressors. So with 3 intercoolers, $$n = 4$$.