SEUIF97

SEUIF97 2, built on Rust, is a major upgrade over SEUIF97 1 built on C, delivering significant improvements in performance, functionality and ecosystem support.

SEUIF97 achieves a 5-20x speedup over naive implementations that use the Rust standard library's powi() in for loops for the basic equations of Regions 1, 2, 3,and 5.

It is suitable for computation-intensive calculations, such as heat cycle calculations, simulations of non-stationary processes, real-time process monitoring and optimizations.

This package supports 12 distinct input state pairs for calculating 36 thermodynamic, transport, and derived properties (see Properties), and thermodynamic process functions (see Thermodynamic Process Functions).

What's New in SEUIF97 2

Property Calculation API

The package provides two types of APIs.

Universal Property Functions

Each function accepts an input pair, an output property ID (o_id).

The following 12 input pairs are implemented:

pt(p,t,o_id) ph(p,h,o_id) ps(p,s,o_id) pv(p,v,o_id)

th(t,h,o_id) ts(t,s,o_id) tv(t,v,o_id)

hs(h,s,o_id)

px(p,x,o_id) tx(p,x,o_id) hx(h,x,o_id) sx(s,x,o_id)

Note: Only linearly related thermodynamic properties are calculable in the wet steam region.

Direct Property Functions

The following 12 input pairs are implemented:

pt2h(p, t)  pt2s(p, t)  pt2v(p, t)  pt2x(p, t)
ph2t(p, h)  ph2s(p, h)  ph2v(p, h)  ph2x(p, h)   
ps2t(p, s)  ps2h(p, s)  ps2v(p, s)  ps2x(p, s)  
pv2t(p, v)  pv2h(p, v)  pv2s(p, v)  pv2x(p, v)  

th2p(t, h)  th2s(t, h)  th2v(t, h)  th2x(t, h)   
ts2p(t, s)  ts2h(t, s)  ts2v(t, s)  ts2x(t, s)  
tv2p(t, v)  tv2h(t, v)  tv2s(t, v)  tv2x(t, v)  

hs2p(h, s)  hs2t(h, s)  hs2v(h, s)  hs2x(h, s)    

px2t(p, x)  px2h(p, x)  px2s(p, x)  px2v(p, x)
tx2p(t, x)  tx2h(t, x)  tx2s(t, x)  tx2v(t, x)

hx2p(h, x)  hx2t(h, x)  hx2s(h, x)  hx2v(h, x)
sx2p(s, x)  sx2t(s, x)  sx2h(s, x)  sx2v(s, x)

Thermodynamic Process Functions

The following thermodynamic process functions are also available:

• ishd(pi, ti, pe): isentropic enthalpy drop for steam expansion (kJ/kg)
• ief(pi, ti, pe, te): isentropic efficiency for superheated steam expansion (%)

Usage

from seuif97 import  pt, pt2s

OH=4

p=16.0
t=535.1
# universal property function with o_id
h=pt(p,t,OH)
# direct property function
s=pt2s(p,t)
print(f"p={p}, t={t} h={h:.3f} s={s:.3f}")

Examples

• T-S Diagram

• H-S Diagram

• H-S Diagram of Steam Turbine Expansion

• The Hybrid Steady-state Simulator of Rankine Cycle in Python

Properties