TPWS

Thermodynamic Properties of Water and Steam

by Howard Chao and Stella Unruh

Verification of Thermodynamic Data

All of the IAPWS IF-97 equations were verified and checked with the suggested values provided in the IAPWS IF-97 release guidelines. Furthermore, additional values (with various units) were computed and compared to values from NIST (all calculated values truncated to 4 digits of precision).

	T	P	V	U	H	S	CV	CP	Phase
	K	MPa	mL/g	kJ/mol	kJ/mol	J/mol K	J/mol K	J/mol K	---
NIST	300	3	1.0022	2.0234	2.0775	7.0667	74.2350	75.1690	liquid
TPWS	300	3	1.0022	2.0236	2.0779	7.0675	74.2467	75.1802	liquid
	T	P	V	U	H	S	CV	CP	Phase
	C	bar	ft3/lbm	kcal/mol	kcal/mol	cal/mol K	cal/mol K	cal/mol K	---
NIST	26.85	0.01	2216.8000	10.3880	10.9840	39.1980	6.0721	8.0695	vapor
TPWS	26.85	0.01	2216.8287	10.3885	10.9844	39.1995	6.0683	8.0865	vapor
NIST	26.85	0.51	0.0161	0.4846	0.4849	1.6925	17.7840	18.0010	liquid
TPWS	26.85	0.51	0.0161	0.4847	0.4849	1.6927	17.7869	18.0039	liquid
	T	P	V	U	H	S	CV	CP	Phase
	F	atm	mL/g	kJ/kg	kJ/kg	J/g K	J/g K	J/g K	---
NIST	80.33	8	1.0031	112.4900	113.3100	0.3929	4.1278	4.1786	liquid
TPWS	80.33	8	1.0031	112.5049	113.3180	0.3929	4.1284	4.1791	liquid
	T	P	V	U	H	S	CV	CP	Phase
	R	psia	m3/mol	Btu/lbmol	Btu/lbmol	Btu/lbmol R	Btu/lbmol R	Btu/lbmol R	---
NIST	600	1	0.4012	19056.0000	20246.0000	36.1980	6.1658	8.1858	vapor
TPWS	600	1	0.4013	19043.2818	20232.7018	36.1435	6.1499	8.1665	vapor
NIST	600	10	1.8325E-05	1952.5000	1953.0000	3.5891	17.1180	18.0200	liquid
TPWS	600	10	1.8330E-05	1951.0064	1951.5496	3.5834	17.0948	17.9991	liquid
	T	P	V	U	H	S	CV	CP	Phase
	R	psia	ft3/lbm	Btu/lbm	Btu/lbm	Btu/lbm R	Btu/lbm R	Btu/lbm R	---
NIST	1140.2	2716.9	0.0305	743.8700	759.1900	0.9372	0.7900	3.6469	liquid
			0.1105	1010.7000	1066.3000	1.2065	0.9600	6.6700	vapor
TPWS	1140.2	2716.9	0.0304	743.3031	758.6086	0.9365	0.7868	3.6126	liquid
			0.1107	1010.6585	1066.2977	1.2064	0.9153	6.0235	vapor
	T	P	V	U	H	S	CV	CP	Phase
	K	bar	ft3/lbmol	kcal/mol	kcal/mol	cal/mol K	cal/mol K	cal/mol K	---
NIST	424.98	5	0.3153	2.7537	2.7590	8.0103	15.1350	18.5660	liquid
			108.1600	11.0260	11.8330	29.3680	7.5753	10.3780	vapor
TPWS	424.98	5	0.3153	2.7541	2.7564	8.0112	15.1487	18.5801	liquid
			108.1611	11.8330	11.8330	29.3684	7.5836	10.3891	vapor

As easily seen from the results, the values generated using tpws.m are virtually equivalent to values obtained from NIST.

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