Calorimetric determination of the thermody_namic properties of saturated water in both the liquid and gaseous states from 100 to 374 degrees C

Abstract

A calorimetric determination has been made of the thermal _properties of saturated water, in both the liquid and gaseous states, from 100° C (56 kg/cm!) to the close vicinity of the critical point, 374° C (225 kg/cm 2). This new determination supplements a previous determination in this laboratory in the range from 0 to 270 0 C. With the new apparatus designed and built to withstand severe conditions of temperature and pressure, satisfactory measurements were possible up to within 1 degree of the critical point.Special tests of the possibility of mixture of the liquid and vapor phases in evaporation experiments indicated freedom from this effect, except within 1 degree of the critical point. These tests included direct measurements of specific volume at 370° C, which confirmed the calori metric results.A compilation was made of the thermal properties of saturated water in the interval from 100 to 374 0 C, giving the vapor pressure and the specific volume, entropy, and enthalpy, or heat content, for both the liquid and gaseous states. This compilation is based on the results of the present measurements, supplemented by data covering the range from 100 to 270 0 C from the previous investigation. These latter data are in accord with those of the present investigation at the same temperatures.A number of comparisons between these values and certain groups of similar data from other laboratories are shown graphically.

Thermal properties of aluminum oxide from 0 to 1200 K

“…In the first place, as pointed out later in this paper (section 5 and figure 8), the heatcapacity values calculated from eq (2) arc slightly higher in the temperature region of overlap than the somewhat more accurate values determined with the low-temperature adiabatic calorimeter. A maximum difference of approximately 0.25 percent occurs at about 50° C, but has deCl'eased to approximately 0.1 percent at 100° C. In the second place, over-all checks on the accuracy of the furnace and ice calorimeter, described elsewhere [2], were carried out by measuring the mean heat capacity of water between 0° and 25° C and between 0° and 250° C. These results arc lower by 0.05 ± 0.14 percent and by 0.02 ± 0.02 percent, respectively, than the corresponding results obtained earlier at this Bureau of use of two precise adiabatic calorimeters [13,22].…”

Measurements of heat capacity and heat of vaporization of water in the range 0 degrees to 100 degrees C

“…This method was applied previously [2,3] to measurements on saturated water and saturated steam from 0 0 to 374 0 C. The description given here includes mention of both the heat-capacity and the vaporization measurements.…”

“…These terminals were clamped with a screw stud and nut between thin mica washers to the metal whose temperature they were to acquire. They were somewhat larger but made according to the same principles as those described in previous reports [2,3]. These terminals were used on the reference block for the "reference junctions" and for the first "tie-downs," and for the eight principal junctions on the envelope shell.…”

Re-evaluation of experimental data on the second virial coefficient for steam and development of its analytical representation as a function of the internal energy

“…Three special calorimetric properties were measured by Osborne et al [5] and [6] from the triple to the critical points. A special calorimetric property γ can be used to calculate the saturated density with the Clapeyron equation…”

“…But after the setting the coefficients regression the weighted linear regression can be used to refitting the regression and to determined covariance matrix of regression coefficients (equations (4) - (7)). According to [11] the original regression is based on measurements of [5], [6], [8], [1], [2] and [3] and uncertainty of measurement to determine the weight was published also in [11].…”