Diagram enthalpy-pressure

Fig. 7. (a) Pressure—enthalpy diagram and (b) system schematic for a compound cycle. 

Some values of physical properties of CO2 appear in Table 1. An excellent pressure—enthalpy diagram (a large Mohier diagram) over 260 to 773 K and 70—20,000 kPa (10—2,900 psi) is available (1). The thermodynamic properties of saturated carbon dioxide vapor and Hquid from 178 to the critical point,... 

Although the T-s diagram is veiy useful for thermodynamic analysis, the pressure enthalpy diagram is used much more in refrigeration practice due to the fact that both evaporation and condensation are isobaric processes so that heat exchanged is equal to enthalpy difference A( = Ah. For the ideal, isentropic compression, the work could be also presented as enthalpy difference AW = Ah. The vapor compression cycle (Ranldne) is presented in Fig. H-73 in p-h coordinates. 

FIG. 11-79 Pressure enthalpy diagram for typical two-stage system with two evaporating temperatures, flash-gas removal, and intercooling. 

Figure B-4. Ammonia pressure-enthalpy diagram. (From Short, Kent and Walls, Pressure-Enthalpy Charts for Selected Fn i neering Substances, Gulf Publishing Company, Houston, TX, 1970.)...

Figure B-7. Freon-12 pressure-enthalpy diagram. (Reprinted by permission and courtesy of E. I, EhiPdnt De Nemours and Co.) Freon and Freon—followed by numerals are DuPont trademarks.

Pressure enthalpy diagram ammonia, 497 carbon dioxide, 498... 

Figure 12-12A. Illustration of isentropic path on log pressure-enthalpy diagram, showing Mollier chart method of finding final temperature and calculation of H for reversible and adiabatic compression. (Used by permission Edmister, W. C. Applied Hydrocarbon Thermodynamics, 1961. Gulf Publishing Company, Houston, Texas. All rights reserved.)...

Figure 11 A. Pressure-enthalpy diagram for water and steam 813...

The thermodynamic properties of a number of compounds are shown in Appendix D as pressure-enthalpy diagrams with lines of constant temperature, entropy, and specific volume. The vapor, liquid, and two-phase regions are clearly evident on these plots. The conditions under which each compound may exhibit ideal gas properties are identified by the region on the plot where the enthalpy is independent of pressure at a given temperature (i.e., the lower the pressure and the higher the temperature relative to the critical conditions, the more nearly the properties can be described by the ideal gas law). 

Figure D-1 Oxygen pressure-enthalpy diagram. (From LN Canjar, FS Manning. Thermodynamic Properties and Reduced Correlations for Gases. Houston, TX Gulf Pub, 1967. Reproduced by permission.)...

Figure D-2 Nitrogen pressure-enthalpy diagram. (From VM Tejada et al. Thermo properties of non-hydrocarbons. Hydrocarbon Proc Petrol Refiner, March 1966. Reprinted by permission.)... 

Figure D-5 Pressure-enthalpy diagram of ethane. (From Hydrocarbon Processing 50(4) 140, 1971.)... 

---