Before examining the superheated vopor table, it is important to take note of one significant difference between a saturated and a superheated vapor. Whereas there is only one temperature that will satisfy the conditions of saturation, asuperheated vapor may have any temperature above the saturation temperature corresponding to its pressure. The specific volume, enthalpy, and entropy of a superheated vapor at any one pressure will very with the temperature. This does not mean that the properties of a superheated vapor are entirely independent of the pressure of the vapor but only that the properties of the superheated vopor at any one pressure will vary with the temperature. Before the properties of a superheated vapor can be determined from a superheated vapor table, it is neccessary to know either the saturation temperature or pressure of the vapor, as well as the actual superheated temperature. Some superheated vapor tables use saturation temperature as the entry property (Table 16-2B) while others, including the one illustration in Fig. 4-9,use pressure as the entry property. In either case, the corresponding pressure or saturation temperature is also listed. notice in Fig. 4-9 that the saturation pressures are located at the top of the table and the corresponding saturation temperatures are shown in parentheses immediately below the listed pressure. The superheated temperatures are listed on the left side of the table in 10F increaments. The body of table provides values for specific volume(v), enthalpy (h), and entropy (s) for each of the superheated temperatures listed and also for the saturated condition. Similar values for superheated temperatures not listed can be determined by direct interpolation
Before examining the superheated vopor table, it is important to take note of one significant difference between a saturated and a superheated vapor. Whereas there is only one temperature that will satisfy the conditions of saturation, asuperheated vapor may have any temperature above the saturation temperature corresponding to its pressure. The specific volume, enthalpy, and entropy of a superheated vapor at any one pressure will very with the temperature. This does not mean that the properties of a superheated vapor are entirely independent of the pressure of the vapor but only that the properties of the superheated vopor at any one pressure will vary with the temperature. Before the properties of a superheated vapor can be determined from a superheated vapor table, it is neccessary to know either the saturation temperature or pressure of the vapor, as well as the actual superheated temperature. Some superheated vapor tables use saturation temperature as the entry property (Table 16-2B) while others, including the one illustration in Fig. 4-9,use pressure as the entry property. In either case, the corresponding pressure or saturation temperature is also listed. notice in Fig. 4-9 that the saturation pressures are located at the top of the table and the corresponding saturation temperatures are shown in parentheses immediately below the listed pressure. The superheated temperatures are listed on the left side of the table in 10F increaments. The body of table provides values for specific volume(v), enthalpy (h), and entropy (s) for each of the superheated temperatures listed and also for the saturated condition. Similar values for superheated temperatures not listed can be determined by direct interpolation
การแปล กรุณารอสักครู่..