A10 kw cooling load is to be served by operating an ideal vapor-compression refrigeration cycle with its evaporator at 400 kpa and its condenser at 800 kpa. calculate the refrigerant mass flow rate and the compressor power requirement when refrigerant-134a is used. (take the required values from the saturated refrigerant-134a tables.)

b) w = 0.927211 kW

Explanation:

from table R-134 a

state 1  

P-1 = 400 kPa

h_1 = [email protected] kpa = 255.55 kJ?kg

s1 = s2 = 0.92961 kJ/kg K

state 2

P-2 = 800 kPa

s2 =s1 = 0.92691

s2> [email protected] 800 kPa = 0.92691 kJ/ kg K

from superheated table for R-134 a at pressure of 800 kPa

using interpolation for obtaining desire value of temperature and enthalapy

T_2 = 34.75 degree C

FOR  ENTHALAPY

h_2 = 270.3928 kJ/kg

state 3

state 4  ( h remain constant)

a) mass flow rate

b) compressor power

w = 0.062456(270.3928 - 255.55)

w = 0.927211 kW

True, in the fact that there is not much difference, however, there is some.  both types of data are descriptive, but qualitative data describes qualities of something using detailed adjectives to describe the appearance, whereas quantitative data generally uses mostly numbers and exact measurements.