40_Lessons_on_Refrigeration_and_Air_Conditioning_www.hvac-eng.ir_96

# 40_Lessons_on_Refrigeration_and_Air_Conditioning_www.hvac-eng.ir_96

• Test Prep
• 2

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From the above data and using refrigerant property values for R 22 at various state points are: State Point T P h s (kJ/kg.K) v Quality o 3 ( C) (bar) (kJ/kg) m /kg 1 7.2 6.254 407.6 1.741 0.03773 1.0 2 37.88 6.254 430.7 1.819 0.04385 Superheated 3 104.9 21.46 466.8 1.819 - Superheated 4 54.4 21.46 269.5 1.227 - 0.0 5 37.65 246.4 1.154 21.46 - Subcooled 6 7.2 6.254 246.4 1.166 0.1903 - 6’ 7.2 6.254 269.5 1.248 0.3063 - 3’ 74.23 21.46 438.6 1.741 - Superheated 1’ 7.2 6.254 208.5 1.030 - 0.0 With LSHX: ) = 161.2 kJ/kg a) Refrigeration effect = (h 1 -h 6 b) Volumic refrigeration effect = (h 1 -h 6 )/v 2 = 3676.2 kJ/m 3 c) Work of compression = (h 3 -h 2 ) = 36.1 kJ/kg ) = 4.465 -h )/ (h d) COP = (h 1 6 3 -h 2 e) Temperature at compressor exit (from P c and s 3 =s 2 ) = 104.9 o C Without LSHX: a) Refrigeration effect = (h 1 -h 6’ ) = 138.1 kJ/kg = 3660.2 kJ/m 3 b) Volumic refrigeration effect = (h -h 1 6’ )/v 1 ) = 31.0 kJ/kg c) Work of compression = (h

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