Explanation Express coefficient of performance. COP = T H T H − T L (I) Here, temperature of low source is T L and temperature of high source is T H . Express the amount of heat added to the cycle. q H = h f g (II) Here, specific enthalpy of evaporation is h f g . Express the net work input for the cycle. W net = q H COP (III) Conclusion: Refer Table A-12, “saturated refrigerant-134a-pressure table”, and write the specific enthalpy of evaporation corresponding to pressure at state 1 of 800 kPa . h f g = 171.82 kJ / kg Refer Table A-12, “saturated refrigerant-134a-pressure table”, and write the saturated temperature corresponding to initial pressure of 800 kPa . T sat = T H = 31.31 °C Refer Table A-12, “saturated refrigerant-134a-pressure table”, and write the saturated temperature corresponding to final pressure of 140 kPa . T sat = T L = − 18.77 °C Substitute 31 .31°C for T H and − 18.77 °C for T L in Equation (I). COP = 31

Thermodynamics: An Engineering Approach ( 9th International Edition ) ISBN:9781260092684

9th Edition

ISBN: 9781260048667

Author: Yunus A. Cengel Dr.; Michael A. Boles

Publisher: McGraw-Hill Education

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Chapter 11.10, Problem 136FEP

To determine

The net work input for the cycle from the following option:

(a) 28 kJ/kg

(b) 34 kJ/kg

(c) 49 kJ/kg

(d) 144 kJ/kg

(e) 275 kJ/kg

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Chapter 11.10, Problem 135FEP

Chapter 11.10, Problem 137FEP

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Chapter 11 Solutions

Thermodynamics: An Engineering Approach ( 9th International Edition ) ISBN:9781260092684

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The net work input for the cycle from the following option: (a) 28 kJ / kg (b) 34 kJ / kg (c) 49 kJ / kg (d) 144 kJ / kg (e) 275 kJ / kg

Solution Summary: The author explains the net work input for the cycle from the following options.

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The net work input for the cycle from the following option:

(a) 28 kJ/kg

(b) 34 kJ/kg

(c) 49 kJ/kg

(d) 144 kJ/kg

(e) 275 kJ/kg

Want to see the full answer?

Chapter 11 Solutions

The net work input for the cycle from the following option: (a) 28 kJ / kg (b) 34 kJ / kg (c) 49 kJ / kg (d) 144 kJ / kg (e) 275 kJ / kg

Solution Summary: The author explains the net work input for the cycle from the following options.

Videos

The net work input for the cycle from the following option: (a) 28 kJ/kg (b) 34 kJ/kg (c) 49 kJ/kg (d) 144 kJ/kg (e) 275 kJ/kg

Want to see the full answer?

Chapter 11 Solutions

The net work input for the cycle from the following option:

(a) 28 kJ/kg

(b) 34 kJ/kg

(c) 49 kJ/kg

(d) 144 kJ/kg

(e) 275 kJ/kg