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Get Full Access to Fundamentals Of Engineering Thermodynamics - 7 Edition - Chapter 10 - Problem 26p
Get Full Access to Fundamentals Of Engineering Thermodynamics - 7 Edition - Chapter 10 - Problem 26p

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# Solved: A vapor-compression air conditioning system

ISBN: 9780470495902 50

## Solution for problem 26P Chapter 10

Fundamentals of Engineering Thermodynamics | 7th Edition

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Problem 26P

PROBLEM 26P

A vapor-compression air conditioning system operates at steady state as shown in Fig. P10.26. The system maintains a cool region at 60°F and discharges energy by heat transfer to the surroundings at 90°F. Refrigerant 134a enters the compressor as a saturated vapor at 40°F and is compressed adiabatically to 160 lbf/in.2 The isentropic compressor efficiency is 80%. Refrigerant exits the condenser as a saturated liquid at 160 lbf/in.2 The mass flow rate of the refrigerant is 0.15 lb/s. Kinetic and potential energy changes are negligible as are changes in pressure for flow through the evaporator and condenser. Determine

(a) the power required by the compressor, in Btu/s.

(b) the coefficient of performance.

(c) the rates of exergy destruction in the compressor and expansion valve, each in Btu/s.

(d) the rates of exergy destruction and exergy transfer accompanying heat transfer, each in Btu/s, for a control volume comprising the evaporator and a portion of the cool region such that heat transfer takes place at TC = 520°R (60°F).

(e) the rates of exergy destruction and exergy transfer accompanying heat transfer, each in Btu/s, for a control volume enclosing the condenser and a portion of the surroundings such that heat transfer takes place at TH = 550°R (90°F)

Let T0 = 550°R.

Fig. 10.26

Step-by-Step Solution:
Step 1 of 3

Meteorology Week #7 10-3-16 DEW POINT TEMPERATURE: for a given pressure and water vapor content, the temperature to which air has to be cooled for saturation to occur. When Dew Point Temp. goes up, there is more moisture in the atmosphere. The only way to change DPT is by changing the amount of water vapor in the air. Dew Point Depression: T-Td Large Dew point Depression= Low Relative Humidity Small Dew point Depression= High Relative Humidity When T=Td, air is saturated Air Temperature is never less than dew point temperature HUMIDITY MEASURE: remote sensing, hydrometers (sling psychrometer) Condensation Nuclei: size of nuclei ranges from 0.1 um to 1um lightweight- suspended for long periods of time Hydroscopic: Water Seeking Hydrophobic: Water repelling Cond

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##### ISBN: 9780470495902

Since the solution to 26P from 10 chapter was answered, more than 528 students have viewed the full step-by-step answer. Fundamentals of Engineering Thermodynamics was written by and is associated to the ISBN: 9780470495902. The full step-by-step solution to problem: 26P from chapter: 10 was answered by , our top Engineering and Tech solution expert on 07/20/17, 09:01AM. This textbook survival guide was created for the textbook: Fundamentals of Engineering Thermodynamics, edition: 7. This full solution covers the following key subjects: transfer, heat, exergy, btu, compressor. This expansive textbook survival guide covers 14 chapters, and 1501 solutions. The answer to “A vapor-compression air conditioning system operates at steady state as shown in Fig. P10.26. The system maintains a cool region at 60°F and discharges energy by heat transfer to the surroundings at 90°F. Refrigerant 134a enters the compressor as a saturated vapor at 40°F and is compressed adiabatically to 160 lbf/in.2 The isentropic compressor efficiency is 80%. Refrigerant exits the condenser as a saturated liquid at 160 lbf/in.2 The mass flow rate of the refrigerant is 0.15 lb/s. Kinetic and potential energy changes are negligible as are changes in pressure for flow through the evaporator and condenser. Determine(a) the power required by the compressor, in Btu/s.________________(b) the coefficient of performance.________________(c) the rates of exergy destruction in the compressor and expansion valve, each in Btu/s.________________(d) the rates of exergy destruction and exergy transfer accompanying heat transfer, each in Btu/s, for a control volume comprising the evaporator and a portion of the cool region such that heat transfer takes place at TC = 520°R (60°F).________________(e) the rates of exergy destruction and exergy transfer accompanying heat transfer, each in Btu/s, for a control volume enclosing the condenser and a portion of the surroundings such that heat transfer takes place at TH = 550°R (90°F)Let T0 = 550°R.Fig. 10.26” is broken down into a number of easy to follow steps, and 205 words.

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