Explanation Write the expression for the total energy consumption per year by large compressor E L arg e . E L arg e = ( P × T ) [ ( ( L F × T F ) η m o t o r ) U n l o a d e d + ( ( L F × T F ) η m o t o r ) L o a d e d ] (I) Here, the power rating is P , the load factor is LF , the time factor is TF , annual operating time is T and motor efficiency is η . Write the expression for the total energy consumption per year by a small compressor E S m a l l . E S m a l l = ( P × T ) [ ( ( L F × T F ) η m o t o r ) U n l o a d e d + ( ( L F × T F ) η m o t o r ) l o a d e d ] (II) Here, the power rating is P , the load factor is LF , the time factor is TF , annual operating time is T and motor efficiency is η in Equation (II) Write the expression for the amount of energy saved by changing to 25 hp the small compressor during 60% of the time. E s a v i n g = E L arg e − E S m a l l (III) Here, the amount of energy saving is E s a v i n g . Write the expression for the amount of money saved by changing to 25 hp the small compressor during 60% of the time. C s a v i n g = E s a v i n g × C (IV) Here, cost saving is C s a v i n g and unit cost of energy is C . Conclusion: Substitute 100 hp for P , 3 , 800 hrs / year for T , 0.35 for L F U n l o a d e d , 0.6 for T F U n l o a d e d , 0.82 for ( η m o t o r ) U n l o a d e d , 0.90 for L F l o a d e d , 0.4 for T F l o a d e d , and 0.90 for ( η m o t o r ) l o a d e d in Equation (I). E L arg e = ( 100 hp ) ( 3 , 800 hrs / year ) [ 0.35 × 0.6 0.82 + 0.90 × 0.4 0.90 ] = ( 100 hp ) ( 0.746 kW 1 hp ) ( 3 , 800 hrs / year ) [ 0

CONNECT FOR THERMODYNAMICS: AN ENGINEERI

9th Edition

ISBN: 9781260048636

Author: CENGEL

Publisher: MCG

See similar textbooks

Videos

Question

Chapter 7.13, Problem 158P

To determine

The amount of energy and money saved by changing to 25 hp the small compressor during 60% of the time.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 7.13, Problem 157P

Chapter 7.13, Problem 159P

Students have asked these similar questions

First monthly exam Gas dynamics Third stage Q1/Water at 15° C flow through a 300 mm diameter riveted steel pipe, E-3 mm with a head loss of 6 m in 300 m length. Determine the flow rate in pipe. Use moody chart. Q2/ Assume a car's exhaust system can be approximated as 14 ft long and 0.125 ft-diameter cast-iron pipe ( = 0.00085 ft) with the equivalent of (6) regular 90° flanged elbows (KL = 0.3) and a muffler. The muffler acts as a resistor with a loss coefficient of KL= 8.5. Determine the pressure at the beginning of the exhaust system (pl) if the flowrate is 0.10 cfs, and the exhaust has the same properties as air.(p = 1.74 × 10-3 slug/ft³, u= 4.7 x 10-7 lb.s/ft²) Use moody chart (1) MIDAS Kel=0.3 Q3/Liquid ammonia at -20°C is flowing through a 30 m long section of a 5 mm diameter copper tube(e = 1.5 × 10-6 m) at a rate of 0.15 kg/s. Determine the pressure drop and the head losses. .μ= 2.36 × 10-4 kg/m.s)p = 665.1 kg/m³

2/Y Y+1 2Cp Q1/ Show that Cda Az x P1 mactual Cdf Af R/T₁ 2pf(P1-P2-zxgxpf) Q2/ A simple jet carburetor has to supply 5 Kg of air per minute. The air is at a pressure of 1.013 bar and a temperature of 27 °C. Calculate the throat diameter of the choke for air flow velocity of 90 m/sec. Take velocity coefficient to be 0.8. Assume isentropic flow and the flow to be compressible. Quiz/ Determine the air-fuel ratio supplied at 5000 m altitude by a carburetor which is adjusted to give an air-fuel ratio of 14:1 at sea level where air temperature is 27 °C and pressure is 1.013 bar. The temperature of air decreases with altitude as given by the expression The air pressure decreases with altitude as per relation h = 19200 log10 (1.013), where P is in bar. State any assumptions made. t = ts P 0.0065h

36 2) Use the method of MEMBERS to determine the true magnitude and direction of the forces in members1 and 2 of the frame shown below in Fig 3.2. 300lbs/ft member-1 member-2 30° Fig 3.2. https://brightspace.cuny.edu/d21/le/content/433117/viewContent/29873977/View

Chapter 7 Solutions

CONNECT FOR THERMODYNAMICS: AN ENGINEERI

Ch. 7.13 - Does a cycle for which Q 0 violate the Clausius...Ch. 7.13 - Does the cyclic integral of heat have to be zero...Ch. 7.13 - Is a quantity whose cyclic integral is zero...Ch. 7.13 - Prob. 4P Ch. 7.13 - Prob. 5P Ch. 7.13 - How do the values of the integral 12Q/T compare...Ch. 7.13 - Prob. 7P Ch. 7.13 - The entropy of a hot baked potato decreases as it...Ch. 7.13 - When a system is adiabatic, what can be said about...Ch. 7.13 - Prob. 10P

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

The amount of energy and money saved by changing to 25 hp the small compressor during 60% of the time.

Solution Summary: The author calculates the amount of energy and money saved by changing to 25hp the small compressor during 60% of the time.

Videos

The amount of energy and money saved by changing to 25 hp the small compressor during 60% of the time.

Want to see the full answer?

Chapter 7 Solutions