Look around your house. What do you own that you think might be manufactured?

Refrigerant 22 flows in a theoretical single-stage compression refrigeration cycle with a mass flow rate of 0.05 kg/s. The conde

Debora [2.8K]

Answer:

a. The work done by the compressor is 447.81 Kj/kg

b. The heat rejected from the condenser in kJ/kg is 187.3 kJ/kg

c. The heat absorbed by the evaporator in kJ/kg is 397.81 Kj/Kg

d. The coefficient of performance is 2.746

e. The refrigerating efficiency is 71.14%

Explanation:

According to the given data we would need first the conversion of temperaturte from C to K as follows:

Temperature at evaporator inlet= Te=-16+273=257 K

Temperatue at condenser exit=Te=48+273=321 K

Enthalpy at evaporator inlet of Te -16=i3=397.81 Kj/Kg

Enthalpy at evaporator exit of Te 48=i1=260.51 Kj/Kg

b. To calculate the the heat rejected from the condenser in kJ/kg we would need to calculate the Enthalpy at the compressor exit by using the compressor equation as follows:

w=i4-i3

W/M=i4-i3

i4=W/M + i3

i4=2.5/0.05 + 397.81

i4=447.81 Kj/kg

a. Enthalpy at the compressor exit=447.81 Kj/kg

Therefore, the heat rejected from the condenser in kJ/kg=i4-i1

the heat rejected from the condenser in kJ/kg=447.81-260.51

the heat rejected from the condenser in kJ/kg=187.3 kJ/kg

c. Temperature at evaporator inlet= Te=-16+273=257 K

The heat absorbed by the evaporator in kJ/kg is Enthalpy at evaporator inlet of Te -16=i3=397.81 Kj/Kg

d. To calculate the coefficient of performance we use the following formula:

coefficient of performance=Refrigerating effect/Energy input

coefficient of performance=137.3/50

coefficient of performance=2.746

the coefficient of performance is 2.746

e. The refrigerating efficiency = COP/COPc

COPc=Te/(Tc-Te)

COPc=255/(321-255)

COPc=3.86

refrigerating efficiency=2.746/3.86

refrigerating efficiency=0.7114=71.14%

8 0

4 years ago

Environmental assessments (EAs) are an important component of any civil engineering project. Delgado Engineering has been contra

Tom [10]

Answer:

Environmental assessments (EAs) are an important component of any civil engineering project. Delgado Engineering has been contracted to design and assess a multibillion-dollar urban rail center in a city, which is divided in the middle by a river. The center will be built on a previously unused island in the center of the river. For each of the four types of civil engineers (construction engineer, geotechnical engineer, structural engineer, transportation engineer), explain why they should be involved in the project—or why they would not be relevant to the project—and what their role would be. Then describe how the EA would proceed, including what might be included in the environmental impact assessment process, such as the use of geographic information systems. Finally, explain what might be in the environmental impact statement or why you think there may be a finding of no significant impact.

6 0

3 years ago

Comparison of density values determines whether an item will float or sink in water. For each of the values below, determine the

geniusboy [140]

Answer:

a) the object floats

b) the object floats

c) the object sinks

Explanation:

when an object is less dense than in the fluid in which it is immersed, it will float due to its weight and volume characteristics, so to solve this problem we must find the mass and volume of each object in order to calculate the density and compare it with that of water

a)

volumen for a cube

V=L^3

L=1.53in=0.0388m

V=0.0388 ^3=5.8691x10^-5m^3=58.69ml

density=m/v

density=13.5g/58.69ml=0.23 g/ml

The wooden block floats because it is less dense than water

b)

m=111mg=0.111g

density=m/v

density=0.111g/0.296ml=0.375g/ml

the metal paperclip floats because it is less dense than water

c)

V=0.93cups=220.0271ml

m=0.88lb=399.1613g

Density=m/v

density=399.1613/220.027ml=1.8141g/ml

the apple sinks because it is denser than water

4 0

3 years ago

You read a research study that concludes that the higher a student's self-esteem, the better he performs in school. This sort of

LiRa [457]

Answer:

Negative correlation

7 0

4 years ago

The rainfall rate in a certain city is 20 inches per year over an infiltration area that covers 33000 acres. Twenty percent of t

Mariana [72]

Answer:

The rate at which water is being withdrawn from the river by the city is 57353 acre-ft/y

Explanation:

Please look at the solution in the attached Word file

Download docx

3 0

4 years ago