Can you use isentropic efficiency for a non-adiabatic compressor?

Can you use isothermal efficiency for an adiabatic compressor?

Answers

Answer 1
Mark brainliest please!

Isothermal work will be less than the adiabatic work for any given compression ratio and set of suction conditions. The ratio of isothermal work to the actual work is the isothermal efficiency. Isothermal paths are not typically used in most industrial compressor calculations.

Compressors

Compressors are used to move gases and vapors in situations where large pressure differences are necessary.

Types of Compressor

Compressors are classified by the way they work: dynamic (centrifugal and axial) or reciprocating. Dynamic compressors use a set of rotating blades to add velocity and pressure to fluid. They operate at high speeds and are driven by steam or gas turbines or electric motors. They tend to be smaller and lighter for a given service than reciprocating machines, and hence have lower costs.

Reciprocating compressors use pistons to push gas to a higher pressure. They are common in natural gas gathering and transmission systems, but are less common in process applications. Reciprocating compressors may be used when very large pressure differences must be achieved; however, since they produce a pulsating flow, they may need to have a receiver vessel to dampen the pulses.

The compression ratio, pout over pin, is a key parameter in understanding compressors and blowers. When the compression ratio is below 4 or so, a blower is usually adequate. Higher ratios require a compressor, or multiple compressor stages, be used.

When the pressure of a gas is increased in an adiabatic system, the temperature of the fluid must rise. Since the temperature change is accompanied by a change in the specific volume, the work necessary to compress a unit of fluid also changes. Consequently, many compressors must be accompanied by cooling to reduce the consequences of the adiabatic temperature rise. The coolant may flow through a jacket which surrounds the housing with liquid coolant. When multiple stage compressors are used, intercooler heat exchangers are often used between the stages.

Dynamic Compressors

Gas enters a centrifugal or axial compressor through a suction nozzle and is directed into the first-stage impeller by a set of guide vanes. The blades push the gas forward and into a diffuser section where the gas velocity is slowed and the kinetic energy transferred from the blades is converted to pressure. In a multistage compressor, the gas encounters another set of guide vanes and the compression step is repeated. If necessary, the gas may pass through a cooling loop between stages.

Compressor Work

To evaluate the work requirements of a compressor, start with the mechanical energy balance. In most compressors, kinetic and potential energy changes are small, so velocity and static head terms may be neglected. As with pumps, friction can be lumped into the work term by using an efficiency. Unlike pumps, the fluid cannot be treated as incompressible, so a differential equation is required:

Compressor Work
Evaluation of the integral requires that the compression path be known - - is it adiabatic, isothermal, or polytropic?
uncooled units -- adiabatic, isentropic compression
complete cooling during compression -- isothermal compression
large compressors or incomplete cooling -- polytropic compression
Before calculating a compressor cycle, gas properties (heat capacity ratio, compressibility, molecular weight, etc.) must be determined for the fluid to be compressed. For mixtures, use an appropriate weighted mean value for the specific heats and molecular weight.

Adiabatic, Isentropic Compression

If there is no heat transfer to or from the gas being compressed, the porocess is adiabatic and isentropic. From thermodynamics and the study of compressible flow, you are supposed to recall that an ideal gas compression path depends on:

Adiabatic Path
This can be rearranged to solve for density in terms of one known pressure and substituted into the work equation, which then can be integrated.
Adiabatic Work
The ratio of the isentropic work to the actual work is called the adiabatic efficiency (or isentropic efficiency). The outlet temperature may be calculated from
Adiabatic Temperature Change
Power is found by multiplying the work by the mass flow rate and adjusting for the units and efficiency.
Isothermal Compression

If heat is removed from the gas during compression, an isothermal compression cycle may be achieved. In this case, the work may be calculated from:

http://facstaff.cbu.edu/rprice/lectures/compress.html

Related Questions

Even though the content of many alcohol blends doesn’t affect engine drive ability using gasoline with alcohol in warm weather may cause

Answers

Even though the content of many alcohol blends doesn't affect engine driveability, using gasoline with alcohol in warm weather may cause: decrease in fuel economy.

Mark brainliest
s

A cylindrical space capsule lands in the ocean. This capsule is 2.44 m long, 1.10 m in diameter, and weighted at one end so that it floats with its long central axis vertical and 0.820 m of its length above the water surface. The mass density of sea water is 1025 kg/m3.What is the magnitude of the buoyant force exerted on the capsule?

Answers

Answer:

The correct answer is "15456.8 N".

Explanation:

According to the question,

The inside volume will be:

= [tex]3.14\times (\frac{1.1}{2} )^2\times (2.44-0.82)[/tex]

= [tex]3.14\times \frac{1.21}{4}\times 1.62[/tex]

= [tex]3.14\times 03025\times 1.62[/tex]

= [tex]1.538757 \ m^3[/tex]

hence,

The buoyant force will be:

= [tex]V\times Pw\times g[/tex]

= [tex]1.538757\times 1025\times 9.8[/tex]

= [tex]15456.8 \ N[/tex]

A brittle material is subjected to a tensile stress of 1.65 MPa. If the specific surface energy and modulus of elasticity for this material are 0.60 J/m2 and 2.0 GPa, respectively. What is the maximum length of a surface flaw that is possible without fracture

Answers

Answer:

The maximum length of a surface flaw that is possible without fracture is

[tex]2.806 \times 10^{-4} m[/tex]

Explanation:

The given values are,

σ=1.65 MPa

γs=0.60 J/m2

E= 2.0 GPa

The maximum possible length is calculated as:

[tex]\begin{gathered}a=\frac{2 E \gamma_{s}}{\pi \sigma^{2}}=\frac{(2)\left(2 \times 10^{9} \mathrm{~N} / \mathrm{m}^{2}\right)(0.60 \mathrm{~N} / \mathrm{m})}{\pi\left(1.65\times 10^{6} \mathrm{~N} / \mathrm{m}^{2}\right)^{2}} \\=2.806 \times 10^{-4} \mathrm{~m}\end{gathered}[/tex]

The maximum length of a surface flaw that is possible without fracture is

[tex]2.806 \times 10^{-4} m[/tex]

Hi, can anyone draw me an isometric image of this shape?​

Answers

I can give me like 10 minutes I gotta find my book
I have 2 accounts here’s the answer

An AM signal having a carrier frequency of 460 kHz is to be mixed with a local oscillator signal at a frequency of 1135 kHz. What does the output of the IF amplifier consist of

Answers

Answer:

the output of the IF amplifier consist of 675 kHz

Explanation:

Given the data in the question;

AM signal carrier frequency [tex]_{RF[/tex]  = 460 kHz

Local oscillator frequency[tex]_{lo[/tex] = 1135 kHz

Now, The output of the IF amplifier consists of difference of local oscillator frequency & AM carrier signal frequency;

FREQUECY[tex]_{IF[/tex] = FREQUECY[tex]_{lo[/tex] - FREQUECY[tex]_{RF[/tex]

so we substitute in our given values

FREQUECY[tex]_{IF[/tex] = 1135 kHz - 460 kHz

FREQUECY[tex]_{IF[/tex] = 675 kHz

Therefore, the output of the IF amplifier consist of 675 kHz

An engineer is applying dimensional analysis to study the flow of air through this horizontal sudden contraction for the purpose of characterizing the pressure drop. The flow is being modeled as constant density and steady. What is the functional relationship of the variables that characterize this situation

Answers

Answer:

The answer is " [tex]\Delta p = f(V1, p, V2, d, D, L)[/tex]"

Explanation:

Please find the complete question in the attached file.

Its change in temperature in pipes depends on rate heads and loss in pipes owing to pipe flow, contractual loss, etc.

The temperature change thus relies on V1 v2 p d D L.

A ceramic specimen with an elastic modulus of 300 GPa is under a tensile stress of 800 MPa. Will it fracture if its most severe flaw is an internal crack of 0.30 mm long with a tip radius of curvature in the amount of 0.0015 mm? Please justify your conclusion. (Hint: Compare the largest stress in the specimen around the crack to the theoretical strength which is roughly E/10).

Answers

Answer:

16Gpa < 30 Gpa

there would be no fracture

Explanation:

fracture can occur if the maximum strength at the top of the biggest flaw is more than the theoretical fracture

to get the theoretical strength =

e/10 = 300/10

= 30 Gpa

we get the magnitude at the buggest flaw

= 2σ√a/ρt

σ = 800

ρτ = 0.0015

a= 0.3/2

[tex]=2*800\sqrt{\frac{\frac{0.3}{2} }{0.0015} }[/tex]

= [tex]=2*800*\sqrt{100} \\=2*800*10\\=16000MPa[/tex]

= 16Gpa < 30 Gpa

the fracture is not going to happen given that the maximum strenght is smaller than the theoretical fracture strength.

Calculate the biaxial stresses σ1 and σ2 for the biaxial stress case, where ε1 = .0020 and ε2 = –.0010 are determined experimentally on an aluminum member of elastic constants, E = 71 GPa and v = 0.35. Also, determine the value for the maximum shear stress.

Answers

Answer:

i) σ1 = 133.5 MPa

  σ2 = -2427 MPa

ii) 78.89 MPa

Explanation:

Given data:

ε1 = 0.0020 and ε2 = –0.0010

E = 71 GPa

v = 0.35

i) Determine the biaxial stresses  σ1 and σ2 using the relations below

ε1 = σ1 / E - v (σ2 / E)   -----( 1 )

ε2 = σ2 / E - v (σ1 / E)  -------( 2 )

resolving equations 1 and 2

σ1 = E / 1 - v^2 {  ε1 + vε2 } ---- ( 3 )

σ2 = E / 1 - v^2 {  ε2 + vε1 } ----- ( 4 )

input the given data into equation 3 and equation 4

σ1 = 133.5 MPa

σ2 = -2427 MPa

ii) Calculate the value of the maximum shear stress ( Zmax )

Zmax = ( σ1 - σ2 ) / 2

         = 133.5 - ( - 2427 ) / 2

         = 78.89 MPa


State two factors that shows that light travels in a straight line​

Answers

Explanation:

Light travels in straight lines

Once light has been produced, it will keep travelling in a straight line until it hits something else. Shadows are evidence of light travelling in straight lines. An object blocks light so that it can't reach the surface where we see the shadow.

Answer:

The two factors are Air and Object

Given below are the measured streamflows in cfs from a storm of 6-hour duration on a stream having a drainage area of 185 mi^2. Derive the unit hydrograph by the inverse procedure. Assume a constant baseflow of 550 cfs.

Hour Day 1 Day 2 Day 3 Day 4
Midnight 550 5,000 19,000 550
6 am 600 4,000 1400
Noon 9000 3000 1000
6 pm 6600 2500 750

Answers

Answer:

33.56 ft^3/sec.in

Explanation:

Duration = 6 hours

drainage area = 185 mi^2

constant baseflow = 550 cfs

Derive the unit hydrograph using the inverse procedure

first step : calculate for the volume of direct runoff hydrograph using the details in table 2 attached below

Vdrh = sum of drh *  duration

        = 29700 * 6 hours ( 216000 secs )

        = 641,520,000 ft^3.

next step : Calculate the volume of runoff in equivalent depth

Vdrh / Area = 641,520,000  / 185 mi^2

                    = 1.49 in

Finally derive the unit hydrograph

Unit of hydrograph = drh /  volume of runoff in equivalent depth

                                = 50 ft^3 / 1.49 in  =  33.56 ft^3/sec.in

Convert the following indoor air quality standards, established by the U.S. Occupational Safety and Health Administration (OSHA), from ppmv to mg/m3 (at 25°C and 1atm) or vice versa.

a. Carbon dioxide (CO2), 5,000 ppmv
b. Formaldehyde (HCHO), 3.6 mg/m^3
c. Nitric oxide (NO), 25 ppmv

Answers

Wouldn’t this be science not engineering?

Question
А
Particle of 2kg mass is being pulled across a smooth horizontal
surface by a horizontal force. The force does 24 Joule of work in
increasing
the particle's
velocity from 5m/s
to v m/s. calculate
the value of v and the position of particle
after 15s​

Answers

Answer:

udhddhdiejebdidjebdhdidh

What possible scenarios may happen if you do the task without using PPE?

Answers

Without PPE, employees are at risk of Cuts and punctures. Chemical burns. Electric shocks. Exposure to excessive noise or vibration.

What is the key objective of data analysis

Answers

Answer: The process of data analysis uses analytical and logical reasoning to gain information from the data. The main purpose of data analysis is to find meaning in data so that the derived knowledge can be used to make informed decisions.

Determine the voltage which must be applied to a 1 k 2 resistor in order that a current of
10 mA may flow.​

Answers

Answer:

The correct solution is "20 volt".

Explanation:

Given that:

Current,

I = 10 mA

or,

 = [tex]10\times 10^{-3} \ A[/tex]

Resistance,

R = 2 K ohm

or,

  = [tex]1\times 10^3 \ ohm[/tex]

Now,

The voltage will be:

⇒ [tex]V=IR[/tex]

By putting the values, we get

        [tex]=10\times 10^{-3}\times 2\times 10^{3}[/tex]

        [tex]= 20 \ volt[/tex]

If you deposit $ 1000 per month into an investment account that pays interest at a rate of 9% per year compounded quarterly.how much will be in your account at the end of 5 years ?assume no interpèriod compounding

Answers

Answer:

5,465.4165939453

Explanation:

formula

A=P(1+r/n)^n(t)

p=1000

r=0.09

n=4

t=5

The number of pulses per second from IGBTs is referred to as

Answers

Referred to as Carrier Frequency

: Một nền kinh tế có cấu trúc như sau:
C = 80 + 0,8(Y - T); T = 100 ;
I = 130; G = 120;
MSr = MS/CPI = 200;
MD = 0,2Y – 10i
Yêu cầu:
1. Xác định thu nhập và lãi suất cân bằng?
2. Muốn sản lượng cân bằng tăng 500 thì chính phủ cần thay đổi thuế như thế nào?
3. Liệu mục tiêu ở câu 2 có thể đạt đựơc bằng chính sách tiền tệ hay không? Tại sao?

Answers

Answer:

Haha I'm a great guy but my friend has been in a day of the day and a lot to be able and I'm happy holi and a lot to the world of the day and day to

An air conditioner removes heat steadily from a house at a rate of 750 kJ/min while drawing electric power at a rate of 5.25 kW. Determine (a) the COP of this air conditioner and (b) the rate of heat transfer to the outside air.Answers:(a) 2.38, (b) 1065 kJ/min

Answers

Answer:

a) the COP of this air conditioner is 2.38

b) the rate of heat transfer to the outside air is 1065 kJ/min

Explanation:

Given the data in the question;

[ Outdoor ] ←  Q[tex]_H[/tex] [ W[tex]_{net, in[/tex] ] Q[tex]_L[/tex] ← [ House ]

Rate of heat removed from the house; Q[tex]_L[/tex]  = 750 kJ/min = ( 750 kJ/min × ( 1 kW / 60 kJ/min ) ) = 12.5 kW

Net-work input; W[tex]_{net, in[/tex] = 5.25 kW

a) The coefficient of performance of the air conditioner; COP.

COP = Q[tex]_L[/tex] / W[tex]_{net, in[/tex]

we substitute

COP = 12.5 kW / 5.25 kW

COP = 2.38

Therefore, the COP of this air conditioner is 2.38

b) the rate of heat transfer to the outside air.

Q[tex]_H[/tex] = Q[tex]_L[/tex] + W[tex]_{net[/tex]

we substitute

Q[tex]_H[/tex] = 12.5 kW + 5.25 kW

Q[tex]_H[/tex] = 17.75 kW

Q[tex]_H[/tex] = ( 17.75 × 60 ) kJ/min

Q[tex]_H[/tex] = 1065 kJ/min

Therefore, the rate of heat transfer to the outside air is 1065 kJ/min

An aggregate blend consists of 65% of aggregate A and 35% of aggregate B. The bulk specific gravities of aggregate A and B are 2.45 and 3.25, respectively. What is the bulk specific gravity of the blend?
a) 2.45
b) 2.68
c) 2.73
d) 2.92

Answers

Answer:

2.68

Explanation:

Percentage by Mass of each Aggregate :

Pa = 65% ; Pb = 35%;

Bulk Specific gravity of each aggregate :

Ga = 2.45 ; Gb = 3.25

Gsb = (Pa + Pb) / (Pa/Ga + Pb/Gb)

Gsb = (65 + 35) / (65/2.45 + 35/3.25)

Gsb = (65 + 35) / 37.299843

Gsb = 100 / 37.299843

Gsb = 2.68

A turbine of a fossil fuel burning installation delivers 1,500 hp of mechanical energy to a generator. The generator then converts 80.0% of the mechanical energy into electrical energy. If the terminal potential difference of the generator is 1790 V, what current does it deliver (in A)

Answers

Answer:

The generator delivers current of 500.11 A

Explanation:

Given the data in the question;

mechanical energy delivered to the generator = 1500 hp

efficiency η = 80.0 %

terminal potential difference of the generator = 1790 V

we know that;

1 hp = 746 W

so

the mechanical energy delivered to the generator will be

Generator Input = ( 1500 × 746 )W = 1119000 W

So the generator output will be;

Generator Output = Generator Input × η

we substitute

Generator Output = 1119000 W × 80.0 %

Generator Output = 1119000 W × 0.8

Generator Output = 895200 W

So the Current will be;

[tex]I[/tex] = Generator Output / terminal potential difference of the generator

we substitute

[tex]I[/tex] =  895200 W / 1790 V

[tex]I[/tex] =  500.11 A

Therefore, The generator delivers current of 500.11 A

What is the per capita GDP of China? Be sure to indicate the calendar year that this information represents.

Answers

10,261.68 USD (2019)

The per capita GDP of China in the Calendar year 2021 was found to be around 12,359 U.S. dollars.

What is GDP?  

GDP termed Gross Domestic Product, has been evaluated with the value producing the economy of the region with the values added with the used products formed to be the less of the economy produced. It has been termed as the measure of the income of a region and not the wealth.

The per capita GDP has been the total income earned by a person in a region during a specified period of time. The calculation has been made by dividing the total gross income of the region by the total population.

China has been the world's most populous country in the East Asian region. It has been found that the per capita GDP of China is low because of its large population. In the calendar year 2021, the per capita GDP of China was 12,359 U.S. dollars.

Learn more about the GDP, here:

https://brainly.com/question/15171681

#SPJ5

Type the correct answer in each box. Spell all words correctly. According to the priority matrix, which tasks should an entrepreneur complete first? According to the priority matrix, entrepreneurs should first complete tasks that are blank and important.

Answers

Answer:

Development of creative and develop ideas

Explanation:

First task as an entrepreneur is to be creative and develop ideas. The person must design the product based on which he will develop the business strategy.

The remaining activities such as marketing, fund raising, recruitment etc. comes at a later stage.

. En la facultad de Ingeniería Industrial se realizó una encuesta a 200 personas para saber que lenguaje de programación preferían para aprender al inicio, se obtuvo: 50 prefieren C, 65 prefieren C#, 77 prefieren Python, 100 prefieren C o C#, 105 prefieren C# o Python, 110 prefieren C o Python, 10 personas prefieren C y Python pero no C#.

Answers

Answer:

lalalalapumpe

Explanation:

4. An aluminum alloy fin of 12 mm thick, 10 mm width and 50 mm long protrudes from a wall, which is maintained at 120C. The ambient air temperature is 22C. The heat transfer coefficient and conductivity of the fin material are 140 W/m2K and 55 W/mk respectively. Determine a. Temperature at the end of the fin b. Temperature at the middle of the fin. c. Calculate the heat dissipation energy of the fin

Answers

Answer:

a) 84.034°C

b) 92.56°C

c) ≈ 88 watts

Explanation:

Thickness of aluminum alloy fin = 12 mm

width = 10 mm

length = 50 mm

Ambient air temperature = 22°C

Temperature of aluminum alloy is maintained at 120°C

a) Determine temperature at end of fin

m = √ hp/Ka

   = √( 140*2 ) / ( 12 * 10^-3 * 55 )

   = √ 280 / 0.66 = 20.60

Attached below is the remaining answers

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