If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by

Consider the following statements: The volumetric efficiency of a reciprocating compressor can be improved by 1. decreasing the clearance volume 2. cooling the intake air 3. heating the intake air Which of the above statements is/are correct?

A

2 only

B

3 only

C

1 and 2

D

1 and 3

In a single stage, single acting reciprocating air compressor, without clearance, the work-done on the air during isentropic compression is ________ the heat required to raise the temperature of air from T₁ to T₂ at a constant pressure.

A

Equal to

B

Less than

C

Greater than

D

None of these

In a single stage, single acting reciprocating air compressor, without clearance, the work-done on the air during isentropic compression is ________ the heat required to raise the temperature of air from T₁ to T₂ at a constant pressure.

A

Equal to

B

Less than

C

Greater than

D

None of these

For a fixed clearance, as the pressure ratio is increased, the volumetric efficiency of a compressor

A

decreases

B

increases

C

remains constant

D

none of the mentioned

In IC engine 1. the ideal air capacity of a two-stroke engine is the mass of air required to concurrently fill the total cylinder volume at inlet temperature and exhaust pressure 2. with increase in air-fuel ratio beyond the value for maximum power, there is a fall in power developed and this fall is more with higher values of air-fuel ratio. 3. the volumetric efficiency of the engine depends on the design of intake and exhaust manifold. Which of the above are correct?

A

1 and 2 only

B

1 and 3 only

C

2 and 3 only

D

1, 2 and 3

If p₁, is the pressure of air entering the L.P. cylinder and p₂ is the pressure of air leaving the L.P. cylinder (or inter-cooler pressure), then the ratio of cylinder diameters for a single acting, two stage reciprocating air compressor with complete intercooling is given by (where D₁ = Dia. of L.P. cylinder, and D₂ = Dia. of H.P. cylinder)

A

D₁/D₂ = p₁ p₂

B

D₁/D₂ = p₁/p₂

C

D₁/D₂ = p₂/p₁

D

None of these

If p₁, is the pressure of air entering the L.P. cylinder and p₂ is the pressure of air leaving the L.P. cylinder (or inter-cooler pressure), then the ratio of cylinder diameters for a single acting, two stage reciprocating air compressor with complete intercooling is given by (where D₁ = Diameter of L.P. cylinder and D₂ = Diameter of H.P. cylinder)

A

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = {{\text{p}}_1}{{\text{p}}_2}$$

B

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = \frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}}$$

C

$$\frac{{{{\text{D}}_1}}}{{{{\text{D}}_2}}} = \frac{{{{\text{p}}_2}}}{{{{\text{p}}_1}}}$$

D

None of these

In a single acting reciprocating air compressor, without clearance, the compression of air may be

A

Isothermal

B

Polytropic

C

Isentropic

D

Any one of these

Volumetric efficiency of a compressor without clearance volume

A

Increases with increase in compression ratio

B

Decreases with increase in compression ratio

C

Is not dependent upon compression ratio

D

May increase/decrease depending on compressor capacity

Volumetric efficiency of a compressor with clearance volume

A

Increases with increase in compression ratio

B

Decreases with increase in compression ratio

C

In not dependent upon compression ratio

D

May increase/decrease depending on compressor capacity

If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by

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