EFPLAB2: Piston Compressor

EFPLAB2 Lab Expermiment: Work of a Piston Compressor

Animation Labratory Test Setup

Bei Bedarf Zusatzinformationen Einblenden.

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p, V - Diagram

A maximum of 5 piston compressor processes are shown in the p, V - diagram. The further recording of piston compressor processes leads to a step-by-step replacement of the already shown processes in the order of creation.

The diagram can be zoomed in by dragging a zoom window with the left mouse button over the preferred area.

Manipulation of the Measurement

With the sliders you can vary the initial conditions of the measurement. Below the sliders, the change of state of compression and expansion of the cycle can be selected. You can set the state change to isothermal, isentropic or polytropic. The input parameters have no influence on a running measurement, but the initial values of the following measurement can be picked.

Pressure on the outlet side p_Out = bar(a)

Pressure on the suction side p_In = bar(a)

Polytropic Exponent n = [1 < n ≤ κ]

Compression and Expansion setting:

Isothermal

Isentropic

Polytropic

Calculation Table

The table shows the step by step of the total work and the volumetric efficiency for the present measurement. Thus, taking into account the selected input parameters. The results are hidden as soon as the input parameters are changed after the measurement is finished.

Isentropic coefficient κ = 1.4 (material property of air)

Polytropic coefficient n = 1.17 (measured at the laboratory test rig)

ausgabe Compression Work

W_{12} = - p_{1} \cdot V_{1} \cdot ln (\frac{V_{2}}{V_{1}}) = 38.12 J

W_{12} = \frac{p_{1} \cdot V_{1}}{κ - 1} \cdot [{(\frac{V_{1}}{V_{2}})}^{κ - 1} - 1] = 38.12 J

W_{12} = \frac{p_{1} \cdot V_{1}}{n - 1} \cdot [{(\frac{V_{1}}{V_{2}})}^{n - 1} - 1] = 38.12 J

Isobaric Ejection Work

W_{23} = - p_{2} \cdot (V_{3} - V_{2}) = 17.83 J

ausgabe Expansion Work

W_{34} = - p_{3} \cdot V_{3} \cdot ln (\frac{V_{4}}{V_{3}}) = - 1.12 J

W_{34} = \frac{p_{3} \cdot V_{3}}{κ - 1} \cdot [{(\frac{V_{3}}{V_{4}})}^{κ - 1} - 1] = 1.12 J

W_{34} = \frac{p_{3} \cdot V_{3}}{n - 1} \cdot [{(\frac{V_{3}}{V_{4}})}^{n - 1} - 1] = 1.12 J

Isobaric Suction Work

W_{41} = - p_{4} \cdot (V_{1} - V_{4}) = 17.83 J

Total Work

W_{t o t} = W_{12} + W_{23} + W_{34} + W_{41} = 36.28 J

Volumetric Efficiency

λ = \frac{V_{S u c t i o n}}{V_{D i s p l a c e m e n t}} = \frac{V_{1} - V_{4}}{V_{1} - V_{3}} = -0.91