P13452: Dresser-Rand Compressor Characterization

Build, Test, Document

Table of Contents

Build, Test, and Integrate

I. System Vibration Isolation

Pre-Fab Design

Image:Figure 1.1

Construction Phase

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Final Product

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Resulting Vibration Reduction

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II. Thermosyphoning Characterization

Previous system, below.

Image:Figure 2.1

The mathematical model that was developed uses the derivation of the convective heat transfer coefficient, h, heat rate, q_t, and the volumetric flow rate, Q_dot, based on thermal physics, natural circulation principles, heat transfer and fluid dynamics.

The assumptions made for this analysis are as follows:

The resulting schematic for the vertically oriented theoretical system appears as follows:

Image:Figure 2.2

The average convective heat transfer coefficient is then, from the dimensionless parameters Gr, Pr, Ra, and Nu:

Image:Figure 2.3

where k is the conductivity, D is the pipe diameter, beta is the volumetric thermal expansion coefficient, Ts is the mean surface temperature, Tinf is the ambient temperature, nu is the kinematic viscosity, and alpha is the thermal diffusivity and Gr, Pr, Ra, and Nu are defined below.

Image:Figure 2.4

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where n=0.25 for a vertically oriented pipe with Laminar flow.

Next, the heat rate equation was derived using extended surfaces analysis and employing the newly calculated heat transfer coefficient:

Image:Figure 2.8

where h is the average heat transfer coefficient, N is the number of fins in the arrangement, Af is the fin area, At is the total exposed area, eta is the fin efficiency, and Ts and Tinf remain the mean surface and ambient temperature respectively. Af and At are defined below.

Image:Figure 2.9

Image:Figure 2.10

Finally, to determine the volumetric flow rate, we first solve for the mass flow rate using simple heat transfer principles:

Image:Figure 2.11

We then use the density of the cold fluid to find the volumetric flow rate:

Image:Figure 2.12

where Cp is the specific heat capacity at constant pressure, and rho is the density of the fluid

Image:Figure 2.13

The fully functional document is stored in the index for the home node.

III. Thermosyphoning Bench Experiment and Reconstruct

--Flow Meter

--Bench Experiment

Image:Figure 3.11

Figure 3.1

IV. Continuous Health Monitoring

-- Health Monitoring is the process of continuously measuring and assessing the overall wellbeing of a system.

--Our design was made keeping a few key points in mind:

Image:Figure 4.2

--The studs were machined and tapped for ¼ NPT threads.

Test Plans & Test Results

I. System Vibration Isolation

II. Thermosyphoning Bench Experiment and Reconstruct

--Flow Meter Calibration

--Bench Experiment

- Experiment 1

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Figure 3.2

- Experiment 2

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Figure 3.3

The plot also demonstrates the system under shut down. About 65 minutes into the test, after steady state at 150 degrees Fahrenheit was reached, the thermostat was turned off. Once again the flow correlates appropriately with the shutdown trend temperatures of the test rig.

- Experiment 3

Image:Figure 3.4

Figure 3.4

--Compressor Thermosyphoning Rebuild

Image:Figure 3.5, Image:Figure 3.6

Figure 3.5, Figure 3.6

- Concluding Observations

III. Thermosyphoning Characterization

- Concluding Observations

- Sources of Error

The slight variations in flow rate between theoretical and empirical values can be attributed to a number of factors.

IV. Continuous Health Monitoring

Image:Figure 4.0

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Final BOM