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Reciprocating Compressor Power Calculation Part 3 (Four-Stage Compression)

Rifka Aisyah

In previous post, I shared how to calculate reciprocating compressor power if number of compression stage is two and three, respectively. In this post, I will use the same problem/example to estimate reciprocating compressor power if number of compression stage is 4. In the end of this posting series, I will show you the difference of each stage and to see how important to determine number of compression stages.

The method used to calculate reciprocating compressor is the same, whether it is two-stage, three-stage, or four-stage. There are several steps which is repetitive.

Example

Compress 2 MMscfd of gas measured at 14.65 psia and 60oF. Intake pressure is 100 psia, and intake temperature is 100oF. Discharge pressure is 900 psia. The gas has a specific gravity of 0.80 (23 MW). What is the required horse power?

Assuming number of stages is 4 Read More

Reciprocating Compressor Power Calculation Part 2 (Three-Stage Compression)

Rifka Aisyah

In previous post, I shared how to calculate reciprocating compressor power if number of compression stage is two. In this post, I will use the same problem/example to estimate reciprocating compressor power if number of compression stage is 3. In the end of this posting series, I will show you the difference of each stage and to see how important to determine number of compression stages.

The method used to calculate reciprocating compressor is the same, whether it is two-stage, three-stage, or four-stage. There are several steps which is repetitive. Read More

Reciprocating Compressor Power Calculation Part 1 (Two-Stage Compression)

Rifka Aisyah 9 Comments

Many of readers in of this technical blog asked me how to calculate reciprocating compressor power. Long time ago I wrote how to estimate centrifugal compressor power.

In this post I want to share how to calculate reciprocating compressor power. This calculation is used for estimation only. For more accurate results, you should consult a compressor manufacturer.

You will find that the method used in this calculation rely on graphical methods. So, please be patient in using this method.

I used calculation method as stated in GPSA.

Let’s start using example. I used example as used in GPSA. Read More

Comparison of Several Pipeline Flow Equation: Which One is The Most Conservative?

Rifka Aisyah Leave a comment

In this post, I want to share to you comparison of several pipeline flow equation. Some of you may already know that there are so many flow equations in pipeline. If you want to understand the details of each equation, I recommend you to check this book. I also use the book as reference in this post.

In general, each flow equation is function of gas flow rate, gas properties, pipeline diameter, pipeline length, and upstream and downstream pressure. There are eleven (11) flow equation described in the book. Read More

I Tried Using Aioflo Pipe Sizing and Flow Calculation

Rifka Aisyah 1 Comment

In this post, I want to share with you my experience using Aioflo Pipe Sizing and Flow Calculation. I found this software when searching for Uconeer professional unit conversion program.

Katmar Software developed many engineering software, one of them is Aioflo Pipe Flow Calculator. Aioflo can calculate pipe sizes, flowrate, and pressure drops for liquids and gases. This is a screenshot of the software.

Screenshot of Aioflow Pipe Size and Flow Calculation
Screenshot of Aioflow Pipe Size and Flow Calculation

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Stage Separation of Gas-Condensate

Rifka Aisyah Leave a comment

Stage separation of gas-condensate is a process in which hydrocarbon mixtures are separated into vapor and liquid phases by flashing to low pressure in several steps. Main purposes of stage separation are:

  1. To obtain a more stable stock-tank liquid
  2. To increase liquid recovery

Figure below shows typical stage separation process.

Stage Separation Process

I want to share to you some terminology that I also just knew about stage separation. A two-stage separation requires one separator and one storage tank, and a three-stage separation requires two separators and one storage tank. I never thought before that the storage tank is always counted as final stage of vapor-liquid separation. Read More

How To Estimate Optimum Insulation Thickness

Rifka Aisyah Leave a comment

In previous post I shared how to estimate insulation thickness for both flat surface and cylindrical surface. In this post I want to share how to estimate optimum insulation thickness.

The total annual cost of insulation is the sum of the cost of heat energy lost and fixed cost. A plot of cost vs insulation thickness will determine the most economical insulation thickness. A dimensionless factor can be used to calculate insulation thickness, depending on the ratio of insulation thickness to pipe diameter in the following equation:

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