Reciprocating Compressor Horsepower Requirements

Input the suction pressure, discharge pressure, # of stages, and compressed gas in MMSCFD to calculate horsepower required for compression.

This calculation determines the brake horsepower (BHP) required to operate a reciprocating compressor based on compression thermodynamics and gas flow requirements.

The fundamental principle at work here is the relationship between:

1. Compression ratio (pressure increase)
2. Number of compression stages
3. Gas flow volume
4. Energy required to compress the gas

In simple terms, the sheet calculates how much power (horsepower) is needed to compress a specific amount of gas from one pressure to another, taking into account that breaking the compression into multiple stages is more efficient than doing it all at once.

Key Insights

• Multi-stage approach: The calculation recognizes that for high overall compression ratios (above 2.5), it's more efficient to divide the compression into stages, keeping each stage's compression ratio below 3.5.
• Stage efficiency: The "F factor" accounts for the fact that multi-stage compression with intercooling between stages is more efficient than single-stage, but there are also diminishing returns (1.00 → 1.08 → 1.10 as stages increase).
• Linear relationship: The horsepower required increases linearly with gas flow (MMSCFD - million standard cubic feet per day), as shown in the cases where only the gas flow changes and everything else remains constant.
• Practical application: This calculation would help engineers properly size compressor motors and evaluate energy consumption for different operating scenarios.

The calculation uses a simplified equation that encapsulates these thermodynamic principles without requiring complex calculations of polytropic compression, heat transfer, and other detailed parameters that would be part of a more comprehensive analysis.