Description
Calculate nominal cold-head on-time and input-energy terms.
Cryogenic calculations require explicit absolute-pressure and temperature bases, density conditions, inventory boundaries and calibration spans. Level signals need not equal volume, nominal input energy differs from cooling delivered, and apparent loss is an accounting residual. Supplied terms do not establish actual equipment condition or safe low-temperature operation.
Calculate nominal cold-head on-time and input-energy terms.
When to use this tool
Use Cold Head Duty Cycle Runtime when you already have elapsedHours, onFraction, ratedOnPowerWatts and need to calculate nominal cold-head on-time and input-energy terms.
How to use the tool and how it works
- Enter elapsedHours, onFraction, ratedOnPowerWatts. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read onHours, inputEnergyWattHours. Use the output convention below.
Require elapsed hours/rated-on power>=0 and onFraction in [0,1]; onHours=hours*fraction, inputEnergyWh=onHours*ratedPowerWatts.1
Power in watts times duration in hours gives watt-hours. Input energy does not by itself determine useful refrigeration or cooling energy.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| elapsedHours | Elapsed Hours | Required. Finite number; minimum 0. |
| onFraction | On Fraction | Required. Finite number; minimum 0; maximum 1. |
| ratedOnPowerWatts | Rated On Power Watts | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| onHours | On Hours | Required. Finite number. |
| inputEnergyWattHours | Supplied on-hours*rated-on power; nominal input energy, not cooling energy delivered. | Required. Finite number. |
{
"input": {
"elapsedHours": 8,
"onFraction": 0.25,
"ratedOnPowerWatts": 100
},
"output": {
"onHours": 2,
"inputEnergyWattHours": 200
}
}Limitations and assumptions
- This assumes the supplied on-power over recorded duty time; off-state draw and transients are omitted. Input energy is not cooling delivered, efficiency or a safe heat-load calculation.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use verified instrument and inventory records with the complete thermophysical and equipment model. Include actual state, geometry, heat transfer, venting and operating limits when local calibration fractions, mean mass flows or nominal volumes cannot answer the engineering question.
References
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