How to Calculate Liquid Water Condensate

Steam condensate systems can improve plant performance.

Industrial heating processes use large boilers to generate steam. This steam is used in various pieces of equipment and processes to provide heat. Once that heat has been taken out of the steam, the steam condenses back to water, which is reused in the boiler. When one pound of steam completely condenses, it produces one pound of liquid water condensate. The thermodynamic model of condensate formation begins with the total heat it contains, which is latent and sensible heat. As the steam condenses to water, it gives up its latent heat and the water retains the sensible heat.

Instructions

1. Determine the temperature and pressure of saturated steam in a system. For instance, assume steam at 200 psia (pounds per square inch absolute) and a temperature of 382 degrees Fahrenheit is used in an industrial heating system. This steam has a latent heat of 842.8 Btu/pound.

2. Determine the heat that is removed from the steam. Assume a steam heating system removes 20,000 Btu/hour.

3. Calculate the total liquid water condensate flow based on the heat removed from the steam. This is done by dividing the total heat removed by the latent heat of the steam. The calculation is 20,000 / 842.8 which is 23.7 lbs/hr (pounds per hour) of liquid condensate.

References

• Spirax-Sarco: Condensate Recovery