Heating Water by Injecting Steam (original) (raw)

Water can be heated by injecting steam.

For some applications a direct heating of water by injecting steam may be convenient. A direct heating system is very simple since it don't require heat exchangers. Fouling of surfaces, which may be a major problem in certain processes, is also avoided.

The required steam flow rate in an steam injection process can be calculated as

ms = P / (hg - (t cp)) (1)

where

ms = steam flow rate (kg/s)

P = heat transfer rate or power from the steam (kW)

hg = specific total enthalpy of the steam before the control valve (kJ/kg)

t = final temperature of the water after the heating (oC)

cp = specific heat water (kJ/kg)

The specific heat of evaporated steam is related to zero degrees Celsius.

Example - Heating a Water Volume by Injecting Steam

100 liter (kg) of water is heated from 20 oC to 80 oC in 5 minutes (300 s). The specific heat of water is 4.2 kJ/kgoC and the power required to heat the water can be calculated as

P = (100 kg) (4.2 kJ/kgoC) ((80 oC) - (20 oC)) / (300 s)

= 84 kW

The absolute steam pressure is 220 kPa and the total enthalpy of the steam is 2711 kJ/kg. The required steam flow rate can be calculated as

ms = (84 kW) / ((2711 kJ/kg) - ((80 oC) (4.2 kJ/kgoC)))

= 0.035 kg/s

= 127 kg/h

The total steam consumption for the heating process can be calculated as

q = (0.035 kg/s) (300 s)

= 10.5 kg

Calculate heat, work, temperature and energy. The thermodynamics of steam and condensate systems. Water and Ice properties.

Heat transfer when steam condensates.

Heat emision from steam or water heating pipes submerged in water - assisted (forced) or natural circulation.

Steam table with sensible, latent and total heat, and specific volume at different gauge pressures and temperatures.

Saturated Steam Table with properties like boiling point, specific volume, density, specific enthalpy, specific heat and latent heat of vaporization.

Vapor and steam enthalpy, specific enthalpy of saturated liquid, saturated vapor and superheated vapor.

Calculating the amount of steam in non-flow batch and continuous flow heating processes.

An introduction to the basic design of steam heating systems.

Thermal properties of water at different temperatures like density, freezing temperature, boiling temperature, latent heat of melting, latent heat of evaporation, critical temperature and more.

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .

Citation

This page can be cited as

Modify the access date according your visit.