Industrial steam boilers are used in many processes such as heating, drying and sterilisation. Steam boilers, which convert the energy of flammable chemicals by transferring it to water, are also the roots of the industrial revolution.

Fuels such as coal, fuel oil and sawdust used in steam boilers are being replaced by Natural gas due to environmental regulations. Therefore, the efficiency of steam boilers is important not only for the cost but also for the environmental impact.

The basic method for calculating the efficiency of steam boilers is the ratio between the energy of the fuel and the enthalpy of the steam produced. Multiplying the flow rate of the Natural gas used as fuel and its thermal energy, the flow rate of the generated steam and its enthalpy gives the energy equation entering and leaving the steam boiler.

Example of Calculation of the efficiency of a steam boiler:

For the above Calculation it is necessary to measure the natural gas flow rate at the inlet of the boiler in Sm3 (standard cubic metres) and the steam flow rate at the outlet in kg/h.

The VA570/520 thermal mass flow meters from CS INSTRUMENTS measure the natural gas flow in Sm3. They can therefore be used as sub-meters without the need for an additional corrector. Steam flow, Pressure and Temperature at the boiler outlet can be measured with the VX570 vortex flow meter. This provides the necessary flow parameters for the input and output energy balance.

The mathematical calculation function of the Data logger DS500, which is to be added to the system, is used for Calculation of the above boiler efficiency and for recording the instantaneous values. The performance of the boiler at different loads and conditions can thus be easily monitored.