Steam output
The most important data is obtained from the performance of the individual steam consumers. However, the internal consumption of the steam boiler system must also be taken into consideration, especially for heating up and deaerating the make-up water and condensate, surface blowdown and heat losses in the pipework.
When determining the necessary steam output of the boiler system, additional factors such as the simultaneity of the maximum outputs of individual consumers, the maximum loading rate and purely technical aspects that can often only be measured with difficulty (for example, security of supply or possible extensions) must also be considered.
The typical steam output distribution is shown below. The calculation of the precise project-specific consumption is described in the following chapter.
List of symbols
|
Symbol |
Unit |
Meaning |
|
ṁS |
[kg/h] |
Steam output; quantity of steam |
|
ṁS,dC |
[kg/h] |
Quantity of steam for direct consumers |
|
ṁS,iC |
[kg/h] |
Quantity of steam for indirect consumers |
|
ṁS,lP |
[kg/h] |
Quantity of steam due to expansion steam |
|
ṁS,OU |
[kg/h] |
Own use of boiler system |
|
ṁS,boi |
[kg/h] |
Steam output of boiler |
|
Q· |
[kW]; [MW] |
Heating output |
|
Q·HX |
[kW]; [MW] |
Thermal output of heat exchanger |
|
r |
[kJ/kg] |
Evaporator enthalpy at corresponding pressure |
|
cp |
[kJ/kgK] |
Specific thermal capacity of water (up to 250°C can be calculated with minimum error with constant cp = 4.19kJ/kgK) |
|
ΔT |
[K] |
Temperature difference |