What is the working principle of steam injectors based on?
The principle that explains the operation of steam injectors was established by Daniel Bernoulli in his book Hydrodynamica, published in 1738.
It explains the so-called Bernoulli equation, which describes the behaviour of a fluid moving along a line of current.
Diagram of Bernoulli’s principle
In essence, the theorem explains that a fluid without viscosity or friction circulating through a closed conduit has a constant energy throughout its entire path.
Bernoulli also deduced that the pressure of said fluid decreases when the speed increases. It should be noted that this principle is only applicable when the flows are isentropic. In thermodynamics, an isentropic process is one in which the entropy of the fluid or gas remains constant. That is, when the effects of irreversible or non-adiabatic processes are small and can be disregarded (turbulence, heat radiation …).
Bernoulli’s principle derives from the principle of conservation of energy: in a constant flow, the sum of all forms of energy in a fluid along a flow line is the same at all points along that line. For this to be the case, the sum of kinetic energy, potential energy and internal energy must remain constant.
That said, Bernoulli’s equation is expressed as follows:
V²x p / 2 + P + pgz = constant
|| velocity of the fluid at the point of consideration
||density of the fluid
||pressure along the line of current
||acceleration due to gravity
||elevation of the point under consideration from a reference level