Systems for supplying liquid fuel emulsion to a combustion system of a gas turbine

Abstract

Liquid fuel supply system (12) for a combustion system (14), in particular a gas turbine, including at least one storage tank (16) for liquid fuel supplying at least one injector (34) connected to a combustion chamber (32) of the combustion system (14), said liquid fuel supply system (12) including a first piping section (18) disposed downstream of the tank (16) and a second piping section (20) disposed downstream of the first piping section (18) and upstream of fuel nozzle (34) in each combustion chamber (32), said first piping section (18) including at least one pressurizing means (22), and at least one injecting point or entering (24) for a water-soluble product, and the second piping section (20) including a mixing and distribution flow device (26) configured to create an emulsion and distributing the emulsion flow rate to at least one piping (28) connected to said nozzle (34).

Claims

1. A liquid fuel supply system for a combustion system, comprising at least one storage tank for liquid fuel capable of supplying the liquid fuel to at least one nozzle connected to a combustion chamber of the combustion system, the liquid fuel supply system comprising: a first piping section disposed downstream of the tank and a second piping section disposed downstream of the first piping section and upstream of the at least one nozzle, the first piping section having a first line that includes a pressurizing means and an injection point of water disposed downstream of the pressurizing means, the water and the liquid fuel forming a mixture within the first line downstream of the injection point; wherein the second piping section comprises a first mixing device, wherein the first mixing device is configured to create an emulsion and spread an emulsion flow to at least one piping connected to the at least one nozzle; wherein a second mixing device is disposed on the first line downstream of the injection point and upstream of the first mixing device such that all of the mixture travels through the second mixing device before entering the first mixing device; and wherein the second mixing device is configured to provide an input flow rate regime to the first mixing device having a Reynolds number greater than or equal to 2000 such that a variability of a concentration of the water in the mixture is at maximum +/−1-30% between each piping in the at least one piping.

2. The liquid fuel supply system according to claim 1, wherein the input flow rate regime has a Reynolds number between 2000 and 3000.

3. The liquid fuel supply system according to claim 1, wherein, the input flow rate regime has a Reynolds number greater than or equal to 3000.

4. The liquid fuel supply system according to claim 1, wherein the second piping section comprises a shut off device upstream of a nozzle of the at least one nozzle.

5. The liquid fuel supply system according to claim 1, wherein the at least one piping comprises a plurality of pipes, wherein the combustion chamber is a first combustion chamber in a plurality of combustion chambers, and wherein each pipe in the plurality of pipes feeds a respective combustion chamber of the plurality of combustion chambers through a respective at least one nozzle, the plurality of pipes being connected to the first mixing device.

6. The liquid fuel supply system according to claim 1, wherein the water comprises a volume between 1% and 10% of a total flow rate in the first piping section.

7. An electricity generation system comprising: a combustion system; and a liquid fuel supply system comprising at least one storage tank for liquid fuel capable of supplying a liquid fuel to at least one nozzle connected to a combustion chamber of the combustion system, the liquid fuel supply system comprising a first piping section disposed downstream of the at least one tank and a second piping section disposed downstream of the first piping section and upstream of the at least one nozzle, the first piping section having a first line that includes a pressurizing means and an injection point of water disposed downstream of the pressurizing means, the water and the liquid fuel forming a mixture within the first line downstream of the injection point; wherein the second piping section comprises a first mixing device, wherein the first mixing device is configured to create an emulsion and spread an emulsion flow to at least one piping connected to the at least one nozzle; wherein a second mixing device is disposed on the first line downstream of the injection point and upstream of the first mixing device such that all of the mixture travels through the second mixing device before entering the first mixing device; and wherein the second mixing device is configured to provide an input flow rate regime to the first mixing device having a Reynolds number greater than or equal to 2000 such that a variability of a concentration of the water in the mixture is at maximum +/−30% between each piping in the at least one piping.

8. The electricity generation system according to claim 7, wherein the comprises a volume between 1% and 50% of a total flow rate in the first piping section.

9. A liquid fuel supply system for a gas turbine comprising: a first piping section having a first line; a second piping section extending from and fluidly coupled to the first piping section; a fuel storage tank fluidly coupled to the first line of the first piping section for supplying a liquid fuel to the liquid fuel supply system; a pump disposed downstream from the fuel storage tank; an injection point of water downstream of the pump and fluidly coupled to the first line of the first piping section, the water and the liquid fuel forming a mixture within the first line; a first mixing device disposed on the second piping section downstream from the injection point and the pump, wherein the first mixing device is fluidly coupled to the first line such that all of the water from the injection point and all the liquid fuel from the fuel supply system enter the first mixing device; a plurality of nozzles each in fluid communication with a respective combustion chamber of a plurality of combustion chambers; and a plurality of piping each extending from the first mixing device to a respective nozzle of the plurality of nozzles, wherein the first mixing device is configured to provide stable emulsion and distribution to each nozzle of the plurality of nozzles; and a second mixing device disposed on the first line downstream of the injection point and upstream of the first mixing device such that all of the mixture travels through the second mixing device before entering the first mixing device; wherein the second mixing device is configured to provide an input flow rate regime to the first mixing device having a Reynolds number greater than or equal to 2000 such that a variability of a concentration of the water in the mixture is at maximum +/−30% between each pipe in the plurality of pipes.

Description

BRIEF DESCRIPTION

(1) A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

(2) FIG. 1 illustrates an electricity generating system including a fuel supply system according to a first embodiment of the invention; and

(3) FIG. 2 illustrates an electricity generating system including a fuel supply system according to a second embodiment of the invention.

DETAILED DESCRIPTION

(4) Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

(5) As illustrated in FIG. 1, an electricity generating system, such as a boiler or a gas turbine, referenced as a whole, includes a liquid fuel supply system 12 and a combustion system 14 connected to the fuel system 12.

(6) The fuel supply system 12 includes a liquid fuel storage tank 16, a first piping section 18 disposed downstream of the tank 16 and a second piping section 20 disposed downstream of the first piping section 18.

(7) The first piping section 18 includes fuel treatment means (not shown) such as, filtration means (not shown), and at least one pressurizing means 22, such as for example a pump. An injection point 24 for a water-soluble product, such as for example water or water-soluble base product such as an additive, is located downstream of the pressurizing means 22 and upstream of the second section of piping 20.

(8) The first piping section 18 has a diameter D making it possible to obtain a regime with a Reynolds number Re of at least 2000, preferably between 2000 and 3000 (transient regime), and for example greater than 3000 (turbulent regime).

(9) The Reynolds number Re is a dimensionless number used in fluid mechanics to characterize a flow, in particular the nature of its regime (laminar, transient, turbulent). The Reynolds number represents the ratio of inertial forces to viscous forces.

(10) The Reynolds number associated with the flow of a fluid in the first piping section 18 is calculated as a function of the density μ, the viscosity η and the average velocity V of said fluid and the diameter D of the first piping section 18 according to the following equation:

(11) $\begin{array}{cc}\mathrm{Re}=\frac{\mu .Math.V.Math.D}{\eta }& \mathrm{Eq}.1\end{array}$

(12) Equation Eq. 1 can also be written as follows:

(13) $\mathrm{Re}=\frac{\mu .Math.V^2}{\eta \left(\frac{V}{D}\right)}$

(14) As illustrated in FIG. 1, the second piping section includes a mixing and flow distribution device 26 apt to create and to distribute the emulsion flow rate to a plurality of piping 28 each provided with shut-off devices 30, for example, a check valve for isolating the fuel supply system 12 from the combustion system 14 when the pressure in the supply system 12 is lower than the static pressure in the combustion system 14.

(15) As illustrated, the combustion system 14 includes a plurality of combustion chambers 32 each connected to a piping 28 of the second section 20 of the fuel supply system 12 via a nozzle 34.

(16) Note that the invention is not limited to a plurality of piping 28, nozzle 34 and combustion chambers 32 and could relate to a single conduit connected to a single combustion chamber by a single injector.

(17) The second piping section 20 is arranged upstream of the nozzle 34. Thus, when the fuel supply system 12 is in operation, the water-soluble product is injected through the inlet 24 into the first section 18, the mixture is then transferred by the pressure generated by the pump 22 to the mixing and distribution device 26. The mixing and distribution device 26 ensures the formation of a stable emulsion and a distribution of the flow to the various nozzle 34 via the several piping 28. Besides, the regime upstream of said mixing and distribution device 26 is configured to promote an emulsion and ensure a variability of the concentration in flow rate to at least one duct 28.

(18) The variability of the concentration of the water-soluble product in the hydrocarbon emulsion is maximum +/−30% between the different emulsion flow rates of the piping 28, since the first section 18 is configured to ensure a transient or turbulent regime at the inlet of the mixing and distribution device 26.

(19) The mixing and distribution device 26 is, for example, a flow divider including at least one distribution chamber (not shown) including an internal flow distribution gears. Such a mixing and distribution device ensures a homogeneous distribution of flow rate to each nozzle in the combustion system, and thus obtain and control several emulsion flow rates without increasing the complexity of the fuel supply system to the combustion chambers without adding a dedicated device to generate an emulsion.

(20) The liquid hydrocarbon and the water-soluble product are mechanically mixed while being transported by the rotating gears to produce the blended fuel.

(21) The fuel supply system of FIG. 2, in which we use the same references for the elements, but differs from the supply system of FIG. 1 only in that the first piping section 18 includes a second mixing device 36 located downstream of the injection point 24 of the water-soluble product, between said injection point 24 and the second section 20, in particular the first mixing and distribution device 26. The second mixing device 36 contributes to the formation of a pre-emulsion and makes it possible to control the regime of flow at the inlet of the first mixing and distribution device 26.

(22) The second mixing device 36 could be, for example, a gear pump or a static mixer. Thus, it is possible to provide a regime with a Reynolds value (Re) greater than 2000 without adapting the diameter of the first piping section 18 downstream of the pressurizing means 22. Thus, the second mixing device 36 makes it possible to ensure first mixture of the hydrocarbon and the water-soluble product and creating a regime of Reynolds Re greater than 2000 upstream of the first mixing and distribution device 26. Thus, the variability of the concentration of the water-soluble product in the emulsion of the hydrocarbon is maximum +/−30% between the different emulsion flow rates of the piping 28 because the first section 18 is configured to ensure a transient or turbulent regime at the inlet of the first mixing and distribution device 26.

(23) In general, the first piping section 18 is configured to obtain an inlet flow rate of the mixing and flow distribution device 26 having a Reynolds number greater than or equal to 2000, preferably between 2000 and 3000 transient), and for example greater than 3000 (turbulent regime), either by varying the diameter of the pipe section, especially between the injection point 24 and the first mixing device 26, or by integrating a second mixing device 36 between said injection point 24 and said first mixing device 26.

(24) Thus, thanks to the arrangement of the mixing and distribution device 26 downstream of a piping section configured to have regime flow at the inlet of the mixing and flow distribution device 26 having a Reynolds number greater than or equal to 2000, an on-line emulsion of immiscible liquids is obtained which ensures a homogeneous distribution of the flow rate of the emulsion in each of the combustion chambers and is capable of maintaining a satisfactory concentration of the water-soluble product in the hydrocarbon emulsion in each of the piping respectively connecting nozzles in combustion chambers.

(25) This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.