MICRO GAS TURBINE HAVING IGNITOR-COUPLING STRUCTURER AND METHOD OF ASSEMBLING THE SAME

Disclosed are a micro gas turbine and a method of assembling the same. The micro gas turbine includes an ignitor assembly having an ignitor, along with an ignitor-coupling structure. The ignitor-coupling structure includes a mounting bracket having first and second ends, the first end being coupled to the ignitor and the second end being provided on its outer circumference with an external screw. A coupling member is mounted to a liner casing surrounding a combustor and has, on its inner circumference, an internal screw corresponding to the external screw. A bellows surrounds the mounting bracket.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. In the following description, it is to be noted that, when the functions of conventional elements and the detailed description of elements related with the present invention may make the gist of the present invention unclear, a detailed description of those elements will be omitted. However, it should be understood that the embodiment of the present invention may be changed to a variety of embodiments by those skilled in the art and the scope and spirit of the present invention are not limited to the embodiment described hereinbelow.

FIG. 2is a cross-sectional view showing the portion around a combustor of a micro gas turbine having an ignitor-coupling structure according to a preferred embodiment of the present invention.

Referring toFIG. 2, the micro gas turbine having the ignitor-coupling structure includes a housing105, a combustor110, an ignitor assembly120, a coupling member124, a burner assembly130, a bellows140, and a liner casing150.

The housing105covers the liner casing150in such a manner that the ignitor assembly120and the burner assembly130both are partially exposed to the outside.

The ignitor assembly120includes an ignitor121and a mounting bracket122.

The ignitor121is mounted such that one end thereof is inserted into the combustor110and another end thereof is exposed to the outside of the housing105.

The mounting bracket122is configured to hold the ignitor121at a first end thereof and to engage the coupling member124at a second end thereof. Here, the second end of the mounting bracket122is provided on its outer circumference with an external screw126.

Further, the second end of the mounting bracket122is provided with an outer circumferential groove128(particularly between a welded portion with the bellows and the external screw126. The groove128defines a space between the mounting bracket122and the coupling member124. The space serves to facilitate the coupling between an upper surface of a second part124bof the coupling member124and the welded portion between the mounting bracket and the bellows and therefore secure a more effective airtight sealing therebetween.

The coupling member124is mounted to the liner casing150. The coupling member124is provided on its inner circumference with an internal screw that corresponds to the external screw126of the mounting bracket122.

Specifically, the coupling member124includes a first part124awhich is inserted into the liner casing150, and a second part124bwhich is bent from the first part124aso that it seats over the liner casing150.

The bellows140surrounds the mounting bracket122of the ignitor assembly such that it is integrally formed with the mounting bracket122by means of e.g. welding.

Next, a method of assembling the micro gas turbine according to the present invention will be described.

First, the housing105is mounted over the liner casing150(first step).

Next, the coupling member124having the internal screw is mounted to the liner casing150surrounding the combustor (second step). Here, the coupling member may be mounted by means of e.g. welding.

Next, the bellows140is integrally welded onto the ignitor assembly120(third step) in which the ignitor121is mounted to the mounting bracket122having the external screw126that corresponds to the internal screw of the coupling member124. The third step in which the external screw126is formed on the outer circumference of the mounting bracket22, and the ignitor assembly120and the bellows140are welded together may also be performed before performing the first or second step.

Next, the sub-assembly body of the ignitor assembly120and the bellows140is inserted into the housing105, and then the ignitor assembly120is rotated to inter-engage the external screw126of the mounting bracket122and the internal screw of the coupling member124(fourth step).

Finally, a contact between the bellows140and the housing105is welded (fifth step).

When assembled as such using the ignitor-coupling structure, unlike the existing structure in which the lower portion of the mounting bracket of the ignitor assembly comes into simple physical contact with the liner casing, the mounting bracket and the liner casing can together form the airtight sealing therebetween by inter-screw engagement between the mounting bracket and the coupling member. Thereby, the fuel-air mixture is prevented from leaking, avoiding reduction in the operation efficiency of the micro gas turbine.

That is to say, the mounting bracket is screw-coupled with the coupling member at the lower end, and the bellows and the mounting bracket are coupled by means of welding, so that airtight sealing can be maintained as a whole.

Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. Therefore, it should be understood that the disclosed embodiments and figures are merely illustrative forms in all aspects, rather than limited ones, so that the technical scope of the present invention is not limited to the embodiments and figures disclosed. Accordingly, the scope of the present invention should be construed as being defined by following claims and as covering all equivalents of claims.