TECHNICAL FIELD

The present disclosure relates to a combustion device and a gas turbine.

BACKGROUND

Patent Document 1 discloses a combustion device and a gas turbine which burn ammonia as a fuel. The combustion device and the gas turbine obtain a combustion exhaust gas used to drive a turbine by premixing ammonia (fuel ammonia) with natural gas and supplying it to a combustor. In order to reduce nitrogen oxides (NOx), a reduction region in which the nitrogen oxides (NOx) generated in a combustion region are reduced using reducing ammonia is formed on a downstream side of the combustor.

A deflection member, which is called a transition piece (or a scroll), is provided downstream from the combustor so as to connect the combustor with an inlet of the turbine, and deflects a flow direction of combustion gas. This deflection member includes an inlet portion which corresponds to a cross-sectional shape of the combustor, an outlet portion which corresponds to a shape of a part of the inlet of the turbine, and a bending portion in which a cross-sectional shape of the deflection member gradually deforms from the inlet portion toward the outlet portion.

DOCUMENT OF RELATED ART

Patent Document

[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2016-191507

SUMMARY

When the combustion gas flows in the deflection member, heat exchange between the deflection member and the combustion gas is promoted, for example, by a collision of the combustion gas with the bending portion of the deflection member or by a high-speed flow of the combustion gas near the outlet portion of the deflection member. At this time, in the deflection member, a high temperature portion which has a high temperature due to the flow or collision of the combustion gas and a low temperature portion which has a relatively low temperature are likely to be formed, and due to the temperature difference, damage such as thermal deformation or cracking may occur.

The present disclosure has been made in view of the above-described problems, and an object thereof is to minimize damage such as thermal deformation or cracking in a deflection member provided between a combustion chamber and an inlet of a turbine caused by a temperature difference.

A combustion device according to an aspect of the present disclosure is a combustion device which burns fuel ammonia with combustion air in a combustion chamber, and includes: a combustor liner which forms the combustion chamber; a burner which is installed at one end of the combustor liner; a deflection member which is provided on a downstream side of the combustor liner in a flow direction of a combustion gas, and is configured to deflect the flow direction of the combustion gas; and at least one ammonia injection hole which is provided between the burner and an outlet of the deflection member and is configured to supply the fuel ammonia into the combustion chamber.

In the combustion device according to the aspect, the at least one ammonia injection hole may be provided in a side wall of the combustor liner.

In the combustion device according to the aspect, the at least one ammonia injection hole may include a plurality of ammonia injection holes, and the plurality of ammonia injection holes may be provided in the side wall of the combustor liner to be asymmetric around a central axis of the combustion chamber.

In the combustion device according to the aspect, a high temperature portion in which a temperature is higher than an average temperature in the deflection member may be identified in advance, and the at least one ammonia injection hole may be disposed such that the temperature of the high temperature portion is lowered by the fuel ammonia supplied from the at least one ammonia injection hole.

In the combustion device according to the aspect, a high temperature portion in which a temperature is higher than an average temperature in the deflection member may be identified in advance, and a supply amount of the fuel ammonia supplied from the at least one ammonia injection hole may be adjusted such that the temperature of the high temperature portion is lowered by the fuel ammonia supplied from the at least one ammonia injection hole.

A gas turbine according to an aspect of the present disclosure includes the combustion device.

According to the present disclosure, fuel ammonia is supplied into a combustor liner from an ammonia injection hole, a combustion field in which the fuel ammonia is burned is formed, and burned ammonia gas having a relatively low temperature is generated. The burned ammonia gas collides with or flows to a portion which is likely to have a high temperature in the deflection member, and it is possible to minimize damage such as thermal deformation or cracking in the deflection member due to a temperature difference.

