US-12618560-B2 - Detection apparatus and combustion system

Abstract

A detection apparatus ( 10 ) for detecting a backfire in a combustion chamber ( 31 ) that burns fuel supplied from a plurality of supply ports includes a light source ( 12 ) that outputs incident light to an optical fiber ( 11 ) laid around the plurality of supply ports, a converter ( 13 ) that receives returned light from the optical fiber ( 11 ) and converts the received returned light into an electric signal, a calculator ( 14 ) that analyzes the returned light converted into an electric signal and calculates a temperature at a predetermined position of the optical fiber ( 11 ), and a detector ( 15 ) configured to detect a backfire in the combustion chamber ( 31 ) based on the calculated temperature.

Inventors

• Shinya MITO

Assignees

• YOKOGAWA ELECTRIC CORPORATION

Dates

Publication Date

20260505

Application Date

20240705

Priority Date

20230707

Claims (10)

1. 1 . A detection apparatus for detecting a backfire in a combustion chamber that burns fuel supplied from a plurality of supply ports, the detection apparatus comprising: an optical fiber laid around the plurality of supply ports; a light source configured by a laser which outputs incident light to the optical fiber; a converter configured by a photodiode which receives returned light from the optical fiber and converts the received returned light into an electric signal; and at least one physical processor, wherein the at least one physical processor analyzes the returned light converted into the electric signal and calculates a temperature at a predetermined position of the optical fiber; and the at least one physical processor detects a backfire in the combustion chamber based on the calculated temperature, wherein the optical fiber is disposed on a side of a supply surface plate for the fuel in the combustion chamber, the side of the supply surface plate facing a space where combustion occurs, the plurality of supply ports being provided on the supply surface plate, and the optical fiber being laid so as to surround some or all of the plurality of supply ports.
2. 2 . The detection apparatus according to claim 1 , wherein the at least one physical processor is configured to analyze the returned light and calculate a temperature at a predetermined plurality of positions of the optical fiber as the temperature at the predetermined position.
3. 3 . The detection apparatus according to claim 1 , wherein the at least one physical processor is configured to analyze the returned light continuously measured over a certain time range and identify a position at which a temperature rise of a certain degree or greater is observed in the optical fiber, and calculate the temperature at the identified position of the optical fiber as the temperature at the predetermined position.
4. 4 . The detection apparatus according to claim 1 , wherein the at least one physical processor is configured to identify a position in the optical fiber based on a difference between a timing at which the incident light is outputted from the light source and a timing at which the returned light based on the incident light is received, and calculate the temperature at the identified position.
5. 5 . The detection apparatus according to claim 1 , wherein the optical fiber is laid around the plurality of supply ports by an adhesive that is resistant to a temperature higher than a combustion temperature in the combustion chamber.
6. 6 . The detection apparatus according to claim 1 , wherein the optical fiber is laid around the plurality of supply ports through a guide formed by welding hollow metal.
7. 7 . The detection apparatus according to claim 1 , further comprising a signal output interface configured to output, in response to detection of a backfire in the combustion chamber, a signal indicating occurrence of the backfire to a control apparatus that controls supply of the fuel to the plurality of supply ports.
8. 8 . The detection apparatus according to claim 1 , further comprising a notification interface configured to notify a user of occurrence of a backfire in response to detection of a backfire in the combustion chamber.
9. 9 . A combustion system comprising: a combustion chamber configured to burn fuel supplied from a plurality of supply ports; and a detection apparatus configured to detect a backfire in the combustion chamber, wherein the detection apparatus comprises: an optical fiber laid around the plurality of supply ports; a light source configured by a laser which outputs incident light to the optical fiber; a converter configured by a photodiode which receives returned light from the optical fiber and converts the received returned light into an electric signal; and at least one physical processor, wherein the at least one physical processor analyzes the returned light converted into the electric signal and calculates a temperature at a predetermined position of the optical fiber; and the at least one physical processor detects a backfire in the combustion chamber based on the calculated temperature, wherein the optical fiber is disposed on a side of a supply surface plate for the fuel in the combustion chamber, the side of the supply surface plate facing a space where combustion occurs, the plurality of supply ports being provided on the supply surface plate, and the optical fiber being laid so as to surround some or all of the plurality of supply ports.
10. 10 . The combustion system according to claim 9 , wherein supply of the fuel to the supply ports is controlled in response to detection of a backfire by the detection apparatus.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority to Japanese Patent Application No. 2023-112557 filed on Jul. 7, 2023, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to a detection apparatus and a combustion system. BACKGROUND In gas turbines equipped with a combustion apparatus that uses lean premix combustion, a detection apparatus for detecting backfire that occurs in the combustion apparatus is known. Backfire is a phenomenon in which the speed at which the flame progresses is higher than the speed of the fluid, such as fuel and air, resulting in the flame moving back up through the fluid. Although backfire can occur in principle in a gas turbine fueled by natural gas, backfire can be suppressed easily by limiting the operating conditions. In recent years, the demand for hydrogen-fired gas turbines fueled by a mixture of natural gas and hydrogen gas, or by hydrogen gas alone, has increased with the aim of achieving a hydrogen-based society. Hydrogen gas has a higher combustion rate than natural gas. Therefore, hydrogen-fired gas turbines are more prone to backfires than gas turbines that consume natural gas as a fuel gas. As the concentration of hydrogen gas in the fuel gas is increased, the conditions under which backfires do not occur become narrower, making it difficult to completely suppress backfires during actual operation. To suppress backfires, a combustion apparatus with a large number of burners, called a cluster burner, inside the combustion apparatus has been studied. However, as the hydrogen gas concentration of the fuel increases, it becomes difficult to completely suppress the actual occurrence of backfires despite the use of a cluster burner. Patent Literature (PTL) 1 describes a combustor including a control apparatus and a plurality of temperature detectors that detect the temperature in a plurality of combustion zones. The plurality of temperature detectors includes at least one of a thermocouple and an optical pyrometer. The control apparatus is programmed to determine the occurrence of a backfire condition within the plurality of combustion zones based on signals from the temperature detectors and to modify the amount of fuel supplied to the premixing apparatus when the backfire condition occurs. CITATION LIST Patent Literature PTL 1: JP 2010-286232 A SUMMARY A detection apparatus according to several embodiments is a detection apparatus for detecting a backfire in a combustion chamber that burns fuel supplied from a plurality of supply ports, the detection apparatus including:a light source configured to output incident light to an optical fiber laid around the plurality of supply ports;a converter configured to receive returned light from the optical fiber and convert the received returned light into an electric signal;a calculator configured to analyze the returned light converted into an electric signal and calculate a temperature at a predetermined position of the optical fiber; anda detector configured to detect a backfire in the combustion chamber based on the calculated temperature. A combustion system according to several embodiments includes a combustion chamber configured to burn fuel supplied from a plurality of supply ports; anda detection apparatus configured to detect a backfire in the combustion chamber, whereinthe detection apparatus includes a light source configured to output incident light to an optical fiber laid around the plurality of supply ports;a converter configured to receive returned light from the optical fiber and convert the received returned light into an electric signal;a calculator configured to analyze the returned light converted into an electric signal and calculate a temperature at a predetermined position of the optical fiber; anda detector configured to detect a backfire in the combustion chamber based on the calculated temperature. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: FIG. 1 is a diagram illustrating an example configuration of a combustion system according to an embodiment; FIG. 2 is a diagram illustrating an example of a plate included in the cluster burner in FIG. 1; FIG. 3 is a cross-sectional diagram illustrating an example of the boundary between the cluster burner and the combustion chamber in FIG. 1; and FIG. 4 is a diagram illustrating an example of a plate provided with an optical fiber. DETAILED DESCRIPTION In a case in which a large number of fuel supply ports are present in a combustion apparatus, as in a cluster burner, it is necessary to detect the temperature of each supply port. However, since space is limited in the combustion apparatus, it is difficult to install temperature detectors in a conventional configuration. In addition, in a conventional configuration, the temperature detectors regularly require extensive maintenance, such as replacement, due to degradation in the detection accuracy