CN116164839A - Method for on-site verification of ultraviolet flame detector of combustion chamber of gas turbine - Google Patents

Abstract

The invention aims to provide a field verification method for an ultraviolet flame detector of a combustion chamber of a gas turbine, wherein an ultraviolet light source releases ultraviolet light on a detection field, an ultraviolet flame detector to be installed detects an optical signal and converts the optical signal into an electric signal, a gas turbine acquisition system acquires the electric signal output of the ultraviolet flame detector to be installed, the electric signal output is compared with an analog output value obtained through an ultraviolet flame detector sample, if the deviation is in an allowable range, the ultraviolet flame detector to be installed is installed and used, and if the deviation is beyond the allowable range, the ultraviolet flame detector to be installed is not used. The invention is mainly applied to the field verification of the ultraviolet flame detector of the combustion chamber of the gas turbine, and is also applicable to the field verification of other types of flame detectors of the combustion chamber of the gas turbine.

Description

Method for on-site verification of ultraviolet flame detector of combustion chamber of gas turbine

Technical Field

The invention relates to an on-site verification method for an invisible photoelectric sensor, in particular to an on-site verification method for an ultraviolet flame detector.

Background

During the development or operation phase of the gas turbine, the flame detector is used for igniting and starting the combustion chamber, and monitoring the combustion condition in the combustion chamber. When the igniter receives the ignition signal, the igniter starts to ignite, after a certain time delay, the fuel supply system starts to supply fuel to the combustion chamber, the fuel is ignited by the igniter after being sprayed out, and the formed torch enters the combustion chamber of the gas turbine to ignite the fuel sprayed out by the main nozzle. When ignition or flame linkage is unsuccessful in the combustion chamber, the control console converts invisible light (flame irradiates ultraviolet light with a certain wavelength) detected by the ultraviolet flame detection equipment into an electric signal to send out an alarm signal, and if necessary, the control console is stopped in an emergency.

So far, a standard verification method and a verification mechanism for a flame detector of a combustion chamber of a gas turbine are not available, and the method for evaluating the flame detector is often that whether the detector can normally monitor the flame of the combustion chamber after the gas turbine is operated, so that misjudgment is not allowed, and the method cannot reliably judge the state of the flame detector of the combustion chamber before the gas turbine is operated.

Disclosure of Invention

The invention aims to provide a practical, quick and reliable on-site verification method for an ultraviolet flame detector of a combustion chamber of a gas turbine.

The purpose of the invention is realized in the following way:

the invention relates to a gas turbine combustion chamber ultraviolet flame detector on-site verification method, which is characterized by comprising the following steps: the ultraviolet light source releases ultraviolet light, the ultraviolet flame monitor sample receives the optical signal and converts the optical signal into an electric signal, the gas turbine acquisition system acquires the output, and the analog output value is recorded;

in the detection site, the ultraviolet light source releases ultraviolet light, the ultraviolet flame monitor to be installed detects an optical signal and converts the optical signal into an electrical signal, the gas turbine acquisition system acquires the electrical signal output of the ultraviolet flame monitor to be installed, compares the electrical signal output with an analog output value obtained through an ultraviolet flame monitor sample, installs the ultraviolet flame monitor to be installed if the deviation is in an allowable range, and does not use the ultraviolet flame monitor to be installed if the deviation exceeds the allowable range.

The invention may further include:

1. the ultraviolet light sources comprise at least 3.

The invention has the advantages that: the invention is mainly applied to the field verification of the ultraviolet flame detector of the combustion chamber of the gas turbine, and is also applicable to the field verification of other types of flame detectors of the combustion chamber of the gas turbine.

Drawings

FIG. 1 is a schematic diagram of a gas turbine combustor flame detector analog signal determination;

FIG. 2 is a schematic diagram of determining a light source based on analog output;

FIG. 3 is a schematic diagram of the field test of the present invention.

Detailed Description

The invention is described in more detail below, by way of example, with reference to the accompanying drawings:

in practical operation, referring to fig. 1-3, the supplier does not provide the necessary performance parameters of the flame detector, and the analog signal light source for verification needs to be determined according to the analog output value of the sample of the flame detector of the combustion chamber and the wavelength range of the light wave detectable by the flame detector. The light source should have basic requirements of stable radiation energy and portability. In the field of the gas turbine unit, the flame detector to be installed is subjected to field verification by means of the analog light source signals through the analog output quantity acquired by the combustion chamber flame detector signal acquisition system.

In fig. 1, mainly analog signals are set: an ultraviolet light source 1 (at least 3), an ultraviolet flame detector sample piece(s) 2, a gas turbine acquisition system 3, an analog output 4.

In fig. 2, the light source intensity is determined according to the collected analog output quantity, and the light source is based on the principle that the reproducibility of the analog output value is good, so that a parallel light source with small light source beam divergence is preferably selected according to practical use conditions.

When the analog output value is larger than the set value (4,5,20 milliamp), the ultraviolet light source 1 is replaced until the selected analog light source signal is: and the corresponding analog output value of the ultraviolet light source 1 is consistent with a set value, so that the determination of the analog signal-ultraviolet light source is completed.

With reference to fig. 2, the analog output, 5ma,20ma, corresponds to the light source intensity, which is sent to the certification authority to determine the intensity and wavelength of the analog light source signal.

The light source is used for a long time, and the influence of the light source intensity stability on the detection result must be considered (according to the requirement of the national standard GB 12791-2006 point type ultraviolet flame detector, the light source intensity change requirement should not exceed +/-5%). In order to ensure the stability, annual (or half year) inspection is performed to judge whether the intensity stability of the light source meets the requirements of national standards.

In fig. 3, mainly analog signals are set: an ultraviolet light source 1 (at least 3), an ultraviolet flame detector(s) 5 to be installed, a gas turbine acquisition system 3, an analog output 4.

At the detection site, by determining the analog light source signal: the ultraviolet light source 1 releases ultraviolet light of a certain wavelength and energy, which signal is detected by the flame detector 5. The flame detector 5 converts the optical signal into an electric signal of 4-20 mA by performing signal conversion by a self circuit. The gas turbine acquisition system 3 acquires the analog output 4. And comparing the analog output value 4 acquired by the acquisition system with the output current value corresponding to the same analog signal 1 of the sample in the figure 1, and analyzing the detection result. For the same light source, the analog output value, especially 5mA, is required to have good reproducibility, is consistent with the analog output corresponding to a flame detector sample (the deviation allowance range is required to be +/-0.25 mA by referring to a mechanical industry department related standard JB/T12389-2015 integrated flame detector), can judge that the state of the flame detector to be installed is normal, and can be installed and used; in the on-site verification, when the analog quantity acquisition value is inconsistent with the analog quantity output value corresponding to the flame detector sample (the deviation exceeds the allowable range), the abnormal state of the flame detector to be installed is judged. The flame detector is not allowed to be used after the influence factors such as the change of the analog signal intensity or the stain on the window of the flame detector are eliminated.

Claims (2)

1. A gas turbine combustion chamber ultraviolet flame detector on-site verification method is characterized in that: the ultraviolet light source releases ultraviolet light, the ultraviolet flame monitor sample receives the optical signal and converts the optical signal into an electric signal, the gas turbine acquisition system acquires the output, and the analog output value is recorded;

in the detection site, the ultraviolet light source releases ultraviolet light, the ultraviolet flame monitor to be installed detects an optical signal and converts the optical signal into an electrical signal, the gas turbine acquisition system acquires the electrical signal output of the ultraviolet flame monitor to be installed, compares the electrical signal output with an analog output value obtained through an ultraviolet flame monitor sample, installs the ultraviolet flame monitor to be installed if the deviation is in an allowable range, and does not use the ultraviolet flame monitor to be installed if the deviation exceeds the allowable range.

2. The method for in-situ verification of a gas turbine combustor ultraviolet flame detector of claim 1, wherein the method comprises the steps of: the ultraviolet light sources comprise at least 3.

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