A monitoring system for the temperature field after a low-pressure turbine of a gas turbine

Abstract

The present application discloses a monitoring system for the temperature field after the low-pressure turbine of a gas turbine, which relates to the field of gas turbines. In this system, each thermocouple is respectively arranged at a flame tube of the combustion chamber of the gas turbine, and all thermocouples are connected to a thermocouple junction box. Each thermocouple respectively collects the single-point gas temperature at each flame tube and transmits it to the thermocouple junction box. When the temperature control device detects that the average gas temperature of all single-point gas temperatures is in an over-temperature abnormal state, it executes over-temperature shutdown protection to avoid significant damage to the hot components of the gas turbine caused by gas over-temperature and improve safety; when the temperature field monitoring component detects that the uniformity of the gas temperature field is in an abnormal state based on all single-point gas temperatures, it outputs an alarm signal to prompt the inspection and adjustment of the uniformity of the gas temperature field in a timely manner, avoiding the turbine blades from being subjected to high thermal stress, which is of great significance to the stable operation of the gas turbine.

Description

Technical Field

[0001] This application relates to the field of gas turbines, and in particular to a temperature field monitoring system for the low-pressure turbine of a gas turbine. Background Art

[0002] As a high-speed rotating power device, gas turbines are widely used in fields such as ship power and ship power generation. Gas turbines use the high-temperature gas generated by fuel combustion in the combustion chamber to enter the gas turbine to drive the impeller to rotate and do work. If the combustion temperature field of the provided high-temperature gas is improper, it is easy to damage the hot components and turbine blades of the gas turbine, affecting the stable operation of the gas turbine. Summary of the Invention

[0003] In view of the above problems and technical requirements, the applicant has proposed a temperature field monitoring system for the low-pressure turbine of a gas turbine. The technical solution of this application is as follows:

[0004] A temperature field monitoring system for the low-pressure turbine of a gas turbine, the system includes a number of thermocouples, a thermocouple junction box, a temperature control device, and a temperature field monitoring component;

[0005] Each thermocouple is respectively arranged at a flame tube of the combustion chamber of the gas turbine, all thermocouples are connected to the thermocouple junction box, and the thermocouple junction box is respectively connected to the temperature control device and the temperature field monitoring component;

[0006] Each thermocouple respectively collects the single-point gas temperature at each flame tube and transmits it to the thermocouple junction box. The thermocouple junction box calculates the average value of all single-point gas temperatures to obtain the average gas temperature and provides it to the temperature control device. When the temperature control device detects that the average gas temperature is in an over-temperature abnormal state, it performs over-temperature shutdown protection;

[0007] The thermocouple junction box also transmits the single-point gas temperatures collected by all thermocouples to the temperature field monitoring component. When the temperature field monitoring component detects that the uniformity of the gas temperature field is in an abnormal state based on all single-point gas temperatures, it outputs an alarm signal.

[0008] A further technical solution is that the temperature control device includes a temperature control component and a temperature regulator. The temperature control component performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state, and the temperature regulator performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state. The temperature control component and the temperature regulator independently detect to achieve dual-redundancy temperature control.

[0009] A further technical solution is that when the temperature field monitoring component detects that the average gas temperature is in an over-temperature abnormal state based on all single-point gas temperatures, it performs over-temperature shutdown protection. The temperature control component, the temperature regulator, and the temperature field monitoring component independently detect to achieve triple-redundancy temperature control.

[0010] A further technical solution thereof is that the method for the temperature field monitoring component to output an alarm signal includes:

[0011] When it is detected that there is at least one abnormal single-point temperature, it is determined that the uniformity of the gas temperature field is in an abnormal state, and an alarm signal indicating the abnormal single-point temperature is output; wherein, the abnormal single-point temperature is the single-point gas temperature whose temperature difference from the average gas temperature reaches the temperature deviation threshold under the corresponding working condition.

[0012] A further technical solution thereof is that before the temperature field monitoring component outputs an alarm signal indicating the abnormal single-point temperature, the method executed by the system further includes:

[0013] The input end of the thermocouple junction box obtains the standard temperature signal of the thermocouple corresponding to the abnormal single-point temperature to replace the abnormal single-point temperature;

[0014] If at this time the average gas temperature is still in the over-temperature abnormal state and / or the uniformity of the gas temperature field is still in the abnormal state, a first troubleshooting indication signal is output, and the first troubleshooting indication signal is used to indicate troubleshooting the working status of the temperature control device, the temperature field monitoring component and the connection line;

[0015] If at this time the average gas temperature is in the normal state and the uniformity of the gas temperature field is also in the normal state, a second troubleshooting indication signal is output, and the second troubleshooting indication signal is used to indicate troubleshooting the working status of the thermocouple corresponding to the abnormal single-point temperature;

[0016] When the temperature field monitoring component receives a normal feedback signal in response to the first troubleshooting indication signal or the second troubleshooting indication signal, an alarm signal indicating the abnormal single-point temperature is output, and the normal feedback signal is used to indicate that the working status of the temperature control device, the temperature field monitoring component and the connection line is normal, or is used to indicate that the working status of the thermocouple corresponding to the abnormal single-point temperature is normal.

[0017] A further technical solution thereof is that the temperature field monitoring component outputs an alarm signal including:

[0018] Under the no-load working condition, if and , the temperature field monitoring component outputs a lower deviation alarm signal, and the lower deviation alarm signal is used to indicate that the nozzle performance at the flame tube corresponding to the abnormal single-point temperature is abnormal, resulting in the abnormal single-point temperature being abnormally low; corresponding to the abnormal single-point temperature, the nozzle performance at the flame tube is abnormal, resulting in the abnormal single-point temperature being abnormally low;

[0019] Under the rated working condition, if and , the temperature field monitoring component outputs a lower deviation alarm signal; if and When the temperature field monitoring component outputs an upper deviation alarm signal, the upper deviation alarm signal is used to indicate an abnormal single-point temperature The abnormal performance of the nozzle at the corresponding combustion chamber liner causes the abnormal single-point temperature to be abnormally high;

[0020] Among them, is the single-point gas temperature and the average gas temperature is the absolute value of the temperature difference between them, is the upper temperature deviation threshold, is the lower temperature deviation threshold, is the temperature fault deviation threshold.

[0021] Its further technical solution is that if , the temperature field monitoring component outputs a fault deviation signal, and the fault deviation signal is used to indicate the abnormal single-point temperature corresponding to the nozzle fault at the combustion chamber liner.

[0022] Its further technical solution is that the temperature control component is also used to perform flameout shutdown protection when it detects that the average gas temperature is in a low-temperature abnormal state.

[0023] Its further technical solution is that the temperature field monitoring component is also used to display the single-point gas temperature at each combustion chamber liner in real time.

[0024] Its further technical solution is that when the temperature control device detects that the average gas temperature during the startup process and the operating condition process exceeds the corresponding temperature threshold, it determines that the average gas temperature is in an over-temperature abnormal state and performs over-temperature shutdown protection.

[0025] The beneficial technical effects of this application are:

[0026] This application discloses a temperature field monitoring system for the low-pressure turbine rear of a gas turbine. When the gas temperature after the low-pressure turbine is in an over-temperature abnormal state, the shutdown protection function can be quickly realized, avoiding significant damage to the hot components of the gas turbine caused by gas over-temperature, improving safety, and when the uniformity of the gas temperature field is in an abnormal state, an alarm signal can be sent in time to prompt the maintenance personnel to check and adjust the uniformity of the gas temperature field in time, avoiding high thermal stress on the turbine blades, which is of great significance to the stable operation of the gas turbine.

[0027] This system can realize a triple-redundancy fast shutdown protection function by using a temperature control component, a temperature regulator and a temperature field monitoring component, and has relatively high reliability. Brief Description of the Drawings

[0028] Figure 1 is the system structure diagram of the temperature field monitoring system for the low-pressure turbine rear of a gas turbine in an embodiment of this application and the function schematic diagram realized by each component. Detailed implementation manners

[0029] The following further describes the detailed implementation manners of the present application with reference to the accompanying drawings.

[0030] The present application discloses a monitoring system for the temperature field after the low-pressure turbine of a gas turbine. Please refer to Figure 1 , the system includes a plurality of thermocouples 1, a thermocouple junction box 2, a temperature control device, and a temperature field monitoring component 3. Each thermocouple 1 is respectively arranged at a flame tube 4 of the combustion chamber of the gas turbine. For example, Figure 1 taking the case where there are 16 flame tubes and 16 thermocouples 1 are respectively arranged as an example.

[0031] All thermocouples 1 are connected to the thermocouple junction box 2. Figure 1 For simplicity, only the connection relationship between some of the thermocouples 1 and the thermocouple connection box 2 is shown. Each thermocouple 1 respectively collects the single-point gas temperature at each flame tube 4 and transmits it to the thermocouple junction box 2.

[0032] The thermocouple junction box 2 is respectively connected to the temperature control device and the temperature field monitoring component. The thermocouple junction box calculates the average value of all single-point gas temperatures to obtain the average gas temperature and provides it to the temperature control device. The temperature control device performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state. In one embodiment, when the temperature control device detects that the average gas temperature during the starting process and the working condition operation process both exceed the corresponding temperature thresholds, it determines that the average gas temperature is in an over-temperature abnormal state and performs over-temperature shutdown protection. For example, in one instance, when it is detected that the average gas temperature during the starting process exceeds 600 °C and the average gas temperature during the working condition operation process exceeds 820 °C, it is determined that the average gas temperature is in an over-temperature abnormal state and over-temperature shutdown protection is performed.

[0033] The temperature control device includes a temperature control component 5 and a temperature regulator 6. The temperature control component 5 performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state, and the temperature regulator 6 performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state. The methods for the temperature control component 5 and the temperature regulator 6 to detect whether the average gas temperature is in an over-temperature abnormal state are the same, that is, the detection method of the temperature control device described above. The temperature control component 5 and the temperature regulator 6 independently detect to achieve dual-redundancy temperature control.

[0034] In addition to performing over-temperature shutdown protection in the event of an over-temperature abnormal state, the temperature control component 5 is also used to perform flameout shutdown protection when it detects that the average gas temperature is in a low-temperature abnormal state. For example, in one instance, when it is detected that the average gas temperature is lower than 200 °C, it is determined that the flame is lost and flameout shutdown protection is performed.

[0035] The thermocouple junction box 2 also transmits the single-point gas temperatures collected by all the thermocouples 1 to the temperature field monitoring component 3, and the temperature field monitoring component 3 outputs an alarm signal when it detects that the uniformity of the gas temperature field is in an abnormal state based on all the single-point gas temperatures.

[0036] In addition to outputting an alarm signal, the temperature field monitoring component 3 performs over-temperature shutdown protection when it detects that the average gas temperature is in an over-temperature abnormal state based on all the single-point gas temperatures. The method by which the temperature field monitoring component 3 detects whether the average gas temperature is in an over-temperature abnormal state is the same as the detection methods of the above-mentioned temperature control component 5 and temperature regulator 6. The temperature control component 5, temperature regulator 6, and temperature field monitoring component 3 perform independent detections to achieve triple-redundancy temperature control. In addition, the temperature field monitoring component 3 also has a display function and is used to display the single-point gas temperatures at each flame tube in real time.

[0037] The method by which the temperature field monitoring component 3 outputs an alarm signal is as follows:

[0038] Determine the temperature difference between each single-point gas temperature and the average gas temperature of all the single-point gas temperatures The temperature difference between the single-point gas temperature collected by any thermocouple and the average gas temperature is . When , the temperature difference ; when , the temperature difference is . For example, in one instance, the single-point gas temperatures collected by each thermocouple and the corresponding calculated temperature differences are as follows in the table:

[0039]

[0040] Take the single-point gas temperatures whose temperature differences from the average gas temperature reach the temperature deviation threshold as abnormal single-point temperatures. When it is detected that there is at least one abnormal single-point temperature, it is determined that the uniformity of the gas temperature field is in an abnormal state, and an alarm signal indicating the abnormal single-point temperature is output. The temperature deviation threshold includes an upper temperature deviation threshold and a lower temperature deviation threshold . The upper temperature deviation threshold and the lower temperature deviation threshold can be equal or unequal. The introduction according to different working conditions is as follows:

[0041] (1) Under the no-load condition, if and , then the single-point gas temperature is an abnormal single-point temperature, and the temperature field monitoring component outputs a lower deviation alarm signal. The lower deviation alarm signal is used to indicate that the nozzle performance at the corresponding flame tube of the abnormal single-point temperature is abnormally low due to abnormal performance. Generally, there is no situation where the abnormal single-point temperature is abnormally high under the no-load condition. is the absolute value of the temperature difference between the single-point gas temperature and the average gas temperature , and is the temperature fault deviation threshold.

[0042] (2) Under the rated condition, generally at 60% - 100% of the rated condition, if and , it is determined that the single-point gas temperature is an abnormal single-point temperature, and the temperature field monitoring component outputs a lower deviation alarm signal. The lower deviation alarm signal is used to indicate that the nozzle performance at the corresponding flame tube of the abnormal single-point temperature is abnormally low due to abnormal performance. If and , it is determined that the single-point gas temperature is an abnormal single-point temperature, and the temperature field monitoring component outputs an upper deviation alarm signal. The upper deviation alarm signal is used to indicate that the nozzle performance at the corresponding flame tube of the abnormal single-point temperature is abnormally high due to abnormal performance.

[0043] (3) Whether under the no-load condition or the rated condition, if , it is determined that the single-point gas temperature is an abnormal single-point temperature, and the temperature field monitoring component outputs a fault deviation signal. The fault deviation signal is used to indicate a nozzle fault at the corresponding flame tube of the abnormal single-point temperature .

[0044] Summarize the above three situations as follows. The alarm signal output by the temperature field monitoring component 3 is an upper deviation alarm signal, a lower deviation alarm signal, or a fault deviation signal, which are respectively as follows:

[0045]

[0046] For example, in an instance, assume , , , then the upper deviation alarm signal indicating the abnormality of the single-point gas temperature collected by the thermocouple 2 can be output according to the above method.

[0047] In one embodiment, when the temperature difference between the single-point gas temperature and the average gas temperature detected by the temperature field monitoring component 3 reaches the temperature deviation threshold, an alarm signal indicating the abnormal single-point temperature is not directly output. The system also executes the following method to detect the working state of the system:

[0048] (1) Obtain the standard temperature signal of the thermocouple corresponding to the abnormal single-point temperature at the input end of the thermocouple junction box to replace the abnormal single-point temperature.

[0049] (2) If the average gas temperature is still in the over-temperature abnormal state and / or the uniformity of the gas temperature field is still in the abnormal state at this time, output a first troubleshooting instruction signal, which is used to indicate troubleshooting the working states of the temperature control device, the temperature field monitoring component, and the connection lines. The maintenance personnel can troubleshoot the working states of the temperature control device, the temperature field monitoring component, and the connection lines according to the first troubleshooting instruction signal. If there is a fault, it can be repaired. If there is no fault, a status normal feedback signal indicating that the working states of the temperature control device, the temperature field monitoring component, and the connection lines are normal is provided to the temperature field monitoring component.

[0050] (3) If the average gas temperature is in the normal state and the uniformity of the gas temperature field is also in the normal state at this time, output a second troubleshooting instruction signal, which is used to indicate troubleshooting the working state of the thermocouple corresponding to the abnormal single-point temperature. The maintenance personnel can troubleshoot the working state of the thermocouple corresponding to the abnormal single-point temperature according to the second troubleshooting instruction signal. If the thermocouple has a fault, it can be replaced or repaired. If the thermocouple has no fault, a status normal feedback signal indicating that the working state of the thermocouple corresponding to the abnormal single-point temperature is normal is provided to the temperature field monitoring component.

[0051] (4) When the temperature field monitoring component receives the status normal feedback signal in response to the first troubleshooting instruction signal or the second troubleshooting instruction signal, it is determined that there is no fault in the working state of the system. It is indeed because of the performance change or fault of the nozzle at the flame tube corresponding to the abnormal single-point temperature that the uniformity of the gas temperature field is in the abnormal state. Then, an alarm signal indicating the abnormal single-point temperature is output according to the above method.

[0052] After the temperature field monitoring component outputs an alarm signal, maintenance personnel can repair or replace the nozzle at the flame tube corresponding to the abnormal single-point temperature according to the alarm signal. If the temperature field monitoring component outputs a fault deviation signal, it means that the nozzle is faulty and a new injector needs to be replaced. If the temperature field monitoring component outputs an upper deviation alarm signal or a lower deviation alarm signal, it means that the nozzle is not faulty but the performance has changed, such as performance changes caused by changes in fuel distribution due to carbon deposits and other reasons. At this time, a new injector can be replaced, or the nozzle at the flame tube corresponding to the abnormal single-point temperature can be exchanged with other nozzles: the nozzle at the flame tube corresponding to the abnormally high abnormal single-point temperature is exchanged with the corresponding nozzle with a lower single-point gas temperature and a small factory flow rate; the nozzle at the flame tube corresponding to the abnormally low abnormal single-point temperature is exchanged with the corresponding nozzle with a higher single-point gas temperature and a large factory flow rate.

[0053] For example, in the above example, the single-point gas temperature collected by thermocouple 2 is abnormally high, and the temperature field monitoring component outputs an upper deviation alarm signal. The maintenance personnel can determine that the single-point gas temperature collected by thermocouple 9 is lower (698°C), and the factory fuel flow rate of the nozzle of the flame tube where thermocouple 9 is located is relatively small compared to other nozzles. In this case, the nozzle of the flame tube where thermocouple 2 is located can be exchanged with the nozzle of the flame tube where thermocouple 9 is located. After the exchange, the single-point gas temperature collected by each thermocouple and the corresponding calculated temperature difference are shown in the following table, which shows that the uniformity of the gas temperature field has returned to normal.

[0054]

[0055] The above is only a preferred embodiment of the present application, and the present application is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present application should be considered to be included in the protection scope of the present application.

Claims

1. A monitoring system for the temperature field after the low-pressure turbine of a gas turbine, characterized in that, The system includes a number of thermocouples, a thermocouple junction box, a temperature control device, and a temperature field monitoring component; Each thermocouple is respectively arranged at a flame tube of the combustion chamber of the gas turbine, and all thermocouples are connected to the thermocouple junction box, and the thermocouple junction box is respectively connected to the temperature control device and the temperature field monitoring component; Each thermocouple respectively collects the single-point gas temperature at each flame tube and transmits it to the thermocouple junction box. The thermocouple junction box calculates the average value of all single-point gas temperatures to obtain the average gas temperature and provides it to the temperature control device. The temperature control device performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state; The thermocouple junction box also transmits the single-point gas temperatures collected by all thermocouples to the temperature field monitoring component. The temperature field monitoring component outputs an alarm signal when detecting that the uniformity of the gas temperature field is in an abnormal state based on all single-point gas temperatures, including: determining that the uniformity of the gas temperature field is in an abnormal state when detecting at least one abnormal single-point temperature, and outputting an alarm signal indicating the abnormal single-point temperature. The abnormal single-point temperature is the single-point gas temperature whose temperature difference from the average gas temperature reaches the temperature deviation threshold under the corresponding working condition; Under the no-load condition, if and , the temperature field monitoring component outputs a lower deviation alarm signal, and the lower deviation alarm signal is used to indicate that the nozzle performance at the corresponding flame tube of the abnormal single-point temperature is abnormally low due to abnormal nozzle performance; under the rated condition, if and , the temperature field monitoring component outputs a lower deviation alarm signal; if and , the temperature field monitoring component outputs an upper deviation alarm signal, and the upper deviation alarm signal is used to indicate that the nozzle performance at the corresponding flame tube of the abnormal single-point temperature is abnormally high due to abnormal nozzle performance; wherein, is the absolute value of the temperature difference between the single-point gas temperature and the average gas temperature , is the temperature upper deviation threshold, is the temperature lower deviation threshold, is the temperature fault deviation threshold.

2. The system according to claim 1, characterized in that, The temperature control device includes a temperature control component and a temperature regulator. The temperature control component performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state. The temperature regulator performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state. The temperature control component and the temperature regulator independently detect to achieve dual-redundancy temperature control.

3. The system according to claim 2, wherein The temperature field monitoring component performs over-temperature shutdown protection when detecting that the average gas temperature is in an over-temperature abnormal state based on all single-point gas temperatures. The temperature control component, the temperature regulator, and the temperature field monitoring component independently detect to achieve triple-redundancy temperature control.

4. The system according to claim 1, wherein Before the temperature field monitoring component outputs an alarm signal indicating the abnormal single-point temperature, the method executed by the system further includes: The input end of the thermocouple junction box obtains the standard temperature signal of the thermocouple corresponding to the abnormal single-point temperature and replaces the abnormal single-point temperature; If the average gas temperature is still in an over-temperature abnormal state and / or the uniformity of the gas temperature field is still in an abnormal state at this time, a first troubleshooting indication signal is output. The first troubleshooting indication signal is used to indicate troubleshooting the working states of the temperature control device, the temperature field monitoring component, and the connection lines; If the average gas temperature is in a normal state and the uniformity of the gas temperature field is also in a normal state at this time, a second troubleshooting indication signal is output. The second troubleshooting indication signal is used to indicate troubleshooting the working state of the thermocouple corresponding to the abnormal single-point temperature; When the temperature field monitoring component receives a status normal feedback signal in response to the first troubleshooting indication signal or the second troubleshooting indication signal, it outputs an alarm signal indicating the abnormal single-point temperature. The status normal feedback signal is used to indicate that the temperature control device, the temperature field monitoring component, and the connection lines are operating normally, or to indicate that the thermocouple corresponding to the abnormal single-point temperature is operating normally.

5. The system according to claim 1, wherein If the temperature field monitoring component outputs a faulty deviation signal, and the faulty deviation signal is used to indicate an abnormal single-point temperature corresponding to the nozzle failure at the flame tube.

6. The system according to claim 2, wherein the temperature control component is further configured to perform flameout and shutdown protection when it detects that the average gas temperature is in a low-temperature abnormal state.

7. The system according to claim 1, wherein The temperature field monitoring component is further configured to display the single-point gas temperature at each flame tube in real time.

8. The system according to claim 1, wherein When the temperature control device detects that the average gas temperature during the startup process and the operating condition process exceeds the corresponding temperature threshold, it determines that the average gas temperature is in an over-temperature abnormal state and performs over-temperature shutdown protection.

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