Thermal power generating unit starting method

Abstract

The invention relates to a thermal power generating unit starting method. The method comprises the following steps that 1, a unit trips; 2, a deaerator of a No.7 machine is put in for heating, and a vacuum pump and a condensate pump of the No.7 machine B are stopped; 3, water is fed into a # 7 boiler, a BCP of the # 7 boiler is started to be normal, a booster pump B of the # 7 boiler is started to run normally, a small machine B is started to run normally, MFT of the # 7 boiler is reset, a fuel oil leakage test is completed, boiler blowing is completed, an A4 oil gun and an A5 oil gun of the # 7A boiler are put in, the boiler is successfully ignited, and an air pre-heater is put in for continuous soot blowing; according to the method, the starting sequence is optimized through the algorithm, the total time (T) required from starting of the unit to full load reaching can be shortened, and therefore the efficiency of the starting process is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal power generation units, and in particular relates to a method for starting a thermal power generation unit. Background Art

[0002] When thermal power units need to be quickly started after tripping, the challenges they face mainly include unit tripping caused by misoperation or malfunction of the protection system. In this case, quickly starting the unit is crucial to reducing economic losses and grid stability. However, since thermal power units have many steps to start and a large amount of operations, this will not only slow down the start-up speed, but may also cause equipment damage during the start-up process, increasing safety risks. Summary of the invention

[0003] (I) Purpose of the invention

[0004] In order to overcome the above shortcomings, the purpose of the present invention is to provide a method for starting a thermal power unit to solve the above technical problems.

[0005] (II) Technical solution

[0006] To achieve the above objectives, the technical solutions provided by this application are as follows:

[0007] A method for starting a thermal power unit comprises the following steps:

[0008] Step 1, the unit trips;

[0009] Step 2, put the deaerator of the #7 unit into heating, and stop the vacuum pump and condensate pump of the #7 unit B;

[0010] Step 3, #7 boiler water supply, #7 boiler BCP start normal, #7 machine B pre-pump start normal, B small machine flushing normal, #7 boiler MFT reset, fuel oil leakage test completed, boiler purge completed, #7A boiler A4, A5 oil guns put into use, boiler ignition successful, put into air preheater continuous soot blowing;

[0011] Step 4, the main engine speed of #7 machine is reduced to zero, the main engine is put into operation, the primary fans of #7 furnace A and B are started and run normally, the steam turbine is rushed, the turning device tripping is checked to be normal, the vacuum pump of #7 machine B is started and it is normal, and the electromechanical pump of #7 is stopped and put into standby;

[0012] Step 5, when the speed of #7 machine rises to 2000r / min-3000r / min, stop the top shaft oil pump of #7 machine A and stop the TOP and MSP of #7 machine normally;

[0013] Step 6: Start the pre-pump of #7 unit A and it runs normally, the A small unit is running normally, the #7 generator-transformer group is paralleled with the system in automatic quasi-synchronous mode, the low-pressure heating of #7 unit is put into operation normally, and the coal mill of #7 furnace C is started and runs normally;

[0014] Step 7, adjust the equipment according to the load power of unit #7.

[0015] Preferably, in step 3, the water level of the #7 furnace water storage tank is 13m.

[0016] Preferably, in step 4, the main steam pressure of unit #7 is 11.7 MPa, the main steam temperature is 535°C, and the reheat steam temperature is 500°C.

[0017] Preferably, in step 7, the adjustment step when the load of unit #7 is 150MW-300MW specifically includes:

[0018] When the load of unit #7 reaches 150MW, close the high bypass regulating valve, bypass valve outlet electric isolation door, high bypass water spray stop valve, high bypass water spray regulating door of unit #7, and cut off the power supply of the electric door;

[0019] When the #7 unit load was 155MW, the A coal mill of #7 furnace was started and operated normally;

[0020] When the #7 unit load is 280MW, the #7 boiler BCP is normal when it is shut down, and the boiler switches to dry operation;

[0021] When the load of unit #7 is 300MW, the D coal mill of #7 furnace is started and operates normally.

[0022] Preferably, in step 7, when the load of unit #7 is 350MW-430MW, the adjustment step specifically includes:

[0023] When the load of unit #7 reaches 350MW, the boiler feed water is switched to the main circuit operation;

[0024] When the load of unit #7 reaches 350MW, the boiler feed water is switched to the main circuit operation;

[0025] When the load of Unit #7 reaches 420MW, the power consumption of Unit #7 switches from standby to normal operation;

[0026] When the load of unit #7 is 430MW, the high-pressure heater of unit #7 operates normally.

[0027] Preferably, in step 7, when the load of unit #7 is 450MW-540MW, the adjustment step specifically includes:

[0028] When the load of unit #7 is 450MW, the condensate pump of unit #7 B is started and operates normally;

[0029] When the load of unit #7 is 480MW, the steam source of small units A and B of unit #7 is transferred from auxiliary steam to the fourth extraction, and the high-pressure steam source of small units is put into use;

[0030] When the #7 unit load is 530MW, the #7 furnace B coal mill is started and runs normally;

[0031] When the load of unit #7 is 540MW, the sootblowing steam source of boiler #7 is switched from auxiliary steam to the screen outlet.

[0032] Preferably, in step 7, when the load of unit #7 is 550MW-655MW, the adjustment step specifically includes:

[0033] When the #7 unit load is 550MW, the inlet flue gas temperature of the A / B air preheater of #7 boiler is 340℃ / 337℃, and the outlet flue gas temperature is 106℃ / 104℃, and the soot blowing procedure of #7 boiler is put into operation;

[0034] When the #7 unit load was 655MW, the #7 furnace E coal mill was started and operated normally;

[0035] When the load of unit #7 reached 877MW, the F coal mill of #7 furnace started and operated normally.

[0036] Preferably, in steps 2-4, an optimization algorithm is used to determine the startup sequence and operating parameters of the best equipment, and the algorithm objective function includes:

[0037] J=a·T+b·E+r·S

[0038] in:

[0039] T is the total time required from the start of the unit to reaching full load.

[0040] E is the total energy consumed in this process,

[0041] S is the system stability index, which can be a function of vibration, pressure fluctuation, etc.

[0042] α, β, γ are weight coefficients;

[0043] Constraints include: safety constraints, ensuring that all operations are within the safety parameters, P min ≤P (t) ≤P max T min ≤T (t) ≤T max .

[0044] Beneficial effects:

[0045] 1. The present invention optimizes the startup sequence through an algorithm, which can reduce the total time (T) required from the start of the unit to reaching full load, thereby improving the efficiency of the startup process.

[0046] 2. The present invention ensures that each startup follows the same process through clear steps, reducing the risks caused by operational differences.

[0047] 3. The steps of the present invention include multiple safety checks and condition confirmations, such as MFT reset, fuel leak test, etc., which help prevent accidents.

[0048] 4. The present invention can ensure that the startup process is both fast and smooth by accurately controlling various parameters during the startup process, such as main steam pressure, main steam temperature and reheat steam temperature. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0050] The present invention provides a method for starting a thermal power unit, comprising the following steps:

[0051] Step 1, the unit trips;

[0052] Step 2, put the deaerator of the #7 unit into heating, and stop the vacuum pump and condensate pump of the #7 unit B;

[0053] Step 3, #7 boiler water supply, #7 boiler water storage tank water level 13m, #7 boiler BCP start normal, #7 machine B pre-pump start normal, B small machine flushing normal, #7 boiler MFT reset, fuel oil leakage test completed, boiler purge completed, #7A boiler A4, A5 oil guns put into use, boiler ignition successful, put into air preheater continuous soot blowing;

[0054] Step 4, the main engine speed of #7 unit is reduced to zero, the main engine cranking is put into operation, the primary fans of #7 furnace A and B are started and run normally, the main steam pressure of #7 unit is 11.7MPa, the main steam temperature is 535℃, the reheat steam temperature is 500℃, the turbine is run, the cranking device tripping is checked to be normal, the vacuum pump of #7 unit B is started and it is normal, and the electromechanical pump of #7 is stopped and put into standby;

[0055] Step 5, when the speed of #7 machine rises to 2000r / min-3000r / min, stop the top shaft oil pump of #7 machine A and stop the TOP and MSP of #7 machine normally;

[0056] Step 6: Start the pre-pump of #7 unit A and it runs normally, the A small unit is running normally, the #7 generator-transformer group is paralleled with the system in automatic quasi-synchronous mode, the low-pressure heating of #7 unit is put into operation normally, and the coal mill of #7 furnace C is started and runs normally;

[0057] Step 7, adjust the equipment according to the load power of unit #7.

[0058] When the load of unit #7 reaches 150MW, close the high bypass regulating valve, bypass valve outlet electric isolation door, high bypass water spray stop valve, high bypass water spray regulating door of unit #7, and cut off the power supply of the electric door;

[0059] When the #7 unit load was 155MW, the A coal mill of #7 furnace was started and operated normally;

[0060] When the #7 unit load is 280MW, the #7 boiler BCP is normal when it is shut down, and the boiler switches to dry operation;

[0061] When the load of unit #7 is 300MW, the D coal mill of #7 furnace is started and operates normally.

[0062] When the load of unit #7 reaches 350MW, the boiler feed water is switched to the main circuit operation;

[0063] When the load of unit #7 reaches 350MW, the boiler feed water is switched to the main circuit operation;

[0064] When the load of Unit #7 reaches 420MW, the power consumption of Unit #7 switches from standby to normal operation;

[0065] When the load of unit #7 is 430MW, the high-pressure heater of unit #7 operates normally.

[0066] When the load of unit #7 is 450MW, the condensate pump of unit #7 B is started and operates normally;

[0067] When the load of unit #7 is 480MW, the steam source of small units A and B of unit #7 is transferred from auxiliary steam to the fourth extraction, and the high-pressure steam source of small units is put into use;

[0068] When the #7 unit load is 530MW, the #7 furnace B coal mill is started and runs normally;

[0069] When the load of unit #7 is 540MW, the sootblowing steam source of boiler #7 is switched from auxiliary steam to the screen outlet.

[0070] When the #7 unit load is 550MW, the inlet flue gas temperature of the A / B air preheater of #7 boiler is 340℃ / 337℃, and the outlet flue gas temperature is 106℃ / 104℃, and the soot blowing procedure of #7 boiler is put into operation;

[0071] When the #7 unit load was 655MW, the #7 furnace E coal mill was started and operated normally;

[0072] When the load of unit #7 reached 877MW, the F coal mill of #7 furnace started and operated normally.

[0073] In steps 2-4, an optimization algorithm is used to determine the startup sequence and operating parameters of the best equipment. The algorithm objective function includes:

[0074] J=a·T+b·E+r·S

[0075] in:

[0076] T is the total time required from the start of the unit to reaching full load.

[0077] E is the total energy consumed in this process,

[0078] S is the system stability index, which can be a function of vibration, pressure fluctuation, etc.

[0079] α, β, γ are weight coefficients;

[0080] Constraints include: Safety constraints, ensuring that all operations are within the safety parameter range

[0081] Internal, P min ≤P (t) ≤P max T min ≤T (t) ≤T max .

[0082] Also included are the following:

[0083] 1. After the unit trips, the electric pump should be started, and the minimum flow should be maintained. Do not add water to the boiler temporarily. If the water level in the water tank is low, the actual situation is that the water tank is always full of water. You can add water appropriately to keep the water level in the water tank normal. The small unit should be restored to operation as soon as possible and the electric pump should be stopped.

[0084] 2. Use a PCV valve and superheater drain valve on the A and B sides to reduce the pressure for a long time to reduce the main steam pressure to the run-in pressure.

[0085] 3. When the pressure in the water tank is greater than 10MPa or the temperature is greater than 320℃, it is prohibited to use the 361 valve to release water and reduce pressure, and it is prohibited to use the 361 valve to adjust the water level of the water tank.

[0086] 4. Because the main steam temperature is low and the main steam pressure is high during extremely hot startup, therefore, during ignition, the middle and upper oil guns should be used as much as possible to start the upper coal mill.

[0087] 5. When establishing the primary air channel and starting the primary fan, it is best to open the upper coal mill to clean the air door and try not to go through the mill channel. When increasing the primary air pressure, it should be done slowly, because all powder pipes have accumulated powder, and most of the accumulated powder will not be ignited when it enters the furnace. It is necessary to prevent the furnace from flameout and deflagration.

[0088] 6. After starting the coal mill, add air slowly to try to raise the separator outlet temperature to a normal value to facilitate ignition. At the same time, closely monitor the wall temperature of each heating surface to prevent overheating.

[0089] 7. The speed of temperature and pressure rise should be controlled according to the extremely hot start temperature and pressure rise curve.

[0090] The present invention optimizes the startup sequence through an algorithm, and can reduce the total time (T) required from the start of the unit to reaching full load, thereby improving the efficiency of the startup process.

[0091] The present invention ensures that each startup follows the same process through clear steps, thereby reducing the risks caused by operational differences.

[0092] The steps of the present invention include multiple safety checks and condition confirmations, such as MFT reset, fuel leak test, etc., which are helpful to prevent accidents.

[0093] The present invention can ensure that the startup process is both fast and stable by accurately controlling various parameters in the startup process, such as main steam pressure, main steam temperature and reheat steam temperature.

[0094] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0095] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for starting a thermal power unit, characterized in that: The following steps are involved: Step 1, the unit trips; Step 2, put the deaerator of the #7 unit into heating, and stop the vacuum pump and condensate pump of the #7 unit B; Step 3, #7 boiler water supply, #7 boiler BCP start normal, #7 machine B pre-pump start normal, B small machine flushing normal, #7 boiler MFT reset, fuel oil leakage test completed, boiler purge completed, #7A boiler A4, A5 oil guns put into use, boiler ignition successful, put into air preheater continuous soot blowing; Step 4, the main engine speed of #7 machine is reduced to zero, the main engine is put into operation, the primary fans of #7 furnace A and B are started and run normally, the steam turbine is rushed, the turning device tripping is checked to be normal, the vacuum pump of #7 machine B is started and it is normal, and the electromechanical pump of #7 is stopped and put into standby; Step 5, when the speed of #7 machine rises to 2000r / min-3000r / min, stop the top shaft oil pump of #7 machine A and stop the TOP and MSP of #7 machine normally; Step 6: Start the pre-pump of #7 unit A and it runs normally, the A small unit is running normally, the #7 generator-transformer group is paralleled with the system in automatic quasi-synchronous mode, the low-pressure heating of #7 unit is put into operation normally, and the coal mill of #7 furnace C is started and runs normally; Step 7, adjust the equipment according to the load power of unit #7.

2. A method for starting a thermal power unit according to claim 1, characterized in that: In step 3, the water level of the #7 furnace water storage tank is 13m.

3. A method for starting a thermal power unit according to claim 1, characterized in that: In step 4, the main steam pressure of unit #7 is 11.7MPa, the main steam temperature is 535℃, and the reheat steam temperature is 500℃.

4. A method for starting a thermal power unit according to claim 1, characterized in that: In step 7, the adjustment steps for the #7 unit load of 150MW-300MW specifically include: When the load of unit #7 reaches 150MW, close the high bypass regulating valve, bypass valve outlet electric isolation door, high bypass water spray stop valve, high bypass water spray regulating door of unit #7, and cut off the power supply of the electric door; When the #7 unit load was 155MW, the A coal mill of #7 furnace was started and operated normally; When the #7 unit load is 280MW, the #7 boiler BCP is normal when it is shut down, and the boiler switches to dry operation; When the load of unit #7 is 300MW, the D coal mill of #7 furnace is started and operates normally.

5. A method for starting a thermal power unit according to claim 1, characterized in that: In step 7, the adjustment steps when the load of unit #7 is 350MW-430MW specifically include: When the load of unit #7 reaches 350MW, the boiler feed water is switched to the main circuit operation; When the load of unit #7 reaches 350MW, the boiler feed water is switched to the main circuit operation; When the load of Unit #7 reaches 420MW, the power consumption of Unit #7 switches from standby to normal operation; When the load of unit #7 is 430MW, the high-pressure heater of unit #7 operates normally.

6. A method for starting a thermal power unit according to claim 1, characterized in that: In step 7, the adjustment steps when the load of unit #7 is 450MW-540MW specifically include: When the load of unit #7 is 450MW, the condensate pump of unit #7 B is started and operates normally; When the load of unit #7 is 480MW, the steam source of small units A and B of unit #7 is transferred from auxiliary steam to the fourth extraction, and the high-pressure steam source of small units is put into use; When the #7 unit load is 530MW, the #7 furnace B coal mill is started and runs normally; When the load of unit #7 is 540MW, the sootblowing steam source of boiler #7 is switched from auxiliary steam to the screen outlet.

7. A method for starting a thermal power unit according to claim 1, characterized in that: In step 7, the adjustment steps when the load of unit #7 is 550MW-655MW specifically include: When the #7 unit load is 550MW, the inlet flue gas temperature of the A / B air preheater of #7 boiler is 340℃ / 337℃, and the outlet flue gas temperature is 106℃ / 104℃, and the soot blowing procedure of #7 boiler is put into operation; When the #7 unit load was 655MW, the #7 furnace E coal mill was started and operated normally; When the load of unit #7 reached 877MW, the F coal mill of #7 furnace started and operated normally.

8. A method for starting a thermal power unit according to claim 1, characterized in that: In steps 2-4, an optimization algorithm is used to determine the startup sequence and operating parameters of the best equipment. The algorithm objective function includes: J=a·T+b·E+r·S in: T is the total time required from the start of the unit to reaching full load. E is the total energy consumed in this process, S is the system stability index, which can be a function of vibration, pressure fluctuation, etc. α, β, γ are weight coefficients; Constraints include: safety constraints, ensuring that all operations are within the safety parameters, P min ≤P (t) ≤P max T min ≤T (t) ≤T max .