Self-stop operation control method for closed circulation cooling water system of gas turbine combined cycle unit

Abstract

The present application relates to the technical field of cooling water system control, especially to a self-shutdown control method for a closed cycle cooling water system of a gas turbine combined cycle unit. The closed cycle cooling water system comprises multiple closed water pumps and multiple closed coolers. The present application realizes full automatic control of three closed water pumps, optimizes the standby logic of the closed water pumps, sets up a primary standby function and a secondary standby function, and integrates all the three closed water pumps into the shutdown control process. Through the closed cooler shutdown process and the closed water pump shutdown process, the most suitable closed cooler and closed water pump are automatically selected for shutdown, and the shutdown of the closed cycle water system is realized in an orderly and efficient manner according to the established rules. Without the need for human judgment and operation by the operation personnel, the full automatic shutdown of the closed cycle cooling water system is realized without disturbing the stable operation state of the unit, and the labor intensity of the operation personnel is reduced, and the safety and the automation level of the unit are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cooling water system control, in particular to a self-shutdown control method for a closed circulation cooling water system of a gas turbine combined cycle unit. BACKGROUND

[0002] The closed circulation cooling water system is a closed loop system for providing cooling medium to various auxiliary machine heat exchangers of a thermal power generating unit under various operating conditions, and the cooling medium is pumped to various equipment coolers by a closed circulation pump for cooling to ensure the normal operation of auxiliary equipment and systems.

[0003] In the related art, a large coal-fired power plant mostly uses two or three units to share one closed circulation cooling water system, and each closed circulation cooling water system is usually designed with three closed circulation pumps to provide cooling medium for multiple unit closed cooling water users.

[0004] At present, the control of the closed circulation cooling water system is mostly manual operation. When two units are running simultaneously, two closed circulation pumps are usually used to supply cooling water medium. At this time, if one unit is shut down, personnel usually manually exit the standby of the shutdown pump first, and then shut down one closed circulation pump to maintain the other closed circulation pump to supply cooling water medium to the unit.

[0005] At the same time, after the closed circulation pump is shut down, one closed circulation pump is selected to be put into standby state, and the closed circulation cooling water recirculation valve pressure target setting value is adjusted. After both units are shut down, the operator decides whether to shut down the closed circulation pump according to the closed cooling water user shutdown condition, and then shuts down the closed circulation pump after exiting the standby state of the closed circulation pump, and closes the closed cooler inlet and outlet valves, pump inlet valves and other equipment.

[0006] In the above process of shutting down the closed circulation cooling water system by manual operation, a large amount of human judgment and operation is required, which is labor-intensive and tedious and repetitive, and also leads to poor system safety. SUMMARY

[0007] In order to overcome the low efficiency and poor safety of the existing cooling water system control method, the present application provides a self-shutdown control method for a closed circulation cooling water system of a gas turbine combined cycle unit.

[0008] The technical solution adopted by the present application to solve its technical problems is: a self-shutdown control method for a closed circulation cooling water system of a gas turbine combined cycle unit, the closed circulation cooling water system comprising multiple closed circulation pumps and multiple closed coolers, the closed circulation pump being provided with multiple standby strategies;

[0009] The self-stop operation control method comprises a closed cooler stop operation method and a closed water pump stop operation method.

[0010] A. Real-time measurement of the outlet header temperature of each closed cooler in the system;

[0011] B. Automatic determination of whether to change the start-stop state of each closed cooler in the current system according to the outlet header temperature;

[0012] The closed water pump stop operation method comprises the following steps:

[0013] A. Obtaining real-time working condition information of the unit and the running time of the closed water pump;

[0014] B. Automatic determination of the number of closed water pumps to be stopped according to the real-time working condition information of the unit and the running time of the closed water pump, and indication of the closed water pumps to be stopped;

[0015] The real-time working condition information comprises the number of units to be stopped, the user operation condition, the recirculation regulating valve opening degree of the closed water pump, and the outlet header pressure of the closed cooler.

[0016] According to another embodiment of the present application, the closed water pump is further configured with a primary backup function and a secondary backup function, and the closed water pump is configured with an identification ID, and the identification IDs have a logical sequence relationship.

[0017] The multi-level backup strategy is:

[0018] The input state of the primary backup function and the secondary backup function of the same closed water pump is in a mutual exclusion relationship, the input state of the primary backup function and the secondary backup function between the closed water pumps is in a mutual exclusion relationship, and the primary backup function and the secondary backup function of the closed water pump are automatically exited after the closed water pump is running.

[0019] According to another embodiment of the present application, further comprising that when there is only one closed cooler working in the closed circulation cooling water system, it is judged whether the outlet header temperature of the closed cooler is greater than a first preset temperature threshold, if yes, the inlet valve and the outlet valve of the second closed cooler are automatically opened according to the logical sequence relationship;

[0020] When there are multiple closed coolers working in the closed circulation cooling water system, it is judged whether the outlet header temperatures of the closed coolers are all lower than a second preset temperature threshold within a first preset time period, if yes, the inlet valve and the outlet valve of the closed cooler with the longest running time are instructed to be closed;

[0021] When all the closed water pumps in the closed circulation cooling water system are stopped, the inlet valves and the outlet valves of all the closed coolers are automatically closed.

[0022] According to another embodiment of the present application, further comprising that the outlet pipe temperature of the closed cooler is acquired in real time by a temperature transmitter, and the running time of the closed cooler is acquired by a timer.

[0023] According to another embodiment of the present application, further comprising that the shutdown method of the closed water pump comprises:

[0024] Based on the outlet pipe pressure of the closed cooler and the opening of the recirculation regulating valve of the closed water pump, it is determined whether the preset shutdown condition of the closed water pump is triggered, if yes, the number of the closed water pumps to be shutdown is determined according to the current number of the running closed water pumps, and the closed water pump with the longest running time is automatically selected as the target closed water pump and is shutdown;

[0025] The preset shutdown condition comprises that at least two closed water pumps are in the running state, the opening of the recirculation regulating valve of the closed water pump is greater than the preset opening value within the second preset time period, the outlet pipe pressure of the closed cooler is greater than the preset pressure value, and the primary standby function and the secondary standby function of the closed water pump are in the exit state; the preset pressure value has different value ranges when the number of the units is different.

[0026] According to another embodiment of the present application, further comprising that when two units are tripped and all the closed cooling water users are shutdown, the primary standby function and the secondary standby function of all the closed water pumps are automatically exited;

[0027] After the primary standby function and the secondary standby function of the closed water pump are exited, the closed water pump in the running state is automatically shutdown;

[0028] After all the closed water pumps are shutdown, the closed cooler is automatically shutdown, the inlet electric valve of the closed water pump and the recirculation regulating valve of the closed water pump are closed, and the closed circulating water system is restored to the initial state.

[0029] According to another embodiment of the present application, further comprising that after the target closed water pump is shutdown, it is determined whether the target closed water pump is in the running state, if yes, it is indicated to be shutdown, and after a third preset time is delayed, the secondary standby function of the target closed water pump is put into operation, and according to the logical sequence relationship, the primary standby function of the next closed water pump is put into operation;

[0030] If no, the closed water pump with the longest running time other than the target closed water pump is selected as the target closed water pump, and it is indicated to be shutdown.

[0031] According to another embodiment of the present application, further comprising that the closed circulating cooling water system comprises a first closed water pump, a second closed water pump and a third closed water pump;

[0032] The conditions under which the first closed-loop water pump can be put into operation include the first closed-loop water pump not being under on-site maintenance or prohibited from operation.

[0033] The activation conditions for the primary standby function of the first closed-loop water pump include either manual activation via the primary standby button or automatic activation via the primary standby button.

[0034] The exit conditions for the first closed-loop water pump's primary standby function include any one of the following: manual exit of the first closed-loop water pump's primary standby button, automatic exit of the first closed-loop water pump's primary standby, the first closed-loop water pump being in secondary standby mode, the first closed-loop water pump being running, the second closed-loop water pump being in primary standby mode, and the third closed-loop water pump being in primary standby mode.

[0035] The conditions under which the secondary standby function of the first closed-loop water pump can be activated include that the first closed-loop water pump is not under on-site maintenance or prohibited from operation.

[0036] The activation conditions for the secondary standby function of the first closed-loop water pump include either manual activation via the secondary standby button or automatic activation via the secondary standby function of the first closed-loop water pump.

[0037] The exit conditions for the secondary standby function of the first closed-loop water pump include any one of the following: manual exit of the secondary standby function of the first closed-loop water pump by pressing the secondary standby button; automatic exit of the secondary standby function of the first closed-loop water pump; the first closed-loop water pump being in primary standby mode; the first closed-loop water pump being running; the second closed-loop water pump being in secondary standby mode; and the third closed-loop water pump being in secondary standby mode.

[0038] According to another embodiment of the present invention, the closed-loop cooling water system further includes a closed-loop cooler shutdown module and a closed-loop water pump shutdown module;

[0039] The closed-loop cooler shutdown module is used to measure the outlet header temperature of each closed-loop cooler in the closed-loop circulating cooling water system in real time, and automatically determine whether to change the start-up and shutdown status of each closed-loop cooler in the current system based on the outlet header temperature.

[0040] The closed-loop pump shutdown module is used to acquire real-time operating information of the unit and the running time of the closed-loop pumps, and automatically determine the number of closed-loop pumps to be shut down based on the real-time operating information of the unit and the running time of the closed-loop pumps, and automatically instruct the target closed-loop pumps to be shut down.

[0041] The beneficial effect of the present application is that the present application realizes full-process automatic control of three closed water pumps, optimizes the standby logic of the closed water pump, sets a first standby function and a second standby function, and integrates all the three closed water pumps into the shutdown control process. Through the closed cooler shutdown process and the closed water pump shutdown process, the most suitable closed cooler and closed water pump are automatically selected for shutdown, and the shutdown of the closed circulating water system is realized in an orderly and efficient manner through the established rules. Without the need for human judgment and operation of the operator, the full-process automatic shutdown of the closed circulating cooling water system is realized without disturbing the stable operation state of the unit, and the labor intensity of the operator is reduced, and the safety and automation level of the unit are improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] The present application will be further described below in conjunction with the drawings and examples.

[0043] Figure 1 is a flowchart of the present application;

[0044] Figure 2 is a process flowchart of the present application;

[0045] Figure 3 is a schematic diagram of the first standby function and the second standby function of the closed water pump of the present application;

[0046] Figure 4 is a logic diagram of the automatic start-stop of the closed water pump of the present application;

[0047] Figure 5 is a shutdown logic diagram of the present application;

[0048] Figure 6 is a shutdown logic diagram of the closed water pump and the closed cooler of the present application;

[0049] Figure 7 is a structure block diagram of the shutdown control system of the present application; DETAILED DESCRIPTION

[0050] Figure 1 is a flowchart of the present application; Figure 2 is a process flowchart of the present application; Figure 3 is a schematic diagram of the first standby function and the second standby function of the closed water pump of the present application; Figure 4 is a logic diagram of the automatic start-stop of the closed water pump of the present application; Figure 5 is a shutdown logic diagram of the present application; Figure 1 ; Figure 6 is a shutdown logic diagram of the present application; Figure 2 ; Figure 7 is a structure block diagram of the shutdown control system of the present application.

[0051] A kind of gas turbine combined cycle unit closed circulation cooling water system self-stop operation control method, the closed circulation cooling water system includes multiple closed water pumps and multiple closed coolers, closed water pump is provided with multiple levels standby strategy;

[0052] The self-stop operation control method includes closed cooler shutdown method and closed water pump shutdown method;The shutdown method of closed cooler includes the following steps:

[0053] A, the outlet header temperature of each closed cooler in real time measurement system is measured;

[0054] B, and according to the outlet header temperature, automatically determine whether to change the start-stop state of each closed cooler in the current system;

[0055] The shutdown method of closed water pump includes the following steps:

[0056] A, obtain unit real-time operating condition information and closed water pump running time;

[0057] B, according to unit real-time operating condition information and closed water pump running time, automatically determine the number of closed water pumps to be stopped, and indicate the closed water pump to be stopped;

[0058] The real-time operating condition information includes unit shutdown quantity, user operation, closed water pump recirculation regulating valve opening and closed cooler outlet header pressure.

[0059] Closed water pump is configured with one-level standby function and two-level standby function, closed water pump is configured with identification ID, and the identification ID has logical sequence relationship;

[0060] The multiple levels standby strategy is as follows:

[0061] The input state of one-level standby function and two-level standby function of the same closed water pump is in mutual exclusion relationship;The input state of one-level standby function and two-level standby function between each closed water pump is in mutual exclusion relationship;After closed water pump runs, automatically exit one-level standby function and two-level standby function of itself.

[0062] In the closed circulation cooling water system, when there is only one closed cooler working, it is judged whether the outlet header temperature of the closed cooler is greater than the first preset temperature threshold, if yes, according to the logical sequence relationship, the inlet valve and the outlet valve of the second closed cooler are automatically opened;

[0063] In the closed circulation cooling water system, when multiple closed coolers work simultaneously, it is judged whether the outlet header temperature of each closed cooler is lower than the second preset temperature threshold in the first preset time period, if yes, the inlet valve and the outlet valve of the closed cooler with the longest running time are instructed to be closed;

[0064] In the case that all the closed water pumps in the closed circulation cooling water system are stopped, the inlet valve and the outlet valve of all the closed coolers are automatically closed.

[0065] The outlet header temperature of the closed cooler is obtained in real time by a temperature transmitter, and the running time of the closed cooler is obtained by a timer.

[0066] The stopping method of the closed water pump comprises:

[0067] Based on the outlet header pressure of the closed cooler and the opening degree of the recirculation regulating valve of the closed water pump, it is determined whether the preset stopping condition of the closed water pump is triggered, if yes, the number of the closed water pumps to be stopped is determined according to the current number of the closed water pumps in operation, and the closed water pump with the longest running time is automatically selected as the target closed water pump and stopped;

[0068] The preset stopping condition comprises that at least two closed water pumps are in the running state, the opening degree of the recirculation regulating valve of the closed water pump is greater than the preset opening degree value within the second preset time period, the outlet header pressure of the closed cooler is greater than the preset pressure value, and the primary standby function and the secondary standby function of the closed water pump are in the exit state; the preset pressure value has different value ranges when the number of units in operation is different.

[0069] When two units are disconnected and all the closed cooling water users are stopped, the primary standby function and the secondary standby function of all the closed water pumps are automatically exited;

[0070] After the primary standby function and the secondary standby function of the closed water pump are exited, the closed water pump in operation is automatically stopped;

[0071] After all the closed water pumps are stopped, the closed cooler is automatically stopped, the inlet electric valve of the closed water pump and the recirculation regulating valve of the closed water pump are closed, and the closed circulation water system is restored to the initial state.

[0072] After the target closed water pump is stopped, it is determined whether the target closed water pump is in the running state, if yes, it is instructed to be stopped, and after a third preset time is delayed, the secondary standby function of the target closed water pump is put into operation, and according to the logical sequence relationship, the primary standby function of the next closed water pump is put into operation;

[0073] If not, the closed water pump with the longest running time other than the target closed water pump is selected as the target closed water pump, and it is instructed to be stopped.

[0074] The closed circulation cooling water system comprises a first closed water pump, a second closed water pump and a third closed water pump.

[0075] The input allowance condition of the primary standby function of the first closed water pump comprises that the first closed water pump is not in the on-site maintenance and prohibited operation state;

[0076] The activation conditions for the primary standby function of the first closed-loop water pump include either manual activation via the primary standby button or automatic activation via the primary standby button.

[0077] The exit conditions for the first closed-loop water pump's primary standby function include any one of the following: manual exit of the first closed-loop water pump's primary standby button, automatic exit of the first closed-loop water pump's primary standby, the first closed-loop water pump being in secondary standby mode, the first closed-loop water pump being running, the second closed-loop water pump being in primary standby mode, and the third closed-loop water pump being in primary standby mode.

[0078] The conditions under which the secondary standby function of the first closed-loop water pump can be activated include that the first closed-loop water pump is not under on-site maintenance or prohibited from operation.

[0079] The activation conditions for the secondary standby function of the first closed-loop water pump include either manual activation via the secondary standby button or automatic activation via the secondary standby function of the first closed-loop water pump.

[0080] The exit conditions for the secondary standby function of the first closed-loop water pump include any one of the following: manual exit of the secondary standby function of the first closed-loop water pump by pressing the secondary standby button; automatic exit of the secondary standby function of the first closed-loop water pump; the first closed-loop water pump being in primary standby mode; the first closed-loop water pump being running; the second closed-loop water pump being in secondary standby mode; and the third closed-loop water pump being in secondary standby mode.

[0081] According to another embodiment of the present invention, the closed-loop cooling water system further includes a closed-loop cooler shutdown module and a closed-loop water pump shutdown module;

[0082] The closed-loop cooler shutdown module is used to measure the outlet header temperature of each closed-loop cooler in the closed-loop circulating cooling water system in real time, and automatically determine whether to change the start-up and shutdown status of each closed-loop cooler in the current system based on the outlet header temperature.

[0083] The closed-loop pump shutdown module is used to acquire real-time operating information of the unit and the running time of the closed-loop pumps, and automatically determine the number of closed-loop pumps to be shut down based on the real-time operating information of the unit and the running time of the closed-loop pumps, and automatically instruct the target closed-loop pumps to be shut down.

[0084] The closed-loop cooling water system includes multiple closed-loop water pumps, and each closed-loop water pump is equipped with a multi-stage backup strategy, combined with the attached... Figure 1 and attached Figure 2 As shown, the process includes the following steps:

[0085] The closed cooler shutdown process comprises: measuring the outlet pipe temperature of each closed cooler in real time, and automatically determining whether to change the start-stop state of each closed cooler in the current system according to the outlet pipe temperature;

[0086] The closed circulation cooling water is applied to a thermal power generating unit, and is used to provide cooling medium for each auxiliary heat exchanger in the unit and constitutes a closed loop. The control method provided by the application is realized based on a multi-level standby strategy. The multi-level standby strategy comprises: the input states of the first standby function and the second standby function of the same closed water pump are in mutual exclusion; the input states of the first standby function and the second standby function of each closed water pump are in mutual exclusion; and the first standby function and the second standby function of the closed water pump are automatically exited after the closed water pump is operated.

[0087] The control modes of the first standby function and the second standby function of each closed water pump are completely consistent.

[0088] As shown in the accompanying Figure 3 , taking the #1 water pump as an example:

[0089] The input allowed condition of the first standby function of the #1 water pump:

[0090] (1) The #1 closed water pump is not in the on-site maintenance and prohibited operation state

[0091] The input condition of the first standby function of the #1 water pump (any one of the following conditions is satisfied):

[0092] (1) The first standby button of the #1 closed water pump is manually input;

[0093] (2) The first standby function of the #1 closed water pump is automatically input.

[0094] The exit condition of the first standby function of the #1 water pump (any one of the following conditions is satisfied):

[0095] (1) The first standby button of the #1 closed water pump is manually exited;

[0096] (2) The first standby function of the #1 closed water pump is automatically exited;

[0097] (3) The #1 closed water pump is in the second standby state;

[0098] (4) The #1 closed water pump has been operated;

[0099] (5) The #2 closed water pump is in the first standby state;

[0100] (6) The #3 closed water pump is in the first standby state;

[0101] The input allowed condition of the second standby function of the #1 water pump:

[0102] (1) #1 closed water pump is not in the on-site maintenance and prohibited operation state

[0103] #1 water pump secondary backup function input conditions (any of the following conditions meet):

[0104] (1) #1 closed water pump secondary backup button manual input;

[0105] (2) #1 closed water pump secondary backup automatic input;

[0106] #1 water pump secondary backup function exit conditions (any of the following conditions meet):

[0107] (1) #1 closed water pump secondary backup button manual exit;

[0108] (2) #1 closed water pump secondary backup automatic exit;

[0109] (3) #1 closed water pump is in the primary backup state;

[0110] (4) #1 closed water pump has been running;

[0111] (5) #2 closed water pump is in the secondary backup state;

[0112] (6) #3 closed water pump is in the secondary backup state.

[0113] In this embodiment, by formulating a multi-level backup strategy, the primary backup and secondary backup functions are configured for each closed water pump, all three closed water pumps are included in the automatic control process, the closed water pump backup logic is optimized, and automatic shutdown control of the three closed water pumps is realized.

[0114] In addition, in the normal operation of the closed water system, the temperature transmitter can be used to measure the temperature of the closed cooler outlet main pipe in real time, and automatically determine whether the second closed cooler needs to be started or one of the closed coolers needs to be shut down according to the temperature. When one of the closed coolers needs to be shut down, the closed cooler with longer running time is preferentially selected to be shut down.

[0115] The closed water pump shutdown process includes: obtaining real-time working condition information of the unit and running time of the closed water pump, and automatically determining the number of closed water pumps to be shut down and automatically selecting the target closed water pump to be shut down according to the real-time working condition information of the unit and the running time of the closed water pump, and instructing it to be shut down,

[0116] The real-time working condition information includes: unit shutdown quantity, user operation, closed water pump recirculation regulating valve opening degree, and closed cooler outlet main pipe pressure.

[0117] In the embodiment, according to the number of unit shutdown and the information of the closed water pump recirculation regulating valve opening degree, cooler outlet mother pressure and the like, the optimal number of closed water pump in shutdown is automatically judged. Specifically, when two units need to shut down one unit, whether one closed water pump needs to be shut down can be automatically judged according to the closed water cooling user operation condition, the closed water pump recirculation regulating valve opening degree, the cooler outlet mother pressure and the like; after two units are completely shut down and all closed water cooling users in the whole plant are completely shut down, all closed water pumps are automatically shut down.

[0118] Before the water pump is shut down, the closed water pump pre-shutdown process is further included, that is, after the number of closed water pumps to be shut down is determined, the most suitable closed water pump is automatically selected as the target closed water pump according to the length of the running time of each closed water pump, and the target closed water pump is shut down, so as to avoid that one or two closed water pumps are in the running state for a long time, thereby affecting the service life of the closed water pump.

[0119] Through the above, compared with the existing method of shutting down the closed circulation cooling water system by manual operation, in the embodiment, the shutdown of the closed cooler and the closed water pump in the automatic control system is automatically controlled in combination with the real-time working condition and the use time of each water pump and the like, and the optimal shutdown control is realized.

[0120] Meanwhile, based on the preset multi-level standby strategy, the one-level standby and two-level standby functions are set, three closed water pumps are all included in the serialized automatic shutdown control process, thereby effectively improving the safety of the closed circulation cooling water system in the shutdown process, reducing the labor cost, and improving the overall automation degree of the power plant.

[0121] In some embodiments, in order to realize the optimal shutdown of the closed cooler, in the application, whether to change the start-stop state of each closed cooler in the current system is automatically determined according to the cooler outlet mother pipe temperature, and the specific process includes:

[0122] In the case that there is only one closed cooler working in the system, whether the outlet mother pipe temperature of the closed cooler is greater than a first preset temperature threshold K1 is judged, if yes, the second closed water pump is automatically determined according to the logical sequence relationship in the standby strategy, and the inlet valve and the outlet valve of the second closed cooler are opened. Optionally, the outlet mother pipe temperature can be obtained by a temperature transmitter, and the first preset temperature threshold K1 is in the range of 35℃-40℃.

[0123] When multiple closed-circuit coolers are operating simultaneously in the system, it is determined whether the outlet header temperature of each closed-circuit cooler is lower than a second preset temperature threshold K2 within a specified second preset time period. If so, the operating time of each closed-circuit cooler is automatically obtained, and the inlet and outlet valves of the closed-circuit cooler with the longest operating time are instructed to be closed. Preferably, the second preset temperature threshold K2 is in the range of 15℃~20℃.

[0124] In addition, the runtime of the closed-loop cooler can be recorded using a timer; the type of timer chosen is not specifically limited in this application. During the operation of the closed-loop water system, the timer starts counting when the corresponding inlet and outlet valves of the closed-loop cooler are fully open, and stops counting when they are closed. The runtime is reset to zero after all the closed-loop water pumps have stopped operating, i.e., after the closed-loop circulating cooling water system has stopped operating.

[0125] In the event that all closed-loop water pumps in the system stop operating, the inlet and outlet valves of all closed-loop coolers will be automatically shut off.

[0126] As attached Figure 4 As shown in this application, based on parameters such as real-time operating conditions and running time, the number of closed-loop water pumps that need to be shut down and the most suitable target closed-loop water pumps to be shut down are automatically determined, so as to avoid running one or two closed-loop water pumps for a long time.

[0127] Based on the opening degree of the closed-loop water pump recirculation regulating valve and the pressure of the closed-loop cooler outlet header, it is determined whether the preset shutdown condition of the closed-loop water pump is triggered. If so, the closed-loop water pump with the longest running time is automatically selected as the target closed-loop water pump and shut down.

[0128] The pre-set shutdown conditions include: (all of the following conditions must be met)

[0129] (1) At least two closed-loop water pumps are in operation;

[0130] (2) The opening degree of the closed-loop water pump recirculation regulating valve is greater than the first preset opening degree value within a preset time period, for example, the opening degree of the closed-loop recirculation regulating valve is greater than 85% and the delay is 30 seconds.

[0131] (3) The pressure PT_PV at the outlet of the closed cooler is greater than the preset pressure value PT_SP, that is, (3) PT_PV-PT_SP>△P,

[0132] Wherein, △P is the pressure control margin of the outlet header of the closed cooler. Preferably, in some exemplary embodiments, △P is (0.1~0.15)*PT_SP;

[0133] PT_SP is the preset value of the closed cooler outlet main pipe pressure, and PT_SP = P2 during the simultaneous operation of the two units, and PT_SP = P1 during the operation of one unit. Preferably, in some exemplary embodiments, P1 is 0.25-0.3 MPa, and P2 is 0.3-0.35 MPa.

[0134] (4) The primary backup function and the secondary backup function of the closed water pump are in the exit state.

[0135] The closed water cooling users include the machine side users and the furnace side users, including but not limited to: electric pump mechanical seal cooler, electric pump pump body chamber cooler, air preheater shaft cooler, etc.

[0136] Since the closed cooler outlet main pipe pressure is automatically controlled by the closed water pump recirculation regulating valve, when the measured value of the closed cooler outlet main pipe pressure is higher than the target set value, the closed water pump recirculation regulating valve opening is increased, and vice versa, so as to maintain the closed cooler outlet main pipe pressure around the target value.

[0137] During the normal operation of the unit closed water system and the simultaneous operation of at least two closed water pumps, when the closed water pump recirculation regulating valve opening is at a large opening for a long time, the closed cooler outlet main pipe pressure is still greater than the target set value, that is, at this time, the closed water pump recirculation regulating valve has no adjustment margin, and cannot control the closed cooler outlet main pipe pressure to maintain around the target set value by further opening the regulating valve, so one closed water pump with the longest operation time is automatically shut down, and before the closed water pump is shut down, the interlocking of all closed water pumps is exited.

[0138] If the closed water pump recirculation regulating valve opening is at a large opening for a long time again and the closed cooler outlet main pipe pressure is still greater than the target set value after one closed water pump is shut down according to the above method during the simultaneous operation of three closed water pumps, then one closed water pump with the longest operation time among the two running closed water pumps is shut down again according to the same control method.

[0139] When both units are completely tripped and all closed cooling water users are shut down, the primary backup and secondary backup functions of all closed water pumps are automatically exited, and after the primary backup and secondary backup functions of all closed water pumps are completely exited, the running closed water pump is automatically shut down, so as to prevent other closed water pumps from being in the primary or secondary backup state when the closed water pump is shut down, and to prevent the interlocking start of other closed water pumps after the closed water pump is shut down.

[0140] Meanwhile, after all closed water pumps are completely shut down, the two closed coolers are automatically shut down, and all closed water pump inlet electric valves and closed water pump recirculation regulating valves are closed, so as to restore the closed water system to the initial state.

[0141] The closed water pump shutdown process further comprises a closed water pump pre-shutdown optimization process. Specifically, after determining the number of closed water pumps to be shut down, the most suitable target closed water pump is selected and shut down through the closed water pump pre-shutdown optimization process, and the pre-shutdown process is optimized as a whole. Specifically, it comprises:

[0142] The running time of each closed water pump is recorded in real time by a timer. The timer starts counting when the closed water pump is running, and stops counting when the closed water pump is shut down. At the same time, the timer time is reset and cleared when all closed water pumps are shut down, i.e. when the closed water system is shut down.

[0143] The running time of #1 closed water pump, #2 closed water pump and #3 closed water pump is recorded as Pump_TimeA, Pump_TimeB and Pump_TimeC respectively. These three values are used as input variables of a numerical judgment device, and the running time of the closed water pump is determined by the numerical judgment device.

[0144] Among them, when the output end IN_MAX of the numerical judgment device is the maximum value judgment end, the output end IN_Med is the intermediate value judgment end, and the output end IN_Min is the minimum value judgment end, i.e.

[0145] When IN_MAX=1, IN1 is the maximum among the three input ends, i.e. Pump_TimeA is the maximum value, and #1 closed water pump has the longest running time.

[0146] When IN_MAX=2, IN2 is the maximum among the three input ends, i.e. Pump_TimeB is the maximum value, and #2 closed water pump has the longest running time.

[0147] When IN_MAX=3, IN3 is the maximum among the three input ends, i.e. Pump_TimeC is the maximum value, and #3 closed water pump has the longest running time.

[0148] The judgment principles of the intermediate value judgment end IN_Med and the minimum value judgment end IN_Min are the same as those of the maximum value judgment end IN_MAX.

[0149] The pre-shutdown pump control ideas and control logic of #1 closed water pump, #2 closed water pump and #3 closed water pump are the same. Taking the case where #1 closed water pump has the longest running time, i.e. IN_MAX=1, as an example, the control logic is as follows:

[0150] (1) When IN_MAX=1, #1 closed water pump has the longest running time. At this time, if #1 closed water pump is in running state, #1 closed water pump is automatically shut down. After 10 seconds, #1 closed water pump is put into secondary standby, and another closed water pump is put into primary standby.

[0151] (2) IN_MAX=1, #1 closed water pump running time longest, at this time if #1 closed water pump is in the state of shutdown, then automatically stop running #2 closed water pump and #3 closed water pump with longer running time, including:

[0152] ① When IN_Med=2, #2 closed water pump running time is longer, then automatically stop running #2 closed water pump, and after 10 seconds of stop running instruction, put #2 closed water pump in secondary standby, and put #1 closed water pump in primary standby;

[0153] ② When IN_Med=2, #3 closed water pump running time is longer, then automatically stop running #3 closed water pump, and after 10 seconds of stop running instruction, put #3 closed water pump in secondary standby, and put #2 closed water pump in primary standby.

[0154] In combination with the accompanying Figure 5 , the accompanying Figure 6 , the accompanying Figure 7 As shown, the closed circulating cooling water system includes multiple closed water pumps, and multiple standby strategies are provided for each closed water pump. When the closed circulating cooling water system is running, the control system includes a closed cooler shutdown module and a closed water pump shutdown module, wherein,

[0155] The closed cooler shutdown module is used to measure the outlet header temperature of each closed cooler in the system in real time, and automatically determine whether to change the start-stop state of each closed cooler in the current system according to the outlet header temperature;

[0156] The closed water pump shutdown module is used to obtain real-time working condition information of the unit and running time of the closed water pump, and automatically determine the number of closed water pumps to be stopped and automatically select the target closed water pump to be stopped and instruct it to be stopped according to the real-time working condition information of the unit and the running time of the closed water pump, wherein the real-time working condition information includes: unit shutdown quantity, user operation condition, closed water pump recirculation regulating valve opening degree and closed cooler outlet header pressure.

[0157] In some embodiments, the multiple standby strategies include:

[0158] Each closed water pump in the system is configured with a primary standby function and a secondary standby function, each closed water pump is configured with an identification ID, and the identification IDs have a logical sequence relationship,

[0159] In addition, the input state of the primary standby function and the secondary standby function of the same closed water pump is in a mutual exclusion relationship,

[0160] In addition, the input state of the primary standby function and the secondary standby function between each closed water pump is in a mutual exclusion relationship;

[0161] And, after the closed water pump is operated, the first and second backup functions of the water pump are automatically exited.

[0162] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memory. The non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. The volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

Claims

1. A self-shutdown control method for a closed-loop circulating cooling water system of a gas turbine combined cycle unit, characterized in that, The closed-loop cooling water system includes multiple closed-loop water pumps and multiple closed-loop coolers, and the closed-loop water pumps are equipped with multi-stage backup strategies. The automatic shutdown control method includes a closed-loop cooler shutdown method and a closed-loop water pump shutdown method; the closed-loop cooler shutdown method includes the following steps: A. Real-time measurement of the outlet header temperature of each closed-loop cooler in the system; B. Based on the outlet header temperature, automatically determine whether to change the start / stop status of each closed-loop cooler in the current system; The shutdown procedure for a closed-loop water pump includes the following steps: A. Obtain real-time operating information of the unit and the running time of the closed-loop water pump; B. Based on the real-time operating information of the unit and the running time of the closed-loop water pumps, automatically determine the number of closed-loop water pumps to be shut down and instruct the closed-loop water pumps that need to be shut down to stop. The real-time operating information includes the number of units out of service, user operating status, opening degree of closed-loop water pump recirculation regulating valve, and pressure of closed-loop cooler outlet main pipe. The closed-loop water pump is configured with a primary backup function and a secondary backup function, and the closed-loop water pump is configured with an identification ID, wherein the identification IDs have a logical sequential relationship. The multi-level backup strategy is as follows: The primary and secondary backup functions of the same closed-loop water pump are mutually exclusive; the primary and secondary backup functions of different closed-loop water pumps are mutually exclusive; after a closed-loop water pump starts running, it automatically deactivates its primary and secondary backup functions. In the case that only one closed-loop cooling water system is working, it is determined whether the outlet header temperature of the closed-loop cooler is greater than the first preset temperature threshold. If so, the inlet valve and outlet valve of the second closed-loop cooler are automatically opened according to the logical sequence relationship. In the case of multiple closed-loop cooling water systems operating simultaneously, it is determined whether the outlet header temperature of each closed-loop cooler is lower than the second preset temperature threshold within a first preset time period. If so, the inlet valve and outlet valve of the closed-loop cooler that has been running the longest are instructed to be closed. When all closed-loop water pumps in the closed-loop cooling water system are shut down, the inlet and outlet valves of all closed-loop coolers are automatically closed. The shutdown methods for the closed-loop water pump include: Based on the pressure of the closed cooler outlet header and the opening of the closed water pump recirculation regulating valve, it is determined whether the preset shutdown condition of the closed water pump is triggered. If so, the number of closed water pumps to be shut down is determined according to the current number of closed water pumps in operation, and the closed water pump with the longest running time is automatically selected as the target closed water pump and shut down. The preset shutdown conditions include at least two closed-loop water pumps being in operation, the opening degree of the closed-loop water pump recirculation regulating valve being greater than the preset opening degree value within a second preset time period, the pressure of the closed-loop cooler outlet header being greater than the preset pressure value, and the primary and secondary standby functions of the closed-loop water pumps being in the off state; the preset pressure value range is different when the number of units in operation is different. The closed-loop cooling water system includes a first closed-loop water pump, a second closed-loop water pump, and a third closed-loop water pump. The conditions under which the first closed-loop water pump can be put into operation include the first closed-loop water pump not being under on-site maintenance or prohibited from operation. The activation conditions for the primary standby function of the first closed-loop water pump include either manual activation via the primary standby button or automatic activation via the primary standby button. The exit conditions for the first closed-loop water pump's primary standby function include any one of the following: manual exit of the first closed-loop water pump's primary standby button, automatic exit of the first closed-loop water pump's primary standby, the first closed-loop water pump being in secondary standby mode, the first closed-loop water pump being running, the second closed-loop water pump being in primary standby mode, and the third closed-loop water pump being in primary standby mode. The conditions under which the secondary standby function of the first closed-loop water pump can be activated include that the first closed-loop water pump is not under on-site maintenance or prohibited from operation. The activation conditions for the secondary standby function of the first closed-loop water pump include either manual activation via the secondary standby button or automatic activation via the secondary standby function of the first closed-loop water pump. The exit conditions for the secondary standby function of the first closed-loop water pump include any one of the following: manual exit of the secondary standby function of the first closed-loop water pump by pressing the secondary standby button; automatic exit of the secondary standby function of the first closed-loop water pump; the first closed-loop water pump being in primary standby mode; the first closed-loop water pump being running; the second closed-loop water pump being in secondary standby mode; and the third closed-loop water pump being in secondary standby mode.

2. The self-shutdown control method for the closed-loop circulating cooling water system of a gas turbine combined cycle unit according to claim 1, characterized in that, The outlet header temperature of the closed-loop cooler is obtained in real time by a temperature transmitter, and the running time of the closed-loop cooler is obtained by a timer.

3. The self-shutdown control method for a closed-loop circulating cooling water system of a gas turbine combined cycle unit according to claim 1, characterized in that, When the two units are disconnected and all closed-loop cooling water users are shut down, the primary and secondary standby functions of all closed-loop water pumps will be automatically deactivated. After deactivating the primary and secondary standby functions of the closed-loop water pump, the running closed-loop water pump will be automatically shut down. After all the closed-loop water pumps stop operating, the closed-loop cooler automatically shuts down and closes the inlet electric valve and recirculation regulating valve of the closed-loop water pumps, restoring the closed-loop circulating water system to its initial state.

4. The self-shutdown control method for a closed-loop circulating cooling water system of a gas turbine combined cycle unit according to claim 1, characterized in that, After the target closed-loop water pump is shut down, it is determined whether the target closed-loop water pump is in operation. If so, it is instructed to shut down. After a delay of three preset times, the secondary standby function of the target closed-loop water pump is activated, and the primary standby function of the next closed-loop water pump is activated according to the logical sequence. If not, the closed-loop pump with the longest operating time other than the target closed-loop pump will be selected as the new target closed-loop pump, and it will be instructed to be shut down.

5. The self-shutdown control method for a closed-loop circulating cooling water system of a gas turbine combined cycle unit according to claim 1, characterized in that, The closed-loop cooling water system includes a closed-loop cooler shutdown module and a closed-loop water pump shutdown module. The closed-loop cooler shutdown module is used to measure the outlet header temperature of each closed-loop cooler in the closed-loop circulating cooling water system in real time, and automatically determine whether to change the start-up and shutdown status of each closed-loop cooler in the current system based on the outlet header temperature. The closed-loop pump shutdown module is used to acquire real-time operating information of the unit and the running time of the closed-loop pumps, and automatically determine the number of closed-loop pumps to be shut down based on the real-time operating information of the unit and the running time of the closed-loop pumps, and automatically instruct the target closed-loop pumps to be shut down.

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