Automatic pump merging and withdrawing control system and method in operation process of feed pump of gas turbine

Abstract

The invention discloses an automatic pump merging and withdrawing control system and method in the running process of a gas turbine feed pump. The system comprises a first switching selection module, a second switching selection module, a third switching selection module, a fourth switching selection module, a fifth switching selection module, a first function module, a second function module, a sixth switching selection module, a seventh switching selection module, a first large selection module, a second large selection module and the like. The method comprises the steps that when a pump retreating request A reduces the rotating speed to be 1, a second switching selection module directly outputs to a pump A rotating speed instruction output value constant 0 module, 0 is output downwards, and otherwise, the current value of a pump A rotating speed instruction is output; and the speed of reducing the rotating speed is obtained by multiplying the converted value of the pump inlet flow by the converted value of the deviation between the water supply set value and the actual water supply flow by the sixth switching selection module, or else, the speed is a constant 99 module. The safety performance in the pump combining and withdrawing processes of the pump is improved, and the operation intensity of operators is relieved.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent control of gas-fired generator sets, and in particular relates to a control system and method for automatically switching pumps during the operation of a gas turbine feedwater pump. Background Art

[0002] Gas generator sets are new types of generator sets developed to meet the world's environmental protection requirements and the new market environment. They mainly use natural gas or harmful gases as fuel to convert energy and generate electricity. The working principle of gas generator sets is to convert gas (such as natural gas, biogas, etc.) into electrical energy. In a combined cycle gas turbine, the gas first enters the turbine steam generator (compressor) to produce high-pressure and high-temperature gas, and then enters the combustion chamber to mix with air and burn. The high-temperature and high-pressure gas drives the turbine to rotate, and then drives the generator to generate electricity. In a gas internal combustion engine, the gas burns directly in the cylinder, drives the piston to move, drives the crankshaft to rotate through the connecting rod, and finally drives the generator to generate electricity.

[0003] During the load change of the unit, the water supply system plays an extremely important role in the safe and stable operation of the unit, and the water supply pump unit itself includes a complex system and corresponding control process, which has a great impact on the water supply system and even the safety of the entire unit operation. In the process of pumping and withdrawing pumps, the operating personnel are involved in the operation of complex equipment. In addition to real-time operation of the pump speed instructions for merging and withdrawing pumps, they also need to operate the pump outlet valve, pump recirculation regulating valve and other primary equipment, and there are many parameters that need to be monitored. The fluctuation of water supply flow, the change of recirculation valve opening, the change of water supply main pipe and pump outlet pressure difference and other parameters all need to be monitored in real time, resulting in the lack of continuity in the entire process of pumping and withdrawing pumps, which is time-consuming, complicated to operate, and the water supply flow fluctuates greatly, affecting the safe and stable operation of the unit. Summary of the invention

[0004] In order to solve the above-mentioned problems, the present invention provides a control system and method for automatic pump merging and pump withdrawal during the operation of a gas turbine feed water pump, so as to solve the problem of automatic pump merging and automatic pump withdrawal during the stable operation of the gas unit with increasing and decreasing loads, improve the safety performance during the pump merging and pump withdrawal process, reduce the operating intensity of the operators, and provide a control strategy for automatic pump merging and pump withdrawal with strong adaptability and robustness for the same type of units.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: The automatic parallel pump control system during the operation of the gas turbine feed water pump includes a first switching selection module, a second switching selection module, a third switching selection module, a fourth switching selection module, a fifth switching selection module, a first function module, a second function module, a sixth switching selection module, a seventh switching selection module, a first general selection module and a second general selection module; Both the first function module and the second function module are connected to the multiplication module and the sixth switch selection module input N; the pump B speed instruction is connected to the fourth switch selection module input N; the first switch selection module is connected to the second switch selection module and the pump A speed instruction in sequence; the first function module and the second function module are connected to the multiplication module and the sixth switch selection module; the third switch selection module and the sixth switch selection module are connected to the first large selection module, and the first large selection module is connected to the first switch selection module input Y; the fourth switch selection module is connected to the fifth switch selection module input N, the less than module is connected to the seventh switch selection module input N, the fifth switch selection module and the seventh switch selection module are connected to the second large selection module, and the second large selection module is connected to the second switch selection module input Y.

[0006] A further improvement of the present invention is that the speed instruction of pump A is connected to the first switching selection module input N, the third switching selection module input Y and the fifth switching selection module input Y respectively.

[0007] A further improvement of the present invention is that it also includes a first non-module, and the pump withdrawal request A pump slows down and connects the first non-module and the switch input of the third switching selection module, and also connects the switch input of the first switching selection module.

[0008] A further improvement of the present invention is that it also includes a second non-module, and the pump request A pump speed increase is connected to the switch input of the second switching selection module, and also connects the switch inputs of the second non-module and the seventh switching selection module.

[0009] A further improvement of the present invention is that the pump inlet flow is connected to the first function module.

[0010] A further improvement of the present invention is that it also includes a first subtraction module, and the water supply set value and the water supply flow rate are connected to the first subtraction module and the second function module.

[0011] A further improvement of the present invention is that it also includes a third function module and a second subtraction module, and the water supply set value and the water supply flow rate are connected to the second subtraction module and the third function module.

[0012] A further improvement of the present invention is that it further comprises a fourth function module and a third subtraction module, and the outlet pressure of pump B and the outlet pressure of pump A are both connected to the third subtraction module and the fourth function module.

[0013] The present invention also provides a method for automatically controlling the pump in and out of operation during the operation of a gas turbine feed water pump. The method is based on the automatic pump in and out of operation control system during the operation of a gas turbine feed water pump, and comprises: When the pump A speed reduction request is "1", the second switching selection module directly outputs to the pump A speed command output value is a constant 0 module, and outputs 0 downward, otherwise the output is based on the current value of the pump A speed command; the speed reduction rate is the sixth switching selection module based on the pump inlet flow conversion value multiplied by the water supply set value and the actual water supply flow deviation conversion value, otherwise the rate is a constant 99 module.

[0014] A further improvement of the present invention is that when the parallel pump request A pump speed increase output is "1", the second switching selection module directly outputs to the pump A speed command output the pump B speed command value after rate limiting, otherwise it outputs the current value, and the output rate is the rate converted from the water supply set value and the actual water supply flow deviation value and the pump A and B pump outlet pressure deviation conversion value to the second selection module, which takes the smaller value; otherwise the rate is not limited to a constant 99 modules; when the parallel pump pressure does not meet the output of "1", the pump A speed command output after rate limiting is the pump B speed command plus a constant 50 module revolutions.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects: The automatic pump merging and withdrawing control system and method for the fuel turbine feed water pump during operation provided by the present invention mainly adopts judgment conditions such as target load, unit load, A and B pump inlet flows, A pump recirculation opening, A pump speed command, B pump speed command, A pump outlet pressure, B pump outlet pressure, etc. to judge the pump withdrawal request A pump speed reduction, pump merging request A pump speed increase, and A pump withdrawal request, etc., to perform precise control of the speed increase and decrease of the feed water pump. Furthermore, the present invention solves the automatic control of pump merging and withdrawing during the unit load increase and decrease, greatly reduces the fluctuation of the feed water flow rate, enables the feed water pump to maintain a speed value suitable for the current feed water flow rate, reduces the operating intensity of the operating personnel, and realizes safe and stable operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a design diagram of the logic configuration scheme of the present invention.

[0017] Figure 2 It is a structural schematic diagram of the automatic pump parallel and retreat control system during the operation of the fuel engine feed water pump of the present invention. DETAILED DESCRIPTION

[0018] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0019] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0020] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0021] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0022] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0023] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0024] like Figure 1 As shown, the present invention uses a combination of an alarm module, a greater than module, a logic or module, a logic and module, a logic not module, an analog disturbance-free switching selection module, etc., mainly based on the target load, unit load, A, B pump inlet flow, A pump recirculation opening, A pump speed command, B pump speed command, A pump outlet pressure, B pump outlet pressure and other judgment conditions, to judge the pump withdrawal request A pump to slow down, the pump parallel request A pump to increase speed, and the pump withdrawal request A pump, etc., to accurately control the speed increase and speed decrease of the water supply pump. This method can meet the effective control of the water supply flow and pump speed under different operating conditions of the unit and reduce the fluctuation of the water supply flow. Through this constraint condition, the water supply pump instruction given value is switched to control the speed of the water supply pump so that the water supply pump maintains a speed value suitable for the current water supply flow.

[0025] The automatic pump connection and pump withdrawal control scheme during the operation of a fuel turbine feed water pump described in the present invention mainly adopts the following technical methods, including analog input: target load, unit load, A pump inlet flow, B pump inlet flow, A pump recirculation instruction, A pump recirculation feedback, pump A flow, A pump speed instruction, B pump speed instruction; switch input: A pump has been selected, parallel pump request to turn on A pump to increase the speed, pump withdrawal request to turn on A pump to reduce the speed; switch output: pump withdrawal request A pump to reduce the speed, parallel pump request A pump to increase the speed, parallel withdrawal request A pump, request to withdraw A pump, parallel pump pressure not met.

[0026] The switch input pump A has been selected, indicating that pump A is selected for parallel pump or pump withdrawal operation. Pump A has been selected and the target load is less than a certain value and the unit load is less than a certain value; or pump A has been selected and the inlet flow of pumps A and B is less than a certain value after selection and the opening of the recirculation valve of pump A is greater than 95%. If either of the two conditions is met, the RS trigger is triggered to withdraw the pump and request pump A to reduce the speed; if the target load is greater than a certain value and the unit load is greater than a certain value and then negated, or the speed command of pump A is less than 2850, or the parallel pump request pump A to increase the speed, or pump A has been selected and negated, any of the four conditions triggers the reset pump withdrawal request pump A to reduce the speed.

[0027] The switch input A pump has been selected, indicating that pump A is selected for parallel pump or pump withdrawal operation. Pump A has been selected and the target load is greater than a certain value and the unit load is greater than a certain value; or pump A has been selected and the inlet flow of pumps A and B is greater than a certain value after the election. If either of the two conditions is met, the RS trigger is triggered to request pump A to increase the speed; the target load is greater than a certain value and the unit load is greater than a certain value and then negated, or the inlet flow of pumps A and B is greater than a certain value after the election, or the speed command deviation of pumps A and B is greater than -0.1 and the outlet pressure deviation of pumps A and B is greater than -0.2, or pump withdrawal request pump A to reduce speed, or pump A has been selected and negated, any of the four conditions triggers the reset parallel pump request pump A to increase speed. Pump withdrawal request pump A to reduce speed or parallel pump request pump A to increase speed is triggered, and pump A is withdrawn. When parallel pump request pump A to increase speed, the speed command deviation of pumps A and B is greater than -0.1 and the outlet pressure deviation of pumps A and B is greater than -0.2 and negated, triggering parallel pump pressure is not met.

[0028] Example 1 like Figure 2As shown, the automatic parallel pump control system during the operation of the gas turbine feed water pump provided in this embodiment includes a first switching selection module 1, a second switching selection module 2, a third switching selection module 3, a fourth switching selection module 4, a fifth switching selection module 5, a first function module 6, a second function module 7, a sixth switching selection module 8, a seventh switching selection module 11, a first general selection module 17 and a second general selection module 18; the first function module 6 and the second function module 7 are both connected to the multiplication module and the sixth switching selection module 8 input N; the pump B speed command is connected to the fourth switching selection module 4 input N; the first switching selection module (1) is respectively It is connected to the second switching selection module 2 and the pump A speed instruction in sequence; the first function module 6 and the second function module 7 are connected to the multiplication module and the sixth switching selection module 8; the third switching selection module 3 and the sixth switching selection module 8 are connected to the first large selection module 17, and the first large selection module 17 is connected to the first switching selection module 1 input Y; the fourth switching selection module 4 is connected to the fifth switching selection module 5 input N, the less than module is connected to the seventh switching selection module 11 input N, the fifth switching selection module 5 and the seventh switching selection module 11 are connected to the second large selection module 18, and the second large selection module 18 is connected to the second switching selection module 2 input Y.

[0029] In this embodiment, the speed command of pump A is connected to the input N of the first switching selection module 1 , the input Y of the third switching selection module 3 , and the input Y of the fifth switching selection module 5 , respectively.

[0030] In this embodiment, a first non-module 12 is further included, and the pump withdrawal request A pump speed reduction is connected to the first non-module 12 and the switch input of the third switching selection module 3, and is also connected to the switch input of the first switching selection module 1.

[0031] In this embodiment, a second non-module 13 is further included, and the pump request A pump speed increase is connected to the switch input of the second switching selection module 2, and the second non-module 13 and the switch input of the seventh switching selection module 11 are also connected.

[0032] In this embodiment, the pump inlet flow is connected to the first function module 6 .

[0033] In this embodiment, a first subtraction module 14 is further included, and the water supply set value and the water supply flow rate are connected to the first subtraction module 14 and the second function module 7 .

[0034] In this embodiment, a third function module 9 and a second subtraction module 15 are further included, and the water supply set value and the water supply flow rate are connected to the second subtraction module 15 and the third function module 9 .

[0035] In this embodiment, a fourth function module 10 and a third subtraction module 16 are further included, and the outlet pressure of pump B and the outlet pressure of pump A are both connected to the third subtraction module 16 and the fourth function module 10 .

[0036] Example 2 like Figure 2 As shown, the automatic parallel pump control system during the operation of the gas turbine feed water pump provided in this embodiment includes a first switching selection module 1, a second switching selection module 2, a third switching selection module 3, a fourth switching selection module 4, a fifth switching selection module 5, a first function module 6, a second function module 7, a sixth switching selection module 8, a third function module 9, a fourth function module 10, a seventh switching selection module 11, a first non-module 12, a second non-module 13, a first subtraction module 14, a second subtraction module 15, a third subtraction module 16, a first general selection module 17, a second general selection module 18, a constant 0 module 19, a constant 50 module 20, and a constant 99 module 21.

[0037] The speed command of pump A is connected to the input N of the first switching selection module 1, the input Y of the third switching selection module 3 and the input Y of the fifth switching selection module 5 respectively; the pump deactivation request for pump A to slow down is connected to the switching switch input of the first non-module 12 and the third switching selection module 3, and is also connected to the switching switch input of the first switching selection module 1; the pump request for pump A to speed up is connected to the switching switch input of the second switching selection module 2, and is also connected to the switching switch input of the second non-module 13 and the seventh switching selection module 11; the pump inlet flow is connected to the first function module 6, the water supply set value and the water supply flow are both connected to the first subtraction module 14 and the second function module 7, and the first function module 6 and the second function module 7 are both connected to the multiplication module and the sixth switching selection module 8 input N; the speed command of pump B is connected to the input N of the fourth switching selection module 4; the water supply set value and the water supply flow are both connected to the second subtraction module 15 and the third function module 9; the outlet pressure of pump B and the outlet pressure of pump A are both connected to the third subtraction module 16 and the fourth function module 10. The first switching selection module 1 is connected to the second switching selection module 2 and the speed command of pump A (and the pump is withdrawn) in sequence; the first function module 6 and the second function module 7 are connected to the multiplication module and the sixth switching selection module 8; the third switching selection module 3 and the sixth switching selection module 8 are connected to the first large selection module 17, and the first large selection module 17 is connected to the input Y of the first switching selection module 1; the fourth switching selection module 4 is connected to the input N of the fifth switching selection module 5, the less than module is connected to the input N of the seventh switching selection module 11, the fifth switching selection module 5 and the seventh switching selection module 11 are connected to the second large selection module 18, and the second large selection module 18 is connected to the input Y of the second switching selection module 2.

[0038] Example 3 like Figure 2 As shown, the method for automatically controlling the pump in parallel and out of operation during the operation of the gas turbine feed water pump provided in this embodiment includes: When the pump A speed reduction request is "1", the second switching selection module 2 directly outputs to the pump A speed command output value as constant 0 module 19, and outputs 0 downward, otherwise the output is based on the current value of the pump A speed command; the speed reduction rate is the sixth switching selection module based on the pump inlet flow conversion value multiplied by the water supply set value and the actual water supply flow deviation conversion value, otherwise the rate is constant 99 module 21.

[0039] In this embodiment, when the parallel pump request A pump speed increase output is "1", the second switching selection module 2 directly outputs to the pump A speed command output the pump B speed command value after the speed limit, otherwise it outputs the current value, and the output rate is the rate converted from the water supply set value and the actual water supply flow deviation value and the pump A and B pump outlet pressure deviation conversion value to the second selection module 18, which takes the smaller value; otherwise, the rate is not limited to the constant 99 module 21. When the parallel pump pressure does not meet the output of "1", the value of the pump A speed command output after the speed limit is the pump B speed command plus the constant 50 module 20 turns.

[0040] The present invention provides a control system and method for automatically merging and retreating pumps during the operation of a fuel turbine feed water pump. The control system and method mainly adopt the target load, unit load, A and B pump inlet flows, A pump recirculation opening, A pump speed command, B pump speed command, A pump outlet pressure, B pump outlet pressure and other judgment conditions to judge the conditions such as the retreat pump request A pump speed reduction, the merging pump request A pump speed increase, and the merging and retreating A pump request, so as to accurately control the speed increase and speed decrease of the feed water pump. The method can meet the effective control of the feed water flow and the pump speed under different operating conditions of the unit and reduce the fluctuation of the feed water flow. Through this constraint condition, the feed water pump instruction given value is switched to control the feed water pump speed so that the feed water pump maintains a speed value suitable for the current feed water flow.

[0041] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0042] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. Automatic pump-in and pump-out control system during operation of gas turbine feedwater pump, characterized in that: It comprises a first switching selection module (1), a second switching selection module (2), a third switching selection module (3), a fourth switching selection module (4), a fifth switching selection module (5), a first function module (6), a second function module (7), a sixth switching selection module (8), a seventh switching selection module (11), a first general election module (17) and a second general election module (18); The first function module (6) and the second function module (7) are both connected to the multiplication module and the sixth switch selection module (8) input N; the pump B speed command is connected to the fourth switch selection module (4) input N; the first switch selection module (1) is connected to the second switch selection module (2) and the pump A speed command in sequence; the first function module (6) and the second function module (7) are connected to the multiplication module and the sixth switch selection module (8); the third switch selection module (3) and the sixth switch selection module (8) are connected to the first general selection module (17), and the first general selection module (17) is connected to the first switch selection module (1) input Y; the fourth switch selection module (4) is connected to the fifth switch selection module (5) input N, the less than module is connected to the seventh switch selection module (11) input N, the fifth switch selection module (5) and the seventh switch selection module (11) are connected to the second general selection module (18), and the second general selection module (18) is connected to the second switch selection module (2) input Y.

2. The automatic pump-in / out control system for the gas turbine feedwater pump during operation according to claim 1, characterized in that: The speed command of pump A is respectively connected to the input N of the first switching selection module (1), the input Y of the third switching selection module (3) and the input Y of the fifth switching selection module (5).

3. The automatic pump-in / out control system for the gas turbine feedwater pump during operation according to claim 2, characterized in that: It also includes a first non-module (12), and the pump withdrawal request A pump slows down and is connected to the first non-module (12) and the switch input of the third switch selection module (3), and is also connected to the switch input of the first switch selection module (1).

4. The automatic pump paralleling and withdrawing control system during the operation of the gas turbine feed water pump according to claim 3 is characterized in that: It also includes a second non-module (13), and the pump request A pump speed increase is connected to the switch input of the second switching selection module (2), and the switch inputs of the second non-module (13) and the seventh switching selection module (11) are also connected.

5. The automatic pump-in / out control system for the gas turbine feedwater pump during operation according to claim 4, characterized in that: The pump inlet flow is connected to the first function module (6).

6. The automatic pump-in / out control system for the gas turbine feedwater pump during operation according to claim 5, characterized in that: It also includes a first subtraction module (14), and the water supply set value and the water supply flow rate are connected to the first subtraction module (14) and the second function module (7).

7. The automatic pump paralleling and withdrawing control system during the operation of the gas turbine feed water pump according to claim 6 is characterized in that: It also includes a third function module (9) and a second subtraction module (15), and the water supply set value and the water supply flow rate are connected to the second subtraction module (15) and the third function module (9).

8. The automatic pump-in / out control system for the operation of a gas turbine feedwater pump according to claim 7, characterized in that: It also includes a fourth function module (10) and a third subtraction module (16), and the B pump outlet pressure and the A pump outlet pressure are both connected to the third subtraction module (16) and the fourth function module (10).

9. Automatic pump-in and pump-out control method during operation of a gas turbine feedwater pump, characterized in that: The method is based on the automatic pump-return control system during the operation of the gas turbine feed water pump as claimed in claim 8, comprising: When the pump A speed reduction request is "1", the second switching selection module (2) directly outputs to the pump A speed command output value constant 0 module (19), and outputs 0 downward, otherwise the output is based on the current value of the pump A speed command; the speed reduction rate is the sixth switching selection module based on the pump inlet flow conversion value multiplied by the water supply set value and the actual water supply flow rate deviation conversion value, otherwise the rate is a constant 99 module (21).

10. The method for automatically controlling the pump in parallel and out of operation during the operation of a gas turbine feedwater pump according to claim 9, characterized in that: When the parallel pump request A pump speed increase output is "1", the second switching selection module (2) directly outputs to the pump A speed command output the pump B speed command value after the speed limit, otherwise it outputs the current value, the output rate is the smaller value of the rate converted from the water supply set value and the actual water supply flow deviation value and the pump A and pump B outlet pressure deviation conversion value to the second selection module (18); otherwise, the rate is not limited to a constant 99 module (21); when the parallel pump pressure does not meet the output of "1", the pump A speed command output after the speed limit is the pump B speed command plus the constant 50 module (20) revolutions.

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