Power plant circulating water waste heat utilization control system and method

Abstract

The present application relates to the technical field of automation control, and particularly relates to a power plant circulating water waste heat utilization control system and method. The system comprises a condenser, a cooling tower, a circulating water heat exchanger connected with a water outlet main pipe of the condenser, a chemical water pool connected with the circulating water heat exchanger, and a chemical water circulating pump arranged between a water outlet of the chemical water pool and a water inlet of the circulating water heat exchanger, the chemical water circulating pump being used for conveying water in the chemical water pool to the circulating water heat exchanger. A detection unit is used for detecting the water temperature of the water outlet of the chemical water pool in real time. A control unit is used for controlling the water amount of the chemical water circulating pump conveying water in the chemical water pool to the circulating water heat exchanger according to the water temperature of the water outlet of the chemical water pool. The present application can prevent the problems of reverse osmosis water yield reduction and membrane group service life reduction caused by too low chemical water temperature by utilizing the power plant circulating water waste heat to heat the fluid in the heat exchanger and then heat the chemical water.

Description

Technical Field

[0001] This invention relates to the field of automation control technology, and in particular to a control system and method for utilizing waste heat from circulating water in power plants. Background Technology

[0002] The heat loss from the cold source in a power plant is the largest loss among thermal power plants. Therefore, reducing and effectively utilizing the cold source loss of the steam turbine is an effective way to improve the overall economic efficiency of the unit operation.

[0003] Membrane systems are the core component of power plant chemical water treatment systems. However, the permeate output of reverse osmosis (RO) units is significantly affected by temperature (RO output decreases by 2%–3% for every 1°C drop in temperature), especially during the low temperatures of winter and spring. When the water temperature drops below 5°C, the lower temperature causes the pores of the RO membrane to shrink, reducing the water flow and increasing wastewater discharge. Simultaneously, the smaller pore size leads to increased pressure on the equipment, causing membrane compaction and impacting its lifespan. Therefore, it is necessary to increase the inlet water temperature to ensure safe and economical operation. Thus, providing a control system and method for the utilization of waste heat from power plant circulating water is a crucial technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a control system and method for utilizing waste heat from power plant circulating water. This invention utilizes the waste heat from power plant circulating water to heat the fluid in the heat exchanger, thereby heating the chemical water. This not only prevents the problem of reduced reverse osmosis permeate production and membrane life caused by excessively low chemical water temperature, but also recovers the heat from the circulating water, reduces the burden on the circulating water cooling tower, and reduces the power consumption of the cooling tower fan and the loss of water from splashing.

[0005] In addition, when the weather warms up or the flow rate of the chemical water changes, the amount of water entering the chemical water heater can be adjusted through the valve until it is completely shut down from the operation of this system.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A power plant circulating water waste heat recovery control system includes:

[0008] Condenser;

[0009] A cooling tower, which is connected to the condenser;

[0010] A circulating water heat exchanger is connected to the outlet header of the condenser and is also connected to the cooling tower.

[0011] a chemical water pool connected with the circulating water heat exchanger, and a chemical water circulating pump arranged between a water outlet of the chemical water pool and a water inlet of the circulating water heat exchanger, the chemical water circulating pump being used to deliver water in the chemical water pool to the circulating water heat exchanger;

[0012] Further comprising:

[0013] a detection unit used to detect water temperature T of the water outlet of the chemical water pool in real time;

[0014] a control unit used to control the amount of water delivered by the chemical water circulating pump from the chemical water pool to the circulating water heat exchanger according to the water temperature T of the water outlet of the chemical water pool.

[0015] In some embodiments of the present application, a first valve is arranged between the circulating water heat exchanger and the condenser, the first valve being used to control the flow into the circulating water heat exchanger;

[0016] a bypass valve arranged between the cooling tower and the condenser, and a second valve arranged between the circulating water heat exchanger and the cooling tower, the bypass valve and the second valve being used to control and isolate the circulating water heat exchanger;

[0017] a third valve arranged between the circulating water heat exchanger and the chemical water circulating pump, a fourth valve arranged between the chemical water pool and the chemical water circulating pump, and a fifth valve arranged between the circulating water heat exchanger and the chemical water pool;

[0018] The control unit is further used to control the bypass valve, the first valve, the second valve, the third valve, the fourth valve and the fifth valve according to the operating state of the power plant circulating water waste heat utilization control system, the operating state including a working state and a shutdown state; wherein,

[0019] when the operating state of the power plant circulating water waste heat utilization control system is the working state, the bypass valve is controlled to be closed and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are controlled to be opened;

[0020] when the operating state of the power plant circulating water waste heat utilization control system is the shutdown state, the bypass valve is controlled to be opened and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are controlled to be closed.

[0021] In some embodiments of the present application, the control unit is provided with a preset water outlet temperature value matrix T0 and a preset water delivery amount matrix A, wherein A (A1, A2, A3, A4) is set for the preset water delivery amount matrix A, A1 is a first preset water delivery amount, A2 is a second preset water delivery amount, A3 is a third preset water delivery amount, A4 is a fourth preset water delivery amount, and A1

[0022] T0 (T01, T02, T03, T04) is set for the preset water outlet temperature value matrix T0, T01 is a first preset water outlet temperature value, T02 is a second preset water outlet temperature value, T03 is a third preset water outlet temperature value, T04 is a fourth preset water outlet temperature value, and T01

[0023] The control unit is configured to select a corresponding water delivery amount as the water amount for controlling the water in the chemical water tank to be delivered to the circulating water heat exchanger according to the relationship between T and the preset water outlet temperature value matrix T0;

[0024] When T < T01, the fourth preset water delivery amount A4 is selected as the water amount for controlling the water in the chemical water tank to be delivered to the circulating water heat exchanger;

[0025] When T01≤T

[0026] When T02≤T

[0027] When T03≤T

[0028] In some embodiments of the present application, further comprising:

[0029] A monitoring unit is configured to monitor the water outlet temperature K of the circulating water heat exchanger in real time;

[0030] The control unit is further configured to adjust the water amount delivered to the circulating water heat exchanger according to the water outlet temperature K of the circulating water heat exchanger;

[0031] The control unit is also provided with a preset circulating water heat exchanger outlet water temperature value matrix R0 and a preset water delivery amount correction coefficient matrix B. For the preset water delivery amount correction coefficient matrix B, B (B1, B2, B3, B4) is set, wherein B1 is a first preset water delivery amount correction coefficient, B2 is a second preset water delivery amount correction coefficient, B3 is a third preset water delivery amount correction coefficient, and B4 is a fourth preset water delivery amount correction coefficient, and 1

[0032] The control unit is also used for selecting a corresponding water delivery amount correction coefficient according to the relationship between K and the preset circulating water heat exchanger outlet water temperature value matrix R0 to correct and adjust each preset water delivery amount.

[0033] When K

[0034] When R01≤K

[0035] When R02≤K

[0036] When R03≤K

[0037] In some embodiments of the present application, the control unit is a PLC controller.

[0038] In order to achieve the above-mentioned purpose, the present application also correspondingly provides a power plant circulating water waste heat utilization control method applied in the power plant circulating water waste heat utilization control system, comprising:

[0039] Real-time detection of the water temperature T of the outlet of the chemical water pool;

[0040] Controlling the water delivery amount of the chemical water circulating pump to deliver the water in the chemical water pool to the circulating water heat exchanger according to the water temperature T of the outlet of the chemical water pool.

[0041] In some embodiments of the present application, further comprising:

[0042] Controlling the bypass valve, the first valve, the second valve, the third valve, the fourth valve and the fifth valve according to an operation state of the power plant circulating water waste heat utilization control system, the operation state including a working state and a shutdown state; wherein,

[0043] When the operation state of the power plant circulating water waste heat utilization control system is the working state, controlling the bypass valve to be closed and the first valve, the second valve, the third valve, the fourth valve and the fifth valve to be opened;

[0044] When the operation state of the power plant circulating water waste heat utilization control system is the shutdown state, controlling the bypass valve to be opened and the first valve, the second valve, the third valve, the fourth valve and the fifth valve to be closed.

[0045] In some embodiments of the present application, a preset outlet water temperature value matrix T0 and a preset water delivery amount matrix A are preset, for the preset water delivery amount matrix A, A (A1, A2, A3, A4) is set, wherein A1 is a first preset water delivery amount, A2 is a second preset water delivery amount, A3 is a third preset water delivery amount, A4 is a fourth preset water delivery amount, and A1

[0046] For the preset outlet water temperature value matrix T0, T0 (T01, T02, T03, T04) is set, wherein T01 is a first preset outlet water temperature value, T02 is a second preset outlet water temperature value, T03 is a third preset outlet water temperature value, T04 is a fourth preset outlet water temperature value, and T01

[0047] According to the relationship between T and the preset outlet water temperature value matrix T0, a corresponding water delivery amount is selected as the water amount for controlling the water in the chemical pool to be delivered to the circulating water heat exchanger;

[0048] When T

[0049] When T01≤T

[0050] When T02≤T

[0051] When T03≤T<T04, the first preset water delivery amount A1 is selected as the water amount for controlling the water in the chemical tank to be delivered to the circulating water heat exchanger.

[0052] In some embodiments of the present application, further comprising:

[0053] real-time water temperature K of the circulating water heat exchanger;

[0054] adjusting the water amount delivered to the circulating water heat exchanger according to the water temperature K of the circulating water heat exchanger;

[0055] a preset circulating water heat exchanger outlet water temperature value matrix R0 and a preset water delivery amount correction coefficient matrix B, wherein B(B1, B2, B3, B4), B1 is the first preset water delivery amount correction coefficient, B2 is the second preset water delivery amount correction coefficient, B3 is the third preset water delivery amount correction coefficient, B4 is the fourth preset water delivery amount correction coefficient, and 1

[0056] selecting the corresponding water delivery amount correction coefficient according to the relationship between K and the preset circulating water heat exchanger outlet water temperature value matrix R0 to correct and adjust each preset water delivery amount;

[0057] When K<R01, the fourth preset water delivery amount correction coefficient B4 is selected to correct the fourth preset water delivery amount A4, and the corrected water delivery amount is A4*B4;

[0058] When R01≤K<R02, the third preset water delivery amount correction coefficient B3 is selected to correct the third preset water delivery amount A3, and the corrected water delivery amount is A3*B3;

[0059] When R02≤K<R03, the second preset water delivery amount correction coefficient B2 is selected to correct the second preset water delivery amount A2, and the corrected water delivery amount is A2*B2;

[0060] When R03≤K<R04, the first preset water delivery amount correction coefficient B1 is selected to correct the first preset water delivery amount A1, and the corrected water delivery amount is A1*B1.

[0061] In some embodiments of the present application, the power plant circulating water waste heat utilization control system is controlled by a PLC control algorithm.

[0062] The present application provides a power plant circulating water waste heat utilization control system and method, which has the beneficial effect that, compared with the prior art,

[0063] The present application uses the waste heat of the circulating water of the power plant to heat the fluid in the heat exchanger, and then heats the chemical water, which not only prevents the problems of reduced reverse osmosis water production and reduced membrane group life caused by too low chemical water temperature, but also recovers the heat of the circulating water, reduces the burden of the circulating water cooling tower, reduces the power consumption of the cooling tower fan and the water loss caused by the scattering of water, improves the safety and economy of the operation of the equipment, and when the air is warmed or the chemical water flow changes, the amount of water entering the chemical water calorimeter can be adjusted through the valve until the operation of the entire system is completely exited, ensuring stable operation of the system, and the use of automatic control technology improves the overall system operation efficiency and optimizes the cost. BRIEF DESCRIPTION OF DRAWINGS

[0064] Figure 1 is a structural block diagram of the power plant circulating water waste heat utilization control system in the embodiment of the present application;

[0065] Figure 2 is a flowchart of the power plant circulating water waste heat utilization control method in the embodiment of the present application. DETAILED DESCRIPTION

[0066] The specific embodiments of the present application will be further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0067] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0068] The terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0069] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0070] Referring to Figure 1 The disclosed embodiments of the present application provide a power plant circulating water waste heat utilization control system, comprising:

[0071] A condenser;

[0072] A cooling tower connected with the condenser;

[0073] A circulating water heat exchanger connected with the water outlet main pipe of the condenser, and also connected with the cooling tower;

[0074] A chemical water pool connected with the circulating water heat exchanger, and a chemical water circulating pump is arranged between the water outlet of the chemical water pool and the water inlet of the circulating water heat exchanger, and the chemical water circulating pump is used to transport water in the chemical water pool to the circulating water heat exchanger;

[0075] Further comprising:

[0076] A detection unit for detecting the water temperature T of the water outlet of the chemical water pool in real time;

[0077] A control unit for controlling the amount of water transported by the chemical water circulating pump from the chemical water pool to the circulating water heat exchanger according to the water temperature T of the water outlet of the chemical water pool.

[0078] It can be understood that the circulating water heat exchanger is arranged in the circulating water outlet main pipe of the condenser, and exchanges heat with the chemical water, and the countercurrent flow design is beneficial to realize the best heat transfer efficiency. The chemical water circulating pump transports water from the chemical water pool to the circulating water heat exchanger, and after absorbing heat, returns to the chemical water pool. The frequency conversion design is convenient for adjusting the flow and saving energy. Through the above design, the working efficiency of the system can be effectively improved and the energy consumption of the system can be greatly reduced.

[0079] In a specific embodiment of the present application, a first valve is arranged between the circulating water heat exchanger and the condenser, and the first valve is used to control the flow into the circulating water heat exchanger;

[0080] A bypass valve is arranged between the cooling tower and the condenser, and a second valve is arranged between the circulating water heat exchanger and the cooling tower, and the bypass valve and the second valve are used to control and isolate the circulating water heat exchanger;

[0081] A third valve is arranged between the circulating water heat exchanger and the chemical water circulating pump, a fourth valve is arranged between the chemical water pool and the chemical water circulating pump, and a fifth valve is arranged between the circulating water heat exchanger and the chemical water pool;

[0082] The control unit is further configured to control the bypass valve, the first valve, the second valve, the third valve, the fourth valve and the fifth valve according to an operating state of the power plant circulating water waste heat utilization control system, the operating state including a working state and a shutdown state; wherein,

[0083] When the operating state of the power plant circulating water waste heat utilization control system is the working state, the bypass valve is controlled to be closed and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are controlled to be opened;

[0084] When the operating state of the power plant circulating water waste heat utilization control system is the shutdown state, the bypass valve is controlled to be opened and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are controlled to be closed.

[0085] In an embodiment of the present application, a preset outlet water temperature value matrix T0 and a preset water delivery amount matrix A are set in the control unit. For the preset water delivery amount matrix A, A (A1, A2, A3, A4) is set, wherein A1 is a first preset water delivery amount, A2 is a second preset water delivery amount, A3 is a third preset water delivery amount, A4 is a fourth preset water delivery amount, and A1 < A2 < A3 < A4;

[0086] For the preset outlet water temperature value matrix T0, T0 (T01, T02, T03, T04) is set, wherein T01 is a first preset outlet water temperature value, T02 is a second preset outlet water temperature value, T03 is a third preset outlet water temperature value, T04 is a fourth preset outlet water temperature value, and T01 < T02 < T03 < T04;

[0087] The control unit is configured to select a corresponding water delivery amount as the water amount for controlling the water in the chemical water pool to be delivered to the circulating water heat exchanger according to the relationship between T and the preset outlet water temperature value matrix T0;

[0088] When T < T01, the fourth preset water delivery amount A4 is selected as the water amount for controlling the water in the chemical water pool to be delivered to the circulating water heat exchanger;

[0089] When T01 ≤ T < T02, the third preset water delivery amount A3 is selected as the water amount for controlling the water in the chemical water pool to be delivered to the circulating water heat exchanger;

[0090] When T02 ≤ T < T03, the second preset water delivery amount A2 is selected as the water amount for controlling the water in the chemical water pool to be delivered to the circulating water heat exchanger;

[0091] When T03≤T<T04, the first preset water delivery amount A1 is selected as the water amount for controlling the water in the chemical tank to be delivered to the circulating water heat exchanger.

[0092] In one embodiment of the present application, further comprising:

[0093] a monitoring unit, configured to monitor the outlet water temperature K of the circulating water heat exchanger in real time;

[0094] the control unit is further configured to adjust the water amount delivered to the circulating water heat exchanger according to the outlet water temperature K of the circulating water heat exchanger;

[0095] a preset circulating water heat exchanger outlet water temperature value matrix R0 and a preset water delivery amount correction coefficient matrix B are further set in the control unit, wherein B(B1, B2, B3, B4) is set for the preset water delivery amount correction coefficient matrix B, B1 is the first preset water delivery amount correction coefficient, B2 is the second preset water delivery amount correction coefficient, B3 is the third preset water delivery amount correction coefficient, B4 is the fourth preset water delivery amount correction coefficient, and 1<B1<B2<B3<B4<1.5; R0(R01, R02, R03, R04) is set for the preset circulating water heat exchanger outlet water temperature value matrix R0, R01 is the first preset circulating water heat exchanger outlet water temperature value, R02 is the second preset circulating water heat exchanger outlet water temperature value, R03 is the third preset circulating water heat exchanger outlet water temperature value, R04 is the fourth preset circulating water heat exchanger outlet water temperature value, and R01<R02<R03<R04;

[0096] the control unit is further configured to select the corresponding water delivery amount correction coefficient according to the relationship between K and the preset circulating water heat exchanger outlet water temperature value matrix R0 to correct and adjust each preset water delivery amount;

[0097] when K<R01, the fourth preset water delivery amount correction coefficient B4 is selected to correct the fourth preset water delivery amount A4, and the corrected water delivery amount is A4*B4;

[0098] when R01≤K<R02, the third preset water delivery amount correction coefficient B3 is selected to correct the third preset water delivery amount A3, and the corrected water delivery amount is A3*B3;

[0099] when R02≤K<R03, the second preset water delivery amount correction coefficient B2 is selected to correct the second preset water delivery amount A2, and the corrected water delivery amount is A2*B2;

[0100] when R03≤K<R04, the first preset water delivery amount correction coefficient B1 is selected to correct the first preset water delivery amount A1, and the corrected water delivery amount is A1*B1.

[0101] In an embodiment of the present application, the control unit is a PLC controller.

[0102] Based on the same technical concept, the present application also correspondingly provides a power plant circulating water waste heat utilization control method, which is applied to a power plant circulating water waste heat utilization control system and comprises the following steps of: Figure 2

[0103] Detecting the water temperature T of the outlet of the chemical water pool in real time;

[0104] Controlling the water amount of the chemical water circulating pump to deliver the water in the chemical water pool to the circulating water heat exchanger according to the water temperature T of the outlet of the chemical water pool.

[0105] In an embodiment of the present application, the power plant circulating water waste heat utilization control system further comprises:

[0106] Controlling the bypass valve, the first valve, the second valve, the third valve, the fourth valve and the fifth valve according to the operation state of the power plant circulating water waste heat utilization control system, wherein the operation state comprises a working state and a shutdown state; and

[0107] When the operation state of the power plant circulating water waste heat utilization control system is the working state, the bypass valve is controlled to be closed and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are controlled to be opened;

[0108] When the operation state of the power plant circulating water waste heat utilization control system is the shutdown state, the bypass valve is controlled to be opened and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are controlled to be closed.

[0109] In an embodiment of the present application, a preset outlet water temperature value matrix T0 and a preset water delivery amount matrix A are preset, wherein A(A1, A2, A3, A4) is set for the preset water delivery amount matrix A, A1 is a first preset water delivery amount, A2 is a second preset water delivery amount, A3 is a third preset water delivery amount, A4 is a fourth preset water delivery amount, and A1

[0110] T0(T01, T02, T03, T04) is set for the preset outlet water temperature value matrix T0, T01 is a first preset outlet water temperature value, T02 is a second preset outlet water temperature value, T03 is a third preset outlet water temperature value, T04 is a fourth preset outlet water temperature value, and T01

[0111] Selecting a corresponding water delivery amount as the water amount of the chemical water circulating pump to deliver the water in the chemical water pool to the circulating water heat exchanger according to the relationship between T and the preset outlet water temperature value matrix T0;

[0112] ​When T < T01, the fourth preset water delivery amount A4 is selected as the water amount for controlling the water in the chemical water tank to be delivered to the circulating water heat exchanger;

[0113] When T01≤T < T02, the third preset water delivery amount A3 is selected as the water amount for controlling the water in the chemical water tank to be delivered to the circulating water heat exchanger;

[0114] When T02≤T < T03, the second preset water delivery amount A2 is selected as the water amount for controlling the water in the chemical water tank to be delivered to the circulating water heat exchanger;

[0115] When T03≤T < T04, the first preset water delivery amount A1 is selected as the water amount for controlling the water in the chemical water tank to be delivered to the circulating water heat exchanger.

[0116] In one embodiment of the present application, further comprising:

[0117] the water temperature K of the circulating water heat exchanger;

[0118] adjusting the water amount delivered to the circulating water heat exchanger according to the water temperature K of the circulating water heat exchanger;

[0119] a preset circulating water heat exchanger outlet water temperature value matrix R0 and a preset water delivery amount correction coefficient matrix B are preset, for the preset water delivery amount correction coefficient matrix B, B (B1, B2, B3, B4) is set, wherein B1 is the first preset water delivery amount correction coefficient, B2 is the second preset water delivery amount correction coefficient, B3 is the third preset water delivery amount correction coefficient, and B4 is the fourth preset water delivery amount correction coefficient, and 1 < B1 < B2 < B3 < B4 < 1.5; for the preset circulating water heat exchanger outlet water temperature value matrix R0, R0 (R01, R02, R03, R04) is set, wherein R01 is the first preset circulating water heat exchanger outlet water temperature value, R02 is the second preset circulating water heat exchanger outlet water temperature value, R03 is the third preset circulating water heat exchanger outlet water temperature value, and R04 is the fourth preset circulating water heat exchanger outlet water temperature value, and R01 < R02 < R03 < R04;

[0120] a corresponding water delivery amount correction coefficient is selected according to the relationship between K and the preset circulating water heat exchanger outlet water temperature value matrix R0 to correct and adjust each preset water delivery amount;

[0121] When K < R01, the fourth preset water delivery amount correction coefficient B4 is selected to correct the fourth preset water delivery amount A4, and the corrected water delivery amount is A4*B4;

[0122] When R01≤K < R02, the third preset water delivery amount correction coefficient B3 is selected to correct the third preset water delivery amount A3, and the corrected water delivery amount is A3*B3;

[0123] When R02≤K<R03, a second preset delivery water quantity correction coefficient B2 is selected to correct the second preset delivery water quantity A2, and the corrected delivery water quantity is A2*B2;

[0124] When R03≤K<R04, a first preset delivery water quantity correction coefficient B1 is selected to correct the first preset delivery water quantity A1, and the corrected delivery water quantity is A1*B1.

[0125] In an embodiment of the present application, the power plant circulating water waste heat utilization control system is controlled by a PLC control algorithm.

[0126] To sum up, the present application utilizes the power plant circulating water waste heat to heat the fluid in the heat exchanger, and further heats the chemical water, which not only prevents the problems of reduced reverse osmosis water production and reduced membrane group service life caused by too low chemical water temperature, but also recovers the circulating water heat, reduces the burden of the circulating water cooling tower, reduces the fan power consumption and water scattering loss of the cooling tower, improves the safety and economy of the equipment operation, and when the air is warmed or the chemical water flow changes, the water quantity entering the chemical water calorimeter can be adjusted by the valve until the whole system is withdrawn from operation, ensuring stable operation of the system, and the automatic control technology improves the overall system operation efficiency and optimizes the cost adjustment. The present application has the advantages of accuracy, real-time and automation.

[0127] The above only describes one embodiment of the present application, but cannot limit the scope of the present application, and any structural changes made according to the present application, as long as the essence of the present application is not lost, should be considered to fall within the scope of the present application.

[0128] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process and related description of the system described above can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0129] It should be noted that the system provided in the above embodiments is only exemplified by the division of the above functional modules, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the modules or steps in the embodiments of the present application can be further divided or combined, for example, the modules in the above embodiments can be combined into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present application are only for distinguishing the modules and steps, and should not be considered as an improper limitation of the present application.

[0130] Those skilled in the art should clearly understand that the modules and method steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware, computer software or a combination of both. The programs corresponding to the software modules and method steps can be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In order to clearly illustrate the interchangeability of electronic hardware and software, the components and steps of each example have been described in the above description in general terms. Whether the functions are performed by electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0131] The term "comprising" or any other similar word is intended to encompass a non-exclusive inclusion, so that a process, method, article, or equipment / device including a series of elements includes not only those elements, but also other elements not explicitly listed, or inherent to the process, method, article, or equipment / device.

[0132] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after such changes or replacements will fall within the protection scope of the present application.

[0133] The above description is only for the preferred embodiments of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A control system for utilizing waste heat from circulating water in a power plant, characterized in that, include: Condenser; A cooling tower, which is connected to the condenser; A circulating water heat exchanger is connected to the outlet header of the condenser and is also connected to the cooling tower. A chemical water tank is connected to the circulating water heat exchanger, and a chemical water circulation pump is provided between the outlet of the chemical water tank and the inlet of the circulating water heat exchanger. The chemical water circulation pump is used to transport water in the chemical water tank to the circulating water heat exchanger. Also includes: A detection unit is used to detect the water temperature T at the outlet of the chemical water tank in real time. The monitoring unit is used to monitor the outlet water temperature K of the circulating water heat exchanger in real time; The control unit contains a preset outlet water temperature matrix T0, a preset delivery water volume matrix A, a preset circulating water heat exchanger outlet water temperature matrix R0, and a preset delivery water volume correction coefficient matrix B. The control unit is used for: Based on the water temperature T detected by the detection unit, it is matched with the preset outlet water temperature value matrix T0, and the corresponding preset delivery water volume is selected as the initial delivery water volume. Based on the water temperature K detected by the monitoring unit, it is matched with the preset circulating water heat exchanger outlet water temperature value matrix R0, and the corresponding preset delivery water volume correction coefficient is selected. The initial water delivery volume is corrected using a selected correction factor to obtain the final water delivery volume, and the operation of the chemical water circulation pump is controlled based on the final water delivery volume.

2. The power plant circulating water waste heat recovery control system according to claim 1, characterized in that, A first valve is provided between the circulating water heat exchanger and the condenser, and the first valve is used to control the flow rate entering the circulating water heat exchanger. A bypass valve is provided between the cooling tower and the condenser, and a second valve is provided between the circulating water heat exchanger and the cooling tower. The bypass valve and the second valve are used to control and isolate the circulating water heat exchanger. A third valve is provided between the circulating water heat exchanger and the chemical water circulating pump; a fourth valve is provided between the chemical water tank and the chemical water circulating pump; and a fifth valve is provided between the circulating water heat exchanger and the chemical water tank. The control unit is also used to control the bypass valve, the first valve, the second valve, the third valve, the fourth valve, and the fifth valve according to the operating status of the power plant circulating water waste heat utilization control system, wherein the operating status includes a working state and a shutdown state; wherein, When the power plant circulating water waste heat utilization control system is in the working state, the bypass valve is closed and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are opened. When the power plant circulating water waste heat utilization control system is in the shutdown state, the bypass valve is opened and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are closed.

3. The power plant circulating water waste heat utilization control system according to claim 2, characterized in that, The control unit is configured with a preset outlet water temperature value matrix T0 and a preset delivery water volume matrix A. For the preset delivery water volume matrix A, A(A1,A2,A3,A4) is set, where A1 is the first preset delivery water volume, A2 is the second preset delivery water volume, A3 is the third preset delivery water volume, and A4 is the fourth preset delivery water volume, and A1 < A2 < A3 < A4. For the preset water outlet temperature value matrix T0, set T0(T01,T02,T03,T04), where T01 is the first preset water outlet temperature value, T02 is the second preset water outlet temperature value, T03 is the third preset water outlet temperature value, T04 is the fourth preset water outlet temperature value, and T01 < T02 < T03 < T04. The control unit is used to select the corresponding water delivery volume based on the relationship between T and the preset outlet water temperature value matrix T0 as the control volume for delivering water from the chemical water tank to the circulating water heat exchanger. When T < T01, the fourth preset water delivery volume A4 is selected as the water volume to be delivered from the chemical water tank to the circulating water heat exchanger. When T01≤T<T02, the third preset water delivery volume A3 is selected as the control volume for delivering water from the chemical water tank to the circulating water heat exchanger. When T02≤T<T03, the second preset water delivery volume A2 is selected as the control volume for delivering water from the chemical water tank to the circulating water heat exchanger. When T03≤T<T04, the first preset water delivery volume A1 is selected as the water volume to be delivered from the chemical water tank to the circulating water heat exchanger.

4. The power plant circulating water waste heat utilization control system according to claim 3, characterized in that, Also includes: The monitoring unit is used to monitor the outlet water temperature K of the circulating water heat exchanger in real time. The control unit is also used to adjust the amount of water supplied to the circulating water heat exchanger according to the outlet water temperature K of the circulating water heat exchanger; The control unit also includes a preset circulating water heat exchanger outlet water temperature value matrix R0 and a preset delivery water volume correction coefficient matrix B. For the preset delivery water volume correction coefficient matrix B, B(B1, B2, B3, B4) is set, where B1 is the first preset delivery water volume correction coefficient, B2 is the second preset delivery water volume correction coefficient, B3 is the third preset delivery water volume correction coefficient, and B4 is the fourth preset delivery water volume correction coefficient, and 1 < B1 < B2 < B3 < B4 < 1.

5. For the preset circulating water heat exchanger outlet water temperature value matrix R0, R0(R01, R02, R03, R04) is set, where R01 is the first preset circulating water heat exchanger outlet water temperature value, R02 is the second preset circulating water heat exchanger outlet water temperature value, R03 is the third preset circulating water heat exchanger outlet water temperature value, and R04 is the fourth preset circulating water heat exchanger outlet water temperature value, and R01 < R02 < R03 < R04. The control unit is also used to select the corresponding delivery water volume correction coefficient according to the relationship between K and the preset circulating water heat exchanger outlet water temperature value matrix R0, so as to correct and adjust each preset delivery water volume. When K < R01, the fourth preset water delivery volume correction coefficient B4 is selected to correct the fourth preset water delivery volume A4, and the corrected water delivery volume is A4*B4. When R01≤K<R02, the third preset water delivery correction coefficient B3 is selected to correct the third preset water delivery A3, and the corrected water delivery is A3*B3; When R02≤K<R03, select the second preset water delivery correction coefficient B2 to correct the second preset water delivery A2, and the corrected water delivery is A2*B2; When R03≤K<R04, the first preset water delivery correction coefficient B1 is selected to correct the first preset water delivery volume A1, and the corrected water delivery volume is A1*B1.

5. A power plant circulating water waste heat utilization control system according to claim 4, characterized in that, The control unit is a PLC controller.

6. A control method for utilizing waste heat from circulating water in a power plant, applied in the power plant circulating water waste heat utilization control system as described in claim 5, characterized in that, include: Real-time monitoring of the water temperature T at the outlet of the chemical water tank; Real-time monitoring of the outlet water temperature (K) of the circulating water heat exchanger; Based on the water temperature T detected by the detection unit, it is matched with the preset outlet water temperature value T0, and the corresponding preset delivery water volume is selected as the initial delivery water volume. Based on the water temperature K detected by the monitoring unit, it is matched with the preset circulating water heat exchanger outlet water temperature value matrix R0, and the corresponding preset delivery water volume correction coefficient is selected. The initial water delivery volume is corrected using a selected correction factor to obtain the final water delivery volume, and the operation of the chemical water circulation pump is controlled based on the final water delivery volume.

7. The method for controlling the utilization of waste heat from circulating water in a power plant according to claim 6, characterized in that, Also includes: The bypass valve, first valve, second valve, third valve, fourth valve, and fifth valve are controlled according to the operating status of the power plant circulating water waste heat utilization control system. The operating status includes both a working state and a shutdown state. When the power plant circulating water waste heat utilization control system is in the working state, the bypass valve is closed and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are opened. When the power plant circulating water waste heat utilization control system is in the shutdown state, the bypass valve is opened and the first valve, the second valve, the third valve, the fourth valve and the fifth valve are closed.

8. The method for controlling the utilization of waste heat from circulating water in a power plant according to claim 6, characterized in that, A preset outlet water temperature value matrix T0 and a preset delivery water volume matrix A are preset. For the preset delivery water volume matrix A, A(A1,A2,A3,A4) is set, where A1 is the first preset delivery water volume, A2 is the second preset delivery water volume, A3 is the third preset delivery water volume, and A4 is the fourth preset delivery water volume, and A1 < A2 < A3 < A4. For the preset water outlet temperature value matrix T0, set T0(T01,T02,T03,T04), where T01 is the first preset water outlet temperature value, T02 is the second preset water outlet temperature value, T03 is the third preset water outlet temperature value, T04 is the fourth preset water outlet temperature value, and T01 < T02 < T03 < T04. Based on the relationship between T and the preset outlet water temperature value matrix T0, the corresponding water delivery volume is selected as the control to deliver the water in the chemical water tank to the circulating water heat exchanger. When T < T01, the fourth preset water delivery volume A4 is selected as the water volume to be delivered from the chemical water tank to the circulating water heat exchanger. When T01≤T<T02, the third preset water delivery volume A3 is selected as the control volume for delivering water from the chemical water tank to the circulating water heat exchanger. When T02≤T<T03, the second preset water delivery volume A2 is selected as the control volume for delivering water from the chemical water tank to the circulating water heat exchanger. When T03≤T<T04, the first preset water delivery volume A1 is selected as the water volume to be delivered from the chemical water tank to the circulating water heat exchanger.

9. The method for controlling the utilization of waste heat from circulating water in a power plant according to claim 8, characterized in that, Also includes: Real-time outlet water temperature (K) of the circulating water heat exchanger; The amount of water supplied to the circulating water heat exchanger is adjusted according to the outlet water temperature K of the circulating water heat exchanger; A preset circulating water heat exchanger outlet water temperature value matrix R0 and a preset delivery water volume correction coefficient matrix B are pre-set. For the preset delivery water volume correction coefficient matrix B, B(B1,B2,B3,B4) is set, where B1 is the first preset delivery water volume correction coefficient, B2 is the second preset delivery water volume correction coefficient, B3 is the third preset delivery water volume correction coefficient, and B4 is the fourth preset delivery water volume correction coefficient, and 1 < B1 < B2 < B3 < B4 < 1.5; for the preset circulating water heat exchanger outlet water temperature value matrix R0, R0(R01,R02,R03,R04) is set, where R01 is the first preset circulating water heat exchanger outlet water temperature value, R02 is the second preset circulating water heat exchanger outlet water temperature value, R03 is the third preset circulating water heat exchanger outlet water temperature value, and R04 is the fourth preset circulating water heat exchanger outlet water temperature value, and R01 < R02 < R03 < R04; Based on the relationship between K and the preset circulating water heat exchanger outlet water temperature value matrix R0, a corresponding water delivery correction coefficient is selected to correct and adjust each preset water delivery volume. When K < R01, the fourth preset water delivery volume correction coefficient B4 is selected to correct the fourth preset water delivery volume A4, and the corrected water delivery volume is A4*B4. When R01≤K<R02, the third preset water delivery correction coefficient B3 is selected to correct the third preset water delivery A3, and the corrected water delivery is A3*B3; When R02≤K<R03, select the second preset water delivery correction coefficient B2 to correct the second preset water delivery A2, and the corrected water delivery is A2*B2; When R03≤K<R04, the first preset water delivery correction coefficient B1 is selected to correct the first preset water delivery volume A1, and the corrected water delivery volume is A1*B1.

10. The method for controlling the utilization of waste heat from circulating water in a power plant according to claim 6, characterized in that, The power plant circulating water waste heat utilization control system is controlled by a PLC control algorithm.

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