A method for preventing corrosion on the water side of a heat exchanger in a thermal power plant

Abstract

The application relates to the technical field of thermal power generation, in particular to a heat exchanger water side anti-corrosion method for a thermal power plant. The method comprises the following steps: obtaining equipment downtime, setting a control mode according to the equipment downtime; obtaining heat exchanger operation parameters, setting first-level anti-corrosion parameters according to the first-level control mode and the heat exchanger operation parameters if the control mode is a first-level control mode; setting second-level anti-corrosion parameters according to the second-level control mode and the heat exchanger operation parameters if the control mode is a second-level control mode. The method realizes anti-corrosion for short-term downtime by setting nitrogen charging parameters, realizes anti-corrosion for long-term downtime by setting dry agent feeding amount and monitoring time nodes, sets different anti-corrosion parameters according to different downtime states, avoids large-area corrosion of a metal surface during equipment downtime, and reduces the anti-corrosion cost.

Description

Technical Field

[0001] The present application relates to the field of thermal power generation technology, and in particular to a method for preventing rust on the water side of a heat exchanger in a thermal power plant. Background Art

[0002] Thermal equipment is the main equipment that is essential for winter heating in thermal power plants. It is used to heat the heating water sent to the heating network system. The steam required for heating is extracted from the steam turbine as a heat source, and the water in the heating network is heated to a certain temperature and sent to users, thereby improving thermal energy efficiency and reducing enterprise operating costs.

[0003] However, if thermal equipment is not properly protected during standby periods, severe oxygen corrosion can occur on the metal surfaces within its water vapor system. This type of corrosion is known as inactivity corrosion. Inactivity corrosion can cause extensive corrosion on the metal surfaces of inactive equipment over a short period of time and can exacerbate corrosion during operational operation. This is extremely harmful and can seriously impact equipment safety. Summary of the Invention

[0004] The purpose of this application is: to solve the above technical problems, this application provides a method for preventing rust on the water side of a heat exchanger in a thermal power plant, aiming to solve the corrosion problem of heating equipment during shutdown.

[0005] In some embodiments of the present application, by setting the first-level control mode and the second-level control mode, different anti-corrosion parameters are set according to different situations of short-term shutdown and long-term shutdown, thereby improving the processing efficiency and ensuring the working efficiency and anti-corrosion ability of the heat exchanger.

[0006] In some embodiments of the present application, corrosion protection for short-term shutdown is achieved by setting nitrogen filling parameters, and corrosion protection for long-term shutdown is achieved by setting desiccant dosage and monitoring time nodes. Different corrosion protection parameters are set according to different shutdown states to avoid large-area corrosion of the metal surface during equipment shutdown and reduce the cost of corrosion protection.

[0007] In some embodiments of the present application, a method for preventing corrosion on the water side of a heat exchanger in a thermal power plant is provided, comprising:

[0008] Obtaining equipment downtime, and setting a control mode according to the equipment downtime;

[0009] Acquire heat exchanger operating parameters, and if the control mode is a primary control mode, set primary anti-rust parameters according to the primary control mode and the heat exchanger operating parameters;

[0010] If the control mode is a secondary control mode, the secondary anti-rust parameters are set according to the secondary control mode and the heat exchanger operating parameters.

[0011] In some embodiments of the present application, when setting a control mode according to the equipment downtime, the method includes:

[0012] Preset downtime threshold;

[0013] If the real-time equipment downtime is less than the downtime threshold, the real-time control mode is set to the first-level control mode;

[0014] If the real-time equipment outage time is greater than the outage time threshold, the real-time control mode is set to the secondary control mode.

[0015] In some embodiments of the present application, when setting the primary anti-rust parameters according to the primary control mode and the heat exchanger operating parameters, the method includes:

[0016] Close the water inlet and outlet gates of the heat exchanger;

[0017] Activate the water side air door;

[0018] Acquire the real-time pressure value inside the heat exchanger, and when the real-time pressure value reaches a preset pressure value, close the water-side air valve;

[0019] Obtaining a water level value of the heat exchanger, setting a nitrogen filling speed according to the water level value of the heat exchanger, and stopping nitrogen filling when the nitrogen concentration inside the heat exchanger reaches a preset concentration value;

[0020] Set drainage parameters and nitrogen monitoring time nodes.

[0021] In some embodiments of the present application, when setting the nitrogen filling rate according to the water volume value of the heat exchanger, it includes:

[0022] Preset the heat exchanger water volume matrix A, set A(A1, A2, A3, A4), where A1 is the preset water volume of the first heat exchanger, A2 is the preset water volume of the second heat exchanger, A3 is the preset water volume of the third heat exchanger, and A4 is the preset water volume of the fourth heat exchanger, and A1<A2<A3<A4;

[0023] A nitrogen filling speed matrix V is preset, and V(V1, V2, V3, V4) is set, where V1 is a preset first nitrogen filling speed, V2 is a preset second nitrogen filling speed, V3 is a preset third nitrogen filling speed, and V4 is a preset fourth nitrogen filling speed, and V1<V2<V3<V4;

[0024] Obtaining a real-time water volume value a of the heat exchanger, and setting a real-time nitrogen filling speed v according to the real-time water volume value a of the heat exchanger;

[0025] If a<A1, the real-time nitrogen filling speed v is set to the preset fourth nitrogen filling speed V4, that is, v=V4;

[0026] If A1<a<A2, the real-time nitrogen filling speed v is set to the preset third nitrogen filling speed V3, that is, v=V3;

[0027] If A2<a<A3, the real-time nitrogen filling speed v is set to the preset second nitrogen filling speed V2, that is, v=V2;

[0028] If A3<a<A4, the real-time nitrogen filling speed v is set to the preset first nitrogen filling speed V1, that is, v=V1.

[0029] In some embodiments of the present application, the setting of drainage parameters includes:

[0030] Preset a first nitrogen pressure range and a second nitrogen pressure range;

[0031] Acquiring a real-time nitrogen pressure value, and draining water when the real-time nitrogen pressure value is within a first nitrogen pressure interval;

[0032] When the drainage is completed, pressurization is performed, and when the real-time nitrogen pressure value is in the second nitrogen pressure interval, pressurization is stopped.

[0033] In some embodiments of the present application, when setting the secondary anti-rust parameters according to the secondary control mode and the heat exchanger operating parameters, the method includes:

[0034] Heat exchanger drainage;

[0035] Close the water inlet and outlet gates of the heat exchanger;

[0036] Open the manhole door of the heat exchanger, obtain the humidity value inside the heat exchanger, and set the drying time according to the humidity value inside the heat exchanger;

[0037] Close the valve and set the desiccant dosage according to the volume of the heat exchanger;

[0038] Setting a desiccant monitoring time node according to the desiccant dosage;

[0039] Close the heat exchanger's water inlet, outlet and manhole doors.

[0040] In some embodiments of the present application, when the drying time is set according to the humidity value inside the heat exchanger, the method includes:

[0041] A preset heat exchanger internal humidity value matrix B is set as B(B1, B2, B3, B4), where B1 is the preset internal humidity value of the first heat exchanger, B2 is the preset internal humidity value of the second heat exchanger, B3 is the preset internal humidity value of the third heat exchanger, and B4 is the preset internal humidity value of the fourth heat exchanger, and B1<B2<B3<B4;

[0042] Preset drying time matrix C, set C(C1, C2, C3, C4), where C1 is the preset first drying time, C2 is the preset second drying time, C3 is the preset third drying time, C4 is the preset fourth drying time, and C1<C2<C3<C4;

[0043] Obtaining a real-time internal humidity value b of the heat exchanger, and setting a real-time drying time c according to the real-time internal humidity value b;

[0044] If B1<b<B2, the real-time drying time c is set to the preset first drying time C1, that is, c=C1;

[0045] If B2<b<B3, the real-time drying time c is set to the preset second drying time C2, that is, c=C2;

[0046] If B3<b<B4, the real-time drying time c is set to the preset third drying time C3, that is, c=C3;

[0047] If b>B4, the real-time drying time c is set to the preset fourth drying time C4, that is, c=C4.

[0048] In some embodiments of the present application, when setting the desiccant monitoring time node according to the desiccant dosage, the method includes:

[0049] A preset desiccant dosage matrix D is set as D(D1, D2, D3, D4), where D1 is the preset first desiccant dosage, D2 is the preset second desiccant dosage, D3 is the preset third desiccant dosage, and D4 is the preset fourth desiccant dosage, and D1 < D2 < D3 < D4;

[0050] A preset time interval matrix T is set to T(T1, T2, T3, T4), where T1 is a preset first time interval, T2 is a preset second time interval, T3 is a preset third time interval, and T4 is a preset fourth time interval, and T1<T2<T3<T4;

[0051] Obtaining a real-time desiccant delivery amount d, and setting a time interval t between a current time node and a next time node according to the real-time desiccant delivery amount d;

[0052] If D1<d<D2, the time interval t is set to the preset first time interval T1, that is, t=T1;

[0053] If D2<d<D3, the time interval t is set to the preset second time interval T2, that is, t=T2;

[0054] If D3<d<D4, the time interval t is set to the preset third time interval T3, that is, t=T3;

[0055] If d>D4, the time interval t is set to the preset fourth time interval T4, that is, t=T4.

[0056] In some embodiments of the present application, when setting the desiccant monitoring time node according to the desiccant dosage, the method further includes:

[0057] Obtaining desiccant failure amount and dryness according to the desiccant monitoring time node;

[0058] Setting the input amount of the compensating desiccant according to the desiccant failure amount and the dryness;

[0059] A correction coefficient is set according to the desiccant failure amount to correct the time interval between the current monitoring time node and the next monitoring time node.

[0060] In some embodiments of the present application, when setting the correction coefficient according to the desiccant failure amount, it includes

[0061] Setting a desiccant failure matrix E, setting E(E1, E2, E3, E4), where E1 is a preset first desiccant failure amount, E2 is a preset second desiccant failure amount, E3 is a preset third desiccant failure amount, and E4 is a preset fourth desiccant failure amount, and E1<E2<E3<E4;

[0062] A preset correction coefficient matrix N is set to N(n1, n2, n3, n4), where n1 is a preset first correction coefficient, n2 is a preset second correction coefficient, n3 is a preset third correction coefficient, and n4 is a preset fourth correction coefficient, and n1<n2<n3<n4<1;

[0063] According to the real-time desiccant failure amount e at the current monitoring time node, the correction coefficient n is set;

[0064] If E1<e<E2, set n=n4, and the corrected time interval t=n4*Ti(i=1,2,3,4);

[0065] If E2<e<E3, set n=n3, and the corrected time interval t=n3*Ti(i=1,2,3,4);

[0066] If E3<e<E4, set n=n2, and the corrected time interval t=n2*Ti(i=1,2,3,4);

[0067] If e>E4, set n=n1, and the corrected time interval t=n1*Ti(i=1, 2, 3, 4).

[0068] Compared with the prior art, the method for preventing rust on the water side of a heat exchanger in a thermal power plant according to the embodiment of the present application has the following beneficial effects:

[0069] By setting the primary control mode and the secondary control mode, different anti-corrosion parameters can be set according to different situations of short-term shutdown and long-term shutdown, so as to improve the processing efficiency and ensure the working efficiency and anti-corrosion ability of the heat exchanger.

[0070] Anti-corrosion can be achieved for short-term outages by setting nitrogen filling parameters, and anti-corrosion can be achieved for long-term outages by setting desiccant dosage and monitoring time nodes. Different anti-corrosion parameters can be set according to different outage states to avoid large-scale corrosion of the metal surface during equipment outage and reduce the cost of anti-corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 This is a method for preventing rust on the water side of a heat exchanger in a thermal power plant in a preferred embodiment of the present application. DETAILED DESCRIPTION

[0072] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0073] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0074] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0075] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0076] like Figure 1 As shown, a method for preventing rust on the water side of a heat exchanger in a thermal power plant according to a preferred embodiment of the present application includes:

[0077] S101: Obtain equipment downtime and set a control mode according to the equipment downtime;

[0078] S102: Obtaining heat exchanger operating parameters. If the control mode is the first-level control mode, setting first-level anti-rust parameters according to the first-level control mode and the heat exchanger operating parameters;

[0079] S103: If the control mode is the secondary control mode, set the secondary anti-rust parameters according to the secondary control mode and the heat exchanger operating parameters.

[0080] Specifically, when setting the control mode based on the equipment downtime, it includes:

[0081] Preset downtime threshold;

[0082] If the real-time equipment downtime is less than the downtime threshold, the real-time control mode is set to the first-level control mode;

[0083] If the real-time equipment downtime is greater than the downtime threshold, the real-time control mode is set to the secondary control mode.

[0084] Specifically, its outage time threshold is set based on the historical operating data of the thermal power plant.

[0085] It can be understood that in the above implementation, the current shutdown status is determined to be short-term or long-term based on the preset shutdown time threshold. By setting the first-level control mode and the second-level control mode, different anti-corrosion parameters are set according to different situations of short-term shutdown and long-term shutdown, thereby improving the processing efficiency and ensuring the working efficiency and anti-corrosion ability of the heat exchanger.

[0086] In a preferred embodiment of the present application, when setting the first-level anti-rust parameters according to the first-level control mode and the heat exchanger operating parameters, it includes:

[0087] Close the water inlet and outlet gates of the heat exchanger;

[0088] Activate the water side air door;

[0089] Obtain the real-time pressure value inside the heat exchanger. When the real-time pressure value reaches the preset pressure value, close the water side air valve;

[0090] Obtain the water level of the heat exchanger, set the nitrogen filling speed according to the water level of the heat exchanger, and stop nitrogen filling when the nitrogen concentration inside the heat exchanger reaches the preset concentration value;

[0091] Set drainage parameters and nitrogen monitoring time nodes.

[0092] Specifically, four hours before shutting down the heating network heaters, increase the amount of ammonia added to the generator set condensate high-mix outlet main pipe to raise the pH of the feed water to 9.5-9.6. After shutting down, close the steam inlet and drain valves on the heater's steam side. Once the steam-side pressure drops to 0.3-0.5 MPa, begin nitrogen injection. Stop nitrogen injection when the nitrogen purity reaches above 99.5%.

[0093] Specifically, check the nitrogen pressure according to the nitrogen monitoring time node and compensate the nitrogen in time.

[0094] Specifically, when setting the nitrogen filling speed according to the water volume value of the heat exchanger, it includes:

[0095] Preset the heat exchanger water volume matrix A, set A(A1, A2, A3, A4), where A1 is the preset water volume of the first heat exchanger, A2 is the preset water volume of the second heat exchanger, A3 is the preset water volume of the third heat exchanger, and A4 is the preset water volume of the fourth heat exchanger, and A1<A2<A3<A4;

[0096] A nitrogen filling speed matrix V is preset, and V(V1, V2, V3, V4) is set, where V1 is a preset first nitrogen filling speed, V2 is a preset second nitrogen filling speed, V3 is a preset third nitrogen filling speed, and V4 is a preset fourth nitrogen filling speed, and V1<V2<V3<V4;

[0097] Obtain the real-time water volume value a of the heat exchanger, and set the real-time nitrogen filling speed v according to the real-time water volume value a of the heat exchanger;

[0098] If a<A1, the real-time nitrogen filling speed v is set to the preset fourth nitrogen filling speed V4, that is, v=V4;

[0099] If A1<a<A2, the real-time nitrogen filling speed v is set to the preset third nitrogen filling speed V3, that is, v=V3;

[0100] If A2<a<A3, the real-time nitrogen filling speed v is set to the preset second nitrogen filling speed V2, that is, v=V2;

[0101] If A3<a<A4, the real-time nitrogen filling speed v is set to the preset first nitrogen filling speed V1, that is, v=V1.

[0102] Specifically, when setting drainage parameters, including

[0103] Preset a first nitrogen pressure range and a second nitrogen pressure range;

[0104] Acquire a real-time nitrogen pressure value, and drain water when the real-time nitrogen pressure value is within a first nitrogen pressure range;

[0105] When the drainage is completed, pressurization is performed, and when the real-time nitrogen pressure value is in the second nitrogen pressure range, pressurization is stopped.

[0106] Specifically, when draining is necessary, slightly open the bottom drain valve, slowly drain all the water, and then close the drain valve. During the draining and protection process, maintain the nitrogen pressure at 0.01MPa to 0.03MPa. When draining is not necessary, maintain the nitrogen pressure at 0.03MPa to 0.05MPa.

[0107] Specifically, when the steam side system of the heating network heater needs to be overhauled, drain the water first. After the overhaul is completed, implement nitrogen filling protection. Nitrogen should be filled in from the top and discharged from the bottom. When the purity of the exhaust nitrogen is greater than 98%, close the exhaust valve and maintain the nitrogen pressure inside the equipment at 0.01~0.03MPa.

[0108] It can be understood that in the above embodiment, corrosion protection for short-term shutdown is achieved by setting nitrogen filling parameters. At the same time, by setting the nitrogen filling speed matrix, the nitrogen filling speed is dynamically adjusted according to the water value in the heat exchanger during shutdown, so as to ensure nitrogen filling efficiency and improve overall work efficiency. At the same time, by establishing nitrogen monitoring time nodes, the corrosion protection effect is guaranteed and large-scale corrosion of the metal surface is avoided during equipment shutdown.

[0109] In a preferred embodiment of the present application, when setting the secondary anti-rust parameters according to the secondary control mode and the heat exchanger operating parameters, it includes:

[0110] Heat exchanger drainage;

[0111] Close the water inlet and outlet gates of the heat exchanger;

[0112] Open the manhole door of the heat exchanger, obtain the humidity value inside the heat exchanger, and set the drying time according to the humidity value inside the heat exchanger;

[0113] Close the valve and set the desiccant dosage according to the volume of the heat exchanger;

[0114] Set the desiccant monitoring time node according to the desiccant dosage;

[0115] Close the heat exchanger's water inlet, outlet and manhole doors.

[0116] Specifically, after stopping the heating supply, drain all the water from the water side of the heat exchanger and close the water inlet and outlet valves of the heat exchanger. Open the manhole door of the heat exchanger and use hot compressed air to blow out the accumulated water in the equipment. After sealing all valves, place desiccant in the water inlet and outlet chambers of the heat exchanger (use industrial anhydrous calcium chloride (particle size 10-15mm) at a concentration of 1-2 kg / m3 or use silica gel (which should be dried at 120-140℃ first) at a concentration of 1-2 kg / m3).

[0117] Specifically, when setting the drying time according to the humidity value inside the heat exchanger, it includes:

[0118] A preset heat exchanger internal humidity value matrix B is set as B(B1, B2, B3, B4), where B1 is the preset internal humidity value of the first heat exchanger, B2 is the preset internal humidity value of the second heat exchanger, B3 is the preset internal humidity value of the third heat exchanger, and B4 is the preset internal humidity value of the fourth heat exchanger, and B1<B2<B3<B4;

[0119] Preset drying time matrix C, set C(C1, C2, C3, C4), where C1 is the preset first drying time, C2 is the preset second drying time, C3 is the preset third drying time, C4 is the preset fourth drying time, and C1<C2<C3<C4;

[0120] Obtain the real-time internal humidity value b of the heat exchanger, and set the real-time drying time c according to the real-time internal humidity value b;

[0121] If B1<b<B2, the real-time drying time c is set to the preset first drying time C1, that is, c=C1;

[0122] If B2<b<B3, the real-time drying time c is set to the preset second drying time C2, that is, c=C2;

[0123] If B3<b<B4, the real-time drying time c is set to the preset third drying time C3, that is, c=C3;

[0124] If b>B4, the real-time drying time c is set to the preset fourth drying time C4, that is, c=C4.

[0125] Specifically, when setting the desiccant monitoring time node based on the desiccant dosage, it includes:

[0126] A preset desiccant dosage matrix D is set as D(D1, D2, D3, D4), where D1 is the preset first desiccant dosage, D2 is the preset second desiccant dosage, D3 is the preset third desiccant dosage, and D4 is the preset fourth desiccant dosage, and D1 < D2 < D3 < D4;

[0127] A preset time interval matrix T is set to T(T1, T2, T3, T4), where T1 is a preset first time interval, T2 is a preset second time interval, T3 is a preset third time interval, and T4 is a preset fourth time interval, and T1<T2<T3<T4;

[0128] Obtain the real-time amount of desiccant delivered d, and set the time interval t between the current time node and the next time node based on the real-time amount of desiccant delivered d;

[0129] If D1<d<D2, the time interval t is set to the preset first time interval T1, that is, t=T1;

[0130] If D2<d<D3, the time interval t is set to the preset second time interval T2, that is, t=T2;

[0131] If D3<d<D4, the time interval t is set to the preset third time interval T3, that is, t=T3;

[0132] If d>D4, the time interval t is set to the preset fourth time interval T4, that is, t=T4.

[0133] It can be understood that in the above embodiment, the drying time is dynamically adjusted by obtaining the real-time humidity value to improve the drying efficiency, and the corrosion protection for long-term shutdown is achieved by adding desiccant, thereby reducing the overall operation and maintenance cost. At the same time, the monitoring cycle is dynamically set by the amount of desiccant input to achieve dynamic monitoring of the shutdown setting, thereby avoiding large-scale corrosion of the metal surface during the equipment shutdown process and reducing the cost of corrosion protection.

[0134] In a preferred embodiment of the present application, when setting the desiccant monitoring time node according to the desiccant dosage, the method further includes:

[0135] Obtain desiccant failure amount and dryness according to desiccant monitoring time nodes;

[0136] Set the amount of compensating desiccant input according to the desiccant failure amount and dryness;

[0137] The correction coefficient is set according to the desiccant failure amount to correct the time interval between the current monitoring time node and the next monitoring time node.

[0138] Specifically, when setting the correction factor based on the desiccant failure amount, it includes

[0139] Setting a desiccant failure matrix E, setting E(E1, E2, E3, E4), where E1 is a preset first desiccant failure amount, E2 is a preset second desiccant failure amount, E3 is a preset third desiccant failure amount, and E4 is a preset fourth desiccant failure amount, and E1<E2<E3<E4;

[0140] A preset correction coefficient matrix N is set to N(n1, n2, n3, n4), where n1 is a preset first correction coefficient, n2 is a preset second correction coefficient, n3 is a preset third correction coefficient, and n4 is a preset fourth correction coefficient, and n1<n2<n3<n4<1;

[0141] According to the real-time desiccant failure amount e at the current monitoring time node, the correction coefficient n is set;

[0142] If E1<e<E2, set n=n4, and the corrected time interval t=n4*Ti(i=1,2,3,4);

[0143] If E2<e<E3, set n=n3, and the corrected time interval t=n3*Ti(i=1,2,3,4);

[0144] If E3<e<E4, set n=n2, and the corrected time interval t=n2*Ti(i=1,2,3,4);

[0145] If e>E4, set n=n1, and the corrected time interval t=n1*Ti(i=1, 2, 3, 4).

[0146] It can be understood that in the above embodiment, by setting the desiccant failure amount and correction coefficient, the monitoring period is dynamically adjusted to ensure that the internal dryness status is monitored in real time during long-term equipment shutdown, thereby improving the anti-corrosion effect and avoiding large-scale corrosion of the metal surface during equipment shutdown.

[0147] According to the first concept of this application, by setting the first-level control mode and the second-level control mode, different anti-corrosion parameters are set according to different situations of short-term shutdown and long-term shutdown, so as to improve the processing efficiency and ensure the working efficiency and anti-corrosion ability of the heat exchanger.

[0148] According to the second concept of the present application, corrosion protection for short-term shutdown is achieved by setting nitrogen filling parameters, and corrosion protection for long-term shutdown is achieved by setting desiccant dosage and monitoring time nodes. Different corrosion protection parameters are set according to different shutdown states to avoid large-scale corrosion of the metal surface during equipment shutdown and reduce the cost of corrosion protection.

[0149] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present application. These improvements and replacements should also be regarded as the scope of protection of the present application.

Claims

1. A method for preventing corrosion of the water side of a heat exchanger in a thermal power plant, characterized in that: Including: Obtain the equipment outage time and set the control mode according to the equipment outage time; Obtain the heat exchanger operation parameters. If the control mode is the primary control mode, set the primary anti-rust parameters according to the primary control mode and the heat exchanger operation parameters; If the control mode is the secondary control mode, set the secondary anti-rust parameters according to the secondary control mode and the heat exchanger operation parameters; When setting the control mode according to the equipment outage time, it includes: Preset the outage time threshold; If the real-time equipment outage time is less than the outage time threshold, set the real-time control mode as the primary control mode; If the real-time equipment outage time is greater than the outage time threshold, set the real-time control mode as the secondary control mode; When setting the primary anti-rust parameters according to the primary control mode and the heat exchanger operation parameters, it includes: Close the inlet and outlet valves of the heat exchanger; Start the air valve on the water side; Obtain the real-time internal pressure value of the heat exchanger. When the real-time pressure value reaches the preset pressure value, close the air valve on the water side; Obtain the heat exchanger water volume value, set the nitrogen filling speed according to the heat exchanger water volume value, and stop nitrogen filling when the nitrogen concentration inside the heat exchanger reaches the preset concentration value; Set the drainage parameters and the nitrogen monitoring time node; When setting the secondary anti-rust parameters according to the secondary control mode and the heat exchanger operation parameters, it includes: Drain the heat exchanger; Close the inlet and outlet valves of the heat exchanger; Open the manhole door of the heat exchanger, obtain the internal humidity value of the heat exchanger, and set the drying duration according to the internal humidity value of the heat exchanger; Close the valves, and set the desiccant dosage according to the internal volume of the heat exchanger; Set the desiccant monitoring time node according to the desiccant dosage; Close the inlet valve, outlet valve and manhole door of the heat exchanger.

2. The method for preventing rust on the water side of a heat exchanger in a thermal power plant according to claim 1, characterized in that: When setting the nitrogen filling speed according to the heat exchanger water volume value, it includes: Preset the heat exchanger water volume matrix A, set A(A1, A2, A3, A4), where A1 is the preset first heat exchanger water volume, A2 is the preset second heat exchanger water volume, A3 is the preset third heat exchanger water volume, A4 is the preset fourth heat exchanger water volume, and A1 < A2 < A3 < A4; Preset the nitrogen filling speed matrix V, set V(V1, V2, V3, V4), where V1 is the preset first nitrogen filling speed, V2 is the preset second nitrogen filling speed, V3 is the preset third nitrogen filling speed, V4 is the preset fourth nitrogen filling speed, and V1 < V2 < V3 < V4; Obtain the real-time water volume value a of the heat exchanger, and set the real-time nitrogen filling speed v according to the real-time heat exchanger water volume value a; If a < A1, set the real-time nitrogen filling speed v as the preset fourth nitrogen filling speed V4, that is, v = V4; If A1 < a < A2, set the real-time nitrogen filling speed v as the preset third nitrogen filling speed V3, that is, v = V3; If A2 < a < A3, set the real-time nitrogen filling speed v as the preset second nitrogen filling speed V2, that is, v = V2; If A3 < a < A4, set the real-time nitrogen filling speed v as the preset first nitrogen filling speed V1, that is, v = V1.

3. The method for preventing rust on the water side of a heat exchanger in a thermal power plant according to claim 2, characterized in that: When setting the drainage parameters, it includes Preset the first nitrogen pressure range and the second nitrogen pressure range; Obtain the real-time nitrogen pressure value. When the real-time nitrogen pressure value is within the first nitrogen pressure range, drain the water; After the drainage is completed, pressurization is carried out. When the real-time nitrogen pressure value is within the second nitrogen pressure range, the pressurization is stopped.

4. The method for preventing rust on the water side of a heat exchanger in a thermal power plant according to claim 3, characterized in that: When setting the drying duration according to the internal humidity value of the heat exchanger, it includes: Presetting the internal humidity value matrix B of the heat exchanger, setting B(B1, B2, B3, B4), where B1 is the preset first internal humidity value of the heat exchanger, B2 is the preset second internal humidity value of the heat exchanger, B3 is the preset third internal humidity value of the heat exchanger, B4 is the preset fourth internal humidity value of the heat exchanger, and B1 < B2 < B3 < B4; Presetting the drying duration matrix C, setting C(C1, C2, C3, C4), where C1 is the preset first drying duration, C2 is the preset second drying duration, C3 is the preset third drying duration, C4 is the preset fourth drying duration, and C1 < C2 < C3 < C4; Obtaining the real-time internal humidity value b of the heat exchanger, and setting the real-time drying duration c according to the real-time internal humidity value b; If B1 < b < B2, setting the real-time drying duration c as the preset first drying duration C1, that is, c = C1; If B2 < b < B3, setting the real-time drying duration c as the preset second drying duration C2, that is, c = C2; If B3 < b < B4, setting the real-time drying duration c as the preset third drying duration C3, that is, c = C3; If b > B4, setting the real-time drying duration c as the preset fourth drying duration C4, that is, c = C4.

5. The method for preventing rust on the water side of a heat exchanger in a thermal power plant according to claim 4, characterized in that: When setting the desiccant monitoring time node according to the desiccant dosage, it includes: Presetting the desiccant dosage matrix D, setting D(D1, D2, D3, D4), where D1 is the preset first desiccant dosage, D2 is the preset second desiccant dosage, D3 is the preset third desiccant dosage, D4 is the preset fourth desiccant dosage, and D1 < D2 < D3 < D4; Presetting the time interval matrix T, setting T(T1, T2, T3, T4), where T1 is the preset first time interval, T2 is the preset second time interval, T3 is the preset third time interval, T4 is the preset fourth time interval, and T1 < T2 < T3 < T4; Obtaining the real-time desiccant dosage d, and setting the time interval t between the current time node and the next time node according to the real-time desiccant dosage d; If D1 < d < D2, setting the time interval t as the preset first time interval T1, that is, t = T1; If D2 < d < D3, setting the time interval t as the preset second time interval T2, that is, t = T2; If D3 < d < D4, setting the time interval t as the preset third time interval T3, that is, t = T3; If d > D4, setting the time interval t as the preset fourth time interval T4, that is, t = T4.

6. The method for preventing rust on the water side of a heat exchanger in a thermal power plant according to claim 5, characterized in that: When setting the desiccant monitoring time node according to the desiccant dosage, it also includes: Obtaining the desiccant failure amount and dryness according to the desiccant monitoring time node; Setting the input amount of the compensating desiccant according to the desiccant failure amount and the dryness; Setting a correction coefficient according to the desiccant failure amount, and correcting the time interval between the current monitoring time node and the next monitoring time node.

7. The method for preventing rust on the water side of a heat exchanger in a thermal power plant according to claim 6, characterized in that: When setting the correction coefficient according to the desiccant failure amount, it includes Set the desiccant failure amount matrix \(E\), and set \(E(E_1, E_2, E_3, E_4)\), where \(E_1\) is the preset first desiccant failure amount, \(E_2\) is the preset second desiccant failure amount, \(E_3\) is the preset third desiccant failure amount, \(E_4\) is the preset fourth desiccant failure amount, and \(E_1 < E_2 < E_3 < E_4\); Preset the correction coefficient matrix \(N\), and set \(N(n_1, n_2, n_3, n_4)\), where \(n_1\) is the preset first correction coefficient, \(n_2\) is the preset second correction coefficient, \(n_3\) is the preset third correction coefficient, \(n_4\) is the preset fourth correction coefficient, and \(n_1 < n_2 < n_3 < n_4 < 1\); According to the real-time desiccant failure amount \(e\) at the current monitoring time node, set the correction coefficient \(n\); If \(E_1 < e < E_2\), set \(n = n_4\), and the corrected time interval \(t = n_4 * T_i\) (\(i = 1, 2, 3, 4\)); If \(E_2 < e < E_3\), set \(n = n_3\), and the corrected time interval \(t = n_3 * T_i\) (\(i = 1, 2, 3, 4\)); If \(E_3 < e < E_4\), set \(n = n_2\), and the corrected time interval \(t = n_2 * T_i\) (\(i = 1, 2, 3, 4\)); If \(e > E_4\), set \(n = n_1\), and the corrected time interval \(t = n_1 * T_i\) (\(i = 1, 2, 3, 4\)).

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