A combustion and feedwater control method that accommodates load changes

Abstract

The application relates to the field of boiler combustion technology, in particular to a combustion and water supply control method suitable for load change. The method comprises the following steps: obtaining a load instruction, setting a control mode and a boiler load change value according to the load instruction and a real-time load value; setting a boiler water supply parameter and a boiler coal feeding parameter according to the control mode and the boiler load change value; obtaining a steam turbine pressure fluctuation value, and correcting the real-time water supply parameter and the coal feeding parameter according to the steam turbine pressure fluctuation value. Different control modes are set through the boiler load change value, so that the operation parameters of the boiler can be corrected in time when the load instruction suddenly decreases or suddenly increases, the problems of underpressure or overpressure caused by long adjustment time are avoided, and the problem that the stable operation of the boiler is affected is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of boiler combustion, in particular to a combustion and feed water control method suitable for load change. BACKGROUND

[0002] The boiler combustion unit at the present stage has once tried to operate AGC control in response to the demand of power grid, but under the AGC mode, there are many problems due to the complexity of coal quality and the particularity of power grid dispatching.

[0003] The frequent repeated change of AGC instruction makes the control quantities such as fuel, feed water and air supply of the unit fluctuate greatly back and forth, which is easy to cause the decline of system stability, and also causes adverse effects on the thermal stress and oxide skin shedding of boiler water wall and superheater pipe material, and increases the possibility of boiler pipe explosion.

[0004] When the fluctuation amplitude of load instruction is large and the fluctuation frequency is high, in order to ensure that the unit quickly responds to the load change, the steam turbine instruction will respond quickly, and the high pressure valve of the steam turbine will fluctuate quickly. When the feed water flow is directly controlled by the traditional coal-water ratio, due to the reasons such as the relatively lagging response of coal quantity and the large coal combustion heat inertia, it is easy to cause the main steam pressure of the unit side to fluctuate greatly, the regulation time is long, and the problems of under pressure or over pressure are serious. SUMMARY

[0005] The purpose of the present application is to solve the above technical problems, and the present application provides a combustion and feed water control method suitable for load change. The purpose is to reduce the large fluctuation of main steam pressure and ensure the safe and stable operation of the boiler.

[0006] In some embodiments of the present application, different control modes are set by acquiring the boiler load variation value, so as to ensure that when the load instruction suddenly decreases or suddenly increases, the operation parameters of the boiler are corrected in time, the problems of long regulation time, under pressure or over pressure, and the influence on the stable operation of the boiler are avoided.

[0007] In some embodiments of the present application, when the load instruction suddenly increases, the real-time feed water temperature and the target coal supply quantity are corrected according to the real-time load instruction, and the real-time coal supply increase rate and the feed water temperature increment are set according to the real-time boiler load variation value, and the two-way gradient regulation is performed, so as to solve the problems of relatively lagging response of coal quantity and large coal combustion heat inertia, and ensure the smooth operation of the boiler.

[0008] In some embodiments of the present application, a combustion and feed water control method suitable for load change is provided, which comprises:

[0009] Acquiring a load instruction, setting a control mode and a boiler load variation value according to the load instruction and a real-time load value;

[0010] setting a boiler feed water parameter and a boiler coal feeding parameter according to the control mode and the boiler load variation value;

[0011] obtaining a steam turbine pressure fluctuation value, and correcting the real-time feed water parameter and the coal feeding parameter according to the steam turbine pressure fluctuation value.

[0012] In some embodiments of the present application, when the boiler load variation value is generated according to the load instruction and the real-time load value, the following steps are included:

[0013] obtaining a load instruction and generating an instruction load value A1;

[0014] obtaining a real-time load value A2;

[0015] generating a boiler load variation value b according to the absolute value of the difference between the instruction load value A1 and the real-time load value A2;

[0016] presetting a boiler load variation threshold value Δb;

[0017] when b> Δb, setting a real-time control mode according to the instruction load value A1 and the real-time load value A2;

[0018] if A1

[0019] if A1> A2, setting the real-time control mode as a secondary control mode.

[0020] In some embodiments of the present application, when the boiler feed water parameter and the boiler coal feeding parameter are set according to the control mode and the boiler load variation value, the following steps are included:

[0021] presetting a boiler load variation value matrix B, and setting B (B1, B2, B3, B4), wherein B1 is a preset first boiler load variation value, B2 is a preset second boiler load variation value, B3 is a preset third boiler load variation value, B4 is a preset fourth boiler load variation value, and B1

[0022] if the real-time control mode is a primary control mode, setting a coal feeding amount reduction rate and a first target coal feeding amount according to the boiler load variation value b, and setting a real-time feed water temperature according to the coal feeding amount difference between the real-time coal feeding amount and the first target coal feeding amount;

[0023] if the real-time control mode is a secondary control mode, setting a coal feeding amount increase rate and a second target coal feeding amount according to the boiler load variation value b, and setting a real-time feed water temperature according to the coal feeding amount difference between the real-time coal feeding amount and the second target coal feeding amount.

[0024] In some embodiments of the present application, when the coal feeding amount increase rate and the second target coal feeding amount are set according to the boiler load variation value b, the following steps are included:

[0025] According to the instruction load value A1, a second target coal feeding amount is set, and according to the boiler load variation value b, a real-time coal feeding increase rate c is set;

[0026] According to the real-time coal feeding increase rate c, a real-time coal feeding amount is adjusted, and when the real-time coal feeding amount is equal to the second target coal feeding amount, the adjustment is stopped.

[0027] In some embodiments of the present application, when the real-time coal feeding increase rate c is set according to the boiler load variation value b, the following steps are included:

[0028] A preset coal feeding increase rate matrix C is set as C (C1, C2, C3, C4), wherein C1 is a preset first coal feeding increase rate, C2 is a preset second coal feeding increase rate, C3 is a preset third coal feeding increase rate, and C4 is a preset fourth coal feeding increase rate, and C1 < C2 < C3 < C4;

[0029] If B1 < b < B2, the real-time coal feeding increase rate c is set as the preset first coal feeding increase rate C1, that is, c = C1;

[0030] If B2 < b < B3, the real-time coal feeding increase rate c is set as the preset second coal feeding increase rate C2, that is, c = C2;

[0031] If B3 < b < B4, the real-time coal feeding increase rate c is set as the preset third coal feeding increase rate C3, that is, c = C3;

[0032] If b > B4, the real-time coal feeding increase rate c is set as the preset fourth coal feeding increase rate C4, that is, c = C4;

[0033] In some embodiments of the present application, when the real-time feed water temperature is set according to the coal feeding amount difference between the real-time coal feeding amount and the second target coal feeding amount, the following steps are included:

[0034] The real-time coal feeding amount and the second target coal feeding amount are obtained, and a coal feeding amount difference d is generated, and according to the coal feeding amount difference d, a real-time feed water temperature increment e is set;

[0035] A standard feed water temperature is obtained, and according to the real-time feed water temperature increment e and the standard feed water temperature, a real-time feed water temperature is set.

[0036] In some embodiments of the present application, when the real-time feed water temperature increment e is set according to the coal feeding amount difference d, the following steps are included:

[0037] A preset coal feeding amount difference matrix D is set as D (D1, D2, D3, D4), wherein D1 is a preset first coal feeding amount difference, D2 is a preset second coal feeding amount difference, D3 is a preset third coal feeding amount difference, and D4 is a preset fourth coal feeding amount difference, and D1 < D2 < D3 < D4;

[0038] presetting a water temperature increment matrix E, setting E (E1, E2, E3, E4), wherein E1 is a preset first water temperature increment, E2 is a preset second water temperature increment, E3 is a preset third water temperature increment, and E4 is a preset fourth water temperature increment, and E1 < E2 < E3 < E4;

[0039] if d < D1, setting a real-time water temperature increment e = 0;

[0040] if D1 < d < D2, setting the real-time water temperature increment e as the preset first water temperature increment E1, i.e. e = E1;

[0041] if D2 < d < D3, setting the real-time water temperature increment e as the preset second water temperature increment E2, i.e. e = E2;

[0042] if D3 < d < D4, setting the real-time water temperature increment e as the preset third water temperature increment E3, i.e. e = E3;

[0043] if d > D4, setting the real-time water temperature increment e as the preset fourth water temperature increment E4, i.e. e = E4.

[0044] In some embodiments of the present application, when the real-time water parameters and the coal feeding parameters are corrected according to the steam turbine pressure fluctuation value, the following steps are included:

[0045] presetting a steam turbine pressure fluctuation matrix F, setting F (F1, F2, F3, F4), wherein F1 is a preset first steam turbine pressure fluctuation value, F2 is a preset second steam turbine pressure fluctuation value, and F3 is a preset third steam turbine pressure fluctuation value, and F1 < F2 < F3;

[0046] presetting a coal feeding rate correction coefficient matrix N, setting N (n1, n2, n3), wherein n1 is a preset first coal feeding rate correction coefficient, n2 is a preset second coal feeding rate correction coefficient, and n3 is a preset third coal feeding rate correction coefficient, and 1 < n1 < n2 < n3;

[0047] obtaining a steam turbine pressure fluctuation value f, setting a real-time coal feeding rate correction coefficient n according to the steam turbine pressure fluctuation value f, and correcting a real-time coal feeding rate c;

[0048] setting a real-time water temperature increment compensation coefficient m according to the steam turbine pressure fluctuation value f, and correcting a real-time water temperature increment e.

[0049] In some embodiments of the present application, when the real-time coal feeding rate correction coefficient n is set according to the steam turbine pressure fluctuation value f, the following steps are included:

[0050] A preset coal feeding rate correction coefficient matrix N is set as N (n1, n2, n3), wherein n1 is a preset first coal feeding rate correction coefficient, n2 is a preset second coal feeding rate correction coefficient, n3 is a preset third coal feeding rate correction coefficient, and 1 < n1 < n2 < n3;

[0051] If f < F1, no real-time coal feeding rate correction coefficient n is set;

[0052] If F1 < f < F2, n = n1 is set, and a corrected real-time coal feeding increase rate c1 = n1 * Ci (i = 1, 2, 3, 4);

[0053] If F2 < f < F3, n = n2 is set, and a corrected real-time coal feeding increase rate c1 = n2 * Ci (i = 1, 2, 3, 4);

[0054] If f > F3, n = n3 is set, and a corrected real-time coal feeding increase rate c1 = n3 * Ci (i = 1, 2, 3, 4).

[0055] In some embodiments of the application, a real-time feed water temperature increment compensation coefficient m is set according to the steam turbine pressure fluctuation value f, comprising:

[0056] A preset feed water temperature increment compensation coefficient matrix M is set as M (m1, m2, m3), wherein m1 is a preset first feed water temperature increment compensation coefficient, m2 is a preset second feed water temperature increment compensation coefficient, m3 is a preset third feed water temperature increment compensation coefficient, and 1 < m1 < m2 < m3;

[0057] A real-time feed water temperature increment compensation coefficient m is set according to the steam turbine pressure fluctuation value, and a real-time feed water temperature increment e is corrected;

[0058] If f < F1, no real-time feed water temperature increment compensation coefficient m is set;

[0059] If F1 < f < F2, m = m1 is set, and a corrected real-time feed water temperature increment e1 = m1 * Ei (i = 1, 2, 3, 4);

[0060] If F2 < f < F3, m = m2 is set, and a corrected real-time feed water temperature increment e1 = m2 * Ei (i = 1, 2, 3, 4);

[0061] If f > F3, m = m3 is set, and a corrected real-time feed water temperature increment e1 = m3 * Ei (i = 1, 2, 3, 4).

[0062] Compared with the prior art, the combustion and feed water control method for load change adaptation according to the embodiments of the application has the beneficial effects that:

[0063] By setting different control modes through acquiring the boiler load variation value, the operation parameters of the boiler are corrected in time when the load instruction is suddenly reduced or increased, so as to avoid the problems of long adjustment time, under-pressure or over-pressure, and further influence on the stable operation of the boiler.

[0064] When the load instruction is suddenly increased, the real-time feed water temperature and target coal supply amount are corrected according to the real-time load instruction, and the real-time coal supply increase rate and feed water temperature increment are set according to the real-time boiler load variation value, so as to perform bidirectional gradient adjustment, solve the problems of relatively lagging coal amount response and large coal combustion heat release inertia, and ensure the stable operation of the boiler. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 is a flowchart of a combustion and feed water control method suitable for load variation in a preferred embodiment of the present application. DETAILED DESCRIPTION

[0066] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but not 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", "back", "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 for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element 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 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 specified, the meaning of "a plurality of" 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", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or 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] As Figure 1As shown, the combustion and water supply control method for adapting to load changes according to the preferred embodiment of the present application comprises:

[0071] S101: Obtain a load instruction, and set a control mode and a boiler load variation value according to the load instruction and a real-time load value;

[0072] S102: Set a boiler water supply parameter and a boiler coal supply parameter according to the control mode and the boiler load variation value;

[0073] S103: Obtain a steam turbine pressure fluctuation value, and correct the real-time water supply parameter and the coal supply parameter according to the steam turbine pressure fluctuation value.

[0074] Specifically, when generating the boiler load variation value according to the load instruction and the real-time load value, the following steps are included:

[0075] Obtain the load instruction and generate an instruction load value A1;

[0076] Obtain a real-time load value A2;

[0077] Generate a boiler load variation value b according to the absolute value of the difference between the instruction load value A1 and the real-time load value A2;

[0078] Pre-set a boiler load variation threshold Δb;

[0079] When b> Δb, set a real-time control mode according to the instruction load value A1 and the real-time load value A2;

[0080] If A1< A2, set the real-time control mode as a first-level control mode;

[0081] If A1> A2, set the real-time control mode as a second-level control mode.

[0082] Specifically, when setting the boiler water supply parameter and the boiler coal supply parameter according to the control mode and the boiler load variation value, the following steps are included:

[0083] Pre-set a boiler load variation value matrix B, and set B (B1, B2, B3, B4), wherein B1 is a pre-set first boiler load variation value, B2 is a pre-set second boiler load variation value, B3 is a pre-set third boiler load variation value, B4 is a pre-set fourth boiler load variation value, and B1< B2< B3< B4;

[0084] If the real-time control mode is the first-level control mode, set a coal supply amount reduction rate and a first target coal supply amount according to the boiler load variation value b, and set a real-time water supply temperature according to the coal supply amount difference between a real-time coal supply amount and the first target coal supply amount;

[0085] If the real-time control mode is the secondary control mode, the coal feeding amount increasing rate and the second target coal feeding amount are set according to the boiler load variation value b, and the real-time feed water temperature is set according to the coal feeding amount difference between the real-time coal feeding amount and the second target coal feeding amount.

[0086] It can be understood that in the above embodiment, the load variation direction is determined by acquiring the instruction load value and the real-time load value, and different control modes are set according to different load variation directions, so as to ensure that the operation parameters of the boiler are timely corrected when the load instruction suddenly decreases or suddenly increases, and the problems of under-pressure or over-pressure caused by long adjustment time and affecting the stable operation of the boiler are avoided.

[0087] In the preferred embodiment of the present application, when the coal feeding amount increasing rate and the second target coal feeding amount are set according to the boiler load variation value b, the following steps are included:

[0088] The second target coal feeding amount is set according to the instruction load value A1, and the real-time coal feeding increasing rate c is set according to the boiler load variation value b;

[0089] The real-time coal feeding amount is adjusted according to the real-time coal feeding increasing rate c, and the adjustment is stopped when the real-time coal feeding amount is equal to the second target coal feeding amount.

[0090] Specifically, when the real-time coal feeding increasing rate c is set according to the boiler load variation value b, the following steps are included:

[0091] A coal feeding amount increasing rate matrix C is preset, and C(C1, C2, C3, C4) is set, wherein C1 is a preset first coal feeding increasing rate, C2 is a preset second coal feeding increasing rate, C3 is a preset third coal feeding increasing rate, and C4 is a preset fourth coal feeding increasing rate, and C1 < C2 < C3 < C4;

[0092] If B1 < b < B2, the real-time coal feeding increasing rate c is set as the preset first coal feeding increasing rate C1, that is, c = C1;

[0093] If B2 < b < B3, the real-time coal feeding increasing rate c is set as the preset second coal feeding increasing rate C2, that is, c = C2;

[0094] If B3 < b < B4, the real-time coal feeding increasing rate c is set as the preset third coal feeding increasing rate C3, that is, c = C3;

[0095] If b > B4, the real-time coal feeding increasing rate c is set as the preset fourth coal feeding increasing rate C4, that is, c = C4;

[0096] Specifically, when the real-time feed water temperature is set according to the coal feeding amount difference between the real-time coal feeding amount and the second target coal feeding amount, the following steps are included:

[0097] obtaining a real-time coal supply amount and a second target coal supply amount and generating a coal supply amount difference d, and setting a real-time feedwater temperature increment e according to the coal supply amount difference d;

[0098] obtaining a standard feedwater temperature, and setting a real-time feedwater temperature according to the real-time feedwater temperature increment e and the standard feedwater temperature.

[0099] Specifically, the standard feedwater temperature is the real-time feedwater temperature obtained when the load variation instruction is received, and the real-time feedwater temperature is set as the standard feedwater temperature.

[0100] Specifically, when setting the real-time feedwater temperature increment e according to the coal supply amount difference d, the following steps are included:

[0101] a preset coal supply amount difference matrix D is set as D (D1, D2, D3, D4), wherein D1 is a preset first coal supply amount difference, D2 is a preset second coal supply amount difference, D3 is a preset third coal supply amount difference, and D4 is a preset fourth coal supply amount difference, and D1 <D2<D3<D4;

[0102] a preset feedwater temperature increment matrix E is set as E (E1, E2, E3, E4), wherein E1 is a preset first feedwater temperature increment, E2 is a preset second feedwater temperature increment, E3 is a preset third feedwater temperature increment, and E4 is a preset fourth feedwater temperature increment, and E1 <E2<E3<E4;

[0103] if d<D1, the real-time feedwater temperature increment e is set as 0;

[0104] if D1<d<D2, the real-time feedwater temperature increment e is set as the preset first water temperature increment E1, i.e. e=E1;

[0105] if D2<d<D3, the real-time feedwater temperature increment e is set as the preset second water temperature increment E2, i.e. e=E2;

[0106] if D3<d<D4, the real-time feedwater temperature increment e is set as the preset third water temperature increment E3, i.e. e=E3;

[0107] if d>D4, the real-time feedwater temperature increment e is set as the preset fourth water temperature increment E4, i.e. e=E4.

[0108] Specifically, when the load suddenly increases, due to the certain hysteresis of the coal supply response, the feedwater temperature is adjusted preferentially, the feedwater temperature is increased, the load is ensured to be met under the same coal supply amount, and the real-time coal supply increase rate and the feedwater temperature increment are set according to the real-time boiler load variation value for dynamic adjustment, so as to ensure the stable operation of the boiler.

[0109] It can be understood that in the above embodiments, when the load command suddenly increases, the real-time feed water temperature and the target coal feeding amount are corrected according to the real-time load command, and the real-time coal feeding increase rate and the feed water temperature increment are set according to the real-time boiler load change value, and two-way gradient adjustment is performed to solve the problems of relatively lagging coal quantity response and large inertia of coal combustion heat release, and ensure the stable operation of the boiler.

[0110] In a preferred embodiment of the embodiment of the present application, when correcting the real-time feed water parameters and coal feeding parameters according to the steam turbine pressure fluctuation value, it includes:

[0111] Preset a steam turbine pressure fluctuation matrix F, set F(F1, F2, F3, F4), where F1 is a preset first steam turbine pressure fluctuation value, F2 is a preset second steam turbine pressure fluctuation value, F3 is a preset third steam turbine pressure fluctuation value, and F1 < F2 < F3;

[0112] Preset a coal feeding rate correction coefficient matrix N, set N(n1, n2, n3), where n1 is a preset first coal feeding rate correction coefficient, n2 is a preset second coal feeding rate correction coefficient, n3 is a preset third coal feeding rate correction coefficient, and 1 < n1 < n2 < n3;

[0113] Obtain the steam turbine pressure fluctuation value f, set the real-time coal feeding rate correction coefficient n according to the steam turbine pressure fluctuation value f, and correct the real-time coal feeding increase rate c;

[0114] Set the real-time feed water temperature increment compensation coefficient m according to the steam turbine pressure fluctuation value f, and correct the real-time feed water temperature increment e.

[0115] Specifically, when setting the real-time coal feeding rate correction coefficient n according to the steam turbine pressure fluctuation value f, it includes:

[0116] Preset a coal feeding rate correction coefficient matrix N, set N(n1, n2, n3), where n1 is a preset first coal feeding rate correction coefficient, n2 is a preset second coal feeding rate correction coefficient, n3 is a preset third coal feeding rate correction coefficient, and 1 < n1 < n2 < n3;

[0117] If f < F1, do not set the real-time coal feeding rate correction coefficient n;

[0118] If F1 < f < F2, set n = n1, and the corrected real-time coal feeding increase rate c1 = n1 * Ci, (i = 1, 2, 3, 4);

[0119] If F2 < f < F3, set n = n2, and the corrected real-time coal feeding increase rate c1 = n2 * Ci, (i = 1, 2, 3, 4);

[0120] If f > F3, set n = n3, and the corrected real-time coal feeding increase rate c1 = n3 * Ci, (i = 1, 2, 3, 4).

[0121] Specifically, the real-time feedwater temperature increment compensation coefficient m is set according to the steam turbine pressure fluctuation value f, including:

[0122] A preset feedwater temperature increment compensation coefficient matrix M is set as M (m1, m2, m3), wherein m1 is a preset first feedwater temperature increment compensation coefficient, m2 is a preset second feedwater temperature increment compensation coefficient, m3 is a preset third feedwater temperature increment compensation coefficient, and 1 < m1 < m2 < m3;

[0123] The real-time feedwater temperature increment compensation coefficient m is set according to the steam turbine pressure fluctuation value, and the real-time feedwater temperature increment e is corrected;

[0124] If f < F1, the real-time feedwater temperature increment compensation coefficient m is not set;

[0125] If F1 < f < F2, m = m1 is set, and the corrected real-time feedwater temperature increment e1 = m1 * Ei (i = 1, 2, 3, 4);

[0126] If F2 < f < F3, m = m2 is set, and the corrected real-time feedwater temperature increment e1 = m2 * Ei (i = 1, 2, 3, 4);

[0127] If f > F3, m = m3 is set, and the corrected real-time feedwater temperature increment e1 = m3 * Ei (i = 1, 2, 3, 4).

[0128] It can be understood that in the above embodiment, by setting the coal feeding rate correction coefficient matrix and the feedwater temperature increment compensation coefficient matrix, the real-time coal feeding increase rate and the feedwater temperature increment are dynamically corrected according to the steam turbine pressure fluctuation value, the problem of causing large steam turbine pressure fluctuation is avoided, and the stable operation of the boiler is ensured.

[0129] In some embodiments of the present application, different control modes are set by acquiring the boiler load variation value, so that when the load instruction suddenly decreases or suddenly increases, the operation parameters of the boiler are corrected in time, the problem of long adjustment time causing underpressure or overpressure is avoided, and the problem of affecting the stable operation of the boiler is further avoided.

[0130] In some embodiments of the present application, when the load instruction suddenly increases, the real-time feedwater temperature and the target coal feeding amount are corrected according to the real-time load instruction, the real-time coal feeding increase rate and the feedwater temperature increment are set according to the real-time boiler load variation value, and bidirectional gradient adjustment is performed, so that the problems of relatively lagging coal amount response and large coal combustion heat release inertia are solved, and the stable operation of the boiler is ensured.

[0131] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, some improvements and replacements can be made without departing from the technical principles of the present application, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A combustion and feedwater control method that accommodates load changes, characterized by, The method comprises the following steps: obtaining a load instruction, setting a control mode and a boiler load variation value according to the load instruction and a real-time load value; setting a boiler feed water parameter and a boiler coal feeding parameter according to the control mode and the boiler load variation value; obtaining a steam turbine pressure fluctuation value, and correcting a real-time feed water parameter and a coal feeding parameter according to the steam turbine pressure fluctuation value; when the boiler load variation value is generated according to the load instruction and the real-time load value, the method comprises the following steps: obtaining a load instruction and generating an instruction load value A1; obtaining a real-time load value A2; generating a boiler load variation value b according to the absolute value of the difference between the instruction load value A1 and the real-time load value A2; presetting a boiler load variation threshold value Δb; when b>Δb, setting a real-time control mode according to the instruction load value A1 and the real-time load value A2; if A1<A2, setting the real-time control mode as a first-level control mode; if A1>A2, setting the real-time control mode as a second-level control mode; when the boiler feed water parameter and the boiler coal feeding parameter are set according to the control mode and the boiler load variation value, the method comprises the following steps: presetting a boiler load variation value matrix B, and setting B (B1, B2, B3, B4), wherein B1 is a preset first boiler load variation value, B2 is a preset second boiler load variation value, B3 is a preset third boiler load variation value, and B4 is a preset fourth boiler load variation value, and B1<B2<B3<B4; if the real-time control mode is the first-level control mode, setting a coal feeding amount reduction rate and a first target coal feeding amount according to the boiler load variation value b, and setting a real-time feed water temperature according to the coal feeding amount difference between a real-time coal feeding amount and the first target coal feeding amount; if the real-time control mode is the second-level control mode, setting a coal feeding amount increase rate and a second target coal feeding amount according to the boiler load variation value b, and setting a real-time feed water temperature according to the coal feeding amount difference between a real-time coal feeding amount and the second target coal feeding amount; when the coal feeding amount increase rate and the second target coal feeding amount are set according to the boiler load variation value b, the method comprises the following steps: setting the second target coal feeding amount according to the instruction load value A1, and setting a real-time coal feeding increase rate c according to the boiler load variation value b; adjusting the real-time coal feeding amount according to the real-time coal feeding increase rate c, and stopping the adjustment when the real-time coal feeding amount is equal to the second target coal feeding amount.

2. The combustion and feedwater control method for load changes according to claim 1, characterized by, when the real-time coal feeding increase rate c is set according to the boiler load variation value b, the method comprises the following steps: presetting a coal feeding amount increase rate matrix C, and setting C (C1, C2, C3, C4), wherein C1 is a preset first coal feeding increase rate, C2 is a preset second coal feeding increase rate, C3 is a preset third coal feeding increase rate, and C4 is a preset fourth coal feeding increase rate, and C1<C2<C3<C4; if B1<b<B2, setting the real-time coal feeding increase rate c as the preset first coal feeding increase rate C1, i.e. c=C1; if B2<b<B3, setting the real-time coal feeding increase rate c as the preset second coal feeding increase rate C2, i.e. c=C2; if B3<b<B4, setting the real-time coal feeding increase rate c as the preset third coal feeding increase rate C3, i.e. c=C3; If b > B4, set the real-time coal feeding increasing rate c as the preset fourth coal feeding increasing rate C4, i.e. c = C4.

3. The combustion and feedwater control method for load changes as claimed in claim 2, characterized by, The method for setting the real-time feed water temperature according to the coal feeding quantity difference between the real-time coal feeding quantity and the second target coal feeding quantity comprises the following steps: Obtain the real-time coal feeding quantity and the second target coal feeding quantity, and generate a coal feeding quantity difference d, and set a real-time feed water temperature increment e according to the coal feeding quantity difference d; Obtain a standard feed water temperature, and set a real-time feed water temperature according to the real-time feed water temperature increment e and the standard feed water temperature.

4. The combustion and feedwater control method for load changes according to claim 3, characterized by, The method for setting the real-time feed water temperature increment e according to the coal feeding quantity difference d comprises the following steps: Pre-set a coal feeding quantity difference matrix D, and set D (D1, D2, D3, D4), wherein D1 is a preset first coal feeding quantity difference, D2 is a preset second coal feeding quantity difference, D3 is a preset third coal feeding quantity difference, and D4 is a preset fourth coal feeding quantity difference, and D1 < D2 < D3 < D4; Pre-set a feed water temperature increment matrix E, and set E (E1, E2, E3, E4), wherein E1 is a preset first feed water temperature increment, E2 is a preset second feed water temperature increment, E3 is a preset third feed water temperature increment, and E4 is a preset fourth feed water temperature increment, and E1 < E2 < E3 < E4; If d < D1, set the real-time feed water temperature increment e = 0; If D1 < d < D2, set the real-time feed water temperature increment e as the preset first water temperature increment E1, i.e. e = E1; If D2 < d < D3, set the real-time feed water temperature increment e as the preset second water temperature increment E2, i.e. e = E2; If D3 < d < D4, set the real-time feed water temperature increment e as the preset third water temperature increment E3, i.e. e = E3; If d > D4, set the real-time feed water temperature increment e as the preset fourth water temperature increment E4, i.e. e = E4.

5. The combustion and feedwater control method for load changes as claimed in claim 4, wherein, The method for correcting the real-time feed water parameters and the coal feeding parameters according to the steam turbine pressure fluctuation value comprises the following steps: Pre-set a steam turbine pressure fluctuation matrix F, and set F (F1, F2, F3, F4), wherein F1 is a preset first steam turbine pressure fluctuation value, F2 is a preset second steam turbine pressure fluctuation value, and F3 is a preset third steam turbine pressure fluctuation value, and F1 < F2 < F3; Pre-set a coal feeding rate correction coefficient matrix N, and set N (n1, n2, n3), wherein n1 is a preset first coal feeding rate correction coefficient, n2 is a preset second coal feeding rate correction coefficient, and n3 is a preset third coal feeding rate correction coefficient, and 1 < n1 < n2 < n3; Obtain a steam turbine pressure fluctuation value f, set a real-time coal feeding rate correction coefficient n according to the steam turbine pressure fluctuation value f, and correct the real-time coal feeding increasing rate c; Set a real-time feed water temperature increment compensation coefficient m according to the steam turbine pressure fluctuation value f, and correct the real-time feed water temperature increment e.

6. The combustion and feedwater control method for load changes as claimed in claim 5, wherein, The method for setting the real-time coal feeding rate correction coefficient n according to the steam turbine pressure fluctuation value f comprises the following steps: Pre-set a coal feeding rate correction coefficient matrix N, and set N (n1, n2, n3), wherein n1 is a preset first coal feeding rate correction coefficient, n2 is a preset second coal feeding rate correction coefficient, and n3 is a preset third coal feeding rate correction coefficient, and 1 < n1 < n2 < n3; If f < F1, do not set the real-time coal feeding rate correction coefficient n; If F1 < f < F2, set n = n1, and the corrected real-time coal feeding increase rate c1 = n1*Ci (i = 1, 2, 3, 4); If F2 < f < F3, set n = n2, and the corrected real-time coal feeding increase rate c1 = n2*Ci (i = 1, 2, 3, 4); If f > F3, set n = n3, and the corrected real-time coal feeding increase rate c1 = n3*Ci (i = 1, 2, 3, 4).

7. The combustion and feedwater control method for load changes as recited in claim 6, characterized by, According to the steam turbine pressure fluctuation value f, set the real-time feed water temperature increment compensation coefficient m, comprising: Pre-set a feed water temperature increment compensation coefficient matrix M, set M (m1, m2, m3), wherein m1 is a preset first feed water temperature increment compensation coefficient, m2 is a preset second feed water temperature increment compensation coefficient, and m3 is a preset third feed water temperature increment compensation coefficient, and 1 < m1 < m2 < m3; According to the steam turbine pressure fluctuation value f, set the real-time feed water temperature increment compensation coefficient m, and correct the real-time feed water temperature increment e; If f < F1, do not set the real-time feed water temperature increment compensation coefficient m; If F1 < f < F2, set m = m1, and the corrected real-time feed water temperature increment e1 = m1*Ei (i = 1, 2, 3, 4); If F2 < f < F3, set m = m2, and the corrected real-time feed water temperature increment e1 = m2*Ei (i = 1, 2, 3, 4); If f > F3, set m = m3, and the corrected real-time feed water temperature increment e1 = m3*Ei (i = 1, 2, 3, 4).

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