A spontaneous combustion detection device for primary air duct

Abstract

The present invention relates to the technical field of coal powder spontaneous combustion, and discloses a spontaneous combustion detection device for a primary air duct, comprising: an acquisition unit, the acquisition unit is used to acquire coal powder composition data entering the primary air duct; a detection unit, the detection unit is arranged in the primary air duct, and a temperature sensor and an oxygen concentration monitor are arranged in the detection unit, the temperature sensor is used to detect the temperature inside the primary air duct, and the oxygen concentration monitor is used to detect the oxygen concentration inside the primary air duct; a control unit, the control unit is used to determine the coal powder hazard level according to the coal powder composition data, and the control unit is also used to predict the primary air duct spontaneous combustion index according to the temperature data and the coal powder hazard level. The present invention determines the hazard level of coal powder spontaneous combustion according to the type and concentration of coal powder, and predicts the primary air duct spontaneous combustion index in combination with the real-time temperature in the primary air duct, thereby improving the accuracy of spontaneous combustion detection results and the safety of power plant operation.

Description

Technical Field

[0001] The invention relates to the technical field of coal powder spontaneous combustion, and in particular to a spontaneous combustion detection device for a primary air duct. Background Art

[0002] There are primary air and secondary air in boiler combustion. Primary air is the part of air that transports pulverized coal into the furnace through pipelines. It is generally provided by the primary fan. One part is heated by the air preheater, called hot primary air, and the other part is not heated, called cold primary air, also called temperature-adjusting air. In addition to maintaining a certain concentration of gas-powder mixture for easy transportation, it also provides sufficient oxygen for the fuel in the early stage of combustion.

[0003] However, coal powder may easily spontaneously combust and explode in the primary air duct of the boiler. It is essential to install a spontaneous combustion detection device in the primary air duct. However, in the prior art, most spontaneous combustion detection devices are based on manual observation, temperature measurement or only detect the outlet temperature of the coal powder. Due to the large variety of coal powders and different combustion characteristics, the spontaneous combustion detection results are not accurate, which results in safety hazards such as thermal explosion, seriously affecting the safe and economical operation of the power plant. Therefore, how to provide a spontaneous combustion detection device for the primary air duct is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] The purpose of the present invention is to provide a spontaneous combustion detection device for a primary air duct. Through the spontaneous combustion detection device of the present invention, the danger level of spontaneous combustion of coal powder can be determined according to the type and concentration of coal powder, and the spontaneous combustion index of the primary air duct can be predicted in combination with the real-time temperature in the primary air duct, thereby improving the accuracy of the spontaneous combustion detection results and the safety of power plant operation.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A spontaneous combustion detection device for a primary air duct, comprising:

[0007] An acquisition unit, the acquisition unit is used to acquire the composition data of the pulverized coal entering the primary air duct;

[0008] A detection unit, the detection unit is arranged in the primary air duct, and a temperature sensor and an oxygen concentration monitor are arranged in the detection unit, the temperature sensor is used to detect the temperature inside the primary air duct, and the oxygen concentration monitor is used to detect the oxygen concentration inside the primary air duct;

[0009] A control unit, the control unit is used to determine the coal powder danger level according to the coal powder composition data, the control unit is also used to predict the primary air duct spontaneous combustion index according to the temperature data and the coal powder danger level, and to correct the primary air duct spontaneous combustion index according to the oxygen concentration;

[0010] The pulverized coal composition data include pulverized coal type and pulverized coal concentration.

[0011] In some embodiments of the present application, when the control unit is used to determine the coal dust hazard level according to the coal dust composition data, it includes:

[0012] The control unit is set with a preset coal powder hazard level A and a preset coal powder type matrix M. For the preset gas type matrix M, M (M1, M2, M3, M4) is set, wherein M1 is a first preset coal powder type, M2 is a second preset coal powder type, M3 is a third preset coal powder type, and M4 is a fourth preset coal powder type;

[0013] For the preset coal dust hazard level A, set A(A1, A2, A3, A4), where A1 is the first preset coal dust hazard level, A2 is the second preset coal dust hazard level, A3 is the third preset coal dust hazard level, and A4 is the fourth preset coal dust hazard level;

[0014] The control unit is set with a preset coal powder concentration interval matrix C. For the preset coal powder concentration interval matrix C, C(C1, C2, C3, C4) is set, wherein C1 is the first preset coal powder concentration interval, C2 is the first preset coal powder concentration interval, C3 is the first preset coal powder concentration interval, C4 is the first preset coal powder concentration interval, and C1<C2<C3<C4;

[0015] When the type of the coal powder is the first preset coal powder type M1 and the coal powder concentration is the first preset coal powder concentration interval C1, the coal powder hazard level is determined to be the first preset coal powder hazard level A1;

[0016] When the type of the coal powder is the second preset coal powder type M2 and the coal powder concentration is the second preset coal powder concentration interval C2, the coal powder hazard level is determined to be the second preset coal powder hazard level A2;

[0017] When the type of the coal powder is the third preset coal powder type M3 and the coal powder concentration is the third preset coal powder concentration interval C3, the coal powder hazard level is determined to be the third preset coal powder hazard level A3;

[0018] When the type of the coal powder is the fourth preset type of coal powder M4 and the coal powder concentration is the fourth preset coal powder concentration interval C4, the coal powder hazard level is determined to be the fourth preset coal powder hazard level A4.

[0019] In some embodiments of the present application, the control unit is further used to predict the primary air duct spontaneous combustion index according to the temperature data and the coal powder danger level, including:

[0020] The control unit is set with a preset temperature interval matrix T and a preset primary air duct spontaneous combustion level matrix H. For the preset temperature interval matrix T, T(T1, T2, T3, T4) is set, wherein T1 is the first preset temperature interval, T2 is the second preset temperature interval, T3 is the third preset temperature interval, T4 is the fourth preset temperature interval, and T1<T2<T3<T4;

[0021] For the preset primary air duct spontaneous combustion index matrix H, set H(H1, H2, H3, H4), where H1 is the first preset primary air duct spontaneous combustion index, H2 is the second preset primary air duct spontaneous combustion index, H3 is the third preset primary air duct spontaneous combustion index, and H4 is the fourth preset primary air duct spontaneous combustion index;

[0022] Real-time detection of the internal temperature v of the primary air duct, and prediction of the spontaneous combustion index of the primary air duct according to the relationship between the coal powder danger level, the real-time temperature and the preset temperature interval matrix;

[0023] When v<T1 and the coal dust hazard level is the first preset coal dust hazard level A1, the primary air duct spontaneous combustion level is predicted to be the first preset primary air duct spontaneous combustion index H1;

[0024] When T1≤v<T2 and the coal powder hazard level is the second preset coal powder hazard level A2, the primary air duct spontaneous combustion level is predicted to be the second preset primary air duct spontaneous combustion index H2;

[0025] When T2≤v<T3 and the coal powder hazard level is the third preset coal powder hazard level A3, the primary air duct spontaneous combustion level is predicted to be the third preset primary air duct spontaneous combustion index H3;

[0026] When T3≤v<T4 and the coal powder hazard level is the fourth preset coal powder hazard level A4, the primary air duct spontaneous combustion level is predicted to be the fourth preset primary air duct spontaneous combustion index H4.

[0027] In some embodiments of the present application, the control unit is further used to correct the primary air duct spontaneous combustion index according to the oxygen concentration, including:

[0028] The control unit is set with a preset oxygen concentration interval matrix K and a preset autoignition index correction coefficient matrix α. For the preset oxygen concentration interval matrix K, K(K1, K2, K3, K4) is set, wherein K1 is a first preset oxygen concentration interval, K2 is a second preset oxygen concentration interval, K3 is a third preset oxygen concentration interval, K4 is a fourth preset oxygen concentration interval, and K1<K2<K3<K4;

[0029] For the preset auto-ignition index correction coefficient matrix α, set α(α1, α2, α3, α4), wherein α1 is the first preset auto-ignition index correction coefficient, α2 is the second preset auto-ignition index correction coefficient, α3 is the third preset auto-ignition index correction coefficient, α4 is the fourth preset auto-ignition index correction coefficient, and α1<α2<α3<α4;

[0030] Real-time detection of the oxygen concentration b inside the primary air duct, and selection of a corresponding correction coefficient to correct the preset i-th primary air duct spontaneous combustion index Hi (i=1, 2, 3, 4) according to the relationship between b and the preset oxygen concentration interval matrix K;

[0031] When b<K1, the first preset spontaneous combustion index correction coefficient α1 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α1*Hi;

[0032] When K1≤b<K2, the second preset spontaneous combustion index correction coefficient α2 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α2*Hi;

[0033] When K2≤b<K3, the third preset spontaneous combustion index correction coefficient α3 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α3*Hi;

[0034] When K3≤b<K4, the fourth preset spontaneous combustion index correction coefficient α4 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α4*Hi.

[0035] In some embodiments of the present application, a speed sensor is further provided in the detection unit, and the speed sensor is used to detect the primary wind speed inside the primary air duct and send the primary wind speed data to the control unit.

[0036] In some embodiments of the present application, the control unit is further used to perform a secondary correction on the primary air duct spontaneous combustion index according to the primary air velocity data, including:

[0037] The control unit is set with a preset primary wind speed interval matrix L and a preset autoignition index secondary correction coefficient matrix β. For the preset primary wind speed interval matrix L, L(L1, L2, L3, L4) is set, wherein L1 is the first preset primary wind speed interval, L2 is the second preset primary wind speed interval, L3 is the third preset primary wind speed interval, L4 is the fourth preset primary wind speed interval, and L1<L2<L3<L4;

[0038] For the preset auto-ignition index quadratic correction coefficient matrix β, set β(β1, β2, β3, β4), wherein β1 is the first preset auto-ignition index quadratic correction coefficient, β2 is the second preset auto-ignition index quadratic correction coefficient, β3 is the third preset auto-ignition index quadratic correction coefficient, β4 is the fourth preset auto-ignition index quadratic correction coefficient, and β1<β2<β3<β4;

[0039] Real-time detection of the primary wind speed n, and selection of a corresponding secondary correction coefficient to correct the preset i-th primary wind duct spontaneous combustion index Hi (i=1, 2, 3, 4) according to the relationship between n and the preset primary wind speed interval matrix L;

[0040] When n<L1, the fourth preset spontaneous combustion index correction coefficient β4 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α1*Hi*β4;

[0041] When L1≤n<L2, the third preset spontaneous combustion index correction coefficient β3 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α2*Hi*β3;

[0042] When L2≤n<L3, the second preset spontaneous combustion index correction coefficient β2 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α3*Hi*β2;

[0043] When L3≤n<L4, the first preset spontaneous combustion index correction coefficient β1 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α4*Hi*β1.

[0044] In some embodiments of the present application, the control unit further predicts the spontaneous combustion time of the primary air duct according to the spontaneous combustion index of the primary air duct, including:

[0045] The control unit is set with a first preset primary air duct spontaneous combustion time D1, a second preset primary air duct spontaneous combustion time D2, a third preset primary air duct spontaneous combustion time D3, and a fourth preset primary air duct spontaneous combustion time D4, and D1<D2<D3<D4;

[0046] When the primary air duct spontaneous combustion index is the first preset primary air duct spontaneous combustion index H1, the primary air duct spontaneous combustion time is predicted to be the first preset primary air duct spontaneous combustion time D1;

[0047] When the primary air duct spontaneous combustion index is the second preset primary air duct spontaneous combustion index H2, the predicted primary air duct spontaneous combustion time is the second preset primary air duct spontaneous combustion time D2;

[0048] When the primary air duct spontaneous combustion index is the third preset primary air duct spontaneous combustion index H3, the primary air duct spontaneous combustion time is predicted to be the third preset primary air duct spontaneous combustion time D3;

[0049] When the primary air duct spontaneous combustion index is the fourth preset primary air duct spontaneous combustion index H4, the predicted primary air duct spontaneous combustion time is the fourth preset primary air duct spontaneous combustion time D4.

[0050] In some embodiments of the present application, it also includes:

[0051] An early warning unit is used to receive the spontaneous combustion time of the primary air duct and send different early warning signals according to the spontaneous combustion time of the primary air duct.

[0052] In some embodiments of the present application, the early warning unit is used to receive the spontaneous combustion time of the primary air duct, and send different early warning signals according to the spontaneous combustion time of the primary air duct, including:

[0053] The control unit is set with a first preset warning signal, a second preset warning signal, a third preset warning signal, and a fourth preset warning signal;

[0054] When the primary air duct spontaneous combustion time is the first preset primary air duct spontaneous combustion time D1, sending the first preset warning signal;

[0055] When the primary air duct spontaneous combustion time is the second preset primary air duct spontaneous combustion time D2, sending the second preset warning signal;

[0056] When the primary air duct spontaneous combustion time is the third preset primary air duct spontaneous combustion time D3, sending the third preset warning signal;

[0057] When the primary air duct spontaneous combustion time is the fourth preset primary air duct spontaneous combustion time D4, the fourth preset warning signal is sent.

[0058] In some embodiments of the present application, a carbon monoxide detector is also provided in the detection unit. The carbon monoxide detector is arranged at a location inside the primary air duct that is prone to spontaneous combustion. The carbon monoxide detector is used to detect the carbon monoxide concentration inside the primary air duct. When the carbon monoxide concentration exceeds a preset carbon monoxide threshold, the control unit sends a warning signal.

[0059] The present invention provides a spontaneous combustion detection device for a primary air duct. Compared with the prior art, the present invention has the following beneficial effects:

[0060] The present invention obtains coal powder composition data through an acquisition unit, the coal powder composition data including coal powder type and coal powder concentration, determines the danger of coal powder spontaneous combustion according to the coal powder type and coal powder concentration, predicts the primary air duct spontaneous combustion index according to real-time detection of the temperature in the primary air duct, and corrects the primary air duct spontaneous combustion index according to the oxygen concentration, thereby improving the accuracy of the spontaneous combustion detection result and the safety of the power plant operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 Schematic diagram of a spontaneous combustion detection device for a primary air duct in an embodiment of the present invention. DETAILED DESCRIPTION

[0062] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0063] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present 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 should not be understood as a limitation on the present application.

[0064] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0065] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0066] like Figure 1 As shown, a spontaneous combustion detection device for a primary air duct according to a preferred embodiment of the present invention comprises:

[0067] An acquisition unit, the acquisition unit is used to acquire the composition data of the pulverized coal entering the primary air duct;

[0068] A detection unit, the detection unit is arranged in the primary air duct, and a temperature sensor and an oxygen concentration monitor are arranged in the detection unit, the temperature sensor is used to detect the temperature inside the primary air duct, and the oxygen concentration monitor is used to detect the oxygen concentration inside the primary air duct;

[0069] A control unit, the control unit is used to determine the coal powder danger level according to the coal powder composition data, the control unit is also used to predict the primary air duct spontaneous combustion index according to the temperature data and the coal powder danger level, and to correct the primary air duct spontaneous combustion index according to the oxygen concentration;

[0070] The pulverized coal composition data include pulverized coal type and pulverized coal concentration.

[0071] In this embodiment, as for the coal powder itself, the higher the volatile content, the easier it is for deflagration to occur. When the combustible volatile content of coal is greater than 35%, it has the maximum explosion pressure, and when the volatile content is less than 15%, the possibility of deflagration is very small. The combustion and explosion characteristics of coal powder are tested through historical data, and the coal powder is classified according to its combustion and explosion characteristics.

[0072] In some embodiments of the present application, when the control unit is used to determine the coal dust hazard level according to the coal dust composition data, it includes:

[0073] The control unit is set with a preset coal powder hazard level A and a preset coal powder type matrix M. For the preset gas type matrix M, M (M1, M2, M3, M4) is set, wherein M1 is a first preset coal powder type, M2 is a second preset coal powder type, M3 is a third preset coal powder type, and M4 is a fourth preset coal powder type;

[0074] For the preset coal dust hazard level A, set A(A1, A2, A3, A4), where A1 is the first preset coal dust hazard level, A2 is the second preset coal dust hazard level, A3 is the third preset coal dust hazard level, and A4 is the fourth preset coal dust hazard level;

[0075] The control unit is set with a preset coal powder concentration interval matrix C. For the preset coal powder concentration interval matrix C, C(C1, C2, C3, C4) is set, wherein C1 is the first preset coal powder concentration interval, C2 is the first preset coal powder concentration interval, C3 is the first preset coal powder concentration interval, C4 is the first preset coal powder concentration interval, and C1<C2<C3<C4;

[0076] When the type of the coal powder is the first preset coal powder type M1 and the coal powder concentration is the first preset coal powder concentration interval C1, the coal powder hazard level is determined to be the first preset coal powder hazard level A1;

[0077] When the type of the coal powder is the second preset coal powder type M2 and the coal powder concentration is the second preset coal powder concentration interval C2, the coal powder hazard level is determined to be the second preset coal powder hazard level A2;

[0078] When the type of the coal powder is the third preset coal powder type M3 and the coal powder concentration is the third preset coal powder concentration interval C3, the coal powder hazard level is determined to be the third preset coal powder hazard level A3;

[0079] When the type of the coal powder is the fourth preset type of coal powder M4 and the coal powder concentration is the fourth preset coal powder concentration interval C4, the coal powder hazard level is determined to be the fourth preset coal powder hazard level A4.

[0080] In some embodiments of the present application, the control unit is further used to predict the primary air duct spontaneous combustion index according to the temperature data and the coal powder danger level, including:

[0081] The control unit is set with a preset temperature interval matrix T and a preset primary air duct spontaneous combustion level matrix H. For the preset temperature interval matrix T, T(T1, T2, T3, T4) is set, wherein T1 is the first preset temperature interval, T2 is the second preset temperature interval, T3 is the third preset temperature interval, T4 is the fourth preset temperature interval, and T1<T2<T3<T4;

[0082] For the preset primary air duct spontaneous combustion index matrix H, set H(H1, H2, H3, H4), where H1 is the first preset primary air duct spontaneous combustion index, H2 is the second preset primary air duct spontaneous combustion index, H3 is the third preset primary air duct spontaneous combustion index, and H4 is the fourth preset primary air duct spontaneous combustion index;

[0083] Real-time detection of the internal temperature v of the primary air duct, and prediction of the spontaneous combustion index of the primary air duct according to the relationship between the coal powder danger level, the real-time temperature and the preset temperature interval matrix;

[0084] When v<T1 and the coal dust hazard level is the first preset coal dust hazard level A1, the primary air duct spontaneous combustion level is predicted to be the first preset primary air duct spontaneous combustion index H1;

[0085] When T1≤v<T2 and the coal powder hazard level is the second preset coal powder hazard level A2, the primary air duct spontaneous combustion level is predicted to be the second preset primary air duct spontaneous combustion index H2;

[0086] When T2≤v<T3 and the coal powder hazard level is the third preset coal powder hazard level A3, the primary air duct spontaneous combustion level is predicted to be the third preset primary air duct spontaneous combustion index H3;

[0087] When T3≤v<T4 and the coal powder hazard level is the fourth preset coal powder hazard level A4, the primary air duct spontaneous combustion level is predicted to be the fourth preset primary air duct spontaneous combustion index H4.

[0088] In some embodiments of the present application, the control unit is further used to correct the primary air duct spontaneous combustion index according to the oxygen concentration, including:

[0089] The control unit is set with a preset oxygen concentration interval matrix K and a preset autoignition index correction coefficient matrix α. For the preset oxygen concentration interval matrix K, K(K1, K2, K3, K4) is set, wherein K1 is a first preset oxygen concentration interval, K2 is a second preset oxygen concentration interval, K3 is a third preset oxygen concentration interval, K4 is a fourth preset oxygen concentration interval, and K1<K2<K3<K4;

[0090] For the preset auto-ignition index correction coefficient matrix α, set α(α1, α2, α3, α4), wherein α1 is the first preset auto-ignition index correction coefficient, α2 is the second preset auto-ignition index correction coefficient, α3 is the third preset auto-ignition index correction coefficient, α4 is the fourth preset auto-ignition index correction coefficient, and α1<α2<α3<α4;

[0091] Real-time detection of the oxygen concentration b inside the primary air duct, and selection of a corresponding correction coefficient to correct the preset i-th primary air duct spontaneous combustion index Hi (i=1, 2, 3, 4) according to the relationship between b and the preset oxygen concentration interval matrix K;

[0092] When b<K1, the first preset spontaneous combustion index correction coefficient α1 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α1*Hi;

[0093] When K1≤b<K2, the second preset spontaneous combustion index correction coefficient α2 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α2*Hi;

[0094] When K2≤b<K3, the third preset spontaneous combustion index correction coefficient α3 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α3*Hi;

[0095] When K3≤b<K4, the fourth preset spontaneous combustion index correction coefficient α4 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α4*Hi.

[0096] In this embodiment, historical data proves that the lower the oxygen concentration, the lower the spontaneous combustion of coal powder. When the volume concentration of oxygen is less than 16%, the deflagration can be completely eliminated. The oxygen concentration in the primary air duct is detected in real time. When the oxygen concentration is low, the spontaneous combustion index of coal powder decreases. When the oxygen concentration is high, the spontaneous combustion index of coal powder increases. In this way, the spontaneous combustion index of the primary air duct is corrected and the spontaneous combustion index of the primary air duct is predicted more accurately.

[0097] In some embodiments of the present application, a speed sensor is further provided in the detection unit, and the speed sensor is used to detect the primary wind speed inside the primary air duct and send the primary wind speed data to the control unit.

[0098] In some embodiments of the present application, the control unit is further used to perform a secondary correction on the primary air duct spontaneous combustion index according to the primary air velocity data, including:

[0099] The control unit is set with a preset primary wind speed interval matrix L and a preset autoignition index secondary correction coefficient matrix β. For the preset primary wind speed interval matrix L, L(L1, L2, L3, L4) is set, wherein L1 is the first preset primary wind speed interval, L2 is the second preset primary wind speed interval, L3 is the third preset primary wind speed interval, L4 is the fourth preset primary wind speed interval, and L1<L2<L3<L4;

[0100] For the preset auto-ignition index quadratic correction coefficient matrix β, set β(β1, β2, β3, β4), wherein β1 is the first preset auto-ignition index quadratic correction coefficient, β2 is the second preset auto-ignition index quadratic correction coefficient, β3 is the third preset auto-ignition index quadratic correction coefficient, β4 is the fourth preset auto-ignition index quadratic correction coefficient, and β1<β2<β3<β4;

[0101] Real-time detection of the primary wind speed n, and selection of a corresponding secondary correction coefficient to correct the preset i-th primary wind duct spontaneous combustion index Hi (i=1, 2, 3, 4) according to the relationship between n and the preset primary wind speed interval matrix L;

[0102] When n<L1, the fourth preset spontaneous combustion index correction coefficient β4 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α1*Hi*β4;

[0103] When L1≤n<L2, the third preset spontaneous combustion index correction coefficient β3 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α2*Hi*β3;

[0104] When L2≤n<L3, the second preset spontaneous combustion index correction coefficient β2 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α3*Hi*β2;

[0105] When L3≤n<L4, the first preset spontaneous combustion index correction coefficient β1 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α4*Hi*β1.

[0106] In this embodiment, historical data shows that when the speed of the primary air at the primary air duct outlet is greater than the speed of the coal powder airflow, the primary air duct spontaneous combustion index can be greatly reduced, so as to perform a secondary correction on the primary air duct spontaneous combustion index. When the primary air speed increases, the primary air duct spontaneous combustion index decreases, and when the primary air speed decreases, the primary air duct spontaneous combustion index increases.

[0107] In some embodiments of the present application, the control unit further predicts the spontaneous combustion time of the primary air duct according to the spontaneous combustion index of the primary air duct, including:

[0108] The control unit is set with a first preset primary air duct spontaneous combustion time D1, a second preset primary air duct spontaneous combustion time D2, a third preset primary air duct spontaneous combustion time D3, and a fourth preset primary air duct spontaneous combustion time D4, and D1<D2<D3<D4;

[0109] When the primary air duct spontaneous combustion index is the first preset primary air duct spontaneous combustion index H1, the primary air duct spontaneous combustion time is predicted to be the first preset primary air duct spontaneous combustion time D1;

[0110] When the primary air duct spontaneous combustion index is the second preset primary air duct spontaneous combustion index H2, the predicted primary air duct spontaneous combustion time is the second preset primary air duct spontaneous combustion time D2;

[0111] When the primary air duct spontaneous combustion index is the third preset primary air duct spontaneous combustion index H3, the primary air duct spontaneous combustion time is predicted to be the third preset primary air duct spontaneous combustion time D3;

[0112] When the primary air duct spontaneous combustion index is the fourth preset primary air duct spontaneous combustion index H4, the predicted primary air duct spontaneous combustion time is the fourth preset primary air duct spontaneous combustion time D4.

[0113] In some embodiments of the present application, it also includes:

[0114] An early warning unit is used to receive the spontaneous combustion time of the primary air duct and send different early warning signals according to the spontaneous combustion time of the primary air duct.

[0115] In some embodiments of the present application, the early warning unit is used to receive the spontaneous combustion time of the primary air duct, and send different early warning signals according to the spontaneous combustion time of the primary air duct, including:

[0116] The control unit is set with a first preset warning signal, a second preset warning signal, a third preset warning signal, and a fourth preset warning signal;

[0117] When the primary air duct spontaneous combustion time is the first preset primary air duct spontaneous combustion time D1, sending the first preset warning signal;

[0118] When the primary air duct spontaneous combustion time is the second preset primary air duct spontaneous combustion time D2, sending the second preset warning signal;

[0119] When the primary air duct spontaneous combustion time is the third preset primary air duct spontaneous combustion time D3, sending the third preset warning signal;

[0120] When the primary air duct spontaneous combustion time is the fourth preset primary air duct spontaneous combustion time D4, the fourth preset warning signal is sent.

[0121] In some embodiments of the present application, a carbon monoxide detector is also provided in the detection unit. The carbon monoxide detector is arranged at a location inside the primary air duct that is prone to spontaneous combustion. The carbon monoxide detector is used to detect the carbon monoxide concentration inside the primary air duct. When the carbon monoxide concentration exceeds a preset carbon monoxide threshold, the control unit sends a warning signal.

[0122] In this embodiment, the oxidation of coal powder in the pipe, that is, the generation of carbon monoxide (which is proportional to the combustion, that is, the spontaneous combustion and smoke are related to the carbon monoxide content), is used. By measuring the carbon monoxide concentration, the spontaneous combustion in the pipeline can be predicted, and measures can be taken according to the prediction to deal with it in time to prevent the occurrence of deflagration.

[0123] In summary, the embodiment of the present invention provides a spontaneous combustion detection device for a primary air duct, which obtains coal powder composition data through an acquisition unit, the coal powder composition data including coal powder type and coal powder concentration, determines the danger of coal powder spontaneous combustion according to the coal powder type and coal powder concentration, detects the temperature in the primary air duct through the detection unit, and predicts the spontaneous combustion index of the primary air duct in combination with the danger of coal powder spontaneous combustion. The detection unit also detects the oxygen concentration in the primary air duct, and corrects the spontaneous combustion index of the primary air duct according to the oxygen concentration, thereby improving the accuracy of the spontaneous combustion detection result and the safety of the power plant operation, and solves the problem that the spontaneous combustion detection devices in the prior art are all manual observation, temperature measurement method or only detect the coal powder outlet temperature, and due to the large number of coal powder types and different combustion characteristics, the spontaneous combustion detection result is not accurate, thereby causing safety hazards such as thermal explosion, which seriously affects the safe and economical operation of the power plant.

[0124] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A spontaneous combustion detection device for a primary air duct, It is characterized in that include: An acquisition unit, the acquisition unit is used to acquire the composition data of the pulverized coal entering the primary air duct; A detection unit, the detection unit is arranged in the primary air duct, and a temperature sensor and an oxygen concentration monitor are arranged in the detection unit, the temperature sensor is used to detect the temperature inside the primary air duct, and the oxygen concentration monitor is used to detect the oxygen concentration inside the primary air duct; A control unit, the control unit is used to determine the coal powder danger level according to the coal powder composition data, the control unit is also used to predict the primary air duct spontaneous combustion index according to the temperature data and the coal powder danger level, and to correct the primary air duct spontaneous combustion index according to the oxygen concentration; The coal powder composition data includes coal powder type and coal powder concentration; When the control unit is used to determine the hazard level of coal powder according to the coal powder composition data, it includes: The control unit is set with a preset coal powder hazard level A and a preset coal powder type matrix M. For the preset gas type matrix M, M (M1, M2, M3, M4) is set, wherein M1 is a first preset coal powder type, M2 is a second preset coal powder type, M3 is a third preset coal powder type, and M4 is a fourth preset coal powder type; For the preset coal dust hazard level A, set A(A1, A2, A3, A4), where A1 is the first preset coal dust hazard level, A2 is the second preset coal dust hazard level, A3 is the third preset coal dust hazard level, and A4 is the fourth preset coal dust hazard level; The control unit is set with a preset coal powder concentration interval matrix C. For the preset coal powder concentration interval matrix C, C(C1, C2, C3, C4) is set, wherein C1 is the first preset coal powder concentration interval, C2 is the first preset coal powder concentration interval, C3 is the first preset coal powder concentration interval, C4 is the first preset coal powder concentration interval, and C1<C2<C3<C4; When the type of the coal powder is the first preset coal powder type M1 and the coal powder concentration is the first preset coal powder concentration interval C1, the coal powder hazard level is determined to be the first preset coal powder hazard level A1; When the type of the coal powder is the second preset coal powder type M2 and the coal powder concentration is the second preset coal powder concentration interval C2, the coal powder hazard level is determined to be the second preset coal powder hazard level A2; When the type of the coal powder is the third preset coal powder type M3 and the coal powder concentration is the third preset coal powder concentration interval C3, the coal powder hazard level is determined to be the third preset coal powder hazard level A3; When the type of the coal powder is the fourth preset coal powder type M4 and the coal powder concentration is the fourth preset coal powder concentration interval C4, the coal powder hazard level is determined to be the fourth preset coal powder hazard level A4; The control unit is also used to predict the spontaneous combustion index of the primary air duct according to the temperature data and the coal powder danger level, including: The control unit is set with a preset temperature interval matrix T and a preset primary air duct spontaneous combustion level matrix H. For the preset temperature interval matrix T, T(T1, T2, T3, T4) is set, wherein T1 is the first preset temperature interval, T2 is the second preset temperature interval, T3 is the third preset temperature interval, T4 is the fourth preset temperature interval, and T1<T2<T3<T4; For the preset primary air duct spontaneous combustion index matrix H, set H(H1, H2, H3, H4), where H1 is the first preset primary air duct spontaneous combustion index, H2 is the second preset primary air duct spontaneous combustion index, H3 is the third preset primary air duct spontaneous combustion index, and H4 is the fourth preset primary air duct spontaneous combustion index; Real-time detection of the internal temperature v of the primary air duct, and prediction of the spontaneous combustion index of the primary air duct according to the relationship between the coal powder danger level, the real-time temperature and the preset temperature interval matrix; When v<T1 and the coal dust hazard level is the first preset coal dust hazard level A1, the primary air duct spontaneous combustion level is predicted to be the first preset primary air duct spontaneous combustion index H1; When T1≤v<T2 and the coal powder hazard level is the second preset coal powder hazard level A2, the primary air duct spontaneous combustion level is predicted to be the second preset primary air duct spontaneous combustion index H2; When T2≤v<T3 and the coal powder hazard level is the third preset coal powder hazard level A3, the primary air duct spontaneous combustion level is predicted to be the third preset primary air duct spontaneous combustion index H3; When T3≤v<T4 and the coal dust hazard level is the fourth preset coal dust hazard level A4, the primary air duct spontaneous combustion level is predicted to be the fourth preset primary air duct spontaneous combustion index H4; The control unit is further used to correct the primary air duct spontaneous combustion index according to the oxygen concentration, including: The control unit is set with a preset oxygen concentration interval matrix K and a preset autoignition index correction coefficient matrix α. For the preset oxygen concentration interval matrix K, K(K1, K2, K3, K4) is set, wherein K1 is a first preset oxygen concentration interval, K2 is a second preset oxygen concentration interval, K3 is a third preset oxygen concentration interval, K4 is a fourth preset oxygen concentration interval, and K1<K2<K3<K4; For the preset auto-ignition index correction coefficient matrix α, set α(α1, α2, α3, α4), wherein α1 is the first preset auto-ignition index correction coefficient, α2 is the second preset auto-ignition index correction coefficient, α3 is the third preset auto-ignition index correction coefficient, α4 is the fourth preset auto-ignition index correction coefficient, and α1<α2<α3<α4; Real-time detection of the oxygen concentration b inside the primary air duct, and selection of a corresponding correction coefficient to correct the preset i-th primary air duct spontaneous combustion index Hi (i=1, 2, 3, 4) according to the relationship between b and the preset oxygen concentration interval matrix K; When b<K1, the first preset spontaneous combustion index correction coefficient α1 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α1*Hi; When K1≤b<K2, the second preset spontaneous combustion index correction coefficient α2 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α2*Hi; When K2≤b<K3, the third preset spontaneous combustion index correction coefficient α3 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α3*Hi; When K3≤b<K4, the fourth preset spontaneous combustion index correction coefficient α4 is selected to correct the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α4*Hi.

2. The spontaneous combustion detection device for a primary air duct according to claim 1, It is characterized in that A speed sensor is also provided in the detection unit, and the speed sensor is used to detect the primary wind speed inside the primary wind duct and send the primary wind speed data to the control unit.

3. The spontaneous combustion detection device for a primary air duct according to claim 2, It is characterized in that The control unit is also used to perform a secondary correction on the primary air duct spontaneous combustion index according to the primary air velocity data, including: The control unit is set with a preset primary wind speed interval matrix L and a preset autoignition index secondary correction coefficient matrix β. For the preset primary wind speed interval matrix L, L(L1, L2, L3, L4) is set, wherein L1 is the first preset primary wind speed interval, L2 is the second preset primary wind speed interval, L3 is the third preset primary wind speed interval, L4 is the fourth preset primary wind speed interval, and L1<L2<L3<L4; For the preset auto-ignition index quadratic correction coefficient matrix β, set β(β1, β2, β3, β4), wherein β1 is the first preset auto-ignition index quadratic correction coefficient, β2 is the second preset auto-ignition index quadratic correction coefficient, β3 is the third preset auto-ignition index quadratic correction coefficient, β4 is the fourth preset auto-ignition index quadratic correction coefficient, and β1<β2<β3<β4; Real-time detection of the primary wind speed n, and selection of a corresponding secondary correction coefficient to correct the preset i-th primary wind duct spontaneous combustion index Hi (i=1, 2, 3, 4) according to the relationship between n and the preset primary wind speed interval matrix L; When n<L1, the fourth preset spontaneous combustion index correction coefficient β4 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α1*Hi*β4; When L1≤n<L2, the third preset spontaneous combustion index correction coefficient β3 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α2*Hi*β3; When L2≤n<L3, the second preset spontaneous combustion index correction coefficient β2 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α3*Hi*β2; When L3≤n<L4, the first preset spontaneous combustion index correction coefficient β1 is selected to perform secondary correction on the preset i-th primary air duct spontaneous combustion index, and the corrected primary air duct spontaneous combustion index is α4*Hi*β1.

4. The spontaneous combustion detection device for a primary air duct according to claim 3, It is characterized in that The control unit also predicts the spontaneous combustion time of the primary air duct according to the spontaneous combustion index of the primary air duct, including: The control unit is set with a first preset primary air duct spontaneous combustion time D1, a second preset primary air duct spontaneous combustion time D2, a third preset primary air duct spontaneous combustion time D3, and a fourth preset primary air duct spontaneous combustion time D4, and D1<D2<D3<D4; When the primary air duct spontaneous combustion index is the first preset primary air duct spontaneous combustion index H1, the primary air duct spontaneous combustion time is predicted to be the first preset primary air duct spontaneous combustion time D1; When the primary air duct spontaneous combustion index is the second preset primary air duct spontaneous combustion index H2, the predicted primary air duct spontaneous combustion time is the second preset primary air duct spontaneous combustion time D2; When the primary air duct spontaneous combustion index is the third preset primary air duct spontaneous combustion index H3, the primary air duct spontaneous combustion time is predicted to be the third preset primary air duct spontaneous combustion time D3; When the primary air duct spontaneous combustion index is the fourth preset primary air duct spontaneous combustion index H4, the predicted primary air duct spontaneous combustion time is the fourth preset primary air duct spontaneous combustion time D4.

5. The spontaneous combustion detection device for a primary air duct according to claim 4, It is characterized in that Also includes: An early warning unit is used to receive the spontaneous combustion time of the primary air duct and send different early warning signals according to the spontaneous combustion time of the primary air duct.

6. The spontaneous combustion detection device for a primary air duct according to claim 5, It is characterized in that The early warning unit is used to receive the spontaneous combustion time of the primary air duct, and send different early warning signals according to the spontaneous combustion time of the primary air duct, including: The control unit is set with a first preset warning signal, a second preset warning signal, a third preset warning signal, and a fourth preset warning signal; When the primary air duct spontaneous combustion time is the first preset primary air duct spontaneous combustion time D1, sending the first preset warning signal; When the primary air duct spontaneous combustion time is the second preset primary air duct spontaneous combustion time D2, sending the second preset warning signal; When the primary air duct spontaneous combustion time is the third preset primary air duct spontaneous combustion time D3, sending the third preset warning signal; When the primary air duct spontaneous combustion time is the fourth preset primary air duct spontaneous combustion time D4, the fourth preset warning signal is sent.

7. The spontaneous combustion detection device for a primary air duct according to claim 1, It is characterized in that A carbon monoxide detector is also provided in the detection unit. The carbon monoxide detector is arranged at a location inside the primary air duct that is prone to spontaneous combustion. The carbon monoxide detector is used to detect the carbon monoxide concentration inside the primary air duct. When the carbon monoxide concentration exceeds a preset carbon monoxide threshold, the control unit sends a warning signal.

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