A coal-fired power plant coal balance monitoring device and method

Abstract

The present invention relates to a coal balance monitoring device and method for a coal-fired power plant, including a ship unloader, a physical weighing verification mechanism, a belt conveyor assembly and a coal feeder. The belt conveyor assembly includes a plurality of belt conveyors, one of which is provided with an inlet belt scale and the other is provided with an upper warehouse belt scale. The physical weighing verification mechanism includes a coal bunker, a coal bunker scale and a feeder. The ship unloader is connected to the coal bunker, and the feeder is connected to the belt conveyor assembly. The present invention corrects the inlet belt scale and the upper warehouse belt scale through an online physical weighing verification mechanism to make up for the deviation of the cumulative flow of the belt scale caused by the deficiency of relying solely on dynamic chain code verification; the average density of the coal pile at the typical volume is obtained by physically measuring each type of coal, and the real-time average density of specific coal types in each area of ​​the coal yard is obtained by the difference method, eliminating the error of the coal pile density measured by only artificial simulation method or digging method, saving time and labor, laying a foundation for the construction of digital power plants, and meeting the requirements of on-site space transformation for coal-fired units in service.

Description

Technical Field

[0001] The invention relates to the field of coal-fired thermal power units, and in particular to a coal balance monitoring device and method for a coal-fired power plant. Background Art

[0002] The fuel cost of large coal-fired power plants accounts for about 70% of the total power generation cost of the power plant. Fuel management is very important for each coal-fired power plant. Good management of the entire coal combustion process is an important basis for the power plant's financial accounting to accurately calculate the power generation cost. For power plants to bid for access to the grid, it is necessary to accurately calculate the daily fuel consumption and power generation cost.

[0003] At present, coal-fired power plants generally conduct regular coal counting activities at the end of each month. The coal counting team is composed of personnel from the fuel department, production department, power generation department and other relevant departments of the power plant. Generally, the power plant's inlet belt scale and warehouse belt scale implement monthly dynamic chain code calibration, and the furnace belt scale implements monthly weight calibration; the coal storage volume in the coal yard is calculated by measuring the coal storage volume and density, among which the coal storage volume in the coal yard is completed by a laser scanner, and the coal density is calculated by simulation or by digging method. Since the inlet belt scale and the warehouse belt scale are calibrated by simulation method and lack physical calibration, it is often encountered that the belt scale simulation calibration meets the requirements, but the coal volume in and out of the coal yard is greatly deviated from the coal storage volume in the power plant coal yard. The main reasons for the large coal imbalance are: on the one hand, the belt scale will produce tension deviation as the running time accumulates, and the dynamic chain code simulation method calibration cannot accurately eliminate it; on the other hand, the coal density is obtained by simulation method or by digging method weighing calculation, and the coal density measurement result has deviation. Summary of the invention

[0004] An object of the present invention is to provide a coal balance monitoring device for a coal-fired power plant.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A coal balance monitoring device for a coal-fired power plant comprises a ship unloader, a physical weighing verification mechanism, a belt conveyor assembly and a coal feeder, wherein the ship unloader is connected to the physical weighing verification mechanism, the physical weighing verification mechanism is connected to the belt conveyor assembly, and the belt conveyor assembly is connected to the coal feeder.

[0007] The belt conveyor assembly includes a plurality of belt conveyors, one of the plurality of belt conveyors is provided with a factory-entry belt scale, and another is provided with a warehouse belt scale.

[0008] The physical weighing verification mechanism includes a coal bunker, a coal bunker scale for weighing the coal bunker, and a feeder connected to the coal bunker. The ship unloader is connected to the coal bunker, and the feeder is connected to the belt conveyor assembly.

[0009] Preferably, the physical weighing verification mechanism further comprises a weighing display, and the weighing display is connected to the coal bunker scale.

[0010] Preferably, the balance monitoring device further comprises a coal plow, and the ship unloader is connected to the coal bunker via the coal plow, and the ship unloader is connected to the belt conveyor assembly via the coal plow.

[0011] Preferably, the belt conveyor assembly includes a first belt conveyor and a second belt conveyor, the first belt conveyor is connected to the feeder, the second belt conveyor is connected to the first belt conveyor, and the factory conveyor scale is arranged on the second belt conveyor.

[0012] Further preferably, the balance monitoring device further comprises a bulk remover, and the bulk remover is arranged between the first belt conveyor and the second belt conveyor.

[0013] Further preferably, the belt conveyor assembly also includes a third belt conveyor and a fourth belt conveyor, the third belt conveyor is connected to the second belt conveyor and is connected to the coal yard, the fourth belt conveyor is connected to the third belt conveyor, and the upper warehouse belt scale is arranged on the fourth belt conveyor.

[0014] Further preferably, the balance monitoring device further comprises a coal crusher, and the coal crusher is arranged between the third belt conveyor and the fourth belt conveyor.

[0015] Further preferably, the belt conveyor assembly also includes a fifth belt conveyor and a sixth belt conveyor, the fifth belt conveyor is connected to the second belt conveyor, the sixth belt conveyor is respectively connected to the third belt conveyor and the fifth belt conveyor, and is connected to the coal yard at the same time.

[0016] Preferably, the ship unloader and the belt conveyor assembly are provided in two groups respectively, the ship unloader is connected to the coal bunker, and the ship unloader is connected to the belt conveyor assembly at the same time.

[0017] Preferably, the coal bunker is cylindrical or pyramidal, and the coal bunker scale and feeder are arranged at the bottom of the coal bunker.

[0018] Another object of the present invention is to provide a method for monitoring coal balance in a coal-fired power plant.

[0019] In order to achieve the above object, the technical solution adopted by the present invention is:

[0020] A method for monitoring coal balance in a coal-fired power plant is implemented by using the above-mentioned coal balance monitoring device for a coal-fired power plant, and the inlet belt scale and the upper warehouse belt scale are calibrated and corrected by a physical weighing calibration mechanism. The method comprises:

[0021] 1) For coal entering the coal bunker, record the weight of the coal bunker W1, deliver coal to the belt conveyor assembly, and conduct comparative tests on the factory conveyor scale and the upper warehouse conveyor scale simultaneously. After the test is completed, stop delivering coal to the belt conveyor assembly. After the belt conveyor assembly has completed the coal transportation, record the weight of the coal bunker W2, the weight of large pieces of coal is W3, and the cumulative amount of coal on the factory conveyor scale / upper warehouse conveyor scale is Wn. Repeat the above comparative test n times, and finally take the average value of the n test results as the correction value k of the factory conveyor scale / upper warehouse conveyor scale.

[0022] ,

[0023] ,

[0024] 2) Divide the coal yard into m areas: F1, F2, ...F n , set the coal type corresponding to each coal yard area: C1, C2, ...C n , measure the volume V1, V2, ...V of each type of coal n , measure the weight of each type of coal WC1, WC2, ...WC n , calculate the average density of each type of coal as DC1, DC2, ...DC n According to the difference method, the new volume V is obtained by nx Then calculate the real-time average density DC of the coal pile ny ,

[0025] 3) According to the cumulative flow rate ΣW of the conveyor belt scale entering the factory 入 , the cumulative flow rate of the upper warehouse belt scale ΣW 上 The coal storage volume ΣWC in the coal yard can realize real-time monitoring of fuel balance, requiring the coal imbalance rate to be no more than 1%, that is:

[0026] .

[0027] Preferably, the average density of the coal is calculated as DC n When a specified weight of coal pile W is brought into the site each time n , and measure the volume V of the coal pile of the specified weight n , repeated x times, the average density of the coal pile each time is:

[0028] .

[0029] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0030] The present invention corrects the factory entrance belt scale and the upper warehouse belt scale through the online physical weighing verification mechanism, so as to make up for the deviation of the cumulative flow of the belt scale caused by the deficiency of relying solely on the dynamic chain code verification; the average density of the coal pile at the typical volume is obtained by physically measuring each type of coal, and the real-time average density of the specific coal types in each area of ​​the coal yard is obtained through the difference method, so as to eliminate the error of the coal pile density measured only by the manual simulation method or the digging method, and save time and labor, laying the foundation for the construction of digital power plants. For the coal-fired units in service, the on-site space can meet the transformation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Attached Figure 1 It is a structural schematic diagram of this embodiment.

[0032] In the above attached figure:

[0033] 1. Ship; 2. Ship unloader; 30. Coal bunker; 31. Coal bunker scale; 32. Weighing display; 33. Feeder; 40. Conveyor belt scale for entering the factory; 41. Conveyor belt scale for loading warehouse; 5. Lump remover; 6. Coal crusher; 7. Coal feeder; 8. Coal plow; 90. Coal yard 1; 91. Coal yard 2. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, 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 the present invention can be understood according to specific circumstances.

[0037] like Figure 1 The coal balance monitoring device of a coal-fired power plant shown in the figure comprises a ship unloader 2, a physical weighing verification mechanism, a belt conveyor assembly, a lump remover 5, a coal crusher 6 and a coal feeder 7. The ship 1 is connected to the ship unloader 2, the ship unloader 2 is connected to the physical weighing verification mechanism, the physical weighing verification mechanism is connected to the belt conveyor assembly, and the belt conveyor assembly is connected to the coal feeder 7.

[0038] In this embodiment: the physical weighing verification mechanism includes a coal bunker 30, a coal bunker scale 31 for weighing the coal bunker 30, a weighing display 32 for displaying the weight weighed by the coal bunker scale 31, and a feeder 33 connected to the coal bunker 30. Among them: the coal bunker 30 is generally designed as a cylinder or a cone, the coal bunker scale 31 and the feeder 33 are arranged at the bottom of the coal bunker 30, and the weighing display 32 is connected to the coal bunker scale 31; the ship unloader 2 is connected to the coal bunker 30, and the feeder 33 is connected to the belt conveyor assembly. In this embodiment: the ship unloader 2 is connected to the coal bunker 30 through the coal plow 8 to cut the coal to the coal bunker 20, and the ship unloader 2 can also be directly connected to the belt conveyor assembly through the coal plow 8 to cut the coal directly to the belt conveyor assembly.

[0039] In this embodiment: the belt conveyor assembly includes a plurality of belt conveyors, one of which is provided with a factory-entry belt scale 40, and another is provided with a warehouse-entry belt scale 41. Specifically: the first belt conveyor 1A / 1B, the second belt conveyor 2A / 2B, the third belt conveyor 5A / 5B, the fourth belt conveyor 6A / 6B, the fifth belt conveyor 3A / 3B, the sixth belt conveyor 4A / 4B, the seventh belt conveyor 7A / 7B and the eighth belt conveyor 8A / 8B, wherein the first belt conveyor 1A / 1B is connected to the feeder 33 and the ship unloader 2 at the same time, the bulk remover 5 is connected to the first belt conveyor 1A / 1B, the second belt conveyor 2A / 2B is connected to the bulk remover 5, the fifth belt conveyor 3A / 3B is connected to the sixth belt conveyor 4A / 4B, the seventh belt conveyor 7A / 7B and the eighth belt conveyor 8A / 8B. The second belt conveyor 2A / 2B is connected, the sixth belt conveyor 4A / 4B is connected to the fifth belt conveyor 3A / 3B and the coal yard at the same time, the third belt conveyor 5A / 5B is connected to the sixth belt conveyor 4A / 4B and the coal yard at the same time, the coal crusher 6 is connected to the third belt conveyor 5A / 5B, the fourth belt conveyor 6A / 6B is connected to the coal crusher 6, the seventh belt conveyor 7A / 7B is connected to the fourth belt conveyor 6A / 6B, the eighth belt conveyor 8A / 8B is connected to the seventh belt conveyor 7A / 7B, and the coal feeder 7 is connected to the eighth belt conveyor 8A / 8B. The in-plant belt scale 40 is set on the second belt conveyor 2A / 2B, and the upper warehouse belt scale 41 is set on the fourth belt conveyor 6A / 6B.

[0040] In this embodiment: the ship unloader 2 and the belt conveyor assembly are respectively provided with two groups, and the factory-entry belt scale 40 and the upper warehouse belt scale 41 are calibrated and corrected by a physical weighing verification mechanism. The factory-entry belt scale 40 and the upper warehouse belt scale 41 on the two groups of lines can be physically verified in turn, without affecting the normal factory-entry coal unloading and upper warehouse coal loading operation.

[0041] When it is necessary to conduct physical verification of the factory-entry belt scale 40 and the upper warehouse belt scale 41: first, conduct dynamic chain code verification on the factory-entry belt scale 40 and the upper warehouse belt scale 41, and verify and check the cumulative device of the belt scale to ensure that the instantaneous value and cumulative value of the belt scale are displayed normally; then use the physical weighing verification mechanism to conduct physical weighing verification on the factory-entry belt scale 40 and the upper warehouse belt scale 41 in turn. During the test, collect and count the weight of large pieces. The weighing value of the physical weighing verification mechanism minus the weight of large pieces is used as the reference value of the coal weight, and the displayed value of the belt scale is corrected in turn. When verifying the upper warehouse belt scale 41, it is necessary to pay attention to the sixth belt conveyor 4A / 4B switching to the third belt conveyor 5A / 5B to prevent coal from being transported to the coal yard and affecting the statistics of the coal weight. Each belt scale is subjected to multiple repetitive tests, and finally the belt scale is corrected with the average value of multiple tests (the ratio of the coal weight reference value to the belt scale display value).

[0042] When the density of different types of coal needs to be calculated, different types of coal are piled in different areas of the coal yard starting from an empty area in a certain area of ​​the coal yard (for example, F11, F12, F13, F14 in coal yard 1, and F21, F22, F23, and F24 in coal yard 2). If the power plant purchases too many types of coal, similar types of coal can be piled in the same place. The stacking density of the coal can be calculated by the amount of coal entering the coal yard and the volume of coal stored in each pile of coal piles to obtain the average density of coal piles of 10 typical volumes of different types of coal under different working conditions, establish the relationship between the coal pile (coal type), the volume of the coal pile and the average density of the coal pile, and obtain the average density of the coal pile under different volumes according to the difference method. The real-time balance data is displayed online based on the cumulative flow of the inlet belt scale 40 and the upper warehouse belt scale 41 entering and leaving the coal yard and the coal storage capacity of the coal yard, and the deviation of the coal quantity imbalance rate is not more than 1%.

[0043] Taking a supercritical 660MW unit of a certain plant as an example, the detailed process of using the invented device is explained:

[0044] (1) First, operate the coal plow 8 to feed coal into the coal bunker 30. When the material level reaches 100%, stop feeding coal and record the weight of the coal bunker as W1. Then start the feeder 33 at the bottom of the coal bunker 30 to conduct a belt scale comparison test. The sixth belt conveyor 4A switches to the third belt conveyor 5A. Perform a comparison test on the in-plant belt scale 40 and the upper warehouse belt scale 41 simultaneously. After the test, stop the feeder 33 at the bottom of the coal bunker 30. Check that all the coal on the first belt conveyor 1A, the second belt conveyor 2A, and the fourth belt conveyor 6A is empty. Record the weight of the coal bunker 30 as W2, the weight of the large pieces of coal as W3, and the cumulative coal volume of the in-plant belt scale 40 / upper warehouse belt scale 41 of the second belt conveyor 2A and the fourth belt conveyor 6A as W2a / W6a. Repeat the test three times and finally take the average of the three test results as the belt scale correction value. For example, the correction calculation formula for the in-plant belt scale 40 on the second belt conveyor 2A is as follows:

[0045]

[0046]

[0047]

[0048]

[0049] Where:

[0050] , , ——respectively represent the weight of coal bunker after loading in the first, second and third tests, t / h;

[0051] , , ——respectively represent the weight of coal bunker after loading in the first, second and third tests, t / h;

[0052] , , ——represents the weight of the first, second and third test coal bunker after the test, t / h;

[0053] , , ——represents the weight of coal excluding large pieces in the first, second and third tests, t / h;

[0054] , , ——Respectively represent the cumulative coal weight of the conveyor belt scale 40 entering the factory for the first, second and third tests, t / h;

[0055] , , ——Respectively represent the correction coefficients of the cumulative coal weight of the conveyor scale 40 entering the factory for the first, second and third tests;

[0056] ——Indicates the average correction coefficient of the cumulative weight of the conveyor belt scale 40 entering the factory.

[0057] The correction coefficients of the remaining factory-entry belt scales 40 and warehouse-loading belt scales 41 can be obtained by adopting the same steps as above, which will not be described again here.

[0058] (2) Coal yard 1 is divided into four areas: F11, F12, F13, and F14, and coal yard 2 is divided into four areas F21, F22, F23, and F24. There are eight types of coal used in the power plant on a daily basis: C1, C2, C3, C4, C5, C6, C7, and C8, which correspond to the eight areas of the above two coal yards. The volumes of the eight coal piles measured by the laser scanner installed in the coal yard are V1, V2, V3, V4, V5, V6, V7, and V8, respectively. The weight of each coal pile is WC1, WC2, WC3, WC4, WC5, WC6, WC7, and WC8, respectively, and the corresponding average densities are DC1, DC2, DC3, DC4, DC5, DC6, DC7, and DC8, respectively. Taking coal type C1 as an example, the process of obtaining the average density is as follows: first, clean the coal yard area F11, and then start to pile up materials. The F11 area is designed to pile up 40,000 tons of coal. The shape of the coal pile is conical. The volume of the coal pile is measured once every 4,000 tons of coal until 40,000 tons of coal are piled up. A total of 10 coal pile volumes are measured, namely: V11, V12, V13, V14, V15, V16, V17, V18, V19, V110. According to the weight and volume, 10 average densities are calculated, namely: DC11, DC12, DC13, DC14, DC15, DC16, DC17, DC18, DC19, DC110:

[0059] ; ; ;

[0060] ; ; ;

[0061] ; ; ; .

[0062] According to the difference method, the average density DC1y of the coal pile is calculated after the new volume V1x is obtained by the laser scanner. The same method as above can be used to calculate the average density of other types of coal, which will not be repeated here.

[0063] (3) After completing the above two steps, the real-time monitoring of fuel balance can be realized based on the cumulative flow rate ΣW2 of the conveyor scale entering the factory, the cumulative flow rate ΣW6 of the upper warehouse coal, and the coal storage volume ΣWC in the coal yard. The coal imbalance rate is required to be no more than 1%, that is,

[0064] .

[0065] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for monitoring coal balance in a coal-fired power plant, characterized in that: The method is implemented by using a coal-fired power plant coal balance monitoring device, which includes a ship unloader, a physical weighing verification mechanism, a belt conveyor assembly and a coal feeder, wherein the ship unloader is connected to the physical weighing verification mechanism, the physical weighing verification mechanism is connected to the belt conveyor assembly, and the belt conveyor assembly is connected to the coal feeder. The belt conveyor assembly includes a plurality of belt conveyors, one of the plurality of belt conveyors is provided with a factory-entry belt scale, and another is provided with a warehouse belt scale. The physical weighing verification mechanism includes a coal bunker, a coal bunker scale for weighing the coal bunker, and a feeder connected to the coal bunker. The ship unloader is connected to the coal bunker, and the feeder is connected to the belt conveyor assembly. The inbound conveyor belt scale and the warehouse conveyor belt scale are calibrated and corrected by a physical weighing calibration mechanism. The method includes: 1) For coal entering the coal bunker, record the weight of the coal bunker W1, deliver coal to the belt conveyor assembly, and conduct comparative tests on the factory conveyor scale and the upper warehouse conveyor scale simultaneously. After the test is completed, stop delivering coal to the belt conveyor assembly. After the belt conveyor assembly has completed the coal transportation, record the weight of the coal bunker W2, the weight of large pieces of coal is W3, and the cumulative amount of coal on the factory conveyor scale / upper warehouse conveyor scale is Wn. Repeat the above comparative test n times, and finally take the average value of the n test results as the correction value k of the factory conveyor scale / upper warehouse conveyor scale. ， ， 2) Divide the coal yard into n areas: F1, F2, ... F n , set the coal type corresponding to each coal yard area: C1, C2, ...C n , measure the volume V1, V2, ...V of each type of coal n , measure the weight of each type of coal WC1, WC2, ...WC n , calculate the average density of each type of coal as DC1, DC2, ...DC n According to the difference method, the new volume V is obtained by nx Then calculate the real-time average density DC of the coal pile ny , 3) According to the cumulative flow rate ΣW of the conveyor belt scale entering the factory 入 , the cumulative flow rate of the upper warehouse belt scale ΣW 上 The coal storage volume ΣWC in the coal yard can realize real-time monitoring of fuel balance, requiring the coal imbalance rate to be no more than 1%, that is, 。 2. The method for monitoring coal balance in a coal-fired power plant according to claim 1, characterized in that: Calculate the average density of coal as DC n When a specified weight of coal pile W is brought into the site each time n , and measure the volume V of the coal pile of the specified weight n , repeated x times, the average density of the coal pile each time is: 。 3. The method for monitoring coal balance in a coal-fired power plant according to claim 1, characterized in that: The physical weighing verification mechanism also includes a weighing display, and the weighing display is connected to the coal bunker scale.

4. The method for monitoring coal balance in a coal-fired power plant according to claim 1, characterized in that: The balance monitoring device also includes a coal plow, through which the ship unloader is connected to the coal bunker, and at the same time, the ship unloader is connected to the belt conveyor assembly through the coal plow.

5. The method for monitoring coal balance in a coal-fired power plant according to claim 1, characterized in that: The belt conveyor assembly comprises a first belt conveyor and a second belt conveyor. The first belt conveyor is connected to the feeder, the second belt conveyor is connected to the first belt conveyor, and the factory-entry belt scale is arranged on the second belt conveyor.

6. The method for monitoring coal balance in a coal-fired power plant according to claim 5, characterized in that: The belt conveyor assembly also includes a third belt conveyor and a fourth belt conveyor. The third belt conveyor is connected to the second belt conveyor and is connected to the coal yard. The fourth belt conveyor is connected to the third belt conveyor. The upper warehouse belt scale is arranged on the fourth belt conveyor.

7. The method for monitoring coal balance in a coal-fired power plant according to claim 6, characterized in that: The belt conveyor assembly also includes a fifth belt conveyor and a sixth belt conveyor. The fifth belt conveyor is connected to the second belt conveyor, and the sixth belt conveyor is respectively connected to the third belt conveyor and the fifth belt conveyor, and is communicated with the coal yard at the same time.

8. The method for monitoring coal balance in a coal-fired power plant according to claim 6, characterized in that: The balance monitoring device further comprises a lump remover and a coal crusher. The lump remover is arranged between the first belt conveyor and the second belt conveyor, and the coal crusher is arranged between the third belt conveyor and the fourth belt conveyor.

9. The method for monitoring coal balance in a coal-fired power plant according to claim 1, characterized in that: The ship unloader and the belt conveyor assembly are respectively provided with two groups, the ship unloader is connected with the coal bunker, and the ship unloader is connected with the belt conveyor assembly at the same time.

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