Optimization Method and Device for Cooled Slag Heat Exchanger and Low-Temperature Economizer of Circulating Fluidized Bed Unit

Abstract

This specification relates to the technical field of thermal power generation, and provides an optimization method and device for a circulating fluidized bed unit's slag cooler and low-temperature economizer. The method includes: collecting the thermal parameters of the slag cooler and low-temperature economizer of the generating unit under the current working condition; determining the power generation efficiency increment of the generating unit under the current working condition relative to when the slag cooler and low-temperature economizer are not installed, as the efficiency increment benchmark; adjusting the cooling water flow rate of the slag cooler to the target flow rate value; under the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, determining the power generation efficiency increment of the low-temperature economizer under different operating modes relative to the efficiency increment benchmark, to form a set of power generation efficiency increments; determining the cooling water flow rate and operating mode of the low-temperature economizer corresponding to the largest one in the set of power generation efficiency increments, and adjusting the operating mode and cooling water flow rate of the low-temperature economizer accordingly. The embodiments of this specification can improve the thermal efficiency of the CFB unit.

Description

Technical Field

[0001] This specification relates to the technical field of thermal power generation, and particularly to an optimization method and device for a slag cooler and a low-temperature economizer of a circulating fluidized bed unit. Background Art

[0002] Circulating Fluidized Bed (CFB) boilers have been widely used in China at present due to their advantages such as wide fuel adaptability, high combustion efficiency, good load regulation, and low emissions of SO2 and NO X For a CFB power station, since low-quality coal with high ash content and low calorific value is usually burned, the boiler slag discharge amount is large, and the slag discharge temperature can often reach above 800°C. If this part of the slag heat is not fully utilized, it will lead to a significant decrease in the boiler thermal efficiency, and then reduce the overall efficiency of the power station.

[0003] Currently, in a CFB boiler, a slag cooler is generally set to cool the boiler slag discharge and recover this part of the heat. At present, the most widely used domestic and foreign is the drum slag cooler, which uses part of the condensate water in the regenerative system to cool the boiler slag discharge, and the heated condensate water returns to the regenerative system again to displace part of the low-pressure extraction steam and increase the output of the unit (i.e., the generator set). For a conventional CFB unit (i.e., a generator set based on a CFB boiler), in order to utilize the waste heat of the boiler flue gas, a low-temperature economizer is usually arranged in the tail flue at the outlet of the air preheater, which also uses part of the condensate water in the regenerative system to cool the boiler flue gas to displace the extraction steam of the regenerative system and increase the output of the unit.

[0004] At present, the research on the slag cooler and the low-temperature economizer mainly focuses on system optimization, that is, to improve the unit efficiency by changing the access point of its cooling water, and usually on the premise of steady-state conditions. However, it is found in the actual operation of the CFB unit that the slag cooler and the low-temperature economizer will affect each other and displace each other, and the unit load and the coal type burned by the boiler often change continuously. Therefore, how to ensure the thermal efficiency of the CFB unit under the change of working conditions and / or coal types has become an urgent technical problem to be solved at present. Summary of the Invention

[0005] The purpose of the embodiments of this specification is to provide an optimization method and device for a slag cooler and a low-temperature economizer of a circulating fluidized bed unit to improve the thermal efficiency of the CFB unit.

[0006] To achieve the above object, on the one hand, the embodiments of this specification provide an optimization method for a slag cooler and a low-temperature economizer of a circulating fluidized bed unit, including:

[0007] Collect the thermal parameters of the slag cooler and the low-temperature economizer of the generator set under the current working conditions;

[0008] Determine the power generation efficiency increment of the generator set under the current working condition relative to that without the slag cooler and the low-temperature economizer according to the thermal parameters, and use it as the efficiency increment reference;

[0009] Adjust the cooling water flow rate of the slag cooler to the target flow rate value;

[0010] Under the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, determine the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment reference under different operation modes, and form a power generation efficiency increment set;

[0011] Determine the cooling water flow rate and operation mode of the low-temperature economizer corresponding to the maximum value in the power generation efficiency increment set;

[0012] Adjust the low-temperature economizer to this operation mode, and adjust the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer.

[0013] For the optimization method of the slag cooler and the low-temperature economizer of the circulating fluidized bed unit in the embodiments of this specification, the determination of the power generation efficiency increment of the generator set under the current working condition relative to that without the slag cooler and the low-temperature economizer according to the thermal parameters includes:

[0014] According to the formula ΔW = (Δm' st1 +Δm″ st1 )·H1 + Δm st2 ·H2 + Δm st3 ·H3, calculate the output work increment of the generator set under the current working condition relative to that without the slag cooler and the low-temperature economizer;

[0015] According to the formula calculate the power generation efficiency increment of the generator set under the current working condition relative to that without the slag cooler and the low-temperature economizer;

[0016] Wherein, ΔW is the output work increment, Δm' st1 is the steam extraction amount saved by the slag cooler in the first target extraction section, Δm″ st1 is the steam extraction amount saved by the low-temperature economizer in the first target extraction section, H1 is the equivalent enthalpy drop of the steam extraction in the first target extraction section, Δm st2 is the steam extraction amount saved by the low-temperature economizer in the corresponding second target extraction section, H2 is the equivalent enthalpy drop of the steam extraction in the second target extraction section, Δm st3 is the steam extraction amount saved by the low-temperature economizer in the corresponding third target extraction section, H3 is the equivalent enthalpy drop of the steam extraction in the third target extraction section, Δη is the power generation efficiency increment, and W is the output work of the generator set without the slag cooler and the low-temperature economizer.

[0017] The optimization method of the slag cooler and the low-temperature economizer for the circulating fluidized bed unit in the embodiments of this specification. The steam extraction amount of the first target extraction section is saved by the slag cooler, the steam extraction amount of the first target extraction section is saved by the low-temperature economizer, and the steam extraction amount of the corresponding second target extraction section is saved by the low-temperature economizer, which are calculated respectively according to the following formulas:

[0018]

[0019]

[0020]

[0021]

[0022] Among them, m wz is the cooling water flow rate of the slag cooler, t w1i and t w1o are respectively the inlet condensate temperature and the outlet condensate temperature of the heater corresponding to the first target extraction section, h s1 is the steam enthalpy value of the first target extraction section, h w1 is the drain enthalpy value of the first target extraction section, m we1 is the inlet cooling water flow rate of the first input branch of the low-temperature economizer, m we2 is the inlet cooling water flow rate of the second input branch of the low-temperature economizer, t w2i and t w2o are respectively the inlet condensate temperature and the outlet condensate temperature of the heater corresponding to the second target extraction section, h s2 is the steam enthalpy value of the second target extraction section, h w2 is the drain enthalpy value of the second target extraction section, h s3 is the steam enthalpy value of the third target extraction section, h w3 is the drain enthalpy value of the third target extraction section.

[0023] The optimization method of the slag cooler and the low-temperature economizer for the circulating fluidized bed unit in the embodiments of this specification. The extraction equivalent enthalpy drop of the first target extraction section and the extraction equivalent enthalpy drop of the second target extraction section are calculated respectively according to the following formulas:

[0024] H1 = h s1 -h c

[0025]

[0026]

[0027] Among them, h s1 is the steam enthalpy value of the first target extraction section, h c is the exhaust steam enthalpy value of the steam turbine, hs2 is the steam enthalpy value of the second target extraction stage, h s3 is the steam enthalpy value of the third target extraction stage, A1 is the heat release of 1 kg of drain water from the second target extraction stage in the corresponding heater of the first target extraction stage, q1 is the heat release of 1 kg of extraction steam from the first target stage in the corresponding heater of the first target extraction stage, A2 is the heat release of 1 kg of drain water from the third target extraction stage in the corresponding heater of the second target extraction stage, and q2 is the heat release of 1 kg of extraction steam from the second target stage in the corresponding heater of the second target extraction stage.

[0028] For the optimization method of the circulating fluidized bed unit's slag cooler and low-temperature economizer in the embodiments of this specification, adjusting the cooling water flow rate of the slag cooler to the target flow rate value includes:

[0029] Obtain the target flow rate value of the slag cooler;

[0030] Confirm whether the absolute value of the difference between the inlet cooling water flow rate of the slag cooler under the current working condition and the target flow rate value is greater than the difference threshold;

[0031] When the absolute value of the difference is greater than the difference threshold, adjust the inlet cooling water flow rate of the slag cooler to the target flow rate value, and re-collect the thermal parameters of the slag cooler and low-temperature economizer of the generator set under the current working condition.

[0032] For the optimization method of the circulating fluidized bed unit's slag cooler and low-temperature economizer in the embodiments of this specification, after adjusting the low-temperature economizer to this operating mode and adjusting the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer, it further includes:

[0033] Output the optimization result;

[0034] Wherein, the optimization result includes:

[0035] The thermal parameters of the slag cooler and the low-temperature economizer before and after optimization;

[0036] The output power increment of the generator set before and after optimization; and,

[0037] The power generation efficiency increment of the generator set before and after optimization.

[0038] For the optimization method of the circulating fluidized bed unit's slag cooler and low-temperature economizer in the embodiments of this specification, the optimization result further includes:

[0039] The heat transfer amount of the slag cooler before and after optimization; and,

[0040] The heat transfer amount of the low-temperature economizer before and after optimization.

[0041] On the other hand, the embodiments of the present specification also provide an optimization device for a circulating fluidized bed unit's slag cooler and low-temperature economizer, including:

[0042] A parameter acquisition module for acquiring the thermal parameters of the slag cooler and low-temperature economizer of the generator set under the current working conditions;

[0043] A reference determination module for determining the power generation efficiency increment of the generator set under the current working conditions relative to when the slag cooler and the low-temperature economizer are not provided based on the thermal parameters, so as to serve as an efficiency increment reference;

[0044] A first adjustment module for adjusting the cooling water flow rate of the slag cooler to a target flow rate value;

[0045] An efficiency determination module for determining the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment reference under different operating modes when the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, and forming a power generation efficiency increment set;

[0046] An optimization parameter determination module for determining the cooling water flow rate and operating mode of the low-temperature economizer corresponding to the maximum value in the power generation efficiency increment set;

[0047] A second adjustment module for adjusting the low-temperature economizer to this operating mode and adjusting the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer.

[0048] On the other hand, the embodiments of the present specification also provide a computer device, including a memory, a processor, and a computer program stored on the memory. When the computer program is run by the processor, it executes the instructions of the above method.

[0049] On the other hand, the embodiments of the present specification also provide a computer storage medium, on which a computer program is stored. When the computer program is run by the processor of a computer device, it executes the instructions of the above method.

[0050] As can be seen from the technical solutions provided by the embodiments of the present specification above, in the embodiments of the present specification, according to the collected thermal parameters of the slag cooler and low-temperature economizer of the generator set under the current working conditions, the slag cooler can be first adjusted to the optimal state, and on this basis, the low-temperature economizer can be adjusted to the optimal state according to the thermal parameters, so that the slag cooler and low-temperature economizer operate in the optimal state; when the working conditions change, the thermal parameters will change, and according to the new thermal parameters, the slag cooler and low-temperature economizer can be optimized again, so as to realize the dynamic optimization of the slag cooler and low-temperature economizer, and further enable the slag cooler and low-temperature economizer to operate in the optimal state for a long time, thereby improving the thermal efficiency of the CFB generator set. Description of the Drawings

[0051] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0052] Figure 1 Shows a schematic diagram of the slag cooler system and the low-temperature economizer system of a coal-fired power plant based on a CFB boiler in some embodiments of this specification;

[0053] Figure 2 Shows a flowchart of the optimization method for the slag cooler and the low-temperature economizer of a circulating fluidized bed unit in some embodiments of this specification;

[0054] Figure 3 Shows a flowchart of the optimization method for the slag cooler and the low-temperature economizer of a circulating fluidized bed unit in some other embodiments of this specification;

[0055] Figure 4 Shows a structural block diagram of the optimization device for the slag cooler and the low-temperature economizer of a circulating fluidized bed unit in some embodiments of this specification;

[0056] Figure 5 Shows a structural block diagram of the optimization device for the slag cooler and the low-temperature economizer of a circulating fluidized bed unit in some other embodiments of this specification;

[0057] Figure 6 Shows a structural block diagram of a computer device in some embodiments of this specification.

[0058]

Description of the Reference Numerals

[0059] 1, Slag cooler system;

[0060] 2, Low-temperature economizer system;

[0061] 3, Slag cooler;

[0062] 4, Bucket conveyor;

[0063] 5, First regulating valve;

[0064] 6, Air preheater;

[0065] 7, Low-temperature economizer;

[0066] 8, Forced draft fan;

[0067] 9, Second regulating valve;

[0068] 10, Third regulating valve;

[0069] 11. First heater

[0070] 12. Second heater

[0071] 13. Third heater

[0072] 41. Parameter acquisition module

[0073] 42. Reference determination module

[0074] 43. First adjustment module

[0075] 44. Efficiency determination module

[0076] 45. Optimization parameter determination module

[0077] 46. Second adjustment module

[0078] 47. Result output module

[0079] 602. Computer device

[0080] 604. Processor

[0081] 606. Memory

[0082] 608. Driving mechanism

[0083] 610. Input / output interface

[0084] 612. Input device

[0085] 614. Output device

[0086] 616. Rendering device

[0087] 618. Graphical user interface

[0088] 620. Network interface

[0089] 622. Communication link

[0090] 624. Communication bus Detailed implementation manners

[0091] In order to enable those skilled in the art of this technology to better understand the technical solutions in this specification, the following will clearly and completely describe the technical solutions in the embodiments of this specification in conjunction with the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this specification.

[0092] Figure 1 The slag cooler system 1 and the low-temperature economizer system 2 of a coal-fired power plant based on a CFB boiler are shown in some embodiments of this specification. Among them, in the slag cooler system 1, the condensed water is divided into three paths: the first path is connected to the condensed water inlet of the slag cooler 3 through the first regulating valve 5 and related pipelines for recovering the waste heat of slag discharge; the second path is connected to the condensed water inlet of the first heater 11 through a pipeline for supplying water to the heater normally; the third path leads to the low-temperature economizer system 2 for recovering the waste heat of the flue gas. The condensed water outlet of the slag cooler 3 is connected to the outlet of the first heater 11 through a pipeline so that the condensed water heated by the ash slag in the slag cooler 3 can be supplied to the second heater 12; after the ash slag enters the slag cooler 3 and is cooled, it can be sent to the coal bunker through the chain bucket conveyor 4. In the low-temperature economizer system 2, the condensed water inlets and outlets of the first heater 11 are respectively joined after passing through the second regulating valve 9 and the third regulating valve 10 and then connected to the condensed water inlet of the low-temperature economizer 7. The condensed water outlet of the low-temperature economizer 7 is connected to the condensed water outlet of the second heater 12 through a pipeline; the boiler flue gas enters the low-temperature economizer 7 to release heat after passing through the air preheater 6, and the boiler flue gas after releasing heat is sent to the dust collector for treatment under the action of an induced draft fan ( Figure 1 not shown in the figure). The ambient cold air enters the air preheater 6 under the action of the forced draft fan 8 and is heated into hot air therein. Among them, the low-temperature economizer is also called the low-pressure economizer, which is mainly used for recovering the waste heat of the flue gas.

[0093] In the embodiments of this specification, the first heater 11, the second heater 12, and the third heater 13 are connected in series in sequence, and the condensed water of the third heater 13 is output to the deaerator. The first heater 11, the second heater 12, and the third heater 13 are all low-pressure heaters, which are part of the regenerative system of a thermal power plant. Among them, the regenerative system refers to the feed water heating system attached to the steam turbine of a thermal power plant, generally including multiple (generally three) high-pressure heaters, one deaerator, multiple (generally three or four) low-pressure heaters, and the corresponding steam pipelines for extracting steam from each extraction port of the steam turbine to heat the condensed water in each heater. Therefore, in the regenerative system, each heater corresponds to one stage of steam extraction from the steam turbine, and the nth stage of steam extraction is the steam extraction from the steam turbine for heating the condensed water in the nth heater. In the embodiments of this specification, the cooling water of the slag cooler 3 and the low-temperature economizer 7 is taken from the condensed water in the regenerative system. Different cooling water volumes of each stage of the heater will change the amount of condensed water flowing through the heater, thereby changing the steam extraction volume of each stage of the regenerative system and further affecting the unit efficiency.

[0094] The application of the slag cooler 3 and the low-temperature economizer 7 in a coal-fired power plant based on a CFB boiler has certain energy-saving effects. Specifically, after the application of the slag cooler 3, part of the condensate that originally flowed through the first heater 11 can flow into the slag cooler 3 to absorb heat, which saves part of the extraction steam section used to heat the first heater 11. Similarly, the application of the low-temperature economizer 7 can also save part of the extraction steam sections used to heat the first heater 11, the second heater 12, and the third heater 13, enabling this part of the extraction steam to return to the steam turbine to continue doing work, thereby increasing the unit output and further improving the unit efficiency. However, considering that the slag cooler 3 and the low-temperature economizer 7 may affect each other, and the unit load and the coal type burned in the boiler often change continuously, it is necessary to optimize the slag cooler 3 and the low-temperature economizer 7 according to the working conditions so that the slag cooler 3 and the low-temperature economizer 7 can operate in the optimal state for a long time, thereby further improving the thermal efficiency of the CFB unit. It should be noted that the slag cooler 3 in the embodiments of this specification can be one or more. When there are multiple slag coolers 3, the multiple slag coolers 3 are arranged in parallel. Similarly, the low-temperature economizer 7 in the embodiments of this specification can also be one or more. When there are multiple low-temperature economizers 7, the multiple low-temperature economizers 7 are also arranged in parallel.

[0095] The optimal state in the embodiments of this specification refers to the optimal state under the given working conditions. When the working conditions change, it is necessary to re-optimize to obtain the optimal state under the changed working conditions.

[0096] The embodiments of this specification provide an optimization method for the slag cooler and the low-temperature economizer of a circulating fluidized bed unit, which can be applied to any suitable computer device to optimize the operating states of the slag cooler 3 and the low-temperature economizer 7 and improve the thermal efficiency of the CFB unit. Refer to Figure 2 As shown, in some embodiments, the optimization method for the slag cooler and the low-temperature economizer of the circulating fluidized bed unit may include the following steps:

[0097] Step 201, collect the thermal parameters of the slag cooler and the low-temperature economizer of the generating unit under the current working conditions.

[0098] By collecting the thermal parameters of the slag cooler and the low-temperature economizer of the generating unit under the current working conditions, it can provide a basis and reference for subsequent optimization. In some embodiments, the thermal parameters may include, but are not limited to, the slag discharge amount of the slag cooler, the ash slag temperature at the inlet and outlet of the slag cooler, the cooling water flow rate of the slag cooler, the inlet flue gas flow rate of the low-temperature economizer, the flue gas temperature at the inlet and outlet of the low-temperature economizer, the outlet cooling water temperature of the low-temperature economizer, the temperatures at the inlet and outlet of the first heater, the temperatures at the inlet and outlet of the second heater, etc. In some embodiments, the collection of the thermal parameters can be real-time collection, or timed collection, or event-triggered collection (for example, executed when receiving a notice of change in unit load or coal type), and can be specifically selected according to needs. Among them, the working conditions may include, but are not limited to, unit load, coal type used in the CFB boiler, etc.

[0099] Step 202: Determine the power generation efficiency increment of the generating unit under the current working conditions relative to when the slag cooler and the low-temperature economizer are not provided, as the efficiency increment benchmark.

[0100] To facilitate the comparison of the effects before and after optimization, the power generation efficiency increment of the generating unit before optimization can be obtained first as the efficiency increment benchmark. In some embodiments, determining the power generation efficiency increment of the generating unit under the current working conditions relative to when the slag cooler and the low-temperature economizer are not provided according to the thermal parameters may include:

[0101] First, calculate the output work increment of the generating unit under the current working conditions relative to when the slag cooler and the low-temperature economizer are not provided according to the formula ΔW=(Δm' st1 +Δm″ st1 )·H1+Δm st2 ·H2+Δm st3 ·H3.

[0102] Then, calculate the power generation efficiency increment of the generating unit under the current working conditions relative to when the slag cooler and the low-temperature economizer are not provided according to the formula .

[0103] Wherein, ΔW is the output work increment, Δm' st1 is the extracted steam amount saved by the slag cooler in the first target extraction section (see Figure 1 shown), Δm″ st1 is the extracted steam amount saved by the low-temperature economizer in the first target extraction section, H1 is the extraction equivalent enthalpy drop of the first target extraction section, Δm st2 is the extracted steam amount saved by the low-temperature economizer in the corresponding second target extraction section (see Figure 1 shown), H2 is the extraction equivalent enthalpy drop of the second target extraction section, Δm st3To save the extraction steam volume of the corresponding third target extraction steam section for the low-temperature economizer, H3 is the extraction steam equivalent enthalpy drop of the third target extraction steam section, Δη is the power generation efficiency increment, and W is the output power of the generator set without the slag cooler and the low-temperature economizer installed.

[0104] In some embodiments, the extraction steam volume saved by the slag cooler for the first target extraction steam section can be calculated according to the following formula:

[0105]

[0106] The extraction steam volume saved by the low-temperature economizer for the first target extraction steam section can be calculated according to the following formula:

[0107]

[0108] The extraction steam volume saved by the low-temperature economizer for the corresponding second target extraction steam section can be calculated according to the following formula:

[0109]

[0110] The extraction steam volume saved by the low-temperature economizer for the corresponding third target extraction steam section can be calculated according to the following formula:

[0111]

[0112] where, m wz is the cooling water flow rate of the slag cooler (see Figure 1 shown), t w1i and t w1o are respectively the inlet condensate temperature and the outlet condensate temperature of the heater corresponding to the first target extraction steam section (see Figure 1 shown), h s1 is the steam enthalpy value of the first target extraction steam section, h w1 is the drain enthalpy value of the first target extraction steam section, m we1 is the inlet cooling water flow rate of the first input branch of the low-temperature economizer (see Figure 1 shown), m we2 is the inlet cooling water flow rate of the second input branch of the low-temperature economizer (see Figure 1 shown), t w2i and t w2o are respectively the inlet condensate temperature and the outlet condensate temperature of the heater corresponding to the second target extraction steam section (see Figure 1 shown), h s2 is the steam enthalpy value of the second target extraction steam section, h w2 is the drain enthalpy value of the second target extraction steam section, h s3 is the steam enthalpy value of the third target extraction steam section, h w3 is the drain enthalpy value of the third target extraction steam section.

[0113] In some embodiments, the extraction equivalent enthalpy drop of the first target extraction stage can be calculated according to the following formula;

[0114] H1 = h s1 - h c

[0115] where h s1 is the steam enthalpy value of the first target extraction stage, and h c is the turbine exhaust enthalpy value.

[0116] In some embodiments, the extraction equivalent enthalpy drop of the second target extraction stage can be calculated according to the following formula;

[0117] where h s2 is the steam enthalpy value of the second target extraction stage, A1 is the heat release of 1 kg of the drain water of the second target extraction stage in the corresponding heater of the first target extraction stage, and q1 is the heat release of 1 kg of the extraction steam of the first target stage in the corresponding heater of the first target extraction stage.

[0118] In some embodiments, the extraction equivalent enthalpy drop of the third target extraction stage can be calculated according to the following formula;

[0119]

[0120] where h s3 is the steam enthalpy value of the second target extraction stage, A2 is the heat release of 1 kg of the drain water of the third target extraction stage in the corresponding heater of the second target extraction stage, and q2 is the heat release of 1 kg of the extraction steam of the second target stage in the corresponding heater of the second target extraction stage.

[0121] Step 203, adjust the cooling water flow rate of the slag cooler to the target flow rate value.

[0122] Since the slag cooler has an impact on the low-temperature economizer, while the low-temperature economizer does not affect the slag cooler, therefore, the cooling water flow rate of the slag cooler can be adjusted to the target flow rate value first to enable the slag cooler to reach the optimal state first, and then the low-temperature economizer can be optimized on this basis; in this way, the optimization process can be simplified and the optimization efficiency can be improved.

[0123] In some embodiments, the adjustment of the cooling water flow rate of the slag cooler to the target flow rate value may include:

[0124] (1) Obtain the target flow rate value and related thermodynamic parameters of the slag cooler.

[0125] To ensure safety, the cooling water temperature at the outlet of the slag cooler should not exceed the upper boundary condition (e.g., 90°C). When the cooling water temperature at the outlet of the slag cooler reaches or approaches this upper boundary condition, the waste heat utilization efficiency of the slag cooler is the highest. Therefore, the cooling water flow rate corresponding to the slag cooler when its outlet cooling water temperature reaches or approaches this upper boundary condition can be used as the target flow rate value. The target flow rate value of the slag cooler and related thermal parameters can be specifically obtained through iterative calculation according to the following formula:

[0126]

[0127] Among them, Q z is the heat transfer quantity of the slag cooler, c z is the specific heat capacity at constant pressure of the ash and slag of the slag cooler, m z is the mass flow rate of the ash and slag of the slag cooler (unit: kg / s), K z is the overall heat transfer coefficient of the slag cooler, A z is the total heat transfer area of the slag cooler, t zi is the inlet ash and slag temperature of the slag cooler, t zo is the outlet ash and slag temperature of the slag cooler, m' wz is the cooling water flow rate corresponding to the slag cooler when its outlet cooling water temperature reaches the upper boundary condition (i.e., the target flow rate value of the slag cooler), t wzo is the outlet cooling water temperature of the slag cooler, t w1i is the inlet cooling water temperature of the heater corresponding to the first target extraction section.

[0128] The purpose of this step is to obtain through theoretical calculation the cooling water flow rate and other thermal parameters corresponding to the slag cooler when its outlet cooling water temperature reaches or approaches this upper boundary condition. Therefore, such as the outlet cooling water temperature of the slag cooler, the slag discharge temperature, and the cooling water flow rate are all unknowns. Therefore, the operating condition of this slag cooler that is expected to be obtained should simultaneously satisfy the above three Q z calculation formulas, and this heat transfer process can actually occur.

[0129] The iterative calculation process is roughly as follows: (a) Set the outlet ash and slag temperature of the slag cooler to 90°C, and calculate its heat release according to formula 1. (b) Assume that the outlet cooling water temperature of the slag cooler is a certain value, and calculate the cooling water flow rate of the slag cooler through formula 2. (c) Calculate the heat transfer quantity of the slag cooler according to the inlet and outlet ash and slag temperatures of the slag cooler and the inlet and outlet cooling water temperatures using formula 3. (d) Compare the heat transfer quantities in steps (a) and (c). If there is a deviation between the two, adjust the outlet cooling water temperature of the slag cooler, and repeat steps (b) and (c) until the formula Q z = c z m z ·(t zi - t zo ) and formula The calculated heat exchange amount is the same, and the calculation is completed at this time.

[0130] (2) Confirm whether the absolute value of the difference between the inlet cooling water flow rate of the slag cooler under the current working condition and the target flow rate value is greater than the difference threshold.

[0131] For example, in one embodiment, if the target flow rate value is m' wz , the inlet cooling water flow rate of the slag cooler under the current working condition is The difference threshold is a (unit: ton / hour), and it can be judged whether holds.

[0132] (3) When the absolute value of the difference is greater than the difference threshold, adjust the inlet cooling water flow rate of the slag cooler to the target flow rate value, and re-collect the thermal parameters of the slag cooler and the low-temperature economizer of the generator set under the current working condition (that is, jump to execute step 201); otherwise, step 204 can be directly executed.

[0133] Among them, when adjusting the inlet cooling water flow rate of the slag cooler, if is greater than m' wz then the opening degree of the first regulating valve can be adjusted smaller until it is reduced to the target flow rate value; if is less than m' wz then the opening degree of the first regulating valve can be increased until it is raised to the target flow rate value.

[0134] Step 204: Under the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, determine the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment reference under different operation modes, and form a power generation efficiency increment set.

[0135] In some embodiments, the operation modes of the low-temperature economizer can be the following three types:

[0136] (1) Close the first regulating valve and open the second regulating valve; in this state, the cooling water of the low-temperature economizer is only provided by the inlet of the first heater;

[0137] (2) Close the second regulating valve and open the first regulating valve; in this state, the cooling water of the low-temperature economizer is only provided by the inlet of the second heater;

[0138] (3) Open the first regulating valve and the second regulating valve at the same time; in this state, the cooling water of the low-temperature economizer is provided by the inlets of the first heater and the second heater at the same time.

[0139] In addition, under each of the above operating modes, it can be further divided into multiple sub-operating modes according to the valve opening, so that the above-mentioned "different operating methods" can be much greater than three. Under the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary (for example, 100 °C), in order to adjust the low-temperature economizer to the optimal state, it is necessary to calculate the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment benchmark under each operating mode one by one, so that a plurality of power generation efficiency increments corresponding to multiple operating modes can be obtained, that is, a power generation efficiency increment set is formed.

[0140] Among them, the calculation method of the power generation efficiency increment of the low-temperature economizer under a certain operating mode is as follows:

[0141] (1) First, according to the inlet cooling water flow rates m we1 、m we2 of the first and second input branches of the low-temperature economizer under this operating mode, the outlet cooling water temperature t weo 、outlet flue gas temperature t fo 、heat transfer quantity Q e of the low-temperature economizer under this working condition are iteratively calculated by using the following calculation formula;

[0142]

[0143] Among them, Q e is the heat transfer quantity of the low-temperature economizer, m f is the flue gas mass flow rate of the low-temperature economizer, h fi and h fo are the flue gas enthalpy values at the inlet and outlet of the low-temperature economizer respectively, K e is the total heat transfer coefficient of the low-temperature economizer, A e is the total heat transfer area of the low-temperature economizer, max is the maximum value, min is the minimum value, Δt1 and Δt2 are intermediate parameters, Δt1 = t fi - t weo , Δt2 = t fo - t wei , t fi is the inlet flue gas temperature of the low-temperature economizer, t weo is the outlet cooling water temperature of the low-temperature economizer, t fo is the outlet flue gas temperature of the low-temperature economizer, t wei is the inlet cooling water temperature of the low-temperature economizer.

[0144] (2) Repeat step 202 to calculate the power generation efficiency increment of the unit under the current working condition relative to when the slag cooler and the low-temperature economizer are not installed.

[0145] Step 205: Determine the cooling water flow rate and operating mode of the low-temperature economizer corresponding to the largest one in the power generation efficiency increment set.

[0146] Each power generation efficiency increment in the set of power generation efficiency increments has a corresponding low-temperature economizer operation mode and low-temperature economizer cooling water flow rate. By comparing each power generation efficiency increment in the set of power generation efficiency increments, the maximum one can be determined; the low-temperature economizer operation mode and low-temperature economizer cooling water flow rate corresponding to the maximum one are the optimal states of the low-temperature economizer under the current working conditions.

[0147] Step 206: Adjust the low-temperature economizer to this operation mode and adjust the inlet cooling water flow rate of the low-temperature economizer to the low-temperature economizer cooling water flow rate.

[0148] By adjusting the operation mode of the low-temperature economizer to the low-temperature economizer operation mode corresponding to the maximum one and adjusting the inlet cooling water flow rate of the low-temperature economizer to the low-temperature economizer cooling water flow rate corresponding to the maximum one, the low-temperature economizer can be in the optimal state under the current working conditions.

[0149] In the embodiments of this specification, according to the thermal parameters of the slag cooler and the low-temperature economizer of the generator set collected under the current working conditions, the slag cooler can be first adjusted to the optimal state, and on this basis, the low-temperature economizer can be adjusted to the optimal state according to the thermal parameters, so that the slag cooler and the low-temperature economizer operate in the optimal state; when the working conditions change, the thermal parameters will change, and according to the new thermal parameters, the slag cooler and the low-temperature economizer can be optimized again, so as to realize the dynamic optimization of the slag cooler and the low-temperature economizer, and further enable the slag cooler and the low-temperature economizer to operate in the optimal state for a long time, thereby improving the thermal efficiency of the CFB generator set.

[0150] Reference Figure 3 As shown, in some other embodiments, the optimization method for the slag cooler and the low-temperature economizer of the circulating fluidized bed unit may include the following steps:

[0151] Step 301: Collect the thermal parameters of the slag cooler and the low-temperature economizer of the generator set under the current working conditions.

[0152] Step 302: Determine the power generation efficiency increment of the generator set relative to when the slag cooler and the low-temperature economizer are not provided under the current working conditions according to the thermal parameters as the efficiency increment reference.

[0153] Step 303: Adjust the cooling water flow rate of the slag cooler to the target flow rate value.

[0154] Step 304: Under the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, determine the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment reference under different operation modes, and form a set of power generation efficiency increments.

[0155] Step 305: Determine the cooling water flow rate and operation mode of the low-temperature economizer corresponding to the maximum value in the set of power generation efficiency increments.

[0156] Step 306: Adjust the low-temperature economizer to this operation mode, and adjust the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer.

[0157] Step 307: Output the optimization result.

[0158] It can be seen that Figure 3 Steps 301 to 306 in the optimization method shown are the same as Figure 2 Steps 201 to 206 in the optimization method shown. The difference is that in Figure 3 the optimization method shown, after completing the optimization of the slag cooler and the low-temperature economizer, it may further include the step of outputting the optimization result (i.e., it may further include Step 307). Among them, the optimization result may include, for example: the thermodynamic parameters of the slag cooler and the low-temperature economizer before and after optimization; the output increment of the generator set before and after optimization; the power generation efficiency increment of the generator set before and after optimization, etc. Among them, before optimization may refer to before optimizing the slag cooler, and after optimization may refer to after completing the optimization of the slag cooler.

[0159] In some other embodiments, the optimization result may further include: the heat transfer amount of the slag cooler before and after optimization; and the heat transfer amount of the low-temperature economizer before and after optimization, so as to more comprehensively understand the optimization effect.

[0160] Although the process flow described above includes multiple operations that appear in a specific order, it should be clearly understood that these processes may include more or fewer operations, and these operations may be executed sequentially or in parallel (for example, using a parallel processor or a multi-threaded environment).

[0161] Taking a typical 350MW CFB unit as an example, the implementation process of the optimization method for the slag cooler and the low-temperature economizer of the circulating fluidized bed unit in the embodiments of this specification is described below. Among them, it is assumed that the unit load under this condition is 349.8MW, and the regenerative system includes seven heaters connected in series in sequence, thus forming seven-stage heaters; the first heater corresponds to the 7th-stage heater of the regenerative system, and the second heater corresponds to the 6th-stage heater of the regenerative system; the 7th-stage heater corresponds to the 7th extraction section, and the 6th-stage heater corresponds to the 6th extraction section.

[0162] (1) Collect the thermodynamic parameters of the slag cooler and the low-temperature economizer. Among them, the collected thermodynamic parameters are as shown in Table 1 below.

[0163] Table 1

[0164]

[0165] (2) Calculate that the extraction steam quantity saved by the slag cooler in the 7th extraction steam section under the current operating condition is 25.2 t / h, and the extraction steam quantities saved by the low-temperature economizer in the 7th extraction steam section and the 6th extraction steam section are 10.2 t / h and 17.6 t / h respectively; the equivalent enthalpy drop value of the extraction steam in the 7th extraction steam section is calculated to be 246.7 kJ / kg by using the equivalent enthalpy drop method, and the equivalent enthalpy drop value of the extraction steam in the 6th extraction steam section is 335.5 kJ / kg.

[0166] (3) According to the equivalent enthalpy drop value of the extraction steam, calculate that under the current operating condition, compared with the unit without the slag cooler and the low-temperature economizer added, the unit can increase the output work by 3.461 MW, and the power generation efficiency can be increased by 0.980%; and record that under the current operating condition, the cooling water flow rate of the slag cooler is 560.1 t / h, and the increased value of the power generation efficiency is 0.988% (as the efficiency increment benchmark).

[0167] (4) Calculate that when the outlet cooling water temperature of the slag cooler reaches the upper boundary condition of 90 °C, the ash slag heat release of the slag cooler is 16.65 MW, and the cooling water flow rate is 392.2 t / h; judge the cooling water volume of the slag cooler under the current operating condition. Since |392.2 - 560.1| > 5 t / h, the first regulating valve can be automatically controlled to adjust the cooling water volume of the slag cooler to 392.2 t / h.

[0168] (5) Under the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, determine the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment benchmark under different operating modes.

[0169] (6) By comparing the power generation efficiency increments of the low-temperature economizer relative to the efficiency increment benchmark under different operating modes, it is obtained that under the operating mode of closing the third regulating valve and opening the second regulating valve (valve opening is 100%), the power generation efficiency of the low-temperature economizer is the best. At this time, the inlet cooling water flow rate of the low-temperature economizer using the 7th heater is 291.5 t / h, the heat exchange quantity of the low-temperature economizer is 18.41 MW, the outlet flue gas temperature is 100 °C, and the outlet cooling water temperature is 107.8 °C. Compared with the unit without the slag cooler and the low-temperature economizer system added, the unit can increase the output work by 3.733 MW, and the power generation efficiency can be increased by 1.056%. Record the increased value of the power generation efficiency Δη' of the unit in this mode as 1.056%, and the cooling water volumes m' we1 、m' we2 are 291.5 t / h and 0 t / h respectively.

[0170] (7) By adjusting the second regulating valve, make the cooling water flow rate output from the 7th heater to the low-temperature economizer reach 291.5 t / h.

[0171] (8) Output the optimization result. Among them, the output optimization result can be as shown in Table 2 below.

[0172] Table 2

[0173]

[0174] Corresponding to the above optimization method of the circulating fluidized bed unit slag cooler and low-temperature economizer, an embodiment of the present specification further provides an optimization device for the circulating fluidized bed unit slag cooler and low-temperature economizer, which can be configured on any suitable computing device. Refer to Figure 4 As shown, in some embodiments, the optimization device for the circulating fluidized bed unit slag cooler and low-temperature economizer may include:

[0175] A parameter acquisition module 41, which can be used to acquire the thermal parameters of the slag cooler and low-temperature economizer of the generator set under the current working condition;

[0176] A reference determination module 42, which can be used to determine the power generation efficiency increment of the generator set under the current working condition relative to when the slag cooler and the low-temperature economizer are not provided according to the thermal parameters, so as to serve as an efficiency increment reference;

[0177] A first adjustment module 43, which can be used to adjust the cooling water flow rate of the slag cooler to a target flow rate value;

[0178] An efficiency determination module 44, which can be used to determine the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment reference under different operating modes when the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, and form a power generation efficiency increment set;

[0179] An optimization parameter determination module 45, which can be used to determine the cooling water flow rate and operating mode of the low-temperature economizer corresponding to the largest value in the power generation efficiency increment set;

[0180] A second adjustment module 46, which can be used to adjust the low-temperature economizer to this operating mode and adjust the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer.

[0181] In some device embodiments, the efficiency determination module 44 determines the power generation efficiency increment of the generator set under the current working condition relative to when the slag cooler and the low-temperature economizer are not provided according to the thermal parameters, including:

[0182] According to the formula ΔW = (Δm' st1 +Δm″ st1 )·H1 + Δm st2 ·H2 + Δm st3 ·H3 to calculate the work output increment of the generator set under the current working condition relative to when the slag cooler and the low-temperature economizer are not provided;

[0183] According to the formula Calculate the power generation efficiency increment of the generator set under the current working condition relative to when the slag cooler and the low-temperature economizer are not provided;

[0184] In some device embodiments, the steam extraction amount saved by the slag cooler in the first target extraction section, the steam extraction amount saved by the low-temperature economizer in the first target extraction section, and the steam extraction amount saved by the low-temperature economizer in the corresponding second target extraction section are respectively calculated according to the following formulas:

[0185]

[0186]

[0187]

[0188]

[0189] In some device embodiments, the equivalent enthalpy drop of steam extraction in the first target extraction section and the equivalent enthalpy drop of steam extraction in the second target extraction section are respectively calculated according to the following formulas:

[0190] H1 = h s1 -h c

[0191]

[0192]

[0193] In some device embodiments, the first adjustment module 43 adjusts the cooling water flow rate of the slag cooler to a target flow rate value, which may include:

[0194] Obtain the target flow rate value of the slag cooler;

[0195] Confirm whether the absolute value of the difference between the inlet cooling water flow rate of the slag cooler and the target flow rate value under the current working condition is greater than the difference threshold;

[0196] When the absolute value of the difference is greater than the difference threshold, adjust the inlet cooling water flow rate of the slag cooler to the target flow rate value, and re-collect the thermal parameters of the slag cooler and the low-temperature economizer of the generator set under the current working condition.

[0197] Reference Figure 5 As shown, in some other embodiments, in addition to the parameter acquisition module 41, the reference determination module 42, the first adjustment module 43, the efficiency determination module 44, the optimization parameter determination module 45, and the second adjustment module 46, the circulating fluidized bed unit slag cooler and low-temperature economizer optimization device may further include a result output module 47. The result output module 47 may be used to output the optimization result.

[0198] Among them, the optimization results may include: the thermodynamic parameters of the slag cooler and the low-temperature economizer before and after optimization; the output increment of the generator set before and after optimization; the power generation efficiency increment of the generator set before and after optimization, etc.

[0199] In some device embodiments, the optimization results may further include: the heat exchange amount of the slag cooler before and after optimization; the heat exchange amount of the low-temperature economizer before and after optimization.

[0200] For the convenience of description, when describing the above devices, they are divided into various units according to functions for separate description. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0201] The embodiments of this specification also provide a computer device. As Figure 6 shown, in some embodiments of this specification, the computer device 602 may include one or more processors 604, such as one or more central processing units (CPUs) or graphics processing units (GPUs), and each processing unit may implement one or more hardware threads. The computer device 602 may also include any memory 606, which is used to store any kind of information such as code, settings, data, etc. In a specific embodiment, a computer program stored on the memory 606 and executable on the processor 604, when the computer program is run by the processor 604, can execute the instructions of the optimization method for the slag cooler and the low-temperature economizer of the circulating fluidized bed unit described in any of the above embodiments. Non-limitingly, for example, the memory 606 may include any one or more combinations of the following: any type of RAM, any type of ROM, flash memory devices, hard disks, optical discs, etc. More generally, any memory can store information using any technology. Further, any memory can provide volatile or non-volatile retention of information. Further, any memory can represent a fixed or removable component of the computer device 602. In one case, when the processor 604 executes the associated instructions stored in any memory or combination of memories, the computer device 602 can perform any operation of the associated instructions. The computer device 602 also includes one or more drive mechanisms 608 for interacting with any memory, such as a hard disk drive mechanism, an optical disc drive mechanism, etc.

[0202] The computer device 602 may also include an input / output interface 610 (I / O) for receiving various inputs (via the input device 612) and for providing various outputs (via the output device 614). One particular output mechanism may include a presentation device 616 and an associated graphical user interface 618 (GUI). In other embodiments, the input / output interface 610 (I / O), the input device 612, and the output device 614 may not be included and the computer device may only act as a computer device in a network. The computer device 602 may also include one or more network interfaces 620 for exchanging data with other devices via one or more communication links 622. One or more communication buses 624 couple the components described above together.

[0203] The communication link 622 may be implemented in any manner, for example, through a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link 622 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc. governed by any protocol or combination of protocols.

[0204] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to some embodiments of the present specification. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processors to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processors produce a means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0205] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processors to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction means that implements the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0206] These computer program instructions can also be loaded onto a computer or other programmable data processors, such that a series of operation steps are performed on the computer or other programmable devices to generate a computer-implemented process, so that the instructions executed on the computer or other programmable devices provide means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1Steps for the functions specified in one or more boxes.

[0207] In a typical configuration, a computer device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0208] Memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

[0209] Computer-readable media includes both permanent and non-permanent, removable and non-removable media and can store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computer device. As defined in this specification, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0210] Those skilled in the art should understand that the embodiments of this specification can be provided as methods, systems, or computer program products. Therefore, the embodiments of this specification can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of this specification can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0211] The embodiments of this specification can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The embodiments of this specification can also be practiced in a distributed computing environment where tasks are performed by remote processors connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0212] It should also be understood that in the embodiments of this specification, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, both A and B exist simultaneously, and B exists alone. Additionally, the character " / " in this text generally indicates that the associated objects before and after are in an "or" relationship.

[0213] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and reference can be made to the corresponding parts of the method embodiments for the relevant content.

[0214] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of this specification. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0215] The above description is only for the embodiments of this application and is not intended to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims

1. An optimization method for a fluidized bed boiler unit's slag cooler and low-temperature economizer, characterized in that, Including: Collecting the thermal parameters of the slag cooler and the low-temperature economizer of the generating unit under the current working condition; Determining the power generation efficiency increment of the generating unit under the current working condition relative to the case where the slag cooler and the low-temperature economizer are not provided according to the thermal parameters, so as to be used as the efficiency increment reference; Adjusting the cooling water flow rate of the slag cooler to a target flow rate value; Under the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, determining the power generation efficiency increment of the low-temperature economizer relative to the efficiency increment reference under different operation modes to form a power generation efficiency increment set; Determining the cooling water flow rate and the operation mode of the low-temperature economizer corresponding to the maximum value in the power generation efficiency increment set; Adjusting the low-temperature economizer to this operation mode and adjusting the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer.

2. The optimization method of the circulating fluidized bed unit slag cooler and low-temperature economizer according to claim 1, characterized in that, The determining the power generation efficiency increment of the generating unit under the current working condition relative to the case where the slag cooler and the low-temperature economizer are not provided according to the thermal parameters includes: According to the formula ΔW = (Δm' st1 + Δm″ st1 )·H1 + Δm st2 ·H2 + Δm st3 ·H3, calculate the output power increment of the generator set under the current working condition relative to the situation when the slag cooler and the low-temperature economizer are not installed; According to the formula calculate the power generation efficiency increment of the generator set under the current working condition relative to the situation where the slag cooler and the low-temperature economizer are not installed; Where, ΔW is the increment of output work, and Δm' st1 is the extraction steam quantity saved by the slag cooler in the first target extraction steam section, and Δm″ st1 is the extraction steam quantity saved by the low-temperature economizer in the first target extraction steam section, H1 is the extraction steam equivalent enthalpy drop in the first target extraction steam section, and Δm st2 is the extraction steam quantity saved by the low-temperature economizer in the corresponding second target extraction steam section, H2 is the extraction steam equivalent enthalpy drop in the second target extraction steam section, and Δm st3 is the extraction steam quantity saved by the low-temperature economizer in the corresponding third target extraction steam section, H3 is the extraction steam equivalent enthalpy drop in the third target extraction steam section, Δη is the increment of power generation efficiency, and W is the output work of the generator set without the slag cooler and the low-temperature economizer.

3. The optimization method of the circulating fluidized bed unit slag cooler and low-temperature economizer according to claim 2, characterized in that, The extraction steam amount saved by the slag cooler in the first target extraction steam section, the extraction steam amount saved by the low-temperature economizer in the first target extraction steam section, the extraction steam amount saved by the low-temperature economizer in the corresponding second target extraction steam section, and the extraction steam amount saved by the low-temperature economizer in the corresponding third target extraction steam section are respectively calculated according to the following formulas: where m wz is the cooling water flow rate of the slag cooler, t w1i and t w1o are the inlet condensate temperature and the outlet condensate temperature of the heater corresponding to the first target extraction stage, h s1 is the steam enthalpy value of the first target extraction stage, h w1 is the drain enthalpy value of the first target extraction stage, m we1 is the inlet cooling water flow rate of the first input branch of the low-temperature economizer, m we2 is the inlet cooling water flow rate of the second input branch of the low-temperature economizer, t w2i and t w2o are the inlet condensate temperature and the outlet condensate temperature of the heater corresponding to the second target extraction stage, h s2 is the steam enthalpy value of the second target extraction stage, h w2 is the drain enthalpy value of the second target extraction stage, h s3 is the steam enthalpy value of the third target extraction stage, h w3 is the drain enthalpy value of the third target extraction stage.

4. The optimization method of the circulating fluidized bed unit slag cooler and low-temperature economizer according to claim 2, characterized in that, The extraction steam equivalent enthalpy drop of the first target extraction steam section, the extraction steam equivalent enthalpy drop of the second target extraction steam section, and the extraction steam equivalent enthalpy drop of the third target extraction steam section are respectively calculated according to the following formulas: H1 = h s1 -h c Among them, h s1 is the steam enthalpy value of the first target extraction section, h c is the turbine exhaust enthalpy value, h s2 is the steam enthalpy value of the second target extraction section, h s3 is the steam enthalpy value of the third target extraction section. A1 is the heat release of 1 kg of the drain water from the second target extraction section in the corresponding heater of the first target extraction section, q1 is the heat release of 1 kg of the extraction steam from the first target section in the corresponding heater of the first target extraction section, A2 is the heat release of 1 kg of the drain water from the third target extraction section in the corresponding heater of the second target extraction section, and q2 is the heat release of 1 kg of the extraction steam from the second target section in the corresponding heater of the second target extraction section.

5. The optimization method of the circulating fluidized bed unit slag cooler and low-temperature economizer according to claim 1, characterized in that The adjusting the cooling water flow rate of the slag cooler to a target flow rate value includes: Obtaining the target flow rate value of the slag cooler; Confirming whether the absolute value of the difference between the inlet cooling water flow rate of the slag cooler and the target flow rate value under the current working condition is greater than the difference threshold; When the absolute value of the difference is greater than the difference threshold, adjusting the inlet cooling water flow rate of the slag cooler to the target flow rate value and re-collecting the thermal parameters of the slag cooler and the low-temperature economizer of the generating unit under the current working condition.

6. The optimization method of the circulating fluidized bed unit slag cooler and low-temperature economizer according to claim 1, characterized in that, After adjusting the low-temperature economizer to this operation mode and adjusting the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer, it further includes: Outputting the optimization result; Wherein, the optimization result includes: The thermal parameters of the slag cooler and the low-temperature economizer before and after optimization; The output power increment of the generating unit before and after optimization; and, The power generation efficiency increment of the generating unit before and after optimization.

7. The optimization method of the circulating fluidized bed unit slag cooler and low-temperature economizer according to claim 6, characterized in that The optimization result further includes: The heat exchange amount of the slag cooler before and after optimization; and, The heat exchange amount of the low-temperature economizer before and after optimization.

8. An optimization device for a circulating fluidized bed unit's slag cooler and low-temperature economizer, characterized in that, Including: A parameter acquisition module for collecting the thermal parameters of the slag cooler and the low-temperature economizer of the generating unit under the current working condition; A reference determination module for determining the power generation efficiency increment of the generating unit under the current working condition relative to the case where the slag cooler and the low-temperature economizer are not provided according to the thermal parameters, so as to be used as the efficiency increment reference; A first adjustment module for adjusting the cooling water flow rate of the slag cooler to a target flow rate value; An efficiency determination module, configured to determine a power generation efficiency increment of the low-temperature economizer relative to the efficiency increment reference under different operating modes on the condition that the outlet flue gas temperature of the low-temperature economizer is not lower than the safety boundary, and form a power generation efficiency increment set; An optimization parameter determination module, configured to determine the cooling water flow rate and the operating mode of the low-temperature economizer corresponding to the maximum value in the power generation efficiency increment set; A second adjustment module, configured to adjust the low-temperature economizer to this operating mode and adjust the inlet cooling water flow rate of the low-temperature economizer to the cooling water flow rate of the low-temperature economizer.

9. A computer device, comprising a memory, a processor, and a computer program stored on the memory, characterized in that, When the computer program is run by the processor, it executes the instructions of the method according to any one of claims 1-7.

10. A computer storage medium, on which a computer program is stored, characterized in that, When the computer program is run by the processor of the computer device, it executes the instructions of the method according to any one of claims 1-7.

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