Control method and control device of low-temperature economizer system

Abstract

The invention relates to a control method and device of a low-temperature economizer system, and relates to the technical field of intelligent control of thermal power stations. The control method comprises the step of controlling whether the booster pump is started or not based on the starting permission condition of the booster pump under the conditions that the condensate pump runs and the water inlet pressure of the booster pump is larger than the preset pressure. By means of the control method, it can be ensured that when the booster pump is started, condensed water exists in the pipeline of the low-temperature economizer system, the water inlet pressure of the booster pump is larger than the preset pressure during starting, it is ensured that cavitation caused by too low pressure in the booster pump is avoided, operation safety of the booster pump is ensured, manual operation of operators is not needed, and the working efficiency is improved. And the operation workload and difficulty are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of intelligent control of thermal power plants, and in particular to a control method and a control device for a low-temperature economizer system. Background Art

[0002] As energy conservation and consumption reduction become new issues in the development of large thermal power plants, many large thermal power plants will choose to add low-temperature economizers at the flue outlet to further reduce the exhaust gas temperature and recover the heat to the low-pressure heating system on the machine side to improve the overall economy of the unit. The low-temperature economizer system involves a wide range of aspects, which will not only affect the low-pressure water supply system of the steam turbine, but also the boiler, electrostatic precipitator and desulfurization system. At present, low-temperature economizer suppliers only manufacture and supply physical equipment according to the parameters of the design institute, and do not provide corresponding control strategies, which will greatly increase the workload and difficulty of operation. When the control strategy is unreasonable and imperfect, manual operation by the operator is prone to misoperation and even major accidents. Summary of the invention

[0003] Based on this, it is necessary to provide a control method and a control device for a low-temperature economizer system that can reduce the operating workload and difficulty in order to address the above technical problems.

[0004] In the first aspect, the present application proposes a control method for a low-temperature economizer system, wherein the low-temperature economizer system comprises: a low-temperature economizer module, a booster pump, a circulation regulating valve, a first regulating valve, a second regulating valve, an outlet main pipe regulating valve, a first low-pressure heater, a second low-pressure heater, a third low-pressure heater and a condensing pump, wherein the low-temperature economizer module comprises a plurality of low-temperature economizers, wherein the water inlet of each of the low-temperature economizers is connected to a water inlet regulating valve, the water inlet regulating valve is connected to the outlet of the booster pump, the inlet of the booster pump is respectively connected to one end of the first regulating valve, the second regulating valve and the circulation regulating valve, and the water outlets of the low-temperature economizers are respectively connected to the The other end of the circulation regulating valve and one end of the outlet main pipe regulating valve, the other end of the first regulating valve is connected to the outlet of the first low-pressure heater, the other end of the second regulating valve is connected to the outlet of the second low-pressure heater, the other end of the outlet main pipe regulating valve is connected to the outlet of the third low-pressure heater, the inlet of the first low-pressure heater is connected to the outlet of the condensate pump, the inlets and outlets of the first low-pressure heater, the second low-pressure heater and the third low-pressure heater are connected in sequence, the temperature of the first low-pressure heater is lower than the temperature of the second low-pressure heater, and the temperature of the second low-pressure heater is lower than the temperature of the third low-pressure heater;

[0005] The control method includes: when the condensate pump is running and the water inlet pressure of the booster pump is greater than a preset pressure, controlling whether the booster pump is started based on a permission condition for starting the booster pump.

[0006] The control method of the above-mentioned low-temperature economizer system, when controlling whether the booster pump in the low-temperature economizer system is started, first needs to determine whether the condensate pump is running, and only when the condensate pump is running and the water inlet pressure of the booster pump is greater than the preset pressure, will the booster pump be started or stopped based on the allowable conditions for starting the booster pump, thereby controlling the start and stop of the booster pump. Through the above-mentioned judgment steps, it can be ensured that when the booster pump is started, there is condensate in the pipeline of the low-temperature economizer system, and the water inlet pressure of the booster pump is greater than the preset pressure when starting, ensuring that cavitation will not occur inside the booster pump due to too low pressure, ensuring the safe operation of the booster pump, and at the same time, no manual operation by the operating personnel is required, reducing the workload and difficulty of operation.

[0007] In one of the embodiments, the step of controlling whether the booster pump is started based on the permission conditions for starting the booster pump includes: when the operating time of any coal mill unit is greater than the preset time, and the corresponding coal seam fire detection has fire, and the inlet flue gas temperature of the low-temperature economizer is greater than the preset temperature, the booster pump is started by controlling the interlock button.

[0008] In one of the embodiments, the control method further includes: after the booster pump is started, the frequency converter of the booster pump adjusts the pressure difference before and after the booster pump based on the unit load.

[0009] In one of the embodiments, after the step after the booster pump is started, the control method further includes: adjusting the opening of the water inlet regulating valve based on the target outlet flue gas temperature of the low-temperature economizer; wherein the minimum opening of the water inlet regulating valve is 5%.

[0010] In one of the embodiments, after the step after the booster pump is started, the control method further includes: adjusting the opening of the circulation regulating valve based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the openings of the circulation regulating valve and the outlet main pipe regulating valve is greater than 10% and less than 120%.

[0011] In one of the embodiments, after the step of starting the booster pump, the control method further includes: adjusting the opening of the outlet main pipe regulating valve based on the target outlet water temperature of the low-temperature economizer.

[0012] In one of the embodiments, after the step after the boost pump is started, the control method further includes: adjusting the opening of the first regulating valve and the opening of the second regulating valve based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the opening of the first regulating valve and the opening of the second regulating valve is 100%.

[0013] In one embodiment, the control method further includes: controlling the booster pump to stop after the boiler main fuel trips and delays for a first preset time, or after the condensate pump stops and delays for a second preset time, or after the water inlet pressure of the booster pump is less than a preset pressure and delays for a third preset time.

[0014] In a second aspect, the present application further proposes a control device for a low-temperature economizer system, which is used to execute the control method for a low-temperature economizer system described in the embodiment of the first aspect, and the control device comprises:

[0015] The booster pump control module is used to control whether the booster pump is started based on the permission condition for starting the booster pump when the condensate pump is running and the water inlet pressure of the booster pump is greater than a preset pressure.

[0016] In one of the embodiments, the booster pump control module is also used to control the booster pump to start by pressing the interlock button when the operating time of any coal mill unit is greater than a preset time, the corresponding coal seam fire detection shows fire, and the inlet flue gas temperature of the low-temperature economizer is greater than a preset temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of a module of a low-temperature economizer system in one embodiment;

[0019] FIG2 is a schematic flow chart of a control method in one embodiment;

[0020] FIG3 is a schematic flow chart of a control method in another embodiment;

[0021] FIG. 4 is a flow chart of a control method in yet another embodiment. DETAILED DESCRIPTION

[0022] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0024] It can be understood that the terms "first", "second", etc. used in the present application can be used in this article to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element.

[0025] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0026] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0027] The control method and control device of the low-temperature economizer system of the embodiment of the present application can be applied to the control of the low-temperature economizer system. Figure 1As shown, the low-temperature economizer system includes: a low-temperature economizer module, a booster pump, a circulation regulating valve, a first regulating valve, a second regulating valve, an outlet main pipe regulating valve, a first low-pressure heater, a second low-pressure heater, a third low-pressure heater and a condensate pump. The low-temperature economizer module includes multiple low-temperature economizers. The water inlet of each low-temperature economizer is connected to a water inlet regulating valve, the water inlet regulating valve is connected to the outlet of the booster pump, the inlet of the booster pump is respectively connected to one end of the first regulating valve, the second regulating valve and the circulation regulating valve, the water outlet of the low-temperature economizer is respectively connected to the other end of the circulation regulating valve and one end of the outlet main pipe regulating valve, the other end of the first regulating valve is connected to the outlet of the first low-pressure heater, the other end of the second regulating valve is connected to the outlet of the second low-pressure heater, the other end of the outlet main pipe regulating valve is connected to the outlet of the third low-pressure heater, the inlet of the first low-pressure heater is connected to the outlet of the condensate pump, the inlets and outlets of the first low-pressure heater, the second low-pressure heater and the third low-pressure heater are connected in sequence, the temperature of the first low-pressure heater is lower than the temperature of the second low-pressure heater, and the temperature of the second low-pressure heater is lower than the temperature of the third low-pressure heater. The first low-pressure heater, the second low-pressure heater and the third low-pressure heater are used to heat the condensate transmitted by the condensate pump, and their inlet temperatures decrease successively. The low-temperature economizer system mainly heats the condensate through the waste heat of the flue gas at the outlet of the boiler air preheater of the generator set, so as to recover the heat into the unit system and improve the economy of the unit.

[0028] In one embodiment, as shown in FIG2 , the control method of the low temperature economizer system includes: when the condensate pump is running and the water inlet pressure of the booster pump is greater than a preset pressure, controlling whether the booster pump is started based on the permission conditions for starting the booster pump.

[0029] Specifically, in the process of judging whether the booster pump can be controlled to start, the present application first needs to judge whether the condensate pump is running and whether the water inlet pressure of the booster pump is greater than the preset pressure. After the condensate pump is running, condensate will exist in the pipeline of the low-temperature economizer system, thereby preventing idling in the absence of condensate. The booster pump can only be started when the water inlet pressure of the booster pump is greater than the preset pressure (such as 0.1MPa) to ensure that cavitation caused by too low pressure will not occur inside the booster pump, thereby ensuring the safe operation of the booster pump. When it is determined that the condensate pump is running and the water inlet pressure of the booster pump is greater than the preset pressure, it is judged whether the low-temperature economizer system meets the permissible conditions for starting the booster pump. The booster pump will only be started when the permissible conditions for starting the booster pump are met. Through the above judgment steps, the safe operation of the booster pump is ensured, and at the same time, there is no need for manual operation by the operating personnel, which reduces the workload and difficulty of operation.

[0030] In one embodiment, as shown in FIG3 , the step of controlling whether the booster pump is started based on the permission conditions for starting the booster pump includes: when the operating time of any coal mill unit is greater than the preset time, and the corresponding coal seam fire detection has fire, and the inlet flue gas temperature of the low-temperature economizer is greater than the preset temperature, the booster pump is started by controlling the interlock button.

[0031] Specifically, the permissible conditions for starting the booster pump in this embodiment include three judgment conditions. Only when the three judgment conditions are detected to be met at the same time will the booster pump controlled by the interlock button be started. When detecting whether the running time of the coal mill unit is greater than the preset time, the actual running time of all coal mill units can be monitored by a timer. If it is detected that the running time of any coal mill unit is greater than the preset time (such as 3 minutes), it means that there is a coal mill unit that has started to operate stably and is providing coal powder to the boiler. When detecting whether the coal seam is burning normally, the coal seam is directly inspected for fire. If there is fire in the corresponding coal seam fire inspection, it means that the boiler is burning normally. When detecting whether the inlet flue gas temperature of the low-temperature economizer is greater than the preset temperature, it can be detected by a temperature sensor set at the inlet of the low-temperature economizer. If the inlet flue gas temperature is greater than the preset temperature (such as 95 degrees Celsius), it means that the flue gas temperature discharged by the boiler is high and has a better recovery rate. When all three judgment conditions are met, the corresponding pulse command for starting the booster pump will be issued to control the start of the booster pump controlled by the interlock button. It is understandable that the low-temperature economizer system includes multiple booster pumps, and the user can independently select the booster pump that needs to work and put in the interlock button. After the booster pump is started, it will drive the condensate to circulate in the pipeline. After the condensate circulates to the low-temperature economizer, it will absorb the heat of the boiler flue gas, thereby reducing the exhaust gas temperature, increasing the condensate temperature, and completing the recovery of the flue gas heat. By judging the permissible conditions for starting the booster pump in this embodiment, the low-temperature economizer can start working in the best working state, improving the energy-saving effect of the low-temperature economizer, and at the same time, there is no need for manual operation by the operator, which can reduce the workload and difficulty of operation.

[0032] In one embodiment, the control method of the low temperature economizer system further includes: after the booster pump is started, the frequency converter of the booster pump adjusts the pressure difference before and after the booster pump based on the unit load.

[0033] Specifically, after the booster pump of this embodiment is started, the booster pump will adjust the pressure difference before and after the pump in real time according to the unit load of the generator set, ensuring that the low-temperature economizer system can operate efficiently under different loads, thereby improving the overall performance of the system. In some embodiments, the corresponding relationship between the unit load and the pressure difference before and after the pump is as follows: X1: 0MW, Y1: 0.2MPa; X2: 300MW, Y2: 0.25MPa; X3: 500MW, Y3: 0.3MPa; X4: 1000MW, Y4: 0.35MPa. Among them, X is the unit load, and Y is the pressure difference before and after the pump.

[0034] In one embodiment, after the step of starting the boost pump, the control method of the low-temperature economizer system also includes: adjusting the opening of the water inlet regulating valve based on the target outlet flue gas temperature of the low-temperature economizer; wherein the minimum opening of the water inlet regulating valve is 5%.

[0035] Specifically, during the start-up and normal operation of the booster pump of the low-temperature economizer system of this embodiment, the outlet flue gas temperature is detected by the temperature sensor set at the flue gas outlet of the low-temperature economizer, and compared with the preset target outlet flue gas temperature, so as to adjust the opening of the water inlet regulating valve to ensure that the outlet flue gas temperature is within the error range of the target outlet flue gas temperature. In some embodiments, the target outlet flue gas temperature is 90°C to 110°C. In some embodiments, the target outlet flue gas temperature is set to 92°C. When it is detected that the outlet flue gas temperature is greater than the target outlet flue gas temperature, the opening of the water inlet regulating valve can be increased to increase the water inlet flow rate and increase the heat exchange. When it is detected that the outlet flue gas temperature is less than the target outlet flue gas temperature, the opening of the water inlet regulating valve can be reduced to reduce the water inlet flow rate and reduce the heat exchange. By setting the target outlet flue gas temperature, low-temperature corrosion of equipment such as low-temperature economizers and dust collectors and overheating and burning of equipment such as dust collectors and desulfurizers can be prevented. At the same time, in order to prevent the pump from being blocked and the gasification of the low-temperature economizer module, the minimum opening of the water inlet regulating valve is 5% when it is automatically controlled.

[0036] In one embodiment, after the step after the boost pump is started, the control method of the low-temperature economizer system also includes: adjusting the opening of the circulation regulating valve based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the openings of the circulation regulating valve and the outlet main pipe regulating valve is greater than 10% and less than 120%.

[0037] Specifically, in this embodiment, the inlet water temperature of the low-temperature economizer is automatically adjusted by a circulation regulating valve. When the inlet water temperature of the low-temperature economizer is too low, low-temperature corrosion may occur in the low-temperature economizer and the dust collector. In some embodiments, the target inlet water temperature is set to 72°C, and the target inlet water temperature is not less than 70°C. When it is detected that the inlet water temperature of the low-temperature economizer is greater than the target inlet water temperature, the opening of the circulation regulating valve is increased to increase the amount of recirculated water, thereby increasing the inlet water temperature. When it is detected that the inlet water temperature of the low-temperature economizer is less than the target inlet water temperature, the opening of the circulation regulating valve is reduced to reduce the amount of recirculated water, thereby reducing the inlet water temperature. In order to prevent pump blocking and overcurrent, the sum of the openings of the circulation regulating valve and the outlet main pipe regulating valve is greater than 10% and less than 120%. It can be understood that the circulation regulating valve, the first regulating valve and the second regulating valve can all adjust the inlet water temperature of the low-temperature economizer. In order to maximize the outlet water flow and recovered heat and reduce the recycling energy consumption, the target inlet water temperature setting value corresponding to the circulation regulating valve is lower than the inlet water temperature setting value corresponding to the first regulating valve and the second regulating valve. At the same time, the circulation regulating valve is closed first when the overall inlet water temperature is high.

[0038] In one embodiment, after the step of starting the booster pump, the control method of the low-temperature economizer system further includes: adjusting the opening of the outlet main pipe regulating valve based on the target outlet water temperature of the low-temperature economizer.

[0039] Specifically, in this embodiment, the outlet water temperature of the low-temperature economizer is automatically adjusted by the outlet main pipe regulating valve. In some embodiments, the target outlet water temperature is set to 86°C. When it is detected that the outlet water temperature of the low-temperature economizer is greater than the target outlet water temperature, the opening of the outlet main pipe regulating valve is increased to increase the water flow rate, thereby reducing the outlet water temperature. When it is detected that the outlet water temperature of the low-temperature economizer is less than the target outlet water temperature, the opening of the outlet main pipe regulating valve is reduced to reduce the water flow rate, thereby increasing the outlet water temperature.

[0040] In one embodiment, after the step after the boost pump is started, the control method of the low-temperature economizer system also includes: adjusting the opening of the first regulating valve and the opening of the second regulating valve based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the opening of the first regulating valve and the opening of the second regulating valve is 100%.

[0041] Specifically, in this embodiment, the inlet water temperature of the low-temperature economizer is automatically adjusted by the first regulating valve and the second regulating valve. When the inlet water temperature of the low-temperature economizer is too low, the low-temperature economizer and the dust collector may have low-temperature corrosion problems. In some embodiments, the target inlet water temperature is set to 72°C, and the target inlet water temperature is not less than 70°C. When it is detected that the inlet water temperature of the low-temperature economizer is greater than the target inlet water temperature, the opening of the first regulating valve is increased and the opening of the second regulating valve is reduced, so that less condensed water heated by the second low-pressure heater enters the low-temperature economizer, thereby reducing the inlet water temperature. When it is detected that the inlet water temperature of the low-temperature economizer is less than the target inlet water temperature, the opening of the first regulating valve is reduced and the opening of the second regulating valve is increased, so that more condensed water heated by the second low-pressure heater enters the low-temperature economizer, thereby increasing the inlet water temperature. In the process of adjusting the opening of the first regulating valve and the second regulating valve, the sum of the opening of the first regulating valve and the opening of the second regulating valve is 100%, so as to avoid affecting the water flow entering the low-temperature economizer module.

[0042] In one embodiment, as shown in Figure 4, the control method of the low-temperature economizer system also includes: controlling the booster pump to stop after the boiler main fuel trips and delays for a first preset time, or the condensate pump stops and delays for a second preset time, or the water inlet pressure of the booster pump is less than the preset pressure and delays for a third preset time.

[0043] Specifically, in the control method of this embodiment, the booster pump will be controlled to stop when any one of the three conditions is detected to be met. When the main fuel trip (MFT) of the boiler occurs, it indicates that an abnormality has occurred in the boiler. At this time, the boiler fuel stops entering and the boiler begins to stop running. However, after the main fuel trip of the boiler, it is still necessary to delay the first preset time (such as 5 minutes). During the first preset time, the boiler fan will be purged, and the exhaust gas temperature is still high. In order to prevent the low-temperature economizer module from vaporizing, it is necessary to delay the first preset time before controlling the booster pump to stop. When the condensate pump stops, the condensate pump no longer delivers condensate to the low-temperature economizer system. At this time, the booster pump is controlled to stop after the second preset time (such as 5 seconds) to miss the start-up time of the condensate pump and prevent the booster pump from tripping by mistake. When the water inlet pressure of the booster pump is less than the preset pressure (such as 0.1MPa), it indicates that there is a problem with the condensate delivery pipeline. At this time, the booster pump is controlled to stop after the third preset time (such as 5 seconds) is delayed to prevent the booster pump from tripping by mistake. After the booster pump stops, the valve in the low-temperature economizer system closes and the controller exits operation.

[0044] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0045] Based on the same inventive concept, the embodiment of the present application also provides a control device for a low-temperature economizer system for implementing the control method for the low-temperature economizer system involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of one or more control devices for low-temperature economizer systems provided below can refer to the limitations of the control method for the low-temperature economizer system above, and will not be repeated here.

[0046] In one embodiment, the present application also proposes a control device for a low-temperature economizer system, which is used to execute the control method of the low-temperature economizer system in the above embodiment, and the control device includes: a booster pump control module, which is used to control whether the booster pump is started based on the permission conditions for starting the booster pump when the condensing pump is running and the water inlet pressure of the booster pump is greater than a preset pressure.

[0047] In one embodiment, the booster pump control module is also used to control the start-up of the booster pump by the interlock button when the operating time of any coal mill unit is greater than a preset time, the corresponding coal seam fire detection is on fire, and the inlet flue gas temperature of the low-temperature economizer is greater than a preset temperature.

[0048] In one embodiment, the control device further includes: an operation control module, which is used for adjusting the pressure difference before and after the booster pump based on the unit load by the frequency converter of the booster pump after the booster pump is started.

[0049] In one embodiment, the operation control module is further used to adjust the opening of the water inlet regulating valve based on the target outlet flue gas temperature of the low-temperature economizer; wherein the minimum opening of the water inlet regulating valve is 5%.

[0050] In one embodiment, the operation control module is also used to adjust the opening of the circulation regulating valve based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the openings of the circulation regulating valve and the outlet main pipe regulating valve is greater than 10% and less than 120%.

[0051] In one embodiment, the operation control module is further used to adjust the opening of the outlet main pipe regulating valve based on the target outlet water temperature of the low-temperature economizer.

[0052] In one embodiment, the operation control module is also used to adjust the opening of the first regulating valve and the opening of the second regulating valve based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the opening of the first regulating valve and the opening of the second regulating valve is 100%.

[0053] In one embodiment, the control device also includes: a stop module, which is used to control the booster pump to stop after the boiler main fuel trips and delays for a first preset time, or the condensate pump stops and delays for a second preset time, or the water inlet pressure of the booster pump is less than the preset pressure and delays for a third preset time.

[0054] Each module in the control device of the low-temperature economizer system can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0055] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0056] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented.

[0057] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0058] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A control method for a low temperature economizer system, characterized in that: The low-temperature economizer system includes: a low-temperature economizer module, a booster pump, a circulation regulating valve, a first regulating valve, a second regulating valve, an outlet main pipe regulating valve, a first low-pressure heater, a second low-pressure heater, a third low-pressure heater and a condensing pump. The low-temperature economizer module includes a plurality of low-temperature economizers. The water inlet of each low-temperature economizer is connected to an inlet regulating valve, the inlet regulating valve is connected to the outlet of the booster pump, the inlet of the booster pump is respectively connected to the first regulating valve, the second regulating valve and one end of the circulation regulating valve, and the water outlet of the low-temperature economizer is respectively connected to the other end of the circulation regulating valve and the outlet main pipe regulating valve. one end of the throttle valve, the other end of the first regulating valve is connected to the outlet of the first low-pressure heater, the other end of the second regulating valve is connected to the outlet of the second low-pressure heater, the other end of the outlet main pipe regulating valve is connected to the outlet of the third low-pressure heater, the inlet of the first low-pressure heater is connected to the outlet of the condensate pump, the inlets and outlets of the first low-pressure heater, the second low-pressure heater and the third low-pressure heater are connected in sequence, the temperature of the first low-pressure heater is lower than the temperature of the second low-pressure heater, and the temperature of the second low-pressure heater is lower than the temperature of the third low-pressure heater; the control method comprises: When the condensate pump is running and the water inlet pressure of the booster pump is greater than a preset pressure, whether the booster pump is started is controlled based on a permission condition for starting the booster pump.

2. The control method of the low temperature economizer system according to claim 1, characterized in that: The step of controlling whether the booster pump is started based on the permission condition for starting the booster pump comprises: When the operating time of any coal mill unit is greater than the preset time, and the corresponding coal seam fire detection is on fire, and the inlet flue gas temperature of the low-temperature economizer is greater than the preset temperature, the booster pump is started by controlling the interlock button.

3. The control method of the low temperature economizer system according to claim 1, characterized in that: The control method further comprises: After the booster pump is started, the frequency converter of the booster pump adjusts the pressure difference before and after the booster pump based on the unit load.

4. The control method of the low temperature economizer system according to claim 3, characterized in that: After the step of starting the booster pump, the control method further includes: The opening of the water inlet regulating valve is adjusted based on the target outlet flue gas temperature of the low-temperature economizer; wherein the minimum opening of the water inlet regulating valve is 5%.

5. The control method of the low temperature economizer system according to claim 3, characterized in that: After the step of starting the booster pump, the control method further includes: The opening of the circulation regulating valve is adjusted based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the openings of the circulation regulating valve and the outlet main pipe regulating valve is greater than 10% and less than 120%.

6. The control method of the low temperature economizer system according to claim 3, characterized in that: After the step of starting the booster pump, the control method further includes: The opening of the outlet main pipe regulating valve is adjusted based on the target outlet water temperature of the low-temperature economizer.

7. The control method of the low temperature economizer system according to claim 3, characterized in that: After the step of starting the booster pump, the control method further includes: The opening of the first regulating valve and the opening of the second regulating valve are adjusted based on the target inlet water temperature of the low-temperature economizer; wherein the sum of the opening of the first regulating valve and the opening of the second regulating valve is 100%.

8. The control method of the low temperature economizer system according to claim 1, characterized in that: The control method further comprises: After the boiler main fuel is tripped and delayed for a first preset time, or the condensate pump is stopped and delayed for a second preset time, or the water inlet pressure of the booster pump is less than the preset pressure and delayed for a third preset time, the booster pump is controlled to stop.

9. A control device for a low temperature economizer system, characterized in that: The control method for executing the low-temperature economizer system according to any one of claims 1 to 8, the control device comprising: The booster pump control module is used to control whether the booster pump is started based on the permission condition for starting the booster pump when the condensate pump is running and the water inlet pressure of the booster pump is greater than a preset pressure.

10. The control device of the low temperature economizer system according to claim 9, characterized in that: The booster pump control module is also used to control the booster pump to start when the operating time of any coal mill unit is greater than a preset time, the corresponding coal seam fire detection is found to be on fire, and the inlet flue gas temperature of the low-temperature economizer is greater than a preset temperature.

Images