An optimization method for power generation from waste heat of sintering ring cooler

Abstract

The present application provides a method for optimizing power generation from waste heat of a sintering ring cooler, which relates to the technical field of sintering waste heat utilization, and includes the following steps: Step 1: Collect waste heat power generation related data at the inlet and outlet of the ring cooler and the boiler, and set the optimization adjustment value; Step 2: Substitute the waste heat power generation related data into the calculation formula of the power generation output power; Step 3: Within a certain range, the flue gas flow rate and flue gas temperature follow a certain rule; Step 4: When the flue gas temperature at the boiler inlet is low within a certain period of time, calculate the current power generation output power and obtain the optimized target temperature value; Step 5: Adjust the flue gas temperature and steam production until the target temperature is reached or close to it. Based on the laws of thermodynamics and fluid mechanics, the present application provides a judgment standard for power generation optimization of a ring cooler waste heat power generation system, and adjusts the flue gas temperature and steam production accordingly, which greatly improves the efficiency of flue gas waste heat power generation.

Description

Technical Field

[0001] The present application relates to the technical field of sintering waste heat utilization, and in particular to a method for optimizing power generation from waste heat of a sintering ring cooler. Background Art

[0002] At present, the waste heat power generation system of the steel plant's ring cooler has basically become standard. Cold air or circulating air is blown from the bellows at the bottom of the trolley to the hot ore. After being heated, it is collected by the upper smoke hood and enters the flue. There are usually three flues, namely high-temperature flue, medium-temperature flue and low-temperature flue. Usually the first two enter different parts of the waste heat boiler to recover waste heat for power generation; the latter is directly discharged or circulated into the lower bellows.

[0003] Currently, the flue gas flow path of waste heat power generation systems with annular coolers is rarely adjusted, typically only after a prolonged period of parameter deviation. Operators rarely consider improving waste heat recovery quality and power generation efficiency. Some do, but lack theoretical knowledge of how to adjust waste heat power generation systems. While measurement points and parameters are available, there's no specific standard for determining these adjustments, leaving operators relying entirely on intuition. In particular, the high potential for fluctuation and randomness of the annular cooler parameters make it difficult to determine how to adjust them. Consequently, adjustments are made based on intuition and only after prolonged periods of poor performance. This results in low waste heat utilization and power generation efficiency.

[0004] In the existing technology, CN101699207A uses the thermal cycle of thermal power generation to expand the thermal cycle of waste heat power generation, which solves the problems of poor stability and low thermoelectric conversion efficiency of the existing sintering pure low-temperature waste heat power generation system. It is aimed at the low-temperature waste heat power generation system and cannot solve the efficiency adjustment problem of the three-flue ring cooler waste heat power generation system of this application. Summary of the Invention

[0005] The present application is made in view of the above-mentioned problems, and its purpose is to provide a method for optimizing power generation from waste heat of sintering ring coolers. Based on the laws of thermodynamics and fluid mechanics, a judgment standard for power generation optimization of the waste heat power generation system of a ring cooler is given, and the flue gas temperature and steam production are adjusted accordingly, which greatly improves the efficiency of flue gas waste heat power generation, provides a basis for the adjustment of the waste heat power generation system of the ring cooler, and meets the national energy conservation and emission reduction needs.

[0006] Specifically, a first aspect of the present application provides a method for optimizing waste heat power generation from a sintering ring cooler, comprising the following steps:

[0007] Step 1: Collect waste heat power generation data at the inlet and outlet of the cooler and boiler, and set the optimized adjustment values;

[0008] Step 2: Substitute the waste heat power generation related data into the power generation output power calculation formula to obtain the current power generation output power W1. Assuming that the optimized power generation output power is W2, the calculation formula is as follows:

[0009]

[0010] Where: W1 / W2 are the current / optimized power output respectively, unit is W;

[0011] K1 / K2 are the current / optimized equipment equivalent efficiency respectively;

[0012] T1 / T2 are the current / optimized target temperature of the flue gas entering the boiler, respectively, in °C;

[0013] T 10 / T 20 are the current / optimized target temperature of the flue gas at the boiler outlet, respectively, in °C;

[0014] T0 is the ambient temperature, unit is °C;

[0015] are the enthalpy of steam at (T1-ΔT1) / / (T2-ΔT2) temperatures, in kJ / kg;

[0016] ΔT1 / ΔT2 are the temperature differences between flue gas and steam at present / after optimization, respectively, in °C;

[0017] ΔT g is the temperature difference between exhaust steam and environment, unit is ℃;

[0018] Q1 / Q2 are the current / optimized flue gas flow rates, in m 3 / h;

[0019] is the enthalpy of exhaust steam, unit is kJ / kg;

[0020] is the enthalpy of boiler inlet water, unit is kJ / kg;

[0021] Step 3: In an environment with fresh air or non-hot air circulation, based on W1, W2 and actual usage, within a certain range, the flue gas flow rate and flue gas temperature follow the following rules:

[0022]

[0023] Where: Q1 / Q2 are the current / optimized flue gas flow rates, in m 3 / h;

[0024] T1 / T2 are the current / optimized target temperature of the flue gas entering the boiler, respectively, in °C;

[0025] T0 is the ambient temperature, unit is °C;

[0026] Step 4: When the flue gas temperature at the boiler inlet is low within a certain period of time, calculate the current power output W1, and use the equation ΔT1 / =ΔT2, T 10 / =T 20 , K1 / =K2 and the formula in step 3 are substituted into the calculation formula of W2 to obtain The value of T2 when the maximum value M is obtained;

[0027] Step 5: When M is greater than the optimized adjustment value, according to The flue gas temperature and steam production are adjusted according to the ratio until the flue gas temperature entering the boiler reaches or approaches the value of T2 calculated in step 4.

[0028] Furthermore, the waste heat power generation related data specifically include the flue gas temperature at the boiler inlet and outlet, the temperature of exhaust steam and steam, the flue gas flow rate, and the ambient temperature.

[0029] Furthermore, the optimized adjustment value is used to measure whether the power generation situation needs to be adjusted at present.

[0030] Furthermore, the boiler inlet flue gas temperature being low within a certain period of time specifically includes: when the frequency of the measured value of the boiler inlet flue gas temperature being between 380° C. and 400° C. exceeds 90% within one hour.

[0031] The method for optimizing waste heat power generation of a sintering ring cooler according to claim 1 is characterized in that Specifically, if T2 is greater than T1, the flue gas temperature and steam production are reduced according to the ratio; otherwise, the flue gas temperature and steam production are increased according to the ratio.

[0032] Furthermore, the flue gas temperature is controlled by reducing the fan frequency and / or reducing the valve opening to reduce the flue gas induced draft and increase the flue gas temperature; by increasing the fan frequency and / or increasing the valve opening to increase the flue gas induced draft and reduce the flue gas temperature.

[0033] Furthermore, the flue gas temperature and the steam temperature have a certain positive proportional relationship, and the steam temperature will be automatically adjusted when the flue gas temperature is controlled.

[0034] Furthermore, the steam production is controlled by reducing the water inlet to the boiler and thus reducing the steam production by lowering the water pump frequency and / or reducing the valve opening; and increasing the water inlet to the boiler and thus increasing the steam production by increasing the water pump frequency and / or increasing the valve opening.

[0035] In the second aspect, the present application also provides a computing device, which has the function of implementing the method described in the first aspect above. The beneficial effects can be found in the description of the first aspect and will not be repeated here. The function can be implemented by hardware, or by executing the corresponding software through hardware. The hardware or software includes one or more modules corresponding to the above functions. In one possible design, the structure of the device includes an acquisition module, a training module, and optionally, a construction module. These modules can implement the function of the training node in the method example of the first aspect above. Please refer to the detailed description in the method example for details, which will not be repeated here.

[0036] In a third aspect, the present application further provides a computing device for implementing the functions of the method described in the first aspect above. The beneficial effects can be found in the description of the first aspect and will not be repeated here. The structure of the computing device includes a processor and a memory, and the memory is used to store instructions and / or data. The memory is coupled to the processor, and when the processor executes the program instructions stored in the memory, the functions of the training node in the example of the first aspect above can be implemented. The structure of the computing device also includes a communication interface for communicating with other devices.

[0037] In a fourth aspect, the present application also provides a computer-readable storage medium, which stores instructions. When the computer-readable storage medium is run on a computer, it enables the computer to execute the method in the above-mentioned first aspect and various possible designs of the first aspect.

[0038] In a fifth aspect, the present application also provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the method in the above-mentioned first aspect and various possible designs of the first aspect.

[0039] In a sixth aspect, the present application also provides a computing chip, which is connected to a memory and is used to read and execute software programs stored in the memory, and to execute the methods in the above-mentioned first aspect and various possible implementations of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0041] Figure 1 A flowchart of the steps of this application;

[0042] The purpose, features and advantages of this drawing will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts are within the scope of protection of this application.

[0044] Obviously, the drawings described below are merely examples or embodiments of the present application. Those skilled in the art can, without inventive effort, apply the present application to other similar scenarios based on these drawings. Furthermore, it is also understood that, although the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, changes in design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as an insufficiency of the content disclosed in this application.

[0045] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0046] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0047] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0048] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0049] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0050] In order to better understand the solutions of the embodiments of the present application, some relevant terms and concepts that may be involved in the embodiments of the present application are first introduced below.

[0051] (1) Exhaust steam refers to steam with a low temperature but high enthalpy value discharged from the low-pressure cylinder of a steam turbine in a thermal power plant or other industrial process. This steam usually has thermal potential energy, but after being introduced into the steam turbine through a pipeline, its thermal potential energy is converted into kinetic energy. The main reason for the generation of exhaust steam is that during the power generation process of the steam turbine, the steam undergoes multiple stages of expansion and performs work, and is eventually discharged at a lower temperature and pressure. Although the temperature of this exhaust steam is not high, it still contains a large enthalpy value. If it can be effectively utilized, it can significantly improve energy utilization efficiency.

[0052] (2) Enthalpy is a physical quantity in thermodynamics that represents the total energy of a system. It is related to internal energy and pressure volume. The total energy of a fluid such as steam or exhaust steam under given time and conditions is called enthalpy, which refers to the sum of the internal energy and the work done by the applied pressure.

[0053] (3) Sintering ring cooler is an important equipment widely used in the metallurgical industry. It is mainly used to cool the high-temperature sintered ore unloaded from the sintering machine and recover the waste heat to achieve the purpose of energy saving and environmental protection. It mainly includes the following steps:

[0054] Material input: After the hot sintered ore cake is crushed by a single roller, it is evenly distributed on the grate plate of the trolley through the feeding chute.

[0055] Cooling Process: The turret system is driven by two transmission systems, each 162° apart. Each system consists of a motor, a reducer, an active friction wheel, and a passive friction wheel, providing identical power and motion. The cooling chamber is used to store high-temperature sintered rings and reduce their temperature.

[0056] Waste heat recovery: The sintering ring cooler not only has a cooling function, but also has a waste heat recovery function. The sensible heat in the exhaust gas is converted into steam through the waste heat boiler for use in subsequent processes or power generation.

[0057] like Figure 1 As shown, in this embodiment, a method for optimizing waste heat power generation of a sintering ring cooler includes the following steps:

[0058] Step 1: Collect waste heat power generation data at the inlet and outlet of the cooler and boiler, and set the optimized adjustment values;

[0059] Step 2: Substitute the waste heat power generation related data into the power generation output power calculation formula to obtain the current power generation output power W1. Assuming that the optimized power generation output power is W2, the calculation formula is as follows:

[0060]

[0061] Step 3: In an environment with fresh air or non-hot air circulation, based on W1, W2 and actual usage, within a certain range, the flue gas flow rate and flue gas temperature follow the following rules:

[0062]

[0063] In this embodiment, the certain range is 320° C. to 540° C., and the extreme values ​​of the flue gas temperature and the steam temperature are both within this range.

[0064] Step 4: When the flue gas temperature at the boiler inlet is low within a certain period of time, calculate the current power output W1, and use the equation ΔT1 / =ΔT2, T 10 / =T 20 , K1 / =K2 and the formula in step 3 are substituted into the calculation formula of W2 to obtain The value of T2 when the maximum value M is obtained;

[0065] Step 5: When M is greater than the optimized adjustment value, according to The flue gas temperature and steam production are adjusted according to the ratio until the flue gas temperature entering the boiler reaches or approaches the value of T2 calculated in step 4.

[0066] In this embodiment, the flue gas temperature reaches or approaches the value of T2 calculated in step 4, that is, the flue gas temperature reaches between 98% and 102% of the value of T2.

[0067] Furthermore, the waste heat power generation related data specifically include the flue gas temperature at the boiler inlet and outlet, the temperature of exhaust steam and steam, the flue gas flow rate, and the ambient temperature.

[0068] Furthermore, the optimized adjustment value is used to measure whether the power generation situation needs to be adjusted at present.

[0069] Furthermore, when the flue gas temperature at the boiler inlet is low within a certain period of time, it specifically includes: when the frequency of the flue gas temperature measured at the boiler inlet being between 380° C. and 400° C. exceeds 90% within one hour.

[0070] The method for optimizing waste heat power generation of a sintering ring cooler according to claim 1 is characterized in that Specifically, if T2 is greater than T1, the flue gas temperature and steam production are reduced according to the ratio; otherwise, the flue gas temperature and steam production are increased according to the ratio.

[0071] Furthermore, the flue gas temperature is controlled by reducing the fan frequency and / or reducing the valve opening to reduce the flue gas induced draft and increase the flue gas temperature; by increasing the fan frequency and / or increasing the valve opening to increase the flue gas induced draft and reduce the flue gas temperature.

[0072] The fan is located below the ring cooler's bellows. It cools the sintered ore and recovers waste heat. Specifically, the blower draws cold air from the bottom of the ring cooler. This air is heated as it passes through the hot sinter layer, turning into high-temperature exhaust gas. This high-temperature exhaust gas can be directed to a waste heat boiler to generate steam or hot water, thereby reusing energy.

[0073] Furthermore, the flue gas temperature and the steam temperature have a certain positive proportional relationship, and the steam temperature will be automatically adjusted when the flue gas temperature is controlled.

[0074] There's a direct relationship between the flue gas temperature and steam temperature of a waste heat boiler (HRSG): the higher the flue gas temperature, the higher the steam temperature produced. Flue gas temperature fluctuations also affect key HRSG performance parameters such as evaporation rate and exhaust gas temperature.

[0075] Furthermore, the steam production is controlled by reducing the water inlet to the boiler and thus reducing the steam production by lowering the water pump frequency and / or reducing the valve opening; and by increasing the water inlet to the boiler and thus increasing the steam production by increasing the water pump frequency and / or increasing the valve opening.

[0076] The main function of the water pump is to inject water into the steam drum, ensuring the normal operation of the water circulation in the entire waste heat boiler system. In a once-through waste heat boiler, the pressure head of the feed water pump converts the feed water into superheated steam through each heating surface once, and the flow of the working medium is also achieved by the pressure head of the feed water pump.

[0077] Water pumps are closely linked to steam production. They provide sufficient pressure head to allow feedwater to efficiently pass through the heating surfaces and become superheated steam. If a water pump shuts down due to a power failure, it will affect the normal operation of the water cycle and, in turn, steam production.

[0078] In the process of controlling the flue gas temperature and the steam production, the valve opening refers to the valve opening of the flue from the annular cooler flue gas to the waste heat boiler, which is used to control the flow rate of the flue gas entering the waste heat boiler.

[0079] In this embodiment, the optimization adjustment value is 1.01, that is, the power generation situation is adjusted to improve the efficiency by 1%. The actual flue gas temperature is 380℃. The frequency of the flue gas temperature measurement value at the boiler inlet within one hour is between 380℃ and 400℃ reaches 92%, which meets the judgment requirements. The maximum value obtained is 1.12, which is greater than the optimized adjustment value of 1.01. The value of T2 when the maximum value is obtained is 410℃. When the boiler inlet temperature is adjusted to 410℃, the output power is the largest. Before 410℃, the output power increases with the increase of temperature; after 410℃, the output power decreases with the increase of temperature.

[0080] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for optimizing waste heat power generation from a sintering ring cooler, characterized in that: The following steps are involved: Step 1: Collect waste heat power generation data at the inlet and outlet of the cooler and boiler, and set the optimized adjustment values; Step 2: Substitute the waste heat power generation related data into the power generation output power calculation formula to obtain the current power generation output power W1. Assuming that the optimized power generation output power is W2, the calculation formula is as follows: Where: W1 / W2 are the current / optimized power output respectively, unit is W; K1 / K2 are the current / optimized equipment equivalent efficiency respectively; T1 / T2 are the current / optimized target temperature of the flue gas entering the boiler, respectively, in °C; T 10 / T 20 are the current / optimized target temperature of the flue gas at the boiler outlet, respectively, in °C; T0 is the ambient temperature, unit is °C; are the enthalpy of steam at (T1-ΔT1) / (T2-ΔT2) temperatures, in kJ / kg; ΔT1 / ΔT2 are the temperature differences between flue gas and steam at present / after optimization, respectively, in °C; ΔT g is the temperature difference between exhaust steam and environment, unit is ℃; Q1 / Q2 are the current / optimized flue gas flow rates, in m 3 / h; is the enthalpy of exhaust steam, unit is kJ / kg; is the enthalpy of boiler inlet water, unit is kJ / kg; Step 3: In an environment with fresh air or non-hot air circulation, based on W1, W2 and actual usage, within a certain range, the flue gas flow rate and flue gas temperature follow the following rules: Where: Q1 / Q2 are the current / optimized flue gas flow rates, in m 3 / h; T1 / T2 are the current / optimized target temperature of the flue gas entering the boiler, respectively, in °C; T0 is the ambient temperature, unit is °C; Step 4: When the flue gas temperature at the boiler inlet is low within a certain period of time, calculate the current power output W1, and use the equation ΔT1=ΔT2, T 10 =T 20 , K1=K2 and the formula in step 3 are substituted into the calculation formula of W2 to obtain The value of T2 when the maximum value M is obtained; Step 5: When M is greater than the optimized adjustment value, according to The flue gas temperature and steam production are adjusted according to the ratio until the flue gas temperature entering the boiler reaches or approaches the value of T2 calculated in step 4.

2. The method for optimizing waste heat power generation from a sintering ring cooler according to claim 1, characterized in that: The waste heat power generation related data specifically include the flue gas temperature at the boiler inlet and outlet, the temperature of exhaust steam and steam, the flue gas flow rate, and the ambient temperature.

3. The method for optimizing waste heat power generation from a sintering ring cooler according to claim 1, characterized in that: The optimized adjustment value is used to measure whether the power generation situation needs to be adjusted at present.

4. The method for optimizing waste heat power generation from a sintering ring cooler according to claim 1, characterized in that: The condition that the flue gas temperature at the boiler inlet is low within a certain period of time specifically includes: when the frequency of the measured flue gas temperature at the boiler inlet being between 380° C. and 400° C. exceeds 90% within one hour.

5. The method for optimizing waste heat power generation from a sintering ring cooler according to claim 1, characterized in that: The basis Specifically, if T2 is greater than T1, the flue gas temperature and steam production are reduced according to the ratio; otherwise, the flue gas temperature and steam production are increased according to the ratio.

6. The method for optimizing waste heat power generation from a sintering ring cooler according to claim 5, characterized in that: The control of the flue gas temperature is carried out by reducing the fan frequency and / or decreasing the valve opening to reduce the flue gas induced draft volume and increase the flue gas temperature; and by increasing the fan frequency and / or increasing the valve opening to increase the flue gas induced draft volume and reduce the flue gas temperature.

7. The method for optimizing waste heat power generation from a sintering ring cooler according to claim 6, characterized in that: The flue gas temperature and the steam temperature have a certain positive proportional relationship, and the steam temperature will be automatically adjusted when the flue gas temperature is controlled.

8. The method for optimizing waste heat power generation from a sintering ring cooler according to claim 5, characterized in that: The steam production is controlled by reducing the water inlet to the boiler and thus reducing the steam production by lowering the water pump frequency and / or reducing the valve opening; and increasing the water inlet to the boiler and thus increasing the steam production by increasing the water pump frequency and / or increasing the valve opening.

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