Waste heat power generation optimization method for sintering circular cooler

Abstract

The invention provides a sintering circular cooler waste heat power generation optimization method, and relates to the technical field of sintering waste heat utilization, and the method comprises the following steps: 1, collecting waste heat power generation related data of a circular cooler and a boiler inlet and outlet, and setting an optimization adjustment value; 2, substituting the waste heat power generation related data into a calculation formula of power generation output power; 3, the flue gas flow and the flue gas temperature follow a certain rule within a certain range; 4, when the flue gas temperature of the boiler inlet is low within a certain period of time, the current power generation output power is calculated, and an optimized target temperature value is obtained; and 5, adjusting the flue gas temperature and the steam production amount until the target temperature is reached or close. On the basis of thermodynamics and fluid mechanics laws, a judgment standard for power generation optimization of the waste heat power generation system of the circular cooler is given, the flue gas temperature and the steam production amount are adjusted according to the judgment standard, and the flue gas waste heat power generation efficiency is greatly improved.

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. The 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 smoke hood on the top 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] At present, the flue gas flow path of the waste heat power generation system of the annular cooler is rarely adjusted. Generally, adjustments are made only when the parameters deviate for a long time. The operating personnel basically do not consider improving the waste heat recovery grade and power generation efficiency. Some personnel have this awareness, but because they do not have theoretical knowledge on how to adjust the waste heat power generation system of the annular cooler, although there are measurement points and measured parameters, there is no specific judgment standard, so it all depends on the feeling of the operating personnel. In particular, the parameters of the annular cooler itself have a large possibility of fluctuation and randomness, so it is difficult to decide how to adjust them. Therefore, they can only be adjusted by feeling and in the case of long-term poor performance. The utilization rate of the waste heat of the annular cooler and the power generation efficiency are low.

[0004] In the prior art, CN101699207A utilizes the thermal cycle of thermal power generation to expand the thermal cycle of waste heat power generation, solving 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 regulation problem of the three-flue ring cooler waste heat power generation system of the present 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 sintering ring cooler waste heat power generation. Based on the laws of thermodynamics and fluid mechanics, a judgment standard for power generation optimization of a ring cooler waste heat power generation system 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 adjusting the ring cooler waste heat power generation system, and meets the national energy conservation and emission reduction needs.

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

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

[0008] Step 2: Substitute the waste heat power generation related data into the calculation formula of power generation output power 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, in W;

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

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

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

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

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

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

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

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

[0021] Step 3: In the environment of fresh air or non-hot air circulation, according to W1, W2 and actual use, 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, in °C;

[0025] T0 is the ambient temperature, in °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 transform 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, 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 optimization 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. within one hour exceeds 90%.

[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 control of the flue gas temperature is carried out 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 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 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, which will not be repeated here. The function can be implemented by hardware, or by executing the corresponding software implementation 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 the third aspect, the present application also provides a computing device, which is used to implement 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 function 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, in which instructions are stored, and when the computer-readable storage medium is run on a computer, the computer executes 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 the chip is used to read and execute a software program stored in the memory, and to execute the methods in the above-mentioned first aspect and various possible implementation methods 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 figure will be further described in conjunction with the embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0044] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient 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] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means 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), which means 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] If there is no special explanation, the "include" and "comprising" mentioned in this application represent open-ended or closed-ended expressions. For example, the "include" and "comprising" may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0049] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": 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 that is 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 will be 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 works, 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 used, 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 work done by the internal energy and 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 rotary trolley device is driven by two sets of transmission systems at 162° to each other. Each system consists of a motor, a reducer, an active friction wheel and a passive friction wheel, providing the same power and movement. 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 power generation from waste heat of a sintering ring cooler comprises the following steps:

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

[0059] Step 2: Substitute the waste heat power generation related data into the calculation formula of power generation output power 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 the environment of fresh air or non-hot air circulation, according to W1, W2 and actual use, 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 transform 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, 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 measured value of the flue gas temperature 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 smoke induced draft volume by lowering the fan frequency and / or reducing the valve opening to increase the smoke temperature; and by increasing the fan frequency and / or increasing the valve opening to increase the smoke induced draft volume and reduce the smoke temperature.

[0072] The fan is a blower under the bellows of the ring cooler. The blower cools the sintered ore by blowing air and recovers waste heat. Specifically, the blower blows cold air from the bottom into the ring cooler. The cold air is heated when passing through the hot sintered ore layer and becomes high-temperature exhaust gas. The high-temperature exhaust gas can be introduced into the waste heat boiler to generate steam or hot water, thereby realizing energy reuse.

[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 is a direct relationship between the flue gas temperature and steam temperature of the waste heat boiler: the higher the flue gas temperature, the higher the steam temperature produced. At the same time, fluctuations in flue gas temperature will affect the key performance parameters of the waste heat boiler, such as evaporation capacity and exhaust gas temperature.

[0075] Furthermore, the steam production is controlled by reducing the water inlet to the boiler and 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 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 to ensure the normal water circulation in the entire waste heat boiler system. In a direct-flow waste heat boiler, the pressure head of the feed water pump turns the feed water into superheated steam through each heating surface once, and the flow of the working medium is also realized by the pressure head of the feed water pump.

[0077] The water pump is closely related to the steam production. The water pump provides sufficient pressure head to enable the feed water to effectively pass through the heating surface and become superheated steam. If the water pump stops due to power failure, it will affect the normal operation of the water cycle and thus affect the 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 flue gas of the annular cooler 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°C. The frequency of the measured flue gas temperature at the boiler inlet within one hour is between 380°C and 400°C 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 maximum. 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 only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining 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 of a sintering ring cooler, characterized in that: The following steps are involved: Step 1: Collect waste heat power generation related data at the inlet and outlet of the ring cooler and boiler, and set the optimization adjustment value; Step 2: Substitute the waste heat power generation related data into the calculation formula of power generation output power 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, in W; K1 / K2 are the current / optimized equipment equivalent efficiencies respectively; T1 / T2 are the current / optimized target temperature of the flue gas entering the boiler, in °C; T 10 / T 20 are the current / optimized target temperature of flue gas at the boiler outlet, in °C; T0 is the ambient temperature, in °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, in °C; ΔT g is the temperature difference between exhaust steam and environment, unit: °C; Q1 / Q2 are the current / optimized flue gas flow rates, in m 3 / h; is the enthalpy of exhaust steam, in kJ / kg; is the enthalpy of boiler inlet water, in kJ / kg; Step 3: In the environment of fresh air or non-hot air circulation, according to W1, W2 and actual use, 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, in °C; T0 is the ambient temperature, in °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 replace 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, 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 of a sintering ring cooler according to claim 1 is 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 of a sintering ring cooler according to claim 1, characterized in that: The optimization 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 of a sintering ring cooler according to claim 1, characterized in that: The when the flue gas temperature at the boiler inlet is low within a certain period of time specifically includes: when the frequency of the measured value of the 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 of 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 of a sintering ring cooler according to claim 5, characterized in that: The control of the flue gas temperature is to reduce the flue gas induced draft volume and increase the flue gas temperature by reducing the fan frequency and / or reducing the valve opening; to increase the flue gas induced draft volume and reduce the flue gas temperature by increasing the fan frequency and / or increasing the valve opening.

7. The method for optimizing waste heat power generation of 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 of 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 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 increasing the steam production by increasing the water pump frequency and / or increasing the valve opening.

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