阅读说明：本技术 一种垃圾发电用锅炉蒸汽量稳定方法 (Method for stabilizing steam quantity of boiler for garbage power generation ) 是由 祝志诚 俞波 缪吉 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种垃圾发电用锅炉蒸汽量稳定方法,包括以下步骤：第一步,根据主蒸汽流量与工艺设定值之间的差值通过负反馈方式控制进入焚烧炉的燃烧配比风的风量配比;第二步,根据炉排上的垃圾层厚调整炉排速度,使相应位置的燃烧压差值符合风量配比与燃烧压差值之间的经验函数关系;第三步,比较主蒸汽流量实测值与工艺设定值的差值,如果超出偏差范围,则返回第一步,如果在偏差范围内则进入下一步；第四步,检验烟气中含氧量是否在允许范围内,如有超出则重复上述第一步到第三步,如果在设定值的允许偏差范围内则维持状态不变。通过上述方法,本发明能够动态调整焚烧动作和垃圾层厚度,降低蒸发量波动,减少设备能耗,提高设备运行寿命。(The invention discloses a method for stabilizing steam quantity of a boiler for garbage power generation, which comprises the following steps: the method comprises the following steps of firstly, controlling the air volume ratio of combustion proportioning air entering an incinerator in a negative feedback mode according to the difference between the main steam flow and a process set value, secondly, adjusting the grate speed according to the thickness of a garbage layer on the grate to enable the combustion differential pressure value at the corresponding position to accord with the empirical function relationship between the air volume ratio and the combustion differential pressure value, thirdly, comparing the difference between the actual measured value of the main steam flow and the process set value, returning to the first step if the difference exceeds a deviation range, and entering the next step if the difference is within the deviation range; and fourthly, checking whether the oxygen content in the smoke is in an allowable range, repeating the first step to the third step if the oxygen content in the smoke is out of the allowable range, and keeping the state unchanged if the oxygen content in the smoke is in the allowable deviation range of the set value. By the method, the incineration action and the thickness of the garbage layer can be dynamically adjusted, the fluctuation of evaporation capacity is reduced, the energy consumption of equipment is reduced, and the service life of the equipment is prolonged.)

1. A method for stabilizing the steam volume of a boiler for garbage power generation is characterized by comprising the following steps of:

firstly, controlling the air quantity ratio of combustion ratio air entering a hearth of an incinerator in a negative feedback mode according to the difference value between the main steam flow and a process set value;

secondly, adjusting the speed of the fire grate according to the thickness of the garbage layer on the fire grate to enable the combustion pressure difference value of the corresponding position to accord with the empirical function relationship between the air volume ratio and the combustion pressure difference value;

thirdly, comparing the difference between the measured main steam flow and the process set value, if the difference exceeds the allowable deviation range of the process set value, returning to the first step again, and if the difference is within the allowable deviation range of the process set value, entering the next step;

and fourthly, checking whether the oxygen content in the smoke is within a set value allowable range, repeating the first step to the third step if the oxygen content in the smoke is beyond the set value, and keeping the state unchanged if the oxygen content in the smoke is within the set value allowable range.

2. The method for stabilizing the steam flow of the boiler for garbage power generation according to claim 1, wherein the oxygen content in the flue gas is 3% ~ 5%.

3. The steam volume stabilizing method for the boiler for garbage power generation as claimed in claim 1, wherein the air volume ratio of the combustion ratio air is controlled by a primary air fan and a secondary air fan, wherein the primary air fan is a main control and the secondary air fan is an auxiliary control.

4. The method for stabilizing steam flow in a boiler for garbage power according to claim 3, wherein when the amount of oxygen contained in the flue gas is insufficient, the amount of air supplied to the secondary fan is controlled preferentially to increase the amount of oxygen contained in the flue gas.

5. The steam flow stabilizing method for a boiler for garbage power as defined in claim 1, wherein the garbage incinerator is a three-stage incinerator, the hearth of the three-stage incinerator is divided into a first combustion section, a second combustion section, a third combustion section and a burnout section, wherein the first combustion section, the third combustion section and the burnout section are provided with differential pressure measuring points, adjustable baffles are provided between different combustion sections and burnout sections, and the baffles are provided with damper structures.

6. The steam flow stabilizing method for a boiler for garbage power generation according to claim 5, wherein the negative pressure pipes of the differential pressure measuring points are installed in the furnace above the grates of the first combustion section, the third combustion section and the burn-out section, and the positive pressure pipes are installed on the lower ash hoppers of the grates of the first combustion section, the third combustion section and the burn-out section.

7. The steam amount stabilizing method for a boiler for garbage power according to claim 5, wherein the opening degree of the damper of the third combustion stage is determined by a differential pressure value.

8. The method of stabilizing steam flow in a boiler for garbage power according to claim 1,

the method for acquiring the empirical function comprises the steps of firstly manually controlling the boiler to normally work for at least more than two months, then drawing a mapping curve between a combustion pressure difference value and an air volume ratio according to data of a plurality of groups of combustion ratio air volume and combustion pressure difference when the steam volume accords with a process set value, and determining the empirical function relationship between the combustion pressure difference value and the air volume ratio according to the mapping curve.

Technical Field

The invention relates to the field of garbage power generation, in particular to a method for stabilizing steam quantity of a boiler for garbage power generation.

Background

With the rapid development of global economy and the improvement of the living standard of substances, the garbage yield is increased day by day, and the pollution to the environment is also serious day by day. A large amount of municipal domestic waste continuously generated every day has become a social problem which pollutes the environment and influences the life. In order to reduce the influence of garbage on the environment, improve the comprehensive utilization level of resources and reduce waste, the garbage incineration power generation technology is rapidly developed in the world. The current common waste incineration power generation mode is that municipal solid waste is pretreated and then put into an incinerator as fuel for combustion, high-temperature flue gas generated after combustion enters a waste heat boiler as a heat exchange medium to push the boiler to heat and generate steam to push a steam turbine to generate power, in the process, the waste source is complex, so the unit heat value is unstable, the total amount and the temperature of the high-temperature flue gas generated in the combustion have certain fluctuation, the fluctuation is transmitted into the waste heat boiler to cause the fluctuation of the steam amount, the rotating speed of the steam turbine is enabled to be uneven, and the long-term accumulation can lead to the reduction of the service life of equipment.

Disclosure of Invention

The invention mainly solves the technical problem of providing a method for stabilizing the steam quantity of a boiler for garbage power generation, which can control the fluctuation of the steam quantity in the boiler, reduce energy consumption and prolong the service life of equipment.

In order to solve the technical problems, the invention adopts a technical scheme that: provided is a method for stabilizing the steam flow of a boiler for garbage power generation, which is characterized by comprising the following steps:

firstly, controlling the air quantity ratio of combustion ratio air entering an incinerator in a negative feedback mode according to the difference value between the main steam flow and a process set value;

secondly, adjusting the speed of the fire grate according to the thickness of the garbage layer on the fire grate to enable the combustion pressure difference value of the corresponding position to accord with the empirical function relationship between the air volume ratio and the combustion pressure difference value;

thirdly, comparing the difference between the measured main steam flow and the process set value, if the difference exceeds the allowable deviation range of the process set value, returning to the first step again, and if the difference is within the allowable deviation range of the process set value, entering the next step;

and fourthly, checking whether the oxygen content in the smoke is within a set value allowable range, repeating the first step to the third step if the oxygen content in the smoke is beyond the set value, and keeping the state unchanged if the oxygen content in the smoke is within the set value allowable range.

In a preferred embodiment of the present invention, the oxygen content in the flue gas is 3% ~ 5%.

In a preferred embodiment of the present invention, the air volume ratio of the combustion ratio air is controlled by a primary air blower and a secondary air blower in a matching manner, wherein the primary air blower is a main control air blower, and the secondary air blower is an auxiliary control air blower.

In a preferred embodiment of the present invention, when the oxygen content in the flue gas is insufficient, the air intake of the secondary air fan is preferentially controlled to increase the oxygen content in the flue gas.

In a preferred embodiment of the invention, the garbage incinerator is a three-section combustion furnace, a hearth of the three-section combustion furnace is divided into a first combustion section, a second combustion section, a third combustion section and an ember section, wherein differential pressure measuring points are distributed on the first combustion section, the third combustion section and the ember section, adjustable baffles are arranged among different combustion sections and ember sections, and a damper structure is arranged on each baffle.

In a preferred embodiment of the invention, the negative pressure pipe of the differential pressure measuring point is arranged in the hearth above the grates of the first combustion section, the third combustion section and the ember section, and the positive pressure pipe is arranged on the lower ash hoppers of the grates of the first combustion section, the third combustion section and the ember section.

In a preferred embodiment of the invention, the damper opening on the damper of the third combustion stage is determined by a differential pressure value.

In a preferred embodiment of the present invention, the method for obtaining the empirical function includes firstly manually controlling the boiler to normally operate for at least two months, then drawing a mapping curve between the combustion pressure difference value and the air volume ratio according to data of a plurality of groups of combustion ratio air volume and combustion pressure difference when the steam volume meets the process set value, and determining the empirical function relationship between the two according to the mapping curve.

The invention has the beneficial effects that: according to the technical scheme, the method is characterized in that a feedback cycle control mode of the evaporation capacity is obtained by analyzing disturbance factors of the total amount of boiler steam which pushes a steam turbine to rotate in the garbage power generation process, and the dynamic control of incineration action and garbage thickness can be realized by combining the conventional automatic control equipment according to the thought, so that the boiler evaporation capacity can be stably kept in a narrow fluctuation range, the energy loss is effectively reduced, and the operation life of the equipment is prolonged.

Detailed Description

The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention, and to clearly and unequivocally define the scope of the present invention.

The embodiment of the invention comprises the following steps:

a method for stabilizing steam quantity of a boiler for garbage power generation comprises the following steps:

the method comprises the steps of firstly, controlling the air volume ratio of combustion proportioning air entering a hearth of the garbage incinerator in a negative feedback mode according to the difference value between the main steam flow and a process set value, wherein the air volume ratio of the combustion proportioning air is controlled by a primary fan and a secondary fan in a matched mode, the primary fan is in a main control mode, the secondary fan is in an auxiliary control mode, the primary fan serves as the main fan and mainly acts on drying garbage and sending garbage fuel into the hearth, and the secondary fan mainly acts on inputting oxygen-enriched combustion air to enable the garbage to be fully combusted.

And secondly, adjusting the thickness of the garbage layer on a fire grate in a hearth of the garbage incinerator according to the air volume ratio of combustion ratio air to ensure that the combustion pressure difference value at the corresponding position meets the empirical function relationship between the air volume ratio and the combustion pressure difference value.

Wherein the furnace of burning furnace divide into three burning section and two after-combustion sections according to the combustion process, wherein first burning section, third burning section and after-combustion section have laid the differential pressure measurement station on one section, the negative pressure pipe position of differential pressure measurement station is on furnace upper portion, and the positive pressure pipe is laid in burning one section, the lower ash bucket department of burning three-section and after-combustion section to can reflect the bed of material height through the penetrability combustion pressure difference that passes the grate bed of material, set up adjustable baffle between different burning sections and the after-combustion section, set up the air door structure on the baffle. The pressure difference value of the first combustion section can be controlled by controlling the speed of an external stoker and a drying grate to control the quantity of garbage entering the furnace, the pressure difference value of the third combustion section can be controlled by the opening degree of a baffle air door to avoid the situation of space or too thick space at the middle and rear part of a material layer, the position of a combustion line can be controlled to prevent empty combustion, the value of the differential pressure of the burnout section can be controlled by controlling the running speed of the grate in a hearth, in addition, the evaporation quantity of steam can be finely adjusted by controlling the opening degree of the baffle air door of the second combustion section, and particularly the evaporation quantity is smaller than a set value; the evaporation amount is smaller than the set value.

And thirdly, comparing the measured value of the main steam flow with the process set value, returning to the first step again if the measured value is different from the process set value, and entering the next step if the measured value is within the process set value.

And fourthly, checking whether the oxygen content in the smoke is within a set value, repeating the first step to the third step if the oxygen content in the smoke is deviated, and keeping the state unchanged if the oxygen content in the smoke is within the set value.

The set value of the oxygen content in the flue gas is 4%, the oxygen content is too low, the oxygen CO content is increased, the combustion is insufficient, the oxygen content is too high, the temperature in the furnace is too high, the power of the fan is wasted, the flow rate of the flue gas is too large, when the oxygen content is insufficient, the air intake of the secondary fan is preferentially controlled to improve the oxygen content in the flue gas, on one hand, the influence of the secondary fan on the oxygen content is larger, on the other hand, the stirring of a stable system can be reduced, and the balance is favorably restored.

The first step of the boiler steam quantity stabilizing method for garbage power generation, which is to determine the air quantity ratio of the combustion proportioning air in a negative feedback mode according to the difference value between the main steam flow and the process set value, substantially means that the deviation between the main steam flow and the set value is utilized to directly control the size of the combustion proportioning air, so that the total heat value generated during combustion is kept stable, and the stability of the evaporation quantity is ensured. The principle is that in actual operation: to heat the feed water to superheated steam at a certain pressure and temperature, the flue gas in the furnace must have a certain total amount of heat exchange Q. Namely, ensuring Q = K smoke temperature and smoke flow. Wherein, flue gas flow accessible primary air fan control, flue gas temperature accessible overgrate air carries out certain control. Specifically, when the actual load is smaller than the target load, the primary fan is slowly started to increase the smoke flow, and the secondary fan is slowly started to increase the temperature in the furnace; when the actual load is larger than the target load, the primary fan is slowly reduced to reduce the smoke gas amount, and the secondary fan is slowly opened to reduce the temperature in the furnace.

The method for obtaining the empirical function in the second step of the boiler steam quantity stabilizing method for the garbage power generation comprises the steps of firstly manually controlling the boiler to normally work for three months, then fitting a mapping curve and calculating the empirical function by using a computer according to data of the opening degree of a fan and the combustion pressure difference when 1000 groups of steam quantity accord with a process set value, then using the opening degree of the fan as an X value and the combustion pressure difference value as a Y value, and determining the relevant values between the combustion pressure difference and the opening degree of the fan under other working conditions through the empirical function so as to avoid the influence of the inaccurate air quantity measuring point on the control precision.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.