阅读说明：本技术 一种直接空冷机组最佳背压调节方法 (Optimal back pressure adjusting method for direct air cooling unit ) 是由 曹超 杨文飞 于 2021-07-15 设计创作，主要内容包括：本发明公开了一种直接空冷机组最佳背压调节方法,属于空冷发电技术领域,调整空冷机组运行工况,确保汽机进汽参数和阀位维持稳定；通过改变背压使得机组功率发生变化,得到背压对机组出力的影响关系；通过改变空冷风机运行频率,得到不同风机频率下,风机能耗与风机频率的关系；在机组负荷和环境温度不变的情况下,通过改变空冷风机运行频率使得机组背压发生变化,得到空冷风机运行频率对背压的影响关系。本发明,能够得到机组在不同的环境条件下的最佳运行背压,提高机组的运行经济性；另一方面,通过风机差异化调节的方式使得机组在同一背压下风机耗电更少,降低直接空冷机组的厂用电率。(The invention discloses an optimal back pressure adjusting method for a direct air cooling unit, which belongs to the technical field of air cooling power generation, and is used for adjusting the operation condition of the air cooling unit and ensuring that steam inlet parameters and a valve position of a steam turbine are kept stable; the power of the unit is changed by changing the backpressure, so that the influence relation of the backpressure on the output of the unit is obtained; obtaining the relation between the fan energy consumption and the fan frequency under different fan frequencies by changing the operation frequency of the air cooling fan; under the condition that the load of the unit and the ambient temperature are not changed, the operating frequency of the air cooling fan is changed to change the backpressure of the unit, and the influence relation of the operating frequency of the air cooling fan on the backpressure is obtained. According to the invention, the optimal running backpressure of the unit under different environmental conditions can be obtained, and the running economy of the unit is improved; on the other hand, the blower power consumption of the unit is less under the same backpressure through the blower differential adjustment mode, and the plant power consumption rate of the direct air cooling unit is reduced.)

1. The optimal back pressure adjusting method for the direct air cooling unit is characterized by comprising the following steps of:

step 1, adjusting the operation condition of an air cooling unit to ensure that steam inlet parameters and valve positions of a steam turbine are kept stable;

step 2, changing the back pressure to change the power of the unit to obtain the influence relation of the back pressure on the output of the unit;

step 3, obtaining the relation between the fan energy consumption and the fan frequency under different fan frequencies by changing the operation frequency of the air cooling fan;

step 4, under the condition that the unit load and the ambient temperature are not changed, the operating frequency of the air cooling fan is changed to change the unit backpressure, so that the influence relation of the operating frequency of the air cooling fan on the backpressure is obtained;

step 5, testing the curve functions of 'fan frequency-power consumption' and 'back pressure-fan frequency' obtained by the tests in the step 2 and the step 3 in different environments;

step 6, finally determining the optimal operating back pressure of different loops of the air cooling system under different load working conditions through function curves of back pressure-power, back pressure-fan frequency and fan frequency-fan power consumption under specific load and specific environment temperature;

step 7, obtaining an optimal back pressure curve function of random group load and environmental temperature change through curve fitting according to the optimal back pressure of the unit under a specific working condition;

step 8, under different environments, an unmanned aerial vehicle is used for carrying an infrared thermal imager to measure the temperature, and air cooling temperature fields of different rows and the same row of different units under the same backpressure under the condition of a certain load and a certain environment are obtained in a wireless communication mode;

and 9, comparing according to the specific experimental data from the step 1 to the step 8 to obtain a conclusion.

2. The method for adjusting the optimal back pressure of the direct air cooling unit according to claim 1, wherein the evaluation values of the operation of the cooling fan in the step 3 are respectively 15Hz, 20Hz, 25Hz, 30Hz, 35Hz, 40Hz, 45Hz and 50 Hz.

3. The method for adjusting the optimal back pressure of the direct air cooling unit according to claim 1, wherein in the step 4, the fan frequency is changed according to 15Hz, 20Hz, 25Hz, 30Hz, 35Hz, 40Hz, 45Hz and 50Hz, and a relation curve of the full operation condition of the air cooling fan to the back pressure is fitted through correction.

4. The method for adjusting the optimal backpressure of the direct air cooling unit as claimed in claim 1, wherein the ambient temperature in step 5 is set to six working conditions of 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃ and 30 ℃.

5. The method for adjusting the optimal back pressure of the direct air cooling unit according to claim 1, wherein in step 8, the frequency of some fans is reduced on the premise that the back pressure of the unit is not changed through the differential control of the fans, so that the effect of saving the service power is achieved.

6. The method for adjusting the optimal back pressure of the direct air cooling unit according to claim 1, wherein the temperature measurement is performed by an unmanned aerial vehicle at 6kPa, 11kPa, 16kPa, 21kPa, 26kPa and 31kPa in step 8.

7. The method for adjusting the optimal back pressure of the direct air cooling unit according to claim 1, wherein the optimal back pressure curve of the direct air cooling unit, which is changed with the load and the environmental condition, is obtained according to different loads of different environmental conditions and is set into DCS.

Technical Field

The invention relates to the technical field of air cooling power generation, in particular to an optimal back pressure adjusting method for a direct air cooling unit.

Background

In order to develop the power industry, most power plants use direct air cooling technology as a cooling scheme. The direct air cooling unit compares traditional wet cooling unit water economy resource, but owing to with fan forced draft cooling, consequently can lead to the station service to use the electricity far above wet cooling unit. The direct air cooling unit is greatly influenced by the environment, the influence of different wind directions, wind speeds and wind temperatures on fans of different units is different, and the influence of environmental change on the back pressure is more sensitive to the windward side than the back pressure side. For operators, in order to operate safely, the backpressure of the unit is generally controlled to be higher, and for convenience, the operators in summer and autumn only control the backpressure of the unit to be a certain higher value in a mode of operating the fan group in a blind manner, which is not favorable for economic operation of the unit: the group is operated the fan and has been increased the power consumption rate on the one hand, and on the other hand, blind setting backpressure is a certain value, may be higher than the minimum that it can reach in fact, and high back pressure unit economic nature is relatively poor.

Therefore, an optimal back pressure adjusting method for the direct air cooling unit is provided.

Disclosure of Invention

The invention aims to solve the problem that operators blindly set the backpressure as a value, which is unfavorable for economic operation of a unit; in order to achieve the backpressure value, the operation mode is that a plurality of fans are operated simultaneously, and the problem of influence of environmental wind at different positions on the fans is not considered, so that the optimal backpressure adjusting method for the direct air cooling unit is provided.

In order to achieve the purpose, the invention adopts the following technical scheme:

an optimal back pressure adjusting method for a direct air cooling unit comprises the following steps:

step 1, adjusting the operation condition of an air cooling unit to ensure that steam inlet parameters and valve positions of a steam turbine are kept stable;

step 2, changing the back pressure to change the power of the unit to obtain the influence relation of the back pressure on the output of the unit;

step 3, obtaining the relation between the fan energy consumption and the fan frequency under different fan frequencies by changing the operation frequency of the air cooling fan;

step 4, under the condition that the unit load and the ambient temperature are not changed, the operating frequency of the air cooling fan is changed to change the unit backpressure, so that the influence relation of the operating frequency of the air cooling fan on the backpressure is obtained;

step 5, testing the curve functions of 'fan frequency-power consumption' and 'back pressure-fan frequency' obtained by the tests in the step 2 and the step 3 in different environments;

step 6, finally determining the optimal operating back pressure of different loops of the air cooling system under different load working conditions through function curves of back pressure-power, back pressure-fan frequency and fan frequency-fan power consumption under specific load and specific environment temperature;

step 7, obtaining an optimal back pressure curve function of random group load and environmental temperature change through curve fitting according to the optimal back pressure of the unit under a specific working condition;

step 8, under different environments, an unmanned aerial vehicle is used for carrying an infrared thermal imager to measure the temperature, and air cooling temperature fields of different rows and the same row of different units under the same backpressure under the condition of a certain load and a certain environment are obtained in a wireless communication mode;

and 9, comparing according to the specific experimental data from the step 1 to the step 8 to obtain a conclusion.

Preferably, the evaluation values of the operation of the cooling fan in the step 3 are respectively 15Hz, 20Hz, 25Hz, 30Hz, 35Hz, 40Hz, 45Hz and 50 Hz.

Preferably, in the step 4, the fan frequency is changed according to 15Hz, 20Hz, 25Hz, 30Hz, 35Hz, 40Hz, 45Hz and 50Hz, and the relationship curve of the full operation condition of the air cooling fan to the back pressure is fitted through correction.

Preferably, the environmental temperature in step 5 is set to six working conditions of 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃ and 30 ℃ respectively.

Preferably, in the step 8, the frequency of some fans is reduced on the premise that the backpressure of the unit is not changed through the differential control of the fans, so that the effect of saving the service power is achieved.

Preferably, the temperature measurements are made with the drone at 6kPa, 11kPa, 16kPa, 21kPa, 26kPa, 31kPa in step 8.

Preferably, the optimal back pressure curve of the unit, which is changed along with the load and the environmental condition, is obtained according to different loads of different environmental conditions and is set into the DCS.

Compared with the prior art, the invention provides an optimal backpressure adjusting method for a direct air cooling unit, which has the following beneficial effects:

1. the backpressure of the air-cooled power plant is reduced, the plant power consumption rate of the direct air-cooled power plant is reduced, and the operation economy of the direct air-cooled power plant is improved;

2. aiming at different environmental conditions and different loads, obtaining a unit optimal backpressure curve which changes along with the load and the environmental conditions, setting the curve into a DCS, and realizing the automatic operation of optimal backpressure on the premise of no intervention of operating personnel in a thermal automatic mode; the mode that the later stage passed through unmanned aerial vehicle scanning obtains air cooling island temperature field distribution, utilizes automatic operation to realize under the unchangeable prerequisite of backpressure, reduces the operating frequency of some fans to reduce the comprehensive station service power consumption rate of direct air cooling unit.

Drawings

FIG. 1 is a basic remote diagram of an optimal backpressure regulating method for a direct air cooling unit according to the present invention;

FIG. 2 is a schematic diagram showing the relationship between the fan frequency and the fan power consumption in the optimal backpressure regulating method for the direct air cooling unit according to the present invention;

fig. 3 is a schematic diagram illustrating a relationship between a fan frequency and a back pressure in an optimal back pressure adjusting method for a direct air cooling unit according to the present invention;

fig. 4 is a schematic diagram illustrating a relationship between back pressure and power variation values in an optimal back pressure adjusting method for a direct air cooling unit according to the present invention;

fig. 5 is a schematic diagram illustrating a relationship between loads and an optimal back pressure at different ambient temperatures in the method for adjusting the optimal back pressure of the direct air cooling unit according to the present invention;

fig. 6 is a diagram illustrating the influence of the fan frequency on the load and the fan power consumption under different temperatures under the 50% THA working condition in the optimal backpressure regulating method for the direct air cooling unit provided by the invention;

fig. 7 shows the influence of the fan frequency on the load and the fan power consumption under different temperatures under 75% THA working condition in the optimal backpressure regulating method for the direct air cooling unit provided by the invention;

fig. 8 shows the influence of the fan frequency on the load and the fan power consumption under different temperatures in the 75% THA working condition in the optimal backpressure regulating method for the direct air cooling unit provided by the invention;

fig. 9 is a table diagram of the optimization test results of the air-cooling fan in the optimal backpressure adjusting method for the direct air-cooling unit according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

Referring to fig. 1, an optimal back pressure adjusting method for a direct air cooling unit includes:

and the operation condition of the air cooling unit is adjusted to ensure that the steam inlet parameters and the valve position of the steam turbine are maintained stable. The power of the unit is changed by changing the backpressure, and the influence relation of the backpressure on the output of the unit is obtained. The back pressure changes to + -1 kPa, + -2 kPa, + -3 kPa.

Furthermore, the relation between the fan energy consumption and the fan frequency under different fan frequencies (15Hz, 20Hz, 25Hz, 30Hz, 35Hz, 40Hz, 45Hz and 50Hz) is obtained by changing the running frequency of the air cooling fan.

Furthermore, under the condition that the unit load and the ambient temperature are not changed, the unit backpressure is changed by changing the operation frequency of the air cooling fan, and the influence relation of the operation frequency of the air cooling fan on the backpressure is obtained. The frequency of the fan is changed according to 15Hz, 20Hz, 25Hz, 30Hz, 35Hz, 40Hz, 45Hz and 50Hz, and the relationship curve of the air cooling fan full operation working condition to the back pressure is fitted through correction.

Furthermore, the test is carried out on the curve functions of 'fan frequency-power consumption' and 'back pressure-fan frequency' obtained by the test at different environmental temperatures, wherein the environmental temperatures are respectively determined as six groups of working conditions of 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃ and 30 ℃.

Furthermore, the optimal operation back pressure of different loops of the air cooling system under different load working conditions is finally determined through function curves of the back pressure-power, the back pressure-fan frequency and the fan frequency-fan power consumption under specific load and specific environment temperature.

Furthermore, according to the optimal back pressure of the unit under the specific working condition, an optimal back pressure curve function of random unit load and environmental temperature change is obtained through curve fitting, the target value (optimal back pressure) of the exhaust pressure of the air cooling fan of the unit is automatically changed by utilizing thermal control automatic adjustment, and the air cooling fan is ensured to be in the most economic operation frequency.

Further, an unmanned aerial vehicle is used for carrying an infrared thermal imager to measure a temperature field under 6kPa, 11kPa, 16kPa, 21kPa, 26kPa and 31kPa, air cooling temperature fields of different units in different rows and the same row under the same backpressure under a certain load and a certain environmental condition are obtained in a wireless communication mode, the frequency of certain fans is reduced on the premise that the backpressure of the unit is not changed through the differential control of the fans, the effect of saving station power is achieved, and the economical efficiency of unit operation is improved

Further, the optimal backpressure regulation optimization test is carried out on the large and Tang cloisonne power plant, and two groups of data are acquired under the working conditions of 100% load and 50% load (the unit is always loaded):

1. because the change of the ambient wind of the unit is large, the influence is ignored, and the optimal fan running frequency is calculated only from two aspects of temperature and load. 2. The influence relation of the backpressure of the unit on the load is calculated by software, and the electric quantity of a frequency converter of the fan is read by the power consumption of the fan. 3. And (3) extrapolating the maximum value of the difference between the influence of the backpressure of the unit on the power and the power consumption of the fan under different environmental temperature conditions under the working conditions of 50%, 75% and 100% of loads by using the data measured by the test.

In the invention, when the unit is under 50% load and the temperature range is between 5 and 15 ℃, the frequency is improved as much as possible on the premise of ensuring safety, so that the backpressure of the unit is close to the blocking backpressure, and the economical efficiency is best; 2. when the temperature range is 15-30 ℃, the fan frequency is kept at about 40Hz, and the economical efficiency is the best. 3. When the unit is 75% loaded and the temperature range is 5-15 ℃, the frequency is improved as much as possible on the premise of ensuring safety, so that the back pressure of the unit is close to the blocking back pressure, and the economy is best; 4. when the temperature range is 15-25 ℃, the fan frequency is kept at about 40Hz, and the economical efficiency is the best; after ambient temperatures exceed 30 ℃, the best economy can be achieved with overfrequency operation. 5. When the load of the unit is 100%, the temperature range is 5-30 ℃, the optimum unit operation backpressure can be obtained only by the overclocking operation, the economy is the best, and when the temperature is higher, the unit backpressure is reduced by adopting a peak spraying mode, so that the load limitation of the unit is prevented.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention and the equivalent alternatives or modifications according to the technical solution and the inventive concept of the present invention within the technical scope of the present invention.