阅读说明：本技术 一种径流式水电站前池水位调平方法及系统 (Method and system for leveling front pool water level of radial flow type hydropower station ) 是由 马跃先 邓旭 王朋 郭峰 郭洋洋 刘纪轩 于 2020-07-22 设计创作，主要内容包括：本发明提出了一种径流式水电站前池水位调平方法及系统,可以根据前池水位变化,进行水位控制点的触发,在触发水位控制点后,可以根据水电站的工程布置情况,计算其水量变化,继而根据机组运行现状和机组的运行效率,计算不同水量对应的机组效率变化情况,实现机组负荷与变化流量的最佳匹配。(The invention provides a method and a system for leveling a front pool water level of a radial-flow type hydropower station, which can trigger a water level control point according to the water level change of the front pool, calculate the water quantity change of the hydropower station according to the engineering arrangement condition of the hydropower station after triggering the water level control point, and then calculate the unit efficiency change condition corresponding to different water quantities according to the unit operation current situation and the unit operation efficiency so as to realize the optimal matching of the unit load and the change flow.)

1. A water level leveling method for a front pool of a radial-flow type hydropower station comprises a pressure front pool, wherein a water level monitoring device is arranged on the pressure front pool, and the method is characterized in that: the method comprises the following steps:

s1: calculating a flow-output curve of each unit: analyzing each unit independently, determining the water level of a forebay to be a normal high water level, sequencing the units according to a sequence of flow from small to large according to the unit operation characteristic curve of a water turbine, calculating the water diversion loss of the unit corresponding to different flow rates and the tail water level corresponding to different flow rates according to the pipeline arrangement, calculating the operation water head of the unit according to the determined forebay water level, calculating the efficiency corresponding to the unit according to the operation water head and the flow rate, and calculating the corresponding output value under the flow rate to obtain the flow rate-output curve corresponding to each unit;

s2: when the current pool water level triggers the water level control point, the water level adjustment is carried out, the water level adjustment specifically comprises the following steps:

s21: acquiring a water level at a trigger moment and a front pool water level before a certain time period, respectively calculating a front pool water level reservoir capacity difference value corresponding to the two water level difference values, and dividing the front pool water level reservoir capacity difference value by the time period to obtain a calculated flow; if the water level rises, the calculated flow is a positive value, and if the water level falls, the calculated flow is a negative value;

s22: the method comprises the following steps of taking a flow-output curve of a starting unit, determining the current power generation flow of the starting unit according to the current output, and performing trial calculation on each unit, wherein the trial calculation method comprises the following steps: acquiring the current generating flow of each set, sequentially superposing the generating flow of each set to calculate the flow, sequentially acquiring the assumed generating flow of each set, respectively calling the flow-output curve according to the assumed generating flow of each set to obtain the assumed output of each set, selecting the set with the maximum assumed output as an adjusting set, and adjusting the output to the assumed output of the set;

s3: when the current pool water level does not trigger the water level control point, no adjustment is performed.

2. The method of leveling the front pool water level of a radial flow type hydropower station according to claim 1, wherein: and in the step S1, when the unit output is calculated according to the flow, if the unit output is greater than the unit limit output, the unit output is taken as the unit limit output.

3. The method of leveling the front pool water level of a radial flow type hydropower station according to claim 2, wherein: the unit limit output may be a rated installation.

4. The method of leveling the front pool water level of a radial flow type hydropower station according to claim 2, wherein: the unit limit output is the number which is obtained by multiplying the rated installation by the over-expansion coefficient, and the over-expansion coefficient is more than 1.

5. The method of leveling the front pool water level of a radial flow type hydropower station according to claim 1, wherein: the water level control points may be selected as a maximum water level and a minimum water level for operation of the forebay.

6. A leveling system applying the method for leveling the front pool water level of the radial flow type hydropower station according to any one of claims 1 to 5, wherein the method comprises the following steps: the leveling system comprises a water level monitoring module and a leveling module, wherein the water level monitoring module is used for monitoring the water level of the forebay, and the leveling module is used for controlling the unit to adjust the load when the monitored water level of the forebay triggers a water level control point.

Technical Field

The invention relates to water conservancy projects, in particular to a method and a system for leveling the front pool water level of a radial flow type hydropower station.

Background

The runoff type hydropower station cannot effectively adjust the incoming flow, the pressure of the incoming flow is usually stabilized through a pressure forebay, the level of the water level of the forebay has obvious influence on the power generation benefit, generally, the higher the water level of the forebay is, the larger the power generation head is, the more obvious the power generation benefit is, and for the water level of the forebay, the repeated fluctuation change also influences the operation stability of a unit, so that a corresponding method needs to be established to stabilize the water level of the forebay of the runoff type hydropower station, namely, the leveling of the water level of the forebay is realized.

The water level change of the pressure forebay can reflect the change of the incoming flow, but the current water level leveling of the pressure forebay is judged by depending on the water level, the judgment can not effectively realize the leveling of the forebay water level, and the repeated adjustment is easy to trigger; when the load of the unit is adjusted according to the front pool water level, a centralized or even distribution mode of a certain unit is also adopted, the distribution mode does not consider the current running situation of the unit and the running efficiency of the unit, and has certain limitation, namely the front pool water level leveling and the efficient matching of the unit and the water quantity cannot be realized.

Disclosure of Invention

Based on the above, the invention provides a method for leveling the water level of a front pool of a radial flow type hydropower station, wherein the radial flow type hydropower station comprises a pressure front pool, a water level monitoring device is arranged on the pressure front pool, and the method is characterized in that: the method comprises the following steps:

s1: calculating a flow-output curve of each unit: analyzing each unit independently, determining the water level of a forebay to be a normal high water level, sequencing the units according to a sequence of flow from small to large according to the unit operation characteristic curve of a water turbine, calculating the water diversion loss of the unit corresponding to different flow rates and the tail water level corresponding to different flow rates according to the pipeline arrangement, calculating the operation water head of the unit according to the determined forebay water level, calculating the efficiency corresponding to the unit according to the operation water head and the flow rate, and calculating the corresponding output value under the flow rate to obtain the flow rate-output curve corresponding to each unit;

s2: when the current pool water level triggers the water level control point, the water level adjustment is carried out, the water level adjustment specifically comprises the following steps:

s21: acquiring a water level at a trigger moment and a front pool water level before a certain time period, respectively calculating a front pool water level reservoir capacity difference value corresponding to the two water level difference values, and dividing the front pool water level reservoir capacity difference value by the time period to obtain a calculated flow; if the water level rises, the calculated flow is a positive value, and if the water level falls, the calculated flow is a negative value;

s22: the method comprises the following steps of taking a flow-output curve of a starting unit, determining the current power generation flow of the starting unit according to the current output, and performing trial calculation on each unit, wherein the trial calculation method comprises the following steps: acquiring the current generating flow of each set, sequentially superposing the generating flow of each set to calculate the flow, sequentially acquiring the assumed generating flow of each set, respectively calling the flow-output curve according to the assumed generating flow of each set to obtain the assumed output of each set, selecting the set with the maximum assumed output as an adjusting set, and adjusting the output to the assumed output of the set;

s3: when the current pool water level does not trigger the water level control point, no adjustment is performed.

Preferably, when the unit output is calculated according to the flow in step S1, if the unit output is greater than the unit limit output, the unit output is taken as the unit limit output.

Preferably, the unit limit output is a rated installation.

Preferably, the unit limit output is a number which is obtained by multiplying a rated installation machine by an over-expansion coefficient, wherein the over-expansion coefficient is greater than 1.

Preferably, the water level control points may be selected as a highest water level and a lowest water level of the operation of the forebay.

A leveling system applying the method for leveling the water level of the front pool of the radial flow type hydropower station is characterized in that: the leveling system comprises a water level monitoring module and a leveling module, wherein the water level monitoring module is used for monitoring the water level of the forebay, and the leveling module is used for controlling the unit to adjust the load when the monitored water level of the forebay triggers a water level control point.

The principle of the invention is as follows:

the monitored front pool water level is used as a reaction amount, and water level adjustment is carried out when a water level control point is triggered according to the change of the front pool water level, wherein the water level adjustment method is to adjust the load of a unit, and the leveling of the front pool water level is realized by changing the water consumption of the unit; when the load of the unit is adjusted, the relationship between the operating efficiency and the flow of the unit is considered, the load adjustment value of the unit is reasonably determined, and then the optimal matching of the load and the flow of the unit is realized.

The invention has the advantages that:

the invention provides a method and a system for leveling a front pool water level of a radial-flow type hydropower station, which can trigger a water level control point according to the water level change of the front pool, calculate the water quantity change of the hydropower station according to the engineering arrangement condition of the hydropower station after triggering the water level control point, and then calculate the unit efficiency change condition corresponding to different water quantities according to the unit operation current situation and the unit operation efficiency so as to realize the optimal matching of the unit load and the change flow.

The specific implementation mode is as follows: the structure defined in the present invention will be explained in detail with reference to the embodiments.

The invention provides a method for leveling the water level of a front pool of a radial-flow type hydropower station, wherein the radial-flow type hydropower station comprises a pressure front pool, a water level monitoring device is arranged on the pressure front pool, and the method is characterized in that: the method comprises the following steps:

s1: calculating a flow-output curve of each unit: analyzing each unit independently, determining the water level of a forebay to be a normal high water level, sequencing the units according to a sequence of flow from small to large according to the unit operation characteristic curve of a water turbine, calculating the water diversion loss of the unit corresponding to different flow rates and the tail water level corresponding to different flow rates according to the pipeline arrangement, calculating the operation water head of the unit according to the determined forebay water level, calculating the efficiency corresponding to the unit according to the operation water head and the flow rate, and calculating the corresponding output value under the flow rate to obtain the flow rate-output curve corresponding to each unit;

s2: when the current pool water level triggers the water level control point, the water level adjustment is carried out, the water level adjustment specifically comprises the following steps:

s21: acquiring a water level at a trigger moment and a front pool water level before a certain time period, respectively calculating a front pool water level reservoir capacity difference value corresponding to the two water level difference values, and dividing the front pool water level reservoir capacity difference value by the time period to obtain a calculated flow; if the water level rises, the calculated flow is a positive value, and if the water level falls, the calculated flow is a negative value;

s22: the method comprises the following steps of taking a flow-output curve of a starting unit, determining the current power generation flow of the starting unit according to the current output, and performing trial calculation on each unit, wherein the trial calculation method comprises the following steps: acquiring the current generating flow of each set, sequentially superposing the generating flow of each set to calculate the flow, sequentially acquiring the assumed generating flow of each set, respectively calling the flow-output curve according to the assumed generating flow of each set to obtain the assumed output of each set, selecting the set with the maximum assumed output as an adjusting set, and adjusting the output to the assumed output of the set;

s3: when the current pool water level does not trigger the water level control point, no adjustment is performed.

Preferably, when the unit output is calculated according to the flow in step S1, if the unit output is greater than the unit limit output, the unit output is taken as the unit limit output.

Preferably, the unit limit output is a rated installation.

Preferably, the unit limit output is a number which is obtained by multiplying a rated installation machine by an over-expansion coefficient, wherein the over-expansion coefficient is greater than 1.

Preferably, the water level control points may be selected as a highest water level and a lowest water level of the operation of the forebay.

A leveling system applying the method for leveling the water level of the front pool of the radial flow type hydropower station is characterized in that: the leveling system comprises a water level monitoring module and a leveling module, wherein the water level monitoring module is used for monitoring the water level of the forebay, and the leveling module is used for controlling the unit to adjust the load when the monitored water level of the forebay triggers a water level control point.

When the quoted flow is calculated reversely according to the output, the output value can be calculated according to different flow combinations, when the calculation is carried out, the generating head is calculated according to the forebay water level, the diversion pipeline diversion loss corresponding to different flows and the tail water level, the operation efficiency is calculated by combining with the unit operation efficiency curve, then the output value is obtained, and the flow value is obtained by searching and reversely calculating according to the output value.

The above-described embodiments are only preferred embodiments of the present invention, and the scope of the present invention should not be construed as being limited to the specific forms set forth in the examples, but also includes equivalent technical means which can be conceived by those skilled in the art from the present inventive concept.