An operating method using ecological flow

Abstract

The present invention provides an operation method using ecological flow. The power station is a reservoir power station, and the tail water of the reservoir power station is discharged into the downstream river. A barrage is built in the downstream river, and the barrage is connected to the diversion channel and the regulating gate respectively. The regulating gate automatically adjusts the gate opening to achieve the discharge of ecological flow. By collecting the reservoir water level value, the river water level at the barrage, and the output of the hydropower station units in real time, the power generation water volume and ecological satisfaction degree of the hydropower station are calculated, and signals are given according to the ecological satisfaction degree to guide the reasonable operation of the reservoir hydropower station and meet the requirements of ecological flow.

Description

Technical Field

[0001] The present invention relates to the field of water conservancy projects, and particularly to an operation method using ecological flow. Background Art

[0002] A reservoir hydropower station is a power station structure built to utilize the regulating performance of a reservoir. Generally, a reservoir hydropower station is a comprehensive utilization hydropower station. In addition to undertaking the power generation task, it generally also undertakes the functions of irrigation, water supply, and ecological improvement of the downstream river. In order to maximize the efficient utilization of water energy, the water volumes for irrigation, water supply, and ecological improvement generally pass through the hydropower station first, and the power generation tail water then passes through diversion structures or gates to meet specific functional requirements.

[0003] Ecological flow is the flow value that meets the ecological requirements of a river. In order to ensure that the river does not dry up and maintain ecological balance, an ecological flow value generally needs to be set. The river channel needs to continuously discharge ecological flow. This flow value is generally small, while the installed capacity of the power station units is large, and the flow for the power station to start and operate is greater than the ecological flow. Discharging the flow directly from the power station cannot meet the requirements. Installing ecological units is costly, and some reservoir power stations did not consider ecological units during the planning and do not have the conditions for installation. If the ecological flow is not discharged through the power station directly, it will cause this part of the flow not to be converted into electrical energy by the power station, resulting in energy waste. Summary of the Invention

[0004] In view of the problems of the prior art, the present invention provides an operation method using ecological flow to improve the utilization efficiency of ecological flow.

[0005] The present invention provides an operation method using ecological flow, which is applicable to a hydropower station. The hydropower station is a reservoir-type hydropower station. A reservoir is built upstream of the hydropower station. The reservoir stores the upstream incoming water through a dam. The water turbine generator set of the hydropower station is connected to the reservoir through a water diversion pipeline. The water turbine generator set of the hydropower station is connected to a tail water system, and the tail water system is connected to the river channel downstream of the dam. It is characterized in that: a river dam is built in the downstream river channel at a certain distance from the hydropower station. The river dam cuts off the river channel. The downstream river channel between the river dam and the dam forms the impounding storage capacity of the river dam. An irrigation canal is built on one side of the river dam to provide the required irrigation water volume. An irrigation gate is arranged at the head of the irrigation canal to control the irrigation water volume of the irrigation canal. An ecological flow regulation gate is built on one side of the river dam. The regulation gate is provided with a gate automatic control system to adjust the opening of the regulation gate. An ecological flow requirement Q1 is set at the river dam. A reservoir water level monitoring device is built on the reservoir. A river channel water level monitoring device of the downstream river channel is arranged at the river dam. The hydropower station is provided with a water turbine generator set output monitoring device. The operation method is applicable to the situation where there is no requirement for the irrigation water volume of the irrigation canal, and the reservoir hydropower station only meets the ecological flow requirement of the downstream river channel. The gate automatic control system is connected to the river channel water level monitoring device to obtain the river channel water level at the river dam. The gate automatic control system can automatically adjust the opening of the regulation gate according to the river channel water level at the river dam, so that the discharge flow of the regulation gate is equal to the ecological flow requirement Q1. The operation method includes the following steps:

[0006] S1: Calculate the daily ecological water requirement W1 at the river dam. The daily ecological water requirement W1 is equal to the ecological flow requirement Q1 multiplied by the time period number of 1 day;

[0007] S2: The hydropower station starts the unit with the minimum installed capacity to the set output. Use the reservoir water level monitoring device to obtain the real-time reservoir water level H1. Use the water turbine generator set output monitoring device to monitor the unit output N1 in real time. Use the river channel water level monitoring device to monitor the river channel water level H22 at the river dam. According to the river channel water level H22 at the river dam, calculate the real-time tail water level H1 of the hydropower station by combining the downstream river channel between the dam and the river dam. According to the real-time reservoir water level H1, the real-time unit output N1 and the real-time tail water level H1, combine the head loss of the water diversion system and the operation efficiency curve of the water turbine generator set to calculate the real-time power generation flow Q2 of the hydropower station, and calculate the power generation water volume W2 up to the current moment on the day. The power generation water volume W2 is equal to the sum of the real-time power generation flows Q2 in each time period multiplied by the corresponding time periods during the operation of the hydropower station. The time up to the current moment on the day is from 0:00 on the day to the calculation time;

[0008] S3: Calculate the ecological satisfaction degree P in real time, where the ecological satisfaction degree P is equal to the power generation water volume W2 divided by the daily ecological water volume requirement W1 at the dam;

[0009] S4: When the ecological satisfaction degree P is greater than or equal to 1, give a signal that the ecological flow has met the requirements; when the ecological satisfaction degree P is less than 1, give a signal that the ecological flow does not meet the requirements;

[0010] S5: The set time of a day is from 0:00 to 24:00 every day. At 0:00 every day, perform the calculation in step S1, clear the power generation water volume W2 in step S2, and then perform steps S2 - S4.

[0011] Preferably, the ecological flow requirement Q1 is 10% of the average annual runoff flow of the river channel at the dam.

[0012] Preferably, the calculation method of the real-time tail water level H1 of the hydropower station is as follows: According to the backwater calculation of the dam, combined with the structural form of the downstream river channel, calculate the real-time tail water level of the hydropower station, or determine the correlation between the tail water level of the hydropower station and the river channel water level at the dam according to the test data, and then use this correlation to calculate the real-time tail water level of the hydropower station based on the river channel water level at the dam.

[0013] Preferably, the set output is the rated installed capacity or 90% of the rated installed capacity.

[0014] Preferably, the calculation method of the real-time power generation flow Q2 of the hydropower station is as follows: According to the reservoir water level and the tail water level, set different flows, then calculate the diversion loss according to the flow in combination with the pipeline layout to obtain the net head of the unit, and then according to the net head and the flow, obtain the operating efficiency of the unit, and then obtain the output value of the unit, and find the flow value closest to the measured output value, which is the real-time power generation flow Q2 of the hydropower station.

[0015] Preferably, the calculation method of the real-time power generation flow Q2 of the hydropower station is as follows: Conduct unit operation tests to obtain the relationship between the unit output and the flow under different reservoir water levels and different tail water levels, and then according to the relationship between the unit output and the flow, combined with different reservoir water levels and tail water levels, obtain the power generation flow corresponding to the unit output.

[0016] The working principle of the present invention is as follows:

[0017] The nature of the reservoir in the present invention is that the reservoir is a water supply reservoir that takes into account the ecological flow requirements, that is, when the reservoir is in operation, water supply scheduling is considered, such as agricultural irrigation water supply or domestic and industrial water supply, etc. The hydropower station is operated in combination with the above water supply requirements, while taking into account the ecological environment requirements of the river. The difference is that all water requirements of the reservoir first pass through the hydropower station, and the tail water of the hydropower station enters the downstream river. A dam is built in the downstream river, and the dam and the dam form the interception and storage capacity of the dam. The water requirements of all reservoirs, such as irrigation, water supply, ecology, etc., are met through the interception and storage capacity, among which the non-ecological flow requirements such as irrigation and water supply are met through the water diversion channel, and the ecological water is met through the regulating gate. The dam is provided with an overflow device, a sand flushing gate, etc., which are used to realize the non-power station water entering the downstream river. An overflow device is built on the dam to achieve the flow requirements under large flow, such as flood control requirements during the flood season.

[0018] The operation method of the present invention is applicable to the case where the reservoir has no other water requirements and only needs to meet the ecological water requirements. Since the reservoir hydropower station is not equipped with ecological units, its existing installed capacity is large. Therefore, it only needs to open several time periods in a day to meet the ecological water requirements of the day. At this time, the reservoir is in the dry season, the reservoir water level is low, and the flow is small. It is necessary to reasonably formulate the operation rules of the reservoir hydropower station. Under the condition of meeting the ecological water requirements, the startup operation is reduced as much as possible to raise the reservoir water level as much as possible to ensure the high water level operation of the reservoir hydropower station. Due to the dry season, the hydropower station unit is operated as a single unit to meet the ecological requirements, and generally does not need to be multiple units.

[0019] During operation, start the hydropower station unit operation, choose to start the unit with the smallest installed capacity of the hydropower station to the set output, such as the rated output or 90% of the rated output, and calculate the power generation flow of the hydropower station. Multiply it by the number of time periods to get the power generation water volume. Accumulate the unit operation time to get the cumulative water consumption of the unit. Take 0:00 to 24:00 every day as the calculation period, calculate the cumulative water consumption from 0:00 to now, and use the daily ecological water volume to calculate the ecological satisfaction, where the daily ecological water volume is the approved ecological flow multiplied by the number of time periods per day. When the ecological satisfaction is less than 1, it indicates that the ecological requirements are not met. When the ecological satisfaction is greater than 1, it indicates that the requirements are met. Users can judge whether the ecological flow meets the standards based on the ecological satisfaction, thereby guiding the start-up and operation of the power station.

[0020] This operation method is applicable to the situation where the minimum startup flow or rated flow corresponding to the unit with the smallest installed capacity of the reservoir hydropower station is greater than the ecological flow requirement. In order to rationally utilize the ecological flow and improve the adaptability of the hydropower station to the flow, this operation method is proposed, and the secondary storage conditions are constructed by using the barrage to achieve the rational utilization of the ecological flow.

[0021] The regulating sluice adopts an automatic control strategy, with the decision-making goal of regulating the discharge flow under the sluice to be equal to the ecological flow requirement. It automatically adjusts the sluice opening according to the water level in front of the sluice, that is, the river water level at the dam. Its adjustment strategy can be determined according to the sluice discharge formula, or the water level in front of the sluice - discharge - opening curve can be determined through tests. According to the goal that the discharge is equal to the ecological flow, the opening is automatically adjusted according to the water level in front of the sluice to ensure the requirement of discharging the ecological flow.

[0022] The advantages of the present invention are as follows:

[0023] The present invention provides an operation method using ecological flow. The power station is a reservoir power station. The tail water of the reservoir power station is discharged into the downstream river. A dam is built on the downstream river. The dam is connected to the diversion channel and the regulating sluice respectively. The regulating sluice automatically adjusts the sluice opening to achieve the discharge of ecological flow. By collecting the reservoir water level value, the river water level at the dam and the output of the hydropower station units in real time, the power generation water volume and ecological satisfaction degree of the hydropower station are calculated. According to the ecological satisfaction degree, a signal is given to guide the reasonable operation of the reservoir hydropower station to meet the requirement of ecological flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following specifically explains and illustrates the content defined by the present invention with reference to the drawings in the specification.

[0026] The present invention provides an operation method using ecological flow. The operation method is applicable to a hydropower station, and the hydropower station is a reservoir-type hydropower station. A reservoir 1 is built upstream of the hydropower station 3. The reservoir 1 stores the upstream incoming water through a dam 2. The water turbine generator set of the hydropower station 3 is connected to the reservoir 1 through a water diversion pipeline. The water turbine generator set of the hydropower station 3 is connected with a tail water system, and the tail water system is connected to the river channel downstream of the dam 2. It is characterized in that: a river blocking dam 5 is built in the downstream river channel 4 at a certain distance from the hydropower station 3. The river blocking dam 5 cuts off the river channel. The downstream river channel 4 between the river blocking dam 5 and the dam 2 forms the impounding storage capacity of the river blocking dam 5. An irrigation canal 6 is built on one side of the river blocking dam 5 for providing the required irrigation water volume. An irrigation gate 7 is arranged at the head of the irrigation canal 6 for controlling the irrigation water volume of the irrigation canal 6. An ecological flow regulation gate 8 is built on one side of the river blocking dam 5. The regulation gate 8 is provided with a gate automatic control system for adjusting the opening degree of the regulation gate 8. An ecological flow requirement Q1 is set at the river blocking dam 5. A reservoir water level monitoring device is built on the reservoir 1. A river channel water level monitoring device for the downstream river channel 4 is arranged at the river blocking dam 5. The hydropower station 3 is provided with a water turbine generator set output monitoring device. The operation method is applicable to the situation where there is no requirement for the irrigation water volume of the irrigation canal 6, and the reservoir 1 and the hydropower station 3 only meet the ecological flow requirement of the downstream river channel 4. The gate automatic control system is connected to the river channel water level monitoring device for obtaining the river channel water level at the river blocking dam 5. The gate automatic control system can automatically adjust the opening degree of the regulation gate 8 according to the river channel water level at the river blocking dam 5, so that the discharge flow of the regulation gate 8 is equal to the ecological flow requirement Q1. The operation method includes the following steps:

[0027] S1: Calculate the daily ecological water requirement W1 at the river blocking dam 5. The daily ecological water requirement W1 is equal to the ecological flow requirement Q1 multiplied by the time period number of 1 day;

[0028] S2: The hydropower station 3 starts the unit with the minimum installed capacity to the set output. Use the reservoir water level monitoring device to obtain the real-time reservoir water level H1. Use the water turbine generator set output monitoring device to monitor the unit output N1 in real time. Use the river channel water level monitoring device to monitor the river channel water level H22 at the river blocking dam 5. According to the river channel water level H22 at the river blocking dam 5, calculate the real-time tail water level H1 of the hydropower station 3 in combination with the downstream river channel 4 between the dam 2 and the river blocking dam 5. According to the real-time reservoir water level H1, the real-time unit output N1 and the real-time tail water level H1, in combination with the head loss of the water diversion system and the operation efficiency curve of the water turbine generator set, calculate the real-time power generation flow Q2 of the hydropower station 3, and calculate the power generation water volume W2 as of the current moment on the same day. The power generation water volume W2 is equal to the sum of the real-time power generation flows Q2 in each time period multiplied by the corresponding time periods during which the hydropower station 3 operates. The time as of the current moment on the same day is from 0:00 on the same day to the calculation time;

[0029] S3: Calculate the ecological satisfaction degree P of the real-time computing ecosystem, where the ecological satisfaction degree P is equal to the power generation water volume W2 divided by the daily ecological water volume requirement W1 at the barrage 5;

[0030] S4: When the ecological satisfaction degree P is greater than or equal to 1, give a signal that the ecological flow has met the requirements; when the ecological satisfaction degree P is less than 1, give a signal that the ecological flow cannot meet the requirements;

[0031] S5: The set time of a day is from 0:00 to 24:00 every day. At 0:00 every day, perform the calculation of step S1, clear the power generation water volume W2 in step S2, and then perform steps S2 - S4.

[0032] The ecological flow requirement Q1 is 10% of the average annual runoff flow of the river channel at the barrage 5, or it can be selected as 10% of the average annual runoff flow of the river channel at the barrage 5 in the non-flood season and 20% of the average annual runoff flow of the river channel at the barrage 5 in the flood season.

[0033] The water level monitored by the river channel water level monitoring device of the downstream river channel 4 set at the barrage 5 is the water level of the river channel upstream of the barrage 5, that is, the water level value caused by the water storage of the barrage 5.

[0034] Preferably, the calculation method of the real-time tail water level H1 of the hydropower station 3 is as follows: Calculate the real-time tail water level of the hydropower station 3 according to the water storage calculation of the barrage 5 and in combination with the structural form of the downstream river channel 4, or determine the correlation between the tail water level of the hydropower station 3 and the river channel water level at the barrage 5 based on test data, and then use this correlation to calculate the real-time tail water level of the hydropower station 3 according to the river channel water level at the barrage 5.

[0035] Preferably, the set output is the rated installed capacity or 90% of the rated installed capacity.

[0036] Preferably, the calculation method of the real-time power generation flow Q2 of the hydropower station 3 is as follows: Set different flows according to the reservoir water level and the tail water level, then calculate the diversion loss according to the flow in combination with the pipeline layout to obtain the net head of the unit, and then obtain the operating efficiency of the unit according to the net head and the flow, and then obtain the output value of the unit, and find the flow value closest to the measured output value, which is the real-time power generation flow Q2 of the hydropower station 3.

[0037] Preferably, the calculation method of the real-time power generation flow Q2 of the hydropower station 3 is as follows: Conduct unit operation tests to obtain the relationship between the unit output and the flow under different reservoir water levels and different tail water levels, and then obtain the corresponding power generation flow under the unit output in combination with different reservoir water levels and tail water levels.

[0038] For example, at 0:00 every day, calculate the daily ecological water volume requirement W1 at the dam 5. Starting from 0:00, obtain the real-time output value, real-time reservoir water level, and tail water level value of the hydropower station 3, calculate the power generation flow rate of the hydropower station 3, and calculate the power generation water volume W2 of the hydropower station 3 up to the current moment. Calculate the ecological satisfaction degree. When the hydropower station 3 is not operating, the real-time output value of the unit is 0, the corresponding power generation flow rate is 0, the power generation water volume W2 is 0, and the ecological satisfaction degree is 0. When the hydropower station 3 starts operating, the power generation water volume W2 is greater than 0, and P2 is greater than 0. As the operating time of the units of the hydropower station 3 increases, the ecological satisfaction degree also continuously increases. When it is greater than or equal to 1, the operation of the hydropower station 3 can meet the ecological requirements.

[0039] The acquisition of the real-time value can be carried out every 1 minute or every 10 minutes or any time period. Use the value at this moment to represent the value of the time period. This is the utilization of the difference principle. Using this calculation method, the power generation flow rate and power generation water volume of the hydropower station 3 can be approximately calculated to meet the engineering requirements.

[0040] The above embodiments are only the preferred embodiments of the present invention. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments. The protection scope of the present invention also includes equivalent technical means that can be conceived by those skilled in the art according to the concept of the present invention.

Claims

1. An operation method using ecological flow, the operation method is applicable to a hydropower station, the hydropower station is a reservoir-type hydropower station, a reservoir is built upstream of the hydropower station, the reservoir stores the upstream incoming water through a dam, the water turbine generator set of the hydropower station is connected to the reservoir through a water diversion pipeline, the water turbine generator set of the hydropower station is connected with a tail water system, and the tail water system is connected to the river channel downstream of the dam, and is characterized in that: A barrage is built in the downstream river channel at a certain distance from the hydropower station. The barrage cuts off the river channel, and the downstream river channel between the barrage and the dam forms the impounding reservoir capacity of the barrage. An intake channel is built on one side of the barrage to provide the required intake water volume. An intake gate is provided at the head of the intake channel to control the intake water volume of the intake channel. An ecological flow regulation gate is built on one side of the barrage, and the regulation gate is provided with a gate automatic control system for adjusting the opening of the regulation gate. An ecological flow requirement Q1 is set at the barrage. A reservoir water level monitoring device is built on the reservoir, a river channel water level monitoring device for the downstream river channel is provided at the barrage, and a water turbine generator set output monitoring device is provided at the hydropower station. The operation method is applicable to the situation where there is no requirement for the intake water volume of the intake channel, and the reservoir hydropower station only meets the ecological flow requirement of the downstream river channel. The gate automatic control system is connected to the river channel water level monitoring device to obtain the river channel water level at the barrage. The gate automatic control system can automatically adjust the opening of the regulation gate according to the river channel water level at the barrage, so that the discharge flow of the regulation gate is equal to the ecological flow requirement Q1. The operation method includes the following steps: S1: Calculate the daily ecological water requirement W1 at the barrage. The daily ecological water requirement W1 is equal to the ecological flow requirement Q1 multiplied by the time period number of 1 day. S2: The hydropower station starts the unit with the minimum installed capacity to the set output. Use the reservoir water level monitoring device to obtain the real-time reservoir water level H1, use the water turbine generator set output monitoring device to monitor the unit output N1 in real time, use the river channel water level monitoring device to monitor the river channel water level H22 at the barrage. According to the river channel water level H22 at the barrage, calculate the real-time tail water level H1 of the hydropower station by combining the downstream river channel between the dam and the barrage. According to the real-time reservoir water level H1, the real-time unit output N1, and the real-time tail water level H1, combine the head loss of the intake system and the operation efficiency curve of the water turbine generator set to calculate the real-time power generation flow Q2 of the hydropower station, and calculate the power generation water volume W2 up to the current moment of the day. The power generation water volume W2 is equal to the sum of the real-time power generation flows Q2 in each time period multiplied by the corresponding time periods during the operation of the hydropower station. The time up to the current moment of the day is from 0:00 of the day to the calculation time. S3: Calculate the ecological satisfaction degree P in real time. The ecological satisfaction degree P is equal to the power generation water volume W2 divided by the daily ecological water requirement W1 at the barrage. S4: When the ecological satisfaction degree P is greater than or equal to 1, give a signal that the ecological flow has met the requirements. When the ecological satisfaction degree P is less than 1, give a signal that the ecological flow cannot meet the requirements. S5: The set time of one day is from 0:00 to 24:00 every day. At 0:00 every day, perform the calculation in step S1, and clear the power generation water volume W2 in step S2, and then perform steps S2 - S4.

2. The operation method using ecological flow according to claim 1, characterized in that: The ecological flow requirement Q1 is 10% of the average annual runoff flow of the river channel at the barrage.

3. The operation method using ecological flow according to claim 1, characterized in that: The calculation method of the real-time tail water level H1 of the hydropower station is as follows: Calculate the real-time tail water level of the hydropower station according to the backwater calculation of the barrage, combined with the structural form of the downstream river channel, or determine the correlation between the tail water level of the hydropower station and the river channel water level at the barrage based on test data, and then use this correlation to calculate the real-time tail water level of the hydropower station according to the river channel water level at the barrage.

4. The operation method using ecological flow according to claim 1, characterized in that: The set output is the rated installed capacity or 90% of the rated installed capacity.

5. The operation method using ecological flow according to claim 1, characterized in that: The calculation method of the real-time power generation flow Q2 of the hydropower station is as follows: Set different flows according to the reservoir water level and the tail water level, then calculate the diversion loss according to the flow combined with the pipeline layout to obtain the net head of the unit, and then obtain the operating efficiency of the unit according to the net head and the flow, and then obtain the output value of the unit. Find the flow value closest to the measured output value, which is the real-time power generation flow Q2 of the hydropower station.

6. The operation method using ecological flow according to claim 1, characterized in that: The calculation method of the real-time power generation flow Q2 of the hydropower station is as follows: Conduct unit operation tests to obtain the relationship between the unit output and the flow under different reservoir water levels and different tail water levels, and then combine different reservoir water levels and tail water levels according to the relationship between the unit output and the flow to obtain the power generation flow corresponding to the unit output.

Images