An ecological flow discharge alarm system

Abstract

The present invention provides an ecological flow discharge alarm system, which is suitable for dam-type hydropower stations. By arranging a sluice gate on the dam and setting a pad, uninterrupted water discharge is achieved. When discharging the ecological flow, the upstream and downstream water level values ​​are determined, and the ecological flow requirements are met under the design working conditions with the upstream and downstream water level values. The upstream reservoir water level and the unit output value are monitored in real time, and the alarm water level is calculated. When the real-time reservoir water level triggers the alarm water level, an alarm is issued to achieve supervision of the ecological flow discharge.

Description

Technical Field

[0001] The present invention relates to the field of water conservancy projects, and in particular to an ecological flow discharge alarm system. Background Art

[0002] Riverbed hydropower station is a common hydropower station structure. It builds a dam in the river to cut off the incoming flow and form a reservoir. For the reservoir, it can fully and effectively regulate the incoming flow, thereby realizing the rational use of water, especially it can cooperate with the unit to generate electricity, which can improve the efficiency of the unit.

[0003] For this type of hydropower station, if a water intake is installed in the downstream river, water used for power generation will be taken away from the station for reuse, resulting in a reduction in the flow of the river downstream of the water intake. Furthermore, when the hydropower station is not in operation, the dam blocks the flow of water, causing a dry-up of the river downstream, impacting the ecological environment.

[0004] In order to ensure the release of ecological flow of riverbed power station, it is possible to choose to set up an uninterrupted ecological flow release device on the spillway on the dam, that is, no matter whether the power station is started or not, and how large the operating output of the unit is, it will be discharged through the ecological flow release device. For example, corresponding fixed pads can be set to achieve uninterrupted release of ecological flow. Under this setting, the gate of the spillway cannot be in a completely closed state, and it always has a certain degree of opening, so the ecological flow can be continuously discharged. However, it is greatly affected by the water level of the reservoir. Therefore, it is necessary to make reasonable settings for its ecological flow release and set alarms when necessary to meet the necessary requirements for ecological flow release. Summary of the Invention

[0005] The present invention aims to solve the problems of the prior art and provides an ecological flow discharge alarm system.

[0006] The present invention provides an ecological flow discharge alarm system, which is suitable for a hydropower station. The hydropower station is a dam-type hydropower station. The dam is built in the river and cuts off the upstream water to form a reservoir. The dam is a gravity dam. A hydropower station is provided on the downstream side of the dam. Several hydro-generator sets are provided in the hydropower station. A spillway is provided on the other downstream side of the dam. The gate plate of the spillway is located in the gate groove and above the gate bottom plate. The gate plate of the spillway is a flat gate, and a hoist is provided above it. The hoist is connected to the flat gate and is used to lift the flat gate. , pads are provided on both sides of the left and right sides of the gate bottom plate, and the pads are located between the gate plate and the gate bottom plate, so as to ensure that the water volume of the reservoir can be discharged from the middle of the pads to meet the ecological flow requirements. It is characterized in that: the width and height of the pads provided in the spillway should meet the requirement that when the upstream of the dam is the designed high water level and the downstream of the dam is the designed tail water level, the discharge flow of the spillway is equal to the ecological flow requirement value; the ecological flow discharge alarm system includes a reservoir water level measuring device, a hydro-generator output monitoring device, a power generation flow calculation module, a tail water level calculation module, an alarm water level calculation module, and an alarm module, which The middle reservoir water level measuring device is located upstream of the dam and fixed on the dam, and is used to obtain the real-time reservoir water level of the reservoir; the hydro-generator output monitoring devices are provided in a plurality, and their number corresponds to the hydro-generator sets, and are used to obtain the real-time unit output of each hydro-generator set; the power generation flow calculation module is used to calculate the real-time power generation flow and the total power generation flow of each hydro-generator set based on the real-time reservoir water level and the real-time unit output; the tailwater level calculation module is used to calculate the tailwater level downstream of the dam based on the total power generation flow and the tailwater flow curve downstream of the dam; The alarm water level calculation module is used to calculate the alarm water level based on the tail water level downstream of the dam calculated by the tail water level calculation module, combined with the design high water level and the design tail water level. The calculation method of the alarm water level is: the design high water level plus the tail water level downstream of the dam calculated by the tail water level calculation module minus the design tail water level; the alarm module is used to determine whether the alarm water level is triggered based on the real-time reservoir water level. If the alarm water level is triggered, an alarm is issued; if the alarm water level is not triggered, no alarm is issued; the standard for triggering the alarm water level is: when the real-time reservoir water level is lower than the alarm water level.

[0007] Preferably, the designed tailwater level is the tailwater level downstream of the dam when all the hydro-generator sets in the power station are fully powered.

[0008] Preferably, the total power generation flow is equal to the sum of the power flows of all the hydro-generator sets.

[0009] Preferably, the real-time power generation flow of each hydro-generator set is calculated based on the real-time reservoir water level and the real-time unit output, combined with the comprehensive characteristic curve or operating characteristic curve of each hydro-generator set, and combined with the tailwater flow curve downstream of the dam.

[0010] Preferably, the tailwater flow curve is a one-to-one correspondence between the water levels downstream of the dam corresponding to different power station power generation flows.

[0011] Preferably, the tailwater flow curve can be obtained through measured data, that is, controlling different power generation flows to obtain different water levels downstream of the dam; it can also be obtained by performing hydraulic calculations based on the river channel downstream of the dam.

[0012] Preferably, the method for determining the width and height of the pad is: when all the hydro-generating units in the hydropower station are fully powered, pads of corresponding width and height are set, and the ecological flow discharged from the gate obtained through the flow monitoring device is equal to the required ecological flow value, then the pad of this width and height is determined to be the size of the pad that needs to be set.

[0013] Preferably, the ecological flow discharge alarm system further includes a control system, which is used to control the hydro-generator set to reduce output or control the hoist to increase the opening of the flat gate when an alarm is triggered.

[0014] The working principle of the present invention is as follows:

[0015] For riverbed hydropower stations, ecological spillways are installed to continuously release ecological flows. A water intake is installed downstream of a riverbed hydropower station. This intake can be the water intake of the downstream hydropower station or other downstream water intakes. Generally, when the power station is operating, the water intake of the water intake is consistent with the water output of the power station to ensure upstream and downstream matching. This can cause the river downstream of the downstream water intake to dry up. In addition, if the riverbed hydropower station is not operating, it will also cause the flow downstream of the dam to dry up.

[0016] To prevent river flow interruptions and protect the ecological environment, a continuous ecological discharge device is installed on the dam. This device works by placing pads beneath the sluice gates to prevent them from completely closing, allowing for continuous gate discharge. This ensures the ecological discharge flow rate regardless of whether the power plant is operating. The height and width of the pads require a reasonable design.

[0017] The hydraulic characteristics of the gate determine that the higher the upstream water level, the greater the downstream flow, and the lower the downstream water level, the greater the downstream flow. Therefore, when determining the pad, it is necessary to first determine its design operating conditions. The upstream reservoir selects a design high water level, which can generally be determined as the normal power generation water level of the power station or the normal water storage level of the reservoir or the beneficial water level of the reservoir; for the downstream water level, it is necessary to select a relatively high water level, such as the water level downstream of the dam when the power station is fully operational, which is the design tailwater level.

[0018] The spacers should be designed to ensure that the ecological spillway can discharge the required ecological flow under the conditions of the design high water level and the design tailwater level. The design tailwater level can be determined through testing. That is, when the power plant is at full power, the spacer size is adjusted until the water level downstream of the dam reaches the required ecological flow. At this point, the water level downstream of the dam takes into account both the power plant's power generation flow and the ecological discharge flow.

[0019] The ecological spillway is kept in a normally open state through the pads, and continuously discharges the ecological flow. However, if the power generation flow of the unit is greater than the incoming flow, the reservoir water level will drop, and the discharge flow of the corresponding ecological spillway will also decrease accordingly, and may even be lower than the ecological flow requirement value. When it is lower than the ecological flow requirement value, a corresponding alarm signal needs to be given, but the water level alarm value lower than the ecological flow requirement value will vary due to different unit outputs and reservoir water levels. At this time, both the reservoir water level and the downstream water level must be considered.

[0020] The alarm system method provided by the present invention is to first calculate the power generation flow of the power station based on the reservoir water level and the unit output. The power generation flow affects the water level downstream of the dam. The water level downstream of the dam can be obtained by converting the tailwater flow curve. The current downstream tailwater level can be obtained by using the unit status, and compared with the design tailwater level. At the same time, the design high water level is used for calculation to obtain the alarm water level, which is compared with the current real-time reservoir water level to give an alarm signal.

[0021] This method system first determines the design operating conditions and uses actual monitoring devices to obtain their real-time status. Through calculation and analysis, the difference in its design operating conditions is obtained, and then the alarm system is designed in combination with the hydraulic relationship between the gate flow rate and the water depth before and after the gate. For example, if the current reservoir water level is low and an alarm occurs, the unit output is reduced through the corresponding control system or the gate opening is manually opened to ensure the release of ecological flow.

[0022] When the power station is not started, the power generation flow obtained is 0. At this time, the reservoir water level can be at a lower level and can also meet the ecological flow discharge requirements. The alarm water level will also be lower, thereby ensuring the normal discharge of the ecological flow. Once it is higher than the alarm water level, there will be no alarm and the ecological flow will be discharged normally. If it is lower than the alarm water level, the alarm will give a warning and make timely adjustments to ensure the discharge of the ecological flow.

[0023] Preferably, the system of the present invention is applicable to small and medium-sized hydropower stations with smaller storage capacity. Since the power generation flow of the power station will affect the reservoir water level, the smaller the storage capacity of the reservoir, the higher the sensitivity of the system will be.

[0024] The advantages of the present invention are:

[0025] The present invention provides an ecological flow discharge alarm system, which is suitable for riverbed hydropower stations. By arranging a sluice gate on the dam and setting pads to achieve uninterrupted water discharge, when discharging the ecological flow, the upstream and downstream water level values ​​are determined, and the ecological flow requirements are met under the design working conditions with the upstream and downstream water level values. The upstream reservoir water level and the unit output value are monitored in real time, and the alarm water level is calculated. When the real-time reservoir water level triggers the alarm water level, an alarm is issued to achieve supervision of the ecological flow discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the power station and sluice gate layout;

[0027] Figure 2 This is a schematic diagram of the layout of the spillway pads and gate plates. DETAILED DESCRIPTION

[0028] The following is a detailed explanation of the structure defined in the present invention with reference to the contents of the drawings in the specification.

[0029] The present invention provides an ecological flow discharge alarm system, which is suitable for a hydropower station 2. The hydropower station 2 is a dam-type hydropower station 2. The dam 1 is built in the river and cuts off the upstream water to form a reservoir. The dam 1 is a gravity dam. The hydropower station 2 is provided on the downstream side of the dam 1. The hydropower station 2 is provided with a plurality of hydro-generator sets. A spillway 3 is provided on the other downstream side of the dam 1. The gate plate 31 of the spillway 3 is located in the gate groove and above the gate bottom plate. The gate plate 31 of the spillway 3 is a flat gate, and a hoist is provided above it. The hoist is connected to the flat gate and is used for For the lifting flat plate gate, pads 32 are provided on both sides of the gate bottom plate, and the pads 32 are located between the gate plate 31 and the gate bottom plate, thereby ensuring that the reservoir water can be discharged from the middle of the pads 32 to meet the ecological flow requirements. It is characterized in that: the width and height of the pads 32 provided in the sluice gate 3 should meet the requirement that when the upstream of the dam 1 is the designed high water level and the downstream of the dam 1 is the designed tail water level, the discharge flow of the sluice gate 3 is equal to the ecological flow requirement value; the ecological flow discharge alarm system includes a reservoir water level measuring device, a hydro-generator output monitoring device, a power generation flow calculation module, a tail water level calculation module, an alarm water level measuring device, a ... The water level calculation module and the alarm module are as follows: the reservoir water level measuring device is located upstream of the dam 1 and fixed on the dam 1, and is used to obtain the real-time water level of the reservoir; the hydro-generator output monitoring device is set to a number, and its number corresponds to the hydro-generator set, and is used to obtain the real-time unit output of each hydro-generator set; the power generation flow calculation module is used to calculate the real-time power generation flow and the total power generation flow of each hydro-generator set according to the real-time reservoir water level and the real-time unit output; the tail water level calculation module is used to calculate the dam 1 according to the total power generation flow, combined with the tail water flow curve downstream of the dam 1. 1 downstream tailwater level; the alarm water level calculation module is used to calculate the alarm water level based on the tailwater level downstream of dam 1 calculated by the tailwater level calculation module in combination with the design high water level and the design tailwater level. The calculation method of the alarm water level is: the design high water level plus the tailwater level downstream of dam 1 calculated by the tailwater level calculation module minus the design tailwater level; the alarm module is used to determine whether the alarm water level is triggered according to the real-time reservoir water level. If the alarm water level is triggered, an alarm is issued; if the alarm water level is not triggered, no alarm is issued; the standard for triggering the alarm water level is: when the real-time reservoir water level is lower than the alarm water level.

[0030] Preferably, the designed tailwater level is the tailwater level downstream of the dam 1 when all the hydro-generator sets of the power station 2 are fully powered, and can be obtained through experiments or calculation methods.

[0031] Preferably, the total power generation flow is equal to the sum of the power flows of all the hydro-generator sets.

[0032] Preferably, the real-time power generation flow of each hydro-generator set is calculated as follows: based on the real-time reservoir water level and the real-time unit output, combined with the comprehensive characteristic curve or operating characteristic curve of each hydro-generator set, and combined with the tailwater flow curve downstream of the dam 1, it is calculated.

[0033] During specific calculations, a trial algorithm can be used to assume that the flow rate of each unit is distributed according to the real-time reservoir water level, so as to obtain the flow rate of each unit. The head loss is calculated in combination with the water diversion system, and the tail water level is calculated in combination with the tail water flow curve, so as to obtain the net power generation head of each unit. According to the net power generation head and flow rate, the operating efficiency is calculated in combination with the comprehensive characteristic curve or the operating characteristic curve, so as to obtain the output value. The output value is compared with the real-time output value, and the trial calculation is used for correction to obtain the actual power generation flow of each unit.

[0034] Preferably, the tailwater flow curve is a one-to-one correspondence between the water level downstream of the dam 1 corresponding to different power generation flows of the power station 2.

[0035] Preferably, the tailwater flow curve can be obtained through measured data, that is, controlling different power generation flows to obtain different water levels downstream of the dam 1; it can also be obtained by performing hydraulic calculations based on the river channel downstream of the dam 1.

[0036] When obtaining the tailwater flow curve, only the power generation flow of hydropower station 2 can be considered, and the curve of the power generation flow of hydropower station 2 and the tailwater channel downstream of dam 1 is obtained; the power generation flow of hydropower station 2 and the ecological flow requirement value can also be considered. At this time, the water level downstream of dam 1 corresponding to the power generation flow is the water level downstream of dam 1 corresponding to the power generation flow superimposed on the ecological flow requirement value.

[0037] Since the required ecological flow rate is generally small, considering only the power generation flow rate, even with some errors, can meet general project requirements. If the ecological discharge flow rate requirement is considered, the calculation is more accurate. Although the gate discharge flow rate may not exactly equal the required ecological flow rate, it is relatively close. Therefore, when conducting a test rate timing, Power Station 2 can be operated to different outputs, while ensuring that the ecological spillway is equipped with a pad. The ecological flow rate is continuously released, different power generation flows are calculated, and the real-time water level downstream of Dam 1 is measured to obtain a curve showing the relationship between the power generation flow rate and the water level downstream of Dam 1. If a calculation method is used, when using a hydraulic method, the water level downstream of Dam 1 is calculated based on the power generation flow rate and the required ecological flow rate.

[0038] Preferably, the method for determining the width and height of the pad 32 is: when all the hydro-generator sets of the hydropower station 2 are fully powered, a pad 32 of corresponding width and height is set, and the ecological flow discharged from the gate obtained by the flow monitoring device is equal to the ecological flow requirement value, then the pad 32 of this width and height is determined to be the size of the pad 32 that needs to be set.

[0039] The width and height of the pad 32 can be determined by experimental calibration or calculated based on the gate opening discharge formula in hydraulics.

[0040] Preferably, the ecological flow discharge alarm system further includes a control system, which is used to control the hydro-generator set to reduce output or control the hoist to increase the opening of the flat gate when an alarm is triggered.

[0041] The above embodiments are only preferred embodiments of the present invention. The protection scope of the present invention should not be regarded as limited to the specific forms described in the embodiments. The protection scope of the present invention also includes equivalent technical means that can be thought of by those skilled in the art based on the concept of the present invention.

Claims

1. An ecological flow discharge alarm system, the ecological flow discharge alarm system is suitable for a hydropower station, the hydropower station is a dam-type hydropower station, the dam is built in the river channel, and cuts off the upstream water to form a reservoir, the dam is a gravity dam, a hydropower station is arranged on the downstream side of the dam, and a water intake is arranged downstream of the hydropower station. When the power station is in operation, the water intake of the water intake is consistent with the water amount of the hydropower station for power generation, which will cause the downstream river of the downstream water intake to be cut off, a number of hydro-generator sets are arranged in the hydropower station, and a spillway is arranged on the other side downstream of the dam, the gate plate of the spillway is located in the gate groove and above the gate bottom plate, the gate plate of the spillway is a flat gate, and a hoist is arranged above it, the hoist is connected to the flat gate for lifting the flat gate, pads are arranged on both sides of the gate bottom plate, the pads are located between the gate plate and the gate bottom plate, thereby ensuring that the reservoir water can be discharged from the middle of the pads to meet the ecological flow requirements, characterized in that: The width and height of the pads set in the spillway should meet the requirement that when the upstream of the dam is the design high water level and the downstream of the dam is the design tailwater level, the discharge flow of the spillway is equal to the ecological flow requirement value; the ecological flow discharge alarm system includes a reservoir water level measuring device, a hydro-generator output monitoring device, a power generation flow calculation module, a tailwater level calculation module, an alarm water level calculation module, and an alarm module, wherein the reservoir water level measuring device is located upstream of the dam and fixed on the dam, and is used to obtain the real-time reservoir water level of the reservoir; the hydro-generator output monitoring device is provided in a number, and its number corresponds to the hydro-generator set, and is used to obtain the real-time unit output of each hydro-generator set; the power generation flow calculation module is used to calculate the real-time power generation flow and the total power generation flow of each hydro-generator set according to the real-time reservoir water level and the real-time unit output; the tailwater level calculation module is used to calculate the tailwater level downstream of the dam according to the total power generation flow and the tailwater flow curve downstream of the dam; The alarm water level calculation module is used to calculate the alarm water level based on the tail water level downstream of the dam calculated by the tail water level calculation module, combined with the design high water level and the design tail water level. The calculation method of the alarm water level is: the design high water level plus the tail water level downstream of the dam calculated by the tail water level calculation module minus the design tail water level; the alarm module is used to determine whether the alarm water level is triggered based on the real-time reservoir water level. If the alarm water level is triggered, an alarm is issued; if the alarm water level is not triggered, no alarm is issued; the standard for triggering the alarm water level is: when the real-time reservoir water level is lower than the alarm water level; the ecological flow discharge alarm system also includes a control system, which is used to control the hydro-generator set to reduce output when an alarm occurs.

2. The ecological flow discharge alarm system according to claim 1, characterized in that: The designed tailwater level is the tailwater level downstream of the dam when all turbine generator units of the hydropower station are fully powered.

3. The ecological flow discharge alarm system according to claim 1, characterized in that: The total power generation flow is equal to the sum of the power generation flow of each hydro-generator set.

4. The ecological flow discharge alarm system according to claim 1, characterized in that: The real-time power generation flow of each hydro-generator set is calculated by the following method: based on the real-time reservoir water level and the real-time unit output, combined with the comprehensive characteristic curve or operation characteristic curve of each hydro-generator set, and combined with the tailwater flow curve downstream of the dam.

5. The ecological flow discharge alarm system according to claim 1 or 4, characterized in that: The tailwater flow curve is a one-to-one correspondence between the water levels downstream of the dam corresponding to different power generation flows of the power station.

6. The ecological flow discharge alarm system according to claim 5, characterized in that: The tailwater flow curve is obtained through measured data, that is, controlling different power generation flows to obtain different water levels downstream of the dam; or obtained through hydraulic calculations based on the river channel downstream of the dam.

7. The ecological flow discharge alarm system according to claim 1, characterized in that: The method for determining the width and height of the pad is as follows: when all the turbine generator sets in the hydropower station are fully powered, pads of corresponding width and height are set. When the ecological flow discharged from the gate obtained by the flow monitoring device is equal to the required ecological flow value, the pad of this width and height is determined to be the size of the pad that needs to be set.

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