Working condition prediction method of water turbine coupling fan system

Abstract

The invention discloses a working condition prediction method for a water turbine coupled fan system, and belongs to the technical field of hydraulic machinery. The method is used for solving the problem that working condition parameters are difficult to predict when the water turbine coupling fan system operates. According to the technical scheme, the method comprises the steps that firstly, energy balance is estimated according to fan rated parameters and available water head flow, and the specific speed of a water turbine is determined; acquiring a unit output-unit rotating speed curve and a unit flow-unit rotating speed curve of the water turbine; defining a relational expression between unit load and unit rotating speed of the fan; drawing a unit output-unit rotating speed curve of the water turbine and a unit load-unit rotating speed curve of the fan together, and determining similar operation condition points; and finally calculating the actual operation rotating speed, flow and output of the water turbine. The method can accurately predict the operation condition parameters of the water turbine coupled fan system, and improves the operation efficiency of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of water turbine coupled fan systems, and more particularly to an operating condition prediction method for a water turbine coupled fan system. Background Art

[0002] In the process of fluid decompression, which is common in the energy and chemical industries, a hydraulic turbine is used to recover the energy wasted in the decompression process, forming a hydraulic turbine-coupled fan system to replace motors and reduce power consumption.

[0003] Common hydraulic turbines are typically used to drive generators in hydropower stations. Their operating head is determined by the difference in head between the upstream and downstream sides of the reservoir, their speed is equal to the synchronous speed of the motor, and the flow rate is primarily controlled by the opening of the guide vanes. However, when the generator is replaced with a fan system, its operating environment fundamentally changes compared to a power station turbine.

[0004] The known parameters in the early stage are the rated speed of the fan n f0 and rated output N f0 , and the head H that can be used in residual energy recovery c and flow Q c Based on the known parameters, it is possible to estimate whether the capacity is balanced and the required turbine specific speed n s However, in a turbine-coupled fan system, the turbine and fan are in a dynamic equilibrium with each other, and it is difficult to accurately estimate the actual speed, flow rate and output parameters. In addition, since the available head usually varies within a certain range, the difficulty of theoretical calculation is further increased.

[0005] When the actual working parameters of the turbine-coupled fan system deviate too much from the design values, it will at least affect the system's matching degree and energy-saving effect, and at worst affect the safe operation of the process system. Summary of the Invention

[0006] In order to overcome the defects and deficiencies in the above-mentioned prior art, the present invention provides a method for predicting the operating conditions of a turbine-coupled fan system. The purpose of the present invention is to provide a method for predicting the operating conditions of a turbine-coupled fan system to solve the problem that the operating parameters of the turbine-coupled fan system are difficult to calculate during operation. The present invention introduces the definition of the fan unit load for the first time, and then obtains the similar operating condition point parameters of the turbine-coupled fan system by plotting the turbine unit output and fan unit load curves, and finally calculates the turbine speed, flow rate, and shaft power. The prediction method proposed by the present invention has clear physical meaning and a simple calculation process, and has excellent theoretical research and engineering application value.

[0007] In order to solve the above problems in the prior art, the present invention is implemented through the following technical solutions.

[0008] The present invention provides an operating condition prediction method for a water turbine coupled wind turbine system, the operating condition prediction method comprising the following steps:

[0009] S1, according to the rated speed n of the fan in the turbine-coupled fan system f0 and rated output N f0 , and the head H that can be used in residual energy recovery c and flow Q c , estimate whether the energy of the turbine-coupled wind turbine system is balanced;

[0010] S2. Estimate the required turbine specific speed n under the condition of satisfying energy balance s , and obtain the unit output-unit speed curve and unit flow-unit speed curve of the turbine;

[0011] S3. Define the relationship between fan unit load and unit speed Where N 11f Indicates the fan unit load, n 11 Indicates the unit speed of the turbine, k N Indicates unit load factor; unit load factor Where k f represents the fan shaft power coefficient, D1 represents the diameter of the turbine runner; N f0 Indicates the rated load of the fan, in kW; n f0 Indicates the rated speed of the fan input end, in r / min; calculates and draws the fan unit load-unit speed curve;

[0012] S4. Draw the unit output-unit speed curve of the turbine and the unit load-unit speed curve of the fan together. The intersection of the two is the similar operating condition point of the turbine and the fan. According to the similar operating condition point of the turbine and the fan, the unit output N is obtained. 11 , unit speed n 11 And from the unit flow-unit speed curve of the turbine, the unit flow Q corresponding to the similar operating conditions of the turbine and the fan is obtained. 11 ; Calculate the corresponding turbine speed n, flow Q and output N based on the available head t .

[0013] Further preferably, in step S2, the specific process of defining the relationship between the unit load and the unit speed of the fan is as follows:

[0014] When the turbine drives the fan in the turbine-coupled fan system, the turbine and the fan always maintain shaft power balance, that is, N t =N f , N t Indicates turbine output, unit kW; Nf Indicates fan load, unit kW;

[0015] The output speed of the turbine and the input speed of the fan are kept equal. The shaft power calculation formula of the fan is obtained from the fan characteristics: Where, P f Indicates the total pressure of the fan, unit is kPa; Q f Indicates the fan ventilation volume, unit: m 3 / s;η f represents the fan efficiency, η r Indicates transmission efficiency;

[0016] Fan full pressure ρ f Indicates air density in kg / m 3 ;D f Indicates the diameter of the fan rotor, in m; n f Indicates the fan speed, unit is r / min; fan ventilation volume The fan load That is, the fan load is proportional to the cube of the speed, and the other terms are expressed as the fan shaft power coefficient k f , then the fan shaft power is expressed as N f =k f n 3 ; Where n represents the speed of the fan input end, unit is r / min; fan shaft power coefficient k f Calculated according to the rated operating parameters of the fan, that is, N f0 Indicates the rated load of the fan, in kW; n f0 Indicates the rated speed of the fan input end, in r / min; when the fan's angle of attack is fixed, the fan shaft power coefficient k f is a constant;

[0017] Since the turbine and fan shaft powers are balanced, N t =k f n 3 ; Fan unit load factor k N Depends on the fan shaft power coefficient k f and turbine diameter D1, i.e.

[0018] Fan unit load N 11f It is expressed using the turbine runner diameter D1 and working water head H, that is, N f =k f n 3 and Substitute into the fan unit load N 11f The relationship between the fan unit load and unit speed is obtained from the expression of

[0019] Further preferably, the horizontal coordinate of the similar operating condition point of the turbine and the fan is the unit speed n 11 , the vertical axis is unit output N 11 When different turbine runner diameters D1 are selected, the positions of the similar operating points of the turbine and the fan change. After the turbine runner diameter is selected, the similar operating points of the turbine and the fan are also determined.

[0020] Further preferably, in step S4, the corresponding turbine speed n is calculated, specifically, the surplus pressure head H, the turbine runner diameter D1 and the unit speed n under typical working conditions are calculated. 11 Substitution The corresponding predicted value of the speed n can be obtained.

[0021] Further preferably, the corresponding output N is calculated t Specifically, it means that the surplus pressure head H and unit output N under typical working conditions are 11 , Substitute the turbine runner diameter D1 into The force N can be calculated t The predicted value of .

[0022] More preferably, the corresponding flow rate Q is calculated, specifically, the surplus pressure head H and unit flow rate Q under typical working conditions are calculated. 11 Substitute the runner diameter D1 into The predicted value of the turbine flow rate Q can be obtained.

[0023] Further preferably, the water turbine coupled fan system includes a water turbine, a fan and a drive shaft, the water turbine converts water flow potential energy into mechanical energy, the water turbine transmits the mechanical energy to the fan through the drive shaft, and the fan drives the air flow.

[0024] More preferably, the water turbine coupled to the wind turbine system further includes a gearbox, and the water turbine transmits mechanical energy to the wind turbine via the drive shaft and the gearbox in sequence.

[0025] More preferably, the turbine is not provided with movable guide vanes, the unit output-unit speed curve of the turbine is a fixed curve, and the unit flow-unit speed curve of the turbine is also a fixed curve.

[0026] Compared with the prior art, the beneficial technical effects brought about by the present invention are as follows:

[0027] This invention proposes a definition of fan unit load for the first time, using the intersection of the turbine unit output and fan unit load curves to determine similar operating points for a turbine-coupled fan system. This theoretical method predicts operating parameters, facilitating the calculation of corresponding speed, output, and flow rate parameters based on changes in working head. The calculation process is simple, effectively resolving the difficulty in predicting operating parameters in turbine-coupled fan systems and offering significant economic, energy-saving, and environmental benefits. Compared to existing technologies, this invention, by establishing a coupling relationship model between the turbine and fan system, avoids the problem of operating parameters deviating from target values ​​due to relying solely on empirical estimation, thereby improving the accuracy and safety of system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is an intersection diagram of the unit output-unit speed curve of the water turbine and the unit load-unit speed curve of the fan;

[0029] Figure 2 This is a schematic structural diagram of the water turbine coupled fan system of the present invention;

[0030] Figure 3 This is a flow chart for predicting the operating conditions of the turbine-coupled fan system of the present invention;

[0031] Figure 4 The intersection diagram of the turbine unit output-unit speed curve and the fan unit load-unit speed curve of Example 4 of the present invention;

[0032] Figure numerals: 1. turbine, 2. drive shaft, 3. reducer, 4. fan. DETAILED DESCRIPTION

[0033] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings and embodiments. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0034] Example 1

[0035] As a preferred embodiment of the present invention, refer to the attached Figure 1 , Attachment Figure 2 and attached Figure 3 As shown, this embodiment provides an operating condition prediction method for a turbine-coupled fan system, which is mainly used to solve the problem of difficulty in predicting operating condition parameters when the turbine-coupled fan system is in operation.

[0036] Refer to the instruction manual Figure 2As shown in the figure, a turbine-fan coupled system primarily consists of a turbine, fan, gearbox, and drive shaft. During operation, the turbine converts excess pressure energy into mechanical energy, which is then transferred to the fan via the drive shaft and gearbox. Ultimately, the fan drives the air flow. Alternatively, the turbine can directly drive the fan via the drive shaft.

[0037] The specific steps of the working condition prediction method are as follows:

[0038] Step 1: According to the rated speed of the fan, the rated speed of the fan in the turbine-coupled fan system n f0 and rated output N f0 , and the head H that can be used in residual energy recovery c and flow Q c , estimate whether the energy is balanced.

[0039] In a turbine-coupled fan system, the first thing to do is to determine whether the system energy is balanced. The rated operating parameters of the fan include the rated speed n f0 and rated output N f0 These parameters are usually provided by the wind turbine manufacturer. The head H that can be used for waste energy recovery in the turbine-coupled wind turbine system c and flow Q c The energy balance is determined by whether the mechanical energy output by the turbine meets the energy required for normal operation of the fan.

[0040] The theoretical output power of the turbine can be calculated by the formula P t =ρgQH c η t Calculate, where ρ is the fluid density, usually water (about 1000 kg / m 3 ); g is the acceleration due to gravity (9.8 m / s 2 ); Q is the flow rate (m 3 / s), H c is the effective head (m), η t Indicates turbine efficiency (usually 0.8-0.95).

[0041] The input power required by the fan can be estimated by its rated parameters. The system can only operate normally when the theoretical output power of the turbine is greater than or equal to the input power required by the fan.

[0042] Step 2: Estimate the required turbine specific speed n under the condition of satisfying energy balance s ; and obtain the unit output-unit speed curve and unit flow-unit speed curve of the turbine.

[0043] Specific speed of turbine n sIt is an important parameter for turbine design and selection, and is closely related to the type, efficiency and operating characteristics of the turbine.

[0044] Specific speed of turbine n s The formula can be Calculation; where n is the turbine speed (r / min), P is the turbine output power (kW), and H is the water head (m).

[0045] According to the water head H of the residual energy recovery in the turbine-coupled fan system c and flow Q c , combined with the power demand of the fan, the required turbine speed n can be estimated s Different specific speed ranges are suitable for different types of turbines:

[0046] - Low specific speed (40-200): suitable for impulse turbines, such as Pelton turbines;

[0047] - Medium specific speed (200-450): suitable for Francis turbines, such as Francis turbines;

[0048] ——High specific speed (450-1000): suitable for axial flow turbines, such as Kaplan turbines.

[0049] Unit output of turbine N 11 and unit speed n 11 are important parameters in the turbine similarity theory, and they are defined as:

[0050] ——Unit speed

[0051] ——Unit output

[0052] ——Unit flow

[0053] Where n is the turbine speed (r / min), D1 is the turbine runner diameter (m), H is the water head (m), N t is the turbine processing (kW), Q is the flow rate (m 3 / s).

[0054] For a specific type of turbine, its unit output-unit speed curve and unit flow-unit speed curve can be obtained through model testing or from the performance curves provided by the turbine manufacturer. These curves reflect the performance characteristics of the turbine under different operating conditions.

[0055] Step 3: Define the relationship between fan unit load and unit speed Where N 11f Indicates the fan unit load, n11 Indicates the unit speed of the turbine, k N Indicates unit load factor; unit load factor Where k f represents the fan shaft power coefficient, D1 represents the diameter of the turbine runner; N f0 Indicates the rated load of the fan, in kW; n f0 Indicates the rated speed of the fan input end, in r / min; calculate and draw the fan unit load-unit speed curve.

[0056] Based on the relationship between the fan's unit load and unit speed, we can calculate the corresponding fan unit load values ​​at different unit speeds and plot a fan unit load-unit speed curve. This curve reflects the fan's load characteristics at different unit speeds. Because the fan's unit load is proportional to the cube of the unit speed, this curve is a cubic function: as the unit speed increases, the unit load increases rapidly.

[0057] Step 4: Refer to the instruction manual Figure 1 As shown, the unit output-unit speed curve of the turbine is plotted together with the unit load-unit speed curve of the fan. The intersection of the two is the similar operating condition point of the turbine and the fan. According to the similar operating condition point of the turbine and the fan, the unit output N is obtained. 11 , unit speed n 11 And from the unit flow-unit speed curve of the turbine, the unit flow Q corresponding to the similar operating conditions of the turbine and the fan is obtained. 11 ; Calculate the corresponding turbine speed n, flow Q and output N based on the available head t .

[0058] Example 2

[0059] As another preferred embodiment of the present invention, this embodiment further supplements and elaborates on the technical solution of the present invention based on the above embodiment 1. In this embodiment, the derivation process of the relationship between the unit load and unit speed of the fan described in the above step 3 is as follows:

[0060] When the turbine drives the fan in the turbine-coupled fan system, the turbine and the fan always maintain shaft power balance, that is, N t =N f , N t Indicates turbine output, unit kW; N f It represents the fan load in kW. The output speed of the turbine and the input speed of the fan are also kept equal, both are n.

[0061] The calculation formula of the fan shaft power is obtained from the fan characteristics: Where, P f Indicates the total pressure of the fan, unit is kPa; Q f Indicates the fan ventilation volume, unit: m 3 / s;η f represents the fan efficiency, η r Indicates transmission efficiency;

[0062] Fan full pressure That is, the fan total pressure P f and Proportional to the fan ventilation volume That is, the fan ventilation volume Q f and According to the above formula, the fan load can be obtained That is, the fan load N f and The fan load is proportional to the cube of the speed, and the other terms are expressed as the fan shaft power coefficient k f , then the fan shaft power is expressed as N f =k f n 3 ; Where n represents the speed of the fan input end, unit is r / min; fan shaft power coefficient k f Calculated according to the rated operating parameters of the fan, that is, N f0 Indicates the rated load of the fan, in kW; n f0 Indicates the rated speed of the fan input end, in r / min; when the fan's angle of attack is fixed, the fan shaft power coefficient k f is a constant.

[0063] Since the turbine and fan shaft powers are balanced, N t =k f n 3 ; Fan unit load factor k N Depends on the fan shaft power coefficient k f and turbine diameter D1, i.e.

[0064] Fan unit load N 11f It is expressed using the turbine runner diameter D1 and working water head H, that is, N f =k f n 3 and Substitute into the fan unit load N 11f The relationship between the fan unit load and unit speed is obtained from the expression of When the diameters of the wind turbine and turbine runner are determined, the unit load factor k N is a constant.

[0065] Example 3

[0066] As another preferred embodiment of the present invention, this embodiment is based on the above embodiment 1 or embodiment 2, and further supplements and elaborates on the technical solution of the present invention. In this embodiment, the horizontal coordinate of the similar operating condition point of the turbine and the fan is the unit speed n 11 , the vertical axis is unit output N 11 When different turbine runner diameters D1 are selected, the positions of the similar operating points of the turbine and the fan change. After the turbine runner diameter is selected, the similar operating points of the turbine and the fan are also determined.

[0067] In step S4, the corresponding turbine speed n is calculated, specifically, the excess pressure head H, turbine runner diameter D1 and unit speed n under typical working conditions are calculated. 11 Substitution The corresponding predicted value of the speed n can be obtained. Calculate the corresponding output N t Specifically, it means that the surplus pressure head H and unit output N under typical working conditions are 11 , Substitute the turbine runner diameter D1 into The force N can be calculated t Calculate the corresponding flow rate Q, specifically, the surplus pressure head H and unit flow rate Q under typical working conditions 11 Substitute the runner diameter D1 into The predicted value of the turbine flow rate Q can be obtained.

[0068] As an implementation method of this embodiment, refer to the attached Figure 2 As shown, the water turbine-coupled fan system includes a water turbine, a fan, and a drive shaft. The water turbine converts the potential energy of the water flow into mechanical energy, which is then transferred to the fan via the drive shaft, thereby driving the air flow. Furthermore, preferably, the water turbine-coupled fan system also includes a gearbox, with the water turbine sequentially transferring the mechanical energy to the fan via the drive shaft and the gearbox.

[0069] Furthermore, the turbine is not provided with movable guide vanes, and the unit output-unit speed curve of the turbine is a fixed curve, and the unit flow-unit speed curve of the turbine is also a fixed curve.

[0070] Example 4

[0071] A thermal power plant has a high back-pressure heating system. During the heating period, a hot water circulation pump is used to supply heat to the city, while during the non-heating period, a closed air cooling system is used for heat dissipation. Due to the significant reduction in the water supply distance, even with variable frequency regulation, the water supply pressure during the non-heating period is still sufficient, with a surplus head of 27.4m-31.5m. A turbine is proposed to recover the excess pressure and use it to drive the axial flow fan of the air cooling system, replacing the motor to save electricity. Currently, it is necessary to predict the actual operating parameters of the turbine-coupled fan system. It is known that the rated power of the axial flow fan (including the reducer system) is 48kW and the rated speed is 960r / min. The turbine runner diameter D1 = 35cm is selected, and the unit output curve-unit speed curve and the unit flow-unit speed curve are obtained. A method for predicting the operating conditions of the turbine-coupled fan system is used to calculate the operating parameters of the turbine. The specific calculation steps are as follows:

[0072] Calculate the fan unit load function:

[0073] (1) Calculate the fan shaft power coefficient k f , according to the formula Determine the fan shaft power coefficient k when the fan blade attack angle is 16° f is 5.425×10^(-8);

[0074] (2) Calculate the fan unit load factor k N , according to the formula The fan shaft power coefficient k f and the rotor diameter D1, the unit load factor k of the fan is obtained. N 1.033×10 -5 ;

[0075] (3) According to the formula The formula for obtaining the fan unit load curve is:

[0076] Draw the turbine unit output curve and the fan unit load curve on the same graph (such as Figure 4 As shown), the intersection of the two curves can be obtained. The unit speed is determined to be 63.73r / min through the intersection, and the unit output and unit load of the turbine are 2.67kW. According to the unit flow-unit speed curve, the unit flow is 0.302m 3 / s.

[0077] according to According to calculation, when the water head H is 27.4m~31.5m, the calculated speed is 953~1022r / min.

[0078] according to When the available water head H=27.4m~31.5m, the shaft power of the turbine is 46.9~57.8kW.

[0079] according to When the available water head H is 27.4m~31.5m, the flow rate of the turbine is 696~747m 3 / h.

[0080] Through a method for predicting the operating conditions of a turbine-coupled fan system, the operating conditions of the turbine-coupled fan system are predicted. The turbine speed, flow rate and shaft power parameters are obtained according to different water heads. Finally, after engineering verification, it can better meet the needs of engineering applications.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for predicting the operating condition of a turbine-coupled fan system, characterized by: The operating condition prediction method includes the following steps: S1, according to the rated speed n of the fan in the turbine-coupled fan system f0 and rated output N f0 , and the head H that can be used in residual energy recovery c and flow Q c , estimate whether the energy of the turbine-coupled wind turbine system is balanced; S2. Estimate the required turbine specific speed n under the condition of satisfying energy balance s , and obtain the unit output-unit speed curve and unit flow-unit speed curve of the turbine; S3. Define the relationship between fan unit load and unit speed Where N 11f Indicates the fan unit load, n 11 Indicates the unit speed of the turbine, k N Indicates unit load factor; unit load factor Where k f represents the fan shaft power coefficient, D1 represents the diameter of the turbine runner; N f0 Indicates the rated load of the fan, in kW; n f0 Indicates the rated speed of the fan input end, in r / min; calculates and draws the fan unit load-unit speed curve; S4. Draw the unit output-unit speed curve of the turbine and the unit load-unit speed curve of the fan together. The intersection of the two is the similar operating condition point of the turbine and the fan. According to the similar operating condition point of the turbine and the fan, the unit output N is obtained. 11 , unit speed n 11 And from the unit flow-unit speed curve of the turbine, the unit flow Q corresponding to the similar operating conditions of the turbine and the fan is obtained. 11 ; Calculate the corresponding turbine speed n, flow Q and output N based on the available head t .

2. The method for predicting the operating condition of a hydro-turbine coupled wind turbine system according to claim 1, wherein: In step S2, the specific process of defining the relationship between the fan unit load and unit speed is as follows: When the turbine drives the fan in the turbine-coupled fan system, the turbine and the fan always maintain shaft power balance, that is, N t =N f , N t Indicates turbine output, unit kW; N f Indicates fan load, unit kW; The output speed of the turbine and the input speed of the fan are kept equal. The shaft power calculation formula of the fan is obtained from the fan characteristics: Where, P f Indicates the total pressure of the fan, unit is kPa; Q f Indicates the fan ventilation volume, unit: m 3 / s;η f represents the fan efficiency, η r Indicates transmission efficiency; Fan full pressure ρ f Indicates air density in kg / m 3 ;D f Indicates the diameter of the fan rotor, in m; n f Indicates the fan speed, unit is r / min; fan ventilation volume The fan load That is, the fan load is proportional to the cube of the speed, and the other terms are expressed as the fan shaft power coefficient k f , then the fan shaft power is expressed as N f =k f n 3 ; Where n represents the speed of the fan input end, unit is r / min; fan shaft power coefficient k f Calculated according to the rated operating parameters of the fan, that is, N f0 Indicates the rated load of the fan, in kW; n f0 Indicates the rated speed of the fan input end, in r / min; when the fan's angle of attack is fixed, the fan shaft power coefficient k f is a constant; Since the turbine and fan shaft powers are balanced, N t =k f n 3 ; Fan unit load factor k N Depends on the fan shaft power coefficient k f and turbine diameter D1, i.e. Fan unit load N 11f It is expressed using the turbine runner diameter D1 and working water head H, that is, N f =k f n 3 and Substitute into the fan unit load N 11f The relationship between the fan unit load and unit speed is obtained from the expression of 3. The method for predicting the operating condition of a hydro-turbine coupled wind turbine system according to claim 1 or 2, characterized in that: The horizontal coordinate of the similar operating condition point of the turbine and the fan is the unit speed n 11 , the vertical axis is unit output N 11 When different turbine runner diameters D1 are selected, the positions of the similar operating points of the turbine and the fan change. After the turbine runner diameter is selected, the similar operating points of the turbine and the fan are also determined.

4. The method for predicting the operating condition of a hydro-turbine coupled wind turbine system according to claim 1 or 2, characterized in that: In step S4, the corresponding turbine speed n is calculated, specifically, the excess pressure head H, turbine runner diameter D1 and unit speed n under typical working conditions are calculated. 11 Substitution The corresponding predicted value of the speed n can be obtained.

5. The method for predicting the operating condition of a hydro-turbine coupled wind turbine system according to claim 4, characterized in that: Calculate the corresponding output N t Specifically, it means that the surplus pressure head H and unit output N under typical working conditions are 11 , Substitute the turbine runner diameter D1 into The force N can be calculated t The predicted value of .

6. The method for predicting the operating condition of a hydro-turbine coupled wind turbine system according to claim 5, characterized in that: Calculate the corresponding flow rate Q, specifically, the surplus pressure head H and unit flow rate Q under typical working conditions 11 Substitute the runner diameter D1 into The predicted value of the turbine flow rate Q can be obtained.

7. The method for predicting the operating condition of a hydro-turbine coupled wind turbine system according to claim 1 or 2, characterized in that: The water turbine coupled fan system includes a water turbine, a fan and a drive shaft. The water turbine converts water flow potential energy into mechanical energy. The water turbine transmits the mechanical energy to the fan through the drive shaft, and the fan drives the air flow.

8. The method for predicting the operating condition of a water turbine coupled wind turbine system according to claim 7, characterized in that: The water turbine coupled to the fan system further includes a gearbox, and the water turbine transmits mechanical energy to the fan via a drive shaft and the gearbox in sequence.

9. The method for predicting the operating condition of a hydro-turbine coupled wind turbine system according to claim 7, wherein: The turbine is not provided with movable guide vanes, and the unit output-unit speed curve of the turbine is a fixed curve, and the unit flow-unit speed curve of the turbine is also a fixed curve.

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