Cooling fan operation optimization method for gas-steam combined cycle generator set

Abstract

The invention belongs to the technical field of gas-steam combined cycle power generation, and particularly relates to a cooling fan operation optimization method for a gas-steam combined cycle generator set. In order to solve the problem that the optimal operation number of cooling fans is difficult to determine during operation of a gas-steam combined cycle generator set, the method comprises the following steps: firstly, developing a cooling performance calculation model of any fan, and then calculating the temperature of circulating water at an outlet of a cooling tower under any environment temperature and air relative humidity by using the model; and a condenser cooling performance curve corresponding to the temperature of the circulating water is obtained by looking up a table, so that the generating capacity of any cooling fan during parallel operation and the power consumption of the fans are calculated, and finally the more generated electric quantity and the more consumed electric quantity during operation of any cooling fan are compared, so that the optimal operation number of the cooling fans is obtained.

Description

Technical Field

[0001] This invention belongs to the field of gas-steam combined cycle power generation technology, specifically relating to a method for optimizing the operation of cooling fans in gas-steam combined cycle generator sets. Background Technology

[0002] For gas-steam combined cycle units that use circulating water for exhaust steam cooling, determining the number of cooling fans to be in operation is a challenge in actual operation. Generally, the more cooling fans in operation, the better the cooling effect on the circulating water, and consequently, the lower the temperature of the circulating water at the cooling tower outlet. This low-temperature circulating water then enters the condenser, providing better cooling for the steam inside, thus reducing the condenser back pressure, increasing the turbine's work capacity, and generating more electricity. However, the cooling fans themselves also consume some electricity. Power plants often cannot determine whether the additional electricity generated by deploying more cooling fans outweighs the additional electricity consumed by the cooling fans themselves. Furthermore, the cooling effect of cooling fans on circulating water is mainly affected by two factors: the first is ambient temperature; the higher the ambient temperature, the worse the cooling effect of the cooling fans. The second factor is relative humidity. Since evaporation is a primary cooling method for circulating water in the cooling tower, when the relative humidity is low, the circulating water can release more vapor into the air, allowing for rapid evaporation. Conversely, when the relative humidity reaches saturation, evaporation ceases. Therefore, atmospheric relative humidity significantly impacts the cooling of circulating water. In actual operation, both ambient temperature and relative humidity fluctuate considerably, causing the cooling effect of the cooling fans on the circulating water to change accordingly. Consequently, even with the same number of cooling fans in operation, sometimes the extra electricity generated exceeds the energy consumed by the fans themselves, making it economically viable, while other times the extra electricity generated is less than the energy consumed by the fans, making it economically unviable. This makes it difficult for power plants to determine the optimal number of cooling fans to operate, hindering the overall economic efficiency of the generator sets.

[0003] Therefore, it is meaningful to develop a calculation model for the cooling effect of fans based on ambient temperature and relative humidity. By using this model to compare the relationship between the increased power generation and increased power consumption under different circulating water cooling effects, it will be possible to determine the optimal number of cooling fans to operate, thereby enabling the generator set to achieve the most economical operating state. Summary of the Invention

[0004] To address the problem of determining the optimal number of cooling fans to operate in gas-steam combined cycle generator sets, this invention provides a method for optimizing the operation of cooling fans in gas-steam combined cycle generator sets. This method comprehensively considers the influence of ambient temperature and relative humidity on the cooling effect of circulating water, and can calculate the optimal number of fans to operate under any environmental conditions, thereby maximizing the economic efficiency of the unit operation.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A method for optimizing the operation of cooling fans in gas-steam combined cycle generator sets includes the following steps:

[0007] Step 1: Develop a cooling performance calculation model for a single cooling fan during operation, and a cooling performance calculation model for multiple cooling fans operating in parallel.

[0008] Step 2: Calculate the power generation and power consumption of any cooling fans operating in parallel;

[0009] Step 3: Optimize the number of cooling fans in operation based on the power generation and power consumption of parallel operation.

[0010] The principle and advantages of the above scheme are as follows: First, a cooling performance calculation model for any cooling fan is developed. Then, the circulating water temperature at the cooling tower outlet is calculated using this model under any ambient temperature and relative humidity. The condenser cooling performance curve corresponding to this circulating water temperature is obtained by looking up a table. Thus, the power generation when any cooling fans are working in parallel and the power consumption of these fans are calculated. Finally, the extra power generated and extra power consumed by any cooling fan during operation are compared to determine the optimal number of cooling fans to operate.

[0011] Furthermore, the development of a cooling performance calculation model for a single cooling fan includes: first, fitting the influence curve of relative humidity on the circulating water temperature at the cooling tower outlet; second, fitting the influence curve of ambient temperature on the circulating water temperature at the cooling tower outlet; and finally, developing a method for calculating the cooling performance of a single fan. The reason for adopting this approach is that ambient temperature and relative humidity are important factors affecting the cooling circulating water of the fan. The impact of changes in these two factors on the cooling performance of the fan must be considered in order to accurately calculate the circulating water temperature at the cooling tower outlet.

[0012] The curve showing the effect of relative air humidity on the circulating water temperature at the cooling tower outlet is as follows:

[0013] The temperature of the circulating water at the outlet of the cooling tower was tested under specific operating conditions, namely: (1) a single cooling fan was running; and (2) the ambient temperature during the test was selected as the local average temperature of spring and autumn, T. 平均温度(3) Ensure the ambient temperature T is within the specified range during the test. 平均 The relative humidity remains basically unchanged. Under this operating condition, the highest relative humidity R is measured respectively. 高湿度 Average relative humidity R 平均湿度 and minimum relative humidity R 低湿度 The corresponding circulating water temperatures at the cooling tower outlet under the three conditions are denoted as Y. 1-高湿度 Y 1-平均湿度 and Y 1-低湿度 The reasons for adopting this scheme are: (1) The average temperature T in spring and autumn is selected as the ambient temperature during the test. Such a temperature value is close to the average temperature of the whole year, and the measured data has the best representativeness; (2) The average ambient temperature T remains basically unchanged during the test, which can ensure that the change of circulating water temperature is not related to the ambient temperature, and is only affected by the relative humidity of the air. This is the only way to reflect the effect of the change of relative humidity of the air on the cooling effect of circulating water.

[0014] Based on the temperature Y of the circulating water at the outlet of the three cooling towers obtained from the test... 1-高湿度 Y 1-平均湿度 Y 1-低湿度 And the corresponding parabolic equation for relative humidity, the parabolic equation being y 1-湿度 =aR 2 +bR+c, where R represents the relative humidity of the air, y 1-湿度 This represents the circulating water temperature at the cooling tower outlet calculated based on the relative humidity of the air when a single cooling fan is running. a, b, and c are coefficients. The advantage of this approach is that only three sets of data need to be measured to fit the parabolic equation, which has the advantages of low workload and high accuracy.

[0015] The curve showing the effect of the fitted ambient temperature on the circulating water temperature at the cooling tower outlet is as follows:

[0016] The temperature of the circulating water at the outlet of the cooling tower was tested under specific operating conditions, namely: (1) a single cooling fan was running; and (2) the relative humidity of the air at the time of testing was selected as the local average relative humidity R during spring and autumn. 平均湿度 (3) Ensure the relative humidity R during the test. 平均湿度 The basic operation remains unchanged; under this operating condition, the highest ambient temperature T was measured respectively. 高温 Average ambient temperature T 平均温度 and lowest ambient temperature T 最低 The corresponding circulating water temperatures at the cooling tower outlet under the three conditions are denoted as Y. 1-高温 Y 1-平均温度 and Y 1-低温 The reasons for adopting this plan are: (1) Selecting the local average relative humidity R during spring and autumn seasons. 平均湿度As the ambient temperature during the test, such a humidity value is close to the average humidity throughout the year, and the measured data has the best representativeness; (2) the average relative humidity R during the test process 平均湿度 The temperature remains basically unchanged, which ensures that the change in circulating water temperature is independent of the average humidity and is only affected by the ambient humidity. This is the only way to reflect the impact of changes in ambient temperature on the cooling effect of circulating water.

[0017] Based on the temperature Y of the circulating water at the outlet of the three cooling towers obtained from the test... 1-高温 Y 1-平均温度 Y 1-低温 And the corresponding environmental temperature fitting parabolic equation, the parabolic equation being y 1-温度 =aT 2 +bT+c, where T represents the ambient temperature, y 1-温度 This represents the circulating water temperature at the cooling tower outlet calculated based on the ambient temperature when a single cooling fan is running. a, b, and c are coefficients. The advantage of this approach is that only three sets of data need to be measured to fit the parabolic equation, which has the advantages of low workload and high accuracy.

[0018] The specific method for calculating the cooling performance of a single cooling fan is as follows:

[0019] The parabola equation y 1-湿度 =aR 2 Plot curve C1 using the formula +bR+c. The x-axis of curve C1 represents the relative humidity R, and the y-axis represents the circulating water temperature at the cooling tower outlet. Find the point on the x-axis corresponding to the actual relative humidity R. Draw a perpendicular line from this point to curve C1, intersecting it at point A. The circulating water temperature at the cooling tower outlet corresponding to point A is the humidity-corrected circulating water temperature Y at the cooling tower outlet. 1-湿度修正 The advantage of this approach is that the change in circulating water temperature at the cooling tower outlet can be determined simply by using a graphical method when the actual relative humidity deviates from the standard value.

[0020] The curve C1 is based on the average ambient temperature T. 平均温度 The fitted result shows that when the actual ambient temperature T 实际温度 With average ambient temperature T 平均温度 When there is inconsistency, curve C1 should be corrected. The specific correction method is as follows: (1) Use y 1-温度 =aT 2 The average ambient temperature T is calculated using +bT+c. 平均温度 The corresponding circulating water temperature Y at the cooling tower outlet 1-平均温度 , use y 1-温度 =aT 2 The actual ambient temperature T is calculated using +bT+c. 实际温度The corresponding circulating water temperature Y at the cooling tower outlet 1-实际温度 Calculate the difference ΔY 1-温度修正 =Y 1-实际温度 -Y 1-平均温度 (2) If T 实际温度 >T 平均温度 Then the final true value Y1=Y 1-湿度修正 +△Y 1-温度修正 If T 实际温度 <T 平均温度 Then the final true value Y1=Y 1-湿度修正 -△Y 1-温度修正 (3) Y1 is the actual value of the circulating water temperature at the outlet of the cooling tower when a single cooling fan is running after humidity correction and ambient temperature correction. The advantage of this approach is that the change in the circulating water temperature at the outlet of the cooling tower caused by the actual ambient humidity deviating from the standard value can be calculated simply by doing so.

[0021] The development of the cooling performance calculation model for multiple cooling fans operating in parallel is the same as the development of the cooling performance calculation model for a single cooling fan operating in parallel.

[0022] Furthermore, the calculation of the power generation when any number of cooling fans are operating in parallel includes:

[0023] Consult the condenser performance curve table to find the specific condenser performance curve corresponding to the actual value of the circulating water temperature at the cooling tower outlet when any cooling fans are working in parallel. Find the corresponding back pressure value based on the steam flow rate and calculate the generated power.

[0024] The principle behind the above scheme is as follows: Manufacturers typically provide condenser performance curves, which show the relationship between steam flow rate, circulating water inlet temperature (i.e., the circulating water temperature at the cooling tower outlet), and turbine back pressure. Since the steam flow rate is determined by the unit load and is independent of the cooling system's operating mode, it can be treated as a fixed value. In this case, as long as the circulating water inlet temperature is determined, the turbine back pressure can be found. Therefore, the turbine back pressure when a single cooling fan is running can be determined based on the circulating water temperature Y1, and then the power generation under this operating condition can be calculated using Formula 1. Similarly, the power generation when two, three, or even more cooling fans are running can be calculated.

[0025] Furthermore, the calculation of the power consumption of any number of cooling fans operating in parallel includes:

[0026] The power consumption of a single cooling fan is calculated based on the current and voltage of the single cooling fan during operation.

[0027] Based on the power consumption of a single cooling fan, the power consumption of multiple cooling fans can be calculated.

[0028] The principle of the above scheme is: the power supply of the cooling fan is AC, which can be calculated based on the voltage and current of the fan during operation. The calculation method is shown in formula (2).

[0029] Furthermore, the optimization of the number of operating cooling fans includes:

[0030] A comparison of the economics of operating a single cooling fan versus operating two cooling fans in parallel reveals the following: If E2 - E1 > W2 - W1, it indicates that the increased power generation from operating two cooling fans in parallel is greater than the increased power consumption from operating a single cooling fan, making it economically worthwhile and suggesting that the power plant should operate two cooling fans. Conversely, if E2 - E1 < W2 - W1, it indicates that the increased power generation from operating two cooling fans in parallel is less than the increased power consumption from operating two cooling fans, making it economically worthwhile and suggesting that the power plant should operate one cooling fan. Here, E1 represents the power generation from operating a single cooling fan, E2 represents the power generation from operating two cooling fans, W1 represents the power consumption of a single cooling fan, and W2 represents the power consumption of two cooling fans.

[0031] Using the same method, the economic efficiency of putting any number of cooling fans into operation is compared to determine the optimal number of cooling fans to operate, thus maximizing the overall economic efficiency of the unit. The advantage of this approach is that the number of cooling fans to be put into operation can be determined through simple calculations and comparisons.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] This invention first develops a calculation model for the cooling performance of any cooling fan. Then, it uses this model to calculate the circulating water temperature at the cooling tower outlet under any ambient temperature and relative humidity. By looking up the table, it obtains the condenser cooling performance curve corresponding to the circulating water temperature. This allows it to calculate the power generation when any cooling fans are operating in parallel, as well as the power consumption of these fans. Finally, it compares the additional power generated and consumed by any cooling fans during operation to determine the optimal number of cooling fans to operate. Attached Figure Description

[0034] Figure 1 This is a flowchart of a method for optimizing the operation of a cooling fan in a gas-steam combined cycle generator set according to the present invention;

[0035] Figure 2 The response curves for relative humidity of air and circulating water temperature at the cooling tower outlet are fitted.

[0036] Figure 3 This is a schematic diagram showing the correction for actual air relative temperature. Detailed Implementation

[0037] To further illustrate the technical solution of the present invention, the present invention will be further described below through embodiments.

[0038] Generally, the more cooling fans put into operation, the better the cooling effect on the exhaust steam in the condenser, which reduces the back pressure of the condenser, enhances the turbine's work capacity, and generates more electricity. However, the cooling fans themselves also consume a certain amount of electricity. Therefore, evaluating the economics of the number of cooling fans in operation essentially involves comparing the additional electricity generated by the steam in the turbine with the electricity consumed by the additional cooling fans. If the additional electricity generated by the turbine is greater than the additional electricity consumed by the cooling fans, it is economically reasonable; otherwise, more cooling fans should not be put into operation. The power generation work of the steam in the turbine is calculated using the following formula:

[0039] (Formula 1)

[0040] In the above formula, The generator's output is expressed in kWh. The steam flow rate inside the steam turbine is expressed in kg / h. The initial enthalpy of the steam before it does work is expressed in kJ / kg. The enthalpy of the steam after work is expressed in kJ / kg. The efficiency of converting heat energy into electrical energy is %. Determined by the initial pressure and temperature of the steam, it usually does not change and is a fixed value; Determined by the performance of the turbine and generator of the equipment, this value is usually constant for generator sets that are already in operation, and ranges from approximately 0.85 to 0.90. It varies with changes in power generation load and can be measured by the unit's DCS system. The saturation temperature is usually determined by the pressure and temperature of the steam after it has done work. However, it should be noted that when the steam enters the condenser, it is usually in a wet saturated state, and its saturation temperature is determined by the exhaust pressure. It can be determined by the exhaust pressure. Therefore, when the circulating water has a good cooling effect on the steam, the exhaust pressure decreases. It also decreased simultaneously, so the power generation... The corresponding increase.

[0041] The electrical energy consumed by the cooling fan can be calculated using the following formula:

[0042] (Formula 2)

[0043] This indicates the motor power of the cooling fan (i.e., the electrical energy consumed by the cooling fan per unit time), in kW; This represents the phase voltage of the motor, in V; The value represents the motor current, in A; 0.85 is the power factor. and All data can be read directly from the unit's DCS system.

[0044] Since the standard configuration of the gas-steam combined cycle generator set is 3 cooling fans, this embodiment uses 3 cooling fans as an example for explanation. If there are more than 3 cooling fans in actual use, the method described herein can be applied in the same way, and the principle is the same.

[0045] like Figure 1 As shown in this embodiment, a method for optimizing the operation of a cooling fan in a gas-steam combined cycle generator set includes the following steps:

[0046] 101: Develop a calculation model for the cooling performance of a single cooling fan.

[0047] First, the influence curve of relative humidity on the circulating water temperature at the cooling tower outlet is fitted; second, the influence curve of ambient temperature on the circulating water temperature at the cooling tower outlet is fitted; finally, a method for calculating the cooling performance of a single fan is developed.

[0048] The curve showing the effect of relative air humidity on the circulating water temperature at the cooling tower outlet is as follows:

[0049] First, the temperature of the circulating water at the outlet of the cooling tower was tested under specific operating conditions. The specific operating conditions were: (1) operation of a single cooling fan; (2) the ambient temperature during the test was selected as the local average temperature of spring and autumn, T. 平均温度 (3) Ensure the ambient temperature T is within the specified range during the test. 平均 The temperature remained essentially unchanged. Under this operating condition, the highest relative humidity R was measured at the cooling tower outlet using an insertion thermometer. 高湿度 Average relative humidity R 平均湿度 and minimum relative humidity R 低湿度 The corresponding circulating water temperatures at the cooling tower outlet under the three conditions are denoted as Y. 1-高湿度 Y 1-平均湿度 and Y 1-低湿度 .

[0050] Secondly, based on the temperatures of the circulating water at the outlets of the three cooling towers obtained from the tests (i.e., Y1-high humidity, Y1-average humidity, and Y...),... 1-低湿度 And the corresponding parabolic equation fitted to the relative humidity of the air, the parabolic equation being y 1-湿度 =aR 2 +bR+c, where R represents the relative humidity of the air, y 1-湿度This represents the circulating water temperature at the cooling tower outlet, calculated based on humidity, when a single fan is running. a, b, and c are coefficients, with specific values ​​provided by the fitting results. The specific fitting method is as follows:

[0051] Given three points (x1, y1), (x2, y2), and (x3, y3) in a plane, fit the equation of a quadratic parabola y = ax 2 The equation +bx+c can be solved by substituting the coordinates of the three points into the equation to obtain a system of three linear equations in three variables. The values ​​of a, b, and c can then be found by solving the system of equations. The specific steps are as follows:

[0052] (1) Substitute the points (x1, y1), (x2, y2), and (x3, y3) into the equation y = ax 2 +bx+c yields:

[0053]

[0054] (2) Solve the system of equations using the matrix method:

[0055] Write the system of equations in matrix form: =

[0056] Based on the properties of matrix multiplication and the inverse matrix: = The values ​​of a, b, and c can be obtained by multiplying the inverse of the coefficient matrix with the constant matrix.

[0057] (3) Obtain the equation of the parabola

[0058] Substitute the calculated values ​​of a, b, and c into y = ax 2 +bx+c gives us the equation of the quadratic parabola that fits these three points.

[0059] The curve showing the effect of the fitted ambient temperature on the circulating water temperature at the cooling tower outlet is as follows:

[0060] First, the temperature of the circulating water at the outlet of the cooling tower was tested under specific operating conditions. The specific operating conditions were: (1) operation of a single cooling fan; (2) the relative humidity of the air at the time of testing was selected as the local average relative humidity R during spring and autumn. 平均湿度 (3) Ensure the relative humidity R during the test. 平均湿度 The temperature remains basically unchanged. Under this operating condition, the highest ambient temperature T is measured at the cooling tower outlet using an insertion thermometer. 高温 Average ambient temperature T 平均温度and lowest ambient temperature T 最低 The corresponding circulating water temperatures at the cooling tower outlet under the three conditions are denoted as Y. 1-高温 Y 1-平均温度 and Y 1-低温 .

[0061] Secondly, based on the temperatures of the circulating water at the three cooling tower outlets obtained from the tests (i.e., Y1-high temperature, Y1-average temperature, and Y1-low temperature) and the corresponding ambient temperatures, a parabolic equation is fitted, and the parabolic equation is y 1-温度 =aT 2 +bT+c, where T represents the ambient temperature, y 1-温度 This represents the circulating water temperature at the cooling tower outlet, calculated based on the ambient temperature when a single fan is running. a, b, and c are coefficients, with their specific values ​​provided by the fitting results. The specific fitting method is described above and will not be repeated here.

[0062] The method for calculating the cooling performance of a single fan includes:

[0063] First, the equation of the parabola y 1-湿度 =aR 2 The curve C1 is plotted as +bR+c, where the x-axis represents the relative humidity R and the y-axis represents the circulating water temperature at the cooling tower outlet. Figure 2 As shown. Find the point on the horizontal axis corresponding to the actual relative humidity R, draw a perpendicular line through this point, intersecting the curve C1 at point A. The circulating water temperature at the cooling tower outlet corresponding to point A is the humidity-corrected circulating water temperature Y at the cooling tower outlet. 1-湿度修正 ,like Figure 3 As shown.

[0064] Secondly, the curve C1 is based on the average ambient temperature T. 平均温度 The fitted result shows that when the actual ambient temperature T 实际温度 With the average ambient temperature T 平均温度 When there is a discrepancy, the curve C1 should be corrected. The specific correction method is as follows: (1) Use the y 1-温度 =aT 2 The average ambient temperature T is calculated using +bT+c. 平均温度 The corresponding circulating water temperature Y at the cooling tower outlet 1-平均温度 , using the y 1-温度 =aT 2 The actual ambient temperature T is calculated using +bT+c. 实际温度 The corresponding circulating water temperature Y at the cooling tower outlet 1-实际温度 Calculate the difference ΔY 1-温度修正 =Y 1-实际温度 -Y 1-平均温度 (2) If T 实际温度>T 平均温度 Then the final true value Y1=Y 1-湿度修正 +△Y 1-温度修正 If T 实际温度 <T 平均温度 Then the final true value Y1=Y 1-湿度修正 -△Y 1-温度修正 (3) Y1 is the actual value of the circulating water temperature at the outlet of the cooling tower when a single fan is running, after humidity correction and ambient temperature correction.

[0065] 102: Develop a calculation model for the cooling performance of two fans operating in parallel.

[0066] The specific method is the same as 101, so I will not repeat it here.

[0067] 103: Develop a calculation model for the cooling performance of three fans operating in parallel.

[0068] The specific method is the same as 101, so I will not repeat it here.

[0069] 104: Calculate the power generation of any number of cooling fans operating in parallel.

[0070] Taking a single fan as an example, the calculation method for the power generation of a single fan is as follows: First, use the cooling performance calculation model of a single fan to determine the circulating water temperature at the cooling tower outlet. This temperature is the circulating water temperature at the condenser. Second, refer to the condenser characteristic curve provided by the manufacturer and find the specific curve that matches the circulating water temperature (if the circulating water temperature given in the curve is not exactly the same as the circulating water temperature calculated by the model, the linear averaging method can be used to calculate the condenser characteristic curve that is completely consistent with the circulating water temperature at the cooling tower outlet). Third, based on the unit's operating conditions, determine the exhaust steam flow rate in the condenser. Combined with the condenser performance curve determined in the second step, determine the condenser back pressure and use Formula 1 (as mentioned above) to calculate the power generation E1 generated by steam.

[0071] Using the same method, the power generation E2 when two cooling fans are working in parallel and the power generation E3 when three cooling fans are working in parallel can be calculated.

[0072] 105: Calculate the power consumption of any number of cooling fans operating in parallel.

[0073] First, calculate the power consumption of the cooling fans. The power consumption W1 of a single cooling fan can be calculated using formula 2; the power consumption W2 of two cooling fans operating in parallel is W1×2; and the power consumption W3 of three cooling fans operating in parallel is W1×3.

[0074] 105: Optimization of the number of operating cooling fans

[0075] Economic comparison between operating a single cooling fan and operating two cooling fans in parallel: If E2 - E1 > W2 - W1, it indicates that the increased power generation from operating two cooling fans in parallel is greater than the increased power consumption from operating a single cooling fan, therefore it is economically worthwhile, indicating that the power plant should operate two cooling fans; if E2 - E1 < W2 - W1, it indicates that the increased power generation from operating two cooling fans in parallel is less than the increased power consumption from operating two cooling fans, therefore it is not economically worthwhile, indicating that the power plant should operate only one cooling fan.

[0076] Using the same method, the economic efficiency of putting any number of cooling fans into operation can be compared, thereby determining the optimal number of cooling fans to operate, so that the overall economic efficiency of the unit can be optimized.

[0077] The foregoing has shown and described the main features and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0078] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for optimizing the operation of cooling fans in a gas-steam combined cycle generator set, characterized in that, Includes the following steps: Step 1: Develop a cooling performance calculation model for a single cooling fan during operation, and a cooling performance calculation model for multiple cooling fans operating in parallel. Step 2: Calculate the power generation and power consumption of any cooling fans operating in parallel; Step 3: Optimize the number of cooling fans in operation based on the power generation and power consumption of parallel operation.

2. The method for optimizing the operation of cooling fans in a gas-steam combined cycle generator set according to claim 1, characterized in that, The development of a cooling performance calculation model for a single cooling fan includes: first, fitting the influence curve of relative humidity of the air on the circulating water temperature at the cooling tower outlet; second, fitting the influence curve of ambient temperature on the circulating water temperature at the cooling tower outlet; and finally, developing a method for calculating the cooling performance of a single fan. The curve showing the effect of relative air humidity on the circulating water temperature at the cooling tower outlet is as follows: The temperature of the circulating water at the outlet of the cooling tower was tested under specific operating conditions, namely: (1) a single cooling fan was running; and (2) the ambient temperature at the time of testing was selected as the local average temperature of spring and autumn, T. 平均温度 (3) Ensure the ambient temperature T is within the specified range during the test. 平均 The relative humidity remains basically unchanged. Under this operating condition, the highest relative humidity R is measured respectively. 高湿度 Average relative humidity R 平均湿度 and minimum relative humidity R 低湿度 The corresponding circulating water temperatures at the cooling tower outlet under the three conditions are denoted as Y. 1-高湿度 Y 1-平均湿度 and Y 1-低湿度 ; Based on the temperature Y of the circulating water at the outlet of the three cooling towers obtained from the test... 1-高湿度 Y 1-平均湿度 Y 1-低湿度 And the corresponding parabolic equation for relative humidity, the parabolic equation being y 1-湿度 =aR 2 +bR+c, where R represents the relative humidity of the air, y 1-湿度 This represents the circulating water temperature at the cooling tower outlet, calculated based on the relative humidity of the air when a single cooling fan is running; a, b, and c are coefficients. The curve showing the effect of the fitted ambient temperature on the circulating water temperature at the cooling tower outlet is as follows: The temperature of the circulating water at the outlet of the cooling tower was tested under specific operating conditions, namely: (1) a single cooling fan was running; and (2) the relative humidity of the air at the time of testing was selected as the local average relative humidity R during spring and autumn. 平均湿度 (3) Ensure the relative humidity R during the test. 平均湿度 The basic operation remains unchanged; under this operating condition, the highest ambient temperature T was measured respectively. 高温 Average ambient temperature T 平均温度 and lowest ambient temperature T 最低 The corresponding circulating water temperatures at the cooling tower outlet under the three conditions are denoted as Y. 1-高温 Y 1-平均温度 and Y 1-低温 ; Based on the temperature Y of the circulating water at the outlet of the three cooling towers obtained from the test... 1-高温 Y 1-平均温度 Y 1-低温 And the corresponding environmental temperature fitting parabolic equation, the parabolic equation being y 1-温度 =aT 2 +bT+c, where T represents the ambient temperature, y 1-温度 This represents the circulating water temperature at the cooling tower outlet calculated based on the ambient temperature when a single cooling fan is running; a, b, and c are coefficients. The specific method for calculating the cooling performance of a single cooling fan is as follows: The parabola equation y 1-湿度 =aR 2 Plot curve C1 using the formula +bR+c. The x-axis of curve C1 represents the relative humidity R, and the y-axis represents the circulating water temperature at the cooling tower outlet. Find the point on the x-axis corresponding to the actual relative humidity R. Draw a perpendicular line from this point to curve C1, intersecting it at point A. The circulating water temperature at the cooling tower outlet corresponding to point A is the humidity-corrected circulating water temperature Y at the cooling tower outlet. 1-湿度修正 ; The curve C1 is based on the average ambient temperature T. 平均温度 The fitted result shows that when the actual ambient temperature T 实际温度 With average ambient temperature T 平均温度 When there is inconsistency, curve C1 should be corrected. The specific correction method is as follows: (1) Use y 1-温度 =aT 2 The average ambient temperature T is calculated using +bT+c. 平均温度 The corresponding circulating water temperature Y at the cooling tower outlet 1-平均温度 , use y 1-温度 =aT 2 The actual ambient temperature T is calculated using +bT+c. 实际温度 The corresponding circulating water temperature Y at the cooling tower outlet 1-实际温度 Calculate the difference ΔY 1-温度修正 =Y 1-实际温度 -Y 1-平均温度 (2) If T 实际温度 >T 平均温度 Then the final true value Y1=Y 1-湿度修正 +△Y 1-温度修正 If T 实际温度 <T 平均温度 Then the final true value Y1=Y 1-湿度修正 -△Y 1-温度修正 (3) Y1 is the actual value of the circulating water temperature at the outlet of the cooling tower when a single cooling fan is running after humidity correction and ambient temperature correction. The development of the cooling performance calculation model for multiple cooling fans operating in parallel is the same as the development of the cooling performance calculation model for a single cooling fan operating in parallel.

3. The method for optimizing the operation of a cooling fan in a gas-steam combined cycle generator set according to claim 2, characterized in that, The calculation of the power generation when any cooling fans are connected in parallel includes: Consult the condenser performance curve table to find the specific condenser performance curve corresponding to the actual value of the circulating water temperature at the cooling tower outlet when any cooling fans are working in parallel. Find the corresponding back pressure value based on the steam flow rate and calculate the generated power.

4. The method for optimizing the operation of a cooling fan in a gas-steam combined cycle generator set according to claim 3, characterized in that, The calculation of the power consumption of any number of cooling fans operating in parallel includes: The power consumption of a single cooling fan is calculated based on the current and voltage of the single cooling fan during operation. Based on the power consumption of a single cooling fan, the power consumption of multiple cooling fans can be calculated.

5. The method for optimizing the operation of a cooling fan in a gas-steam combined cycle generator set according to claim 3, characterized in that, The optimization of the number of operating cooling fans includes: A comparison of the economics of operating a single cooling fan versus operating two cooling fans in parallel reveals the following: If E2 - E1 > W2 - W1, it indicates that the increased power generation from operating two cooling fans in parallel is greater than the increased power consumption from operating one cooling fan; therefore, the power plant should operate two cooling fans. If E2 - E1 < W2 - W1, it indicates that the increased power generation from operating two cooling fans in parallel is less than the increased power consumption from operating one cooling fan; therefore, the power plant should operate one cooling fan. Here, E1 represents the power generation from operating a single cooling fan, E2 represents the power generation from operating two cooling fans, W1 represents the power consumption of a single cooling fan, and W2 represents the power consumption of both cooling fans. Using the same method, the economic efficiency of putting any number of cooling fans into operation is compared to determine the optimal number of cooling fans to operate, so that the overall economic efficiency of the unit is optimal.

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