Design method of high-level water tank

Abstract

The application discloses a design method of a high-position water tank and relates to the technical field of water cooling systems of wind driven generators, and comprises the following steps: S1, determining the total liquid volume V1 when liquid filling is completed, the lowest working condition temperature T1, the highest working condition temperature T2, the exhaust pressure p1 of a breather valve and the inhalation pressure p2 of the breather valve; S2, obtaining the first lowest initial volume V01 of gas according to the exhaust pressure p1 of the breather valve; S3, obtaining the second lowest initial volume V02 of gas according to the inhalation pressure p2 of the breather valve; S4, comparing the first lowest initial volume V01 of gas and the second lowest initial volume V02 of gas, and taking the maximum value as the lowest initial volume V0 of gas; S5, determining the highest low early warning volume V4; and S6, obtaining the total capacity V of the high-position water tank. The method can be used as a design guiding document of the high-position water tank of the water cooling system, can improve the design accuracy and can make the application of the high-position water tank be widely promoted.

Description

Technical Field

[0001] This invention relates to the field of wind turbine water cooling system technology, and in particular to a design method for an elevated water tank. Background Technology

[0002] With economic and technological development, the power output of single generators is increasing, the size of internal components is growing, various technologies are improving, and the integration of control units is becoming increasingly sophisticated, resulting in a significant increase in heat generation. The main principle of a cooling system is to remove the heat generated during equipment operation through heat exchange via a flowing medium, releasing the heat to the external environment.

[0003] The density of liquid in a cooling system changes with temperature. In some wind turbine water-cooling systems, elevated water tanks are used instead of expansion tanks to absorb the volume of thermal expansion and replenish the volume of reduced volume due to cooling. Conventional elevated water tanks are usually open structures. In offshore wind power conditions, the entry of salt gases can cause coolant deterioration and corrosion of the internal structure of the equipment, leading to unreliable long-term operation. Closed structures cannot effectively guarantee the safety of the equipment. Elevated water tanks are often equipped with breather valves. The exhaust pressure p1 and intake pressure p2 of the breather valve must be set to ensure that the breather valve remains closed during temperature changes. The pressure difference between the inside and outside of the elevated water tank is regulated to maintain pressure balance within the tank body. During normal operation, the elevated water tank should not trigger a low-level alarm and the breather valve should remain closed. In other words, the elevated water tank must be able to function without triggering a low-level alarm and without the breather valve venting or inhaling, regardless of the temperature range during filling or system operation. This prevents the air from the outside environment from coming into contact with the liquid inside the system, thus preventing the liquid from deteriorating and salty gases from entering and corroding the equipment.

[0004] However, the design method and calculation process for elevated water tanks have not yet been publicly determined. They are usually designed using saturation design methods, which lack theoretical support. Summary of the Invention

[0005] The purpose of this invention is to provide a design method for elevated water tanks to address the aforementioned problems. Elevated water tanks designed using this method do not trigger alarms at low liquid levels and the breather valve remains closed during normal operation. This method can serve as a design guide for elevated water tanks in water-cooling systems, improving design accuracy. Combined with the higher reliability of elevated water tanks compared to expansion tanks, this method enables the widespread application of elevated water tanks.

[0006] The technical solution adopted in this invention is as follows:

[0007] A design method for an elevated water tank includes the following steps:

[0008] S1. Determine the total liquid volume V1 when filling is complete, the minimum operating temperature T1, the maximum operating temperature T2, the exhaust pressure p1 of the breather valve, and the inhalation pressure p2 of the breather valve.

[0009] S2. Calculate the first minimum initial volume V01 of the gas based on the exhaust pressure p1 of the breathing valve;

[0010] S3. Calculate the second minimum initial volume V02 of the gas based on the inhalation pressure p2 of the breathing valve;

[0011] S4. Compare the first minimum initial volume V01 of the gas and the second minimum initial volume V02 of the gas, and take the maximum value as the minimum initial volume V0 of the gas.

[0012] S5. Determine the highest and lowest warning volumes V4;

[0013] S6. Calculate the total capacity V of the high-level water tank;

[0014] The order of steps S2 and S3 can be interchanged.

[0015] Optionally, step S1 may also include obtaining the system volume V11 and the pre-set liquid filling volume V12 in the high-level water tank, wherein the total liquid volume V1 when the filling is completed is equal to the sum of the system volume V11 and the liquid filling volume V12 in the high-level water tank.

[0016] Alternatively, step S2 may include the following steps:

[0017] S201. Calculate the increase in liquid volume V1 after the liquid filling is completed at the lowest operating temperature, and the increase in liquid volume V2 after the liquid is raised to the highest operating temperature, which is the decrease in gas volume at the lowest operating temperature and the highest operating temperature.

[0018] S202. Based on the exhaust pressure p1 of the breather valve and the increase in liquid volume V2, the first minimum initial volume V01 of the gas is obtained using the ideal gas law.

[0019] Alternatively, in step S201, the formula for calculating the increase in liquid volume V2 is: V2=(V1*ρ1) / ρ2-V1;

[0020] In the formula, ρ1 is the liquid density at the lowest operating temperature, and ρ2 is the liquid density at the highest operating temperature.

[0021] Alternatively, in step S202, the formula for calculating the first minimum initial volume V01 of the gas is: V01=(p1*V2*T1) / (p1*T1-p0*T2).

[0022] In the formula, p0 is atmospheric pressure.

[0023] Alternatively, step S3 may include the following steps:

[0024] S301. Calculate the decrease in liquid volume V1 after the liquid filling is completed at the highest operating temperature, and the amount of gas volume increase V3 after the liquid volume drops to the lowest operating temperature.

[0025] S302. The second minimum initial volume V02 of the gas is obtained by using the ideal gas law based on the inhalation pressure p2 of the breathing valve and the decrease in liquid volume V3.

[0026] Alternatively, in step S301, the formula for calculating the decrease in liquid volume V3 is: V3=V1-(V1*ρ2) / ρ1;

[0027] In the formula, ρ1 is the liquid density at the lowest operating temperature, and ρ2 is the liquid density at the highest operating temperature.

[0028] Alternatively, in step S302, the formula for calculating the second minimum initial volume V02 of the gas is: V02=(p2*V3*T2) / (p0*T1-p2*T2;

[0029] In the formula, p0 is atmospheric pressure.

[0030] Alternatively, in step S5, the maximum low warning volume V4 is determined based on the decrease in liquid volume V3.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] This invention discloses a design method for a high-level water tank, which solves the problem that current high-level water tank designs using saturation design lack theoretical support. This facilitates the design of the dimensions of the high-level water tank in a wind turbine water-cooling system, improving design accuracy. The high-level water tank designed using this method allows for filling at the lowest operating temperature, while the breather valve does not vent at the highest operating temperature. Furthermore, it ensures that filling occurs at the highest operating temperature, and that the level switch alarm is not triggered at the lowest operating temperature, and the breather valve does not draw in air. This guarantees that within the operating temperature range, low liquid levels do not trigger alarms, and the breather valve neither vents nor draws in air. Attached Figure Description

[0033] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0034] Figure 1 This is a schematic diagram of the volume of the elevated water tank;

[0035] Figure 2 This is a schematic diagram showing the height of the elevated water tank;

[0036] Figure 3 This is a schematic diagram of the process structure of the present invention. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings.

[0038] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0039] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is merely one example of a series of equivalent or similar features.

[0040] A design method for elevated water tanks, such as Figure 1-3 As shown, it includes the following steps:

[0041] S1. Determine the total liquid volume V1 when filling is complete, the minimum operating temperature T1, the maximum operating temperature T2, the exhaust pressure p1 of the breather valve, and the inhalation pressure p2 of the breather valve.

[0042] S2. Calculate the first minimum initial volume V01 of the gas based on the exhaust pressure p1 of the breathing valve;

[0043] S3. Calculate the second minimum initial volume V02 of the gas based on the inhalation pressure p2 of the breathing valve;

[0044] S4. Compare the first minimum initial volume V01 of the gas and the second minimum initial volume V02 of the gas, and take the maximum value as the minimum initial volume V0 of the gas.

[0045] S5. Determine the highest and lowest warning volumes V4;

[0046] S6. Calculate the total capacity V of the high-level water tank;

[0047] The order of steps S2 and S3 can be interchanged.

[0048] Since the high-level water tank needs to be able to fill with liquid regardless of the operating temperature range, and the system should not alarm for low liquid level and should not allow the breather valve to vent or inhale air under any operating temperature range, and the pressure change is greatest between the extremes of the operating temperature range, the conditions can be transformed into: when filling with liquid at the lowest operating temperature, the pressure should be less than the breather valve's venting pressure p1 at the highest operating temperature; when filling with liquid at the highest operating temperature, the pressure should be greater than the breather valve's inhalation pressure p2 at the lowest operating temperature. Furthermore, under the same conditions, the larger the initial gas volume, the smaller the pressure change. The data obtained at the endpoint is the minimum initial volume value of the gas. At the same time, the pressure change corresponding to the exhaust and inhalation of the breather valve may not be the same. Therefore, it is necessary to compare the first minimum initial volume V01 and the second minimum initial volume V02 of the gas and take the maximum value as the minimum initial volume V0 of the gas, so as to ensure that the breather valve is always in the closed state within the operating temperature range. Furthermore, when the operating temperature is at its highest, liquid filling is performed. At the lowest operating temperature, the liquid volume in the high-level water tank is greater than the maximum low warning volume V4, thus ensuring that the volume of liquid reduced due to temperature will not cause a low liquid level alarm.

[0049] In a specific implementation, step S1 also includes obtaining the system volume V11 and the liquid filling volume V12 in the preset high-level water tank. The total liquid volume V1 when the filling is completed is equal to the sum of the system volume V11 and the liquid filling volume V12 in the high-level water tank.

[0050] Since the elevated water tank is connected to the cooling system and is used to absorb the volume of thermal expansion of the system and to replenish the volume of reduced volume due to cooling, when considering the increase and decrease of liquid volume, it is necessary to consider the system volume V11 and the preset liquid volume V12 in the elevated water tank. This ensures that when the entire system is working within the operating temperature range, even if the liquid volume in the elevated water tank increases due to absorbing the volume of thermal expansion of the system, the breather valve will not release air, and when the liquid volume in the elevated water tank decreases due to replenishing the volume of reduced volume due to cooling, there will be no low liquid level alarm and the breather valve will not draw in air.

[0051] Furthermore, the total capacity V of the elevated water tank is equal to the sum of the liquid volume V12 and the minimum initial volume V0 of the gas in the tank.

[0052] As a specific implementation method, step S2 includes the following steps:

[0053] S201. Calculate the increase in liquid volume V1 after the liquid filling is completed at the lowest operating temperature, and the increase in liquid volume V2 after the liquid is raised to the highest operating temperature, which is the decrease in gas volume at the lowest operating temperature and the highest operating temperature.

[0054] S202. Based on the exhaust pressure p1 of the breather valve and the increase in liquid volume V2, the first minimum initial volume V01 of the gas is obtained using the ideal gas law.

[0055] Since liquid filling occurs at the lowest operating temperature, the gas pressure must be less than the exhaust pressure p1 of the breather valve when the temperature rises to the highest operating temperature. Given the total liquid volume V1 and the operating temperature range, the increase in liquid volume V2 can be calculated, thus obtaining the decrease in gas volume. Then, the first minimum initial gas volume V01 can be obtained according to the ideal gas law pV=nRT.

[0056] As a specific implementation method, in step S201, the formula for calculating the increase in liquid volume V2 is: V2=(V1*ρ1) / ρ2-V1;

[0057] In the formula, ρ1 is the liquid density at the lowest operating temperature, and ρ2 is the liquid density at the highest operating temperature.

[0058] As a specific implementation method, in step S202, the formula for calculating the first minimum initial volume V01 of the gas is: V01=(p1*V2*T1) / (p1*T1-p0*T2).

[0059] In the formula, p0 is atmospheric pressure.

[0060] As a specific implementation method, step S3 includes the following steps:

[0061] S301. Calculate the decrease in liquid volume V1 after the liquid filling is completed at the highest operating temperature, and the amount of gas volume increase V3 after the liquid volume drops to the lowest operating temperature.

[0062] S302. The second minimum initial volume V02 of the gas is obtained by using the ideal gas law based on the inhalation pressure p2 of the breathing valve and the decrease in liquid volume V3.

[0063] Since liquid filling occurs at the highest operating temperature, the gas pressure must be greater than the inhalation pressure p2 of the breather valve when the temperature drops to the lowest operating temperature. Given the total liquid volume V1 and the operating temperature range, the decrease in liquid volume V3 can be calculated, thus obtaining the increase in gas volume. Then, the second minimum initial gas volume V02 can be obtained using the ideal gas law pV=nRT.

[0064] As a specific implementation method, in step S301, the formula for calculating the decrease in liquid volume V3 is: V3=V1-(V1*ρ2) / ρ1;

[0065] In the formula, ρ1 is the liquid density at the lowest operating temperature, and ρ2 is the liquid density at the highest operating temperature.

[0066] As a specific implementation method, in step S302, the formula for calculating the second minimum initial volume V02 of the gas is: V02=(p2*V3*T2) / (p0*T1-p2*T2;

[0067] In the formula, p0 is atmospheric pressure.

[0068] In a specific implementation, in step S5, the maximum low warning volume V4 is determined based on the amount of liquid volume reduction V3.

[0069] Since the liquid volume reduction V3 is the maximum volume reduction caused by temperature within the operating temperature range, it ensures that any temperature change within the operating temperature range will not trigger a low liquid level warning. Furthermore, the maximum low warning volume V4 is the volume inside the high-level water tank, and the formula for calculating the maximum low warning volume V4 is: V4 = V1² - V3.

[0070] As a specific implementation method, after step S6, the method further includes the following steps: determining the bottom area A of the high-level water tank, and calculating the filling completion height H1, the low warning height H2, and the total height H3 of the high-level water tank based on the bottom area A.

[0071] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0072] This invention discloses a design method for a high-level water tank, which solves the problem that current high-level water tank designs using saturation design lack theoretical support. This facilitates the design of the dimensions of the high-level water tank in a wind turbine water-cooling system, improving design accuracy. The high-level water tank designed using this method allows for filling at the lowest operating temperature, while the breather valve does not vent at the highest operating temperature. Furthermore, it ensures that filling occurs at the highest operating temperature, and that the level switch alarm is not triggered at the lowest operating temperature, and the breather valve does not draw in air. This guarantees that within the operating temperature range, low liquid levels do not trigger alarms, and the breather valve neither vents nor draws in air.

[0073] The following is a specific example:

[0074] Given condition: System volume V11 = 0.600 The volume of liquid filling the high-level water tank is V12 = 0.02512. The minimum operating temperature T1 = 273.15 K, the maximum operating temperature T2 = 323.15 K, the exhaust pressure of the breather valve p1 = 1.71 * 10^5 Pa, the inhalation pressure of the breather valve p2 = 0.71 * 10^5 Pa, the atmospheric pressure p0 = 1.01 * 10^5 Pa, and the liquid density at the minimum operating temperature ρ1 = 1081 kg / m³. The liquid density at the highest operating temperature is ρ2 = 1058 kg / m³. .

[0075] Therefore, the total liquid volume when filling is complete is V1 = V11 + V12 = 0.62512. ;

[0076] Therefore, the increase in liquid volume V2 = (V1 * ρ1) / ρ2 - V1 = 0.01359 ;

[0077] Therefore, the first minimum initial volume of the gas, V01, is calculated as follows: V01 = (p1 * V2 * T1) / (p1 * T1 - p0 * T2) = 0.04511 ;

[0078] Therefore, the decrease in liquid volume V3 = V1 - (V1 * ρ2) / ρ1 = 0.01330 ;

[0079] Therefore, the second minimum initial volume of the gas, V02, is calculated as follows: V02 = (p2 * V3 * T2) / (p0 * T1 - p2 * T2) = 0.06570 ;

[0080] Therefore, the maximum low warning volume V4 = V12 - V3 = 0.01182 ;

[0081] Therefore, the minimum initial volume of the gas is V0 = V02 = 0.06570. ;

[0082] Therefore, the total capacity of the elevated water tank is V = V1² + V0 = 0.09082. ;

[0083] Therefore, in this embodiment, the elevated water tank is cylindrical, with a designed diameter D = 400 mm and a base area A = 0.1256. ;

[0084] Therefore, the height of the completed filling is H1 = V1² / A = 0.2m;

[0085] Therefore, the low warning altitude H2 = V4 / A = 0.09411m;

[0086] Therefore, the total height of the elevated water tank H3 = V / A = 0.7231m.

[0087] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method of designing a high-level water tank, characterized by, The method comprises the following steps: S1, determining a total liquid volume V1 at the completion of liquid filling, a minimum working temperature T1, a maximum working temperature T2, an exhaust pressure p1 of the breathing valve, and an intake pressure p2 of the breathing valve; obtaining a system volume V11 and a liquid filling volume V12 in a high-level water tank, and the total liquid volume V1 at the completion of liquid filling is equal to the sum of the system volume V11 and the liquid filling volume V12 in the high-level water tank; S2, obtaining a first minimum initial volume V01 of the gas according to the exhaust pressure p1 of the breathing valve; S201, obtaining a liquid volume increase V2 of the total liquid volume V1 after the total liquid volume V1 is increased to the maximum working temperature, that is, a gas volume decrease between the minimum working temperature and the maximum working temperature; The calculation formula of the liquid volume increase V2 is V2=(V1*ρ1) / ρ2-V1; In the formula, ρ1 is the liquid density at the minimum working temperature, and ρ2 is the liquid density at the maximum working temperature; S202, obtaining the first minimum initial volume V01 of the gas according to the exhaust pressure p1 of the breathing valve and the liquid volume increase V2 through the ideal gas state equation; The calculation formula of the first minimum initial volume V01 of the gas is V01=(p1*V2*T1) / (p1*T1-p0*T2); In the formula, p0 is the atmospheric pressure; S3, obtaining a second minimum initial volume V02 of the gas according to the intake pressure p2 of the breathing valve; S301, obtaining a liquid volume decrease V3 of the total liquid volume V1 after the total liquid volume V1 is decreased to the minimum working temperature, that is, a gas volume increase between the maximum working temperature and the minimum working temperature; The calculation formula of the liquid volume decrease V3 is V3=V1-(V1*ρ2) / ρ1; In the formula, ρ1 is the liquid density at the minimum working temperature, and ρ2 is the liquid density at the maximum working temperature; S302, obtaining the second minimum initial volume V02 of the gas according to the intake pressure p2 of the breathing valve and the liquid volume decrease V3 through the ideal gas state equation; The calculation formula of the second minimum initial volume V02 of the gas is V02=(p2*V3*T2) / (p0*T1-p2*T2); In the formula, p0 is the atmospheric pressure; S4, comparing the first minimum initial volume V01 of the gas and the second minimum initial volume V02 of the gas, and taking the maximum value as the minimum initial volume V0 of the gas; S5, determining a maximum-low warning volume V4: when liquid filling is performed at the maximum working temperature, the liquid volume in the high-level water tank is greater than the maximum-low warning volume V4 at the minimum working temperature; S6, obtaining a total capacity V of the high-level water tank; The order of steps S2 and S3 can be exchanged.

2. The method of designing a high-rise water tank as claimed in claim 1, wherein, In step S5, the maximum-low warning volume V4 is determined according to the liquid volume decrease V3.

3. The method of designing a high-rise water tank as claimed in claim 1, wherein, After step S6, step S7 is further included: determining a bottom area A of the high-level water tank, and obtaining a liquid filling completion height H1, a low warning height H2, and a total height H3 of the high-level water tank according to the bottom area A.

Images