A hydraulic and thermal calculation method, device, equipment and medium for a closed cooling tower

Abstract

The present invention discloses a method, device, electronic device, and medium for calculating the hydraulic and thermal performance of a closed cooling tower. The closed cooling tower includes a counterflow closed cooling tower and a crossflow closed cooling tower. The method includes: calculating air state parameters based on environmental conditions, and assigning the air state parameters to the tower air parameters without considering backflow; selecting the form of the closed cooling tower, calculating the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan; setting initial values for the tower outlet water temperature and the heat exchange light pipe water film temperature, and calculating the heat exchange light pipe regional state parameters; and iteratively calculating the tower outlet water temperature and the heat exchange light pipe water film temperature. The present invention overcomes the inaccuracies caused by the traditional method's reliance on empirical formulas, and adopts a bidirectional iterative algorithm for iterative correction, achieving higher calculation accuracy under multivariable coupling conditions. The present invention can be widely applied in the fields of thermal calculation and cooling technology.

Description

Technical Field

[0001] The present invention relates to the field of thermal calculation and cooling technology, and in particular to a hydraulic and thermal calculation method, device, electronic equipment and medium for a closed cooling tower. Background Art

[0002] The demand for energy conservation and consumption reduction in various industries is becoming increasingly urgent. Due to their high energy and water conservation advantages, closed cooling towers are widely used in fields such as chemical, metallurgical, pharmaceutical, data centers, and central air conditioning systems in large commercial buildings. With the diversification of application scenarios and the increase in application demand, the optimized operation of closed cooling towers has become crucial. However, traditional design and operation control methods mostly rely on the experience of technicians and static models, which cannot effectively deal with the complex multivariable coupling problems in actual operating conditions, resulting in low system efficiency and difficulty in fully realizing energy conservation effects. The operation of closed cooling towers involves complex thermal and hydraulic coupling processes, including the interaction of water film heat transfer, air flow, and spray systems. Existing modeling methods have difficulty accurately describing these dynamic processes, especially under large load fluctuations and complex environmental conditions. The errors are large, affecting the global optimization of the system. With the increasing requirements for energy conservation and environmental protection, there is an urgent need for a calculation method that can accurately simulate the thermal performance of closed cooling towers to optimize their operation control and tap their energy-saving potential. Summary of the Invention

[0003] In order to solve at least one of the technical problems existing in the prior art to a certain extent, the object of the present invention is to provide a hydraulic and thermal calculation method, device, electronic equipment and medium for a closed cooling tower.

[0004] The first technical solution adopted by the present invention is:

[0005] A method for calculating the hydraulic and thermodynamic properties of a closed cooling tower, wherein the closed cooling tower includes a counterflow closed cooling tower and a crossflow closed cooling tower, comprises the following steps:

[0006] Calculate the air state parameters according to the environmental conditions and assign them to the tower air parameters without considering the backflow;

[0007] Select the form of closed cooling tower, calculate the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan;

[0008] Set the initial values of the water temperature at the tower outlet and the water film temperature of the heat exchange tube, calculate the state parameters of the heat exchange tube area, and build the heat exchange mechanism model of each component of the closed cooling tower;

[0009] The tower water temperature and the heat exchange tube water film temperature are iteratively calculated. When the preset iteration termination condition is met, the calculated values for the tower water temperature and the heat exchange tube water film are output. For example, the iteration termination condition can be when the absolute value of the error between the calculated value and the iterated value is less than 0.001; or when the iteration step size is less than 0.001, and when the number of iterations exceeds 200, if the iteration step size is still greater than 0.1, the iterative calculation loop is terminated. After the calculation is completed, the calculated values for the tower water temperature and the heat exchange tube water film temperature are output and assigned to the initial value.

[0010] Furthermore, the counter-flow closed cooling tower includes a heat exchange light tube, a variable frequency cooling fan, a variable frequency spray water pump, a spray system, a water pool, an automatic water replenishment system and a water collector;

[0011] The spray system is located at the top of the cooling tower and is connected to the variable frequency spray water pump through a circulating water pipe. The variable frequency spray water pump delivers water to the spray system, and the spray system sprays the circulating water to the heat exchange tube for evaporation and heat transfer.

[0012] The water pool is located at the bottom of the cooling tower and is used to collect the spray water that falls back after cooling;

[0013] The automatic water replenishment system is connected to the water pool to maintain the water balance in the system;

[0014] The variable frequency cooling fan drives the air to flow, thereby achieving heat exchange between the air and the heat exchange light pipe;

[0015] The water collector is located above the sprinkler system and is used to collect moisture brought out by air flow to reduce water loss.

[0016] Furthermore, the cross-flow closed cooling tower includes heat exchange filler, heat exchange light pipe, variable frequency cooling fan, variable frequency spray water pump, spray system, water pool, automatic water replenishment system, and water collector;

[0017] The spray system is located at the top of the cooling tower and is connected to the variable frequency spray water pump through a circulating water pipe. The variable frequency spray water pump delivers water to the spray system, and the spray system sprays the circulating water to the heat exchange tube for evaporation and heat transfer.

[0018] The filler is located below the heat exchange light tube and is used to cool the spray water falling from above to achieve circulating cooling;

[0019] The water pool is located at the bottom of the cooling tower and is used to collect the spray water that falls back after cooling;

[0020] The automatic water replenishment system is connected to the water pool to maintain the water balance in the system;

[0021] The variable frequency cooling fan drives the air to flow, and the air is divided after entering the cooling tower. One part of the air is transferred to the water film on the surface of the heat exchange tube, and the other part is transferred to the spray water through the heat exchange filler.

[0022] The water collector is located above the sprinkler system and is used to collect moisture brought out by air flow to reduce water loss.

[0023] Furthermore, the environmental conditions include ambient temperature and relative humidity; the air state parameters include dry-bulb temperature, wet-bulb temperature, moisture content, relative humidity, and air enthalpy of the ambient air;

[0024] The method of calculating the air state parameters according to the environmental conditions and assigning the air state parameters to the tower air parameters without considering the backflow includes:

[0025] According to the dry-bulb temperature of the closed cooling tower's environment, calculate the atmospheric saturated air water vapor partial pressure corresponding to the dry-bulb temperature; according to the atmospheric saturated air water vapor partial pressure and the atmospheric pressure of the closed cooling tower's environment, calculate the saturated air moisture content corresponding to the atmospheric dry-bulb temperature of the closed cooling tower's environment; according to the atmospheric saturated air water vapor partial pressure and the relative humidity of the closed cooling tower's environment, calculate the water vapor pressure corresponding to the dry-bulb temperature of the closed cooling tower's environment; according to the water vapor pressure corresponding to the dry-bulb temperature and the atmospheric pressure of the closed cooling tower's environment, calculate the actual air moisture content of the closed cooling tower's environment; according to the actual air moisture content and the atmospheric dry-bulb temperature of the closed cooling tower's environment, calculate the air enthalpy value of the closed cooling tower's environment; according to the air enthalpy value, calculate the air wet-bulb temperature of the closed cooling tower's environment;

[0026] The humidity of the air entering the tower is equal to the humidity of the environment, the enthalpy of the air entering the tower is equal to the air enthalpy of the environment, the temperature of the air entering the tower is equal to the dry bulb temperature of the environment, and the relative humidity of the air entering the tower is equal to the relative humidity of the environment.

[0027] Furthermore, the selection of the closed cooling tower form and calculation of the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan include:

[0028] Calculations are performed based on the selected operating mode. Mode 1 is a counterflow closed cooling tower, and Mode 2 is a crossflow closed cooling tower. Counterflow closed cooling towers do not require heat exchange filler parameter calculations, while crossflow closed cooling towers do. In addition, both require parameter calculations for the variable frequency cooling fan and variable frequency spray water pump, using the same calculation method.

[0029] Obtain the operating frequency of the variable frequency cooling fan based on external input variables and calculate the air volume and power of the variable frequency cooling fan. If the cross-flow closed cooling tower in operation mode 2 is selected, the calculated cooling fan air volume needs to be split. Based on the air split coefficient and the cooling fan air volume, calculate the air volume passing through the heat exchange packing layer and the air volume passing through the heat exchange light pipe area respectively.

[0030] Based on external input variables, the operating frequency of the variable frequency sprinkler pump and the pipe resistance from the pool to the sprinkler system are obtained, the required head of the sprinkler pump is calculated, and the operating parameters of the sprinkler pump and the sprinkler water circulation flow rate are iteratively calculated;

[0031] If the cross-flow closed cooling tower of mode 2 is selected, the heat exchange filler parameters are calculated: the volumetric mass coefficient of the heat exchange filler is calculated based on the filler air inlet volume and the filler fitting parameters.

[0032] Furthermore, the initial values of the outlet water temperature and the heat exchange tube water film temperature are set, and the state parameters of the heat exchange tube area are calculated, including:

[0033] Perform heat exchange filler layer calculation according to the selected operating mode. If you select mode 1 counterflow closed cooling tower, this step can be skipped. If you select mode 2 crossflow closed cooling tower, perform heat exchange filler layer thermal calculation: calculate the filler layer water temperature and the air enthalpy out of the filler layer based on the inlet water temperature, inlet air parameters, and air flow through the filler layer.

[0034] Based on the cooling water flow into the tower, the spray water flow, the heat exchange tube structure, and the parameters of the air entering the tower, the convective heat transfer coefficient between the outer wall of the tube and the water film, the heat transfer coefficient of the cooling water in the heat exchange tube, and the convective heat transfer coefficient between the water film outside the tube and the air are calculated; based on the definition of the Lewis number and the convective heat transfer coefficient between the water film outside the tube and the air, the mass transfer coefficient between the air and the water film is calculated.

[0035] Furthermore, the iterative calculation of the tower water temperature and the heat exchange tube water film temperature includes:

[0036] Initialize the iterative calculation of the counterflow closed cooling tower: use the outlet water temperature as the outer iteration variable and the heat exchange tube water film temperature as the inner iteration variable, nest the two for iterative calculation, set the initial values of the outlet water temperature and the heat exchange tube water film temperature, and set the initial iteration step size;

[0037] Initialize the iterative calculation of a cross-flow closed cooling tower: use the spray water temperature as the outer iteration variable, the outlet water temperature as the middle iteration variable, and the heat exchange tube water film temperature as the inner iteration variable. The three are nested for iterative calculation. Set the initial values of the outlet water temperature, heat exchange tube water film temperature, and spray water temperature, and set the initial iteration step size.

[0038] Iterative calculation search: The iterative calculation search method used by the counterflow closed cooling tower is the same as that used by the crossflow closed cooling tower. Both use a bidirectional iteration method to iterate from the inside out. In the multi-layer nested iteration, the inner layer is iterated first, and then gradually returns to the outer layer. Whenever the upper layer variables are adjusted, the lower layer will be recalculated. Finally, through layer-by-layer iteration and correction, the global optimal solution is found.

[0039] Iterative calculation error judgment: First, calculate the error between the current assumption value and the target value, and decide whether to increase or decrease the current value based on the sign of the error; in each iteration, if the error is positive, the adjustment value increases upward; if the error is negative, it decreases downward; the program also records the direction of adjustment. When it is found that it has been adjusted once in two different directions, the adjustment step size is halved to improve the calculation accuracy and prevent over-adjustment; the whole process is repeated until the error is less than the set threshold or the adjustment step size is less than the preset step size, and the optimal solution is obtained.

[0040] The second technical solution adopted by the present invention is:

[0041] A hydraulic and thermodynamic calculation device for a closed cooling tower, wherein the closed cooling tower includes a counterflow closed cooling tower and a crossflow closed cooling tower, comprising:

[0042] Parameter assignment module, used to calculate air state parameters according to environmental conditions, and assign the air state parameters to the tower air parameters without considering backflow;

[0043] The mode selection module is used to select the type of closed cooling tower, calculate the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan;

[0044] The initial setting module is used to set the initial values of the water temperature at the outlet of the tower and the water film temperature of the heat exchange tube, calculate the state parameters of the heat exchange tube area, and build the heat exchange mechanism model of each component of the closed cooling tower;

[0045] The iterative calculation module is used to iteratively calculate the tower water temperature and the heat exchange tube water film temperature, and output the calculated values of the tower water temperature and the heat exchange tube water film when the preset iteration termination condition is reached.

[0046] The third technical solution adopted by the present invention is:

[0047] An electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the hydraulic and thermal calculation method for a closed cooling tower as described above.

[0048] The fourth technical solution adopted by the present invention is:

[0049] A computer-readable storage medium stores at least one instruction, at least one program, a code set, or an instruction set, which is loaded and executed by a processor to implement the hydraulic and thermal calculation method for a closed cooling tower as described above.

[0050] The fifth technical solution adopted by the present invention is:

[0051] A computer program product or computer program includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the aforementioned hydraulic and thermodynamic calculation method for a closed cooling tower.

[0052] The beneficial effects of the present invention are as follows: In traditional calculation methods, fuzzy processing or empirical formulas are usually used for some key variables, resulting in large errors in the calculation results compared with the actual operating data. To this end, the present invention is based on the integration and derivation of heat transfer principles to obtain calculation derivation formulas for intermediate key variables such as water film temperature, and adopts a bidirectional iterative algorithm to correct the coupling relationship between each variable, which significantly reduces the calculation error. In addition, the present invention can handle different forms of closed cooling towers through the mode selection function: mode 1 is used for countercurrent closed cooling towers, and mode 2 is used for crossflow closed cooling towers. In the two modes, by sharing part of the code for the same heat transfer process, the program structure is simplified, the maintainability and scalability are improved, and the accuracy and efficiency of the calculation are ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following introduction is made to the drawings of the embodiments of the present invention or the related technical solutions in the prior art. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0054] Figure 1 This is a structural diagram of a counter-flow closed cooling tower system according to an embodiment of the present invention.

[0055] Figure 2 This is a structural diagram of a cross-flow closed cooling tower system according to an embodiment of the present invention.

[0056] Figure 3 This is a calculation logic diagram of a counterflow closed cooling tower according to an embodiment of the present invention.

[0057] Figure 4 This is a calculation logic diagram of a cross-flow closed cooling tower according to an embodiment of the present invention.

[0058] Figure 1 Reference numerals: 1. Air duct; 2. Ladder; 3. Side panel; 4. Circulating cooling water inlet and outlet; 5. Air inlet window; 6. Spray water supply pipe; 7. Spray water pump; 8. Valve; 9. Heat exchange light pipe; 10. Heat exchange filler (can also be filler-free, in the embodiment of the present invention, the countercurrent type is filler-free); 11. Spray pipe network; 12. Water collector; 13. Cooling fan; 14. Electric motor.

[0059] Figure 2 Reference numerals: 1. Air duct; 2. Ladder; 3. Side panel; 4. Spray water supply pipe; 5. Inspection door; 6. Inspection walkway; 7. Valve; 8. Spray water pump; 9. Air inlet window; 10. Heat exchange filler; 11. Heat exchange light tube; 12. Spray water nozzle; 13. Cooling fan; 14. Motor. DETAILED DESCRIPTION

[0060] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided for ease of explanation only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0061] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0062] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0063] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0064] A typical closed cooling tower system includes multiple components, including heat exchange tubes, heat exchange fillers, cooling fans, spray pumps, spray systems, reservoirs, automatic water replenishment systems, and water collectors. Operation involves complex heat transfer and fluid flow processes. Traditional closed cooling tower thermal calculation methods typically rely on simplified static models, often based on empirical formulas or design data for a single operating condition. This approach can provide relatively stable results when the cooling tower load fluctuates slightly. However, with changes in multiple variables such as ambient temperature, humidity, and cooling water flow, traditional models struggle to accurately reflect the system's dynamic changes. Furthermore, common calculation methods fail to fully account for the complex coupling of water film heat transfer and air flow within the closed cooling tower, resulting in significant errors in simulation results, impacting both system optimization design and actual operation. Even with multiple simulations, the resulting data often fails to reflect the system's actual operation under different operating conditions, often leading to data duplication and insufficient calculation accuracy.

[0065] Based on this, the present invention provides a hydraulic and thermal calculation scheme for a closed cooling tower. The scheme is based on a thermodynamic coupling model of the closed cooling tower. The model inputs include key parameters such as ambient temperature, humidity, spray pump frequency, cooling water inlet temperature, and cooling fan frequency. The output of the simulation calculation scheme includes operating parameters such as the cooling tower airflow state parameter, cooling water outlet temperature, and system energy consumption. Traditional calculation schemes often use fuzzy processing or empirical formulas for some key variables, resulting in large errors in the calculated results compared to actual operating data. The present invention, based on integration and derivation of heat transfer principles, derives calculation formulas for intermediate key variables such as water film temperature. It also uses a bidirectional iterative algorithm to correct the coupling relationship between these variables, significantly reducing calculation errors. In addition, the present invention can handle different types of closed cooling towers through a mode selection function: Mode 1 is for counterflow closed cooling towers, and Mode 2 is for crossflow closed cooling towers. By sharing some code for the same heat transfer process in both modes, the program structure is simplified, maintaining and scalability are improved, and the accuracy and efficiency of the calculation are ensured.

[0066] The closed cooling tower of the present invention includes a counter-flow closed cooling tower and a cross-flow closed cooling tower.

[0067] 1) See Figure 1 The countercurrent closed cooling tower includes a heat exchange light tube, a variable frequency cooling fan, a variable frequency spray water pump, a spray system, a water pool, an automatic water replenishment system and a water collector;

[0068] The spray system is located at the top of the cooling tower and is connected to the variable frequency spray water pump through a circulating water pipe. The variable frequency spray water pump delivers water to the spray system, and the spray system sprays the circulating water to the heat exchange tube for evaporation and heat transfer.

[0069] The water pool is located at the bottom of the cooling tower and is used to collect the spray water that falls back after cooling;

[0070] The automatic water replenishment system is connected to the water pool to maintain the water balance in the system;

[0071] The variable frequency cooling fan drives the air to flow, thereby achieving heat exchange between the air and the heat exchange light pipe;

[0072] The water collector is located above the sprinkler system and is used to collect moisture brought out by air flow to reduce water loss.

[0073] 2) See Figure 2 The cross-flow closed cooling tower includes heat exchange filler, heat exchange light tube, variable frequency cooling fan, variable frequency spray water pump, spray system, water pool, automatic water replenishment system, and water collector;

[0074] The spray system is located at the top of the cooling tower and is connected to the variable frequency spray water pump through a circulating water pipe. The variable frequency spray water pump delivers water to the spray system, and the spray system sprays the circulating water to the heat exchange tube for evaporation and heat transfer.

[0075] The filler is located below the heat exchange light tube and is used to cool the spray water falling from above to achieve circulating cooling;

[0076] The water pool is located at the bottom of the cooling tower and is used to collect the spray water that falls back after cooling;

[0077] The automatic water replenishment system is connected to the water pool to maintain the water balance in the system;

[0078] The variable frequency cooling fan drives the air to flow, and the air is divided after entering the cooling tower. One part of the air is transferred to the water film on the surface of the heat exchange tube, and the other part is transferred to the spray water through the heat exchange filler.

[0079] The water collector is located above the sprinkler system and is used to collect moisture brought out by air flow to reduce water loss.

[0080] Example 1

[0081] See also Figure 3 and Figure 4 This embodiment provides a hydraulic and thermal calculation method for a closed cooling tower, comprising the following steps:

[0082] S1. Calculate the inlet air dry-bulb temperature, wet-bulb temperature, moisture content, relative humidity, and air enthalpy based on ambient temperature and relative humidity conditions, and assign these parameters to the tower inlet air parameters without considering backflow.

[0083] Specifically, the ambient dry-bulb temperature and relative humidity are used to calculate thermophysical properties such as the wet-bulb temperature, the water vapor content (i.e., moisture content) in the air, and the air's enthalpy. These parameters are crucial for subsequent heat and mass transfer processes, as the state of the air directly affects the evaporation and cooling capacity of the water film. Once calculated, these parameters are assigned to the air entering the cooling tower, serving as the basis for subsequent heat transfer calculations.

[0084] As an optional implementation, step S1 specifically includes the following steps:

[0085] S11. Calculate the atmospheric saturated air water vapor partial pressure corresponding to the dry-bulb temperature of the closed cooling tower based on the dry-bulb temperature of the environment in which the closed cooling tower is located. Calculate the saturated air moisture content corresponding to the atmospheric dry-bulb temperature of the closed cooling tower based on the atmospheric saturated air water vapor partial pressure and the atmospheric pressure of the closed cooling tower's environment. Calculate the water vapor pressure corresponding to the dry-bulb temperature of the closed cooling tower's environment based on the atmospheric saturated air water vapor partial pressure and the relative humidity of the closed cooling tower's environment. Calculate the actual air moisture content of the closed cooling tower's environment based on the water vapor pressure corresponding to the dry-bulb temperature and the atmospheric pressure of the closed cooling tower's environment. Calculate the air enthalpy of the closed cooling tower's environment based on the actual air moisture content and the atmospheric dry-bulb temperature of the closed cooling tower's environment. Calculate the air wet-bulb temperature of the closed cooling tower's environment based on the air enthalpy.

[0086] S12. Without considering backflow, assign the above atmospheric parameters to the tower inlet air parameters. The tower inlet air humidity is equal to the ambient air humidity, the tower inlet air enthalpy is equal to the atmospheric air enthalpy, the tower inlet air temperature is equal to the atmospheric dry-bulb temperature, and the tower inlet air relative humidity is equal to the atmospheric relative humidity.

[0087] S2. Calculate the heat exchange filler parameters, spray pump head and power, and cooling fan air volume and power based on the selected cooling tower type.

[0088] In some embodiments, step S2 specifically includes the following steps:

[0089] S21. Perform calculations based on the selected operating mode. Mode 1 is a counterflow closed cooling tower, and Mode 2 is a crossflow closed cooling tower. While the counterflow closed cooling tower does not require heat exchange filler parameter calculations, the crossflow closed cooling tower does. Furthermore, both require parameter calculations for the variable-frequency cooling fan and variable-frequency spray pump, using the same calculation method. Specifically, the same heat transfer process in both programs uses the same program segment, while different heat transfer processes are calculated independently.

[0090] S22. Calculate the cooling fan air volume and power based on the external input variable, the cooling fan operating frequency. If operating mode 2, a cross-flow closed cooling tower, is selected, the calculated cooling fan air volume must be split. Based on the air split coefficient and the cooling fan air volume, the air volume passing through the heat exchange packing layer and the air volume passing through the heat exchange light pipe area are calculated separately.

[0091] S23. Calculate the required head of the sprinkler pump based on the external input variables, the sprinkler pump operating frequency, and the pipe resistance from the pool to the sprinkler system. Iteratively calculate the sprinkler pump operating parameters and the sprinkler water circulation flow rate.

[0092] S24. Calculate the heat exchange packing based on the selected operating mode. If Mode 1, a counterflow closed cooling tower, is selected, this step can be skipped. If Mode 2, a crossflow closed cooling tower, is selected, calculate the heat exchange packing parameters. Calculate the heat exchange packing volumetric mass coefficient based on the packing inlet air volume and the packing fitting parameters.

[0093] Specifically, performance curves for the spray water pump and cooling fan are fitted using product design manuals and operational data, with the air volume / water volume / power corresponding to their external input variable operating frequency. If operating mode 2 is selected, the heat exchange packing parameters must be calculated. The heat exchange packing volumetric mass coefficient is calculated using the external input variable packing quantity and the cooling fan cooling capacity calculated above. Furthermore, the inlet air of a crossflow cooling tower is split, meaning that the air entering the tower is divided into two parts. One part flows through the heat exchange light pipe layer: this part of the air comes into contact with the water film outside the light pipe, further cooling the water film through evaporation, removing heat. The other part flows through the heat exchange packing layer. The air passing through the packing layer comes into contact with the spray water, initially cooling the spray water and increasing heat transfer efficiency. Therefore, when selecting mode 2, after determining the fan air volume, the external input variable air split coefficient is also required to calculate the air flow through the heat exchange packing layer and the heat exchange light pipe layer separately.

[0094] S3. Set the initial values of the water temperature at the outlet of the tower and the water film temperature of the heat exchange tube, calculate the state parameters of the system heat exchange filler layer and the heat exchange tube area, and construct a heat exchange mechanism model for each component of the closed cooling tower.

[0095] In some embodiments, step S3 includes the following steps:

[0096] S31. Perform heat exchange packing layer calculations based on the selected operating mode. If Mode 1, a counterflow closed cooling tower, is selected, this step can be skipped. If Mode 2, a crossflow closed cooling tower, is selected, perform heat exchange packing layer thermal calculations. Based on the inlet water temperature, inlet air parameters, and air flow through the packing layer, calculate the packing layer water temperature and the outlet air enthalpy.

[0097] For the heat transfer calculation of spray water flowing through the packing of a crossflow closed cooling tower, the air and cooling water flow directions in the crossflow tower are perpendicular. In order to fully consider the heat transfer within each microelement, the packing is divided into three directions: length D, height H, and width W. The microelement in the L direction is divided to take into account the different wind speeds in the horizontal direction of the air inlet surface, the microelement in the W direction is divided to take into account the changes in the state of the air passing through the packing, and the microelement in the H direction is divided to take into account the continuous changes in the state of the water during the falling process and the velocity gradient in the vertical direction of the air inlet surface. Therefore, the heat transfer calculation of the microelement of the crossflow tower is more complicated. With W*H as the air inlet surface and D*W as the water inlet surface, the water inlet temperature is the same at the same height H and the inlet enthalpy is the same at the same length D. The microelement is divided in the order of D→W→H for calculation simplification. When a microelement of the cooling tower is used as the research object, when the microelement is divided small enough, it is acceptable to use the outlet water temperature instead of the average water temperature in the calculation. According to the heat and moisture balance of air and water in the microelement of the cooling tower Where k is the correction coefficient, which is used to correct the error caused by the heat taken away by the evaporated water. It is related to the outlet water temperature and is taken in the program. β xv is the bulk density coefficient of the filler, q m,w is the cooling water flow rate, c w is the specific heat capacity of water, h t t ″ is the enthalpy of saturated air corresponding to the water temperature t, h θ is the air enthalpy. After all the micro-element calculations are completed, the micro-element parameters of the air outlet and water outlet surfaces can be obtained. The air and water outlet parameters can be obtained by summing the total enthalpy of the cooling water in the water surface micro-element and the total enthalpy of the air in the air outlet micro-element, and then dividing by the corresponding flow rate and the amount of packing.

[0098] S32. Based on the cooling water flow into the tower, the spray water flow, the heat exchange tube structure, and the parameters of the air entering the tower, calculate the convective heat transfer coefficient between the outer wall of the tube and the water film, the heat transfer coefficient of the cooling water in the heat exchange tube, and the convective heat transfer coefficient between the water film outside the tube and the air.

[0099] The heat transfer process in the closed cooling tower is mainly divided into heat transfer between the cooling water in the tube and the water film, and heat transfer between the water film and the incoming air. The total heat transfer coefficient K1 between the cooling water and the water film includes the heat transfer coefficient α of the cooling water in the tube. coolingwater, the convection heat transfer coefficient α between the tube wall and the water film waterfilm And the heat transfer coefficient of the tube wall itself α tube The heat transfer between the water film and the incoming air is mainly through evaporation, and the heat transfer process follows the heat transfer equation dQ = β x (i″ t -i)dA, where β x is the mass transfer coefficient based on the enthalpy-humidity difference of the coil surface area as the driving force, kg / (m 2 .s), i″ t is the water film temperature t m The corresponding enthalpy of saturated air, i is the air enthalpy, defined by the Lewis number where c p For the constant pressure specific heat, the heat transfer coefficient of the fluid across the tube bundle surface is obtained and combined with the Lewis number, β can be obtained x .

[0100] In cooling towers, the air volume is generally large, and the air temperature varies little. When calculating air properties, the inlet air temperature is used as the average value, and errors can be corrected later using correlation coefficients. Furthermore, the calculation of these heat transfer coefficients is often based on theoretical models and experimental formulas. However, the operating environment in actual operating conditions is often more complex, with numerous influencing factors. This can lead to a certain deviation between the theoretical calculation and the actual heat transfer effect. Therefore, when calculating these heat transfer coefficients, correction factors are often introduced to adjust them. By monitoring parameters such as inlet and outlet water temperature, flow rate, and air humidity, the actual heat transfer effect can be determined. By comparing these measured data with the results of theoretical calculations, an appropriate correction factor can be determined, making the calculation model more accurate to actual operating conditions. This continuous correction and adjustment can significantly improve the accuracy of the calculations.

[0101] S4. According to the selected operation mode, iteratively calculate the water temperature out of the tower, the water film temperature of the heat exchange tube, and the spray water temperature (cross-flow closed tower) of the model.

[0102] In some embodiments, step S4 specifically includes the following steps:

[0103] S41. Initialization of iterative calculation of countercurrent closed cooling tower: the outlet water temperature is used as the outer iteration variable, and the heat exchange tube water film temperature is used as the inner iteration variable. The two are nested for iterative calculation. The initial values of the outlet water temperature and the heat exchange tube water film temperature are set, and the initial iteration step size is set.

[0104] The cooling method of a closed cooling tower is different from that of an open cooling tower. The cooling water of an open tower is in direct contact with the air in the filler to reduce the temperature, while the cooling water of a closed tower flows through the pipe and is attached to the outer wall of the pipe through external spray water to evaporate and absorb heat through phase change to reduce the temperature and achieve the cooling purpose. The spray water is attached to the outer wall of the pipe to form a layer of water film, which absorbs the heat emitted by the cooling water in the pipe and evaporates, bringing the heat to the incoming air. Therefore, the water film plays a vital role in the entire heat transfer process. Speaking of the water film temperature, it is also affected by multiple variables such as the temperature and humidity of the incoming air, the flow rate and temperature of the cooling water in the pipe. It is almost unrealistic to calculate the water film temperature by fitting an empirical formula. Therefore, in order to simplify the calculation, the water film temperature is directly used as an iterative variable in the program. Therefore, compared with the standard open countercurrent cooling tower, the closed countercurrent cooling tower has an additional water film temperature iterative variable t m In order to utilize the calculation method of the standard model, the cooling water outlet temperature is still used as the outer iteration variable, and the purpose of the inner nested iteration part is to iteratively calculate the corresponding water film temperature.

[0105] To facilitate calculations and simplify the process, the following assumptions are generally made: (1) The spray water film has a uniform temperature throughout the heat exchanger and remains constant. (2) The surface area of the water film is approximately equal to the surface area of the coil, as the water film is generally very thin. (3) The circulating water is evenly distributed across the different tube banks, meaning that there is water on the surface of each coil.

[0106] The heat transfer process of the closed cooling tower mainly involves two heat transfer equations. First, the hot water transfers heat to the water film outside the coil: dQ = K1 (Tt m )dA, where K1 is the total heat transfer coefficient between the cooling water and the water film, which can be obtained based on relevant literature and empirical formulas. T is the qualitative temperature of the cooling water, and the program uses the average inlet and outlet water temperatures. Another heat transfer equation is the heat transfer between the water film and the air: dQ = β x (i″ t -i)dA, where β x is the mass transfer coefficient based on the enthalpy-humidity difference of the coil surface area as the driving force, kg / (m 2 .s), i″ t is the water film temperature t m The corresponding enthalpy value of saturated air, i is the air enthalpy value. Based on the above two heat transfer equations, the heat transfer process of the model is derived.

[0107] First, the heat gain of air during the entire heat transfer process is the heat transfer between the water film and the air: G air_mass di=β x (i″ t -i)dA, which satisfies: By solving the integral, we can get: Among them, Mw is called the area cooling number of the water film, Similarly, according to dQ=K1(Tt m )dA, we can get K1(Tt m )dA=G coolingwater_mass c water dT, and by integrating the above formula, we can get T2=t+(T1-t m )e -NTU , where NTU is called the number of heat transfer units in the closed cooling tower, Finally, all the heat dissipated by the cooling water is taken away by the air, and then it will satisfy: G air_mass (i2-i1)=G coolingwater_mass c water (T2-T1), bring in T2 and i2 obtained by integration, and after integration we can get:

[0108]

[0109] The outlet temperature of the outer layer iteration cooling water is the same as that of the starting tower. Inner layer iterative water film temperature assignment The iterative process first obtains the total heat transfer coefficient from the cooling water in the tube to the water film according to the set cooling water outlet temperature and air inlet parameters, and then brings in the t m In the formula, the success of the iteration is determined by judging the error between the calculated value and the actual value of the water film temperature through the single variable one-way iteration method. After completing the internal iteration, the water film temperature is brought into T2=t+(T1-t m )e -NTU The calculated value of the cooling water outlet temperature is obtained in the process. Similarly, the single variable one-way iteration method is used to determine whether the iteration is successful by judging the error between the calculated value and the actual value of the outlet water temperature.

[0110] S42. Initialization of iterative calculation of cross-flow closed cooling tower: spray water temperature is used as the outer iteration variable, outlet water temperature is used as the middle iteration variable, and heat exchange tube water film temperature is used as the inner iteration variable. The three are nested for iterative calculation. The initial values of outlet water temperature, heat exchange tube water film temperature, and spray water temperature are set, and the initial iteration step size is set.

[0111] The heat transfer process of a crossflow closed tower is essentially a combination of a counterflow closed tower and a crossflow open tower. Compared to the iterative process for a counterflow closed tower, an additional iteration of the spray water temperature is required. Spray water is pumped from the reservoir to the top and sprayed down, where it adheres to the coils for heat exchange. Some of the heat dissipated by the cooling water is carried away by the air to the atmosphere, while some is absorbed by the spray water and falls to the packing layer for cooling. After cooling in the seasoning layer, the spray water returns to the reservoir for the next cycle. Therefore, under ideal circulation conditions, the heat exchange between the coils and the packing is coupled. During the calculation, the packing is divided into microelements in the same way as in a crossflow open tower, except that it is spray circulating water, not cooling water, that passes through the packing. Therefore, compared to a counterflow closed tower, an iteration of the spray water temperature is added to the outermost layer. The iterations of the internal cooling water outlet temperature and the water film temperature are the same as those for the counterflow tower above. After completing the two internal iterations, the heat balance equation is used:

[0112]

[0113] The heat gain of the spray water in the circulation process and the calculated value of the spray water temperature can be obtained. Similarly, through the single variable single item iteration method, the error between the calculated value of the spray water temperature and the assumed value is compared to determine whether the iteration is successful.

[0114] S43. Counterflow and crossflow closed cooling towers use the same iterative search method: a bidirectional iterative approach, working from the inside out. In nested layers, the inner layers should be iterated first, then gradually returned to the outer layers. Adjustments to the upper layers trigger recalculations of the lower layers. Ultimately, through layer-by-layer iteration and correction, the global optimal solution is found.

[0115] In summary, the method of the present invention has at least the following advantages and beneficial effects compared to the prior art:

[0116] (1) The present invention calculates the water film temperature and other key parameters by differentiation and deduction based on the basic principles of heat transfer, overcoming the inaccuracy caused by the traditional method relying on empirical formulas, and adopts a bidirectional iterative algorithm for iterative correction, achieving higher calculation accuracy under multivariable coupling conditions.

[0117] (2) The program of the present invention can flexibly cope with different types of closed cooling towers through mode selection (counterflow and crossflow), making the present invention more adaptable to a wide range of application scenarios and reducing the workload of customized development for specific systems.

[0118] (3) The present invention can simulate the dynamic operating characteristics of a closed cooling tower under different loads and environmental conditions, providing more reliable results than traditional static models, making adjustments and controls in actual operations more precise.

[0119] (4) For the design and optimization of closed cooling towers, the present invention can help engineers quickly verify the thermal performance under different design schemes, improve design efficiency, shorten the development cycle, and reduce the actual testing requirements.

[0120] Example 2

[0121] This embodiment provides a hydraulic and thermodynamic calculation device for a closed cooling tower, wherein the closed cooling tower includes a counterflow closed cooling tower and a crossflow closed cooling tower, including:

[0122] Parameter assignment module, used to calculate air state parameters according to environmental conditions, and assign the air state parameters to the tower air parameters without considering backflow;

[0123] The mode selection module is used to select the type of closed cooling tower, calculate the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan;

[0124] The initial setting module is used to set the initial values of the water temperature at the outlet of the tower and the water film temperature of the heat exchange tube, calculate the state parameters of the heat exchange tube area, and build the heat exchange mechanism model of each component of the closed cooling tower;

[0125] Iterative calculation module is used to iteratively calculate the tower water temperature and the water film temperature of the heat exchange tube.

[0126] Since the device is a hydraulic and thermal calculation device for a closed cooling tower in an embodiment of the present invention, and the principle of solving the problem by the device is similar to that of the method, the implementation of the device can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0127] Example 3

[0128] An embodiment of the present invention further provides an electronic device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the following Figure 3 and / or Figure 4 A hydraulic and thermal calculation method for a closed cooling tower is shown.

[0129] It is understood that the memory may include random access memory (RAM) or read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function, instructions for implementing the various method embodiments described above, etc.; the data storage area may store data created based on the use of the server, etc.

[0130] The processor may include one or more processing cores. The processor utilizes various interfaces and circuits to connect various components within the server. It executes various server functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in memory, as well as accessing data stored in memory. Optionally, the processor may be implemented using at least one of the following hardware forms: digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The processor may integrate one or a combination of a central processing unit (CPU) and a modem. The CPU primarily processes the operating system and application programs, while the modem handles wireless communications. It is understood that the modem may not be integrated into the processor and may be implemented separately via a single chip.

[0131] Since the electronic device is an electronic device corresponding to the hydraulic and thermal calculation method for a closed cooling tower in an embodiment of the present invention, and the principle of solving the problem by the electronic device is similar to that of the method, the implementation of the electronic device can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0132] Example 4

[0133] An embodiment of the present invention further provides a computer-readable storage medium, wherein the storage medium stores at least one instruction, at least one program, code set or instruction set, and the at least one instruction, the at least one program, the code set or instruction set is loaded and executed by a processor to implement the following Figure 3 and / or Figure 4 A hydraulic and thermal calculation method for a closed cooling tower is shown.

[0134] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0135] Since the storage medium is the storage medium corresponding to the hydraulic and thermal calculation method for a closed cooling tower in an embodiment of the present invention, and the principle of solving the problem by the storage medium is similar to that of the method, the implementation of the storage medium can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0136] Example 5

[0137] In some possible implementations, various aspects of the methods of the embodiments of the present invention may also be implemented in the form of a program product, which includes program code. When the program product is executed on a computer device, the program code is used to cause the computer device to execute the steps of the method for calculating the hydraulic and thermal dynamics of a closed cooling tower according to various exemplary embodiments of the present application as described above in this specification. The executable computer program code or "code" used to execute the various embodiments may be written in a high-level programming language such as C, C++, C#, Smalltalk, Java, JavaScript, Visual Basic, Structured Query Language (e.g., Transact-SQL), Perl, or in various other programming languages.

[0138] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0139] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0140] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the essence of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A method for calculating the hydraulic and thermal performance of a closed cooling tower, characterized in that: The closed cooling tower includes a counterflow closed cooling tower and a crossflow closed cooling tower, and comprises the following steps: Calculate the air state parameters according to the environmental conditions and assign them to the tower air parameters without considering the backflow; Select the form of closed cooling tower, calculate the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan; Set the initial values of the water temperature at the outlet of the tower and the water film temperature of the heat exchange tube, and calculate the state parameters of the heat exchange tube area; Iteratively calculate the tower water temperature and the heat exchange tube water film temperature, and output the calculated values of the tower water temperature and the heat exchange tube water film when the preset iteration termination condition is reached; The selection of the closed cooling tower form, calculation of the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan, includes: Calculations are performed based on the selected operating mode. Mode 1 is a counterflow closed cooling tower, and Mode 2 is a crossflow closed cooling tower. Counterflow closed cooling towers do not require heat exchange filler parameter calculations, while crossflow closed cooling towers do. In addition, both require parameter calculations for the variable frequency cooling fan and variable frequency spray water pump, using the same calculation method. Obtain the operating frequency of the variable frequency cooling fan based on external input variables and calculate the air volume and power of the variable frequency cooling fan. If the cross-flow closed cooling tower in operation mode 2 is selected, the calculated cooling fan air volume needs to be split. Based on the air split coefficient and the cooling fan air volume, calculate the air volume passing through the heat exchange packing layer and the air volume passing through the heat exchange light pipe area respectively. Based on external input variables, the operating frequency of the variable frequency sprinkler pump and the pipe resistance from the pool to the sprinkler system are obtained, the required head of the sprinkler pump is calculated, and the operating parameters of the sprinkler pump and the sprinkler water circulation flow rate are iteratively calculated; If the cross-flow closed cooling tower of mode 2 is selected, the heat exchange filler parameter calculation is performed: the volumetric mass coefficient of the heat exchange filler is calculated based on the filler air flow rate and the filler fitting parameters; The setting of the initial values of the outlet water temperature and the water film temperature of the heat exchange tube and the calculation of the state parameters of the heat exchange tube area include: Perform heat exchange filler layer calculation according to the selected operating mode. If you select mode 1 counterflow closed cooling tower, skip this step. If you select mode 2 crossflow closed cooling tower, perform heat exchange filler layer thermal calculation: calculate the filler layer water temperature and the air enthalpy out of the filler layer based on the inlet water temperature, inlet air parameters, and air flow through the filler layer. Based on the cooling water flow into the tower, the spray water flow, the heat exchange tube structure, and the parameters of the air entering the tower, the convective heat transfer coefficient between the outer wall of the tube and the water film, the heat transfer coefficient of the cooling water in the heat exchange tube, and the convective heat transfer coefficient between the water film outside the tube and the air are calculated; based on the definition of the Lewis number and the convective heat transfer coefficient between the water film outside the tube and the air, the mass transfer coefficient between the air and the water film is calculated.

2. The hydraulic and thermal calculation method of a closed cooling tower according to claim 1, characterized in that: The counter-current closed cooling tower includes a heat exchange light tube, a variable frequency cooling fan, a variable frequency spray water pump, a spray system, a water pool, an automatic water replenishment system and a water collector; The spray system is located at the top of the cooling tower and is connected to the variable frequency spray water pump through a circulating water pipe. The variable frequency spray water pump delivers water to the spray system, and the spray system sprays the circulating water to the heat exchange tube for evaporation and heat transfer. The water pool is located at the bottom of the cooling tower and is used to collect the spray water that falls back after cooling; The automatic water replenishment system is connected to the water pool to maintain the water balance in the system; The variable frequency cooling fan drives the air to flow, thereby achieving heat exchange between the air and the heat exchange light pipe; The water collector is located above the sprinkler system and is used to collect moisture brought out by air flow to reduce water loss.

3. The hydraulic and thermal calculation method of a closed cooling tower according to claim 1, characterized in that: The cross-flow closed cooling tower includes heat exchange filler, heat exchange light tube, variable frequency cooling fan, variable frequency spray water pump, spray system, water pool, automatic water replenishment system, and water collector; The spray system is located at the top of the cooling tower and is connected to the variable frequency spray water pump through a circulating water pipe. The variable frequency spray water pump delivers water to the spray system, and the spray system sprays the circulating water to the heat exchange tube for evaporation and heat transfer. The filler is located below the heat exchange light tube and is used to cool the spray water falling from above to achieve circulating cooling; The water pool is located at the bottom of the cooling tower and is used to collect the spray water that falls back after cooling; The automatic water replenishment system is connected to the water pool to maintain the water balance in the system; The variable frequency cooling fan drives the air to flow, and the air is divided after entering the cooling tower. One part of the air is transferred to the water film on the surface of the heat exchange tube, and the other part is transferred to the spray water through the heat exchange filler. The water collector is located above the sprinkler system and is used to collect moisture brought out by air flow to reduce water loss.

4. The hydraulic and thermal calculation method of a closed cooling tower according to claim 1, characterized in that: The environmental conditions include ambient temperature and relative humidity; the air state parameters include dry-bulb temperature, wet-bulb temperature, moisture content, relative humidity, and air enthalpy of the ambient air; The method of calculating the air state parameters according to the environmental conditions and assigning the air state parameters to the tower air parameters without considering the backflow includes: According to the dry bulb temperature of the closed cooling tower environment, calculate the atmospheric saturated air water vapor partial pressure corresponding to the dry bulb temperature; According to the partial pressure of water vapor in the saturated air and the atmospheric pressure of the closed cooling tower, calculate the saturated air moisture content corresponding to the dry-bulb temperature of the closed cooling tower; according to the partial pressure of water vapor in the saturated air and the relative humidity of the closed cooling tower, calculate the water vapor pressure corresponding to the dry-bulb temperature of the closed cooling tower; according to the water vapor pressure corresponding to the dry-bulb temperature and the atmospheric pressure of the closed cooling tower, calculate the actual air moisture content of the closed cooling tower; according to the actual air moisture content and the dry-bulb temperature of the closed cooling tower, calculate the air enthalpy of the closed cooling tower; according to the air enthalpy, calculate the air wet-bulb temperature of the closed cooling tower; The humidity of the air entering the tower is equal to the humidity of the environment, the enthalpy of the air entering the tower is equal to the air enthalpy of the environment, the temperature of the air entering the tower is equal to the dry bulb temperature of the environment, and the relative humidity of the air entering the tower is equal to the relative humidity of the environment.

5. The hydraulic and thermal calculation method of a closed cooling tower according to claim 1, characterized in that: The iterative calculation of the tower water temperature and the heat exchange tube water film temperature includes: Initialize the iterative calculation of the counterflow closed cooling tower: use the outlet water temperature as the outer iteration variable and the heat exchange tube water film temperature as the inner iteration variable, nest the two for iterative calculation, set the initial values of the outlet water temperature and the heat exchange tube water film temperature, and set the initial iteration step size; Initialize the iterative calculation of a cross-flow closed cooling tower: use the spray water temperature as the outer iteration variable, the outlet water temperature as the middle iteration variable, and the heat exchange tube water film temperature as the inner iteration variable. The three are nested for iterative calculation. Set the initial values of the outlet water temperature, heat exchange tube water film temperature, and spray water temperature, and set the initial iteration step size. Iterative calculation search: The iterative calculation search method used by the counterflow closed cooling tower is the same as that used by the crossflow closed cooling tower. Both use a bidirectional iteration method to iterate from the inside out. In the multi-layer nested iteration, the inner layer is iterated first, and then gradually returns to the outer layer. Whenever the upper layer variables are adjusted, the lower layer will be recalculated. Finally, through layer-by-layer iteration and correction, the global optimal solution is found. Iterative calculation error judgment: First, calculate the error between the current assumption value and the target value, and decide whether to increase or decrease the current value based on the sign of the error; in each iteration, if the error is positive, the adjustment value increases upward; if the error is negative, it decreases downward; the program also records the direction of adjustment. When it is found that it has been adjusted once in two different directions, the adjustment step size is halved to improve the calculation accuracy and prevent over-adjustment; the whole process is repeated until the error is less than the set threshold or the adjustment step size is less than the preset step size, and the optimal solution is obtained.

6. A hydraulic and thermal calculation device for a closed cooling tower, using the hydraulic and thermal calculation method for a closed cooling tower according to any one of claims 1 to 5, characterized in that: The closed cooling tower includes a counterflow closed cooling tower and a crossflow closed cooling tower, including: Parameter assignment module, used to calculate air state parameters according to environmental conditions, and assign the air state parameters to the tower air parameters without considering backflow; The mode selection module is used to select the type of closed cooling tower, calculate the head and power of the variable frequency spray water pump, and the air volume and power of the variable frequency cooling fan; The initial setting module is used to set the initial values of the water temperature at the tower outlet and the water film temperature of the heat exchange tube, and calculate the state parameters of the heat exchange tube area; The iterative calculation module is used to iteratively calculate the tower water temperature and the heat exchange tube water film temperature, and output the calculated values of the tower water temperature and the heat exchange tube water film when the preset iteration termination condition is reached.

7. An electronic device, characterized in that: The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the method described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that The storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the method according to any one of claims 1 to 5.

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