A compressor front heat exchanger outlet temperature real-time optimization method, device and computer readable storage medium

Abstract

The present application relates to compressed air energy storage system control technical field, especially to a kind of compressor front heat exchanger outlet temperature real-time optimization method and device.The method establishes heat exchanger simplified mechanism model, gas holder mechanism model and the thermodynamic dynamic coupling model of compressor, obtains the correlation of compressor inlet pressure, inlet temperature, speed and pressure ratio and heat exchanger efficiency;Compressor power consumption is expressed as a single variable function only related to heat exchanger efficiency based on the dynamic coupling model;Introduce heat exchanger efficiency simplified multivariable optimization problem, adopt steepest descent method combined with Newton method, obtain optimal heat exchanger efficiency value;According to the optimal heat exchanger efficiency value, the optimal set value of heat exchanger outlet air temperature is calculated, and it is input into heat medium water control loop to realize temperature real-time optimization control.The present application can realize the real-time optimization of compressor front heat exchanger outlet air temperature, effectively balance heat exchanger cooling effect and pressure loss influence.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage system control technology, and in particular to a method, apparatus and computer-readable storage medium for real-time optimization of the outlet temperature of a compressor preheater. Background Technology

[0002] Reducing the compression work during the compression process is a crucial method for improving the round-trip efficiency of compressed air energy storage systems. Cooling the outlet air of the previous stage compressor via a heat exchanger reduces compressor power consumption; however, this incurs pressure losses, increasing compressor power consumption. Therefore, the operating state of the heat exchanger is critical, affecting both the compressor inlet temperature and pressure, and consequently, the compressor's work output. In multi-stage compressed air energy storage systems, the pressure in the storage chamber constantly changes during the charging process, resulting in continuous changes in the back pressure of the final stage compressor, operating under a variable pressure ratio. A constant heat exchanger air outlet temperature control cannot meet the optimal operating requirements of the actual system under variable pressure ratio operation. Therefore, a rapid online optimization method for the variable pressure ratio compressor heat exchanger air outlet temperature is needed to provide the optimal controlled variable for the heat exchanger temperature control of the heat transfer medium water in the compression-controlled energy storage system, thereby reducing compression work and improving the system's round-trip efficiency. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, the first objective of this invention is to provide a method for real-time optimization of the outlet temperature of a compressor preheater, comprising:

[0005] S1. Establish a simplified mechanism model of the heat exchanger, a mechanism model of the gas storage chamber, and a thermodynamic dynamic coupling model of the compressor to obtain the correlation between the compressor inlet pressure, inlet temperature, speed, and pressure ratio and the heat exchanger performance. S2, Based on the dynamic coupling model, the compressor power consumption is expressed as a single-variable function that is only related to the heat exchanger efficiency; S3 introduces heat exchanger efficiency to simplify the multivariate optimization problem, and uses the steepest gradient descent method combined with Newton's method to obtain the optimal heat exchanger efficiency value; S4. Calculate the optimal setpoint for the heat exchanger outlet air temperature based on the optimal heat exchanger efficiency value, and input it into the heat medium water control loop to achieve real-time temperature optimization control.

[0006] In one embodiment of the present invention, S1 further includes: S11. A simplified mechanism model of the heat exchanger is constructed based on the energy equations of the water side, air side, and heat transfer of the heat exchanger. The energy equation for the water side of the heat exchanger is: ; in, For the quality of the heat transfer fluid inside the heat exchanger; For the quality of the metal heat transfer tubes of the heat exchanger; Specific heat capacity of the metal heat transfer tubes in the heat exchanger; The inlet temperature of the heat exchanger's heat transfer fluid; This refers to the outlet temperature of the heat exchanger's heat transfer fluid. The specific heat capacity of the heat exchanger's heat transfer medium, water; The rate of change of the outlet temperature of the heat exchanger's heat medium water; This refers to the flow rate of the heat exchanger's heat transfer medium. For heat transfer in the heat exchanger; The energy equation for the air side of the heat exchanger is: ; in, The mass of air inside the heat exchanger; This refers to the compressed air outlet temperature of the heat exchanger. The rate of change of compressed air outlet temperature in the heat exchanger; This refers to the compressed air inlet temperature of the heat exchanger. This refers to the mass flow rate of compressed air. The specific heat capacity of compressed air at constant pressure in the heat exchanger; The heat exchanger heat transfer equation is: ; in, The heat transfer coefficient; The heat transfer coefficient; S12, the compression and charging process is simulated using an ideal gas model, the pressure equation of the gas storage chamber is constructed, and the compressor outlet pressure is obtained based on the condition that the air flow is stable during the compressor charging and storage stage.

[0007] In one embodiment of the present invention, the method for obtaining the compressor outlet pressure in step S12 is as follows: Using an ideal gas model, the formula for the pressure in the gas storage chamber during the compression and charging process is: ; Using the ideal gas formula The pressure equation for the gas storage chamber can be derived: ; in, It refers to the air quality in the gas storage chamber; It is the energy stored in the gas storage chamber; It is the enthalpy value of the air outlet from the compressor; It is the rate of change of air quality in the air storage chamber, i.e., the air flow rate of the compressor. ; It is the pressure in the gas storage chamber; It is the air temperature at the inlet of the gas storage chamber; It is the gas constant; It is the polyvariate coefficient; This refers to the volume of the gas storage chamber; Under the condition of maintaining a stable airflow, the compressor outlet pressure is obtained by using the pressure in the air receiver chamber: ; in, It is the drag coefficient. It is the air density at the compressor outlet.

[0008] In one embodiment of the present invention, S2 further includes: S21, Based on compressor airflow, compressor isentropic efficiency, and compressor inlet and outlet temperatures, construct the compressor power consumption equation: ; in, The compressor consumes power; This refers to the airflow rate of the compressor. The compressor has isentropic efficiency; Compressor inlet air temperature; This refers to the compressor pressure ratio; S22, based on the compressor characteristic curve fitting, the relationship between compressor air flow and compressor isentropic efficiency is expressed.

[0009] In one embodiment of the present invention, S22 further includes: The compressor airflow equation is fitted based on the compressor characteristic curve: ; in, ; ; ; In the formula, This refers to the compressor inlet temperature under rated operating conditions. This refers to the compressor inlet pressure under rated operating conditions. This refers to the compressor speed; The isentropic efficiency equation of the compressor is fitted based on the compressor characteristic curve: .

[0010] In one embodiment of the present invention, S3 further includes: S31 introduces the heat exchanger efficiency definition as the ratio of actual heat exchange to maximum possible heat exchange. The heat exchanger thermal efficiency relationship is used to represent the compressor inlet air temperature and pressure. Under the condition of stable air flow, the compressor power consumption problem is transformed into a single variable optimization problem of heat exchanger heat exchange efficiency. S32, a hybrid optimization algorithm combining the steepest gradient descent method and Newton's method is used to solve the single-variable function in stages. In the initial stage, the steepest gradient descent method is used for rapid convergence, and when approaching the extreme point, it is switched to Newton's method for precise optimization to obtain the optimal heat exchanger efficiency value.

[0011] In one embodiment of the present invention, S31 further includes: The heat exchanger efficiency is defined as the ratio of the actual heat transfer to the maximum possible heat transfer. The expression for this ratio is: ; in, For actual heat exchange, To maximize the heat exchange capacity, For the mass flow rate of the fluid, The temperature difference between the inlet and outlet of the fluid itself. The inlet temperature of the hot fluid. This refers to the inlet temperature of the cold fluid. The relationship between heat exchanger thermal efficiency and compressor inlet air temperature and pressure is expressed as follows: ; ; In the formula, This refers to the outlet temperature of the previous stage compressor. This refers to the inlet temperature of the heat exchanger's heat transfer fluid. This refers to the outlet pressure of the previous stage compressor. Furthermore, under the condition of stable airflow, the compressor outlet pressure can be calculated from the pressure in the air storage chamber, and its expression is: ; Since the compressor outlet pressure is regulated by the compressor speed, the compressor power consumption can only be optimized through the heat exchanger's heat exchange efficiency. Therefore, the compressor power consumption problem is simplified to a single-variable optimization problem concerning the heat exchanger's heat exchange efficiency: .

[0012] In one embodiment of the present invention, S32 further includes: S321, Select initial value of heat exchanger efficiency Given the calculation termination error ,make ; S322, take Search for the minimum value and adjust the iteration step size. Solve for, such that ; make , ; S323, Calculate the gradient value of the compressor power consumption equation. ,like If the iteration stops, output the result. Otherwise, repeat step S322; S324, taking the steepest gradient descent result as the initial point, let k=0. When the gradient value of the compressor power consumption equation does not meet the iteration conditions, let: , ; S325, Calculate the gradient of the compressor power consumption equation. and second gradient ,if Stop iteration and output. Otherwise, repeat step S324; S326, after stopping the iteration, based on the output To achieve the optimal outlet temperature of the heat exchanger: ; in, This refers to the outlet temperature of the previous stage compressor. This refers to the inlet temperature of the heat exchanger's heat transfer medium water.

[0013] To achieve the above objectives, a second aspect of the present invention provides a device for real-time optimization of the outlet temperature of a compressor preheater, comprising: The multi-objective optimization model construction module is used to establish a simplified mechanism model of the heat exchanger, a mechanism model of the gas storage chamber, and a thermodynamic dynamic coupling model of the compressor, and to obtain the correlation between the compressor inlet pressure, inlet temperature, speed, and pressure ratio and the heat exchanger performance. The heat exchanger performance parameterization module is used to express the compressor power consumption as a single-variable function that is only related to the heat exchanger performance based on the dynamic coupling model. The hybrid optimization algorithm execution module is used to simplify the multivariate optimization problem by introducing heat exchanger performance. It uses the steepest gradient descent method combined with Newton's method to obtain the optimal heat exchanger performance value. The temperature setpoint conversion module is used to calculate the optimal setpoint of the heat exchanger outlet air temperature based on the optimal heat exchanger efficiency value, and input it into the heat medium water control loop to achieve real-time temperature optimization control.

[0014] To achieve the above objectives, a third aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0015] The methods, systems, and storage media of this invention generally ignore heat exchanger pressure loss and use a constant heat exchanger outlet air temperature as the control target. The better the heat exchanger cools the outlet air temperature of the previous stage compressor, the less power consumption of the next stage compressor. However, the better the heat exchanger's heat exchange efficiency, the greater the pressure loss, which in turn increases the compressor's power consumption. Therefore, the operating state of the heat exchanger is crucial, as it affects both the compressor inlet temperature and inlet pressure, thus influencing the compressor's work output. In a multi-stage air compression energy storage system, the pressure in the storage chamber constantly changes during the charging and storage process. Therefore, the back pressure of the last stage compressor constantly changes, resulting in a variable pressure ratio operating state. A constant heat exchanger outlet air temperature control cannot meet the optimal operating requirements under the actual system's variable pressure ratio operation. Therefore, this invention proposes a real-time optimization method for the air outlet temperature of the heat exchanger before the last stage variable pressure ratio compressor in a multi-stage air compression energy storage system. This method can calculate the optimal air outlet temperature of the heat exchanger before the compressor in real time based on the compressor's operating state, serving as the optimal setpoint for the heat transfer medium water control loop, thereby reducing compressor power consumption and improving the system's round-trip efficiency.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 A flowchart illustrating the real-time optimization method for the outlet temperature of the compressor preheater provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the real-time optimization process for the outlet temperature of the compressor preheater provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of the real-time optimization device for the outlet temperature of the compressor preheater provided in an embodiment of the present invention. Detailed Implementation

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] The following describes a method and apparatus for real-time optimization of the outlet temperature of a compressor preheater according to an embodiment of the present invention, with reference to the accompanying drawings.

[0021] Example 1 Figure 1 This is a flowchart of a method for real-time optimization of the outlet temperature of a compressor preheater according to an embodiment of the present invention.

[0022] The optimization method proposed in this invention is used to condition the outlet temperature of the heat exchanger before the last stage variable ratio compressor in a multi-stage air compression energy storage system. Specifically, the last stage variable ratio compressor system of the multi-stage air compression energy storage system includes a heat exchanger, a compressor, and an air storage chamber.

[0023] like Figure 2 As shown, this invention calculates the optimal air outlet temperature of the heat exchanger based on the compressor's operating status and uses it as the set value for the heat exchanger's heat medium water control loop through an online real-time optimization system, thereby reducing compression power consumption and improving the system's round-trip efficiency.

[0024] Specifically, such as Figure 1 As shown, the method for real-time optimization of the outlet temperature of the compressor preheater includes the following steps: S1. Establish a thermodynamic dynamic coupling model of the heat exchanger, gas storage chamber and compressor to obtain the correlation between compressor inlet pressure, inlet temperature, speed and pressure ratio and heat exchanger efficiency.

[0025] At the technical implementation level, the heat exchanger model is described by energy conservation equations on both the water and air sides. The energy equation for the water side is: ; in, For the quality of the heat transfer fluid inside the heat exchanger; For the quality of the metal heat transfer tubes of the heat exchanger; Specific heat capacity of the metal heat transfer tubes in the heat exchanger; The inlet temperature of the heat exchanger's heat transfer fluid; This refers to the outlet temperature of the heat exchanger's heat transfer fluid. The specific heat capacity of the heat exchanger's heat transfer medium, water; The rate of change of the outlet temperature of the heat exchanger's heat medium water; This refers to the flow rate of the heat exchanger's heat transfer medium. For heat transfer in the heat exchanger; ; in, The mass of air inside the heat exchanger; This refers to the compressed air outlet temperature of the heat exchanger. The rate of change of compressed air outlet temperature in the heat exchanger; This refers to the compressed air inlet temperature of the heat exchanger. This refers to the mass flow rate of compressed air. The specific heat capacity of compressed air at constant pressure in the heat exchanger; The heat exchanger heat transfer equation is: ; in, The heat transfer coefficient; The heat transfer coefficient is denoted as .

[0026] The compression and charging process is simulated using an ideal gas model, and the pressure equation of the gas storage chamber is constructed. Based on the condition that the air flow is stable during the compressor charging and storage stage, the compressor outlet pressure is obtained.

[0027] Specifically, using an ideal gas model, the formula for expressing the pressure in the gas storage chamber during the compression and charging process is: ; Using the ideal gas formula The pressure equation for the gas storage chamber can be derived: ; in, It refers to the air quality in the gas storage chamber; It is the energy stored in the gas storage chamber; It is the enthalpy value of the air outlet from the compressor; It is the rate of change of air quality in the air storage chamber, i.e., the air flow rate of the compressor. ; It is the pressure in the gas storage chamber; It is the air temperature at the inlet of the gas storage chamber; It is the gas constant; It is the polyvariate coefficient; This refers to the volume of the gas storage chamber; Under the condition of maintaining a stable airflow, the compressor outlet pressure is obtained by using the pressure in the air receiver chamber: ; in, It is the drag coefficient. It is the air density at the compressor outlet.

[0028] This step is applicable to the dynamic control scenario of the last stage compressor in a multi-stage air compression energy storage system. By calculating the optimal heat exchanger efficiency in real time, the heat exchanger outlet air temperature can be converted into the setpoint of the heat transfer medium water control loop, thereby achieving coordinated optimization control of the compressor and heat exchanger. When the compressor is operating at a variable pressure ratio, this model can effectively balance the cooling effect of the heat exchanger and the pressure loss effect, ensuring that the compressor operates under optimal conditions, significantly reducing compression work and improving the system's round-trip efficiency. The establishment of this model provides a precise physical correlation basis for subsequent optimization algorithms and is a key technical step in achieving system energy efficiency improvement.

[0029] S2, Based on the dynamic coupling model, the compressor power consumption is expressed as a single-variable function that is only related to the heat exchanger efficiency.

[0030] Specifically, in this invention, the step of "representing the compressor power consumption as a single-variable function related only to the heat exchanger efficiency based on the dynamic coupling model" is the core step in achieving real-time optimization of the heat exchanger outlet air temperature. This step simplifies the multivariate optimization problem, which originally involved compressor inlet pressure, inlet temperature, speed, and pressure ratio, into a single-variable optimization problem related only to heat exchanger efficiency by introducing heat exchanger efficiency as a key variable. This significantly reduces computational complexity and improves optimization efficiency.

[0031] Further, step S2 includes: S21, Based on compressor airflow, compressor isentropic efficiency, and compressor inlet and outlet temperatures, construct the compressor power consumption equation: ; in, The compressor consumes power; This refers to the airflow rate of the compressor. The compressor has isentropic efficiency; Compressor inlet air temperature; This refers to the compressor pressure ratio; S22, based on the compressor characteristic curve fitting, the relationship between compressor air flow and compressor isentropic efficiency is expressed.

[0032] The compressor airflow equation is fitted based on the compressor characteristic curve: ; in, ; ; ; In the formula, This refers to the compressor inlet temperature under rated operating conditions. This refers to the compressor inlet pressure under rated operating conditions. This refers to the compressor speed; The isentropic efficiency equation of the compressor is fitted based on the compressor characteristic curve: .

[0033] Substituting the compressor flow equation and isentropic efficiency equation back into the compressor power consumption equation, it can be clearly seen that the compressor power consumption is only related to four physical quantities: compressor inlet temperature, pressure, speed, and pressure ratio.

[0034] The compressor airflow equation is used as an example to illustrate the establishment of the compressor fitting model. The compressor characteristic curve under rated operating conditions shows that the compressor airflow is only related to the pressure ratio, as shown in the following equation.

[0035] ; Table 1 shows the typical operating point data of the compressor characteristic curve. Table 1 Compressor air flow rate and pressure ratio under rated operating conditions

[0036] The least squares method was used for fitting.

[0037] Table 2 shows the data of the intersection points of the compressor outlet pressure of 12MPa and the compressor performance curves A, B, C, and D.

[0038] Table 2 Compressor equivalent speed and flow rate when compressor outlet pressure is 12MPa

[0039] Substituting the compressor outlet pressure of 12MPa and the compressor equivalent speed and flow rate from Table 2 into the compressor air flow equation, we obtain the following set of equations: ; ; ; Solving the system of equations yields: ; This yields the compressor power consumption function, which is then used as the optimization objective function. The optimization variables are four physical quantities: compressor inlet temperature, pressure, speed, and pressure ratio.

[0040] At the application level, this step is suitable for real-time control of the last stage compressor in a multi-stage air compression energy storage system. During system operation, the pressure in the air storage chamber... The dynamic changes over time cause the compressor to operate under variable pressure ratio conditions. Traditional control methods typically fix the heat exchanger outlet temperature, which cannot adapt to dynamic system changes. This invention models the compressor power consumption as a single-variable function of the heat exchanger efficiency, enabling rapid response to system state changes in the compressor control loop and providing optimal setpoints for the heat transfer medium water control, thereby minimizing compressor power consumption.

[0041] From a technical perspective, this step transforms the originally complex multivariate optimization problem into a single-variable optimization problem through variable substitution and model simplification, significantly reducing the computational burden and improving the real-time performance and convergence speed of the optimization algorithm. In practical systems, this method can dynamically adjust the outlet air temperature of the heat exchanger, balancing the trade-off between heat exchange efficiency and pressure loss, thereby effectively reducing compressor power consumption and improving the overall round-trip efficiency of the system. This technique has significant engineering application value in compressed air energy storage systems.

[0042] S3 introduces the heat exchanger efficiency to simplify the multivariate optimization problem. The steepest gradient descent method combined with Newton's method is used to obtain the optimal heat exchanger efficiency value.

[0043] Specifically, the hybrid optimization algorithm used in the steps of this invention combines the steepest gradient descent method with Newton's method, aiming to optimize the outlet air temperature of the compressor's preheater in real time, thereby minimizing the compressor's power consumption.

[0044] Further, step S3 includes: S31 introduces the heat exchanger efficiency definition as the ratio of actual heat exchange to maximum possible heat exchange. The heat exchanger thermal efficiency relationship is used to represent the compressor inlet air temperature and pressure. Under the condition of stable air flow, the compressor power consumption problem is transformed into a single variable optimization problem of heat exchanger heat exchange efficiency. The heat exchanger efficiency is defined as the ratio of the actual heat transfer to the maximum possible heat transfer. The expression for this ratio is: ; in, For actual heat exchange, To maximize the heat exchange capacity, For the mass flow rate of the fluid, The temperature difference between the inlet and outlet of the fluid itself. The inlet temperature of the hot fluid. This refers to the inlet temperature of the cold fluid. The relationship between heat exchanger thermal efficiency and compressor inlet air temperature and pressure is expressed as follows: ; ; In the formula, This refers to the outlet temperature of the previous stage compressor. This refers to the inlet temperature of the heat exchanger's heat transfer fluid. This refers to the outlet pressure of the previous stage compressor. Furthermore, under the condition of stable airflow, the compressor outlet pressure can be calculated from the pressure in the air storage chamber, and its expression is: ; Since the compressor outlet pressure is regulated by the compressor speed, the compressor power consumption can only be optimized through the heat exchanger's heat exchange efficiency. Therefore, the compressor power consumption problem is simplified to a single-variable optimization problem concerning the heat exchanger's heat exchange efficiency: .

[0045] S32, a hybrid optimization algorithm combining the steepest gradient descent method and Newton's method is used to solve the single-variable function in stages. In the initial stage, the steepest gradient descent method is used for rapid convergence, and when approaching the extreme point, it is switched to Newton's method for precise optimization to obtain the optimal heat exchanger efficiency value.

[0046] S321, Select initial value of heat exchanger efficiency Given the calculation termination error ,make ; S322, take Search for the minimum value and adjust the iteration step size. Solve for, such that ; make , ; S323, Calculate the gradient value of the compressor power consumption equation. ,like If the iteration stops, output the result. Otherwise, repeat step S322; S324, taking the steepest gradient descent result as the initial point, let k=0. When the gradient value of the compressor power consumption equation does not meet the iteration conditions, let: , ; S325, Calculate the gradient of the compressor power consumption equation. and second gradient ,if Stop iteration and output. Otherwise, repeat step S324; S326, after stopping the iteration, based on the output To achieve the optimal outlet temperature of the heat exchanger: ; in, This refers to the outlet temperature of the previous stage compressor. This refers to the inlet temperature of the heat exchanger's heat transfer medium water.

[0047] At the technical implementation level, the optimization process is divided into two stages. The initial stage uses the steepest gradient descent method, the core idea of ​​which is to search along the negative direction of the objective function's gradient, with the iterative formula being: ,in For the search direction, This is the step size. To accelerate initial convergence, a larger step size and a more lenient termination error are typically set. ,For example This stage involves only 3 to 5 iterations. It is suitable for regions with large gradients in the objective function and far from extreme points, and can quickly approximate the neighborhood of the optimal solution.

[0048] When the iteration approaches the extreme point, it switches to Newton's method. Newton's method uses the first derivative (gradient) and second derivative (Hessian matrix) of the objective function for a quadratic approximation. The iterative formula is as follows: This method exhibits second-order convergence speed when the objective function has significant curvature, making it suitable for high-precision optimization. In this invention, the initial values ​​for Newton's method are provided by the steepest gradient descent method, thus avoiding the sensitivity of Newton's method to initial values.

[0049] In terms of technical effectiveness, this hybrid optimization algorithm significantly improves optimization efficiency and accuracy. Compared with a single optimization method, it reduces the number of iterations by approximately 40% and the computation time to less than 60% of the original method, while minimizing compressor power consumption and improving system round-trip efficiency, demonstrating good engineering practical value.

[0050] S4. Calculate the optimal setpoint for the heat exchanger outlet air temperature based on the optimal heat exchanger efficiency value, and input it into the heat medium water control loop to achieve real-time temperature optimization control.

[0051] Specifically, in the steps of this invention, calculating the optimal setpoint for the heat exchanger outlet air temperature based on the optimal heat exchanger efficiency value and inputting it into the heat transfer fluid control loop to achieve real-time temperature optimization control is a key step in achieving the goal of minimizing compressor power consumption in the entire system. This step is technically based on the functional relationship between heat exchanger efficiency and compressor inlet air temperature. An optimization algorithm is used to solve for the optimal efficiency value, which is ultimately converted into a setpoint for the heat exchanger outlet air temperature to guide the operation of the heat transfer fluid control system.

[0052] The real-time optimization method for the outlet temperature of the heat exchanger before the last stage compressor in the multi-stage air compression energy storage system of the present invention can optimize the outlet air temperature of the heat exchanger before the compressor in real time, effectively balance the heat exchange cooling effect and the pressure loss effect, minimize the power consumption of the compressor under the variable pressure ratio condition, and improve the system round-trip efficiency.

[0053] Example 2 Figure 3 This is a structural diagram of a real-time optimization device for the outlet temperature of a compressor preheater according to an embodiment of the present invention.

[0054] like Figure 3 As shown, the real-time optimization device for the outlet temperature of the compressor's inlet heat exchanger includes: The multi-objective optimization model construction module is used to establish a simplified mechanism model of the heat exchanger, a mechanism model of the gas storage chamber, and a thermodynamic dynamic coupling model of the compressor, and to obtain the correlation between the compressor inlet pressure, inlet temperature, speed, and pressure ratio and the heat exchanger performance. The heat exchanger performance parameterization module is used to express the compressor power consumption as a single-variable function that is only related to the heat exchanger performance based on the dynamic coupling model. The hybrid optimization algorithm execution module is used to simplify the multivariate optimization problem by introducing heat exchanger performance. It uses the steepest gradient descent method combined with Newton's method to obtain the optimal heat exchanger performance value. The temperature setpoint conversion module is used to calculate the optimal setpoint of the heat exchanger outlet air temperature based on the optimal heat exchanger efficiency value, and input it into the heat medium water control loop to achieve real-time temperature optimization control.

[0055] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-described method for real-time optimization of the outlet temperature of the compressor preheater.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A method for real-time optimization of the outlet temperature of a compressor preheater heat exchanger, characterized in that, include: S1. Establish a simplified mechanism model of the heat exchanger, a mechanism model of the gas storage chamber, and a thermodynamic dynamic coupling model of the compressor to obtain the correlation between the compressor inlet pressure, inlet temperature, speed, and pressure ratio and the heat exchanger performance. S2, Based on the dynamic coupling model, the compressor power consumption is expressed as a single-variable function that is only related to the heat exchanger efficiency; S3 introduces heat exchanger efficiency to simplify the multivariate optimization problem, and uses the steepest gradient descent method combined with Newton's method to obtain the optimal heat exchanger efficiency value; S4. Calculate the optimal setpoint for the heat exchanger outlet air temperature based on the optimal heat exchanger efficiency value, and input it into the heat medium water control loop to achieve real-time temperature optimization control.

2. The method as described in claim 1, characterized in that, S1 further includes: S11. A simplified mechanism model of the heat exchanger is constructed based on the energy equations of the water side, air side, and heat transfer of the heat exchanger. The energy equation for the water side of the heat exchanger is: ； in, For the quality of the heat transfer fluid inside the heat exchanger; For the quality of the metal heat transfer tubes of the heat exchanger; Specific heat capacity of the metal heat transfer tubes in the heat exchanger; The inlet temperature of the heat exchanger's heat transfer fluid; This refers to the outlet temperature of the heat exchanger's heat transfer fluid. The specific heat capacity of the heat exchanger's heat transfer medium, water; The rate of change of the outlet temperature of the heat exchanger's heat medium water; This refers to the flow rate of the heat exchanger's heat transfer medium. For heat transfer in the heat exchanger; The energy equation for the air side of the heat exchanger is: ； in, The mass of air inside the heat exchanger; The compressed air outlet temperature of the heat exchanger; The rate of change of compressed air outlet temperature in the heat exchanger; This refers to the compressed air inlet temperature of the heat exchanger. This refers to the mass flow rate of compressed air. The specific heat capacity of compressed air at constant pressure in the heat exchanger; The heat exchanger heat transfer equation is: ； in, The heat transfer coefficient; The heat transfer coefficient; S12, the compression and charging process is simulated using an ideal gas model, the pressure equation of the gas storage chamber is constructed, and the compressor outlet pressure is obtained based on the condition that the air flow is stable during the compressor charging and storage stage.

3. The method as described in claim 2, characterized in that, The method for obtaining the compressor outlet pressure in step S12 is as follows: Using an ideal gas model, the formula for the pressure in the gas storage chamber during the compression and charging process is: ； Using the ideal gas formula The pressure equation for the gas storage chamber can be derived: ； in, It refers to the air quality in the gas storage chamber; It is the energy stored in the gas storage chamber; It is the enthalpy value of the air outlet from the compressor; It is the rate of change of air quality in the air storage chamber, i.e., the air flow rate of the compressor. ; It is the pressure in the gas storage chamber; It is the air temperature at the inlet of the gas storage chamber; It is the gas constant; It is the polyvariate coefficient; This refers to the volume of the gas storage chamber; Under the condition of maintaining a stable airflow, the compressor outlet pressure is obtained by using the pressure in the air receiver chamber: ； in, It is the drag coefficient. It is the air density at the compressor outlet.

4. The method as described in claim 1, characterized in that, S2 further includes: S21, Based on compressor airflow, compressor isentropic efficiency, and compressor inlet and outlet temperatures, construct the compressor power consumption equation: ； in, The compressor consumes power; This refers to the airflow rate of the compressor. The compressor has isentropic efficiency; Compressor inlet air temperature; This refers to the compressor pressure ratio; S22, based on the compressor characteristic curve fitting, the relationship between compressor air flow and compressor isentropic efficiency is expressed.

5. The method as described in claim 4, characterized in that, S22 further includes: The compressor airflow equation is fitted based on the compressor characteristic curve: ； in, ； ； ； In the formula, This refers to the compressor inlet temperature under rated operating conditions. This refers to the compressor inlet pressure under rated operating conditions. This refers to the compressor speed; The isentropic efficiency equation of the compressor is fitted based on the compressor characteristic curve: 。 6. The method as described in claim 1, characterized in that, S3 further includes: S31 introduces the heat exchanger efficiency definition as the ratio of actual heat exchange to maximum possible heat exchange. The heat exchanger thermal efficiency relationship is used to represent the compressor inlet air temperature and pressure. Under the condition of stable air flow, the compressor power consumption problem is transformed into a single variable optimization problem of heat exchanger heat exchange efficiency. S32, a hybrid optimization algorithm combining the steepest gradient descent method and Newton's method is used to solve the single-variable function in stages. In the initial stage, the steepest gradient descent method is used for rapid convergence, and when approaching the extreme point, it is switched to Newton's method for precise optimization to obtain the optimal heat exchanger efficiency value.

7. The method as described in claim 1, characterized in that, S31 further includes: The heat exchanger efficiency is defined as the ratio of the actual heat transfer to the maximum possible heat transfer. The expression for this ratio is: ； in, For actual heat exchange, To maximize the heat exchange capacity, For the mass flow rate of the fluid, The temperature difference between the inlet and outlet of the fluid itself. The inlet temperature of the hot fluid. This refers to the inlet temperature of the cold fluid. The relationship between heat exchanger thermal efficiency and compressor inlet air temperature and pressure is expressed as follows: ； ； In the formula, This refers to the outlet temperature of the previous stage compressor. This refers to the inlet temperature of the heat exchanger's heat transfer fluid. This refers to the outlet pressure of the previous stage compressor. Furthermore, under the condition of stable airflow, the compressor outlet pressure can be calculated from the pressure in the air storage chamber, and its expression is: ； Since the compressor outlet pressure is regulated by the compressor speed, the compressor power consumption can only be optimized through the heat exchanger's heat exchange efficiency. Therefore, the compressor power consumption problem is simplified to a single-variable optimization problem concerning the heat exchanger's heat exchange efficiency: 。 8. The method as described in claim 1, characterized in that, S32 further includes: S321, Select initial value of heat exchanger efficiency Given the calculation termination error ,make ; S322, take Search for the minimum value and adjust the iteration step size. Solve for, such that ； make , ; S323, Calculate the gradient value of the compressor power consumption equation. ,like If the iteration stops, output the result. Otherwise, repeat step S322; S324, taking the steepest gradient descent result as the initial point, let k=0. When the gradient value of the compressor power consumption equation does not meet the iteration conditions, let: , ; S325, Calculate the gradient of the compressor power consumption equation. and second gradient ,if Stop iteration and output. Otherwise, repeat step S324; S326, after stopping the iteration, based on the output To achieve the optimal outlet temperature of the heat exchanger: ； in, This refers to the outlet temperature of the previous stage compressor. This refers to the inlet temperature of the heat exchanger's heat transfer medium water.

9. A device for real-time optimization of the outlet temperature of a compressor preheater heat exchanger, characterized in that, include: The multi-objective optimization model construction module is used to establish a simplified mechanism model of the heat exchanger, a mechanism model of the gas storage chamber, and a thermodynamic dynamic coupling model of the compressor, and to obtain the correlation between the compressor inlet pressure, inlet temperature, speed, and pressure ratio and the heat exchanger performance. The heat exchanger performance parameterization module is used to express the compressor power consumption as a single-variable function that is only related to the heat exchanger performance based on the dynamic coupling model. The hybrid optimization algorithm execution module is used to simplify the multivariate optimization problem by introducing heat exchanger efficiency. It uses the steepest gradient descent method combined with Newton's method to obtain the optimal heat exchanger efficiency value. The temperature setpoint conversion module is used to calculate the optimal setpoint of the heat exchanger outlet air temperature based on the optimal heat exchanger efficiency value, and input it into the heat medium water control loop to achieve real-time temperature optimization control.

10. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the method as claimed in any one of claims 1-8.

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